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Sample records for circulating cd4 t-cells

  1. Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides.

    PubMed

    Mukhopadhya, Indrani; Murray, Graeme I; Duncan, Linda; Yuecel, Raif; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

    2016-09-01

    CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

  2. Circulating subsets and CD4(+)CD25(+) regulatory T cell function in chronic inflammatory demyelinating polyradiculoneuropathy.

    PubMed

    Sanvito, Lara; Makowska, Anna; Gregson, Norman; Nemni, Raffaello; Hughes, Richard A C

    2009-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory disease of the peripheral nervous system that is probably autoimmune in origin. Different components of the adaptive and innate immunity may be responsible for the aberrant response towards nerve antigens. To investigate this, we examined lymphocyte subsets and regulatory T cell (Treg) function in the blood of CIDP patients, healthy controls (HC) and subjects with non-immune mediated neuropathies (other neuropathies, ON). We used flow cytometry to determine the frequency of monocytes, B cells, natural killer (NK) and NK-T cells, total and activated CD4(+) and CD8(+) T cells, effector memory and central memory CD4(+) and CD8(+) T cells, and CD4(+)CD25(high)Foxp3(+) Tregs. Treg function was studied after polyclonal stimulation and antigen specific stimulation with myelin protein peptides in CIDP and HC. There was an increased frequency of monocytes (p = 0.02) and decreased frequency of NK cells (p = 0.02) in CIDP compared with HC but not ON. There were no significant differences in other populations. Treg function was impaired in CIDP compared to HC (p = 0.02), whilst T cell proliferation to myelin protein peptides before and after depletion of Tregs was not different between patients and controls. This study shows increased circulating monocytes and reduced NK cells in CIDP. Although Treg frequency was not altered, we confirm that Tregs display a defect of suppressive function. Myelin protein peptides were not the target of the altered peripheral regulation of the immune response. The mechanisms of peripheral immune tolerance in CIDP and their relevance to the pathogenesis deserve further exploration.

  3. Statins Increase the Frequency of Circulating CD4+FOXP3+ Regulatory T Cells in Healthy Individuals

    PubMed Central

    Rodríguez-Perea, Ana Lucía; Montoya, Carlos J.; Olek, Sven; Chougnet, Claire A.; Velilla, Paula A.

    2015-01-01

    Statins have been shown to modulate the number and the suppressive function of CD4+FOXP3+ T cells (Treg) in inflammatory conditions. However, it is not well established whether statin could also affect Treg in absence of inflammation. To address this question, eighteen normocholesterolemic male subjects were treated with lovastatin or atorvastatin daily for 45 days. The frequency and phenotype of circulating Treg were evaluated at days 0, 7, 30, and 45. mRNA levels of FOXP3, IDO, TGF-β, and IL-10 were measured in CD4+ T cells. We found that both statins significantly increased Treg frequency and FOXP3 mRNA levels at day 30. At day 45, Treg numbers returned to baseline values; however, TGF-β and FOXP3 mRNA levels remained high, accompanied by increased percentages of CTLA-4- and GITR-expressing Treg. Treg Ki-67 expression was decreased upon statin treatment. Treg frequency positively correlated with plasma levels of high-density lipoprotein cholesterol (HDL-c), suggesting a role for HDL-c in Treg homeostasis. Therefore, statins appear to have inflammation-independent immune-modulatory effects. Thus, the increase in Treg cells frequency likely contributes to immunomodulatory effect of statins, even in healthy individuals. PMID:25759848

  4. Skin CD4+ memory T cells exhibit combined cluster-mediated retention and equilibration with the circulation

    PubMed Central

    Collins, Nicholas; Jiang, Xiaodong; Zaid, Ali; Macleod, Bethany L.; Li, Jane; Park, Chang Ook; Haque, Ashraful; Bedoui, Sammy; Heath, William R.; Mueller, Scott N.; Kupper, Thomas S.; Gebhardt, Thomas; Carbone, Francis R.

    2016-01-01

    Although memory T cells within barrier tissues can persist as permanent residents, at least some exchange with blood. The extent to which this occurs is unclear. Here we show that memory CD4+ T cells in mouse skin are in equilibrium with the circulation at steady state. These cells are dispersed throughout the inter-follicular regions of the dermis and form clusters with antigen presenting cells around hair follicles. After infection or administration of a contact sensitizing agent, there is a sustained increase in skin CD4+ T-cell content, which is confined to the clusters, with a concomitant CCL5-dependent increase in CD4+ T-cell recruitment. Skin CCL5 is derived from CD11b+ cells and CD8+ T cells, with the elimination of the latter decreasing CD4+ T-cell numbers. These results reveal a complex pattern of tissue-retention and equilibration for CD4+ memory T cells in skin, which is altered by infection and inflammation history. PMID:27160938

  5. Substantial increase in the frequency of circulating CD4+NKG2D+ T cells in patients with cervical intraepithelial neoplasia grade 1

    PubMed Central

    2013-01-01

    Background The NKG2D receptor confers important activating signals to NK cells via ligands expressed during cellular stress and viral infection. This receptor has generated great interest because not only is it expressed on NK cells, but it is also seen in virtually all CD8+ cytotoxic T cells and is classically considered absent in CD4+ T cells. However, recent studies have identified a distinctive population of CD4+ T cells that do express NKG2D, which could represent a particular cytotoxic effector population involved in viral infections and chronic diseases. On the other hand, increased incidence of human papillomavirus-associated lesions in CD4+ T cell-immunocompromised individuals suggests that CD4+ T cells play a key role in controlling the viral infection. Therefore, this study was focused on identifying the frequency of NKG2D-expressing CD4+ T cells in patients with cervical intraepithelial neoplasia (CIN) 1. Additionally, factors influencing CD4+NKG2D+ T cell expansion were also measured. Results Close to 50% of patients with CIN 1 contained at least one of the 37 HPV types detected by our genotyping system. A tendency for increased CD4+ T cells and CD8+ T cells and decreased NK cells was found in CIN 1 patients. The percentage of circulating CD4+ T cells co-expressing the NKG2D receptor significantly increased in women with CIN 1 versus control group. Interestingly, the increase of CD4+NKG2D+ T cells was seen in patients with CIN 1, despite the overall levels of CD4+ T cells did not significantly increase. We also found a significant increase of soluble MICB in CIN 1 patients; however, no correlation with the presence of CD4+NKG2D+ T cells was seen. While TGF-beta was significantly decreased in the group of CIN 1 patients, both TNF-alpha and IL-15 showed a tendency to increase in this group. Conclusions Taken together, our results suggest that the significant increase within the CD4+NKG2D+ T cell population in CIN 1 patients might be the result of a

  6. Abundance and specificity of influenza reactive circulating memory follicular helper and non-follicular helper CD4 T cells in healthy adults.

    PubMed

    Leddon, Scott A; Richards, Katherine A; Treanor, John J; Sant, Andrea J

    2015-09-01

    CD4 T-cell responses are functionally complex and regulate many aspects of innate and adaptive immunity. Follicular helper (Tfh) cells are CD4 T cells specialized to support B-cell production of isotype-switched, high-affinity antibody. So far, studies of Tfh cells in humans have focused on their differentiation requirements, with little research devoted to their antigen specificity. Here, after separating circulating human memory CD4 T cells based on expression of CXCR5, a signature marker of Tfh, we have quantified and assayed the influenza protein antigen specificity of blood Tfh cells and CD4 T cells lacking this marker. Through the use of peptide pools derived from nucleoprotein (NP) or haemagglutinin (HA) and a panel of human donors, we have discovered that circulating Tfh cells preferentially recognize peptide epitopes from HA while cells lacking CXCR5 are enriched for specificity toward NP. These studies suggest that reactive CD4 T cells specific for distinct viral antigens may have generalized differences in their functional potential due to their previous stimulation history. PMID:26094691

  7. Impairment of circulating CD4+CD25+ regulatory T cells in patients with chronic inflammatory demyelinating polyradiculoneuropathy.

    PubMed

    Chi, Li-Jun; Wang, Hua-Bing; Wang, Wei-Zhi

    2008-03-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated peripheral nervous system disease. CD4+CD25+ T regulatory cells (Tregs) have been unequivocally shown to be critical in maintaining immune tolerance and preventing auto-immune diseases by suppressing self-reactive T cells. Thus, we hypothesized that the numbers and/or the function of Tregs would be deranged during the progressive or relapse phases of CIDP. The number of Tregs was determined by flow cytometry according to their characteristic CD4+CD25(high) membrane phenotype. Functional characterization of Tregs was analyzed by suppression of proliferation and secretion of cytokines by co-cultured effector CD4+CD25- T cells. FOXP3 message expression level was assessed by quantitative real-time polymerase chain reaction. The results showed significant reduction in both the number and the suppressive function of Tregs in the patients with CIDP compared with healthy controls. Also, Tregs isolated from CIDP patients expressed lower levels of FoxP3 mRNA. During the progressive or the relapsing phases of CIDP, the number of Tregs was reduced, and the suppressive function of them decreased. These findings may be helpful to our understanding of the possible role of Tregs in the pathogenesis of CIDP.

  8. An Imbalance between Frequency of CD4+CD25+FOXP3+ Regulatory T Cells and CCR4+ and CCR9+ Circulating Helper T Cells Is Associated with Active Perennial Allergic Conjunctivitis

    PubMed Central

    Galicia-Carreón, J.; Santacruz, C.; Ayala-Balboa, J.; Robles-Contreras, A.; Perez-Tapia, S. M.; Garfias, Y.; Hong, E.; Jiménez-Martínez, M. C.

    2013-01-01

    Allergic conjunctivitis (AC) is one of the most common eye disorders in ophthalmology. In mice models, it has been suggested that control of allergic conjunctivitis is a delicate balance between Tregs and inflammatory migrating effector cells. Our aim was to evaluate the frequency of Tregs and the frequency of homing receptors expressing cells in peripheral blood mononuclear cells (PBMC) from patients with perennial allergic conjunctivitis (PAC). The analyses of phenotypic markers on CD4+ T cells and both soluble or intracellular cytokines were performed by flow cytometry. CD4+CD25+ cells were 15 times more frequent in PBMC from patients than HC; the vast majority of these CD4+CD25+ cells were FOXP3−, and most of CD4+ T cells were CCR4+ and CCR9+ cells. Upon allergen-stimulation, no significant changes were observed in frequency of Treg; however, an increased frequency of CD4+CCR4+CCR9+ cells, CD4+CD103+ cells and CD4+CD108+ cells with increased IL-5, IL-6, and IL-8 production was observed. These findings suggest an immune dysregulation in PAC, characterized by diminished frequency of Tregs and increased frequency of circulating activated CD4+ T cells; upon allergen-stimulation, these cells were expressing cell-surface molecules related to mucosa homing and were able to trigger an inflammatory microenvironment. PMID:24368924

  9. Functional and Phenotypic Plasticity of CD4+ T Cell Subsets

    PubMed Central

    Caza, Tiffany; Landas, Steve

    2015-01-01

    The remarkable plasticity of CD4+ T cells allows individuals to respond to environmental stimuli in a context-dependent manner. A balance of CD4+ T cell subsets is critical to mount responses against pathogen challenges to prevent inappropriate activation, to maintain tolerance, and to participate in antitumor immune responses. Specification of subsets is a process beginning in intrathymic development and continuing within the circulation. It is highly flexible to adapt to differences in nutrient availability and the tissue microenvironment. CD4+ T cell subsets have significant cross talk, with the ability to “dedifferentiate” given appropriate environmental signals. This ability is dependent on the metabolic status of the cell, with mTOR acting as the rheostat. Autoimmune and antitumor immune responses are regulated by the balance between regulatory T cells and Th17 cells. When a homeostatic balance of subsets is not maintained, immunopathology can result. CD4+ T cells carry complex roles within tumor microenvironments, with context-dependent immune responses influenced by oncogenic drivers and the presence of inflammation. Here, we examine the signals involved in CD4+ T cell specification towards each subset, interconnectedness of cytokine networks, impact of mTOR signaling, and cellular metabolism in lineage specification and provide a supplement describing techniques to study these processes. PMID:26583116

  10. Increase in frequencies of circulating Th-17 cells correlates with microbial translocation, immune activation and exhaustion in HIV-1 infected patients with poor CD4 T-cell reconstitution.

    PubMed

    Valiathan, Ranjini; Asthana, Deshratn

    2016-05-01

    We analyzed the association of circulating Th-17 cells (cTh-17) with immune activation (IA), immune exhaustion (IE) and regulatory T-cells (T-regs) in 20 human immunodeficiency virus-1 (HIV-1) infected patients with impaired restoration of CD4 T-cell counts despite prolonged suppression of plasma viremia (discordant) and compared it with 20 HIV-1 infected patients showing good immunologic and virologic responses (concordant) following highly active antiretroviral therapy (HAART). Discordant HIV-1 infected patients showed significantly higher frequencies of cTh-17 cells compared to concordant patients and healthy controls after PMA+Ionomicin stimulation. Discordant patients also showed higher CD4 T-cell immune activation (HLA-DR+CD38+) than concordant patients which directly correlated with microbial translocation. Additionally, CD4 T-cells of discordant patients showed higher frequencies of CD4 T-cells expressing multiple immune exhaustion markers (Tim3+PD-1+) which correlated with immune activation indicating that combined analysis of inhibitory molecules along with PD-1 might be a better predictor for immune exhaustion of CD4 T-cells. Increased cTh-17 cell frequency correlated inversely with CD4 T-cell percentages and absolute counts and directly with CD4 T-cell immune activation and T-reg frequencies. Persistent CD4 T-cell immune activation might favor differentiation of activated CD4 T-cells toward cTh-17 phenotype in discordant patients. Discordant patients had significantly lower baseline CD4 T-cell counts and higher viral load at the initiation of HAART and higher immune activation and immune exhaustion after being on HAART for long time indicating that these factors might be associated with an increase in cTh-17 cell frequency, thus, increasing the risk of disease progression despite virologic control.

  11. A Subset of Circulating Blood Mycobacteria-Specific CD4 T Cells Can Predict the Time to Mycobacterium tuberculosis Sputum Culture Conversion

    PubMed Central

    Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P.; Coetzee, Gerrit; Conradie, Francesca; Ismail, Nazir; Kaplan, Gilla; Fallows, Dorothy

    2014-01-01

    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR+Ki67+ on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67+HLA-DR+ Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67+HLA-DR+ T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ+IL2+TNFα+ CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67+HLA-DR+) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment. PMID:25048802

  12. A subset of circulating blood mycobacteria-specific CD4 T cells can predict the time to Mycobacterium tuberculosis sputum culture conversion.

    PubMed

    Riou, Catherine; Gray, Clive M; Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P; Coetzee, Gerrit; Conradie, Francesca; Ismail, Nazir; Kaplan, Gilla; Fallows, Dorothy

    2014-01-01

    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR+ Ki67+ on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67+ HLA-DR+ Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67+ HLA-DR+ T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ+ IL2+ TNFα+ CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67+ HLA-DR+) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment.

  13. A subset of circulating blood mycobacteria-specific CD4 T cells can predict the time to Mycobacterium tuberculosis sputum culture conversion.

    PubMed

    Riou, Catherine; Gray, Clive M; Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P; Coetzee, Gerrit; Conradie, Francesca; Ismail, Nazir; Kaplan, Gilla; Fallows, Dorothy

    2014-01-01

    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR+ Ki67+ on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67+ HLA-DR+ Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67+ HLA-DR+ T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ+ IL2+ TNFα+ CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67+ HLA-DR+) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment. PMID:25048802

  14. Sialylation regulates peripheral tolerance in CD4+ T cells.

    PubMed

    Brennan, Patrick J; Saouaf, Sandra J; Van Dyken, Steve; Marth, Jamey D; Li, Bin; Bhandoola, Avinash; Greene, Mark I

    2006-05-01

    Decreased binding by the 6C10 auto-antibody serves as a unique marker for CD4+ T cell unresponsiveness after the induction of T cell tolerance in Vbeta8.1 TCR transgenic mice. We further define the nature of the epitope recognized by the 6C10 antibody to be a subset of Thy-1 bearing incompletely sialylated N-linked glycans, and furthermore, we demonstrate that tolerant CD4+ T cells have an increased degree of cell-surface sialylation. To test the significance of the altered glycosylation state identified by the 6C10 auto-antibody in the tolerant CD4+ T cell population, surface sialic acid was cleaved enzymatically. Treatment of purified peripheral CD4+ T cells with Vibrio cholerae sialidase (VCS) leads to increased 6C10 binding, significantly enhances proliferation in the tolerant CD4+ population and corrects defects in phosphotyrosine signaling observed in the tolerant CD4+ T cell. Furthermore, in vivo administration of VCS enhances proliferation in both tolerant and naive CD4+ T cell subsets. These studies suggest that sialylation of glycoproteins on the surface of the CD4+ T cell contributes to the regulation of T cell responsiveness in the tolerant state. PMID:16291658

  15. Isolation and Characterization of Salmonid CD4+ T Cells.

    PubMed

    Maisey, Kevin; Montero, Ruth; Corripio-Miyar, Yolanda; Toro-Ascuy, Daniela; Valenzuela, Beatriz; Reyes-Cerpa, Sebastián; Sandino, Ana María; Zou, Jun; Wang, Tiehui; Secombes, Christopher J; Imarai, Mónica

    2016-05-15

    This study reports the isolation and functional characterization of rainbow trout (Oncorhynchus mykiss) CD4-1(+) T cells and the establishment of an IL-15-dependent CD4-1(+) T cell line. By using Abs specific for CD4-1 and CD3ε it was possible to isolate the double-positive T cells in spleen and head kidney. The morphology and the presence of transcripts for T cell markers in the sorted CD4-1(+)CD3ε(+) cells were studied next. Cells were found to express TCRα, TCRβ, CD152 (CTLA-4), CD154 (CD40L), T-bet, GATA-3, and STAT-1. The sorted CD4-1(+) T cells also had a distinctive functional attribute of mammalian T lymphocytes, namely they could undergo Ag-specific proliferation, using OVA as a model Ag. The OVA-stimulated cells showed increased expression of several cytokines, including IFN-γ1, IL-4/13A, IL-15, IL-17D, IL-10, and TGF-β1, perhaps indicating that T cell proliferation led to differentiation into distinct effector phenotypes. Using IL-15 as a growth factor, we have selected a lymphoid cell line derived from rainbow trout head kidney cells. The morphology, cell surface expression of CD4-1, and the presence of transcripts of T cell cytokines and transcription factors indicated that this is a CD4-1(+) T cell line. To our knowledge, this is the first demonstration of the presence of CD4-1(+)CD3ε(+) T cells in salmonids. As in mammals, CD4-1(+) T cells may be the master regulators of immune responses in fish, and therefore these findings and the new model T cell line developed will contribute to a greater understanding of T cell function and immune responses in teleost fish. PMID:27053758

  16. CD4 (T-Cell) Tests

    MedlinePlus

    ... 3 to 6 months when starting antiretroviral therapy (ART, see fact sheet 403 ). Once treatment has increased ... Fact Sheet 514 ) Monitoring treatment success: With successful ART, CD4 counts rise. Sometimes they rise quickly. Other ...

  17. Impact of sepsis on CD4 T cell immunity

    PubMed Central

    Cabrera-Perez, Javier; Condotta, Stephanie A.; Badovinac, Vladimir P.; Griffith, Thomas S.

    2014-01-01

    Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state. PMID:24791959

  18. Dysregulation of CD4(+) T Cell Subsets in Intracranial Aneurysm.

    PubMed

    Zhang, Hai-Feng; Zhao, Ming-Guang; Liang, Guo-Biao; Yu, Chun-Yong; He, Wenxiu; Li, Zhi-Qing; Gao, Xu

    2016-02-01

    Intracranial aneurysms (IAs) and potential IA rupture are one of the direct causes of permanent brain damage and mortality. Interestingly, the major risk factors of IA development, including hemodynamic stress, hypertension, smoking, and genetic predispositions, are closely associated with a proinflammatory immune status. Therefore, we examined the roles of CD4(+) T cells in IA pathogenesis. IA patients exhibited peripheral CD4(+) T-cell imbalance, with overrepresented T helper 1 (Th1) and Th17 activities and underrepresented Th2 and regulatory T (Treg) activities, including increased IFN-γ, TNF-α, and IL-17 production and decreased IL-10 production from total CD4(+) T cells. Chemokine receptors CXCR3 and CCR6 were used to identify Th1, Th2, and Th17 cell subsets, and CD4(+)CD25(hi) was used to identify Treg cells. Based on these markers, the data then showed altered cytokine production by each cell type and shifted subpopulation frequency. Moreover, this shift in frequency was directly correlated with IA severity. To examine the underlying mechanism of CD4(+) T cell skewing, we cocultured CD4(+) T cells with autologous monocytes and found that coculture with monocytes could significantly increase IFN-γ and IL-17 production through contact-independent mechanisms, demonstrating that monocytes could potentially contribute to the altered CD4(+) T cell composition in IA. Analyzing mRNA transcripts revealed significantly upregulated IL-1β and TNF-α expression by monocytes from IA patients. We found a loss of CD4(+) T cell subset balance that was likely to promote a higher state of inflammation in IA, which may exacerbate the disease through a positive feedback loop.

  19. NY-ESO-1-specific circulating CD4+ T cells in ovarian cancer patients are prevalently T(H)1 type cells undetectable in the CD25+ FOXP3+ Treg compartment.

    PubMed

    Redjimi, Nassima; Duperrier-Amouriaux, Karine; Raimbaud, Isabelle; Luescher, Immanuel; Dojcinovic, Danijel; Classe, Jean-Marc; Berton-Rigaud, Dominique; Frenel, Jean-Sébastien; Bourbouloux, Emmanuelle; Valmori, Danila; Ayyoub, Maha

    2011-01-01

    Spontaneous CD4(+) T-cell responses to the tumor-specific antigen NY-ESO-1 (ESO) are frequently found in patients with epithelial ovarian cancer (EOC). If these responses are of effector or/and Treg type, however, has remained unclear. Here, we have used functional approaches together with recently developed MHC class II/ESO tetramers to assess the frequency, phenotype and function of ESO-specific cells in circulating lymphocytes from EOC patients. We found that circulating ESO-specific CD4(+) T cells in EOC patients with spontaneous immune responses to the antigen are prevalently T(H)1 type cells secreting IFN-γ but no IL-17 or IL-10 and are not suppressive. We detected tetramer(+) cells ex vivo, at an average frequency of 1:25,000 memory cells, that is, significantly lower than in patients immunized with an ESO vaccine. ESO tetramer(+) cells were mostly effector memory cells at advanced stages of differentiation and were not detected in circulating CD25(+)FOXP3(+)Treg. Thus, spontaneous CD4(+) T-cell responses to ESO in cancer patients are prevalently of T(H)1 type and not Treg. Their relatively low frequency and advanced differentiation stage, however, may limit their efficacy, that may be boosted by immunogenic ESO vaccines.

  20. Plasticity of Human CD4 T Cell Subsets

    PubMed Central

    Geginat, Jens; Paroni, Moira; Maglie, Stefano; Alfen, Johanna Sophie; Kastirr, Ilko; Gruarin, Paola; De Simone, Marco; Pagani, Massimiliano; Abrignani, Sergio

    2014-01-01

    Human beings are exposed to a variety of different pathogens, which induce tailored immune responses and consequently generate highly diverse populations of pathogen-specific T cells. CD4+ T cells have a central role in adaptive immunity, since they provide essential help for both cytotoxic T cell- and antibody-mediated responses. In addition, CD4+ regulatory T cells are required to maintain self-tolerance and to inhibit immune responses that could damage the host. Initially, two subsets of CD4+ helper T cells were identified that secrete characteristic effector cytokines and mediate responses against different types of pathogens, i.e., IFN-γ secreting Th1 cells that fight intracellular pathogens, and IL-4 producing Th2 cells that target extracellular parasites. It is now well established that this dichotomy is insufficient to describe the complexity of CD4+ T cell differentiation, and in particular the human CD4 compartment contains a myriad of T cell subsets with characteristic capacities to produce cytokines and to home to involved tissues. Moreover, it has become increasingly clear that these T cell subsets are not all terminally differentiated cells, but that the majority is plastic and that in particular central memory T cells can acquire different properties and functions in secondary immune responses. In addition, there is compelling evidence that helper T cells can acquire regulatory functions upon chronic stimulation in inflamed tissues. The plasticity of antigen-experienced human T cell subsets is highly relevant for translational medicine, since it opens new perspectives for immune-modulatory therapies for chronic infections, autoimmune diseases, and cancer. PMID:25566245

  1. Human regulatory T cells control TCR signaling and susceptibility to suppression in CD4+ T cells.

    PubMed

    Chellappa, Stalin; Lieske, Nora V; Hagness, Morten; Line, Pål D; Taskén, Kjetil; Aandahl, Einar M

    2016-07-01

    Human CD4(+)CD25(hi)FOXP3(+) regulatory T cells maintain immunologic tolerance and prevent autoimmune and inflammatory immune responses. Regulatory T cells undergo a similar activation cycle as conventional CD4(+) T cells upon antigen stimulation. Here, we demonstrate that T cell receptors and costimulation are required to activate the regulatory T cell suppressive function. Regulatory T cells suppressed the T cell receptor signaling in effector T cells in a time-dependent manner that corresponded with inhibition of cytokine production and proliferation. Modulation of the activation level and thereby the suppressive capacity of regulatory T cells imposed distinct T cell receptor signaling signatures and hyporesponsiveness in suppressed and proliferating effector T cells and established a threshold for effector T cell proliferation. The immune suppression of effector T cells was completely reversible upon removal of regulatory T cells. However, the strength of prior immune suppression by regulatory T cells and corresponding T cell receptor signaling in effector T cells determined the susceptibility to suppression upon later reexposure to regulatory T cells. These findings demonstrate how the strength of the regulatory T cell suppressive function determines intracellular signaling, immune responsiveness, and the later susceptibility of effector T cells to immune suppression and contribute to unveiling the complex interactions between regulatory T cells and effector T cells. PMID:26715685

  2. Circulating precursor CCR7(lo)PD-1(hi) CXCR5⁺ CD4T cells indicate Tfh cell activity and promote antibody responses upon antigen reexposure.

    PubMed

    He, Jing; Tsai, Louis M; Leong, Yew Ann; Hu, Xin; Ma, Cindy S; Chevalier, Nina; Sun, Xiaolin; Vandenberg, Kirsten; Rockman, Steve; Ding, Yan; Zhu, Lei; Wei, Wei; Wang, Changqi; Karnowski, Alexander; Belz, Gabrielle T; Ghali, Joanna R; Cook, Matthew C; Riminton, D Sean; Veillette, André; Schwartzberg, Pamela L; Mackay, Fabienne; Brink, Robert; Tangye, Stuart G; Vinuesa, Carola G; Mackay, Charles R; Li, Zhanguo; Yu, Di

    2013-10-17

    Follicular B helper T (Tfh) cells support high affinity and long-term antibody responses. Here we found that within circulating CXCR5⁺ CD4T cells in humans and mice, the CCR7(lo)PD-1(hi) subset has a partial Tfh effector phenotype, whereas CCR7(hi)PD-1(lo) cells have a resting phenotype. The circulating CCR7(lo)PD-1(hi) subset was indicative of active Tfh differentiation in lymphoid organs and correlated with clinical indices in autoimmune diseases. Thus the CCR7(lo)PD-1(hi) subset provides a biomarker to monitor protective antibody responses during infection or vaccination and pathogenic antibody responses in autoimmune diseases. Differentiation of both CCR7(hi)PD-1(lo) and CCR7(lo)PD-1(hi) subsets required ICOS and BCL6, but not SAP, suggesting that circulating CXCR5⁺ helper T cells are primarily generated before germinal centers. Upon antigen reencounter, CCR7(lo)PD-1(hi) CXCR5⁺ precursors rapidly differentiate into mature Tfh cells to promote antibody responses. Therefore, circulating CCR7(lo)PD-1(hi) CXCR5⁺ CD4T cells are generated during active Tfh differentiation and represent a new mechanism of immunological early memory.

  3. A novel differentiation pathway from CD4+ T cells to CD4T cells for maintaining immune system homeostasis

    PubMed Central

    Zhao, X; Sun, G; Sun, X; Tian, D; Liu, K; Liu, T; Cong, M; Xu, H; Li, X; Shi, W; Tian, Y; Yao, J; Guo, H; Zhang, D

    2016-01-01

    CD4+ T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4+ T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4−CD8−NK1.1− double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4+ rather than CD8+ T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4+ T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases. PMID:27077809

  4. CD4+ T cell activation in multiple sclerosis.

    PubMed

    Verselis, S J; Goust, J M

    1987-02-01

    Interleukin-2 (IL-2) production by CD4-enriched T cells from multiple sclerosis (MS) patients and normal individuals stimulated with concanavalin A (conA) and/or autologous and allogeneic B lymphoid cell lines (B-LCL) was evaluated 24, 48 and 96 h after stimulation. ConA-stimulated CD4+ cells from MS patients did not produce significantly more IL-2 than normal CD4+ cells. In contrast, autologous B-LCL-induced IL-2 production by MS CD4+ cells significantly (P = 0.026) exceeded that produced by normal CD4+ cells identically stimulated after 24 h in culture. Differences in IL-2 production by CD4+ cells from MS patients reached highest significance using allogeneic B-LCL, whose stimulatory capacity was similar, whether established from normal individuals or MS patients. This increased IL-2 production in response to B-LCL may represent a supranormal response of CD4+ cells from MS patients to class II major histocompatibility (MHC)-associated stimuli. It suggests that the deficiency of suppressor T cell functions postulated to play a role in MS does not arise from a lack of IL-2 induction and might indicate that bursts of IL-2 production could play a role in MS. PMID:3492511

  5. Peripheral and site-specific CD4(+) CD28(null) T cells from rheumatoid arthritis patients show distinct characteristics.

    PubMed

    Pieper, J; Johansson, S; Snir, O; Linton, L; Rieck, M; Buckner, J H; Winqvist, O; van Vollenhoven, R; Malmström, V

    2014-02-01

    Proinflammatory CD4(+) CD28(null) T cells are frequently found in the circulation of patients with rheumatoid arthritis (RA), but are less common in the rheumatic joint. In the present study, we sought to identify functional differences between CD4(+) CD28(null) T cells from blood and synovial fluid in comparison with conventional CD28-expressing CD4(+) T cells. Forty-four patients with RA, displaying a distinct CD4(+) CD28(null) T cell population in blood, were recruited for this study; the methylation status of the IFNG locus was examined in isolated T cell subsets, and intracellular cytokine production (IFN-γ, TNF, IL-17) and chemokine receptor expression (CXCR3, CCR6 and CCR7) were assessed by flow cytometry on T cells from the two compartments. Circulating CD4(+) CD28(null) T cells were significantly more hypomethylated in the CNS-1 region of the IFNG locus than conventional CD4(+) CD28(+) T cells and produced higher levels of both IFN-γ and TNF after TCR cross-linking. CD4(+) CD28(null) T cells from the site of inflammation expressed significantly more CXCR3 and CCR6 compared to their counterparts in blood. While IL-17A production could hardly be detected in CD4(+) CD28(null) cells from the blood, a significant production was observed in CD4(+) CD28(null) T cells from synovial fluid. CD4(+) CD28(null) T cells were not only found to differ from conventional CD4(+) CD28(+) T cells in the circulation, but we could also demonstrate that synovial CD4(+) CD28(null) T cells showed additional effector functions (IL-17 coproduction) as compared to the same subset in peripheral blood, suggesting an active role for these cells in the perpetuation of inflammation in the subset of patients having a CD28(null) population.

  6. Defective CD8 T Cell Memory Following Acute Infection Without CD4 T Cell Help

    NASA Astrophysics Data System (ADS)

    Sun, Joseph C.; Bevan, Michael J.

    2003-04-01

    The CD8+ cytotoxic T cell response to pathogens is thought to be CD4+ helper T cell independent because infectious agents provide their own inflammatory signals. Mice that lack CD4+ T cells mount a primary CD8 response to Listeria monocytogenes equal to that of wild-type mice and rapidly clear the infection. However, protective memory to a challenge is gradually lost in the former animals. Memory CD8+ T cells from normal mice can respond rapidly, but memory CD8+ T cells that are generated without CD4 help are defective in their ability to respond to secondary encounters with antigen. The results highlight a previously undescribed role for CD4 help in promoting protective CD8 memory development.

  7. CD4+ T cell anergy prevents autoimmunity and generates regulatory T cell precursors

    PubMed Central

    Kalekar, Lokesh A.; Schmiel, Shirdi E.; Nandiwada, Sarada L.; Lam, Wing Y.; Barsness, Laura O.; Zhang, Na; Stritesky, Gretta L.; Malhotra, Deepali; Pauken, Kristen E.; Linehan, Jonathan L.; O’Sullivan, M. Gerard; Fife, Brian T.; Hogquist, Kristin A.; Jenkins, Marc K.; Mueller, Daniel L.

    2015-01-01

    The role that anergy, an acquired state of T cell functional unresponsiveness, plays in natural peripheral tolerance remains unclear. In this study, we demonstrate that anergy is selectively induced in fetal antigen-specific maternal CD4+ T cells during pregnancy. A naturally occurring subpopulation of anergic polyclonal CD4+ T cells, enriched in self antigen-specific T cell receptors, is also observed in healthy hosts. Neuropilin-1 expression in anergic conventional CD4+ T cells is associated with thymic regulatory T cell (Treg cell)-related gene hypomethylation, and this correlates with their capacity to differentiate into Foxp3+ Treg cells that suppress immunopathology. Thus, our data suggest that not only is anergy induction important in preventing autoimmunity, but it also generates the precursors for peripheral Treg cell differentiation. PMID:26829766

  8. CD4 T-cell memory generation and maintenance.

    PubMed

    Gasper, David J; Tejera, Melba Marie; Suresh, M

    2014-01-01

    Immunologic memory is the adaptive immune system's powerful ability to remember a previous antigen encounter and react with accelerated vigor upon antigen re-exposure. It provides durable protection against reinfection with pathogens and is the foundation for vaccine-induced immunity. Unlike the relatively restricted immunologic purview of memory B cells and CD8 T cells, the field of CD4 T-cell memory must account for multiple distinct lineages with diverse effector functions, the issue of lineage commitment and plasticity, and the variable distribution of memory cells within each lineage. Here, we discuss the evidence for lineage-specific CD4 T-cell memory and summarize the known factors contributing to memory-cell generation, plasticity, and long-term maintenance.

  9. Access of protective antiviral antibody to neuronal tissues requires CD4 T-cell help.

    PubMed

    Iijima, Norifumi; Iwasaki, Akiko

    2016-05-26

    Circulating antibodies can access most tissues to mediate surveillance and elimination of invading pathogens. Immunoprivileged tissues such as the brain and the peripheral nervous system are shielded from plasma proteins by the blood-brain barrier and blood-nerve barrier, respectively. Yet, circulating antibodies must somehow gain access to these tissues to mediate their antimicrobial functions. Here we examine the mechanism by which antibodies gain access to neuronal tissues to control infection. Using a mouse model of genital herpes infection, we demonstrate that both antibodies and CD4 T cells are required to protect the host after immunization at a distal site. We show that memory CD4 T cells migrate to the dorsal root ganglia and spinal cord in response to infection with herpes simplex virus type 2. Once inside these neuronal tissues, CD4 T cells secrete interferon-γ and mediate local increase in vascular permeability, enabling antibody access for viral control. A similar requirement for CD4 T cells for antibody access to the brain is observed after intranasal challenge with vesicular stomatitis virus. Our results reveal a previously unappreciated role of CD4 T cells in mobilizing antibodies to the peripheral sites of infection where they help to limit viral spread. PMID:27225131

  10. Access of protective antiviral antibody to neuronal tissues requires CD4 T-cell help.

    PubMed

    Iijima, Norifumi; Iwasaki, Akiko

    2016-05-26

    Circulating antibodies can access most tissues to mediate surveillance and elimination of invading pathogens. Immunoprivileged tissues such as the brain and the peripheral nervous system are shielded from plasma proteins by the blood-brain barrier and blood-nerve barrier, respectively. Yet, circulating antibodies must somehow gain access to these tissues to mediate their antimicrobial functions. Here we examine the mechanism by which antibodies gain access to neuronal tissues to control infection. Using a mouse model of genital herpes infection, we demonstrate that both antibodies and CD4 T cells are required to protect the host after immunization at a distal site. We show that memory CD4 T cells migrate to the dorsal root ganglia and spinal cord in response to infection with herpes simplex virus type 2. Once inside these neuronal tissues, CD4 T cells secrete interferon-γ and mediate local increase in vascular permeability, enabling antibody access for viral control. A similar requirement for CD4 T cells for antibody access to the brain is observed after intranasal challenge with vesicular stomatitis virus. Our results reveal a previously unappreciated role of CD4 T cells in mobilizing antibodies to the peripheral sites of infection where they help to limit viral spread.

  11. Dendritic Cells Enhance HIV Infection of Memory CD4(+) T Cells in Human Lymphoid Tissues.

    PubMed

    Reyes-Rodriguez, Angel L; Reuter, Morgan A; McDonald, David

    2016-02-01

    Dendritic cells (DCs) play a key role in controlling infections by coordinating innate and adaptive immune responses to invading pathogens. Paradoxically, DCs can increase HIV-1 dissemination in vitro by binding and transferring infectious virions to CD4(+) T cells, a process called transinfection. Transinfection has been well characterized in cultured cell lines and circulating primary T cells, but it is unknown whether DCs enhance infection of CD4(+) T cells in vivo. In untreated HIV infection, massive CD4(+) T-cell infection and depletion occur in secondary lymphoid tissues long before decline is evident in the peripheral circulation. To study the role of DCs in HIV infection of lymphoid tissues, we utilized human tonsil tissues, cultured either as tissue blocks or as aggregate suspension cultures, in single-round infection experiments. In these experiments, addition of monocyte-derived DCs (MDDCs) to the cultures increased T-cell infection, particularly in CD4(+) T cells expressing lower levels of HLA-DR. Subset analysis demonstrated that MDDCs increased HIV-1 infection of central and effector memory T-cell populations. Depletion of endogenous myeloid DCs (myDCs) from the cultures decreased memory T-cell infection, and readdition of MDDCs restored infection to predepletion levels. Using an HIV-1 fusion assay, we found that MDDCs equally increased HIV delivery into naïve, central, and effector memory T cells in the cultures, whereas predepletion of myDCs reduced fusion into memory T cells. Together, these data suggest that resident myDCs facilitate memory T-cell infection in lymphoid tissues, implicating DC-mediated transinfection in driving HIV dissemination within these tissues in untreated HIV/AIDS.

