Phosphoproteomics profiling suggests a role for nuclear βΙPKC in transcription processes of undifferentiated murine embryonic stem cells.

PubMed

Costa-Junior, Helio Miranda; Garavello, Nicole Milaré; Duarte, Mariana Lemos; Berti, Denise Aparecida; Glaser, Talita; de Andrade, Alexander; Labate, Carlos A; Ferreira, André Teixeira da Silva; Perales, Jonas Enrique Aguilar; Xavier-Neto, José; Krieger, José Eduardo; Schechtman, Deborah

2010-12-03

Protein kinase C (PKC) plays a key role in embryonic stem cell (ESC) proliferation, self-renewal, and differentiation. However, the function of specific PKC isoenzymes have yet to be determined. Of the PKCs expressed in undifferentiated ESCs, βIPKC was the only isoenzyme abundantly expressed in the nuclei. To investigate the role of βΙPKC in these cells, we employed a phosphoproteomics strategy and used two classical (cPKC) peptide modulators and one βIPKC-specific inhibitor peptide. We identified 13 nuclear proteins that are direct or indirect βΙPKC substrates in undifferentiated ESCs. These proteins are known to be involved in regulating transcription, splicing, and chromatin remodeling during proliferation and differentiation. Inhibiting βΙPKC had no effect on DNA synthesis in undifferentiated ESCs. However, upon differentiation, many cells seized to express βΙPKC and βΙPKC was frequently found in the cytoplasm. Taken together, our results suggest that βIPKC takes part in the processes that maintain ESCs in their undifferentiated state.

MK2206 in Treating Younger Patients With Recurrent or Refractory Solid Tumors or Leukemia

ClinicalTrials.gov

2014-04-28

Accelerated Phase Chronic Myelogenous Leukemia; Acute Leukemias of Ambiguous Lineage; Acute Myeloid Leukemia/Transient Myeloproliferative Disorder; Acute Undifferentiated Leukemia; Aggressive NK-cell Leukemia; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Blastic Phase Chronic Myelogenous Leukemia; Blastic Plasmacytoid Dendritic Cell Neoplasm; Childhood Burkitt Lymphoma; Childhood Chronic Myelogenous Leukemia; Childhood Diffuse Large Cell Lymphoma; Childhood Grade III Lymphomatoid Granulomatosis; Childhood Immunoblastic Large Cell Lymphoma; Childhood Nasal Type Extranodal NK/T-cell Lymphoma; Chronic Eosinophilic Leukemia; Chronic Myelomonocytic Leukemia; Chronic Neutrophilic Leukemia; Chronic Phase Chronic Myelogenous Leukemia; Intraocular Lymphoma; Juvenile Myelomonocytic Leukemia; Mast Cell Leukemia; Myeloid/NK-cell Acute Leukemia; Noncutaneous Extranodal Lymphoma; Post-transplant Lymphoproliferative Disorder; Primary Central Nervous System Hodgkin Lymphoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Progressive Hairy Cell Leukemia, Initial Treatment; Prolymphocytic Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

Dendritic Cells in Kidney Transplant Biopsy Samples Are Associated with T Cell Infiltration and Poor Allograft Survival

PubMed Central

De Serres, Sacha A.; Safa, Kassem; Bijol, Vanesa; Ueno, Takuya; Onozato, Maristela L.; Iafrate, A. John; Herter, Jan M.; Lichtman, Andrew H.; Mayadas, Tanya N.; Guleria, Indira; Rennke, Helmut G.; Najafian, Nader; Chandraker, Anil

2015-01-01

Progress in long-term renal allograft survival continues to lag behind the progress in short-term transplant outcomes. Dendritic cells are the most efficient antigen-presenting cells, but surprisingly little attention has been paid to their presence in transplanted kidneys. We used dendritic cell–specific intercellular adhesion molecule-3–grabbing nonintegrin as a marker of dendritic cells in 105 allograft biopsy samples from 105 kidney transplant recipients. High dendritic cell density was associated with poor allograft survival independent of clinical variables. Moreover, high dendritic cell density correlated with greater T cell proliferation and poor outcomes in patients with high total inflammation scores, including inflammation in areas of tubular atrophy. We then explored the association between dendritic cells and histologic variables associated with poor prognosis. Multivariate analysis revealed an independent association between the densities of dendritic cells and T cells. In biopsy samples with high dendritic cell density, electron microscopy showed direct physical contact between infiltrating lymphocytes and cells that have the ultrastructural morphologic characteristics of dendritic cells. The origin of graft dendritic cells was sought in nine sex-mismatched recipients using XY fluorescence in situ hybridization. Whereas donor dendritic cells predominated initially, the majority of dendritic cells in late allograft biopsy samples were of recipient origin. Our data highlight the prognostic value of dendritic cell density in allograft biopsy samples, suggest a new role for these cells in shaping graft inflammation, and provide a rationale for targeting dendritic cell recruitment to promote long-term allograft survival. PMID:25855773

Nivolumab and Ipilimumab in Treating Patients With Rare Tumors

ClinicalTrials.gov

2018-06-27

Acinar Cell Carcinoma; Adenoid Cystic Carcinoma; Adrenal Cortex Carcinoma; Adrenal Gland Pheochromocytoma; Anal Canal Neuroendocrine Carcinoma; Anal Canal Undifferentiated Carcinoma; Appendix Mucinous Adenocarcinoma; Bartholin Gland Transitional Cell Carcinoma; Bladder Adenocarcinoma; Cervical Adenocarcinoma; Cholangiocarcinoma; Chordoma; Colorectal Squamous Cell Carcinoma; Desmoid-Type Fibromatosis; Endometrial Transitional Cell Carcinoma; Endometrioid Adenocarcinoma; Esophageal Neuroendocrine Carcinoma; Esophageal Undifferentiated Carcinoma; Extrahepatic Bile Duct Carcinoma; Fallopian Tube Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Fibromyxoid Tumor; Gastric Neuroendocrine Carcinoma; Gastric Squamous Cell Carcinoma; Gastrointestinal Stromal Tumor; Giant Cell Carcinoma; Intestinal Neuroendocrine Carcinoma; Intrahepatic Cholangiocarcinoma; Lung Carcinoid Tumor; Lung Sarcomatoid Carcinoma; Major Salivary Gland Carcinoma; Malignant Odontogenic Neoplasm; Malignant Peripheral Nerve Sheath Tumor; Malignant Testicular Sex Cord-Stromal Tumor; Metaplastic Breast Carcinoma; Metastatic Malignant Neoplasm of Unknown Primary Origin; Minimally Invasive Lung Adenocarcinoma; Mixed Mesodermal (Mullerian) Tumor; Mucinous Adenocarcinoma; Mucinous Cystadenocarcinoma; Nasal Cavity Adenocarcinoma; Nasal Cavity Carcinoma; Nasopharyngeal Carcinoma; Nasopharyngeal Papillary Adenocarcinoma; Nasopharyngeal Undifferentiated Carcinoma; Oral Cavity Carcinoma; Oropharyngeal Undifferentiated Carcinoma; Ovarian Adenocarcinoma; Ovarian Germ Cell Tumor; Ovarian Mucinous Adenocarcinoma; Ovarian Squamous Cell Carcinoma; Ovarian Transitional Cell Carcinoma; Pancreatic Acinar Cell Carcinoma; Pancreatic Neuroendocrine Carcinoma; Paraganglioma; Paranasal Sinus Adenocarcinoma; Paranasal Sinus Carcinoma; Parathyroid Gland Carcinoma; Pituitary Gland Carcinoma; Placental Choriocarcinoma; Placental-Site Gestational Trophoblastic Tumor; Primary Peritoneal High Grade Serous Adenocarcinoma; Pseudomyxoma Peritonei; Rare Disorder; Scrotal Squamous Cell Carcinoma; Seminal Vesicle Adenocarcinoma; Seminoma; Serous Cystadenocarcinoma; Small Intestinal Adenocarcinoma; Small Intestinal Squamous Cell Carcinoma; Spindle Cell Neoplasm; Squamous Cell Carcinoma of the Penis; Teratoma With Malignant Transformation; Testicular Non-Seminomatous Germ Cell Tumor; Thyroid Gland Carcinoma; Tracheal Carcinoma; Transitional Cell Carcinoma; Undifferentiated Gastric Carcinoma; Ureter Adenocarcinoma; Ureter Squamous Cell Carcinoma; Urethral Adenocarcinoma; Urethral Squamous Cell Carcinoma; Vaginal Adenocarcinoma; Vaginal Squamous Cell Carcinoma, Not Otherwise Specified; Vulvar Carcinoma

Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases.

PubMed

Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

2009-11-01

Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-alpha) and also induced allogeneic naive CD4(+) T cells to proliferate and to produce type 1 cytokines such as interferon-gamma and tumor necrosis factor-alpha. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and endothelial microparticles could be an important immunmodulatory therapeutic target.

Apoptosis and cell proliferation in the development of gastric carcinomas: associations with c-myc and p53 protein expression.

PubMed

Ishii, Hideaki H; Gobé, Glenda C; Pan, Wenshen; Yoneyama, Juichi; Ebihara, Yoshiro

2002-09-01

Patients with gastric carcinomas have a poor prognosis and low survival rates. The aim of the present paper was to characterize cellular and molecular properties to provide insight into aspects of tumor progression in early compared with advanced gastric cancers. One hundred and nine graded gastric carcinomas (early or advanced stage, undifferentiated or differentiated type) with paired non-cancer tissue were studied to define the correlation between apoptosis (morphology, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling), cell proliferation (Ki-67 expression, morphology) and expression and localization of two proteins frequently having altered expression in cancers, namely p53 and c-myc. Overall, apoptosis was lower in early stage, differentiated and undifferentiated gastric carcinomas compared with advanced-stage cancers. Cell proliferation was comparatively high in all stages. There was a high level of p53 positivity in all stages. Only the early- and advanced-stage undifferentiated cancers that were p53 positive had a significantly higher level of apoptosis (P < 0.05). Cell proliferation was significantly greater (P < 0.05) only in the early undifferentiated cancers that had either c-myc or p53-positivity. The results indicate that low apoptosis and high cell proliferation combine to drive gastric cancer development. The molecular controls for high cell proliferation of the early stage undifferentiated gastric cancers involve overexpression of both p53 and c-myc. Overexpression of p53 may also control cancer development in that its expression is associated with higher levels of apoptosis in early and late-stage undifferentiated, cancers. Copyright 2002 Blackwell Publishing Asia Pty Ltd

Paclitaxel Albumin-Stabilized Nanoparticle Formulation and Bevacizumab in Treating Patients With Stage IV Melanoma That Cannot Be Removed by Surgery or Gynecological Cancers

ClinicalTrials.gov

2018-02-05

Cervical Adenosarcoma; Cervical Adenosquamous Carcinoma; Cervical Carcinosarcoma; Cervical Squamous Cell Carcinoma, Not Otherwise Specified; Endometrial Clear Cell Adenocarcinoma; Endometrial Endometrioid Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Fallopian Tube Adenocarcinoma; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Epithelial Tumor; Malignant Peritoneal Neoplasm; Ovarian Carcinosarcoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Melanoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Stage IV Skin Melanoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma; Uterine Corpus Carcinosarcoma

Down-regulated RPS3a/nbl expression during retinoid-induced differentiation of HL-60 cells: a close association with diminished susceptibility to actinomycin D-stimulated apoptosis.

PubMed

Russell, L; Naora, H; Naora, H

2000-04-01

The efficacy of anticancer agents significantly depends on the differential susceptibility of undifferentiated cancer cells and differentiated normal cells to undergo apoptosis. We previously found that enhanced expression of RPS3a/nbl, which apparently encodes a ribosomal protein, seems to prime cells for apoptosis, while suppressing such enhanced expression triggers cell death. The present study found that HL-60 cells induced to differentiate by all-trans retinoic acid did not undergo apoptosis following treatment with actinomycin D whereas undifferentiated HL-60 cells were highly apoptosis-susceptible, confirming earlier suggestions that differentiated cells have diminished apoptosis-susceptibility. Undifferentiated HL-60 cells highly expressed RPS3a/nbl whereas all-trans retinoic acid -induced differentiated cells exhibited markedly reduced levels, suggesting that apoptosis-resistance of differentiated cells could be due to low RPS3a/nbl expression. Down-regulation of enhanced RPS3a/nbl expression was also observed in cells induced to differentiate with the retinoid 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-napthalenyl)-1- propenyl]benzoic acid without any significant induction of cell death. While down-regulation of RPS3a/nbl expression during differentiation did not apparently induce apoptosis, RPS3a/nbl antisense oligomers triggered death of undifferentiated HL-60 cells, but not of retinoid-induced differentiated cells. It therefore seems that while down-regulation of enhanced RPS3a/nbl expression can induce apoptosis in undifferentiated cells, down-regulation of enhanced RPS3a/nbl expression during differentiation occurs independently of apoptosis, and could be regarded as reverting the primed condition to the unprimed (low RPS3a/nbl) state.

Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases

PubMed Central

Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

2009-01-01

Background Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Design and Methods Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Results Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-α) and also induced allogeneic naive CD4+ T cells to proliferate and to produce type 1 cytokines such as interferon-γ and tumor necrosis factor-α. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Conclusions Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and endothelial microparticles could be an important immunmodulatory therapeutic target. PMID:19648164

mTORC1 is essential for leukemia propagation but not stem cell self-renewal

PubMed Central

Hoshii, Takayuki; Tadokoro, Yuko; Naka, Kazuhito; Ooshio, Takako; Muraguchi, Teruyuki; Sugiyama, Naoyuki; Soga, Tomoyoshi; Araki, Kimi; Yamamura, Ken-ichi; Hirao, Atsushi

2012-01-01

Although dysregulation of mTOR complex 1 (mTORC1) promotes leukemogenesis, how mTORC1 affects established leukemia is unclear. We investigated the role of mTORC1 in mouse hematopoiesis using a mouse model of conditional deletion of Raptor, an essential component of mTORC1. Raptor deficiency impaired granulocyte and B cell development but did not alter survival or proliferation of hematopoietic progenitor cells. In a mouse model of acute myeloid leukemia (AML), Raptor deficiency significantly suppressed leukemia progression by causing apoptosis of differentiated, but not undifferentiated, leukemia cells. mTORC1 did not control cell cycle or cell growth in undifferentiated AML cells in vivo. Transplantation of Raptor-deficient undifferentiated AML cells in a limiting dilution revealed that mTORC1 is essential for leukemia initiation. Strikingly, a subset of AML cells with undifferentiated phenotypes survived long-term in the absence of mTORC1 activity. We further demonstrated that the reactivation of mTORC1 in those cells restored their leukemia-initiating capacity. Thus, AML cells lacking mTORC1 activity can self-renew as AML stem cells. Our findings provide mechanistic insight into how residual tumor cells circumvent anticancer therapies and drive tumor recurrence. PMID:22622041

Pluripotency of adult stem cells derived from human and rat pancreas

NASA Astrophysics Data System (ADS)

Kruse, C.; Birth, M.; Rohwedel, J.; Assmuth, K.; Goepel, A.; Wedel, T.

Adult stem cells are undifferentiated cells found within fully developed tissues or organs of an adult individuum. Until recently, these cells have been considered to bear less self-renewal ability and differentiation potency compared to embryonic stem cells. In recent studies an undifferentiated cell type was found in primary cultures of isolated acini from exocrine pancreas termed pancreatic stellate cells. Here we show that pancreatic stellate-like cells have the capacity of extended self-renewal and are able to differentiate spontaneously into cell types of all three germ layers expressing markers for smooth muscle cells, neurons, glial cells, epithelial cells, chondrocytes and secretory cells (insulin, amylase). Differentiation and subsequent formation of three-dimensional cellular aggregates (organoid bodies) were induced by merely culturing pancreatic stellate-like cells in hanging drops. These cells were developed into stable, long-term, in vitro cultures of both primary undifferentiated cell lines as well as organoid cultures. Thus, evidence is given that cell lineages of endodermal, mesodermal, and ectodermal origin arise spontaneously from a single adult undifferentiated cell type. Based on the present findings it is assumed that pancreatic stellate-like cells are a new class of lineage uncommitted pluripotent adult stem cells with a remarkable self-renewal ability and differentiation potency. The data emphasize the versatility of adult stem cells and may lead to a reappraisal of their use for the treatment of inherited disorders or acquired degenerative diseases.

MV-NIS or Investigator's Choice Chemotherapy in Treating Patients With Ovarian, Fallopian, or Peritoneal Cancer

ClinicalTrials.gov

2018-04-27

Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Endometrioid Tumor; Malignant Ovarian Serous Tumor; Ovarian Seromucinous Carcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

TGF-β1-Induced Epithelial–Mesenchymal Transition Promotes Monocyte/Macrophage Properties in Breast Cancer Cells

PubMed Central

Johansson, Joel; Tabor, Vedrana; Wikell, Anna; Jalkanen, Sirpa; Fuxe, Jonas

2015-01-01

Breast cancer progression toward metastatic disease is linked to re-activation of epithelial–mesenchymal transition (EMT), a latent developmental process. Breast cancer cells undergoing EMT lose epithelial characteristics and gain the capacity to invade the surrounding tissue and migrate away from the primary tumor. However, less is known about the possible role of EMT in providing cancer cells with properties that allow them to traffic to distant sites. Given the fact that pro-metastatic cancer cells share a unique capacity with immune cells to traffic in-and-out of blood and lymphatic vessels we hypothesized that tumor cells undergoing EMT may acquire properties of immune cells. To study this, we performed gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an EMT program after long-term treatment with TGF-β1 for 2 weeks. As expected, EMT cells acquired traits of mesenchymal cell differentiation and migration. However, in addition, we found another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER−/PR−) characteristics. The results identify an EMT-induced monocyte/macrophage gene cluster, which may play a role in breast cancer cell dissemination and metastasis. PMID:25674539

Bevacizumab, Cisplatin, Radiation Therapy, and Fluorouracil in Treating Patients With Stage IIB, Stage III, Stage IVA, or Stage IVB Nasopharyngeal Cancer

ClinicalTrials.gov

2018-01-04

Stage II Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage III Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage III Nasopharyngeal Undifferentiated Carcinoma AJCC v7; Stage IV Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage IV Nasopharyngeal Undifferentiated Carcinoma AJCC v7

Investigations of the functional states of dendritic cells under different conditioned microenvironments by Fourier transformed infrared spectroscopy.

PubMed

Dong, Rong; Long, Jinhua; Xu, Xiaoli; Zhang, Chunlin; Wen, Zongyao; Li, Long; Yao, Weijuan; Zeng, Zhu

2014-01-10

Dendritic cells are potent and specialized antigen presenting cells, which play a crucial role in initiating and amplifying both the innate and adaptive immune responses. The dendritic cell-based vaccination against cancer has been clinically achieved promising successes. But there are still many challenges in its clinical application, especially for how to identify the functional states. The CD14+ monocytes were isolated from human peripheral blood after plastic adherence and purified to approximately 98% with cocktail immunomagnetic beads. The immature dendritic cells and mature dendritic cells were induced by traditional protocols. The resulting dendritic cells were cocultured with normal cells and cancer cells. The functional state of dendritic cells including immature dendritic cells (imDCs) and mature dendritic cells (mDCs) under different conditioned microenvironments were investigated by Fourier transformed infrared spectroscopy (FTIR) and molecular biological methods. The results of Fourier transformed infrared spectroscopy showed that the gene transcription activity and energy states of dendritic cells were specifically suppressed by tumor cells (P < 0.05 or 0.01). The expression levels of NF-kappa B (NF-κB) in dendritic cells were also specifically inhibited by tumor-derived factors (P < 0.05 or 0.01). Moreover, the ratios of absorption intensities of Fourier transformed infrared spectroscopy at given wave numbers were closely correlated with the expression levels of NF-κB (R2:0.69 and R2:0.81, respectively). Our results confirmed that the ratios of absorption intensities of Fourier transformed infrared spectroscopy at given wave numbers were positively correlated with the expression levels of NF-κB, suggesting that Fourier transformed infrared spectroscopy technology could be clinically applied to identify the functional states of dendritic cell when performing dendritic cell-based vaccination. It's significant for the simplification and standardization of dendritic cell-based vaccination clinical preparation protocols.

Immunosuppressant effect of IDS 30, a stinging nettle leaf extract, on myeloid dendritic cells in vitro.

PubMed

Broer, Johanna; Behnke, Bert

2002-04-01

Dendritic cells are important antigen presenting cells that play a role in the initiation of rheumatoid arthritis (RA). The stinging nettle leaf extract IDS 30 (Hox alpha) has been recommended for adjuvant therapy of rheumatic diseases. We investigated the immunomodulating effect of IDS 30 extract on the maturation of hematopoietic dendritic cells. Human dendritic cells were generated from peripheral blood mononuclear cells cultured in granulocyte macrophage-colony stimulating factor and interleukin 4 (IL-4). Dendritic cell maturation was induced by keyhole limped hemocyanin (KLH). Dendritic cell phenotype was characterized by flow cytometric analysis; dendritic cell cytokine production was measured by ELISA. The ability of dendritic cells to activate naive autologous T cells was evaluated by mixed leukocyte reaction. IDS 30 prevented the maturation of dendritic cells, but did not affect their viability. IDS 30 reduced the expression of CD83 and CD86. It increased the expression of chemokine receptor 5 and CD36 in a dose dependent manner. The secretion of tumor necrosis factor-alpha was reduced. Application of IDS 30 to dendritic cells in culture caused a high endocytosis of dextran and a low capacity to stimulate T cell proliferation. Our in vitro results showed the suppressive effect of IDS 30 on the maturation of human myeloid dendritic cells, leading to reduced induction of primary T cell responses. This may contribute to the therapeutic effect of IDS 30 on T cell mediated inflammatory diseases like RA.

Rhabdoid and Undifferentiated Phenotype in Renal Cell Carcinoma: Analysis of 32 Cases Indicating a Distinctive Common Pathway of Dedifferentiation Frequently Associated With SWI/SNF Complex Deficiency.

PubMed

Agaimy, Abbas; Cheng, Liang; Egevad, Lars; Feyerabend, Bernd; Hes, Ondřej; Keck, Bastian; Pizzolitto, Stefano; Sioletic, Stefano; Wullich, Bernd; Hartmann, Arndt

2017-02-01

Undifferentiated (anaplastic) and rhabdoid cell features are increasingly recognized as adverse prognostic findings in renal cell carcinoma (RCC), but their molecular pathogenesis has not been studied sufficiently. Recent studies identified alterations in the Switch Sucrose nonfermentable (SWI/SNF) chromatin remodeling complex as molecular mechanisms underlying dedifferentiation and rhabdoid features in carcinomas of different organs. We herein have analyzed 32 undifferentiated RCCs having in common an undifferentiated (anaplastic) phenotype, prominent rhabdoid features, or both, irrespective of the presence or absence of conventional RCC component. Cases were stained with 6 SWI/SNF pathway members (SMARCB1, SMARCA2, SMARCA4, ARID1A, SMARCC1, and SMARCC2) in addition to conventional RCC markers. Patients were 20 males and 12 females aged 32 to 85 years (mean, 59). A total of 22/27 patients with known stage presented with ≥pT3. A differentiated component varying from microscopic to major component was detected in 20/32 cases (16 clear cell and 2 cases each chromophobe and papillary RCC). The undifferentiated component varied from rhabdoid dyscohesive cells to large epithelioid to small monotonous anaplastic cells. Variable loss of at least 1 SWI/SNF complex subunit was noted in the undifferentiated/rhabdoid component of 21/32 cases (65%) compared with intact or reduced expression in the differentiated component. A total of 15/17 patients (88%) with follow-up died of metastatic disease (mostly within 1 y). Only 2 patients were disease free at last follow-up (1 and 6 y). No difference in survival, age distribution, or sex was observed between the SWI/SNF-deficient and the SWI/SNF-intact group. This is the first study exploring the role of SWI/SNF deficiency as a potential mechanism underlying undifferentiated and rhabdoid phenotype in RCC. Our results highlight the association between the aggressive rhabdoid phenotype and the SWI/SNF complex deficiency, consistent with studies on similar neoplasms in other organs. Thorough sampling of such tumors that are usually huge and locally advanced is necessary for recognizing the clone of origin and hence for proper subtyping and also for differentiating them from undifferentiated urothelial carcinoma.

Divergent Effects of Dendritic Cells on Pancreatitis

DTIC Science & Technology

2015-09-01

role of dendritic cells in pancreatitis. Dendritic cells are professional antigen presenting cells which initiate innate and adaptive immune... Lymphoid -tissue-specific homing of bone- marrow-derived dendritic cells . Blood. 113:6638–6647. http://dx.doi .org/10.1182/blood-2009-02-204321 Dapito...Award Number: W81XWH-12-1-0313 TITLE: Divergent Effects of Dendritic Cells on Pancreatitis PRINCIPAL INVESTIGATOR: Dr. George Miller

Deregulation of the CEACAM expression pattern causes undifferentiated cell growth in human lung adenocarcinoma cells.

PubMed

Singer, Bernhard B; Scheffrahn, Inka; Kammerer, Robert; Suttorp, Norbert; Ergun, Suleyman; Slevogt, Hortense

2010-01-18

CEACAM1, CEA/CEACAM5, and CEACAM6 are cell adhesion molecules (CAMs) of the carcinoembryonic antigen (CEA) family that have been shown to be deregulated in lung cancer and in up to 50% of all human cancers. However, little is known about the functional impact of these molecules on undifferentiated cell growth and tumor progression. Here we demonstrate that cell surface expression of CEACAM1 on confluent A549 human lung adenocarcinoma cells plays a critical role in differentiated, contact-inhibited cell growth. Interestingly, CEACAM1-L, but not CEACAM1-S, negatively regulates proliferation via its ITIM domain, while in proliferating cells no CEACAM expression is detectable. Furthermore, we show for the first time that CEACAM6 acts as an inducer of cellular proliferation in A549 cells, likely by interfering with the contact-inhibiting signal triggered by CEACAM1-4L, leading to undifferentiated anchorage-independent cell growth. We also found that A549 cells expressed significant amounts of non-membrane anchored variants of CEACAM5 and CEACAM6, representing a putative source for the increased CEACAM5/6 serum levels frequently found in lung cancer patients. Taken together, our data suggest that post-confluent contact inhibition is established and maintained by CEACAM1-4L, but disturbances of CEACAM1 signalling by CEACAM1-4S and other CEACAMs lead to undifferentiated cell growth and malignant transformation.

Septic shock sera containing circulating histones induce dendritic cell-regulated necrosis in fatal septic shock patients.

PubMed

Raffray, Loic; Douchet, Isabelle; Augusto, Jean-Francois; Youssef, Jihad; Contin-Bordes, Cecile; Richez, Christophe; Duffau, Pierre; Truchetet, Marie-Elise; Moreau, Jean-Francois; Cazanave, Charles; Leroux, Lionel; Mourrissoux, Gaelle; Camou, Fabrice; Clouzeau, Benjamin; Jeannin, Pascale; Delneste, Yves; Gabinski, Claude; Guisset, Olivier; Lazaro, Estibaliz; Blanco, Patrick

2015-04-01

Innate immune system alterations, including dendritic cell loss, have been reproducibly observed in patients with septic shock and correlated to adverse outcomes or nosocomial infections. The goal of this study is to better understand the mechanisms behind this observation in order to better assess septic shock pathogenesis. Prospective, controlled experimental study. Research laboratory at an academic medical center. The study enrolled 71 patients, 49 with septic shock and 22 with cardiogenic shock. Seventeen healthy controls served as reference. In vitro monocyte-derived dendritic cells were generated from healthy volunteers. Sera were assessed for their ability to promote in vitro dendritic cell death through flow cytometry detection in each group of patients. The percentage of apoptotic or necrotic dendritic cells was evaluated by annexin-V and propidium iodide staining. We observed that only patients with septic shock and not patients with pure cardiogenic shock were characterized by a rapid and profound loss of circulating dendritic cells. In vitro analysis revealed that sera from patients with septic shock induced higher dendritic cell death compared to normal sera or cardiogenic shock (p<0.005). Sera from surviving patients induced dendritic cell death through a caspase-dependent apoptotic pathway, whereas sera from nonsurviving patients induced dendritic cell-regulated necrosis. Dendritic cell necrosis was not due to necroptosis but was dependent of the presence of circulating histone. The toxicity of histones toward dendritic cell could be prevented by recombinant human activated protein C. Finally, we observed a direct correlation between the levels of circulating histones in patients and the ability of the sera to promote dendritic cell-regulated necrosis. The study demonstrates a differential mechanism of dendritic cell death in patients with septic shock that is dependent on the severity of the disease.

In vivo and in vitro sensitivity of blastic plasmacytoid dendritic cell neoplasm to SL-401, an interleukin-3 receptor targeted biologic agent.

PubMed

Angelot-Delettre, Fanny; Roggy, Anne; Frankel, Arthur E; Lamarthee, Baptiste; Seilles, Estelle; Biichle, Sabeha; Royer, Bernard; Deconinck, Eric; Rowinsky, Eric K; Brooks, Christopher; Bardet, Valerie; Benet, Blandine; Bennani, Hind; Benseddik, Zehaira; Debliquis, Agathe; Lusina, Daniel; Roussel, Mikael; Solly, Françoise; Ticchioni, Michel; Saas, Philippe; Garnache-Ottou, Francine

2015-02-01

Blastic plasmacytoid dendritic cell neoplasm is an aggressive malignancy derived from plasmacytoid dendritic cells. There is currently no accepted standard of care for treating this neoplasm, and therapeutic strategies have never been prospectively evaluated. Since blastic plasmacytoid dendritic cell neoplasm cells express high levels of interleukin-3 receptor α chain (IL3-Rα or CD123), antitumor effects of the interleukin-3 receptor-targeted drug SL-401 against blastic plasmacytoid dendritic cell neoplasm were evaluated in vitro and in vivo. The cytotoxicity of SL-401 was assessed in patient-derived blastic plasmacytoid dendritic cell neoplasm cell lines (CAL-1 and GEN2.2) and in primary blastic plasmacytoid dendritic cell neoplasm cells isolated from 12 patients using flow cytometry and an in vitro cytotoxicity assay. The cytotoxic effects of SL-401 were compared to those of several relevant cytotoxic agents. SL-401 exhibited a robust cytotoxicity against blastic plasmacytoid dendritic cell neoplasm cells in a dose-dependent manner. Additionally, the cytotoxic effects of SL-401 were observed at substantially lower concentrations than those achieved in clinical trials to date. Survival of mice inoculated with a blastic plasmacytoid dendritic cell neoplasm cell line and treated with a single cycle of SL-401 was significantly longer than that of untreated controls (median survival, 58 versus 17 days, P<0.001). These findings indicate that blastic plasmacytoid dendritic cell neoplasm cells are highly sensitive to SL-401, and support further evaluation of SL-401 in patients suffering from blastic plasmacytoid dendritic cell neoplasm. Copyright© Ferrata Storti Foundation.

In vivo and in vitro sensitivity of blastic plasmacytoid dendritic cell neoplasm to SL-401, an interleukin-3 receptor targeted biologic agent

PubMed Central

Angelot-Delettre, Fanny; Roggy, Anne; Frankel, Arthur E.; Lamarthee, Baptiste; Seilles, Estelle; Biichle, Sabeha; Royer, Bernard; Deconinck, Eric; Rowinsky, Eric K.; Brooks, Christopher; Bardet, Valerie; Benet, Blandine; Bennani, Hind; Benseddik, Zehaira; Debliquis, Agathe; Lusina, Daniel; Roussel, Mikael; Solly, Françoise; Ticchioni, Michel; Saas, Philippe; Garnache-Ottou, Francine

2015-01-01

Blastic plasmacytoid dendritic cell neoplasm is an aggressive malignancy derived from plasmacytoid dendritic cells. There is currently no accepted standard of care for treating this neoplasm, and therapeutic strategies have never been prospectively evaluated. Since blastic plasmacytoid dendritic cell neoplasm cells express high levels of interleukin-3 receptor α chain (IL3-Rα or CD123), antitumor effects of the interleukin-3 receptor-targeted drug SL-401 against blastic plasmacytoid dendritic cell neoplasm were evaluated in vitro and in vivo. The cytotoxicity of SL-401 was assessed in patient-derived blastic plasmacytoid dendritic cell neoplasm cell lines (CAL-1 and GEN2.2) and in primary blastic plasmacytoid dendritic cell neoplasm cells isolated from 12 patients using flow cytometry and an in vitro cytotoxicity assay. The cytotoxic effects of SL-401 were compared to those of several relevant cytotoxic agents. SL-401 exhibited a robust cytotoxicity against blastic plasmacytoid dendritic cell neoplasm cells in a dose-dependent manner. Additionally, the cytotoxic effects of SL-401 were observed at substantially lower concentrations than those achieved in clinical trials to date. Survival of mice inoculated with a blastic plasmacytoid dendritic cell neoplasm cell line and treated with a single cycle of SL-401 was significantly longer than that of untreated controls (median survival, 58 versus 17 days, P<0.001). These findings indicate that blastic plasmacytoid dendritic cell neoplasm cells are highly sensitive to SL-401, and support further evaluation of SL-401 in patients suffering from blastic plasmacytoid dendritic cell neoplasm. PMID:25381130

Undifferentiated Neuroblastoma Cells Are More Sensitive to Photogenerated Oxidative Stress Than Differentiated Cells.

PubMed

Lee, Chu-I; Perng, Jing-Huei; Chen, Huang-Yo; Hong, Yi-Ren; Wang, Jyh-Jye

2015-09-01

Neuroblastoma is one of the most aggressive cancers and has a complex form of differentiation. We hypothesized that advanced cellular differentiation may alter the susceptibility of neuroblastoma to photodynamic treatment (PDT) and confer selective survival advantage. We demonstrated that hematoporphyrin uptake by undifferentiated SH-SY5Y cells was lower than that of differentiated counterparts, yet the former were more susceptible to PDT-induced oxidative stress killing. Photogenerated reactive oxygen species (ROS) in undifferentiated cells efficiently stimulated cell cycle arrest at G2/M phase, mitochondrial apoptotic pathway activation, the sustained phosphorylation of Akt/GSK-3β and ERK. Differentiated cells with more resistance to PDT exhibited a ROS-independent and a prolonged activation of ERK. Both SH-SY5Y cells exposed to PDT exhibited ROS-independent p38 and JNK activation. These results may have important implications for neuroblastoma patients undergoing photodynamic therapy. © 2015 Wiley Periodicals, Inc.

Identification of integrin heterodimers functioning on the surface of undifferentiated porcine primed embryonic stem cells.

PubMed

Kim, Hwa-Young; Baek, Song; Han, Na Rae; Lee, Eunsong; Park, Choon-Keun; Lee, Seung Tae

2018-05-29

In vitro expansion of undifferentiated porcine primed embryonic stem (ES) cells is facilitated by use of non-cellular niches that mimic three-dimensional (3D) microenvironments enclosing an inner cell mass of porcine blastocysts. Therefore, we investigated the integrin heterodimers on the surface of undifferentiated porcine primed ES cells for the purpose of developing a non-cellular niche to support in vitro maintenance of the self-renewal ability of porcine primed ES cells. Immunocytochemistry and a fluorescence immunoassay were performed to assess integrin α and β subunit levels, and attachment and antibody inhibition assays were used to evaluate the function of integrin heterodimers. The integrin α 3 , α 5 , α 6 , α 9 , α V , and β 1 subunits, but not the α 1 , α 2 , α 4 , α 7 , and α 8 subunits, were identified on the surface of undifferentiated porcine primed ES cells. Subsequently, significant increase of their adhesion to fibronectin, tenascin C and vitronectin were observed and functional blocking of integrin heterodimer α 5 β 1 , α 9 β 1 , or α V β 1 showed significantly inhibited adhesion to fibronectin, tenascin C, or vitronectin. No integrin α 6 β 1 heterodimer?mediated adhesion to laminin was detected. These results demonstrate that active α 5 β 1 , α 9 β 1 , and α V β 1 integrin heterodimers are present on the surface of undifferentiated porcine primed ES cells, together with inactive integrin α 3 (presumed) and α 6 subunits. This article is protected by copyright. All rights reserved.

Dendritic Kv3.3 potassium channels in cerebellar purkinje cells regulate generation and spatial dynamics of dendritic Ca2+ spikes.

PubMed

Zagha, Edward; Manita, Satoshi; Ross, William N; Rudy, Bernardo

2010-06-01

Purkinje cell dendrites are excitable structures with intrinsic and synaptic conductances contributing to the generation and propagation of electrical activity. Voltage-gated potassium channel subunit Kv3.3 is expressed in the distal dendrites of Purkinje cells. However, the functional relevance of this dendritic distribution is not understood. Moreover, mutations in Kv3.3 cause movement disorders in mice and cerebellar atrophy and ataxia in humans, emphasizing the importance of understanding the role of these channels. In this study, we explore functional implications of this dendritic channel expression and compare Purkinje cell dendritic excitability in wild-type and Kv3.3 knockout mice. We demonstrate enhanced excitability of Purkinje cell dendrites in Kv3.3 knockout mice, despite normal resting membrane properties. Combined data from local application pharmacology, voltage clamp analysis of ionic currents, and assessment of dendritic Ca(2+) spike threshold in Purkinje cells suggest a role for Kv3.3 channels in opposing Ca(2+) spike initiation. To study the physiological relevance of altered dendritic excitability, we measured [Ca(2+)](i) changes throughout the dendritic tree in response to climbing fiber activation. Ca(2+) signals were specifically enhanced in distal dendrites of Kv3.3 knockout Purkinje cells, suggesting a role for dendritic Kv3.3 channels in regulating propagation of electrical activity and Ca(2+) influx in distal dendrites. These findings characterize unique roles of Kv3.3 channels in dendrites, with implications for synaptic integration, plasticity, and human disease.

The processing of asparagine-linked oligosaccharides in HT-29 cells is a function of their state of enterocytic differentiation. An accumulation of Man9,8-GlcNAc2-Asn species is indicative of an impaired N-glycan trimming in undifferentiated cells.

PubMed

Ogier-Denis, E; Codogno, P; Chantret, I; Trugnan, G

1988-05-05

Studies on the regulation of the enterocytic differentiation of the human colon cancer cell line HT-29, which is differentiated in the absence (Glc-) but not in the presence of glucose (Glc+), have recently shown that the post-translational processing of sucrase-isomaltase and particularly its glycosylation vary as a function of cell differentiation (Trugnan G., Rousset, M., Chantret, I., Barbat, A., and Zweibaum, A. (1987) J. Cell Biol. 104, 1199-1205). Other studies indicate that in undifferentiated HT-29 Glc+ cells there is an accumulation of UDP-N-acetylhexosamine, which is involved in the glycosylation process (Wice, B. M., Trugnan, G., Pinto, M., Rousset, M., Chevalier, G., Dussaulx, E., Lacroix, B., and Zweibaum, A. (1985) J. Biol. Chem. 260, 139-146). The purpose of the present work is to investigate whether an overall alteration of protein glycosylation is associated with the inability of HT-29 cells to differentiate. At least three alterations are detected: (i) after a 10-min pulse, the incorporation of D-[2-3H]mannose in undifferentiated cells is severely reduced, compared to differentiated cells. (ii) After a 24-h period of labeling with D-[2-3H]mannose, undifferentiated cells accumulate more than 60% of the radioactivity in the high mannose glycopeptides, whereas differentiated HT-29 Glc- cells accumulate only 38%. (iii) The analysis of the high mannose oligosaccharides transferred "en bloc" from the lipid precursor shows that Man9,8-GlcNAc2 species accumulate in undifferentiated cells, whereas no such accumulation can be detected in differentiated cells. This glycosylation pattern is consistent with an impairment of the trimming of high mannose into complex glycans. It is concluded that N-glycan processing is correlated with the state of enterocytic differentiation of HT-29 cells.

Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

PubMed Central

Bassity, Elizabeth; Clark, Theodore G.

2012-01-01

Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

Different regulation of aryl hydrocarbon receptor-regulated genes in response to dioxin in undifferentiated and neuronally differentiated human neuroblastoma SH-SY5Y cells.

PubMed

Imran, Saima; Ferretti, Patrizia; Vrzal, Radim

2015-01-01

Some environmental pollutants derived from industrial processes have been suggested to be responsible for neurological impairment in children, especially in heavily polluted areas. Since these compounds are usually activators of aryl hydrocarbon receptor (AhR), it would be important to better understand the molecular pathways downstream of AhR leading to neural deficits. To this purpose, appropriate in vitro human neural model is much needed. Here we have investigated whether undifferentiated and neuronally differentiated human neuroblastoma cells, SH-SY5Y cells, can provide a suitable model for monitoring AhR activity induced by environmental pollutants, focusing on 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD), a known activator of AhR. Further characterization of differentiated SH-SY5Y showed an increase in AhRR (aryl hydrocarbon receptor repressor), no change in ARNT1 (AhR nuclear translocator 1), and a decrease in ARNT2 expression with differentiation; in contrast, AhR was undetectable in both undifferentiated and differentiated cells. Nonetheless, treatment of parental as well as differentiated SH-SY5Y cells with TCDD resulted in the induction of AhR-regulated genes, CYP1A1 and CYP1B1; AhRR expression was also affected, but to a much smaller extent. These results indicate that undifferentiated SH-SY5Y are less sensitive to TCDD than neuronally differentiated ones, suggesting a higher resistance of the undifferentiated tumor cells to toxic insults. They also suggest that TCDD in these cells may not act via direct activation of AhR that is undetectable in SH-SY5Y as well as in differentiated neurons. Hence, these cells do not provide an appropriate model for studying ligand-mediated activation of AhR.

Olaparib or Cediranib Maleate and Olaparib Compared With Standard Platinum-Based Chemotherapy in Treating Patients With Recurrent Platinum-Sensitive Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-11

BRCA Rearrangement; Deleterious BRCA1 Gene Mutation; Deleterious BRCA2 Gene Mutation; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Tumor; Ovarian Seromucinous Carcinoma; Ovarian Serous Tumor; Ovarian Transitional Cell Carcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Immunohistowax processing, a new fixation and embedding method for light microscopy, which preserves antigen immunoreactivity and morphological structures: visualisation of dendritic cells in peripheral organs

PubMed Central

Pajak, B.; De Smedt, T.; Moulin, V.; De Trez, C.; Maldonado-Lopez, R.; Vansanten, G.; Briend, E.; Urbain, J.; Leo, O.; Moser, M.

2000-01-01

Aims—To describe a new fixation and embedding method for tissue samples, immunohistowax processing, which preserves both morphology and antigen immunoreactivity, and to use this technique to investigate the role of dendritic cells in the immune response in peripheral tissues. Methods—This technique was used to stain a population of specialised antigen presenting cells (dendritic cells) that have the unique capacity to sensitise naive T cells, and therefore to induce primary immune responses. The numbers of dendritic cells in peripheral organs of mice either untreated or injected with live Escherichia coli were compared. Results—Numbers of dendritic cells were greatly decreased in heart, kidney, and intestine after the inoculation of bacteria. The numbers of dendritic cells in the lung did not seem to be affected by the injection of E coli. However, staining of lung sections revealed that some monocyte like cells acquired morphological and phenotypic features of dendritic cells, and migrated into blood vessels. Conclusions—These observations suggest that the injection of bacteria induces the activation of dendritic cells in peripheral organs, where they play the role of sentinels, and/or their movement into lymphoid organs, where T cell priming is likely to occur. Key Words: dendritic cell • Escherichia coli • immunohistochemistry PMID:10961175

[Undifferentiated blastic cell crisis of chronic myelogenous leukemia with myeloblastic tumor in the skin].

PubMed

Kawakami, K; Kiyosaki, M; Amaya, H; Nakamaki, T; Hino, K; Tomoyasu, S

2000-04-01

A 54-year-old female, who had been treated for 4 years in the chronic phase of chronic myelogenous leukemia (CML) was admitted for management of a CML blastic crisis. Blast cells showed strong positive expression of CD7 and HLA-DR, and weakly expressed CD2, CD5 and CD10, as well. The cells were peroxidase negative in peripheral blood and bone marrow. An undifferentiated blastic crisis was diagnosed and she was treated with Interferon-alpha and VP(vincristine 2 mg/week; prednisolone 30 mg/day). A 5-7 mm in diameter tumor in the skin of the anterior right chest appeared one week after VP therapy. The tumor consisted of blasts which were CD13, CD33 and peroxidase positive, unlike the peripheral undifferentiated blasts. This is a rare case of mixed blast crisis with an increase in undifferentiated blasts in peripheral blood and bone marrow, and myeloblastic tumor formation in the skin.

Targeting the Gdnf Gene in peritubular myoid cells disrupts undifferentiated spermatogonial cell development

PubMed Central

Chen, Liang-Yu; Willis, William D.; Eddy, Edward M.

2016-01-01

Spermatogonial stem cells (SSCs) are a subpopulation of undifferentiated spermatogonia located in a niche at the base of the seminiferous epithelium delimited by Sertoli cells and peritubular myoid (PM) cells. SSCs self-renew or differentiate into spermatogonia that proliferate to give rise to spermatocytes and maintain spermatogenesis. Glial cell line-derived neurotrophic factor (GDNF) is essential for this process. Sertoli cells produce GDNF and other growth factors and are commonly thought to be responsible for regulating SSC development, but limited attention has been paid to the role of PM cells in this process. A conditional knockout (cKO) of the androgen receptor gene in PM cells resulted in male infertility. We found that testosterone (T) induces GDNF expression in mouse PM cells in vitro and neonatal spermatogonia (including SSCs) co-cultured with T-treated PM cells were able to colonize testes of germ cell-depleted mice after transplantation. This strongly suggested that T-regulated production of GDNF by PM cells is required for spermatogonial development, but PM cells might produce other factors in vitro that are responsible. In this study, we tested the hypothesis that production of GDNF by PM cells is essential for spermatogonial development by generating mice with a cKO of the Gdnf gene in PM cells. The cKO males sired up to two litters but became infertile due to collapse of spermatogenesis and loss of undifferentiated spermatogonia. These studies show for the first time, to our knowledge, that the production of GDNF by PM cells is essential for undifferentiated spermatogonial cell development in vivo. PMID:26831079

Ultrastructural study of the semicircular canal cells of the frog Rana esculenta.

PubMed

Oudar, O; Ferrary, E; Feldmann, G

1988-03-01

The ultrastructure of the nonsensory cells (dark cells, transitional cells, and undifferentiated cells) of the frog semicircular canal was studied by using transmission electron microscopy in an attempt to correlate the structure with the functions of these epithelial cells. All the nonsensory cells were linked by tight junctions and desmosomes; this suggested that there is little paracellular ionic transport from perilymph to endolymph. In the dark cell epithelium, the apical intercellular spaces were dilated; in the basal part, numerous basolateral plasma membrane infoldings, containing mitochondria, delimited electron-lucent spaces. The undifferentiated cells and the transitional cells were devoid of any basal membrane infolding. Surrounding the semicircular canal, very flattened and interdigitated mesothelial cells constituted a thin multilayer tissue which limited the perilymphatic space. The morphological aspect of the dark cells suggests that they may play a role in the secretion and/or in the reabsorption of endolymph, which bathes the apical pole of these cells. The undifferentiated and transitional cells can play a role in the maintenance of the endolymphatic ionic composition because of their apical tight junctions and desmosomes.

gone early, a Novel Germline Factor, Ensures the Proper Size of the Stem Cell Precursor Pool in the Drosophila Ovary

PubMed Central

Matsuoka, Shinya; Gupta, Swati; Suzuki, Emiko; Hiromi, Yasushi; Asaoka, Miho

2014-01-01

In order to sustain lifelong production of gametes, many animals have evolved a stem cell–based gametogenic program. In the Drosophila ovary, germline stem cells (GSCs) arise from a pool of primordial germ cells (PGCs) that remain undifferentiated even after gametogenesis has initiated. The decision of PGCs to differentiate or remain undifferentiated is regulated by somatic stromal cells: specifically, epidermal growth factor receptor (EGFR) signaling activated in the stromal cells determines the fraction of germ cells that remain undifferentiated by shaping a Decapentaplegic (Dpp) gradient that represses PGC differentiation. However, little is known about the contribution of germ cells to this process. Here we show that a novel germline factor, Gone early (Goe), limits the fraction of PGCs that initiate gametogenesis. goe encodes a non-peptidase homologue of the Neprilysin family metalloendopeptidases. At the onset of gametogenesis, Goe was localized on the germ cell membrane in the ovary, suggesting that it functions in a peptidase-independent manner in cell–cell communication at the cell surface. Overexpression of Goe in the germline decreased the number of PGCs that enter the gametogenic pathway, thereby increasing the proportion of undifferentiated PGCs. Inversely, depletion of Goe increased the number of PGCs initiating differentiation. Excess PGC differentiation in the goe mutant was augmented by halving the dose of argos, a somatically expressed inhibitor of EGFR signaling. This increase in PGC differentiation resulted in a massive decrease in the number of undifferentiated PGCs, and ultimately led to insufficient formation of GSCs. Thus, acting cooperatively with a somatic regulator of EGFR signaling, the germline factor goe plays a critical role in securing the proper size of the GSC precursor pool. Because goe can suppress EGFR signaling activity and is expressed in EGF-producing cells in various tissues, goe may function by attenuating EGFR signaling, and thereby affecting the stromal environment. PMID:25420147

p16 expression in follicular dendritic cell sarcoma: a potential mimicker of human papillomavirus-related oropharyngeal squamous cell carcinoma.

PubMed

Zhang, Lingxin; Yang, Chen; Lewis, James S; El-Mofty, Samir K; Chernock, Rebecca D

2017-08-01

Follicular dendritic cell sarcoma is a rare mesenchymal neoplasm that most commonly occurs in cervical lymph nodes. It has histologic and clinical overlap with the much more common p16-positive human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx, which characteristically has nonkeratinizing morphology and often presents as an isolated neck mass. Not surprisingly, follicular dendritic cell sarcomas are commonly misdiagnosed as squamous cell carcinoma. Immunohistochemistry is helpful in separating the 2 entities. Follicular dendritic cell sarcoma expresses dendritic markers such as CD21 and CD23 and is almost always cytokeratin negative. However, in many cases of HPV-related oropharyngeal carcinoma, only p16 immunohistochemistry as a prognostic and surrogate marker for HPV is performed. p16 expression in follicular dendritic cell sarcoma has not been characterized. Here, we investigate the expression of p16 in follicular dendritic cell sarcoma and correlate it with retinoblastoma protein expression. A pilot study of dendritic marker expression in HPV-related oropharyngeal squamous cell carcinoma was also performed. We found that 4 of 8 sarcomas expressed p16 with strong and diffuse staining in 2 cases. In 2 of the 4 cases, p16 expression corresponded to loss of retinoblastoma protein expression. Dendritic marker expression (CD21 and CD23) was not found in HPV-related oropharyngeal squamous cell carcinomas. As such, positive p16 immunohistochemistry cannot be used as supportive evidence for the diagnosis of squamous cell carcinoma as strong and diffuse p16 expression may also occur in follicular dendritic cell sarcoma. Cytokeratins and dendritic markers are critical in separating the two tumor types. Copyright © 2017 Elsevier Inc. All rights reserved.

Enhanced cytotoxic activity of effector T-cells against cholangiocarcinoma by dendritic cells pulsed with pooled mRNA.

PubMed

Junking, Mutita; Grainok, Janya; Thepmalee, Chutamas; Wongkham, Sopit; Yenchitsomanus, Pa-Thai

2017-10-01

Cholangiocarcinoma is a malignancy of bile duct epithelia with an increasing in incidence rate worldwide. Surgery is the only curative treatment, while adjuvant chemotherapy and radiotherapy render poor responses. Cell-based immunotherapy is a potential strategy for cholangiocarcinoma treatment. However, variation of tumor antigens in cholangiocarcinoma leads to the ineffectiveness of cell-based immunotherapy. In this study, we examined the activation of effector T-cells by dendritic cells pulsed with protein lysate or total RNA from cholangiocarcinoma cell lines for their cytolytic activity against cholangiocarcinoma. Broad-spectrum antigen types with respect to RNA antigen sources were obtained from combination of three cholangiocarcinoma cell lines (KKU-213, KKU-100, and KKU-055). Compared with protein lysate-pulsed dendritic cells, total RNA-pulsed dendritic cells induced anti-tumor effector T-cell response with higher killing ability to KKU-100 and KKU-213 cells compared with protein lysate-pulsed dendritic cells. Moreover, pooled messenger RNA from three cholangiocarcinoma cell lines significantly increased the specific killing capacity of activated lymphocytes against KKU-213 cells. These results suggest that activation of anti-tumor effector T-cells against cholangiocarcinoma by RNA-pulsed dendritic cells is more effective than that by protein lysate-pulsed dendritic cells. In addition, pulsing dendritic cells with pooled messenger RNA from multiple cell lines enhanced the efficacy of a cellular immune response against cholangiocarcinoma.

Hesr1 and Hesr3 are essential to generate undifferentiated quiescent satellite cells and to maintain satellite cell numbers

PubMed Central

Fukada, So-ichiro; Yamaguchi, Masahiko; Kokubo, Hiroki; Ogawa, Ryo; Uezumi, Akiyoshi; Yoneda, Tomohiro; Matev, Miroslav M.; Motohashi, Norio; Ito, Takahito; Zolkiewska, Anna; Johnson, Randy L.; Saga, Yumiko; Miyagoe-Suzuki, Yuko; Tsujikawa, Kazutake; Takeda, Shin’ichi; Yamamoto, Hiroshi

2011-01-01

Satellite cells, which are skeletal muscle stem cells, divide to provide new myonuclei to growing muscle fibers during postnatal development, and then are maintained in an undifferentiated quiescent state in adult skeletal muscle. This state is considered to be essential for the maintenance of satellite cells, but their molecular regulation is unknown. We show that Hesr1 (Hey1) and Hesr3 (Heyl) (which are known Notch target genes) are expressed simultaneously in skeletal muscle only in satellite cells. In Hesr1 and Hesr3 single-knockout mice, no obvious abnormalities of satellite cells or muscle regenerative potentials are observed. However, the generation of undifferentiated quiescent satellite cells is impaired during postnatal development in Hesr1/3 double-knockout mice. As a result, myogenic (MyoD and myogenin) and proliferative (Ki67) proteins are expressed in adult satellite cells. Consistent with the in vivo results, Hesr1/3-null myoblasts generate very few Pax7+ MyoD– undifferentiated cells in vitro. Furthermore, the satellite cell number gradually decreases in Hesr1/3 double-knockout mice even after it has stabilized in control mice, and an age-dependent regeneration defect is observed. In vivo results suggest that premature differentiation, but not cell death, is the reason for the reduced number of satellite cells in Hesr1/3 double-knockout mice. These results indicate that Hesr1 and Hesr3 are essential for the generation of adult satellite cells and for the maintenance of skeletal muscle homeostasis. PMID:21989910

In situ label-free quantification of human pluripotent stem cells with electrochemical potential.

PubMed

Yea, Cheol-Heon; Jeong, Ho-Chang; Moon, Sung-Hwan; Lee, Mi-Ok; Kim, Kyeong-Jun; Choi, Jeong-Woo; Cha, Hyuk-Jin

2016-01-01

Conventional methods for quantification of undifferentiated pluripotent stem cells such as fluorescence-activated cell sorting and real-time PCR analysis have technical limitations in terms of their sensitivity and recyclability. Herein, we designed a real-time in situ label-free monitoring system on the basis of a specific electrochemical signature of human pluripotent stem cells in vitro. The intensity of the signal of hPSCs highly corresponded to the cell number and remained consistent in a mixed population with differentiated cells. The electrical charge used for monitoring did not markedly affect the proliferation rate or molecular characteristics of differentiated human aortic smooth muscle cells. After YM155 treatment to ablate undifferentiated hPSCs, their specific signal was significantly reduced. This suggests that detection of the specific electrochemical signature of hPSCs would be a valid approach to monitor potential contamination of undifferentiated hPSCs, which can assess the risk of teratoma formation efficiently and economically. Copyright © 2015 Elsevier Ltd. All rights reserved.

Oral Prion Disease Pathogenesis Is Impeded in the Specific Absence of CXCR5-Expressing Dendritic Cells

PubMed Central

Bradford, Barry M.; Reizis, Boris

2017-01-01

ABSTRACT After oral exposure, the early replication of certain prion strains upon stromal cell-derived follicular dendritic cells (FDC) in the Peyer's patches in the small intestine is essential for the efficient spread of disease to the brain. However, little is known of how prions are initially conveyed from the gut lumen to establish infection on FDC. Our previous data suggest that mononuclear phagocytes such as CD11c+ conventional dendritic cells play an important role in the initial propagation of prions from the gut lumen into Peyer's patches. However, whether these cells conveyed orally acquired prions toward FDC within Peyer's patches was not known. The chemokine CXCL13 is expressed by FDC and follicular stromal cells and modulates the homing of CXCR5-expressing cells toward the FDC-containing B cell follicles. Here, novel compound transgenic mice were created in which a CXCR5 deficiency was specifically restricted to CD11c+ cells. These mice were used to determine whether CXCR5-expressing conventional dendritic cells propagate prions toward FDC after oral exposure. Our data show that in the specific absence of CXCR5-expressing conventional dendritic cells the early accumulation of prions upon FDC in Peyer's patches and the spleen was impaired, and disease susceptibility significantly reduced. These data suggest that CXCR5-expressing conventional dendritic cells play an important role in the efficient propagation of orally administered prions toward FDC within Peyer's patches in order to establish host infection. IMPORTANCE Many natural prion diseases are acquired by oral consumption of contaminated food or pasture. Once the prions reach the brain they cause extensive neurodegeneration, which ultimately leads to death. In order for the prions to efficiently spread from the gut to the brain, they first replicate upon follicular dendritic cells within intestinal Peyer's patches. How the prions are first delivered to follicular dendritic cells to establish infection was unknown. Understanding this process is important since treatments which prevent prions from infecting follicular dendritic cells can block their spread to the brain. We created mice in which mobile conventional dendritic cells were unable to migrate toward follicular dendritic cells. In these mice the early accumulation of prions on follicular dendritic cells was impaired and oral prion disease susceptibility was reduced. This suggests that prions exploit conventional dendritic cells to facilitate their initial delivery toward follicular dendritic cells to establish host infection. PMID:28275192

Ursolic acid isolated from Uncaria rhynchophylla activates human dendritic cells via TLR2 and/or TLR4 and induces the production of IFN-gamma by CD4+ naïve T cells.

PubMed

Jung, Tae-Young; Pham, Thanh Nhan Nguyen; Umeyama, Akemi; Shoji, Noboru; Hashimoto, Toshihiro; Lee, Je-Jung; Takei, Masao

2010-09-25

Ursolic acid is triterpene isolated from Uncaria rhynchophylla and is a pharmacologically active substance. The induction of dendritic cell maturation is critical for the induction of Ag-specific T-lymphocyte response and may be essential for the development of human vaccine relying on T cell immunity. In this study, we investigated that the effect of Ursolic acid on the phenotypic and functional maturation of human monocyte-derived dendritic cells in vitro. Dendritic cells harvested on day 8 were examined using functional assay. The expression levels of CD1a, CD80, CD83, CD86, HLA-DR and CCR7 on Ursolic acid-primed dendritic cells was slightly enhanced. Ursolic acid dose-dependently enhanced the T cell stimulatory capacity in an allogeneic mixed lymphocyte reaction, as measured by T cell proliferation. The production of IL-12p70 induced by Ursolic acid-primed dendritic cells was inhibited by the anti-Toll-like receptor-2 (TLR2) mAb and anti-TLR4 mAb. Moreover, Ursolic acid-primed dendritic cells expressed levels of mRNA coding for both TLR2 and TLR4. The majority of cells produced considerable interferon-gamma (IFN-gamma), but also small amounts of interleukin (IL-4)-4. Ursolic acid-primed dendritic cells have an intermediate migratory capacity towards CCL19 and CCL21. These results suggest that Ursolic acid modulates human dendritic cells function in a fashion that favors Th1 polarization via the activation of IL-12p70 dependent on TLR2 and/or TLR4, and may be used on dendritic cells-based vaccines for cancer immunotherapy. 2010 Elsevier B.V. All rights reserved.

Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor

PubMed Central

1992-01-01

Antigen-presenting, major histocompatibility complex (MHC) class II- rich dendritic cells are known to arise from bone marrow. However, marrow lacks mature dendritic cells, and substantial numbers of proliferating less-mature cells have yet to be identified. The methodology for inducing dendritic cell growth that was recently described for mouse blood now has been modified to MHC class II- negative precursors in marrow. A key step is to remove the majority of nonadherent, newly formed granulocytes by gentle washes during the first 2-4 d of culture. This leaves behind proliferating clusters that are loosely attached to a more firmly adherent "stroma." At days 4-6 the clusters can be dislodged, isolated by 1-g sedimentation, and upon reculture, large numbers of dendritic cells are released. The latter are readily identified on the basis of their distinct cell shape, ultrastructure, and repertoire of antigens, as detected with a panel of monoclonal antibodies. The dendritic cells express high levels of MHC class II products and act as powerful accessory cells for initiating the mixed leukocyte reaction. Neither the clusters nor mature dendritic cells are generated if macrophage colony-stimulating factor rather than granulocyte/macrophage colony-stimulating factor (GM-CSF) is applied. Therefore, GM-CSF generates all three lineages of myeloid cells (granulocytes, macrophages, and dendritic cells). Since > 5 x 10(6) dendritic cells develop in 1 wk from precursors within the large hind limb bones of a single animal, marrow progenitors can act as a major source of dendritic cells. This feature should prove useful for future molecular and clinical studies of this otherwise trace cell type. PMID:1460426

Acute erythroblastic leukemia presenting as acute undifferentiated leukemia: a report of two cases with ultrastructural features.

PubMed

Reiffers, J; Bernard, P; Larrue, J; Dachary, D; David, B; Boisseau, M; Broustet, A

1985-01-01

This report describes two elderly patients with acute leukemia in which blast cells were undifferentiated with conventional light microscopy (L.M.) and cytochemistry. Blast cells were identified as belonging to the erythroblastic line by their ultrastructural features: glycogen deposits, lipidic vacuoles, cytoplasmic ferritin molecules and rhopheocytotic invagination. Moreover, blast cells were surrounding a central macrophage. Thus, these two patients had acute erythroblastic leukemia which differs from erythroleukemia (M6 of FAB classification) in which blast cells present myeloblastic characteristics.

Cediranib Maleate and Olaparib or Standard Chemotherapy in Treating Patients With Recurrent Platinum-Resistant or -Refractory Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-15

Deleterious BRCA1 Gene Mutation; Deleterious BRCA2 Gene Mutation; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Elesclomol Sodium and Paclitaxel in Treating Patients With Recurrent or Persistent Ovarian Epithelial Cancer, Fallopian Tube Cancer, or Primary Peritoneal Cancer

ClinicalTrials.gov

2017-05-02

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Tumor; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Trisomy 4 in a case of acute undifferentiated myeloblastic leukemia with hand-mirror cells.

PubMed

Kao, Y S; McCormick, C; Vial, R

1990-04-01

A case of acute undifferentiated myelocytic leukemic with trisomy 4 is described. The patient is a 61-year-old woman who developed leukemia 4 1/2 years after receiving radiation therapy for uterine carcinoma. Many leukemic cells exhibited hand-mirror configuration after the bone marrow aspirate was left at room temperature overnight. The relationship between trisomy 4 and hand-mirror cells in acute myelocytic leukemia is unknown.

Undifferentiated carcinoma of the esophagus: a clinicopathological study of 16 cases☆

PubMed Central

Singhi, Aatur D.; Seethala, Raja R.; Nason, Katie; Foxwell, Tyler J.; Roche, Robyn L.; McGrath, Kevin M.; Levy, Ryan M.; Luketich, James D.; Davison, Jon M.

2015-01-01

Summary Undifferentiated carcinoma of the esophagus is a rare histologic variant of esophageal carcinoma. Using criteria based on studies of undifferentiated carcinomas arising at other sites, we have collected 16 cases of resected esophageal undifferentiated carcinomas. Patients ranged in age from 39 to 84 years (mean, 65.5 years) and were predominantly male (94%). The tumors were characterized by an expansile growth pattern of neoplastic cells organized in solid sheets and without significant glandular, squamous, or neuroendocrine differentiation. The neoplastic cells had a syncytial-like appearance, little intervening stroma, and patchy tumor necrosis. In a subset of cases, the tumor cells adopted a sarcomatoid (n = 2), rhabdoid (n = 1), or minor component (<5%) of glandular morphology (n = 3). In 1 case, reactive osteoclast-like giant cells were found interspersed among the neoplastic cells. Lymphovascular invasion, perineural invasion, and lymph node metastases were identified in 88%, 56%, and 81% of cases, respectively. In 12 (75%) specimens, the background esophageal mucosa was notable for Barrett esophagus. Consistent with the epithelial nature of these neoplasms, cytokeratin positivity was identified in all cases. In addition, SALL4 expression was present in 8 (67%) of 12 cases. Follow-up information was available for 15 (94%) of 16 patients, all of whom were deceased. Survival after surgery ranged from 1 to 50 months (mean, 11.9 months). Before death, 67% patients had documented locoregional recurrence and/or distant organ metastases. In summary, esophageal undifferentiated carcinomas are aggressive neoplasms and associated with a high incidence of recurrence and/or metastases and a dismal prognosis. PMID:25582499

Effects of granulocyte-macrophage colony-stimulating factor and interleukin 6 on the growth of leukemic blasts in suspension culture.

PubMed

Tsao, C J; Cheng, T Y; Chang, S L; Su, W J; Tseng, J Y

1992-05-01

We examined the stimulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 6 (IL)-6 on the in vitro proliferation of leukemic blast cells from patients with acute leukemia. Bone marrow or peripheral blood leukemic blast cells were obtained from 21 patients, including 14 cases of acute myeloblastic leukemia (AML), four cases of acute lymphoblastic leukemia (ALL), two cases of acute undifferentiated leukemia, and one case of acute mixed-lineage leukemia. The proliferation of leukemic blast cells was evaluated by measuring the incorporation of 3H-thymidine into cells incubated with various concentrations of cytokines for 3 days. GM-CSF stimulated the DNA synthesis (with greater than 2.0 stimulation index) of blast cells in 9 of 14 (64%) AML cases, two cases of acute undifferentiated leukemia and one case of acute mixed-lineage leukemia. Only two cases of AML blasts responded to IL-6 to grow in the short-term suspension cultures. GM-CSF and IL-6 did not display a synergistic effect on the growth of leukemic cells. Moreover, GM-CSF and IL-6 did not stimulate the proliferation of ALL blast cells. Binding study also revealed the specific binding of GM-CSF on the blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia. Our results indicated that leukemic blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia possessed functional GM-CSF receptors.

Commensal oral bacteria antigens prime human dendritic cells to induce Th1, Th2 or Treg differentiation.

PubMed

Kopitar, A N; Ihan Hren, N; Ihan, A

2006-02-01

In various immunopathologic conditions, bacterial flora induce an immune response which results in inflammatory manifestations, e.g. periapical granuloma. Dendritic cells provide the main orchestration of specific immune responses. The aim of our study was to test the capacity of distinct oral bacterial antigens (prepared from Streptococcus mitis, Propionibacterium acnes, and Bacteroides spp.) to prime human dendritic cells for stimulation of the T-lymphocyte response. To assess the T-lymphocyte response, the expression of CD25, CD69, intracellular interferon gamma (cIFN-gamma), and intracellular interleukin 4 (cIL-4) was determined. Dendritic cells were prepared from leukocyte buffy coat from healthy blood donors. Monocytes were stimulated with IL-4 and GM-CSF and dendritic cells activated with bacterial lysates. Cell suspensions contained up to 90% dendritic cells, which represented 2-12% of the initial number of mononuclear cells. Lymphocyte subsets that developed in lymphocyte cultures after 1 week of stimulation were analyzed by flow cytometry. Dendritic cells, primed with antigens of Bacteroides fragilis have shown significantly higher activation and expression of intercellular IFN-gamma by T lymphocytes compared to negative controls. The dendritic cells primed with antigens of P. acnes had no effect on T-lymphocyte activation or cytokine production; instead they induced differentiation of T lymphocytes into CD25bright cells (regulatory T cells) with a potentially inhibitory effect on immune response. Dendritic cells primed with antigens of S. mitis induced increased expression of cIL-4. We conclude that commensal oral bacteria antigens prepared from B. fragilis, S. mitis, and P. acnes prime human dendritic cells to induce Th1, Th2, and T(reg) differentiation, respectively. This may advance our understanding of immunopathologic manifestations in the oral cavity and offer new possibilities for redirecting immune responses in mucosal vaccination.

Pembrolizumab, Bevacizumab, and Cyclophosphamide in Treating Patients With Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-05-03

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease.

PubMed

Smith, R E; Reyes, N J; Khandelwal, P; Schlereth, S L; Lee, H S; Masli, S; Saban, D R

2016-08-01

Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. © Society for Leukocyte Biology.

Secondary allergic T cell responses are regulated by dendritic cell-derived thrombospondin-1 in the setting of allergic eye disease

PubMed Central

Smith, R. E.; Reyes, N. J.; Khandelwal, P.; Schlereth, S. L.; Lee, H. S.; Masli, S.; Saban, D. R.

2016-01-01

Allergic eye disease, as in most forms of atopy, ranges in severity among individuals from immediate hypersensitivity to a severe and debilitating chronic disease. Dendritic cells play a key role in stimulating pathogenic T cells in allergen re-exposure, or secondary responses. However, molecular cues by dendritic cells underpinning allergic T cell response levels and the impact that this control has on consequent severity of allergic disease are poorly understood. Here, we show that a deficiency in thrombospondin-1, a matricellular protein known to affect immune function, has subsequent effects on downstream T cell responses during allergy, as revealed in an established mouse model of allergic eye disease. More specifically, we demonstrate that a thrombospondin-1 deficiency specific to dendritic cells leads to heightened secondary T cell responses and consequent clinical disease. Interestingly, whereas thrombospondin-1-deficient dendritic cells augmented activity of allergen-primed T cells, this increase was not recapitulated with naïve T cells in vitro. The role of dendritic cell-derived thrombospondin-1 in regulating secondary allergic T cell responses was confirmed in vivo, as local transfer of thrombospondin-1-sufficient dendritic cells to the ocular mucosa of thrombospondin-1 null hosts prevented the development of augmented secondary T cell responses and heightened allergic eye disease clinical responses. Finally, we demonstrate that topical instillation of thrombospondin-1-derived peptide reduces T cell activity and clinical progression of allergic eye disease. Taken together, this study reveals an important modulatory role of dendritic cell-derived thrombospondin-1 on secondary allergic T cell responses and suggests the possible dysregulation of dendritic cell-derived thrombospondin-1 expression as a factor in allergic eye disease severity. PMID:26856994

LPS-treated bone marrow-derived dendritic cells induce immune tolerance through modulating differentiation of CD4+ regulatory T cell subpopulations mediated by 3G11 and CD127.

PubMed

Zhou, Fang; Zhang, Guang-Xian; Rostami, Abdolmohamad

2017-06-01

Intravenous transfer of LPS-treated bone marrow-derived dendritic cells blocks development of autoimmunity induced by CD4 + T cells in vivo. However, cellular mechanisms of dendritic cell-mediated immune tolerance have not yet been fully elucidated. Here, we report that there are two new subpopulations of CD4 + CD25 + FoxP3 + GITR + regulatory T cells (CD127 + 3G11 + and CD127 + 3G11 - cells). LPS-treated dendritic cells facilitate development of CD4 + CD127 + 3G11 - regulatory T cells but inhibit that of CD4 + CD127 + 3G11 + regulatory T cells. LPS-induced tolerogenic dendritic cells may cause immune tolerance through modulating balance of different subsets of CD4 + regulatory T cells mediated by CD127 and 3G11. Our results imply a new potential cellular mechanism of dendritic cell-mediated immune tolerance.

Behavior of Xeno-Transplanted Undifferentiated Human Induced Pluripotent Stem Cells Is Impacted by Microenvironment Without Evidence of Tumors.

PubMed

Martínez-Cerdeño, Veronica; Barrilleaux, Bonnie L; McDonough, Ashley; Ariza, Jeanelle; Yuen, Benjamin T K; Somanath, Priyanka; Le, Catherine T; Steward, Craig; Horton-Sparks, Kayla; Knoepfler, Paul S

2017-10-01

Human pluripotent stem cells (hPSC) have great clinical potential through the use of their differentiated progeny, a population in which there is some concern over risks of tumorigenicity or other unwanted cellular behavior due to residual hPSC. Preclinical studies using human stem cells are most often performed within a xenotransplant context. In this study, we sought to measure how undifferentiated hPSC behave following xenotransplant. We directly transplanted undifferentiated human induced pluripotent stem cells (hIPSC) and human embryonic stem cells (hESC) into the adult mouse brain ventricle and analyzed their fates. No tumors or precancerous lesions were present at more than one year after transplantation. This result differed with the tumorigenic capacity we observed after allotransplantation of mouse ESC into the mouse brain. A substantial population of cellular derivatives of undifferentiated hESC and hIPSC engrafted, survived, and migrated within the mouse brain parenchyma. Within brain structures, transplanted cell distribution followed a very specific pattern, suggesting the existence of distinct microenvironments that offer different degrees of permissibility for engraftment. Most of the transplanted hESC and hIPSC that developed into brain cells were NeuN+ neuronal cells, and no astrocytes were detected. Substantial cell and nuclear fusion occurred between host and transplanted cells, a phenomenon influenced by microenvironment. Overall, hIPSC appear to be largely functionally equivalent to hESC in vivo. Altogether, these data bring new insights into the behavior of stem cells without prior differentiation following xenotransplantation into the adult brain.

Endocytic pathways downregulate the L1-type cell adhesion molecule neuroglian to promote dendrite pruning in Drosophila.

PubMed

Zhang, Heng; Wang, Yan; Wong, Jack Jing Lin; Lim, Kah-Leong; Liou, Yih-Cherng; Wang, Hongyan; Yu, Fengwei

2014-08-25

Pruning of unnecessary axons and/or dendrites is crucial for maturation of the nervous system. However, little is known about cell adhesion molecules (CAMs) that control neuronal pruning. In Drosophila, dendritic arborization neurons, ddaCs, selectively prune their larval dendrites. Here, we report that Rab5/ESCRT-mediated endocytic pathways are critical for dendrite pruning. Loss of Rab5 or ESCRT function leads to robust accumulation of the L1-type CAM Neuroglian (Nrg) on enlarged endosomes in ddaC neurons. Nrg is localized on endosomes in wild-type ddaC neurons and downregulated prior to dendrite pruning. Overexpression of Nrg alone is sufficient to inhibit dendrite pruning, whereas removal of Nrg causes precocious dendrite pruning. Epistasis experiments indicate that Rab5 and ESCRT restrain the inhibitory role of Nrg during dendrite pruning. Thus, this study demonstrates the cell-surface molecule that controls dendrite pruning and defines an important mechanism whereby sensory neurons, via endolysosomal pathway, downregulate the cell-surface molecule to trigger dendrite pruning. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

DTIC Science & Technology

2014-07-01

and J.W. Young, Human dendritic cells : potent antigen-presenting cells at the crossroads of innate and adaptive immunity. J Immunol, 2005. 175(3): p...by Listeria-Stimulated Human Dendritic Cells : Implications for Cancer Vaccine Therapy PRINCIPAL INVESTIGATOR: David J. Chung, MD, PhD...5a. CONTRACT NUMBER Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells : Implications for Cancer Vaccine

Chlamydia trachomatis Cellular Exit Alters Interactions with Host Dendritic Cells

PubMed Central

Sherrid, Ashley M.

2017-01-01

ABSTRACT The strategies utilized by pathogens to exit host cells are an area of pathogenesis which has received surprisingly little attention, considering the necessity of this step for infections to propagate. Even less is known about how exit through these pathways affects downstream host-pathogen interactions and the generation of an immune response. Chlamydia trachomatis exits host epithelial cells through two equally active mechanisms: lysis and extrusion. Studies have characterized the outcome of interactions between host innate immune cells, such as dendritic cells and macrophages, and free, extracellular Chlamydia bacteria, such as those resulting from lysis. Exit via extrusion generates a distinct, host-membrane-bound compartment of Chlamydia separate from the original infected cell. In this study, we assessed the effect of containment within extrusions upon the interaction between Chlamydia and host dendritic cells. Extrusion dramatically affected the outcome of Chlamydia-dendritic cell interactions for both the bacterium and the host cell. Dendritic cells rapidly underwent apoptosis in response to engulfment of an extrusion, while uptake of an equivalent dose of free Chlamydia had no such effect. Containment within an extrusion also prolonged bacterial survival within dendritic cells and altered the initial innate immune signaling by the dendritic cell. PMID:28223346

Pegylated Liposomal Doxorubicin Hydrochloride With Atezolizumab and/or Bevacizumab in Treating Patients With Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-20

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; High Grade Fallopian Tube Serous Adenocarcinoma; High Grade Ovarian Serous Adenocarcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Seromucinous Carcinoma; Primary Peritoneal High Grade Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Immunological Characterization of Whole Tumour Lysate-Loaded Dendritic Cells for Cancer Immunotherapy

PubMed Central

Ottobrini, Luisa; Biasin, Mara; Borelli, Manuela; Lucignani, Giovanni; Trabattoni, Daria; Clerici, Mario

2016-01-01

Introduction Dendritic cells play a key role as initiators of T-cell responses, and even if tumour antigen-loaded dendritic cells can induce anti-tumour responses, their efficacy has been questioned, suggesting a need to enhance immunization strategies. Matherials & Methods We focused on the characterization of bone marrow-derived dendritic cells pulsed with whole tumour lysate (TAA-DC), as a source of known and unknown antigens, in a mouse model of breast cancer (MMTV-Ras). Dendritic cells were evaluated for antigen uptake and for the expression of MHC class I/II and costimulatory molecules and markers associated with maturation. Results Results showed that antigen-loaded dendritic cells are characterized by a phenotypically semi-mature/mature profile and by the upregulation of genes involved in antigen presentation and T-cell priming. Activated dendritic cells stimulated T-cell proliferation and induced the production of high concentrations of IL-12p70 and IFN-γ but only low levels of IL-10, indicating their ability to elicit a TH1-immune response. Furthermore, administration of Antigen loaded-Dendritic Cells in MMTV-Ras mice evoked a strong anti-tumour response in vivo as demonstrated by a general activation of immunocompetent cells and the release of TH1 cytokines. Conclusion Data herein could be useful in the design of antitumoral DC-based therapies, showing a specific activation of immune system against breast cancer. PMID:26795765

Pro-inflammatory Cytokine Expression of Spleen Dendritic Cells in Mouse Toxoplasmosis

PubMed Central

Nam, Ho-Woo; Ahn, Hye-Jin

2011-01-01

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of CD8α+/CD11c+ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis. PMID:21738265

Clonal type I interferon-producing and dendritic cell precursors are contained in both human lymphoid and myeloid progenitor populations.

PubMed

Chicha, Laurie; Jarrossay, David; Manz, Markus G

2004-12-06

Because of different cytokine responsiveness, surface receptor, and transcription factor expression, human CD11c(-) natural type I interferon-producing cells (IPCs) and CD11c(+) dendritic cells were thought to derive through lymphoid and myeloid hematopoietic developmental pathways, respectively. To directly test this hypothesis, we used an in vitro assay allowing simultaneous IPC, dendritic cell, and B cell development and we tested lymphoid and myeloid committed hematopoietic progenitor cells for their developmental capacity. Lymphoid and common myeloid and granulocyte/macrophage progenitors were capable of developing into both functional IPCs, expressing gene transcripts thought to be associated with lymphoid lineage development, and into dendritic cells. However, clonal progenitors for both populations were about fivefold more frequent within myeloid committed progenitor cells. Thus, in humans as in mice, natural IPC and dendritic cell development robustly segregates with myeloid differentiation. This would fit with natural interferon type I-producing cell and dendritic cell activity in innate immunity, the evolutionary older arm of the cellular immune system.

Dendritic Cells and Innate Immunity in Kidney Transplantation

PubMed Central

Zhuang, Quan; Lakkis, Fadi G.

2015-01-01

Summary This review summarizes emerging concepts related to the roles of dendritic cells and innate immunity in organ transplant rejection. First, it highlights the primary role that recipient, rather than donor, dendritic cells have in rejection and reviews their origin and function in the transplanted kidney. Second, it introduces the novel concept that recognition of allogeneic non-self by host monocytes (referred to here as innate allorecognition) is necessary for initiating rejection by inducing monocyte differentiation into mature, antigen-presenting dendritic cells. Both concepts provide opportunities for preventing rejection by targeting monocytes or dendritic cells. PMID:25629552

Sialyl-lactotetra, a novel cell surface marker of undifferentiated human pluripotent stem cells.

PubMed

Barone, Angela; Säljö, Karin; Benktander, John; Blomqvist, Maria; Månsson, Jan-Eric; Johansson, Bengt R; Mölne, Johan; Aspegren, Anders; Björquist, Petter; Breimer, Michael E; Teneberg, Susann

2014-07-04

Cell surface glycoconjugates are used as markers for undifferentiated pluripotent stem cells. Here, antibody binding and mass spectrometry characterization of acid glycosphingolipids isolated from a large number (1 × 10(9) cells) of human embryonic stem cell (hESC) lines allowed identification of several novel acid glycosphingolipids, like the gangliosides sialyl-lactotetraosylceramide and sialyl-globotetraosylceramide, and the sulfated glycosphingolipids sulfatide, sulf-lactosylceramide, and sulf-globopentaosylceramide. A high cell surface expression of sialyl-lactotetra on hESC and human induced pluripotent stem cells (hiPSC) was demonstrated by flow cytometry, immunohistochemistry, and electron microscopy, whereas sulfated glycosphingolipids were only found in intracellular compartments. Immunohistochemistry showed distinct cell surface anti-sialyl-lactotetra staining on all seven hESC lines and three hiPSC lines analyzed, whereas no staining of hESC-derived hepatocyte-like or cardiomyocyte-like cells was obtained. Upon differentiation of hiPSC into hepatocyte-like cells, the sialyl-lactotetra epitope was rapidly down-regulated and not detectable after 14 days. These findings identify sialyl-lactotetra as a promising marker of undifferentiated human pluripotent stem cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

A genetic platform to model sarcomagenesis from primary adult mesenchymal stem cells

PubMed Central

Guarnerio, Jlenia; Riccardi, Luisa; Taulli, Riccardo; Maeda, Takahiro; Wang, Guocan; Hobbs, Robin M.; Song, Min Sup; Sportoletti, Paolo; Bernardi, Rosa; Bronson, Roderick T.; Castillo-Martin, Mireia; Cordon-Cardo, Carlos; Lunardi, Andrea; Pandolfi, Pier Paolo

2015-01-01

The regulatory factors governing adult mesenchymal stem cells (MSCs) physiology and their tumorigenic potential are still largely unknown, which substantially delays the identification of effective therapeutic approaches for the treatment of aggressive and lethal form of MSC-derived mesenchymal tumors, such as undifferentiated sarcomas. Here we have developed a novel platform to screen and quickly identify genes and pathways responsible for adult MSCs transformation, modeled undifferentiated sarcoma in vivo, and, ultimately, tested the efficacy of targeting the identified oncopathways. Importantly, by taking advantage of this new platform, we demonstrate the key role of an aberrant LRF-DLK1-SOX9 pathway in the pathogenesis of undifferentiated sarcoma with important therapeutic implications. PMID:25614485

Cigarette smoke-induced accumulation of lung dendritic cells is interleukin-1α-dependent in mice

PubMed Central

2012-01-01

Background Evidence suggests that dendritic cells accumulate in the lungs of COPD patients and correlate with disease severity. We investigated the importance of IL-1R1 and its ligands IL-1α and β to dendritic cell accumulation and maturation in response to cigarette smoke exposure. Methods Mice were exposed to cigarette smoke using a whole body smoke exposure system. IL-1R1-, TLR4-, and IL-1α-deficient mice, as well as anti-IL-1α and anti-IL-1β blocking antibodies were used to study the importance of IL-1R1 and TLR4 to dendritic cell accumulation and activation. Results Acute and chronic cigarette smoke exposure led to increased frequency of lung dendritic cells. Accumulation and activation of dendritic cells was IL-1R1/IL-1α dependent, but TLR4- and IL-1β-independent. Corroborating the cellular data, expression of CCL20, a potent dendritic cells chemoattractant, was IL-1R1/IL-1α-dependent. Studies using IL-1R1 bone marrow-chimeric mice revealed the importance of IL-1R1 signaling on lung structural cells for CCL20 expression. Consistent with the importance of dendritic cells in T cell activation, we observed decreased CD4+ and CD8+ T cell activation in cigarette smoke-exposed IL-1R1-deficient mice. Conclusion Our findings convey the importance of IL-1R1/IL-1α to the recruitment and activation of dendritic cells in response to cigarette smoke exposure. PMID:22992200

Phase I (Safety) Study of Autologous Tolerogenic Dendritic Cells in Type 1 Diabetic Patients

PubMed Central

Giannoukakis, Nick; Phillips, Brett; Finegold, David; Harnaha, Jo; Trucco, Massimo

2011-01-01

OBJECTIVE The safety of dendritic cells to selectively suppress autoimmunity, especially in type 1 diabetes, has never been ascertained. We investigated the safety of autologous dendritic cells, stabilized into an immunosuppressive state, in established adult type 1 diabetic patients. RESEARCH DESIGN AND METHODS A randomized, double-blind, phase I study was conducted. A total of 10, otherwise generally healthy, insulin-requiring type 1 diabetic patients between 18 and 60 years of age, without any other known or suspected health conditions, received autologous dendritic cells, unmanipulated or engineered ex vivo toward an immunosuppressive state. Ten million cells were administered intradermally in the abdomen once every 2 weeks for a total of four administrations. The primary end point determined the proportion of patients with adverse events on the basis of the physician’s global assessment, hematology, biochemistry, and immune monitoring for a period of 12 months. RESULTS The dendritic cells were safely tolerated. There were no discernible adverse events in any patient throughout the study. Other than a significant increase in the frequency of peripheral B220+ CD11c− B cells, mainly seen in the recipients of engineered dendritic cells during the dendritic cell administration period, there were no statistically relevant differences in other immune populations or biochemical, hematological, and immune biomarkers compared with baseline. CONCLUSIONS Treatment with autologous dendritic cells, in a native state or directed ex vivo toward a tolerogenic immunosuppressive state, is safe and well tolerated. Dendritic cells upregulated the frequency of a potentially beneficial B220+ CD11c− B-cell population, at least in type 1 diabetes autoimmunity. PMID:21680720

WASp-dependent actin cytoskeleton stability at the dendritic cell immunological synapse is required for extensive, functional T cell contacts.

PubMed

Malinova, Dessislava; Fritzsche, Marco; Nowosad, Carla R; Armer, Hannah; Munro, Peter M G; Blundell, Michael P; Charras, Guillaume; Tolar, Pavel; Bouma, Gerben; Thrasher, Adrian J

2016-05-01

The immunological synapse is a highly structured and molecularly dynamic interface between communicating immune cells. Although the immunological synapse promotes T cell activation by dendritic cells, the specific organization of the immunological synapse on the dendritic cell side in response to T cell engagement is largely unknown. In this study, confocal and electron microscopy techniques were used to investigate the role of dendritic cell actin regulation in immunological synapse formation, stabilization, and function. In the dendritic cell-restricted absence of the Wiskott-Aldrich syndrome protein, an important regulator of the actin cytoskeleton in hematopoietic cells, the immunological synapse contact with T cells occupied a significantly reduced surface area. At a molecular level, the actin network localized to the immunological synapse exhibited reduced stability, in particular, of the actin-related protein-2/3-dependent, short-filament network. This was associated with decreased polarization of dendritic cell-associated ICAM-1 and MHC class II, which was partially dependent on Wiskott-Aldrich syndrome protein phosphorylation. With the use of supported planar lipid bilayers incorporating anti-ICAM-1 and anti-MHC class II antibodies, the dendritic cell actin cytoskeleton organized into recognizable synaptic structures but interestingly, formed Wiskott-Aldrich syndrome protein-dependent podosomes within this area. These findings demonstrate that intrinsic dendritic cell cytoskeletal remodeling is a key regulatory component of normal immunological synapse formation, likely through consolidation of adhesive interaction and modulation of immunological synapse stability. © The Author(s).

Dendritic cells in Barrett's esophagus and esophageal adenocarcinoma.

PubMed

Bobryshev, Yuri V; Tran, Dinh; Killingsworth, Murray C; Buckland, Michael; Lord, Reginald V N

2009-01-01

Like other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett's esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett's intestinal metaplasia and esophageal adenocarcinoma and this prompted our study. We used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett's esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett's intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14). CD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett's IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett's esophagus and form clusters with T cells and B cells directly within the lamina propria. These findings demonstrate that dendritic cells are present in Barrett's tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett's esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett's esophagus and adenocarcinoma.

Morphology, classification, and distribution of the projection neurons in the dorsal lateral geniculate nucleus of the rat.

PubMed

Ling, Changying; Hendrickson, Michael L; Kalil, Ronald E

2012-01-01

The morphology of confirmed projection neurons in the dorsal lateral geniculate nucleus (dLGN) of the rat was examined by filling these cells retrogradely with biotinylated dextran amine (BDA) injected into the visual cortex. BDA-labeled projection neurons varied widely in the shape and size of their cell somas, with mean cross-sectional areas ranging from 60-340 µm(2). Labeled projection neurons supported 7-55 dendrites that spanned up to 300 µm in length and formed dendritic arbors with cross-sectional areas of up to 7.0 × 10(4) µm(2). Primary dendrites emerged from cell somas in three broad patterns. In some dLGN projection neurons, primary dendrites arise from the cell soma at two poles spaced approximately 180° apart. In other projection neurons, dendrites emerge principally from one side of the cell soma, while in a third group of projection neurons primary dendrites emerge from the entire perimeter of the cell soma. Based on these three distinct patterns in the distribution of primary dendrites from cell somas, we have grouped dLGN projection neurons into three classes: bipolar cells, basket cells and radial cells, respectively. The appendages seen on dendrites also can be grouped into three classes according to differences in their structure. Short "tufted" appendages arise mainly from the distal branches of dendrites; "spine-like" appendages, fine stalks with ovoid heads, typically are seen along the middle segments of dendrites; and "grape-like" appendages, short stalks that terminate in a cluster of ovoid bulbs, appear most often along the proximal segments of secondary dendrites of neurons with medium or large cell somas. While morphologically diverse dLGN projection neurons are intermingled uniformly throughout the nucleus, the caudal pole of the dLGN contains more small projection neurons of all classes than the rostral pole.

Bortezomib as a new therapeutic approach for blastic plasmacytoid dendritic cell neoplasm

PubMed Central

Philippe, Laure; Ceroi, Adam; Bôle-Richard, Elodie; Jenvrin, Alizée; Biichle, Sabeha; Perrin, Sophie; Limat, Samuel; Bonnefoy, Francis; Deconinck, Eric; Saas, Philippe; Garnache-Ottou, Francine; Angelot-Delettre, Fanny

2017-01-01

Blastic plasmacytoid dendritic cell neoplasm is an aggressive hematologic malignancy with a poor prognosis. No consensus regarding optimal treatment modalities is currently available. Targeting the nuclear factor-kappa B pathway is considered a promising approach since blastic plasmacytoid dendritic cell neoplasm has been reported to exhibit constitutive activation of this pathway. Moreover, nuclear factor-kappa B inhibition in blastic plasmacytoid dendritic cell neoplasm cell lines, achieved using either an experimental specific inhibitor JSH23 or the clinical drug bortezomib, interferes in vitro with leukemic cell proliferation and survival. Here we extended these data by showing that primary blastic plasmacytoid dendritic cell neoplasm cells from seven patients were sensitive to bortezomib-induced cell death. We confirmed that bortezomib efficiently inhibits the phosphorylation of the RelA nuclear factor-kappa B subunit in blastic plasmacytoid dendritic cell neoplasm cell lines and primary cells from patients in vitro and in vivo in a mouse model. We then demonstrated that bortezomib can be associated with other drugs used in different chemotherapy regimens to improve its impact on leukemic cell death. Indeed, when primary blastic plasmacytoid dendritic cell neoplasm cells from a patient were grafted into mice, bortezomib treatment significantly increased the animals’ survival, and was associated with a significant decrease of circulating leukemic cells and RelA nuclear factor-kappa B subunit expression. Overall, our results provide a rationale for the use of bortezomib in combination with other chemotherapy for the treatment of patients with blastic plasmacytoid dendritic cell neoplasm. Based on our data, a prospective clinical trial combining proteasome inhibitor with classical drugs could be envisaged. PMID:28798071

Deletion of Wiskott–Aldrich syndrome protein triggers Rac2 activity and increased cross-presentation by dendritic cells

PubMed Central

Baptista, Marisa A. P.; Keszei, Marton; Oliveira, Mariana; Sunahara, Karen K. S.; Andersson, John; Dahlberg, Carin I. M.; Worth, Austen J.; Liedén, Agne; Kuo, I-Chun; Wallin, Robert P. A.; Snapper, Scott B.; Eidsmo, Liv; Scheynius, Annika; Karlsson, Mikael C. I.; Bouma, Gerben; Burns, Siobhan O.; Forsell, Mattias N. E.; Thrasher, Adrian J.; Nylén, Susanne; Westerberg, Lisa S.

2016-01-01

Wiskott–Aldrich syndrome (WAS) is caused by loss-of-function mutations in the WASp gene. Decreased cellular responses in WASp-deficient cells have been interpreted to mean that WASp directly regulates these responses in WASp-sufficient cells. Here, we identify an exception to this concept and show that WASp-deficient dendritic cells have increased activation of Rac2 that support cross-presentation to CD8+ T cells. Using two different skin pathology models, WASp-deficient mice show an accumulation of dendritic cells in the skin and increased expansion of IFNγ-producing CD8+ T cells in the draining lymph node and spleen. Specific deletion of WASp in dendritic cells leads to marked expansion of CD8+ T cells at the expense of CD4+ T cells. WASp-deficient dendritic cells induce increased cross-presentation to CD8+ T cells by activating Rac2 that maintains a near neutral pH of phagosomes. Our data reveals an intricate balance between activation of WASp and Rac2 signalling pathways in dendritic cells. PMID:27425374

Enhanced expression of extracellular calcium sensing receptor in monocyte-differentiated versus undifferentiated HL-60 cells: potential role in regulation of a nonselective cation channel

NASA Technical Reports Server (NTRS)

Yamaguchi, T.; Ye, C.; Chattopadhyay, N.; Sanders, J. L.; Vassilev, P. M.; Brown, E. M.; O'Malley, B. W. (Principal Investigator)

2000-01-01

Human promyelocytic leukemia cells (HL-60) have been used widely as a model for studying the differentiation of hematopoietic progenitor cells in vitro. After treatment with phorbol-12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], HL-60 cells differentiate into cells with the phenotype of monocytes/macrophages. We previously showed that peripheral blood monocytes and the murine J774 monocytic cell line express the CaR, and myeloid progenitors in the bone marrow and myeloid cells in peripheral blood other than monocytes express lower levels of the CaR. Therefore, we investigated whether undifferentiated HL-60 cells express a functional G protein-coupled, extracellular calcium (Ca(2+)(o))-sensing receptor (CaR) and if the expression of the CaR increases as these cells differentiate along the monocytic lineage. The use of reverse transcription-polymerase chain reaction (RT-PCR) with CaR-specific primers, followed by sequencing of the amplified products, identified an authentic CaR transcript in undifferentiated HL-60 cells. Both immunocytochemistry and Western blot analysis using a CaR-specific antiserum detected low levels of CaR protein expression in undifferentiated HL-60 cells. The levels of CaR protein increased considerably following treatment of the cells with PMA (50 nM) or 1,25(OH)(2)D(3) (100 nM) for 5 days. Northern analysis using a CaR-specific riboprobe identified CaR transcripts in undifferentiated HL-60 cells, but CaR mRNA levels did not change appreciably after treatment with either agent, suggesting that upregulation of CaR protein occurs at a translational level. PMA-treated HL-60 cells expressed a nonselective cation channel (NCC), and the calcimimetic CaR activator, NPS R-467, but not its less active stereoisomer, NPS S-467, as well as the polycationic CaR agonist, neomycin, activated this NCC, demonstrating that the CaR expressed in these cells is functionally active. Therefore, HL-60 cells exhibit an increase in CaR protein expression, occurring at a translational level during their differentiation into cells with a monocyte/macrophage phenotype in response to treatment with PMA or 1, 25(OH)(2)D(3), which is functionally linked to activation of a nonselective cation channel.

Hormonal Regulation of Dendritic Cell Differentiation in the Thymus.

PubMed

Shirshev, S V; Orlova, E G; Loginova, O A; Nekrasova, I V; Gorbunova, O L; Maslennikova, I L

2018-06-19

We studied the effect of hormones estriol, ghrelin, kisspeptin, and chorionic gonadotropin in concentrations corresponding to their content in the peripheral blood in each trimester of pregnancy on the expression of membrane molecules on myeloid and plasmacytoid dendritic cells of the thymus. It was found that thymic myeloid dendritic cells are sensitive to the action of estriol and kisspeptin. Estriol in a concentration of the first trimester of pregnancy reduces the number of myeloid dendritic cells expressing receptor for thymic stromal lymphopoietin (CD11c+TSLP-R + ) and inhibitory molecule B7-H3 (CD11c + CD276 + ). In contrast to estriol, kisspeptin regulates the processes of differentiation of thymic myeloid dendritic cells in concentrations typical of the second-third trimesters and reduced their total number (CD11c + ) and the number of cells expressing TSLP-R (CD11c + TSLP-R + ). Estriol and kisspeptin do not affect the total number of plasmacytoid dendritic cells (CD303 + ) and expression of TSLP-R and CD276 by these cells. Ghrelin and chorionic gonadotropin in the studied concentrations had no significant effect on the total number of thymic myeloid and plasmacytoid dendritic cells and on the expression of membrane molecules of TSLP-R and CD276.

Cellular Location and Expression of Na+, K+-ATPase α Subunits Affect the Anti-Proliferative Activity of Oleandrin

PubMed Central

Yang, Peiying; Cartwright, Carrie; Efuet, Ekem; Hamilton, Stanley R.; Wistuba, Ignacio Ivan; Menter, David; Addington, Crandell; Shureiqi, Imad; Newman, Robert A.

2015-01-01

The purpose of this study was to investigate whether intracellular distribution of Na+, K+-ATPase α3 subunit, a receptor for cardiac glycosides including oleandrin, is differentially altered in cancer versus normal cells and whether this altered distribution can be therapeutically targeted to inhibit cancer cell survival. The cellular distribution of Na+, K+-ATPase α3 isoform was investigated in paired normal and cancerous mucosa biopsy samples from patients with lung and colorectal cancers by immunohistochemical staining. The effects of oleandrin on α3 subunit intracellular distribution, cell death, proliferation, and EKR phosphorylation were examined in differentiated and undifferentiated human colon cancer CaCO-2 cells. While Na+, K+-ATPase α3 isoform was predominantly located near the cytoplasmic membrane in normal human colon and lung epithelia, the expression of this subunit in their paired cancer epithelia was shifted to a peri-nuclear position in both a qualitative and quantitative manner. Similarly, distribution of α3 isoform was also shifted from a cytoplasmic membrane location in differentiated human colon cancer CaCO-2 cells to a peri-nuclear position in undifferentiated CaCO-2 cells. Intriguingly, oleandrin exerted threefold stronger anti-proliferative activity in undifferentiated CaCO-2 cells (IC50, 8.25 nM) than in differentiated CaCO-2 cells (IC50, >25 nM). Oleandrin (10 to 20 nM) caused an autophagic cell death and altered ERK phosphorylation in undifferentiated but not in differentiated CaCO-2 cells. These data demonstrate that the intracellular location of Na+, K+-ATPase α3 isoform is altered in human cancer versus normal cells. These changes in α3 cellular location and abundance may indicate a potential target of opportunity for cancer therapy. PMID:23073998

Muscarinic regulation of Kenyon cell dendritic arborizations in adult worker honey bees

PubMed Central

Dobrin, Scott E.; Herlihy, J. Daniel; Robinson, Gene E.; Fahrbach, Susan E.

2011-01-01

The experience of foraging under natural conditions increases the volume of mushroom body neuropil in worker honey bees. A comparable increase in neuropil volume results from treatment of worker honey bees with pilocarpine, an agonist for muscarinic-type cholinergic receptors. A component of the neuropil growth induced by foraging experience is growth of dendrites in the collar region of the calyces. We show here, via analysis of Golgi-impregnated collar Kenyon cells with wedge arborizations, that significant increases in standard measures of dendritic complexity were also found in worker honey bees treated with pilocarpine. This result suggests that signaling via muscarinic-type receptors promotes the increase in Kenyon cell dendritic complexity associated with foraging. Treatment of worker honey bees with scopolamine, a muscarinic inhibitor, inhibited some aspects of dendritic growth. Spine density on the Kenyon cell dendrites varied with sampling location, with the distal portion of the dendritic field having greater total spine density than either the proximal or medial section. This observation may be functionally significant because of the stratified organization of projections from visual centers to the dendritic arborizations of the collar Kenyon cells. Pilocarpine treatment had no effect on the distribution of spines on dendrites of the collar Kenyon cells. PMID:21262388

"Subpial Fan Cell" - A Class of Calretinin Neuron in Layer 1 of Adult Monkey Prefrontal Cortex.

PubMed

Gabbott, Paul L A

2016-01-01

Layer 1 of the cortex contains populations of neurochemically distinct neurons and afferent fibers which markedly affect neural activity in the apical dendritic tufts of pyramidal cells. Understanding the causal mechanisms requires knowledge of the cellular architecture and synaptic organization of layer 1. This study has identified eight morphological classes of calretinin immunopositive (CRet+) neurons (including Cajal-Retzius cells) in layer 1 of the prefrontal cortex (PFC) in adult monkey (Macaca fasicularis), with a distinct class - termed "subpial fan (SPF) cell" - described in detail. SPF cells were rare horizontal unipolar CRet+ cells located directly beneath the pia with a single thick primary dendrite that branched into a characteristic fan-like dendritic tree tangential to the pial surface. Dendrites had spines, filamentous processes and thorny branchlets. SPF cells lay millimeters apart with intralaminar axons that ramified widely in upper layer 1. Such cells were GABA immunonegative (-) and occurred in areas beyond PFC. Interspersed amidst SPF cells displaying normal structural integrity were degenerating CRet+ neurons (including SPF cells) and clumps of lipofuscin-rich cellular debris. The number of degenerating SPF cells increased during adulthood. Ultrastructural analyses indicated SPF cell somata received asymmetric (A - presumed excitatory) and symmetric (S - presumed inhibitory) synaptic contacts. Proximal dendritic shafts received mainly S-type and distal shafts mostly A-type input. All dendritic thorns and most dendritic spines received both synapse types. The tangential areal density of SPF cell axonal varicosities varied radially from parent somata - with dense clusters in more distal zones. All boutons formed A-type contacts with CRet- structures. The main post-synaptic targets were dendritic shafts (67%; mostly spine-bearing) and dendritic spines (24%). SPF-SPF cell innervation was not observed. Morphometry of SPF cells indicated a unique class of CRet+/GABA- neuron in adult monkey PFC - possibly a subtype of persisting Cajal-Retzius cell. The distribution and connectivity of SPF cells suggest they act as integrative hubs in upper layer 1 during postnatal maturation. The main synaptic output of SPF cells likely provides a transminicolumnar excitatory influence across swathes of apical dendritic tufts - thus affecting information processing in discrete patches of layer 1 in adult monkey PFC.

Clonal Type I Interferon–producing and Dendritic Cell Precursors Are Contained in Both Human Lymphoid and Myeloid Progenitor Populations

PubMed Central

Chicha, Laurie; Jarrossay, David; Manz, Markus G.

2004-01-01

Because of different cytokine responsiveness, surface receptor, and transcription factor expression, human CD11c− natural type I interferon–producing cells (IPCs) and CD11c+ dendritic cells were thought to derive through lymphoid and myeloid hematopoietic developmental pathways, respectively. To directly test this hypothesis, we used an in vitro assay allowing simultaneous IPC, dendritic cell, and B cell development and we tested lymphoid and myeloid committed hematopoietic progenitor cells for their developmental capacity. Lymphoid and common myeloid and granulocyte/macrophage progenitors were capable of developing into both functional IPCs, expressing gene transcripts thought to be associated with lymphoid lineage development, and into dendritic cells. However, clonal progenitors for both populations were about fivefold more frequent within myeloid committed progenitor cells. Thus, in humans as in mice, natural IPC and dendritic cell development robustly segregates with myeloid differentiation. This would fit with natural interferon type I–producing cell and dendritic cell activity in innate immunity, the evolutionary older arm of the cellular immune system. PMID:15557348

Immunotherapy with myeloid cells for tolerance induction

PubMed Central

Rodriguez-García, Mercedes; Boros, Peter; Bromberg, Jonathan S.; Ochando, Jordi C.

2013-01-01

Purpose of review Understanding the interplay between myeloid dendritic cells and T cells under tolerogenic conditions, and whether their interactions induce the development of antigen-specific regulatory T cells (Tregs) is critical to uncover the mechanisms involved in the induction of indefinite allograft survival. Recent findings Myeloid dendritic cell–T-cell interactions are seminal events that determine the outcome of the immune response, and multiple in-vitro protocols suggest the generation of tolerogenic myeloid dendritic cells that modulate T-cell responses, and determine the outcome of the immune response to an allograft following adoptive transfer. We believe that identifying specific conditions that lead to the generation of tolerogenic myeloid dendritic cells and Tregs are critical for the manipulation the immune response towards the development of transplantation tolerance. Summary We summarize recent findings regarding specific culture conditions that generate tolerogenic myeloid dendritic cells that induce T-cell hyporesponsiveness and Treg development, and represents a novel immunotherapeutic approach to promote the induction of indefinite graft survival prolongation. The interpretations presented here illustrate that different mechanisms govern the generation tolerogenic myeloid dendritic cells, and we discuss the concomitant therapeutic implications. PMID:20616727

Morphologic Integration of Hilar Ectopic Granule Cells into Dentate Gyrus Circuitry in the Pilocarpine Model of Temporal Lobe Epilepsy

PubMed Central

Cameron, Michael C.; Zhan, Ren-Zhi; Nadler, J. Victor

2014-01-01

After pilocarpine-induced status epilepticus, many granule cells born into the postseizure environment migrate aberrantly into the dentate hilus. Hilar ectopic granule cells (HEGCs) are hyperexcitable and may therefore increase circuit excitability. This study determined the distribution of their axons and dendrites. HEGCs and normotopic granule cells were filled with biocytin during whole-cell patch clamp recording in hippocampal slices from pilocarpine-treated rats. The apical dendrite of 86% of the biocytin-labeled HEGCs extended to the outer edge of the dentate molecular layer. The total length and branching of HEGC apical dendrites that penetrated the molecular layer were significantly reduced compared with apical dendrites of normotopic granule cells. HEGCs were much more likely to have a hilar basal dendrite than normotopic granule cells. They were about as likely as normotopic granule cells to project to CA3 pyramidal cells within the slice, but were much more likely to send at least one recurrent mossy fiber into the molecular layer. HEGCs with burst capability had less well-branched apical dendrites than nonbursting HEGCs, their dendrites were more likely to be confined to the hilus, and some exhibited dendritic features similar to those of immature granule cells. HEGCs thus have many paths along which to receive synchronized activity from normotopic granule cells and to transmit their own hyperactivity to both normotopic granule cells and CA3 pyramidal cells. They may therefore contribute to the highly interconnected granule cell hubs that have been proposed as crucial to development of a hyperexcitable, potentially seizure-prone circuit. PMID:21455997

Suppression of zinc dendrites in zinc electrode power cells

NASA Technical Reports Server (NTRS)

Damjanovic, A.; Diggle, J. W.

1970-01-01

Addition of various tetraalkyl quarternary ammonium salts, to alkaline zincate electrolyte of cell, prevents formation of zinc dendrites during charging of zinc electrode. Electrode capacity is not impaired and elimination of dendrites prolongs cell life.

SP600125 has a remarkable anticancer potential against undifferentiated thyroid cancer through selective action on ROCK and p53 pathways.

PubMed

Grassi, Elisa Stellaria; Vezzoli, Valeria; Negri, Irene; Lábadi, Árpád; Fugazzola, Laura; Vitale, Giovanni; Persani, Luca

2015-11-03

Thyroid cancer is the most common endocrine malignancy with increasing incidence worldwide.The majority of thyroid cancer cases are well differentiated with favorable outcome. However, undifferentiated thyroid cancers are one of the most lethal human malignancies because of their invasiveness, metastatization and refractoriness even to the most recently developed therapies.In this study we show for the first time a significant hyperactivation of ROCK/HDAC6 pathway in thyroid cancer tissues, and its negative correlation with p53 DNA binding ability.We demonstrate that a small compound, SP600125 (SP), is able to induce cell death selectively in undifferentiated thyroid cancer cell lines by specifically acting on the pathogenic pathways of cancer development. In detail, SP acts on the ROCK/HDAC6 pathway involved in dedifferentiation and invasiveness of undifferentiated human cancers, by restoring its physiological activity level. As main consequence, cancer cell migration is inhibited and, at the same time, cell death is induced through the mitotic catastrophe. Moreover, SP exerts a preferential action on the mutant p53 by increasing its DNA binding ability. In TP53-mutant cells that survive mitotic catastrophe this process results in p21 induction and eventually lead to premature senescence. In conclusion, SP has been proved to be able to simultaneously block cell replication and migration, the two main processes involved in cancer development and dissemination, making it an ideal candidate for developing new drugs against anaplastic thyroid cancer.

Bortezomib as a new therapeutic approach for blastic plasmacytoid dendritic cell neoplasm.

PubMed

Philippe, Laure; Ceroi, Adam; Bôle-Richard, Elodie; Jenvrin, Alizée; Biichle, Sabeha; Perrin, Sophie; Limat, Samuel; Bonnefoy, Francis; Deconinck, Eric; Saas, Philippe; Garnache-Ottou, Francine; Angelot-Delettre, Fanny

2017-11-01

Blastic plasmacytoid dendritic cell neoplasm is an aggressive hematologic malignancy with a poor prognosis. No consensus regarding optimal treatment modalities is currently available. Targeting the nuclear factor-kappa B pathway is considered a promising approach since blastic plasmacytoid dendritic cell neoplasm has been reported to exhibit constitutive activation of this pathway. Moreover, nuclear factor-kappa B inhibition in blastic plasmacytoid dendritic cell neoplasm cell lines, achieved using either an experimental specific inhibitor JSH23 or the clinical drug bortezomib, interferes in vitro with leukemic cell proliferation and survival. Here we extended these data by showing that primary blastic plasmacytoid dendritic cell neoplasm cells from seven patients were sensitive to bortezomib-induced cell death. We confirmed that bortezomib efficiently inhibits the phosphorylation of the RelA nuclear factor-kappa B subunit in blastic plasmacytoid dendritic cell neoplasm cell lines and primary cells from patients in vitro and in vivo in a mouse model. We then demonstrated that bortezomib can be associated with other drugs used in different chemotherapy regimens to improve its impact on leukemic cell death. Indeed, when primary blastic plasmacytoid dendritic cell neoplasm cells from a patient were grafted into mice, bortezomib treatment significantly increased the animals' survival, and was associated with a significant decrease of circulating leukemic cells and RelA nuclear factor-kappa B subunit expression. Overall, our results provide a rationale for the use of bortezomib in combination with other chemotherapy for the treatment of patients with blastic plasmacytoid dendritic cell neoplasm. Based on our data, a prospective clinical trial combining proteasome inhibitor with classical drugs could be envisaged. Copyright© Ferrata Storti Foundation.

High-Density ZnO Nanowires as a Reversible Myogenic-Differentiation Switch.

PubMed

Errico, Vito; Arrabito, Giuseppe; Fornetti, Ersilia; Fuoco, Claudia; Testa, Stefano; Saggio, Giovanni; Rufini, Stefano; Cannata, Stefano; Desideri, Alessandro; Falconi, Christian; Gargioli, Cesare

2018-04-25

Mesoangioblasts are outstanding candidates for stem-cell therapy and are already being explored in clinical trials. However, a crucial challenge in regenerative medicine is the limited availability of undifferentiated myogenic progenitor cells because growth is typically accompanied by differentiation. Here reversible myogenic-differentiation switching during proliferation is achieved by functionalizing the glass substrate with high-density ZnO nanowires (NWs). Specifically, mesoangioblasts grown on ZnO NWs present a spherical viable undifferentiated cell state without lamellopodia formation during the entire observation time (8 days). Consistently, the myosin heavy chain, typically expressed in skeletal muscle tissue and differentiated myogenic progenitors, is completely absent. Remarkably, NWs do not induce any damage while they reversibly block differentiation, so that the differentiation capabilities are completely recovered upon cell removal from the NW-functionalized substrate and replating on standard culture glass. This is the first evidence of a reversible myogenic-differentiation switch that does not affect the viability. These results can be the first step toward for the in vitro growth of a large number of undifferentiated stem/progenitor cells and therefore can represent a breakthrough for cell-based therapy and tissue engineering.

Reversible structural alterations of undifferentiated and differentiated human neuroblastoma cells induced by phorbol ester.

PubMed Central

Tint, I S; Bonder, E M; Feder, H H; Reboulleau, C P; Vasiliev, J M; Gelfand, I M

1992-01-01

Morphological alterations in the structure of undifferentiated and morphologically differentiated human neuroblastoma cells induced by phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, were examined by video microscopy and immunomorphology. In undifferentiated cells, PMA induced the formation of motile actin-rich lamellas and of stable cylindrical processes rich in microtubules. Formation of stable processes resulted either from the collapse of lamellas or the movement of the cell body away from the base of a process. In differentiated cells, PMA induced the rapid extension of small lamellas and subsequent formation of short-lived elongated processes from the lateral edges of neurites. Additionally, growth cones exhibited enhanced modulation in shape after PMA treatment. These reversible reorganizations were similar to the actinoplast-tubuloplast transformations exhibited by PMA-treated fibroblasts. We suggest that actinoplast-tubuloplast reorganizations play essential roles in morphogenesis where stable cytoplasmic extensions are induced by external stimuli. In particular, PMA-induced reorganizations of neural cells in culture may be a model for morphological modulations that occur in nerve tissue. Images PMID:1518842

Mannan-MUC1-pulsed dendritic cell immunotherapy: a phase I trial in patients with adenocarcinoma.

PubMed

Loveland, Bruce E; Zhao, Anne; White, Shane; Gan, Hui; Hamilton, Kate; Xing, Pei-Xiang; Pietersz, Geoffrey A; Apostolopoulos, Vasso; Vaughan, Hilary; Karanikas, Vaios; Kyriakou, Peter; McKenzie, Ian F C; Mitchell, Paul L R

2006-02-01

Tumor antigen-loaded dendritic cells show promise for cancer immunotherapy. This phase I study evaluated immunization with autologous dendritic cells pulsed with mannan-MUC1 fusion protein (MFP) to treat patients with advanced malignancy. Eligible patients had adenocarcinoma expressing MUC1, were of performance status 0 to 1, with no autoimmune disease. Patients underwent leukapheresis to generate dendritic cells by culture ex vivo with granulocyte macrophage colony-stimulating factor and interleukin 4 for 5 days. Dendritic cells were then pulsed overnight with MFP and harvested for reinjection. Patients underwent three cycles of leukapheresis and reinjection at monthly intervals. Patients with clinical benefit were able to continue with dendritic cell-MFP immunotherapy. Ten patients with a range of tumor types were enrolled, with median age of 60 years (range, 33-70 years); eight patients were of performance status 0 and two of performance status 1. Dendritic cell-MFP therapy led to strong T-cell IFNgamma Elispot responses to the vaccine and delayed-type hypersensitivity responses at injection sites in nine patients who completed treatments. Immune responses were sustained at 1 year in monitored patients. Antibody responses were seen in three patients only and were of low titer. Side effects were grade 1 only. Two patients with clearly progressive disease (ovarian and renal carcinoma) at entry were stable after initial therapy and went on to further leukapheresis and dendritic cell-MFP immunotherapy. These two patients have now each completed over 3 years of treatment. Immunization produced T-cell responses in all patients with evidence of tumor stabilization in 2 of the 10 advanced cancer patients treated. These data support further clinical evaluation of this dendritic cell-MFP immunotherapy.

Orchestration of transplantation tolerance by regulatory dendritic cell therapy or in-situ targeting of dendritic cells.

PubMed

Morelli, Adrian E; Thomson, Angus W

2014-08-01

Extensive research in murine transplant models over the past two decades has convincingly demonstrated the ability of regulatory dendritic cells (DCregs) to promote long-term allograft survival. We review important considerations regarding the source of therapeutic DCregs (donor or recipient) and their mode of action, in-situ targeting of DCregs, and optimal therapeutic regimens to promote DCreg function. Recent studies have defined protocols and mechanisms whereby ex-vivo-generated DCregs of donor or recipient origin subvert allogeneic T-cell responses and promote long-term organ transplant survival. Particular interest has focused on how donor antigen is acquired, processed and presented by autologous dendritic cells, on the stability of DCregs, and on in-situ targeting of dendritic cells to promote their tolerogenic function. New evidence of the therapeutic efficacy of DCregs in a clinically relevant nonhuman primate organ transplant model and production of clinical grade DCregs support early evaluation of DCreg therapy in human graft recipients. We discuss strategies currently used to promote dendritic cell tolerogenicity, including DCreg therapy and in-situ targeting of dendritic cells, with a view to improved understanding of underlying mechanisms and identification of the most promising strategies for therapeutic application.

Non-Small Cell Carcinoma of the Lung With Osteoclast-Like Giant Cells.

PubMed

Dahm, Hans Helmut

2017-05-01

Carcinomas of the lung with benign osteoclast-like giant cells are rare. A literature search showed only 8 previously reported examples. These tumors resemble a giant cell tumor of bone. Many of these tumors, which occur in most epithelium-containing organs, are composed of an undifferentiated, sarcomatoid component that contains benign osteoclast-like giant cells and a conventional carcinoma. In some tumors the epithelial origin may be revealed by immunohistochemistry only; others lack any evidence of an epithelial component. A 59-year-old man had an inoperable tumor in the upper lobe of the left lung. The tumor did not respond to radiation therapy, and chemotherapy resulted in minimal relief of symptoms. Light microscopy of biopsy samples showed benign osteoclast-like giant cells distributed irregularly between proliferations of undifferentiated medium-sized tumor cells. Approximately one third of the undifferentiated tumor cells were cytokeratin AE1/AE3-positive, and a minor alveolar clear cell component of the tumor was cytokeratin 7-positive. The osteoclast-like giant cells were strongly CD68-positive. The clinical and histologic findings supported the diagnosis of a non-small cell carcinoma of the lung with benign osteoclast-like giant cells. The differential diagnosis is composed of giant cell carcinoma, carcinosarcoma, and mesenchymal tumors of the lung.

Primary undifferentiated small round cell sarcoma of the deep abdominal wall with a novel variant of t(10;19) CIC-DUX4 gene fusion.

PubMed

Tsukamoto, Yoshitane; Futani, Hiroyuki; Yoshiya, Shinichi; Watanabe, Takahiro; Kihara, Takako; Matsuo, Shohei; Hirota, Seiichi

2017-10-01

We experienced a 38-year-old Japanese male with t(10;19) CIC-DUX4 -positive undifferentiated small round cell sarcoma in the deep abdominal wall. Three months before his first visit to our hospital, he noticed a mass in his right abdominal wall. Computed tomography on admission revealed a solid abdominal tumor 70×53mm in size and multiple small tumors in both lungs. The biopsy of the abdominal tumor revealed undifferentiated small round cell sarcoma, suggestive of Ewing sarcoma. Under the clinical diagnosis of Ewing-like sarcoma of the abdominal wall with multiple lung metastases, several cycles of ICE (ifosfamide, carboplatin and etoposide) therapy were performed. After the chemotherapy, the lung metastases disappeared, while the primary lesion rapidly grew. Additional VDC (vincristine, doxorubicin and cyclophosphamide) therapy was carried out without apparent effect. Although the surgical removal of the primary lesion was done, peritoneal dissemination and a huge metastatic liver tumor appeared thereafter. The patient died of disease progression two months after the surgery. The total clinical course was approximately one year, showing that the tumor was extremely aggressive. The tumor cells of the surgical specimen were positive for CD99, WT1, calretinin, INI1, ERG and Fli1 by immunohistochemistry. Fusion gene analyses using the frozen surgical material revealed negativity for EWSR1-Fli1, EWSR1-ERG and t(4;19) CIC-DUX4 fusions, but positivity for t(10;19) CIC-DUX4 fusion. Thus, we made a final pathological diagnosis of t(10;19) CIC-DUX4-positive undifferentiated small round cell sarcoma. To our knowledge, this is the 13th case of t(10;19) CIC-DUX4 undifferentiated small round cell sarcoma with precise clinicopathological information. Especially in our case, two types of t(10;19) CIC-DUX4 fusion transcripts were observed, both of which are in-frame and novel. Copyright © 2017 Elsevier GmbH. All rights reserved.

β2-Microglobulin as a potential factor for the expansion of mesenchymal stem cells

PubMed Central

Zhu, Ying; Su, Yongping; Cheng, Tianmin; Chung, Leland W. K.

2010-01-01

Multipotent mesenchymal stem cells (MSCs) hold great promise in regenerative medicine, but one of the biggest challenges facing for their application is the ex vivo expansion to obtain enough undifferentiated cells. Fetal bovine serum (FBS), which can elicit possible contaminations of prion, virus, zoonosis or immunological reaction against xenogenic serum antigens, still remains essential to the culture formulations. There is an urgent need to identify potential factors for the undifferentiated expansion of MSCs to reduce the use of FBS or eventually replace it. A previously recognized housekeeping gene, β2-microglobulin (β2M), is demonstrated to act as a novel growth factor to stimulate the undifferentiated ex vivo expansion and preserve the pluripotency of adult MSCs from various sources. The use of β2M might have promising implications for future clinical application of MSCs. PMID:19466557

Dendritic cell-associated immune inflammation of cardiac mucosa: a possible factor in the formation of Barrett's esophagus.

PubMed

Bobryshev, Yuri V; Tran, Dinh; Killingsworth, Murray C; Buckland, Michael; Lord, Reginald V N

2009-03-01

The development of Barrett's esophagus is poorly understood, but it has been suggested that cardiac mucosa is a precursor of intestinal type metaplasia and that inflammation of cardiac mucosa may play a role in the formation of Barrett's esophagus. The present study was undertaken to examine the presence and distribution of immune-inflammatory cells in cardiac mucosa, specifically focusing on dendritic cells because of their importance as regulators of immune reactions. Endoscopic biopsy specimens were obtained from 12 patients with cardiac mucosa without Barrett's esophagus or adenocarcinoma and from 21 patients with Barrett's esophagus without dysplasia (intestinal metaplasia). According to histology, in nine of the 21 specimens with Barrett's esophagus, areas of mucosa composed of cardiac type epithelium-lined glands were present as well. Immunohistochemical staining and electron microscopy were used to examine immune-inflammatory cells in paraffin-embedded sections. Immune-inflammatory cells, including T cells, B cells, dendritic cells, macrophages, and mast cells, were present in the connective tissue matrix that surrounded cardiac type epithelium-lined glands in all patients with cardiac mucosa. Clustering of dendritic cells with each other and with lymphocytes and the intrusion of dendritic cells between glandular mucus cells were observed. In the Barrett's esophagus specimens that contained cardiac type glands, computerized CD83 expression quantitation revealed that there were more dendritic cells in cardiac mucosa than in intestinal metaplasia. Immune-inflammatory infiltrates containing dendritic cells are consistently present in cardiac mucosa. The finding of a larger number of dendritic cells in areas of cardiac mucosa in Barrett's esophagus biopsies suggests that the immune inflammation of cardiac mucosa might play a role in modifying the local tissue environment to promote the development of specialized intestinal type metaplasia.

Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

DTIC Science & Technology

2015-09-01

Award Number: W81XWH-11-1-0384 TITLE: Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells : Implications for...Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells : Implications for Cancer Vaccine Therapy 5b. GRANT NUMBER CA100463 5c...Listeria monocytogenes (Lm) on human dendritic cells (DCs) to optimize Lm-based DC cancer vaccines. The project aims are: 1) Compare the activation and

FMR1 Epigenetic Silencing Commonly Occurs in Undifferentiated Fragile X-Affected Embryonic Stem Cells

PubMed Central

Avitzour, Michal; Mor-Shaked, Hagar; Yanovsky-Dagan, Shira; Aharoni, Shira; Altarescu, Gheona; Renbaum, Paul; Eldar-Geva, Talia; Schonberger, Oshrat; Levy-Lahad, Ephrat; Epsztejn-Litman, Silvina; Eiges, Rachel

2014-01-01

Summary Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from epigenetic silencing of the X-linked FMR1 gene by a CGG expansion in its 5′-untranslated region. Taking advantage of a large set of FXS-affected human embryonic stem cell (HESC) lines and isogenic subclones derived from them, we show that FMR1 hypermethylation commonly occurs in the undifferentiated state (six of nine lines, ranging from 24% to 65%). In addition, we demonstrate that hypermethylation is tightly linked with FMR1 transcriptional inactivation in undifferentiated cells, coincides with loss of H3K4me2 and gain of H3K9me3, and is unrelated to CTCF binding. Taken together, these results demonstrate that FMR1 epigenetic gene silencing takes place in FXS HESCs and clearly highlights the importance of examining multiple cell lines when investigating FXS and most likely other epigenetically regulated diseases. PMID:25418717

FMR1 epigenetic silencing commonly occurs in undifferentiated fragile X-affected embryonic stem cells.

PubMed

Avitzour, Michal; Mor-Shaked, Hagar; Yanovsky-Dagan, Shira; Aharoni, Shira; Altarescu, Gheona; Renbaum, Paul; Eldar-Geva, Talia; Schonberger, Oshrat; Levy-Lahad, Ephrat; Epsztejn-Litman, Silvina; Eiges, Rachel

2014-11-11

Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from epigenetic silencing of the X-linked FMR1 gene by a CGG expansion in its 5'-untranslated region. Taking advantage of a large set of FXS-affected human embryonic stem cell (HESC) lines and isogenic subclones derived from them, we show that FMR1 hypermethylation commonly occurs in the undifferentiated state (six of nine lines, ranging from 24% to 65%). In addition, we demonstrate that hypermethylation is tightly linked with FMR1 transcriptional inactivation in undifferentiated cells, coincides with loss of H3K4me2 and gain of H3K9me3, and is unrelated to CTCF binding. Taken together, these results demonstrate that FMR1 epigenetic gene silencing takes place in FXS HESCs and clearly highlights the importance of examining multiple cell lines when investigating FXS and most likely other epigenetically regulated diseases.

Mapping of dendritic lesions in patients with herpes simplex keratitis using in vivo confocal microscopy

PubMed Central

Yokogawa, Hideaki; Kobayashi, Akira; Mori, Natsuko; Sugiyama, Kazuhisa

2015-01-01

Purpose To produce a two-dimensional reconstruction map of dendritic lesions in patients with herpes simplex keratitis (HSK) using in vivo confocal microscopy. Methods Four eyes of four patients (mean 65.8 years) with HSK presenting with a dendritic lesion were enrolled. Slit-lamp biomicroscopy and in vivo laser confocal microscopy were performed. Acquired confocal images at the level of the epithelium were arranged and mapped into subconfluent montages. Changes in the shape and degree of light reflection of abnormal cells and deposits around dendritic lesions as well as other corneal layers were qualitatively evaluated. Results Mapping of dendritic lesion was successful in all cases, and the subconfluent montages clearly showed the larger image of dendritic lesion. In all cases, the dendritic lesion consisted of hyperreflective irregular epithelial cells, and was surrounded by distorted and elongated epithelial cells. In three cases, hyperreflective deposits were noted at the midline of the lesion. The corneal stroma showed a hyperreflective honeycomb pattern. In two cases, inflammatory cells were observed at the level of endothelial cell layer. Conclusion Mapping of dendritic lesions in patients with HSK was successful in all patients using in vivo confocal microscopy. Cellular level observation of dendritic lesion at a relatively larger magnification may help understand the in vivo morphological change of HSK. Further study in more patients with HSK and nonherpetic dendritic lesion is needed to utilize confocal microscopy images in differential diagnosis and follow-up of the epithelial lesions with dendrite. PMID:26445524

Mapping of dendritic lesions in patients with herpes simplex keratitis using in vivo confocal microscopy.

PubMed

Yokogawa, Hideaki; Kobayashi, Akira; Mori, Natsuko; Sugiyama, Kazuhisa

2015-01-01

To produce a two-dimensional reconstruction map of dendritic lesions in patients with herpes simplex keratitis (HSK) using in vivo confocal microscopy. Four eyes of four patients (mean 65.8 years) with HSK presenting with a dendritic lesion were enrolled. Slit-lamp biomicroscopy and in vivo laser confocal microscopy were performed. Acquired confocal images at the level of the epithelium were arranged and mapped into subconfluent montages. Changes in the shape and degree of light reflection of abnormal cells and deposits around dendritic lesions as well as other corneal layers were qualitatively evaluated. Mapping of dendritic lesion was successful in all cases, and the subconfluent montages clearly showed the larger image of dendritic lesion. In all cases, the dendritic lesion consisted of hyperreflective irregular epithelial cells, and was surrounded by distorted and elongated epithelial cells. In three cases, hyperreflective deposits were noted at the midline of the lesion. The corneal stroma showed a hyperreflective honeycomb pattern. In two cases, inflammatory cells were observed at the level of endothelial cell layer. Mapping of dendritic lesions in patients with HSK was successful in all patients using in vivo confocal microscopy. Cellular level observation of dendritic lesion at a relatively larger magnification may help understand the in vivo morphological change of HSK. Further study in more patients with HSK and nonherpetic dendritic lesion is needed to utilize confocal microscopy images in differential diagnosis and follow-up of the epithelial lesions with dendrite.

Evaluation of accessory cell heterogeneity. III. Role of dendritic cells in the in vitro activation of the antibody response to soluble antigens.

PubMed

Erb, P; Ramila, G; Sklenar, I; Kennedy, M; Sunshine, G H

1985-05-01

Dendritic cells and macrophages obtained from spleen and peritoneal exudate were tested as accessory cells for the activation of lymphokine production by T cells, for supporting T-B cooperation and for the induction of antigen-specific T helper cells. Dendritic cells as well as macrophages were able to activate T cells for interleukin-2 secretion and functioned as accessory cells in T-B cooperation, but only macrophages induced T helper cells, which cooperate with B cells by a linked recognition interaction, to soluble antigens. Dendritic cell- and antigen-activated T cells also did not help B cells in the presence of Con A supernatants which contained various T cell- and B cell-stimulatory factors. The failure of dendritic cells to differentiate memory into functional T helper cells, but their efficient accessory cell function in T-B cooperation, where functional T helper cells are already present, can be best explained by a differential accessory cell requirement for T helper cell activation dependent on the differentiation stage of the T helper cell.

Functional properties of granule cells with hilar basal dendrites in the epileptic dentate gyrus.

PubMed

Kelly, Tony; Beck, Heinz

2017-01-01

The maturation of adult-born granule cells and their functional integration into the network is thought to play a key role in the proper functioning of the dentate gyrus. In temporal lobe epilepsy, adult-born granule cells in the dentate gyrus develop abnormally and possess a hilar basal dendrite (HBD). Although morphological studies have shown that these HBDs have synapses, little is known about the functional properties of these HBDs or the intrinsic and network properties of the granule cells that possess these aberrant dendrites. We performed patch-clamp recordings of granule cells within the granule cell layer "normotopic" from sham-control and status epilepticus (SE) animals. Normotopic granule cells from SE animals possessed an HBD (SE + HBD + cells) or not (SE + HBD - cells). Apical and basal dendrites were stimulated using multiphoton uncaging of glutamate. Two-photon Ca 2+ imaging was used to measure Ca 2+ transients associated with back-propagating action potentials (bAPs). Near-synchronous synaptic input integrated linearly in apical dendrites from sham-control animals and was not significantly different in apical dendrites of SE + HBD - cells. The majority of HBDs integrated input linearly, similar to apical dendrites. However, 2 of 11 HBDs were capable of supralinear integration mediated by a dendritic spike. Furthermore, the bAP-evoked Ca 2+ transients were relatively well maintained along HBDs, compared with apical dendrites. This further suggests an enhanced electrogenesis in HBDs. In addition, the output of granule cells from epileptic tissue was enhanced, with both SE + HBD - and SE + HBD + cells displaying increased high-frequency (>100 Hz) burst-firing. Finally, both SE + HBD - and SE + HBD + cells received recurrent excitatory input that was capable of generating APs, especially in the absence of feedback inhibition. Taken together, these data suggest that the enhanced excitability of HBDs combined with the altered intrinsic and network properties of granule cells collude to promote excitability and synchrony in the epileptic dentate gyrus. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Structural basis of orientation sensitivity of cat retinal ganglion cells.

PubMed

Leventhal, A G; Schall, J D

1983-11-10

We investigated the structural basis of the physiological orientation sensitivity of retinal ganglion cells (Levick and Thibos, '82). The dendritic fields of 840 retinal ganglion cells labeled by injections of horseradish peroxidase into the dorsal lateral geniculate nucleus (LGNd) or optic tracts of normal cats. Siamese cats, and cat deprived of patterned visual experience from birth by monocular lid-suture (MD) were studied. Mathematical techniques designed to analyze direction were used to find the dendritic field orientation of each cell. Statistical techniques designed for angular data were used to determine the relationship between dendritic field orientation and angular position on the retina (polar angle). Our results indicate that 88% of retinal ganglion cells have oriented dendritic fields and that dendritic field orientation is related systematically to retinal position. In all regions of retina more that 0.5 mm from the area centralis the dendritic fields of retinal ganglion cells are oriented radially, i.e., like the spokes of a wheel having the area centralis at its hub. This relationship was present in all animals and cell types studied and was strongest for cells located close to the horizontal meridian (visual streak) of the retina. Retinal ganglion cells appear to be sensitive to stimulus orientation because they have oriented dendritic fields.

Long-term maintenance of human induced pluripotent stem cells by automated cell culture system.

PubMed

Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

2015-11-17

Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells.

Epidermal Viral Immunity Induced by CD8α+ Dendritic Cells But Not by Langerhans Cells

NASA Astrophysics Data System (ADS)

Allan, Rhys S.; Smith, Chris M.; Belz, Gabrielle T.; van Lint, Allison L.; Wakim, Linda M.; Heath, William R.; Carbone, Francis R.

2003-09-01

The classical paradigm for dendritic cell function derives from the study of Langerhans cells, which predominate within skin epidermis. After an encounter with foreign agents, Langerhans cells are thought to migrate to draining lymph nodes, where they initiate T cell priming. Contrary to this, we show here that infection of murine epidermis by herpes simplex virus did not result in the priming of virus-specific cytotoxic T lymphocytes by Langerhans cells. Rather, the priming response required a distinct CD8α+ dendritic cell subset. Thus, the traditional view of Langerhans cells in epidermal immunity needs to be revisited to accommodate a requirement for other dendritic cells in this response.

BCOR-CCNB3 Fusions Are Frequent in Undifferentiated Sarcomas of Male Children

PubMed Central

Peters, Tricia L.; Kumar, Vijetha; Polikepahad, Sumanth; Lin, Frank Y.; Sarabia, Stephen F.; Liang, Yu; Wang, Wei-Lien; Lazar, Alexander J.; Doddapaneni, Harsha Vardhan; Chao, Hsu; Muzny, Donna M.; Wheeler, David A.; Okcu, M. Fatih; Plon, Sharon E.; Hicks, M. John; López-Terrada, Dolores; Parsons, D. Williams; Roy, Angshumoy

2014-01-01

The BCOR-CCNB3 fusion gene, resulting from a chromosome X paracentric inversion, was recently described in translocation-negative ‘Ewing-like’ sarcomas arising in bone and soft tissue. Genetic subclassification of undifferentiated unclassified sarcomas may potentially offer markers for reproducible diagnosis and substrates for therapy. Using whole transcriptome paired end RNA sequencing (RNA-seq) we unexpectedly identified BCOR-CCNB3 fusion transcripts in an undifferentiated spindle cell sarcoma. RNA-seq results were confirmed through direct RT-PCR of tumor RNA and cloning of the genomic breakpoints from tumor DNA. Five additional undifferentiated sarcomas with BCOR-CCNB3 fusions were identified in a series of 42 pediatric and adult unclassified sarcomas. Genomic breakpoint analysis demonstrated unique breakpoint locations in each case at the DNA level even though the resulting fusion mRNA was identical in all cases. All patients with BCOR-CCNB3 sarcoma were males diagnosed in mid-childhood (7-13 years of age). Tumors were equally distributed between axial and extra-axial locations. Five of the six tumors were soft tissue lesions with either predominant spindle cell morphology or spindle cell areas interspersed with ovoid to round cells. CCNB3 immunohistochemistry showed strong nuclear positivity in 5 tumors prior to oncologic therapy, but was patchy to negative in post-treatment tumor samples. An RT-PCR assay developed to detect the fusion transcript in archival formalin-fixed tissue was positive in all 6 cases, with high sensitivity and specificity in both pre- and post-treated samples. This study adds to recent reports on the clinicopathologic spectrum of BCOR-CCNB3 fusion-positive sarcomas, a newly-emerging entity within the undifferentiated unclassified sarcoma category, and describes a simple RT-PCR assay that in conjunction with CCNB3 immunohistochemistry can be useful in diagnosing these tumors. PMID:25360585

Manipulation of visible-light polarization with dendritic cell-cluster metasurfaces.

PubMed

Fang, Zhen-Hua; Chen, Huan; An, Di; Luo, Chun-Rong; Zhao, Xiao-Peng

2018-06-26

Cross-polarization conversion plays an important role in visible light manipulation. Metasurface with asymmetric structure can be used to achieve polarization conversion of linearly polarized light. Based on this, we design a quasi-periodic dendritic metasurface model composed of asymmetric dendritic cells. The simulation indicates that the asymmetric dendritic structure can vertically rotate the polarization direction of the linear polarization wave in visible light. Silver dendritic cell-cluster metasurface samples were prepared by the bottom-up electrochemical deposition. It experimentally proved that they could realize the cross - polarization conversion in visible light. Cross-polarized propagating light is deflected into anomalous refraction channels. Dendritic cell-cluster metasurface with asymmetric quasi-periodic structure conveys significance in cross-polarization conversion research and features extensive practical application prospect and development potential.

Endometrial and ovarian carcinomas with undifferentiated components: clinically aggressive and frequently underrecognized neoplasms.

PubMed

Tafe, Laura J; Garg, Karuna; Chew, Ivy; Tornos, Carmen; Soslow, Robert A

2010-06-01

Carcinomas of the endometrium and ovary with undifferentiated components are uncommon neoplasms that are likely underdiagnosed. They are important to recognize as they have been shown to be clinically aggressive. We identified 32 carcinomas with undifferentiated components as defined by Silva and co-workers, 26 endometrial and 6 of ovarian origin. The patient age ranged from 21 to 76 years (median 55); 40% of patients were

Myeloid dendritic cells frequencies are increased in children with autism spectrum disorder and associated with amygdala volume and repetitive behaviors

PubMed Central

Breece, Elizabeth; Paciotti, Brian; Nordahl, Christine Wu; Ozonoff, Sally; Van de Water, Judy A.; Rogers, Sally J.; Amaral, David; Ashwood, Paul

2012-01-01

The pathophysiology of Autism Spectrum Disorder (ASD) is not yet known; however, studies suggest that dysfunction of the immune system affects many children with ASD. Increasing evidence points to dysfunction of the innate immune system including activation of microglia and perivascular macrophages, increases in inflammatory cytokines/chemokines in brain tissue and CSF, and abnormal peripheral monocyte cell function. Dendritic cells are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, antigen presentation, activation of naïve T cells, induction of tolerance and cytokine/chemokine production. In this study, we assessed circulating frequencies of myeloid dendritic cells (defined as Lin-1−BDCA1+CD11c+ and Lin-1−BDCA3+CD123−) and plasmacytoid dendritic cells (Lin-1− BDCA2+CD123+ or Lin-1−BDCA4+ CD11c−) in 57 children with ASD, and 29 typically developing controls of the same age, all of who were enrolled as part of the Autism Phenome Project (APP). The frequencies of dendritic cells and associations with behavioral assessment and MRI measurements of amygdala volume were compared in the same participants. The frequencies of myeloid dendritic cells were significantly increased in children with ASD compared to typically developing controls (p < 0.03). Elevated frequencies of myeloid dendritic cells were positively associated with abnormal right and left amygdala enlargement, severity of gastrointestinal symptoms and increased repetitive behaviors. The frequencies of plasmacytoid dendritic cells were also associated with amygdala volumes as well as developmental regression in children with ASD. Dendritic cells play key roles in modulating immune responses and differences in frequencies or functions of these cells may result in immune dysfunction in children with ASD. These data further implicate innate immune cells in the complex pathophysiology of ASD. PMID:23063420

Golgi, electron-microscopic and combined Golgi-electron-microscopic studies of the mitral cells in the goldfish olfactory bulb.

PubMed

Oka, Y

1983-04-01

The local neuronal circuitry of goldfish olfactory bulb was analyzed in Golgi preparations combining light- and electron-microscopy, as well as in routinely prepared ultrastructural preparations. Mitral cells were identified with the light-microscope in Golgi-impregnated thick sections according to the following criteria: (1) cell bodies were distributed irregularly in a wide layer between 100 and 200 micrometer from the surface, (2) cell bodies were larger than other neurons (10-20 micrometer in diameter), and (3) the dendrites were directed toward the superficially-located olfactory nerve layer where they ended as highly branched glomerular tufts. These impregnated cells were examined by electron-microscopy in serial section. The results demonstrate synaptic organization in relation to the mitral cells. (1) Glomerular tufts received afferent input from primary olfactory axons which made Gray's Type I synaptic contacts. These dendrites also had reciprocal dendrodendritic synapses with dendrites of certain non-mitral cells. (2) Dendritic shafts of mitral cells made reciprocal dendritic synapses with dendrites of certain non-mitral cells. (3) Cell bodies and their initial axon segments had reciprocal synapses with certain dendrites but occurred infrequently. In reciprocal synapses, the direction of the Gray Type I (asymmetrical) is away from the mitral cell while those with Gray Type II synapses (symmetrical) are toward the mitral cell. Assuming that the type I synapse is excitatory and Type II is inhibitory, these findings explain the electrophysiological demonstration of self-inhibition discharge found in mitral cells.

Linking macroscopic with microscopic neuroanatomy using synthetic neuronal populations.

PubMed

Schneider, Calvin J; Cuntz, Hermann; Soltesz, Ivan

2014-10-01

Dendritic morphology has been shown to have a dramatic impact on neuronal function. However, population features such as the inherent variability in dendritic morphology between cells belonging to the same neuronal type are often overlooked when studying computation in neural networks. While detailed models for morphology and electrophysiology exist for many types of single neurons, the role of detailed single cell morphology in the population has not been studied quantitatively or computationally. Here we use the structural context of the neural tissue in which dendritic trees exist to drive their generation in silico. We synthesize the entire population of dentate gyrus granule cells, the most numerous cell type in the hippocampus, by growing their dendritic trees within their characteristic dendritic fields bounded by the realistic structural context of (1) the granule cell layer that contains all somata and (2) the molecular layer that contains the dendritic forest. This process enables branching statistics to be linked to larger scale neuroanatomical features. We find large differences in dendritic total length and individual path length measures as a function of location in the dentate gyrus and of somatic depth in the granule cell layer. We also predict the number of unique granule cell dendrites invading a given volume in the molecular layer. This work enables the complete population-level study of morphological properties and provides a framework to develop complex and realistic neural network models.

Linking Macroscopic with Microscopic Neuroanatomy Using Synthetic Neuronal Populations

PubMed Central

Schneider, Calvin J.; Cuntz, Hermann; Soltesz, Ivan

2014-01-01

Dendritic morphology has been shown to have a dramatic impact on neuronal function. However, population features such as the inherent variability in dendritic morphology between cells belonging to the same neuronal type are often overlooked when studying computation in neural networks. While detailed models for morphology and electrophysiology exist for many types of single neurons, the role of detailed single cell morphology in the population has not been studied quantitatively or computationally. Here we use the structural context of the neural tissue in which dendritic trees exist to drive their generation in silico. We synthesize the entire population of dentate gyrus granule cells, the most numerous cell type in the hippocampus, by growing their dendritic trees within their characteristic dendritic fields bounded by the realistic structural context of (1) the granule cell layer that contains all somata and (2) the molecular layer that contains the dendritic forest. This process enables branching statistics to be linked to larger scale neuroanatomical features. We find large differences in dendritic total length and individual path length measures as a function of location in the dentate gyrus and of somatic depth in the granule cell layer. We also predict the number of unique granule cell dendrites invading a given volume in the molecular layer. This work enables the complete population-level study of morphological properties and provides a framework to develop complex and realistic neural network models. PMID:25340814

Metastatic Melanoma Secreted IL-10 Down-Regulates CD1 Molecules on Dendritic Cells in Metastatic Tumor Lesions

PubMed Central

Gerlini, Gianni; Tun-Kyi, Adrian; Dudli, Christa; Burg, Günter; Pimpinelli, Nicola; Nestle, Frank O.

2004-01-01

CD1 molecules are expressed by antigen-presenting cells such as dendritic cells and mediate primary immune responses to lipids and glycolipids which have been shown to be expressed by various tumors. Glycolipids are expressed by melanoma cells but, despite their immunogenicity, no efficient spontaneous immune responses are elicited. As IL-10 has previously been shown to down-regulate CD1a on dendritic cells and is known to be expressed by various melanoma cell lines, we investigated if melanoma-derived IL-10 could down-regulate CD1 molecule expression on dendritic cells as a possible way to circumvent immune recognition. We found that CD1a, CD1b, CD1c, and CD1d were significantly down-regulated on dendritic cells in metastatic (n = 10) but not in primary melanoma lesions (n = 10). We further detected significantly higher IL-10 protein levels in metastatic than in primary melanomas. Moreover, supernatants from metastatic melanomas were significantly more effective in down-regulating CD1 molecules on dendritic cells than supernatants from primary melanoma cultures. This effect was blocked using a neutralizing IL-10 antibody in a dose dependent manner. Our findings suggest that metastatic but not primary melanomas can down-regulate CD1 molecules on infiltrating dendritic cells by secreting IL-10 which may represent a novel way to escape the immune response directed against the tumor. PMID:15579430

Clonal yeast biofilms can reap competitive advantages through cell differentiation without being obligatorily multicellular

PubMed Central

Hanghøj, Kristian Ebbesen; Andersen, Kaj Scherz; Boomsma, Jacobus J.

2016-01-01

How differentiation between cell types evolved is a fundamental question in biology, but few studies have explored single-gene phenotypes that mediate first steps towards division of labour with selective advantage for groups of cells. Here, we show that differential expression of the FLO11 gene produces stable fractions of Flo11+ and Flo11− cells in clonal Saccharomyces cerevisiae biofilm colonies on medium with intermediate viscosity. Differentiated Flo11+/− colonies, consisting of adhesive and non-adhesive cells, obtain a fourfold growth advantage over undifferentiated colonies by overgrowing glucose resources before depleting them, rather than depleting them while they grow as undifferentiated Flo11− colonies do. Flo11+/− colonies maintain their structure and differentiated state by switching non-adhesive cells to adhesive cells with predictable probability. Mixtures of Flo11+ and Flo11− cells from mutant strains that are unable to use this epigenetic switch mechanism produced neither integrated colonies nor growth advantages, so the condition-dependent selective advantages of differentiated FLO11 expression can only be reaped by clone-mate cells. Our results show that selection for cell differentiation in clonal eukaryotes can evolve before the establishment of obligate undifferentiated multicellularity, and without necessarily leading to more advanced organizational complexity. PMID:27807261

Spaceflight Transcriptomes: Unique Responses to a Novel Environment

PubMed Central

Paul, Anna-Lisa; Zupanska, Agata K.; Ostrow, Dejerianne T.; Zhang, Yanping; Sun, Yijun; Li, Jian-Liang; Shanker, Savita; Farmerie, William G.; Amalfitano, Claire E.

2012-01-01

Abstract The spaceflight environment presents unique challenges to terrestrial biology, including but not limited to the direct effects of gravity. As we near the end of the Space Shuttle era, there remain fundamental questions about the response and adaptation of plants to orbital spaceflight conditions. We address a key baseline question of whether gene expression changes are induced by the orbital environment, and then we ask whether undifferentiated cells, cells presumably lacking the typical gravity response mechanisms, perceive spaceflight. Arabidopsis seedlings and undifferentiated cultured Arabidopsis cells were launched in April, 2010, as part of the BRIC-16 flight experiment on STS-131. Biologically replicated DNA microarray and averaged RNA digital transcript profiling revealed several hundred genes in seedlings and cell cultures that were significantly affected by launch and spaceflight. The response was moderate in seedlings; only a few genes were induced by more than 7-fold, and the overall intrinsic expression level for most differentially expressed genes was low. In contrast, cell cultures displayed a more dramatic response, with dozens of genes showing this level of differential expression, a list comprised primarily of heat shock–related and stress-related genes. This baseline transcriptome profiling of seedlings and cultured cells confirms the fundamental hypothesis that survival of the spaceflight environment requires adaptive changes that are both governed and displayed by alterations in gene expression. The comparison of intact plants with cultures of undifferentiated cells confirms a second hypothesis: undifferentiated cells can detect spaceflight in the absence of specialized tissue or organized developmental structures known to detect gravity. Key Words: Tissue culture—Microgravity—Low Earth orbit—Space Shuttle—Microarray. Astrobiology 12, 40–56. PMID:22221117

“Subpial Fan Cell” — A Class of Calretinin Neuron in Layer 1 of Adult Monkey Prefrontal Cortex

PubMed Central

Gabbott, Paul L. A.

2016-01-01

Layer 1 of the cortex contains populations of neurochemically distinct neurons and afferent fibers which markedly affect neural activity in the apical dendritic tufts of pyramidal cells. Understanding the causal mechanisms requires knowledge of the cellular architecture and synaptic organization of layer 1. This study has identified eight morphological classes of calretinin immunopositive (CRet+) neurons (including Cajal-Retzius cells) in layer 1 of the prefrontal cortex (PFC) in adult monkey (Macaca fasicularis), with a distinct class — termed “subpial fan (SPF) cell” — described in detail. SPF cells were rare horizontal unipolar CRet+ cells located directly beneath the pia with a single thick primary dendrite that branched into a characteristic fan-like dendritic tree tangential to the pial surface. Dendrites had spines, filamentous processes and thorny branchlets. SPF cells lay millimeters apart with intralaminar axons that ramified widely in upper layer 1. Such cells were GABA immunonegative (-) and occurred in areas beyond PFC. Interspersed amidst SPF cells displaying normal structural integrity were degenerating CRet+ neurons (including SPF cells) and clumps of lipofuscin-rich cellular debris. The number of degenerating SPF cells increased during adulthood. Ultrastructural analyses indicated SPF cell somata received asymmetric (A — presumed excitatory) and symmetric (S — presumed inhibitory) synaptic contacts. Proximal dendritic shafts received mainly S-type and distal shafts mostly A-type input. All dendritic thorns and most dendritic spines received both synapse types. The tangential areal density of SPF cell axonal varicosities varied radially from parent somata — with dense clusters in more distal zones. All boutons formed A-type contacts with CRet- structures. The main post-synaptic targets were dendritic shafts (67%; mostly spine-bearing) and dendritic spines (24%). SPF-SPF cell innervation was not observed. Morphometry of SPF cells indicated a unique class of CRet+/GABA- neuron in adult monkey PFC — possibly a subtype of persisting Cajal-Retzius cell. The distribution and connectivity of SPF cells suggest they act as integrative hubs in upper layer 1 during postnatal maturation. The main synaptic output of SPF cells likely provides a transminicolumnar excitatory influence across swathes of apical dendritic tufts — thus affecting information processing in discrete patches of layer 1 in adult monkey PFC. PMID:27147978

Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study.

PubMed

Song, Zheng-Mei; Chen, Ni; Liu, Jia-Hui; Tang, Huan; Deng, Xiaoyong; Xi, Wen-Song; Han, Kai; Cao, Aoneng; Liu, Yuanfang; Wang, Haifang

2015-10-01

Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food-related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco-2 cells, differentiated Caco-2 cells and Caco-2 monolayer. TiO2 NPs with a concentration less than 200 µg ml(-1) did not induce any toxicity in differentiated cells and Caco-2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml(-1) inhibited the growth of undifferentiated Caco-2 cells. Undifferentiated Caco-2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco-2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food. Copyright © 2015 John Wiley & Sons, Ltd.

Secretory IgA in complex with Lactobacillus rhamnosus potentiates mucosal dendritic cell-mediated Treg cell differentiation via TLR regulatory proteins, RALDH2 and secretion of IL-10 and TGF-β

PubMed Central

Mikulic, Josip; Longet, Stéphanie; Favre, Laurent; Benyacoub, Jalil; Corthesy, Blaise

2017-01-01

The importance of secretory IgA in controlling the microbiota is well known, yet how the antibody affects the perception of the commensals by the local immune system is still poorly defined. We have previously shown that the transport of secretory IgA in complex with bacteria across intestinal microfold cells results in an association with dendritic cells in Peyer’s patches. However, the consequences of such an interaction on dendritic cell conditioning have not been elucidated. In this study, we analyzed the impact of the commensal Lactobacillus rhamnosus, alone or associated with secretory IgA, on the responsiveness of dendritic cells freshly recovered from mouse Peyer’s patches, mesenteric lymph nodes, and spleen. Lactobacillus rhamnosus-conditioned mucosal dendritic cells are characterized by increased expression of Toll-like receptor regulatory proteins [including single immunoglobulin interleukin-1 receptor-related molecule, suppressor of cytokine signaling 1, and Toll-interacting molecule] and retinaldehyde dehydrogenase 2, low surface expression of co-stimulatory markers, high anti- versus pro-inflammatory cytokine production ratios, and induction of T regulatory cells with suppressive function. Association with secretory IgA enhanced the anti-inflammatory/regulatory Lactobacillus rhamnosus-induced conditioning of mucosal dendritic cells, particularly in Peyer’s patches. At the systemic level, activation of splenic dendritic cells exposed to Lactobacillus rhamnosus was partially dampened upon association with secretory IgA. These data suggest that secretory IgA, through coating of commensal bacteria, contributes to the conditioning of mucosal dendritic cells toward tolerogenic profiles essential for the maintenance of intestinal homeostasis. PMID:26972771

The number and growth pattern of plasmacytoid dendritic cells vary in different types of reactive lymph nodes: an immunohistochemical study.

PubMed

Rollins-Raval, Marian A; Marafioti, Teresa; Swerdlow, Steven H; Roth, Christine G

2013-06-01

Plasmacytoid dendritic cells, which play a fundamental role in the innate immune response, are best known for their presence in hyaline-vascular Castleman disease and histiocytic necrotizing lymphadenitis. The relative number and distribution in many reactive entities as detected using more sensitive methods are uncertain, and their diagnostic implications are unknown. Immunohistochemical studies for plasmacytoid dendritic cell-associated markers CD123 and CD2AP were performed on 42 lymph nodes with hyaline-vascular Castleman disease, histiocytic necrotizing lymphadenitis, sarcoidosis, necrotizing granulomatous inflammation, viral infection, dermatopathic lymphadenopathy, autoimmune disease, and a histologic pattern compatible with toxoplasmosis. The overall plasmacytoid dendritic cell numbers and growth patterns (tight aggregates, loose aggregates/clusters, scattered single cells) were assessed. Plasmacytoid dendritic cells were present in all cases and were predominantly distributed in loose aggregates/clusters or singly. They were most numerous in granulomatous inflammation and histiocytic necrotizing lymphadenitis, whereas viral infections showed the fewest overall numbers and a predominant pattern of scattered single cells. Tight aggregates of plasmacytoid dendritic cells were most numerous in hyaline-vascular Castleman disease (100% sensitive, 68% specific). Plasmacytoid dendritic cells are not limited to a small number of reactive lymphadenopathies but are found in many reactive processes, often with a predominant pattern of loose aggregates/clusters and scattered single cells. However, tight aggregates were a characteristic feature of hyaline-vascular Castleman disease, and viral infections typically showed only few scattered cells distributed singly. Copyright © 2013 Elsevier Inc. All rights reserved.

Tracking the Spatial and Functional Gradient of Monocyte-To-Macrophage Differentiation in Inflamed Lung.

PubMed

Sen, Debasish; Jones, Stephen M; Oswald, Erin M; Pinkard, Henry; Corbin, Kaitlin; Krummel, Matthew F

2016-01-01

Myeloid-derived cells such as monocytes, dendritic cells (DCs), and macrophages are at the heart of the immune effector function in an inflammatory response. But because of the lack of an efficient imaging system to trace these cells live during their migration and maturation in their native environment at sub-cellular resolution, our knowledge is limited to data available from specific time-points analyzed by flow cytometry, histology, genomics and other immunological methods. Here, we have developed a ratiometric imaging method for measuring monocyte maturation in inflamed mouse lungs in situ using real-time using 2-photon imaging and complementary methods. We visualized that while undifferentiated monocytes were predominantly found only in the vasculature, a semi-differentiated monocyte/macrophage population could enter the tissue and resembled more mature and differentiated populations by morphology and surface phenotype. As these cells entered and differentiated, they were already selectively localized near inflamed airways and their entry was associated with changes in motility and morphology. We were able to visualize these during the act of differentiation, a process that can be demonstrated in this way to be faster on a per-cell basis under inflammatory conditions. Finally, our in situ analyses demonstrated increases, in the differentiating cells, for both antigen uptake and the ability to mediate interactions with T cells. This work, while largely confirming proposed models for in situ differentiation, provides important in situ data on the coordinated site-specific recruitment and differentiation of these cells and helps elaborate the predominance of immune pathology at the airways. Our novel imaging technology to trace immunogenic cell maturation in situ will complement existing information available on in situ differentiation deduced from other immunological methods, and assist better understanding of the spatio-temporal cellular behavior during an inflammatory response.

Vaccine Therapy in Treating Patients With Stage IIIC-IV Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer Following Surgery and Chemotherapy

ClinicalTrials.gov

2017-10-12

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Tumor; Fallopian Tube Mucinous Neoplasm; Fallopian Tube Serous Neoplasm; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Cystadenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Cystadenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Antigen-loaded dendritic cell migration: MR imaging in a pancreatic carcinoma model.

PubMed

Zhang, Zhuoli; Li, Weiguo; Procissi, Daniele; Li, Kangan; Sheu, Alexander Y; Gordon, Andrew C; Guo, Yang; Khazaie, Khashayarsha; Huan, Yi; Han, Guohong; Larson, Andrew C

2015-01-01

To test the following hypotheses in a murine model of pancreatic cancer: (a) Vaccination with antigen-loaded iron-labeled dendritic cells reduces T2-weighted signal intensity at magnetic resonance (MR) imaging within peripheral draining lymph nodes ( LN lymph node s) and (b) such signal intensity reductions are associated with tumor size changes after dendritic cell vaccination. The institutional animal care and use committee approved this study. Panc02 cells were implanted into the flanks of 27 C57BL/6 mice bilaterally. After tumors reached 10 mm, cell viability was evaluated, and iron-labeled dendritic cell vaccines were injected into the left hind footpad. The mice were randomly separated into the following three groups (n = 9 in each): Group 1 was injected with 1 million iron-labeled dendritic cells; group 2, with 2 million cells; and control mice, with 200 mL of phosphate-buffered saline. T1- and T2-weighted MR imaging of labeled dendritic cell migration to draining LN lymph node s was performed before cell injection and 6 and 24 hours after injection. The signal-to-noise ratio ( SNR signal-to-noise ratio ) of the draining LN lymph node s was measured. One-way analysis of variance ( ANOVA analysis of variance ) was used to compare Prussian blue-positive dendritic cell measurements in LN lymph node s. Repeated-measures ANOVA analysis of variance was used to compare in vivo T2-weighted SNR signal-to-noise ratio LN lymph node measurements between groups over the observation time points. Trypan blue assays showed no significant difference in mean viability indexes (unlabeled vs labeled dendritic cells, 4.32% ± 0.69 [standard deviation] vs 4.83% ± 0.76; P = .385). Thirty-five days after injection, the mean left and right flank tumor sizes, respectively, were 112.7 mm(2) ± 16.4 and 109 mm(2) ± 24.3 for the 1-million dendritic cell group, 92.2 mm(2) ± 9.9 and 90.4 mm(2) ± 12.8 for the 2-million dendritic cell group, and 193.7 mm(2) ± 20.9 and 189.4 mm(2) ± 17.8 for the control group (P = .0001 for control group vs 1-million cell group; P = .00007 for control group vs 2-million cell group). There was a correlation between postinjection T2-weighted SNR signal-to-noise ratio decreases in the left popliteal LN lymph node 24 hours after injection and size changes at follow-up for tumors in both flanks (R = 0.81 and R = 0.76 for left and right tumors, respectively). MR imaging approaches can be used for quantitative measurement of accumulated iron-labeled dendritic cell-based vaccines in draining LN lymph node s. The amount of dendritic cell-based vaccine in draining LN lymph node s correlates well with observed protective effects.

Utilization of human amniotic mesenchymal cells as feeder layers to sustain propagation of human embryonic stem cells in the undifferentiated state.