  12. Analysis of CD4-positive T cell subpopulation in sarcoidosis.

    PubMed Central

    Gerli, R; Darwish, S; Broccucci, L; Minotti, V; Spinozzi, F; Cernetti, C; Bertotto, A; Rambotti, P

    1988-01-01

    Double-labelling immunofluorescence analysis within the CD4+ cell subset was carried out in 27 bronchoalveolar lavage fluids and 11 peripheral blood samples of sarcoidosis patients with anti-TQ1, anti-2H4 and anti-4B4 monoclonal antibodies. Helper/inducer CD4+TQ1-/4B4+ cells were strongly increased in the lung and slightly, but significantly, decreased in the blood of sarcoidosis patients with respect to normal controls. No differences were found in the number of both lung and blood CD4+2H4+ cells between sarcoidosis patients and controls. The findings are further evidence for a compartmentalization of T cell subsets in sarcoidosis. PMID:3263230

  13. Specificity of regulatory CD4+CD25+ T cells for self-T cell receptor determinants.

    PubMed

    Buenafe, Abigail C; Tsaknaridis, Laura; Spencer, Leslie; Hicks, Kevin S; McMahan, Rachel H; Watson, Lisa; Culbertson, Nicole E; Latocha, Dorian; Wegmann, Keith; Finn, Tom; Bartholomew, Richard; Burrows, Gregory G; Whitham, Ruth; Bourdette, Dennis N; Jones, Richard E; Offner, Halina; Chou, Yuan K; Vandenbark, Arthur A

    2004-04-01

    Although the phenotypic and regulatory properties of the CD4(+)CD25(+) T cell lineage (Treg cells) have been well described, the specificities remain largely unknown. We demonstrate here that the CD4(+)CD25(+) Treg population includes the recognition of a broad spectrum of human TCR CDR2 determinants found in the germline V gene repertoire as well as that of a clonotypic nongermline-encoded CDR3beta sequence present in a recombinant soluble T cell receptor (TCR) protein. Regulatory activity was demonstrated in T cell lines responsive to TCR but not in T cell lines responsive to control antigens. Inhibitory activity of TCR-reactive T cells required cell-cell contact and involved CTLA-4, GITR, IL-10, and IL-17. Thus, the T-T regulatory network includes Treg cells with specificity directed toward self-TCR determinants.

  14. Induction of CD4 suppressor T cells with anti-Leu-8 antibody

    SciTech Connect

    Kanof, M.E.; Strober, W.; James, S.P.

    1987-07-01

    To characterize the conditions under which CD4 T cells suppress polyclonal immunoglobulin synthesis, we investigated the capacity of CD4 T cells that coexpress the surface antigen recognized by the monoclonal antibody anti-Leu-8 to mediate suppression. In an in vitro system devoid of CD8 T cells, CD4, Leu-8+ T cells suppressed pokeweed mitogen-induced immunoglobulin synthesis. Similarly, suppressor function was induced in unfractionated CD4 T cell populations after incubation with anti-Leu-8 antibody under cross-linking conditions. This induction of suppressor function by anti-Leu-8 antibody was not due to expansion of the CD4, Leu-8+ T cell population because CD4 T cells did not proliferate in response to anti-Leu-8 antibody. However, CD4, Leu-8+ T cell-mediated suppression was radiosensitive. Finally, CD4, Leu-8+ T cells do not inhibit immunoglobulin synthesis when T cell lymphokines were used in place of helper CD4 T cells (CD4, Leu-8- T cells), suggesting that CD4 T cell-mediated suppression occurs at the T cell level. We conclude that CD4 T cells can be induced to suppress immunoglobulin synthesis by modulation of the membrane antigen recognized by anti-Leu-8 antibody.

  15. CD4+ T cells are important mediators of oxidative stress that cause hypertension in response to placental ischemia.

    PubMed

    Wallace, Kedra; Cornelius, Denise C; Scott, Jeremy; Heath, Judith; Moseley, Janae; Chatman, Krystal; LaMarca, Babbette

    2014-11-01

    Preeclampsia is associated with oxidative stress, which is suspected to play a role in hypertension, placental ischemia, and fetal demise associated with the disease. Various cellular sources of oxidative stress, such as neutrophils, monocytes, and CD4(+) T cells have been suggested as culprits in the pathophysiology of preeclampsia. The objective of this study was to examine a role of circulating and placental CD4(+) T cells in oxidative stress in response to placental ischemia during pregnancy. CD4(+) T cells and oxidative stress were measured in preeclamptic and normal pregnant women, placental ischemic and normal pregnant rats, and normal pregnant recipient rats of placental ischemic CD4(+) T cells. Women with preeclampsia had significantly increased circulating (P=0.02) and placental CD4(+) T cells (P=0.0001); lymphocyte secretion of myeloperoxidase (P=0.004); and placental reactive oxygen species (P=0.0004) when compared with normal pregnant women. CD4(+) T cells from placental ischemic rats cause many facets of preeclampsia when injected into normal pregnant recipient rats on gestational day 13. On gestational day 19, blood pressure increased in normal pregnant recipients of placental ischemic CD4(+) T cells (P=0.002) compared with that in normal pregnant rats. Similar to preeclamptic patients, CD4(+) T cells from placental ischemic rats secreted significantly more myeloperoxidase (P=0.003) and induced oxidative stress in cultured vascular cells (P=0.003) than normal pregnant rat CD4(+)Tcells. Apocynin, a nicotinamide adenine dinucleotide phosphate inhibitor, attenuated hypertension and all oxidative stress markers in placental ischemic and normal pregnant recipient rats of placental ischemic CD4(+)Tcells (P=0.05). These data demonstrate an important role for CD4(+) T cells in mediating another factor, oxidative stress, to cause hypertension during preeclampsia.

  16. CD4+T cells are important mediators of oxidative stress that cause hypertension in response to placental ischemia

    PubMed Central

    Wallace, Kedra; Cornelius, Denise C.; Scott, Jeremy; Heath, Judith; Moseley, Janae; Chatman, Krystal; LaMarca, Babbette

    2014-01-01

    Preeclampsia is associated with oxidative stress which is suspected to play a role in hypertension, placental ischemia and fetal demise associated with the disease. Various cellular sources of oxidative stress such as neutrophils, monocytes and CD4+T cells have been suggested as culprits in the pathophysiology of preeclampsia. The objective of this study was to examine a role for circulating and placental CD4+T cells in oxidative stress in response to placental ischemia during pregnancy. CD4+T cells and oxidative stress was measured in preeclamptic and normal pregnant women, placental ischemic and normal pregnant rats and normal pregnant recipient rats of placental ischemic CD4+ T cells. Preeclamptic women had significantly increased circulating (p=0.02) and placental CD4+T cells (p=0.0001); lymphocyte secretion of myeloperoxidase (p=0.004); and placental reactive oxygen species (p=0.0004) compared to normal pregnant women. CD4+T cells from placental ischemic rats cause many facets of preeclampsia when injected into normal pregnant recipient rats on gestational day 13. On gestational day 19 blood pressure increased in normal pregnant recipients of placental ischemic CD4+T cells (p=0.002) compared to normal pregnant rats. Similar to preeclamptic patients, CD4+ T cells from placental ischemic rats secreted significantly more myeloperoxidase (p=0.003) and induced oxidative stress in cultured vascular cells (p=0.003) than normal pregnant rat CD4+Tcells. Apocynin, an NADPH inhibitor, attenuated hypertension, and all oxidative stress markers in placental ischemic and normal pregnant recipient rats of placental ischemic CD4+Tcells (p=0.05). These data demonstrate an important role for CD4+T cells in mediating another factor, oxidative stress, to cause hypertension during preeclampsia. PMID:25259742

  17. Preclinical targeting of human T-cell malignancies using CD4-specific chimeric antigen receptor (CAR)-engineered T cells.

    PubMed

    Pinz, K; Liu, H; Golightly, M; Jares, A; Lan, F; Zieve, G W; Hagag, N; Schuster, M; Firor, A E; Jiang, X; Ma, Y

    2016-03-01

    Peripheral T-cell lymphomas (PTCLs) are aggressive lymphomas with no effective upfront standard treatment and ineffective options in relapsed disease, resulting in poorer clinical outcomes as compared with B-cell lymphomas. The adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) is a promising new approach for treatment of hematological malignancies. However, preclinical reports of targeting T-cell lymphoma with CARs are almost non-existent. Here we have designed a CAR, CD4CAR, which redirects the antigen specificity of CD8+ cytotoxic T cells to CD4-expressing cells. CD4CAR T cells derived from human peripheral blood mononuclear cells and cord blood effectively redirected T-cell specificity against CD4+ cells in vitro. CD4CAR T cells efficiently eliminated a CD4+ leukemic cell line and primary CD4+ PTCL patient samples in co-culture assays. Notably, CD4CAR T cells maintained a central memory stem cell-like phenotype (CD8+CD45RO+CD62L+) under standard culture conditions. Furthermore, in aggressive orthotropic T-cell lymphoma models, CD4CAR T cells efficiently suppressed the growth of lymphoma cells while also significantly prolonging mouse survival. Combined, these studies demonstrate that CD4CAR-expressing CD8+ T cells are efficacious in ablating malignant CD4+ populations, with potential use as a bridge to transplant or stand-alone therapy for the treatment of PTCLs.

  18. Preclinical targeting of human T-cell malignancies using CD4-specific chimeric antigen receptor (CAR)-engineered T cells.

    PubMed

    Pinz, K; Liu, H; Golightly, M; Jares, A; Lan, F; Zieve, G W; Hagag, N; Schuster, M; Firor, A E; Jiang, X; Ma, Y

    2016-03-01

    Peripheral T-cell lymphomas (PTCLs) are aggressive lymphomas with no effective upfront standard treatment and ineffective options in relapsed disease, resulting in poorer clinical outcomes as compared with B-cell lymphomas. The adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) is a promising new approach for treatment of hematological malignancies. However, preclinical reports of targeting T-cell lymphoma with CARs are almost non-existent. Here we have designed a CAR, CD4CAR, which redirects the antigen specificity of CD8+ cytotoxic T cells to CD4-expressing cells. CD4CAR T cells derived from human peripheral blood mononuclear cells and cord blood effectively redirected T-cell specificity against CD4+ cells in vitro. CD4CAR T cells efficiently eliminated a CD4+ leukemic cell line and primary CD4+ PTCL patient samples in co-culture assays. Notably, CD4CAR T cells maintained a central memory stem cell-like phenotype (CD8+CD45RO+CD62L+) under standard culture conditions. Furthermore, in aggressive orthotropic T-cell lymphoma models, CD4CAR T cells efficiently suppressed the growth of lymphoma cells while also significantly prolonging mouse survival. Combined, these studies demonstrate that CD4CAR-expressing CD8+ T cells are efficacious in ablating malignant CD4+ populations, with potential use as a bridge to transplant or stand-alone therapy for the treatment of PTCLs. PMID:26526988

  19. MicroRNA Profile of Circulating CD4-positive Regulatory T Cells in Human Adults and Impact of Differentially Expressed MicroRNAs on Expression of Two Genes Essential to Their Function*

    PubMed Central

    Fayyad-Kazan, Hussein; Rouas, Redouane; Fayyad-Kazan, Mohammad; Badran, Rabih; El Zein, Nabil; Lewalle, Philippe; Najar, Medhi; Hamade, Eva; Jebbawi, Fadi; Merimi, Makram; Romero, Pedro; Burny, Arsène; Badran, Bassam; Martiat, Philippe

    2012-01-01

    Regulatory T cells (Tregs) are characterized by a high expression of IL-2 receptor α chain (CD25) and of forkhead box P3 (FOXP3), the latter being essential for their development and function. Another major player in the regulatory function is the cytotoxic T-lymphocyte associated molecule-4 (CTLA-4) that inhibits cytotoxic responses. However, the regulation of CTLA-4 expression remains less well explored. We therefore studied the microRNA signature of circulating CD4+ Tregs isolated from adult healthy donors and identified a signature composed of 15 differentially expressed microRNAs. Among those, miR-24, miR-145, and miR-210 were down-regulated in Tregs compared with controls and were found to have potential target sites in the 3′-UTR of FOXP3 and CTLA-4; miR-24 and miR-210 negatively regulated FOXP3 expression by directly binding to their two target sites in its 3′-UTR. On the other hand, miR-95, which is highly expressed in adult peripheral blood Tregs, positively regulated FOXP3 expression via an indirect mechanism yet to be identified. Finally, we showed that miR-145 negatively regulated CTLA-4 expression in human CD4+ adult peripheral blood Tregs by binding to its target site in CTLA-4 transcript 3′-UTR. To our knowledge, this is the first identification of a human adult peripheral blood CD4+ Treg microRNA signature. Moreover, unveiling one mechanism regulating CTLA-4 expression is novel and may lead to a better understanding of the regulation of this crucial gene. PMID:22294691

  20. Evaluation of CD4+ T cells proliferating to grass pollen in seasonal allergic subjects by flow cytometry

    PubMed Central

    RIMANIOL, A C; GARCIA, G; TILL, S J; CAPEL, F; GRAS, G; BALABANIAN, K; EMILIE, D; HUMBERT, M

    2003-01-01

    Our objective was to characterize T-cell responses to Phleum pratense in grass pollen allergic individuals and healthy controls using the fluorescent dye PKH26. Peripheral blood mononuclear cells were stimulated with P. pratense, or with recall antigens, and CD3+/CD4+ and CD3+/CD8+ T-cells that had proliferated were analysed by flow cytometry. In the presence of P. pratense CD4+/CD3+ T-cells proliferated more in grass pollen sensitive atopic patients than in nonallergic controls or in nongrass pollen sensitive atopic subjects. PPD and TT recall antigens elicited uniformly high proliferation in all T-cell subsets. Only half of pollen sensitive patients also had an increased proliferation of CD3+/CD8+ T-cells in response to P. pratense. We determined precursor frequency of CD4+ T cells in the original population that responded to P. pratense and found values ranging from 1 × 10−3 to 0·6 × 10−1, in the same range as those measured for PPD and TT. In conclusion, grass pollen sensitive atopic patients show enhanced CD4+ T-cell reactivity to P. pratense, and this could be related to the presence of elevated numbers of circulating allergen-specific CD4+ T cells. This flow cytometric method should allow the identification of other phenotypic markers such as intracellular cytokines in allergen specific responding CD4+ T cells. PMID:12653839

  1. Activation requirements and responses to TLR ligands in human CD4+ T cells: comparison of two T cell isolation techniques.

    PubMed

    Lancioni, Christina L; Thomas, Jeremy J; Rojas, Roxana E

    2009-05-15

    Direct regulation of T cell function by microbial ligands through Toll-like receptors (TLR) is an emerging area of T cell biology. Currently either immunomagnetic cell sorting (IMACS) or fluorescence-activated cell sorting (FACS), are utilized to isolate T-cell subsets for such studies. However, it is unknown to what extent differences in T cell purity between these isolation techniques influence T cell functional assays. We compared the purity, response to mitogen, activation requirements, and response to TLR ligands between human CD4(+) T cells isolated either by IMACS (IMACS-CD4(+)) or by IMACS followed by FACS (IMACS/FACS-CD4(+)). As expected, IMACS-CD4(+) were less pure than IMACS/FACS-CD4(+) (92.5%+/-1.4% versus 99.7%+/-0.2%, respectively). Consequently, IMACS-CD4(+) proliferated and produced cytokines in response to mitogen alone and had lower activation requirements compared to IMACS/FACS-CD4(+). In addition IMACS-CD4(+) but not IMACS/FACS-CD4(+) responses were upregulated by the TLR-4 ligand lipopolysaccharide (LPS). On the other hand, TLR-2 and TLR-5 engagement induced costimulation in both IMACS-CD4(+) and highly purified IMACS-/FACS-CD4(+). Altogether these results indicate that small differences in cell purity can significantly alter T cell responses to TLR ligands. This study stresses the importance of a stringent purification method when investigating the role of microbial ligands in T cell function. PMID:19272393

  2. Antibody induced CD4 down-modulation of T cells is site-specifically mediated by CD64(+) cells.

    PubMed

    Vogel, Stephanie; Grabski, Elena; Buschjäger, Daniela; Klawonn, Frank; Döring, Marius; Wang, Junxi; Fletcher, Erika; Bechmann, Ingo; Witte, Torsten; Durisin, Martin; Schraven, Burkhart; Mangsbo, Sara M; Schönfeld, Kurt; Czeloth, Niklas; Kalinke, Ulrich

    2015-12-16

    Treatment of PBMC with the CD4-specific mAb BT-061 induces CD4 down-modulation of T cells. Here we report that addition of BT-061 to purified T cells did not confer this effect, whereas incubation of T cells in BT-061 coated wells restored CD4 down-modulation. These results implied that Fcγ receptor mediated cell-cell interactions played a role. In consistence with this hypothesis PBMC depleted of CD64(+) monocytes did not confer CD4 down-modulation of BT-061 decorated T cells. Strikingly, CD4 down-modulation was observed in BT-061 treated synovial fluid punctuated from patients' inflamed joints that comprised enhanced numbers of CD64(+) cells. In contrast, in a circulating whole blood system injection of BT-061 did not induce CD4 down-modulation, due to CD64 saturation by serum IgG. Similarly, tonsil derived mononuclear cells devoid of CD64(+) cells did not show CD4 down-modulation, whereas addition of blood derived monocytes restored the effect. Thus, the interaction of BT-061 decorated T cells with CD64(+) cells is needed for CD4 down-modulation, implying that in patients BT-061 would primarily induce CD4 down-modulation at inflammatory sites. These results highlight the need not only to examine the interaction of a given mAb with single FcγR, but also the immunological environment that is appropriate to support such interactions.

  3. Antibody induced CD4 down-modulation of T cells is site-specifically mediated by CD64(+) cells.

    PubMed

    Vogel, Stephanie; Grabski, Elena; Buschjäger, Daniela; Klawonn, Frank; Döring, Marius; Wang, Junxi; Fletcher, Erika; Bechmann, Ingo; Witte, Torsten; Durisin, Martin; Schraven, Burkhart; Mangsbo, Sara M; Schönfeld, Kurt; Czeloth, Niklas; Kalinke, Ulrich

    2015-01-01

    Treatment of PBMC with the CD4-specific mAb BT-061 induces CD4 down-modulation of T cells. Here we report that addition of BT-061 to purified T cells did not confer this effect, whereas incubation of T cells in BT-061 coated wells restored CD4 down-modulation. These results implied that Fcγ receptor mediated cell-cell interactions played a role. In consistence with this hypothesis PBMC depleted of CD64(+) monocytes did not confer CD4 down-modulation of BT-061 decorated T cells. Strikingly, CD4 down-modulation was observed in BT-061 treated synovial fluid punctuated from patients' inflamed joints that comprised enhanced numbers of CD64(+) cells. In contrast, in a circulating whole blood system injection of BT-061 did not induce CD4 down-modulation, due to CD64 saturation by serum IgG. Similarly, tonsil derived mononuclear cells devoid of CD64(+) cells did not show CD4 down-modulation, whereas addition of blood derived monocytes restored the effect. Thus, the interaction of BT-061 decorated T cells with CD64(+) cells is needed for CD4 down-modulation, implying that in patients BT-061 would primarily induce CD4 down-modulation at inflammatory sites. These results highlight the need not only to examine the interaction of a given mAb with single FcγR, but also the immunological environment that is appropriate to support such interactions. PMID:26670584

  4. Antibody induced CD4 down-modulation of T cells is site-specifically mediated by CD64+ cells

    PubMed Central

    Vogel, Stephanie; Grabski, Elena; Buschjäger, Daniela; Klawonn, Frank; Döring, Marius; Wang, Junxi; Fletcher, Erika; Bechmann, Ingo; Witte, Torsten; Durisin, Martin; Schraven, Burkhart; Mangsbo, Sara M.; Schönfeld, Kurt; Czeloth, Niklas; Kalinke, Ulrich

    2015-01-01

    Treatment of PBMC with the CD4-specific mAb BT-061 induces CD4 down-modulation of T cells. Here we report that addition of BT-061 to purified T cells did not confer this effect, whereas incubation of T cells in BT-061 coated wells restored CD4 down-modulation. These results implied that Fcγ receptor mediated cell-cell interactions played a role. In consistence with this hypothesis PBMC depleted of CD64+ monocytes did not confer CD4 down-modulation of BT-061 decorated T cells. Strikingly, CD4 down-modulation was observed in BT-061 treated synovial fluid punctuated from patients’ inflamed joints that comprised enhanced numbers of CD64+ cells. In contrast, in a circulating whole blood system injection of BT-061 did not induce CD4 down-modulation, due to CD64 saturation by serum IgG. Similarly, tonsil derived mononuclear cells devoid of CD64+ cells did not show CD4 down-modulation, whereas addition of blood derived monocytes restored the effect. Thus, the interaction of BT-061 decorated T cells with CD64+ cells is needed for CD4 down-modulation, implying that in patients BT-061 would primarily induce CD4 down-modulation at inflammatory sites. These results highlight the need not only to examine the interaction of a given mAb with single FcγR, but also the immunological environment that is appropriate to support such interactions. PMID:26670584

  5. Peripheral canine CD4(+)CD8(+) double-positive T cells - unique amongst others.

    PubMed

    von Buttlar, Heiner; Bismarck, Doris; Alber, Gottfried

    2015-12-15

    T lymphocytes co-expressing CD4 and CD8 ("double-positive T cells") are commonly associated with a thymic developmental stage of T cells. Their first description in humans and pigs as extrathymic T cells with a memory phenotype almost 30 years ago came as a surprise. Meanwhile peripheral double-positive T cells have been described in a growing number of different species. In this review we highlight novel data from our very recent studies on canine peripheral double-positive T cells which point to unique features of double-positive T cells in the dog. In contrast to porcine CD4(+)CD8(+) T cells forming a homogenous cellular population based on their expression of CD4 and CD8α, canine CD4(+)CD8(+) T cells can be divided into three different cellular subsets with distinct expression levels of CD4 and CD8α. Double-positive T cells expressing CD8β are present in humans and dogs but absent in swine. Moreover, canine CD4(+)CD8(+) T cells can not only develop from CD4(+) single-positive T cells but also from CD8(+) single-positive T cells. Together, this places canine CD4(+)CD8(+) T cells closer to their human than porcine counterparts since human double-positive T cells also appear to be heterogeneous in their CD4 and CD8α expression and have both CD4(+) and CD8(+) T cells as progenitor cells. However, CD4(+) single-positive T cells are the more potent progenitors for canine double-positive T cells, whereas CD8(+) single-positive T cells are more potent progenitors for human double-positive T cells. Canine double-positive T cells have an activated phenotype and may have as yet unrecognized roles in vivo in immunity to infection or in inflammatory diseases such as chronic infection, autoimmunity, allergy, or cancer.

  6. Exclusive Transduction of Human CD4+ T Cells upon Systemic Delivery of CD4-Targeted Lentiviral Vectors.

    PubMed

    Zhou, Qi; Uhlig, Katharina M; Muth, Anke; Kimpel, Janine; Lévy, Camille; Münch, Robert C; Seifried, Janna; Pfeiffer, Anett; Trkola, Alexandra; Coulibaly, Cheick; von Laer, Dorothee; Wels, Winfried S; Hartwig, Udo F; Verhoeyen, Els; Buchholz, Christian J

    2015-09-01

    Playing a central role in both innate and adaptive immunity, CD4(+) T cells are a key target for genetic modifications in basic research and immunotherapy. In this article, we describe novel lentiviral vectors (CD4-LV) that have been rendered selective for human or simian CD4(+) cells by surface engineering. When applied to PBMCs, CD4-LV transduced CD4(+) but not CD4(-) cells. Notably, also unstimulated T cells were stably genetically modified. Upon systemic or intrasplenic administration into mice reconstituted with human PBMCs or hematopoietic stem cells, reporter gene expression was predominantly detected in lymphoid organs. Evaluation of GFP expression in organ-derived cells and blood by flow cytometry demonstrated exclusive gene transfer into CD4(+) human lymphocytes. In bone marrow and spleen, memory T cells were preferentially hit. Toward therapeutic applications, we also show that CD4-LV can be used for HIV gene therapy, as well as for tumor therapy, by delivering chimeric Ag receptors. The potential for in vivo delivery of the FOXP3 gene was also demonstrated, making CD4-LV a powerful tool for inducible regulatory T cell generation. In summary, our work demonstrates the exclusive gene transfer into a T cell subset upon systemic vector administration opening an avenue toward novel strategies in immunotherapy.

  7. Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection

    PubMed Central

    Glennie, Nelson D.; Yeramilli, Venkata A.; Beiting, Daniel P.; Volk, Susan W.; Weaver, Casey T.

    2015-01-01

    Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. PMID:26216123

  8. Beta-catenin signaling mediates CD4 expression on mature CD8+ T cells.

    PubMed

    Schenkel, Jason M; Zloza, Andrew; Li, Wei; Narasipura, Srinivas D; Al-Harthi, Lena

    2010-08-15

    Upon activation, a subset of mature human CD8(+) T cells re-expresses CD4 dimly. This CD4(dim)CD8(bright) T cell population is genuine and enriched in antiviral CD8(+) T cell responses. The signaling pathway that leads to CD4 re-expression on mature CD8(+) T cells is not clear. Given that Wnt/beta-catenin signaling plays a critical role in the transition of CD4(-)CD8(-) to CD4(+)CD8(+) thymocytes, we determined whether beta-catenin mediates CD4 expression on mature CD8(+) T cells. We demonstrate that active beta-catenin expression is 20-fold higher on CD4(dim)CD8(bright) than CD4(-)CD8(+) T cells. Activation of beta-catenin signaling, through LiCl or transfection with a constitutively active construct of beta-catenin, induced CD4 on CD8(+) T cells by approximately 10-fold. Conversely, inhibition of beta-catenin signaling through transfection with a dominant-negative construct for T cell factor-4, a downstream effector of beta-catenin signaling, diminished CD4 expression on CD8(+) T cells by 50% in response to T cell activation. Beta-catenin-mediated induction of CD4 on CD8(+) T cells is transcriptionally regulated, as it induced CD4 mRNA, and T cell factor/lymphoid enhancer factor sites were identified within the human CD4 promoter. Further, beta-catenin expression induced the antiapoptotic factor BcL-xL, suggesting that beta-catenin may mediate protection against activation-induced cell death. Collectively, these data demonstrate that beta-catenin is critical in inducing CD4 expression on mature CD8(+) T cells, suggesting that it is a common pathway for CD4 upregulation among thymocytes and mature CD8(+) T cells. PMID:20631314

  9. CD4+ T-cell deficiency in HIV patients responding to antiretroviral therapy is associated with increased expression of interferon-stimulated genes in CD4+ T cells.

    PubMed

    Fernandez, Sonia; Tanaskovic, Sara; Helbig, Karla; Rajasuriar, Reena; Kramski, Marit; Murray, John M; Beard, Michael; Purcell, Damian; Lewin, Sharon R; Price, Patricia; French, Martyn A

    2011-12-15

    Most patients with human immunodeficiency virus (HIV) who remain CD4(+) T-cell deficient on antiretroviral therapy (ART) exhibit marked immune activation. As CD4(+) T-cell activation may be mediated by microbial translocation or interferon-alpha (IFN-α), we examined these factors in HIV patients with good or poor CD4(+) T-cell recovery on long-term ART. Messenger RNA levels for 3 interferon-stimulated genes were increased in CD4(+) T cells of patients with poor CD4(+) T-cell recovery, whereas levels in patients with good recovery did not differ from those in healthy controls. Poor CD4(+) T-cell recovery was also associated with CD4(+) T-cell expression of markers of activation, senescence, and apoptosis, and with increased serum levels of the lipopolysaccharide receptor and soluble CD14, but these were not significantly correlated with expression of the interferon-stimulated genes. Therefore, CD4(+) T-cell recovery may be adversely affected by the effects of IFN-α, which may be amenable to therapeutic intervention.

  10. Macrophages overexpressing Aire induce CD4+Foxp3+ T cells.

    PubMed

    Sun, Jitong; Fu, Haiying; Wu, Jing; Zhu, Wufei; Li, Yi; Yang, Wei

    2013-01-01

    Aire plays an important role in central immune tolerance by regulating the transcription of thousands of genes. However, the role of Aire in the peripheral immune system is poorly understood. Regulatory T (Treg) cells are considered essential for the maintenance of peripheral tolerance, but the effect of Aire on Treg cells in the peripheral immune system is currently unknown. In this study, we investigated the effects of macrophages overexpressing Aire on CD4+Foxp3+ Treg cells by co-culturing Aire-overexpressing RAW264.7 cells or their supernatant with splenocytes. The results show that macrophages overexpressing Aire enhanced the expression of Foxp3 mRNA and induced different subsets of Treg cells in splenocytes through cell-cell contact or a co-culture supernatants. TGF-β is a key molecule in the increases of CD4+CD45RA+Foxp3hi T cell and activating Treg (aTreg) levels observed following cell‑supernatant co-culturing. Subsets of Treg cells were induced by Aire-overexpressing macrophages, and the manipulation of Treg cells by the targeting of Aire may provide a method for the treatment of inflammatory or autoimmune diseases.

  11. CD4+ T Cell Help Selectively Enhances High-Avidity Tumor Antigen-Specific CD8+ T Cells.

    PubMed

    Zhu, Ziqiang; Cuss, Steven M; Singh, Vinod; Gurusamy, Devikala; Shoe, Jennifer L; Leighty, Robert; Bronte, Vincenzo; Hurwitz, Arthur A

    2015-10-01

    Maintaining antitumor immunity remains a persistent impediment to cancer immunotherapy. We and others have previously reported that high-avidity CD8(+) T cells are more susceptible to tolerance induction in the tumor microenvironment. In the present study, we used a novel model where T cells derived from two independent TCR transgenic mouse lines recognize the same melanoma antigenic epitope but differ in their avidity. We tested whether providing CD4(+) T cell help would improve T cell responsiveness as a function of effector T cell avidity. Interestingly, delivery of CD4(+) T cell help during in vitro priming of CD8(+) T cells improved cytokine secretion and lytic capacity of high-avidity T cells, but not low-avidity T cells. Consistent with this observation, copriming with CD4(+) T cells improved antitumor immunity mediated by higher avidity, melanoma-specific CD8(+) T cells, but not T cells with similar specificity but lower avidity. Enhanced tumor immunity was associated with improved CD8(+) T cell expansion and reduced tolerization, and it was dependent on presentation of both CD4(+) and CD8(+) T cell epitopes by the same dendritic cell population. Our findings demonstrate that CD4(+) T cell help preferentially augments high-avidity CD8(+) T cells and provide important insight for understanding the requirements to elicit and maintain durable tumor immunity.

  12. Regulated expression of human CD4 rescues helper T cell development in mice lacking expression of endogenous CD4.

    PubMed Central

    Killeen, N; Sawada, S; Littman, D R

    1993-01-01

    During T cell development, precursor thymocytes that co-express the CD4 and CD8 glycoproteins give rise to mature progeny expressing one of these molecules to the exclusion of the other. Continued expression of only CD4 is the hallmark of mature helper T cells, whereas cytotoxic T cells express CD8 and extinguish CD4. The differentiation program that generates the two T cell subsets is likely to be intimately tied to regulation of expression of these cell surface molecules. We now describe the use of a murine CD4 enhancer in the generation of transgenic mice expressing physiologic levels of human CD4. The transgene is appropriately regulated during T cell development and includes the necessary cis-acting sequences for extinguishing expression in the CD8 lineage. Furthermore, in mice whose endogenous CD4 gene is inactivated, the transgenic human CD4 mediates rescue of the CD4 lineage and restoration of normal helper cell functions. The generation of these mice exemplifies a general approach for developing reliable animal models for the human immune system. Images PMID:8467804

  13. Ex vivo analysis of human memory CD4 T cells specific for hepatitis C virus using MHC class II tetramers

    PubMed Central

    Day, Cheryl L.; Seth, Nilufer P.; Lucas, Michaela; Appel, Heiner; Gauthier, Laurent; Lauer, Georg M.; Robbins, Gregory K.; Szczepiorkowski, Zbigniew M.; Casson, Deborah R.; Chung, Raymond T.; Bell, Shannon; Harcourt, Gillian; Walker, Bruce D.; Klenerman, Paul; Wucherpfennig, Kai W.

    2003-01-01

    Containment of hepatitis C virus (HCV) and other chronic human viral infections is associated with persistence of virus-specific CD4 T cells, but ex vivo characterization of circulating CD4 T cells has not been achieved. To further define the phenotype and function of these cells, we developed a novel approach for the generation of tetrameric forms of MHC class II/peptide complexes that is based on the cellular peptide-exchange mechanism. HLA-DR molecules were expressed as precursors with a covalently linked CLIP peptide, which could be efficiently exchanged with viral peptides following linker cleavage. In subjects who spontaneously resolved HCV viremia, but not in those with chronic progressive infection, HCV tetramer–labeled cells could be isolated by magnetic bead capture despite very low frequencies (1:1,200 to 1:111,000) among circulating CD4 T cells. These T cells expressed a set of surface receptors (CCR7+CD45RA–CD27+) indicative of a surveillance function for secondary lymphoid structures and had undergone significant in vivo selection since they utilized a restricted Vβ repertoire. These studies demonstrate a relationship between clinical outcome and the presence of circulating CD4 T cells directed against this virus. Moreover, they show that rare populations of memory CD4 T cells can be studied ex vivo in human diseases. PMID:12975468

  14. Selective Loss of Early Differentiated, Highly Functional PD1high CD4 T Cells with HIV Progression

    PubMed Central

    Paris, Robert M.; Petrovas, Constantinos; Ferrando-Martinez, Sara; Moysi, Eirini; Boswell, Kristin L.; Archer, Eva; Yamamoto, Takuya; Ambrozak, David; Casazza, Joseph P.; Haubrich, Richard; Connors, Mark; Ake, Julie; Kim, Jerome H.; Koup, Richard A.

    2015-01-01

    The role of PD-1 expression on CD4 T cells during HIV infection is not well understood. Here, we describe the differential expression of PD-1 in CD127high CD4 T cells within the early/intermediate differentiated (EI) (CD27highCD45RAlow) T cell population among uninfected and HIV-infected subjects, with higher expression associated with decreased viral replication (HIV-1 viral load). A significant loss of circulating PD-1highCTLA-4low CD4 T cells was found specifically in the CD127highCD27highCD45RAlow compartment, while initiation of antiretroviral treatment, particularly in subjects with advanced disease, reversed these dynamics. Increased HIV-1 Gag DNA was also found in PD-1high compared to PD-1low ED CD4 T cells. In line with an increased susceptibility to HIV infection, PD-1 expression in this CD4 T cell subset was associated with increased activation and expression of the HIV co-receptor, CCR5. Rather than exhaustion, this population produced more IFN-g, MIP1-a, IL-4, IL-10, and IL-17a compared to PD-1low EI CD4 T cells. In line with our previous findings, PD-1high EI CD4 T cells were also characterized by a high expression of CCR7, CXCR5 and CCR6, a phenotype associated with increased in vitro B cell help. Our data show that expression of PD-1 on early-differentiated CD4 T cells may represent a population that is highly functional, more susceptible to HIV infection and selectively lost in chronic HIV infection. PMID:26678998

  15. Blimp-1-mediated CD4 T cell exhaustion causes CD8 T cell dysfunction during chronic toxoplasmosis.

    PubMed

    Hwang, SuJin; Cobb, Dustin A; Bhadra, Rajarshi; Youngblood, Ben; Khan, Imtiaz A

    2016-08-22

    CD8, but not CD4, T cells are considered critical for control of chronic toxoplasmosis. Although CD8 exhaustion has been previously reported in Toxoplasma encephalitis (TE)-susceptible model, our current work demonstrates that CD4 not only become exhausted during chronic toxoplasmosis but this dysfunction is more pronounced than CD8 T cells. Exhausted CD4 population expressed elevated levels of multiple inhibitory receptors concomitant with the reduced functionality and up-regulation of Blimp-1, a transcription factor. Our data demonstrates for the first time that Blimp-1 is a critical regulator for CD4 T cell exhaustion especially in the CD4 central memory cell subset. Using a tamoxifen-dependent conditional Blimp-1 knockout mixed bone marrow chimera as well as an adoptive transfer approach, we show that CD4 T cell-intrinsic deletion of Blimp-1 reversed CD8 T cell dysfunction and resulted in improved pathogen control. To the best of our knowledge, this is a novel finding, which demonstrates the role of Blimp-1 as a critical regulator of CD4 dysfunction and links it to the CD8 T cell dysfunctionality observed in infected mice. The critical role of CD4-intrinsic Blimp-1 expression in mediating CD4 and CD8 T cell exhaustion may provide a rational basis for designing novel therapeutic approaches. PMID:27481131

  16. Increased competition for antigen during priming negatively impacts the generation of memory CD4 T cells

    PubMed Central

    Blair, David A.; Lefrançois, Leo

    2007-01-01

    The factors involved in the differentiation of memory CD4 T cells from naïve precursors are poorly understood. We developed a system to examine the effect of increased competition for antigen by CD4 T cells on the generation of memory in response to infection with a recombinant vesicular stomatitis virus. Competition was initially regulated by increasing the precursor frequency of adoptively transferred naïve T cell antigen receptor transgenic CD4 T cells. Despite robust proliferation at high precursor frequencies, memory CD4 T cells did not develop, whereas decreasing the input number of naïve CD4 T cells promoted memory development after infection. The lack of memory development was linked to reduced blastogenesis and poor effector cell induction, but not to initial recruitment or proliferation of antigen-specific CD4 T cells. To prove that availability of antigen alone could regulate memory CD4 T cell development, we used treatment with an mAb specific for the epitope recognized by the transferred CD4 T cells. At high doses, this mAb effectively inhibited the antigen-specific CD4 T cell response. However, at a very low dose of mAb, primary CD4 T cell expansion was unaffected, although memory development was dramatically reduced. Moreover, the induction of effector function was concomitantly inhibited. Thus, competition for antigen during CD4 T cell priming is a major contributing factor to the development of the memory CD4 T cell pool. PMID:17827281

  17. Quantitative and qualitative characterization of expanded CD4+ T cell clones in rheumatoid arthritis patients

    PubMed Central

    Ishigaki, Kazuyoshi; Shoda, Hirofumi; Kochi, Yuta; Yasui, Tetsuro; Kadono, Yuho; Tanaka, Sakae; Fujio, Keishi; Yamamoto, Kazuhiko

    2015-01-01

    Rheumatoid arthritis (RA) is an autoimmune destructive arthritis associated with CD4+ T cell-mediated immunity. Although expanded CD4+ T cell clones (ECs) has already been confirmed, the detailed characteristics of ECs have not been elucidated in RA. Using combination of a single-cell analysis and next-generation sequencing (NGS) in TCR repertoire analysis, we here revealed the detailed nature of ECs by examining peripheral blood (PB) from 5 RA patients and synovium from 1 RA patient. When we intensively investigated the single-cell transcriptome of the most expanded clones in memory CD4+ T cells (memory-mECs) in RA-PB, senescence-related transcripts were up-regulated, indicating circulating ECs were constantly stimulated. Tracking of the transcriptome shift within the same memory-mECs between PB and the synovium revealed the augmentations in senescence-related gene expression and the up-regulation of synovium-homing chemokine receptors in the synovium. Our in-depth characterization of ECs in RA successfully demonstrated the presence of the specific immunological selection pressure, which determines the phenotype of ECs. Moreover, transcriptome tracking added novel aspects to the underlying sequential immune processes. Our approach may provide new insights into the pathophysiology of RA. PMID:26245356

  18. Impaired CD4 T Cell Memory Response to Streptococcus pneumoniae Precedes CD4 T Cell Depletion in HIV-Infected Malawian Adults

    PubMed Central

    Mzinza, David; Harawa, Visopo; Miles, David J. C.; Jambo, Kondwani C.; Gordon, Stephen B.; Williams, Neil A.; Heyderman, Robert S.