PubMed

Zhang, Kehua; Cai, Zhe; Li, Yang; Shu, Jun; Pan, Lin; Wan, Fang; Li, Hong; Huang, Xiaojie; He, Chun; Liu, Yanqiu; Cui, Xiaohui; Xu, Yang; Gao, Yan; Wu, Liqun; Cao, Shanxia; Li, Lingsong

2011-08-01

Human embryonic stem (ES) cells are usually maintained in the undifferentiated state by culturing on feeder cells layers of mouse embryonic fibroblasts (MEFs). However, MEFs are not suitable to support human ES cells used for clinical purpose because of risk of zoonosis from animal cells. Therefore, human tissue-based feeder layers need to be developed for human ES cells for clinical purpose. Hereof we report that human amniotic mesenchymal cells (hAMCs) could act as feeder cells for human ES cells, because they are easily obtained and relatively exempt from ethical problem. Like MEFs, hAMCs could act as feeder cells for human ES cells to grow well on. The self-renewal rate of human ES cells cultured on hAMCs feeders was higher than that on MEFs and human amniotic epithelial cells determined by measurement of colonial diameters and growth curve as well as cell cycle analysis. Both immunofluorescence staining and immunoblotting showed that human ES cells cultured on hAMCs expressed stem cell markers such as Oct-3/4, Sox2, and NANOG. Verified by embryoid body formation in vitro and teratoma formation in vivo, we found out that after 20 passages of culture, human ES cells grown on hAMCs feeders could still retain the potency of differentiating into three germ layers. Taken together, our data suggested hAMCs may be safe feeder cells to sustain the propagation of human ES cells in undifferentiated state for future therapeutic use.

PRMT5 as a druggable target for glioblastoma therapy.

PubMed

Banasavadi-Siddegowda, Yeshavanth Kumar; Welker, Alessandra M; An, Min; Yang, Xiaozhi; Zhou, Wei; Shi, Guqin; Imitola, Jaime; Li, Chenglong; Hsu, Sigmund; Wang, Jiang; Phelps, Mitch; Zhang, Jianying; Beattie, Christine E; Baiocchi, Robert; Kaur, Balveen

2018-05-18

In spite of standard multimodal therapy consisting of surgical resection followed by radiation and concurrent chemotherapy, prognosis for glioblastoma (GBM) patients remains poor. The identification of both differentiated and undifferentiated "stem cell like" populations in the tumor highlights the significance of finding novel targets that affect the heterogeneous tumor cell population. Protein arginine methyltransferase 5 (PRMT5) is one such candidate gene whose nuclear expression correlates with poor survival and has been reported to be required for survival of differentiated GBM cells and self-renewal of undifferentiated GBM cells. In the current study we screened the specificity and efficacy of 4 novel PRMT5 inhibitors in the treatment of GBM. Efficacies of these inhibitors were screened using an in vitro GBM neurosphere model and an in vivo intracranial zebrafish model of glioma. Standard molecular biology methods were employed to investigate changes in cell cycle, growth, and senescence. In vitro and in vivo studies revealed that among the 4 PRMT5 inhibitors, treatment of GBM cells with compound 5 (CMP5) mirrored the effects of PRMT5 knockdown wherein it led to apoptosis of differentiated GBM cells and drove undifferentiated primary patient derived GBM cells into a nonreplicative senescent state. In vivo antitumor efficacy combined with the specificity of CMP5 underscores the importance of developing it for translation.

Ultrastructural demonstration of Cx43 gap junctions in induced pluripotent stem cells from human cord blood.

PubMed

Beckmann, Anja; Schubert, Madline; Hainz, Nadine; Haase, Alexandra; Martin, Ulrich; Tschernig, Thomas; Meier, Carola

2016-11-01

Gap junction proteins are essential for direct intercellular communication but also influence cellular differentiation and migration. The expression of various connexin gap junction proteins has been demonstrated in embryonic stem cells, with Cx43 being the most intensely studied. As Cx43 is the most prominent gap junction protein in the heart, cardiomyocyte-differentiated stem cells have been studied intensely. To date, however, little is known about the expression and the subcellular distribution of Cx43 in undifferentiated stem cells or about the structural arrangement of channels. We, therefore, here investigate expression of Cx43 in undifferentiated human cord-blood-derived induced pluripotent stem cells (hCBiPS2). For this purpose, we carried out quantitative real-time PCR and immunohistochemistry. For analysis of Cx43 ultrastructure and protein assembly, we performed freeze-fracture replica immunogold labeling (FRIL). Cx43 expression was detected at mRNA and protein level in hCBIPS2 cells. For the first time, ultrastructural data are presented on gap junction morphology in induced pluripotent stem (iPS) cells from cord blood: Our FRIL and electron microscopical analysis revealed the occurrence of gap junction plaques in undifferentiated iPS cells. In addition, these gap junctions were shown to contain the gap junction protein Cx43.

The transcription factor IRF8 counteracts BCR-ABL to rescue dendritic cell development in chronic myelogenous leukemia.

PubMed

Watanabe, Tomoya; Hotta, Chie; Koizumi, Shin-ichi; Miyashita, Kazuho; Nakabayashi, Jun; Kurotaki, Daisuke; Sato, Go R; Yamamoto, Michio; Nakazawa, Masatoshi; Fujita, Hiroyuki; Sakai, Rika; Fujisawa, Shin; Nishiyama, Akira; Ikezawa, Zenro; Aihara, Michiko; Ishigatsubo, Yoshiaki; Tamura, Tomohiko

2013-11-15

BCR-ABL tyrosine kinase inhibitors (TKI) have dramatically improved therapy for chronic myelogenous leukemia (CML). However, several problems leading to TKI resistance still impede a complete cure of this disease. IFN regulatory factor-8 (IRF8) is a transcription factor essential for the development and functions of immune cells, including dendritic cells. Irf8(-/-) mice develop a CML-like disease and IRF8 expression is downregulated in patients with CML, suggesting that IRF8 is involved in the pathogenesis of CML. In this study, by using a murine CML model, we show that BCR-ABL strongly inhibits a generation of dendritic cells from an early stage of their differentiation in vivo, concomitant with suppression of Irf8 expression. Forced expression of IRF8 overrode BCR-ABL (both wild-type and T315I-mutated) to rescue dendritic cell development in vitro, indicating that the suppression of Irf8 causes dendritic cell deficiency. Gene expression profiling revealed that IRF8 restored the expression of a significant portion of BCR-ABL-dysregulated genes and predicted that BCR-ABL has immune-stimulatory potential. Indeed, IRF8-rescued BCR-ABL-expressing dendritic cells were capable of inducing CTLs more efficiently than control dendritic cells. Altogether, our findings suggest that IRF8 is an attractive target in next-generation therapies for CML. ©2013 AACR

Can dendritic cells see light?

NASA Astrophysics Data System (ADS)

Chen, Aaron C.-H.; Huang, Ying-Ying; Sharma, Sulbha K.; Hamblin, Michael R.

2010-02-01

There are many reports showing that low-level light/laser therapy (LLLT) can enhance wound healing, upregulate cell proliferation and has anti-apoptotic effects by activating intracellular protective genes. In the field of immune response study, it is not known with any certainty whether light/laser is proinflammatory or anti-inflammatory. Increasingly in recent times dendritic cells have been found to play an important role in inflammation and the immunological response. In this study, we try to look at the impact of low level near infrared light (810-nm) on murine bone-marrow derived dendritic cells. Changes in surface markers, including MHC II, CD80 and CD11c and the secretion of interleukins induced by light may provide additional evidence to reveal the mystery of how light affects the maturation of dendritic cells as well how these light-induced mature dendritic cells would affect the activation of adaptive immune response.

Sodium and calcium currents in neuroblastoma x glioma hybrid cells before and after morphological differentiation by dibutyryl cyclic AMP.

PubMed

Bodewei, R; Hering, S; Schubert, B; Wollenberger, A

1985-04-01

Sodium and calcium inward currents (INa and ICa) were measured in neuroblastoma X glioma hybrid cells of clones 108CC5 and 108CC15 by a single suction pipette method for internal perfusion and voltage clamp. Morphologically undifferentiated, exponentially growing cells were compared with cells differentiated by cultivation with 1 mmol/l dibutyryl cyclic AMP. Outward currents were eliminated by perfusing the cells with a K+-free solution. Voltage dependence and ion selectivity as well as steady state inactivation characteristics of INa and ICa resembled those of differentiated mouse neuroblastoma cells, clone N1E-115 (Moolenaar and Spector 1978, 1979). These parameters were identical in undifferentiated and differentiated cells of both clones. After differentiation the average density of the peak sodium and calcium currents was increased two and four-fold, respectively, in both cell lines. Our data indicate that exponentially growing, morphologically undifferentiated 108CC5 and 108CC15 neuroblastoma X glioma hybrid cells possess functional Na+ and Ca2+ channels undistinguishable from those of non-proliferating cells of these clones differentiated morphologically by treatment with dibutyryl cyclic AMP. That Na+ and Ca2+ spikes were not detected by other authors in these cells prior to morphological differentiation by dibutyryl cyclic AMP may be attributed to the fact that at the low resting membrane potential measured the Na+ and Ca2+ channels are inactivated.

CT findings associated with blastic plasmacytoid dendritic cell neoplasm: a case report

PubMed Central

Choi, Jung W; Jeong, Katherine; Sokol, Lubomir

2016-01-01

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that is frequently misdiagnosed. We present a case of a 53-year-old man diagnosed with blastic plasmacytoid dendritic cell neoplasm with extensive computed tomography (CT) findings and provide an imaging focused review of this uncommon malignancy. PMID:27504192

Phenotype and function of CD209+ bovine blood dendritic cells, monocyte-derived-dendritic cells and monocyte-derived macrophages

USDA-ARS?s Scientific Manuscript database

Phylogenic comparisons of the mononuclear phagocyte system (MPS) of humans and mice demonstrate phenotypic divergence of dendritic cell (DC) subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny a...

A Comparison between Growth Morphology of "Eutectic" Cells/Dendrites and Single-Phase Cells/Dendrites

NASA Technical Reports Server (NTRS)

Tewari, S. N.; Raj, S. V.; Locci, I. E.

2003-01-01

Directionally solidified (DS) intermetallic and ceramic-based eutectic alloys with an in-situ composite microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve heir high-temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic "colonies." Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability analysis of Mullins and Sekerka has been extended to describe their formation. Onset of their formation shows a good agreement with this approach; however, unlike the single-phase cells and dendrites, there is limited examination of their growth speed dependence of spacing, morphology, and spatial distribution. The purpose of this study is to compare the growth speed dependence of the morphology, spacing, and spatial distribution of eutectic cells and dendrites with that for the single-phase cells and dendrites.

Antigen-loaded Dendritic Cell Migration: MR Imaging in a Pancreatic Carcinoma Model

PubMed Central

Li, Weiguo; Procissi, Daniele; Li, Kangan; Sheu, Alexander Y.; Gordon, Andrew C.; Guo, Yang; Khazaie, Khashayarsha; Huan, Yi; Han, Guohong; Larson, Andrew C.

2015-01-01

Purpose To test the following hypotheses in a murine model of pancreatic cancer: (a) Vaccination with antigen-loaded iron-labeled dendritic cells reduces T2-weighted signal intensity at magnetic resonance (MR) imaging within peripheral draining lymph nodes (LNlymph nodes) and (b) such signal intensity reductions are associated with tumor size changes after dendritic cell vaccination. Materials and Methods The institutional animal care and use committee approved this study. Panc02 cells were implanted into the flanks of 27 C57BL/6 mice bilaterally. After tumors reached 10 mm, cell viability was evaluated, and iron-labeled dendritic cell vaccines were injected into the left hind footpad. The mice were randomly separated into the following three groups (n = 9 in each): Group 1 was injected with 1 million iron-labeled dendritic cells; group 2, with 2 million cells; and control mice, with 200 mL of phosphate-buffered saline. T1- and T2-weighted MR imaging of labeled dendritic cell migration to draining LNlymph nodes was performed before cell injection and 6 and 24 hours after injection. The signal-to-noise ratio (SNRsignal-to-noise ratio) of the draining LNlymph nodes was measured. One-way analysis of variance (ANOVAanalysis of variance) was used to compare Prussian blue–positive dendritic cell measurements in LNlymph nodes. Repeated-measures ANOVAanalysis of variance was used to compare in vivo T2-weighted SNRsignal-to-noise ratio LNlymph node measurements between groups over the observation time points. Results Trypan blue assays showed no significant difference in mean viability indexes (unlabeled vs labeled dendritic cells, 4.32% ± 0.69 [standard deviation] vs 4.83% ± 0.76; P = .385). Thirty-five days after injection, the mean left and right flank tumor sizes, respectively, were 112.7 mm2 ± 16.4 and 109 mm2 ± 24.3 for the 1-million dendritic cell group, 92.2 mm2 ± 9.9 and 90.4 mm2 ± 12.8 for the 2-million dendritic cell group, and 193.7 mm2 ± 20.9 and 189.4 mm2 ± 17.8 for the control group (P = .0001 for control group vs 1-million cell group; P = .00007 for control group vs 2-million cell group). There was a correlation between postinjection T2-weighted SNRsignal-to-noise ratio decreases in the left popliteal LNlymph node 24 hours after injection and size changes at follow-up for tumors in both flanks (R = 0.81 and R = 0.76 for left and right tumors, respectively). Conclusion MR imaging approaches can be used for quantitative measurement of accumulated iron-labeled dendritic cell–based vaccines in draining LNlymph nodes. The amount of dendritic cell–based vaccine in draining LNlymph nodes correlates well with observed protective effects. © RSNA, 2014 Online supplemental material is available for this article. PMID:25222066

Maintenance of dendritic spine morphology by partitioning-defective 1b through regulation of microtubule growth.

PubMed

Hayashi, Kenji; Suzuki, Atsushi; Hirai, Syu-ichi; Kurihara, Yasuyuki; Hoogenraad, Casper C; Ohno, Shigeo

2011-08-24

Dendritic spines are postsynaptic structures that receive excitatory synaptic input from presynaptic terminals. Actin and its regulatory proteins play a central role in morphogenesis of dendritic spines. In addition, recent studies have revealed that microtubules are indispensable for the maintenance of mature dendritic spine morphology by stochastically invading dendritic spines and regulating dendritic localization of p140Cap, which is required for actin reorganization. However, the regulatory mechanisms of microtubule dynamics remain poorly understood. Partitioning-defective 1b (PAR1b), a cell polarity-regulating serine/threonine protein kinase, is thought to regulate microtubule dynamics by inhibiting microtubule binding of microtubule-associated proteins. Results from the present study demonstrated that PAR1b participates in the maintenance of mature dendritic spine morphology in mouse hippocampal neurons. Immunofluorescent analysis revealed PAR1b localization in the dendrites, which was concentrated in dendritic spines of mature neurons. PAR1b knock-down cells exhibited decreased mushroom-like dendritic spines, as well as increased filopodia-like dendritic protrusions, with no effect on the number of protrusions. Live imaging of microtubule plus-end tracking proteins directly revealed decreases in distance and duration of microtubule growth following PAR1b knockdown in a neuroblastoma cell line and in dendrites of hippocampal neurons. In addition, reduced accumulation of GFP-p140Cap in dendritic protrusions was confirmed in PAR1b knock-down neurons. In conclusion, the present results suggested a novel function for PAR1b in the maintenance of mature dendritic spine morphology by regulating microtubule growth and the accumulation of p140Cap in dendritic spines.

Neural stem cells rescue nervous purkinje neurons by restoring molecular homeostasis of tissue plasminogen activator and downstream targets.

PubMed

Li, Jianxue; Imitola, Jaime; Snyder, Evan Y; Sidman, Richard L

2006-07-26

Neural stem cells (NSCs) offer special therapeutic prospects because they can be isolated from the CNS, expanded ex vivo, and re-implanted into diseased CNS where they not only migrate and differentiate according to cues from host tissue but also appear to be capable of affecting host cells. In nervous (nr) mutant mice Purkinje neuron (PN) mitochondria become abnormal by the second postnatal week, and a majority of PNs die in the fourth to fifth weeks. We previously identified in nr cerebellum a 10-fold increase in tissue plasminogen activator (tPA) as a key component of the mechanism causing nr PN death. Here we report that undifferentiated wild-type murine NSCs, when transplanted into the newborn nr cerebellar cortex, do not replace host PNs but contact imperiled PNs and support their mitochondrial function, dendritic growth, and synaptogenesis, subsequently leading to the rescue of host PNs and restoration of motor coordination. This protection of nr PNs also is verified by an in vitro organotypic slice model in which nr cerebellar slices are cocultured with NSCs. Most importantly, the integrated NSCs in young nr cerebellum rectify excessive tPA mRNA and protein to close to normal levels and protect the mitochondrial voltage-dependent anion channel and neurotrophins, downstream targets of the tPA/plasmin proteolytic system. This report demonstrates for the first time that NSCs can rescue imperiled host neurons by rectifying their gene expression, elevating somatic stem cell therapeutic potential beyond solely cell replacement strategy.

p15Ink4b is Key in Dendritic Cell Development | Center for Cancer Research

Cancer.gov

An important step in the initiation of leukemia is the ability of pre-leukemic and leukemic cells to evade the immune system. Dendritic cells are instrumental in maintaining the body’s immunity, and CCR scientists have shown for the first time that the tumor suppressor protein p15Ink4b regulates the differentiation and maturation of conventional dendritic cells.

Specific skin lesions in chronic myelomonocytic leukemia: a spectrum of myelomonocytic and dendritic cell proliferations: a study of 42 cases.

PubMed

Vitte, Franck; Fabiani, Bettina; Bénet, Claire; Dalac, Sophie; Balme, Brigitte; Delattre, Claire; Vergier, Béatrice; Beylot-Barry, Marie; Vignon-Pennamen, Dominique; Ortonne, Nicolas; Algros, Marie Paule; Carlotti, Agnès; Samaleire, Dimitri; Frouin, Eric; Levy, Anne; Laroche, Liliane; Theate, Ivan; Monnien, Franck; Mugneret, Francine; Petrella, Tony

2012-09-01

Chronic myelomonocytic leukemia (CMML) is a rare clonal hematopoietic disorder that can also involve the skin. The histopathology of these skin lesions is not clearly defined, and few data are available in the literature. To better understand tumoral skin involvements in CMML we carried out an extensive, retrospective clinicopathologic study of 42 cases selected from the database of the French Study Group of Cutaneous Lymphomas. On the basis of clinical data, morphology, and phenotype we identified 4 clinicopathologic profiles representing 4 distinct groups. The first group comprised myelomonocytic cell tumors (n=18), exhibiting a proliferation of granulocytic or monocytic blast cells, which were CD68 and/or MPO positive but negative for dendritic cell markers. The second group comprised mature plasmacytoid dendritic cell tumors (n=16), denoted by a proliferation of mature plasmacytoid dendritic cells, which were CD123, TCL1, and CD303 positive but CD56, CD1a, and S100 negative. The third group comprised blastic plasmacytoid dendritic cell tumors (n=4), characterized by a proliferation of monomorphous medium-sized blast cells, which were CD4, CD56, CD123, TCL1 positive but CD1a and S100 negative. The fourth group consisted of a putatively novel category of tumor that we named blastic indeterminate dendritic cell tumors (n=4), distinguished by a proliferation of large blast cells that not only exhibited monocytic markers but also the dendritic markers CD1a and S100. These 4 groups showed distinctive outcomes. Finally, we showed, by fluorescence in situ hybridization analysis, a clonal link between bone marrow disease and skin lesions in 4 patients. Herein, we have described a novel scheme for pathologists and physicians to handle specific lesions in CMML, which correspond to a spectrum of myelomonocytic and dendritic cell proliferations with different outcomes. A minimal panel of immunohistochemical markers including CD68, CD1a, S100, Langerin, and CD123 is necessary to make the correct classification in this spectrum of cutaneous CMML tumors, in which dendritic cell lineage plays an important role.

Single-cell gene expression profiling reveals functional heterogeneity of undifferentiated human epidermal cells

PubMed Central

Tan, David W. M.; Jensen, Kim B.; Trotter, Matthew W. B.; Connelly, John T.; Broad, Simon; Watt, Fiona M.

2013-01-01

Human epidermal stem cells express high levels of β1 integrins, delta-like 1 (DLL1) and the EGFR antagonist LRIG1. However, there is cell-to-cell variation in the relative abundance of DLL1 and LRIG1 mRNA transcripts. Single-cell global gene expression profiling showed that undifferentiated cells fell into two clusters delineated by expression of DLL1 and its binding partner syntenin. The DLL1+ cluster had elevated expression of genes associated with endocytosis, integrin-mediated adhesion and receptor tyrosine kinase signalling. Differentially expressed genes were not independently regulated, as overexpression of DLL1 alone or together with LRIG1 led to the upregulation of other genes in the DLL1+ cluster. Overexpression of DLL1 and LRIG1 resulted in enhanced extracellular matrix adhesion and increased caveolin-dependent EGFR endocytosis. Further characterisation of CD46, one of the genes upregulated in the DLL1+ cluster, revealed it to be a novel cell surface marker of human epidermal stem cells. Cells with high endogenous levels of CD46 expressed high levels of β1 integrin and DLL1 and were highly adhesive and clonogenic. Knockdown of CD46 decreased proliferative potential and β1 integrin-mediated adhesion. Thus, the previously unknown heterogeneity revealed by our studies results in differences in the interaction of undifferentiated basal keratinocytes with their environment. PMID:23482486

Renal dendritic cells sample blood-borne antigen and guide T-cell migration to the kidney by means of intravascular processes.

PubMed

Yatim, Karim M; Gosto, Minja; Humar, Rishab; Williams, Amanda L; Oberbarnscheidt, Martin H

2016-10-01

Bony fish are among the first vertebrates to possess an innate and adaptive immune system. In these species, the kidney has a dual function: filtering solutes similar to mammals and acting as a lymphoid organ responsible for hematopoiesis and antigen processing. Recent studies have shown that the mammalian kidney has an extensive network of mononuclear phagocytes, whose function is not fully understood. Here, we employed two-photon intravital microscopy of fluorescent reporter mice to demonstrate that renal dendritic cells encase the microvasculature in the cortex, extend dendrites into the peritubular capillaries, and sample the blood for antigen. We utilized a mouse model of systemic bacterial infection as well as immune complexes to demonstrate antigen uptake by renal dendritic cells. As a consequence, renal dendritic cells mediated T-cell migration into the kidney in an antigen-dependent manner in the setting of bacterial infection. Thus, renal dendritic cells may be uniquely positioned to play an important role not only in surveillance of systemic infection but also in local infection and autoimmunity. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Modulation of Dendritic Cell Activation and Subsequent Th1 Cell Polarization by Lidocaine

PubMed Central

Chung, Yeonseok

2015-01-01

Dendritic cells play an essential role in bridging innate and adaptive immunity by recognizing cellular stress including pathogen- and damage-associated molecular patterns and by shaping the types of antigen-specific T cell immunity. Although lidocaine is widely used in clinical settings that trigger cellular stress, it remains unclear whether such treatment impacts the activation of innate immune cells and subsequent differentiation of T cells. Here we showed that lidocaine inhibited the production of IL–6, TNFα and IL–12 from dendritic cells in response to toll-like receptor ligands including lipopolysaccharide, poly(I:C) and R837 in a dose-dependent manner. Notably, the differentiation of Th1 cells was significantly suppressed by the addition of lidocaine while the same treatment had little effect on the differentiation of Th17, Th2 and regulatory T cells in vitro. Moreover, lidocaine suppressed the ovalbumin-specific Th1 cell responses in vivo induced by the adoptive transfer of ovalbumin-pulsed dendritic cells. These results demonstrate that lidocaine inhibits the activation of dendritic cells in response to toll-like receptor signals and subsequently suppresses the differentiation of Th1 cell responses. PMID:26445366

Glycosyltransferase ST6GAL1 contributes to the regulation of pluripotency in human pluripotent stem cells

PubMed Central

Wang, Yu-Chieh; Stein, Jason W.; Lynch, Candace L.; Tran, Ha T.; Lee, Chia-Yao; Coleman, Ronald; Hatch, Adam; Antontsev, Victor G.; Chy, Hun S.; O’Brien, Carmel M.; Murthy, Shashi K.; Laslett, Andrew L.; Peterson, Suzanne E.; Loring, Jeanne F.

2015-01-01

Many studies have suggested the significance of glycosyltransferase-mediated macromolecule glycosylation in the regulation of pluripotent states in human pluripotent stem cells (hPSCs). Here, we observed that the sialyltransferase ST6GAL1 was preferentially expressed in undifferentiated hPSCs compared to non-pluripotent cells. A lectin which preferentially recognizes α-2,6 sialylated galactosides showed strong binding reactivity with undifferentiated hPSCs and their glycoproteins, and did so to a much lesser extent with differentiated cells. In addition, downregulation of ST6GAL1 in undifferentiated hPSCs led to a decrease in POU5F1 (also known as OCT4) protein and significantly altered the expression of many genes that orchestrate cell morphogenesis during differentiation. The induction of cellular pluripotency in somatic cells was substantially impeded by the shRNA-mediated suppression of ST6GAL1, partially through interference with the expression of endogenous POU5F1 and SOX2. Targeting ST6GAL1 activity with a sialyltransferase inhibitor during cell reprogramming resulted in a dose-dependent reduction in the generation of human induced pluripotent stem cells (hiPSCs). Collectively, our data indicate that ST6GAL1 plays an important role in the regulation of pluripotency and differentiation in hPSCs, and the pluripotent state in human cells can be modulated using pharmacological tools to target sialyltransferase activity. PMID:26304831

Dendritic excitation–inhibition balance shapes cerebellar output during motor behaviour

PubMed Central

Jelitai, Marta; Puggioni, Paolo; Ishikawa, Taro; Rinaldi, Arianna; Duguid, Ian

2016-01-01

Feedforward excitatory and inhibitory circuits regulate cerebellar output, but how these circuits interact to shape the somatodendritic excitability of Purkinje cells during motor behaviour remains unresolved. Here we perform dendritic and somatic patch-clamp recordings in vivo combined with optogenetic silencing of interneurons to investigate how dendritic excitation and inhibition generates bidirectional (that is, increased or decreased) Purkinje cell output during self-paced locomotion. We find that granule cells generate a sustained depolarization of Purkinje cell dendrites during movement, which is counterbalanced by variable levels of feedforward inhibition from local interneurons. Subtle differences in the dendritic excitation–inhibition balance generate robust, bidirectional changes in simple spike (SSp) output. Disrupting this balance by selectively silencing molecular layer interneurons results in unidirectional firing rate changes, increased SSp regularity and disrupted locomotor behaviour. Our findings provide a mechanistic understanding of how feedforward excitatory and inhibitory circuits shape Purkinje cell output during motor behaviour. PMID:27976716

Kidney dendritic cells in acute and chronic renal disease.

PubMed

Hochheiser, Katharina; Tittel, André; Kurts, Christian

2011-06-01

Dendritic cells are not only the master regulators of adaptive immunity, but also participate profoundly in innate immune responses. Much has been learned about their basic immunological functions and their roles in various diseases. Comparatively little is still known about their role in renal disease, despite their obvious potential to affect immune responses in the kidney, and immune responses that are directed against renal components. Kidney dendritic cells form an abundant network in the renal tubulointerstitium and constantly survey the environment for signs of injury or infection, in order to alert the immune system to the need to initiate defensive action. Recent studies have identified a role for dendritic cells in several murine models of acute renal injury and chronic nephritis. Here we summarize the current knowledge on the role of kidney dendritic cells that has been obtained from the study of murine models of renal disease. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

The E3 ligase c-Cbl regulates dendritic cell activation

PubMed Central

Chiou, Shin-Heng; Shahi, Payam; Wagner, Ryan T; Hu, Hongbo; Lapteva, Natalia; Seethammagari, Mamatha; Sun, Shao-Cong; Levitt, Jonathan M; Spencer, David M

2011-01-01

The activation of innate and adaptive immunity is always balanced by inhibitory signalling mechanisms to maintain tissue integrity. We have identified the E3 ligase c-Cbl––known for its roles in regulating lymphocyte signalling––as a modulator of dendritic cell activation. In c-Cbl-deficient dendritic cells, Toll-like receptor-induced expression of proinflammatory factors, such as interleukin-12, is increased, correlating with a greater potency of dendritic-cell-based vaccines against established tumours. This proinflammatory phenotype is accompanied by an increase in nuclear factor (NF)-κB activity. In addition, c-Cbl deficiency reduces both p50 and p105 levels, which have been shown to modulate the stimulatory function of NF-κB. Our data indicate that c-Cbl has a crucial, RING-domain-dependent role in regulating dendritic cell maturation, probably by facilitating the regulatory function of p105 and/or p50. PMID:21799517

Non-equivalent antigen presenting capabilities of dendritic cells and macrophages in generating brain-infiltrating CD8 + T cell responses.

PubMed

Malo, Courtney S; Huggins, Matthew A; Goddery, Emma N; Tolcher, Heather M A; Renner, Danielle N; Jin, Fang; Hansen, Michael J; Pease, Larry R; Pavelko, Kevin D; Johnson, Aaron J

2018-02-12

The contribution of antigen-presenting cell (APC) types in generating CD8 + T cell responses in the central nervous system (CNS) is not fully defined, limiting the development of vaccines and understanding of immune-mediated neuropathology. Here, we generate a transgenic mouse that enables cell-specific deletion of the H-2Kb MHC class I molecule. By deleting H-2K b on dendritic cells and macrophages, we compare the effect of each APC in three distinct models of neuroinflammation: picornavirus infection, experimental cerebral malaria, and a syngeneic glioma. Dendritic cells and macrophages both activate CD8 + T cell responses in response to these CNS immunological challenges. However, the extent to which each of these APCs contributes to CD8 + T cell priming varies. These findings reveal distinct functions for dendritic cells and macrophages in generating CD8 + T cell responses to neurological disease.

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study.

PubMed

Jelinek, Herbert F; Ristanović, Dušan; Milošević, Nebojša T

2011-09-30

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

A Rare Case of Retroperitoneal Follicular Dendritic Cell Sarcoma Identified by 99mTc-HYNIC-TOC SPECT/CT.

PubMed

Li, Yi; Xu, Xiaoping; Xu, Junyan; Huang, Dan

2018-05-31

Follicular dendritic cell sarcoma is a very rare neoplasm, which is not lymphoma, but originates from a type of immune cells called follicular dendritic cells. We presented a 37-year-old woman who has suffered from obstructive jaundice, weight loss and right upper abdominal pain for 2 months. The contrast CT revealed masses located in the region of pancreatic head and lots of enlarged retroperitoneal lymph nodes, both of which were enhanced on the artery phase of CT images. Meanwhile, Tc-HYNIC-TOC SPECT/CT revealed high activity in the corresponding lesions. After biopsy, the masses were pathologically confirmed as retroperitoneal follicular dendritic cell sarcoma.

Convective exosome-tracing microfluidics for analysis of cell-non-autonomous neurogenesis.

PubMed

Oh, Hyun Jeong; Shin, Yoojin; Chung, Seok; Hwang, Do Won; Lee, Dong Soo

2017-01-01

The effective role of exosome delivering neurogenic microRNA (miRNA) enables to induce efficient differentiation process during neurogenesis. The microfludic system capable of visualizing the exosomal behavior such as secretion, migration, and uptake of individual exosomes can be used as a robust technique to understand the exosome-mediated change of cellular behavior. Here, we developed the exosome-tracing microfluidic system to visualize exosomal transport carrying the neurogenic miRNA from leading to neighboring cells, and found a new mode of exosome-mediated cell-non-autonomous neurogenesis. The miR-193a facilitated neurogenesis in F11 cells by blocking proliferation-related target genes. In addition to time-lapse live-cell imaging using microfluidics visualized the convective transport of exosomes from differentiated to undifferentiated cells. Individual exosomes containing miR-193a from differentiated donor cells were taken up by undifferentiated cells to lead them to neurogenesis. Induction of anti-miR-193a was sufficient to block neurogenesis in F11 cells. Inhibition of the exosomal production by manumycin-A and treatment of anti-miR-193a in the differentiated donor cells failed to induce neurogenesis in undifferentiated recipient cells. These findings indicate that exosomes of neural progenitors and neurogenic miRNA within these exosomes propagate cell-non-autonomous differentiation to neighboring progenitors, to delineate the roles of exosome mediating neurogenesis of population of homologous neural progenitor cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chronic pharmacological blockade of the Na+ /Ca2+ exchanger modulates the growth and development of the Purkinje cell dendritic arbor in mouse cerebellar slice cultures.

PubMed

Sherkhane, Pradeep; Kapfhammer, Josef P

2017-09-01

The Na + /Ca 2+ exchanger (NCX) is a bidirectional plasma membrane antiporter involved in Ca 2+ homeostasis in eukaryotes. NCX has three isoforms, NCX1-3, and all of them are expressed in the cerebellum. Immunostaining on cerebellar slice cultures indicates that NCX is widely expressed in the cerebellum, including expression in Purkinje cells. The pharmacological blockade of the forward mode of NCX (Ca 2+ efflux mode) by bepridil moderately inhibited growth and development of Purkinje cell dendritic arbor in cerebellar slice cultures. However, the blockade of the reverse mode (Ca 2+ influx mode) by KB-R7943 severely reduced the dendritic arbor and induced a morphological change with thickened distal dendrites. The effect of KB-R7943 on dendritic growth was unrelated to the activity of voltage-gated calcium channels and was also apparent in the absence of bioelectrical activity indicating that it was mediated by NCX expressed in Purkinje cells. We have used additional NCX inhibitors including CB-DMB, ORM-10103, SEA0400, YM-244769, and SN-6 which have higher specificity for NCX isoforms and target either the forward, reverse, or both modes. These inhibitors caused a strong dendritic reduction similar to that seen with KB-R7943, but did not elicit thickening of distal dendrites. Our findings indicate that disturbance of the NCX-dependent calcium transport in Purkinje cells induces a reduction of dendritic arbor, which is presumably caused by changes in the calcium handling, and underline the importance of the calcium equilibrium for the dendritic development in cerebellar Purkinje cells. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

[Quantitative analysis of the structure of neuronal dendritic spines in the striatum using the Leitz-ASM system].

PubMed

Leontovich, T A; Zvegintseva, E G

1985-10-01

Two principal classes of striatum long axonal neurons (sparsely ramified reticular cells and densely ramified dendritic cells) were analyzed quantitatively in four animal species: hedgehog, rabbit, dog and monkey. The cross section area, total dendritic length and the area of dendritic field were measured using "LEITZ-ASM" system. Classes of neurons studied were significantly different in dogs and monkeys, while no differences were noted between hedgehog and rabbit. Reticular neurons of different species varied much more than dendritic ones. Quantitative analysis has revealed the progressive increase in the complexity of dendritic tree in mammals from rabbit to monkey.

Migration of Toxoplasma gondii–Infected Dendritic Cells across Human Retinal Vascular Endothelium

PubMed Central

Furtado, João M.; Bharadwaj, Arpita S.; Ashander, Liam M.; Olivas, Antoinette; Smith, Justine R.

2012-01-01

Purpose. Toxoplasma gondii, the parasite responsible for ocular toxoplasmosis, accesses the retina from the bloodstream. We investigated the dendritic cell as a potential taxi for T. gondii tachyzoites moving across the human retinal endothelium, and examined the participation of adhesion molecules and chemokines in this process. Methods. CD14-positive monocytes were isolated from human peripheral blood by antibody-mediated cell enrichment, and cultured in granulocyte-macrophage colony-stimulating factor and interleukin-4 to generate dendritic cells. Transmigration assays were performed over 18 hours in transwells seeded with human retinal endothelial cells and using dendritic cells exposed to laboratory or natural strains of T. gondii tachyzoites. Parasites were tagged with yellow fluorescent protein to verify infection. In some experiments, endothelial monolayers were preincubated with antibody directed against adhesion molecules, or chemokine was added to lower chambers of transwells. Results. Human monocyte–derived dendritic cell preparations infected with laboratory or natural strain T. gondii tachyzoites transmigrated in larger numbers across simulated human retinal endothelium than uninfected dendritic cells (P ≤ 0.0004 in 5 of 6 experiments). Antibody blockade of intercellular adhesion molecule (ICAM)–1, vascular cell adhesion molecule (VCAM)–1, and activated leukocyte cell adhesion molecule (ALCAM) inhibited transmigration (P ≤ 0.007), and CCL21 or CXCL10 increased transmigration (P ≤ 0.031). Conclusions. Transmigration of human dendritic cells across retinal endothelium is increased following infection with T. gondii. Movement may be impacted by locally produced chemokines and is mediated in part by ICAM-1, VCAM-1, and ALCAM. These findings have implications for development of novel therapeutics aimed at preventing retinal infection by T. gondii. PMID:22952125

Lung dendritic cells are stimulated by ultrafine particles and play a key role in particle adjuvant activity.

PubMed

de Haar, Colin; Kool, Mirjam; Hassing, Ine; Bol, Marianne; Lambrecht, Bart N; Pieters, Raymond

2008-05-01

The adjuvant activity of air pollution particles on allergic airway sensitization is well known, but the cellular mechanisms underlying this adjuvant potential are not clear. We sough to study the role of dendritic cells and the costimulatory molecules CD80 and CD86 in the adjuvant activity of ultrafine carbon black particles (CBP). The proliferation of CFSE-labeled DO11.10 CD4 cells was studied after intranasal exposure to particles and ovalbumin (OVA). Next the frequency of myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells and their expression of CD80 and CD86 were studied in the peribronchial lymph nodes (PBLNs). The expression of costimulatory molecules was also studied on bone marrow-derived mDCs after exposure to CBPs in vitro, and the importance of costimulation in CBP adjuvant activity was assessed by using CD80/CD86-deficient mice or cytotoxic T lymphocyte-associated antigen 4 (CTLA4)-Ig in vivo. Our data show that CBPs plus OVA caused proliferation of DO11.10 CD4 cells and high levels of cytokine production in the PBLNs. Furthermore, the combined CBP plus OVA exposure increased the number of mDCs and expression of costimulatory molecules in the PBLNs. In addition, CBPs upregulated the expression of CD80/CD86 molecules on dendritic cells in vitro, which are necessary for the particle adjuvant effects in vivo. Together this study shows the importance of dendritic cells and costimulation in particle adjuvant activity. Furthermore, we show for the first time that CBPs can also directly induce maturation of dendritic cells.

Dendritic branching angles of pyramidal cells across layers of the juvenile rat somatosensory cortex.

PubMed

Leguey, Ignacio; Bielza, Concha; Larrañaga, Pedro; Kastanauskaite, Asta; Rojo, Concepción; Benavides-Piccione, Ruth; DeFelipe, Javier

2016-09-01

The characterization of the structural design of cortical microcircuits is essential for understanding how they contribute to function in both health and disease. Since pyramidal neurons represent the most abundant neuronal type and their dendritic spines constitute the major postsynaptic elements of cortical excitatory synapses, our understanding of the synaptic organization of the neocortex largely depends on the available knowledge regarding the structure of pyramidal cells. Previous studies have identified several apparently common rules in dendritic geometry. We study the dendritic branching angles of pyramidal cells across layers to further shed light on the principles that determine the geometric shapes of these cells. We find that the dendritic branching angles of pyramidal cells from layers II-VI of the juvenile rat somatosensory cortex suggest common design principles, despite the particular morphological and functional features that are characteristic of pyramidal cells in each cortical layer. J. Comp. Neurol. 524:2567-2576, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Calcium transient prevalence across the dendritic arbour predicts place field properties.

PubMed

Sheffield, Mark E J; Dombeck, Daniel A

2015-01-08

Establishing the hippocampal cellular ensemble that represents an animal's environment involves the emergence and disappearance of place fields in specific CA1 pyramidal neurons, and the acquisition of different spatial firing properties across the active population. While such firing flexibility and diversity have been linked to spatial memory, attention and task performance, the cellular and network origin of these place cell features is unknown. Basic integrate-and-fire models of place firing propose that such features result solely from varying inputs to place cells, but recent studies suggest instead that place cells themselves may play an active role through regenerative dendritic events. However, owing to the difficulty of performing functional recordings from place cell dendrites, no direct evidence of regenerative dendritic events exists, leaving any possible connection to place coding unknown. Using multi-plane two-photon calcium imaging of CA1 place cell somata, axons and dendrites in mice navigating a virtual environment, here we show that regenerative dendritic events do exist in place cells of behaving mice, and, surprisingly, their prevalence throughout the arbour is highly spatiotemporally variable. Furthermore, we show that the prevalence of such events predicts the spatial precision and persistence or disappearance of place fields. This suggests that the dynamics of spiking throughout the dendritic arbour may play a key role in forming the hippocampal representation of space.

Calcium transient prevalence across the dendritic arbor predicts place field properties

PubMed Central

Sheffield, Mark E. J.; Dombeck, Daniel A.

2014-01-01

Establishing the hippocampal cellular ensemble that represents an animal’s environment involves the emergence and disappearance of place fields in specific CA1 pyramidal neurons1–4, and the acquisition of different spatial firing properties across the active population5. While such firing flexibility and diversity have been linked to spatial memory, attention and task performance6,7, the cellular and network origin of these place cell features is unknown. Basic integrate-and-fire models of place firing propose that such features result solely from varying inputs to place cells8,9, but recent studies3,10 instead suggest that place cells themselves may play an active role through regenerative dendritic events. However, due to the difficulty of performing functional recordings from place cell dendrites, no direct evidence of regenerative dendritic events exists, leaving any possible connection to place coding unknown. Using multi-plane two-photon calcium imaging of CA1 place cell somata, axons, and dendrites in mice navigating a virtual environment, we show that regenerative dendritic events do exist in place cells of behaving mice and, surprisingly, their prevalence throughout the arbor is highly spatiotemporally variable. Further, we show that the prevalence of such events predicts the spatial precision and persistence or disappearance of place fields. This suggests that the dynamics of spiking throughout the dendritic arbor may play a key role in forming the hippocampal representation of space. PMID:25363782

Morphological characterization of rat entorhinal neurons in vivo: soma-dendritic structure and axonal domains.

PubMed

Lingenhöhl, K; Finch, D M

1991-01-01

We used in vivo intracellular labeling with horseradish peroxidase in order to study the soma-dendritic morphology and axonal projections of rat entorhinal neurons. The cells responded to hippocampal stimulation with inhibitory postsynaptic potentials, and thus likely received direct or indirect hippocampal input. All cells (n = 24) showed extensive dendritic domains that extended in some cases for more than 1 mm. The dendrites of layer II neurons were largely restricted to layers I and II or layers I-III, while the dendrites of deeper cells could extend through all cortical layers. Computed 3D rotations showed that the basilar dendrites of deep pyramids extended roughly parallel to the cortical layering, and that they were mostly confined to the layer containing the soma and layers immediately adjacent. Total dendritic lengths averaged 9.8 mm +/- 3.8 (SD), and ranged from 5 mm to more than 18 mm. Axonal processes could be visualized in 21 cells. Most of these showed axonal branching within the entorhinal cortex, sometimes extensive. Efferent axonal domains were reconstructed in detail in 3 layer II stellate cells. All 3 projected axons across the subicular complex to the dentate gyrus. One of these cells showed an extensive net-like axonal domain that also projected to several other structures, including the hippocampus proper, subicular complex, and the amygdalo-piriform transition area. The axons of layer III and IV cells projected to the angular bundle, where they continued in a rostral direction. In contrast to the layer II, III and IV cells, no efferent axonal branches leaving the entorhinal cortex could be visualized in 5 layer V neurons. The data indicate that entorhinal neurons can integrate input from a considerable volume of entorhinal cortex by virtue of their extensive dendritic domains, and provide a further basis for specifying the layers in which cells receive synaptic input. The extensive axonal branching pattern seen in most of the cells would support divergent propagation of their activity.

Democracy-independence trade-off in oscillating dendrites and its implications for grid cells.

PubMed

Remme, Michiel W H; Lengyel, Máté; Gutkin, Boris S

2010-05-13

Dendritic democracy and independence have been characterized for near-instantaneous processing of synaptic inputs. However, a wide class of neuronal computations requires input integration on long timescales. As a paradigmatic example, entorhinal grid fields have been thought to be generated by the democratic summation of independent dendritic oscillations performing direction-selective path integration. We analyzed how multiple dendritic oscillators embedded in the same neuron integrate inputs separately and determine somatic membrane voltage jointly. We found that the interaction of dendritic oscillations leads to phase locking, which sets an upper limit on the timescale for independent input integration. Factors that increase this timescale also decrease the influence that the dendritic oscillations exert on somatic voltage. In entorhinal stellate cells, interdendritic coupling dominates and causes these cells to act as single oscillators. Our results suggest a fundamental trade-off between local and global processing in dendritic trees integrating ongoing signals. Copyright 2010 Elsevier Inc. All rights reserved.

Golgi-type I and Golgi-type II neurons in the ventral anterior thalamic nucleus of the adult human: morphological features and quantitative analysis.

PubMed

Al-Hussain Bani Hani, Saleh M; El-Dwairi, Qasim A; Bataineh, Ziad M; Al-Haidari, Mohammad S; Al-Alami, Jamil

2008-05-01

The morphological and quantitative features of neurons in the adult human ventral anterior thalamic nucleus were studied in Golgi preparations. Two neuronal types were found and their quantitative features were studied. Golgi-type I neurons were medium to large cells with dense dendritic trees and dendritic protrusions and short hair-like appendages. They have somatic mean diameter of 30.8 microm (+/-9.4, n = 85). They have an average 100.3 dendritic branches, 48.97 dendritic branching points, and 58.85 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 3.1 microm (+/-1, n = 80), 1.85 microm (+/-0.8, n = 145), and 1.5 microm (+/-0.4, n = 160), respectively. Golgi-type II neurons were small to medium cells with few sparsely branching dendrites and dendritic stalked appendages with or without terminal swellings. They have somatic mean diameters of 22.2 microm (+/-5.8, n = 120). They have an average 33.76 dendritic branches, 16.49 dendritic branching points, and 21.97 dendritic tips. The mean diameters of their primary, secondary, and tertiary dendrites were 1.6 microm (+/-0.86, n = 70), 1.15 microm (+/-0.55, n = 118), and 1 microm (+/-0.70, n = 95), respectively. These quantitative data may form the basis for further quantitative studies involving aging or some degenerative diseases that may affect cell bodies and/or dendritic trees of the Golgi-type I and/or Golgi-type II thalamic neurons.

Hydrocortisone prevents immunosuppression by interleukin-10+ natural killer cells after trauma-hemorrhage.

PubMed

Roquilly, Antoine; Broquet, Alexis; Jacqueline, Cédric; Masson, Damien; Segain, Jean Pierre; Braudeau, Cecile; Vourc'h, Mickael; Caillon, Jocelyne; Altare, Frédéric; Josien, Regis; Retière, Christelle; Villadangos, Jose; Asehnoune, Karim

2014-12-01

Trauma induces a state of immunosuppression, which is responsible for the development of nosocomial infections. Hydrocortisone reduces the rate of pneumonia in patients with trauma. Because alterations of dendritic cells and natural killer cells play a central role in trauma-induced immunosuppression, we investigated whether hydrocortisone modulates the dendritic cell/natural killer cell cross talk in the context of posttraumatic pneumonia. Experimental study. Research laboratory from an university hospital. Bagg Albino/cJ mice (weight, 20-24 g). First, in an a priori substudy of a multicenter, randomized, double-blind, placebo-controlled trial of hydrocortisone (200 mg/d for 7 d) in patients with severe trauma, we have measured the blood levels of five cytokines (tumor necrosis factor-α, interleukin-6, interleukin-10, interleukin-12, interleukin-17) at day 1 and day 8. In a second step, the effects of hydrocortisone on dendritic cell/natural killer cell cross talk were studied in a mouse model of posttraumatic pneumonia. Hydrocortisone (0.6 mg/mice i.p.) was administered immediately after hemorrhage. Twenty-four hours later, the mice were challenged with Staphylococcus aureus (7 × 10 colony-forming units). Using sera collected during a multicenter study in patients with trauma, we found that hydrocortisone decreased the blood level of interleukin-10, a cytokine centrally involved in the regulation of dendritic cell/natural killer cell cluster. In a mouse model of trauma-hemorrhage-induced immunosuppression, splenic natural killer cells induced an interleukin-10-dependent elimination of splenic dendritic cell. Hydrocortisone treatment reduced this suppressive function of natural killer cells and increased survival of mice with posthemorrhage pneumonia. The reduction of the interleukin-10 level in natural killer cells by hydrocortisone was partially dependent on the up-regulation of glucocorticoid-induced tumor necrosis factor receptor-ligand (TNFsf18) on dendritic cell. These data demonstrate that trauma-induced immunosuppression is characterized by an interleukin-10-dependent elimination of dendritic cell by natural killer cells and that hydrocortisone improves outcome by limiting this immunosuppressive feedback loop.

Multivalent glycopeptide dendrimers for the targeted delivery of antigens to dendritic cells.

PubMed

García-Vallejo, Juan J; Ambrosini, Martino; Overbeek, Annemieke; van Riel, Wilhelmina E; Bloem, Karien; Unger, Wendy W J; Chiodo, Fabrizio; Bolscher, Jan G; Nazmi, Kamran; Kalay, Hakan; van Kooyk, Yvette

2013-04-01

Dendritic cells are the most powerful type of antigen presenting cells. Current immunotherapies targeting dendritic cells have shown a relative degree of success but still require further improvement. One of the most important issues to solve is the efficiency of antigen delivery to dendritic cells in order to achieve an appropriate uptake, processing, and presentation to Ag-specific T cells. C-type lectins have shown to be ideal receptors for the targeting of antigens to dendritic cells and allow the use of their natural ligands - glycans - instead of antibodies. Amongst them, dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) is an interesting candidate due to its biological properties and the availability of its natural carbohydrate ligands. Using Le(b)-conjugated poly(amido amine) (PAMAM) dendrimers we aimed to characterize the optimal level of multivalency necessary to achieve the desired internalization, lysosomal delivery, Ag-specific T cell proliferation, and cytokine response. Increasing DC-SIGN ligand multivalency directly translated in an enhanced binding, which might also be interesting for blocking purposes. Internalization, routing to lysosomal compartments, antigen presentation and cytokine response could be optimally achieved with glycopeptide dendrimers carrying 16-32 glycan units. This report provides the basis for the design of efficient targeting of peptide antigens for the immunotherapy of cancer, autoimmunity and infectious diseases. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dendritic cells cross-present HIV antigens from live as well as apoptotic infected CD4+ T lymphocytes

NASA Astrophysics Data System (ADS)

Marañón, Concepción; Desoutter, Jean-François; Hoeffel, Guillaume; Cohen, William; Hanau, Daniel; Hosmalin, Anne

2004-04-01

A better understanding of the antigen presentation pathways that lead to CD8+ T cell recognition of HIV epitopes in vivo is needed to achieve better immune control of HIV replication. Here, we show that cross-presentation of very small amounts of HIV proteins from apoptotic infected CD4+ T lymphocytes by dendritic cells to CD8+ T cells is much more efficient than other known HIV presentation pathways, i.e., direct presentation of infectious virus or cross-presentation of defective virus. Unexpectedly, dendritic cells also take up actively antigens into endosomes from live infected CD4+ T lymphocytes and cross-present them as efficiently as antigens derived from apoptotic infected cells. Moreover, live infected CD4+ T cells costimulate cross-presenting dendritic cells in the process. Therefore, dendritic cells can present very small amounts of viral proteins from infected T cells either after apoptosis, which is frequent during HIV infection, or not. Thus, if HIV expression is transiently induced while costimulation is enhanced (for instance after IL-2 and IFN immune therapy), this HIV antigen presentation pathway could be exploited to eradicate latently infected reservoirs, which are poorly recognized by patients' immune systems.

[Phenotypes of dendritic cells in central lymph of healthy rabbits and during correction of experimental atherosclerosis].

PubMed

Kuznetsov, A V

1992-09-01

Dendritic cells of central lymph of rabbits have been identified according to the form of the cell body, characteristics of formation and branchiness of its processes in health, in atherosclerosis, its correction with radon, polyphenol preparations made of Sanguisorba officinalis and in combination of the latter. Two main types of dendritic cells have been distinguished. Type I is characterized by a rounded body with clear outlines, protrusions and one compact process. Such cells are often found in lymph of intact animals. Type II has a cell body of various forms with two and more compact or branching processes. This type is mainly detected in atherosclerosis and its correction. The prevalence of the above phenotypes of dendritic cells is attributed to the response of the immune system to atherosclerosis and its correction.

Method for evaluation of human induced pluripotent stem cell quality using image analysis based on the biological morphology of cells.

PubMed

Wakui, Takashi; Matsumoto, Tsuyoshi; Matsubara, Kenta; Kawasaki, Tomoyuki; Yamaguchi, Hiroshi; Akutsu, Hidenori

2017-10-01

We propose an image analysis method for quality evaluation of human pluripotent stem cells based on biologically interpretable features. It is important to maintain the undifferentiated state of induced pluripotent stem cells (iPSCs) while culturing the cells during propagation. Cell culture experts visually select good quality cells exhibiting the morphological features characteristic of undifferentiated cells. Experts have empirically determined that these features comprise prominent and abundant nucleoli, less intercellular spacing, and fewer differentiating cellular nuclei. We quantified these features based on experts' visual inspection of phase contrast images of iPSCs and found that these features are effective for evaluating iPSC quality. We then developed an iPSC quality evaluation method using an image analysis technique. The method allowed accurate classification, equivalent to visual inspection by experts, of three iPSC cell lines.

Modulation of human Th17 cell responses through complement receptor 3 (CD11 b/CD18) ligation on monocyte-derived dendritic cells.

PubMed

Nowatzky, Johannes; Manches, Olivier; Khan, Shaukat Ali; Godefroy, Emmanuelle; Bhardwaj, Nina

2018-06-13

Apoptotic cell receptors contribute to the induction of tolerance by modulating dendritic cell function following the uptake of apoptotic cells or microparticles. Dendritic cells that have bound or ingested apoptotic cells produce only low amounts of pro-inflammatory cytokines and fail to prime effector T cell responses. Specifically, ligation of the apoptotic cell receptor CR3 (CD11 b/CD18) on human monocyte-derived dendritic cells (moDC) down-modates proinflammatory cytokine secretion, but the consequences for human Th17 cell homeostasis and effector responses remain unknown. Here, we aimed to establish whether CD11b-ligated moDC modulate Th17 cell effector reponses to assess their potential for future use in moDC-based suppressive immunotherapy. We generated a bead-based surrogate system to target CD11b on monocyte-derived human dendritic cells and examined the effects of CD11b ligation on Th17-skewing cytokine secretion, priming, expansion and functional plasticity in DC/T cell co-culture systems at the poly- and monoclonal level. We show that Th17 cell expansion within the human memory CD4 + T cell compartment was efficiently constricted by targeting the CD11b receptor on moDC. This tolerogenic capacity was primarily dependent on cytokine skewing. Furthermore, ligation of CD11b on healthy homozygous carriers of the rs11143679 (ITGAM) variant - a strong genetic susceptibility marker for human systemic lupus erythematosus - also down-modulated the secretion of Th17-skewing cytokines. Overall, our findings underline the potential of targeted CD11b ligation on human dendritic cells for the engineering of suppressive immunotherapy for Th17-related autoimmune disorders. Copyright © 2018 Elsevier Ltd. All rights reserved.

Myeloblastic and lymphoblastic markers in acute undifferentiated leukemia and chronic myelogenous leukemia in blast crisis.

PubMed

Shumak, K H; Baker, M A; Taub, R N; Coleman, M S

1980-11-01

Blast cells were obtained from 17 patients with acute undifferentiated leukemia and 13 patients with chronic myelogenous leukemia in blast crisis. The blasts were tested with anti-i serum in cytotoxicity tests and with antisera to myeloblastic leukemia-associated antigens in immunofluorescence tests. The terminal deoxynucleotidyl transferase (TDT) content of the blasts was also measured. Lymphoblasts react strongly with anti-i, do not react with anti-myeloblast serum, and have high levels of TDT; myeloblasts react weakly with anti-i, do not react with anti-myeloblast serum, and have very low levels of TDT. Of the 17 patients with acute undifferentiated leukemia, there were six with blasts which reacted like lymphoblasts, six with blasts which reacted like myeloblasts, and five with blasts bearing different combinations of these lymphoblastic and myeloblastic markers. Eight of the 11 patients with lymphoblastic or mixed lymphoblastic-myeloblastic markers, but only one of the six with myeloblastic markers, achieved complete or partial remission in response to therapy. Thus, in acute undifferentiated leukemia, classification of blasts with these markers may be of prognostic value. Of the 13 patients with chronic myelogenous leukemia in blast crises, the markers were concordant (for myeloblasts) in only two cases. Three of the 13 patients had TDT-positive blasts, but the reactions of these cells with anti-i and with anti-myeloblast serum differed from those seen with lymphoblasts from patients with acute lymphoblastic leukemia. Although the cell involved in "lymphoid" blast crisis of chronic myelogenous leukemia is similar in many respects to that involved in acute lymphoblastic leukemia, these cells are not identical.

Contrast-enhanced CT features of hepatoblastoma: Can we predict histopathology?

PubMed

Baheti, Akshay D; Luana Stanescu, A; Li, Ning; Chapman, Teresa

Hepatoblastoma is the most common hepatic malignancy occurring in the pediatric population. Intratumoral cellular behavior varies, and the small-cell undifferentiated histopathology carries a poorer prognosis than other tissue subtypes. Neoadjuvant chemotherapy is recommended for this tumor subtype prior to surgical resection in most cases. Early identification of tumors with poor prognosis could have a significant clinical impact. Objective The aim of this work was to identify imaging features of small-cell undifferentiated subtype hepatoblastoma that can help distinguish this subtype from more favorable tumors and potentially guide the clinical management. We also sought to characterize contrast-enhanced CT (CECT) features of hepatoblastoma that correlate with metastatic disease and patient outcome. Our study included 34 patients (24 males, 10 females) with a mean age of 16months (range: 0-46months) with surgically confirmed hepatoblastoma and available baseline abdominal imaging by CECT. Clinical data and CT abdominal images were retrospectively analyzed. Five tumors with small-cell undifferentiated components were identified. All of these tumors demonstrated irregular margins on CT imaging. Advanced PRETEXT stage, vascular invasion and irregular margins were associated with metastatic disease and decreased survival. Capsular retraction was also significantly associated with decreased survival. Irregular tumor margins demonstrated statistically significant association with the presence of small-cell undifferentiated components. No other imaging feature showed statistically significant association. Tumor margin irregularity, vascular invasion, capsular retraction, and PRETEXT stage correlate with worse patient outcomes. Irregular tumor margin was the only imaging feature significantly associated with more aggressive tumor subtype. Copyright © 2017 Elsevier Inc. All rights reserved.

IMMUNOHISTOCHEMICAL ANALYSIS FOR CD21, CD35, CALDESMON AND S100 PROTEIN ON DENDRITIC CELLS TYPES IN ORAL LYMPHOMAS

PubMed Central

Mesquita, Ricardo Alves; de Araújo, Vera Cavalcanti; Paes, Roberto Antônio Pinto; Nunes, Fábio Daumas; de Sousa, Suzana Cantanhede Orsini Machado

2009-01-01

Objective: Follicular dendritic cells (FDCs) and interdigitating dendritic cells (IDCs) are dendritic cells found in lymphoid follicles, reactive follicles and in lymphomas. The goal of this study was to evaluate the presence and distribution of FDCs and IDCs in oral lymphomas. Material and Methods: Immunohistochemistry reactions were applied to 50 oral lymphomas using the antibodies anti-CD21, anti-CD35 and anti-caldesmon to FDCs, and anti-S100 protein to IDCs. Caldesmon+/FDCs and S100+/IDCs were quantified in Imagelab® software. Results: FDCs revealed by CD21 and CD35 were positively stained in two cases of diffuse large B-cell lymphoma, one MALT lymphoma, and in one case of mantle cell lymphoma. FDCs were immunopositive to caldesmon in all cases, as well as IDCs to S100 protein. Burkitt lymphoma presented a lower amount of caldesmon+/FDCs and S100+/IDCs than diffuse large B-cell lymphoma and plasmablastic lymphoma of the oral mucosa type. Conclusions: The microenvironment determined by neoplastic lymphoid cells in oral lymphomas is responsible by the development and expression of dendritic cells types. PMID:19466261

Heterogeneous integration of adult-generated granule cells into the epileptic brain

PubMed Central

Murphy, Brian L.; Pun, Raymund Y.K.; Yin, Hulian; Faulkner, Christian R.; Loepke, Andreas W.; Danzer, Steve C.

2011-01-01

The functional impact of adult-generated granule cells in the epileptic brain is unclear, with data supporting both protective and maladaptive roles. These conflicting findings could be explained if new granule cells integrate heterogeneously, with some cells taking neutral or adaptive roles, while others contribute to recurrent circuitry supporting seizures. Here, we tested this hypothesis by completing detailed morphological characterizations of age- and experience-defined cohorts of adult-generated granule cells from transgenic mice. The majority of newborn cells exposed to an epileptogenic insult exhibited reductions in dendritic spine number, suggesting reduced excitatory input to these cells. A significant subset, however, exhibited higher spine numbers. These latter cells tended to have enlarged cell bodies, long basal dendrites or both. Moreover, cells with basal dendrites received significantly more recurrent mossy fiber input through their apical dendrites, indicating that these cells are robustly integrated into the pathological circuitry of the epileptic brain. These data imply that newborn cells play complex – and potentially conflicting – roles in epilepsy. PMID:21209195

Pyramidal neurons in the septal and temporal CA1 field of the human and hedgehog tenrec hippocampus.

PubMed

Liagkouras, Ioannis; Michaloudi, Helen; Batzios, Christos; Psaroulis, Dimitrios; Georgiadis, Marios; Künzle, Heinz; Papadopoulos, Georgios C

2008-07-07

The present study examines comparatively the cellular density of disector-counted/Nissl-stained CA1 pyramidal neurons and the morphometric characteristics (dendritic number/length, spine number/density and Sholl-counted dendritic branch points/20 microm) of the basal and apical dendritic systems of Golgi-impregnated CA1 neurons, in the septal and temporal hippocampus of the human and hedgehog tenrec brain. The obtained results indicate that in both hippocampal parts the cellular density of the CA1 pyramidal neurons is lower in human than in tenrec. However, while the human pyramidal cell density is higher in the septal hippocampal part than in the temporal one, in the tenrec the density of these cells is higher in the temporal part. The dendritic tree of the CA1 pyramidal cells, more developed in the septal than in temporal hippocampus in both species studied, is in general more complex in the human hippocampus. The basal and the apical dendritic systems exhibit species related morphometric differences, while dendrites of different orders exhibit differences in their number and length, and in their spine density. Finally, in both species, as well as hippocampal parts and dendritic systems, changes of dendritic morphometric features along ascending dendritic orders fluctuate in a similar way, as do the number of dendritic branch points in relation to the distance from the neuron soma.

Dendritic cell and histiocytic neoplasms: biology, diagnosis, and treatment.

PubMed

Dalia, Samir; Shao, Haipeng; Sagatys, Elizabeth; Cualing, Hernani; Sokol, Lubomir

2014-10-01

Dendritic and histiocytic cell neoplasms are rare malignancies that make up less than 1% of all neoplasms arising in lymph nodes or soft tissues. These disorders have distinctive disease biology, clinical presentations, pathology, and unique treatment options. Morphology and immunohistochemistry evaluation by a hematopathologist remains key for differentiating between these neoplasms. In this review, we describe tumor biology, clinical features, pathology, and treatment of follicular dendritic cell sarcoma, interdigitating dendritic cell sarcoma, indeterminate dendritic cell sarcoma, histiocytic sarcoma, fibroblastic reticular cell tumors, and disseminated juvenile xanthogranuloma. A literature search for articles published between 1990 and 2013 was undertaken. Articles are reviewed and salient findings are systematically described. Patients with dendritic cell and histiocytic neoplasms have distinct but variable clinical presentations; however, because many tumors have recently been recognized, their true incidence is uncertain. Although the clinical features can present in many organs, most occur in the lymph nodes or skin. Most cases are unifocal and solitary presentations have good prognoses with surgical resection. The role of adjuvant therapy in these disorders remains unclear. In cases with disseminated disease, prognosis is poor and data on treatment options are limited, although chemotherapy and referral to a tertiary care center should be considered. Excisional biopsy is the preferred method of specimen collection for tissue diagnosis, and immunohistochemistry is the most important diagnostic method for differentiating these disorders from other entities. Dendritic cell and histiocytic cell neoplasms are rare hematological disorders with variable clinical presentations and prognoses. Immunohistochemistry remains important for diagnosis. Larger pooled analyses or clinical trials are needed to better understand optimal treatment options in these rare disorders. Whenever possible, patients should be referred to a tertiary care center for disease management.

Effects of all-trans-retinoic acid on human SH-SY5Y neuroblastoma as in vitro model in neurotoxicity research.

PubMed

Cheung, Yuen-Ting; Lau, Way Kwok-Wai; Yu, Man-Shan; Lai, Cora Sau-Wan; Yeung, Sze-Chun; So, Kwok-Fai; Chang, Raymond Chuen-Chung

2009-01-01

Human neuroblastoma SH-SY5Y is a dopaminergic neuronal cell line which has been used as an in vitro model for neurotoxicity experiments. Although the neuroblastoma is usually differentiated by all-trans-retinoic acid (RA), both RA-differentiated and undifferentiated SH-SY5Y cells have been used in neuroscience research. However, the changes in neuronal properties triggered by RA as well as the subsequent responsiveness to neurotoxins have not been comprehensively studied. Therefore, we aim to re-evaluate the differentiation property of RA on this cell line. We hypothesize that modulation of signaling pathways and neuronal properties during RA-mediated differentiation in SH-SY5Y cells can affect their susceptibility to neurotoxins. The differentiation property of RA was confirmed by showing an extensive outgrowth of neurites, increased expressions of neuronal nuclei, neuron specific enolase, synaptophysin and synaptic associated protein-97, and decreased expression of inhibitor of differentiation-1. While undifferentiated SH-SY5Y cells were susceptible to 6-OHDA and MPP+, RA-differentiation conferred SH-SY5Y cells higher tolerance, potentially by up-regulating survival signaling, including Akt pathway as inhibition of Akt removed RA-induced neuroprotection against 6-OHDA. As a result, the real toxicity cannot be revealed in RA-differentiated cells. Therefore, undifferentiated SH-SY5Y is more appropriate for studying neurotoxicity or neuroprotection in experimental Parkinson's disease research.

Paclitaxel, Polyglutamate Paclitaxel, or Observation in Treating Patients With Stage III or Stage IV Ovarian Epithelial, Peritoneal Cancer, or Fallopian Tube Cancer

ClinicalTrials.gov

2017-05-03

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

The Global Spike: Conserved Dendritic Properties Enable Unique Ca2+ Spike Generation in Low-Threshold Spiking Neurons.

PubMed

Connelly, William M; Crunelli, Vincenzo; Errington, Adam C

2015-11-25

Low-threshold Ca(2+) spikes (LTS) are an indispensible signaling mechanism for neurons in areas including the cortex, cerebellum, basal ganglia, and thalamus. They have critical physiological roles and have been strongly associated with disorders including epilepsy, Parkinson's disease, and schizophrenia. However, although dendritic T-type Ca(2+) channels have been implicated in LTS generation, because the properties of low-threshold spiking neuron dendrites are unknown, the precise mechanism has remained elusive. Here, combining data from fluorescence-targeted dendritic recordings and Ca(2+) imaging from low-threshold spiking cells in rat brain slices with computational modeling, the cellular mechanism responsible for LTS generation is established. Our data demonstrate that key somatodendritic electrical conduction properties are highly conserved between glutamatergic thalamocortical neurons and GABAergic thalamic reticular nucleus neurons and that these properties are critical for LTS generation. In particular, the efficiency of soma to dendrite voltage transfer is highly asymmetric in low-threshold spiking cells, and in the somatofugal direction, these neurons are particularly electrotonically compact. Our data demonstrate that LTS have remarkably similar amplitudes and occur synchronously throughout the dendritic tree. In fact, these Ca(2+) spikes cannot occur locally in any part of the cell, and hence we reveal that LTS are generated by a unique whole-cell mechanism that means they always occur as spatially global spikes. This all-or-none, global electrical and biochemical signaling mechanism clearly distinguishes LTS from other signals, including backpropagating action potentials and dendritic Ca(2+)/NMDA spikes, and has important consequences for dendritic function in low-threshold spiking neurons. Low-threshold Ca(2+) spikes (LTS) are critical for important physiological processes, including generation of sleep-related oscillations, and are implicated in disorders including epilepsy, Parkinson's disease, and schizophrenia. However, the mechanism underlying LTS generation in neurons, which is thought to involve dendritic T-type Ca(2+) channels, has remained elusive due to a lack of knowledge of the dendritic properties of low-threshold spiking cells. Combining dendritic recordings, two-photon Ca(2+) imaging, and computational modeling, this study reveals that dendritic properties are highly conserved between two prominent low-threshold spiking neurons and that these properties underpin a whole-cell somatodendritic spike generation mechanism that makes the LTS a unique global electrical and biochemical signal in neurons. Copyright © 2015 Connelly et al.

FURTHER STUDY OF SOMA, DENDRITE, AND AXON EXCITATION IN SINGLE NEURONS

PubMed Central

Eyzaguirre, Carlos; Kuffler, Stephen W.

1955-01-01

The present investigation continues a previous study in which the soma-dendrite system of sensory neurons was excited by stretch deformation of the peripheral dendrite portions. Recording was done with intracellular leads which were inserted into the cell soma while the neuron was activated orthodromically or antidromically. The analysis was also extended to axon conduction. Crayfish, Procambarus alleni (Faxon) and Orconectes virilis (Hagen), were used. 1. The size and time course of action potentials recorded from the soma-dendrite complex vary greatly with the level of the cell's membrane potential. The latter can be changed over a wide range by stretch deformation which sets up a "generator potential" in the distal portions of the dendrites. If a cell is at its resting unstretched equilibrium potential, antidromic stimulation through the axon causes an impulse which normally overshoots the resting potential and decays into an afternegativity of 15 to 20 msec. duration. The postspike negativity is not followed by an appreciable hyperpolarization (positive) phase. If the membrane potential is reduced to a new steady level a postspike positivity appears and increases linearly over a depolarization range of 12 to 20 mv. in various cells. At those levels the firing threshold of the cell for orthodromic discharges is generally reached. 2. The safety factor for conduction between axon and cell soma is reduced under three unrelated conditions, (a) During the recovery period (2 to 3 msec.) immediately following an impulse which has conducted fully over the cell soma, a second impulse may be delayed, may invade the soma partially, or may be blocked completely. (b) If progressive depolarization is produced by stretch, it leads to a reduction of impulse height and eventually to complete block of antidromic soma invasion, resembling cathodal block, (c) In some cells, when the normal membrane potential is within several millivolts of the relaxed resting state, an antidromic impulse may be blocked and may set up within the soma a local potential only. The local potential can sum with a second one or it may sum with potential changes set up in the dendrites, leading to complete invasion of the soma. Such antidromic invasion block can always be relieved by appropriate stretch which shifts the membrane potential out of the "blocking range" nearer to the soma firing level. During the afterpositivity of an impulse in a stretched cell the membrane potential may fall below or near the blocking range. During that period another impulse may be delayed or blocked. 3. Information regarding activity and conduction in dendrites has been obtained indirectly, mainly by analyzing the generator action under various conditions of stretch. The following conclusions have been reached: The large dendrite branches have similar properties to the cell body from which they arise and carry the same kind of impulses. In the finer distal filaments of even lightly depolarized dendrites, however, no axon type all-or-none conduction occurs since the generator potential persists to a varying degree during antidromic invasion of the cell. With the membrane potential at its resting level the dendrite terminals contribute to the prolonged impulse afternegativity of the soma. 4. Action potentials in impaled axons and in cell bodies have been compared. It is thought that normally the over-all duration of axon impulses is shorter. Local activity during reduction of the safety margin for conduction was studied. 5. An analysis was made of high frequency grouped discharges which occasionally arise in cells. They differ in many essential aspects from the regular discharges set up by the generator action. It is proposed that grouped discharges occur only when invasion of dendrites is not synchronous, due to a delay in excitation spread between soma and dendrites. Each impulse in a group is assumed to be caused by an impulse in at least one of the large dendrite branches. Depolarization of dendrites abolishes the grouped activity by facilitating invasion of the large dendrite branches. PMID:13252238

The DC-SIGN-CD56 interaction inhibits the anti-dendritic cell cytotoxicity of CD56 expressing cells.

PubMed

Nabatov, Alexey A; Raginov, Ivan S

2015-01-01

This study aimed to clarify interactions of the pattern-recognition receptor DC-SIGN with cells from the HIV-infected peripheral blood lymphocyte cultures. Cells from control and HIV-infected peripheral blood lymphocyte cultures were tested for the surface expression of DC-SIGN ligands. The DC-SIGN ligand expressing cells were analyzed for the role of DC-SIGN-ligand interaction in their functionality. In the vast majority of experiments HIV-infected lymphocytes did not express detectable DC-SIGN ligands on their cell surfaces. In contrast, non-infected cells, carrying NK-specific marker CD56, expressed cell surface DC-SIGN ligands. The weakly polysialylated CD56 was identified as a novel DC-SIGN ligand. The treatment of DC-SIGN expressing dendritic cells with anti-DC-SIGN antibodies increased the anti-dendritic cell cytotoxicity of CD56(pos) cells. The treatment of CD56(pos) cells with a peptide, blocking the weakly polysialylated CD56-specifc trans-homophilic interactions, inhibited their anti-dendritic cells cytotoxicity. The interaction between DC-SIGN and CD56 inhibits homotypic intercellular interactions of CD56(pos) cells and protects DC-SIGN expressing dendritic cells against CD56(pos) cell-mediated cytotoxicity. This finding can have an impact on the development of approaches to HIV infection and cancer therapy as well as in transplantation medicine.

Interaction of an opportunistic fungus Purpureocillium lilacinum with human macrophages and dendritic cells.

PubMed

Peixoto, Mariana Lima Perazzini; Santos, Dilvani Oliveira; Souza, Ivy de Castro Campos de; Neri, Eloah Christina Lyrio; Sequeira, Danielly Correa Moreira de; De Luca, Paula Mello; Borba, Cíntia de Moraes

2014-01-01

Purpureocillium lilacinum is emerging as a causal agent of hyalohyphomycosis that is refractory to antifungal drugs; however, the pathogenic mechanisms underlying P. lilacinum infection are not understood. In this study, we investigated the interaction of P. lilacinum conidia with human macrophages and dendritic cells in vitro. Spores of a P. lilacinum clinical isolate were obtained by chill-heat shock. Mononuclear cells were isolated from eight healthy individuals. Monocytes were separated by cold aggregation and differentiated into macrophages by incubation for 7 to 10 days at 37°C or into dendritic cells by the addition of the cytokines human granulocyte-macrophage colony stimulating factor and interleukin-4. Conidial suspension was added to the human cells at 1:1, 2:1, and 5:1 (conidia:cells) ratios for 1h, 6h, and 24h, and the infection was evaluated by Giemsa staining and light microscopy. After 1h interaction, P. lilacinum conidia were internalized by human cells and after 6h contact, some conidia became inflated. After 24h interaction, the conidia produced germ tubes and hyphae, leading to the disruption of macrophage and dendritic cell membranes. The infection rate analyzed after 6h incubation of P. lilacinum conidia with cells at 2:1 and 1:1 ratios was 76.5% and 25.5%, respectively, for macrophages and 54.3% and 19.5%, respectively, for cultured dendritic cells. P. lilacinum conidia are capable of infecting and destroying both macrophages and dendritic cells, clearly demonstrating the ability of this pathogenic fungus to invade human phagocytic cells.

Three-dimensional spatial modeling of spines along dendritic networks in human cortical pyramidal neurons

PubMed Central

Larrañaga, Pedro; Benavides-Piccione, Ruth; Fernaud-Espinosa, Isabel; DeFelipe, Javier; Bielza, Concha

2017-01-01

We modeled spine distribution along the dendritic networks of pyramidal neurons in both basal and apical dendrites. To do this, we applied network spatial analysis because spines can only lie on the dendritic shaft. We expanded the existing 2D computational techniques for spatial analysis along networks to perform a 3D network spatial analysis. We analyzed five detailed reconstructions of adult human pyramidal neurons of the temporal cortex with a total of more than 32,000 spines. We confirmed that there is a spatial variation in spine density that is dependent on the distance to the cell body in all dendrites. Considering the dendritic arborizations of each pyramidal cell as a group of instances of the same observation (the neuron), we used replicated point patterns together with network spatial analysis for the first time to search for significant differences in the spine distribution of basal dendrites between different cells and between all the basal and apical dendrites. To do this, we used a recent variant of Ripley’s K function defined to work along networks. The results showed that there were no significant differences in spine distribution along basal arbors of the same neuron and along basal arbors of different pyramidal neurons. This suggests that dendritic spine distribution in basal dendritic arbors adheres to common rules. However, we did find significant differences in spine distribution along basal versus apical networks. Therefore, not only do apical and basal dendritic arborizations have distinct morphologies but they also obey different rules of spine distribution. Specifically, the results suggested that spines are more clustered along apical than in basal dendrites. Collectively, the results further highlighted that synaptic input information processing is different between these two dendritic domains. PMID:28662210

Three-dimensional spatial modeling of spines along dendritic networks in human cortical pyramidal neurons.

PubMed

Anton-Sanchez, Laura; Larrañaga, Pedro; Benavides-Piccione, Ruth; Fernaud-Espinosa, Isabel; DeFelipe, Javier; Bielza, Concha

2017-01-01

We modeled spine distribution along the dendritic networks of pyramidal neurons in both basal and apical dendrites. To do this, we applied network spatial analysis because spines can only lie on the dendritic shaft. We expanded the existing 2D computational techniques for spatial analysis along networks to perform a 3D network spatial analysis. We analyzed five detailed reconstructions of adult human pyramidal neurons of the temporal cortex with a total of more than 32,000 spines. We confirmed that there is a spatial variation in spine density that is dependent on the distance to the cell body in all dendrites. Considering the dendritic arborizations of each pyramidal cell as a group of instances of the same observation (the neuron), we used replicated point patterns together with network spatial analysis for the first time to search for significant differences in the spine distribution of basal dendrites between different cells and between all the basal and apical dendrites. To do this, we used a recent variant of Ripley's K function defined to work along networks. The results showed that there were no significant differences in spine distribution along basal arbors of the same neuron and along basal arbors of different pyramidal neurons. This suggests that dendritic spine distribution in basal dendritic arbors adheres to common rules. However, we did find significant differences in spine distribution along basal versus apical networks. Therefore, not only do apical and basal dendritic arborizations have distinct morphologies but they also obey different rules of spine distribution. Specifically, the results suggested that spines are more clustered along apical than in basal dendrites. Collectively, the results further highlighted that synaptic input information processing is different between these two dendritic domains.

Input Source and Strength Influences Overall Firing Phase of Model Hippocampal CA1 Pyramidal Cells During Theta: Relevance to REM Sleep Reactivation and Memory Consolidation

PubMed Central

Booth, Victoria; Poe, Gina R.

2005-01-01

In simulation studies using a realistic model CA1 pyramidal cell, we accounted for the shift in mean firing phase from theta cycle peaks to theta cycle troughs during REM sleep reactivation of hippocampal CA1 place cells over several days of growing familiarization with an environment (Poe et al., 2000). Changes in the theta drive between proximal and distal dendritic regions of the cell modulated the theta phase of firing when stimuli were presented at proximal and distal dendritic locations. Stimuli at proximal dendritic sites (proximal to 100 μm from the soma) invoked firing with a significant phase preference at the depolarizing theta peaks, while distal stimuli (> 290 μm from the soma) invoked firing at hyperpolarizing theta troughs. The location-related phase preference depended on active dendritic conductances, a sufficient electrotonic separation between input sites and theta-induced subthreshold membrane potential oscillations in the cell. The simulation results predict that the shift in mean theta phase during REM sleep cellular reactivation could occur through potentiation of distal dendritic (temporo-ammonic) synapses and depotentiation of proximal dendritic (Schaffer collateral) synapses over the course of familiarization. PMID:16411243

The neuronal structure of paramamillary nuclei in Bison bonasus: Nissl and Golgi pictures.

PubMed

Robak, A; Szteyn, S; Równiak, M

1998-01-01

The studies were carried out on the hypothalamus of bison bonasus aged 2 and 3 months. Sections were made by means of Bagiński's technique and Nissl and Klüver-Barrera methods. Four types of neurons were distinguished in the paramamillary nuclei: nucleus supramamillaris (Sm) and nucleus tuberomammillaris pars posterior (Tmp). Type I, small and medium-size, triangular or fusiform cells, which have 2-3 slender, poorly ramified dendrites; typical leptodendritic neurons. Type II, medium size neurons with quadrangular or spindle-shaped perikaryons. Most of them have 3-4 thick dendritic trunks with ramifying relatively long dendrites. These cells show stalked-appearance and possess different appendages sparsely distributed. Type III is similar to type II, but is made of medium-size to large multipolar cells having quadrangular, triangular or fusiform perikaryons and relatively short dendrites. Type IV, small and medium-size, globular cells with 2 or 3 dendritic trunks, which dichotomously subdivide into quaternary dendrites. In all types of neurons, axons emerge from the perikaryon or initial portion of a dendritic trunk. Type I was found in both studied nuclei. Types II and III constitute mainly the nucleus tuberomamillaris pars posterior. Type IV preponderate in the nucleus supramamillaris. The characteristic feature of Tmp cells, in Nissl picture was irregular contour of their somas and clumps of rough Nisls granules, which appear to lie outside the perikaryons. In Sm there were also lightly stained small rounded cells having both small amount of the cytoplasm and tigroid matter.

Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

DTIC Science & Technology

2012-07-01

Mediated by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy PRINCIPAL INVESTIGATOR: David J. Chung, M D , Ph D...CONTRACT NUMBER Evaluation of Immune Responses Mediated by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy 5b...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The purpose of this project is to study the immunomodulatory effect of Listeria on

Dendritic cell immunization route determines CD8+ T cell trafficking to inflamed skin: role for tissue microenvironment and dendritic cells in establishment of T cell-homing subsets.

PubMed

Dudda, Jan C; Simon, Jan C; Martin, Stefan

2004-01-15

The effector/memory T cell pool branches in homing subsets selectively trafficking to organs such as gut or skin. Little is known about the critical factors in the generation of skin-homing CD8+ T cells, although they are crucial effectors in skin-restricted immune responses such as contact hypersensitivity and melanoma defense. In this study, we show that intracutaneous, but not i.v. injection of bone marrow-derived dendritic cells induced skin-homing CD8+ T cells with up-regulated E-selectin ligand expression and effector function in contact hypersensitivity. The skin-homing potential and E-selectin ligand expression remained stable in memory phase without further Ag contact. In contrast, i.p. injection induced T cells expressing the gut-homing integrin alpha(4)beta(7). Although differential expression of these adhesion molecules was strictly associated with the immunization route, the postulated skin-homing marker CCR4 was transiently up-regulated in all conditions. Interestingly, dendritic cells from different tissues effectively induced the corresponding homing markers on T cells in vitro. Our results suggest a crucial role for the tissue microenvironment and dendritic cells in the instruction of T cells for tissue-selective homing and demonstrate that Langerhans cells are specialized to target T cells to inflamed skin.

Dalantercept in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2018-02-13

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Recurrent Uterine Corpus Carcinoma

Brivanib Alaninate in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2017-11-02

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Recurrent Uterine Corpus Carcinoma

The expression and function of cathepsin E in dendritic cells.

PubMed

Chain, Benjamin M; Free, Paul; Medd, Patrick; Swetman, Claire; Tabor, Alethea B; Terrazzini, Nadia

2005-02-15

Cathepsin E is an aspartic proteinase that has been implicated in Ag processing within the class II MHC pathway. In this study, we document the presence of cathepsin E message and protein in human myeloid dendritic cells, the preeminent APCs of the immune system. Cathepsin E is found in a perinuclear compartment, which is likely to form part of the endoplasmic reticulum, and also a peripheral compartment just beneath the cell membrane, with a similar distribution to that of Texas Red-dextran within 2 min of endocytosis. To investigate the function of cathepsin E in processing, a new soluble targeted inhibitor was synthesized by linking the microbial aspartic proteinase inhibitor pepstatin to mannosylated BSA via a cleavable disulfide linker. This inhibitor was shown to block cathepsin D/E activity in cell-free assays and within dendritic cells. The inhibitor blocked the ability of dendritic cells from wild-type as well as cathepsin D-deficient mice to present intact OVA, but not an OVA-derived peptide, to cognate T cells. The data therefore support the hypothesis that cathepsin E has an important nonredundant role in the class II MHC Ag processing pathway within dendritic cells.

Blastic plasmacytoid dendritic cell neoplasm in an elderly woman.

PubMed

Foong, H B B; Chong, M; Taylor, E M; Carlson, J A; Petrella, T

2013-04-01

Blastic plasmacytoid dendritic cell neoplasm (a.k.a. NK cell lymphoma, CD4+CD56+ haematodermic neoplasm) is a rare aggressive tumour that arises from plasmacytoid dendritic cell precursors. We report the first case from Malaysia of a 79-year-old Chinese woman who presented with purpuric plaques and nodules produced by pleomorphic CD4+, CD56+, CD68+, CD123+ and CD303+, but CD2APmononuclear cell infiltrates. Leukemic dissemination occurred and she succumbed to disease without treatment 4 weeks after diagnosis and 9 months after onset of cutaneous disease.

Lactobacillus delbrueckii subsp lactis CIDCA 133 modulates response of human epithelial and dendritic cells infected with Bacillus cereus.

PubMed

Rolny, I S; Tiscornia, I; Racedo, S M; Pérez, P F; Bollati-Fogolín, M

2016-11-30

It is known that probiotic microorganisms are able to modulate pathogen virulence. This ability is strain dependent and involves multiple interactions between microorganisms and relevant host's cell populations. In the present work we focus on the effect of a potentially probiotic lactobacillus strain (Lactobacillus delbrueckii subsp. lactis CIDCA 133) in an in vitro model of Bacillus cereus infection. Our results showed that infection of intestinal epithelial HT-29 cells by B. cereus induces nuclear factor kappa B (NF-κB) pathway. Noteworthy, the presence of strain L. delbrueckii subsp.lactis CIDCA 133 increases stimulation. However, B. cereus-induced interleukin (IL)-8 production by epithelial cells is partially abrogated by L. delbrueckii subsp. lactis CIDCA 133. These findings suggest that signalling pathways other than that of NF-κB are involved. In a co-culture system (HT-29 and monocyte-derived dendritic cells), B. cereus was able to translocate from the epithelial (upper) to the dendritic cell compartment (lower). This translocation was partially abrogated by the presence of lactobacilli in the upper compartment. In addition, infection of epithelial cells in the co-culture model, led to an increase in the expression of CD86 by dendritic cells. This effect could not be modified in the presence of lactobacilli. Interestingly, infection of enterocytes with B. cereus triggers production of proinflammatory cytokines by dendritic cells (IL-8, IL-6 and tumour necrosis factor alpha (TNF-α)). The production of TNF-α (a protective cytokine in B. cereus infections) by dendritic cells was increased in the presence of lactobacilli. The present work demonstrates for the first time the effect of L. delbrueckii subsp. lactis CIDCA 133, a potentially probiotic strain, in an in vitro model of B. cereus infection. The presence of the probiotic strain modulates cell response both in infected epithelial and dendritic cells thus suggesting a possible beneficial effect of selected lactobacilli strains on the course of B. cereus infection.

Feline atopic dermatitis. A model for Langerhans cell participation in disease pathogenesis.

PubMed

Roosje, P J; Whitaker-Menezes, D; Goldschmidt, M H; Moore, P F; Willemse, T; Murphy, G F

1997-10-01

Atopic dermatitis is a disorder characterized by cutaneous exanthemata as a consequence of exaggerated eczematous reactions to topical and systemic allergens. Langerhans cells, expressing CD1a and HLA-DR, and dermal dendritic cells, expressing HLA-DR, are known to be potent antigen-presenting cells and are thought to play an important role in the pathogenesis of atopic dermatitis. The immunophenotype of lesional skin in atopic dermatitis in humans involves increased numbers of CD1a+/MHC class II+ dendritic cells in addition to activated T cells, mast cells, and macrophages. To establish feline skin as a model for the study of human atopic dermatitis, and to elucidate the role of dendritic cells in feline atopic dermatitis, we investigated the presence of CD1a+ cells and MHC class II+ cells in the epidermis and dermis of lesional feline skin and in skin of healthy control animals. Immunohistochemistry revealed that MHC class II+ epidermal dendritic cells were CD1a+ in normal feline skin and significantly increased numbers of CD1a+ cells and MHC class II+ cells were present in the epidermis and dermis of lesional skin. These data provide the first correlative documentation of CD1a expression by feline dendritic cells containing Birbeck granules, and indicate the utility of feline skin in the study of human cutaneous atopy.

Abrogation of E-cadherin-mediated cell-cell contact in mouse embryonic stem cells results in reversible LIF-independent self-renewal.

PubMed

Soncin, Francesca; Mohamet, Lisa; Eckardt, Dominik; Ritson, Sarah; Eastham, Angela M; Bobola, Nicoletta; Russell, Angela; Davies, Steve; Kemler, Rolf; Merry, Catherine L R; Ward, Christopher M

2009-09-01

We have previously demonstrated that differentiation of embryonic stem (ES) cells is associated with downregulation of cell surface E-cadherin. In this study, we assessed the function of E-cadherin in mouse ES cell pluripotency and differentiation. We show that inhibition of E-cadherin-mediated cell-cell contact in ES cells using gene knockout (Ecad(-/-)), RNA interference (EcadRNAi), or a transhomodimerization-inhibiting peptide (CHAVC) results in cellular proliferation and maintenance of an undifferentiated phenotype in fetal bovine serum-supplemented medium in the absence of leukemia inhibitory factor (LIF). Re-expression of E-cadherin in Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells restores cellular dependence to LIF supplementation. Although reversal of the LIF-independent phenotype in Ecad(-/-) ES cells is dependent on the beta-catenin binding domain of E-cadherin, we show that beta-catenin null (betacat(-/-)) ES cells also remain undifferentiated in the absence of LIF. This suggests that LIF-independent self-renewal of Ecad(-/-) ES cells is unlikely to be via beta-catenin signaling. Exposure of Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells to the activin receptor-like kinase inhibitor SB431542 led to differentiation of the cells, which could be prevented by re-expression of E-cadherin. To confirm the role of transforming growth factor beta family signaling in the self-renewal of Ecad(-/-) ES cells, we show that these cells maintain an undifferentiated phenotype when cultured in serum-free medium supplemented with Activin A and Nodal, with fibroblast growth factor 2 required for cellular proliferation. We conclude that transhomodimerization of E-cadherin protein is required for LIF-dependent ES cell self-renewal and that multiple self-renewal signaling networks subsist in ES cells, with activity dependent upon the cellular context.

Plasmacytoid dendritic cell leukaemia/lymphoma: towards a well defined entity?

PubMed

Garnache-Ottou, Francine; Feuillard, Jean; Saas, Philippe

2007-02-01

CD4(+)/CD56(+) haematodermic neoplasm or 'early' plasmacytoid dendritic cell leukaemia/lymphoma (pDCL) was described as a disease entity in the last World Health Organisation/European Organisation for Research and Treatment of Cancer classification for cutaneous lymphomas. These leukaemia/lymphomas co-express CD4 and CD56 without any other lineage-specific markers and have been identified as arising from plasmacytoid dendritic cells. Despite a fairly homogeneous pattern of markers expressed by most pDCL, numerous distinctive features (e.g. cytological aspects and aberrant marker expression) have been reported. This may be related to the 'lineage-independent developmental' programme of dendritic cells, which may be able to develop from either immature or already committed haematopoietic progenitors. This highlights the need for specific validated markers to diagnose such aggressive leukaemia. Here, we propose--among others (e.g. T-cell leukaemia 1)--blood dendritic cell antigen-2 and high levels of CD123 expression as potential markers. In addition, we propose a multidisciplinary approach including several fields of haematology to improve pDCL diagnosis.

The types of neurons of the somatic oculomotor nucleus in the European bison. Nissl and Golgi studies.

PubMed

Szteyn, S; Robak, A; Równiak, M

1997-01-01

The neuronal structure of the somatic oculomotor nucleus (SON) was studied on the basis of Nissl and Golgi preparations, obtained from mesencephalons of 4 European bisons. We distinguished four types of neurons in the investigated nucleus: 1. The large multipolar nerve cells with 5-8 thick dendritic trunks and a thin axon which emerges directly from the soma. These are the most numerous neurons in the SON. 2. The small multipolar neurons. These cells have 4-6 thick dendritic trunks. An axon arises mostly from initial segment of one of the dendrites. This type represents about 8% neurons of SON. 3. The triangular neurons. From perikaryon 3 thick dendritic trunks emerge. A thin axon arises directly from the cell body. These cells make about 10% neurons of SON. 4. The pear-shaped cells which have 1 or 2 dendritic trunks concentrate at one pole of the neurons. In the SON there are about 2% pear-shaped cells. Their features correspond to the features attributed by many authors to the interneurons.

Interactions between airway epithelial cells and dendritic cells during viral infections using an in vitro co-culture model

EPA Science Inventory

Rationale: Historically, single cell culture models have been limited in pathological and physiological relevance. A co-culture model of dendritic cells (DCs) and differentiated human airway epithelial cells was developed to examine potential interactions between these two cell t...

Human cytomegalovirus alters localization of MHC class II and dendrite morphology in mature Langerhans cells.

PubMed

Lee, Andrew W; Hertel, Laura; Louie, Ryan K; Burster, Timo; Lacaille, Vashti; Pashine, Achal; Abate, Davide A; Mocarski, Edward S; Mellins, Elizabeth D

2006-09-15

Hemopoietic stem cell-derived mature Langerhans-type dendritic cells (LC) are susceptible to productive infection by human CMV (HCMV). To investigate the impact of infection on this cell type, we examined HLA-DR biosynthesis and trafficking in mature LC cultures exposed to HCMV. We found decreased surface HLA-DR levels in viral Ag-positive as well as in Ag-negative mature LC. Inhibition of HLA-DR was independent of expression of unique short US2-US11 region gene products by HCMV. Indeed, exposure to UV-inactivated virus, but not to conditioned medium from infected cells, was sufficient to reduce HLA-DR on mature LC, implicating particle binding/penetration in this effect. Reduced surface levels reflected an altered distribution of HLA-DR because total cellular HLA-DR was not diminished. Accumulation of HLA-DR was not explained by altered cathepsin S activity. Mature, peptide-loaded HLA-DR molecules were retained within cells, as assessed by the proportion of SDS-stable HLA-DR dimers. A block in egress was implicated, as endocytosis of surface HLA-DR was not increased. Immunofluorescence microscopy corroborated the intracellular retention of HLA-DR and revealed markedly fewer HLA-DR-positive dendritic projections in infected mature LC. Unexpectedly, light microscopic analyses showed a dramatic loss of the dendrites themselves and immunofluorescence revealed that cytoskeletal elements crucial for the formation and maintenance of dendrites are disrupted in viral Ag-positive cells. Consistent with these dendrite effects, HCMV-infected mature LC exhibit markedly reduced chemotaxis in response to lymphoid chemokines. Thus, HCMV impedes MHC class II molecule trafficking, dendritic projections, and migration of mature LC. These changes likely contribute to the reduced activation of CD4+ T cells by HCMV-infected mature LC.

[Undifferentiated cutaneous angiosarcoma of the head: identification by the endothelial marker Ulex europaeus agglutinin I].

PubMed

Bork, K; Fries, J; Hoede, N; Korting, G W; Dienes, P

1985-06-01

Cutaneous angiosarcoma of the head is a rare tumor of the elderly and can occur in an undifferentiated form without any clinical or histological signs of the vascular origin of this tumor. In these cases, the tumor can be identified by using endothelial cell markers, such as factor-VIII-related antigen and ulex europaeus agglutinin I, in an immunofluorescence technique or a peroxidase-antiperoxidase method. A 78-year-old patient is described who died within 18 months from such a tumor, which was diagnosed using the endothelial cell marker, ulex europaeus agglutinin I.

Interactions of Cryptococcus with Dendritic Cells

PubMed Central

Wozniak, Karen L.

2018-01-01

The fungal pathogens Cryptococcus neoformans and Cryptococcus gattii can cause life-threatening infections in immune compromised and immune competent hosts. These pathogens enter the host via inhalation, and respiratory tract innate immune cells such as dendritic cells (DCs) are one of the first host cells they encounter. The interactions between Cryptococcus and innate immune cells play a critical role in the progression of disease in the host. This review will focus specifically on the interactions between Cryptococcus and dendritic cells (DCs), including recognition/processing by DCs, effects of immune mediators on DC recruitment and activity, and the potential for DC vaccination against cryptococcosis. PMID:29543719

Interactions of Cryptococcus with Dendritic Cells.

PubMed

Wozniak, Karen L

2018-03-15

The fungal pathogens Cryptococcus neoformans and Cryptococcus gattii can cause life-threatening infections in immune compromised and immune competent hosts. These pathogens enter the host via inhalation, and respiratory tract innate immune cells such as dendritic cells (DCs) are one of the first host cells they encounter. The interactions between Cryptococcus and innate immune cells play a critical role in the progression of disease in the host. This review will focus specifically on the interactions between Cryptococcus and dendritic cells (DCs), including recognition/processing by DCs, effects of immune mediators on DC recruitment and activity, and the potential for DC vaccination against cryptococcosis.

Down regulation of ITGA4 and ITGA5 genes after formation of 3D spherules by human Wharton's jelly stem cells (hWJSCs).

PubMed

Mostafavi-Pour, Zohreh; Ashrafi, Mohammad Reza; Talaei-Khozani, Tahereh

2018-06-01

Human Wharton's jelly mesenchymal stem cells (hWJSCs) are multipotent stem cells that could be aggregated into 3D spherules. ITGA4 and ITGA5 genes encode α4 and α5 subunits of integrins, respectively. In this study, we analyzed expression levels of ITGA4 and ITGA5 gene mRNAs in undifferentiated and 3D spherules forming hWJSCs in order to determine their expression pattern for possible future treatment of cancer cells in a co-culture fashion. For the purpose of obtaining hWJSCs, umbilical cords were collected from patients with caesarian section at full term delivery. The cells were then characterized according to cell surface markers using flow cytometry. Furthermore pluripotency of the obtained cells was verified. Subsequently the cells were aggregated in 3D spherules using hanging drop cultures. Expression levels of ITGA4 and ITGA5 gene mRNAs were determined by RT-PCR and Real time PCR, both in the initial undifferentiated cells and those aggregated in the spherules. The obtained hWJSCs demonstrated pluripotency, differentiating to adipogenic and osteogenic cells. They also expressed mesenchymal stem cell surface markers. Following the aggregation of these cells and formation of 3D spherules, mRNA expression levels of both genes were significantly reduced (P < 0.05) compared with the initial undifferentiated state. The results of this study demonstrated that aggregation of hWJSCs into spherules alters their expression of ITGA4 and ITGA5. The implications of such an alteration would require further research.

Transplantation of neurons derived from human iPS cells cultured on collagen matrix into guinea-pig cochleae.

PubMed

Ishikawa, Masaaki; Ohnishi, Hiroe; Skerleva, Desislava; Sakamoto, Tatsunori; Yamamoto, Norio; Hotta, Akitsu; Ito, Juichi; Nakagawa, Takayuki

2017-06-01

The present study examined the efficacy of a neural induction method for human induced pluripotent stem (iPS) cells to eliminate undifferentiated cells and to determine the feasibility of transplanting neurally induced cells into guinea-pig cochleae for replacement of spiral ganglion neurons (SGNs). A stepwise method for differentiation of human iPS cells into neurons was used. First, a neural induction method was established on Matrigel-coated plates; characteristics of cell populations at each differentiation step were assessed. Second, neural stem cells were differentiated into neurons on a three-dimensional (3D) collagen matrix, using the same protocol of culture on Matrigel-coated plates; neuron subtypes in differentiated cells on a 3D collagen matrix were examined. Then, human iPS cell-derived neurons cultured on a 3D collagen matrix were transplanted into intact guinea-pig cochleae, followed by histological analysis. In vitro analyses revealed successful induction of neural stem cells from human iPS cells, with no retention of undifferentiated cells expressing OCT3/4. After the neural differentiation of neural stem cells, approximately 70% of cells expressed a neuronal marker, 90% of which were positive for vesicular glutamate transporter 1 (VGLUT1). The expression pattern of neuron subtypes in differentiated cells on a 3D collagen matrix was identical to that of the differentiated cells on Matrigel-coated plates. In addition, the survival of transplant-derived neurons was achieved when inflammatory responses were appropriately controlled. Our preparation method for human iPS cell-derived neurons efficiently eliminated undifferentiated cells and contributed to the settlement of transplant-derived neurons expressing VGLUT1 in guinea-pig cochleae. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

The distribution of excitatory amino acid receptors on acutely dissociated dorsal horn neurons from postnatal rats.

PubMed

Arancio, O; Yoshimura, M; Murase, K; MacDermott, A B

1993-01-01

Excitatory amino acid receptor distribution was mapped on acutely dissociated neurons from postnatal rat spinal cord dorsal horn. N-methyl D-aspartate, quisqualate and kainate were applied to multiple locations along the somal and dendritic surfaces of voltage-clamped neurons by means of a pressure application system. To partially compensate for the decrement of response amplitude due to current loss between the site of activation on the dendrite and the recording electrode at the soma, a solution containing 0.15 M KCl was applied on the cell bodies and dendrites of some cells to estimate an empirical length constant. In the majority of the cells tested, the dendritic membrane had regions of higher sensitivity to excitatory amino acid agonists than the somatic membrane, with dendritic response amplitudes reaching more than seven times those at the cell body. A comparison of the relative changes in sensitivity between each combination of two of the three excitatory amino acid agonists along the same dendrite showed different patterns of agonist sensitivity along the dendrite in the majority of the cells. These data were obtained from dorsal horn neurons that had developed and formed synaptic connections in vivo. They demonstrate that in contrast to observations made on ventral horn neurons, receptor density for all the excitatory amino acid receptors on dorsal horn neurons, including the N-methyl-D-aspartate receptor, are generally higher on the dendrites than on the soma. Further, these results are similar to those obtained from dorsal horn neurons grown in culture.

Retinal ganglion cell dendritic fields in old-world monkeys are oriented radially.

PubMed

Schall, J D; Perry, V H; Leventhal, A G

1986-03-12

We analyzed the dendritic field morphology of 297 ganglion cells from peripheral regions of monkey retina. Most of the dendritic fields were elongated, and there was a significant tendency for the dendritic fields to be oriented radially, i.e., like the spokes of a wheel with the fovea at the hub. An overrepresentation of radial orientations in the peripheral retina of primates might explain why humans are best able to detect stimuli which are oriented radially using peripheral vision.

Efficient priming of CD4 T cells by Langerin-expressing dendritic cells targeted with porcine epidemic diarrhea virus spike protein domains in pigs.

PubMed

Subramaniam, Sakthivel; Cao, Dianjun; Tian, Debin; Cao, Qian M; Overend, Christopher; Yugo, Danielle M; Matzinger, Shannon R; Rogers, Adam J; Heffron, C Lynn; Catanzaro, Nicholas; Kenney, Scott P; Opriessnig, Tanja; Huang, Yao-Wei; Labarque, Geoffrey; Wu, Stephen Q; Meng, Xiang-Jin

2017-01-02

Porcine epidemic diarrhea virus (PEDV) first emerged in the United States in 2013 causing high mortality and morbidity in neonatal piglets with immense economic losses to the swine industry. PEDV is an alpha-coronavirus replicating primarily in porcine intestinal cells. PEDV vaccines are available in Asia and Europe, and conditionally-licensed vaccines recently became available in the United States but the efficacies of these vaccines in eliminating PEDV from swine populations are questionable. In this study, the immunogenicity of a subunit vaccine based on the spike protein of PEDV, which was directly targeted to porcine dendritic cells (DCs) expressing Langerin, was assessed. The PEDV S antigen was delivered to the dendritic cells through a single-chain antibody specific to Langerin and the targeted cells were stimulated with cholera toxin adjuvant. This approach, known as "dendritic cell targeting," greatly improved PEDV S antigen-specific T cell interferon-γ responses in the CD4 pos CD8 pos T cell compartment in pigs as early as 7days upon transdermal administration. When the vaccine protein was targeted to Langerin pos DCs systemically through intramuscular vaccination, it induced higher serum IgG and IgA responses in pigs, though these responses require a booster dose, and the magnitude of T cell responses were lower as compared to transdermal vaccination. We conclude that PEDV spike protein domains targeting Langerin-expressing dendritic cells significantly increased CD4 T cell immune responses in pigs. The results indicate that the immunogenicity of protein subunit vaccines can be greatly enhanced by direct targeting of the vaccine antigens to desirable dendritic cell subsets in pigs. Copyright © 2016 Elsevier B.V. All rights reserved.

Dendritic excitability modulates dendritic information processing in a purkinje cell model.

PubMed

Coop, Allan D; Cornelis, Hugo; Santamaria, Fidel

2010-01-01

Using an electrophysiological compartmental model of a Purkinje cell we quantified the contribution of individual active dendritic currents to processing of synaptic activity from granule cells. We used mutual information as a measure to quantify the information from the total excitatory input current (I(Glu)) encoded in each dendritic current. In this context, each active current was considered an information channel. Our analyses showed that most of the information was encoded by the calcium (I(CaP)) and calcium activated potassium (I(Kc)) currents. Mutual information between I(Glu) and I(CaP) and I(Kc) was sensitive to different levels of excitatory and inhibitory synaptic activity that, at the same time, resulted in the same firing rate at the soma. Since dendritic excitability could be a mechanism to regulate information processing in neurons we quantified the changes in mutual information between I(Glu) and all Purkinje cell currents as a function of the density of dendritic Ca (g(CaP)) and Kca (g(Kc)) conductances. We extended our analysis to determine the window of temporal integration of I(Glu) by I(CaP) and I(Kc) as a function of channel density and synaptic activity. The window of information integration has a stronger dependence on increasing values of g(Kc) than on g(CaP), but at high levels of synaptic stimulation information integration is reduced to a few milliseconds. Overall, our results show that different dendritic conductances differentially encode synaptic activity and that dendritic excitability and the level of synaptic activity regulate the flow of information in dendrites.

Con-nectin axons and dendrites.

PubMed

Beaudoin, Gerard M J

2006-07-03

Unlike adherens junctions, synapses are asymmetric connections, usually between axons and dendrites, that rely on various cell adhesion molecules for structural stability and function. Two cell types of adhesion molecules found at adherens junctions, cadherins and nectins, are thought to mediate homophilic interaction between neighboring cells. In this issue, Togashi et al. (see p. 141) demonstrate that the differential localization of two heterophilic interacting nectins mediates the selective attraction of axons and dendrites in cooperation with cadherins.

Frequency of Dendritic Cells and Their Expression of Costimulatory Molecules in Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Saad, Khaled; Zahran, Asmaa M.; Elsayh, Khalid I.; Abdel-Rahman, Ahmed A.; Al-Atram, Abdulrahman A.; Hussein, Almontaser; El-Gendy, Yasmin G.

2017-01-01

The aim of our study was to evaluate the frequencies of myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) in children with ASD. Subjects were 32 children with ASD and 30 healthy children as controls. The numbers of mDCs and pDCs and the expression of CD86 and CD80 on the entire DCs were detected by flow cytometry. ASD children…

PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud

PubMed Central

Norrie, Jacqueline L.; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C.; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T.; Galli, Antonella; Ji, Hongkai

2016-01-01

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4. Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. PMID:27827819

PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud.

PubMed

Norrie, Jacqueline L; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T; Galli, Antonella; Ji, Hongkai; Vokes, Steven A

2016-12-15

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4 Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. © 2016. Published by The Company of Biologists Ltd.

Human neuroblastoma SH-SY5Y cells show increased resistance to hyperthermic stress after differentiation, associated with elevated levels of Hsp72.

PubMed

Cheng, Lesley; Smith, Danielle J; Anderson, Robin L; Nagley, Phillip

2011-01-01

Terminally differentiated neurones in the central nervous system need to be protected from stress. We ask here whether differentiation of progenitor cells to neurones is accompanied by up-regulation of Hsp72, with acquisition of enhanced thermotolerance. Human neuroblastoma SH-SY5Y cells were propagated in an undifferentiated form and subsequently differentiated into neurone-like cells. Thermotolerance tests were carried out by exposure of cells to various temperatures, monitoring nuclear morphology as index of cell death. Abundance of Hsp72 was measured in cell lysates by western immunoblotting. The differentiation of SH-SY5Y cells was accompanied by increased expression of Hsp72. Further, in both cell states, exposure to mild hyperthermic stress (43°C for 30 min) increased Hsp72 expression. After differentiation, SH-SY5Y cells were more resistant to hyperthermic stress compared to their undifferentiated state, correlating with levels of Hsp72. Stable exogenous expression of Hsp72 in SH-SY5Y cells (transfected line 5YHSP72.1, containing mildly elevated levels of Hsp72), led to enhanced resistance to hyperthermic stress. Hsp72 was found to be inducible in undifferentiated 5YHSP72.1 cells; such heat-treated cells displayed enhanced thermotolerance. Treatment of cells with KNK437, a suppressor of Hsp72 induction, resulted in acute thermosensitisation of all cell types tested here. Hsp72 has a major role in the enhanced hyperthermic resistance acquired during neuronal differentiation of SH-SY5Y cells. These findings model the requirement in intact organisms for highly differentiated neurones to be specially protected against thermal stress.

Neutrophils, dendritic cells and Toxoplasma.

PubMed

Denkers, Eric Y; Butcher, Barbara A; Del Rio, Laura; Bennouna, Soumaya

2004-03-09

Toxoplasma gondii rapidly elicits strong Type 1 cytokine-based immunity. The necessity for this response is well illustrated by the example of IFN-gamma and IL-12 gene knockout mice that rapidly succumb to the effects of acute infection. The parasite itself is skilled at sparking complex interactions in the innate immune system that lead to protective immunity. Neutrophils are one of the first cell types to arrive at the site of infection, and the cells release several proinflammatory cytokines and chemokines in response to Toxoplasma. Dendritic cells are an important source of IL-12 during infection with T. gondii and other microbial pathogens, and they are also specialized for high-level antigen presentation to T lymphocytes. Tachyzoites express at least two types of molecules that trigger innate immune cell cytokine production. One of these involves Toll-like receptor/MyD88 pathways common to many microbial pathogens. The second pathway is less conventional and involves molecular mimicry between a parasite cyclophilin and host CC chemokine receptor 5-binding ligands. Neutrophils, dendritic cells and Toxoplasma work together to elicit the immune response required for host survival. Cytokine and chemokine cross-talk between parasite-triggered neutrophils and dendritic cells results in recruitment, maturation and activation of the latter. Neutrophil-empowered dendritic cells possess properties expected of highly potent antigen presenting cells that drive T helper 1 generation.

Presence and regulation of the endocannabinoid system in human dendritic cells.

PubMed

Matias, Isabel; Pochard, Pierre; Orlando, Pierangelo; Salzet, Michel; Pestel, Joel; Di Marzo, Vincenzo

2002-08-01

Cannabinoid receptors and their endogenous ligands, the endocannabinoids, have been detected in several blood immune cells, including monocytes/macrophages, basophils and lymphocytes. However, their presence in dendritic cells, which play a key role in the initiation and development of the immune response, has never been investigated. Here we have analyzed human dendritic cells for the presence of the endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), the cannabinoid CB1 and CB2 receptors, and one of the enzymes mostly responsible for endocannabinoid hydrolysis, the fatty acid amide hydrolase (FAAH). By using a very sensitive liquid chromatography-atmospheric pressure chemical ionization-mass spectrometric (LC-APCI-MS) method, lipids extracted from immature dendritic cells were shown to contain 2-AG, anandamide and the anti-inflammatory anandamide congener, N-palmitoylethanolamine (PalEtn) (2.1 +/- 1.0, 0.14 +/- 0.02 and 8.2 +/- 3.9 pmol x 10(-7) cells, respectively). The amounts of 2-AG, but not anandamide or PalEtn, were significantly increased following cell maturation induced by bacterial lipopolysaccharide (LPS) or the allergen Der p 1 (2.8- and 1.9-fold, respectively). By using both RT-PCR and Western immunoblotting, dendritic cells were also found to express measurable amounts of CB1 and CB2 receptors and of FAAH. Cell maturation did not consistently modify the expression of these proteins, although in some cell preparations a decrease of the levels of both CB1 and CB2 mRNA transcripts was observed after LPS stimulation. These findings demonstrate for the first time that the endogenous cannabinoid system is present in human dendritic cells and can be regulated by cell activation.

Cellular and dendritic growth in a binary melt - A marginal stability approach

NASA Technical Reports Server (NTRS)

Laxmanan, V.

1986-01-01

A simple model for the constrained growth of an array of cells or dendrites in a binary alloy in the presence of an imposed positive temperature gradient in the liquid is proposed, with the dendritic or cell tip radius calculated using the marginal stability criterion of Langer and Muller-Krumbhaar (1977). This approach, an approach adopting the ad hoc assumption of minimum undercooling at the cell or dendrite tip, and an approach based on the stability criterion of Trivedi (1980) all predict tip radii to within 30 percent of each other, and yield a simple relationship between the tip radius and the growth conditions. Good agreement is found between predictions and data obtained in a succinonitrile-acetone system, and under the present experimental conditions, the dendritic tip stability parameter value is found to be twice that obtained previously, possibly due to a transition in morphology from a cellular structure with just a few side branches, to a more fully developed dendritic structure.

A dendrite-autonomous mechanism for direction selectivity in retinal starburst amacrine cells.

PubMed

Hausselt, Susanne E; Euler, Thomas; Detwiler, Peter B; Denk, Winfried

2007-07-01

Detection of image motion direction begins in the retina, with starburst amacrine cells (SACs) playing a major role. SACs generate larger dendritic Ca(2+) signals when motion is from their somata towards their dendritic tips than for motion in the opposite direction. To study the mechanisms underlying the computation of direction selectivity (DS) in SAC dendrites, electrical responses to expanding and contracting circular wave visual stimuli were measured via somatic whole-cell recordings and quantified using Fourier analysis. Fundamental and, especially, harmonic frequency components were larger for expanding stimuli. This DS persists in the presence of GABA and glycine receptor antagonists, suggesting that inhibitory network interactions are not essential. The presence of harmonics indicates nonlinearity, which, as the relationship between harmonic amplitudes and holding potential indicates, is likely due to the activation of voltage-gated channels. [Ca(2+)] changes in SAC dendrites evoked by voltage steps and monitored by two-photon microscopy suggest that the distal dendrite is tonically depolarized relative to the soma, due in part to resting currents mediated by tonic glutamatergic synaptic input, and that high-voltage-activated Ca(2+) channels are active at rest. Supported by compartmental modeling, we conclude that dendritic DS in SACs can be computed by the dendrites themselves, relying on voltage-gated channels and a dendritic voltage gradient, which provides the spatial asymmetry necessary for direction discrimination.

Histopathology of human superficial herpes simplex keratitis.

PubMed Central

Maudgal, P. C.; Missotten, L.

1978-01-01

In vivo corneal replicas were made in 20 cases of patients with superficial dendritic ulcers of the cornea. Histopathological study of the replicas and superficial epithelial cells showed that the dendrites are composed of rounded epithelial cells and variable sized syncytia containing bizarre shaped nuclei. Pseudopodia-like processes containing DNA and some RNA extend from the syncytia into the surrounding epithelial cells, which on coming into contact with these processes become rounded and liquefied to give rise to another syncytium. The epithelial cells adjacent to the dendrite and elongated and usually orientated parallel to the long axis of the lesion. Surrounding the terminal bulbs, they are disposed in an arcuate fashion. These cells show C-mitotic lesions, intranuclear and cytoplasmic inclusion bodies, and polykaryocyte formation. Microscopic examination of the corneal replicas shows the intranuclear lesions and rounding of cells up to about 2 mm away from the dendritic ulcers. These areas appear normal on clinical examination. Images PMID:629910

Identification of a dendritic cell receptor that couples sensing of necrosis to immunity.

PubMed

Sancho, David; Joffre, Olivier P; Keller, Anna M; Rogers, Neil C; Martínez, Dolores; Hernanz-Falcón, Patricia; Rosewell, Ian; Reis e Sousa, Caetano

2009-04-16

Injury or impaired clearance of apoptotic cells leads to the pathological accumulation of necrotic corpses, which induce an inflammatory response that initiates tissue repair. In addition, antigens present in necrotic cells can sometimes provoke a specific immune response and it has been argued that necrosis could explain adaptive immunity in seemingly infection-free situations, such as after allograft transplantation or in spontaneous and therapy-induced tumour rejection. In the mouse, the CD8alpha+ subset of dendritic cells phagocytoses dead cell remnants and cross-primes CD8+ T cells against cell-associated antigens. Here we show that CD8alpha+ dendritic cells use CLEC9A (also known as DNGR-1), a recently-characterized C-type lectin, to recognize a preformed signal that is exposed on necrotic cells. Loss or blockade of CLEC9A does not impair the uptake of necrotic cell material by CD8+ dendritic cells, but specifically reduces cross-presentation of dead-cell-associated antigens in vitro and decreases the immunogenicity of necrotic cells in vivo. The function of CLEC9A requires a key tyrosine residue in its intracellular tail that allows the recruitment and activation of the tyrosine kinase SYK, which is also essential for cross-presentation of dead-cell-associated antigens. Thus, CLEC9A functions as a SYK-coupled C-type lectin receptor to mediate sensing of necrosis by the principal dendritic-cell subset involved in regulating cross-priming to cell-associated antigens.

[Role of CD2-associated protein in podocyte differentiation.].

PubMed

Jiang, Hua-Jun; Chang, Ying; Zhu, Zhong-Hua; Liu, Jian-She; Deng, An-Guo; Zhang, Chun

2008-02-25

To study the cellular changes and the potential role of CD2-associated protein (CD2AP) in podocyte differentiation, conditionally immortalized murine podocyte cell line was cultured in RPMI 1640 medium under permissive condition at 33 °C. After transfection with CD2AP small interfering RNA (siRNA) the cells were shifted to non-permissive condition at 37 °C. Simultaneously, untransfected cells were taken as differentiation control. The podocyte proliferation rate was determined by MTT method. The expressions of CD2AP, WT1, synaptopodin and nephrin mRNAs were examined by RT-PCR. CD2AP, WT1 and nephrin protein expressions were examined by Western blot. The distribution of CD2AP, nephrin, F-actin and tubulin in differentiated and undifferentiated podocytes was detected by laser scanning confocal microscopy. The results showed: (1) CD2AP, WT1 and nephrin were stably expressed in differentiated and undifferentiated podocytes while synaptopodin was only expressed in differentiated podocytes. (2) CD2AP and nephrin mRNA and protein expressions were up-regulated during podocyte differentiation (P<0.05). (3) CD2AP and tubulin were distributed in the cytoplasm and perinulcear region in undifferentiated podocytes, and F-actin was predominantly localized to a cortical belt and paralleled to the cell axis. Under differentiation condition, CD2AP distribution profile was presented as peripheral accumulation, tubulin took on fascicular style and F-actin extended into foot processes in podocytes. CD2AP colocalized with nephrin and F-actin in undifferentiated podocytes. (4) After transfection with CD2AP siRNA, the expression of CD2AP was partially inhibited and cell growth was arrested; Synaptopodin, the differentiation podocyte marker, was apparently down-regulated; The differentiation of podocytes was delayed. The results demonstrate that podocyte differentiation is accompanied by cytoskeleton rearrangement and cell morphology change. CD2AP might play an essential role in podocyte differentiation.

Undifferentiated embryonic cell transcription factor 1 (UTF1) and deleted in azoospermia-like (DAZL) expression in the testes of donkeys.

PubMed

Lee, Y S; Jung, H J; Yoon, M J

2017-04-01

Putative markers for each specific germ cell stage can be a useful tool to study the fate and functions of these cells. Undifferentiated embryonic cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans, rats and horses. The deleted in azoospermia-like (DAZL) protein is also expressed by differentiated spermatogonia and primary spermatocytes in several species. However, whether the expression patterns of these molecular markers are identical and applicable to donkeys remains to be elucidated. The objective of this study was to investigate the expression patterns of UTF1 and DAZL in donkey testicular tissue, using immunohistochemistry (IHC). Testicular samples were collected from routine field castration of donkeys in Korea. The reproductive stages (pre- or post-puberty) of the testes were determined from the morphological characteristics of cross-sections of the seminiferous tubules. For IHC, the UTF1 and DAZL primary antibodies were diluted at 1:100 and 1:200, respectively. The immunolabelling revealed that UTF1 was expressed in approximately 50% of spermatogonia in the pre-pubertal stage, whereas its expression was limited to an early subset of spermatogonia in the post-pubertal stage. DAZL was expressed in some, but not all, spermatogonia in the pre-pubertal spermatogonia, and interestingly, its expression was also observed in spermatogonia and primary spermatocytes in the post-pubertal stage. Co-immunolabelling of the germ cells with both UTF1 and DAZL revealed three types of protein expression patterns at both reproductive stages, namely UTF1 only, DAZL only and both UTF1 and DAZL. These protein molecules were not expressed in Sertoli and Leydig cells. In conclusion, a co-immunolabelling system with UTF1 and DAZL antibodies may be used to identify undifferentiated (UTF1 only), differentiating (UTF1 and DAZL), and differentiated spermatogonia (DAZL only) in donkey testes. © 2017 Blackwell Verlag GmbH.

Enrichment of undifferentiated type a spermatogonia from goat testis using discontinuous percoll density gradient and differential plating.

PubMed

Heidari, Banafsheh; Gifani, Minoo; Shirazi, Abolfazl; Zarnani, Amir-Hassan; Baradaran, Behzad; Naderi, Mohammad Mehdi; Behzadi, Bahareh; Borjian-Boroujeni, Sara; Sarvari, Ali; Lakpour, Niknam; Akhondi, Mohammad Mehdi

2014-04-01

The well documented source for adult multipotent stem cells is Spermatogonial Stem Cells (SSCs). They are the foundation of spermatogenesis in the testis throughout adult life by balancing self-renewal and differentiation. The aim of this study was to assess the effect of percoll density gradient and differential plating on enrichment of undifferentiated type A spermatogonia in dissociated cellular suspension of goat testes. Additionally, we evaluated the separated fractions of the gradients in percoll and samples in differential plating at different times for cell number, viability and purification rate of goat SSCs in culture. Testicular cells were successfully isolated from one month old goat testis using two-step enzymatic digestion and followed by two purification protocols, differential plating with different times of culture (3, 4, 5, and 6 hr) and discontinuous percoll density with different gradients (20, 28, 30, and 32%). The difference of percentage of undifferentiated SSCs (PGP9.5 positive) in each method was compared using ANOVA and comparison between the highest percentage of corresponding value between two methods was carried out by t-test using Sigma Stat (ver. 3.5). The highest PGP9.5 (94.6±0.4) and the lowest c-Kit positive (25.1±0.7) in Percoll method was significantly (p ≤ 0.001) achieved in 32% percoll gradient. While the corresponding rates in differential plating method for the highest PGP9.5 positive cells (81.3±1.1) and lowest c-Kit (17.1±1.4) was achieved after 5 hr culturing (p < 0.001). The enrichment of undifferentiated type A spermatogonia using Percoll was more efficient than differential plating method (p < 0.001). Percoll density gradient and differential plating were efficient and fast methods for enrichment of type A spermatogonial stem cells from goat testes.

Enrichment of Undifferentiated Type A Spermatogonia from Goat Testis Using Discontinuous Percoll Density Gradient and Differential Plating

PubMed Central

Heidari, Banafsheh; Gifani, Minoo; Shirazi, Abolfazl; Zarnani, Amir-Hassan; Baradaran, Behzad; Naderi, Mohammad Mehdi; Behzadi, Bahareh; Borjian-Boroujeni, Sara; Sarvari, Ali; Lakpour, Niknam; Akhondi, Mohammad Mehdi

2014-01-01

Background The well documented source for adult multipotent stem cells is Spermatogonial Stem Cells (SSCs). They are the foundation of spermatogenesis in the testis throughout adult life by balancing self-renewal and differentiation. The aim of this study was to assess the effect of percoll density gradient and differential plating on enrichment of undifferentiated type A spermatogonia in dissociated cellular suspension of goat testes. Additionally, we evaluated the separated fractions of the gradients in percoll and samples in differential plating at different times for cell number, viability and purification rate of goat SSCs in culture. Methods Testicular cells were successfully isolated from one month old goat testis using two-step enzymatic digestion and followed by two purification protocols, differential plating with different times of culture (3, 4, 5, and 6 hr) and discontinuous percoll density with different gradients (20, 28, 30, and 32%). The difference of percentage of undifferentiated SSCs (PGP9.5 positive) in each method was compared using ANOVA and comparison between the highest percentage of corresponding value between two methods was carried out by t-test using Sigma Stat (ver. 3.5). Results The highest PGP9.5 (94.6±0.4) and the lowest c-Kit positive (25.1±0.7) in Percoll method was significantly (p ≤ 0.001) achieved in 32% percoll gradient. While the corresponding rates in differential plating method for the highest PGP9.5 positive cells (81.3±1.1) and lowest c-Kit (17.1±1.4) was achieved after 5 hr culturing (p < 0.001). The enrichment of undifferentiated type A spermatogonia using Percoll was more efficient than differential plating method (p < 0.001). Conclusion Percoll density gradient and differential plating were efficient and fast methods for enrichment of type A spermatogonial stem cells from goat testes. PMID:24834311

Integrative analysis reveals CD38 as a therapeutic target for plasma cell-rich pre-disease and established rheumatoid arthritis and systemic lupus erythematosus.

PubMed

Cole, Suzanne; Walsh, Alice; Yin, Xuefeng; Wechalekar, Mihir D; Smith, Malcolm D; Proudman, Susanna M; Veale, Douglas J; Fearon, Ursula; Pitzalis, Costantino; Humby, Frances; Bombardieri, Michele; Axel, Amy; Adams, Homer; Chiu, Christopher; Sharp, Michael; Alvarez, John; Anderson, Ian; Madakamutil, Loui; Nagpal, Sunil; Guo, Yanxia

2018-05-02

Plasmablasts and plasma cells play a key role in many autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This study was undertaken to evaluate the potential of targeting CD38 as a plasma cell/plasmablast depletion mechanism by daratumumab in the treatment of patients with RA and SLE. RNA-sequencing analysis of synovial biopsies from various stages of RA disease progression, flow cytometry analysis of peripheral blood mononuclear cells (PBMC) from patients with RA or SLE and healthy donors, immunohistochemistry assessment (IHC) of synovial biopsies from patients with early RA, and ex vivo immune cell depletion assays using daratumumab (an anti-CD38 monoclonal antibody) were used to assess CD38 as a therapeutic target. We demonstrated that the plasma cell/plasmablast-related genes CD38, XBP1, IRF4, PRDM1, IGJ and TNFSF13B are significantly up-regulated in synovial biopsies from patients with arthralgia, undifferentiated arthritis (UA), early RA and established RA as compared to healthy controls and control patients with osteoarthritis. In addition, the highest CD38 expression was observed on plasma cells and plasmablasts compared to natural killer (NK) cells, classical dendritic cells (DCs), plasmacytoid DCs (pDCs) and T cells, in blood from healthy controls and patients with SLE and RA. Furthermore, IHC showed CD38 staining in the same region as CD3 and CD138 staining in synovial tissue biopsies from patients with early RA. Most importantly, our data show for the first time that daratumumab effectively depletes plasma cells/plasmablasts in PBMC from patients with SLE and RA in a dose-dependent manner ex vivo. These results indicate that CD38 may be a potential target for RA disease interception and daratumumab should be evaluated clinically for the treatment of both RA and SLE.

Ectopic bone regeneration by human bone marrow mononucleated cells, undifferentiated and osteogenically differentiated bone marrow mesenchymal stem cells in beta-tricalcium phosphate scaffolds.

PubMed

Ye, Xinhai; Yin, Xiaofan; Yang, Dawei; Tan, Jian; Liu, Guangpeng

2012-07-01

Tissue engineering approaches using the combination of porous ceramics and bone marrow mesenchymal stem cells (BMSCs) represent a promising bone substitute for repairing large bone defects. Nevertheless, optimal conditions for constructing tissue-engineered bone have yet to be determined. It remains unclear if transplantation of predifferentiated BMSCs is superior to undifferentiated BMSCs or freshly isolated bone marrow mononucleated cells (BMNCs) in terms of new bone formation in vivo. The aim of this study was to investigate the effect of in vitro osteogenic differentiation (β-glycerophosphate, dexamethasone, and l-ascorbic acid) of human BMSCs on the capability to form tissue-engineered bone in unloaded conditions after subcutaneous implantation in nude mice. After isolation from human bone marrow aspirates, BMNCs were divided into three parts: one part was seeded onto porous beta-tricalcium phosphate ceramics immediately and transplanted in a heterotopic nude mice model; two parts were expanded in vitro to passage 2 before cell seeding and in vivo transplantation, either under osteogenic conditions or not. Animals were sacrificed for micro-CT and histological evaluation at 4, 8, 12, 16, and 20 weeks postimplantation. The results showed that BMSCs differentiated into osteo-progenitor cells after induction, as evidenced by the altered cell morphology and elevated alkaline phosphatase activity and calcium deposition, but their clonogenicity, proliferating rate, and seeding efficacy were not significantly affected by osteogenic differentiation, compared with undifferentiated cells. Extensive new bone formed in the pores of all the scaffolds seeded with predifferentiated BMSCs at 4 weeks after implantation, and maintained for 20 weeks. On the contrary, scaffolds containing undifferentiated BMSCs revealed limited bone formation only in 1 out of 6 cases at 8 weeks, and maintained for 4 weeks. For scaffolds with BMNCs, woven bone was observed sporadically only in one case at 8 weeks. Overall, this study suggests that ectopic osteogenesis of cell/scaffold composites is more dependent on the in vitro expansion condition, and osteo-differentiated BMSCs hold the highest potential concerning in vivo bone regeneration.

Maximization of the connectivity repertoire as a statistical principle governing the shapes of dendritic arbors

PubMed Central

Wen, Quan; Stepanyants, Armen; Elston, Guy N.; Grosberg, Alexander Y.; Chklovskii, Dmitri B.

2009-01-01

The shapes of dendritic arbors are fascinating and important, yet the principles underlying these complex and diverse structures remain unclear. Here, we analyzed basal dendritic arbors of 2,171 pyramidal neurons sampled from mammalian brains and discovered 3 statistical properties: the dendritic arbor size scales with the total dendritic length, the spatial correlation of dendritic branches within an arbor has a universal functional form, and small parts of an arbor are self-similar. We proposed that these properties result from maximizing the repertoire of possible connectivity patterns between dendrites and surrounding axons while keeping the cost of dendrites low. We solved this optimization problem by drawing an analogy with maximization of the entropy for a given energy in statistical physics. The solution is consistent with the above observations and predicts scaling relations that can be tested experimentally. In addition, our theory explains why dendritic branches of pyramidal cells are distributed more sparsely than those of Purkinje cells. Our results represent a step toward a unifying view of the relationship between neuronal morphology and function. PMID:19622738

miR-451 regulates dendritic cell cytokine responses to influenza infection1

PubMed Central

Rosenberger, Carrie M.; Podyminogin, Rebecca L.; Navarro, Garnet; Zhao, Guo-Wei; Askovich, Peter S.; Weiss, Mitchell J.; Aderem, Alan

2012-01-01

MicroRNAs are important post-transcriptional regulators in immune cells, but how viral infection regulates microRNA expression to shape dendritic cell responses has not been well characterized. We identified 20 miRNAs that were differentially expressed in primary murine dendritic cells in response to the double-stranded RNA agonist poly(I:C), a subset of which were modestly regulated by influenza infection. miR-451 was unique because it was induced more strongly in primary splenic and lung dendritic cells by live viral infection than by purified agonists of pattern recognition receptors. We determined that miR-451 regulates a subset of pro-inflammatory cytokine responses. Three types of primary dendritic cells treated with anti-sense RNA antagomirs directed against miR-451 secreted elevated levels of IL-6, TNF, CCL5/RANTES, and CCL3/MIP1α, and these results were confirmed using miR-451null cells. miR-451 negatively regulates YWHAZ/14-3-3ζ protein levels in various cell types, and we measured a similar inhibition of YWHAZ levels in dendritic cells. It is known that YWHAZ can control the activity of two negative regulators of cytokine production: FOXO3, which is an inhibitory transcription factor, and ZFP36/Tristetraprolin, which binds to AU-rich elements within 3′-UTRs to destabilize cytokine mRNAs. Inhibition of miR-451 expression correlated with increased YWHAZ protein expression and decreased ZFP36 expression, providing a possible mechanism for the elevated secretion of IL-6, TNF, CCL5/RANTES, and CCL3/MIP1α. miR-451 levels are themselves increased by IL-6 and type I interferon, potentially forming a regulatory loop. These data suggest that viral infection specifically induces a miRNA that directs a negative regulatory cascade to tune dendritic cell cytokine production. PMID:23169590

Carboplatin and Paclitaxel With or Without Bevacizumab in Treating Patients With Stage III or Stage IV Ovarian Epithelial, Primary Peritoneal, or Fallopian Tube Cancer

ClinicalTrials.gov

2017-10-23

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Mixed Epithelial Tumor; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Dendrodendritic Synapses in the Mouse Olfactory Bulb External Plexiform Layer

PubMed Central

Bartel, Dianna L.; Rela, Lorena; Hsieh, Lawrence; Greer, Charles A.

2014-01-01

Odor information relayed by olfactory bulb projection neurons, mitral and tufted cells (M/T), is modulated by pairs of reciprocal dendrodendritic synaptic circuits in the external plexiform layer (EPL). Interneurons, which are accounted for largely by granule cells, receive depolarizing input from M/T dendrites and in turn inhibit current spread in M/T dendrites via hyperpolarizing reciprocal dendrodendritic synapses. Because the location of dendrodendritic synapses may significantly affect the cascade of odor information, we assessed synaptic properties and density within sublaminae of the EPL and along the length of M/T secondary dendrites. In electron micrographs the M/T to granule cell synapse appeared to predominate and were equivalent in both the outer and inner EPL. However, the dendrodendritic synapses from granule cell spines onto M/T dendrites, were more prevalent in the outer EPL. In contrast, individual gephyrin-IR puncta, a postsynaptic scaffolding protein at inhibitory synapses used here as a proxy for the granule to M/T dendritic synapse was equally distributed throughout the EPL. Of significance to the organization of intrabulbar circuits, gephyrin-IR synapses are not uniformly distributed along M/T secondary dendrites. Synaptic density, expressed as a function of surface area, increases distal to the cell body. Furthermore, the distributions of gephyrin-IR puncta are heterogeneous and appear as clusters along the length of the M/T dendrites. Consistent with computational models, our data suggest that temporal coding in M/T cells is achieved by precisely located inhibitory input and that distance from the soma is compensated with an increase in synaptic density. PMID:25420934

Transcriptional Changes during Naturally Acquired Zika Virus Infection Render Dendritic Cells Highly Conducive to Viral Replication.

PubMed

Sun, Xiaoming; Hua, Stephane; Chen, Hsiao-Rong; Ouyang, Zhengyu; Einkauf, Kevin; Tse, Samantha; Ard, Kevin; Ciaranello, Andrea; Yawetz, Sigal; Sax, Paul; Rosenberg, Eric S; Lichterfeld, Mathias; Yu, Xu G

2017-12-19

Although dendritic cells are among the human cell population best equipped for cell-intrinsic antiviral immune defense, they seem highly susceptible to infection with the Zika virus (ZIKV). Using highly purified myeloid dendritic cells isolated from individuals with naturally acquired acute infection, we here show that ZIKV induces profound perturbations of transcriptional signatures relative to healthy donors. Interestingly, we noted a remarkable downregulation of antiviral interferon-stimulated genes and innate immune sensors, suggesting that ZIKV can actively suppress interferon-dependent immune responses. In contrast, several host factors known to support ZIKV infection were strongly upregulated during natural ZIKV infection; these transcripts included AXL, the main entry receptor for ZIKV; SOCS3, a negative regulator of ISG expression; and IDO-1, a recognized inducer of regulatory T cell responses. Thus, during in vivo infection, ZIKV can transform the transcriptome of dendritic cells in favor of the virus to render these cells highly conducive to ZIKV infection. Published by Elsevier Inc.

Control of axonal sprouting and dendrite branching by the Nrg-Ank complex at the neuron-glia interface.

PubMed

Yamamoto, Misato; Ueda, Ryu; Takahashi, Kuniaki; Saigo, Kaoru; Uemura, Tadashi

2006-08-22

Neurons are highly polarized cells with distinct subcellular compartments, including dendritic arbors and an axon. The proper function of the nervous system relies not only on correct targeting of axons, but also on development of neuronal-class-specific geometry of dendritic arbors [1-4]. To study the intercellular control of the shaping of dendritic trees in vivo, we searched for cell-surface proteins expressed by Drosophila dendritic arborization (da) neurons [5-7]. One of them was Neuroglian (Nrg), a member of the Ig superfamily ; Nrg and vertebrate L1-family molecules have been implicated in various aspects of neuronal wiring, such as axon guidance, axonal myelination, and synapse formation [9-12]. A subset of the da neurons in nrg mutant embryos exhibited deformed dendritic arbors and abnormal axonal sprouting. Our functional analysis in a cell-type-selective manner strongly suggested that those da neurons employed Nrg to interact with the peripheral glia for suppressing axonal sprouting and for forming second-order dendritic branches. At least for the former role, Nrg functioned in concert with the intracellular adaptor protein Ankyrin (Ank) [13]. Thus, the neuron-glia interaction that is mediated by Nrg, together with Ank under some situations, contributes to axonal and dendritic morphogenesis.

Long Glucocorticoid-induced Leucine Zipper (L-GILZ) Protein Interacts with Ras Protein Pathway and Contributes to Spermatogenesis Control*

PubMed Central

Bruscoli, Stefano; Velardi, Enrico; Di Sante, Moises; Bereshchenko, Oxana; Venanzi, Alessandra; Coppo, Maddalena; Berno, Valeria; Mameli, Maria Grazia; Colella, Renato; Cavaliere, Antonio; Riccardi, Carlo

2012-01-01

Correct function of spermatogonia is critical for the maintenance of spermatogenesis throughout life, but the cellular pathways regulating undifferentiated spermatogonia proliferation, differentiation, and survival are only partially known. We show here that long glucocorticoid-induced leucine zipper (L-GILZ) is highly expressed in spermatogonia and primary spermatocytes and controls spermatogenesis. Gilz deficiency in knock-out (gilz KO) mice leads to a complete loss of germ cell lineage within first cycles of spermatogenesis, resulting in male sterility. Spermatogenesis failure is intrinsic to germ cells and is associated with increased proliferation and aberrant differentiation of undifferentiated spermatogonia and with hyperactivity of Ras signaling pathway as indicated by an increase of ERK and Akt phosphorylation. Spermatogonia differentiation does not proceed beyond the prophase of the first meiotic division due to massive apoptosis associated with accumulation of unrepaired chromosomal damage. These results identify L-GILZ as a novel important factor for undifferentiated spermatogonia function and spermatogenesis. PMID:22110132

Regulated Assembly of Vacuolar ATPase Is Increased during Cluster Disruption-induced Maturation of Dendritic Cells through a Phosphatidylinositol 3-Kinase/mTOR-dependent Pathway*

PubMed Central

Liberman, Rachel; Bond, Sarah; Shainheit, Mara G.; Stadecker, Miguel J.; Forgac, Michael

2014-01-01

The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps composed of a peripheral V1 domain and a membrane-embedded V0 domain. Regulated assembly of V1 and V0 represents an important regulatory mechanism for controlling V-ATPase activity in vivo. Previous work has shown that V-ATPase assembly increases during maturation of bone marrow-derived dendritic cells induced by activation of Toll-like receptors. This increased assembly is essential for antigen processing, which is dependent upon an acidic lysosomal pH. Cluster disruption of dendritic cells induces a semi-mature phenotype associated with immune tolerance. Thus, semi-mature dendritic cells are able to process and present self-peptides to suppress autoimmune responses. We have investigated V-ATPase assembly in bone marrow-derived, murine dendritic cells and observed an increase in assembly following cluster disruption. This increased assembly is not dependent upon new protein synthesis and is associated with an increase in concanamycin A-sensitive proton transport in FITC-loaded lysosomes. Inhibition of phosphatidylinositol 3-kinase with wortmannin or mTORC1 with rapamycin effectively inhibits the increased assembly observed upon cluster disruption. These results suggest that the phosphatidylinositol 3-kinase/mTOR pathway is involved in controlling V-ATPase assembly during dendritic cell maturation. PMID:24273170

Nintedanib in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2017-09-08

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Malignant Uterine Corpus Mixed Epithelial and Mesenchymal Neoplasm; Recurrent Uterine Corpus Carcinoma

A Single Subset of Dendritic Cells Controls the Cytokine Bias of Natural Killer T Cell Responses to Diverse Glycolipid Antigens

PubMed Central

Arora, Pooja; Baena, Andres; Yu, Karl O.A.; Saini, Neeraj K.; Kharkwal, Shalu S.; Goldberg, Michael F.; Kunnath-Velayudhan, Shajo; Carreño, Leandro J.; Venkataswamy, Manjunatha M.; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R.; Jervis, Peter J.; Veerapen, Natacha; Besra, Gurdyal S.; Porcelli, Steven A.

2014-01-01

Summary Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α+ DEC-205+ dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α+ dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses. PMID:24412610

Synaptic integration in dendrites: exceptional need for speed

PubMed Central

Golding, Nace L; Oertel, Donata

2012-01-01

Some neurons in the mammalian auditory system are able to detect and report the coincident firing of inputs with remarkable temporal precision. A strong, low-voltage-activated potassium conductance (gKL) at the cell body and dendrites gives these neurons sensitivity to the rate of depolarization by EPSPs, allowing neurons to assess the coincidence of the rising slopes of unitary EPSPs. Two groups of neurons in the brain stem, octopus cells in the posteroventral cochlear nucleus and principal cells of the medial superior olive (MSO), extract acoustic information by assessing coincident firing of their inputs over a submillisecond timescale and convey that information at rates of up to 1000 spikes s−1. Octopus cells detect the coincident activation of groups of auditory nerve fibres by broadband transient sounds, compensating for the travelling wave delay by dendritic filtering, while MSO neurons detect coincident activation of similarly tuned neurons from each of the two ears through separate dendritic tufts. Each makes use of filtering that is introduced by the spatial distribution of inputs on dendrites. PMID:22930273

DSCAM-mediated control of dendritic and axonal arbor outgrowth enforces tiling and inhibits synaptic plasticity

PubMed Central

Simmons, Aaron B.; Bloomsburg, Samuel J.; Sukeena, Joshua M.; Miller, Calvin J.; Ortega-Burgos, Yohaniz; Borghuis, Bart G.

2017-01-01

Mature mammalian neurons have a limited ability to extend neurites and make new synaptic connections, but the mechanisms that inhibit such plasticity remain poorly understood. Here, we report that OFF-type retinal bipolar cells in mice are an exception to this rule, as they form new anatomical connections within their tiled dendritic fields well after retinal maturity. The Down syndrome cell-adhesion molecule (Dscam) confines these anatomical rearrangements within the normal tiled fields, as conditional deletion of the gene permits extension of dendrite and axon arbors beyond these borders. Dscam deletion in the mature retina results in expanded dendritic fields and increased cone photoreceptor contacts, demonstrating that DSCAM actively inhibits circuit-level plasticity. Electrophysiological recordings from Dscam−/− OFF bipolar cells showed enlarged visual receptive fields, demonstrating that expanded dendritic territories comprise functional synapses. Our results identify cell-adhesion molecule-mediated inhibition as a regulator of circuit-level neuronal plasticity in the adult retina. PMID:29114051

A Novel Heat Shock Protein 70-based Vaccine Prepared from DC-Tumor Fusion Cells.

PubMed

Weng, Desheng; Calderwood, Stuart K; Gong, Jianlin

2018-01-01

We have developed an enhanced molecular chaperone-based vaccine through rapid isolation of Hsp70 peptide complexes after the fusion of tumor and dendritic cells (Hsp70.PC-F). In this approach, the tumor antigens are introduced into the antigen processing machinery of dendritic cells through the cell fusion process and thus we can obtain antigenic tumor peptides or their intermediates that have been processed by dendritic cells. Our results show that Hsp70.PC-F has increased immunogenicity compared to preparations from tumor cells alone and therefore constitutes an improved formulation of chaperone protein-based tumor vaccine.

Niche players

PubMed Central

Seandel, Marco; Falciatori, Ilaria; Shmelkov, Sergey V.; Kim, Jiyeon; James, Daylon; Rafii, Shahin

2010-01-01

The undifferentiated spermatogonia of adult mouse testes are composed of both true stem cells and committed progenitors. It is unclear what normally prevents these adult germ cells from manifesting multipotency. The critical elements of the spermatogonial stem cell niche, while poorly understood, are thought to be composed of Sertoli cells with several other somatic cell types in close proximity. We recently discovered a novel orphan G-protein coupled receptor (GPR125) that is restricted to undifferentiated spermatogonia within the testis. GPR125 expression was maintained when the progenitor cells were extracted from the in vivo niche and propagated under growth conditions that recapitulate key elements of the niche. Such conditions preserved the ability of the cells to generate multipotent derivatives, known as multipotent adult spermatogonial derived progenitor cells (MASCs). Upon differentiation, the latter produced a variety tissues including functional endothelium, illustrating the potential applications of such cells. Thus, GPR125 represents a novel target for purifying adult stem and progenitors from tissues, with the goal of developing autologous multipotent cell lines. PMID:18256534

A comparative study of the microstructures observed in statically cast and continuously cast Bi-In-Sn ternary eutectic alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, S.; Soda, H.; McLean, A.

2000-01-01

A ternary eutectic alloy with a composition of 57.2 pct Bi, 24.8 pct In, and 18 pct Sn was continuously cast into wire of 2 mm diameter with casting speeds of 14 and 79 mm/min using the Ohno Continuous Casting (OCC) process. The microstructures obtained were compared with those of statically cast specimens. Extensive segregation of massive Bi blocks, Bi complex structures, and tin-rich dendrites was found in specimens that were statically cast. Decomposition of {radical}Sn by a eutectoid reaction was confirmed based on microstructural evidence. Ternary eutectic alloy with a cooling rate of approximately 1 C/min formed a doublemore » binary eutectic. The double binary eutectic consisted of regions of BiIn and decomposed {radical}Sn in the form of a dendrite cell structure and regions of Bi and decomposed {radical}Sn in the form of a complex-regular cell. The Bi complex-regular cells, which are a ternary eutectic constituent, existed either along the boundaries of the BiIn-decomposed {radical}Sn dendrite cells or at the front of elongated dendrite cell structures. In the continuously cast wires, primary Sn dendrites coupled with a small Bi phase were uniformly distributed within the Bi-In alloy matrix. Neither massive Bi phase, Bi complex-regular cells, no BiIn eutectic dendrite cells were observed, resulting in a more uniform microstructure in contrast to the heavily segregated structures of the statically cast specimens.« less

Distal gap junctions and active dendrites can tune network dynamics.

PubMed

Saraga, Fernanda; Ng, Leo; Skinner, Frances K

2006-03-01

Gap junctions allow direct electrical communication between CNS neurons. From theoretical and modeling studies, it is well known that although gap junctions can act to synchronize network output, they can also give rise to many other dynamic patterns including antiphase and other phase-locked states. The particular network pattern that arises depends on cellular, intrinsic properties that affect firing frequencies as well as the strength and location of the gap junctions. Interneurons or GABAergic neurons in hippocampus are diverse in their cellular characteristics and have been shown to have active dendrites. Furthermore, parvalbumin-positive GABAergic neurons, also known as basket cells, can contact one another via gap junctions on their distal dendrites. Using two-cell network models, we explore how distal electrical connections affect network output. We build multi-compartment models of hippocampal basket cells using NEURON and endow them with varying amounts of active dendrites. Two-cell networks of these model cells as well as reduced versions are explored. The relationship between intrinsic frequency and the level of active dendrites allows us to define three regions based on what sort of network dynamics occur with distal gap junction coupling. Weak coupling theory is used to predict the delineation of these regions as well as examination of phase response curves and distal dendritic polarization levels. We find that a nonmonotonic dependence of network dynamic characteristics (phase lags) on gap junction conductance occurs. This suggests that distal electrical coupling and active dendrite levels can control how sensitive network dynamics are to gap junction modulation. With the extended geometry, gap junctions located at more distal locations must have larger conductances for pure synchrony to occur. Furthermore, based on simulations with heterogeneous networks, it may be that one requires active dendrites if phase-locking is to occur in networks formed with distal gap junctions.

Functions of TGF-β-exposed plasmacytoid dendritic cells.

PubMed

Saas, Philippe; Perruche, Sylvain

2012-01-01

Plasmacytoid dendritic cells (pDCs) belong to the family of dendritic cells and possess specific features that distinguish them from conventional dendritic cells. For instance, pDC are the main interferon-alpha-secreting cells. Plasmacytoid dendritic cells exert both proinflammatory and regulatory functions. This is attested by the involvement of pDC through interferon-alpha secretion in several autoimmune diseases, and by the implication of pDC in tolerance. The same is true for TGF-β that plays a dual role in inflammation. In this review, we discuss recent data on pDC and TGF-β interactions. As with many cell types, pDCs are able to respond to TGF-β using the classic Smad signaling pathway. In addition, pDCs are capable to secrete TGF-β, in particular in response to TGF-β exposure. Exposure of pDCs to TGF-β prevents type I interferon secretion in response to TLR7/9 ligands. In contrast, the consequences of TGF-β on the antigen-presenting cell capacities of pDC are less clear, since TGF-β-exposed pDCs may lead to both regulatory T-cell and interleukin-17-secreting cell polarization. Here, we discuss the factors that may influence this polarization. We also discuss how pDCs exposed to TGF-β may participate in tolerance induction and maintenance, or, on the contrary, in autoimmune diseases.

Development of an Aquatic Bioassay Using the Medaka (Oryzias latipes) to Assess Human Health Risks: Tumor Immunodiagnosis.

DTIC Science & Technology

1992-04-27

Skeletal muscle 5 *Undifferentiated sarcoma Peripheral nerve 3 *Undifferentiated sarcoma Peritoneum 1 Hepatocellular carcinoma Liver 2...KD) Neurofilament (3 proteins 68, 150, Detects neuronal cell origin and 200 KD) Other: Alpha-l antitrypsin Common marker for hepatocellular carcinoma Alpha... hepatocellular carcinoma from cholangiocellular carcinoma (8). 14 4 FIGURE 1. Avldln-Blotin-PeroxidSse Complex Tecbnlqu6. :4odif led from A.K.Bhan

Neuregulin 1 Deficiency Modulates Adolescent Stress-Induced Dendritic Spine Loss in a Brain Region-Specific Manner and Increases Complement 4 Expression in the Hippocampus.

PubMed

Clarke, David J; Chohan, Tariq W; Kassem, Mustafa S; Smith, Kristie L; Chesworth, Rose; Karl, Tim; Kuligowski, Michael P; Fok, Sandra Y; Bennett, Maxwell R; Arnold, Jonathon C

2018-03-16

One neuropathological feature of schizophrenia is a diminished number of dendritic spines in the prefrontal cortex and hippocampus. The neuregulin 1 (Nrg1) system is involved in the plasticity of dendritic spines, and chronic stress decreases dendritic spine densities in the prefrontal cortex and hippocampus. Here, we aimed to assess whether Nrg1 deficiency confers vulnerability to the effects of adolescent stress on dendritic spine plasticity. We also assessed other schizophrenia-relevant neurobiological changes such as microglial cell activation, loss of parvalbumin (PV) interneurons, and induction of complement factor 4 (C4). Adolescent male wild-type (WT) and Nrg1 heterozygous mice were subjected to chronic restraint stress before their brains underwent Golgi impregnation or immunofluorescent staining of PV interneurons, microglial cells, and C4. Stress in WT mice promoted dendritic spine loss and microglial cell activation in the prefrontal cortex and the hippocampus. However, Nrg1 deficiency rendered mice resilient to stress-induced dendritic spine loss in the infralimbic cortex and the CA3 region of the hippocampus without affecting stress-induced microglial cell activation in these brain regions. Nrg1 deficiency and adolescent stress combined to trigger increased dendritic spine densities in the prelimbic cortex. In the hippocampal CA1 region, Nrg1 deficiency accentuated stress-induced dendritic spine loss. Nrg1 deficiency increased C4 protein and decreased C4 mRNA expression in the hippocampus, and the number of PV interneurons in the basolateral amygdala. This study demonstrates that Nrg1 modulates the impact of stress on the adolescent brain in a region-specific manner. It also provides first evidence of a link between Nrg1 and C4 systems in the hippocampus.

The Effect of Traditional Chinese Formula Danchaiheji on the Differentiation of Regulatory Dendritic Cells

PubMed Central

Wang, Xiaodong; Tong, Jingzhi; Li, Keqiu; Jing, Yaqing

2016-01-01

Recently, regulatory dendritic cells (DCregs), a newly described dendritic cell subset with potent immunomodulatory function, have attracted increased attention for their utility in treating immune response-related diseases, such as graft-versus-host disease, hypersensitivity, and autoimmune diseases. Danchaiheji (DCHJ) is a traditional Chinese formula that has been used for many years in the clinic. However, whether DCHJ can program dendritic cells towards a regulatory phenotype and the underlying mechanism behind this process remain unknown. Herein, we investigate the effects of traditional Chinese DCHJ on DCregs differentiation and a mouse model of skin transplantation. The current study demonstrates that DCHJ can induce dendritic cells to differentiate into DCregs, which are represented by high CD11b and low CD86 and HLA-DR expression as well as the secretion of IL-10 and TGF-β. In addition, DCHJ inhibited DC migration and T cell proliferation, which correlated with increased IDO expression. Furthermore, DCHJ significantly prolonged skin graft survival time in a mouse model of skin transplantation without any liver or kidney toxicity. The traditional Chinese formula DCHJ has the potential to be a potent immunosuppressive agent with high efficiency and nontoxicity. PMID:27525028

Nanoparticles, [Gd@C82(OH)22]n, induces dendritic cell maturation and activates Th1 immune responses

PubMed Central

Yang, De; Zhao, Yuliang; Guo, Hua; Li, Yana; Tewary, Poonam; Xing, Gengmei; Hou, Wei; Oppenheim, Joost J.; Zhang, Ning

2010-01-01

Dendritic cells play a pivotal role in host immune defense, such as elimination of foreign pathogen and inhibition of tumorigenesis. In this paper, we report that [Gd@C82(OH)22]n could induce phenotypic maturation of dendritic cells by stimulating DC production of cytokines including IL-12p70, upregulating DC costimulatory (CD80, CD83, and CD86) and MHC (HLA-A,B,C and HLA-DR) molecules, and switching DCs from a CCL5-responsive to a CCL19-responsive phenotype. We found that [Gd@C82(OH)22]n can induce dendritic cells to become functionally mature as illustrated by their capacity to activate allogeneic T cells. Mice immunized with ovalbumin in the presence of [Gd@C82(OH)22]n exhibit enhanced ovalbumin-specific Th1-polarized immune response as evidenced by the predominantly increased production of IFNγ, IL-1β, and IL-2. The [Gd@C82(OH)22]n nanoparticle is a potent activator of dendritic cells and Th1 immune responses. These new findings also provide a rational understanding of the potent anticancer activities of [Gd@C82(OH)22]n nanoparticles reported previously. PMID:20121217

Pathogen-Sensing and Regulatory T Cells: Integrated Regulators of Immune Responses

PubMed Central

Grossman, Zvi; Paul, William E.

2014-01-01

We present the concept that pathogen-sensing and Tregs mutually regulate immune responses to conventional and tumor antigens through countervailing effects on dendritic cells. Normally, conventional CD4 T cells recognizing their cognate antigen-presented by a dendritic cell will respond only if the dendritic cell also receives a signal through its pathogen-sensing/ danger / adjuvant recognition systems (the pathogen-sensing triad). However, if Tregs capable of interacting with the same DC are absent, dendritic cells are competent to present antigens, both foreign and self, even without the stimulation provided by the pathogen-sensing triad. Tregs recognizing an antigen presented by the DC that is also presenting antigen to a conventional CD4 T cell will prevent such responses but a signal delivered by a member of the pathogen-sensing traid will overcome the Tregs’inhibitory action and will allow responses to go forward. These considerations take on special meaning for responses to “weak antigens” such as many of the antigens displayed by spontaneous human tumors. PMID:24894087

DSCAM Localization and Function at the Mouse Cone Synapse

PubMed Central

de Andrade, Gabriel Belem; Long, Samuel S.; Fleming, Harrison; Li, Wei; Fuerst, Peter G.

2014-01-01

The Down Syndrome Cell Adhesion Molecule (DSCAM) is required for regulation of cell number, soma spacing and cell type specific dendrite avoidance in many types of retinal ganglion and amacrine cells. In this study we assay the organization of cells making up the outer plexiform layer of the retina in the absence of Dscam. Some types of OFF bipolar cells, type 3b and type 4 bipolar cells, had defects in dendrite arborization in the Dscam mutant retina, while other cell types appeared similar to wild type. The cone synapses that these cells project their dendrites to were intact, as visualized by electron microscopy, and had a distribution and density that was not significantly different than wild type. The spacing of type 3b bipolar cell dendrites was further analyzed by Voronoi domain analysis, Density Recovery Profiling (DRP) analysis and Nearest Neighbor Analysis (NNA). Spacing was found to be significantly different when comparing wild type and mutant type 3b bipolar cell dendrites. Defects in arborization of these bipolar cells could not be attributed to the disorganization of inner plexiform layer cells that occurs in the Dscam mutant retina or an increase in cell number, as they arborized when Dscam was targeted in retinal ganglion cells only or in the bax null retina. Localization of DSCAM was assayed and the protein was localized near to cone synapses in mouse, macaque and ground squirrel retinas. DSCAM protein was detected in several types of bipolar cells, including type 3b and type 4 bipolar cells. PMID:24477985

Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration.

PubMed

Ude, Victor C; Brown, David M; Viale, Luca; Kanase, Nilesh; Stone, Vicki; Johnston, Helinor J

2017-08-23

Copper oxide nanomaterials (CuO NMs) are exploited in a diverse array of products including antimicrobials, inks, cosmetics, textiles and food contact materials. There is therefore a need to assess the toxicity of CuO NMs to the gastrointestinal (GI) tract since exposure could occur via direct oral ingestion, mucocillary clearance (following inhalation) or hand to mouth contact. Undifferentiated Caco-2 intestinal cells were exposed to CuO NMs (10 nm) at concentrations ranging from 0.37 to 78.13 μg/cm 2 Cu (equivalent to 1.95 to 250 μg/ml) and cell viability assessed 24 h post exposure using the alamar blue assay. The benchmark dose (BMD 20), determined using PROAST software, was identified as 4.44 μg/cm 2 for CuO NMs, and 4.25 μg/cm 2 for copper sulphate (CuSO 4 ), which informed the selection of concentrations for further studies. The differentiation status of cells and the impact of CuO NMs and CuSO 4 on the integrity of the differentiated Caco-2 cell monolayer were assessed by measurement of trans-epithelial electrical resistance (TEER), staining for Zonula occludens-1 (ZO-1) and imaging of cell morphology using scanning electron microscopy (SEM). The impact of CuO NMs and CuSO 4 on the viability of differentiated cells was performed via assessment of cell number (DAPI staining), and visualisation of cell morphology (light microscopy). Interleukin-8 (IL-8) production by undifferentiated and differentiated Caco-2 cells following exposure to CuO NMs and CuSO 4 was determined using an ELISA. The copper concentration in the cell lysate, apical and basolateral compartments were measured with Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) and used to calculate the apparent permeability coefficient (P app ); a measure of barrier permeability to CuO NMs. For all experiments, CuSO 4 was used as an ionic control. CuO NMs and CuSO 4 caused a concentration dependent decrease in cell viability in undifferentiated cells. CuO NMs and CuSO 4 translocated across the differentiated Caco-2 cell monolayer. CuO NM mediated IL-8 production was over 2-fold higher in undifferentiated cells. A reduction in cell viability in differentiated cells was not responsible for the lower level of cytokine production observed. Both CuO NMs and CuSO 4 decreased TEER values to a similar extent, and caused tight junction dysfunction (ZO-1 staining), suggesting that barrier integrity was disrupted. CuO NMs and CuSO 4 stimulated IL-8 production by Caco-2 cells, decreased barrier integrity and thereby increased the P app and translocation of Cu. There was no significant enhancement in potency of the CuO NMs compared to CuSO 4 . Differentiated Caco-2 cells were identified as a powerful model to assess the impacts of ingested NMs on the GI tract.

The neuronal differentiation process involves a series of antioxidant proteins.

PubMed

Oh, J-E; Karlmark Raja, K; Shin, J-H; Hengstschläger, M; Pollak, A; Lubec, G

2005-11-01

Involvement of individual antioxidant proteins (AOXP) and antioxidants in the differentiation process has been already reported. A systematic search strategy for detecting differentially regulated AOXP in neuronal differentiation, however, has not been published so far. The aim of this study was to provide an analytical tool identifying AOXP and to generate a differentiation-related AOXP expressional pattern. The undifferentiated N1E-115 neuroblastoma cell line was switched into a neuronal phenotype by DMSO treatment and used for proteomic experiments: We used two-dimensional gel electrophoresis followed by unambiguous mass spectrometrical (MALDI-TOF-TOF) identification of proteins to generate a map of AOXP. 16 AOXP were unambiguously determined in both cell lines; catalase, thioredoxin domain-containing protein 4 and hypothetical glutaredoxin/glutathione S-transferase C terminus-containing protein were detectable in the undifferentiated cells only. Five AOXP were observed in both, undifferentiated and differentiated cells and thioredoxin, thioredoxin-like protein p19, thioredoxin reductase 1, superoxide dismutases (Mn and Cu-Zn), glutathione synthetase, glutathione S-transferase P1 and Mu1 were detected in differentiated cells exclusively. Herein a differential expressional pattern is presented that reveals so far unpublished antioxidant principles involved in neuronal differentiation by a protein chemical approach, unambiguously identifying AOXP. This finding not only shows concomitant determination of AOXP but also serves as an analytical tool and forms the basis for design of future studies addressing AOXP and differentiation per se.