    2011-01-01

    Objective Invasive pneumococcal disease (IPD) is a leading cause of morbidity and mortality in HIV-infected African adults. CD4 T cell depletion may partially explain this high disease burden but those with relatively preserved T cell numbers are still at increased risk of IPD. This study evaluated the extent of pneumococcal-specific T cell memory dysfunction in asymptomatic HIV infection early on in the evolution of the disease. Methods Peripheral blood mononuclear cells were isolated from asymptomatic HIV-infected and HIV-uninfected Malawian adults and stained to characterize the underlying degree of CD4 T cell immune activation, senescence and regulation. Pneumococcal-specific T cell proliferation, IFN-γ, IL-17 production and CD154 expression was assessed using flow cytometry and ELISpot. Results We find that in asymptomatic HIV-infected Malawian adults, there is considerable immune disruption with an increase in activated and senescent CD4+CD38+PD-1+ and CD4+CD25highFoxp3+ Treg cells. In the context of high pneumococcal exposure and therefore immune stimulation, show a failure in pneumococcal-specific memory T cell proliferation, skewing of T cell cytokine production with preservation of interleukin-17 but decreased interferon-gamma responses, and failure of activated T cells to express the co-stimulatory molecule CD154. Conclusion Asymptomatic HIV-infected Malawian adults show early signs of pneumococcal- specific immune dysregulation with a shift in the balance of CD4 memory, T helper 17 cells and Treg. Together these data offer a mechanistic understanding of how antigen-specific T cell dysfunction occurs prior to T cell depletion and may explain the early susceptibility to IPD in those with relatively preserved CD4 T cell numbers. PMID:21980502

  19. TNF-α blockade induces IL-10 expression in human CD4+ T cells

    NASA Astrophysics Data System (ADS)

    Evans, Hayley G.; Roostalu, Urmas; Walter, Gina J.; Gullick, Nicola J.; Frederiksen, Klaus S.; Roberts, Ceri A.; Sumner, Jonathan; Baeten, Dominique L.; Gerwien, Jens G.; Cope, Andrew P.; Geissmann, Frederic; Kirkham, Bruce W.; Taams, Leonie S.

    2014-02-01

    IL-17+ CD4+ T (Th17) cells contribute to the pathogenesis of several human inflammatory diseases. Here we demonstrate that TNF inhibitor (TNFi) drugs induce the anti-inflammatory cytokine IL-10 in CD4+ T cells including IL-17+ CD4+ T cells. TNFi-mediated induction of IL-10 in IL-17+ CD4+ T cells is Treg-/Foxp3-independent, requires IL-10 and is overcome by IL-1β. TNFi-exposed IL-17+ CD4+ T cells are molecularly and functionally distinct, with a unique gene signature characterized by expression of IL10 and IKZF3 (encoding Aiolos). We show that Aiolos binds conserved regions in the IL10 locus in IL-17+ CD4+ T cells. Furthermore, IKZF3 and IL10 expression levels correlate in primary CD4+ T cells and Aiolos overexpression is sufficient to drive IL10 in these cells. Our data demonstrate that TNF-α blockade induces IL-10 in CD4+ T cells including Th17 cells and suggest a role for the transcription factor Aiolos in the regulation of IL-10 in CD4+ T cells.

  20. Itk Signals Promote Neuroinflammation by Regulating CD4+ T-Cell Activation and Trafficking

    PubMed Central

    Kannan, Arun K.; Kim, Do-Geun

    2015-01-01

    Here we demonstrate that interleukin-2-inducible T-cell kinase (Itk) signaling in cluster of differentiation 4-positive (CD4+) T cells promotes experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). We show that Itk−/− mice exhibit reduced disease severity, and transfer of Itk−/− CD4+ T cells into T cell-deficient recipients results in lower disease severity. We observed a significant reduction of CD4+ T cells in the CNS of Itk−/− mice or recipients of Itk−/− CD4+ T cells during EAE, which is consistent with attenuated disease. Itk−/− CD4+ T cells exhibit defective response to myelin antigen stimulation attributable to displacement of filamentous actin from the CD4+ coreceptor. This results in inadequate transmigration of Itk−/− CD4+ T cells into the CNS and across brain endothelial barriers in vitro. Finally, Itk−/− CD4+ T cells show significant reduction in production of T-helper 1 (Th1) and Th17 cytokines and exhibit skewed T effector/T regulatory cell ratios. These results indicate that signaling by Itk promotes autoimmunity and CNS inflammation, suggesting that it may be a viable target for treatment of MS. PMID:25568116

  1. Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells

    PubMed Central

    Provine, Nicholas M.; Larocca, Rafael A.; Aid, Malika; Penaloza-MacMaster, Pablo; Badamchi-Zadeh, Alexander; Borducchi, Erica N.; Yates, Kathleen B.; Abbink, Peter; Kirilova, Marinela; Ng’ang’a, David; Bramson, Jonathan; Haining, W. Nicholas

    2016-01-01

    CD4+ T cell help is critical for optimal CD8+ T cell memory differentiation and maintenance in many experimental systems. In addition, many reports have identified reduced primary CD8+ T cell responses in the absence of CD4+ T cell help, which often coincides with reduced Ag or pathogen clearance. In this study, we demonstrate that absence of CD4+ T cells at the time of adenovirus vector immunization of mice led to immediate impairments in early CD8+ T cell functionality and differentiation. Unhelped CD8+ T cells exhibited a reduced effector phenotype, decreased ex vivo cytotoxicity, and decreased capacity to produce cytokines. This dysfunctional state was imprinted within 3 d of immunization. Unhelped CD8+ T cells expressed elevated levels of inhibitory receptors and exhibited transcriptomic exhaustion and anergy profiles by gene set enrichment analysis. Dysfunctional, impaired effector differentiation also occurred following immunization of CD4+ T cell–deficient mice with a poxvirus vector. This study demonstrates that following priming with viral vectors, CD4+ T cell help is required to promote both the expansion and acquisition of effector functions by CD8+ T cells, which is accomplished by preventing immediate dysfunction. PMID:27448585

  2. CD4+ invariant natural killer T cells protect from murine GVHD lethality through expansion of donor CD4+CD25+FoxP3+ regulatory T cells.

    PubMed

    Schneidawind, Dominik; Pierini, Antonio; Alvarez, Maite; Pan, Yuqiong; Baker, Jeanette; Buechele, Corina; Luong, Richard H; Meyer, Everett H; Negrin, Robert S

    2014-11-20

    Dysregulated donor T cells lead to destruction of host tissues resulting in graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). We investigated the impact of highly purified (>95%) donor CD4(+) invariant natural killer T (iNKT) cells on GVHD in a murine model of allogeneic HCT. We found that low doses of adoptively transferred donor CD4(+) iNKT cells protect from GVHD morbidity and mortality through an expansion of donor CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs). These Tregs express high levels of the Ikaros transcription factor Helios and expand from the Treg pool of the donor graft. Furthermore, CD4(+) iNKT cells preserve T-cell-mediated graft-versus-tumor effects. Our studies reveal new aspects of the cellular interplay between iNKT cells and Tregs in the context of tolerance induction after allogeneic HCT and set the stage for clinical translation. PMID:25293774

  3. A novel differentiation pathway from CD4T cells to CD4T cells for maintaining immune system homeostasis.

    PubMed

    Zhao, X; Sun, G; Sun, X; Tian, D; Liu, K; Liu, T; Cong, M; Xu, H; Li, X; Shi, W; Tian, Y; Yao, J; Guo, H; Zhang, D

    2016-01-01

    CD4(+) T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4(+) T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4(-)CD8(-)NK1.1(-) double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4(+) rather than CD8(+) T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4(+) T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases. PMID:27077809

  4. Use of MHC class II tetramers to investigate CD4+ T cell responses: problems and solutions.

    PubMed

    Cecconi, Virginia; Moro, Monica; Del Mare, Sara; Dellabona, Paolo; Casorati, Giulia

    2008-11-01

    MHC-class I tetramers technology enabled the characterization of peptide-specific T cells at the single cell level in a variety of studies. Several laboratories have also developed MHC-class II multimers to characterize Ag-specific CD4+ T cells. However, the generation and use of MHC-class II multimers seems more problematic than that of MHC-I multimers. We have generated HLA-DR*1101 tetramers in a versatile empty form, which can be loaded after purification with peptides of interest. We discuss the impact of critical biological and structural parameters for the optimal staining of Ag-specific CD4+ T cells using HLA-DR*1101 tetramers, such as: (i) activation state of CD4+ T cells; (ii) membrane trafficking in the target CD4+ T cells; (iii) binding characteristics of the loaded CD4 epitope. Our data indicate that reorganization of TCR on the plasma membrane upon CD4+ T cell activation, as well as an homogenous binding frame of the CD4 epitopes to the soluble HLA-DR monomer, are critical for a stable TCR/MHC-class II tetramer interaction. These factors, together with the low frequencies and affinities of specific CD4+ T cells, explain the need for in vitro expansion or ex vivo enrichment of specific T cells for the optimal visualization with MHC-class II tetramers. PMID:18612991

  5. Polyfunctional cytokine responses by central memory CD4+T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. Mycobacterium ...

  6. Polyfunctional cytokine responses by central memory CD4*T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB. Mycobacterium bovis in...

  7. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), Interleukin-2 (IL-2) and Tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the a...

  8. Transmission of survival signals through Delta-like 1 on activated CD4+ T cells

    PubMed Central

    Furukawa, Takahiro; Ishifune, Chieko; Tsukumo, Shin-ichi; Hozumi, Katsuto; Maekawa, Yoichi; Matsui, Naoko; Kaji, Ryuji; Yasutomo, Koji

    2016-01-01

    Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remains unclear. In this report we demonstrate that the CD4+ T cell Notch ligand Dll1 transduces signals required for their survival. Co-transfer of CD4+ T cells from Dll1−/− and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1−/− mice compared with control cells. Dll1−/− mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1−/− mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data demonstrate that Dll1 is an independent regulator of Notch-signaling important for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses. PMID:27659682

  9. The Interplay Between Monocytes/Macrophages and CD4+ T Cell Subsets in Rheumatoid Arthritis

    PubMed Central

    Roberts, Ceri A.; Dickinson, Abigail K.; Taams, Leonie S.

    2015-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation of the synovial lining (synovitis). The inflammation in the RA joint is associated with and driven by immune cell infiltration, synovial hyperproliferation, and excessive production of proinflammatory mediators, such as tumor necrosis factor α (TNFα), interferon γ (IFNγ), interleukin (IL)-1β, IL-6, and IL-17, eventually resulting in damage to the cartilage and underlying bone. The RA joint harbors a wide range of immune cell types, including monocytes, macrophages, and CD4+ T cells (both proinflammatory and regulatory). The interplay between CD14+ myeloid cells and CD4+ T cells can significantly influence CD4+ T cell function, and conversely, effector vs. regulatory CD4+ T cell subsets can exert profound effects on monocyte/macrophage function. In this review, we will discuss how the interplay between CD4+ T cells and monocytes/macrophages may contribute to the immunopathology of RA. PMID:26635790

  10. CD4 T Cell Help via B Cells Is Required for Lymphopenia-Induced CD8 T Cell Proliferation.

    PubMed

    Ayasoufi, Katayoun; Fan, Ran; Fairchild, Robert L; Valujskikh, Anna

    2016-04-01

    Ab-mediated lymphoablation is commonly used in solid organ and hematopoietic cell transplantation. However, these strategies fail to control pathogenic memory T cells efficiently and to improve long-term transplant outcomes significantly. Understanding the mechanisms of T cell reconstitution is critical for enhancing the efficacy of Ab-mediated depletion in sensitized recipients. Using a murine analog of anti-thymocyte globulin (mATG) in a mouse model of cardiac transplantation, we previously showed that peritransplant lymphocyte depletion induces rapid memory T cell proliferation and only modestly prolongs allograft survival. We now report that T cell repertoire following depletion is dominated by memory CD4 T cells. Additional depletion of these residual CD4 T cells severely impairs the recovery of memory CD8 T cells after mATG treatment. The CD4 T cell help during CD8 T cell recovery depends on the presence of B cells expressing CD40 and intact CD40/CD154 interactions. The requirement for CD4 T cell help is not limited to the use of mATG in heart allograft recipients, and it is observed in nontransplanted mice and after CD8 T cell depletion with mAb instead of mATG. Most importantly, limiting helper signals increases the efficacy of mATG in controlling memory T cell expansion and significantly extends heart allograft survival in sensitized recipients. Our findings uncover the novel role for helper memory CD4 T cells during homeostatic CD8 T cell proliferation and open new avenues for optimizing lymphoablative therapies in allosensitized patients.

  11. Therapeutic Potential of Hyporesponsive CD4+ T Cells in Autoimmunity

    PubMed Central

    Maggi, Jaxaira; Schafer, Carolina; Ubilla-Olguín, Gabriela; Catalán, Diego; Schinnerling, Katina; Aguillón, Juan C.

    2015-01-01

    The interaction between dendritic cells (DCs) and T cells is crucial on immunity or tolerance induction. In an immature or semi-mature state, DCs induce tolerance through T-cell deletion, generation of regulatory T cells, and/or induction of T-cell anergy. Anergy is defined as an unresponsive state that retains T cells in an “off” mode under conditions in which immune activation is undesirable. This mechanism is crucial for the control of T-cell responses against self-antigens, thereby preventing autoimmunity. Tolerogenic DCs (tDCs), generated in vitro from peripheral blood monocytes of healthy donors or patients with autoimmune pathologies, were shown to modulate immune responses by inducing T-cell hyporesponsiveness. Animal models of autoimmune diseases confirmed the impact of T-cell anergy on disease development and progression in vivo. Thus, the induction of T-cell hyporesponsiveness by tDCs has become a promising immunotherapeutic strategy for the treatment of T-cell-mediated autoimmune disorders. Here, we review recent findings in the area and discuss the potential of anergy induction for clinical purposes. PMID:26441992

  12. The frequency of α4β7high memory CD4+ T cells correlates with susceptibility to rectal SIV infection

    PubMed Central

    Martinelli, Elena; Veglia, Filippo; Goode, Diana; Guerra-Perez, Natalia; Aravantinou, Meropi; Arthos, James; Piatak, Michael; Lifson, Jeffrey D.; Blanchard, James; Gettie, Agegnehu; Robbiani, Melissa

    2013-01-01

    Background Integrin α4β7 (α4β7) mediates the homing of CD4+ T cells to gut-associated lymphoid tissues (GALT), which constitute a highly favorable environment for HIV expansion and dissemination. HIV and SIV envelope proteins bind to and signal through α4β7 and during acute infection SIV preferentially infects α4β7high CD4+ T cells. We postulated that the availability of these cells at the time of challenge could influence mucosal SIV transmission and acute viral load (VL). Methods We challenged 17 rhesus macaques with 3000 TCID50 of SIVmac239 rectally and followed the subsets of α4β7+ T and dendritic cells (DCs) by flow cytometry in blood and tissues, before and after challenge. Results We found that the frequency of memory CD4+ T cells that expressed high levels of α4β7 (α4β7high memory CD4+ T cells) in blood before challenge correlated strongly with susceptibility to infection and acute VL. Notably, not only at the time of challenge, but also their frequency 3 weeks before challenge correlated with infection. This association extended to the rectal tissue as we observed a strong direct correlation between the frequency of α4β7high memory CD4+ T cells in blood and rectum before and after challenge. The frequency of α4β7+ myeloid DCs and α4β7high CD80+ DCs also correlated with infection and acute VL, while blood CCR5+ and CD69+ CD4+ T cells could not be associated with infection. Conclusions Our results suggest that animals with higher frequency of α4β7high CD4+ T cells in circulation and in rectal tissue could be more susceptible to SIV rectal transmission. PMID:23797688

  13. The ion channel TRPV1 regulates the activation and proinflammatory properties of CD4+ T cells

    PubMed Central

    Bertin, Samuel; Aoki-Nonaka, Yukari; de Jong, Petrus Rudolf; Stanwood, Shawna R.; Srikanth, Sonal; Lee, Jihyung; To, Keith; Abramson, Lior; Yu, Timothy; Han, Tiffany; Touma, Ranim; Li, Xiangli; González-Navajas, José M.; Herdman, Scott; Corr, Maripat; Fu, Guo; Dong, Hui; Gwack, Yousang; Franco, Alessandra; Jefferies, Wilfred A.; Raz, Eyal

    2016-01-01

    TRPV1 is a Ca2+-permeable channel mostly studied as a pain receptor in sensory neurons. However, its role in other cell types is poorly understood. Here, we demonstrate that TRPV1 is functionally expressed in CD4+ T cells where it acts as a non-store-operated Ca2+ channel and contributes to T cell receptor (TCR)-induced Ca2+ influx, TCR signaling and T cell activation. In models of T cell-mediated colitis, TRPV1 promotes colitogenic T cell responses and intestinal inflammation. Furthermore, genetic and pharmacological inhibition of TRPV1 in human CD4+ T cells recapitulates the phenotype of murine Trpv1−/− CD4+ T cells. These findings suggest that TRPV1 inhibition could represent a new therapeutic strategy to restrain proinflammatory T cell responses. PMID:25282159

  14. Myeloid dendritic cells induce HIV-1 latency in non-proliferating CD4+ T cells.

    PubMed

    Evans, Vanessa A; Kumar, Nitasha; Filali, Ali; Procopio, Francesco A; Yegorov, Oleg; Goulet, Jean-Philippe; Saleh, Suha; Haddad, Elias K; da Fonseca Pereira, Candida; Ellenberg, Paula C; Sekaly, Rafick-Pierre; Cameron, Paul U; Lewin, Sharon R

    2013-01-01

    Latently infected resting CD4(+) T cells are a major barrier to HIV cure. Understanding how latency is established, maintained and reversed is critical to identifying novel strategies to eliminate latently infected cells. We demonstrate here that co-culture of resting CD4(+) T cells and syngeneic myeloid dendritic cells (mDC) can dramatically increase the frequency of HIV DNA integration and latent HIV infection in non-proliferating memory, but not naïve, CD4(+) T cells. Latency was eliminated when cell-to-cell contact was prevented in the mDC-T cell co-cultures and reduced when clustering was minimised in the mDC-T cell co-cultures. Supernatants from infected mDC-T cell co-cultures did not facilitate the establishment of latency, consistent with cell-cell contact and not a soluble factor being critical for mediating latent infection of resting CD4(+) T cells. Gene expression in non-proliferating CD4(+) T cells, enriched for latent infection, showed significant changes in the expression of genes involved in cellular activation and interferon regulated pathways, including the down-regulation of genes controlling both NF-κB and cell cycle. We conclude that mDC play a key role in the establishment of HIV latency in resting memory CD4(+) T cells, which is predominantly mediated through signalling during DC-T cell contact.

  15. IL-7 signaling imparts polyfunctionality and stemness potential to CD4(+) T cells.

    PubMed

    Ding, Zhi-Chun; Liu, Chufeng; Cao, Yang; Habtetsion, Tsadik; Kuczma, Michal; Pi, Wenhu; Kong, Heng; Cacan, Ercan; Greer, Susanna F; Cui, Yan; Blazar, Bruce R; Munn, David H; Zhou, Gang

    2016-06-01

    The functional status of CD4(+) T cells is a critical determinant of antitumor immunity. Polyfunctional CD4(+) T cells possess the ability to concomitantly produce multiple Th1-type cytokines, exhibiting a functional attribute desirable for cancer immunotherapy. However, the mechanisms by which these cells are induced are neither defined nor it is clear if these cells can be used therapeutically to treat cancer. Here, we report that CD4(+) T cells exposed to exogenous IL-7 during antigenic stimulation can acquire a polyfunctional phenotype, characterized by their ability to simultaneously express IFNγ, IL-2, TNFα and granzyme B. This IL-7-driven polyfunctional phenotype was associated with increased histone acetylation in the promoters of the effector genes, indicative of increased chromatin accessibility. Moreover, forced expression of a constitutively active (CA) form of STAT5 recapitulated IL-7 in inducing CD4(+) T-cell polyfunctionality. Conversely, the expression of a dominant negative (DN) form of STAT5 abolished the ability of IL-7 to induce polyfunctional CD4(+) T cells. These in-vitro-generated polyfunctional CD4(+) T cells can traffic to tumor and expand intratumorally in response to immunization. Importantly, adoptive transfer of polyfunctional CD4(+) T cells following lymphodepletive chemotherapy was able to eradicate large established tumors. This beneficial outcome was associated with the occurrence of antigen epitope spreading, activation of the endogenous CD8(+) T cells and persistence of donor CD4(+) T cells exhibiting memory stem cell attributes. These findings indicate that IL-7 signaling can impart polyfunctionality and stemness potential to CD4(+) T cells, revealing a previously unknown property of IL-7 that can be exploited in adoptive T-cell immunotherapy.

  16. The CD4+ T cell methylome contributes to a distinct CD4+ T cell transcriptional signature in Mycobacterium bovis-infected cattle

    PubMed Central

    Doherty, Rachael; Whiston, Ronan; Cormican, Paul; Finlay, Emma K.; Couldrey, Christine; Brady, Colm; O’Farrelly, Cliona; Meade, Kieran G.

    2016-01-01

    We hypothesised that epigenetic regulation of CD4+ T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4+ T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4+ T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4+ T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4+ T cell response during mycobacterial infection in cattle. PMID:27507428

  17. The CD4(+) T cell methylome contributes to a distinct CD4(+) T cell transcriptional signature in Mycobacterium bovis-infected cattle.

    PubMed

    Doherty, Rachael; Whiston, Ronan; Cormican, Paul; Finlay, Emma K; Couldrey, Christine; Brady, Colm; O'Farrelly, Cliona; Meade, Kieran G

    2016-01-01

    We hypothesised that epigenetic regulation of CD4(+) T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4(+) T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4(+) T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4(+) T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4(+) T cell response during mycobacterial infection in cattle. PMID:27507428

  18. Stephanthraniline A suppressed CD4(+) T cell-mediated immunological hepatitis through impairing PKCθ function.

    PubMed

    Chen, Feng-Yang; Zhou, Li-Fei; Li, Xiao-Yu; Zhao, Jia-Wen; Xu, Shi-Fang; Huang, Wen-Hai; Gao, Li-Juan; Hao, Shu-Juan; Ye, Yi-Ping; Sun, Hong-Xiang

    2016-10-15

    Stephanthraniline A (STA), a C21 steroid isolated from Stephanotis mucronata (Blanco) Merr., was previously shown to inhibit T cells activation and proliferation in vitro and in vivo. The purpose of this study was to further evaluate the in vivo immunosuppressive activity of STA and to elucidate its potential mechanisms. The results showed that pretreatment with STA significantly attenuated concanavalin A (Con A)-induced hepatitis and reduced CD4(+) T cells activation and aggregation in hepatic tissue in mice. STA directly suppressed the activation and proliferation of Con A-induced CD4(+) T cells, and inhibited NFAT, NFκB and MAPK signaling cascades in activated CD4(+) T cells in vitro. Moreover, it was proved that STA inhibited T cells activation and proliferation through proximal T cell-receptor (TCR) signaling- and Ca(2+) signaling-independent way. The molecular docking studies predicted that STA could tight bind to PKCθ via five hydrogen. The further findings indicated STA directly inhibited PKCθ kinase activity, and its phosphorylation in activated CD4(+) T cells in vitro. Collectively, the present study indicated that STA could protect against CD4(+) T cell-mediated immunological hepatitis in mice through PKCθ and its downstream NFAT, NFκB and MAPK signaling cascades. These results highlight the potential of STA as an effective leading compound for use in the treatment of CD4(+) T cell-mediated inflammatory and autoimmune diseases.

  19. Memory CD4+ T cells do not induce graft-versus-host disease.

    PubMed

    Anderson, Britt E; McNiff, Jennifer; Yan, Jun; Doyle, Hester; Mamula, Mark; Shlomchik, Mark J; Shlomchik, Warren D

    2003-07-01

    Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality in allogeneic stem cell transplantation (alloSCT). Donor T cells that accompany stem cell grafts cause GVHD by attacking recipient tissues; therefore, all patients receive GVHD prophylaxis by depletion of T cells from the allograft or through immunosuppressant drugs. In addition to providing a graft-versus-leukemia effect, donor T cells are critical for reconstituting T cell-mediated immunity. Ideally, immunity to infectious agents would be transferred from donor to host without GVHD. Most donors have been exposed to common pathogens and have an increased precursor frequency of memory T cells against pathogenic antigens. We therefore asked whether memory CD62L-CD44+ CD4+ T cells would induce less GVHD than unfractionated or naive CD4+ T cells. Strikingly, we found that memory CD4 cells induced neither clinical nor histologic GVHD. This effect was not due to the increased number of CD4+CD25+ regulatory T cells found in the CD62L-CD44+ fraction because memory T cells depletion of these cells did not cause GVHD. Memory CD4 cells engrafted and responded to antigen both in vivo and in vitro. If these murine results are applicable to human alloSCT, selective administration of memory T cells could greatly improve post-transplant immune reconstitution.

  20. Characterization of CD4+ T cell subsets in allergy

    PubMed Central

    Wambre, Erik; James, Eddie A; Kwok, William W

    2013-01-01

    Allergen specific TH2 cells are a key component of allergic disease, but their characterization has been hindered by technical limitations and lack of epitope data. Knowledge about the factors that drive the differentiation of naïve T cells into allergy-promoting TH2 cells and the influence of allergen specific immunotherapy on the phenotype and function of allergen-specific T cells have also been limited. Recent advances indicate that innate and adaptive immune factors drive the development of diverse subsets of allergen-specific T cells. While allergen-specific T cells are present even in non-allergic subjects, highly differentiated TH2 cells are present only in allergic subjects and their disappearance correlates with successful immunotherapy. Therefore, elimination of pathogenic TH2 cells is an essential step in tolerance induction. PMID:22889592

  1. Tapping CD4 T cells for cancer immunotherapy: the choice of personalized genomics.

    PubMed

    Zanetti, Maurizio

    2015-03-01

    Cellular immune responses that protect against tumors typically have been attributed to CD8 T cells. However, CD4 T cells also play a central role. It was shown recently that, in a patient with metastatic cholangiocarcinoma, CD4 T cells specific for a peptide from a mutated region of ERBB2IP could arrest tumor progression. This and other recent findings highlight new opportunities for CD4 T cells in cancer immunotherapy. In this article, I discuss the role and regulation of CD4 T cells in response to tumor Ags. Emphasis is placed on the types of Ags and mechanisms that elicit tumor-protective responses. I discuss the advantages and drawbacks of cancer immunotherapy through personalized genomics. These considerations should help to guide the design of next-generation therapeutic cancer vaccines.

  2. HIVgp120 activates autoreactive CD4-specific T cell responses by unveiling of hidden CD4 peptides during processing

    PubMed Central

    1995-01-01

    T cells are made tolerant only to those self-peptides that are presented in sufficient amounts by antigen-presenting cells. They ignore cryptic self-determinants, such as either those not generated by processing machinery or generated in insufficient amounts. It is anticipated that mechanisms that either change antigen processing or increase the yield of previously "invisible" peptides may be capable of inducing T cell priming and, if they are self-maintained, may sustain autoimmune diseases. Herein, we demonstrate for the first time a mechanism by which the gp120 human immunodeficiency virus-I, by downregulating plasma membrane CD4 and increasing its processing, unveils hidden CD4 epitopes, inducing an autoimmune-specific T cell response. PMID:7760011

  3. Sequestration from Immune CD4^+ T Cells of Mycobacteria Growing in Human Macrophages

    NASA Astrophysics Data System (ADS)

    Pancholi, Preeti; Mirza, Asra; Bhardwaj, Nina; Steinman, Ralph M.

    1993-05-01

    CD4^+ helper T cells mediate resistance to tuberculosis, presumably by enhancing the antimicrobial activity of macrophages within which the Mycobacterium tuberculosis organism grows. A first step in resistance should be the presentation of mycobacterial antigens by macrophages to CD4^+ T cells. However, when the antigenic stimulus is limited to organisms growing in human monocytes, the organisms become sequestered from immune CD4^+ T cells. This block in presentation is selective for growing mycobacteria and not for other stimuli. Sequestration would allow replicating organisms to persist in infected individuals and may contribute to virulence.

  4. Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

    NASA Astrophysics Data System (ADS)

    Shedlock, Devon J.; Shen, Hao

    2003-04-01

    Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4-/- hosts, whereas memory CD8 cells generated in CD4-/- mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.

  5. Immune activation induces immortalization of HTLV-1 LTR-Tax transgenic CD4+ T cells.

    PubMed

    Swaims, Alison Y; Khani, Francesca; Zhang, Yingyu; Roberts, Arthur I; Devadas, Satish; Shi, Yufang; Rabson, Arnold B

    2010-10-21

    Infection with the human T-cell leukemia virus-1 (HTLV-1) results in a variety of diseases including adult T-cell leukemia/lymphoma (ATL). Although the pathogenesis of these disorders is poorly understood, it involves complex interactions with the host immune system. Activation of infected T cells may play an important role in disease pathogenesis through induction of the oncogenic HTLV-1 Tax transactivator protein. To test this hypothesis, we employed transgenic mice in which Tax is regulated by the HTLV-1 LTR. T-cell receptor stimulation of LTR-Tax CD4(+) T cells induced Tax expression, hyper-proliferation, and immortalization in culture. The transition to cellular immortalization was accompanied by markedly increased expression of the antiapoptotic gene, mcl-1, previously implicated as important in T-cell survival. Immortalized cells exhibited a CD4(+)CD25(+)CD3(-) phenotype commonly observed in ATL. Engraftment of activated LTR-Tax CD4(+) T cells into NOD/Shi-scid/IL-2Rγ null mice resulted in a leukemia-like phenotype with expansion and tissue infiltration of Tax(+), CD4(+) lymphocytes. We suggest that immune activation of infected CD4(+) T cells plays an important role in the induction of Tax expression, T-cell proliferation, and pathogenesis of ATL in HTLV-1-infected individuals. PMID:20634377

  6. Allergic Sensitization Underlies Hyperreactive Antigen-Specific CD4+ T Cell Responses in Coincident Filarial Infection.

    PubMed

    Gazzinelli-Guimarães, Pedro H; Bonne-Année, Sandra; Fujiwara, Ricardo T; Santiago, Helton C; Nutman, Thomas B

    2016-10-01

    Among the various hypotheses put forward to explain the modulatory influence of helminth infection on allergic effector responses in humans, the IL-10-induced suppression of Th2-associated responses has been the leading candidate. To explore this helminth/allergy interaction more fully, parasite- and allergen-specific CD4(+) T cell responses in 12 subjects with filarial infections, and coincident allergic sensitization (filarial [Fil](+)allergy [A](+)) were compared with the responses to three appropriate control groups (Fil(-)A(-) [n = 13], Fil(-)A(+) [n = 12], Fil(+)A(-) [n = 11]). The most important findings revealed that Fil(+)A(+) had marked (p < 0.0001 for all cytokines) increases in parasite Ag-driven Th2 (IL-4, IL-5, IL-13), Th9 (IL-9), and the regulatory (IL-10) cytokines when compared with Fil(+)A(-) Moreover, using multiparameter flow cytometry, filarial parasite Ag induced a marked increase in not only the frequency of CD4(+) T cells producing IL-4, IL-5, IL-2, and TNF-α in Fil(+)A(+) when compared with Fil(+)A(-) patients, but also in the frequencies of polyfunctional Th2-like (CD4(+)IL-4(+)IL-5(+) and CD4(+)IL-2(+)IL-4(+)IL-5(+)TNF-α(+)) cells. The Th2-associated responses seen in the Fil(+)A(+) group were correlated with serum IgE levels (p < 0.01, r = 0.5165 for IL-4; p < 0.001, r = 0.5544 for IL-5; and p < 0.001, r = 0.4901 for IL-13) and levels of circulating eosinophils (p < 0.0116, r = 0.5656) and their degranulation/activation products (major basic protein [p < 0.001, r = 0.7353] and eosinophil-derived neurotoxin [p < 0.01, r = 0.7059]). CD4(+) responses to allergen were not different (to a large extent) among the groups. Taken together, our data suggest that allergic sensitization coincident with filarial infection drives parasite Ag-specific T cell hyperresponsiveness, which is characterized largely by an augmented Th2-dominated immune response. PMID:27566825

  7. SAMHD1 restricts HIV-1 reverse transcription in quiescent CD4+ T-cells

    PubMed Central

    2012-01-01

    Background Quiescent CD4+ T lymphocytes are highly refractory to HIV-1 infection due to a block at reverse transcription. Results Examination of SAMHD1 expression in peripheral blood lymphocytes shows that SAMHD1 is expressed in both CD4+ and CD8+ T cells at levels comparable to those found in myeloid cells. Treatment of CD4+ T cells with Virus-Like Particles (VLP) containing Vpx results in the loss of SAMHD1 expression that correlates with an increased permissiveness to HIV-1 infection and accumulation of reverse transcribed viral DNA without promoting transcription from the viral LTR. Importantly, CD4+ T-cells from patients with Aicardi-Goutières Syndrome harboring mutation in the SAMHD1 gene display an increased susceptibility to HIV-1 infection that is not further enhanced by VLP-Vpx-treatment. Conclusion Here, we identified SAMHD1 as the restriction factor preventing efficient viral DNA synthesis in non-cycling resting CD4+ T-cells. These results highlight the crucial role of SAMHD1 in mediating restriction of HIV-1 infection in quiescent CD4+ T-cells and could impact our understanding of HIV-1 mediated CD4+ T-cell depletion and establishment of the viral reservoir, two of the HIV/AIDS hallmarks. PMID:23092122

  8. Regulatory T cells prevent CD8 T cell maturation by inhibiting CD4 Th cells at tumor sites.

    PubMed

    Chaput, Nathalie; Darrasse-Jèze, Guillaume; Bergot, Anne-Sophie; Cordier, Corinne; Ngo-Abdalla, Stacie; Klatzmann, David; Azogui, Orly

    2007-10-15

    Natural regulatory T cells (Tregs) are present in high frequencies among tumor-infiltrating lymphocytes and in draining lymph nodes, supposedly facilitating tumor development. To investigate their role in controlling local immune responses, we analyzed intratumoral T cell accumulation and function in the presence or absence of Tregs. Tumors that grew in normal BALB/c mice injected with the 4T1 tumor cell line were highly infiltrated by Tregs, CD4 and CD8 cells, all having unique characteristics. Most infiltrating Tregs expressed low levels of CD25Rs and Foxp3. They did not proliferate even in the presence of IL-2 but maintained a strong suppressor activity. CD4 T cells were profoundly anergic and CD8 T cell proliferation and cytotoxicity were severely impaired. Depletion of Tregs modified the characteristics of tumor infiltrates. Tumors were initially invaded by activated CD4(+)CD25(-) T cells, which produced IL-2 and IFN-gamma. This was followed by the recruitment of highly cytotoxic CD8(+) T cells at tumor sites leading to tumor rejection. The beneficial effect of Treg depletion in tumor regression was abrogated when CD4 helper cells were also depleted. These findings indicate that the massive infiltration of tumors by Tregs prevents the development of a successful helper response. The Tregs in our model prevent Th cell activation and subsequent development of efficient CD8 T cell activity required for the control of tumor growth. PMID:17911581

  9. Methodologies for the Analysis of HCV-Specific CD4+ T Cells

    PubMed Central

    Lokhande, Megha U.; Thimme, Robert; Klenerman, Paul; Semmo, Nasser

    2015-01-01

    Virus-specific CD4+ T cells play a major role in viral infections, such as hepatitis C virus (HCV). Viral clearance is associated with vigorous and multi-specific CD4+ T-cell responses, while chronic infection has been shown to be associated with weak or absent T-cell responses. Most of these studies have used functional assays to analyze virus-specific CD4+ T-cell responses; however, these and other detection methods have various limitations. Therefore, the important question of whether virus-specific CD4+ T cells are completely absent or primarily impaired in specific effector functions during chronic infection, has yet to be analyzed in detail. A novel assay, in which virus-specific CD4+ T-cell frequencies can be determined by de novo CD154 (CD40 ligand) expression in response to viral antigens, can help to overcome some of the limitations of functional assays and restrictions of multimer-based methods. This and other current established methods for the detection of HCV-specific CD4+ T cells will be discussed in this review. PMID:25767470

  10. Multiple CD4+ T cell subsets produce immunomodulatory interleukin-10 during respiratory syncytial virus infection

    PubMed Central

    Weiss, Kayla A.; Christiaansen, Allison F.; Fulton, Ross B.; Meyerholz, David K.; Varga, Steven M.