Measuring Lithium Dendritic Growth in Polymer Electrolytes

NASA Astrophysics Data System (ADS)

He, Yuping; Downing, Gregory; Wang, Howard

The nature of Li dendritic growth in polymeric electrolytes for rechargeable batteries has been investigated using simultaneous electrochemical and neutron depth profiling (NDP) measurements. A symmetric sandwich cell of Li / poly(ethyleneoxide) (PEO) : lithium bis(trifluoromethane)sulfonamide (LiTFSI) / Li was used as a model system in this study. Operating the cell at a constant electric current of 0.1 mA, in situ NDP measurements show that after a period of steady Li plating, dendrites start to grow, which eventually short-circuit the sandwich cell. 3D Li mapping reveals heterogeneous lateral distribution of Li over length scales from below a millimeter to centimeters. Most Li in the electrolyte layer resides in dendrites growing from the top electrode, it is observed that dendrites also grow from the bottom electrode, where presumably only Li oxidation reaction occurs. The revelation poses new design and engineering challenges in using Li metal electrode in future development of rechargeable batteries.

MV-NIS Infected Mesenchymal Stem Cells in Treating Patients With Recurrent Ovarian Cancer

ClinicalTrials.gov

2018-01-31

Malignant Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Ovarian Carcinoma

Rotavirus Activates Lymphocytes from Non-Obese Diabetic Mice by Triggering Toll-Like Receptor 7 Signaling and Interferon Production in Plasmacytoid Dendritic Cells

PubMed Central

Pane, Jessica A.; Webster, Nicole L.; Coulson, Barbara S.

2014-01-01

It has been proposed that rotavirus infection promotes the progression of genetically-predisposed children to type 1 diabetes, a chronic autoimmune disease marked by infiltration of activated lymphocytes into pancreatic islets. Non-obese diabetic (NOD) mice provide a model for the human disease. Infection of adult NOD mice with rhesus monkey rotavirus (RRV) accelerates diabetes onset, without evidence of pancreatic infection. Rather, RRV spreads to the pancreatic and mesenteric lymph nodes where its association with antigen-presenting cells, including dendritic cells, induces cellular maturation. RRV infection increases levels of the class I major histocompatibility complex on B cells and proinflammatory cytokine expression by T cells at these sites. In autoimmunity-resistant mice and human mononuclear cells from blood, rotavirus-exposed plasmacytoid dendritic cells contribute to bystander polyclonal B cell activation through type I interferon expression. Here we tested the hypothesis that rotavirus induces bystander activation of lymphocytes from NOD mice by provoking dendritic cell activation and proinflammatory cytokine secretion. NOD mouse splenocytes were stimulated with rotavirus and assessed for activation by flow cytometry. This stimulation activated antigen-presenting cells and B cells independently of virus strain and replicative ability. Instead, activation depended on virus dose and was prevented by blockade of virus decapsidation, inhibition of endosomal acidification and interference with signaling through Toll-like receptor 7 and the type I interferon receptor. Plasmacytoid dendritic cells were more efficiently activated than conventional dendritic cells by RRV, and contributed to the activation of B and T cells, including islet-autoreactive CD8+ T cells. Thus, a double-stranded RNA virus can induce Toll-like receptor 7 signaling, resulting in lymphocyte activation. Our findings suggest that bystander activation mediated by type I interferon contributes to the lymphocyte activation observed following RRV infection of NOD mice, and may play a role in diabetes acceleration by rotavirus. PMID:24676425

Relationship between ketamine-induced developmental neurotoxicity and NMDA receptor-mediated calcium influx in neural stem cell-derived neurons.

PubMed

Wang, Cheng; Liu, Fang; Patterson, Tucker A; Paule, Merle G; Slikker, William

2017-05-01

Ketamine, a noncompetitive NMDA receptor antagonist, is used as a general anesthetic and recent data suggest that general anesthetics can cause neuronal damage when exposure occurs during early brain development. To elucidate the underlying mechanisms associated with ketamine-induced neurotoxicity, stem cell-derived models, such as rodent neural stem cells harvested from rat fetuses and/or neural stem cells derived from human induced pluripotent stem cells (iPSC) can be utilized. Prolonged exposure of rodent neural stem cells to clinically-relevant concentrations of ketamine resulted in elevated NMDA receptor levels as indicated by NR1subunit over-expression in neurons. This was associated with enhanced damage in neurons. In contrast, the viability and proliferation rate of undifferentiated neural stem cells were not significantly affected after ketamine exposure. Calcium imaging data indicated that 50μM NMDA did not cause a significant influx of calcium in typical undifferentiated neural stem cells; however, it did produce an immediate elevation of intracellular free Ca 2+ [Ca 2+ ] i in differentiated neurons derived from the same neural stem cells. This paper reviews the literature on this subject and previous findings suggest that prolonged exposure of developing neurons to ketamine produces an increase in NMDA receptor expression (compensatory up-regulation) which allows for a higher/toxic influx of calcium into neurons once ketamine is removed from the system, leading to neuronal cell death likely due to elevated reactive oxygen species generation. The absence of functional NMDA receptors in cultured neural stem cells likely explains why clinically-relevant concentrations of ketamine did not affect undifferentiated neural stem cell viability. Published by Elsevier B.V.

Monkey extensor digitorum communis motoneuron pool: Proximal dendritic trees and small motoneurons.

PubMed

Jenny, Arthur B; Cheney, Paul D; Jenny, Andrew K

2018-05-14

Transverse sections of the monkey cervical spinal cord from a previous study (Jenny and Inukai, 1983) were reanalyzed using Neurolucida to create a three-dimensional display of extensor digitorum communis (EDC) motoneurons and proximal dendrites that had been labeled with horse radish peroxidase (HRP). The EDC motoneuron pool was located primarily in the C8 and T1 segments of the spinal cord. Small motoneurons (cell body areas less than 500 μm 2 and presumed to be gamma motoneurons) comprised about ten percent of the motoneurons and were located throughout the length of the motoneuron pool. Most small motoneurons were oblong in shape and had one or two major dendrites originating from the cell body in the transverse plane of section. The majority of the HRP labeled dendritic trees were directed either superiorly, dorsal-medially to the mid zone area between the base of the dorsal horn and the upper portion of the ventral horn, or medially to the ventromedial gray matter. The longer HRP labeled dendrites usually continued in the same radial direction as when originating from the cell body. As such we considered the radial direction of the longer proximal HRP labeled dendrites to be a reasonable estimate of the radial direction of the more distal dendritic tree. Our data suggest that the motoneuron dendritic tree as seen in transverse section has direction-oriented dendrites that extend toward functional terminal regions. Copyright © 2018 Elsevier B.V. All rights reserved.

Frequent Calcium Oscillations Lead to NFAT Activation in Human Immature Dendritic Cells*

PubMed Central

Vukcevic, Mirko; Zorzato, Francesco; Spagnoli, Giulio; Treves, Susan

2010-01-01

Spontaneous Ca2+ oscillations have been observed in a number of excitable and non-excitable cells, but in most cases their biological role remains elusive. In the present study we demonstrate that spontaneous Ca2+ oscillations occur in immature human monocyte-derived dendritic cells but not in dendritic cells stimulated to undergo maturation with lipopolysaccharide or other toll like-receptor agonists. We investigated the mechanism and role of spontaneous Ca2+ oscillations in immature dendritic cells and found that they are mediated by the inositol 1,4,5-trisphosphate receptor as they were blocked by pretreatment of cells with the inositol 1,4,5-trisphosphate receptor antagonist Xestospongin C and 2-aminoethoxydiphenylborate. A component of the Ca2+ signal is also due to influx from the extracellular environment and may be involved in maintaining the level of the intracellular Ca2+ stores. As to their biological role, our results indicate that they are intimately linked to the “immature” phenotype and are associated with the translocation of the transcription factor NFAT into the nucleus. In fact, once the Ca2+ oscillations are blocked with 2-aminoethoxydiphenylborate or by treating the cells with lipopolysaccharide, NFAT remains cytoplasmic. The results presented in this report provide novel insights into the physiology of monocyte-derived dendritic cells and into the mechanisms involved in maintaining the cells in the immature stage. PMID:20348098

ISOLATION OF CHICKEN FOLLICULAR DENDRITIC CELLS

USDA-ARS?s Scientific Manuscript database

The aim of the present study was to isolate chicken follicular dendritic cells (FDC). A combination of methods involving panning, iodixanol density gradient centrifugation, and magnetic cell separation technology made it possible to obtain functional FDC from the cecal tonsils from chickens, which h...

Preparation of Horizontal Slices of Adult Mouse Retina for Electrophysiological Studies.

PubMed

Feigenspan, Andreas; Babai, Norbert Zsolt

2017-01-27

Vertical slice preparations are well established to study circuitry and signal transmission in the adult mammalian retina. The plane of sectioning in these preparations is perpendicular to the retinal surface, making it ideal for the study of radially oriented neurons like photoreceptors and bipolar cells. However, the large dendritic arbors of horizontal cells, wide-field amacrine cells, and ganglion cells are mostly truncated, leaving markedly reduced synaptic activity in these cells. Whereas ganglion cells and displaced amacrine cells can be studied in a whole-mounted preparation of the retina, horizontal cells and amacrine cells located in the inner nuclear layer are only poorly accessible for electrodes in whole retina tissue. To achieve maximum accessibility and synaptic integrity, we developed a horizontal slice preparation of the mouse retina, and studied signal transmission at the synapse between photoreceptors and horizontal cells. Horizontal sectioning allows (1) easy and unambiguous visual identification of horizontal cell bodies for electrode targeting, and (2) preservation of the extended horizontal cell dendritic fields, as a prerequisite for intact and functional cone synaptic input to horizontal cell dendrites. Horizontal cells from horizontal slices exhibited tonic synaptic activity in the dark, and they responded to brief flashes of light with a reduction of inward current and diminished synaptic activity. Immunocytochemical evidence indicates that almost all cones within the dendritic field of a horizontal cell establish synapses with its peripheral dendrites. The horizontal slice preparation is therefore well suited to study the physiological properties of horizontally extended retinal neurons as well as sensory signal transmission and integration across selected synapses.

Dendritic Properties Control Energy Efficiency of Action Potentials in Cortical Pyramidal Cells

PubMed Central

Yi, Guosheng; Wang, Jiang; Wei, Xile; Deng, Bin

2017-01-01

Neural computation is performed by transforming input signals into sequences of action potentials (APs), which is metabolically expensive and limited by the energy available to the brain. The metabolic efficiency of single AP has important consequences for the computational power of the cell, which is determined by its biophysical properties and morphologies. Here we adopt biophysically-based two-compartment models to investigate how dendrites affect energy efficiency of APs in cortical pyramidal neurons. We measure the Na+ entry during the spike and examine how it is efficiently used for generating AP depolarization. We show that increasing the proportion of dendritic area or coupling conductance between two chambers decreases Na+ entry efficiency of somatic AP. Activating inward Ca2+ current in dendrites results in dendritic spike, which increases AP efficiency. Activating Ca2+-activated outward K+ current in dendrites, however, decreases Na+ entry efficiency. We demonstrate that the active and passive dendrites take effects by altering the overlap between Na+ influx and internal current flowing from soma to dendrite. We explain a fundamental link between dendritic properties and AP efficiency, which is essential to interpret how neural computation consumes metabolic energy and how biophysics and morphologies contribute to such consumption. PMID:28919852

Dendritic Properties Control Energy Efficiency of Action Potentials in Cortical Pyramidal Cells.

PubMed

Yi, Guosheng; Wang, Jiang; Wei, Xile; Deng, Bin

2017-01-01

Neural computation is performed by transforming input signals into sequences of action potentials (APs), which is metabolically expensive and limited by the energy available to the brain. The metabolic efficiency of single AP has important consequences for the computational power of the cell, which is determined by its biophysical properties and morphologies. Here we adopt biophysically-based two-compartment models to investigate how dendrites affect energy efficiency of APs in cortical pyramidal neurons. We measure the Na + entry during the spike and examine how it is efficiently used for generating AP depolarization. We show that increasing the proportion of dendritic area or coupling conductance between two chambers decreases Na + entry efficiency of somatic AP. Activating inward Ca 2+ current in dendrites results in dendritic spike, which increases AP efficiency. Activating Ca 2+ -activated outward K + current in dendrites, however, decreases Na + entry efficiency. We demonstrate that the active and passive dendrites take effects by altering the overlap between Na + influx and internal current flowing from soma to dendrite. We explain a fundamental link between dendritic properties and AP efficiency, which is essential to interpret how neural computation consumes metabolic energy and how biophysics and morphologies contribute to such consumption.

Endocrine disrupting chemicals affect the adipogenic differentiation of mesenchymal stem cells in distinct ontogenetic windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biemann, Ronald, E-mail: ronald.biemann@medizin.uni-halle.de; Navarrete Santos, Anne; Navarrete Santos, Alexander

Highlights: Black-Right-Pointing-Pointer Endocrine disrupting chemicals affect adipogenesis in mesenchymal stem cells (MSC). Black-Right-Pointing-Pointer The adipogenic impact depends strongly on the window of exposure. Black-Right-Pointing-Pointer Bisphenol A reduces the potential of MSC to differentiate into adipocytes. Black-Right-Pointing-Pointer DEHP and TBT trigger the adipogenic differentiation of mesenchymal stem cells. Black-Right-Pointing-Pointer BPA, DEHP and TBT did not affect adipogenesis in embryonic stem cells. -- Abstract: Endocrine disrupting chemicals (EDC) like bisphenol A (BPA), bis(2-ethylhexyl)phthalate (DEHP) and tributyltin (TBT) are ubiquitously present in the environment and in human tissues. They bind to nuclear hormone receptors and affect cellular and developmental processes. In this study,more » we show that BPA, DEHP and TBT affect the adipogenic differentiation of murine mesenchymal stem cells (MSC, C3H/10T1/2) in a concentration-, stage- and compound-specific manner. C3H/10T1/2 cells and embryonic stem cells (CGR8) were exposed to BPA, DEHP or TBT at different stages of cell determination and differentiation (undifferentiated growth, adipogenic induction and terminal adipogenic differentiation). The final amount of differentiated adipocytes, cellular triglyceride content and mRNA expression of adipogenic marker genes (adiponectin, FABP4, PPAR{gamma}2, LPL) were quantified and compared with corresponding unexposed cells. BPA (10 {mu}M) decreased subsequent adipogenic differentiation of MSC, when cells were exposed during undifferentiated growth. In contrast, DEHP (100 {mu}M) during the hormonal induction period, and TBT (100 nM) in all investigated stages, enhanced adipogenesis. Importantly, exposure of undifferentiated murine embryonic stem cells did not show any effect of the investigated EDC on subsequent adipogenic differentiation.« less

Identification, characterization and isolation of a common progenitor for osteoclasts, macrophages and dendritic cells from murine bone marrow and periphery

PubMed Central

Jacome-Galarza, Christian E.; Lee, Sun-Kyeong; Lorenzo, Joseph A.; LeonardoAguila, Hector

2012-01-01

Osteoclasts are specialized bone resorbing cells that derive from monocyte precursors. We have identified three populations of cells with high osteoclastogenic potential in murine bone marrow, which expressed the phenotype: B220−CD3−CD11b−/low CD115+ and either CD117hi, CD117intermediate or CD117low. We have evaluated these populations for their ability to also generate macrophages and dendritic cells. At a single cell level, the population expressing higher CD117 levels was able to generate bone-resorbing osteoclasts, phagocytic macrophages and antigen-presenting dendritic cells in vitro with efficiencies of over 90 percent, indicating that there exists a common developmental pathway for these cell types. Cells with osteoclastogenic potential also exist in blood and peripheral hematopoietic organs. Their functional meaning and/or their relationship with bone marrow progenitors is not well established. Hence, we characterized murine peripheral cell populations for their ability to form osteoclasts, macrophages and dendritic cells in vitro. The spleen and peripheral blood monocyte progenitors share phenotypic markers with bone marrow progenitors, but differ in their expression of CD11b, which was low in bone marrow but high in periphery. We propose that circulating monocyte progenitors are derived from a common bone marrow osteoclasts/macrophage/dendritic cell progenitor (OcMDC), which we have now characterized at a clonal level. However, the lineage relationship between the bone marrow and peripheral monocyte progenitors has yet to be defined. PMID:23165930

The Interactive Roles of Lipopolysaccharides and dsRNA/Viruses on Respiratory Epithelial Cells and Dendritic Cells in Allergic Respiratory Disorders: The Hygiene Hypothesis.

PubMed

Lin, Tsang-Hsiung; Su, Hsing-Hao; Kang, Hong-Yo; Chang, Tsung-Hsien

2017-10-23

The original hygiene hypothesis declares "more infections in early childhood protect against later atopy". According to the hygiene hypothesis, the increased incidence of allergic disorders in developed countries is explained by the decrease of infections. Epithelial cells and dendritic cells play key roles in bridging the innate and adaptive immune systems. Among the various pattern-recognition receptor systems of epithelial cells and dendritic cells, including toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and others, TLRs are the key systems of immune response regulation. In humans, TLRs consist of TLR1 to TLR10. They regulate cellular responses through engagement with TLR ligands, e.g., lipopolysaccharides (LPS) acts through TLR4 and dsRNA acts through TLR3, but there are certain common components between these two TLR pathways. dsRNA activates epithelial cells and dendritic cells in different directions, resulting in allergy-related Th2-skewing tendency in epithelial cells, and Th1-skewing tendency in dendritic cells. The Th2-skewing effect by stimulation of dsRNA on epithelial cells could be suppressed by the presence of LPS above some threshold. When LPS level decreases, the Th2-skewing effect increases. It may be via these interrelated networks and related factors that LPS modifies the allergic responses and provides a plausible mechanism of the hygiene hypothesis. Several hygiene hypothesis-related phenomena, seemingly conflicting, are also discussed in this review, along with their proposed mechanisms.

Adenosine Deaminase Enhances the Immunogenicity of Human Dendritic Cells from Healthy and HIV-Infected Individuals

PubMed Central

Massanella, Marta; Rodríguez-García, Marta; Blanco, Julià; Gatell, José M.; García, Felipe; Gallart, Teresa; Lluis, Carme; Mallol, Josefa

2012-01-01

ADA is an enzyme implicated in purine metabolism, and is critical to ensure normal immune function. Its congenital deficit leads to severe combined immunodeficiency (SCID). ADA binding to adenosine receptors on dendritic cell surface enables T-cell costimulation through CD26 crosslinking, which enhances T-cell activation and proliferation. Despite a large body of work on the actions of the ecto-enzyme ADA on T-cell activation, questions arise on whether ADA can also modulate dendritic cell maturation. To this end we investigated the effects of ADA on human monocyte derived dendritic cell biology. Our results show that both the enzymatic and non-enzymatic activities of ADA are implicated in the enhancement of CD80, CD83, CD86, CD40 and CCR7 expression on immature dendritic cells from healthy and HIV-infected individuals. These ADA-mediated increases in CD83 and costimulatory molecule expression is concomitant to an enhanced IL-12, IL-6, TNF-α, CXCL8(IL-8), CCL3(MIP1-α), CCL4(MIP-1β) and CCL5(RANTES) cytokine/chemokine secretion both in healthy and HIV-infected individuals and to an altered apoptotic death in cells from HIV-infected individuals. Consistently, ADA-mediated actions on iDCs are able to enhance allogeneic CD4 and CD8-T-cell proliferation, globally yielding increased iDC immunogenicity. Taken together, these findings suggest that ADA would promote enhanced and correctly polarized T-cell responses in strategies targeting asymptomatic HIV-infected individuals. PMID:23240012

Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke.

PubMed

Bruno, A; Cipollina, C; Di Vincenzo, S; Siena, L; Dino, P; Di Gaudio, F; Gjomarkaj, M; Pace, E

2017-09-05

Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke. The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA. The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1. Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrastructural characteristics of three undifferentiated mouse embryonic stem cell lines and their differentiated three-dimensional derivatives: a comparative study.

PubMed

Alharbi, Suzan; Elsafadi, Mona; Mobarak, Mohammed; Alrwili, Ali; Vishnubalaji, Radhakrishnan; Manikandan, Muthurangan; Al-Qudsi, Fatma; Karim, Saleh; Al-Nabaheen, May; Aldahmash, Abdullah; Mahmood, Amer

2014-04-01

The fine structures of mouse embryonic stem cells (mESCs) grown as colonies and differentiated in three-dimensional (3D) culture as embryoid bodies (EBs) were analyzed by transmission electron microscopy. Undifferentiated mESCs expressed markers that proved their pluripotency. Differentiated EBs expressed different differentiation marker proteins from the three germ layers. The ultrastructure of mESCs revealed the presence of microvilli on the cell surfaces, large and deep infolded nuclei, low cytoplasm-to-nuclear ratios, frequent lipid droplets, nonprominent Golgi apparatus, and smooth endoplasmic reticulum. In addition, we found prominent juvenile mitochondria and free ribosomes-rich cytoplasm in mESCs. Ultrastructure of the differentiated mESCs as EBs showed different cell arrangements, which indicate the different stages of EB development and differentiation. The morphologies of BALB/c and 129 W9.5 EBs were very similar at day 4, whereas C57BL/6 EBs were distinct from the others at day 4. This finding suggested that differentiation of EBs from different cell lines occurs in the same pattern but not at the same rate. Conversely, the ultrastructure results of BALB/c and 129 W9.5 ESCs revealed differentiating features, such as the dilated profile of a rough endoplasmic reticulum. In addition, we found low expression levels of undifferentiated markers on the outer cells of BALB/c and 129 W9.5 mESC colonies, which suggests a faster differentiation potential.

Olfactory granule cell development in normal and hyperthyroid rats.

PubMed

Brunjes, P C; Schwark, H D; Greenough, W T

1982-10-01

Dendritic development was examined in olfactory bulbs of both normal 7-, 14-, 21- and 60-day-old rats and littermates treated on postnatal days 1-4 with 1 microgram/g body weight of L-thyroxine sodium. Tissue was processed via the Golgi-Cox technique and subjected to quantitative analyses of mitral and internal layer granule cell development. These populations of granule cells were selected because their pattern of late proliferation suggested potentially greater susceptibility to postnatal hormonal alterations. Although neonatal hyperthyroidism induces widespread acceleration of maturation, including precocious chemosensitivity, granule cell development was unaffected relative to littermate controls. Both normal and hyperthyroid groups exhibited an inverted U-shaped pattern of cellular development, with rapid dendritic dendritic growth and expansion occurring during the earliest ages tested, but with loss of processes and dendritic field size occurring after day 21.

Vaccination with dendritic cells pulsed with hepatitis C pseudo particles induces specific immune responses in mice

PubMed Central

Weigand, Kilian; Voigt, Franziska; Encke, Jens; Hoyler, Birgit; Stremmel, Wolfgang; Eisenbach, Christoph

2012-01-01

AIM: To explore dendritic cells (DCs) multiple functions in immune modulation. METHODS: We used bone-marrow derived dendritic cells from BALB/c mice pulsed with pseudo particles from the hepatitis C virus to vaccinate naive BALB/c mice. Hepatitis C virus (HCV) pseudo particles consist of the genotype 1b derived envelope proteins E1 and E2, covering a non-HCV core structure. Thus, not a single epitope, but the whole “viral surface” induces immunogenicity. For vaccination, mature and activated DC were injected subcutaneously twice. RESULTS: Humoral and cellular immune responses measured by enzyme-linked immunosorbent assay and interferon-gamma enzyme-linked immunosorbent spot test showed antibody production as well as T-cells directed against HCV. Furthermore, T-cell responses confirmed two highly immunogenic regions in E1 and E2 outside the hypervariable region 1. CONCLUSION: Our results indicate dendritic cells as a promising vaccination model for HCV infection that should be evaluated further. PMID:22371638

Comparative analysis of signature genes in porcine reproductive and respiratory syndrome virus (PRRSV)-infected porcine monocyte-derived dendritic cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells, e.g. monocytes, macrophages and dendritic cells (DCs), are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these cell...

A bloody mess: dendritic cells use hemophagocytosis to regulate viral inflammation.

PubMed

Miller, Elizabeth; Bhardwaj, Nina

2013-09-19

Previous studies have highlighted the immune-dampening effects of apoptotic cell uptake by phagocytes. Ohyagi et al. (2013) expose a unique mechanism of immune regulation during viral infection, which is mediated through phagocytosis of apoptotic red cells by dendritic cells. Copyright © 2013 Elsevier Inc. All rights reserved.

Cell Type–Specific Three-Dimensional Structure of Thalamocortical Circuits in a Column of Rat Vibrissal Cortex

PubMed Central

de Kock, Christiaan P. J.; Bruno, Randy M.; Ramirez, Alejandro; Meyer, Hanno S.; Dercksen, Vincent J.; Helmstaedter, Moritz; Sakmann, Bert

2012-01-01

Soma location, dendrite morphology, and synaptic innervation may represent key determinants of functional responses of individual neurons, such as sensory-evoked spiking. Here, we reconstruct the 3D circuits formed by thalamocortical afferents from the lemniscal pathway and excitatory neurons of an anatomically defined cortical column in rat vibrissal cortex. We objectively classify 9 cortical cell types and estimate the number and distribution of their somata, dendrites, and thalamocortical synapses. Somata and dendrites of most cell types intermingle, while thalamocortical connectivity depends strongly upon the cell type and the 3D soma location of the postsynaptic neuron. Correlating dendrite morphology and thalamocortical connectivity to functional responses revealed that the lemniscal afferents can account for some of the cell type- and location-specific subthreshold and spiking responses after passive whisker touch (e.g., in layer 4, but not for other cell types, e.g., in layer 5). Our data provides a quantitative 3D prediction of the cell type–specific lemniscal synaptic wiring diagram and elucidates structure–function relationships of this physiologically relevant pathway at single-cell resolution. PMID:22089425

Use of Stirred Suspension Bioreactors for Male Germ Cell Enrichment.

PubMed

Sakib, Sadman; Dores, Camila; Rancourt, Derrick; Dobrinski, Ina

2016-01-01

Spermatogenesis is a stem cell based system. Both therapeutic and biomedical research applications of spermatogonial stem cells require a large number of cells. However, there are only few germ line stem cells in the testis, contained in the fraction of undifferentiated spermatogonia. The lack of specific markers makes it difficult to isolate these cells. The long term maintenance and proliferation of nonrodent germ cells in culture has so far been met with limited success, partially due to the lack of highly enriched starting populations. Differential plating, which depends on the differential adhesion properties of testicular somatic and germ cells to tissue culture dishes, has been the method of choice for germ cell enrichment, especially for nonrodent germ cells. However, for large animals, this process becomes labor intensive and increases variability due to the need for extensive handling. Here, we describe the use of stirred suspension bioreactors, as a novel system for enriching undifferentiated germ cells from 1-week-old pigs. This method capitalizes on the adherent properties of somatic cells within a controlled environment, thus promoting the enrichment of progenitor cells with minimal handling and variability.

Role of hepatocyte growth factor in the development of dendritic cells from CD34+ bone marrow cells.

PubMed

Ovali, E; Ratip, S; Kibaroglu, A; Tekelioglu, Y; Cetiner, M; Karti, S; Aydin, F; Bayik, M; Akoglu, T

2000-05-01

Hepatocyte growth factor (HGF) is known to augment the effects of stem cell factor, interleukin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoetin, and granulocyte colony-stimulating factor, all of which are involved in hematopoiesis. HGF is also known to have a role in immune responses. The aim of this study was to investigate whether HGF is involved in the development of dendritic cells (DC) from CD34+ bone marrow cells. CD34+ cells obtained from three healthy donors were incubated in various combinations of HGF, GM-CSF, and tumor necrosis factor (TNF) for 12 days. Developing cell populations were analyzed for surface markers, morphology and functional capacities by flow cytometry, light microscopy and mixed lymphocyte reaction, respectively. Incubation with HGF alone generated greater number of dendritic cells from CD34+ bone marrow cells than incubation with GM-CSF, or a combination of GM-CSF with TNF. HGF was also found to potentiate the effect of GM-CSF on DC and monocyte development. The effects of HGF were inhibited by the concurrent use of TNF. HGF appears to be a significant factor in the development of dendritic cells from CD34+ bone marrow cells.

Thymic Dendritic Cells Are Primary Targets for the Oncogenic Virus SL3-3

PubMed Central

Uittenbogaart, Christel H.; Law, Wendy; Leenen, Pieter J. M.; Bristol, Gregory; van Ewijk, Willem; Hays, Esther F.

1998-01-01

The murine retrovirus SL3-3 causes malignant transformation of thymocytes and thymic lymphoma in mice of the AKR and NFS strains when they are inoculated neonatally. The objective of the present study was to identify the primary target cells for the virus in the thymuses of these mice. Immunohistochemical studies of the thymus after neonatal inoculation of the SL3-3 virus showed that cells expressing the viral envelope glycoprotein (gp70+ cells) were first seen at 2 weeks of age. These virus-expressing cells were found in the cortex and at the corticomedullary junction in both mouse strains. The gp70+ cells had the morphology and immunophenotype of dendritic cells. They lacked macrophage-specific antigens. Cell separation studies showed that bright gp70+ cells were detected in a fraction enriched for dendritic cells. At 3 weeks of age, macrophages also expressed gp70. At that time, both gp70+ dendritic cells and macrophages were found at the corticomedullary junction and in foci in the thymic cortex. At no time during this 3-week period was the virus expressed in cortical and medullary epithelial cells or in thymic lymphoid cells. Infectious cell center assays indicated that cells expressing infectious virus were present in small numbers at 2 weeks after inoculation but increased at 5 weeks of age by several orders of magnitude, indicating virus spread to the thymic lymphoid cells. Thus, at 2 weeks after neonatal inoculation of SL3-3, thymic dendritic cells are the first cells to express the virus. At 3 weeks of age, macrophages also express the virus. In subsequent weeks, the virus spreads to the thymocytes. This pathway of virus expression in the thymus allows the inevitable provirus integration in a thymocyte that results in a clonal lymphoma. PMID:9811752

Cutaneous myeloid dendritic cell dyscrasia: A cutaneous clonal monocytosis associated with chronic myeloproliferative disorders and peripheral blood monocytosis.

PubMed

Magro, Cynthia M; Momtahen, Shabnam; Verma, Shalini; Abraham, Ronnie M; Friedman, Constantin; Nuovo, Gerard J; Tam, Wayne

2016-12-01

Monocytes are critical components of the innate immune system and they can differentiate into dendritic cells (DCs). Cutaneous neoplasms of dendritic cell origin are uncommon and mostly represented by histiocytic lesions derived primarily from Langerhans cells. The myeloid DC (mDC) while recognized in the immunology literature does not have a well-defined neoplastic cutaneous counterpart. Eleven patients with a diagnosis of cutaneous mDC dyscrasia were evaluated. Routine hematoxylin and eosin stain were performed followed by selective phenotypic studies. The patients were older without a gender predilection and exhibited an asymptomatic papular skin rash with a waxing and waning course. The biopsies demonstrated a dermal based monomorphic small mononuclear cell infiltrate. The cells expressed CD14, CD11c, HLA-DR, as well as granzyme and lysozyme that defines terminally differentiated monocyte/dendritic cells. Expression of BDCA-3 (CD141) by the tumor cells indicated that they were myeloid dendritic cells (mDC2). Each patient had a prior or subsequent diagnosis of an abnormal bone marrow biopsy that included myelodysplastic syndrome, myelofibrosis, chronic myelomonocytic leukemia, and acute myelogenous leukemia. We propose the term cutaneous mDC cell dyscrasia for distinctive infiltrates of differentiated mDCs reflective of underlying myeloproliferative disease. The clinical course is variable and can be indolent although it is strongly correlated with myelodysplastic syndrome that included leukemia. Copyright © 2016 Elsevier Inc. All rights reserved.

Identification of dendritic cells in the blood and synovial fluid of children with Juvenile Idiopathic Arthritis.

PubMed

Tabarkiewicz, Jacek; Postępski, Jacek; Olesińska, Edyta; Roliński, Jacek; Tuszkiewicz-Misztal, Ewa

2011-01-01

Childhood chronic arthritis of unknown etiology is known collectively as juvenile idiopathic arthritis (JIA) and consists of heterogeneous subtypes with unique clinical patterns of disease. JIA is the commonest rheumatic disease in children and may still result in significant disability, with joint deformity, growth impairment, and persistence of active arthritis into adulthood. Basic research is rather focused on rheumatoid arthritis, and this lead to small number of publications considering JIA. In this study we examine, by flow cytometry, the expression of dendritic cells (DCs) in the peripheral blood and synovial fluid of children with active JIA in a group of 220 patients. We reveal a significant decrease in the percentage of immature DCs in the blood of patients compared to control children. Surprisingly, we found higher percentages of mature circulating dendritic cells. Both populations of DCs, immature and mature, were accumulated in patients' synovial fluid. We also confirmed the presence of CD206+/CD209+ in JIA samples, which can represent a population of macrophages with dendritic cells morphology. Our results support the thesis that dendritic cells are crucial in the induction and maintenance of autoimmune response and local inflammation during juvenile idiopathic arthritis.

Regeneration of Drosophila sensory neuron axons and dendrites is regulated by the Akt pathway involving Pten and microRNA bantam

PubMed Central

Song, Yuanquan; Ori-McKenney, Kassandra M.; Zheng, Yi; Han, Chun; Jan, Lily Yeh; Jan, Yuh Nung

2012-01-01

Both cell-intrinsic and extrinsic pathways govern axon regeneration, but only a limited number of factors have been identified and it is not clear to what extent axon regeneration is evolutionarily conserved. Whether dendrites also regenerate is unknown. Here we report that, like the axons of mammalian sensory neurons, the axons of certain Drosophila dendritic arborization (da) neurons are capable of substantial regeneration in the periphery but not in the CNS, and activating the Akt pathway enhances axon regeneration in the CNS. Moreover, those da neurons capable of axon regeneration also display dendrite regeneration, which is cell type-specific, developmentally regulated, and associated with microtubule polarity reversal. Dendrite regeneration is restrained via inhibition of the Akt pathway in da neurons by the epithelial cell-derived microRNA bantam but is facilitated by cell-autonomous activation of the Akt pathway. Our study begins to reveal mechanisms for dendrite regeneration, which depends on both extrinsic and intrinsic factors, including the PTEN–Akt pathway that is also important for axon regeneration. We thus established an important new model system—the fly da neuron regeneration model that resembles the mammalian injury model—with which to study and gain novel insights into the regeneration machinery. PMID:22759636

Twenty years of embryonic stem cell research in farm animals

USDA-ARS?s Scientific Manuscript database

Notable distinctions between an embryonic stem cell (ESC) and somatic cell are that the ESC can maintain an undifferentiated state indefinitely, self renew, and is pluripotent, meaning that the ESC can potentially generate cells representing all the three primordial germ layers and contribute to the...

Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits.

PubMed

Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

2015-12-24

Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits.

Characterization of acute undifferentiated leukemia by combined analysis of plasma membrane-associated gamma-glutamyltranspeptidase and soluble terminal transferase.

PubMed

Heumann, D; Losa, G; Barras, C; Morell, A; von Fliedner, V

1985-08-01

gamma-Glutamyltranspeptidase (gamma-GT) is a plasma membrane-associated enzyme present in blasts of certain acute leukemias. We analyzed 90 cases of undifferentiated and differentiated acute leukemias for gamma-GT, using a colorimetric assay. Blasts of all patients with common acute lymphoblastic leukemia (ALL) and T-ALL were negative for gamma-GT (less than 5 units). In contrast, gamma-GT was significantly elevated in acute myeloblastic or monoblastic leukemia blasts (P less than .001). In 16 cases of acute undifferentiated leukemia (AUL) studied, the levels of gamma-GT ranged from 0 to 93 units; in eight cases, gamma-GT was positive (greater than 5 units), and six of these had 2% to 5% Sudan black-positive leukemic cells in the blast-enriched suspension. Combined gamma-GT/TdT analysis revealed that both enzyme markers were mutually exclusive in 75% of AUL cases, suggesting that gamma-GT+/TdT-blasts are of nonlymphoid origin, and gamma-GT-/TdT+ blasts are of lymphoid origin. Two cases were devoid of both enzyme activities and could represent truly undifferentiated leukemia. Thus, combined gamma-GT/TdT analysis underlines the heterogeneity of AUL and appears to be useful in defining the lineage commitment of undifferentiated leukemic blasts.

Metabolism of two Go alpha isoforms in neuronal cells during differentiation.

PubMed

Brabet, P; Pantaloni, C; Bockaert, J; Homburger, V

1991-07-15

We have previously shown that undifferentiated N1E-115 neuroblastoma cells express only one isoform of Go alpha (pI = 5.8), whereas differentiated neuroblastoma cells expressed, in addition to this isoform, another Go alpha with a more acidic pI (5.55). Moreover, primary cultures of cerebellar granule cells, which are extremely well differentiated cells yielding a high density of synapses, expressed only a single Go alpha isoform with a pI of 5.55 (Brabet, P., Pantaloni, C., Rodriguez Martinez, J., Bockaert, J., and Homburger, V. (1990) J. Neurochem. 54, 1310-1320). In this report, using biosynthetic labeling with [35S]methionine and specific quantitative immunoprecipitation with a polyclonal antibody raised against the purified Go alpha protein, we have determined 1) the degradation rate of total Go alpha (sum of the two isoforms) in differentiated as well as in undifferentiated neuroblastoma cells and in cerebellar granule cells, 2) the degradation rates of each isoform in differentiated neuroblastoma cells. The t 1/2 for total Go alpha protein degradation was very different in the three neuronal cell populations and was 28 +/- 5 h (n = 5), 58 +/- 9 h (n = 5), and 154 +/- 22 h (n = 6) in undifferentiated, differentiated neuroblastoma, and granule cells, respectively. Using two-dimensional gel analysis of immunoprecipitates, we have also determined the individual t 1/2 for degradation of each Go alpha isoform in differentiated neuroblastoma cells, in which the two Go alpha isoforms were expressed. Results indicated that the two Go alpha isoforms exhibit similar t1/2 for degradation (49 +/- 5 h, n = 3). Thus, the t1/2 for degradation of the more basic Go alpha isoform is higher in differentiated neuroblastoma cells (49 +/- 5 h, n = 3) than in undifferentiated neuroblastoma cells (28 +/- 5 h, n = 5) which expressed only the more basic Go alpha isoform. It can be concluded that the degradation rate of the more basic Go alpha isoform is not a characteristic of the protein itself but depends on the state of the cell differentiation. The comparison between the t1/2 for degradation of the more acidic Go alpha isoform is differentiated neuroblastoma cells (51 +/- 6 h, n = 3) with that of cerebellar granule cells (154 +/- 22 h, n = 6) suggests that there is also a decrease in the degradation rate of the more acidic Go alpha isoform during differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)

Proton receptor GPR68 expression in dendritic-cell-like S100β-positive cells of rat anterior pituitary gland: GPR68 induces interleukin-6 gene expression in extracellular acidification.

PubMed

Horiguchi, Kotaro; Higuchi, Masashi; Yoshida, Saishu; Nakakura, Takashi; Tateno, Kozue; Hasegawa, Rumi; Takigami, Shu; Ohsako, Shunji; Kato, Takako; Kato, Yukio

2014-11-01

S100β-positive cells, which do not express the classical pituitary hormones, appear to possess multifunctional properties and are assumed to be heterogeneous in the anterior pituitary gland. The presence of several protein markers has shown that S100β-positive cells are composed of populations such as stem/progenitor cells, epithelial cells, astrocytes and dendritic cells. Recently, we succeeded in separating S100β-positive cells into round-cell (dendritic-cell-like) and process-cell types. We also found the characteristic expression of anti-inflammatory factors (interleukin-6, Il-6) and membrane receptors (integrin β-6) in the round type. Here, we further investigate the function of the subpopulation of S100β-positive cells. Since IL-6 is also a paracrine factor that regulates hormone producing-cells, we examine whether a correlation exists among extracellular acid stress, IL-6 and hormone production by using primary cultures of anterior pituitary cells. Dendritic-cell-like S100β-positive cells notably expressed Gpr68 (proton receptor) and Il-6. Furthermore, the expression of Il-6 and proopiomelanocortin (Pomc) was up-regulated by extracellular acidification. The functional role of IL-6 and GPR68 in the gene expression of Pomc during extracellular acidification was also examined. Small interfering RNA for Il-6 up-regulated Pomc expression and that for Gpr68 reversed the down-regulation of Il-6 and up-regulated Pomc expression by extracellular acidification. Thus, S100β-positive dendritic-like cells can sense an increase in extracellular protons via GPR68 and respond by the production of IL-6 in order to suppress the up-regulation of Pomc expression.

Comparative analysis of signature genes in PRRSV-infected porcine monocyte-derived dendritic cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells including monocytes, macrophages and dendritic cells (DCs) are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these c...

Dynamics of action potential backpropagation in basal dendrites of prefrontal cortical pyramidal neurons.

PubMed

Zhou, Wen-Liang; Yan, Ping; Wuskell, Joseph P; Loew, Leslie M; Antic, Srdjan D

2008-02-01

Basal dendrites of neocortical pyramidal neurons are relatively short and directly attached to the cell body. This allows electrical signals arising in basal dendrites to strongly influence the neuronal output. Likewise, somatic action potentials (APs) should readily propagate back into the basilar dendritic tree to influence synaptic plasticity. Two recent studies, however, determined that sodium APs are severely attenuated in basal dendrites of cortical pyramidal cells, so that they completely fail in distal dendritic segments. Here we used the latest improvements in the voltage-sensitive dye imaging technique (Zhou et al., 2007) to study AP backpropagation in basal dendrites of layer 5 pyramidal neurons of the rat prefrontal cortex. With a signal-to-noise ratio of > 15 and minimal temporal averaging (only four sweeps) we were able to sample AP waveforms from the very last segments of individual dendritic branches (dendritic tips). We found that in short- (< 150 microm) and medium (150-200 microm in length)-range basal dendrites APs backpropagated with modest changes in AP half-width or AP rise-time. The lack of substantial changes in AP shape and dynamics of rise is inconsistent with the AP-failure model. The lack of substantial amplitude boosting of the third AP in the high-frequency burst also suggests that in short- and medium-range basal dendrites backpropagating APs were not severely attenuated. Our results show that the AP-failure concept does not apply in all basal dendrites of the rat prefrontal cortex. The majority of synaptic contacts in the basilar dendritic tree actually received significant AP-associated electrical and calcium transients.

The Dendritic Cell Major Histocompatibility Complex II (MHC II) Peptidome Derives from a Variety of Processing Pathways and Includes Peptides with a Broad Spectrum of HLA-DM Sensitivity*

PubMed Central

Clement, Cristina C.; Becerra, Aniuska; Yin, Liusong; Zolla, Valerio; Huang, Liling; Merlin, Simone; Follenzi, Antonia; Shaffer, Scott A.; Stern, Lawrence J.; Santambrogio, Laura

2016-01-01

The repertoire of peptides displayed in vivo by MHC II molecules derives from a wide spectrum of proteins produced by different cell types. Although intracellular endosomal processing in dendritic cells and B cells has been characterized for a few antigens, the overall range of processing pathways responsible for generating the MHC II peptidome are currently unclear. To determine the contribution of non-endosomal processing pathways, we eluted and sequenced over 3000 HLA-DR1-bound peptides presented in vivo by dendritic cells. The processing enzymes were identified by reference to a database of experimentally determined cleavage sites and experimentally validated for four epitopes derived from complement 3, collagen II, thymosin β4, and gelsolin. We determined that self-antigens processed by tissue-specific proteases, including complement, matrix metalloproteases, caspases, and granzymes, and carried by lymph, contribute significantly to the MHC II self-peptidome presented by conventional dendritic cells in vivo. Additionally, the presented peptides exhibited a wide spectrum of binding affinity and HLA-DM susceptibility. The results indicate that the HLA-DR1-restricted self-peptidome presented under physiological conditions derives from a variety of processing pathways. Non-endosomal processing enzymes add to the number of epitopes cleaved by cathepsins, altogether generating a wider peptide repertoire. Taken together with HLA-DM-dependent and-independent loading pathways, this ensures that a broad self-peptidome is presented by dendritic cells. This work brings attention to the role of “self-recognition” as a dynamic interaction between dendritic cells and the metabolic/catabolic activities ongoing in every parenchymal organ as part of tissue growth, remodeling, and physiological apoptosis. PMID:26740625

Human amniotic epithelial cell feeder layers maintain mouse embryonic stem cell pluripotency via epigenetic regulation of the c-Myc promoter.

PubMed

Liu, Te; Cheng, Weiwei; Liu, Tianjin; Guo, Lihe; Huang, Qin; Jiang, Lizhen; Du, Xiling; Xu, Fuhui; Liu, Zhixue; Lai, Dongmei

2010-02-01

Mouse embryonic stem cells (ESCs) are typically cultured on a feeder layer of mouse embryonic fibroblasts (MEFs), with leukemia inhibitory factor (LIF) added to maintain them in an undifferentiated state. We have previously shown that human amniotic epithelial cells (hAECs) can be used as feeder cells to maintain mouse ESC pluripotency, but the mechanism for this is unknown. In the present study, we found that CpG islands 5' of the c-Myc gene remain hypomethylated in mouse ESCs cultured on hAECs. In addition, levels of acetylation of histone H3 and trimethylation of histone H3K4 in the c-Myc gene promoter were higher in ES cells cultured on hAECs than those in ES cells cultured on MEFs. These data suggested that hAECs can alter mouse ESC gene expression via epigenetic modification of c-Myc, providing a possible mechanism for the hAEC-induced maintenance of ESCs in an undifferentiated state.

Donor Dependent Variations in Hematopoietic Differentiation among Embryonic and Induced Pluripotent Stem Cell Lines

PubMed Central

Féraud, Olivier; Valogne, Yannick; Melkus, Michael W.; Zhang, Yanyan; Oudrhiri, Noufissa; Haddad, Rima; Daury, Aurélie; Rocher, Corinne; Larbi, Aniya; Duquesnoy, Philippe; Divers, Dominique; Gobbo, Emilie; Brunet de la Grange, Philippe; Louache, Fawzia; Bennaceur-Griscelli, Annelise; Mitjavila-Garcia, Maria Teresa

2016-01-01

Hematopoiesis generated from human embryonic stem cells (ES) and induced pluripotent stem cells (iPS) are unprecedented resources for cell therapy. We compared hematopoietic differentiation potentials from ES and iPS cell lines originated from various donors and derived them using integrative and non-integrative vectors. Significant differences in differentiation toward hematopoietic lineage were observed among ES and iPS. The ability of engraftment of iPS or ES-derived cells in NOG mice varied among the lines with low levels of chimerism. iPS generated from ES cell-derived mesenchymal stem cells (MSC) reproduce a similar hematopoietic outcome compared to their parental ES cell line. We were not able to identify any specific hematopoietic transcription factors that allow to distinguish between good versus poor hematopoiesis in undifferentiated ES or iPS cell lines. There is a relatively unpredictable variation in hematopoietic differentiation between ES and iPS cell lines that could not be predicted based on phenotype or gene expression of the undifferentiated cells. These results demonstrate the influence of genetic background in variation of hematopoietic potential rather than the reprogramming process. PMID:26938212

Glutamate-Bound NMDARs Arising from In Vivo-like Network Activity Extend Spatio-temporal Integration in a L5 Cortical Pyramidal Cell Model

PubMed Central

Farinella, Matteo; Ruedt, Daniel T.; Gleeson, Padraig; Lanore, Frederic; Silver, R. Angus

2014-01-01

In vivo, cortical pyramidal cells are bombarded by asynchronous synaptic input arising from ongoing network activity. However, little is known about how such ‘background’ synaptic input interacts with nonlinear dendritic mechanisms. We have modified an existing model of a layer 5 (L5) pyramidal cell to explore how dendritic integration in the apical dendritic tuft could be altered by the levels of network activity observed in vivo. Here we show that asynchronous background excitatory input increases neuronal gain and extends both temporal and spatial integration of stimulus-evoked synaptic input onto the dendritic tuft. Addition of fast and slow inhibitory synaptic conductances, with properties similar to those from dendritic targeting interneurons, that provided a ‘balanced’ background configuration, partially counteracted these effects, suggesting that inhibition can tune spatio-temporal integration in the tuft. Excitatory background input lowered the threshold for NMDA receptor-mediated dendritic spikes, extended their duration and increased the probability of additional regenerative events occurring in neighbouring branches. These effects were also observed in a passive model where all the non-synaptic voltage-gated conductances were removed. Our results show that glutamate-bound NMDA receptors arising from ongoing network activity can provide a powerful spatially distributed nonlinear dendritic conductance. This may enable L5 pyramidal cells to change their integrative properties as a function of local network activity, potentially allowing both clustered and spatially distributed synaptic inputs to be integrated over extended timescales. PMID:24763087

Rapid, directed transport of DC-SIGN clusters in the plasma membrane

PubMed Central

Liu, Ping; Weinreb, Violetta; Ridilla, Marc; Betts, Laurie; Patel, Pratik; de Silva, Aravinda M.; Thompson, Nancy L.; Jacobson, Ken

2017-01-01

C-type lectins, including dendritic cell–specific intercellular adhesion molecule-3–grabbing nonintegrin (DC-SIGN), are all-purpose pathogen receptors that exist in nanoclusters in plasma membranes of dendritic cells. A small fraction of these clusters, obvious from the videos, can undergo rapid, directed transport in the plane of the plasma membrane at average speeds of more than 1 μm/s in both dendritic cells and MX DC-SIGN murine fibroblasts ectopically expressing DC-SIGN. Surprisingly, instantaneous speeds can be considerably greater. In MX DC-SIGN cells, many cluster trajectories are colinear with microtubules that reside close to the ventral membrane, and the microtubule-depolymerizing drug, nocodazole, markedly reduced the areal density of directed movement trajectories, suggesting a microtubule motor–driven transport mechanism; by contrast, latrunculin A, which affects the actin network, did not depress this movement. Rapid, retrograde movement of DC-SIGN may be an efficient mechanism for bringing bound pathogen on the leading edge and projections of dendritic cells to the perinuclear region for internalization and processing. Dengue virus bound to DC-SIGN on dendritic projections was rapidly transported toward the cell center. The existence of this movement within the plasma membrane points to an unexpected lateral transport mechanism in mammalian cells and challenges our current concepts of cortex-membrane interactions. PMID:29134199

Transient potentials in dendritic systems of arbitrary geometry.

PubMed

Butz, E G; Cowan, J D

1974-09-01

A simple graphical calculus is developed that generates analytic solutions for membrane potential transforms at any point on the dendritic tree of neurons with arbitrary dendritic geometries, in response to synaptic "current" inputs. Such solutions permit the computation of transients in neurons with arbitrary geometry and may facilitate analysis of the role of dendrites in such cells.

Established Stem Cell Model of Spinal Muscular Atrophy Is Applicable in the Evaluation of the Efficacy of Thyrotropin-Releasing Hormone Analog

PubMed Central

Ohuchi, Kazuki; Kato, Zenichiro; Seki, Junko; Kawase, Chizuru; Tamai, Yuya; Ono, Yoko; Nagahara, Yuki; Noda, Yasuhiro; Kameyama, Tsubasa; Ando, Shiori; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Hara, Hideaki; Kaneko, Hideo

2016-01-01

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by the degeneration of spinal motor neurons. This disease is mainly caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Currently, no effective treatment is available, and only symptomatic treatment can be provided. Our purpose in the present study was to establish a human SMA-derived induced pluripotent stem cell (SMA-iPSC) disease model and assay a therapeutic drug in preparation for the development of a novel treatment of SMA. We generated iPSCs from the skin fibroblasts of a patient with SMA and confirmed that they were pluripotent and undifferentiated. The neural differentiation of SMA-iPSCs shortened the dendrite and axon length and increased the apoptosis of the spinal motor neurons. In addition, we found activated astrocytes in differentiated SMA-iPSCs. Using this model, we confirmed that treatment with the thyrotropin-releasing hormone (TRH) analog, 5-oxo-l-prolyl-l-histidyl-l-prolinamide, which had marginal effects in clinical trials, increases the SMN protein level. This increase was mediated through the transcriptional activation of the SMN2 gene and inhibition of glycogen synthase kinase-3β activity. Finally, the TRH analog treatment resulted in dendrite and axon development of spinal motor neurons in differentiated SMA-iPSCs. These results suggest that this human in vitro disease model stimulates SMA pathology and reveal the potential efficacy of TRH analog treatment for SMA. Therefore, we can screen novel therapeutic drugs such as TRH for SMA easily and effectively using the human SMA-iPSC model. Significance Platelet-derived growth factor (PDGF) has recently been reported to produce the greatest increase in survival motor neuron protein levels by inhibiting glycogen synthase kinase (GSK)-3β; however, motor neurons lack PDGF receptors. A human in vitro spinal muscular atrophy-derived induced pluripotent stem cell model was established, which showed that the thyrotropin releasing hormone (TRH) analog promoted transcriptional activation of the SMN2 gene and inhibition of GSK-3β activity, resulting in the increase and stabilization of the SMN protein and axon elongation of spinal motor neurons. These results reveal the potential efficacy of TRH analog treatment for SMA. PMID:26683872

Established Stem Cell Model of Spinal Muscular Atrophy Is Applicable in the Evaluation of the Efficacy of Thyrotropin-Releasing Hormone Analog.

PubMed

Ohuchi, Kazuki; Funato, Michinori; Kato, Zenichiro; Seki, Junko; Kawase, Chizuru; Tamai, Yuya; Ono, Yoko; Nagahara, Yuki; Noda, Yasuhiro; Kameyama, Tsubasa; Ando, Shiori; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Hara, Hideaki; Kaneko, Hideo

2016-02-01

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by the degeneration of spinal motor neurons. This disease is mainly caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Currently, no effective treatment is available, and only symptomatic treatment can be provided. Our purpose in the present study was to establish a human SMA-derived induced pluripotent stem cell (SMA-iPSC) disease model and assay a therapeutic drug in preparation for the development of a novel treatment of SMA. We generated iPSCs from the skin fibroblasts of a patient with SMA and confirmed that they were pluripotent and undifferentiated. The neural differentiation of SMA-iPSCs shortened the dendrite and axon length and increased the apoptosis of the spinal motor neurons. In addition, we found activated astrocytes in differentiated SMA-iPSCs. Using this model, we confirmed that treatment with the thyrotropin-releasing hormone (TRH) analog, 5-oxo-l-prolyl-l-histidyl-l-prolinamide, which had marginal effects in clinical trials, increases the SMN protein level. This increase was mediated through the transcriptional activation of the SMN2 gene and inhibition of glycogen synthase kinase-3β activity. Finally, the TRH analog treatment resulted in dendrite and axon development of spinal motor neurons in differentiated SMA-iPSCs. These results suggest that this human in vitro disease model stimulates SMA pathology and reveal the potential efficacy of TRH analog treatment for SMA. Therefore, we can screen novel therapeutic drugs such as TRH for SMA easily and effectively using the human SMA-iPSC model. Significance: Platelet-derived growth factor (PDGF) has recently been reported to produce the greatest increase in survival motor neuron protein levels by inhibiting glycogen synthase kinase (GSK)-3β; however, motor neurons lack PDGF receptors. A human in vitro spinal muscular atrophy-derived induced pluripotent stem cell model was established, which showed that the thyrotropin releasing hormone (TRH) analog promoted transcriptional activation of the SMN2 gene and inhibition of GSK-3β activity, resulting in the increase and stabilization of the SMN protein and axon elongation of spinal motor neurons. These results reveal the potential efficacy of TRH analog treatment for SMA. ©AlphaMed Press.

Combination Chemotherapy and Peripheral Stem Cell Transplantation in Treating Patients With Stage III Ovarian Cancer

ClinicalTrials.gov

2017-08-08

Malignant Ovarian Mixed Epithelial Tumor; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Cystadenocarcinoma; Ovarian Serous Cystadenocarcinoma; Primary Peritoneal Carcinoma; Stage III Ovarian Cancer; Undifferentiated Ovarian Carcinoma

Neocortical layers I and II of the hedgehog (Erinaceus europaeus). I. Intrinsic organization.

PubMed

Valverde, F; Facal-Valverde, M V

1986-01-01

The intrinsic organization and interlaminar connections in neocortical layers I and II have been studied in adult hedgehogs (Erinaceus europaeus) using the Golgi method. Layer I contains a dense plexus of horizontal fibers, the terminal dendritic bouquets of pyramidal cells of layer II and of underlying layers, and varieties of intrinsic neurons. Four main types of cells were found in layer I. Small horizontal cells represent most probably persisting foetal horizontal cells described for other mammals. Large horizontal cells, tufted cells, and spinous horizontal cells were also found in this layer. Layer II contains primitive pyramidal cells representing the most outstanding feature of the neocortex of the hedgehog. Most pyramidal cells in layer II have two, three or more apical dendrites, richly covered by spines predominating over the basal dendrites. These cells resemble pyramidal cells found in the piriform cortex, hippocampus and other olfactory areas. It is suggested that the presence of these neurons reflects the retention of a primitive character in neocortical evolution. Cells with intrinsic axons were found among pyramidal cells in layer II. These have smooth dendrites penetrating layer I and local axons forming extremely complex terminal arborizations around the bodies and proximal dendritic portions of pyramidal cells. They most probably effect numerous axo-somatic contacts resembling basket cells. The similarity of some axonal terminals with the chandelier type of axonal arborization is discussed. Other varieties of cells located in deep cortical layers and having ascending axons for layers I and II were also studied. It is concluded that the two first neocortical layers represent a level of important integration in this primitive mammal.

Dendro-dendritic interactions between motion-sensitive large-field neurons in the fly.

PubMed

Haag, Juergen; Borst, Alexander

2002-04-15

For visual course control, flies rely on a set of motion-sensitive neurons called lobula plate tangential cells (LPTCs). Among these cells, the so-called CH (centrifugal horizontal) cells shape by their inhibitory action the receptive field properties of other LPTCs called FD (figure detection) cells specialized for figure-ground discrimination based on relative motion. Studying the ipsilateral input circuitry of CH cells by means of dual-electrode and combined electrical-optical recordings, we find that CH cells receive graded input from HS (large-field horizontal system) cells via dendro-dendritic electrical synapses. This particular wiring scheme leads to a spatial blur of the motion image on the CH cell dendrite, and, after inhibiting FD cells, to an enhancement of motion contrast. This could be crucial for enabling FD cells to discriminate object from self motion.

Olfactory epithelium influences the orientation of mitral cell dendrites during development.

PubMed

López-Mascaraque, Laura; García, Concepción; Blanchart, Albert; De Carlos, Juan A

2005-02-01

We have established previously that, although the olfactory epithelium is absent in the homozygous Pax-6 mutant mouse, an olfactory bulb-like structure (OBLS) does develop. Moreover, this OBLS contains cells that correspond to mitral cells, the primary projection neurons in the olfactory bulb. The current study aimed to address whether the dendrites of mitral cells in the olfactory bulb or in the OBLS mitral-like cells, exhibit a change in orientation in the presence of the olfactory epithelium. The underlying hypothesis is that the olfactory epithelium imparts a trophic signal on mitral and mitral-like cell that influences the growth of their primary dendrites, orientating them toward the surface of the olfactory bulb. Hence, we cultured hemibrains from wild-type and Pax 6 mutant mice from two different embryonic stages (embryonic days 14 and 15) either alone or in coculture with normal olfactory epithelial explants or control tissue (cerebellum). Our results indicate that the final dendritic orientation of mitral and mitral-like cells is directly influenced both by age and indeed by the presence of the olfactory epithelium. Copyright 2004 Wiley-Liss, Inc.

Effects of a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen and ultraviolet-A radiation on murine dendritic epidermal cells.

PubMed

Aubin, F; Alcalay, J; Dall'Acqua, F; Kripke, M L

1990-06-01

Although some psoralens are therapeutically active in the treatment of cutaneous hyperproliferative diseases when combined with UVA (320-400 nm) radiation, the toxic effects of these compounds have led physicians to seek new photochemotherapeutic agents. One such agent is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional psoralen compound. We investigated the effects of repetitive treatments with TMAP plus UVA radiation on the number of dendritic immune cells in murine epidermis and on the induction of phototoxicity. Mice treated 3 times per week for 4 weeks with 129 microgram TMAP plus 10 kJ/m2 UVA radiation exhibited no gross or microscopic evidence of phototoxicity. During this treatment, the numbers of ATPase+, Ia+, and Thy-l+ dendritic epidermal cells were greatly reduced, and by the end of the treatment period, few dendritic immune cells could be detected. We conclude that morphological alterations of cutaneous immune cells can occur in the absence of overt phototoxicity, and that TMAP plus low-dose UVA radiation decreases the numbers of detectable Langerhans cells and Thy-1+ cells in murine skin.

Generating synchrony from the asynchronous: compensation for cochlear traveling wave delays by the dendrites of individual brainstem neurons

PubMed Central

McGinley, Matthew J.; Liberman, M. Charles; Bal, Ramazan; Oertel, Donata

2012-01-01

Broadband transient sounds, such as clicks and consonants, activate a traveling wave in the cochlea. This wave evokes firing in auditory nerve fibers that are tuned to high frequencies several milliseconds earlier than in fibers tuned to low frequencies. Despite this substantial traveling wave delay, octopus cells in the brainstem receive broadband input and respond to clicks with submillisecond temporal precision. The dendrites of octopus cells lie perpendicular to the tonotopically organized array of auditory nerve fibers, placing the earliest arriving inputs most distally and the latest arriving closest to the soma. Here, we test the hypothesis that the topographic arrangement of synaptic inputs on dendrites of octopus cells allows octopus cells to compensate the traveling wave delay. We show that in mice the full cochlear traveling wave delay is 1.6 ms. Because the dendrites of each octopus cell spread across about one third of the tonotopic axis, a click evokes a soma directed sweep of synaptic input lasting 0.5 ms in individual octopus cells. Morphologically and biophysically realistic, computational models of octopus cells show that soma-directed sweeps with durations matching in vivo measurements result in the largest and sharpest somatic excitatory postsynaptic potentials (EPSPs). A low input resistance and activation of a low-voltage-activated potassium conductance that are characteristic of octopus cells are important determinants of sweep sensitivity. We conclude that octopus cells have dendritic morphologies and biophysics tailored to accomplish the precise encoding of broadband transient sounds. PMID:22764237

Dendritic Cell-Mediated T Cell Proliferation -A Functional Bioindicator of Inflammatory Source-Specific Particulate Matter

EPA Science Inventory

Previously we found that dendritic cells (DC) were sensitive functional bioindicators of ambient PM (APM) exposure mediating Th2-allergic inflammation in the draining lymph nodes. Here, the ability of bone-marrow-derived DC (DC) and putative BM-derived basophils (Ba) to present a...

Phenotypic, ultra-structural and functional characterization of bovine peripheral blood dendritic cell subsets

USDA-ARS?s Scientific Manuscript database

Dendritic cells (DC) are multifunctional cells that bridge the gap between innate and adaptive immune systems. In bovine, significant information is lacking on the precise identity and role of peripheral blood DC subsets. In this study, we identify and characterize bovine peripheral blood DC subsets...

Pre-differentiation of human neural stem cells into GABAergic neurons prior to transplant results in greater repopulation of the damaged brain and accelerates functional recovery after transient ischemic stroke.

PubMed

Abeysinghe, Hima C S; Bokhari, Laita; Quigley, Anita; Choolani, Mahesh; Chan, Jerry; Dusting, Gregory J; Crook, Jeremy M; Kobayashi, Nao R; Roulston, Carli L

2015-09-29

Despite attempts to prevent brain injury during the hyperacute phase of stroke, most sufferers end up with significant neuronal loss and functional deficits. The use of cell-based therapies to recover the injured brain offers new hope. In the current study, we employed human neural stem cells (hNSCs) isolated from subventricular zone (SVZ), and directed their differentiation into GABAergic neurons followed by transplantation to ischemic brain. Pre-differentiated GABAergic neurons, undifferentiated SVZ-hNSCs or media alone were stereotaxically transplanted into the rat brain (n=7/group) 7 days after endothelin-1 induced stroke. Neurological outcome was assessed by neurological deficit scores and the cylinder test. Transplanted cell survival, cellular phenotype and maturation were assessed using immunohistochemistry and confocal microscopy. Behavioral assessments revealed accelerated improvements in motor function 7 days post-transplant in rats treated with pre-differentiated GABAergic cells in comparison to media alone and undifferentiated hNSC treated groups. Histopathology 28 days-post transplant indicated that pre-differentiated cells maintained their GABAergic neuronal phenotype, showed evidence of synaptogenesis and up-regulated expression of both GABA and calcium signaling proteins associated with neurotransmission. Rats treated with pre-differentiated cells also showed increased neurogenic activity within the SVZ at 28 days, suggesting an additional trophic role of these GABAergic cells. In contrast, undifferentiated SVZ-hNSCs predominantly differentiated into GFAP-positive astrocytes and appeared to be incorporated into the glial scar. Our study is the first to show enhanced exogenous repopulation of a neuronal phenotype after stroke using techniques aimed at GABAergic cell induction prior to delivery that resulted in accelerated and improved functional recovery.

Astragalus Root and Elderberry Fruit Extracts Enhance the IFN-β Stimulatory Effects of Lactobacillus acidophilus in Murine-Derived Dendritic Cells

PubMed Central

Frøkiær, Hanne; Henningsen, Louise; Metzdorff, Stine Broeng; Weiss, Gudrun; Roller, Marc; Flanagan, John; Fromentin, Emilie; Ibarra, Alvin

2012-01-01

Many foods and food components boost the immune system, but little data are available regarding the mechanisms by which they do. Bacterial strains have disparate effects in stimulating the immune system. Indendritic cells, the gram-negative bacteria Escherichia coli upregulates proinflammatory cytokines, whereas gram-positive Lactobacillus acidophilus induces a robust interferon (IFN)-β response. The immune-modulating effects of astragalus root and elderberry fruit extracts were examined in bone marrow-derived murine dendritic cells that were stimulated with L. acidophilus or E. coli. IFN-β and other cytokines were measured by ELISA and RT-PCR. Endocytosis of fluorescence-labeled dextran and L. acidophilus in the presence of elderberry fruit or astragalus root extract was evaluated in dendritic cells. Our results show that both extracts enhanced L. acidophilus-induced IFN-β production and slightly decreased the proinflammatory response to E. coli. The enhanced IFN-β production was associated with upregulation of toll-like receptor 3 and to a varying degree, the cytokines IL-12, IL-6, IL-1β and TNF-α. Both extracts increased endocytosis in immature dendritic cells, and only slightly influenced the viability of the cells. In conclusion, astragalus root and elderberry fruit extracts increase the IFN-β inducing activity of L. acidophilus in dendritic cells, suggesting that they may exert antiviral and immune-enhancing activity. PMID:23118903

Intensity-Modulated or Proton Radiation Therapy for Sinonasal Malignancy

ClinicalTrials.gov

2018-02-13

Adenoid Cystic Carcinoma; Squamous Cell Carcinoma; Sinonasal Carcinoma; Sinonasal Undifferentiated Carcinoma; Mucoepidermoid Carcinoma; Schneiderian Carcinoma; Myoepithelial Carcinoma; Esthesioneuroblastoma; Melanoma

Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

DTIC Science & Technology

2013-07-01

by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy PRINCIPAL INVESTIGATOR: David J. Chung, MD, PhD...2013 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-11-1-0384 Evaluation of Immune Responses Mediated by Listeria -Stimulated Human Dendritic...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The purpose of this project is to study the immunomodulatory effect of Listeria on human

[Incidence of anaplastic tumor in structure of other histologic forms of the thyroid gland cancer].

PubMed

Vinnik, Iu A; Gorbenko, V N; Vas'ko, A R; Kikhtenko, E V; Gargin, V V

2014-01-01

The degrees of invasiveness, proliferative activity, morphofunctional activity of nuclei in the thyroidal gland tumors were studied, while analyzing material, obtained in 1343 patients, suffering thyroidal gland cancer (THGC) and operated on in 2000-2013 yrs. Morphological point quantity of malignancy (as a criterion of the tumor progression grade) and mitotic activity in cellular population were determined in various kinds of THGC. Undifferentiated (anaplastic carcinoma) type of THGC is the most malignant one. There were determined a spindle-like, giant-cell and squamous-cell forms of undifferentiated THGC. The presence of sites of differentiated cancer in 33% of histological preparations witnesses the interrelationship with the earlier existed pathological process.

Use of electron microscopy to classify canine perivascular wall tumors.

PubMed

Palmieri, C; Avallone, G; Cimini, M; Roccabianca, P; Stefanello, D; Della Salda, L

2013-03-01

The histologic classification of canine perivascular wall tumors (PWTs) is controversial. Many PWTs are still classified as hemangiopericytomas (HEPs), and the distinction from peripheral nerve sheath tumors (PNSTs) is still under debate. A recent histologic classification of canine soft tissue sarcomas included most histologic types of PWT but omitted those that were termed undifferentiated. Twelve cases of undifferentiated canine PWTs were evaluated by transmission electron microscopy. The ultrastructural findings supported a perivascular wall origin for all cases with 4 categories of differentiation: myopericytic (n = 4), myofibroblastic (n = 1), fibroblastic (n = 2), and undifferentiated (n = 5). A PNST was considered unlikely in each case based on immunohistochemical expression of desmin and/or the lack of typical ultrastructural features, such as basal lamina. Electron microscopy was pivotal for the subclassification of canine PWTs, and the results support the hypothesis that canine PWTs represent a continuum paralleling the phenotypic plasticity of vascular mural cells. The hypothesis that a subgroup of PWTs could arise from a pluripotent mesenchymal perivascular wall cell was also considered and may explain the diverse differentiation of canine PWTs.

Chronic alcohol exposure affects the cell components involved in membrane traffic in neuronal dendrites.

PubMed

Romero, Ana M; Renau-Piqueras, Jaime; Marín, M Pilar; Esteban-Pretel, Guillermo

2015-01-01

The specific traffic of the membrane components in neurons is a major requirement to establish and maintain neuronal domains-the axonal and the somatodendritic domains-and their polarized morphology. Unlike axons, dendrites contain membranous organelles, which are involved in the secretory pathway, including the endoplasmic reticulum, the Golgi apparatus and post-Golgi apparatus carriers, the cytoskeleton, and plasma membrane. A variety of molecules and factors are also involved in this process. Previous studies have shown that chronic alcohol exposure negatively affects several of these cell components, such as the Golgi apparatus or cytoskeleton in neurons. Yet very little information is available on the possible effects of this exposure on the remaining cell elements involved in intracellular trafficking in neurons, particularly in dendrites. By qualitative and quantitative electron microscopy, immunofluorescence and immunoblotting, we herein show that chronic exposure to moderate levels (30 mM) of ethanol in cultured neurons reduces the volume and surface density of the rough endoplasmic reticulum, and increases the levels of GRP78, a chaperone involved in endoplasmic reticulum stress. Ethanol also significantly diminishes the proportion of neurons that show an extension of Golgi into dendrites and dendritic Golgi outposts, a structure present exclusively in longer, thicker apical dendrites. Both Golgi apparatus types were also fragmented into a large number of cells. We also investigated the effect of alcohol on the levels of microtubule-based motor proteins KIF5, KIF17, KIFC2, dynein, and myosin IIb, responsible for transporting different cargoes in dendrites. Of these, alcohol differently affects several of them by lowering dynein and raising KIF5, KIFC2, and myosin IIb. These results, together with other previously published ones, suggest that practically all the protein trafficking steps in dendrites are altered to a greater or lesser extent by chronic alcohol exposure in neuronal cells, which may have negative repercussions for the development and maintenance of their polarized morphology and function.

Adoptive TReg Cell for Suppression of aGVHD After UCB HSCT for Heme Malignancies

ClinicalTrials.gov

2018-03-26

Acute Lymphoblastic Leukemia; Burkitt Lymphoma; Natural Killer Cell Malignancies; Chronic Myelogenous Leukemia; Myelodysplastic Syndromes; Large-cell Lymphoma; Chronic Lymphocytic Leukemia; Small Lymphocytic Lymphoma; Marginal Zone B-Cell Lymphoma; Follicular Lymphoma; Lymphoplasmacytic Lymphoma; Mantle-Cell Lymphoma; Prolymphocytic Leukemia; Hodgkin Lymphoma; Multiple Myeloma; Acute Myelogenous Leukemia; Biphenotypic Leukemia; Undifferentiated Leukemia

Musical representation of dendritic spine distribution: a new exploratory tool.

PubMed

Toharia, Pablo; Morales, Juan; de Juan, Octavio; Fernaud, Isabel; Rodríguez, Angel; DeFelipe, Javier

2014-04-01

Dendritic spines are small protrusions along the dendrites of many types of neurons in the central nervous system and represent the major target of excitatory synapses. For this reason, numerous anatomical, physiological and computational studies have focused on these structures. In the cerebral cortex the most abundant and characteristic neuronal type are pyramidal cells (about 85 % of all neurons) and their dendritic spines are the main postsynaptic target of excitatory glutamatergic synapses. Thus, our understanding of the synaptic organization of the cerebral cortex largely depends on the knowledge regarding synaptic inputs to dendritic spines of pyramidal cells. Much of the structural data on dendritic spines produced by modern neuroscience involves the quantitative analysis of image stacks from light and electron microscopy, using standard statistical and mathematical tools and software developed to this end. Here, we present a new method with musical feedback for exploring dendritic spine morphology and distribution patterns in pyramidal neurons. We demonstrate that audio analysis of spiny dendrites with apparently similar morphology may "sound" quite different, revealing anatomical substrates that are not apparent from simple visual inspection. These morphological/music translations may serve as a guide for further mathematical analysis of the design of the pyramidal neurons and of spiny dendrites in general.

Dendrite architecture organized by transcriptional control of the F-actin nucleator Spire.

PubMed

Ferreira, Tiago; Ou, Yimiao; Li, Sally; Giniger, Edward; van Meyel, Donald J

2014-02-01

The architectures of dendritic trees are crucial for the wiring and function of neuronal circuits because they determine coverage of receptive territories, as well as the nature and strength of sensory or synaptic inputs. Here, we describe a cell-intrinsic pathway sculpting dendritic arborization (da) neurons in Drosophila that requires Longitudinals Lacking (Lola), a BTB/POZ transcription factor, and its control of the F-actin cytoskeleton through Spire (Spir), an actin nucleation protein. Loss of Lola from da neurons reduced the overall length of dendritic arbors, increased the expression of Spir, and produced inappropriate F-actin-rich dendrites at positions too near the cell soma. Selective removal of Lola from only class IV da neurons decreased the evasive responses of larvae to nociception. The increased Spir expression contributed to the abnormal F-actin-rich dendrites and the decreased nocifensive responses because both were suppressed by reduced dose of Spir. Thus, an important role of Lola is to limit expression of Spir to appropriate levels within da neurons. We found Spir to be expressed in dendritic arbors and to be important for their development. Removal of Spir from class IV da neurons reduced F-actin levels and total branch number, shifted the position of greatest branch density away from the cell soma, and compromised nocifensive behavior. We conclude that the Lola-Spir pathway is crucial for the spatial arrangement of branches within dendritic trees and for neural circuit function because it provides balanced control of the F-actin cytoskeleton.

The Cell-Surface N-Glycome of Human Embryonic Stem Cells and Differentiated Hepatic Cells thereof.

PubMed

Montacir, Houda; Freyer, Nora; Knöspel, Fanny; Urbaniak, Thomas; Dedova, Tereza; Berger, Markus; Damm, Georg; Tauber, Rudolf; Zeilinger, Katrin; Blanchard, Véronique

2017-07-04

Human embryonic stem cells (hESCs) are pluripotent stem cells that offer a wide range of applications in regenerative medicine. In addition, they have been proposed as an appropriate alternative source of hepatocytes. In this work, hESCs were differentiated into definitive endodermal cells (DECs), followed by maturation into hepatocyte-like cells (HLCs). Their cell-surface N-glycome was profiled and also compared with that of primary human hepatocytes (PHHs). Undifferentiated hESCs contained large amounts of high-mannose N-glycans. In contrast, complex-type N-glycans such as asialylated or monosialylated biantennary and triantennary N-glycans were dominant in HLCs, and fully galactosylated structures were significantly more abundant than in undifferentiated hESCs. The cell-surface N-glycosylation of PHHs was more biologically processed than that of HLCs, with bisialylated biantennary and trisialylated triantennary structures predominant. This is the first report of the cell surface N-glycome of PHHs and of HLCs being directly generated from hESCs without embryoid body formation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mice cloned from skin cells.

PubMed

Li, Jinsong; Greco, Valentina; Guasch, Géraldine; Fuchs, Elaine; Mombaerts, Peter

2007-02-20

Adult stem cells represent unique populations of undifferentiated cells with self-renewal capacity. In many tissues, stem cells divide less often than their progeny. It has been widely speculated, but largely untested, that their undifferentiated and quiescent state may make stem cells more efficient as donors for cloning by nuclear transfer (NT). Here, we report the use of nuclei from hair follicle stem cells and other skin keratinocytes as NT donors. When keratinocyte stem cells (KSCs) were used as NT donors, 19 liveborn mice were obtained, 9 of which survived to adulthood. Embryonic keratinocytes and cumulus cells also gave rise to cloned mice. Although cloning efficiencies were similar (<6% per transferred blastocyst), success rates were consistently higher for males than for females. Adult keratinocyte stem cells were better NT donors than so-called transit amplifying (TA) keratinocytes in both sexes (1.6% vs. 0% in females and 5.4% vs. 2.8% in males). Our findings reveal skin as a source of readily accessible stem cells, the nuclei of which can be reprogrammed to the pluripotent state by exposure to the cytoplasm of unfertilized oocytes.

Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas.

PubMed

Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

2014-08-01

Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas.

Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas

PubMed Central

Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

2014-01-01

Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas. PMID:25081193

Dendritic spikes amplify the synaptic signal to enhance detection of motion in a simulation of the direction-selective ganglion cell.

PubMed

Schachter, Michael J; Oesch, Nicholas; Smith, Robert G; Taylor, W Rowland

2010-08-19

The On-Off direction-selective ganglion cell (DSGC) in mammalian retinas responds most strongly to a stimulus moving in a specific direction. The DSGC initiates spikes in its dendritic tree, which are thought to propagate to the soma with high probability. Both dendritic and somatic spikes in the DSGC display strong directional tuning, whereas somatic PSPs (postsynaptic potentials) are only weakly directional, indicating that spike generation includes marked enhancement of the directional signal. We used a realistic computational model based on anatomical and physiological measurements to determine the source of the enhancement. Our results indicate that the DSGC dendritic tree is partitioned into separate electrotonic regions, each summing its local excitatory and inhibitory synaptic inputs to initiate spikes. Within each local region the local spike threshold nonlinearly amplifies the preferred response over the null response on the basis of PSP amplitude. Using inhibitory conductances previously measured in DSGCs, the simulation results showed that inhibition is only sufficient to prevent spike initiation and cannot affect spike propagation. Therefore, inhibition will only act locally within the dendritic arbor. We identified the role of three mechanisms that generate directional selectivity (DS) in the local dendritic regions. First, a mechanism for DS intrinsic to the dendritic structure of the DSGC enhances DS on the null side of the cell's dendritic tree and weakens it on the preferred side. Second, spatially offset postsynaptic inhibition generates robust DS in the isolated dendritic tips but weak DS near the soma. Third, presynaptic DS is apparently necessary because it is more robust across the dendritic tree. The pre- and postsynaptic mechanisms together can overcome the local intrinsic DS. These local dendritic mechanisms can perform independent nonlinear computations to make a decision, and there could be analogous mechanisms within cortical circuitry.

Transient Potentials in Dendritic Systems of Arbitrary Geometry

PubMed Central

Butz, Edward G.; Cowan, Jack D.

1974-01-01

A simple graphical calculus is developed that generates analytic solutions for membrane potential transforms at any point on the dendritic tree of neurons with arbitrary dendritic geometries, in response to synaptic “current” inputs. Such solutions permit the computation of transients in neurons with arbitrary geometry and may facilitate analysis of the role of dendrites in such cells. PMID:4416699

Neurotrophic and Neurotoxic Effects of Amyloid |beta Protein: Reversal by Tachykinin Neuropeptides

NASA Astrophysics Data System (ADS)

Yankner, Bruce A.; Duffy, Lawrence K.; Kirschner, Daniel A.

1990-10-01

The amyloid β protein is deposited in the brains of patients with Alzheimer's disease but its pathogenic role is unknown. In culture, the amyloid β protein was neurotrophic to undifferentiated hippocampal neurons at low concentrations and neurotoxic to mature neurons at higher concentrations. In differentiated neurons, amyloid β protein caused dendritic and axonal retraction followed by neuronal death. A portion of the amyloid β protein (amino acids 25 to 35) mediated both the trophic and toxic effects and was homologous to the tachykinin neuropeptide family. The effects of the amyloid β protein were mimicked by tachykinin antagonists and completely reversed by specific tachykinin agonists. Thus, the amyloid β protein could function as a neurotrophic factor for differentiating neurons, but at high concentrations in mature neurons, as in Alzheimer's disease, could cause neuronal degeneration.

Differentiation of neuroblastoma cell line N1E-115 involves several signaling cascades.

PubMed

Oh, Ji-eun; Karlmark, Karlin Raja; Shin, Joo-ho; Pollak, Arnold; Freilinger, Angelika; Hengstschläger, Markus; Lubec, Gert

2005-03-01

No systematic searches for differential expression of signaling proteins (SP) in undifferentiated vs. differentiated cell lineages were published and herein we used protein profiling for this purpose. The NIE-115 cell line was cultivated and an aliquot was differentiated with dimethylsulfoxide (DMSO), that is known to lead to a neuronal phenotype. Cell lysates were prepared, run on two-dimensional gel electrophoresis followed by MALDI-TOF-TOF identification of proteins and maps of identified SPs were generated. Seven SPs were comparable, 27 SPs: GTP-binding/Ras-related proteins, kinases, growth factors, calcium binding proteins, phosphatase-related proteins were observed in differentiated NIE-115 cells and eight SPs of the groups mentioned above were observed in undifferentiated cells only. Switching-on/off of several individual SPs from different signaling cascades during the differentiation process is a key to understand mechanisms involved. The findings reported herein are challenging in vitro and in vivo studies to confirm a functional role for deranged SPs.

Osteopontin is a Novel Marker of Pancreatic Ductal Tissues and of Undifferentiated Pancreatic Precursors in Mice

PubMed Central

Kilic, Gamze; Wang, Junfeng; Sosa-Pineda, Beatriz

2008-01-01

Matricellular proteins mediate both tissue morphogenesis and tissue homeostasis in important ways because they modulate cell-matrix and cell-cell interactions. In this study, we found that the matricellular protein osteopontin (Opn) is a novel marker of undifferentiated pancreatic precursors and pancreatic ductal tissues in mice. Our analysis also underscored a specific, dynamic profile of Opn expression in embryonic pancreatic tissues that suggests the participation of this protein’s function in processes involving cell migration, cell-cell interactions, or both. Surprisingly, our analysis of Opn-deficient pancreata did not reveal obvious alterations in the morphology or differentiation of these tissues. Therefore, in embryonic pancreatic tissues, it is possible that other proteins act redundantly to Opn or that this protein’s function is dispensable for pancreas development. Finally, the maintenance of Opn expression in pancreatic tissues of adults argues for a possible function of this protein in injury and pathologic responses. PMID:16518820

Notch3-Jagged signaling controls the pool of undifferentiated airway progenitors

PubMed Central

Mori, Munemasa; Mahoney, John E.; Stupnikov, Maria R.; Paez-Cortez, Jesus R.; Szymaniak, Aleksander D.; Varelas, Xaralabos; Herrick, Dan B.; Schwob, James; Zhang, Hong; Cardoso, Wellington V.

2015-01-01

Basal cells are multipotent airway progenitors that generate distinct epithelial cell phenotypes crucial for homeostasis and repair of the conducting airways. Little is known about how these progenitor cells expand and transition to differentiation to form the pseudostratified airway epithelium in the developing and adult lung. Here, we show by genetic and pharmacological approaches that endogenous activation of Notch3 signaling selectively controls the pool of undifferentiated progenitors of upper airways available for differentiation. This mechanism depends on the availability of Jag1 and Jag2, and is key to generating a population of parabasal cells that later activates Notch1 and Notch2 for secretory-multiciliated cell fate selection. Disruption of this mechanism resulted in aberrant expansion of basal cells and altered pseudostratification. Analysis of human lungs showing similar abnormalities and decreased NOTCH3 expression in subjects with chronic obstructive pulmonary disease suggests an involvement of NOTCH3-dependent events in the pathogenesis of this condition. PMID:25564622

YKL-40 in Serum Samples From Patients With Newly Diagnosed Stage III-IV Ovarian Epithelial, Primary Peritoneal Cavity, or Fallopian Tube Cancer Receiving Chemotherapy

ClinicalTrials.gov

2018-05-21

Fallopian Tube Adenocarcinoma; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Brenner Tumor; Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Endometrioid Tumor; Malignant Ovarian Mixed Epithelial Tumor; Malignant Ovarian Mucinous Tumor; Malignant Ovarian Neoplasm; Malignant Ovarian Serous Tumor; Malignant Ovarian Transitional Cell Tumor; Ovarian Adenocarcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Increased oxidative stress and antioxidant expression in mouse keratinocytes following exposure to paraquat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, Adrienne T.; Gray, Joshua P.; Shakarjian, Michael P.

Paraquat (1,1'-dimethyl-4,4'-bipyridinium) is a widely used herbicide known to induce skin toxicity. This is thought to be due to oxidative stress resulting from the generation of cytotoxic reactive oxygen intermediates (ROI) during paraquat redox cycling. The skin contains a diverse array of antioxidant enzymes which protect against oxidative stress including superoxide dismutase (SOD), catalase, glutathione peroxidase-1 (GPx-1), heme oxygenase-1 (HO-1), metallothionein-2 (MT-2), and glutathione-S-transferases (GST). In the present studies we compared paraquat redox cycling in primary cultures of undifferentiated and differentiated mouse keratinocytes and determined if this was associated with oxidative stress and altered expression of antioxidant enzymes. We foundmore » that paraquat readily undergoes redox cycling in both undifferentiated and differentiated keratinocytes, generating superoxide anion and hydrogen peroxide as well as increased protein oxidation which was greater in differentiated cells. Paraquat treatment also resulted in increased expression of HO-1, Cu,Zn-SOD, catalase, GSTP1, GSTA3 and GSTA4. However, no major differences in expression of these enzymes were evident between undifferentiated and differentiated cells. In contrast, expression of GSTA1-2 was significantly greater in differentiated relative to undifferentiated cells after paraquat treatment. No changes in expression of MT-2, Mn-SOD, GPx-1, GSTM1 or the microsomal GST's mGST1, mGST2 and mGST3, were observed in response to paraquat. These data demonstrate that paraquat induces oxidative stress in keratinocytes leading to increased expression of antioxidant genes. These intracellular proteins may be important in protecting the skin from paraquat-mediated cytotoxicity.« less

Stage-specific expression of DDX4 and c-kit at different developmental stages of the porcine testis.

PubMed

Lee, Ran; Lee, Won-Young; Park, Hyun-Jung; Ha, Woo-Tae; Woo, Jae-Seok; Chung, Hak-Jae; Lee, Ji-Heon; Hong, Kwonho; Song, Hyuk

2018-03-01

Spermatogenesis begins with spermatogonial stem cells (SSCs), which are located in the basement membrane of the adult testes. Previous studies have described specific biomarkers for undifferentiated porcine spermatogonia or SSCs; however, these markers are not sufficient to understand spermatogenesis at different developmental stages. The objective of this study was characterize the expression of DEAD-Box polypeptide 4 (DDX4, also known as VASA) and tyrosine-protein kinase kit (c-kit), as potential markers of male germ cells in the porcine testis. In porcine testis tissue at prepubertal stages (5, 30, and 60 days), DDX4 and c-kit protein expression was detected in the most undifferentiated spermatogonia, which also express protein gene product 9.5 (PGP9.5). However, in porcine testis tissues from pubertal and postpubertal stages (90, 120, and 150 days), DDX4 and c-kit were not detected in PGP9.5-positive undifferentiated spermatogonia. The DDX4 expression pattern was similar to that of c-kit in the porcine testis. In adult porcine testes, DDX4-expressing cells were located on the lumenal side, compared to synaptonemal complex protein 3-positive primary spermatocytes, but DDX-4 was not co-expressed with acrosin, a known acrosome marker. In addition, DDX4 was detected in PGP9.5-expressing porcine SSCs in culture. Based on our results, we suggest that DDX4 and c-kit are putative markers of undifferentiated spermatogonia in the prepubertal porcine testis. While in the postpubertal porcine testis, they are markers of differentiated spermatocytes. These findings may facilitate future studies of porcine spermatogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Depletion of kidney CD11c+ F4/80+ cells impairs the recovery process in ischaemia/reperfusion-induced acute kidney injury.

PubMed

Kim, Myung-Gyu; Boo, Chang Su; Ko, Yoon Sook; Lee, Hee Young; Cho, Won Yong; Kim, Hyoung Kyu; Jo, Sang-Kyung

2010-09-01

Recent studies provided evidence of the potential role of CD11c(+) F4/80(+) dendritic subset in mediating injury and repair. The purpose of this study was to examine the role of kidney CD11c(+) F4/80(+) dendritic subset in the recovery phase of ischaemia/reperfusion injury (IRI). Following ischaemia/reperfusion (I/R), liposome clodronate or phosphate buffered saline (PBS) was administered, and on day 7 biochemical and histologic kidney damage was assessed. Activation and depletion of CD11c(+) F4/80(+) dendritic subset were confirmed by flow cytometry. Isolation of kidney CD11c(+) cells on days 1 and 7 with in vitro culture for measuring cytokines was performed to define functional characteristics of these cells, and adoptive transfer of CD11c(+) cells was also done. Following kidney IRI, the percentage of CD11c(+) F4/80(+) kidney dendritic cell subset that co-expresses maturation marker increased. Liposome clodronate injection after I/R resulted in preferential depletion of CD11c(+) F4/80(+) kidney dendritic subset, and depletion of these cells was associated with persistent kidney injury, more apoptosis, inflammation and impaired tubular cell proliferation. CD11c(+) F4/80(+) cell depletion was also associated with higher tissue levels of pro-inflammatory cytokines and lower level of IL-10, indicating the persistence of inflammatory milieu. Isolated kidney CD11c(+) cells on day 7 showed different phenotype with increased production of IL-10 compared with those on day 1. Adoptive transfer of CD11c(+) cells partially reversed impaired tissue recovery. Our results suggest that kidney CD11c(+) F4/80(+) dendritic subset might contribute to the recovery process by dynamic phenotypic change from pro-inflammatory to anti-inflammatory with modulation of immune response.

High dendritic expression of Ih in the proximity of the axon origin controls the integrative properties of nigral dopamine neurons.

PubMed

Engel, Dominique; Seutin, Vincent

2015-11-15

The hyperpolarization-activated cation current Ih is expressed in dopamine neurons of the substantia nigra, but the subcellular distribution of the current and its role in synaptic integration remain unknown. We used cell-attached patch recordings to determine the localization profile of Ih along the somatodendritic axis of nigral dopamine neurons in slices from young rats. Ih density is higher in axon-bearing dendrites, in a membrane area close to the axon origin, than in the soma and axon-lacking dendrites. Dual current-clamp recordings revealed a similar contribution of Ih to the waveform of single excitatory postsynaptic potentials throughout the somatodendritic domain. The Ih blocker ZD 7288 increased the temporal summation in all dendrites with a comparable effect in axon- and non-axon dendrites. The strategic position of Ih in the proximity of the axon may influence importantly transitions between pacemaker and bursting activities and consequently the downstream release of dopamine. Dendrites of most neurons express voltage-gated ion channels in their membrane. In combination with passive properties, active currents confer to dendrites a high computational potential. The hyperpolarization-activated cation current Ih present in the dendrites of some pyramidal neurons affects their membrane and integration properties, synaptic plasticity and higher functions such as memory. A gradient of increasing h-channel density towards distal dendrites has been found to be responsible for the location independence of excitatory postsynaptic potential (EPSP) waveform and temporal summation in cortical and hippocampal pyramidal cells. However, reports on other cell types revealed that smoother gradients or even linear distributions of Ih can achieve homogeneous temporal summation. Although the existence of a robust, slowly activating Ih current has been repeatedly demonstrated in nigral dopamine neurons, its subcellular distribution and precise role in synaptic integration are unknown. Using cell-attached patch-clamp recordings, we find a higher Ih current density in the axon-bearing dendrite than in the soma or in dendrites without axon in nigral dopamine neurons. Ih is mainly concentrated in the dendritic membrane area surrounding the axon origin and decreases with increasing distances from this site. Single EPSPs and temporal summation are similarly affected by blockade of Ih in axon- and non-axon-bearing dendrites. The presence of Ih close to the axon is pivotal to control the integrative functions and the output signal of dopamine neurons and may consequently influence the downstream coding of movement. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Different tissue phagocytes sample apoptotic cells to direct distinct homeostasis programs.

PubMed

Cummings, Ryan J; Barbet, Gaetan; Bongers, Gerold; Hartmann, Boris M; Gettler, Kyle; Muniz, Luciana; Furtado, Glaucia C; Cho, Judy; Lira, Sergio A; Blander, J Magarian

2016-11-24

Recognition and removal of apoptotic cells by professional phagocytes, including dendritic cells and macrophages, preserves immune self-tolerance and prevents chronic inflammation and autoimmune pathologies. The diverse array of phagocytes that reside within different tissues, combined with the necessarily prompt nature of apoptotic cell clearance, makes it difficult to study this process in situ. The full spectrum of functions executed by tissue-resident phagocytes in response to homeostatic apoptosis, therefore, remains unclear. Here we show that mouse apoptotic intestinal epithelial cells (IECs), which undergo continuous renewal to maintain optimal barrier and absorptive functions, are not merely extruded to maintain homeostatic cell numbers, but are also sampled by a single subset of dendritic cells and two macrophage subsets within a well-characterized network of phagocytes in the small intestinal lamina propria. Characterization of the transcriptome within each subset before and after in situ sampling of apoptotic IECs revealed gene expression signatures unique to each phagocyte, including macrophage-specific lipid metabolism and amino acid catabolism, and a dendritic-cell-specific program of regulatory CD4 + T-cell activation. A common 'suppression of inflammation' signature was noted, although the specific genes and pathways involved varied amongst dendritic cells and macrophages, reflecting specialized functions. Apoptotic IECs were trafficked to mesenteric lymph nodes exclusively by the dendritic cell subset and served as critical determinants for the induction of tolerogenic regulatory CD4 + T-cell differentiation. Several of the genes that were differentially expressed by phagocytes bearing apoptotic IECs overlapped with susceptibility genes for inflammatory bowel disease. Collectively, these findings provide new insights into the consequences of apoptotic cell sampling, advance our understanding of how homeostasis is maintained within the mucosa and set the stage for development of novel therapeutics to alleviate chronic inflammatory diseases such as inflammatory bowel disease.

Dendrites In Vitro and In Vivo Contain Microtubules of Opposite Polarity and Axon Formation Correlates with Uniform Plus-End-Out Microtubule Orientation.

PubMed

Yau, Kah Wai; Schätzle, Philipp; Tortosa, Elena; Pagès, Stéphane; Holtmaat, Anthony; Kapitein, Lukas C; Hoogenraad, Casper C

2016-01-27

In cultured vertebrate neurons, axons have a uniform arrangement of microtubules with plus-ends distal to the cell body (plus-end-out), whereas dendrites contain mixed polarity orientations with both plus-end-out and minus-end-out oriented microtubules. Rather than non-uniform microtubules, uniparallel minus-end-out microtubules are the signature of dendrites in Drosophila and Caenorhabditis elegans neurons. To determine whether mixed microtubule organization is a conserved feature of vertebrate dendrites, we used live-cell imaging to systematically analyze microtubule plus-end orientations in primary cultures of rat hippocampal and cortical neurons, dentate granule cells in mouse organotypic slices, and layer 2/3 pyramidal neurons in the somatosensory cortex of living mice. In vitro and in vivo, all microtubules had a plus-end-out orientation in axons, whereas microtubules in dendrites had mixed orientations. When dendritic microtubules were severed by laser-based microsurgery, we detected equal numbers of plus- and minus-end-out microtubule orientations throughout the dendritic processes. In dendrites, the minus-end-out microtubules were generally more stable and comparable with plus-end-out microtubules in axons. Interestingly, at early stages of neuronal development in nonpolarized cells, newly formed neurites already contained microtubules of opposite polarity, suggesting that the establishment of uniform plus-end-out microtubules occurs during axon formation. We propose a model in which the selective formation of uniform plus-end-out microtubules in the axon is a critical process underlying neuronal polarization. Live-cell imaging was used to systematically analyze microtubule organization in primary cultures of rat hippocampal neurons, dentate granule cells in mouse organotypic slices, and layer 2/3 pyramidal neuron in somatosensory cortex of living mice. In vitro and in vivo, all microtubules have a plus-end-out orientation in axons, whereas microtubules in dendrites have mixed orientations. Interestingly, newly formed neurites of nonpolarized neurons already contain mixed microtubules, and the specific organization of uniform plus-end-out microtubules only occurs during axon formation. Based on these findings, the authors propose a model in which the selective formation of uniform plus-end-out microtubules in the axon is a critical process underlying neuronal polarization. Copyright © 2016 the authors 0270-6474/16/361072-15$15.00/0.

Identifying Tumor Progenitor Cells | Center for Cancer Research

Cancer.gov

All cells within a tumor are not identical. In fact, only a small subset appears to be capable of actually generating the tumor. These tumor-initiating cells tend to resemble normal stem cells, which have the unique ability to give rise to differentiated cells while simultaneously producing additional undifferentiated stem cells. Most chemotherapeutics affect the bulk of a

Modeling somatic and dendritic spike mediated plasticity at the single neuron and network level.

PubMed

Bono, Jacopo; Clopath, Claudia

2017-09-26

Synaptic plasticity is thought to be the principal neuronal mechanism underlying learning. Models of plastic networks typically combine point neurons with spike-timing-dependent plasticity (STDP) as the learning rule. However, a point neuron does not capture the local non-linear processing of synaptic inputs allowed for by dendrites. Furthermore, experimental evidence suggests that STDP is not the only learning rule available to neurons. By implementing biophysically realistic neuron models, we study how dendrites enable multiple synaptic plasticity mechanisms to coexist in a single cell. In these models, we compare the conditions for STDP and for synaptic strengthening by local dendritic spikes. We also explore how the connectivity between two cells is affected by these plasticity rules and by different synaptic distributions. Finally, we show that how memory retention during associative learning can be prolonged in networks of neurons by including dendrites.Synaptic plasticity is the neuronal mechanism underlying learning. Here the authors construct biophysical models of pyramidal neurons that reproduce observed plasticity gradients along the dendrite and show that dendritic spike dependent LTP which is predominant in distal sections can prolong memory retention.

UTF1, a Putative Marker for Spermatogonial Stem Cells in Stallions

PubMed Central

Jung, Heejun; Roser, Janet F.; Yoon, Minjung

2014-01-01

Spermatogonial stem cells (SSCs) continuously undergo self-renewal and differentiation to sustain spermatogenesis throughout adulthood in males. In stallions, SSCs may be used for the production of progeny from geldings after cryopreservation and therapy for infertile and subfertile stallions. Undifferentiated cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans and rats. The main purposes of this study are to determine the following: 1) changes in the expression pattern of UTF1 at various reproductive stages of stallions, 2) subpopulations of spermatogonia that express UTF1. Testicular samples were collected and categorized based on the age of the horses as follows: pre-pubertal (<1 yr), pubertal (1–1.5 yr), post-pubertal (2–3 yr), and adult (4–8 yr). Western blot analysis was utilized to determine the cross-activity of the UTF1 antibody to horse testes tissues. Immunohistochemistry was conducted to investigate the UTF1 expression pattern in germ cells at different reproductive stages. Whole mount staining was applied to determine the subpopulation of UTF1-positive spermatogonia. Immunohistological analysis showed that most germ cells in the pre-pubertal and pubertal stages were immunolabeled with UTF1, whereas only a few germ cells in the basal compartment of the seminiferous tubule cross-sections of post-pubertal and adult tissues were UTF1-positive. No staining was observed in the Sertoli or Leydig cells at any reproductive stages. Whole mount staining showed that As, Apr, and chains of 4, 8, 16 Aal spermatogonia were immunolabeled with UTF1 in the post-pubertal stallion tubule. Isolated single germ cells were also immunolabeled with UTF1. In conclusion, UTF1 is expressed in undifferentiated spermatogonia, and its antibody can be used as a putative marker for SSCs in stallions. PMID:25272017

Transforming growth factor-beta controls T helper type 1 cell development through regulation of natural killer cell interferon-gamma.

PubMed

Laouar, Yasmina; Sutterwala, Fayyaz S; Gorelik, Leonid; Flavell, Richard A

2005-06-01

Interferon-gamma and interleukin 12 produced by the innate arm of the immune system are important regulators of T helper type 1 (T(H)1) cell development, but signals that negatively regulate their expression remain controversial. Here we show that transforming growth factor-beta (TGF-beta) controlled T(H)1 differentiation through the regulation of interferon-gamma produced by natural killer (NK) cells. Blockade of TGF-beta signaling in NK cells caused the accumulation of a large pool of NK cells secreting copious interferon-gamma, responsible for T(H)1 differentiation and protection from leishmania infection. In contrast, blockade of TGF-beta signaling in dendritic cells did not affect dendritic cell homeostasis or interleukin 12 production, thus indicating a previously undescribed demarcation of the function of TGF-beta in NK cells versus dendritic cells.

Genetic response and morphologic characterization of chicken bone-marrow derived dendritic cells during infection with high and low pathogenic avian influenza viruses

USDA-ARS?s Scientific Manuscript database

Dendritic cells (DC) are professional antigen-presenting cells of the immune system that function to initiate primary immune responses. Progenitors of DCs are derived from haematopoietic stem cells in the bone marrow (BM) that migrate in non-lymphoid tissues to develop into immature DCs. Here, they ...

Active Dendrites and Differential Distribution of Calcium Channels Enable Functional Compartmentalization of Golgi Cells.

PubMed

Rudolph, Stephanie; Hull, Court; Regehr, Wade G

2015-11-25

Interneurons are essential to controlling excitability, timing, and synaptic integration in neuronal networks. Golgi cells (GoCs) serve these roles at the input layer of the cerebellar cortex by releasing GABA to inhibit granule cells (grcs). GoCs are excited by mossy fibers (MFs) and grcs and provide feedforward and feedback inhibition to grcs. Here we investigate two important aspects of GoC physiology: the properties of GoC dendrites and the role of calcium signaling in regulating GoC spontaneous activity. Although GoC dendrites are extensive, previous studies concluded they are devoid of voltage-gated ion channels. Hence, the current view holds that somatic voltage signals decay passively within GoC dendrites, and grc synapses onto distal dendrites are not amplified and are therefore ineffective at firing GoCs because of strong passive attenuation. Using whole-cell recording and calcium imaging in rat slices, we find that dendritic voltage-gated sodium channels allow somatic action potentials to activate voltage-gated calcium channels (VGCCs) along the entire dendritic length, with R-type and T-type VGCCs preferentially located distally. We show that R- and T-type VGCCs located in the dendrites can boost distal synaptic inputs and promote burst firing. Active dendrites are thus critical to the regulation of GoC activity, and consequently, to the processing of input to the cerebellar cortex. In contrast, we find that N-type channels are preferentially located near the soma, and control the frequency and pattern of spontaneous firing through their close association with calcium-activated potassium (KCa) channels. Thus, VGCC types are differentially distributed and serve specialized functions within GoCs. Interneurons are essential to neural processing because they modulate excitability, timing, and synaptic integration within circuits. At the input layer of the cerebellar cortex, a single type of interneuron, the Golgi cell (GoC), carries these functions. The extent of inhibition depends on both spontaneous activity of GoCs and the excitatory synaptic input they receive. In this study, we find that different types of calcium channels are differentially distributed, with dendritic calcium channels being activated by somatic activity, boosting synaptic inputs and enabling bursting, and somatic calcium cannels promoting regular firing. We therefore challenge the current view that GoC dendrites are passive and identify the mechanisms that contribute to GoCs regulating the flow of sensory information in the cerebellar cortex. Copyright © 2015 the authors 0270-6474/15/3515492-13$15.00/0.

Neuropil threads occur in dendrites of tangle-bearing nerve cells.

PubMed

Braak, H; Braak, E

1988-01-01

Transparent Golgi preparations counterstained for Alzheimer's neurofibrillary changes rendered possible the demonstration of neuropil threads in defined cellular processes. Only dendrites of tangle-bearing cortical nerve cells were found to contain neuropil threads. Processes of glial cells as well as axons present in the material were devoid of neuropil threads.

Dendritic cells control fibroblastic reticular network tension and lymph node expansion.

PubMed

Acton, Sophie E; Farrugia, Aaron J; Astarita, Jillian L; Mourão-Sá, Diego; Jenkins, Robert P; Nye, Emma; Hooper, Steven; van Blijswijk, Janneke; Rogers, Neil C; Snelgrove, Kathryn J; Rosewell, Ian; Moita, Luis F; Stamp, Gordon; Turley, Shannon J; Sahai, Erik; Reis e Sousa, Caetano

2014-10-23

After immunogenic challenge, infiltrating and dividing lymphocytes markedly increase lymph node cellularity, leading to organ expansion. Here we report that the physical elasticity of lymph nodes is maintained in part by podoplanin (PDPN) signalling in stromal fibroblastic reticular cells (FRCs) and its modulation by CLEC-2 expressed on dendritic cells. We show in mouse cells that PDPN induces actomyosin contractility in FRCs via activation of RhoA/C and downstream Rho-associated protein kinase (ROCK). Engagement by CLEC-2 causes PDPN clustering and rapidly uncouples PDPN from RhoA/C activation, relaxing the actomyosin cytoskeleton and permitting FRC stretching. Notably, administration of CLEC-2 protein to immunized mice augments lymph node expansion. In contrast, lymph node expansion is significantly constrained in mice selectively lacking CLEC-2 expression in dendritic cells. Thus, the same dendritic cells that initiate immunity by presenting antigens to T lymphocytes also initiate remodelling of lymph nodes by delivering CLEC-2 to FRCs. CLEC-2 modulation of PDPN signalling permits FRC network stretching and allows for the rapid lymph node expansion--driven by lymphocyte influx and proliferation--that is the critical hallmark of adaptive immunity.

Elderberry and Elderflower Extracts, Phenolic Compounds, and Metabolites and Their Effect on Complement, RAW 264.7 Macrophages and Dendritic Cells

PubMed Central

Ho, Giang Thanh Thi; Wangensteen, Helle; Barsett, Hilde

2017-01-01

Modulation of complement activity and inhibition of nitric oxide (NO) production by macrophages and dendritic cells may have therapeutic value in inflammatory diseases. Elderberry and elderflower extracts, constituents, and metabolites were investigated for their effects on the complement system, and on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages and murine dendritic D2SC/I cells. The EtOH crude extracts from elderberry and elderflower and the isolated anthocyanins and procyanidins possessed strong complement fixating activity and strong inhibitory activity on NO production in RAW cells and dendritic cells. Phenolic compounds in the range of 0.1–100 µM showed a dose-dependent inhibition of NO production, with quercetin, rutin, and kaempferol as the most potent ones. Among the metabolites, caffeic acid and 3,4-dihydroxyphenylacetic acid showed the strongest inhibitory effects on NO production in both cell lines, without having cytotoxic effect. Only 4-methylcatechol was cytotoxic at the highest tested concentration (100 µM). Elderberry and elderflower constituents may possess inflammatory modulating activity, which increases their nutritional value. PMID:28282861

Elderberry and Elderflower Extracts, Phenolic Compounds, and Metabolites and Their Effect on Complement, RAW 264.7 Macrophages and Dendritic Cells.

PubMed

Ho, Giang Thanh Thi; Wangensteen, Helle; Barsett, Hilde

2017-03-08

Modulation of complement activity and inhibition of nitric oxide (NO) production by macrophages and dendritic cells may have therapeutic value in inflammatory diseases. Elderberry and elderflower extracts, constituents, and metabolites were investigated for their effects on the complement system, and on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages and murine dendritic D2SC/I cells. The EtOH crude extracts from elderberry and elderflower and the isolated anthocyanins and procyanidins possessed strong complement fixating activity and strong inhibitory activity on NO production in RAW cells and dendritic cells. Phenolic compounds in the range of 0.1-100 µM showed a dose-dependent inhibition of NO production, with quercetin, rutin, and kaempferol as the most potent ones. Among the metabolites, caffeic acid and 3,4-dihydroxyphenylacetic acid showed the strongest inhibitory effects on NO production in both cell lines, without having cytotoxic effect. Only 4-methylcatechol was cytotoxic at the highest tested concentration (100 µM). Elderberry and elderflower constituents may possess inflammatory modulating activity, which increases their nutritional value.

Morphological differentiation of N1E-115 neuroblastoma cells by dimethyl sulfoxide activation of lipid second messengers.

PubMed

Clejan, S; Dotson, R S; Wolf, E W; Corb, M P; Ide, C F

1996-04-10

Quantitative changes in the lipid second messenger diacylglycerol (DAG) were studied in the rat neuroblastoma N1E-115 following exposure to the differentiating agent dimethylsulfoxide (DMSO). Relatively high basal levels of DAG are present in these cells, and addition of 2% DMSO elicited a biphasic increase in DAG levels, dependent on the presence of extracellular Ca2+. Exposure to DMSO also elicited a rapid increase in inositol phosphate and a slight increase in phosphatidic acid (PA), trailing that of DAG. The molecular species (MS) of DAG were analyzed. Within 60 s of DMSO application there were transient increases of DAG representative of phosphatidylinositol (PI) hydrolysis. At longer intervals, more DAG originated from phosphatidylcholine. The MS composition of newly formed PA resembled that of PI and native DAG. Inhibition studies indicated that DAG is formed in the DMSO-treated cells by phospholipases C and that PA formed later is a result of DAG phosphorylation and not activity of phospholipase D (PLD). Undifferentiated cells exhibited an active PLD pathway. In contrast, PLD in DMSO-differentiated cells was not active. In examining the involvement of the sphingomyelin pathway, DMSO exposure was found to increase ceramide levels with a concomitant decrease in sphingomyelin. Addition of the exogenous, soluble analog C6-ceramide to undifferentiated cells resulted in dramatic reductions in DAG and PA levels and PLD activity. These results indicate that DMSO treatment inactivates PLD while activating phospholipases C and the sphingomyelin pathway, suggesting a "switch" between signal transduction pathways in the undifferentiated and differentiated states of N1E-115.

Variable Action Potential Backpropagation during Tonic Firing and Low-Threshold Spike Bursts in Thalamocortical But Not Thalamic Reticular Nucleus Neurons.

PubMed

Connelly, William M; Crunelli, Vincenzo; Errington, Adam C

2017-05-24

Backpropagating action potentials (bAPs) are indispensable in dendritic signaling. Conflicting Ca 2+ -imaging data and an absence of dendritic recording data means that the extent of backpropagation in thalamocortical (TC) and thalamic reticular nucleus (TRN) neurons remains unknown. Because TRN neurons signal electrically through dendrodendritic gap junctions and possibly via chemical dendritic GABAergic synapses, as well as classical axonal GABA release, this lack of knowledge is problematic. To address this issue, we made two-photon targeted patch-clamp recordings from rat TC and TRN neuron dendrites to measure bAPs directly. These recordings reveal that "tonic"' and low-threshold-spike (LTS) "burst" APs in both cell types are always recorded first at the soma before backpropagating into the dendrites while undergoing substantial distance-dependent dendritic amplitude attenuation. In TC neurons, bAP attenuation strength varies according to firing mode. During LTS bursts, somatic AP half-width increases progressively with increasing spike number, allowing late-burst spikes to propagate more efficiently into the dendritic tree compared with spikes occurring at burst onset. Tonic spikes have similar somatic half-widths to late burst spikes and undergo similar dendritic attenuation. In contrast, in TRN neurons, AP properties are unchanged between LTS bursts and tonic firing and, as a result, distance-dependent dendritic attenuation remains consistent across different firing modes. Therefore, unlike LTS-associated global electrical and calcium signals, the spatial influence of bAP signaling in TC and TRN neurons is more restricted, with potentially important behavioral-state-dependent consequences for synaptic integration and plasticity in thalamic neurons. SIGNIFICANCE STATEMENT In most neurons, action potentials (APs) initiate in the axosomatic region and propagate into the dendritic tree to provide a retrograde signal that conveys information about the level of cellular output to the locations that receive most input: the dendrites. In thalamocortical and thalamic reticular nucleus neurons, the site of AP generation and the true extent of backpropagation remain unknown. Using patch-clamp recordings, this study measures dendritic propagation of APs directly in these neurons. In either cell type, high-frequency low-threshold spike burst or lower-frequency tonic APs undergo substantial voltage attenuation as they spread into the dendritic tree. Therefore, backpropagating spikes in these cells can only influence signaling in the proximal part of the dendritic tree. Copyright © 2017 Connelly et al.

Large variability in synaptic N-methyl-D-aspartate receptor density on interneurons and a comparison with pyramidal-cell spines in the rat hippocampus.

PubMed

Nyíri, G; Stephenson, F A; Freund, T F; Somogyi, P

2003-01-01

Pyramidal cells receive input from several types of GABA-releasing interneurons and innervate them reciprocally. Glutamatergic activation of interneurons involves both alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) type glutamate receptors expressed in type I synapses, mostly on their dendritic shafts. On average, the synaptic AMPA receptor content is several times higher on interneurons than in the spines of pyramidal cells. To compare the NMDA receptor content of synapses, we used a quantitative postembedding immunogold technique on serial electron microscopic sections, and analysed the synapses on interneuron dendrites and pyramidal cell spines in the CA1 area. Because all NMDA receptors contain the obligatory NR1 subunit, receptor localisation was carried out using antibodies recognising all splice variants of the NR1 subunit. Four populations of synapse were examined: i). on spines of pyramidal cells in stratum (str.) radiatum and str. oriens; ii). on parvalbumin-positive interneuronal dendritic shafts in str. radiatum; iii). on randomly found dendritic shafts in str. oriens and iv). on somatostatin-positive interneuronal dendritic shafts and somata in str. oriens. On average, the size of the synapses on spines was about half of those on interneurons. The four populations of synapse significantly differed in labelling for the NR1 subunit. The median density of NR1 subunit labelling was highest on pyramidal cell spines. It was lowest in the synapses on parvalbumin-positive dendrites in str. radiatum, where more than half of these synapses were immunonegative. In str. oriens, synapses on interneurons had a high variability of receptor content; some dendrites were similar to those in str. radiatum, including the proximal synapses of somatostatin-positive cells, whereas others had immunoreactivity for the NR1 subunit similar to or higher than synapses on pyramidal cell spines. These results show that synaptic NMDA receptor density differs between pyramidal cells and interneurons. Some interneurons may have a high NMDA receptor content, whereas others, like some parvalbumin-expressing cells, a particularly low synaptic NMDA receptor content. Consequently, fast glutamatergic activation of interneurons is expected to show cell type-specific time course and state-dependent dynamics.

Early increase and late decrease of purkinje cell dendritic spine density in prion-infected organotypic mouse cerebellar cultures.

PubMed

Campeau, Jody L; Wu, Gengshu; Bell, John R; Rasmussen, Jay; Sim, Valerie L

2013-01-01

Prion diseases are infectious neurodegenerative diseases associated with the accumulation of protease-resistant prion protein, neuronal loss, spongiform change and astrogliosis. In the mouse model, the loss of dendritic spines is one of the earliest pathological changes observed in vivo, occurring 4-5 weeks after the first detection of protease-resistant prion protein in the brain. While there are cell culture models of prion infection, most do not recapitulate the neuropathology seen in vivo. Only the recently developed prion organotypic slice culture assay has been reported to undergo neuronal loss and the development of some aspects of prion pathology, namely small vacuolar degeneration and tubulovesicular bodies. Given the rapid replication of prions in this system, with protease-resistant prion protein detectable by 21 days, we investigated whether the dendritic spine loss and altered dendritic morphology seen in prion disease might also develop within the lifetime of this culture system. Indeed, six weeks after first detection of protease-resistant prion protein in tga20 mouse cerebellar slice cultures infected with RML prion strain, we found a statistically significant loss of Purkinje cell dendritic spines and altered dendritic morphology in infected cultures, analogous to that seen in vivo. In addition, we found a transient but statistically significant increase in Purkinje cell dendritic spine density during infection, at the time when protease-resistant prion protein was first detectable in culture. Our findings support the use of this slice culture system as one which recapitulates prion disease pathology and one which may facilitate study of the earliest stages of prion disease pathogenesis.

High-resolution immunogold localization of AMPA type glutamate receptor subunits at synaptic and non-synaptic sites in rat hippocampus.

PubMed

Baude, A; Nusser, Z; Molnár, E; McIlhinney, R A; Somogyi, P

1995-12-01

The cellular and subcellular localization of the GluRA, GluRB/C and GluRD subunits of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) type glutamate receptor was determined in the rat hippocampus using polyclonal antipeptide antibodies in immunoperoxidase and immunogold procedures. For the localization of the GluRD subunit a new polyclonal antiserum was developed using the C-terminal sequence of the protein (residues 869-881), conjugated to carrier protein and absorbed to colloidal gold for immunization. The purified antibodies immunoprecipitated about 25% of 3[H]AMPA binding activity from the hippocampus, cerebellum or whole brain, but very little from neocortex. These antibodies did not precipitate a significant amount of 3[H]kainate binding activity. The antibodies also recognize the GluRD subunit, but not the other AMPA receptor subunits, when expressed in transfected COS-7 cells and only when permeabilized with detergent, indicating an intracellular epitope. All subunits were enriched in the neuropil of the dendritic layers of the hippocampus and in the molecular layer of the dentate gyrus. The cellular distribution of the GluRD subunit was studied more extensively. The strata radiatum, oriens and the dentate molecular layer were more strongly immunoreactive than the stratum lacunosum moleculare, the stratum lucidum and the hilus. However, in the stratum lucidum of the CA3 area and in the hilus the weakly reacting dendrites were surrounded by immunopositive rosettes, shown in subsequent electron microscopic studies to correspond to complex dendritic spines. In the stratum radiatum, the weakly reacting apical dendrites contrasted with the surrounding intensely stained neuropil. The cell bodies of pyramidal and granule cells were moderately reactive. Some non-principal cells and their dendrites in the pyramidal cell layer and in the alveus also reacted very strongly for the GluRD subunit. At the subcellular level, silver intensified immunogold particles for the GluRA, GluRB/C and GluRD subunits were present at type 1 synaptic membrane specializations on dendritic spines of pyramidal cells throughout all layers of the CA1 and CA3 areas. The most densely labelled synapses tended to be on the largest spines and many smaller spines remained unlabelled. Immunoparticle density at type 1 synapses on dendritic shafts of some non-principal cells was consistently higher than at labelled synapses of dendritic spines of pyramidal cells. Synapses established between dendritic spines and mossy fibre terminals, were immunoreactive for all studied subunits in stratum lucidum of the CA3 area. The postembedding immunogold method revealed that the AMPA type receptors are concentrated within the main body of the anatomically defined type 1 (asymmetrical) synaptic junction. Often only a part of the membrane specialization showed clustered immunoparticles. There was a sharp decrease in immunoreactive receptor density at the edge of the synaptic specialization. Immunolabelling was consistently demonstrated at extrasynaptic sites on dendrites, dendritic spines and somata. The results demonstrate that the GluRA, B/C and D subunits of the AMPA type glutamate receptor are present in many of the glutamatergic synapses formed by the entorhinal, CA3 pyramidal and mossy fibre terminals. Some interneurons have a higher density of AMPA type receptors in their asymmetrical afferent synapses than pyramidal cells. This may contribute to a lower activation threshold of interneurons as compared to principal cells by the same afferents in the hippocampal formation.

Oxygen Tension Modulates Differentiation and Primary Macrophage Functions in the Human Monocytic THP-1 Cell Line

PubMed Central

Grodzki, Ana Cristina G.; Giulivi, Cecilia; Lein, Pamela J.

2013-01-01

The human THP-1 cell line is widely used as an in vitro model system for studying macrophage differentiation and function. Conventional culture conditions for these cells consist of ambient oxygen pressure (∼20% v/v) and medium supplemented with the thiol 2-mercaptoethanol (2-ME) and serum. In consideration of the redox activities of O2 and 2-ME, and the extensive experimental evidence supporting a role for reactive oxygen species (ROS) in the differentiation and function of macrophages, we addressed the question of whether culturing THP-1 cells under a more physiologically relevant oxygen tension (5% O2) in the absence of 2-ME and serum would alter THP-1 cell physiology. Comparisons of cultures maintained in 18% O2 versus 5% O2 indicated that reducing oxygen tension had no effect on the proliferation of undifferentiated THP-1 cells. However, decreasing the oxygen tension to 5% O2 significantly increased the rate of phorbol ester-induced differentiation of THP-1 cells into macrophage-like cells as well as the metabolic activity of both undifferentiated and PMA-differentiated THP-1 cells. Removal of both 2-ME and serum from the medium decreased the proliferation of undifferentiated THP-1 cells but increased metabolic activity and the rate of differentiation under either oxygen tension. In differentiated THP-1 cells, lowering the oxygen tension to 5% O2 decreased phagocytic activity, the constitutive release of β-hexosaminidase and LPS-induced NF-κB activation but enhanced LPS-stimulated release of cytokines. Collectively, these data demonstrate that oxygen tension influences THP-1 cell differentiation and primary macrophage functions, and suggest that culturing these cells under tightly regulated oxygen tension in the absence of exogenous reducing agent and serum is likely to provide a physiologically relevant baseline from which to study the role of the local redox environment in regulating THP-1 cell physiology. PMID:23355903

Rebamipide induces dendritic cell recruitment to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-exposed rat gastric mucosa based on IL-1β upregulation.

PubMed

Yamamichi, Nobutake; Oka, Masashi; Inada, Ken-ichi; Konno-Shimizu, Maki; Kageyama-Yahara, Natsuko; Tamai, Hideyuki; Kato, Jun; Fujishiro, Mitsuhiro; Kodashima, Shinya; Niimi, Keiko; Ono, Satoshi; Tsutsumi, Yutaka; Ichinose, Masao; Koike, Kazuhiko

2012-07-20

Rebamipide is usually used for mucosal protection, healing of gastric ulcers, treatment of gastritis, etc., but its effects on gastric malignancy have not been elucidated. Using Lewis and Buffalo rat strains treated with peroral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), we evaluated the effect of rebamipide on the induction of tumor-suppressive dendritic cells, which are known to be heterogeneous antigen-presenting cells of bone marrow origin and are critical for the initiation of primary T-cell responses. Using CD68 as a marker for dendritic cells, the stomach pyloric mucosae of Lewis and Buffalo rats were immunohistochemically analyzed in the presence or absence of rebamipide and MNNG. After a 14-day treatment of rebamipide alone, no significant change in number of CD68-expressing cells was detected in either rat strain. However, after concurrent exposure to MNNG for 14 days, treatment with rebamipide slightly increased CD68-positive cells in the Lewis strain, and significantly increased them in the Buffalo strain. Analysis of two chemotactic factors of dendritic cells, IL-1β and TNF-α, in the gastric cancer cells showed that expression of IL-1β, but not TNF-α, was induced by rebamipide in a dose-dependent manner. A luciferase promoter assay using gastric SH-10-TC cells demonstrated that an element mediating rebamipide action exists in the IL-1β gene promoter region. In conclusion, rebamipide has potential tumor-suppressive effects on gastric tumorigenesis via the recruitment of dendritic cells, based on the upregulation of the IL-1β gene in gastric epithelial cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Passive dendrites enable single neurons to compute linearly non-separable functions.

PubMed

Cazé, Romain Daniel; Humphries, Mark; Gutkin, Boris

2013-01-01

Local supra-linear summation of excitatory inputs occurring in pyramidal cell dendrites, the so-called dendritic spikes, results in independent spiking dendritic sub-units, which turn pyramidal neurons into two-layer neural networks capable of computing linearly non-separable functions, such as the exclusive OR. Other neuron classes, such as interneurons, may possess only a few independent dendritic sub-units, or only passive dendrites where input summation is purely sub-linear, and where dendritic sub-units are only saturating. To determine if such neurons can also compute linearly non-separable functions, we enumerate, for a given parameter range, the Boolean functions implementable by a binary neuron model with a linear sub-unit and either a single spiking or a saturating dendritic sub-unit. We then analytically generalize these numerical results to an arbitrary number of non-linear sub-units. First, we show that a single non-linear dendritic sub-unit, in addition to the somatic non-linearity, is sufficient to compute linearly non-separable functions. Second, we analytically prove that, with a sufficient number of saturating dendritic sub-units, a neuron can compute all functions computable with purely excitatory inputs. Third, we show that these linearly non-separable functions can be implemented with at least two strategies: one where a dendritic sub-unit is sufficient to trigger a somatic spike; another where somatic spiking requires the cooperation of multiple dendritic sub-units. We formally prove that implementing the latter architecture is possible with both types of dendritic sub-units whereas the former is only possible with spiking dendrites. Finally, we show how linearly non-separable functions can be computed by a generic two-compartment biophysical model and a realistic neuron model of the cerebellar stellate cell interneuron. Taken together our results demonstrate that passive dendrites are sufficient to enable neurons to compute linearly non-separable functions.

Passive Dendrites Enable Single Neurons to Compute Linearly Non-separable Functions

PubMed Central

Cazé, Romain Daniel; Humphries, Mark; Gutkin, Boris

2013-01-01

Local supra-linear summation of excitatory inputs occurring in pyramidal cell dendrites, the so-called dendritic spikes, results in independent spiking dendritic sub-units, which turn pyramidal neurons into two-layer neural networks capable of computing linearly non-separable functions, such as the exclusive OR. Other neuron classes, such as interneurons, may possess only a few independent dendritic sub-units, or only passive dendrites where input summation is purely sub-linear, and where dendritic sub-units are only saturating. To determine if such neurons can also compute linearly non-separable functions, we enumerate, for a given parameter range, the Boolean functions implementable by a binary neuron model with a linear sub-unit and either a single spiking or a saturating dendritic sub-unit. We then analytically generalize these numerical results to an arbitrary number of non-linear sub-units. First, we show that a single non-linear dendritic sub-unit, in addition to the somatic non-linearity, is sufficient to compute linearly non-separable functions. Second, we analytically prove that, with a sufficient number of saturating dendritic sub-units, a neuron can compute all functions computable with purely excitatory inputs. Third, we show that these linearly non-separable functions can be implemented with at least two strategies: one where a dendritic sub-unit is sufficient to trigger a somatic spike; another where somatic spiking requires the cooperation of multiple dendritic sub-units. We formally prove that implementing the latter architecture is possible with both types of dendritic sub-units whereas the former is only possible with spiking dendrites. Finally, we show how linearly non-separable functions can be computed by a generic two-compartment biophysical model and a realistic neuron model of the cerebellar stellate cell interneuron. Taken together our results demonstrate that passive dendrites are sufficient to enable neurons to compute linearly non-separable functions. PMID:23468600

Pathological modifications of plant stem cell destiny

USDA-ARS?s Scientific Manuscript database

In higher plants, the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai...

Dendritic Immunotherapy Improvement for an Optimal Control Murine Model

PubMed Central

Chimal-Eguía, J. C.; Castillo-Montiel, E.

2017-01-01

Therapeutic protocols in immunotherapy are usually proposed following the intuition and experience of the therapist. In order to deduce such protocols mathematical modeling, optimal control and simulations are used instead of the therapist's experience. Clinical efficacy of dendritic cell (DC) vaccines to cancer treatment is still unclear, since dendritic cells face several obstacles in the host environment, such as immunosuppression and poor transference to the lymph nodes reducing the vaccine effect. In view of that, we have created a mathematical murine model to measure the effects of dendritic cell injections admitting such obstacles. In addition, the model considers a therapy given by bolus injections of small duration as opposed to a continual dose. Doses timing defines the therapeutic protocols, which in turn are improved to minimize the tumor mass by an optimal control algorithm. We intend to supplement therapist's experience and intuition in the protocol's implementation. Experimental results made on mice infected with melanoma with and without therapy agree with the model. It is shown that the dendritic cells' percentage that manages to reach the lymph nodes has a crucial impact on the therapy outcome. This suggests that efforts in finding better methods to deliver DC vaccines should be pursued. PMID:28912828

Two-Photon Na+ Imaging Reports Somatically Evoked Action Potentials in Rat Olfactory Bulb Mitral and Granule Cell Neurites.

PubMed

Ona-Jodar, Tiffany; Gerkau, Niklas J; Sara Aghvami, S; Rose, Christine R; Egger, Veronica

2017-01-01

Dendrodendritic synaptic interactions are a hallmark of neuronal processing in the vertebrate olfactory bulb. Many classes of olfactory bulb neurons including the principal mitral cells (MCs) and the axonless granule cells (GCs) dispose of highly efficient propagation of action potentials (AP) within their dendrites, from where they can release transmitter onto each other. So far, backpropagation in GC dendrites has been investigated indirectly via Ca 2+ imaging. Here, we used two-photon Na + imaging to directly report opening of voltage-gated sodium channels due to AP propagation in both cell types. To this end, neurons in acute slices from juvenile rat bulbs were filled with 1 mM SBFI via whole-cell patch-clamp. Calibration of SBFI signals revealed that a change in fluorescence Δ F / F by 10% corresponded to a Δ[Na + ] i of ∼22 mM. We then imaged proximal axon segments of MCs during somatically evoked APs (sAP). While single sAPs were detectable in ∼50% of axons, trains of 20 sAPs at 50 Hz always resulted in substantial Δ F / F of ∼15% (∼33 mM Δ[Na + ] i ). Δ F / F was significantly larger for 80 Hz vs. 50 Hz trains, and decayed with half-durations τ 1/2 ∼0.6 s for both frequencies. In MC lateral dendrites, AP trains yielded small Δ F / F of ∼3% (∼7 mM Δ[Na + ] i ). In GC apical dendrites and adjacent spines, single sAPs were not detectable. Trains resulted in an average dendritic Δ F / F of 7% (16 mM Δ[Na + ] i ) with τ 1/2 ∼1 s, similar for 50 and 80 Hz. Na + transients were indistinguishable between large GC spines and their adjacent dendrites. Cell-wise analysis revealed two classes of GCs with the first showing a decrease in Δ F / F along the dendrite with distance from the soma and the second an increase. These classes clustered with morphological parameters. Simulations of Δ[Na + ] i replicated these behaviors via negative and positive gradients in Na + current density, assuming faithful AP backpropagation. Such specializations of dendritic excitability might confer specific temporal processing capabilities to bulbar principal cell-GC subnetworks. In conclusion, we show that Na + imaging provides a valuable tool for characterizing AP invasion of MC axons and GC dendrites and spines.

Two-Photon Na+ Imaging Reports Somatically Evoked Action Potentials in Rat Olfactory Bulb Mitral and Granule Cell Neurites

PubMed Central

Ona-Jodar, Tiffany; Gerkau, Niklas J.; Sara Aghvami, S.; Rose, Christine R.; Egger, Veronica

2017-01-01

Dendrodendritic synaptic interactions are a hallmark of neuronal processing in the vertebrate olfactory bulb. Many classes of olfactory bulb neurons including the principal mitral cells (MCs) and the axonless granule cells (GCs) dispose of highly efficient propagation of action potentials (AP) within their dendrites, from where they can release transmitter onto each other. So far, backpropagation in GC dendrites has been investigated indirectly via Ca2+ imaging. Here, we used two-photon Na+ imaging to directly report opening of voltage-gated sodium channels due to AP propagation in both cell types. To this end, neurons in acute slices from juvenile rat bulbs were filled with 1 mM SBFI via whole-cell patch-clamp. Calibration of SBFI signals revealed that a change in fluorescence ΔF/F by 10% corresponded to a Δ[Na+]i of ∼22 mM. We then imaged proximal axon segments of MCs during somatically evoked APs (sAP). While single sAPs were detectable in ∼50% of axons, trains of 20 sAPs at 50 Hz always resulted in substantial ΔF/F of ∼15% (∼33 mM Δ[Na+]i). ΔF/F was significantly larger for 80 Hz vs. 50 Hz trains, and decayed with half-durations τ1/2 ∼0.6 s for both frequencies. In MC lateral dendrites, AP trains yielded small ΔF/F of ∼3% (∼7 mM Δ[Na+]i). In GC apical dendrites and adjacent spines, single sAPs were not detectable. Trains resulted in an average dendritic ΔF/F of 7% (16 mM Δ[Na+]i) with τ1/2 ∼1 s, similar for 50 and 80 Hz. Na+ transients were indistinguishable between large GC spines and their adjacent dendrites. Cell-wise analysis revealed two classes of GCs with the first showing a decrease in ΔF/F along the dendrite with distance from the soma and the second an increase. These classes clustered with morphological parameters. Simulations of Δ[Na+]i replicated these behaviors via negative and positive gradients in Na+ current density, assuming faithful AP backpropagation. Such specializations of dendritic excitability might confer specific temporal processing capabilities to bulbar principal cell-GC subnetworks. In conclusion, we show that Na+ imaging provides a valuable tool for characterizing AP invasion of MC axons and GC dendrites and spines. PMID:28293175

Dendrites of dentate gyrus granule cells contribute to pattern separation by controlling sparsity

PubMed Central

Chavlis, Spyridon; Petrantonakis, Panagiotis C.

2016-01-01

ABSTRACT The hippocampus plays a key role in pattern separation, the process of transforming similar incoming information to highly dissimilar, nonverlapping representations. Sparse firing granule cells (GCs) in the dentate gyrus (DG) have been proposed to undertake this computation, but little is known about which of their properties influence pattern separation. Dendritic atrophy has been reported in diseases associated with pattern separation deficits, suggesting a possible role for dendrites in this phenomenon. To investigate whether and how the dendrites of GCs contribute to pattern separation, we build a simplified, biologically relevant, computational model of the DG. Our model suggests that the presence of GC dendrites is associated with high pattern separation efficiency while their atrophy leads to increased excitability and performance impairments. These impairments can be rescued by restoring GC sparsity to control levels through various manipulations. We predict that dendrites contribute to pattern separation as a mechanism for controlling sparsity. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:27784124

Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits

PubMed Central

Ujfalussy, Balázs B; Makara, Judit K; Branco, Tiago; Lengyel, Máté

2015-01-01

Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits. DOI: http://dx.doi.org/10.7554/eLife.10056.001 PMID:26705334

Meigo governs dendrite targeting specificity by modulating Ephrin level and N-glycosylation

PubMed Central

Sekine, Sayaka U; Haraguchi, Shuka; Chao, Kinhong; Kato, Tomoko; Luo, Liqun; Miura, Masayuki; Chihara, Takahiro

2016-01-01

Neural circuit assembly requires precise dendrite and axon targeting. We identified an evolutionarily conserved endoplasmic reticulum (ER) protein, Meigo, from a mosaic genetic screen in Drosophila melanogaster. Meigo was cell-autonomously required in olfactory receptor neurons and projection neurons to target their axons and dendrites to the lateral antennal lobe and to refine projection neuron dendrites into individual glomeruli. Loss of Meigo induced an unfolded protein response and reduced the amount of neuronal cell surface proteins, including Ephrin. Ephrin overexpression specifically suppressed the projection neuron dendrite refinement defect present in meigo mutant flies, and ephrin knockdown caused a similar projection neuron dendrite refinement defect. Meigo positively regulated the level of Ephrin N-glycosylation, which was required for its optimal function in vivo. Thus, Meigo, an ER-resident protein, governs neuronal targeting specificity by regulating ER folding capacity and protein N-glycosylation. Furthermore, Ephrin appears to be an important substrate that mediates Meigo’s function in refinement of glomerular targeting. PMID:23624514

Using the mouse embryonic stem cell test (EST) to evaluate the embryotoxicity of haloacetic acids

EPA Science Inventory

The Embryonic Stem Cell Test (EST) is used to predict the embryotoxic potential of a test compound by combining the data from cytotoxicity assays in undifferentiated mouse embryonic stem (mES) cells and differentiated mouse cells with the data from a differentiation assay in mES ...

Quantitative Analysis of Dendritic Cell Haptotaxis.

PubMed

Schwarz, Jan; Sixt, Michael

2016-01-01

Chemokines are the main guidance cues directing leukocyte migration. Opposed to early assumptions, chemokines do not necessarily act as soluble cues but are often immobilized within tissues, e.g., dendritic cell migration toward lymphatic vessels is guided by a haptotactic gradient of the chemokine CCL21. Controlled assay systems to quantitatively study haptotaxis in vitro are still missing. In this chapter, we describe an in vitro haptotaxis assay optimized for the unique properties of dendritic cells. The chemokine CCL21 is immobilized in a bioactive state, using laser-assisted protein adsorption by photobleaching. The cells follow this immobilized CCL21 gradient in a haptotaxis chamber, which provides three dimensionally confined migration conditions. © 2016 Elsevier Inc. All rights reserved.

Direct antigen presentation and gap junction mediated cross-presentation during apoptosis.

PubMed

Pang, Baoxu; Neijssen, Joost; Qiao, Xiaohang; Janssen, Lennert; Janssen, Hans; Lippuner, Christoph; Neefjes, Jacques

2009-07-15

MHC class I molecules present peptides from endogenous proteins. Ags can also be presented when derived from extracellular sources in the form of apoptotic bodies. Cross-presentation of such Ags by dendritic cells is required for proper CTL responses. The fate of Ags in cells initiated for apoptosis is unclear as is the mechanism of apoptosis-derived Ag transfer into dendritic cells. Here we show that novel Ags can be generated by caspases and be presented by MHC class I molecules of apoptotic cells. Since gap junctions function until apoptotic cells remodel to form apoptotic bodies, transfer and cross-presentation of apoptotic peptides by neighboring and dendritic cells occurs. We thus define a novel phase in classical Ag presentation and cross-presentation by MHC class I molecules: presentation of Ags created by caspase activities in cells in apoptosis.

Dendritic cells in cancer immunotherapy

NASA Astrophysics Data System (ADS)

Le Gall, Camille M.; Weiden, Jorieke; Eggermont, Loek J.; Figdor, Carl G.

2018-06-01

Camille M. Le Gall, Jorieke Weiden, Loek J. Eggermont and Carl G. Figdor provide an overview of immunotherapeutics for cancer treatment that harness dendritic cells, their challenges in clinical use, and approaches employed to enhance their recruitment and activation to promote effective anti-tumour immunity.

'Educated' dendritic cells act as messengers from memory to naive T helper cells.

PubMed

Alpan, Oral; Bachelder, Eric; Isil, Eda; Arnheiter, Heinz; Matzinger, Polly

2004-06-01

Ingested antigens lead to the generation of effector T cells that secrete interleukin 4 (IL-4) rather than interferon-gamma (IFN-gamma) and are capable of influencing naive T cells in their immediate environment to do the same. Using chimeric mice generated by aggregation of two genotypically different embryos, we found that the conversion of a naive T cell occurs only if it can interact with the same antigen-presenting cell, although not necessarily the same antigen, as the effector T cell. Using a two-step culture system in vitro, we found that antigen-presenting dendritic cells can act as 'temporal bridges' to relay information from orally immunized memory CD4 T cells to naive CD4 T cells. The orally immunized T cells use IL-4 and IL-10 (but not CD40 ligand) to 'educate' dendritic cells, which in turn induce naive T cells to produce the same cytokines as those produced by the orally immunized memory T cells.

Transcriptional Classification and Functional Characterization of Human Airway Macrophage and Dendritic Cell Subsets

PubMed Central

Patel, Vineet I.; Booth, J. Leland; Duggan, Elizabeth S.; Cate, Steven; White, Vicky L.; Hutchings, David; Kovats, Susan; Burian, Dennis M.; Dozmorov, Mikhail; Metcalf, Jordan P.

2016-01-01

The respiratory system is a complex network of many cell types, including subsets of macrophages and dendritic cells that work together to maintain steady-state respiration. Due to limitations in acquiring cells from healthy human lung, these subsets remain poorly characterized transcriptionally and phenotypically. We set out to systematically identify these subsets in human airways by developing a schema of isolating large numbers of cells by whole lung bronchoalveolar lavage. Six subsets of phagocytic antigen presenting (HLA-DR+) cells were consistently observed. Aside from alveolar macrophages, subsets of Langerin+, BDCA1− CD14+, BDCA1+ CD14+, BDCA1+ CD14−, and BDCA1− CD14− cells were identified. These subsets varied in their ability to internalize Escherichia coli, Staphylococcus aureus, and Bacillus anthracis particles. All subsets were more efficient at internalizing S. aureus and B. anthracis compared to E. coli. Alveolar macrophages and CD14+ cells were overall more efficient at particle internalization compared to the four other populations. Subsets were further separated into two groups based on their inherent capacities to upregulate surface CD83, CD86, and CCR7 expression levels. Whole genome transcriptional profiling revealed a clade of “true dendritic cells” consisting of Langerin+, BDCA1+ CD14+, and BDCA1+ CD14− cells. The dendritic cell clade was distinct from a macrophage/monocyte clade, as supported by higher mRNA expression levels of several dendritic cell-associated genes, including CD1, FLT3, CX3CR1, and CCR6. Each clade, and each member of both clades, were discerned by specific upregulated genes, which can serve as markers for future studies in healthy and diseased states. PMID:28031342

Bone marrow-derived mesenchymal stem cells assembled with low-dose BMP-2 in a three-dimensional hybrid construct enhances posterolateral spinal fusion in syngeneic rats.

PubMed

Hu, Tao; Abbah, Sunny Akogwu; Toh, Soo Yein; Wang, Ming; Lam, Raymond Wing Moon; Naidu, Mathanapriya; Bhakta, Gajadhar; Cool, Simon M; Bhakoo, Kishore; Li, Jun; Goh, James Cho-Hong; Wong, Hee-Kit

2015-12-01

The combination of potent osteoinductive growth factor, functional osteoblastic cells, and osteoconductive materials to induce bone formation is a well-established concept in bone tissue engineering. However, supraphysiological dose of growth factor, such as recombinant human bone morphogenetic protein 2 (rhBMP-2), which is necessary in contemporary clinical application, have been reported to result in severe side effects. We hypothesize that the synergistic osteoinductive capacity of low-dose bone morphogenetic protein 2 (BMP-2) combined with undifferentiated bone marrow-derived stromal cells (BMSCs) is comparable to that of osteogenically differentiated BMSCs when used in a rodent model of posterolateral spinal fusion. A prospective study using a rodent model of posterolateral spinal fusion was carried out. Thirty-six syngeneic Fischer rats comprised the patient sample. Six groups of implants were evaluated as follows (n=6): (1) 10 µg BMP-2 with undifferentiated BMSCs; (2) 10 µg BMP-2 with osteogenic-differentiated BMSCs; (3) 2.5 µg BMP-2 with undifferentiated BMSCs; (4) 2.5 µg BMP-2 with osteogenic-differentiated BMSCs; (5) 0.5 µg BMP-2 with undifferentiated BMSCs; and (6) 0.5 µg BMP-2 with osteogenic-differentiated BMSCs. Optimal in vitro osteogenic differentiation of BMSCs was determined by quantitative real-time polymerase chain reaction (qRT-PCR) gene analysis whereas in vivo bone formation capacity was evaluated by manual palpation, micro-computed tomography, and histology. Rat BMSCs cultured in fibrin matrix that was loaded into the pores of medical-grade poly epsilon caprolactone tricalcium phosphate scaffolds differentiated toward osteogenic lineage by expressing osterix, runt-related transcription factor 2, and osteocalcium mRNA when supplemented with dexamethasone, ascorbic acid, and β-glycerophosphate. Whereas qRT-PCR revealed optimal increase in osteogenic genes expression after 7 days of in vitro culture, in vivo transplantation study showed that pre-differentiation of BMSCs before transplantation failed to promote posterolateral spinal fusion when co-delivered with low-dose BMP-2 (1/6 or 17% fusion rate). In contrast, combined delivery of undifferentiated BMSCs with low-dose BMP-2 (2.5 µg) demonstrated significantly higher fusion rate (4/6 or 67%) as well as significantly increased volume of new bone formation (p<.05). In summary, this study supports the combination of undifferentiated BMSCs and low-dose rhBMP-2 for bone tissue engineering construct. Copyright © 2015 Elsevier Inc. All rights reserved.

Amplitude Normalization of Dendritic EPSPs at the Soma of Binaural Coincidence Detector Neurons of the Medial Superior Olive

PubMed Central

Winters, Bradley D.; Jin, Shan-Xue; Ledford, Kenneth R.

2017-01-01

The principal neurons of the medial superior olive (MSO) encode cues for horizontal sound localization through comparisons of the relative timing of EPSPs. To understand how the timing and amplitude of EPSPs are maintained during propagation in the dendrites, we made dendritic and somatic whole-cell recordings from MSO principal neurons in brain slices from Mongolian gerbils. In somatic recordings, EPSP amplitudes were largely uniform following minimal stimulation of excitatory synapses at visualized locations along the dendrites. Similar results were obtained when excitatory synaptic transmission was eliminated in a low calcium solution and then restored at specific dendritic sites by pairing input stimulation and focal application of a higher calcium solution. We performed dual dendritic and somatic whole-cell recordings to measure spontaneous EPSPs using a dual-channel template-matching algorithm to separate out those events initiated at or distal to the dendritic recording location. Local dendritic spontaneous EPSP amplitudes increased sharply in the dendrite with distance from the soma (length constant, 53.6 μm), but their attenuation during propagation resulted in a uniform amplitude of ∼0.2 mV at the soma. The amplitude gradient of dendritic EPSPs was also apparent in responses to injections of identical simulated excitatory synaptic currents in the dendrites. Compartmental models support the view that these results extensively reflect the influence of dendritic cable properties. With relatively few excitatory axons innervating MSO neurons, the normalization of dendritic EPSPs at the soma would increase the importance of input timing versus location during the processing of interaural time difference cues in vivo. SIGNIFICANCE STATEMENT The neurons of the medial superior olive analyze cues for sound localization by detecting the coincidence of binaural excitatory synaptic inputs distributed along the dendrites. Previous studies have shown that dendritic voltages undergo severe attenuation as they propagate to the soma, potentially reducing the influence of distal inputs. However, using dendritic and somatic patch recordings, we found that dendritic EPSP amplitude increased with distance from the soma, compensating for dendritic attenuation and normalizing EPSP amplitude at the soma. Much of this normalization reflected the influence of dendritic morphology. As different combinations of presynaptic axons may be active during consecutive cycles of sound stimuli, somatic EPSP normalization renders spike initiation more sensitive to synapse timing than dendritic location. PMID:28213442

Turtle Functions Downstream of Cut in Differentially Regulating Class Specific Dendrite Morphogenesis in Drosophila

PubMed Central

Sulkowski, Mikolaj J.; Iyer, Srividya Chandramouli; Kurosawa, Mathieu S.; Iyer, Eswar Prasad R.; Cox, Daniel N.

2011-01-01

Background Dendritic morphology largely determines patterns of synaptic connectivity and electrochemical properties of a neuron. Neurons display a myriad diversity of dendritic geometries which serve as a basis for functional classification. Several types of molecules have recently been identified which regulate dendrite morphology by acting at the levels of transcriptional regulation, direct interactions with the cytoskeleton and organelles, and cell surface interactions. Although there has been substantial progress in understanding the molecular mechanisms of dendrite morphogenesis, the specification of class-specific dendritic arbors remains largely unexplained. Furthermore, the presence of numerous regulators suggests that they must work in concert. However, presently, few genetic pathways regulating dendrite development have been defined. Methodology/Principal Findings The Drosophila gene turtle belongs to an evolutionarily conserved class of immunoglobulin superfamily members found in the nervous systems of diverse organisms. We demonstrate that Turtle is differentially expressed in Drosophila da neurons. Moreover, MARCM analyses reveal Turtle acts cell autonomously to exert class specific effects on dendritic growth and/or branching in da neuron subclasses. Using transgenic overexpression of different Turtle isoforms, we find context-dependent, isoform-specific effects on mediating dendritic branching in class II, III and IV da neurons. Finally, we demonstrate via chromatin immunoprecipitation, qPCR, and immunohistochemistry analyses that Turtle expression is positively regulated by the Cut homeodomain transcription factor and via genetic interaction studies that Turtle is downstream effector of Cut-mediated regulation of da neuron dendrite morphology. Conclusions/Significance Our findings reveal that Turtle proteins differentially regulate the acquisition of class-specific dendrite morphologies. In addition, we have established a transcriptional regulatory interaction between Cut and Turtle, representing a novel pathway for mediating class specific dendrite development. PMID:21811639

γ-Tocopherol supplementation of allergic female mice augments development of CD11c+CD11b+ dendritic cells in utero and allergic inflammation in neonates

PubMed Central

Abdala-Valencia, Hiam; Soveg, Frank

2016-01-01

γ-Tocopherol increases responses to allergen challenge in allergic adult mice, but it is not known whether γ-tocopherol regulates the development of allergic disease. Development of allergic disease often occurs early in life. In clinical studies and animal models, offspring of allergic mothers have increased responsiveness to allergen challenge. Therefore, we determined whether γ-tocopherol augments development of allergic responses in offspring of allergic female mice. Allergic female mice were supplemented with γ-tocopherol starting at mating. The pups from allergic mothers developed allergic lung responses, whereas pups from saline-treated mothers did not respond to allergen challenge. The γ-tocopherol supplementation of allergic female mice increased the numbers of eosinophils twofold in the pup bronchoalveolar lavage and lungs after allergen challenge. There was also about a twofold increase in pup lung CD11b+ subsets of CD11c+ dendritic cells and in numbers of these dendritic cells expressing the transcription factor IRF4. There was no change in several CD11b− dendritic cell subsets. Furthermore, maternal supplementation with γ-tocopherol increased the number of fetal liver CD11b+CD11c+ dendritic cells twofold in utero. In the pups, γ-tocopherol increased lung expression of the inflammatory mediators CCL11, amphiregulin, activin A, and IL-5. In conclusion, maternal supplementation with γ-tocopherol increased fetal development of subsets of dendritic cells that are critical for allergic responses and increased development of allergic responses in pups from allergic mothers. These results have implications for supplementation of allergic mothers with γ-tocopherol in prenatal vitamins. PMID:26801566

Distinct Dendritic Arborization and In Vivo Firing Patterns of Parvalbumin-Expressing Basket Cells in the Hippocampal Area CA3

PubMed Central

Tukker, John J.; Lasztóczi, Bálint; Katona, Linda; Roberts, J. David B.; Pissadaki, Eleftheria K.; Dalezios, Yannis; Márton, László; Zhang, Limei; Klausberger, Thomas; Somogyi, Peter

2015-01-01

Hippocampal CA3 area generates temporally structured network activity such as sharp waves and gamma and theta oscillations. Parvalbumin-expressing basket cells, making GABAergic synapses onto cell bodies and proximal dendrites of pyramidal cells, control pyramidal cell activity and participate in network oscillations in slice preparations, but their roles in vivo remain to be tested. We have recorded the spike timing of parvalbumin-expressing basket cells in areas CA2/3 of anesthetized rats in relation to CA3 putative pyramidal cell firing and activity locally and in area CA1. During theta oscillations, CA2/3 basket cells fired on the same phase as putative pyramidal cells, but, surprisingly, significantly later than downstream CA1 basket cells. This indicates a distinct modulation of CA3 and CA1 pyramidal cells by basket cells, which receive different inputs. We observed unexpectedly large dendritic arborization of CA2/3 basket cells in stratum lacunosum moleculare (33% of length, 29% surface, and 24% synaptic input from a total of ~35,000), different from the dendritic arborizations of CA1 basket cells. Area CA2/3 basket cells fired phase locked to both CA2/3 and CA1 gamma oscillations, and increased firing during CA1 sharp waves, thus supporting the role of CA3 networks in the generation of gamma oscillations and sharp waves. However, during ripples associated with sharp waves, firing of CA2/3 basket cells was phase locked only to local but not CA1 ripples, suggesting the independent generation of fast oscillations by basket cells in CA1 and CA2/3. The distinct spike timing of basket cells during oscillations in CA1 and CA2/3 suggests differences in synaptic inputs paralleled by differences in dendritic arborizations. PMID:23595740

Spermatogonial Stem Cell Niche and Spermatogonial Stem Cell Transplantation in Zebrafish

PubMed Central

Nóbrega, Rafael Henrique; Greebe, Caaj Douwe; van de Kant, Henk; Bogerd, Jan; de França, Luiz Renato; Schulz, Rüdiger W.

2010-01-01

Background Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis, and reside within a specific microenvironment in the testes called “niche” which regulates stem cell properties, such as, self-renewal, pluripotency, quiescence and their ability to differentiate. Methodology/Principal Findings Here, we introduce zebrafish as a new model for the study of SSCs in vertebrates. Using 5′-bromo-2′-deoxyuridine (BrdU), we identified long term BrdU-retaining germ cells, type A undifferentiated spermatogonia as putative stem cells in zebrafish testes. Similar to rodents, these cells were preferentially located near the interstitium, suggesting that the SSC niche is related to interstitial elements and might be conserved across vertebrates. This localization was also confirmed by analyzing the topographical distribution of type A undifferentiated spermatogonia in normal, vasa::egfp and fli::egfp zebrafish testes. In the latter one, the topographical arrangement suggested that the vasculature is important for the SSC niche, perhaps as a supplier of nutrients, oxygen and/or signaling molecules. We also developed an SSC transplantation technique for both male and female recipients as an assay to evaluate the presence, biological activity, and plasticity of the SSC candidates in zebrafish. Conclusions/Significance We demonstrated donor-derived spermato- and oogenesis in male and female recipients, respectively, indicating the stemness of type A undifferentiated spermatogonia and their plasticity when placed into an environment different from their original niche. Similar to other vertebrates, the transplantation efficiency was low. This might be attributed to the testicular microenvironment created after busulfan depletion in the recipients, which may have caused an imbalance between factors regulating self-renewal or differentiation of the transplanted SSCs. PMID:20862221

Reduced immune responses in chimeric mice engrafted with bone marrow cells from mice with airways inflammation.

PubMed

Scott, Naomi M; Ng, Royce L X; McGonigle, Terence A; Gorman, Shelley; Hart, Prue H

2015-11-01

During respiratory inflammation, it is generally assumed that dendritic cells differentiating from the bone marrow are immunogenic rather than immunoregulatory. Using chimeric mice, the outcomes of airways inflammation on bone marrow progenitor cells were studied. Immune responses were analyzed in chimeric mice engrafted for >16 weeks with bone marrow cells from mice with experimental allergic airways disease (EAAD). Responses to sensitization and challenge with the allergen causing inflammation in the bone marrow-donor mice were significantly reduced in the chimeric mice engrafted with bone marrow cells from mice with EAAD (EAAD-chimeric). Responses to intranasal LPS and topical fluorescein isothiocyanate (non-specific challenges) were significantly attenuated. Fewer activated dendritic cells from the airways and skin of the EAAD-chimeric mice could be tracked to the draining lymph nodes, and may contribute to the significantly reduced antigen/chemical-induced hypertrophy in the draining nodes, and the reduced immune responses to sensitizing allergens. Dendritic cells differentiating in vitro from the bone marrow of >16 weeks reconstituted EAAD-chimeric mice retained an ability to poorly prime immune responses when transferred into naïve mice. Dendritic cells developing from bone marrow progenitors during airways inflammation are altered such that daughter cells have reduced antigen priming capabilities.

Frequent loss of claudin-4 expression in dedifferentiated and undifferentiated endometrial carcinomas.

PubMed

Tessier-Cloutier, Basile; Soslow, Robert A; Stewart, Colin J R; Köbel, Martin; Lee, Cheng-Han

2018-04-19

Dedifferentiated endometrial carcinomas (DDECs)/undifferentiated endometrial carcinomas (UECs) are aggressive endometrial cancers with frequent genomic inactivation of core components of switch/sucrose non-fermentable (SWI/SNF) complex proteins. Claudin-4, an epithelial intercellular tight junction protein, was recently found to be expressed in SWI/SNF-deficient undifferentiated carcinomas but not in SWI/SNF-deficient sarcomas. The aim of this study was to examine claudin-4 expression in UECs/DDECs and other high-grade uterine carcinomas. We examined claudin-4 expression by immunohistochemistry (clone 3E2C1) on tissue microarrays that contained 44 UECs/DDECs (24 SWI/SNF-deficient), 50 carcinosarcomas, 164 grade 3 endometrioid carcinomas, 57 serous carcinomas, and 20 clear cell carcinomas. Tumours with <5% claudin-4 expression were considered to be negative. Nearly all SWI/SNF-deficient, and most SWI/SNF-proficient, UECs/DDECs showed a complete absence of claudin-4 expression in the undifferentiated component, whereas the differentiated component in DDECs showed consistent and diffuse claudin-4 expression. Only one SWI/SNF-deficient DDEC showed focal expression of claudin-4 in the undifferentiated component, as compared with diffuse expression in the corresponding differentiated component. Claudin-4 expression was consistently absent in the sarcomatous component of carcinosarcoma, and it was absent in 24% of grade 3 endometrioid carcinomas and serous carcinomas. Claudin-4 expression can be absent or very focal in a subset of high-grade endometrial carcinomas, and is almost always absent in the undifferentiated components of SWI/SNF-deficient UECs/DDECs, despite the apparent epithelial origin in the case of DDECs. Therefore, claudin-4 expression cannot be used to infer mesenchymal or epithelial tumour origin in the endometrium. The consistent loss or down-regulation of claudin-4, a tight junction protein, in SWI/SNF-deficient UECs/DDECs further supports the undifferentiated nature of these tumours. © 2018 John Wiley & Sons Ltd.

Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation.

PubMed

Menon, Alessandra; Creo, Pasquale; Piccoli, Marco; Bergante, Sonia; Conforti, Erika; Banfi, Giuseppe; Randelli, Pietro; Anastasia, Luigi

2018-01-01

Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21%) has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF), the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the "hypoxic niches" present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue.

5-Azacitidine Monotherapy Followed by Related Haploidentical Hematopoietic Stem Cell Transplantation Achieves Durable Remission in a Pediatric Patient With Acute Undifferentiated Leukemia Refractory to High-Dose Chemotherapy.

PubMed

Polishchuk, Veronika; Khazal, Sajad; Berulava, Giorgi; Roth, Michael; Mahadeo, Kris M

2016-06-01

Patients with acute leukemias of undifferentiated lineage (AUL) generally have guarded prognosis. Here, we describe the first reported pediatric patient with AUL refractory to high-dose chemotherapy who achieved clinical remission with ALL maintenance therapy and 5-azacitidine. His induction remission was followed by consolidation with reduced toxicity haploidentical hematopoietic stem cell transplant (HSCT). At 9 months post-HSCT, the patient is alive and in remission. This combination therapy of remission induction with ALL maintenance therapy and 5-azacitidine and consolidation with reduced toxicity haploidentical HSCT is novel and promising for patients who lack conventional donors and are not candidates for myeloablative therapy. © 2016 Wiley Periodicals, Inc.

Characterization of chicken dendritic cell markers

USDA-ARS?s Scientific Manuscript database

Animal and Natural Resources Institute, ARS-USDA, Beltsville, MD, USA. New mouse monoclonal antibodies which detect CD80 and CD83 were developed to characterize chicken dendritic cells (DCs). The characteristics of these molecules have been studied in human, swine, ovine, feline, and canine but not ...

ROCK1 and 2 differentially regulate actomyosin organization to drive cell and synaptic polarity

PubMed Central

Badoual, Mathilde; Asmussen, Hannelore; Patel, Heather; Whitmore, Leanna; Horwitz, Alan Rick

2015-01-01

RhoGTPases organize the actin cytoskeleton to generate diverse polarities, from front–back polarity in migrating cells to dendritic spine morphology in neurons. For example, RhoA through its effector kinase, RhoA kinase (ROCK), activates myosin II to form actomyosin filament bundles and large adhesions that locally inhibit and thereby polarize Rac1-driven actin polymerization to the protrusions of migratory fibroblasts and the head of dendritic spines. We have found that the two ROCK isoforms, ROCK1 and ROCK2, differentially regulate distinct molecular pathways downstream of RhoA, and their coordinated activities drive polarity in both cell migration and synapse formation. In particular, ROCK1 forms the stable actomyosin filament bundles that initiate front–back and dendritic spine polarity. In contrast, ROCK2 regulates contractile force and Rac1 activity at the leading edge of migratory cells and the spine head of neurons; it also specifically regulates cofilin-mediated actin remodeling that underlies the maturation of adhesions and the postsynaptic density of dendritic spines. PMID:26169356

Immunopathologic features of allergic contact dermatitis in humans: participation of plasmacytoid dendritic cells in the pathogenesis of the disease?

PubMed

Bangert, Christine; Friedl, Josef; Stary, Georg; Stingl, Georg; Kopp, Tamara

2003-12-01

Contrary to our abundant knowledge about the sensitization phase of human contact hypersensitivity, little is known about the cell types orchestrating the effector phase. In order to address this issue, we phenotypically analyzed biopsies from 72 h epicutaneous patch test reactions (n=10) and normal human skin (n=5) for the presence of various leukocyte differentiation antigens. The inflammatory infiltrate was dominated by CD3+/CD4+ T cells with approximately 30% of the cells coexpressing CD25 and CTLA-4, a phenotype consistent with either activated effector or regulatory T cells. In our search for professional antigen-presenting cells, we were surprised to find not only sizeable numbers of CD1a+ dendritic cells and CD1c+ dendritic cells, but also of CD123+, CD45RA+, BDCA-2+, CLA+, and CD62L+ plasmacytoid dendritic cells. Although virtually absent in normal human skin, these cells were detectable already 6 h after hapten challenge and were often found in close proximity to CD56+ natural killer cells, indicative of a functional interaction between these cell types. The detailed knowledge of the cellular composition of the inflammatory infiltrate in allergic contact dermatitis and its kinetics should form the basis for the investigation of the immunologic and molecular events operative in the perpetuation and resolution of the eczematous response.

Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

PubMed

Ugonna, Kelechi; Bingle, Colin D; Plant, Karen; Wilson, Kirsty; Everard, Mark L

2014-01-01

We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

EVIR: chimeric receptors that enhance dendritic cell cross-dressing with tumor antigens.

PubMed

Squadrito, Mario Leonardo; Cianciaruso, Chiara; Hansen, Sarah K; De Palma, Michele

2018-03-01

We describe a lentivirus-encoded chimeric receptor, termed extracellular vesicle (EV)-internalizing receptor (EVIR), which enables the selective uptake of cancer-cell-derived EVs by dendritic cells (DCs). The EVIR enhances DC presentation of EV-associated tumor antigens to CD8 + T cells primarily through MHCI recycling and cross-dressing. EVIRs should facilitate exploring the mechanisms and implications of horizontal transfer of tumor antigens to antigen-presenting cells.

Lithium dendrite growth through solid polymer electrolyte membranes

NASA Astrophysics Data System (ADS)

Harry, Katherine; Schauser, Nicole; Balsara, Nitash

2015-03-01

Replacing the graphite-based anode in current batteries with a lithium foil will result in a qualitative increase in the energy density of lithium batteries. The primary reason for not adopting lithium-foil anodes is the formation of dendrites during cell charging. In this study, stop-motion X-ray microtomography experiments were used to directly monitor the growth of lithium dendrites during electrochemical cycling of symmetric lithium-lithium cells with a block copolymer electrolyte. In an attempt to understand the relationship between viscoelastic properties of the electrolyte on dendrite formation, a series of complementary experiments including cell cycling, tomography, ac impedance, and rheology, were conducted above and below the glass transition temperature of the non-conducting poly(styrene) block; the conducting phase is a mixture of rubbery poly(ethylene oxide) and a lithium salt. The tomography experiments enable quantification of the evolution of strain in the block copolymer electrolyte. Our work provides fundamental insight into the dynamics of electrochemical deposition of metallic films in contact with high modulus polymer electrolytes. Rational approaches for slowing down and, perhaps, eliminating dendrite growth are proposed.

Emitter formation in dendritic web silicon solar cells

NASA Technical Reports Server (NTRS)

Meier, D. L.; Rohatgi, A.; Campbell, R. B.; Alexander, P.; Fonash, S. J.; Singh, R.

1984-01-01

The use of liquid dopants and liquid masks for p-n junction formation in dendritic web solar cells was investigated and found to be equivalent to the use of gaseous dopants and CVD SiO2 masks previously used. This results in a projected cost reduction of 0.02 1980$/Watt for a 25 MW/year production line, and makes possible junction formation processes having a higher throughput than more conventional processes. The effect of a low-energy (0.4 keV) hydrogen ion implant on dendritic web solar cells was also investigated. Such an implant was observed to improve Voc and Jsc substantially. Measurements of internal quantum efficiency suggest that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. The diffusion length for electrons in the p-type base increased from 53 microns to 150 microns in one case, with dendritic web cell efficiency being boosted to 15.2 percent. The mechanism by which low-energy hydrogen ions can penetrate deeply into the silicon to effect the observed improvement is not known at this time.

[Role of Langerhans cells in the physiopathology of atopic dermatitis].

PubMed

Bieber, T

1995-12-01

The demonstration of IgE receptors on the surface of epidermal dendritic cells and on other antigen presenting cells is a crucial element in the understanding of the pathophysiological role of these cells in the genesis of atopic disease, and especially the atopic dermatitis (AD). The sensibilisation phase to an aeroallergen at the level of nasal or bronchial mucosa and even at the skin may be mediated by dendritic cells expressing Fc epsilon RI. Distinct forms of AD may then represent the equivalent of the ellicitation phase of the classical allergic contact dermatitis. Fc epsilon RI would lead, via specific IgE, to an efficient antigen capture, to the activation of the dendritic cells and finally to an antigen presentation. Thus, AD may represent the paradigma of an IgE-mediated type IV reaction.

A Synthetic MUC1 Anticancer Vaccine Containing Mannose Ligands for Targeting Macrophages and Dendritic Cells.

PubMed

Glaffig, Markus; Stergiou, Natascha; Hartmann, Sebastian; Schmitt, Edgar; Kunz, Horst

2018-01-08

A MUC1 anticancer vaccine equipped with covalently linked divalent mannose ligands was found to improve the antigen uptake and presentation by targeting mannose-receptor-positive macrophages and dendritic cells. It induced much stronger specific IgG immune responses in mice than the non-mannosylated reference vaccine. Mannose coupling also led to increased numbers of macrophages, dendritic cells, and CD4 + T cells in the local lymph organs. Comparison of di- and tetravalent mannose ligands revealed an increased binding of the tetravalent version, suggesting that higher valency improves binding to the mannose receptor. The mannose-coupled vaccine and the non-mannosylated reference vaccine induced IgG antibodies that exhibited similar binding to human breast tumor cells. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lymphatic exosomes promote dendritic cell migration along guidance cues

PubMed Central

Brown, Markus; Johnson, Louise A.; Leone, Dario A.; Majek, Peter; Senfter, Daniel; Bukosza, Nora; Asfour, Gabriele; Langer, Brigitte; Parapatics, Katja; Hong, Young-Kwon; Bennett, Keiryn L.; Sixt, Michael

2018-01-01

Lymphatic endothelial cells (LECs) release extracellular chemokines to guide the migration of dendritic cells. In this study, we report that LECs also release basolateral exosome-rich endothelial vesicles (EEVs) that are secreted in greater numbers in the presence of inflammatory cytokines and accumulate in the perivascular stroma of small lymphatic vessels in human chronic inflammatory diseases. Proteomic analyses of EEV fractions identified >1,700 cargo proteins and revealed a dominant motility-promoting protein signature. In vitro and ex vivo EEV fractions augmented cellular protrusion formation in a CX3CL1/fractalkine-dependent fashion and enhanced the directional migratory response of human dendritic cells along guidance cues. We conclude that perilymphatic LEC exosomes enhance exploratory behavior and thus promote directional migration of CX3CR1-expressing cells in complex tissue environments. PMID:29650776

A role for a rat homolog of staufen in the transport of RNA to neuronal dendrites.

PubMed

Tang, S J; Meulemans, D; Vazquez, L; Colaco, N; Schuman, E

2001-11-08

RNAs are present in dendrites and may be used for local protein synthesis in response to synaptic activity. To begin to understand dendritic RNA targeting, we cloned a rat homolog of staufen, a Drosophila gene that participates in mRNA targeting during development. In hippocampal neurons, rat staufen protein displays a microtubule-dependent somatodendritic distribution pattern that overlaps with dendritic RNAs. To determine whether r-staufen is required for dendritic RNA targeting, we constructed a mutant version containing the RNA binding domains (stau-RBD) but lacking the C-terminal portion potentially involved in dendritic targeting. Stau-RBD expression was restricted to the cell bodies and proximal dendrites. Expression of stau-RBD significantly decreased, while overexpression of wild-type r-staufen increased, the amount of dendritic mRNA. Taken together, these results suggest that the rat staufen protein plays an important role in the delivery of RNA to dendrites.

Expression and function of orphan nuclear receptor TLX in adult neural stem cells.

PubMed

Shi, Yanhong; Chichung Lie, D; Taupin, Philippe; Nakashima, Kinichi; Ray, Jasodhara; Yu, Ruth T; Gage, Fred H; Evans, Ronald M

2004-01-01

The finding of neurogenesis in the adult brain led to the discovery of adult neural stem cells. TLX was initially identified as an orphan nuclear receptor expressed in vertebrate forebrains and is highly expressed in the adult brain. The brains of TLX-null mice have been reported to have no obvious defects during embryogenesis; however, mature mice suffer from retinopathies, severe limbic defects, aggressiveness, reduced copulation and progressively violent behaviour. Here we show that TLX maintains adult neural stem cells in an undifferentiated, proliferative state. We show that TLX-expressing cells isolated by fluorescence-activated cell sorting (FACS) from adult brains can proliferate, self-renew and differentiate into all neural cell types in vitro. By contrast, TLX-null cells isolated from adult mutant brains fail to proliferate. Reintroducing TLX into FACS-sorted TLX-null cells rescues their ability to proliferate and to self-renew. In vivo, TLX mutant mice show a loss of cell proliferation and reduced labelling of nestin in neurogenic areas in the adult brain. TLX can silence glia-specific expression of the astrocyte marker GFAP in neural stem cells, suggesting that transcriptional repression may be crucial in maintaining the undifferentiated state of these cells.

The multifaceted biology of plasmacytoid dendritic cells

PubMed Central

Swiecki, Melissa; Colonna, Marco

2015-01-01

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that specializes in the production of type I interferons (IFNs). pDCs promote antiviral immune responses and have been implicated in the pathogenesis of autoimmune diseases characterized by a type I IFN signature. However, pDCs can also induce tolerogenic immune responses. Here, we review recent progress from the field of pDC biology, focusing on: the molecular mechanisms that regulate pDC development and functions; the pathways involved in their sensing of pathogens and endogenous nucleic acids; the function of pDCs at mucosal sites; and their roles in infections, autoimmunity and cancer. PMID:26160613

Signaling network of dendritic cells in response to pathogens: a community-input supported knowledgebase.

PubMed

Patil, Sonali; Pincas, Hanna; Seto, Jeremy; Nudelman, German; Nudelman, Irina; Sealfon, Stuart C

2010-10-07

Dendritic cells are antigen-presenting cells that play an essential role in linking the innate and adaptive immune systems. Much research has focused on the signaling pathways triggered upon infection of dendritic cells by various pathogens. The high level of activity in the field makes it desirable to have a pathway-based resource to access the information in the literature. Current pathway diagrams lack either comprehensiveness, or an open-access editorial interface. Hence, there is a need for a dependable, expertly curated knowledgebase that integrates this information into a map of signaling networks. We have built a detailed diagram of the dendritic cell signaling network, with the goal of providing researchers with a valuable resource and a facile method for community input. Network construction has relied on comprehensive review of the literature and regular updates. The diagram includes detailed depictions of pathways activated downstream of different pathogen recognition receptors such as Toll-like receptors, retinoic acid-inducible gene-I-like receptors, C-type lectin receptors and nucleotide-binding oligomerization domain-like receptors. Initially assembled using CellDesigner software, it provides an annotated graphical representation of interactions stored in Systems Biology Mark-up Language. The network, which comprises 249 nodes and 213 edges, has been web-published through the Biological Pathway Publisher software suite. Nodes are annotated with PubMed references and gene-related information, and linked to a public wiki, providing a discussion forum for updates and corrections. To gain more insight into regulatory patterns of dendritic cell signaling, we analyzed the network using graph-theory methods: bifan, feedforward and multi-input convergence motifs were enriched. This emphasis on activating control mechanisms is consonant with a network that subserves persistent and coordinated responses to pathogen detection. This map represents a navigable aid for presenting a consensus view of the current knowledge on dendritic cell signaling that can be continuously improved through contributions of research community experts. Because the map is available in a machine readable format, it can be edited and may assist researchers in data analysis. Furthermore, the availability of a comprehensive knowledgebase might help further research in this area such as vaccine development. The dendritic cell signaling knowledgebase is accessible at http://tsb.mssm.edu/pathwayPublisher/DC_pathway/DC_pathway_index.html.

Mulberry cells in the thyroid: warthin-finkeldey-like cells in hashimoto thyroiditis-associated lymphoma.

PubMed

Lapadat, Razvan; Nam, Moon Woo; Mehrotra, Swati; Velankar, Milind; Pambuccian, Stefan E

2017-03-01

Warthin-Finkeldey type giant cells were first described in autopsies performed on young children who died during the highly lethal measles epidemic in Palermo during the winter of 1908. The cells had 8-15 nuclei without identifiable cytoplasm within the germinal centers of lymphoid organs resembling megakaryocytes. We describe a case of Hashimoto thyroiditis with an enlarging substernal throid mass. The resection specimen contained many Warthin-Finkeldey-Like Cells (WFLC) in an extranodal marginal zone lymphoma (MALT type) with focal transformation to diffuse large B-cell lymphoma. The WFLC showed nuclear features similar to those of neighboring follicular dendritic cells (FDCs), favoring the hypothesis that these cells might be the product of fusion of FDCs. This is supported by immunostaining results and the occurrence of similar cells in follicular dendritic cell sarcomas and in "dysplastic" FDCs in hyaline vascular type Castleman disease, a possible precursor of follicular dendritic cell tumors. Diagn. Cytopathol. 2017;45:212-216. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Transition from a planar interface to cellular and dendritic structures during rapid solidification processing

NASA Technical Reports Server (NTRS)

Laxmanan, V.

1986-01-01

The development of theoretical models which characterize the planar-cellular and cell-dendrite transitions is described. The transitions are analyzed in terms of the Chalmers number, the solute Peclet number, and the tip stability parameter, which correlate microstructural features and processing conditions. The planar-cellular transition is examined using the constitutional supercooling theory of Chalmers et al., (1953) and it is observed that the Chalmers number is between 0 and 1 during dendritic and cellular growth. Analysis of cell-dendrite transition data reveal that the transition occurs when the solute Peclet number goes through a minimum, the primary arm spacings go through a maximum, and the Chalmers number is equal to 1/2. The relation between the tip stability parameter and the solute Peclet number is investigated and it is noted that the tip stability parameter is useful for studying dendritic growth in alloys.

Palisade pattern of mormyrid Purkinje cells: a correlated light and electron microscopic study.

PubMed

Meek, J; Nieuwenhuys, R

1991-04-01

The present study is devoted to a detailed analysis of the structural and synaptic organization of mormyrid Purkinje cells in order to evaluate the possible functional significance of their dendritic palisade pattern. For this purpose, the properties of Golgi-impregnated as well as unimpregnated Purkinje cells in lobe C1 and C3 of the cerebellum of Gnathonemus petersii were light and electron microscopically analyzed, quantified, reconstructed, and mutually compared. Special attention was paid to the degree of regularity of their dendritic trees, their relations with Bergmann glia, and the distribution and numerical properties of their synaptic connections with parallel fibers, stellate cells, "climbing" fibers, and Purkinje axonal boutons. The highest degree of palisade specialization was encountered in lobe C1, where Purkinje cells have on average 50 palisade dendrites with a very regular distribution in a sagittal plane. Their spine density decreases from superficial to deep (from 14 to 6 per micron dendritic length), a gradient correlated with a decreasing parallel fiber density but an increasing parallel fiber diameter. Each Purkinje cell makes on average 75,000 synaptic contacts with parallel fibers, some of which are rather coarse (0.45 microns), and provided with numerous short collaterals. Climbing fibers do not climb, since their synaptic contacts are restricted to the ganglionic layer (i.e., the layer of Purkinje and eurydendroid projection cells), where they make about 130 synaptic contacts per cell with 2 or 3 clusters of thorns on the proximal dendrites. These clusters contain also a type of "shunting" elements that make desmosome-like junctions with both the climbing fiber boutons and the necks of the thorns. The axons of Purkinje cells in lobe C1 make small terminal arborizations, with about 20 boutons, that may be substantially (up to 500 microns) displaced rostrally or caudally with respect to the soma. Purkinje axonal boutons were observed to make synaptic contacts with eurydendroid projection cells and with the proximal dendritic and somatic receptive surface of Purkinje cells, where about 15 randomly distributed boutons per neuron occur. The organization of Purkinje cells in lobe C3 differs markedly from that in C1 and seems to be less regular and specialized, although the overall palisade pattern is even more regular than in lobe C1 because of the absence of large eurydendroid neurons. However, individual neurons have a less regular dendritic tree, there is no apical-basal gradient in spine density or parallel fiber density and diameter, and there are no "shunting" elements in the climbing fiber glomeruli.(ABSTRACT TRUNCATED AT 400 WORDS)

Tissue engineering-based cartilage repair with mesenchymal stem cells in a porcine model.

PubMed

Chang, Chih-Hung; Kuo, Tzong-Fu; Lin, Feng-Huei; Wang, Jyh-Horng; Hsu, Yuan-Ming; Huang, Huei-Ting; Loo, Shiao-Tung; Fang, Hsu-Wei; Liu, Hwa-Chang; Wang, Wen-Chih

2011-12-01

This in vivo pilot study explored the use of mesenchymal stem cell (MSC) containing tissue engineering constructs in repair of osteochondral defects. Osteochondral defects were created in the medial condyles of both knees of 16 miniature pigs. One joint received a cell/collagen tissue engineering construct with or without pretreatment with transforming growth factor β (TGF-β) and the other joint from the same pig received no treatment or the gel scaffold only. Six months after surgery, in knees with no treatment, all defects showed contracted craters; in those treated with the gel scaffold alone, six showed a smooth gross surface, one a hypertrophic surface, and one a contracted crater; in those with undifferentiated MSCs, five defects had smooth, fully repaired surfaces or partially repaired surfaces, and one defect poor repair; in those with TGF-β-induced differentiated MSCs, seven defects had smooth, fully repaired surfaces or partially repaired surfaces, and three defects showed poor repair. In Pineda score grading, the group with undifferentiated MSC, but not the group with TGF-β-induced differentiated MSCs, had significantly lower subchondral, cell morphology, and total scores than the groups with no or gel-only treatment. The compressive stiffness was larger in cartilage without surgical treatment than the treated area within each group. In conclusion, this preliminary pilot study suggests that using undifferentiated MSCs might be a better approach than using TGF-β-induced differentiated MSCs for in vivo tissue engineered treatment of osteochondral defects. Copyright © 2011 Orthopaedic Research Society.

Low cost solar array project cell and module formation research area: Process research of non-CZ silicon material

NASA Technical Reports Server (NTRS)

1981-01-01

Liquid diffusion masks and liquid applied dopants to replace the CVD Silox masking and gaseous diffusion operations specified for forming junctions in the Westinghouse baseline process sequence for producing solar cells from dendritic web silicon were investigated. The baseline diffusion masking and drive processes were compared with those involving direct liquid applications to the dendritic web silicon strips. Attempts were made to control the number of variables by subjecting dendritic web strips cut from a single web crystal to both types of operations. Data generated reinforced earlier conclusions that efficiency levels at least as high as those achieved with the baseline back junction formation process can be achieved using liquid diffusion masks and liquid dopants. The deliveries of dendritic web sheet material and solar cells specified by the current contract were made as scheduled.

Dedifferentiated endometrial carcinomas with neuroendocrine features: a clinicopathologic, immunohistochemical, and molecular genetic study.

PubMed

Espinosa, Iñigo; De Leo, Antonio; D'Angelo, Emanuela; Rosa-Rosa, Juan M; Corominas, Marina; Gonzalez, Alan; Palacios, José; Prat, Jaime

2018-02-01

Undifferentiated endometrial carcinoma is an aggressive type of uterine cancer, which is occasionally associated with a low-grade endometrioid carcinoma component. This combination is referred to as "dedifferentiated endometrioid endometrial carcinoma." Neuroendocrine expression may occur in undifferentiated endometrial carcinoma, but its significance in dedifferentiated endometrial carcinomas is unknown. To gain insight into the pathogenesis of these tumors we have analyzed the immunophenotype (ARID1A, MLH1, PMS2, MSH2, MSH6, p53, β-catenin, SMARCB1, synaptophysin, chromogranin A, and CD56) and mutational status (PTEN, KRAS, PIK3CA, TP53 and POLE) of 4 dedifferentiated endometrial carcinomas with strong and diffuse neuroendocrine expression. All tumors demonstrated neuroendocrine expression in ≥70% of the cells in the undifferentiated carcinoma areas. Loss of expression of at least 1 DNA mismatch repair protein was observed in 2 cases, and p53 immunoreaction was aberrant (mutated/inactivated) in one case. All carcinomas were negative for β-catenin and maintained nuclear SMARCB1 (INI1) and ARID1A expression. Three tumors shared identical endometrioid molecular profile (PTEN and/or PIK3CA mutations) in both components. One tumor had POLE exonuclease domain mutation in the undifferentiated component. In one case, TP53 mutation was found exclusively in the undifferentiated component. Two patients died with peritoneal carcinomatosis and abdominal metastases, respectively; one patient died of a renal failure without evidence of disease, and the last patient is alive and free of disease at 3.3 years. Dedifferentiated endometrial carcinomas with neuroendocrine features are clinically and molecularly heterogeneous tumors. Probably, these carcinomas might acquire undifferentiated phenotype through mutations in TP53 and POLE. Copyright © 2017 Elsevier Inc. All rights reserved.

In vitro haematopoiesis of a novel dendritic-like cell present in murine spleen.

PubMed

Tan, Jonathan K H; O'Neill, Helen C

2010-12-01

Dendritic cells (DC) are important antigen presenting cells (APC) which induce and control the adaptive immune response. In spleen alone, multiple DC subsets can be distinguished by cell surface marker phenotype. Most of these have been shown to develop from progenitors in bone marrow and to seed lymphoid and tissue sites during development. This study advances in vitro methodology for haematopoiesis of dendritic-like cells from progenitors in spleen. Since spleen progenitors undergo differentiation in vitro to produce these cells, the possibility exists that spleen represents a specific niche for differentiation of this subset. The fact that an equivalent cell subset has been shown to exist in spleen also supports that hypothesis. Studies have been directed at investigating the specific functional role of this novel subset as an APC accessible to blood-borne antigen, as well as the conditions under which haematopoiesis is initiated in spleen, and the type of progenitor involved.

Efficiency and Impact of Positive and Negative Magnetic Separation on Monocyte Derived Dendritic Cell Generation.

PubMed

Kowalewicz-Kulbat, Magdalena; Ograczyk, Elżbieta; Włodarczyk, Marcin; Krawczyk, Krzysztof; Fol, Marek

2016-06-01

The immunomagnetic separation technique is the basis of monocyte isolation and further generation of monocyte-derived dendritic cells. To compare the efficiency of monocyte positive and negative separation, concentration of beads, and their impact on generated dendritic cells. Monocytes were obtained using monoclonal antibody-coated magnetic beads followed the Ficoll-Paque gradient separation of mononuclear cell fraction from the peripheral blood of 6 healthy volunteers. CD14 expression was analyzed by flow cytometry. Both types of magnetic separation including recommended and reduced concentrations of beads did not affect the yield and the purity of monocytes and their surface CD14 expression. However, DCs originated from the "positively" separated monocytes had noticeable higher expression of CD80.

Production Methods for a Mesenchymal Stem Cell Therapeutic as a Medical Defense Countermeasure

DTIC Science & Technology

2012-02-01

differentiation of murine embryonic stem cells into vascular progenitors. BMC Cell Biol. 2008;9:2. 56. Johnson EA, Dao TL, Kan RK. Status epilepticus ...their undifferentiated and multipotent status . BMC Cell Biol. 2011;12:12. 52. Sun Y, Chen L, Hou XG, Hou WK, Dong JJ, Sun L, et al. Differentiation of

Radiation-Induced Immune Modulation in Prostate Cancer

DTIC Science & Technology

2008-01-01

cancers. 15. SUBJECT TERMS Radiation, Dendritic Cells , Cytokines, PSA 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...radiation is more than a cytotoxic agent. Our recent study has shown that radiation modulates the immune system by affecting dendritic cell (DC...translate radiation-induced tumor cell death into generation of tumor immunity in the hope of optimizing therapy for localized and disseminated prostate

Neuroligin-1 overexpression in newborn granule cells in vivo.

PubMed

Schnell, Eric; Bensen, Aesoon L; Washburn, Eric K; Westbrook, Gary L

2012-01-01

Adult-born dentate granule cells integrate into the hippocampal network, extend neurites and form synapses in otherwise mature tissue. Excitatory and inhibitory inputs innervate these new granule cells in a stereotyped, temporally segregated manner, which presents a unique opportunity to study synapse development in the adult brain. To examine the role of neuroligins as synapse-inducing molecules in vivo, we infected dividing neural precursors in adult mice with a retroviral construct that increased neuroligin-1 levels during granule cell differentiation. By 21 days post-mitosis, exogenous neuroligin-1 was expressed at the tips of dendritic spines and increased the number of dendritic spines. Neuroligin-1-overexpressing cells showed a selective increase in functional excitatory synapses and connection multiplicity by single afferent fibers, as well as an increase in the synaptic AMPA/NMDA receptor ratio. In contrast to its synapse-inducing ability in vitro, neuroligin-1 overexpression did not induce precocious synapse formation in adult-born neurons. However, the dendrites of neuroligin-1-overexpressing cells did have more thin protrusions during an early period of dendritic outgrowth, suggesting enhanced filopodium formation or stabilization. Our results indicate that neuroligin-1 expression selectively increases the degree, but not the onset, of excitatory synapse formation in adult-born neurons.

The Long and Winding Road: From the High-Affinity Choline Uptake Site to Clinical Trials for Malignant Brain Tumors.

PubMed

Lowenstein, P R; Castro, M G

2016-01-01

Malignant brain tumors are one of the most lethal cancers. They originate from glial cells which infiltrate throughout the brain. Current standard of care involves surgical resection, radiotherapy, and chemotherapy; median survival is currently ~14-20 months postdiagnosis. Given that the brain immune system is deficient in priming systemic immune responses to glioma antigens, we proposed to reconstitute the brain immune system to achieve immunological priming from within the brain. Two adenoviral vectors are injected into the resection cavity or remaining tumor. One adenoviral vector expresses the HSV-1-derived thymidine kinase which converts ganciclovir into a compound only cytotoxic to dividing glioma cells. The second adenovirus expresses the cytokine fms-like tyrosine kinase 3 ligand (Flt3L). Flt3L differentiates precursors into dendritic cells and acts as a chemokine that attracts dendritic cells to the brain. HSV-1/ganciclovir killing of tumor cells releases tumor antigens that are taken up by dendritic cells within the brain tumor microenvironment. Tumor killing also releases HMGB1, an endogenous TLR2 agonist that activates dendritic cells. HMGB1-activated dendritic cells, loaded with glioma antigens, migrate to cervical lymph nodes to stimulate a systemic CD8+ T cells cytotoxic immune response against glioma. This immune response is specific to glioma tumors, induces immunological memory, and does neither cause brain toxicity nor autoimmune responses. An IND was granted by the FDA on 4/7/2011. A Phase I, first in person trial, to test whether reengineering the brain immune system is potentially therapeutic is ongoing. © 2016 Elsevier Inc. All rights reserved.

The Trophic Life Cycle Stage of the Opportunistic Fungal Pathogen Pneumocystis murina Hinders the Ability of Dendritic Cells To Stimulate CD4+ T Cell Responses

PubMed Central

Evans, Heather M.; Simpson, Andrew; Shen, Shu; Stromberg, Arnold J.; Pickett, Carol L.

2017-01-01

ABSTRACT The life cycle of the opportunistic fungal pathogen Pneumocystis murina consists of a trophic stage and an ascus-like cystic stage. Infection with the cyst stage induces proinflammatory immune responses, while trophic forms suppress the cytokine response to multiple pathogen-associated molecular patterns (PAMPs), including β-glucan. A targeted gene expression assay was used to evaluate the dendritic cell response following stimulation with trophic forms alone, with a normal mixture of trophic forms and cysts, or with β-glucan. We demonstrate that stimulation with trophic forms downregulated the expression of multiple genes normally associated with the response to infection, including genes encoding transcription factors. Trophic forms also suppressed the expression of genes related to antigen processing and presentation, including the gene encoding the major histocompatibility complex (MHC) class II transactivator, CIITA. Stimulation of dendritic cells with trophic forms, but not a mixture of trophic forms and cysts, reduced the expression of MHC class II and the costimulatory molecule CD40 on the surface of the cells. These defects in the expression of MHC class II and costimulatory molecules corresponded with a reduced capacity for trophic form-loaded dendritic cells to stimulate CD4+ T cell proliferation and polarization. These data are consistent with the delayed innate and adaptive responses previously observed in immunocompetent mice inoculated with trophic forms compared to responses in mice inoculated with a mixture of trophic forms and cysts. We propose that trophic forms broadly inhibit the ability of dendritic cells to fulfill their role as antigen-presenting cells. PMID:28694293

Selection and dynamics of embryonic stem cell integration into early mouse embryos

PubMed Central

Alexandrova, Stoyana; Kalkan, Tuzer; Humphreys, Peter; Riddell, Andrew; Scognamiglio, Roberta; Trumpp, Andreas; Nichols, Jennifer

2016-01-01

The process by which pluripotent cells incorporate into host embryos is of interest to investigate cell potency and cell fate decisions. Previous studies suggest that only a minority of the embryonic stem cell (ESC) inoculum contributes to the adult chimaera. How incoming cells are chosen for integration or elimination remains unclear. By comparing a heterogeneous mix of undifferentiated and differentiating ESCs (serum/LIF) with more homogeneous undifferentiated culture (2i/LIF), we examine the role of cellular heterogeneity in this process. Time-lapse ex vivo imaging revealed a drastic elimination of serum/LIF ESCs during early development in comparison with 2i/LIF ESCs. Using a fluorescent reporter for naive pluripotency (Rex1-GFP), we established that the acutely eliminated serum/LIF ESCs had started to differentiate. The rejected cells were apparently killed by apoptosis. We conclude that a selection process exists by which unwanted differentiating cells are eliminated from the embryo. However, occasional Rex1− cells were able to integrate. Upregulation of Rex1 occurred in a proportion of these cells, reflecting the potential of the embryonic environment to expedite diversion from differentiation priming to enhance the developing embryonic epiblast. PMID:26586221

Travelling waves in a model of quasi-active dendrites with active spines

NASA Astrophysics Data System (ADS)

Timofeeva, Y.

2010-05-01

Dendrites, the major components of neurons, have many different types of branching structures and are involved in receiving and integrating thousands of synaptic inputs from other neurons. Dendritic spines with excitable channels can be present in large densities on the dendrites of many cells. The recently proposed Spike-Diffuse-Spike (SDS) model that is described by a system of point hot-spots (with an integrate-and-fire process) embedded throughout a passive tree has been shown to provide a reasonable caricature of a dendritic tree with supra-threshold dynamics. Interestingly, real dendrites equipped with voltage-gated ion channels can exhibit not only supra-threshold responses, but also sub-threshold dynamics. This sub-threshold resonant-like oscillatory behaviour has already been shown to be adequately described by a quasi-active membrane. In this paper we introduce a mathematical model of a branched dendritic tree based upon a generalisation of the SDS model where the active spines are assumed to be distributed along a quasi-active dendritic structure. We demonstrate how solitary and periodic travelling wave solutions can be constructed for both continuous and discrete spine distributions. In both cases the speed of such waves is calculated as a function of system parameters. We also illustrate that the model can be naturally generalised to an arbitrary branched dendritic geometry whilst remaining computationally simple. The spatio-temporal patterns of neuronal activity are shown to be significantly influenced by the properties of the quasi-active membrane. Active (sub- and supra-threshold) properties of dendrites are known to vary considerably among cell types and animal species, and this theoretical framework can be used in studying the combined role of complex dendritic morphologies and active conductances in rich neuronal dynamics.

Blocking Virus Replication during Acute Murine Cytomegalovirus Infection Paradoxically Prolongs Antigen Presentation and Increases the CD8+ T Cell Response by Preventing Type I IFN-Dependent Depletion of Dendritic Cells.

PubMed

Loo, Christopher P; Snyder, Christopher M; Hill, Ann B

2017-01-01

Increasing amounts of pathogen replication usually lead to a proportionate increase in size and effector differentiation of the CD8 + T cell response, which is attributed to increased Ag and inflammation. Using a murine CMV that is highly sensitive to the antiviral drug famciclovir to modulate virus replication, we found that increased virus replication drove increased effector CD8 + T cell differentiation, as expected. Paradoxically, however, increased virus replication dramatically decreased the size of the CD8 + T cell response to two immunodominant epitopes. The decreased response was due to type I IFN-dependent depletion of conventional dendritic cells and could be reproduced by specific depletion of dendritic cells from day 2 postinfection or by sterile induction of type I IFN. Increased virus replication and type I IFN specifically inhibited the response to two immunodominant epitopes that are known to be dependent on Ag cross-presented by DCs, but they did not inhibit the response to "inflationary" epitopes whose responses can be sustained by infected nonhematopoietic cells. Our results show that type I IFN can suppress CD8 + T cell responses to cross-presented Ag by depleting cross-presenting conventional dendritic cells. Copyright © 2016 by The American Association of Immunologists, Inc.

Major role for CD8 T cells in the protection against Toxoplasma gondii following dendritic cell vaccination.

PubMed

Guiton, R; Zagani, R; Dimier-Poisson, I

2009-10-01

Toxoplasma gondii is the causative agent of toxoplasmosis, a worldwide zoonosis for which an effective vaccine is needed. Vaccination with pulsed dendritic cells is very efficient but their use in a vaccination protocol is unconceivable. Nevertheless, unravelling the induced effector mechanisms is crucial to design new vaccine strategies. We vaccinated CBA/J mice with parasite extract-pulsed dendritic cells, challenged them with T. gondii cysts and carried out in vivo depletion of CD4(+) or CD8(+) T lymphocytes to study the subsequent cellular immune response and protective mechanisms. CD4(+) lymphocytes were poorly implicated either in spleen and mesenteric lymph node (MLN) cytokine secretion or in mice protection. By contrast, the increasing number of intracerebral cysts and depletion of CD8(+) cells were strongly correlated, revealing a prominent role for CD8(+) lymphocytes in the protection of mice. Splenic CD8(+) lymphocytes induce a strong Th1 response controlled by a Th2 response whereas CD8(+) cells from MLNs inhibit both Th1 and Th2 responses. CD8(+) cells are the main effectors following dendritic cell vaccination and Toxoplasma infection while CD4(+) T cells only play a minor role. This contrasts with T. gondii infection which elicits the generation of CD4(+) and CD8(+) T cells that provide protective immunity.

Semaphorin-1a prevents Drosophila olfactory projection neuron dendrites from mis-targeting into select antennal lobe regions.

PubMed

Shen, Hung-Chang; Chu, Sao-Yu; Hsu, Tsai-Chi; Wang, Chun-Han; Lin, I-Ya; Yu, Hung-Hsiang

2017-04-01

Elucidating how appropriate neurite patterns are generated in neurons of the olfactory system is crucial for comprehending the construction of the olfactory map. In the Drosophila olfactory system, projection neurons (PNs), primarily derived from four neural stem cells (called neuroblasts), populate their cell bodies surrounding to and distribute their dendrites in distinct but overlapping patterns within the primary olfactory center of the brain, the antennal lobe (AL). However, it remains unclear whether the same molecular mechanisms are employed to generate the appropriate dendritic patterns in discrete AL glomeruli among PNs produced from different neuroblasts. Here, by examining a previously explored transmembrane protein Semaphorin-1a (Sema-1a) which was proposed to globally control initial PN dendritic targeting along the dorsolateral-to-ventromedial axis of the AL, we discover a new role for Sema-1a in preventing dendrites of both uni-glomerular and poly-glomerular PNs from aberrant invasion into select AL regions and, intriguingly, this Sema-1a-deficient dendritic mis-targeting phenotype seems to associate with the origins of PNs from which they are derived. Further, ectopic expression of Sema-1a resulted in PN dendritic mis-projection from a select AL region into adjacent glomeruli, strengthening the idea that Sema-1a plays an essential role in preventing abnormal dendritic accumulation in select AL regions. Taken together, these results demonstrate that Sema-1a repulsion keeps dendrites of different types of PNs away from each other, enabling the same types of PN dendrites to be sorted into destined AL glomeruli and permitting for functional assembly of olfactory circuitry.

Extrinsic Repair of Injured Dendrites as a Paradigm for Regeneration by Fusion in Caenorhabditis elegans

PubMed Central

Oren-Suissa, Meital; Gattegno, Tamar; Kravtsov, Veronika; Podbilewicz, Benjamin

2017-01-01

Injury triggers regeneration of axons and dendrites. Research has identified factors required for axonal regeneration outside the CNS, but little is known about regeneration triggered by dendrotomy. Here, we study neuronal plasticity triggered by dendrotomy and determine the fate of complex PVD arbors following laser surgery of dendrites. We find that severed primary dendrites grow toward each other and reconnect via branch fusion. Simultaneously, terminal branches lose self-avoidance and grow toward each other, meeting and fusing at the tips via an AFF-1-mediated process. Ectopic branch growth is identified as a step in the regeneration process required for bypassing the lesion site. Failure of reconnection to the severed dendrites results in degeneration of the distal end of the neuron. We discover pruning of excess branches via EFF-1 that acts to recover the original wild-type arborization pattern in a late stage of the process. In contrast, AFF-1 activity during dendritic auto-fusion is derived from the lateral seam cells and not autonomously from the PVD neuron. We propose a model in which AFF-1-vesicles derived from the epidermal seam cells fuse neuronal dendrites. Thus, EFF-1 and AFF-1 fusion proteins emerge as new players in neuronal arborization and maintenance of arbor connectivity following injury in Caenorhabditis elegans. Our results demonstrate that there is a genetically determined multi-step pathway to repair broken dendrites in which EFF-1 and AFF-1 act on different steps of the pathway. EFF-1 is essential for dendritic pruning after injury and extrinsic AFF-1 mediates dendrite fusion to bypass injuries. PMID:28283540

CD4+ acute undifferentiated leukaemia, probably early monoblastic type, developing in a patient with myelodysplastic syndrome and bone marrow fibrosis.

PubMed

Guenova, M; Taskov, H; Zechev, J

1997-07-01

We report here a patient who presented with pancytopenia, hypercellular bone marrow and three-lineage dysplasia associated with an increase of reticulin fibres. After a 5-month period, anaemia and thrombocytopenia progressed very rapidly and the white blood count increased showing 45% blasts with monocytoid morphology, but cytochemically undifferentiated in nature. The immunophenotype revealed an unusual expression of CD4, CD36 and HLA-DR in the absence of any other myeloid or lymphoid lineage-associated markers. The patient died unexpectedly during the course of chemotherapy. The occurrence of CD4, CD36 and HLA-DR on the blast cells cannot determine the lineage of differentiation with certainty but provides some evidence that the leukaemic cells were probably derived from a very early monocytic progenitor with maturation arrest. These cells had apparently complex interactions with pathologic megakaryocytes and cytokine production.

Interlaminar differences in the pyramidal cell phenotype in parietal cortex of an Indian bat, cynopterus sphinx.

PubMed

Srivastava, U C; Pathak, S V

2010-10-30

To study interlaminar phenotypic variations in the pyramidal neurons of parietal isocortex in bat (Cynopterus sphinx), Golgi and Nissl methods have been employed. The parietal isocortex is relatively thin in the bat as compared to prototheria with layer III, V and VI accounting for more than two—thirds of total cortical thickness. Thick cell free layer I and thinnest accentuated layer II are quite in connotation with other chiropterids. Poor demarcation of layer III/IV in the present study is also in connotation with primitive eutherian mammal (i.e. prototherian) and other chiropterids. Most of the pyramidal cells in the different layers of the parietal isocortex are of typical type as seen in other eutherians but differ significantly in terms of soma shape and size, extent of dendritic arbor, diameter of dendrites and spine density. Percentage of pyramidal neurons, diameter of apical dendrite and spine density on apical dendrite appear to follow an increasing trend from primitive to advanced mammals; but extent of dendrites are probably governed by the specific life patterns of these mammals. It is thus concluded that 'typical' pyramidal neurons in parietal isocortex are similar in therians but different from those in prototherians. It is possible that these cells might have arisen among early eutherians after divergence from prototherian stock.

Selective stabilization of tau in axons and microtubule-associated protein 2C in cell bodies and dendrites contributes to polarized localization of cytoskeletal proteins in mature neurons.

PubMed

Hirokawa, N; Funakoshi, T; Sato-Harada, R; Kanai, Y

1996-02-01

In mature neurons, tau is abundant in axons, whereas microtubule-associated protein 2 (MAP2) and MAP2C are specifically localized in dendrites. Known mechanisms involved in the compartmentalization of these cytoskeletal proteins include the differential localization of mRNA (MAP2 mRNA in dendrites, MAP2C mRNA in cell body, and Tau mRNA in proximal axon revealed by in situ hybridization) (Garner, C.C., R.P. Tucker, and A. Matus. 1988. Nature (Lond.). 336:674-677; Litman, P., J. Barg, L. Rindzooski, and I. Ginzburg. 1993. Neuron. 10:627-638), suppressed transit of MAP2 into axons (revealed by cDNA transfection into neurons) (Kanai, Y., and N. Hirokawa. 1995. Neuron. 14:421-432), and differential turnover of MAP2 in axons vs dendrites (Okabe, S., and N. Hirokawa. 1989. Proc. Natl. Acad. Sci. USA. 86:4127-4131). To investigate whether differential turnover of MAPs contributes to localization of other major MAPs in general, we microinjected biotinylated tau, MAP2C, or MAP2 into mature spinal cord neurons in culture (approximately 3 wk) and then analyzed their fates by antibiotin immunocytochemistry. Initially, each was detected in axons and dendrites, although tau persisted only in axons, whereas MAP2C and MAP2 were restricted to cell bodies and dendrites. Injected MAP2C and MAP2 bound to dendritic microtubules more firmly than to microtubules in axons, while injected tau bound to axonal microtubules more firmly than to microtubules in dendrites. Thus, beyond contributions from mRNA localization and selective axonal transport, compartmentalization of each of the three major MAPs occurs through local differential turnover.

Remodeling of the mononuclear phagocyte network underlies chronic inflammation and disease progression in heart failure: critical importance of the cardiosplenic axis.

PubMed

Ismahil, Mohamed Ameen; Hamid, Tariq; Bansal, Shyam S; Patel, Bindiya; Kingery, Justin R; Prabhu, Sumanth D

2014-01-17

The role of mononuclear phagocytes in chronic heart failure (HF) is unknown. Our aim was to delineate monocyte, macrophage, and dendritic cell trafficking in HF and define the contribution of the spleen to cardiac remodeling. We evaluated C57Bl/6 mice with chronic HF 8 weeks after coronary ligation. As compared with sham-operated controls, HF mice exhibited: (1) increased proinflammatory CD11b+ F4/80+ CD206- macrophages and CD11b+ F4/80+ Gr-1(hi) monocytes in the heart and peripheral blood, respectively, and reduced CD11b+ F4/80+ Gr-1(hi) monocytes in the spleen; (2) significantly increased CD11c+ B220- classical dendritic cells and CD11c+ low)B220+ plasmacytoid dendritic cells in both the heart and spleen, and increased classic dendritic cells and plasmacytoid dendritic cells in peripheral blood and bone marrow, respectively; (3) increased CD4+ helper and CD8+ cytotoxic T-cells in the spleen; and (4) profound splenic remodeling with abundant white pulp follicles, markedly increased size of the marginal zone and germinal centers, and increased expression of alarmins. Splenectomy in mice with established HF reversed pathological cardiac remodeling and inflammation. Splenocytes adoptively transferred from mice with HF, but not from sham-operated mice, homed to the heart and induced long-term left ventricular dilatation, dysfunction, and fibrosis in naive recipients. Recipient mice also exhibited monocyte activation and splenic remodeling similar to HF mice. Activation of mononuclear phagocytes is central to the progression of cardiac remodeling in HF, and heightened antigen processing in the spleen plays a critical role in this process. Splenocytes (presumably splenic monocytes and dendritic cells) promote immune-mediated injurious responses in the failing heart and retain this memory on adoptive transfer.

Different tissue phagocytes sample apoptotic cells to direct distinct homeostasis programs

PubMed Central

Cummings, Ryan J.; Barbet, Gaetan; Bongers, Gerold; Hartmann, Boris M.; Gettler, Kyle; Muniz, Luciana; Furtado, Glaucia C.; Cho, Judy; Lira, Sergio A.; Blander, J. Magarian

2017-01-01

Recognition and removal of apoptotic cells by professional phagocytes, including dendritic cells and macrophages, preserves immune self-tolerance and prevents chronic inflammation and autoimmune pathologies1,2. The diverse array of phagocytes that reside within different tissues, combined with the necessarily prompt nature of apoptotic cell clearance, makes it difficult to study this process in situ. The full spectrum of functions executed by tissue-resident phagocytes in response to homeostatic apoptosis, therefore, remains unclear. Here we show that mouse apoptotic intestinal epithelial cells (IECs), which undergo continuous renewal to maintain optimal barrier and absorptive functions3, are not merely extruded to maintain homeostatic cell numbers4, but are also sampled by a single subset of dendritic cells and two macrophage subsets within a well-characterized network of phagocytes in the small intestinal lamina propria5,6. Characterization of the transcriptome within each subset before and after in situ sampling of apoptotic IECs revealed gene expression signatures unique to each phagocyte, including macrophage-specific lipid metabolism and amino acid catabolism, and a dendritic-cell-specific program of regulatory CD4+ T-cell activation. A common ‘suppression of inflammation’ signature was noted, although the specific genes and pathways involved varied amongst dendritic cells and macrophages, reflecting specialized functions. Apoptotic IECs were trafficked to mesenteric lymph nodes exclusively by the dendritic cell subset and served as critical determinants for the induction of tolerogenic regulatory CD4+ T-cell differentiation. Several of the genes that were differentially expressed by phagocytes bearing apoptotic IECs overlapped with susceptibility genes for inflammatory bowel disease7. Collectively, these findings provide new insights into the consequences of apoptotic cell sampling, advance our understanding of how homeostasis is maintained within the mucosa and set the stage for development of novel therapeutics to alleviate chronic inflammatory diseases such as inflammatory bowel disease. PMID:27828940

Amplitude Normalization of Dendritic EPSPs at the Soma of Binaural Coincidence Detector Neurons of the Medial Superior Olive.

PubMed

Winters, Bradley D; Jin, Shan-Xue; Ledford, Kenneth R; Golding, Nace L

2017-03-22

The principal neurons of the medial superior olive (MSO) encode cues for horizontal sound localization through comparisons of the relative timing of EPSPs. To understand how the timing and amplitude of EPSPs are maintained during propagation in the dendrites, we made dendritic and somatic whole-cell recordings from MSO principal neurons in brain slices from Mongolian gerbils. In somatic recordings, EPSP amplitudes were largely uniform following minimal stimulation of excitatory synapses at visualized locations along the dendrites. Similar results were obtained when excitatory synaptic transmission was eliminated in a low calcium solution and then restored at specific dendritic sites by pairing input stimulation and focal application of a higher calcium solution. We performed dual dendritic and somatic whole-cell recordings to measure spontaneous EPSPs using a dual-channel template-matching algorithm to separate out those events initiated at or distal to the dendritic recording location. Local dendritic spontaneous EPSP amplitudes increased sharply in the dendrite with distance from the soma (length constant, 53.6 μm), but their attenuation during propagation resulted in a uniform amplitude of ∼0.2 mV at the soma. The amplitude gradient of dendritic EPSPs was also apparent in responses to injections of identical simulated excitatory synaptic currents in the dendrites. Compartmental models support the view that these results extensively reflect the influence of dendritic cable properties. With relatively few excitatory axons innervating MSO neurons, the normalization of dendritic EPSPs at the soma would increase the importance of input timing versus location during the processing of interaural time difference cues in vivo SIGNIFICANCE STATEMENT The neurons of the medial superior olive analyze cues for sound localization by detecting the coincidence of binaural excitatory synaptic inputs distributed along the dendrites. Previous studies have shown that dendritic voltages undergo severe attenuation as they propagate to the soma, potentially reducing the influence of distal inputs. However, using dendritic and somatic patch recordings, we found that dendritic EPSP amplitude increased with distance from the soma, compensating for dendritic attenuation and normalizing EPSP amplitude at the soma. Much of this normalization reflected the influence of dendritic morphology. As different combinations of presynaptic axons may be active during consecutive cycles of sound stimuli, somatic EPSP normalization renders spike initiation more sensitive to synapse timing than dendritic location. Copyright © 2017 the authors 0270-6474/17/373138-12$15.00/0.

Activity-Dependent Gating of Calcium Spikes by A-type K+ Channels Controls Climbing Fiber Signaling in Purkinje Cell Dendrites

PubMed Central

Otsu, Yo; Marcaggi, Païkan; Feltz, Anne; Isope, Philippe; Kollo, Mihaly; Nusser, Zoltan; Mathieu, Benjamin; Kano, Masanobu; Tsujita, Mika; Sakimura, Kenji; Dieudonné, Stéphane

2014-01-01

Summary In cerebellar Purkinje cell dendrites, heterosynaptic calcium signaling induced by the proximal climbing fiber (CF) input controls plasticity at distal parallel fiber (PF) synapses. The substrate and regulation of this long-range dendritic calcium signaling are poorly understood. Using high-speed calcium imaging, we examine the role of active dendritic conductances. Under basal conditions, CF stimulation evokes T-type calcium signaling displaying sharp proximodistal decrement. Combined mGluR1 receptor activation and depolarization, two activity-dependent signals, unlock P/Q calcium spikes initiation and propagation, mediating efficient CF signaling at distal sites. These spikes are initiated in proximal smooth dendrites, independently from somatic sodium action potentials, and evoke high-frequency bursts of all-or-none fast-rising calcium transients in PF spines. Gradual calcium spike burst unlocking arises from increasing inactivation of mGluR1-modulated low-threshold A-type potassium channels located in distal dendrites. Evidence for graded activity-dependent CF calcium signaling at PF synapses refines current views on cerebellar supervised learning rules. PMID:25220810

Activity-dependent gating of calcium spikes by A-type K+ channels controls climbing fiber signaling in Purkinje cell dendrites.

PubMed

Otsu, Yo; Marcaggi, Païkan; Feltz, Anne; Isope, Philippe; Kollo, Mihaly; Nusser, Zoltan; Mathieu, Benjamin; Kano, Masanobu; Tsujita, Mika; Sakimura, Kenji; Dieudonné, Stéphane

2014-10-01

In cerebellar Purkinje cell dendrites, heterosynaptic calcium signaling induced by the proximal climbing fiber (CF) input controls plasticity at distal parallel fiber (PF) synapses. The substrate and regulation of this long-range dendritic calcium signaling are poorly understood. Using high-speed calcium imaging, we examine the role of active dendritic conductances. Under basal conditions, CF stimulation evokes T-type calcium signaling displaying sharp proximodistal decrement. Combined mGluR1 receptor activation and depolarization, two activity-dependent signals, unlock P/Q calcium spikes initiation and propagation, mediating efficient CF signaling at distal sites. These spikes are initiated in proximal smooth dendrites, independently from somatic sodium action potentials, and evoke high-frequency bursts of all-or-none fast-rising calcium transients in PF spines. Gradual calcium spike burst unlocking arises from increasing inactivation of mGluR1-modulated low-threshold A-type potassium channels located in distal dendrites. Evidence for graded activity-dependent CF calcium signaling at PF synapses refines current views on cerebellar supervised learning rules. Copyright © 2014 Elsevier Inc. All rights reserved.

Cell-Autonomous Regulation of Dendritic Spine Density by PirB.

PubMed

Vidal, George S; Djurisic, Maja; Brown, Kiana; Sapp, Richard W; Shatz, Carla J

2016-01-01

Synapse density on cortical pyramidal neurons is modulated by experience. This process is highest during developmental critical periods, when mechanisms of synaptic plasticity are fully engaged. In mouse visual cortex, the critical period for ocular dominance (OD) plasticity coincides with the developmental pruning of synapses. At this time, mice lacking paired Ig-like receptor B (PirB) have excess numbers of dendritic spines on L5 neurons; these spines persist and are thought to underlie the juvenile-like OD plasticity observed in adulthood. Here we examine whether PirB is required specifically in excitatory neurons to exert its effect on dendritic spine and synapse density during the critical period. In mice with a conditional allele of PirB (PirB fl/fl ), PirB was deleted only from L2/3 cortical pyramidal neurons in vivo by timed in utero electroporation of Cre recombinase. Sparse mosaic expression of Cre produced neurons lacking PirB in a sea of wild-type neurons and glia. These neurons had significantly elevated dendritic spine density, as well as increased frequency of miniature EPSCs, suggesting that they receive a greater number of synaptic inputs relative to Cre - neighbors. The effect of cell-specific PirB deletion on dendritic spine density was not accompanied by changes in dendritic branching complexity or axonal bouton density. Together, results imply a neuron-specific, cell-autonomous action of PirB on synaptic density in L2/3 pyramidal cells of visual cortex. Moreover, they are consistent with the idea that PirB functions normally to corepress spine density and synaptic plasticity, thereby maintaining headroom for cells to encode ongoing experience-dependent structural change throughout life.

Cell migration and antigen capture are antagonistic processes coupled by myosin II in dendritic cells

PubMed Central

Chabaud, Mélanie; Heuzé, Mélina L.; Bretou, Marine; Vargas, Pablo; Maiuri, Paolo; Solanes, Paola; Maurin, Mathieu; Terriac, Emmanuel; Le Berre, Maël; Lankar, Danielle; Piolot, Tristan; Adelstein, Robert S.; Zhang, Yingfan; Sixt, Michael; Jacobelli, Jordan; Bénichou, Olivier; Voituriez, Raphaël; Piel, Matthieu; Lennon-Duménil, Ana-Maria

2015-01-01

The immune response relies on the migration of leukocytes and on their ability to stop in precise anatomical locations to fulfil their task. How leukocyte migration and function are coordinated is unknown. Here we show that in immature dendritic cells, which patrol their environment by engulfing extracellular material, cell migration and antigen capture are antagonistic. This antagonism results from transient enrichment of myosin IIA at the cell front, which disrupts the back-to-front gradient of the motor protein, slowing down locomotion but promoting antigen capture. We further highlight that myosin IIA enrichment at the cell front requires the MHC class II-associated invariant chain (Ii). Thus, by controlling myosin IIA localization, Ii imposes on dendritic cells an intermittent antigen capture behaviour that might facilitate environment patrolling. We propose that the requirement for myosin II in both cell migration and specific cell functions may provide a general mechanism for their coordination in time and space. PMID:26109323

In situ electrochemical detection of embryonic stem cell differentiation.

PubMed

Yea, Cheol-Heon; An, Jeung Hee; Kim, Jungho; Choi, Jeong-Woo

2013-06-20

Stem cell sensors have emerged as a promising technique to electrochemically monitor the functional status and viability of stem cells. However, efficient electrochemical analysis techniques are required for the development of effective electrochemical stem cell sensors. In the current study, we report a newly developed electrochemical cyclic voltammetry (CV) system to determine the status of mouse embryonic stem (ES) cells. 1-Naphthly phosphate (1-NP), which was dephosphorylated by alkaline phosphatase into a 1-naphthol on an undifferentiated mouse ES cell, was used as a substrate to electrochemically monitor the differentiation status of mouse ES cells. The peak current in the cyclic voltammetry of 1-NP increased linearly with the concentration of pure 1-NP (R(2)=0.9623). On the other hand, the peak current in the electrochemical responses of 1-NP decreased as the number of undifferentiated ES cells increased. The increased dephosphorylation of 1-NP to 1-naphthol made a decreased electrochemical signal. Non-toxicity of 1-NP was confirmed. In conclusion, the proposed electrochemical analysis system can be applied to an electrical stem cell chip for diagnosis, drug detection and on-site monitoring. Copyright © 2013 Elsevier B.V. All rights reserved.

What on "irf" is this gene 4? Irf4 transcription-factor-dependent dendritic cells are required for T helper 2 cell responses in murine skin.

PubMed

Flutter, Barry; Nestle, Frank O

2013-10-17

Interferon regulatory factors play an important role in the transcriptional regulation of immunity. In this issue of Immunity, Kumamoto et al. (2013) and Gao et al. (2013) identify an Irf4-dependent migratory dendritic cell subset required for T helper 2 cell polarization following cutaneous challenge. Copyright © 2013 Elsevier Inc. All rights reserved.

Dendritic Cell-Based Genetic Immunotherapy for Ovarian Cancer

DTIC Science & Technology

2008-12-01

transduction of dendritic cells (DCs) is inefficient because of the lack of the primary Ad receptor, CAR. CD40 is a surface marker expressed by DCs that...ligands or antibodies that can bind to the cell surface markers expressed by DCs. The tumor antigen or peptides are linked to the ligands...thus pose the risk of insertional mutagenesis and oncogenesis. The various cell- surface markers that have been exploited for targeting DCs have

PDC expressing CD36, CD61 and IL-10 may contribute to propagation of immune tolerance.

PubMed

Parcina, Marijo; Schiller, Martin; Gierschke, Aline; Heeg, Klaus; Bekeredjian-Ding, Isabelle

2009-05-01

Human plasmacytoid dendritic cells (PDC) are blood dendritic cell antigen 2 (BDCA2) and blood dendritic cell antigen 4 (BDCA4) positive leukocytes that do not express common lineage markers. They have been described as proinflammatory innate immune cells and are the major source of alphaIFN in the human body. PDC-derived secretion of type I IFNs upon triggering of nucleic acid-sensing toll-like receptors (TLR) primes immune cells to rapidly respond to microbial stimuli and promotes a Th1 response. Here, we report that human PDC express CD36 and CD61 (beta3 integrin), both involved in uptake of apoptotic cells and in induction of tolerance. Freshly isolated PDC and PDC within human blood leukocytes constitutively express IL-10. Thus, PDC may possess a so far neglected role in propagation of immune tolerance.

The Potential of Cellular- and Viral-Based Immunotherapies for Malignant Glioma-Dendritic Cell Vaccines, Adoptive Cell Transfer, and Oncolytic Viruses.

PubMed

Maxwell, Russell; Luksik, Andrew S; Garzon-Muvdi, Tomas; Lim, Michael

2017-06-01

Malignant gliomas, including glioblastoma and anaplastic astrocytoma, are the most frequent primary brain tumors and present with many treatment challenges. In this review, we discuss the potential of cellular- and viral-based immunotherapies in the treatment of malignant glioma, specifically focusing on dendritic cell vaccines, adoptive cell therapy, and oncolytic viruses. Diverse cellular- and viral-based strategies have been engineered and optimized to generate either a specific or broad antitumor immune response in malignant glioma. Due to their successes in the preclinical arena, many of these therapies have undergone phase I and II clinical testing. These early clinical trials have demonstrated the feasibility, safety, and efficacy of these immunotherapies. Dendritic cell vaccines, adoptive cell transfer, and oncolytic viruses may have a potential role in the treatment of malignant glioma. However, these modalities must be investigated in well-designed phase III trials to prove their efficacy.

Immune heterogeneity in neuroinflammation: dendritic cells in the brain.

PubMed

Colton, Carol A

2013-03-01

Dendritic cells (DC) are critical to an integrated immune response and serve as the key link between the innate and adaptive arms of the immune system. Under steady state conditions, brain DC's act as sentinels, continually sampling their local environment. They share this function with macrophages derived from the same basic hemopoietic (bone marrow-derived) precursor and with parenchymal microglia that arise from a unique non-hemopoietic origin. While multiple cells may serve as antigen presenting cells (APCs), dendritic cells present both foreign and self-proteins to naïve T cells that, in turn, carry out effector functions that serve to protect or destroy. The resulting activation of the adaptive response is a critical step to resolution of injury or infection and is key to survival. In this review we will explore the critical roles that DCs play in the brain's response to neuroinflammatory disease with emphasis on how the brain's microenvironment impacts these actions.

Designing oral vaccines targeting intestinal dendritic cells.

PubMed

Devriendt, Bert; De Geest, Bruno G; Cox, Eric

2011-04-01

Most pathogens colonize and invade the host at mucosal surfaces, such as the lung and the intestine. To combat intestinal pathogens the induction of local adaptive immune responses is required, which is mainly achieved through oral vaccination. However, most vaccines are ineffective when given orally owing to the hostile environment in the gastrointestinal tract. The encapsulation of antigens in biodegradable microparticulate delivery systems enhances their immunogenicity; however, the uptake of these delivery systems by intestinal immune cells is rather poor. Surface decoration of the particulates with targeting ligands could increase the uptake and mediate the selective targeting of the vaccine to intestinal antigen-presenting cells, including dendritic cells. In this review, current knowledge on dendritic cell subsets is discussed, along with progress in the development of selective antigen targeting to these cells, in addition to focusing on data obtained in mice and, where possible, the pig, as a non-rodent animal model for humans. Moreover, the potential use and benefits of Fcγ receptor-mediated targeting of antigen delivery systems are highlighted. In conclusion, dendritic cell targeting ligands grafted on antigen carrier systems should preferably bind to a conserved endocytotic receptor, facilitating the design of a multispecies vaccine platform, which could elicit robust protective immune responses against enteric pathogens.

Influence of immunotherapy with autologous dendritic cells on innate and adaptive immune response in cancer.

PubMed

Matias, Bruna F; de Oliveira, Tânia M; Rodrigues, Cláudia M; Abdalla, Douglas R; Montes, Letícia; Murta, Eddie F C; Michelin, Márcia A

2013-01-01

The objective of this study was to evaluate some of the mechanisms involved in the activation of the immune system in patients with advanced-stage cancer (n = 7) who received an autologous dendritic cell vaccine. We examined the immune response mediated by macrophages (CD14+), natural killer cells (CD56+), and B lymphocytes (CD19+) by flow cytometry and assessed the expression of Th1 (IFN-γ, TNF-α, IL-2, and IL-12), Th2 (IL-4), and Treg (TGF-β) cytokines by flow cytometry and an enzyme-linked immunosorbent assay. The CD14+ TNF-α+ population was significantly increased (P < 0.04) when patients received the vaccine; IL-2 expression in both NK cells and in B lymphocytes was increased after a transient initial increase showed a nearly significant decrease (P < 0.07 and P < 0.06 respectively), whereas the CD19+ and CD56+ populations did not show significant changes. Dendritic cell-based immunotherapy led to increased secretion of IFN-γ and IL-12 and reduced secretion of TGF-β. In conclusion, it is likely that the autologous dendritic cell vaccine stimulated the immune cells from the peripheral blood of patients with cancer and generally increased the production of Th1 cytokines, which are related to immunomodulatory responses against cancer.

Influence of Immunotherapy with Autologous Dendritic Cells on Innate and Adaptive Immune Response in Cancer

PubMed Central

Matias, Bruna F.; de Oliveira, Tânia M.; Rodrigues, Cláudia M.; Abdalla, Douglas R.; Montes, Letícia; Murta, Eddie F.C.; Michelin, Márcia A.

2013-01-01

The objective of this study was to evaluate some of the mechanisms involved in the activation of the immune system in patients with advanced-stage cancer (n = 7) who received an autologous dendritic cell vaccine. We examined the immune response mediated by macrophages (CD14+), natural killer cells (CD56+), and B lymphocytes (CD19+) by flow cytometry and assessed the expression of Th1 (IFN-γ, TNF-α, IL-2, and IL-12), Th2 (IL-4), and Treg (TGF-β) cytokines by flow cytometry and an enzyme-linked immunosorbent assay. The CD14+ TNF-α+ population was significantly increased (P < 0.04) when patients received the vaccine; IL-2 expression in both NK cells and in B lymphocytes was increased after a transient initial increase showed a nearly significant decrease (P < 0.07 and P < 0.06 respectively), whereas the CD19+ and CD56+ populations did not show significant changes. Dendritic cell-based immunotherapy led to increased secretion of IFN-γ and IL-12 and reduced secretion of TGF-β. In conclusion, it is likely that the autologous dendritic cell vaccine stimulated the immune cells from the peripheral blood of patients with cancer and generally increased the production of Th1 cytokines, which are related to immunomodulatory responses against cancer. PMID:23926442

Onset of Curved Dendrite Growth in an Al-Cu Welding Pool: A Phase Field Study

NASA Astrophysics Data System (ADS)

Wang, Lei; Wei, Yanhong

2018-02-01

A phase field model is developed to predict curved dendrite growth in the gas tungsten arc (GTA) welding pool of an Al-Cu alloy. The equations of temperature gradient, pulling velocity and dendrite growth orientation are proposed to consider the transient solidification process during welding. Solidification microstructures and solute diffusion along the fusion boundary in the welding pool are predicted by using the phase field model coupled with transient solidification conditions. Predicted primary dendrites are curved and point toward the welding direction. Welding experiments are carried out to observe solidification microstructures of the weld. Comparisons of simulation results with experimental measurements are conducted. Predicted dendritic morphology, dendrite growth orientation, primary dendrite arm spacing and initial cell spacing give a good agreement with experimental measurements.

Three-dimensional synaptic analyses of mitral cell and external tufted cell dendrites in rat olfactory bulb glomeruli.

PubMed

Bourne, Jennifer N; Schoppa, Nathan E

2017-02-15

Recent studies have suggested that the two excitatory cell classes of the mammalian olfactory bulb, the mitral cells (MCs) and tufted cells (TCs), differ markedly in physiological responses. For example, TCs are more sensitive and broadly tuned to odors than MCs and also are much more sensitive to stimulation of olfactory sensory neurons (OSNs) in bulb slices. To examine the morphological bases for these differences, we performed quantitative ultrastructural analyses of glomeruli in rat olfactory bulb under conditions in which specific cells were labeled with biocytin and 3,3'-diaminobenzidine. Comparisons were made between MCs and external TCs (eTCs), which are a TC subtype in the glomerular layer with large, direct OSN signals and capable of mediating feedforward excitation of MCs. Three-dimensional analysis of labeled apical dendrites under an electron microscope revealed that MCs and eTCs in fact have similar densities of several chemical synapse types, including OSN inputs. OSN synapses also were distributed similarly, favoring a distal localization on both cells. Analysis of unlabeled putative MC dendrites further revealed gap junctions distributed uniformly along the apical dendrite and, on average, proximally with respect to OSN synapses. Our results suggest that the greater sensitivity of eTCs vs. MCs is due not to OSN synapse number or absolute location but rather to a conductance in the MC dendrite that is well positioned to attenuate excitatory signals passing to the cell soma. Functionally, such a mechanism could allow rapid and dynamic control of OSN-driven action potential firing in MCs through changes in gap junction properties. J. Comp. Neurol. 525:592-609, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Dscam1-mediated self-avoidance counters netrin-dependent targeting of dendrites in Drosophila.

PubMed

Matthews, Benjamin J; Grueber, Wesley B

2011-09-13

Dendrites and axons show precise targeting and spacing patterns for proper reception and transmission of information in the nervous system. Self-avoidance promotes complete territory coverage and nonoverlapping spacing between processes from the same cell [1, 2]. Neurons that lack Drosophila Down syndrome cell adhesion molecule 1 (Dscam1) show aberrant overlap, fasciculation, and accumulation of dendrites and axons, demonstrating a role in self-recognition and repulsion leading to self-avoidance [3-11]. Fasciculation and accumulation of processes suggested that Dscam1 might promote process spacing by counterbalancing developmental signals that otherwise promote self-association [9, 12]. Here we show that Dscam1 functions to counter Drosophila sensory neuron dendritic targeting signals provided by secreted Netrin-B and Frazzled, a netrin receptor. Loss of Dscam1 function resulted in aberrant dendrite accumulation at a Netrin-B-expressing target, whereas concomitant loss of Frazzled prevented accumulation and caused severe deficits in dendritic territory coverage. Netrin misexpression was sufficient to induce ectopic dendritic targeting in a Frazzled-dependent manner, whereas Dscam1 was required to prevent ectopic accumulation, consistent with separable roles for these receptors. Our results suggest that Dscam1-mediated self-avoidance counters extrinsic signals that are required for normal dendritic patterning, but whose action would otherwise favor neurite accumulation. Counterbalancing roles for Dscam1 may be deployed in diverse contexts during neural circuit formation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dscam1-mediated self-avoidance counters Netrin-dependent targeting of dendrites in Drosophila

PubMed Central

Matthews, Benjamin J.; Grueber, Wesley B.

2011-01-01

SUMMARY Dendrites and axons show precise targeting and spacing patterns for proper reception and transmission of information in the nervous system. Self-avoidance promotes complete territory coverage and non-overlapping spacing between processes from the same cell [1, 2]. Neurons that lack Drosophila Down syndrome cell adhesion molecule 1 (Dscam1) show aberrant overlap, fasciculation, and accumulation of dendrites and axons, demonstrating a role in self-recognition and repulsion leading to self-avoidance [3–11]. Fasciculation and accumulation of processes suggested that Dscam1 might promote process spacing by counterbalancing developmental signals that otherwise promote self-association [9, 12]. Here we show that Dscam1 functions to counter sensory neuron dendritic targeting signals provided by secreted Netrin-B and Frazzled, a netrin receptor. Loss of Dscam1 function resulted in aberrant dendrite accumulation at a Netrin-B expressing target, whereas concomitant loss of Frazzled prevented accumulation and caused severe deficits in dendritic territory coverage. Netrin misexpression was sufficient to induce ectopic dendritic targeting in a Frazzled-dependent manner, whereas Dscam1 was required to prevent ectopic accumulation, consistent with separable roles for these receptors. Our results suggest that Dscam1-mediated self-avoidance counter extrinsic signals that are required for normal dendritic patterning, but whose action would otherwise favor neurite accumulation. Counterbalancing roles for Dscam1 may be deployed in diverse contexts during neural circuit formation. PMID:21871804

Maraba MG1 Virus Enhances Natural Killer Cell Function via Conventional Dendritic Cells to Reduce Postoperative Metastatic Disease

PubMed Central

Zhang, Jiqing; Tai, Lee-Hwa; Ilkow, Carolina S; Alkayyal, Almohanad A; Ananth, Abhirami A; de Souza, Christiano Tanese; Wang, Jiahu; Sahi, Shalini; Ly, Lundi; Lefebvre, Charles; Falls, Theresa J; Stephenson, Kyle B; Mahmoud, Ahmad B; Makrigiannis, Andrew P; Lichty, Brian D; Bell, John C; Stojdl, David F; Auer, Rebecca C

2014-01-01

This study characterizes the ability of novel oncolytic rhabdoviruses (Maraba MG1) to boost natural killer (NK) cell activity. Our results demonstrate that MG1 activates NK cells via direct infection and maturation of conventional dendritic cells. Using NK depletion and conventional dendritic cells ablation studies in vivo, we established that both are required for MG1 efficacy. We further explored the efficacy of attenuated MG1 (nonreplicating MG1-UV2min and single-cycle replicating MG1-Gless) and demonstrated that these viruses activate conventional dendritic cells, although to a lesser extent than live MG1. This translates to equivalent abilities to remove tumor metastases only at the highest viral doses of attenuated MG1. In tandem, we characterized the antitumor ability of NK cells following preoperative administration of live and attenuated MG1. Our results demonstrates that a similar level of NK activation and reduction in postoperative tumor metastases was achieved with equivalent high viral doses concluding that viral replication is important, but not necessary for NK activation. Biochemical characterization of a panel of UV-inactivated MG1 (2–120 minutes) revealed that intact viral particle and target cell recognition are essential for NK cell–mediated antitumor responses. These findings provide mechanistic insight and preclinical rationale for safe perioperative virotherapy to effectively reduce metastatic disease following cancer surgery. PMID:24695102

Visual Stimuli Evoked Action Potentials Trigger Rapidly Propagating Dendritic Calcium Transients in the Frog Optic Tectum Layer 6 Neurons.

PubMed

Svirskis, Gytis; Baranauskas, Gytis; Svirskiene, Natasa; Tkatch, Tatiana

2015-01-01

The superior colliculus in mammals or the optic tectum in amphibians is a major visual information processing center responsible for generation of orientating responses such as saccades in monkeys or prey catching avoidance behavior in frogs. The conserved structure function of the superior colliculus the optic tectum across distant species such as frogs, birds monkeys permits to draw rather general conclusions after studying a single species. We chose the frog optic tectum because we are able to perform whole-cell voltage-clamp recordings fluorescence imaging of tectal neurons while they respond to a visual stimulus. In the optic tectum of amphibians most visual information is processed by pear-shaped neurons possessing long dendritic branches, which receive the majority of synapses originating from the retinal ganglion cells. Since the first step of the retinal input integration is performed on these dendrites, it is important to know whether this integration is enhanced by active dendritic properties. We demonstrate that rapid calcium transients coinciding with the visual stimulus evoked action potentials in the somatic recordings can be readily detected up to the fine branches of these dendrites. These transients were blocked by calcium channel blockers nifedipine CdCl2 indicating that calcium entered dendrites via voltage-activated L-type calcium channels. The high speed of calcium transient propagation, >300 μm in <10 ms, is consistent with the notion that action potentials, actively propagating along dendrites, open voltage-gated L-type calcium channels causing rapid calcium concentration transients in the dendrites. We conclude that such activation by somatic action potentials of the dendritic voltage gated calcium channels in the close vicinity to the synapses formed by axons of the retinal ganglion cells may facilitate visual information processing in the principal neurons of the frog optic tectum.

mRNA for the EAAC1 Subtype of Glutamate Transporter is Present in Neuronal Dendrites In Vitro and Dramatically Increases In Vivo After a Seizure

PubMed Central

Ross, John R.; Porter, Brenda E.; Buckley, Peter T.; Eberwine, James H.; Robinson, Michael B.

2011-01-01

The neuronal Na+-dependent glutamate transporter, excitatory amino acid carrier 1 (EAAC1, also called EAAT3), has been implicated in the control of synaptic spillover of glutamate, synaptic plasticity, and the import of cysteine for neuronal synthesis of glutathione. EAAC1 protein is observed in both perisynaptic regions of the synapse and in neuronal cell bodies. Although amino acid residues in the carboxyl terminal tail have been implicated in the dendritic targeting of EAAC1 protein, it is not known if mRNA for EAAC1 may also be targeted to dendrites. Sorting of mRNA to specific cellular domains provides a mechanism by which signals can rapidly increase translation in a local environment; this form of regulated translation has been linked to diverse biological phenomena ranging from establishment of polarity during embryogenesis to synapse development and synaptic plasticity. In the present study, EAAC1 mRNA sequences were amplified from dendritic samples that were mechanically harvested from low-density hippocampal neuronal cultures. In parallel analyses, mRNA for histone deacetylase 2 (HDAC-2) and glial fibrillary acidic protein (GFAP) was not detected, suggesting that these samples are not contaminated with cell body or glial mRNAs. EAAC1 mRNA also co-localized with Map2a (a marker of dendrites) but not Tau1 (a marker of axons) in hippocampal neuronal cultures by in situ hybridization. In control rats, EAAC1 mRNA was observed in soma and proximal dendrites of hippocampal pyramidal neurons. Following pilocarpine- or kainate-induced seizures, EAAC1 mRNA was present in CA1 pyramidal cell dendrites up to 200 μm from the soma. These studies provide the first evidence that EAAC1 mRNA localizes to dendrites and suggest that dendritic targeting of EAAC1 mRNA is increased by seizure activity and may be regulated by neuronal activity/depolarization. PMID:21185901

Characterization of terrestrial solar cells for space applications: Electrical characteristics of thin Westinghouse dendritic web cells as a function of solar intensity, temperature, and incidence angle

NASA Technical Reports Server (NTRS)

Stella, P. M.; Anspaugh, B. E.

1985-01-01

Electrical characteristics of thin (100- and 140-micron) Westinghouse dendritic-web N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. Performance is also shown as a function of solar illlumination angle of incidence for AMO.

Chitin Recognition via Chitotriosidase Promotes Pathologic Type-2 Helper T Cell Responses to Cryptococcal Infection

PubMed Central

Wiesner, Darin L.; Specht, Charles A.; Lee, Chrono K.; Smith, Kyle D.; Mukaremera, Liliane; Lee, S. Thera; Lee, Chun G.; Elias, Jack A.; Nielsen, Judith N.; Boulware, David R.; Bohjanen, Paul R.; Jenkins, Marc K.; Levitz, Stuart M.; Nielsen, Kirsten

2015-01-01

Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection. PMID:25764512

Chitin recognition via chitotriosidase promotes pathologic type-2 helper T cell responses to cryptococcal infection.

PubMed

Wiesner, Darin L; Specht, Charles A; Lee, Chrono K; Smith, Kyle D; Mukaremera, Liliane; Lee, S Thera; Lee, Chun G; Elias, Jack A; Nielsen, Judith N; Boulware, David R; Bohjanen, Paul R; Jenkins, Marc K; Levitz, Stuart M; Nielsen, Kirsten

2015-03-01

Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection.

Mesenchymal stem cells induce mature dendritic cells into a novel Jagged-2-dependent regulatory dendritic cell population.

PubMed

Zhang, Bin; Liu, Rui; Shi, Dan; Liu, Xingxia; Chen, Yuan; Dou, Xiaowei; Zhu, Xishan; Lu, Chunhua; Liang, Wei; Liao, Lianming; Zenke, Martin; Zhao, Robert C H

2009-01-01

Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2-dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.

Thymic cytoarchitecture changes in mice exposed to vanadium.

PubMed

Ustarroz-Cano, Martha; Garcia-Pelaez, Isabel; Cervantes-Yepez, Silvana; Lopez-Valdez, Nelly; Fortoul, Teresa I

2017-12-01

The thymus is a vital immune system organ wherein selection of T-lymphocytes occurs in a process regulated by dendritic and epithelial thymic cells. Previously, we have reported that in a mouse model of vanadium inhalation, a decrease in CD11c dendritic cells was observed. In the present study, we report on a thymic cortex-medulla distribution distortion in these hosts due to apparent effects of the inhaled vanadium on cytokeratin-5 (K5 + ) epithelial cells in the same mouse model - after 1, 2, and 4 weeks of exposure - by immunohistochemistry. These cells - together with dendritic cells - eliminate autoreactive T-cell clones and regulate the production of regulatory T-cells in situ. Because both cell types are involved in the negative selection of autoreactive clones, a potential for an increase in development of autoimmune conditions could be a possible consequence among individuals who might be exposed often to vanadium in air pollution, including dwellers of highly polluted cities with elevated levels of particulate matter onto which vanadium is often adsorbed.

Repression of mammosphere formation of human breast cancer cells by soy isoflavone genistein and blueberry polyphenolic acids suggests diet-mediated targeting of cancer stem-like/progenitor cells

USDA-ARS?s Scientific Manuscript database

Mammary stem cells are undifferentiated epithelial cells which initiate mammary tumors and render them resistant to anticancer therapies, when deregulated. Diets rich in fruits and vegetables are implicated in breast cancer risk reduction, yet underlying mechanisms are poorly understood. Here, we ad...

Changes in the regulation of heat shock gene expression in neuronal cell differentiation.

PubMed

Oza, Jay; Yang, Jingxian; Chen, Kuang Yu; Liu, Alice Y-C

2008-01-01

Neuronal differentiation of the NG108-15 neuroblastoma-glioma hybrid cells is accompanied by a marked attenuation in the heat shock induction of the Hsp70-firefly luciferase reporter gene activity. Analysis of the amount and activation of heat shock factor 1, induction of mRNA(hsp), and the synthesis and accumulation of heat shock proteins (HSPs) in the undifferentiated and differentiated cells suggest a transcriptional mechanism for this attenuation. Concomitant with a decreased induction of the 72-kDa Hsp70 protein in the differentiated cells, there is an increased abundance of the constitutive 73-kDa Hsc70, a protein known to function in vesicle trafficking. Assessment of sensitivity of the undifferentiated and differentiated cells against stress-induced cell death reveals a significantly greater vulnerability of the differentiated cells toward the cytotoxic effects of arsenite and glutamate/glycine. This study shows that changes in regulation of the HSP and HSC proteins are components of the neuronal cell differentiation program and that the attenuated induction of HSPs likely contributes to neuronal vulnerability whereas the increased expression of Hsc70 likely has a role in neural-specific functions.

Morphological Characterization of the Action Potential Initiation Segment in GnRH Neuron Dendrites and Axons of Male Mice.

PubMed

Herde, Michel K; Herbison, Allan E

2015-11-01

GnRH neurons are the final output neurons of the hypothalamic network controlling fertility in mammals. In the present study, we used ankyrin G immunohistochemistry and neurobiotin filling of live GnRH neurons in brain slices from GnRH-green fluorescent protein transgenic male mice to examine in detail the location of action potential initiation in GnRH neurons with somata residing at different locations in the basal forebrain. We found that the vast majority of GnRH neurons are bipolar in morphology, elaborating a thick (primary) and thinner (secondary) dendrite from opposite poles of the soma. In addition, an axon-like process arising predominantly from a proximal dendrite was observed in a subpopulation of GnRH neurons. Ankyrin G immunohistochemistry revealed the presence of a single action potential initiation zone ∼27 μm in length primarily in the secondary dendrite of GnRH neurons and located 30 to 140 μm distant from the cell soma, depending on the type of process and location of the cell body. In addition to dendrites, the GnRH neurons with cell bodies located close to hypothalamic circumventricular organs often elaborated ankyrin G-positive axon-like structures. Almost all GnRH neurons (>90%) had their action potential initiation site in a process that initially, or ultimately after a hairpin loop, was coursing in the direction of the median eminence. These studies indicate that action potentials are initiated in different dendritic and axonal compartments of the GnRH neuron in a manner that is dependent partly on the neuroanatomical location of the cell body.

Selective vulnerability of dentate granule cells prior to amyloid deposition in PDAPP mice: digital morphometric analyses.