    2011-01-01

    The host immune response is believed to contribute to the severity of pulmonary disease induced by acute respiratory syncytial virus (RSV) infection. Because RSV-induced pulmonary disease is associated with immunopathology, we evaluated the role of IL-10 in modulating the RSV-specific immune response. We found that IL-10 protein levels in the lung were increased following acute RSV infection with maximum production corresponding to the peak of the virus-specific T cell response. The majority of IL-10 producing cells in the lung during acute RSV infection were CD4+ T cells. The IL-10-producing CD4+ T cells included Foxp3+Tregs, Foxp3− CD4+ T cells that co-produce IFN-γ, and Foxp3− CD4+ T cells that do not co-produce IFN-γ. RSV infection of IL-10-deficient mice resulted in more severe disease, as measured by increased weight loss and airway resistance, as compared to control mice. We also observed an increase in the magnitude of the RSV-induced CD8+ and CD4+ T cell response that correlated with increased disease severity in the absence of IL-10 or following IL-10R blockade. Interestingly, IL-10R blockade during acute RSV infection altered CD4+ T cell subset distribution, resulting in a significant increase in IL-17A-producing CD4+ T cells and a concomitant decrease in Foxp3+ regulatory T cells. These results demonstrate that IL-10 plays a critical role in modulating the adaptive immune response to RSV by limiting T-cell-mediated pulmonary inflammation and injury. PMID:21844390

  11. Spontaneous Proliferation of H2M-/- CD4 T Cells Results in Unusual Acute Hepatocellular Necrosis

    PubMed Central

    Do, Jeong-su; Baldwin, William M.; Min, Booki

    2014-01-01

    Naïve CD4 T cells are triggered to undergo spontaneous proliferation, a proliferative response induced in response to homeostatic stimulation, when exposed to severe lymphopenic environments. They spontaneously acquire proinflammatory effector phenotypes, playing a major role in inducing chronic inflammation in the intestine that is believed to be induced by T cell recognition of commensal antigens. While the antigens inducing the T cell responses and inflammation are being extensively investigated, the role of clonality of T cells involved in this process remains poorly understood. In this study, we utilized naïve CD4 T cells isolated from B6 H2M−/− mice, in which MHCII molecules are complexed with a single CLIP molecule, and examined spontaneous proliferation and intestinal inflammation of CD4 T cells expressing limited T cell receptor repertoire diversity. We found that H2M−/− CD4 T cells undergo robust spontaneous proliferation, differentiate into IFNγ-producing Th1 type effector cells, and, most unexpectedly, induce severe acute hepatocellular necrosis. T cell interaction with MHCII molecule on cells of hematopoietic origin was essential to induce the pathology. Interestingly, B cells are fully capable of preventing necrotic inflammation via IL-10-independent and B7-H1-dependent mechanism. This could be a useful animal model to examine T cell-mediated liver inflammation and B cell-mediated immune regulation. PMID:25313460

  12. Selective capacity of metreleptin administration to reconstitute CD4+ T-cell number in females with acquired hypoleptinemia.

    PubMed

    Matarese, Giuseppe; La Rocca, Claudia; Moon, Hyun-Seuk; Huh, Joo Young; Brinkoetter, Mary T; Chou, Sharon; Perna, Francesco; Greco, Dario; Kilim, Holly P; Gao, Chuanyun; Arampatzi, Kalliope; Wang, Zhaoxi; Mantzoros, Christos S

    2013-02-26

    Leptin is an adipocyte-derived hormone that controls food intake and reproductive and immune functions in rodents. In uncontrolled human studies, low leptin levels are associated with impaired immune responses and reduced T-cell counts; however, the effects of leptin replacement on the adaptive immune system have not yet been reported in the context of randomized, controlled studies and/or in conditions of chronic acquired leptin deficiency. To address these questions, we performed a randomized, double-blinded, placebo-controlled trial of recombinant methionyl-human leptin (metreleptin) administration in replacement doses in women experiencing the female triad (hypothalamic amenorrhea) with acquired chronic hypoleptinemia induced by negative energy balance. Metreleptin restored both CD4(+) T-cell counts and their in vitro proliferative responses in these women. These changes were accompanied by a transcriptional signature in which genes relevant to cell survival and hormonal response were up-regulated, and apoptosis genes were down-regulated in circulating immune cells. We also observed that signaling pathways involved in cell growth/survival/proliferation, such as the STAT3, AMPK, mTOR, ERK1/2, and Akt pathways, were activated directly by acute in vivo metreleptin administration in peripheral blood mononuclear cells and CD4(+) T-cells both from subjects with chronic hypoleptinemia and from normoleptinemic, lean female subjects. Our data show that metreleptin administration, in doses that normalize circulating leptin levels, induces transcriptional changes, activates intracellular signaling pathways, and restores CD4(+) T-cell counts. Thus, metreleptin may prove to be a safe and effective therapy for selective CD4(+) T-cell immune reconstitution in hypoleptinemic states such as tuberculosis and HIV infection in which CD4(+) T cells are reduced.

  13. Clonally expanded CD4+ T cells can produce infectious HIV-1 in vivo.

    PubMed

    Simonetti, Francesco R; Sobolewski, Michele D; Fyne, Elizabeth; Shao, Wei; Spindler, Jonathan; Hattori, Junko; Anderson, Elizabeth M; Watters, Sarah A; Hill, Shawn; Wu, Xiaolin; Wells, David; Su, Li; Luke, Brian T; Halvas, Elias K; Besson, Guillaume; Penrose, Kerri J; Yang, Zhiming; Kwan, Richard W; Van Waes, Carter; Uldrick, Thomas; Citrin, Deborah E; Kovacs, Joseph; Polis, Michael A; Rehm, Catherine A; Gorelick, Robert; Piatak, Michael; Keele, Brandon F; Kearney, Mary F; Coffin, John M; Hughes, Stephen H; Mellors, John W; Maldarelli, Frank

    2016-02-16

    Reservoirs of infectious HIV-1 persist despite years of combination antiretroviral therapy and make curing HIV-1 infections a major challenge. Most of the proviral DNA resides in CD4(+)T cells. Some of these CD4(+)T cells are clonally expanded; most of the proviruses are defective. It is not known if any of the clonally expanded cells carry replication-competent proviruses. We report that a highly expanded CD4(+) T-cell clone contains an intact provirus. The highly expanded clone produced infectious virus that was detected as persistent plasma viremia during cART in an HIV-1-infected patient who had squamous cell cancer. Cells containing the intact provirus were widely distributed and significantly enriched in cancer metastases. These results show that clonally expanded CD4(+)T cells can be a reservoir of infectious HIV-1. PMID:26858442

  14. Interleukin-27-Producing CD4(+) T Cells Regulate Protective Immunity during Malaria Parasite Infection.

    PubMed

    Kimura, Daisuke; Miyakoda, Mana; Kimura, Kazumi; Honma, Kiri; Hara, Hiromitsu; Yoshida, Hiroki; Yui, Katsuyuki

    2016-03-15

    Interleukin-27 (IL-27) is a heterodimeric regulatory cytokine of the IL-12 family, which is produced by macrophages, dendritic cells, and B cells upon stimulation through innate immune receptors. Here, we described regulatory CD4(+) T cells that produce IL-27 in response to T cell receptor stimulation during malaria infection, inhibiting IL-2 production and clonal expansion of other T cells in an IL-27-dependent manner. IL-27-producing CD4(+) T cells were Foxp3(-)CD11a(+)CD49d(+) malaria antigen-specific CD4(+) T cells and were distinct from interferon-γ (IFN-γ) producing Th1 or IL-10 producing Tr1 cells. In mice lacking IL-27 in T cells, IL-2 production was restored and clonal expansion and IFN-γ production by specific CD4(+) T cells were improved, culminating in reduced parasite burden. This study highlights a unique population of IL-27 producing regulatory CD4(+) T cells and their critical role in the regulation of the protective immune response against malaria parasites.

  15. CD4 T cell activation by B cells in human Leishmania (Viannia) infection

    PubMed Central

    2014-01-01

    Background An effective adaptive immune response requires activation of specific CD4 T cells. The capacity of B cells to activate CD4 T cells in human cutaneous leishmaniasis caused by Leishmania (Viannia) has not been evaluated. Methods CD4 T cell activation by B cells of cutaneous leishmaniasis patients was evaluated by culture of PBMCs or purified B cells and CD4 T cells with Leishmania panamensis antigens. CD4 T cell and B cell activation markers were evaluated by flow cytometry and 13 cytokines were measured in supernatants with a bead-based capture assay. The effect of Leishmania antigens on BCR-mediated endocytosis of ovalbumin was evaluated in the Ramos human B cell line by targeting the antigen with anti-IgM-biotin and anti-biotin-ovalbumin-FITC. Results Culture of PBMCs from cutaneous leishmaniasis patients with Leishmania antigens resulted in upregulation of the activation markers CD25 and CD69 as well as increased frequency of CD25hiCD127- cells among CD4 T cells. Concomitantly, B cells upregulated the costimulatory molecule CD86. These changes were not observed in PBMCs from healthy subjects, indicating participation of Leishmania-specific lymphocytes expanded in vivo. Purified B cells from these patients, when interacting with purified CD4 T cells and Leishmania antigens, were capable of inducing significant increases in CD25 and CD69 expression and CD25hiCD127- frequency in CD4 T cells. These changes were associated with upregulation of CD86 in B cells. Comparison of changes in CD4 T cell activation parameters between PBMC and B cell/CD4 T cell cultures showed no statistically significant differences; further, significant secretion of IFN-γ, TNF-α, IL-6 and IL-13 was induced in both types of cultures. Additionally, culture with Leishmania antigens enhanced BCR-mediated endocytosis of ovalbumin in Ramos human B cells. Conclusions The capacity of B cells specific for Leishmania antigens in peripheral blood of cutaneous leishmaniasis patients to

  16. Characterizing the dynamics of CD4+ T cell priming within a lymph node1

    PubMed Central

    Linderman, Jennifer J.; Riggs, Thomas; Pande, Manjusha; Miller, Mark; Marino, Simeone; Kirschner, Denise E.

    2011-01-01

    Generating adaptive immunity after infection or immunization requires physical interaction within a lymph node (LN) T-zone between antigen-bearing dendritic cells (DCs) and rare cognate T cells. Many fundamental questions remain regarding the dynamics of DC-CD4+ T cell interactions leading to priming. For example, it is not known how the production of primed CD4+ T cells relates to the numbers of cognate T cells, antigen-bearing DCs, or peptide-MHCII level on the DC. To address these questions, we developed an agent-based model of a LN to examine the relationships among cognate T cell frequency, DC density, parameters characterizing DC-T interactions and the output of primed T cells. We found that the output of primed CD4+ T cells is linearly related to cognate frequency, but non-linearly related to the number of antigen-bearing DCs present during infection. This addresses the applicability of two photon microscopy studies to understanding actual infection dynamics, as these types of experiments increase the cognate frequency by orders of magnitude as compared to physiologic levels. We found a trade-off between the quantity of peptide-MHCII on the surface of individual DCs and number of antigen-bearing DCs present in the LN in contributing to the production of primed CD4+ T cells. Interestingly, pMHCII half-life plays a minor, although still significant, role in determining CD4+ T cell priming, unlike the primary role that has been suggested for CD8+ T cell priming. Finally, we identify several pathogen-targeted mechanisms that, if altered in their efficiency, can significantly effect the generation of primed CD4+ T cells. PMID:20154206

  17. Methionine enkephalin is hydrolyzed by aminopeptidase N on CD4+ and CD8+ spleen T cells.

    PubMed

    Miller, B C; Thiele, D L; Hersh, L B; Cottam, G L

    1994-05-15

    Exogenous methionine enkephalin incubated with CD4+ or CD8+ T cells purified from murine spleen is metabolized primarily, if not exclusively, by aminopeptidase N (aminopeptidase M, EC 3.4.11.2), a membrane-anchored ectopeptidase. The enzyme activity is identified by its substrate specificity, sensitivity to inhibition by amastatin, and immunoreactivity with antibody to rat kidney aminopeptidase N. Activation of CD4+ T cells results in a small increase per cell in aminopeptidase N activity.

  18. Nuclear Retention of Multiply Spliced HIV-1 RNA in Resting CD4+ T Cells

    PubMed Central

    Lassen, Kara G; Ramyar, Kasra X; Bailey, Justin R; Zhou, Yan; Siliciano, Robert F

    2006-01-01

    HIV-1 latency in resting CD4+ T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART). We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4+ T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS) HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4+ T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4+ T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB) was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4+ T cells. Overexpression of PTB in resting CD4+ T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4+ T cells. Virus culture experiments showed that overexpression of PTB in resting CD4+ T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications. PMID:16839202

  19. CD4+ T cells mediate mucosal and systemic immune responses to experimental hookworm infection

    PubMed Central

    DONDJI, B.; SUN, T.; BUNGIRO, R. D.; VERMEIRE, J. J.; HARRISON, L. M.; BIFULCO, C.; CAPPELLO, M.

    2011-01-01

    SUMMARY Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4+ T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4+ for up to 9 days following intraperitoneal injection (200 μg) of a murine anti-mouse CD4 monoclonal IgG (clone GK1·5). CD4+ T-cell-depleted hamsters infected with the hookworm Ancylostoma ceylanicum exhibited a threefold higher mean intestinal worm burden and more severe anaemia than animals that received isotype control IgG. In addition, depletion of CD4+ T cells was associated with impaired cellular and humoral (serum and mucosal) immune responses to hookworm antigens. These data demonstrate an effector role for CD4+ T cells in hookworm immunity and disease pathogenesis. Ultimately, these studies may yield important insights into the relationship between intestinal nematode infections and diseases that are associated with CD4+ T-cell depletion, including HIV. PMID:20500671

  20. The differentiation and protective function of cytolytic CD4 T cells in influenza infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells that recognize peptide antigen in the context of Class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity play a role in chronic, as well as, acute infections...

  1. Bronchoalveolar CD4+ T cell responses to respiratory antigens are impaired in HIV-infected adults

    PubMed Central

    Sepako, Enoch; Fullerton, Duncan G; Mzinza, David; Glennie, Sarah; Wright, Adam K; Heyderman, Robert S; Gordon, Stephen B

    2011-01-01

    Rationale HIV-infected adults are at an increased risk of lower respiratory tract infections. HIV infection impairs systemic acquired immunity, but there is limited information in humans on HIV-related cell-mediated immune defects in the lung. Objective To investigate antigen-specific CD4+ T cell responses to influenza virus, Streptococcus pneumoniae and Mycobacterium tuberculosis antigens in bronchoalveolar lavage (BAL) and peripheral blood between HIV-infected individuals and HIV-uninfected Malawian adults. Methods We obtained BAL fluid and blood from HIV-infected individuals (n=21) and HIV-uninfected adults (n=24). We determined the proportion of T cell subsets including naive, memory and regulatory T cells using flow cytometry, and used intracellular cytokine staining to identify CD4+ T cells recognising influenza virus-, S pneumoniae- and M tuberculosis-antigens. Main results CD4+ T cells in BAL were predominantly of effector memory phenotype compared to blood, irrespective of HIV status (p<0.001). There was immune compartmentalisation with a higher frequency of antigen-specific CD4+ T cells against influenza virus, S pneumoniae and M tuberculosis retained in BAL compared to blood in HIV-uninfected adults (p<0.001 in each case). Influenza virus- and M tuberculosis-specific CD4+ T cell responses in BAL were impaired in HIV-infected individuals: proportions of total antigen-specific CD4+ T cells and of polyfunctional IFN-γ and TNF-α-secreting cells were lower in HIV-infected individuals than in HIV-uninfected adults (p<0.05 in each case). Conclusions BAL antigen-specific CD4+ T cell responses against important viral and bacterial respiratory pathogens are impaired in HIV-infected adults. This might contribute to the susceptibility of HIV-infected adults to lower respiratory tract infections such as pneumonia and tuberculosis. PMID:21357587

  2. TNFAIP3 promotes survival of CD4 T cells by restricting MTOR and promoting autophagy.

    PubMed

    Matsuzawa, Yu; Oshima, Shigeru; Takahara, Masahiro; Maeyashiki, Chiaki; Nemoto, Yasuhiro; Kobayashi, Masanori; Nibe, Yoichi; Nozaki, Kengo; Nagaishi, Takashi; Okamoto, Ryuichi; Tsuchiya, Kiichiro; Nakamura, Tetsuya; Ma, Averil; Watanabe, Mamoru

    2015-01-01

    Autophagy plays important roles in metabolism, differentiation, and survival in T cells. TNFAIP3/A20 is a ubiquitin-editing enzyme that is thought to be a negative regulator of autophagy in cell lines. However, the role of TNFAIP3 in autophagy remains unclear. To determine whether TNFAIP3 regulates autophagy in CD4 T cells, we first analyzed Tnfaip3-deficient naïve CD4 T cells in vitro. We demonstrated that Tnfaip3-deficient CD4 T cells exhibited reduced MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) puncta formation, increased mitochondrial content, and exaggerated reactive oxygen species (ROS) production. These results indicate that TNFAIP3 promotes autophagy after T cell receptor (TCR) stimulation in CD4 T cells. We then investigated the mechanism by which TNFAIP3 promotes autophagy signaling. We found that TNFAIP3 bound to the MTOR (mechanistic target of rapamycin) complex and that Tnfaip3-deficient cells displayed enhanced ubiquitination of the MTOR complex and MTOR activity. To confirm the effects of enhanced MTOR activity in Tnfaip3-deficient cells, we analyzed cell survival following treatment with Torin1, an MTOR inhibitor. Tnfaip3-deficient CD4 T cells exhibited fewer cell numbers than the control cells in vitro and in vivo. In addition, the impaired survival of Tnfaip3-deficient cells was ameliorated with Torin1 treatment in vitro and in vivo. The effect of Torin1 was abolished by Atg5 deficiency. Thus, enhanced MTOR activity regulates the survival of Tnfaip3-deficient CD4 T cells. Taken together, our findings illustrate that TNFAIP3 restricts MTOR signaling and promotes autophagy, providing new insight into the manner in which MTOR and autophagy regulate survival in CD4 T cells.

  3. TNFAIP3 promotes survival of CD4 T cells by restricting MTOR and promoting autophagy

    PubMed Central

    Matsuzawa, Yu; Oshima, Shigeru; Takahara, Masahiro; Maeyashiki, Chiaki; Nemoto, Yasuhiro; Kobayashi, Masanori; Nibe, Yoichi; Nozaki, Kengo; Nagaishi, Takashi; Okamoto, Ryuichi; Tsuchiya, Kiichiro; Nakamura, Tetsuya; Ma, Averil; Watanabe, Mamoru

    2015-01-01

    Autophagy plays important roles in metabolism, differentiation, and survival in T cells. TNFAIP3/A20 is a ubiquitin-editing enzyme that is thought to be a negative regulator of autophagy in cell lines. However, the role of TNFAIP3 in autophagy remains unclear. To determine whether TNFAIP3 regulates autophagy in CD4 T cells, we first analyzed Tnfaip3-deficient naïve CD4 T cells in vitro. We demonstrated that Tnfaip3-deficient CD4 T cells exhibited reduced MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) puncta formation, increased mitochondrial content, and exaggerated reactive oxygen species (ROS) production. These results indicate that TNFAIP3 promotes autophagy after T cell receptor (TCR) stimulation in CD4 T cells. We then investigated the mechanism by which TNFAIP3 promotes autophagy signaling. We found that TNFAIP3 bound to the MTOR (mechanistic target of rapamycin) complex and that Tnfaip3-deficient cells displayed enhanced ubiquitination of the MTOR complex and MTOR activity. To confirm the effects of enhanced MTOR activity in Tnfaip3-deficient cells, we analyzed cell survival following treatment with Torin1, an MTOR inhibitor. Tnfaip3-deficient CD4 T cells exhibited fewer cell numbers than the control cells in vitro and in vivo. In addition, the impaired survival of Tnfaip3-deficient cells was ameliorated with Torin1 treatment in vitro and in vivo. The effect of Torin1 was abolished by Atg5 deficiency. Thus, enhanced MTOR activity regulates the survival of Tnfaip3-deficient CD4 T cells. Taken together, our findings illustrate that TNFAIP3 restricts MTOR signaling and promotes autophagy, providing new insight into the manner in which MTOR and autophagy regulate survival in CD4 T cells. PMID:26043155

  4. CD4 T cells in murine acquired immunodeficiency syndrome: polyclonal progression to anergy

    PubMed Central

    1992-01-01

    We have examined the kinetics of changes that occur in the helper T cell subset during murine acquired immunodeficiency syndrome, which occurs after infection with the mix of viruses known as BM5. We find that there is expansion of the CD4 T cells by 2 wk, 50% of the CD4 T cells become large as the disease progresses, and the CD4 T cell population is increasingly comprised of cells with a memory/activated phenotype. These effects are apparent by 2 wk postinfection, and the change is nearly complete by 6-8 wk. The phenotypic shift is paralleled by the loss of the ability of the CD4 T cells to proliferate or to produce interleukin 2 (IL-2), IL-3, IL-4, and interferon gamma in response to stimulation with mitogens, superantigen, or anti-CD3. There is no obvious expansion or deletion of CD4 T cells expressing particular V beta genes, as might be expected if a conventional superantigen were driving the changes. The results suggest, however, that the total CD4 population has been driven to anergy by some potent polyclonal stimulus directly associated with viral infection. PMID:1588283

  5. CD4+ follicular helper T cell infiltration predicts breast cancer survival

    PubMed Central

    Gu-Trantien, Chunyan; Loi, Sherene; Garaud, Soizic; Equeter, Carole; Libin, Myriam; de Wind, Alexandre; Ravoet, Marie; Le Buanec, Hélène; Sibille, Catherine; Manfouo-Foutsop, Germain; Veys, Isabelle; Haibe-Kains, Benjamin; Singhal, Sandeep K.; Michiels, Stefan; Rothé, Françoise; Salgado, Roberto; Duvillier, Hugues; Ignatiadis, Michail; Desmedt, Christine; Bron, Dominique; Larsimont, Denis; Piccart, Martine; Sotiriou, Christos; Willard-Gallo, Karen

    2013-01-01

    CD4+ T cells are critical regulators of immune responses, but their functional role in human breast cancer is relatively unknown. The goal of this study was to produce an image of CD4+ T cells infiltrating breast tumors using limited ex vivo manipulation to better understand the in vivo differences associated with patient prognosis. We performed comprehensive molecular profiling of infiltrating CD4+ T cells isolated from untreated invasive primary tumors and found that the infiltrating T cell subpopulations included follicular helper T (Tfh) cells, which have not previously been found in solid tumors, as well as Th1, Th2, and Th17 effector memory cells and Tregs. T cell signaling pathway alterations included a mixture of activation and suppression characterized by restricted cytokine/chemokine production, which inversely paralleled lymphoid infiltration levels and could be reproduced in activated donor CD4+ T cells treated with primary tumor supernatant. A comparison of extensively versus minimally infiltrated tumors showed that CXCL13-producing CD4+ Tfh cells distinguish extensive immune infiltrates, principally located in tertiary lymphoid structure germinal centers. An 8-gene Tfh signature, signifying organized antitumor immunity, robustly predicted survival or preoperative response to chemotherapy. Our identification of CD4+ Tfh cells in breast cancer suggests that they are an important immune element whose presence in the tumor is a prognostic factor. PMID:23778140

  6. Major histocompatibility complex class I-restricted alloreactive CD4+ T cells.

    PubMed

    Boyle, Louise H; Goodall, Jane C; Gaston, J S Hill

    2004-05-01

    Although it is well established that CD4+ T cells generally recognize major histocompatibility complex (MHC) class II molecules, MHC class I-reactive CD4+ T cells have occasionally been reported. Here we describe the isolation and characterization of six MHC class I-reactive CD4+ T-cell lines, obtained by co-culture of CD4+ peripheral blood T cells with the MHC class II-negative, transporter associated with antigen processing (TAP)-negative cell line, T2, transfected with human leucocyte antigen (HLA)-B27. Responses were inhibited by the MHC class I-specific monoclonal antibody (mAb), W6/32, demonstrating the direct recognition of MHC class I molecules. In four cases, the restriction element was positively identified as HLA-A2, as responses by these clones were completely inhibited by MA2.1, an HLA-A2-specific mAb. Interestingly, three of the CD4+ T-cell lines only responded to cells expressing HLA-B27, irrespective of their restricting allele, implicating HLA-B27 as a possible source of peptides presented by the stimulatory MHC class I alleles. In addition, these CD4+ MHC class I alloreactive T-cell lines could recognize TAP-deficient cells and therefore may have particular clinical relevance to situations where the expression of TAP molecules is decreased, such as viral infection and transformation of cells. PMID:15096184

  7. The story of CD4+ CD28- T cells revisited: solved or still ongoing?

    PubMed

    Maly, Kathrin; Schirmer, Michael

    2015-01-01

    CD4(+)CD28(-) T cells are a unique type of proinflammatory T cells characterised by blockade of costimulatory CD28 receptor expression at the transcriptional level, which is still reversible by IL-12. In healthy individuals older than 65 years, these cells may accumulate to up to 50% of total CD4(+) T lymphocytes as in many immune-mediated diseases, immunodeficiency, and specific infectious diseases. Here we focus on CD4(+)CD28(-) T cells in chronic immune-mediated diseases, summarizing various phenotypic and functional characteristics, which vary depending on the underlying disease, disease activity, and concurrent treatment. CD4(+)CD28(-) T cells present as effector/memory cells with increased replicative history and oligoclonality but reduced apoptosis. As an alternative costimulatory signal instead of CD28, not only natural killer cell receptors and Toll-like receptors, but also CD47, CTLA-4, OX40, and 4-1BB have to be considered. The proinflammatory and cytotoxic capacities of these cells indicate an involvement in progression and maintenance of chronic immune-mediated disease. So far it has been shown that treatment with TNF-α blockers, abatacept, statins, and polyclonal antilymphocyte globulins (ATG) mediates reduction of the CD4(+)CD28(-) T cell level. The clinical relevance of targeting CD4(+)CD28(-) T cells as a therapeutic option has not been examined so far. PMID:25834833

  8. Long-Lived CD4+IFN-γ+ T Cells rather than Short-Lived CD4+IFN-γ+IL-10+ T Cells Initiate Rapid IL-10 Production To Suppress Anamnestic T Cell Responses during Secondary Malaria Infection

    PubMed Central

    Villegas-Mendez, Ana; Inkson, Colette A.; Shaw, Tovah N.; Strangward, Patrick

    2016-01-01

    CD4+ T cells that produce IFN-γ are the source of host-protective IL-10 during primary infection with a number of different pathogens, including Plasmodium spp. The fate of these CD4+IFN-γ+IL-10+ T cells following clearance of primary infection and their subsequent influence on the course of repeated infections is, however, presently unknown. In this study, utilizing IFN-γ–yellow fluorescent protein (YFP) and IL-10–GFP dual reporter mice, we show that primary malaria infection–induced CD4+YFP+GFP+ T cells have limited memory potential, do not stably express IL-10, and are disproportionately lost from the Ag-experienced CD4+ T cell memory population during the maintenance phase postinfection. CD4+YFP+GFP+ T cells generally exhibited a short-lived effector rather than effector memory T cell phenotype postinfection and expressed high levels of PD-1, Lag-3, and TIGIT, indicative of cellular exhaustion. Consistently, the surviving CD4+YFP+GFP+ T cell–derived cells were unresponsive and failed to proliferate during the early phase of secondary infection. In contrast, CD4+YFP+GFP− T cell–derived cells expanded rapidly and upregulated IL-10 expression during secondary infection. Correspondingly, CD4+ T cells were the major producers within an accelerated and amplified IL-10 response during the early stage of secondary malaria infection. Notably, IL-10 exerted quantitatively stronger regulatory effects on innate and CD4+ T cell responses during primary and secondary infections, respectively. The results in this study significantly improve our understanding of the durability of IL-10–producing CD4+ T cells postinfection and provide information on how IL-10 may contribute to optimized parasite control and prevention of immune-mediated pathology during repeated malaria infections. PMID:27630165

  9. The BMP Pathway Participates in Human Naive CD4+ T Cell Activation and Homeostasis

    PubMed Central

    Martínez, Víctor G.; Sacedón, Rosa; Hidalgo, Laura; Valencia, Jaris; Fernández-Sevilla, Lidia M.; Hernández-López, Carmen

    2015-01-01

    Bone Morphogenetic Proteins (BMPs) form a group of secreted factors that belongs to the TGF-β superfamily. Among different roles in a number of immune cell types, BMPs are known to regulate T cell development within the thymus, although the role of BMP signaling in human mature T cells remains elusive. In this study, we demonstrate that canonical BMP signaling is necessary during two critical events that regulate the size and function of human naive CD4+ T cell population: activation and homeostasis. Upon stimulation via TCR, naive CD4+ T cells upregulate the expression of BMP ligands triggering canonical BMP signaling in CD25+ cells. Blockade of BMP signaling severely impairs CD4+ T cell proliferation after activation mainly through regulation of IL-2, since the addition of this cytokine recuperates normal T cell expansion after inhibition of BMP signaling. Similarly, activation of canonical BMP pathway is required for both the maintenance of cell survival and the homeostatic proliferation induced by IL-7, a key factor for T cell homeostasis. Moreover, upregulation of two critical receptors for T cell homeostasis, CXCR4 and CCR9, triggered by IL-7 is also abrogated in the absence of BMP signaling. Collectively, we describe important roles of the canonical BMP signaling in human naive CD4+ T cell activation and homeostasis that could be valuable for clinical application. PMID:26110906

  10. Metabolic programming and PDHK1 control CD4+ T cell subsets and inflammation.

    PubMed

    Gerriets, Valerie A; Kishton, Rigel J; Nichols, Amanda G; Macintyre, Andrew N; Inoue, Makoto; Ilkayeva, Olga; Winter, Peter S; Liu, Xiaojing; Priyadharshini, Bhavana; Slawinska, Marta E; Haeberli, Lea; Huck, Catherine; Turka, Laurence A; Wood, Kris C; Hale, Laura P; Smith, Paul A; Schneider, Martin A; MacIver, Nancie J; Locasale, Jason W; Newgard, Christopher B; Shinohara, Mari L; Rathmell, Jeffrey C

    2015-01-01

    Activation of CD4+ T cells results in rapid proliferation and differentiation into effector and regulatory subsets. CD4+ effector T cell (Teff) (Th1 and Th17) and Treg subsets are metabolically distinct, yet the specific metabolic differences that modify T cell populations are uncertain. Here, we evaluated CD4+ T cell populations in murine models and determined that inflammatory Teffs maintain high expression of glycolytic genes and rely on high glycolytic rates, while Tregs are oxidative and require mitochondrial electron transport to proliferate, differentiate, and survive. Metabolic profiling revealed that pyruvate dehydrogenase (PDH) is a key bifurcation point between T cell glycolytic and oxidative metabolism. PDH function is inhibited by PDH kinases (PDHKs). PDHK1 was expressed in Th17 cells, but not Th1 cells, and at low levels in Tregs, and inhibition or knockdown of PDHK1 selectively suppressed Th17 cells and increased Tregs. This alteration in the CD4+ T cell populations was mediated in part through ROS, as N-acetyl cysteine (NAC) treatment restored Th17 cell generation. Moreover, inhibition of PDHK1 modulated immunity and protected animals against experimental autoimmune encephalomyelitis, decreasing Th17 cells and increasing Tregs. Together, these data show that CD4+ subsets utilize and require distinct metabolic programs that can be targeted to control specific T cell populations in autoimmune and inflammatory diseases.

  11. Granzyme B mediated function of Parvovirus B19-specific CD4+ T cells

    PubMed Central

    Kumar, Arun; Perdomo, Maria F; Kantele, Anu; Hedman, Lea; Hedman, Klaus; Franssila, Rauli

    2015-01-01

    A novel conception of CD4+ T cells with cytolytic potential (CD4+ CTL) is emerging. These cells appear to have a part in controlling malignancies and chronic infections. Human parvovirus B19 can cause a persistent infection, yet no data exist on the presence of B19-specific CD4+ CTLs. Such cells could have a role in the pathogenesis of some autoimmune disorders reported to be associated with B19. We explored the cytolytic potential of human parvovirus B19-specific T cells by stimulating peripheral blood mononuclear cell (PBMC) with recombinant B19-VP2 virus-like particles. The cytolytic potential was determined by enzyme immunoassay-based quantitation of granzyme B (GrB) and perforin from the tissue culture supernatants, by intracellular cytokine staining (ICS) and by detecting direct cytotoxicity. GrB and perforin responses with the B19 antigen were readily detectable in B19-seropositive individuals. T-cell depletion, HLA blocking and ICS experiments showed GrB and perforin to be secreted by CD4+ T cells. CD4+ T cells with strong GrB responses were found to exhibit direct cytotoxicity. As anticipated, ICS of B19-specific CD4+ T cells showed expected co-expression of GrB, perforin and interferon gamma (IFN-γ). Unexpectedly, also a strong co-expression of GrB and interleukin 17 (IL-17) was detected. These cells expressed natural killer (NK) cell surface marker CD56, together with the CD4 surface marker. To our knowledge, this is the first report on virus-specific CD4+ CTLs co-expressing CD56 antigen. Our results suggest a role for CD4+ CTL in B19 immunity. Such cells could function within both immune regulation and triggering of autoimmune phenomena such as systemic lupus erythematosus (SLE) or rheumatoid arthritis. PMID:26246896

  12. Artesunate inhibits proliferation of naïve CD4(+) T cells but enhances function of effector T cells.

    PubMed

    Lee, Sung Ho; Cho, Young-Chang; Kim, Kyung Hee; Lee, Ik-Soo; Choi, Hyun Jin; Kang, Bok Yun

    2015-06-01

    Artesunate is an artemisinin derivative from Artemisia annua and is being applied as a first-line drug for malaria treatment. In addition to anti-malarial effects, anti-cancer, anti-viral, and anti-inflammatory activities have been reported for artemisinin derivatives. In this study, we investigated the effects of artesunate on naïve T cell activation and Th1/Th2 differentiation. Artesunate inhibited the proliferation of CD4(+) T cells and the production of IL-2, T cell growth factor. Moreover, artesunate reduced the expression of cell surface protein CD25 (IL-2 receptor alpha chain) and CD69 on CD4(+) T cells. Artesunate showed inhibitory effects on naïve T cell activation but artesunate increased the production of IFN-γ and IL-4 under Th1 and Th2 skewed condition respectively. Therefore, these results suggest that artesunate has a negative mitogenic effect on CD4(+) T cells but reinforces the function of effector T cells. PMID:25370606

  13. Detectable expression of IL-35 in CD4+ T cells from peripheral blood of chronic hepatitis B patients.

    PubMed

    Liu, Fen; Tong, Fuyi; He, Yan; Liu, Haiyan

    2011-04-01

    Epstein-Barr virus-induced gene 3 (Ebi3) and the p35 subunit of IL-12 have been reported to form a heterodimeric cytokine, named IL-35, in human and mouse. In mice, IL-35 has been shown to be constitutively expressed by CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) and suggested to contribute to their suppressive activity. However, human CD4(+)CD25(+)Foxp3(+) Tregs do not constitutively express detectable amounts of IL-35 in both mRNA and protein levels. Circulating CD4(+)CD25(+) Treg frequency of chronic Hepatitis B patients significantly correlates with serum viral load. In this study, we investigated whether IL-35 expression could be detected in CD4(+) T cells from peripheral blood of chronic Hepatitis B patients. Using both RT-PCR and immunoprecipitation plus Western blot analysis, we demonstrated that IL-35 expression could be detected in the CD4(+) T cells from peripheral blood of Chronic Hepatitis B patients.

  14. B7-deficient autoreactive T cells are highly susceptible to suppression by CD4(+)CD25(+) regulatory T cells.

    PubMed

    May, Kenneth F; Chang, Xing; Zhang, Huiming; Lute, Kenneth D; Zhou, Penghui; Kocak, Ergun; Zheng, Pan; Liu, Yang

    2007-02-01

    CD4(+)CD25(+) regulatory T cells (Tregs) suppress immunity to infections and tumors as well as autoimmunity and graft-vs-host disease. Since Tregs constitutively express CTLA-4 and activated T cells express B7-1 and B7-2, it has been suggested that the interaction between CTLA-4 on Tregs and B7-1/2 on the effector T cells may be required for immune suppression. In this study, we report that autopathogenic T cells from B7-deficient mice cause multiorgan inflammation when adoptively transferred into syngeneic RAG-1-deficient hosts. More importantly, this inflammation is suppressed by adoptive transfer of purified wild-type (WT) CD4(+)CD25(+) T cells. WT Tregs also inhibited lymphoproliferation and acquisition of activation markers by the B7-deficient T cells. An in vitro suppressor assay revealed that WT and B7-deficient T cells are equally susceptible to WT Treg regulation. These results demonstrate that B7-deficient T cells are highly susceptible to immune suppression by WT Tregs and refute the hypothesis that B7-CTLA-4 interaction between effector T cells and Tregs plays an essential role in Treg function.

  15. Measurement of CD8 and CD4 T Cell Responses in Mouse Lungs

    PubMed Central

    Fett, Craig; Zhao, Jincun; Perlman, Stanley

    2016-01-01

    Study of the adaptive immune response to a viral challenge in an animal model often includes analysis of the T cell response. Here we discuss in detail the methods that are used to characterize the CD8 and CD4 T cell response following viral challenge in the lung. PMID:27390762

  16. High avidity autoreactive CD4+ T cells induce host CTL, overcome Tregs and mediate tumor destruction

    PubMed Central

    Brandmaier, Andrew G.; Leitner, Wolfgang W.; Ha, Sung P.; Sidney, John; Restifo, Nicholas P.; Touloukian, Christopher E.

    2009-01-01

    Despite progress made over the past 25 years, existing immunotherapies have limited clinical effectiveness in patients with cancer. Immune tolerance consistently blunts the generated immune response, and the largely solitary focus on CD8+ T cell immunity has proven ineffective in the absence of CD4+ T cell help. To address these twin-tier deficiencies, we developed a translational model of melanoma immunotherapy focused on the exploitation of high avidity CD4+ T cells that become generated in germline antigen deficient mice. We had previously identified a TRP-1 specific HLA-DRB1*0401-restricted epitope. Using this epitope in conjunction with a newly described TRP-1 germline-knockout, we demonstrate that endogenous TRP-1 expression alters the functionality of the auto-reactive T cell repertoire. More importantly, we show, by using MHC-mismatched combinations, that CD4+ T cells derived from the self-antigen deficient host indirectly triggers the eradication of established B16 lung metastases. We demonstrate that the treatment effect is mediated entirely by endogenous CD8+ T cells and is not affected by the depletion of host Tregs. These findings suggest that high avidity CD4+ T cells can overcome endogenous conditions and mediate their anti-tumor effects exclusively through the elicitation of CD8+ T cell immunity. PMID:19561540

  17. Notch Signaling Regulates Antigen Sensitivity of Naive CD4+ T Cells by Tuning Co-stimulation

    PubMed Central

    Laky, Karen; Evans, Sharron; Perez-Diez, Ainhoa

    2015-01-01

    SUMMARY Adaptive immune responses begin when naive CD4+ T cells engage peptide+major histocompatibility complex class II and co-stimulatory molecules on antigen-presenting cells (APCs). Notch signaling can influence effector functions in differentiated CD4+ T helper and T regulatory cells. Whether and how ligand-induced Notch signaling influences the initial priming of CD4+ T cells has not been addressed. We have found that Delta Like Ligand 4 (DLL4)-induced Notch signaling potentiates phosphatidylinositol 3-OH kinase (PI3K)-dependent signaling downstream of the T cell receptor+CD28, allowing naive CD4+ T cells to respond to lower doses of antigen. In vitro, DLL4-deficient APCs were less efficient stimulators of CD4+ T cell activation, metabolism, proliferation, and cytokine secretion. With deletion of DLL4 from CD11c+ APCs in vivo, these deficits translated to an impaired ability to mount an effective CD4+-dependent anti-tumor response. These data implicate Notch signaling as an important regulator of adaptive immune responses. PMID:25607460

  18. HLA Class-II Associated HIV Polymorphisms Predict Escape from CD4+ T Cell Responses

    PubMed Central

    Erdmann, Nathan; Du, Victor Y.; Carlson, Jonathan; Schaefer, Malinda; Jureka, Alexander; Sterrett, Sarah; Yue, Ling; Dilernia, Dario; Lakhi, Shabir; Tang, Jianming; Sidney, John; Gilmour, Jill; Allen, Susan; Hunter, Eric; Heath, Sonya; Bansal, Anju; Goepfert, Paul A.

    2015-01-01

    Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1) exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP) in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE) or its non-adapted (NAE) version were evaluated for immunogenicity. Using a CD8-depleted IFN-γ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p<0.0001). However, regardless of the group, the magnitude of responses to AE was lower as compared to NAE (p<0.0001). CD4+ T cell responses in patients with acute HIV infection (AHI) demonstrated poor immunogenicity towards AE as compared to NAE encoded by their transmitted founder virus. Longitudinal data in AHI off antiretroviral therapy demonstrated sequence changes that were biologically confirmed to represent CD4+ escape mutations. These data demonstrate an innovative application of HLA-associated polymorphisms to identify biologically relevant CD4+ epitopes and suggests CD4+ T cells are active participants in driving HIV evolution. PMID:26302050

  19. CD4+ T Cell Priming as Biomarker to Study Immune Response to Preventive Vaccines

    PubMed Central

    Ciabattini, Annalisa; Pettini, Elena; Medaglini, Donata

    2013-01-01

    T cell priming is a critical event in the initiation of the immune response to vaccination since it deeply influences both the magnitude and the quality of the immune response induced. CD4+ T cell priming, required for the induction of high-affinity antibodies and immune memory, represents a key target for improving and modulating vaccine immunogenicity. A major challenge in the study of in vivo T cell priming is due to the low frequency of antigen-specific T cells. This review discusses the current knowledge on antigen-specific CD4+ T cell priming in the context of vaccination, as well as the most advanced tools for the characterization of the in vivo T cell priming and the opportunities offered by the application of systems biology. PMID:24363656

  20. Antigens for CD4 and CD8 T Cells in Tuberculosis

    PubMed Central

    Lindestam Arlehamn, Cecilia S.; Lewinsohn, David; Sette, Alessandro; Lewinsohn, Deborah

    2014-01-01

    Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis (MTB), represents an important cause of morbidity and mortality worldwide for which an improved vaccine and immunodiagnostics are urgently needed. CD4+ and CD8+ T cells play an important role in host defense to TB. Definition of the antigens recognized by these T cells is critical for improved understanding of the immunobiology of TB and for development of vaccines and diagnostics. Herein, the antigens and epitopes recognized by classically HLA class I– and II–restricted CD4+ and CD8+ T cells in humans infected with MTB are reviewed. Immunodominant antigens and epitopes have been defined using approaches targeting particular TB proteins or classes of proteins and by genome-wide discovery approaches. Antigens and epitopes recognized by classically restricted CD4+ and CD8+ T cells show extensive breadth and diversity in MTB-infected humans. PMID:24852051

  1. Adenoviral transduction of naive CD4 T cells to study Treg differentiation.

    PubMed

    Warth, Sebastian C; Heissmeyer, Vigo

    2013-08-13

    Regulatory T cells (Tregs) are essential to provide immune tolerance to self as well as to certain foreign antigens. Tregs can be generated from naive CD4 T cells in vitro with TCR- and co-stimulation in the presence of TGFβ and IL-2. This bears enormous potential for future therapies, however, the molecules and signaling pathways that control differentiation are largely unknown. Primary T cells can be manipulated through ectopic gene expression, but common methods fail to target the most important naive state of the T cell prior to primary antigen recognition. Here, we provide a protocol to express ectopic genes in naive CD4 T cells in vitro before inducing Treg differentiation. It applies transduction with the replication-deficient adenovirus and explains its generation and production. The adenovirus can take up large inserts (up to 7 kb) and can be equipped with promoters to achieve high and transient overexpression in T cells. It effectively transduces naive mouse T cells if they express a transgenic Coxsackie adenovirus receptor (CAR). Importantly, after infection the T cells remain naive (CD44(low), CD62L(high)) and resting (CD25(-), CD69(-)) and can be activated and differentiated into Tregs similar to non-infected cells. Thus, this method enables manipulation of CD4 T cell differentiation from its very beginning. It ensures that ectopic gene expression is already in place when early signaling events of the initial TCR stimulation induces cellular changes that eventually lead into Treg differentiation.

  2. Identification of beryllium-dependent peptides recognized by CD4+ T cells in chronic beryllium disease.

    PubMed

    Falta, Michael T; Pinilla, Clemencia; Mack, Douglas G; Tinega, Alex N; Crawford, Frances; Giulianotti, Marc; Santos, Radleigh; Clayton, Gina M; Wang, Yuxiao; Zhang, Xuewu; Maier, Lisa A; Marrack, Philippa; Kappler, John W; Fontenot, Andrew P

    2013-07-01

    Chronic beryllium disease (CBD) is a granulomatous disorder characterized by an influx of beryllium (Be)-specific CD4T cells into the lung. The vast majority of these T cells recognize Be in an HLA-DP–restricted manner, and peptide is required for T cell recognition. However, the peptides that stimulate Be-specific T cells are unknown. Using positional scanning libraries and fibroblasts expressing HLA-DP2, the most prevalent HLA-DP molecule linked to disease, we identified mimotopes and endogenous self-peptides that bind to MHCII and Be, forming a complex recognized by pathogenic CD4T cells in CBD. These peptides possess aspartic and glutamic acid residues at p4 and p7, respectively, that surround the putative Be-binding site and cooperate with HLA-DP2 in Be coordination. Endogenous plexin A peptides and proteins, which share the core motif and are expressed in lung, also stimulate these TCRs. Be-loaded HLA-DP2–mimotope and HLA-DP2–plexin A4 tetramers detected high frequencies of CD4T cells specific for these ligands in all HLADP2+ CBD patients tested. Thus, our findings identify the first ligand for a CD4T cell involved in metal-induced hypersensitivity and suggest a unique role of these peptides in metal ion coordination and the generation of a common antigen specificity in CBD.

  3. Simian immunodeficiency virus-induced CD4+ T cell deficits in cytokine secretion profile are dependent on monkey origin.

    PubMed

    Marcondes, Maria Cecilia G; Penedo, Maria Cecilia T; Lanigan, Caroline; Hall, Deshon; Watry, Debbie D; Zandonatti, Michelle; Fox, Howard S

    2006-01-01

    Facets of the immune response early after human immunodeficiency virus (HIV) infection influence the course of disease. In the simian immunodeficiency virus (SIV)-rhesus monkey system, a global dysfunction of CD4(+) T cell cytokine secretion was reported to develop early after infection [McKay PF, Barouch DH, Schmitz JE, Veazey RS, Gorgone DA, Lifton MA, Williams KC, and Letvin NL: J Virol 2003;77:4695-4702]. Because differences have been found in SIV pathogenesis depending on the origin of the monkeys, we investigated the correlation between animal background, defined by country of origin (India or China), and circulating T cell cytokine secretion as well as cycling ability within the first 3 mo of SIV infection. An early loss of CD4(+) T cells that produce interferon (IFN)-gamma and interleukin (IL)-2, those that produce IFN-gamma but not tumor necrosis factor (TNF)-alpha, as well as those that do not express IFN-gamma but can express IL-2 or TNF-alpha, was observed in animals of Indian, but not of Chinese, origin after SIV infection. After infection CD4(+) T cells in Chinese macaques developed an increased proliferating pool of T cells compared with Indian animals. These data reveal host diversity in the global effects of SIV infection on functional subsets of immune cells, which can add to a better understanding of differences observed in populations from diverse ethnic origins.

  4. Control of HPV-associated tumors by innovative therapeutic HPV DNA vaccine in the absence of CD4+ T cells

    PubMed Central

    2014-01-01

    Human papillomavirus (HPV) infections are particularly problematic for HIV + and solid organ transplant patients with compromised CD4+ T cell-dependent immunity as they produce more severe and progressive disease compared to healthy individuals. There are no specific treatments for chronic HPV infection, resulting in an urgent unmet need for a modality that is safe and effective for both immunocompromised and otherwise normal patients with recalcitrant disease. DNA vaccination is attractive because it avoids the risks of administration of live vectors to immunocompromised patients, and can induce potent HPV-specific cytotoxic T cell responses. We have developed a DNA vaccine (pNGVL4a-hCRTE6E7L2) encoding calreticulin (CRT) fused to E6, E7 and L2 proteins of HPV-16, the genotype associated with approximately 90% vaginal, vulvar, anal, penile and oropharyngeal HPV-associated cancers and the majority of cervical cancers. Administration of the DNA vaccine by intramuscular (IM) injection followed by electroporation induced significantly greater HPV-specific immune responses compared to IM injection alone or mixed with alum. Furthermore, pNGVL4a-hCRTE6E7L2 DNA vaccination via electroporation of mice carrying an intravaginal HPV-16 E6/E7-expressing syngeneic tumor demonstrated more potent therapeutic effects than IM vaccination alone. Of note, administration of the DNA vaccine by IM injection followed by electroporation elicited potent E6 and E7-specific CD8+ T cell responses and antitumor effects despite CD4+ T cell-depletion, although no antibody response was detected. While CD4+ T cell-depletion did reduce the E6 and E7-specific CD8+ T cell response, it remained sufficient to prevent subcutaneous tumor growth and to eliminate circulating tumor cells in a model of metastatic HPV-16+ cancer. Thus, the antibody response was CD4-dependent, whereas CD4+ T cell help enhanced the E6/E7-specific CD8+ T cell immunity, but was not required. Taken together, our data suggest that

  5. CD8+ T cell migration to the skin requires CD4+ help in a murine model of contact hypersensitivity.

    PubMed

    Fyhrquist, Nanna; Wolff, Henrik; Lauerma, Antti; Alenius, Harri

    2012-01-01

    The relative roles of CD4+ and CD8+ T cells in contact hypersensitivity responses have not been fully solved, and remain an important question. Using an adoptive transfer model, we investigated the role of the respective T cell subset. Magnetic bead separated CD4+ and CD8+ T cells from oxazolone sensitized C57BL/6 mice were transferred into RAG-/- mice, followed by hapten challenge and analysis of inflammatory parameters at 24 hours post exposure. The CD4+ T cell recipient mice developed partial contact hypersensitivity responses to oxazolone. CD8+ T cells caused significant amplification of the response in recipients of both CD4+ and CD8+ T cells including ear swelling, type 1 inflammatory mediators, and cell killing. Unexpectedly, CD8+ T cells were not sufficient to mediate contact hypersensitivity, although abundantly present in the lymph nodes in the CD8+ T cell reconstituted mice. There were no signs of inflammation at the site of hapten exposure, indicating impaired recruitment of CD8+ T cells in the absence of CD4+ T cells. These data show that CD4+ T cells mediate contact hypersensitivity to oxazolone, but CD8+ T cells contribute with the most potent effector mechanisms. Moreover, our results suggest that CD4+ T cell function is required for the mobilization of CD8+ effector T cells to the site of hapten exposure. The results shed new light on the relative importance of CD4+ and CD8+ T cells during the effector phase of contact hypersensitivity. PMID:22916101

  6. CD4 ligands inhibit the formation of multifunctional transduction complexes involved in T cell activation.

    PubMed

    Jabado, N; Pallier, A; Le Deist, F; Bernard, F; Fischer, A; Hivroz, C

    1997-01-01

    Ligands binding to the CD4 molecule can inhibit TCR-mediated T cell activation. We have previously reported that transcription factors regulating the expression of the IL-2 gene, NF-AT, NF-kappaB, and AP-1, are targets of this inhibitory effect in an in vitro model using peripheral human CD4+ T cells activated by a CD3 mAb. Two T cell activation pathways involved in the regulation of these transcription factors, calcium flux and the p21ras pathway, were investigated as potential targets. Binding of HIV envelope glycoprotein gp160/gp120 or a CD4 mAb to the CD4+ T cells, prior to TCR/CD3 activation, inhibited the intracellular calcium elevation. This event strongly suggested an inhibition of PLCgamma1 activity. Tyrosine phosphorylation of PLCgamma1, induced by CD3 activation, was not affected, but its association with tyrosine-phosphorylated proteins, including a 62-kDa protein, was disrupted. This PLCgamma1-associated p62 was found to be immunoreactive to p62-Sam68 Abs. The activation-induced phosphorylation of two p21ras effectors, Raf-1 and Erk2, was inhibited by the CD4 ligands, indirectly pointing to inhibition of the p21ras activation pathway. In addition, we demonstrate that TCR activation of normal CD4+ T cells induced the formation of p120GAP and PLCgamma1-containing complexes. These complexes also contain other unidentified proteins. CD4 ligand binding induced a defective formation of these transduction complexes. This may result in inefficient signaling, partially accounting for the inhibitory effects of the CD4 ligands on both p21ras and calcium-activation pathways.

  7. Tyrosine kinase activity of CD4-associated p56lck may not be required for CD4-dependent T-cell activation.

    PubMed Central

    Collins, T L; Burakoff, S J

    1993-01-01

    The lymphoid-specific tyrosine kinase p56lck (Lck) is critical for the development and activation of T lymphocytes, and Lck kinase activity has been implicated in both T-cell antigen receptor/CD3- and CD4-mediated signaling. CD4-dependent T-cell activation has been demonstrated to be dependent upon the association of CD4 with Lck. To examine the role of the kinase activity of Lck in CD4-dependent T-cell activation, we have generated several kinase-deficient mutants of Lck. When transfected into CD4+ murine T-cell hybridoma cells, these mutants cause approximately 90% diminution in CD4-associated Lck kinase activity. Specifically, upon CD4 crosslinking there is decreased Lck autophosphorylation and decreased phosphorylation of an exogenous substrate. When CD4 is crosslinked to the T-cell antigen receptor-CD3 complex, decreased phosphorylation of associated substrates is also observed. In spite of this striking inhibition of Lck kinase function, cells expressing the kinase-deficient mutants demonstrate normal or enhanced CD4-dependent antigen responsiveness. These data demonstrate that the level of Lck kinase activity does not correlate with its CD4-associated function and suggest that the kinase activity of Lck may not be required for CD4-mediated signaling. Images Fig. 1 Fig. 2 Fig. 3 PMID:7505449

  8. Role of miRNAs in CD4 T cell plasticity during inflammation and tolerance

    PubMed Central

    Sethi, Apoorva; Kulkarni, Neeraja; Sonar, Sandip; Lal, Girdhari

    2013-01-01

    Gene expression is tightly regulated in a tuneable, cell-specific and time-dependent manner. Recent advancement in epigenetics and non-coding RNA (ncRNA) revolutionized the concept of gene regulation. In order to regulate the transcription, ncRNA can promptly response to the extracellular signals as compared to transcription factors present in the cells. microRNAs (miRNAs) are ncRNA (~22 bp) encoded in the genome, and present as intergenic or oriented antisense to neighboring genes. The strategic location of miRNA in coding genes helps in the coupled regulation of its expression with host genes. miRNA together with complex machinery called RNA-induced silencing complex (RISC) interacts with target mRNA and degrade the mRNA or inhibits the translation. CD4 T cells play an important role in the generation and maintenance of inflammation and tolerance. Cytokines and chemokines present in the inflamed microenvironment controls the differentiation and function of various subsets of CD4 T cells [Th1, Th2, Th17, and regulatory CD4 T cells (Tregs)]. Recent studies suggest that miRNAs play an important role in the development and function of all subsets of CD4 T cells. In current review, we focused on how various miRNAs are regulated by cell's extrinsic and intrinsic signaling, and how miRNAs affect the transdifferentiation of subsets of CD4 T cell and controls their plasticity during inflammation and tolerance. PMID:23386861

  9. Role of miRNAs in CD4 T cell plasticity during inflammation and tolerance.

    PubMed

    Sethi, Apoorva; Kulkarni, Neeraja; Sonar, Sandip; Lal, Girdhari

    2013-01-01

    Gene expression is tightly regulated in a tuneable, cell-specific and time-dependent manner. Recent advancement in epigenetics and non-coding RNA (ncRNA) revolutionized the concept of gene regulation. In order to regulate the transcription, ncRNA can promptly response to the extracellular signals as compared to transcription factors present in the cells. microRNAs (miRNAs) are ncRNA (~22 bp) encoded in the genome, and present as intergenic or oriented antisense to neighboring genes. The strategic location of miRNA in coding genes helps in the coupled regulation of its expression with host genes. miRNA together with complex machinery called RNA-induced silencing complex (RISC) interacts with target mRNA and degrade the mRNA or inhibits the translation. CD4 T cells play an important role in the generation and maintenance of inflammation and tolerance. Cytokines and chemokines present in the inflamed microenvironment controls the differentiation and function of various subsets of CD4 T cells [Th1, Th2, Th17, and regulatory CD4 T cells (Tregs)]. Recent studies suggest that miRNAs play an important role in the development and function of all subsets of CD4 T cells. In current review, we focused on how various miRNAs are regulated by cell's extrinsic and intrinsic signaling, and how miRNAs affect the transdifferentiation of subsets of CD4 T cell and controls their plasticity during inflammation and tolerance.

  10. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    NASA Astrophysics Data System (ADS)

    Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

    2014-01-01

    The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

  11. Computational modeling of heterogeneity and function of CD4+ T cells

    PubMed Central

    Carbo, Adria; Hontecillas, Raquel; Andrew, Tricity; Eden, Kristin; Mei, Yongguo; Hoops, Stefan; Bassaganya-Riera, Josep

    2014-01-01

    The immune system is composed of many different cell types and hundreds of intersecting molecular pathways and signals. This large biological complexity requires coordination between distinct pro-inflammatory and regulatory cell subsets to respond to infection while maintaining tissue homeostasis. CD4+ T cells play a central role in orchestrating immune responses and in maintaining a balance between pro- and anti- inflammatory responses. This tight balance between regulatory and effector reactions depends on the ability of CD4+ T cells to modulate distinct pathways within large molecular networks, since dysregulated CD4+ T cell responses may result in chronic inflammatory and autoimmune diseases. The CD4+ T cell differentiation process comprises an intricate interplay between cytokines, their receptors, adaptor molecules, signaling cascades and transcription factors that help delineate cell fate and function. Computational modeling can help to describe, simulate, analyze, and predict some of the behaviors in this complicated differentiation network. This review provides a comprehensive overview of existing computational immunology methods as well as novel strategies used to model immune responses with a particular focus on CD4+ T cell differentiation. PMID:25364738

  12. Reconstitution of CD4 T Cells in Bronchoalveolar Lavage Fluid after Initiation of Highly Active Antiretroviral Therapy▿

    PubMed Central

    Knox, Kenneth S.; Vinton, Carol; Hage, Chadi A.; Kohli, Lisa M.; Twigg, Homer L.; Klatt, Nichole R.; Zwickl, Beth; Waltz, Jeffrey; Goldman, Mitchell; Douek, Daniel C.; Brenchley, Jason M.

    2010-01-01

    The massive depletion of gastrointestinal-tract CD4 T cells is a hallmark of the acute phase of HIV infection. In contrast, the depletion of the lower-respiratory-tract mucosal CD4 T cells as measured in bronchoalveolar lavage (BAL) fluid is more moderate and similar to the depletion of CD4 T cells observed in peripheral blood (PB). To understand better the dynamics of disease pathogenesis and the potential for the reconstitution of CD4 T cells in the lung and PB following the administration of effective antiretroviral therapy, we studied cell-associated viral loads, CD4 T-cell frequencies, and phenotypic and functional profiles of antigen-specific CD4 T cells from BAL fluid and blood before and after the initiation of highly active antiretroviral therapy (HAART). The major findings to emerge were the following: (i) BAL CD4 T cells are not massively depleted or preferentially infected by HIV compared to levels for PB; (ii) BAL CD4 T cells reconstitute after the initiation of HAART, and their infection frequencies decrease; (iii) BAL CD4 T-cell reconstitution appears to occur via the local proliferation of resident BAL CD4 T cells rather than redistribution; and (iv) BAL CD4 T cells are more polyfunctional than CD4 T cells in blood, and their functional profile is relatively unchanged after the initiation of HAART. Taken together, these data suggest mechanisms for mucosal CD4 T-cell depletion and interventions that might aid in the reconstitution of mucosal CD4 T cells. PMID:20610726

  13. Aire-Overexpressing Dendritic Cells Induce Peripheral CD4T Cell Tolerance.

    PubMed

    Li, Dongbei; Li, Haijun; Fu, Haiying; Niu, Kunwei; Guo, Yantong; Guo, Chuan; Sun, Jitong; Li, Yi; Yang, Wei

    2015-12-29

    Autoimmune regulator (Aire) can promote the ectopic expression of peripheral tissue-restricted antigens (TRAs) in thymic medullary epithelial cells (mTECs), which leads to the deletion of autoreactive T cells and consequently prevents autoimmune diseases. However, the functions of Aire in the periphery, such as in dendritic cells (DCs), remain unclear. This study's aim was to investigate the effect of Aire-overexpressing DCs (Aire cells) on the functions of CD4T cells and the treatment of type 1 diabetes (T1D). We demonstrated that Aire cells upregulated the mRNA levels of the tolerance-related molecules CD73, Lag3, and FR4 and the apoptosis of CD4T cells in STZ-T1D mouse-derived splenocytes. Furthermore, following insulin stimulation, Aire cells decreased the number of CD4⁺ IFN-γ⁺ T cells in both STZ-T1D and WT mouse-derived splenocytes and reduced the expression levels of TCR signaling molecules (Ca(2+) and p-ERK) in CD4T cells. We observed that Aire cells-induced CD4T cells could delay the development of T1D. In summary, Aire-expressing DCs inhibited TCR signaling pathways and decreased the quantity of CD4⁺IFN-γ⁺ autoreactive T cells. These data suggest a mechanism for Aire in the maintenance of peripheral immune tolerance and provide a potential method to control autoimmunity by targeting Aire.

  14. CD3-CD4+ lymphoid variant of hypereosinophilic syndrome: nodal and extranodal histopathological and immunophenotypic features of a peripheral indolent clonal T-cell lymphoproliferative disorder.

    PubMed

    Lefèvre, Guillaume; Copin, Marie-Christine; Roumier, Christophe; Aubert, Hélène; Avenel-Audran, Martine; Grardel, Nathalie; Poulain, Stéphanie; Staumont-Sallé, Delphine; Seneschal, Julien; Salles, Gilles; Ghomari, Kamel; Terriou, Louis; Leclech, Christian; Morati-Hafsaoui, Chafika; Morschhauser, Franck; Lambotte, Olivier; Ackerman, Félix; Trauet, Jacques; Geffroy, Sandrine; Dumezy, Florent; Capron, Monique; Roche-Lestienne, Catherine; Taieb, Alain; Hatron, Pierre-Yves; Dubucquoi, Sylvain; Hachulla, Eric; Prin, Lionel; Labalette, Myriam; Launay, David; Preudhomme, Claude; Kahn, Jean-Emmanuel

    2015-08-01

    The CD3(-)CD4(+) lymphoid variant of hypereosinophilic syndrome is characterized by hypereosinophilia and clonal circulating CD3(-)CD4(+) T cells. Peripheral T-cell lymphoma has been described during this disease course, and we observed in our cohort of 23 patients 2 cases of angio-immunoblastic T-cell lymphoma. We focus here on histopathological (n=12 patients) and immunophenotypic (n=15) characteristics of CD3(-)CD4(+) lymphoid variant of hypereosinophilic syndrome. Atypical CD4(+) T cells lymphoid infiltrates were found in 10 of 12 CD3(-)CD4(+) L-HES patients, in lymph nodes (n=4 of 4 patients), in skin (n=9 of 9) and other extra-nodal tissues (gut, lacrymal gland, synovium). Lymph nodes displayed infiltrates limited to the interfollicular areas or even an effacement of nodal architecture, associated with proliferation of arborizing high endothelial venules and increased follicular dendritic cell meshwork. Analysis of 2 fresh skin samples confirmed the presence of CD3(-)CD4(+) T cells. Clonal T cells were detected in at least one tissue in 8 patients, including lymph nodes (n=4 of 4): the same clonal T cells were detected in blood and in at least one biopsy, with a maximum delay of 23 years between samples. In the majority of cases, circulating CD3(-)CD4(+) T cells were CD2(hi) (n=9 of 14), CD5(hi) (n=12 of 14), and CD7(-)(n=4 of 14) or CD7(low) (n=10 of 14). Angio-immunoblastic T-cell lymphoma can also present with CD3(-)CD4(+) T cells; despite other common histopathological and immunophenotypic features, CD10 expression and follicular helper T-cell markers were not detected in lymphoid variant of hypereosinophilic syndrome patients, except in both patients who developed angio-immunoblastic T-cell lymphoma, and only at T-cell lymphoma diagnosis. Taken together, persistence of tissular clonal T cells and histopathological features define CD3(-)CD4(+) lymphoid variant of hypereosinophilic syndrome as a peripheral indolent clonal T-cell lymphoproliferative

  15. Out-of-Sequence Signal 3 Paralyzes Primary CD4(+) T-Cell-Dependent Immunity.

    PubMed

    Sckisel, Gail D; Bouchlaka, Myriam N; Monjazeb, Arta M; Crittenden, Marka; Curti, Brendan D; Wilkins, Danice E C; Alderson, Kory A; Sungur, Can M; Ames, Erik; Mirsoian, Annie; Reddy, Abhinav; Alexander, Warren; Soulika, Athena; Blazar, Bruce R; Longo, Dan L; Wiltrout, Robert H; Murphy, William J

    2015-08-18

    Primary T cell activation involves the integration of three distinct signals delivered in sequence: (1) antigen recognition, (2) costimulation, and (3) cytokine-mediated differentiation and expansion. Strong immunostimulatory events such as immunotherapy or infection induce profound cytokine release causing "bystander" T cell activation, thereby increasing the potential for autoreactivity and need for control. We show that during strong stimulation, a profound suppression of primary CD4(+) T-cell-mediated immune responses ensued and was observed across preclinical models and patients undergoing high-dose interleukin-2 (IL-2) therapy. This suppression targeted naive CD4(+) but not CD8(+) T cells and was mediated through transient suppressor of cytokine signaling-3 (SOCS3) inhibition of the STAT5b transcription factor signaling pathway. These events resulted in complete paralysis of primary CD4(+) T cell activation, affecting memory generation and induction of autoimmunity as well as impaired viral clearance. These data highlight the critical regulation of naive CD4(+) T cells during inflammatory conditions.

  16. The life (and death) of CD4+CD28null T cells in inflammatory diseases

    PubMed Central

    Dumitriu, Ingrid E

    2015-01-01

    Inflammation contributes to the development and perpetuation of several disorders and T lymphocytes orchestrate the inflammatory immune response. Although the role of T cells in inflammation is widely recognized, specific therapies that tackle inflammatory networks in disease are yet to be developed. CD4+CD28null T cells are a unique subset of helper T lymphocytes that recently shot back into the limelight as potential catalysts of inflammation in several inflammatory disorders such as autoimmunity, atherosclerosis and chronic viral infections. In contrast to conventional helper T cells, CD4+CD28null T cells have an inbuilt ability to release inflammatory cytokines and cytotoxic molecules that can damage tissues and amplify inflammatory pathways. It comes as no surprise that patients who have high numbers of these cells have more severe disease and poor prognosis. In this review, I provide an overview on the latest advances in the biology of CD4+CD28null T cells. Understanding the complex functions and dynamics of CD4+CD28null T cells may open new avenues for therapeutic intervention to prevent progression of inflammatory diseases. PMID:26190355

  17. Out-of-Sequence Signal 3 Paralyzes Primary CD4(+) T-Cell-Dependent Immunity.

    PubMed

    Sckisel, Gail D; Bouchlaka, Myriam N; Monjazeb, Arta M; Crittenden, Marka; Curti, Brendan D; Wilkins, Danice E C; Alderson, Kory A; Sungur, Can M; Ames, Erik; Mirsoian, Annie; Reddy, Abhinav; Alexander, Warren; Soulika, Athena; Blazar, Bruce R; Longo, Dan L; Wiltrout, Robert H; Murphy, William J

    2015-08-18

    Primary T cell activation involves the integration of three distinct signals delivered in sequence: (1) antigen recognition, (2) costimulation, and (3) cytokine-mediated differentiation and expansion. Strong immunostimulatory events such as immunotherapy or infection induce profound cytokine release causing "bystander" T cell activation, thereby increasing the potential for autoreactivity and need for control. We show that during strong stimulation, a profound suppression of primary CD4(+) T-cell-mediated immune responses ensued and was observed across preclinical models and patients undergoing high-dose interleukin-2 (IL-2) therapy. This suppression targeted naive CD4(+) but not CD8(+) T cells and was mediated through transient suppressor of cytokine signaling-3 (SOCS3) inhibition of the STAT5b transcription factor signaling pathway. These events resulted in complete paralysis of primary CD4(+) T cell activation, affecting memory generation and induction of autoimmunity as well as impaired viral clearance. These data highlight the critical regulation of naive CD4(+) T cells during inflammatory conditions. PMID:26231116

  18. T cell receptor signaling pathway is overexpressed in CD4(+) T cells from HAM/TSP individuals.

    PubMed

    Pinto, Mariana Tomazini; Malta, Tathiane Maistro; Rodrigues, Evandra Strazza; Takayanagui, Osvaldo Massaiti; Tanaka, Yuetsu; Covas, Dimas Tadeu; Kashima, Simone

    2015-01-01

    Human T-lymphotropic virus type 1 (HTLV-1) is a human retrovirus related to the chronic neuroinflammatory disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). CD4(+) T cells activation appears to play a key role on HTLV-1 infection. Here we investigated the expression of genes associated to T cell activation CD3e molecule, epsilon (CD3ɛ), lymphocyte-specific protein tyrosine kinase (LCK), vav 1 guanine nucleotide exchange factor (VAV1), and zeta-chain (TCR) associated protein kinase 70kDa (ZAP70) on T lymphocytes of HTLV-1-infected individuals and compared to healthy uninfected individuals (CT). We observed that CD3ɛ, LCK, ZAP70, and VAV1 gene expression were increased in CD4(+) T cells from HAM/TSP group compared to HTLV-1 asymptomatic patients (HAC). Moreover, ZAP70 and VAV1 were also upregulated in HAM/TSP compared to CT group. We detected a positive correlation among all these genes. We also observed that CD3ɛ, LCK, and VAV1 genes had a positive correlation with the proviral load (PVL) and Tax expression. These results suggest that PVL and Tax protein could drive CD3ɛ, LCK, and VAV1 gene expression in CD4(+) T cells, and these genes function on a synchronized way on the CD4(+) T cell activation. The elucidation of the mechanisms underlying T cell receptor signaling pathway is of considerable interest and might lead to new insights into the mechanism of HAM/TSP.

  19. CCL2 Increases X4-tropic HIV-1 Entry into Resting CD4+ T Cells*

    PubMed Central

    Campbell, Grant R.; Spector, Stephen A.

    2008-01-01

    During human immunodeficiency virus type 1 (HIV-1) infection, there is a strong positive correlation between CCL2 levels and HIV viral load. To determine whether CCL2 alters HIV-1 infection of resting CD4+ T cells, we infected purified resting CD4+ T cells after incubation with CCL2. We show that CCL2 up-regulates CXCR4 on resting CD4+ T cells in a CCR2-dependent mechanism, and that this augmentation of CXCR4 expression by CCL2 increases the ability of these cells to be chemoattracted to CXCR4 using gp120 and renders them more permissive to X4-tropic HIV-1 infection. Thus, CCL2 has the capacity to render a large population of lymphocytes more susceptible to HIV-1 late in the course of infection. PMID:18784079

  20. Induction of CD4+ Regulatory and Polarized Effector/helper T Cells by Dendritic Cells

    PubMed Central

    2016-01-01

    Dendritic cells (DCs) are considered to play major roles during the induction of T cell immune responses as well as the maintenance of T cell tolerance. Naive CD4+ T cells have been shown to respond with high plasticity to signals inducing their polarization into effector/helper or regulatory T cells. Data obtained from in vitro generated bone-marrow (BM)-derived DCs as well as genetic mouse models revealed an important but not exclusive role of DCs in shaping CD4+ T cell responses. Besides the specialization of some conventional DC subsets for the induction of polarized immunity, also the maturation stage, activation of specialized transcription factors and the cytokine production of DCs have major impact on CD4+ T cells. Since in vitro generated BM-DCs show a high diversity to shape CD4+ T cells and their high similarity to monocyte-derived DCs in vivo, this review reports data mainly on BM-DCs in this process and only touches the roles of transcription factors or of DC subsets, which have been discussed elsewhere. Here, recent findings on 1) the conversion of naive into anergic and further into Foxp3− regulatory T cells (Treg) by immature DCs, 2) the role of RelB in steady state migratory DCs (ssmDCs) for conversion of naive T cells into Foxp3+ Treg, 3) the DC maturation signature for polarized Th2 cell induction and 4) the DC source of IL-12 for Th1 induction are discussed. PMID:26937228

  1. Blood-Derived CD4 T Cells Naturally Resist Pyroptosis During Abortive HIV-1 Infection

    PubMed Central

    Muñoz-Arias, Isa; Doitsh, Gilad; Yang, Zhiyuan; Sowinski, Stefanie; Ruelas, Debbie; Greene, Warner C.

    2015-01-01

    Summary Progression to AIDS is driven by CD4 T-cell depletion, mostly involving pyroptosis elicited by abortive HIV infection of CD4 T cells in lymphoid tissues. Inefficient reverse transcription in these cells leads to cytoplasmic accumulation of viral DNAs that are detected by the DNA sensor IFI16, resulting in inflammasome assembly, caspase-1 activation, and pyroptosis. Unexpectedly, we found that peripheral blood-derived CD4 T cells naturally resist pyroptosis. This resistance is partly due to their deeper resting state, resulting in fewer HIV-1 reverse transcripts and lower IFI16 expression. However, when co-cultured with lymphoid-derived cells, blood-derived CD4 T cells become sensitized to pyroptosis, likely recapitulating interactions occurring within lymphoid tissues. Sensitization correlates with higher levels of activated NF-κB, IFI16 expression, and reverse transcription. Blood-derived lymphocytes re-purified from co-cultures lose sensitivity to pyroptosis. These differences highlight how the lymphoid tissue microenvironment encountered by trafficking CD4 T lymphocytes dynamically shapes their biological response to HIV. PMID:26468749

  2. CD4(+) T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia.

    PubMed

    de la Rua, Nicholas M; Samuelson, Derrick R; Charles, Tysheena P; Welsh, David A; Shellito, Judd E

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4(+) T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4(+) T-cells is mediated by a robust memory humoral response, CD8(+) T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8(+) T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8(+) T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4(+) T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8(+) T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8(+) T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8(+) T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ(+) CD8(+) T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8(+) T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG. PMID:27242785

  3. CD4+ T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia

    PubMed Central

    de la Rua, Nicholas M.; Samuelson, Derrick R.; Charles, Tysheena P.; Welsh, David A.; Shellito, Judd E.

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4+ T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4+ T-cells is mediated by a robust memory humoral response, CD8+ T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8+ T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8+ T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4+ T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8+ T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8+ T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8+ T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ+ CD8+ T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8+ T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG. PMID:27242785

  4. Cord Blood Derived CD4+CD25high T Cells Become Functional Regulatory T Cells upon Antigen Encounter

    PubMed Central

    Mayer, Elisabeth; Bannert, Christina; Gruber, Saskia; Klunker, Sven; Spittler, Andreas; Akdis, Cezmi A.

    2012-01-01

    Background: Upon antigen exposure, cord blood derived T cells respond to ubiquitous environmental antigens by high proliferation. To date it remains unclear whether these “excessive” responses relate to different regulatory properties of the putative T regulatory cell (Treg) compartment or even expansion of the Treg compartment itself. Methods: Cord blood (>37 week of gestation) and peripheral blood (healthy controls) were obtained and different Treg cell subsets were isolated. The suppressive potential of Treg populations after antigen exposure was evaluated via functional inhibition assays ([3H]thymidine incorporation assay and CFSE staining) with or without allergen stimulation. The frequency and markers of CD4+CD25highFoxP3+ T cells were characterized by mRNA analysis and flow cytometry. Results: Cord blood derived CD4+CD25high cells did not show substantial suppressor capacity upon TCR activation, in contrast to CD4+CD25high cells freshly purified from adult blood. This could not be explained by a lower frequency of FoxP3+CD4+CD25highcells or FOXP3 mRNA expression. However, after antigen-specific stimulation in vitro, these cells showed strong proliferation and expansion and gained potent suppressive properties. The efficiency of their suppressive capacity can be enhanced in the presence of endotoxins. If T-cells were sorted according to their CD127 expression, a tiny subset of Treg cells (CD4+CD25+CD127low) is highly suppressive even without prior antigen exposure. Conclusion: Cord blood harbors a very small subset of CD4+CD25high Treg cells that requires antigen-stimulation to show expansion and become functional suppressive Tregs. PMID:22272233

  5. Extensive CD4 and CD8 T Cell Cross-Reactivity between Alphaherpesviruses.

    PubMed

    Jing, Lichen; Laing, Kerry J; Dong, Lichun; Russell, Ronnie M; Barlow, Russell S; Haas, Juergen G; Ramchandani, Meena S; Johnston, Christine; Buus, Soren; Redwood, Alec J; White, Katie D; Mallal, Simon A; Phillips, Elizabeth J; Posavad, Christine M; Wald, Anna; Koelle, David M

    2016-03-01

    The Alphaherpesvirinae subfamily includes HSV types 1 and 2 and the sequence-divergent pathogen varicella zoster virus (VZV). T cells, controlled by TCR and HLA molecules that tolerate limited epitope amino acid variation, might cross-react between these microbes. We show that memory PBMC expansion with either HSV or VZV enriches for CD4 T cell lines that recognize the other agent at the whole-virus, protein, and peptide levels, consistent with bidirectional cross-reactivity. HSV-specific CD4 T cells recovered from HSV-seronegative persons can be explained, in part, by such VZV cross-reactivity. HSV-1-reactive CD8 T cells also cross-react with VZV-infected cells, full-length VZV proteins, and VZV peptides, as well as kill VZV-infected dermal fibroblasts. Mono- and cross-reactive CD8 T cells use distinct TCRB CDR3 sequences. Cross-reactivity to VZV is reconstituted by cloning and expressing TCRA/TCRB receptors from T cells that are initially isolated using HSV reagents. Overall, we define 13 novel CD4 and CD8 HSV-VZV cross-reactive epitopes and strongly imply additional cross-reactive peptide sets. Viral proteins can harbor both CD4 and CD8 HSV/VZV cross-reactive epitopes. Quantitative estimates of HSV/VZV cross-reactivity for both CD4 and CD8 T cells vary from 10 to 50%. Based on these findings, we hypothesize that host herpesvirus immune history may influence the pathogenesis and clinical outcome of subsequent infections or vaccinations for related pathogens and that cross-reactive epitopes and TCRs may be useful for multi-alphaherpesvirus vaccine design and adoptive cellular therapy. PMID:26810224

  6. Bromelain treatment reduces CD25 expression on activated CD4+ T cells in vitro.

    PubMed

    Secor, Eric R; Singh, Anurag; Guernsey, Linda A; McNamara, Jeff T; Zhan, Lijun; Maulik, Nilanjana; Thrall, Roger S

    2009-03-01

    Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4(+) T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4(+) T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, found as a soluble fraction (sCD25) and is a therapeutic target in inflammation, autoimmunity and allergy. Br treatment of anti-CD3 stimulated CD4(+) T cells reduced CD25 expression in a dose and time dependent manner. This reduction of CD25 was dependent on the proteolytic action of Br as the addition of E64 (a cysteine protease inhibitor) abrogated this response. The concentration of sCD25 was increased in supernatants of Br treated activated CD4(+) T cells as compared to control cells, suggesting that Br proteolytically cleaved cell-surface CD25. This novel mechanism of action identifies how Br may exert its therapeutic benefits in inflammatory conditions.