PubMed

Wu, Chi-Cheng; Chawla, Faisal; Games, Dora; Rydel, Russell E; Freedman, Stephen; Schenk, Dale; Young, Warren G; Morrison, John H; Bloom, Floyd E

2004-05-04

Increasing evidence from mouse models of Alzheimer's disease shows that overexpression of a mutant form of the amyloid precursor protein (APP) and its product, beta-amyloid peptide, initiate pathological changes before amyloid deposition. To evaluate the cytological basis for one of these early changes, namely reduced volume of the dentate gyrus (DG), we have used high-throughput diOlistic cell loading and 3D neuronal reconstruction to investigate potential dendritic pathology of granule cells (GCs) in 90-day-old PDAPP mice. Labeled GCs from fixed hippocampal slices were selected randomly and imaged digitally by using confocal laser-scanning microscopy. The dendritic complexity of GCs was quantified according to subordinate morphological parameters, including soma position within the granule cell layer (superficial versus deep) and topographic location within the DG (dorsal versus ventral blade) along the anterior-posterior hippocampal axis. Initial analysis, which included all sampled GC types, revealed a 12% reduction of total dendritic length in PDAPP mice compared with littermate controls. Further analysis, performed with refined subgroups, found that superficially located GCs in the dorsal blade were profoundly altered, exhibiting a 23% loss in total dendritic length, whereas neurons in the ventral blade were unaffected. Superficial GCs were particularly vulnerable (a 32% reduction) in the posterior region of the DG. Furthermore, the dendritic reductions of this select group were uniformly localized within middle-to-outer portions of the dentate molecular layer. We conclude that substantial dendritic pathology is evident in 90-day-old PDAPP mice for a spatially defined subset of GCs well before amyloid accumulation occurs.

Selective vulnerability of dentate granule cells prior to amyloid deposition in PDAPP mice: Digital morphometric analyses

PubMed Central

Wu, Chi-Cheng; Chawla, Faisal; Games, Dora; Rydel, Russell E.; Freedman, Stephen; Schenk, Dale; Young, Warren G.; Morrison, John H.; Bloom, Floyd E.

2004-01-01

Increasing evidence from mouse models of Alzheimer's disease shows that overexpression of a mutant form of the amyloid precursor protein (APP) and its product, β-amyloid peptide, initiate pathological changes before amyloid deposition. To evaluate the cytological basis for one of these early changes, namely reduced volume of the dentate gyrus (DG), we have used high-throughput diOlistic cell loading and 3D neuronal reconstruction to investigate potential dendritic pathology of granule cells (GCs) in 90-day-old PDAPP mice. Labeled GCs from fixed hippocampal slices were selected randomly and imaged digitally by using confocal laser-scanning microscopy. The dendritic complexity of GCs was quantified according to subordinate morphological parameters, including soma position within the granule cell layer (superficial versus deep) and topographic location within the DG (dorsal versus ventral blade) along the anterior-posterior hippocampal axis. Initial analysis, which included all sampled GC types, revealed a 12% reduction of total dendritic length in PDAPP mice compared with littermate controls. Further analysis, performed with refined subgroups, found that superficially located GCs in the dorsal blade were profoundly altered, exhibiting a 23% loss in total dendritic length, whereas neurons in the ventral blade were unaffected. Superficial GCs were particularly vulnerable (a 32% reduction) in the posterior region of the DG. Furthermore, the dendritic reductions of this select group were uniformly localized within middle-to-outer portions of the dentate molecular layer. We conclude that substantial dendritic pathology is evident in 90-day-old PDAPP mice for a spatially defined subset of GCs well before amyloid accumulation occurs. PMID:15118092

Synaptology of physiologically identified ganglion cells in the cat retina: a comparison of retinal X- and Y-cells.

PubMed

Weber, A J; Stanford, L R

1994-05-15

It has long been known that a number of functionally different types of ganglion cells exist in the cat retina, and that each responds differently to visual stimulation. To determine whether the characteristic response properties of different retinal ganglion cell types might reflect differences in the number and distribution of their bipolar and amacrine cell inputs, we compared the percentages and distributions of the synaptic inputs from bipolar and amacrine cells to the entire dendritic arbors of physiologically characterized retinal X- and Y-cells. Sixty-two percent of the synaptic input to the Y-cell was from amacrine cell terminals, while the X-cells received approximately equal amounts of input from amacrine and bipolar cells. We found no significant difference in the distributions of bipolar or amacrine cell inputs to X- and Y-cells, or ON-center and OFF-center cells, either as a function of dendritic branch order or distance from the origin of the dendritic arbor. While, on the basis of these data, we cannot exclude the possibility that the difference in the proportion of bipolar and amacrine cell input contributes to the functional differences between X- and Y-cells, the magnitude of this difference, and the similarity in the distributions of the input from the two afferent cell types, suggest that mechanisms other than a simple predominance of input from amacrine or bipolar cells underlie the differences in their response properties. More likely, perhaps, is that the specific response features of X- and Y-cells originate in differences in the visual responses of the bipolar and amacrine cells that provide their input, or in the complex synaptic arrangements found among amacrine and bipolar cell terminals and the dendrites of specific types of retinal ganglion cells.

Tetraspanin-3 regulates protective immunity against Eimera tenella infection following immunization with dendritic cell-derived exosomes

USDA-ARS?s Scientific Manuscript database

The effects of immunization with dendritic cell (DC) exosomes, which had been incubated or non-incubated with an anti-tetraspanin-3 (Tspan-3) blocking antibody (Ab), were studied using an experimental model of Eimeria tenella avian coccidiosis. Purified exosomes from cecal tonsil and splenic DCs exp...

Parasite Fate and Involvement of Infected Cells in the Induction of CD4+ and CD8+ T Cell Responses to Toxoplasma gondii

PubMed Central

Dupont, Christopher D.; Christian, David A.; Selleck, Elizabeth M.; Pepper, Marion; Leney-Greene, Michael; Harms Pritchard, Gretchen; Koshy, Anita A.; Wagage, Sagie; Reuter, Morgan A.; Sibley, L. David; Betts, Michael R.; Hunter, Christopher A.

2014-01-01

During infection with the intracellular parasite Toxoplasma gondii, the presentation of parasite-derived antigens to CD4+ and CD8+ T cells is essential for long-term resistance to this pathogen. Fundamental questions remain regarding the roles of phagocytosis and active invasion in the events that lead to the processing and presentation of parasite antigens. To understand the most proximal events in this process, an attenuated non-replicating strain of T. gondii (the cpsII strain) was combined with a cytometry-based approach to distinguish active invasion from phagocytic uptake. In vivo studies revealed that T. gondii disproportionately infected dendritic cells and macrophages, and that infected dendritic cells and macrophages displayed an activated phenotype characterized by enhanced levels of CD86 compared to cells that had phagocytosed the parasite, thus suggesting a role for these cells in priming naïve T cells. Indeed, dendritic cells were required for optimal CD4+ and CD8+ T cell responses, and the phagocytosis of heat-killed or invasion-blocked parasites was not sufficient to induce T cell responses. Rather, the selective transfer of cpsII-infected dendritic cells or macrophages (but not those that had phagocytosed the parasite) to naïve mice potently induced CD4+ and CD8+ T cell responses, and conferred protection against challenge with virulent T. gondii. Collectively, these results point toward a critical role for actively infected host cells in initiating T. gondii-specific CD4+ and CD8+ T cell responses. PMID:24722202

Dental pulp stem cells promote regeneration of damaged neuron cells on the cellular model of Alzheimer's disease.

PubMed

Wang, Feixiang; Jia, Yali; Liu, Jiajing; Zhai, Jinglei; Cao, Ning; Yue, Wen; He, Huixia; Pei, Xuetao

2017-06-01

Alzheimer's disease (AD) is an incurable neurodegenerative disease and many types of stem cells have been used in AD therapy with some favorable effects. In this study, we investigated the potential therapeutical effects of human dental pulp stem cells (hDPSCs) on AD cellular model which established by okadaic acid (OA)-induced damage to human neuroblastoma cell line, SH-SY5Y, in vitro for 24 h. After confirmed the AD cellular model, the cells were co-culture with hDPSCs by transwell co-culture system till 24 h for treatment. Then the cytomorphology of the hDPSCs-treated cells were found to restore gradually with re-elongation of retracted dendrites. Meanwhile, Cell Counting Kit-8 assay and Hoechst 33258 staining showed that hDPSCs caused significant increase in the viability and decrease in apoptosis of the model cells, respectively. Observation of DiI labeling also exhibited the prolongation dendrites in hDPSCs-treated cells which were obviously different from the retraction dendrites in AD model cells. Furthermore, specific staining of α-tubulin and F-actin demonstrated that the hDPSCs-treated cells had the morphology of restored neurons, with elongated dendrites, densely arranged microfilaments, and thickened microtubular fibrils. In addition, results from western blotting revealed that phosphorylation at Ser 396 of Tau protein was significantly suppressed by adding of hDPSCs. These results indicate that hDPSCs may promote regeneration of damaged neuron cells in vitro model of AD and may serve as a useful cell source for treatment of AD. © 2017 International Federation for Cell Biology.

Liposomes containing NY‑ESO‑1/tetanus toxoid and adjuvant peptides targeted to human dendritic cells via the Fc receptor for cancer vaccines.

PubMed

Cruz, Luis J; Rueda, Felix; Simón, Lorena; Cordobilla, Begoña; Albericio, Fernando; Domingo, Joan C

2014-04-01

To improve the immunological response against tumors, a vaccine based on nanoliposomes targeted to the Fcg-receptor was developed to enhance the immunogenicity of tumor-associated antigens (TAAs). Using human dendritic cells in vitro, a fragment of the TAA NY-ESO-1 combined with a T-helper peptide from the tetanus toxoid encapsulated in nanoliposomes was evaluated. In addition, peptides Palm-IL-1 and MAP-IFN-g were coadministered as adjuvants to enhance the immunological response. Coadministration of Palm-IL-1 or MAP-IFN-g peptide adjuvants and the hybrid NY-ESO-1-tetanus toxoid (soluble or encapsulated in nanoliposomes without targeting) increased immunogenicity. However, the most potent immunological response was obtained when the peptide adjuvants were encapsulated in liposomes targeted to human dendritic cells via the Fc receptor. This targeted vaccine strategy is a promising tool to activate and deliver antigens to dendritic cells, thus improving immunotherapeutic response in situations in which the immune system is frequently compromised, as in advanced cancers.

SNAP-25 requirement for dendritic growth of hippocampal neurons.

PubMed

Grosse, G; Grosse, J; Tapp, R; Kuchinke, J; Gorsleben, M; Fetter, I; Höhne-Zell, B; Gratzl, M; Bergmann, M

1999-06-01

Structure and dimension of the dendritic arbor are important determinants of information processing by the nerve cell, but mechanisms and molecules involved in dendritic growth are essentially unknown. We investigated early mechanisms of dendritic growth using mouse fetal hippocampal neurons in primary culture, which form processes during the first week in vitro. We detected a key component of regulated exocytosis, SNAP-25 (synaptosomal associated protein of 25 kDa), in axons and axonal terminals as well as in dendrites identified by the occurrence of the dendritic markers transferrin receptor and MAP2. Selective inactivation of SNAP-25 by botulinum neurotoxin A (BoNTA) resulted in inhibition of axonal growth and of vesicle recycling in axonal terminals. In addition, dendritic growth of hippocampal pyramidal and granule neurons was significantly inhibited by BoNTA. In contrast, cleavage of synaptobrevin by tetanus toxin had an effect on neither axonal nor dendritic growth. Our observations indicate that SNAP-25, but not synaptobrevin, is involved in constitutive axonal growth and dendrite formation by hippocampal neurons.

Nak regulates localization of clathrin sites in higher-order dendrites to promote local dendrite growth.

PubMed

Yang, Wei-Kang; Peng, Yu-Huei; Li, Hsun; Lin, Hsiu-Chen; Lin, Yu-Ching; Lai, Tzu-Ting; Suo, Hsien; Wang, Chien-Hsiang; Lin, Wei-Hsiang; Ou, Chan-Yen; Zhou, Xin; Pi, Haiwei; Chang, Henry C; Chien, Cheng-Ting

2011-10-20

During development, dendrites arborize in a field several hundred folds of their soma size, a process regulated by intrinsic transcription program and cell adhesion molecule (CAM)-mediated interaction. However, underlying cellular machineries that govern distal higher-order dendrite extension remain largely unknown. Here, we show that Nak, a clathrin adaptor-associated kinase, promotes higher-order dendrite growth through endocytosis. In nak mutants, both the number and length of higher-order dendrites are reduced, which are phenocopied by disruptions of clathrin-mediated endocytosis. Nak interacts genetically with components of the endocytic pathway, colocalizes with clathrin puncta, and is required for dendritic localization of clathrin puncta. More importantly, these Nak-containing clathrin structures preferentially localize to branching points and dendritic tips that are undergoing active growth. We present evidence that the Drosophila L1-CAM homolog Neuroglian is a relevant cargo of Nak-dependent internalization, suggesting that localized clathrin-mediated endocytosis of CAMs facilitates the extension of nearby higher-order dendrites. Copyright © 2011 Elsevier Inc. All rights reserved.

Laminar Differences in Dendritic Structure of Pyramidal Neurons in the Juvenile Rat Somatosensory Cortex.

PubMed

Rojo, Concepción; Leguey, Ignacio; Kastanauskaite, Asta; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier; Benavides-Piccione, Ruth

2016-06-01

Pyramidal cell structure varies between different cortical areas and species, indicating that the cortical circuits that these cells participate in are likely to be characterized by different functional capabilities. Structural differences between cortical layers have been traditionally reported using either the Golgi method or intracellular labeling, but the structure of pyramidal cells has not previously been systematically analyzed across all cortical layers at a particular age. In the present study, we investigated the dendritic architecture of complete basal arbors of pyramidal neurons in layers II, III, IV, Va, Vb, and VI of the hindlimb somatosensory cortical region of postnatal day 14 rats. We found that the characteristics of basal dendritic morphologies are statistically different in each cortical layer. The variations in size and branching pattern that exist between pyramidal cells of different cortical layers probably reflect the particular functional properties that are characteristic of the cortical circuit in which they participate. This new set of complete basal dendritic arbors of 3D-reconstructed pyramidal cell morphologies across each cortical layer will provide new insights into interlaminar information processing in the cerebral cortex. © The Author 2016. Published by Oxford University Press.

High areal capacity hybrid magnesium-lithium-ion battery with 99.9% Coulombic efficiency for large-scale energy storage.

PubMed

Yoo, Hyun Deog; Liang, Yanliang; Li, Yifei; Yao, Yan

2015-04-01

Hybrid magnesium-lithium-ion batteries (MLIBs) featuring dendrite-free deposition of Mg anode and Li-intercalation cathode are safe alternatives to Li-ion batteries for large-scale energy storage. Here we report for the first time the excellent stability of a high areal capacity MLIB cell and dendrite-free deposition behavior of Mg under high current density (2 mA cm(-2)). The hybrid cell showed no capacity loss for 100 cycles with Coulombic efficiency as high as 99.9%, whereas the control cell with a Li-metal anode only retained 30% of its original capacity with Coulombic efficiency well below 90%. The use of TiS2 as a cathode enabled the highest specific capacity and one of the best rate performances among reported MLIBs. Postmortem analysis of the cycled cells revealed dendrite-free Mg deposition on a Mg anode surface, while mossy Li dendrites were observed covering the Li surface and penetrated into separators in the Li cell. The energy density of a MLIB could be further improved by developing electrolytes with higher salt concentration and wider electrochemical window, leading to new opportunities for its application in large-scale energy storage.

Layer 5 Pyramidal Neurons' Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis

PubMed Central

Urrego, Diana; Troncoso, Julieta; Múnera, Alejandro

2015-01-01

This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1). It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans. PMID:26064916

CD83 Antibody Inhibits Human B Cell Responses to Antigen as well as Dendritic Cell-Mediated CD4 T Cell Responses.

PubMed

Wong, Kuan Y; Baron, Rebecca; Seldon, Therese A; Jones, Martina L; Rice, Alison M; Munster, David J

2018-05-15

Anti-CD83 Ab capable of Ab-dependent cellular cytotoxicity can deplete activated CD83 + human dendritic cells, thereby inhibiting CD4 T cell-mediated acute graft-versus-host disease. As CD83 is also expressed on the surface of activated B lymphocytes, we hypothesized that anti-CD83 would also inhibit B cell responses to stimulation. We found that anti-CD83 inhibited total IgM and IgG production in vitro by allostimulated human PBMC. Also, Ag-specific Ab responses to immunization of SCID mice xenografted with human PBMC were inhibited by anti-CD83 treatment. This inhibition occurred without depletion of all human B cells because anti-CD83 lysed activated CD83 + B cells by Ab-dependent cellular cytotoxicity and spared resting (CD83 - ) B cells. In cultured human PBMC, anti-CD83 inhibited tetanus toxoid-stimulated B cell proliferation and concomitant dendritic cell-mediated CD4 T cell proliferation and expression of IFN-γ and IL-17A, with minimal losses of B cells (<20%). In contrast, the anti-CD20 mAb rituximab depleted >80% of B cells but had no effect on CD4 T cell proliferation and cytokine expression. By virtue of the ability of anti-CD83 to selectively deplete activated, but not resting, B cells and dendritic cells, with the latter reducing CD4 T cell responses, anti-CD83 may be clinically useful in autoimmunity and transplantation. Advantages might include inhibited expansion of autoantigen- or alloantigen-specific B cells and CD4 T cells, thus preventing further production of pathogenic Abs and inflammatory cytokines while preserving protective memory and regulatory cells. Copyright © 2018 by The American Association of Immunologists, Inc.

ALTERATION OF CATECHOLAMINES IN PHOECHROMOCYTOMA (PC12) CELLS IN VITRO BY THE METABOLITES OF CHLOROTRIAZINE HERBICIDE

EPA Science Inventory

The effects of four major chlorotriazine metabolites on the constitutive synthesis of the catecholamines dopamine (DA) and norepinephrine (NE) were examined using undifferentiated PC12 cells. NE release and intracellular DA and NE concentrations were quantified following treatme...

Longitudinal expression of Toll-like receptors on dendritic cells in uncomplicated pregnancy and postpartum

PubMed Central

Young, Brett C.; Stanic, Aleksandar K.; Panda, Britta; Rueda, Bo R.; Panda, Alexander

2014-01-01

OBJECTIVE Toll-like receptors (TLRs) are integral parts of the innate immune system and have been implicated in complications of pregnancy. The longitudinal expression of TLRs on dendritic cells in the maternal circulation during uncomplicated pregnancies is unknown. The objective of this study was to prospectively evaluate TLRs 1-9 as expressed on dendritic cells in the maternal circulation at defined intervals throughout pregnancy and postpartum. STUDY DESIGN This was a prospective cohort of 30 pregnant women with uncomplicated pregnancies and 30 nonpregnant controls. TLRs and cytokine expression was measured in unstimulated dendritic cells at 4 defined intervals during pregnancy and postpartum. Basal expression of TLRs and cytokines was measured by multicolor flow cytometry. The percent-positive dendritic cells for each TLRs were compared with both nonpregnant and postpartum levels with multivariate linear regression. RESULTS TLRs 1, 7, and 9 were elevated compared with nonpregnant controls with persistent elevation of TLR 1 and interleukin-12 (IL-12) into the postpartum period. Concordantly, levels of IL-6, IL-12, interferon alpha, and tumor necrosis factor alpha increased during pregnancy and returned to levels similar to nonpregnant controls during the postpartum period. The elevated levels of TLR 1 and IL-12 were persistent postpartum, challenging notions that immunologic changes during pregnancy resolve after the prototypical postpartum period. CONCLUSION Normal pregnancy is associated with time-dependent changes in TLR expression compared with nonpregnant controls; these findings may help elucidate immunologic dysfunction in complicated pregnancies. PMID:24291497

Sensory Neuroanatomy of Parastrongyloides trichosuri, a Nematode Parasite of Mammals: Amphidial Neurons of the First-Stage Larva

PubMed Central

Zhu, He; Li, Jian; Nolan, Thomas J.; Schad, Gerhard A.; Lok, James B.

2011-01-01

Owing to its ability to switch between free-living and parasitic modes of development, Parastrongyloides trichosuri represents a valuable model with which to study the evolution of parasitism among the nematodes, especially aspects pertaining to morphogenesis of infective third-stage larvae. In the free-living nematode Caenorhabditis elegans, developmental fates of third-stage larvae are determined in part by environmental cues received by chemosensory neurons in the amphidial sensillae. As a basis for comparative study, we have described the neuroanatomy of the amphidial sensillae of P. trichosuri. Using computational methods we incorporated serial electron micrographs into a three-dimensional reconstruction of the amphidial neurons of this parasite. Each amphid is innervated by 13 neurons, and the dendritic processes of 10 of these extend nearly to the amphidial pore. Dendritic processes of two specialized neurons leave the amphidial channel and terminate within invaginations of the sheath cell. One of these is similar to the finger cell of C. elegans, terminating in digitiform projections. The other projects a single cilium into the sheath cell. The dendritic process of a third specialized neuron terminates within the tight junction of the amphid. Each amphidial neuron was traced from the tip of its dendrite(s) to its cell body in the lateral ganglion. Positions of these cell bodies approximate those of morphologically similar amphidial neurons in Caenorhabditis elegans, so the standard nomenclature for amphidial neurons in C. elegans was adopted. A map of cell bodies within the lateral ganglion of P. trichosuri was prepared to facilitate functional study of these neurons. PMID:21456026

The cytoarchitecture of the torus semicircularis in the Tegu lizard, Tupinambis nigropunctatus.

PubMed

Browner, R H; Rubinson, K

1977-12-15

The torus semicircularis (TS) of the Tegu lizard extends from the superficial caudal mesencephalon, dorsal to the exiting trochlear nerve, to a position ventral to the middle part of the optic tectum and its ventricle. It has an oblique orientation with the caudal pole abutting the midline while the rostal end is lateral and slightly ventral. The TS consists of a central nucleus and several adjacent cell groups. The central nucleus and the laminar nucleus, situated medially, extend the entire length of the TS while the cortical nucleus, situated dorsally and laterally, is present only in the caudal superficial portion. The central nucleus is composed of ovoid neurons with branched, radiating dendrites. The dendrites are directed medially and laterally with spines on the distal portion of the dendritic tree. The laminar nucleus consists of three to five neuronal layers. It is mainly composed of fusiform neurons with one dendritic trunk from each extremity of the soma. There is little branching and few dendritic spines. The cortical nucleus is a laminated region consisting of alternating layers of neurons and lateral lemniscal fibers. The neurons of the superficial layers are fusiform with their long axis perpendicular to the long axis of the brainstem. They possess two main dendritic trunks which parallel the laminae and are covered with dendritic spines. The deeper layers consist of pyramidal neurons with three dendritic trunks, secondary branches, and few spines. The long axis of these neurons extends from the center of the TS to the periphery. Two dendritic trunks extend dorsally or laterally towards the surface, while the third extends towards the central nucleus. The dendrites, thus, extend across the laminae. In addition, a cell-free lateral zone is described.

Compartmentalized beta subunit distribution determines characteristics and ethanol sensitivity of somatic, dendritic, and terminal large-conductance calcium-activated potassium channels in the rat central nervous system.

PubMed

Wynne, P M; Puig, S I; Martin, G E; Treistman, S N

2009-06-01

Neurons are highly differentiated and polarized cells, whose various functions depend upon the compartmentalization of ion channels. The rat hypothalamic-neurohypophysial system (HNS), in which cell bodies and dendrites reside in the hypothalamus, physically separated from their nerve terminals in the neurohypophysis, provides a particularly powerful preparation in which to study the distribution and regional properties of ion channel proteins. Using electrophysiological and immunohistochemical techniques, we characterized the large-conductance calcium-activated potassium (BK) channel in each of the three primary compartments (soma, dendrite, and terminal) of HNS neurons. We found that dendritic BK channels, in common with somatic channels but in contrast to nerve terminal channels, are insensitive to iberiotoxin. Furthermore, analysis of dendritic BK channel gating kinetics indicates that they, like somatic channels, have fast activation kinetics, in contrast to the slow gating of terminal channels. Dendritic and somatic channels are also more sensitive to calcium and have a greater conductance than terminal channels. Finally, although terminal BK channels are highly potentiated by ethanol, somatic and dendritic channels are insensitive to the drug. The biophysical and pharmacological properties of somatic and dendritic versus nerve terminal channels are consistent with the characteristics of exogenously expressed alphabeta1 versus alphabeta4 channels, respectively. Therefore, one possible explanation for our findings is a selective distribution of auxiliary beta1 subunits to the somatic and dendritic compartments and beta4 to the terminal compartment. This hypothesis is supported immunohistochemically by the appearance of distinct punctate beta1 or beta4 channel clusters in the membrane of somatic and dendritic or nerve terminal compartments, respectively.

Extrinsic Repair of Injured Dendrites as a Paradigm for Regeneration by Fusion in Caenorhabditis elegans.

PubMed

Oren-Suissa, Meital; Gattegno, Tamar; Kravtsov, Veronika; Podbilewicz, Benjamin

2017-05-01

Injury triggers regeneration of axons and dendrites. Research has identified factors required for axonal regeneration outside the CNS, but little is known about regeneration triggered by dendrotomy. Here, we study neuronal plasticity triggered by dendrotomy and determine the fate of complex PVD arbors following laser surgery of dendrites. We find that severed primary dendrites grow toward each other and reconnect via branch fusion. Simultaneously, terminal branches lose self-avoidance and grow toward each other, meeting and fusing at the tips via an AFF-1-mediated process. Ectopic branch growth is identified as a step in the regeneration process required for bypassing the lesion site. Failure of reconnection to the severed dendrites results in degeneration of the distal end of the neuron. We discover pruning of excess branches via EFF-1 that acts to recover the original wild-type arborization pattern in a late stage of the process. In contrast, AFF-1 activity during dendritic auto-fusion is derived from the lateral seam cells and not autonomously from the PVD neuron. We propose a model in which AFF-1-vesicles derived from the epidermal seam cells fuse neuronal dendrites. Thus, EFF-1 and AFF-1 fusion proteins emerge as new players in neuronal arborization and maintenance of arbor connectivity following injury in Caenorhabditis elegans Our results demonstrate that there is a genetically determined multi-step pathway to repair broken dendrites in which EFF-1 and AFF-1 act on different steps of the pathway. EFF-1 is essential for dendritic pruning after injury and extrinsic AFF-1 mediates dendrite fusion to bypass injuries. Copyright © 2017 by the Genetics Society of America.

Semaphorin-1a prevents Drosophila olfactory projection neuron dendrites from mis-targeting into select antennal lobe regions

PubMed Central

Chu, Sao-Yu; Wang, Chun-Han; Lin, I-Ya

2017-01-01

Elucidating how appropriate neurite patterns are generated in neurons of the olfactory system is crucial for comprehending the construction of the olfactory map. In the Drosophila olfactory system, projection neurons (PNs), primarily derived from four neural stem cells (called neuroblasts), populate their cell bodies surrounding to and distribute their dendrites in distinct but overlapping patterns within the primary olfactory center of the brain, the antennal lobe (AL). However, it remains unclear whether the same molecular mechanisms are employed to generate the appropriate dendritic patterns in discrete AL glomeruli among PNs produced from different neuroblasts. Here, by examining a previously explored transmembrane protein Semaphorin-1a (Sema-1a) which was proposed to globally control initial PN dendritic targeting along the dorsolateral-to-ventromedial axis of the AL, we discover a new role for Sema-1a in preventing dendrites of both uni-glomerular and poly-glomerular PNs from aberrant invasion into select AL regions and, intriguingly, this Sema-1a-deficient dendritic mis-targeting phenotype seems to associate with the origins of PNs from which they are derived. Further, ectopic expression of Sema-1a resulted in PN dendritic mis-projection from a select AL region into adjacent glomeruli, strengthening the idea that Sema-1a plays an essential role in preventing abnormal dendritic accumulation in select AL regions. Taken together, these results demonstrate that Sema-1a repulsion keeps dendrites of different types of PNs away from each other, enabling the same types of PN dendrites to be sorted into destined AL glomeruli and permitting for functional assembly of olfactory circuitry. PMID:28448523

Sequoia, a tramtrack-related zinc finger protein, functions as a pan-neural regulator for dendrite and axon morphogenesis in Drosophila.

PubMed

Brenman, J E; Gao, F B; Jan, L Y; Jan, Y N

2001-11-01

Morphological complexity of neurons contributes to their functional complexity. How neurons generate different dendritic patterns is not known. We identified the sequoia mutant from a previous screen for dendrite mutants. Here we report that Sequoia is a pan-neural nuclear protein containing two putative zinc fingers homologous to the DNA binding domain of Tramtrack. sequoia mutants affect the cell fate decision of a small subset of neurons but have global effects on axon and dendrite morphologies of most and possibly all neurons. In support of sequoia as a specific regulator of neuronal morphogenesis, microarray experiments indicate that sequoia may regulate downstream genes that are important for executing neurite development rather than altering a variety of molecules that specify cell fates.

Design and characterization of hybrid peptide sol-gel materials for the solid state induction of neuronal differentiation

NASA Astrophysics Data System (ADS)

Jedlicka, Sabrina S.

2007-12-01

Cell-based therapeutics are a rapidly growing area of research, with considerable promise in the treatment of neurological diseases. One of the primary limitations to neuronal cell-based devices is the necessity to maintain cells in an immature or undifferentiated state in culture prior to transplantation. In many cases, the undifferentiated cell does not express the desired characteristics for implantation. Biologically functional nanomaterials provide the ability to manipulate the direct extracellular environment surrounding cells; influencing their fate and differentiation path. The ability to engineer the interface between the cells and culture materials provides a repeatable, stable means of directing cells down a specific growth path determined by endogenous signaling pathways. This materials approach to cellular engineering can limit the need for added exogenous growth factors, "feeder" layers, or animal sera, in addition to creating a homogenous cell population for transplantation. In this work, hybrid peptide ormosil materials were developed; designed to mimic the developing mammalian brain during corticogenesis. These materials have been developed to enhance the GABAergic phenotype of P19 embryonic carcinoma cells and immature immortalized neurons. The ability to develop a homogenous, directed cell population has implications in stem cell research, regenerative medicine, cell-based devices and biosensing technology.

Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation

PubMed Central

Creo, Pasquale; Bergante, Sonia; Conforti, Erika; Banfi, Giuseppe

2018-01-01

Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21%) has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF), the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the “hypoxic niches” present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue. PMID:29713352

Isolation of dendritic-cell-like S100β-positive cells in rat anterior pituitary gland.

PubMed

Horiguchi, Kotaro; Fujiwara, Ken; Yoshida, Saishu; Higuchi, Masashi; Tsukada, Takehiro; Kanno, Naoko; Yashiro, Takashi; Tateno, Kozue; Osako, Shunji; Kato, Takako; Kato, Yukio

2014-07-01

S100β-protein-positive cells in the anterior pituitary gland appear to possess multifunctional properties. Because of their pleiotropic features, S100β-positive cells are assumed to be of a heterogeneous or even a non-pituitary origin. The observation of various markers has allowed these cells to be classified into populations such as stem/progenitor cells, epithelial cells, astrocytes and dendritic cells. The isolation and characterization of each heterogeneous population is a prerequisite for clarifying the functional character and origin of the cells. We attempt to isolate two of the subpopulations of S100β-positive cells from the anterior lobe. First, from transgenic rats that express green fluorescent protein (GFP) driven by the S100β protein promoter, we fractionate GFP-positive cells with a cell sorter and culture them so that they can interact with laminin, a component of the extracellular matrix. We observe that one morphological type of GFP-positive cells possesses extended cytoplasmic processes and shows high adhesiveness to laminin (process type), whereas the other is round in shape and exhibits low adherence to laminin (round type). We successfully isolate cells of the round type from the cultured GFP-positive cells by taking advantage of their low affinity to laminin and then measure mRNA levels of the two cell types by real-time polymerase chain reaction. The resultant data show that the process type expresses vimentin (mesenchymal cell marker) and glial fibrillary acidic protein (astrocyte marker). The round type expresses dendritic cell markers, CD11b and interleukin-6. Thus, we found a method for isolating dendritic-cell-like S100β-positive cells by means of their property of adhering to laminin.

The ultrastructure of conjunctival melanocytic tumors.

PubMed Central

Jakobiec, F A

1984-01-01

The ultrastructure of conjunctival melanocytic lesions in 49 patients was evaluated to find significant differences between benign and malignant cells. The patients studied included 9 with benign epithelial (racial) melanosis, 2 with pigmented squamous cell papillomas, 16 with conjunctival nevi, 18 with primary acquired melanosis, and 11 with invasive nodules of malignant melanoma. In benign epithelial melanosis, dendritic melanocytes were situated along the basement membrane region of the conjunctival epithelium, with one basilar dendritic melanocyte lodged among every five or six basilar keratinocytes. The dendritic melanocytes extended arborizing cellular processes between the basilar and among the suprabasilar keratinocytes, which manifested considerable uptake of melanin granules into their cytoplasm. The benign dendritic melanocytes possessed nuclei with clumped heterochromatin at the nuclear membrane, small, tightly wound nucleoli, and large, elongated, fully melaninized melanin granules. In two patients with benign hyperplasia of the dendritic melanocytes, occasional dendritic melanocytes were located in a suprabasilar position, but were always separated from each other by keratinocytes or their processes. In the two black patients with benign pigmented squamous papillomas, the benign dendritic melanocytes were located hapharzardly at all levels of the acanthotic epithelium and not just along the basement membrane region. Melanin uptake by the proliferating keratinocytes was minimal. In benign melanocytic nevi of the conjunctiva, nevus cells within the intraepithelial junctional nests displayed a more rounded cellular configuration; short villi and broader cellular processes suggestive of abortive dendrites were found. The nuclear chromatin pattern was clumped at the nuclear membrane, but the nucleoli were somewhat larger than those of benign dendritic melanocytes in epithelial melanosis. The melanosomes were smaller and rounder than those in dendritic melanocytes and exhibited more haphazard arrangements of the melanofilaments, which were only partially melaninized. Mitochondria were more numerous than in dendritic melanocytes, and monoribosomes predominated over polyribosomes. Cytoplasmic filaments were inconspicuous. Cells in the immediate subepithelial connective tissue zone had features identical to those of the cells within the junctional nests. Smaller, lymphocytoid cells with less numerous and more rudimentary melanosomes were found in the middle and deeper portions of the lesions.(ABSTRACT TRUNCATED AT 400 WORDS) Images FIGURE 21 FIGURE 22 FIGURE 42 FIGURE 67 FIGURE 1 FIGURE 62 FIGURE 26 FIGURE 29 FIGURE 37 FIGURE 11 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 15 FIGURE 16 FIGURE 17 FIGURE 18 FIGURE 19 FIGURE 20 FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 27 FIGURE 28 FIGURE 30 FIGURE 31 FIGURE 32 FIGURE 33 FIGURE 34 FIGURE 35 FIGURE 36 FIGURE 38 FIGURE 39 FIGURE 40 FIGURE 41 FIGURE 43 FIGURE 44 FIGURE 45 FIGURE 46 FIGURE 47 FIGURE 48 FIGURE 49 FIGURE 50 FIGURE 51 FIGURE 52 FIGURE 53 FIGURE 54 FIGURE 55 FIGURE 56 FIGURE 57 FIGURE 58 FIGURE 59 FIGURE 60 FIGURE 61 FIGURE 63 FIGURE 64 FIGURE 65 FIGURE 66 FIGURE 68 FIGURE 69 FIGURE 70 FIGURE 71 FIGURE 72 FIGURE 73 FIGURE 74 FIGURE 75 FIGURE 76 FIGURE 77 FIGURE 78 FIGURE 79 FIGURE 80 FIGURE 81 FIGURE 82 FIGURE 83 FIGURE 84 FIGURE 85 FIGURE 86 FIGURE 87 FIGURE 88 FIGURE 89 PMID:6398936

Galectin-3 Shapes Antitumor Immune Responses by Suppressing CD8+ T Cells via LAG-3 and Inhibiting Expansion of Plasmacytoid Dendritic Cells.

PubMed

Kouo, Theodore; Huang, Lanqing; Pucsek, Alexandra B; Cao, Minwei; Solt, Sara; Armstrong, Todd; Jaffee, Elizabeth

2015-04-01

Galectin-3 is a 31-kDa lectin that modulates T-cell responses through several mechanisms, including apoptosis, T-cell receptor (TCR) cross-linking, and TCR downregulation. We found that patients with pancreatic ductal adenocarcinoma (PDA) who responded to a granulocyte-macrophage colony-stimulating factor-secreting allogeneic PDA vaccine developed neutralizing antibodies to galectin-3 after immunization. We show that galectin-3 binds activated antigen-committed CD8(+) T cells only in the tumor microenvironment. Galectin-3-deficient mice exhibit improved CD8(+) T-cell effector function and increased expression of several inflammatory genes. Galectin-3 binds to LAG-3, and LAG-3 expression is necessary for galectin-3-mediated suppression of CD8(+) T cells in vitro. Lastly, galectin-3-deficient mice have elevated levels of circulating plasmacytoid dendritic cells, which are superior to conventional dendritic cells in activating CD8(+) T cells. Thus, inhibiting galectin-3 in conjunction with CD8(+) T-cell-directed immunotherapies should enhance the tumor-specific immune response. ©2015 American Association for Cancer Research.

An endogenous 55 kDa TNF receptor mediates cell death in a neural cell line.

PubMed

Sipe, K J; Srisawasdi, D; Dantzer, R; Kelley, K W; Weyhenmeyer, J A

1996-06-01

Tumor necrosis factor-alpha (TNF) is associated with developmental and injury-related events in the central nervous system (CNS). In the present study, we have examined the role of TNF on neurons using the clonal murine neuroblastoma line, N1E-115 (N1E). N1E cells represent a well-defined model for studying neuronal development since they can be maintained as either undifferentiated, mitotically active neuroblasts or as differentiated, mature neurons. Northern and reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that both undifferentiated and differentiated N1Es express transcripts for the 55 kDa TNF receptor (TNFR), but not the 75 kDa TNFR. The biological activity of the expressed TNF receptor was demonstrated by a dose dependent cytotoxicity to either recombinant murine or human TNF when the cells were incubated with the transcriptional inhibitor actinomycin D. The lack of the 75 kDa receptor mRNA expression and the dose dependent response to rHuTNF, an agonist specific for the murine 55 kDa receptor, suggest that the TNF induced cytotoxicity is mediated through the 55 kDa receptor in both the undifferentiated and differentiated N1Es. Light microscopic observations, flow cytometric analysis of hypodiploid DNA, and electrophoretic analysis of nucleosomal DNA fragmentation of N1Es treated with actinomycin D and TNF revealed features characteristic of both necrotic and apoptotic cell death. These findings demonstrate that blast and mature N1E cells express the 55 kDa TNF receptor which is responsible for inducing both necrotic and apoptotic death in these cells. The observation that actinomycin D renders N1E cells susceptible to the cytotoxic effects of TNF indicates that a sensitization step, such as removal of an endogenous protective factor or viral-mediated inhibition of transcription, may be necessary for TNF cytotoxicity in neurons.

Absence of Toll-like receptor 4 signaling results in delayed Yersinia enterocolitica YopP-induced cell death of dendritic cells.

PubMed

Gröbner, Sabine; Schulz, Sebastian; Soldanova, Irena; Gunst, Dani S J; Waibel, Michaela; Wesselborg, Sebastian; Borgmann, Stefan; Autenrieth, Ingo B

2007-01-01

In an initial period (< or =4 h) Toll-like receptor 4 (TLR4) signaling is required for Yersinia enterocolitica YopP-induced dendritic cell (DC) death. Later (>4 h), DC die independent of TLR4 signaling. In TLR4-deficient DC caspase 8 cleavage is delayed, indicating that TLR4 signaling accelerates caspase 8 activation, leading to DC death.

Targeting the (Un)differentiated State of Cancer.

PubMed

Kemeny, Lajos V; Fisher, David E

2018-05-14

Dedifferentation in cancer is associated with intrinsic and acquired resistance to therapies. In this issue of Cancer Cell, Tsoi et al. identify four differentiation states in melanoma and provide evidence that melanoma cells develop drug resistance through a stepwise dedifferentiation process, making them vulnerable to ferroptotic cell death-inducing compounds. Copyright © 2018 Elsevier Inc. All rights reserved.

Adoptively transferred dendritic cells restore primary cell-mediated inflammatory competence to acutely malnourished weanling mice.

PubMed

Hillyer, Lyn; Whitley, Charlene; Olver, Amy; Webster, Michelle; Steevels, Tessa; Woodward, Bill

2008-02-01

Immune depression associated with prepubescent malnutrition underlies a staggering burden of infection-related morbidity. This investigation centered on dendritic cells as potentially decisive in this phenomenon. C57BL/6J mice, initially 19 days old, had free access for 14 days to a complete diet or to a low-protein formulation that induced wasting deficits of protein and energy. Mice were sensitized by i.p. injection of sheep red blood cells on day 9, at which time one-half of the animals in each dietary group received a simultaneous injection of 10(6) syngeneic dendritic cells (JAWS II). All mice were challenged with the immunizing antigen in the right hind footpad on day 13, and the 24-hour delayed hypersensitivity response was assessed as percentage increase in footpad thickness. The low-protein diet reduced the inflammatory immune response, but JAWS cells, which exhibited immature phenotypic and functional characteristics, increased the response of both the malnourished group and the controls. By contrast, i.p. injection of 10(6) syngeneic T cells did not influence the inflammatory immune response of mice subjected to the low-protein protocol. Antigen-presenting cell numbers limited primary inflammatory cell-mediated competence in this model of wasting malnutrition, an outcome that challenges the prevailing multifactorial model of malnutrition-associated immune depression. Thus, a new dendritic cell-centered perspective emerges regarding the cellular mechanism underlying immune depression in acute pediatric protein and energy deficit.

Viscum album neutralizes tumor-induced immunosuppression in a human in vitro cell model

PubMed Central

Steinborn, Carmen; Klemd, Amy Marisa; Sauer, Barbara; Garcia-Käufer, Manuel; Urech, Konrad; Follo, Marie; Ücker, Annekathrin; Kienle, Gunver Sophia; Huber, Roman

2017-01-01

Tumor cells have the capacity to secrete immunosuppressive substances in order to diminish dendritic cell (DC) activity and thereby escape from immune responses. The impact of mistletoe (Viscum album) extracts (VAE), which are frequently used as an additive anti-cancer therapy to stimulate the immune response, is still unknown. Using a human cellular system, the impact of two different VAE (VAEA + VAEI) on the maturation of human dendritic cells and on T cell function has been investigated using flow cytometry, automated fluorescence microscopy and cytokine bead array assays. Furthermore, we examined whether VAEI was able to counteract tumor-induced immunosuppression within this cellular system using a renal cancer cell model. The role of mistletoe lectin (ML) was analyzed using ML-specific antibodies and ML-depleted VAEI. VAEI and VAEA augmented the maturation of dendritic cells. VAEI abrogated tumor-induced immunosuppression of dendritic cells and both processes were partially mediated by ML since ML-depleted VAEI and ML-specific antibodies almost neutralized the rehabilitative effects of VAEI on DC maturation. Using these settings, co-culture experiments with purified CD4+ T cells had no influence on T cell proliferation and activation but did have an impact on IFN-γ secretion. The study provides a potential mode-of-action of VAE as an additive cancer therapy based on immunomodulatory effects. However, the impact on the in vivo situation has to be evaluated in further studies. PMID:28719632

Laminin- and basement membrane-polycaprolactone blend nanofibers as a scaffold for regenerative medicine.

PubMed

Neal, Rebekah A; Lenz, Steven M; Wang, Tiffany; Abebayehu, Daniel; Brooks, Benjamin P C; Ogle, Roy C; Botchwey, Edward A

2014-09-01

Mimicking one or more components of the basement membrane (BM) holds great promise for overcoming insufficiencies in tissue engineering therapies. We have electrospun laminin nanofibers (NFs) isolated from the murine Engelbreth-Holm Swarm (EHS) tumor and evaluated them as a scaffold for embryonic stem cell culture. Seeded human embryonic stem cells were found to better maintain their undifferentiated, colony environment when cultured on laminin NFs compared to laminin mats, with 75% remaining undifferentiated on NFs. Mouse embryonic stem cells cultured on 10% laminin-polycaprolactone (PCL) NFs maintained their colony formation for twice as long without passage compared to those on PCL or gelatin substrates. In addition, we have established a protocol for electrospinning reconstituted basement membrane aligned (RBM)-PCL NFs within 10° of angular deviation. Neuron-like PC12 cells show significantly greater attachment (p < 0.001) and percentage of neurite-extending cells in vitro on 10% RBM-PCL NFs when compared to 1% and 0% RBM-PCL NFs (p < 0.015 and p < 0.001, respectively). Together, these results implicate laminin- and RBM-PCL scaffolds as a promising biomimetic substrate for regenerative medicine applications.

Zap70 functions to maintain stemness of mouse embryonic stem cells by negatively regulating Jak1/Stat3/c-Myc signaling

PubMed Central

Cha, Young; Moon, Bo-Hyun; Lee, Mi-Ok; Ahn, Hee-Jin; Lee, Hye-Jin; Lee, Kyung-Ah; Fornace, Albert J.; Kim, Kwang-Soo; Cha, Hyuk-Jin; Park, Kyung-Soon

2011-01-01

Zeta-chain associated protein kinase-70 (Zap70), a Syk family tyrosine kinase, has been reported to be present exclusively in normal T cells, Natural Killer (NK) cells, and B cells, serving as a pivotal regulator of antigen-mediated receptor signaling and development. In this study, we report that Zap70 is expressed in undifferentiated mouse embryonic stem cells (mESCs) and may critically regulate self-renewal and pluripotency in mESCs. We found that Zap70 knocked-down mESCs (Zap70KD) show sustained self-renewal and defective differentiation. In addition, we present evidence that the sustained self-renewal in Zap70KD is associated with enhanced Jak/Stat3 signaling and c-Myc induction. These altered signaling appears to result from up-regulated LIFR and down-regulated SHP-1 phosphatase activity. Based on these results, we propose that, in undifferentiated mESCs, Zap70 plays important roles in modulating the balance between self-renewal capacity and pluripotent differentiation ability as a key regulator of the Jak/Stat3/c-Myc signaling pathway. PMID:20641039

Modulation of Differentiation Processes in Murine Embryonic Stem Cells Exposed to Parabolic Flight-Induced Acute Hypergravity and Microgravity.

PubMed

Acharya, Aviseka; Brungs, Sonja; Henry, Margit; Rotshteyn, Tamara; Singh Yaduvanshi, Nirmala; Wegener, Lucia; Jentzsch, Simon; Hescheler, Jürgen; Hemmersbach, Ruth; Boeuf, Helene; Sachinidis, Agapios

2018-06-15

Embryonic developmental studies under microgravity conditions in space are very limited. To study the effects of short-term altered gravity on embryonic development processes, we exposed mouse embryonic stem cells (mESCs) to phases of hypergravity and microgravity and studied the differentiation potential of the cells using wide-genome microarray analysis. During the 64th European Space Agency's parabolic flight campaign, mESCs were exposed to 31 parabolas. Each parabola comprised phases lasting 22 s of hypergravity, microgravity, and a repeat of hypergravity. On different parabolas, RNA was isolated for microarray analysis. After exposure to 31 parabolas, mESCs (P31 mESCs) were further differentiated under normal gravity (1 g) conditions for 12 days, producing P31 12-day embryoid bodies (EBs). After analysis of the microarrays, the differentially expressed genes were analyzed using different bioinformatic tools to identify developmental and nondevelopmental biological processes affected by conditions on the parabolic flight experiment. Our results demonstrated that several genes belonging to GOs associated with cell cycle and proliferation were downregulated in undifferentiated mESCs exposed to gravity changes. However, several genes belonging to developmental processes, such as vasculature development, kidney development, skin development, and to the TGF-β signaling pathway, were upregulated. Interestingly, similar enriched and suppressed GOs were obtained in P31 12-day EBs compared with ground control 12-day EBs. Our results show that undifferentiated mESCs exposed to alternate hypergravity and microgravity phases expressed several genes associated with developmental/differentiation and cell cycle processes, suggesting a transition from the undifferentiated pluripotent to a more differentiated stage of mESCs.

Phenotypic and functional analysis of CD1a+ dendritic cells from cats chronically infected with feline immunodeficiency virus.

PubMed

Zhang, Lin; Reckling, Stacie; Dean, Gregg A

2015-10-01

Numerous studies suggest dendritic cell (DC) dysfunction is central to the dysregulated immune response during HIV infection; however, in vivo studies are lacking. In the present study we used feline immunodeficiency virus (FIV) infection of cats as a model for HIV-1 infection to assess the maturation and function of dendritic cells, in vivo and in vitro. We compared CD1a+ DC migration, surface phenotype, endocytosis, mixed leukocyte reaction (MLR) and regulatory T cell (Treg) phenotype induction by CD1a+ cells isolated from lymph nodes of FIV-infected and control cats. Results showed that resident CD1a+ DC in lymph nodes of chronically FIV-infected cats are phenotypically mature, can stimulate normal primary T cell proliferation, override Treg suppression and do not skew toward Treg induction. In contrast, FIV infection had deleterious effects on antigen presentation and migratory capacity of CD1a+ cells in tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varga, Nora; Vereb, Zoltan; Rajnavoelgyi, Eva

2011-10-28

Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth ofmore » undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.« less

Complementary theta resonance filtering by two spatially segregated mechanisms in CA1 hippocampal pyramidal neurons.

PubMed

Hu, Hua; Vervaeke, Koen; Graham, Lyle J; Storm, Johan F

2009-11-18

Synaptic input to a neuron may undergo various filtering steps, both locally and during transmission to the soma. Using simultaneous whole-cell recordings from soma and apical dendrites from rat CA1 hippocampal pyramidal cells, and biophysically detailed modeling, we found two complementary resonance (bandpass) filters of subthreshold voltage signals. Both filters favor signals in the theta (3-12 Hz) frequency range, but have opposite location, direction, and voltage dependencies: (1) dendritic H-resonance, caused by h/HCN-channels, filters signals propagating from soma to dendrite when the membrane potential is close to rest; and (2) somatic M-resonance, caused by M/Kv7/KCNQ and persistent Na(+) (NaP) channels, filters signals propagating from dendrite to soma when the membrane potential approaches spike threshold. Hippocampal pyramidal cells participate in theta network oscillations during behavior, and we suggest that that these dual, polarized theta resonance mechanisms may convey voltage-dependent tuning of theta-mediated neural coding in the entorhinal/hippocampal system during locomotion, spatial navigation, memory, and sleep.

Differential polarization of cortical pyramidal neuron dendrites through weak extracellular fields

PubMed Central

Obermayer, Klaus

2018-01-01

The rise of transcranial current stimulation (tCS) techniques have sparked an increasing interest in the effects of weak extracellular electric fields on neural activity. These fields modulate ongoing neural activity through polarization of the neuronal membrane. While the somatic polarization has been investigated experimentally, the frequency-dependent polarization of the dendritic trees in the presence of alternating (AC) fields has received little attention yet. Using a biophysically detailed model with experimentally constrained active conductances, we analyze the subthreshold response of cortical pyramidal cells to weak AC fields, as induced during tCS. We observe a strong frequency resonance around 10-20 Hz in the apical dendrites sensitivity to polarize in response to electric fields but not in the basal dendrites nor the soma. To disentangle the relative roles of the cell morphology and active and passive membrane properties in this resonance, we perform a thorough analysis using simplified models, e.g. a passive pyramidal neuron model, simple passive cables and reconstructed cell model with simplified ion channels. We attribute the origin of the resonance in the apical dendrites to (i) a locally increased sensitivity due to the morphology and to (ii) the high density of h-type channels. Our systematic study provides an improved understanding of the subthreshold response of cortical cells to weak electric fields and, importantly, allows for an improved design of tCS stimuli. PMID:29727454

Variation of Neisseria gonorrhoeae Lipooligosaccharide Directs Dendritic Cell–Induced T Helper Responses

PubMed Central

van Vliet, Sandra J.; Steeghs, Liana; Bruijns, Sven C. M.; Vaezirad, Medi M.; Snijders Blok, Christian; Arenas Busto, Jésus A.; Deken, Marcel; van Putten, Jos P. M.; van Kooyk, Yvette

2009-01-01

Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS) molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4+ T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival. PMID:19834553

Chronic corticosterone administration reduces dendritic complexity in mature, but not young granule cells in the rat dentate gyrus.

PubMed

Yau, Suk-Yu; Li, Ang; Tong, Jian-Bin; Bostrom, Crystal; Christie, Brian R; Lee, Tatia M C; So, Kwok-Fai

2016-09-21

Our previous work has shown that exposure to the stress hormone corticosterone (40 mg/kg CORT) for two weeks induces dendritic atrophy of pyramidal neurons in the hippocampal CA3 region and behavioral deficits. However, it is unclear whether this treatment also affects the dentate gyrus (DG), a subregion of the hippocampus comprising a heterogeneous population of young and mature neurons. We examined the effect of CORT treatment on the dendritic complexity of mature and young granule cells in the DG. We utilized a Golgi staining method to investigate the dendritic morphology and spine density of young neurons in the inner granular cell layer (GCL) and mature neurons in the outer GCL in response to CORT application. The expressions of glucocorticoid receptors during neuronal maturation were examined using Western blot analysis in a primary hippocampal neuronal culture. Sholl analysis revealed that CORT treatment decreased the number of intersections and shortened the dendritic length in mature, but not young, granule cells. However, the spine density of mature and young neurons was not affected. Western blot analysis showed a progressive increase in the protein levels of glucocorticoid receptors (GRs) in the cultured primary hippocampal neurons during neuronal maturation. These data suggest that mature neurons are likely more vulnerable to chronic exposure to CORT; this may be due to their higher expression of GRs when compared to younger DG neurons.

Cell-autonomous inactivation of the Reelin pathway impairs adult neurogenesis in the hippocampus

PubMed Central

Teixeira, Catia M.; Kron, Michelle M.; Masachs, Nuria; Zhang, Helen; Lagace, Diane C.; Martinez, Albert; Reillo, Isabel; Duan, Xin; Bosch, Carles; Pujadas, Lluis; Brunso, Lucas; Song, Hongjun; Eisch, Amelia J.; Borrell, Victor; Howell, Brian W.; Parent, Jack M.; Soriano, Eduardo

2012-01-01

Adult hippocampal neurogenesis is thought to be essential for learning and memory and has been implicated in the pathogenesis of several disorders. Although recent studies have identified key factors regulating neuroprogenitor proliferation in the adult hippocampus, the mechanisms that control the migration and integration of adult-born neurons into circuits are largely unknown. Reelin is an extracellular matrix protein that is vital for neuronal development. Activation of the Reelin cascade leads to phosphorylation of disabled-1 (Dab1), an adaptor protein required for Reelin signaling. Here we used transgenic mouse and retroviral reporters along with Reelin signaling gain- and loss-of-function studies to show that the Reelin pathway regulates migration and dendritic development of adult-generated hippocampal neurons. Whereas overexpression of Reelin accelerated dendritic maturation, inactivation of the Reelin signaling pathway specifically in adult neuroprogenitor cells resulted in aberrant migration, decreased dendrite development, formation of ectopic dendrites in the hilus and the establishment of aberrant circuits. Our findings support a cell-autonomous and critical role for the Reelin pathway in regulating dendritic development and the integration of adult-generated granule cells and point to this pathway as a key regulator of adult neurogenesis. Moreover, our data reveal a novel role of the Reelin cascade in adult brain function with potential implications for the pathogenesis of several neurological and psychiatric disorders. PMID:22933789

B-Cell Depletion Promotes Aortic Infiltration of Immunosuppressive Cells and Is Protective of Experimental Aortic Aneurysm.

PubMed

Schaheen, Basil; Downs, Emily A; Serbulea, Vlad; Almenara, Camila C P; Spinosa, Michael; Su, Gang; Zhao, Yunge; Srikakulapu, Prasad; Butts, Cherié; McNamara, Coleen A; Leitinger, Norbert; Upchurch, Gilbert R; Meher, Akshaya K; Ailawadi, Gorav

2016-11-01

B-cell depletion therapy is widely used for treatment of cancers and autoimmune diseases. B cells are abundant in abdominal aortic aneurysms (AAA); however, it is unknown whether B-cell depletion therapy affects AAA growth. Using experimental models of murine AAA, we aim to examine the effect of B-cell depletion on AAA formation. Wild-type or apolipoprotein E-knockout mice were treated with mouse monoclonal anti-CD20 or control antibodies and subjected to an elastase perfusion or angiotensin II infusion model to induce AAA, respectively. Anti-CD20 antibody treatment significantly depleted B1 and B2 cells, and strikingly suppressed AAA growth in both models. B-cell depletion resulted in lower circulating IgM levels, but did not affect the levels of IgG or cytokine/chemokine levels. Although the total number of leukocyte remained unchanged in elastase-perfused aortas after anti-CD20 antibody treatment, the number of B-cell subtypes was significantly lower. Interestingly, plasmacytoid dendritic cells expressing the immunomodulatory enzyme indole 2,3-dioxygenase were detected in the aortas of B-cell-depleted mice. In accordance with an increase in indole 2,3-dioxygenase+ plasmacytoid dendritic cells, the number of regulatory T cells was higher, whereas the expression of proinflammatory genes was lower in aortas of B-cell-depleted mice. In a coculture model, the presence of B cells significantly lowered the number of indole 2,3-dioxygenase+ plasmacytoid dendritic cells without affecting total plasmacytoid dendritic cell number. The present results demonstrate that B-cell depletion protects mice from experimental AAA formation and promotes emergence of an immunosuppressive environment in aorta. © 2016 American Heart Association, Inc.

Spectral Monitoring of Surfactant Clearance during Alveolar Epithelial Type II Cell Differentiation

PubMed Central

Swain, Robin J.; Kemp, Sarah J.; Goldstraw, Peter; Tetley, Teresa D.; Stevens, Molly M.

2008-01-01

In this study, we report on the noninvasive identification of spectral markers of alveolar type II (ATII) cell differentiation in vitro using Raman microspectroscopy. ATII cells are progenitor cells for alveolar type I (ATI) cells in vivo, and spontaneously differentiate toward an ATI-like phenotype in culture. We analyzed undifferentiated and differentiated primary human ATII cells, and correlated Raman spectral changes to cellular changes in morphology and marker protein synthesis (surfactant protein C, alkaline phosphatase, caveolin-1). Undifferentiated ATII cells demonstrated spectra with strong phospholipid vibrations, arising from alveolar surfactant stored within cytoplasmic lamellar bodies (Lbs). Differentiated ATI-like cells yielded spectra with significantly less lipid content. Factor analysis revealed a phospholipid-dominated spectral component as the main discriminator between the ATII and ATI-like phenotypes. Spectral modeling of the data revealed a significant decrease in the spectral contribution of cellular lipids—specifically phosphatidyl choline, the main constituent of surfactant, as ATII cells differentiate. These observations were consistent with the clearance of surfactant from Lbs as ATII cells differentiate, and were further supported by cytochemical staining for Lbs. These results demonstrate the first spectral characterization of primary human ATII cells, and provide insight into the biochemical properties of alveolar surfactant in its unperturbed cellular environment. PMID:18820234

A novel monoclonal antibody, C41, reveals IL-13Ralpha1 expression by murine germinal center B cells and follicular dendritic cells.

PubMed

Poudrier, J; Graber, P; Herren, S; Berney, C; Gretener, D; Kosco-Vilbois, M H; Gauchat, J F

2000-11-01

Responsiveness to IL-13 involves at least two chains, IL-4Ralpha and IL-13Ralpha1. Although mouse B cells express IL-4Ralpha, little is known about their expression of IL-13Ralpha chains. To investigate this topic further, we have generated a monoclonal antibody (C41) specific for murine IL-13Ralpha1. Using C41, IL-13Ralpha1 expression was detected on germinal center (GC) B cells by flow cytometry and immunohistochemistry. In addition, IL-13Ralpha1 was observed on follicular dendritic cells, but not interdigitating dendritic cells in the T cell areas. Furthermore, resting B cells also expressed IL-13Ralpha1, and in the presence of IL-13 produced increased amounts of IgM in response to in vitro CD40 stimulation. However, C41 was unable to neutralize this bioactivity. The distribution of IL-13Ralpha1 on murine B cells and during GC reactions suggests a role for IL-13 during B cell differentiation.

Ultrastructural studies of vasopressin neurons of the paraventricular nucleus of the hypothalamus using a monoclonal antibody to vasopressin: analysis of synaptic input.

PubMed

Silverman, A J; Hou-Yu, A; Zimmerman, E A

1983-05-01

The ultrastructure of the vasopressin neurons of the paraventricular nucleus of the hypothalamus was studied by immunocytochemical techniques. Tissue antigen was detected in unembedded tissue sections using a monoclonal antibody that recognizes vasopressin but not oxytocin or vasotocin. At the light-microscopic level, reaction product was seen to fill the cytoplasm of the neuron cell body as well as large portions of the dendrite and axon. Immunoreactive spines were seen on both somatic and dendritic surfaces and their presence was confirmed at the ultrastructural level. In the light-microscope, axonal processes do not have spines and are thinner and more varicose than dendritic processes. At the electron-microscopic level, both axons and dendrites of the vasopressin cells are filled with reactive neurosecretory granules. The presence of large numbers of these organelles made it difficult to distinguish proximal dendrites from Herring bodies (axonal swellings). At the ultrastructural level, reaction product was also observed in the cytoplasm of all segments of the vasopressin cells. The presence of reaction product outside of membranous compartments is undoubtably due to disruption of membranes by detergent treatment or exposure to basic pH. However, the staining procedure used did allow us to examine the synaptic input to the vasopressin cells. All portions of the vasopressin neuron receive a diverse innervation. The somata have synapses on their surfaces and on spines. These axo-somatic terminals are primarily, but not exclusively, symmetrical and the presynaptic elements contain spherical or elongate vesicles. On the dendrites, terminals again were observed on the surface or on spines. these axo-dendritic synapses were usually asymmetrical. The presynaptic elements contained clear spherical, elongate or pleomorphic vesicles. Occasional varicosities with dense-core granules were seen to make en passant contacts with dendrites; these contacts did not have obvious membrane specializations. Input to vasopressin axons was studied both along the paraventricular-neurohypophysial tract and in the median eminence. Vasopressin axons receive a synaptic input (axo-axonic), predominately of the asymmetric variety with clear, spherical vesicles in the presynaptic element. These findings demonstrate that the vasopressin neurons of the paraventricular nucleus receive a diverse innervation.

Synthetic and biogenic magnetite nanoparticles for tracking of stem cells and dendritic cells

NASA Astrophysics Data System (ADS)

Schwarz, Sebastian; Fernandes, Fabiana; Sanroman, Laura; Hodenius, Michael; Lang, Claus; Himmelreich, Uwe; Schmitz-Rode, Thomas; Schueler, Dirk; Hoehn, Mathias; Zenke, Martin; Hieronymus, Thomas

2009-05-01

Accurate delivery of cells to target organs is critical for success of cell-based therapies with stem cells or immune cells such as antigen-presenting dendritic cells (DC). Labeling with contrast agents before implantation provides a powerful means for monitoring cellular migration using magnetic resonance imaging (MRI). In this study, we investigated the uptake of fully synthesized or bacterial magnetic nanoparticles (MNPs) into hematopoietic Flt3 + stem cells and DC from mouse bone marrow. We show that (i) uptake of both synthetic and biogenic nanoparticles into cells endow magnetic activity and (ii) low numbers of MNP-loaded cells are readily detected by MRI.

Differential excitability and modulation of striatal medium spiny neuron dendrites

PubMed Central

Day, Michelle; Wokosin, David; Plotkin, Joshua L.; Tian, Xinyoung; Surmeier, D. James

2011-01-01

The loss of striatal dopamine (DA) in Parkinson's disease (PD) models triggers a cell-type specific reduction in the density of dendritic spines in D2 receptor-expressing striatopallidal medium spiny neurons (D2 MSNs). How the intrinsic properties of MSN dendrites, where the vast majority of DA receptors are found, contribute to this adaptation is not clear. To address this question, two-photon laser scanning microscopy (2PLSM) was performed in patch-clamped mouse MSNs identified in striatal slices by expression of green fluorescent protein (eGFP) controlled by DA receptor promoters. These studies revealed that single back-propagating action potentials (bAP) produced more reliable elevations in cytosolic Ca2+ concentration at distal dendritic locations in D2 MSNs than at similar locations in D1 receptor-expressing striatonigral MSNs (D1 MSNs). In both cell types, the dendritic Ca2+ entry elicited by bAPs was enhanced by pharmacological blockade of Kv4, but not Kv1 K+ channels. Local application of DA depressed dendritic bAP-evoked Ca2+ transients, whereas application of ACh increased these Ca2+ transients in D2 MSNs—but not in D1 MSNs. Following DA depletion, bAP-evoked Ca2+ transients were enhanced in distal dendrites and spines in D2 MSNs. Taken together, these results suggest that normally D2 MSN dendrites are more excitable than those of D1 MSNs and that DA depletion exaggerates this asymmetry, potentially contributing to adaptations in PD models. PMID:18987196

Empowering gamma delta T cells with antitumor immunity by dendritic cell-based immunotherapy

PubMed Central

Van Acker, Heleen H; Anguille, Sébastien; Van Tendeloo, Viggo F; Lion, Eva

2015-01-01

Gamma delta (γδ) T cells are the all-rounders of our immune-system with their major histocompatibility complex-unrestricted cytotoxicity, capacity to secrete immunosti-mulatory cytokines and ability to promote the generation of tumor antigen-specific CD8+ and CD4+ T cell responses. Dendritic cell (DC)-based vaccine therapy has the prospective to harness these unique features of the γδ T cells in the fight against cancer. In this review, we will discuss our current knowledge on DC-mediated γδ T cell activation and related opportunities for tumor immunologists. PMID:26405575

It's Lonely at the Top: Winning Climbing Fibers Ascend Dendrites Solo

PubMed Central

Draft, Ryan W.; Lichtman, Jeff W.

2009-01-01

In mammals, climbing fiber axons compete for sole innervation at each Purkinje cell. At the same time, synapses disappear from Purkinje somata and appear in great numbers on the dendrites. In this issue of Neuron, Hashimoto et al. show that, by the time climbing fibers ascend the dendrites, the winner and losers are already decided. PMID:19607787

Slowing down light using a dendritic cell cluster metasurface waveguide

PubMed Central

Fang, Z. H.; Chen, H.; Yang, F. S.; Luo, C. R.; Zhao, X. P.

2016-01-01

Slowing down or even stopping light is the first task to realising optical information transmission and storage. Theoretical studies have revealed that metamaterials can slow down or even stop light; however, the difficulty of preparing metamaterials that operate in visible light hinders progress in the research of slowing or stopping light. Metasurfaces provide a new opportunity to make progress in such research. In this paper, we propose a dendritic cell cluster metasurface consisting of dendritic structures. The simulation results show that dendritic structure can realise abnormal reflection and refraction effects. Single- and double-layer dendritic metasurfaces that respond in visible light were prepared by electrochemical deposition. Abnormal Goos-Hänchen (GH) shifts were experimentally obtained. The rainbow trapping effect was observed in a waveguide constructed using the dendritic metasurface sample. The incident white light was separated into seven colours ranging from blue to red light. The measured transmission energy in the waveguide showed that the energy escaping from the waveguide was zero at the resonant frequency of the sample under a certain amount of incident light. The proposed metasurface has a simple preparation process, functions in visible light, and can be readily extended to the infrared band and communication wavelengths. PMID:27886279

Input integration around the dendritic branches in hippocampal dentate granule cells.

PubMed

Kamijo, Tadanobu Chuyo; Hayakawa, Hirofumi; Fukushima, Yasuhiro; Kubota, Yoshiyuki; Isomura, Yoshikazu; Tsukada, Minoru; Aihara, Takeshi

2014-08-01

Recent studies have shown that the dendrites of several neurons are not simple translators but are crucial facilitators of excitatory postsynaptic potential (EPSP) propagation and summation of synaptic inputs to compensate for inherent voltage attenuation. Granule cells (GCs)are located at the gateway for valuable information arriving at the hippocampus from the entorhinal cortex. However, the underlying mechanisms of information integration along the dendrites of GCs in the hippocampus are still unclear. In this study, we investigated the input integration around dendritic branches of GCs in the rat hippocampus. We applied differential spatiotemporal stimulations to the dendrites using a high-speed glutamate-uncaging laser. Our results showed that when two sites close to and equidistant from a branching point were simultaneously stimulated, a nonlinear summation of EPSPs was observed at the soma. In addition, nonlinear summation (facilitation) depended on the stimulus location and was significantly blocked by the application of a voltage-dependent Ca(2+) channel antagonist. These findings suggest that the nonlinear summation of EPSPs around the dendritic branches of hippocampal GCs is a result of voltage-dependent Ca(2+) channel activation and may play a crucial role in the integration of input information.

Coding and decoding with dendrites.

PubMed

Papoutsi, Athanasia; Kastellakis, George; Psarrou, Maria; Anastasakis, Stelios; Poirazi, Panayiota

2014-02-01

Since the discovery of complex, voltage dependent mechanisms in the dendrites of multiple neuron types, great effort has been devoted in search of a direct link between dendritic properties and specific neuronal functions. Over the last few years, new experimental techniques have allowed the visualization and probing of dendritic anatomy, plasticity and integrative schemes with unprecedented detail. This vast amount of information has caused a paradigm shift in the study of memory, one of the most important pursuits in Neuroscience, and calls for the development of novel theories and models that will unify the available data according to some basic principles. Traditional models of memory considered neural cells as the fundamental processing units in the brain. Recent studies however are proposing new theories in which memory is not only formed by modifying the synaptic connections between neurons, but also by modifications of intrinsic and anatomical dendritic properties as well as fine tuning of the wiring diagram. In this review paper we present previous studies along with recent findings from our group that support a key role of dendrites in information processing, including the encoding and decoding of new memories, both at the single cell and the network level. Copyright © 2013 Elsevier Ltd. All rights reserved.

Defibrotide interferes with several steps of the coagulation-inflammation cycle and exhibits therapeutic potential to treat severe malaria.

PubMed

Francischetti, Ivo M B; Oliveira, Carlo J; Ostera, Graciela R; Yager, Stephanie B; Debierre-Grockiego, Françoise; Carregaro, Vanessa; Jaramillo-Gutierrez, Giovanna; Hume, Jen C C; Jiang, Lubin; Moretz, Samuel E; Lin, Christina K; Ribeiro, José M C; Long, Carole A; Vickers, Brandi K; Schwarz, Ralph T; Seydel, Karl B; Iacobelli, Massimo; Ackerman, Hans C; Srinivasan, Prakash; Gomes, Regis B; Wang, Xunde; Monteiro, Robson Q; Kotsyfakis, Michail; Sá-Nunes, Anderson; Waisberg, Michael

2012-03-01

The coagulation-inflammation cycle has been implicated as a critical component in malaria pathogenesis. Defibrotide (DF), a mixture of DNA aptamers, displays anticoagulant, anti-inflammatory, and endothelial cell (EC)-protective activities and has been successfully used to treat comatose children with veno-occlusive disease. DF was investigated here as a drug to treat cerebral malaria. DF blocks tissue factor expression by ECs incubated with parasitized red blood cells and attenuates prothrombinase activity, platelet aggregation, and complement activation. In contrast, it does not affect nitric oxide bioavailability. We also demonstrated that Plasmodium falciparum glycosylphosphatidylinositol (Pf-GPI) induces tissue factor expression in ECs and cytokine production by dendritic cells. Notably, dendritic cells, known to modulate coagulation and inflammation systemically, were identified as a novel target for DF. Accordingly, DF inhibits Toll-like receptor ligand-dependent dendritic cells activation by a mechanism that is blocked by adenosine receptor antagonist (8-p-sulfophenyltheophylline) but not reproduced by synthetic poly-A, -C, -T, and -G. These results imply that aptameric sequences and adenosine receptor mediate dendritic cells responses to the drug. DF also prevents rosetting formation, red blood cells invasion by P. falciparum and abolishes oocysts development in Anopheles gambiae. In a murine model of cerebral malaria, DF affected parasitemia, decreased IFN-γ levels, and ameliorated clinical score (day 5) with a trend for increased survival. Therapeutic use of DF in malaria is proposed.

In vivo dendritic cell depletion reduces breeding efficiency, affecting implantation and early placental development in mice.

PubMed

Krey, Gesa; Frank, Pierre; Shaikly, Valerie; Barrientos, Gabriela; Cordo-Russo, Rosalia; Ringel, Frauke; Moschansky, Petra; Chernukhin, Igor V; Metodiev, Metodi; Fernández, Nelson; Klapp, Burghard F; Arck, Petra C; Blois, Sandra M

2008-09-01

Implantation of mammalian embryos into their mother's uterus ensures optimal nourishment and protection throughout development. Complex molecular interactions characterize the implantation process, and an optimal synchronization of the components of this embryo-maternal dialogue is crucial for a successful reproductive outcome. In the present study, we investigated the role of dendritic cells (DC) during implantation process using a transgenic mouse system (DTRtg) that allows transient depletion of CD11c+ cells in vivo through administration of diphtheria toxin. We observed that DC depletion impairs the implantation process, resulting in a reduced breeding efficiency. Furthermore, the maturity of uterine natural killer cells at dendritic cell knockout (DCKO) implantation sites was affected as well; as demonstrated by decreased perforin expression and reduced numbers of periodic-acid-Schiff (PAS)-positive cells. This was accompanied by disarrangements in decidual vascular development. In the present study, we were also able to identify a novel DC-dependent protein, phosphatidylinositol transfer protein beta (PITPbeta), involved in implantation and trophoblast development using a proteomic approach. Indeed, DCKO mice exhibited substantial anomalies in placental development, including hypocellularity of the spongiotrophoblast and labyrinthine layers and reduced numbers of trophoblast giant cells. Giant cells also down-regulated their expression of two characteristic markers of trophoblast differentiation, placental lactogen 1 and proliferin. In view of these findings, dendritic cells emerge as possible modulators in the orchestration of events leading to the establishment and maintenance of pregnancy.

Effector cell signature in peripheral blood following nasal allergen challenge in grass pollen allergic individuals.

PubMed

Shamji, M H; Bellido, V; Scadding, G W; Layhadi, J A; Cheung, D K M; Calderon, M A; Asare, A; Gao, Z; Turka, L A; Tchao, N; Togias, A; Phippard, D; Durham, S R

2015-02-01

Several studies have demonstrated the time course of inflammatory mediators in nasal fluids following nasal allergen challenge (NAC), whereas the effects of NAC on cells in the periphery are unknown. We examined the time course of effector cell markers (for basophils, dendritic cells and T cells) in peripheral blood after nasal grass pollen allergen challenge. Twelve participants with seasonal allergic rhinitis underwent a control (diluent) challenge followed by NAC after an interval of 14 days. Nasal symptoms and peak nasal inspiratory flow (PNIF) were recorded along with peripheral basophil, T-cell and dendritic cell responses (flow cytometry), T-cell proliferative responses (thymidine incorporation), and cytokine expression (FluoroSpot assay). Robust increases in nasal symptoms and decreases in PNIF were observed during the early (0-1 h) response and modest significant changes during the late (1-24 h) response. Sequential peaks in peripheral blood basophil activation markers were observed (CD107a at 3 h, CD63 at 6 h, and CD203c(bright) at 24 h). T effector/memory cells (CD4(+) CD25(lo) ) were increased at 6 h and accompanied by increases in CD80(+) and CD86(+) plasmacytoid dendritic cells (pDCs). Ex vivo grass antigen-driven T-cell proliferative responses and the frequency of IL-4(+) CD4(+) T cells were significantly increased at 6 h after NAC when compared to the control day. Basophil, T-cell, and dendritic cell activation increased the frequency of allergen-driven IL-4(+) CD4(+) T cells, and T-cell proliferative responses are detectable in the periphery after NAC. These data confirm systemic cellular activation following a local nasal provocation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Genomic Programming of Human Neonatal Dendritic Cells in Congenital Systemic and In Vitro Cytomegalovirus Infection Reveal Plastic and Robust Immune Pathway Biology Responses

PubMed Central

Dantoft, Widad; Martínez-Vicente, Pablo; Jafali, James; Pérez-Martínez, Lara; Martin, Kim; Kotzamanis, Konstantinos; Craigon, Marie; Auer, Manfred; Young, Neil T.; Walsh, Paul; Marchant, Arnaud; Angulo, Ana; Forster, Thorsten; Ghazal, Peter

2017-01-01

Neonates and especially premature infants are highly susceptible to infection but still can have a remarkable resilience that is poorly understood. The view that neonates have an incomplete or deficient immune system is changing. Human neonatal studies are challenging, and elucidating host protective responses and underlying cognate pathway biology, in the context of viral infection in early life, remains to be fully explored. In both resource rich and poor settings, human cytomegalovirus (HCMV) is the most common cause of congenital infection. By using unbiased systems analyses of transcriptomic resources for HCMV neonatal infection, we find the systemic response of a preterm congenital HCMV infection, involves a focused IFN regulatory response associated with dendritic cells. Further analysis of transcriptional-programming of neonatal dendritic cells in response to HCMV infection in culture revealed an early dominant IFN-chemokine regulatory subnetworks, and at later times the plasticity of pathways implicated in cell-cycle control and lipid metabolism. Further, we identify previously unknown suppressed networks associated with infection, including a select group of GPCRs. Functional siRNA viral growth screen targeting 516-GPCRs and subsequent validation identified novel GPCR-dependent antiviral (ADORA1) and proviral (GPR146, RGS16, PTAFR, SCTR, GPR84, GPR85, NMUR2, FZ10, RDS, CCL17, and SORT1) roles. By contrast a gene family cluster of protocadherins is significantly differentially induced in neonatal cells, suggestive of possible immunomodulatory roles. Unexpectedly, programming responses of adult and neonatal dendritic cells, upon HCMV infection, demonstrated comparable quantitative and qualitative responses showing that functionally, neonatal dendritic cell are not overly compromised. However, a delay in responses of neonatal cells for IFN subnetworks in comparison with adult-derived cells are notable, suggestive of subtle plasticity differences. These findings support a set-point control mechanism rather than immaturity for explaining not only neonatal susceptibility but also resilience to infection. In summary, our findings show that neonatal HCMV infection leads to a highly plastic and functional robust programming of dendritic cells in vivo and in vitro. In comparison with adults, a minimal number of subtle quantitative and temporal differences may contribute to variability in host susceptibility and resilience, in a context dependent manner. PMID:28993767

Genomic Programming of Human Neonatal Dendritic Cells in Congenital Systemic and In Vitro Cytomegalovirus Infection Reveal Plastic and Robust Immune Pathway Biology Responses.

PubMed

Dantoft, Widad; Martínez-Vicente, Pablo; Jafali, James; Pérez-Martínez, Lara; Martin, Kim; Kotzamanis, Konstantinos; Craigon, Marie; Auer, Manfred; Young, Neil T; Walsh, Paul; Marchant, Arnaud; Angulo, Ana; Forster, Thorsten; Ghazal, Peter

2017-01-01

Neonates and especially premature infants are highly susceptible to infection but still can have a remarkable resilience that is poorly understood. The view that neonates have an incomplete or deficient immune system is changing. Human neonatal studies are challenging, and elucidating host protective responses and underlying cognate pathway biology, in the context of viral infection in early life, remains to be fully explored. In both resource rich and poor settings, human cytomegalovirus (HCMV) is the most common cause of congenital infection. By using unbiased systems analyses of transcriptomic resources for HCMV neonatal infection, we find the systemic response of a preterm congenital HCMV infection, involves a focused IFN regulatory response associated with dendritic cells. Further analysis of transcriptional-programming of neonatal dendritic cells in response to HCMV infection in culture revealed an early dominant IFN-chemokine regulatory subnetworks, and at later times the plasticity of pathways implicated in cell-cycle control and lipid metabolism. Further, we identify previously unknown suppressed networks associated with infection, including a select group of GPCRs. Functional siRNA viral growth screen targeting 516-GPCRs and subsequent validation identified novel GPCR-dependent antiviral (ADORA1) and proviral (GPR146, RGS16, PTAFR, SCTR, GPR84, GPR85, NMUR2, FZ10, RDS, CCL17, and SORT1) roles. By contrast a gene family cluster of protocadherins is significantly differentially induced in neonatal cells, suggestive of possible immunomodulatory roles. Unexpectedly, programming responses of adult and neonatal dendritic cells, upon HCMV infection, demonstrated comparable quantitative and qualitative responses showing that functionally, neonatal dendritic cell are not overly compromised. However, a delay in responses of neonatal cells for IFN subnetworks in comparison with adult-derived cells are notable, suggestive of subtle plasticity differences. These findings support a set-point control mechanism rather than immaturity for explaining not only neonatal susceptibility but also resilience to infection. In summary, our findings show that neonatal HCMV infection leads to a highly plastic and functional robust programming of dendritic cells in vivo and in vitro . In comparison with adults, a minimal number of subtle quantitative and temporal differences may contribute to variability in host susceptibility and resilience, in a context dependent manner.