  7. Conventional and Regulatory CD4+ T Cells That Share Identical TCRs Are Derived from Common Clones.

    PubMed

    Wolf, Kyle J; Emerson, Ryan O; Pingel, Jeanette; Buller, R Mark; DiPaolo, Richard J

    2016-01-01

    Results from studies comparing the diversity and specificity of the TCR repertoires expressed by conventional (Tconv) and regulatory (Treg) CD4+ T cell have varied depending on the experimental system employed. We developed a new model in which T cells express a single fixed TCRα chain, randomly rearranged endogenous TCRβ chains, and a Foxp3-GFP reporter. We purified CD4+Foxp3- and CD4+Foxp3+ cells, then performed biased controlled multiplex PCR and high throughput sequencing of endogenous TCRβ chains. We identified >7,000 different TCRβ sequences in the periphery of 5 individual mice. On average, ~12% of TCR sequences were expressed by both conventional and regulatory populations within individual mice. The CD4+ T cells that expressed shared TCR sequences were present at higher frequencies compared to T cells expressing non-shared TCRs. Furthermore, nearly all (>90%) of the TCR sequences that were shared within mice were identical at the DNA sequence level, indicating that conventional and regulatory T cells that express shared TCRs are derived from common clones. Analysis of TCR repertoire overlap in the thymus reveals that a large proportion of Tconv and Treg sharing observed in the periphery is due to clonal expansion in the thymus. Together these data show that there are a limited number of TCR sequences shared between Tconv and Tregs. Also, Tconv and Tregs sharing identical TCRs are found at relatively high frequencies and are derived from common progenitors, of which a large portion are generated in the thymus. PMID:27100298

  8. Conventional and Regulatory CD4+ T Cells That Share Identical TCRs Are Derived from Common Clones

    PubMed Central

    Emerson, Ryan O.; Pingel, Jeanette; Buller, R. Mark; DiPaolo, Richard J.

    2016-01-01

    Results from studies comparing the diversity and specificity of the TCR repertoires expressed by conventional (Tconv) and regulatory (Treg) CD4+ T cell have varied depending on the experimental system employed. We developed a new model in which T cells express a single fixed TCRα chain, randomly rearranged endogenous TCRβ chains, and a Foxp3-GFP reporter. We purified CD4+Foxp3- and CD4+Foxp3+ cells, then performed biased controlled multiplex PCR and high throughput sequencing of endogenous TCRβ chains. We identified >7,000 different TCRβ sequences in the periphery of 5 individual mice. On average, ~12% of TCR sequences were expressed by both conventional and regulatory populations within individual mice. The CD4+ T cells that expressed shared TCR sequences were present at higher frequencies compared to T cells expressing non-shared TCRs. Furthermore, nearly all (>90%) of the TCR sequences that were shared within mice were identical at the DNA sequence level, indicating that conventional and regulatory T cells that express shared TCRs are derived from common clones. Analysis of TCR repertoire overlap in the thymus reveals that a large proportion of Tconv and Treg sharing observed in the periphery is due to clonal expansion in the thymus. Together these data show that there are a limited number of TCR sequences shared between Tconv and Tregs. Also, Tconv and Tregs sharing identical TCRs are found at relatively high frequencies and are derived from common progenitors, of which a large portion are generated in the thymus. PMID:27100298

  9. Restoring homeostasis of CD4+ T cells in hepatitis-B-virus-related liver fibrosis

    PubMed Central

    Cheng, Li-Sha; Liu, Yun; Jiang, Wei

    2015-01-01

    Immune-mediated liver injury is widely seen during hepatitis B virus (HBV) infection. Unsuccessful immune clearance of HBV results in chronic hepatitis and increases the risk of liver cirrhosis and hepatocellular carcinoma. HBV-related liver fibrosis (HBVLF), occurring as a result of HBV-induced chronic hepatitis, is a reversible, intermediate stage of chronic hepatitis B (CHB) and liver cirrhosis. Therefore, defining the pathogenesis of HBVLF is of practical significance for achieving better clinical outcomes. Recently, the homeostasis of CD4+ T cells was considered to be pivotal in the process of HBVLF. To better uncover the underlying mechanisms, in this review, we systematically retrospect the impacts of different CD4+ T-cell subsets on CHB and HBVLF. We emphasize CD4+ T-cell homeostasis and the important balance between regulatory T (Treg) and T helper 17 (Th17) cells. We discuss some cytokines associated with Treg and Th17 cells such as interleukin (IL)-17, IL-22, IL-21, IL-23, IL-10, IL-35 and IL-33, as well as surface molecules such as programmed cell death protein 1, cytotoxic T lymphocyte-associated antigen 4, T cell immunoglobulin domain and mucin domain-containing molecule 3 and cannabinoid receptor 2 that have potential therapeutic implications for the homeostasis of CD4+ T cells in CHB and HBVLF. PMID:26478664

  10. Regulatory T-cells are essential to promote proper CD4 T-cell priming upon mucosal infection

    PubMed Central

    Soerens, Andrew G.; Da Costa, Andreia; Lund, Jennifer M.

    2016-01-01

    Regulatory T-cells (Tregs) limit autoimmunity and immunopathology using a variety of suppressive mechanisms, but their roles during pathogen-directed immune responses remain unclear. Following Herpes Simplex virus-2 (HSV-2) infection, mice lacking Tregs fail to control viral replication, pointing to a role for Tregs in facilitating productive immune responses. Using adoptive transfer of TCR transgenic CD4 T-cells into Treg-sufficient or Treg-depleted mice prior to HSV-2 infection, we found that Tregs are required for timely accumulation of HSV-2-specific CD4 T-cells within the infected tissues. Further, Tregs are critical for appropriate trafficking of dendritic cells (DCs) from the vaginal mucosa to the dLN, which results in fully effective CD4 T-cell priming, activation, and ultimately migration to the infected tissues. Using CTLA-4 conditional knockout mice, we demonstrate that Tregs impact DC migration through a CTLA-4-mediated mechanism. Together, our data highlight the critical role of Tregs in proper potentiation of adaptive immune responses to microbial infection. PMID:27007674

  11. The Differentiation and Protective Function of Cytolytic CD4 T Cells in Influenza Infection

    PubMed Central

    Brown, Deborah M.; Lampe, Anna T.; Workman, Aspen M.

    2016-01-01

    CD4 T cells that recognize peptide antigen in the context of class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity (CD4 CTL) play a role in chronic as well as acute infections, such as influenza A virus (IAV) infection. In the last couple of decades, techniques to measure the frequency and activity of these cytolytic cells has demonstrated their abundance in infections, such as human immunodeficiency virus, mouse pox, murine gamma herpes virus, cytomegalovirus, Epstein–Barr virus, and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and antitumor immunity through their ability to acquire perforin-mediated cytolytic activity and contribution to lysis of virally infected targets or tumors. As early as the 1980s, CD4 T cell clones with cytolytic potential were identified after influenza virus infection, yet much of this early work was dependent on in vitro culture and little was known about the physiological relevance of CD4 CTL. Here, we discuss the direct role CD4 CTL play in protection against lethal IAV infection and the factors that drive the generation of perforin-mediated lytic activity in CD4 cells in vivo during IAV infection. While focusing on CD4 CTL generated during IAV infection, we pull comparisons from the literature in other antiviral and antitumor systems. Further, we highlight what is currently known about CD4 CTL secondary and memory responses, as well as vaccination strategies to induce these potent killer cells that provide an extra layer of cell-mediated immune protection against heterosubtypic IAV infection. PMID:27014272

  12. The Differentiation and Protective Function of Cytolytic CD4 T Cells in Influenza Infection.

    PubMed

    Brown, Deborah M; Lampe, Anna T; Workman, Aspen M

    2016-01-01

    CD4 T cells that recognize peptide antigen in the context of class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity (CD4 CTL) play a role in chronic as well as acute infections, such as influenza A virus (IAV) infection. In the last couple of decades, techniques to measure the frequency and activity of these cytolytic cells has demonstrated their abundance in infections, such as human immunodeficiency virus, mouse pox, murine gamma herpes virus, cytomegalovirus, Epstein-Barr virus, and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and antitumor immunity through their ability to acquire perforin-mediated cytolytic activity and contribution to lysis of virally infected targets or tumors. As early as the 1980s, CD4 T cell clones with cytolytic potential were identified after influenza virus infection, yet much of this early work was dependent on in vitro culture and little was known about the physiological relevance of CD4 CTL. Here, we discuss the direct role CD4 CTL play in protection against lethal IAV infection and the factors that drive the generation of perforin-mediated lytic activity in CD4 cells in vivo during IAV infection. While focusing on CD4 CTL generated during IAV infection, we pull comparisons from the literature in other antiviral and antitumor systems. Further, we highlight what is currently known about CD4 CTL secondary and memory responses, as well as vaccination strategies to induce these potent killer cells that provide an extra layer of cell-mediated immune protection against heterosubtypic IAV infection. PMID:27014272

  13. The Differentiation and Protective Function of Cytolytic CD4 T Cells in Influenza Infection.

    PubMed

    Brown, Deborah M; Lampe, Anna T; Workman, Aspen M

    2016-01-01

    CD4 T cells that recognize peptide antigen in the context of class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity (CD4 CTL) play a role in chronic as well as acute infections, such as influenza A virus (IAV) infection. In the last couple of decades, techniques to measure the frequency and activity of these cytolytic cells has demonstrated their abundance in infections, such as human immunodeficiency virus, mouse pox, murine gamma herpes virus, cytomegalovirus, Epstein-Barr virus, and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and antitumor immunity through their ability to acquire perforin-mediated cytolytic activity and contribution to lysis of virally infected targets or tumors. As early as the 1980s, CD4 T cell clones with cytolytic potential were identified after influenza virus infection, yet much of this early work was dependent on in vitro culture and little was known about the physiological relevance of CD4 CTL. Here, we discuss the direct role CD4 CTL play in protection against lethal IAV infection and the factors that drive the generation of perforin-mediated lytic activity in CD4 cells in vivo during IAV infection. While focusing on CD4 CTL generated during IAV infection, we pull comparisons from the literature in other antiviral and antitumor systems. Further, we highlight what is currently known about CD4 CTL secondary and memory responses, as well as vaccination strategies to induce these potent killer cells that provide an extra layer of cell-mediated immune protection against heterosubtypic IAV infection.

  14. Third-party CD4+ invariant natural killer T cells protect from murine GVHD lethality.

    PubMed

    Schneidawind, Dominik; Baker, Jeanette; Pierini, Antonio; Buechele, Corina; Luong, Richard H; Meyer, Everett H; Negrin, Robert S

    2015-05-28

    Graft-versus-host disease (GVHD) is driven by extensive activation and proliferation of alloreactive donor T cells causing significant morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). Invariant natural killer T (iNKT) cells are a potent immunoregulatory T-cell subset in both humans and mice. Here, we explored the role of adoptively transferred third-party CD4(+) iNKT cells for protection from lethal GVHD in a murine model of allogeneic HCT across major histocompatibility barriers. We found that low numbers of CD4(+) iNKT cells from third-party mice resulted in a significant survival benefit with retained graft-versus-tumor effects. In vivo expansion of alloreactive T cells was diminished while displaying a T helper cell 2-biased phenotype. Notably, CD4(+) iNKT cells from third-party mice were as protective as CD4(+) iNKT cells from donor mice although third-party CD4(+) iNKT cells were rejected early after allogeneic HCT. Adoptive transfer of third-party CD4(+) iNKT cells resulted in a robust expansion of donor CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) that were required for protection from lethal GVHD. However, in vivo depletion of myeloid-derived suppressor cells abrogated both Treg expansion and protection from lethal GVHD. Despite the fact that iNKT cells are a rare cell population, the almost unlimited third-party availability and feasibility of in vitro expansion provide the basis for clinical translation.

  15. Inflammation Enhances IL-2 Driven Differentiation of Cytolytic CD4 T Cells

    PubMed Central

    Workman, Aspen M.; Jacobs, Ashley K.; Vogel, Alexander J.; Condon, Shirley; Brown, Deborah M.

    2014-01-01

    Cytolytic CD4 T cells (CD4 CTL) have been identified in vivo in response to viral infections; however, the factors necessary for driving the cytolytic phenotype have not been fully elucidated. Our previously published work suggests IL-2 may be the master regulator of perforin-mediated cytotoxicity in CD4 effectors. To further dissect the role of IL-2 in CD4 CTL generation, T cell receptor transgenic mice deficient in the ability to produce IL-2 or the high affinity IL-2 receptor (IL-2Rα, CD25) were used. Increasing concentrations of IL-2 were necessary to drive perforin (Prf) expression and maximal cytotoxicity. Granzyme B (GrB) expression and killing correlated with STAT5 activation and CD25 expression in vitro, suggesting that signaling through the high affinity IL-2R is critical for full cytotoxicity. IL-2 signaling was also necessary in vivo for inducing the Th1 phenotype and IFN-γ expression in CD4 T cells during influenza A (IAV) infection. In addition, GrB expression, as measured by mean fluorescent intensity, was decreased in CD25 deficient cells; however, the frequency of CD4 cells expressing GrB was unchanged. Similarly, analysis of cytolytic markers such as CD107a/b and Eomesodermin indicate high IL-2Rα expression is not necessary to drive the CD4 CTL phenotype during IAV infection. Thus, inflammatory signals induced by viral infection may overcome the need for strong IL-2 signals in driving cytotoxicity in CD4 cells. PMID:24586481

  16. Identification of Mycobacterium tuberculosis vaccine candidates using human CD4+ T-cells expression cloning

    PubMed Central

    Coler, Rhea N.; Dillon, Davin C.; Skeiky, Yasir A. W.; Kahn, Maria; Orme, Ian M.; Lobet, Yves; Reed, Steven G.; Alderson, Mark R.

    2009-01-01

    To identify Mycobacterium tuberculosis (Mtb) antigens as candidates for a subunit vaccine against tuberculosis (TB), we have employed a CD4+ T-cell expression screening method. Mtb-specific CD4+ T-cell lines from nine healthy PPD positive donors were stimulated with different antigenic substrates including autologous dendritic cells (DC) infected with Mtb, culture filtrate proteins (CFP), and purified protein derivative of Mtb (PPD). These lines were used to screen a genomic Mtb library expressed in Escherichia coli and processed and presented by autologous DC. This screening led to the recovery of numerous T-cell antigens, including both novel and previously described antigens. One of these novel antigens, referred to as Mtb9.8 (Rv0287), was recognized by multiple T-cell lines, stimulated with either Mtb-infected DC or CFP. Using the mouse and guinea pig models of TB, high levels of IFN-γ were produced, and solid protection from Mtb challenge was observed following immunization with Mtb9.8 formulated in either AS02A or AS01B Adjuvant Systems. These results demonstrate that T-cell screening of the Mtb genome can be used to identify CD4+ T-cell antigens that are candidates for vaccine development. PMID:19000730

  17. Human CD4 T cell epitopes selective for Vaccinia versus Variola virus.

    PubMed

    Probst, Alicia; Besse, Aurore; Favry, Emmanuel; Imbert, Gilles; Tanchou, Valérie; Castelli, Florence Anne; Maillere, Bernard

    2013-04-01

    Due to the high degree of sequence identity between Orthopoxvirus species, the specific B and T cell responses raised against these viruses are largely cross-reactive and poorly selective. We therefore searched for CD4 T cell epitopes present in the conserved parts of the Vaccinia genome (VACV) but absent from Variola viruses (VARV), with a view to identifying immunogenic sequences selective for VACV. We identified three long peptide fragments from the B7R, B10R and E7R proteins by in silico comparisons of the poxvirus genomes, and evaluated the recognition of these fragments by VACV-specific T cell lines derived from healthy donors. For the 12 CD4 T cell epitopes identified, we assessed their binding to common HLA-DR allotypes and their capacity to induce peptide-specific CD4 T-cell lines. Four peptides from B7R and B10R displayed a broad binding specificity for HLA-DR molecules and induced multiple T cell lines from healthy donors. Besides their absence from VARV, the two B10R peptide sequences were mutated in the Cowpox virus and completely absent from the Monkeypox genome. This work contributes to the development of differential diagnosis of poxvirus infections.

  18. Identification of novel Mycobacterium tuberculosis CD4 T-cell antigens via high throughput proteome screening

    PubMed Central

    Nayak, Kaustuv; Jing, Lichen; Russell, Ronnie M.; Davies, D. Huw; Hermanson, Gary; Molina, Douglas M.; Liang, Xiaowu; Sherman, David R.; Kwok, William W.; Yang, Junbao; Kenneth, John; Ahamed, Syed F.; Chandele, Anmol; Kaja, Murali-Krishna; Koelle, David M.

    2015-01-01

    Elicitation of CD4 IFN-gamma T cell responses to Mycobacterium tuberculosis (MTB) is a rational vaccine strategy to prevent clinical tuberculosis. Diagnosis of MTB infection is based on T-cell immune memory to MTB antigens. The MTB proteome contains over four thousand open reading frames (ORFs). We conducted a pilot antigen identification study using 164 MTB proteins and MTB-specific T-cells expanded in vitro from 12 persons with latent MTB infection. Enrichment of MTB-reactive T-cells from PBMC used cell sorting or an alternate system compatible with limited resources. MTB proteins were used as single antigens or combinatorial matrices in proliferation and cytokine secretion readouts. Overall, our study found that 44 MTB proteins were antigenic, including 27 not previously characterized as CD4 T-cell antigens. Antigen truncation, peptide, NTM homology, and HLA class II tetramer studies confirmed malate synthase G (encoded by gene Rv1837) as a CD4 T-cell antigen. This simple, scalable system has potential utility for the identification of candidate MTB vaccine and biomarker antigens. PMID:25857935

  19. Alternative splicing of MALT1 controls signalling and activation of CD4+ T cells

    PubMed Central

    Meininger, Isabel; Griesbach, Richard A.; Hu, Desheng; Gehring, Torben; Seeholzer, Thomas; Bertossi, Arianna; Kranich, Jan; Oeckinghaus, Andrea; Eitelhuber, Andrea C.; Greczmiel, Ute; Gewies, Andreas; Schmidt-Supprian, Marc; Ruland, Jürgen; Brocker, Thomas; Heissmeyer, Vigo; Heyd, Florian; Krappmann, Daniel

    2016-01-01

    MALT1 channels proximal T-cell receptor (TCR) signalling to downstream signalling pathways. With MALT1A and MALT1B two conserved splice variants exist and we demonstrate here that MALT1 alternative splicing supports optimal T-cell activation. Inclusion of exon7 in MALT1A facilitates the recruitment of TRAF6, which augments MALT1 scaffolding function, but not protease activity. Naive CD4+ T cells express almost exclusively MALT1B and MALT1A expression is induced by TCR stimulation. We identify hnRNP U as a suppressor of exon7 inclusion. Whereas selective depletion of MALT1A impairs T-cell signalling and activation, downregulation of hnRNP U enhances MALT1A expression and T-cell activation. Thus, TCR-induced alternative splicing augments MALT1 scaffolding to enhance downstream signalling and to promote optimal T-cell activation. PMID:27068814

  20. CD4+ T Cells Promote Antibody Production but Not Sustained Affinity Maturation during Borrelia burgdorferi Infection

    PubMed Central

    Elsner, Rebecca A.; Hastey, Christine J.

    2014-01-01

    CD4 T cells are crucial for enhancing B cell-mediated immunity, supporting the induction of high-affinity, class-switched antibody responses, long-lived plasma cells, and memory B cells. Previous studies showed that the immune response to Borrelia burgdorferi appears to lack robust T-dependent B cell responses, as neither long-lived plasma cells nor memory B cells form for months after infection, and nonswitched IgM antibodies are produced continuously during this chronic disease. These data prompted us to evaluate the induction and functionality of B. burgdorferi infection-induced CD4 TFH cells. We report that CD4 T cells were effectively primed and TFH cells induced after B. burgdorferi infection. These CD4 T cells contributed to the control of B. burgdorferi burden and supported the induction of B. burgdorferi-specific IgG responses. However, while affinity maturation of antibodies against a prototypic T-dependent B. burgdorferi protein, Arthritis-related protein (Arp), were initiated, these increases were reversed later, coinciding with the previously observed involution of germinal centers. The cessation of affinity maturation was not due to the appearance of inhibitory or exhausted CD4 T cells or a strong induction of regulatory T cells. In vitro T-B cocultures demonstrated that T cells isolated from B. burgdorferi-infected but not B. burgdorferi-immunized mice supported the rapid differentiation of B cells into antibody-secreting plasma cells rather than continued proliferation, mirroring the induction of rapid short-lived instead of long-lived T-dependent antibody responses in vivo. The data further suggest that B. burgdorferi infection drives the humoral response away from protective, high-affinity, and long-lived antibody responses and toward the rapid induction of strongly induced, short-lived antibodies of limited efficacy. PMID:25312948

  1. Human Memory CD4+ T Cell Immune Responses against Giardia lamblia

    PubMed Central

    Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina

    2015-01-01

    The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4+ T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4+ effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4+ EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4+ T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4+ EM T cell response of which IL-17A production seems to be an important component. PMID:26376930

  2. Human Memory CD4+ T Cell Immune Responses against Giardia lamblia.

    PubMed

    Saghaug, Christina Skår; Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina; Hanevik, Kurt

    2016-01-01

    The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4(+) T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4(+) effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4(+) EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4(+) T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4(+) EM T cell response of which IL-17A production seems to be an important component. PMID:26376930

  3. IL-15 induces CD4+ effector memory T cell production and tissue emigration in nonhuman primates

    PubMed Central

    Picker, Louis J.; Reed-Inderbitzin, Edward F.; Hagen, Shoko I.; Edgar, John B.; Hansen, Scott G.; Legasse, Alfred; Planer, Shannon; Piatak, Michael; Lifson, Jeffrey D.; Maino, Vernon C.; Axthelm, Michael K.; Villinger, Francois

    2006-01-01

    HIV infection selectively targets CD4+ effector memory T (TEM) cells, resulting in dramatic depletion of CD4+ T cells in mucosal effector sites in early infection. Regeneration of the TEM cell compartment is slow and incomplete, even when viral replication is controlled by antiretroviral therapy (ART). Here, we demonstrate that IL-15 dramatically increases in vivo proliferation of rhesus macaque (RM) CD4+ and CD8+ TEM cells with little effect on the naive or central memory T (TCM) cell subsets, a response pattern that is quite distinct from that of either IL-2 or IL-7. TEM cells produced in response to IL-15 did not accumulate in blood. Rather, 5-bromo-2′-deoxyuridine (BrdU) labeling studies suggest that many of these cells rapidly disperse to extralymphoid effector sites, where they manifest (slow) decay kinetics indistinguishable from that of untreated controls. In RMs with uncontrolled SIV infection and highly activated immune systems, IL-15 did not significantly increase CD4+ TEM cell proliferation, but with virologic control and concomitant reduction in immune activation by ART, IL-15 responsiveness was again observed. These data suggest that therapeutic use of IL-15 in the setting of ART might facilitate specific restoration of the CD4+ T cell compartment that is the primary target of HIV with less risk of exhausting precursor T cell compartments or generating potentially deleterious regulatory subsets. PMID:16691294

  4. Leishmania-infected macrophages sequester endogenously synthesized parasite antigens from presentation to CD4+ T cells.

    PubMed

    Kima, P E; Soong, L; Chicharro, C; Ruddle, N H; McMahon-Pratt, D

    1996-12-01

    CD4+ T cell lines raised against the protective leishmanial antigens GP46 and P8 were used to study the presentation of endogenously synthesized Leishmania antigens by infected cells. Using two different sources of macrophages, the I4.07 macrophage cell line (H-2k) which constitutively expresses major histocompatibility complex (MHC) class II molecules, and elicited peritoneal exudate cells, we found that cells infected with Leishmania amastigotes presented little, if any endogenously synthesized parasite antigens to CD4+ T cells. In contrast, promastigote-infected macrophages did present endogenous parasite molecules to CD4+ T cells, although only for a limited time, with maximal presentation occurring within 24 h of infection and decreasing to minimal antigen presentation at 72 h post-infection. These observations suggest that once within the macrophage, Leishmania amastigote antigens are sequestered from the MHC class II pathway of antigen presentation. This allows live parasites to persist in infected hosts by evading the activation of CD4+ T cells, a major and critical anti-leishmanial component of the host immune system. Studies with drugs that modify fusion patterns of phagosomes suggest that the mechanism of this antigen sequestration includes targeted fusion of the parasitophorous vacuole with certain endocytic compartments.

  5. ADAR1 Facilitates HIV-1 Replication in Primary CD4+ T Cells

    PubMed Central

    van Hamme, John L.; Jansen, Machiel H.; van Dort, Karel A.; Vanderver, Adeline; Rice, Gillian I.; Crow, Yanick J.; Kootstra, Neeltje A.; Kuijpers, Taco W.

    2015-01-01

    Unlike resting CD4+ T cells, activated CD4+T cells are highly susceptible to infection of human immunodeficiency virus 1 (HIV-1). HIV-1 infects T cells and macrophages without activating the nucleic acid sensors and the anti-viral type I interferon response. Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA editing enzyme that displays antiviral activity against several RNA viruses. Mutations in ADAR1 cause the autoimmune disorder Aicardi-Goutieères syndrome (AGS). This disease is characterized by an inappropriate activation of the interferon-stimulated gene response. Here we show that HIV-1 replication, in ADAR1-deficient CD4+T lymphocytes from AGS patients, is blocked at the level of protein translation. Furthermore, viral protein synthesis block is accompanied by an activation of interferon-stimulated genes. RNA silencing of ADAR1 in Jurkat cells also inhibited HIV-1 protein synthesis. Our data support that HIV-1 requires ADAR1 for efficient replication in human CD4+T cells. PMID:26629815

  6. HIV-1 gp120 induces NFAT nuclear translocation in resting CD4+ T-cells

    SciTech Connect

    Cicala, Claudia . E-mail: ccicala@nih.gov; Arthos, James; Censoplano, Nina; Cruz, Catherine; Chung, Eva; Martinelli, Elena; Lempicki, Richard A.; Natarajan, Ven; VanRyk, Donald; Daucher, Marybeth; Fauci, Anthony S.

    2006-02-05

    The replication of human immunodeficiency virus (HIV) in CD4+ T-cells is strongly dependent upon the state of activation of infected cells. Infection of sub-optimally activated cells is believed to play a critical role in both the transmission of virus and the persistence of CD4+ T-cell reservoirs. There is accumulating evidence that HIV can modulate signal-transduction pathways in a manner that may facilitate replication in such cells. We previously demonstrated that HIV gp120 induces virus replication in resting CD4+ T cells isolated from HIV-infected individuals. Here, we show that in resting CD4+ T-cells, gp120 activates NFATs and induces their translocation into the nucleus. The HIV LTR encodes NFAT recognition sites, and NFATs may play a critical role in promoting viral replication in sub-optimally activated cells. These observations provide insight into a potential mechanism by which HIV is able to establish infection in resting cells, which may have implications for both transmission of HIV and the persistence of viral reservoirs.

  7. The Influence of Costimulation and Regulatory Cd4+ T Cells on Intestinal Iga Immune Responses

    PubMed Central

    Kagrdic, Dubrav; Kjerrulf, Martin; Bromander, Annakari; Vajdy, Michael; Hörnquist, Elisabeth; Lycke, Nils

    1998-01-01

    It is thought that IgA B-cell differentiation is highly dependent on activated CD4+ T cells. In particular, cell-cell interactions in the Peyer's patches involving CD40 and/or CD80/CD86 have been implicated in germinal-center formation and IgA B-cell development. Also soluble factors, such as IL-4, IL-5, IL-6, and TGFβ may be critical for IgA B-cell differentiation in vivo. Here we report on some paradoxical findings with regard to IgA B-cell differentiation and specific mucosal immune responses that we have recently made using gene knockout mice. More specifically, we have investigated to what extent absence of CD4+ T cells, relevant cytokines, or T-cell-B-cell interactions would influence IgA B-cell differentiation in vivo. Using CD4– or IL- 4-gene knockout mice or mice made transgenic for CTLA4Ig, we found that, although specific responses were impaired, total IgA production and IgA B-cell differentiation appeared to proceed normally. However, a poor correlation was found between, on the one hand, GC formation and IgA differentiation and, on the other hand, the ability to respond to T-celldependent soluble protein antigens in these mice. Thus, despite the various deficiencies in CD4+ T-cell functions seemingly intact IgA B-cell development was observed. PMID:9716905

  8. Salmonella enterica Serovar Typhi Impairs CD4 T Cell Responses by Reducing Antigen Availability

    PubMed Central

    Atif, Shaikh M.; Winter, Sebastian E.; Winter, Maria G.; McSorley, Stephen J.

    2014-01-01

    Salmonella enterica serovar Typhi is associated with a disseminated febrile illness in humans, termed typhoid fever, while Salmonella enterica serovar Typhimurium causes localized gastroenteritis in immunocompetent individuals. One of the genetic differences between both pathogens is the presence in S. Typhi of TviA, a regulatory protein that shuts down flagellin (FliC) expression when bacteria transit from the intestinal lumen into the intestinal mucosa. Here we investigated the consequences of TviA-mediated flagellum gene regulation on flagellin-specific CD4 T cell responses in a mouse model of S. Typhimurium infection. Introduction of the S. Typhi tviA gene into S. Typhimurium suppressed antigen presentation of dendritic cells to flagellin-specific CD4 T cells in vitro. Furthermore, TviA-mediated repression of flagellin expression impaired the activation and proliferation of naive flagellin-specific CD4 T cells in Peyer's patches and mesenteric lymph nodes, which was accompanied by increased bacterial dissemination to the spleen. We conclude that TviA-mediated repression of flagellin expression reduces antigen availability, thereby weakening flagellin-specific CD4 T cell responses. PMID:24643532

  9. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the assessment of this response in bovine infections was not fe...

  10. CD4(+) T cells epigenetically modified by oxidative stress cause lupus-like autoimmunity in mice.

    PubMed

    Strickland, Faith M; Li, YePeng; Johnson, Kent; Sun, Zhichao; Richardson, Bruce C

    2015-08-01

    Lupus develops when genetically predisposed people encounter environmental agents such as UV light, silica, infections and cigarette smoke that cause oxidative stress, but how oxidative damage modifies the immune system to cause lupus flares is unknown. We previously showed that oxidizing agents decreased ERK pathway signaling in human T cells, decreased DNA methyltransferase 1 and caused demethylation and overexpression of genes similar to those from patients with active lupus. The current study tested whether oxidant-treated T cells can induce lupus in mice. We adoptively transferred CD4(+) T cells treated in vitro with oxidants hydrogen peroxide or nitric oxide or the demethylating agent 5-azacytidine into syngeneic mice and studied the development and severity of lupus in the recipients. Disease severity was assessed by measuring anti-dsDNA antibodies, proteinuria, hematuria and by histopathology of kidney tissues. The effect of the oxidants on expression of CD40L, CD70, KirL1 and DNMT1 genes and CD40L protein in the treated CD4(+) T cells was assessed by Q-RT-PCR and flow cytometry. H2O2 and ONOO(-) decreased Dnmt1 expression in CD4(+) T cells and caused the upregulation of genes known to be suppressed by DNA methylation in patients with lupus and animal models of SLE. Adoptive transfer of oxidant-treated CD4(+) T cells into syngeneic recipients resulted in the induction of anti-dsDNA antibody and glomerulonephritis. The results show that oxidative stress may contribute to lupus disease by inhibiting ERK pathway signaling in T cells leading to DNA demethylation, upregulation of immune genes and autoreactivity.

  11. Rheumatoid arthritis-associated RBPJ polymorphism alters memory CD4+ T cells.

    PubMed

    Orent, William; Mchenry, Allison R; Rao, Deepak A; White, Charles; Klein, Hans-Ulrich; Bassil, Ribal; Srivastava, Gyan; Replogle, Joseph M; Raj, Towfique; Frangieh, Michael; Cimpean, Maria; Cuerdon, Nicole; Chibnik, Lori; Khoury, Samia J; Karlson, Elizabeth W; Brenner, Michael B; De Jager, Philip; Bradshaw, Elizabeth M; Elyaman, Wassim

    2016-01-15

    Notch signaling has recently emerged as an important regulator of immune responses in autoimmune diseases. The recombination signal-binding protein for immunoglobulin kappa J region (RBPJ) is a transcriptional repressor, but converts into a transcriptional activator upon activation of the canonical Notch pathway. Genome-wide association studies of rheumatoid arthritis (RA) identified a susceptibility locus, rs874040(CC), which implicated the RBPJ gene. Here, chromatin state mapping generated using the chromHMM algorithm reveals strong enhancer regions containing DNase I hypersensitive sites overlapping the rs874040 linkage disequilibrium block in human memory, but not in naïve CD4(+) T cells. The rs874040 overlapping this chromatin state was associated with increased RBPJ expression in stimulated memory CD4(+) T cells from healthy subjects homozygous for the risk allele (CC) compared with memory CD4(+) T cells bearing the protective allele (GG). Transcriptomic analysis of rs874040(CC) memory T cells showed a repression of canonical Notch target genes IL (interleukin)-9, IL-17 and interferon (IFN)γ in the basal state. Interestingly, activation of the Notch pathway using soluble Notch ligand, Jagged2-Fc, induced IL-9 and IL-17A while delta-like 4Fc, another Notch ligand, induced higher IFNγ expression in the rs874040(CC) memory CD4(+) T cells compared with their rs874040(GG) counterparts. In RA, RBPJ expression is elevated in memory T cells from RA patients compared with control subjects, and this was associated with induced inflammatory cytokines IL-9, IL-17A and IFNγ in response to Notch ligation in vitro. These findings demonstrate that the rs874040(CC) allele skews memory T cells toward a pro-inflammatory phenotype involving Notch signaling, thus increasing the susceptibility to develop RA. PMID:26604133

  12. CD1-restricted CD4+ T cells in major histocompatibility complex class II-deficient mice

    PubMed Central

    1995-01-01

    Rather unexpectedly, major histocompatibility complex class II- deficient mice have a significant population of peripheral CD4+ T lymphocytes. We have investigated these cells at the population and clonal levels. CD4+ T lymphocytes from class II-deficient animals are thymically derived, appear early in ontogeny, exhibit the phenotype of resting memory cells, are potentially functional by several criteria, and have a diverse T cell receptor repertoire. They do not include substantially elevated numbers of NK1.1+ cells. Hybridomas derived after polyclonal stimulation of the CD4+ lymphocytes from class II- deficient animals include a subset with an unusual reactivity pattern, responding to splenocytes from many mouse strains including the strain of origin. Most members of this subset recognize the major histocompatibility complex class Ib molecule CD1; their heterogeneous reactivities and T cell receptor usage further suggest the involvement of peptides and/or highly variable posttranslational modifications. PMID:7561702

  13. Novel insights into the regulatory architecture of CD4+ T cells in rheumatoid arthritis.

    PubMed

    Aterido, Adrià; Palacio, Carlos; Marsal, Sara; Avila, Gabriela; Julià, Antonio

    2014-01-01

    Rheumatoid arthritis (RA) is the most frequent autoimmune chronic inflammatory disease of the joints and it is characterized by the inflammation of the synovial membrane and the subsequent destruction of the joints. In RA, CD4+ T cells are the main drivers of disease initiation and the perpetuation of the damaging inflammatory process. To date, however, the genetic regulatory mechanisms of CD4+ T cells associated with RA etiology are poorly understood. The genome-wide analysis of expression quantitative trait loci (eQTL) in disease-relevant cell types is a recent genomic integration approach that is providing significant insights into the genetic regulatory mechanisms of many human pathologies. The objective of the present study was to analyze, for the first time, the genome-wide genetic regulatory mechanisms associated with the gene expression of CD4+ T cells in RA. Whole genome gene expression profiling of CD4+ T cells and the genome-wide genotyping (598,258 SNPs) of 29 RA patients with an active disease were performed. In order to avoid the excessive burden of multiple testing associated with genome-wide trans-eQTL analysis, we developed and implemented a novel systems genetics approach. Finally, we compared the genomic regulation pattern of CD4+ T cells in RA with the genomic regulation observed in reference lymphoblastoid cell lines (LCLs). We identified a genome-wide significant cis-eQTL associated with the expression of FAM66C gene (P = 6.51e-9). Using our new systems genetics approach we identified six statistically significant trans-eQTLs associated with the expression of KIAA0101 (P<7.4e-8) and BIRC5 (P = 5.35e-8) genes. Finally, comparing the genomic regulation profiles between RA CD4+ T cells and control LCLs we found 20 genes showing differential regulatory patterns between both cell types. The present genome-wide eQTL analysis has identified new genetic regulatory elements that are key to the activity of CD4+ T cells in RA.

  14. Increased 5-hydroxymethylcytosine in CD4(+) T cells in systemic lupus erythematosus.

    PubMed

    Zhao, Ming; Wang, Jing; Liao, Wei; Li, Duo; Li, Mengying; Wu, Haijing; Zhang, Yiqun; Gershwin, M Eric; Lu, Qianjin

    2016-05-01

    One of the major disappointments in autoimmunity has been the relative lack of informative data when genomewide associations (GWAS) have been applied to patients with systemic lupus erythematosus (SLE). Indeed, there is increasing evidence that SLE is characterized by widespread epigenetic changes. 5-Hydroxymethylcytosine (5-hmC) is a newly discovered modified form of cytosine suspected to be an important epigenetic modification in embryonic development, cell differentiation and cancer. DNA methylation dynamics have already been implicated in the pathogenesis of SLE, while little is known about hydroxymethylation in this process. Here, we show an increased 5-hmC level in genomic DNA in CD4(+) T cells of patients with SLE compared with healthy controls, accompanied by the up-regulated expression of the Ten-eleven translocation TET2 and TET3, which can enzymatically convert 5-methylcytosine (5-mC) to 5-hmC. Moreover, we present the differential patterns of DNA hydroxymethylation in genome-wide promoter regions in SLE CD4(+) T cells compared with healthy controls. We identified 2748 genes with increased 5-hmC levels in promoter regions in SLE CD4(+) T cells, which were enriched in critical pathways, including neurotrophin signaling, WNT signaling, MAPK signaling, calcium signaling and the mTOR signaling pathway. Through a combined analysis of differential DNA hydroxymethylation profile and gene expression profile in SLE CD4(+) T cells, we found 131 genes with the increased 5-hmC in promoter regions and up-regulated expression in SLE CD4(+) T cells compared with healthy controls, including selected immune-related genes, i.e. SOCS1, NR2F6 and IL15RA, which were also confirmed by ChIP-qPCR. Furthermore, we demonstrate that CTCF, as a transcription factor, can mediate DNA hydroxymethylation and contribute to overexpression of SOCS1 in CD4(+) T cells through binding to the promoter region of SOCS1. Taken together, our study reveals a critical differential 5-hmC in the

  15. Novel Insights into the Regulatory Architecture of CD4+ T Cells in Rheumatoid Arthritis

    PubMed Central

    Aterido, Adrià; Palacio, Carlos; Marsal, Sara; Ávila, Gabriela; Julià, Antonio

    2014-01-01

    Rheumatoid arthritis (RA) is the most frequent autoimmune chronic inflammatory disease of the joints and it is characterized by the inflammation of the synovial membrane and the subsequent destruction of the joints. In RA, CD4+ T cells are the main drivers of disease initiation and the perpetuation of the damaging inflammatory process. To date, however, the genetic regulatory mechanisms of CD4+ T cells associated with RA etiology are poorly understood. The genome-wide analysis of expression quantitative trait loci (eQTL) in disease-relevant cell types is a recent genomic integration approach that is providing significant insights into the genetic regulatory mechanisms of many human pathologies. The objective of the present study was to analyze, for the first time, the genome-wide genetic regulatory mechanisms associated with the gene expression of CD4+ T cells in RA. Whole genome gene expression profiling of CD4+ T cells and the genome-wide genotyping (598,258 SNPs) of 29 RA patients with an active disease were performed. In order to avoid the excessive burden of multiple testing associated with genome-wide trans-eQTL analysis, we developed and implemented a novel systems genetics approach. Finally, we compared the genomic regulation pattern of CD4+ T cells in RA with the genomic regulation observed in reference lymphoblastoid cell lines (LCLs). We identified a genome-wide significant cis-eQTL associated with the expression of FAM66C gene (P = 6.51e−9). Using our new systems genetics approach we identified six statistically significant trans-eQTLs associated with the expression of KIAA0101 (P<7.4e−8) and BIRC5 (P = 5.35e−8) genes. Finally, comparing the genomic regulation profiles between RA CD4+ T cells and control LCLs we found 20 genes showing differential regulatory patterns between both cell types. The present genome-wide eQTL analysis has identified new genetic regulatory elements that are key to the activity of CD4+ T cells in RA. PMID:24959711

  16. Increased frequency of CD4-8-T cells bearing T-cell receptor alpha beta chains in peripheral blood of atomic bomb survivors exposed to high doses.

    PubMed

    Kusunoki, Y; Kyoizumi, S; Hirai, Y; Fujita, S; Akiyama, M

    1994-07-01

    A rare T-cell subpopulation, CD4-8- alpha beta T cells, may be differentiated through a pathway (or pathways) different from the pathway(s) of conventional CD4+ or CD8+ T cells. In the present study, the frequencies of CD4-8-T cells in peripheral-blood alpha beta T cells in 409 atomic bomb survivors (160 estimated to have been exposed to 1.5 Gy or more and 249 controls) were determined to investigate late effects of radiation on the composition of human T-cell subpopulations. The frequency of CD4-8- alpha beta T-cell decreased significantly with the subject's age and was higher in females than males. A significant increase in the frequency was found in the survivors exposed to more than 1.5 Gy, suggesting that the previous radiation exposure altered differentiation and development of T cells.

  17. Impaired CD4+CD25+ regulatory T cell activity in the peripheral blood of patients with autoimmune sensorineural hearing loss.

    PubMed

    Xia, Ming; Zhang, Han Bing; Liu, Fang; Yin, Hai Ying; Xu, An Ting

    2008-09-01

    CD4+CD25+ regulatory T cells exert an immune regulatory function and thus play an important role in the control of self-reactivity in the pathogenesis of autoimmune inflammatory conditions. The aim of the study presented here is to perform a quantitative and functional analyses of these cells in patients with autoimmune sensorineural hearing loss (ASNHL). T cell subsets (CD4+CD25+, CD4+CD25(high), CD4+, and CD8+) from the peripheral blood of 17 patients with ASNHL, 16 patients with noise induced hearing loss (NHL), and 100 normal controls were analyzed by flow cytometry. The CD4/CD8 ratio was also analyzed. In addition, the suppressive capability of CD4+CD25+ T cells was tested in vitro by measuring their ability to suppress the proliferation and IFN-gamma secretion of CD4+CD25- T cells. No significant difference was found in the T cell subsets of ASNHL patients compared to normal controls or NHL patients, except that the proportion of CD4+ T cells was elevated in ASNHL patients. However, we did observe defective regulatory function of CD4+CD25+ T cells in patients with ASNHL. Our data supported the idea that CD4+CD25+ regulatory T cells played an immunosuppressive function in the periphery. The impaired suppressive activity of these cells may be an important factor in the pathogenesis of ASNHL.

  18. Acute Cardiac Rejection Requires Directly Cytotoxic CD4 T cells: A Parallel Pathway between Fas and Perforin1

    PubMed Central

    Grazia, Todd J.; Plenter, Robert J.; Weber, Sarah M.; Lepper, Helen M.; Victorino, Francisco; Zamora, Martin R.; Pietra, Biagio A.; Gill, Ronald G.

    2009-01-01

    Background CD4 T cells can suffice as effector cells to mediate primary acute cardiac allograft rejection. While CD4 T cells can readily kill appropriate target cells in vitro, the corresponding role of such cytolytic activity for mediating allograft rejection in vivo is unknown. Therefore, we determined whether the cytolytic effector molecules perforin and/or FasL (CD95L) were necessary for CD4 T cell-mediated rejection in vivo. Methods Wild type C3H(H-2k) or Fas (CD95)-deficient C3Hlpr (H-2k) hearts were transplanted into immune-deficient C57B6rag−/− (H-2b) mice. Recipients then were reconstituted with naïve purified CD4 T cells from either wild-type, perforin (pfp)-deficient, or FasL (gld)-deficient T cell donors. Results In vitro, alloreactive CD4 T cells were competent to lyse donor MHC class II+ target cells, largely by a Fas-dependent mechanism. In vivo, the individual disruption of either donor Fas expression (lpr) or CD4 T cell-derived perforin had no signifcant impact on acute rejection. However, FasL-deficient (gld) CD4 T cells demonstrated delayed allograft rejection. Importantly, the simultaneous removal of both donor Fas expression and CD4 T cell perforin completely abrograted acute rejection, despite the persistence of CD4 T cells within the graft. Conclusions Results demonstrate that the direct rejection of cardiac allografts by CD4 effector T cells requires the alternative contribution of graft Fas expression and T cell perforin expression. To our knowledge, this is the first demonstration that cytolytic activity by CD4 T cells can play an obligate role for primary acute allograft rejection in vivo. PMID:20061916

  19. Staphylococcus aureus convert neonatal conventional CD4(+) T cells into FOXP3(+) CD25(+) CD127(low) T cells via the PD-1/PD-L1 axis.

    PubMed

    Rabe, Hardis; Nordström, Inger; Andersson, Kerstin; Lundell, Anna-Carin; Rudin, Anna

    2014-03-01

    The gut microbiota provides an important stimulus for the induction of regulatory T (Treg) cells in mice, whether this applies to newborn children is unknown. In Swedish children, Staphylococcus aureus has become a common early colonizer of the gut. Here, we sought to study the effects of bacterial stimulation on neonatal CD4(+) T cells for the induction of CD25(+) CD127(low) Treg cells in vitro. The proportion of circulating CD25(+) CD127(low) Treg cells and their expression of FOXP3, Helios and CTLA-4 was examined in newborns and adults. To evaluate if commensal gut bacteria could induce Treg cells, CellTrace violet-stained non-Treg cells from cord or peripheral blood from adults were co-cultured with autologous CD25(+) CD127(low) Treg cells and remaining mononuclear cells and stimulated with S. aureus. Newborns had a significantly lower proportion of CD25(+) CD127(low) Treg cells than adults, but these cells were Helios(+) and CTLA-4(+) to a higher extent than in adults. FOXP3(+) CD25(+) CD127(low) T cells were induced mainly in neonatal CellTrace-stained non-Treg cells after stimulation with S. aureus. In cell cultures from adults, S. aureus induced CD25(+) CD127(low) T cells only if sorted naive CD45RA(+) non-Treg cells were used, but these cells expressed less FOXP3 than those induced from newborns. Sorted neonatal CD25(+) CD127(low) T cells from S. aureus-stimulated cultures were still suppressive. Finally, blocking PD-L1 during stimulation reduced the induction of FOXP3(+) CD25(+) CD127(low) T cells. These results suggest that newborns have a higher proportion of circulating thymically derived Helios(+) Treg cells than adults and that S. aureus possess an ability to convert neonatal conventional CD4(+) T cells into FOXP3(+) CD25(+) CD127(low) Treg cells via the PD-1/PD-L1 axis.

  20. Absence of CD4(+) T cell help generates corrupt CD8(+) effector T cells in sarcoma-bearing Swiss mice treated with NLGP vaccine.

    PubMed

    Ghosh, Sarbari; Sarkar, Madhurima; Ghosh, Tithi; Guha, Ipsita; Bhuniya, Avishek; Biswas, Jaydip; Mallick, Atanu; Bose, Anamika; Baral, Rathindranath

    2016-07-01

    One of the prime objectives of cancer immunology and immunotherapy is to study the issues related to rescue and/or maintenance of the optimum effector CD8(+) T cell functions by minimizing tumor-induced negative factors. In this regard the influence of host intrinsic CD4(+) helper T cells towards generation and maintenance of CD8(+) effector T cells appears controversial in different experimental settings. Therefore, the present study was aimed to re-analyze the influence of CD4(+) helper T cells towards effector T cells during neem leaf glycoprotein (NLGP)-vaccine-mediated tumor growth restriction. CD4 depletion (mAb; Clone GK1.5) surprisingly resulted in significant increase in CD8(+) T cells in different immune organs from NLGP-treated sarcoma-bearing mice. However, such CD8 surge could not restrict the sarcoma growth in NLGP-treated CD4-depleted mice. Furthermore, CD4 depletion in early phase hinders CD8(+) T cell activation and terminal differentiation by targeting crucial transcription factor Runx3. CD4 depletion decreases accumulation of CD8α(+) dendritic cells within tumor draining lymph node, hampers antigen cross priming and CD86-CD28 interactions for optimum CD8(+) T cell functions. In order to search the mechanism of CD4(+) T cell help on NLGP-mediated CD8 effector functions, the role of CD4(+) helper T cell-derived IL-2 on optimization of CD8 functions was found using STAT5 signaling, but complete response requires physical contact of CD4(+) helper T cells with its CD8 counterpart. In conclusion, it was found that CD4(+) T cell help is not required to generate CD8(+) T cells but was found to be an integral phenomenon in maintenance of its anti-tumor functions even in NLGP-vaccine-mediated sarcoma growth restriction.

  1. Absence of CD4(+) T cell help generates corrupt CD8(+) effector T cells in sarcoma-bearing Swiss mice treated with NLGP vaccine.

    PubMed

    Ghosh, Sarbari; Sarkar, Madhurima; Ghosh, Tithi; Guha, Ipsita; Bhuniya, Avishek; Biswas, Jaydip; Mallick, Atanu; Bose, Anamika; Baral, Rathindranath

    2016-07-01

    One of the prime objectives of cancer immunology and immunotherapy is to study the issues related to rescue and/or maintenance of the optimum effector CD8(+) T cell functions by minimizing tumor-induced negative factors. In this regard the influence of host intrinsic CD4(+) helper T cells towards generation and maintenance of CD8(+) effector T cells appears controversial in different experimental settings. Therefore, the present study was aimed to re-analyze the influence of CD4(+) helper T cells towards effector T cells during neem leaf glycoprotein (NLGP)-vaccine-mediated tumor growth restriction. CD4 depletion (mAb; Clone GK1.5) surprisingly resulted in significant increase in CD8(+) T cells in different immune organs from NLGP-treated sarcoma-bearing mice. However, such CD8 surge could not restrict the sarcoma growth in NLGP-treated CD4-depleted mice. Furthermore, CD4 depletion in early phase hinders CD8(+) T cell activation and terminal differentiation by targeting crucial transcription factor Runx3. CD4 depletion decreases accumulation of CD8α(+) dendritic cells within tumor draining lymph node, hampers antigen cross priming and CD86-CD28 interactions for optimum CD8(+) T cell functions. In order to search the mechanism of CD4(+) T cell help on NLGP-mediated CD8 effector functions, the role of CD4(+) helper T cell-derived IL-2 on optimization of CD8 functions was found using STAT5 signaling, but complete response requires physical contact of CD4(+) helper T cells with its CD8 counterpart. In conclusion, it was found that CD4(+) T cell help is not required to generate CD8(+) T cells but was found to be an integral phenomenon in maintenance of its anti-tumor functions even in NLGP-vaccine-mediated sarcoma growth restriction. PMID:27178306

  2. Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

    PubMed Central

    Pérez-Santiago, Josué; Ouchi, Dan; Urrea, Victor; Carrillo, Jorge; Cabrera, Cecilia; Villà-Freixa, Jordi; Puig, Jordi; Paredes, Roger; Negredo, Eugènia; Clotet, Bonaventura; Massanella, Marta; Blanco, Julià

    2016-01-01

    Background: The failure to increase CD4+ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4+ T-cell homeostasis and impacts clinical evolution. Methods: We evaluated different definitions of immunodiscordance based on CD4+ T-cell counts (cutoff) or CD4+ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals. Results: Cutoff definition of CD4+ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4+ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4+ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4+ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4+ values were maintained in these participants over time. Conclusion: A cutoff value of CD4+ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup

  3. Inflammation-induced effector CD4+ T cell interstitial migration is alpha-v integrin dependent

    PubMed Central

    Overstreet, Michael G.; Gaylo, Alison; Angermann, Bastian; Hughson, Angela; Hyun, Young-min; Lambert, Kris; Acharya, Mridu; Billroth-Maclurg, Alison C.; Rosenberg, Alexander F.; Topham, David J.; Yagita, Hideo; Kim, Minsoo; Lacy-Hulbert, Adam; Meier-Schellersheim, Martin; Fowell, Deborah J.

    2014-01-01

    Leukocytes must traverse inflamed tissues to effectively control local infection. Although motility in dense tissues appears to be integrin-independent actin-myosin based, during inflammation changes to the extracellular matrix (ECM) may necessitate distinct motility requirements. Indeed, we found that T cell interstitial motility was critically dependent on RGD-binding integrins in the inflamed dermis. Inflammation-induced deposition of fibronectin was functionally linked to increased αv integrin expression on effector CD4+ T cells. Using intravital multi-photon imaging, we found that CD4+ T cell motility was dependent on αv expression. Selective αv blockade or knockdown arrested TH1 motility in the inflamed tissue and attenuated local effector function. These data show a context-dependent specificity of lymphocyte movement in inflamed tissues that is essential for protective immunity. PMID:23933892

  4. Harnessing the plasticity of CD4(+) T cells to treat immune-mediated disease.

    PubMed

    DuPage, Michel; Bluestone, Jeffrey A

    2016-03-01

    CD4(+) T cells differentiate and acquire distinct functions to combat specific pathogens but can also adapt their functions in response to changing circumstances. Although this phenotypic plasticity can be potentially deleterious, driving immune pathology, it also provides important benefits that have led to its evolutionary preservation. Here, we review CD4(+) T cell plasticity by examining the molecular mechanisms that regulate it - from the extracellular cues that initiate and drive cells towards varying phenotypes, to the cytosolic signalling cascades that decipher these cues and transmit them into the cell and to the nucleus, where these signals imprint specific gene expression programmes. By understanding how this functional flexibility is achieved, we may open doors to new therapeutic approaches that harness this property of T cells. PMID:26875830

  5. Ubiquitin Ligases and Deubiquitinating Enzymes in CD4+ T Cell Effector Fate Choice and Function.

    PubMed

    Layman, Awo A K; Oliver, Paula M

    2016-05-15

    The human body is exposed to potentially pathogenic microorganisms at barrier sites such as the skin, lungs, and gastrointestinal tract. To mount an effective response against these pathogens, the immune system must recruit the right cells with effector responses that are appropriate for the task at hand. Several types of CD4(+) T cells can be recruited, including Th cells (Th1, Th2, and Th17), T follicular helper cells, and regulatory T cells. These cells help to maintain normal immune homeostasis in the face of constantly changing microbes in the environment. Because these cells differentiate from a common progenitor, the composition of their intracellular milieu of proteins changes to appropriately guide their effector function. One underappreciated process that impacts the levels and functions of effector fate-determining factors is ubiquitylation. This review details our current understanding of how ubiquitylation regulates CD4(+) T cell effector identity and function.

  6. CD4+CD25+ T Cells in primary malignant hypertension related kidney injury

    PubMed Central

    Huang, Hongdong; Luo, Yang; Liang, Yumei; Long, Xidai; Peng, Youming; Liu, Zhihua; Wen, Xiaojun; Jia, Meng; Tian, Ru; Bai, Chengli; Li, Cui; He, Fuliang; Lin, Qiushi; Wang, Xueyan; Dong, Xiaoqun

    2016-01-01

    CD4+CD25+ T cells are critical for maintenance of immunologic self-tolerance. We measured the number of CD4+CD25+ cells in the patients with primary malignant hypertension related kidney injury, to explore the molecular pathogenesis of this disease. We selected 30 patients with primary malignant hypertension related kidney injury and 30 healthy volunteers. Information on clinical characteristics and laboratory tests was obtained from each subject. The number of CD4+CD25+ cells and glomerular injury were assessed by flow cytometry and histopathology, respectively. Both serum IL-2, IL-4, and IL-6 and endothelial cell markers were analyzed by ELISA. ADAMTS13 antibody was detected by Western blotting. CD4+CD25+ cells were significantly reduced in patients with primary malignant hypertension related kidney injury compared to controls (P < 0.05). The number of CD4+CD25+ cells was negatively related to blood urea nitrogen, serum uric acid, proteinuria, and supernatant IL-4; whereas positively associated with estimated glomerular filtration rate in patients. Gradually decreasing CD4+CD25+ cells were also found as increasing renal injury. Additionally, patients exhibited increasing supernatant IL-4, serum IL-2 and IL-6, endothelial cell markers, and anti-ADAMTS13 antibody compared with controls (all P < 0.05). CD4+CD25+ cells may play a key role in the pathogenesis of primary malignant hypertension related kidney injury. PMID:27278520

  7. Crystal structure of a complete ternary complex of T-cell receptor, peptide-MHC, and CD4

    SciTech Connect

    Yin, Yiyuan; Wang, Xin Xiang; Mariuzza, Roy A

    2012-07-11

    Adaptive immunity depends on specific recognition by a T-cell receptor (TCR) of an antigenic peptide bound to a major histocompatibility complex (pMHC) molecule on an antigen-presenting cell (APC). In addition, T-cell activation generally requires binding of this same pMHC to a CD4 or CD8 coreceptor. Here, we report the structure of a complete TCR-pMHC-CD4 ternary complex involving a human autoimmune TCR, a myelin-derived self-peptide bound to HLA-DR4, and CD4. The complex resembles a pointed arch in which TCR and CD4 are each tilted ~65° relative to the T-cell membrane. By precluding direct contacts between TCR and CD4, the structure explains how TCR and CD4 on the T cell can simultaneously, yet independently, engage the same pMHC on the APC. The structure, in conjunction with previous mutagenesis data, places TCR-associated CD3εγ and CD3εδ subunits, which transmit activation signals to the T cell, inside the TCR-pMHC-CD4 arch, facing CD4. By establishing anchor points for TCR and CD4 on the T-cell membrane, the complex provides a basis for understanding how the CD4 coreceptor focuses TCR on MHC to guide TCR docking on pMHC during thymic T-cell selection.

  8. AP-2 Is the Crucial Clathrin Adaptor Protein for CD4 Downmodulation by HIV-1 Nef in Infected Primary CD4+ T Cells.

    PubMed

    Gondim, Marcos Vinicius; Wiltzer-Bach, Linda; Maurer, Brigitte; Banning, Carina; Arganaraz, Enrique; Schindler, Michael

    2015-12-01

    HIV-1 Nef-mediated CD4 downmodulation involves various host factors. We investigated the importance of AP-1, AP-2, AP-3, V1H-ATPase, β-COP, and ACOT8 for CD4 downmodulation in HIV-1-infected short hairpin RNA (shRNA)-expressing CD4(+) T cells and characterized direct interaction with Nef by Förster resonance energy transfer (FRET). Binding of lentiviral Nefs to CD4 and AP-2 was conserved, and only AP-2 knockdown impaired Nef-mediated CD4 downmodulation from primary T cells. Altogether, among the factors tested, AP-2 is the most important player for Nef-mediated CD4 downmodulation.

  9. HIV-1 Antibody Neutralization Breadth Is Associated with Enhanced HIV-Specific CD4+ T Cell Responses

    PubMed Central

    Soghoian, Damien Z.; Lindqvist, Madelene; Ghebremichael, Musie; Donaghey, Faith; Carrington, Mary; Seaman, Michael S.; Kaufmann, Daniel E.; Walker, Bruce D.

    2015-01-01

    ABSTRACT Antigen-specific CD4+ T helper cell responses have long been recognized to be a critical component of effective vaccine immunity. CD4+ T cells are necessary to generate and maintain humoral immune responses by providing help to antigen-specific B cells for the production of antibodies. In HIV infection, CD4+ T cells are thought to be necessary for the induction of Env-specific broadly neutralizing antibodies. However, few studies have investigated the role of HIV-specific CD4+ T cells in association with HIV neutralizing antibody activity in vaccination or natural infection settings. Here, we conducted a comprehensive analysis of HIV-specific CD4+ T cell responses in a cohort of 34 untreated HIV-infected controllers matched for viral load, with and without neutralizing antibody breadth to a panel of viral strains. Our results show that the breadth and magnitude of Gag-specific CD4+ T cell responses were significantly higher in individuals with neutralizing antibodies than in those without neutralizing antibodies. The breadth of Gag-specific CD4+ T cell responses was positively correlated with the breadth of neutralizing antibody activity. Furthermore, the breadth and magnitude of gp41-specific, but not gp120-specific, CD4+ T cell responses were significantly elevated in individuals with neutralizing antibodies. Together, these data suggest that robust Gag-specific CD4+ T cells and, to a lesser extent, gp41-specific CD4+ T cells may provide important intermolecular help to Env-specific B cells that promote the generation or maintenance of Env-specific neutralizing antibodies. IMPORTANCE One of the earliest discoveries related to CD4+ T cell function was their provision of help to B cells in the development of antibody responses. Yet little is known about the role of CD4+ T helper responses in the setting of HIV infection, and no studies to date have evaluated the impact of HIV-specific CD4+ T cells on the generation of antibodies that can neutralize

  10. Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets

    PubMed Central

    Ryan, John F.; Hovde, Rachel; Glanville, Jacob; Lyu, Shu-Chen; Ji, Xuhuai; Gupta, Sheena; Tibshirani, Robert J.; Jay, David C.; Boyd, Scott D.; Chinthrajah, R. Sharon; Davis, Mark M.; Galli, Stephen J.; Maecker, Holden T.; Nadeau, Kari C.

    2016-01-01

    Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional “roadmap” of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an “anergic” Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation. PMID:26811452

  11. Ectonucleotidase activity and immunosuppression in astrocyte-CD4 T cell bidirectional signaling

    PubMed Central

    Filipello, Fabia; Romagnani, Andrea; Mazzitelli, Sonia; Matteoli, Michela; Verderio, Claudia; Grassi, Fabio

    2016-01-01

    Astrocytes play a crucial role in neuroinflammation as part of the glia limitans, which regulates infiltration of the brain parenchyma by leukocytes. The signaling pathways and molecular events, which result from the interaction of activated T cells with astrocytes are poorly defined. Here we show that astrocytes promote the expression and enzymatic activity of CD39 and CD73 ectonucleotidases in recently activated CD4 cells by a contact dependent mechanism that is independent of T cell receptor interaction with class II major histocompatibility complex (MHC). Transforming growth factor-β (TGF-β) is robustly upregulated and sufficient to promote ectonucleotidases expression. T cell adhesion to astrocyte results in differentiation to an immunosuppressive phenotype defined by expression of the transcription factor Rorγt, which characterizes the CD4 T helper 17 subset. CD39 activity in T cells in turn inhibits spontaneous calcium oscillations in astrocytes that correlated with enhanced and reduced transcription of CCL2 chemokine and Sonic hedgehog (Shh), respectively. We hypothesize this TCR-independent interaction promote an immunosuppressive program in T cells to control possible brain injury by deregulated T cell activation during neuroinflammation. On the other hand, the increased secretion of CCL2 with concomitant reduction of Shh might promote leukocytes extravasation into the brain parenchyma. PMID:26784253

  12. Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets.

    PubMed

    Ryan, John F; Hovde, Rachel; Glanville, Jacob; Lyu, Shu-Chen; Ji, Xuhuai; Gupta, Sheena; Tibshirani, Robert J; Jay, David C; Boyd, Scott D; Chinthrajah, R Sharon; Davis, Mark M; Galli, Stephen J; Maecker, Holden T; Nadeau, Kari C

    2016-03-01

    Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional "roadmap" of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an "anergic" Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation. PMID:26811452

  13. Friend of GATA-1 Represses GATA-3–dependent Activity in CD4+ T Cells

    PubMed Central

    Zhou, Meixia; Ouyang, Wenjun; Gong, Qian; Katz, Samuel G.; White, J. Michael; Orkin, Stuart H.; Murphy, Kenneth M.

    2001-01-01

    The development of naive CD4+ T cells into a T helper (Th) 2 subset capable of producing interleukin (IL)-4, IL-5, and IL-13 involves a signal transducer and activator of transcription (Stat)6-dependent induction of GATA-3 expression, followed by Stat6-independent GATA-3 autoactivation. The friend of GATA (FOG)-1 protein regulates GATA transcription factor activity in several stages of hematopoietic development including erythrocyte and megakaryocyte differentiation, but whether FOG-1 regulates GATA-3 in T cells is uncertain. We show that FOG-1 can repress GATA-3–dependent activation of the IL-5 promoter in T cells. Also, FOG-1 overexpression during primary activation of naive T cells inhibited Th2 development in CD4+ T cells. FOG-1 fully repressed GATA-3–dependent Th2 development and GATA-3 autoactivation, but not Stat6-dependent induction of GATA-3. FOG-1 overexpression repressed development of Th2 cells from naive T cells, but did not reverse the phenotype of fully committed Th2 cells. Thus, FOG-1 may be one factor capable of regulating the Th2 development. PMID:11714753

  14. Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets.

    PubMed

    Ryan, John F; Hovde, Rachel; Glanville, Jacob; Lyu, Shu-Chen; Ji, Xuhuai; Gupta, Sheena; Tibshirani, Robert J; Jay, David C; Boyd, Scott D; Chinthrajah, R Sharon; Davis, Mark M; Galli, Stephen J; Maecker, Holden T; Nadeau, Kari C

    2016-03-01

    Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional "roadmap" of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an "anergic" Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation.

  15. Human CD4+ CD25+ Foxp3+ regulatory T cells do not constitutively express IL-35.

    PubMed

    Bardel, Emilie; Larousserie, Frédérique; Charlot-Rabiega, Pascaline; Coulomb-L'Herminé, Aurore; Devergne, Odile

    2008-11-15

    EBV-induced gene 3 (EBI3) can associate with p28 to form the heterodimeric cytokine IL-27, or with the p35 subunit of IL-12 to form the EBI3/p35 heterodimer, recently named IL-35. In mice, IL-35 has been shown to be constitutively expressed by CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg cells) and suggested to contribute to their suppressive activity. In this study, we investigated whether human Treg cells express IL-35. Double-staining analysis of human thymuses showed that neither Foxp3(+) nor CD25(+) cells coexpressed EBI3. Similarly, Foxp3(+) cells present in human lymph nodes, tonsils, spleens, and intestines did not express EBI3. Consistent with these in situ observations, Treg cells purified from blood or tonsils were negative for EBI3 by immunoblotting. Other human T cell subsets, including effector T cells, naive and memory CD4(+) T cells, CD8(+) and gammadelta T cells also did not constitutively express EBI3, which contrasts with IL-35 expression observed in murine CD8(+) and gammadelta T cells. Furthermore, although CD3/CD28 stimulation consistently induced low levels of EBI3 in various CD4(+) T cell subsets, no EBI3 could be detected in CD3/CD28-stimulated Treg cells. RT-PCR analysis showed that, whereas p35 transcripts were detected in both Teff and Treg cells, EBI3 transcripts were detected only in activated Teff cells, but not in resting or activated Treg cells. Thus, in contrast to their murine counterpart, human Treg cells do not express detectable amounts of IL-35.

  16. Small CD4 Mimetics Prevent HIV-1 Uninfected Bystander CD4 + T Cell Killing Mediated by Antibody-dependent Cell-mediated Cytotoxicity

    PubMed Central

    Richard, Jonathan; Veillette, Maxime; Ding, Shilei; Zoubchenok, Daria; Alsahafi, Nirmin; Coutu, Mathieu; Brassard, Nathalie; Park, Jongwoo; Courter, Joel R.; Melillo, Bruno; Smith, Amos B.; Shaw, George M.; Hahn, Beatrice H.; Sodroski, Joseph; Kaufmann, Daniel E.; Finzi, Andrés

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection causes a progressive depletion of CD4 + T cells. Despite its importance for HIV-1 pathogenesis, the precise mechanisms underlying CD4 + T-cell depletion remain incompletely understood. Here we make the surprising observation that antibody-dependent cell-mediated cytotoxicity (ADCC) mediates the death of uninfected bystander CD4 + T cells in cultures of HIV-1-infected cells. While HIV-1-infected cells are protected from ADCC by the action of the viral Vpu and Nef proteins, uninfected bystander CD4 + T cells bind gp120 shed from productively infected cells and are efficiently recognized by ADCC-mediating antibodies. Thus, gp120 shedding represents a viral mechanism to divert ADCC responses towards uninfected bystander CD4 + T cells. Importantly, CD4-mimetic molecules redirect ADCC responses from uninfected bystander cells to HIV-1-infected cells; therefore, CD4-mimetic compounds might have therapeutic utility in new strategies aimed at specifically eliminating HIV-1-infected cells. PMID:26870823

  17. Small CD4 Mimetics Prevent HIV-1 Uninfected Bystander CD4 + T Cell Killing Mediated by Antibody-dependent Cell-mediated Cytotoxicity.

    PubMed

    Richard, Jonathan; Veillette, Maxime; Ding, Shilei; Zoubchenok, Daria; Alsahafi, Nirmin; Coutu, Mathieu; Brassard, Nathalie; Park, Jongwoo; Courter, Joel R; Melillo, Bruno; Smith, Amos B; Shaw, George M; Hahn, Beatrice H; Sodroski, Joseph; Kaufmann, Daniel E; Finzi, Andrés

    2016-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection causes a progressive depletion of CD4 + T cells. Despite its importance for HIV-1 pathogenesis, the precise mechanisms underlying CD4 + T-cell depletion remain incompletely understood. Here we make the surprising observation that antibody-dependent cell-mediated cytotoxicity (ADCC) mediates the death of uninfected bystander CD4 + T cells in cultures of HIV-1-infected cells. While HIV-1-infected cells are protected from ADCC by the action of the viral Vpu and Nef proteins, uninfected bystander CD4 + T cells bind gp120 shed from productively infected cells and are efficiently recognized by ADCC-mediating antibodies. Thus, gp120 shedding represents a viral mechanism to divert ADCC responses towards uninfected bystander CD4 + T cells. Importantly, CD4-mimetic molecules redirect ADCC responses from uninfected bystander cells to HIV-1-infected cells; therefore, CD4-mimetic compounds might have therapeutic utility in new strategies aimed at specifically eliminating HIV-1-infected cells.

  18. Maraviroc intensification in patients with suppressed HIV viremia has limited effects on CD4+ T cell recovery and gene expression

    PubMed Central

    Beliakova-Bethell, Nadejda; Jain, Sonia; Woelk, Christopher H.; Witt, Mallory D.; Sun, Xiaoying; Lada, Steven M.; Spina, Celsa A.; Goicoechea, Miguel; Rought, Steffney E.; Haubrich, Richard; Dubé, Michael P.

    2014-01-01

    Addition of the CCR5 inhibitor Maraviroc (MVC) to ongoing antiretroviral therapy increases CD4+ T cell counts in some virologically suppressed patients with suboptimal CD4+ T cell recovery. To understand the mechanisms by which MVC elicits increases in CD4+ T cell counts, the present study was undertaken to identify host factors (i.e. genes) that are modulated and are correlated with CD4+ T cell recovery during the 24 weeks of MVC intensification in 32 subjects. Median changes of CD4+ T cell counts over 24 weeks of MVC compared to baseline were 38 cells/mm3 (p < 0.001). The median slope of CD4+ T cell recovery was 39 cells/mm3 per year before initiation of MVC and 76 cells/mm3 per year during MVC intensification, however, this increase was not statistically significant (p = 0.33). Microarray analysis (N = 31,426 genes) identified a single differentially expressed gene, tumor necrosis factor alpha (TNF), which was modestly (1.44-fold, p < 0.001) downregulated by MVC at week 24 compared to baseline. TNF differential expression was evaluated using an independent method of droplet digital PCR, but the difference was not significant (p = 0.6). Changes in gene expression did not correlate with CD4+ T cell recovery or any changes in the CD4+ T cell maturation, proliferation and activation phenotypes. In summary, our data suggest that modest improvements of CD4+ T cell counts during MVC intensification cannot be explained by changes in gene expression elicited by MVC. However, the modest changes in T cell composition, including reduction of the percentages of Tregs, proliferating CD4+ T cells and senescent CD8+ T cells, suggest immunologically favorable effects of MVC. PMID:24769244

  19. Azithromycin suppresses CD4+ T-cell activation by direct modulation of mTOR activity

    PubMed Central

    Ratzinger, F.; Haslacher, H.; Poeppl, W.; Hoermann, G.; Kovarik, J. J.; Jutz, S.; Steinberger, P.; Burgmann, H.; Pickl, W. F.; Schmetterer, K. G.

    2014-01-01

    Advanced macrolides, such as azithromycin (AZM) or clarithromycin (CLM), are antibiotics with immunomodulatory properties. Here we have sought to evaluate their in vitro influence on the activation of CD4+ T-cells. Isolated CD4+ T-cells were stimulated with agonistic anti-CD3/anti-CD28 monoclonal antibodies in the presence of 0.6 mg/L, 2.5 mg/L, 10 mg/L or 40 mg/L AZM or CLM. Cell proliferation, cytokine level in supernatants and cell viability was assessed. Intracellular signaling pathways were evaluated using reporter cell lines, FACS analysis, immunoblotting and in vitro kinase assays. AZM inhibited cell proliferation rate and cytokine secretion of CD4+ T-cells in a dose-dependent manner. Similarly, high concentrations of CLM (40 mg/L) also suppressed these T-cell functions. Analysis of molecular signaling pathways revealed that exposure to AZM reduced the phosphorylation of the S6 ribosomal protein, a downstream target of mTOR. This effect was also observed at 40 mg/L CLM. In vitro kinase studies using recombinant mTOR showed that AZM inhibited mTOR activity. In contrast to rapamycin, this inhibition was independent of FKBP12. We show for the first time that AZM and to a lesser extent CLM act as immunosuppressive agents on CD4+ T-cells by inhibiting mTOR activity. Our results might have implications for the clinical use of macrolides. PMID:25500904

  20. IL-35 expression in peripheral blood CD4(+) T cells from chronic hepatitis B virus-infected patients directly correlates with virus load.

    PubMed

    Zhou, Yali; Zhang, Hong; Li, Yumin

    2015-05-01

    Interleukin 35 (IL-35) functions in an anti-inflammatory fashion by inhibiting T-cell proliferation, whereas CD4(+) T cells play an important role in cellular immunity. In a hepatitis B virus (HBV) infection, the viral proteins stimulate the immune system to generate antiviral molecules, which correlate to HBV DNA load. We investigated the impact of HBV DNA load on the expression of IL-35 mRNA in CD4(+) T cells, and the expression of IL-35 cytokine in serum of the patients with chronic HBV infection. Here we report that the frequency of circulating CD4(+) T cells correlates with the HBV DNA load in the serum of chronic hepatitis B (CHB) patients. An increased number of CD4(+) T cells were found in those patients with higher levels of HBV DNA. Regulatory T cells (T regs) also showed this trend, but circulating cytotoxic lymphocytes (CTLs) showed a negative correlation with serum HBV DNA load. In addition, significantly more IL-35 mRNA was found in the CD4(+) T cells of CHB patients, compared to healthy controls. Patients in the high viral load group showed increased levels of IL-35 mRNA, compared with those in the low viral load group. The level of IL-35 cytokine in the serum of CHB patients was significantly higher than in the healthy controls and in those infected with HBV, the patients with a higher viral load had more serum IL-35 cytokines, compared to those with a lower viral load. Our study suggests that increased serum IL-35 could be directly related to increased levels of IL-35 mRNA in CD4(+) T cells and HBV DNA load in CHB patients. The possible role of IL-35 as an immune regulator in chronic HBV infection should be investigated further.

  1. Expression of fas protein on CD4+T cells irradiated by low level He-Ne

    NASA Astrophysics Data System (ADS)

    Nie, Fan; Zhu, Jing; Zhang, Hui-Guo

    2005-07-01

    Objective: To investigate the influence on the Expression of Fas protein on CD4+ T cells irradiated by low level He-Ne laser in the cases of psoriasis. Methods:the expression of CD4+ T Fas protein was determined in the casee of psoriasis(n=5) pre and post-low level laser irradiation(30 min、60min and 120min)by flow cytometry as compared withthe control(n=5). Results:In the cases of psoriasis,the expression of CD4+T FAS protein 21.4+/-3.1% was increased significantly than that of control group 16.8+/-2.1% pre-irradiation, p<0.05in the control,there is no difference between pre and post- irradiation,p>0.05in the cases , the expression of CD4+T Fas protein wae positively corelated to the irradiation times, when the energy density arrived to 22.92J/cm2(60 minutes)and 45.84J/cm2(120minutes), the expression of CD4+ T Fas protein was increased significantly as compared with pre-irradiation,p<0.05.Conclusion: The expression of CD4+T Fas protein may be increased by low level He-Ne laser irradiation ,the uncontrolled status of apoptosis could be corrected.

  2. Peripheral tolerance through clonal deletion of mature CD4-CD8+ T cells.

    PubMed

    Carlow, D A; Teh, S J; van Oers, N S; Miller, R G; Teh, H S

    1992-05-01

    Transgenic mice bearing the alpha beta transgenes encoding a defined T cell receptor specific for the male (H-Y) antigen presented by the H-2Db class I MHC molecule were used to study mechanisms of peripheral tolerance. Female transgenic mice produce large numbers of functionally homogeneous CD8+ male antigen-reactive T cells in the thymus that subsequently accumulate in the peripheral lymphoid organs. We have used three experimental approaches to show that male reactive CD8+ T cells can be eliminated from peripheral lymphoid organs after exposure to male antigen. (i) In female transgenic mice that were neonatally tolerized with male spleen cells, male reactive CD8+ T cells continued to be produced in large numbers in the thymus but were virtually absent in the lymph nodes. (ii) Injection of thymocytes from female transgenic mice into female mice neonatally tolerized with the male antigen, or into normal male mice, led to the specific elimination of male-reactive CD8+ T cells in the lymph nodes. (iii) Four days after male lymphoid cells were injected intravenously into female transgenic mice, male antigen-reactive CD8+ T cells recovered from the lymph nodes of recipient mice were highly apoptotic when compared to CD4+ (non-male reactive) T cells. These data indicate that tolerance to extrathymic antigen can be achieved through elimination of mature T cells in the peripheral lymphoid organs.

  3. Bystander Activation and Anti-Tumor Effects of CD8+ T Cells Following Interleukin-2 Based Immunotherapy Is Independent of CD4+ T Cell Help

    PubMed Central

    Grossenbacher, Steven K.; Hsiao, Hui-Hua; Zamora, Anthony E.; Mirsoian, Annie; Koehn, Brent; Blazar, Bruce R.; Weiss, Jonathan M.; Wiltrout, Robert H.; Sckisel, Gail D.; Murphy, William J.

    2014-01-01

    We have previously demonstrated that immunotherapy combining agonistic anti-CD40 and IL-2 (IT) results in synergistic anti-tumor effects. IT induces expansion of highly cytolytic, antigen-independent “bystander-activated” (CD8+CD44high) T cells displaying a CD25−NKG2D+ phenotype in a cytokine dependent manner, which were responsible for the anti-tumor effects. While much attention has focused on CD4+ T cell help for antigen-specific CD8+ T cell expansion, little is known regarding the role of CD4+ T cells in antigen-nonspecific bystander-memory CD8+ T cell expansion. Utilizing CD4 deficient mouse models, we observed a significant expansion of bystander-memory T cells following IT which was similar to the non-CD4 depleted mice. Expanded bystander-memory CD8+ T cells upregulated PD-1 in the absence of CD4+ T cells which has been published as a hallmark of exhaustion and dysfunction in helpless CD8+ T cells. Interestingly, compared to CD8+ T cells from CD4 replete hosts, these bystander expanded cells displayed comparable (or enhanced) cytokine production, lytic ability, and in vivo anti-tumor effects suggesting no functional impairment or exhaustion and were enriched in an effector phenotype. There was no acceleration of the post-IT contraction phase of the bystander memory CD8+ response in CD4-depleted mice. The response was independent of IL-21 signaling. These results suggest that, in contrast to antigen-specific CD8+ T cell expansion, CD4+ T cell help is not necessary for expansion and activation of antigen-nonspecific bystander-memory CD8+ T cells following IT, but may play a role in regulating conversion of these cells from a central memory to effector phenotype. Additionally, the expression of PD-1 in this model appears to be a marker of effector function and not exhaustion. PMID:25119341

  4. Skin CD4+ T cells produce interferon-gamma in vitro in response to streptococcal antigens in chronic plaque psoriasis.

    PubMed

    Brown, D W; Baker, B S; Ovigne, J M; Hardman, C; Powles, A V; Fry, L

    2000-03-01

    Recently, we have demonstrated that group A streptococcal antigen reactive T cells are present in the skin lesions of chronic plaque psoriasis. To determine the cytokine profile (interferon-gamma, interleukin-4 and interleukin-10) of these T cells in response to streptococcal antigens, T cell lines were cultured from untreated lesional skin of 13 patients with chronic plaque psoriasis and 12 patients with other inflammatory skin diseases. T cell lines were incubated with or without a sonicated heat-killed mixture of group A streptococcal isolates for 18 h in the presence of a transport inhibitor, stained for surface CD4 or CD8 and intracellular cytokine expression, and analyzed by flow cytometry. Psoriatic T cell lines were grown from 10 of 13 patients and were predominately CD4+ (64%-85%) with 10%-32% CD8+ T cells. Variable numbers of CD4+ T cells produced interferon-gamma (0.8%-35%, median 13.9) in eight of 10 T cell lines (p < 0.02). In contrast, CD4+ T cells in five of 12 T cell lines obtained from disease controls did not produce or produced minimal interferon-gamma in response to group A streptococcal isolates; this was significantly different from the psoriatic T cell lines (p < 0.05). Small numbers of interleukin-10 positive (0.8%-1.3%) and interleukin-4 positive (2.1%-2.5%) CD4+ T cells induced by group A streptococcal isolates were also present in two out of five and three out of five psoriatic T cell lines, respectively. This was significantly less in each case than the numbers of CD4+/interferon-gamma+ T cells (p < 0.05). Cytokine-positive CD8+ T cells were rarely observed. These findings demonstrate that a subpopulation of CD4+ T cells in chronic plaque psoriasis skin lesions produces interferon-gamma in response to streptococcal antigens and may be relevant to the pathogenesis of psoriasis.

  5. Analysis of HIV-1- and CMV-specific memory CD4 T-cell responses during primary and chronic infection.

    PubMed

    Harari, Alexandre; Rizzardi, G Paolo; Ellefsen, Kim; Ciuffreda, Donatella; Champagne, Patrick; Bart, Pierre-Alexandre; Kaufmann, Daniel; Telenti, Amalio; Sahli, Roland; Tambussi, Giuseppe; Kaiser, Laurent; Lazzarin, Adriano; Perrin, Luc; Pantaleo, Giuseppe

    2002-08-15

    CD4 T-cell-specific memory antiviral responses to human immunodeficiency virus type 1 (HIV-1) and cytomegalovirus (CMV) were investigated in 16 patients with documented primary HIV-1 infection (4 of the 16 subjects also had primary CMV infection) and compared with those observed in patients with chronic HIV-1 and CMV coinfection. Virus-specific memory CD4 T cells were characterized on the basis of the expression of the chemokine receptor CCR7. HIV-1- and CMV-specific interferon-gamma-secreting CD4 T cells were detected in patients with primary and chronic HIV-1 and CMV coinfection and were mostly contained in the cell population lacking expression of CCR7. The magnitude of the primary CMV-specific CD4 T-cell response was significantly greater than that of chronic CMV infection, whereas there were no differences between primary and chronic HIV-1-specific CD4 T-cell responses. A substantial proportion of CD4(+)CCR7(-) T cells were infected with HIV-1. These results advance the characterization of antiviral memory CD4 T-cell response and the delineation of the potential mechanisms that likely prevent the generation of a robust CD4 T-cell immune response during primary infection.

  6. Green tea epigallocatechin-3-gallate modulates differentiation of naive CD4+ T cells into specific lineage effector cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4+ T helper (Th) subsets Th1, Th9, and Th17 cells are implicated in inducing autoimmunity whereas regulatory T cells (Treg) have a protective effect. We previously showed that epigallocatechin-3-gallate (EGCG) attenuated experimental autoimmune encephalomyelitis (EAE) and altered CD4+ T cell subpo...

  7. Innate PLZF+ CD4+ αβ T cells develop and expand in the absence of Itk1

    PubMed Central

    Prince, Amanda L.; Watkin, Levi B.; Yin, Catherine C.; Selin, Liisa K.; Kang, Joonsoo; Schwartzberg, Pamela L.; Berg, Leslie J.

    2014-01-01

    T cell development in the thymus produces multiple lineages of cells, including innate T cells. Studies in mice harboring alterations in TCR signaling proteins or transcriptional regulators have revealed an expanded population of CD4+ innate T cells in the thymus that produce IL-4 and express the transcription factor PLZF. In these mice, IL-4 produced by the CD4+ PLZF+ T cell population leads to the conversion of conventional CD8+ thymocytes into innate CD8+ T cells resembling memory T cells expressing Eomesodermin. The expression of PLZF, the signature iNKT cell transcription factor, in these innate CD4+ T cells suggests that they might be a subset of αβ or γδ TCR+ NKT cells or MAIT cells. To address these possibilities, we characterized the CD4+ PLZF+ innate T cells in itk-/- mice. We show that itk-/- innate PLZF+ CD4+ T cells are not CD1d-dependent NKT cells, MR1-dependent MAIT cells, nor γδ T cells. Further, although the itk-/- innate PLZF+ CD4+ T cells express αβ TCRs, neither β2m-dependent MHC class I nor any MHC class II molecules are required for their development. In contrast to iNKT cells and MAIT cells, this population has a highly diverse TCRα chain repertoire. Analysis of peripheral tissues indicates that itk-/- innate PLZF+ CD4+ T cells preferentially home to spleen and mesenteric lymph nodes due to increased expression of gut-homing receptors, and that their expansion is regulated by commensal gut flora. These data support the conclusion that itk-/- innate PLZF+ CD4+ T cells are a novel subset of innate T cells. PMID:24928994

  8. CD4+ CD25+ T cells with the phenotypic and functional characteristics of regulatory T cells are enriched in the synovial fluid of patients with rheumatoid arthritis.

    PubMed

    Möttönen, M; Heikkinen, J; Mustonen, L; Isomäki, P; Luukkainen, R; Lassila, O

    2005-05-01

    CD4(+) CD25(+) regulatory T (T(reg)) cells play a critical role in the maintenance of peripheral tolerance and the prevention of autoimmunity. In the present study, we have explored the characteristics of CD4(+) CD25(+) T(reg) cells in patients with rheumatoid arthritis (RA). The frequency and phenotype of CD4(+) CD25(+) T cells in paired samples of synovial fluid (SF) and peripheral blood (PB) from patients with RA and PB from normal controls were analysed. An increased frequency of CD4+ cells T cells expressing CD25 was detected in SF compared to PB from patients with RA. No significant difference was observed in the numbers of CD4(+) CD25(+) T cells in PB from patients and controls. SF CD4(+) CD25(+) T cells expressed high levels of CTLA-4 (both surface and intracellular), GITR and OX40, as well as Foxp3 transcripts. Functionally, SF CD4(+) CD25(+) T cells were impaired in their proliferative responses and could suppress the proliferation of their CD4(+) CD25(-) counterparts. In conclusion, these data demonstrate that CD4(+) CD25(+) T(reg) cells, with the potential to regulate the function of effector T cells and antigen-presenting cells, accumulate in the synovium of patients with RA.

  9. Defining CD4 T cell memory by the epigenetic landscape of CpG DNA methylation.

    PubMed

    Komori, H Kiyomi; Hart, Traver; LaMere, Sarah A; Chew, Pamela V; Salomon, Daniel R

    2015-02-15

    Memory T cells are primed for rapid responses to Ag; however, the molecular mechanisms responsible for priming remain incompletely defined. CpG methylation in promoters is an epigenetic modification, which regulates gene transcription. Using targeted bisulfite sequencing, we examined methylation of 2100 genes (56,000 CpGs) mapped by deep sequencing of T cell activation in human naive and memory CD4 T cells. Four hundred sixty-six CpGs (132 genes) displayed differential methylation between naive and memory cells. Twenty-one genes exhibited both differential methylation and gene expression before activation, linking promoter DNA methylation states to gene regulation; 6 of 21 genes encode proteins closely studied in T cells, whereas 15 genes represent novel targets for further study. Eighty-four genes demonstrated differential methylation between memory and naive cells that correlated to differential gene expression following activation, of which 39 exhibited reduced methylation in memory cells coupled with increased gene expression upon activation compared with naive cells. These reveal a class of primed genes more rapidly expressed in memory compared with naive cells and putatively regulated by DNA methylation. These findings define a DNA methylation signature unique to memory CD4 T cells that correlates with activation-induced gene expression.

  10. Functional Heterogeneity in CD4(+) T Cell Responses Against a Bacterial Pathogen.

    PubMed

    Milam, Ashley Viehmann; Allen, Paul M

    2015-01-01

    To investigate how CD4(+) T cells function against a bacterial pathogen, we generated a Listeria monocytogenes-specific CD4(+) T cell model. In this system, two TCRtg mouse lines, LLO56 and LLO118, recognize the same immunodominant epitope (LLO190-205) of L. monocytogenes and have identical in vitro responses. However, in vivo LLO56 and LLO118 display vastly different responses during both primary and secondary infection. LLO118 dominates in the primary response and in providing CD8 T cell help. LLO56 predominates in the secondary response. We have also shown that both specific [T cell receptor (TCR)-mediated] and non-specific stimuli (bypassing the TCR) elicit distinct responses from the two transgenics, leading us to conclude that the strength of self-pMHC signaling during development tightly dictates the cell's future response in the periphery. Herein, we review our findings in this transfer system, focusing on the contribution of the immunomodulatory molecule CD5 and the importance of self-interaction in peripheral maintenance of the cell. We also discuss the manner in which individual TCR affinities to foreign and self-pMHC contribute to the outcome of an immune response; our assertion is that there exists a spectrum of possible T cell responses to recognition of cognate antigen during infection, adding immense diversity to the immune system's response to pathogens. PMID:26697015

  11. Defining CD4 T cell memory by the epigenetic landscape of CpG DNA methylation.

    PubMed

    Komori, H Kiyomi; Hart, Traver; LaMere, Sarah A; Chew, Pamela V; Salomon, Daniel R

    2015-02-15

    Memory T cells are primed for rapid responses to Ag; however, the molecular mechanisms responsible for priming remain incompletely defined. CpG methylation in promoters is an epigenetic modification, which regulates gene transcription. Using targeted bisulfite sequencing, we examined methylation of 2100 genes (56,000 CpGs) mapped by deep sequencing of T cell activation in human naive and memory CD4 T cells. Four hundred sixty-six CpGs (132 genes) displayed differential methylation between naive and memory cells. Twenty-one genes exhibited both differential methylation and gene expression before activation, linking promoter DNA methylation states to gene regulation; 6 of 21 genes encode proteins closely studied in T cells, whereas 15 genes represent novel targets for further study. Eighty-four genes demonstrated differential methylation between memory and naive cells that correlated to differential gene expression following activation, of which 39 exhibited reduced methylation in memory cells coupled with increased gene expression upon activation compared with naive cells. These reveal a class of primed genes more rapidly expressed in memory compared with naive cells and putatively regulated by DNA methylation. These findings define a DNA methylation signature unique to memory CD4 T cells that correlates with activation-induced gene expression. PMID:25576597

  12. Selectively increased expression and functions of chemokine receptor CCR9 on CD4+ T cells from patients with T-cell lineage acute lymphocytic leukemia.

    PubMed

    Qiuping, Zhang; Qun, Li; Chunsong, Hu; Xiaolian, Zhang; Baojun, Huang; Mingzhen, Yang; Chengming, Lao; Jinshen, He; Qingping, Gao; Kejian, Zhang; Zhimin, Sun; Xuejun, Zhang; Junyan, Liu; Jinquan, Tan

    2003-10-01

    In a total of 38 typical T-cell lineage acute lymphocytic leukemia (T-ALL) and T-cell lineage chronic lymphocytic leukemia (T-CLL) cases investigated, we found that CC chemokine receptor CCR9 was selectively and frequently expressed on T-ALL CD4+ T cells, was moderately expressed on T-CLL CD4+ T cells, and was rarely expressed on normal CD4+ T cells. These findings were demonstrated at protein and mRNA levels using flow cytometry and real-time quantitative reverse transcription-PCR technique and were verified by digital confocal microscopy and Northern blotting. Thymus-expressed chemokine, a ligand for CCR9, selectively induced T-ALL CD4+ T-cell chemotaxis and adhesion. Interleukin (IL)-2 and IL-4, together, down-regulated the expression and functions of CCR9 in T-ALL CD4+ T cells including chemotaxis and adhesion. It was also demonstrated that IL-2 and IL-4, together, internalized CCR9 on T-ALL CD4+ T cells and subsequently inhibited functions of CCR9 in these cells. Thymus-expressed chemokine mRNA was highly expressed in CD4+ T cells, involving lymph node and skin in T-ALL patients, and was expressed at moderate levels in lymph node and skin tissues in T-CLL patients. Our findings may provide new clues to understanding various aspects of T-ALL CD4+ T cells, such as functional expression of CCR9-thymus-expressed chemokine receptor-ligand pairs as well as the effects of IL-2 and IL-4, which may be especially important in cytokine/chemokine environment for the pathophysiological events of T-ALL CD4+ T-cell trafficking. PMID:14559839

  13. A differential equation model of HIV infection of CD4+ T-cells with cure rate

    NASA Astrophysics Data System (ADS)

    Zhou, Xueyong; Song, Xinyu; Shi, Xiangyun

    2008-06-01

    A differential equation model of HIV infection of CD4+ T-cells with cure rate is studied. We prove that if the basic reproduction number R0<1, the HIV infection is cleared from the T-cell population and the disease dies out; if R0>1, the HIV infection persists in the host. We find that the chronic disease steady state is globally asymptotically stable if R0>1. Furthermore, we also obtain the conditions for which the system exists an orbitally asymptotically stable periodic solution. Numerical simulations are presented to illustrate the results.

  14. Tumour-specific CD4 T cells eradicate melanoma via indirect recognition of tumour-derived antigen.

    PubMed

    Shklovskaya, Elena; Terry, Alexandra M; Guy, Thomas V; Buckley, Adrian; Bolton, Holly A; Zhu, Erhua; Holst, Jeff; Fazekas de St. Groth, Barbara

    2016-07-01

    The importance of CD4 T cells in tumour immunity has been increasingly recognised, with recent reports describing robust CD4 T cell-dependent tumour control in mice whose immune-regulatory mechanisms have been disturbed by irradiation, chemotherapy, immunomodulatory therapy and/or constitutive immunodeficiency. Tumour control in such models has been attributed in large part to direct Major Histocompatibility Complex (MHC) class II-dependent CD4 T cell killing of tumour cells. To test whether CD4 T cells can eradicate tumours without directly killing tumour cells, we developed an animal model in which tumour-derived antigen could be presented to T-cell receptor (TCR)-transgenic CD4 T cells by host but not tumour MHC class II molecules. In I-E(+) mice bearing I-E(null) tumours, naive I-E-restricted CD4 T cells proliferated locally in tumour-draining lymph nodes after recognising tumour-derived antigen on migratory dendritic cells. In lymphopaenic but not immunosufficient hosts, CD4 T cells differentiated into polarised T helper type 1 (Th1) cells expressing interferon gamma (IFNγ), tumor necrosis factor alpha (TNFα) and interleukin (IL)-2 but little IL-17, and cleared established tumours. Tumour clearance was enhanced by higher TCR affinity for tumour antigen-MHC class II and was critically dependent on IFNγ, as demonstrated by early tumour escape in animals treated with an IFNγ blocking antibody. Thus, CD4 T cells and IFNγ can control tumour growth without direct T-cell killing of tumour cells, and without requiring additional adaptive immune cells such as CD8 T cells and B cells. Our results support a role for effective CD4 T cell-dependent tumour immunity against MHC class II-negative tumours. PMID:26837456

  15. A novel SIV gag-specific CD4(+)T-cell clone suppresses SIVmac239 replication in CD4(+)T cells revealing the interplay between antiviral effector cells and their infected targets.

    PubMed

    Ayala, Victor I; Trivett, Matthew T; Coren, Lori V; Jain, Sumiti; Bohn, Patrick S; Wiseman, Roger W; O'Connor, David H; Ohlen, Claes; Ott, David E

    2016-06-01

    To study CD4(+)T-cell suppression of AIDS virus replication, we isolated nine rhesus macaque SIVGag-specific CD4(+)T-cell clones. One responding clone, Gag68, produced a typical cytotoxic CD8(+)T-cell response: induction of intracellular IFN-γ, MIP-1α, MIP-1β, and CD107a degranulation. Gag68 effectively suppressed the spread of SIVmac239 in CD4(+)T cells with a corresponding reduction of infected Gag68 effector cells, suggesting that CD4(+)effectors need to suppress their own infection in addition to their targets to be effective. Gag68 TCR cloning and gene transfer into CD4(+)T cells enabled additional experiments with this unique specificity after the original clone senesced. Our data supports the idea that CD4(+)T cells can directly limit AIDS virus spread in T cells. Furthermore, Gag68 TCR transfer into CD4(+)T-cell clones with differing properties holds promise to better understand the suppressive effector mechanisms used by this important component of the antiviral response using the rhesus macaque model.

  16. CD4+ T-cell epitope prediction using antigen processing constraints.

    PubMed

    Mettu, Ramgopal R; Charles, Tysheena; Landry, Samuel J

    2016-05-01

    T-cell CD4+ epitopes are important targets of immunity against infectious diseases and cancer. State-of-the-art methods for MHC class II epitope prediction rely on supervised learning methods in which an implicit or explicit model of sequence specificity is constructed using a training set of peptides with experimentally tested MHC class II binding affinity. In this paper we present a novel method for CD4+ T-cell eptitope prediction based on modeling antigen-processing constraints. Previous work indicates that dominant CD4+ T-cell epitopes tend to occur adjacent to sites of initial proteolytic cleavage. Given an antigen with known three-dimensional structure, our algorithm first aggregates four types of conformational stability data in order to construct a profile of stability that allows us to identify regions of the protein that are most accessible to proteolysis. Using this profile, we then construct a profile of epitope likelihood based on the pattern of transitions from unstable to stable regions. We validate our method using 35 datasets of experimentally measured CD4+ T cell responses of mice bearing I-Ab or HLA-DR4 alleles as well as of human subjects. Overall, our results show that antigen processing constraints provide a significant source of predictive power. For epitope prediction in single-allele systems, our approach can be combined with sequence-based methods, or used in instances where little or no training data is available. In multiple-allele systems, sequence-based methods can only be used if the allele distribution of a population is known. In contrast, our approach does not make use of MHC binding prediction, and is thus agnostic to MHC class II genotypes. PMID:26891811

  17. GITR ligand-costimulation activates effector and regulatory functions of CD4{sup +} T cells

    SciTech Connect

    Igarashi, Hanna; Cao, Yujia; Iwai, Hideyuki; Piao, Jinhua; Kamimura, Yosuke; Hashiguchi, Masaaki; Amagasa, Teruo; Azuma, Miyuki

    2008-05-16

    Engagement of glucocorticoid-induced TNFR-related protein (GITR) enables the costimulation of both CD25{sup -}CD4{sup +} effector (Teff) and CD25{sup +}CD4{sup +} regulatory (Treg) cells; however, the effects of GITR-costimulation on Treg function remain controversial. In this study, we examined the effects of GITR ligand (GITRL) binding on the respective functions of CD4{sup +} T cells. GITRL-P815 transfectants efficiently augmented anti-CD3-induced proliferation and cytokine production by Teff cells. Proliferation and IL-10 production in Treg were also enhanced by GITRL transfectants when exogenous IL-2 and stronger CD3 stimulation was provided. Concomitant GITRL-costimulation of Teff and Treg converted the anergic state of Treg into a proliferating state, maintaining and augmenting their function. Thus, GITRL-costimulation augments both effector and regulatory functions of CD4{sup +} T cells. Our results suggest that highly activated and increased ratios of Treg reverse the immune-enhancing effects of GITRL-costimulation in Teff, which may be problematic for therapeutic applications using strong GITR agonists.

  18. Myd88 Initiates Early Innate Immune Responses and Promotes CD4 T Cells during Coronavirus Encephalomyelitis

    PubMed Central

    Butchi, Niranjan; Kapil, Parul; Puntambekar, Shweta; Stohlman, Stephen A.; Hinton, David R.

    2015-01-01

    ABSTRACT Myd88 signaling is critical to the control of numerous central nervous system (CNS) infections by promoting both innate and adaptive immune responses. Nevertheless, the extent to which Myd88 regulates type I interferon (IFN) versus proinflammatory factors and T cell function, as well as the anatomical site of action, varies extensively with the pathogen. CNS infection by neurotropic coronavirus with replication confined to the brain and spinal cord induces protective IFN-α/β via Myd88-independent activation of melanoma differentiation-associated gene 5 (MDA5). However, a contribution of Myd88-dependent signals to CNS pathogenesis has not been assessed. Infected Myd88−/− mice failed to control virus, exhibited enhanced clinical disease coincident with increased demyelination, and succumbed to infection within 3 weeks. The induction of IFN-α/β, as well as of proinflammatory cytokines and chemokines, was impaired early during infection. However, defects in both IFN-α/β and select proinflammatory factors were rapidly overcome prior to T cell recruitment. Myd88 deficiency also specifically blunted myeloid and CD4 T cell recruitment into the CNS without affecting CD8 T cells. Moreover, CD4 T cells but not CD8 T cells were impaired in IFN-γ production. Ineffective virus control indeed correlated most prominently with reduced antiviral IFN-γ in the CNS of Myd88−/− mice. The results demonstrate a crucial role for Myd88 both in early induction of innate immune responses during coronavirus-induced encephalomyelitis and in specifically promoting protective CD4 T cell activation. In the absence of these responses, functional CD8 T cells are insufficient to control viral spread within the CNS, resulting in severe demyelination. IMPORTANCE During central nervous system (CNS) infections, signaling through the adaptor protein Myd88 promotes both innate and adaptive immune responses. The extent to which Myd88 regulates antiviral type I IFN, proinflammatory

  19. Granzyme B Contributes to the Optimal Graft-Versus-Tumor Effect Mediated by Conventional CD4+ T Cells

    PubMed Central

    Du, Wei; Leigh, Nicholas D.; Bian, Guanglin; Alqassim, Emad; O'Neill, Rachel E.; Mei, Lin; Qiu, Jingxin; Liu, Hong; McCarthy, Philip L.; Cao, Xuefang

    2016-01-01

    Granzyme B (GzmB) is a key cytotoxic molecule utilized by T cells to kill pathogen-infected cells or transformed tumor cells. Previous studies using allogeneic hematopoietic cell transplantation (allo-HCT) murine models showed that GzmB is required for CD8+ T cells to cause graft-versus-host disease (GVHD). However, our recent study demonstrated that GzmB-mediated damage of CD8+ T cells diminished their graft-versus-tumor (GVT) activity. In this study, we examined the role of GzmB in GVT effect mediated by conventional CD4+CD25− T cells (CD4+ Tcon). GzmB−/−CD4+ Tcon cells exhibited decreased GVT activity compared to wild-type (WT) CD4+ Tcon cells, suggesting that GzmB is required for the optimal GVT activity of CD4+ Tcon cells. On the other hand, GzmB−/− CD4+CD25+ regulatory T cells were as suppressive as WT regulatory T cells in suppressing GVT activity, which is consistent with our previous report showing that GzmB is not required for regulatory T cell-mediated suppression of GVHD. These results demonstrate that GzmB causes opposite impacts on GVT effect mediated by CD4+CD25− versus CD8+ T cells. Interestingly, GzmB−/− total T cells exhibited GVT activity equivalent to that of WT total T cells, suggesting that the opposite impacts of GzmB on the GVT effect of CD4+CD25− versus CD8+ T cells may neutralize each other, which can only be observed when an individual T cell subset is examined. Importantly, these differential roles suggest that targeting GzmB in selective T cell subsets may have the potential to enhance the beneficial GVT effect.

  20. Oct1 and OCA-B are selectively required for CD4 memory T cell function.

    PubMed

    Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N; Snook, Jeremy; Kuchroo, Vijay K; Yosef, Nir; Chan, Raymond C; Regev, Aviv; Williams, Matthew A; Tantin, Dean

    2015-11-16

    Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4(+) memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4(+) T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4(+) T cell memory.

  1. Excess Lymphangiogenesis Cooperatively Induced by Macrophages and CD4(+) T Cells Drives the Pathogenesis of Lymphedema.

    PubMed

    Ogata, Fusa; Fujiu, Katsuhito; Matsumoto, Sahohime; Nakayama, Yukiteru; Shibata, Munehiko; Oike, Yuichi; Koshima, Isao; Watabe, Tetsuro; Nagai, Ryozo; Manabe, Ichiro

    2016-03-01

    Lymphedema is a debilitating progressive condition that severely restricts quality of life and is frequently observed after cancer surgery. The mechanism underlying lymphedema development remains poorly understood, and no effective pharmacological means to prevent or alleviate the ailment is currently available. Using a mouse model of lymphedema, we show here that excessive generation of immature lymphatic vessels is essential for initial edema development and that this early process is also important for later development of lymphedema pathology. We found that CD4(+) T cells interact with macrophages to promote lymphangiogenesis, and that both lymphangiogenesis and edema were greatly reduced in macrophage-depleted mice, lymphocyte-deficient Rag2(?/?) mice or CD4(+) T-cell-deficient mice. Mechanistically, T helper type 1 and T helper type 17 cells activate lesional macrophages to produce vascular endothelial growth factor-C, which promotes lymphangiogenesis, and inhibition of this mechanism suppressed not only early lymphangiogenesis, but also later development of lymphedema. Finally, we show that atorvastatin suppresses excessive lymphangiogenesis and lymphedema by inhibiting T helper type 1 and T helper type 17 cell activation. These results demonstrate that the interaction between CD4(+) T cells and macrophages is a potential therapeutic target for prevention of lymphedema after surgery.

  2. Excess Lymphangiogenesis Cooperatively Induced by Macrophages and CD4(+) T Cells Drives the Pathogenesis of Lymphedema.

    PubMed

    Ogata, Fusa; Fujiu, Katsuhito; Matsumoto, Sahohime; Nakayama, Yukiteru; Shibata, Munehiko; Oike, Yuichi; Koshima, Isao; Watabe, Tetsuro; Nagai, Ryozo; Manabe, Ichiro

    2016-03-01

    Lymphedema is a debilitating progressive condition that severely restricts quality of life and is frequently observed after cancer surgery. The mechanism underlying lymphedema development remains poorly understood, and no effective pharmacological means to prevent or alleviate the ailment is currently available. Using a mouse model of lymphedema, we show here that excessive generation of immature lymphatic vessels is essential for initial edema development and that this early process is also important for later development of lymphedema pathology. We found that CD4(+) T cells interact with macrophages to promote lymphangiogenesis, and that both lymphangiogenesis and edema were greatly reduced in macrophage-depleted mice, lymphocyte-deficient Rag2(?/?) mice or CD4(+) T-cell-deficient mice. Mechanistically, T helper type 1 and T helper type 17 cells activate lesional macrophages to produce vascular endothelial growth factor-C, which promotes lymphangiogenesis, and inhibition of this mechanism suppressed not only early lymphangiogenesis, but also later development of lymphedema. Finally, we show that atorvastatin suppresses excessive lymphangiogenesis and lymphedema by inhibiting T helper type 1 and T helper type 17 cell activation. These results demonstrate that the interaction between CD4(+) T cells and macrophages is a potential therapeutic target for prevention of lymphedema after surgery. PMID:27015456

  3. Oct1 and OCA-B are selectively required for CD4 memory T cell function

    PubMed Central

    Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N.; Snook, Jeremy; Kuchroo, Vijay K.; Yosef, Nir; Chan, Raymond C.; Regev, Aviv

    2015-01-01

    Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4+ memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4+ T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4+ T cell memory. PMID:26481684

  4. Public T cell receptors confer high-avidity CD4 responses to HIV controllers

    PubMed Central

    Galperin, Moran; Lambotte, Olivier; Gras, Stéphanie; Lim, Annick; Mukhopadhyay, Madhura; Campbell, Kristy-Anne; Lemercier, Brigitte; Claireaux, Mathieu; Hendou, Samia; Lechat, Pierre; de Truchis, Pierre; Boufassa, Faroudy; Rossjohn, Jamie; Delfraissy, Jean-François; Arenzana-Seisdedos, Fernando; Chakrabarti, Lisa A.

    2016-01-01

    The rare patients who are able to spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient cellular immune response. To identify the molecular determinants that underlie this response, we characterized the T cell receptor (TCR) repertoire directed at Gag293, the most immunoprevalent CD4 epitope in the HIV-1 capsid. HIV controllers from the ANRS CODEX cohort showed a highly skewed TCR repertoire that was characterized by a predominance of TRAV24 and TRBV2 variable genes, shared CDR3 motifs, and a high frequency of public clonotypes. The most prevalent public clonotypes generated TCRs with affinities at the higher end of values reported for naturally occurring TCRs. The high-affinity Gag293-specific TCRs were cross-restricted by up to 5 distinct HLA-DR alleles, accounting for the expression of these TCRs in HIV controllers of diverse genetic backgrounds. Transfer of these TCRs to healthy donor CD4+ T cells conferred high antigen sensitivity and polyfunctionality, thus recapitulating key features of the controller CD4 response. Transfer of a high-affinity Gag293-specific TCR also redirected CD8+ T cells to target HIV-1 capsid via nonconventional MHC II restriction. Together, these findings indicate that TCR clonotypes with superior functions are associated with HIV control. Amplification or transfer of such clonotypes may contribute to immunotherapeutic approaches aiming at a functional HIV cure. PMID:27111229

  5. Public T cell receptors confer high-avidity CD4 responses to HIV controllers.

    PubMed

    Benati, Daniela; Galperin, Moran; Lambotte, Olivier; Gras, Stéphanie; Lim, Annick; Mukhopadhyay, Madhura; Nouël, Alexandre; Campbell, Kristy-Anne; Lemercier, Brigitte; Claireaux, Mathieu; Hendou, Samia; Lechat, Pierre; de Truchis, Pierre; Boufassa, Faroudy; Rossjohn, Jamie; Delfraissy, Jean-François; Arenzana-Seisdedos, Fernando; Chakrabarti, Lisa A

    2016-06-01

    The rare patients who are able to spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient cellular immune response. To identify the molecular determinants that underlie this response, we characterized the T cell receptor (TCR) repertoire directed at Gag293, the most immunoprevalent CD4 epitope in the HIV-1 capsid. HIV controllers from the ANRS CODEX cohort showed a highly skewed TCR repertoire that was characterized by a predominance of TRAV24 and TRBV2 variable genes, shared CDR3 motifs, and a high frequency of public clonotypes. The most prevalent public clonotypes generated TCRs with affinities at the higher end of values reported for naturally occurring TCRs. The high-affinity Gag293-specific TCRs were cross-restricted by up to 5 distinct HLA-DR alleles, accounting for the expression of these TCRs in HIV controllers of diverse genetic backgrounds. Transfer of these TCRs to healthy donor CD4+ T cells conferred high antigen sensitivity and polyfunctionality, thus recapitulating key features of the controller CD4 response. Transfer of a high-affinity Gag293-specific TCR also redirected CD8+ T cells to target HIV-1 capsid via nonconventional MHC II restriction. Together, these findings indicate that TCR clonotypes with superior functions are associated with HIV control. Amplification or transfer of such clonotypes may contribute to immunotherapeutic approaches aiming at a functional HIV cure. PMID:27111229

  6. Mycobacterium tuberculosis-Specific IL-21+IFN-γ+CD4+ T Cells Are Regulated by IL-12.

    PubMed

    Li, Li; Jiang, Yuxia; Lao, Suihua; Yang, Binyan; Yu, Sifei; Zhang, Yannan; Wu, Changyou

    2016-01-01

    In the current study of Mycobacterium tuberculosis (MTB)-specific T and B cells, we found that MTB-specific peptides from early secreted antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) induced the expression of IL-21 predominantly in CD4(+) T cells. A fraction of IL-21-expressing CD4(+) T cells simultaneously expressed Th1 cytokines but did not secrete Th2 or Th17 cytokines, suggesting that MTB-specific IL-21-expressing CD4(+) T cells were different from Th1, Th2 and Th17 subpopulations. The majority of MTB-specific IL-21-expressing CD4(+) T cells co-expressed IFN-γ and IL-21+IFN-γ(+)CD4(+) T cells exhibited obviously polyfunctionality. In addition, MTB-specific IL-21-expressing CD4(+) T cells displayed a CD45RO+CD62Ll(ow)CCR7(low)CD40L(high)ICOS(high) phenotype. Bcl-6-expression was significantly higher in IL-21-expressing CD4(+) T cells than IL-21-CD4(+) T cells. Moreover, IL-12 could up-regulate MTB-specific IL-21 expression, especially the frequency of IL-21(+)IFN-γ+CD4(+) T cells. Taken together, our results demonstrated that MTB-specific IL-21(+)IFN-γ(+)CD4(+) T cells from local sites of tuberculosis (TB) infection could be enhanced by IL-12, which have the features of both Tfh and Th1 cells and may have an important role in local immune responses against TB infection.

  7. Human CD4+ T cells require exogenous cystine for glutathione and DNA synthesis.

    PubMed

    Levring, Trine B; Kongsbak, Martin; Rode, Anna K O; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte Menné; Geisler, Carsten

    2015-09-01

    Adaptive immune responses require activation and expansion of antigen-specific T cells. Whereas early T cell activation is independent of exogenous cystine (Cys2), T cell proliferation is dependent of Cys2. However, the exact roles of Cys2 in T cell proliferation still need to be determined. The aim of this study was to elucidate why activated human T cells require exogenous Cys2 in order to proliferate. We activated purified naïve human CD4+ T cells and found that glutathione (GSH) levels and DNA synthesis were dependent on Cys2 and increased in parallel with increasing concentrations of Cys2. Vice-versa, the GSH synthesis inhibitor L-buthionine-sulfoximine (BSO) and inhibition of Cys2 uptake with glutamate inhibited GSH and DNA synthesis in parallel. We further found that thioredoxin (Trx) can partly substitute for GSH during DNA synthesis. Finally, we show that GSH or Trx is required for the activity of ribonucleotide reductase (RNR), the enzyme responsible for generation of the deoxyribonucleotide DNA building blocks. In conclusion, we show that activated human T cells require exogenous Cys2 to proliferate and that this is partly explained by the fact that Cys2 is required for production of GSH, which in turn is required for optimal RNR-mediated deoxyribonucleotide synthesis and DNA replication.

  8. The effects of an anti-CD4 monoclonal antibody, keliximab, on peripheral blood CD4+ T-cells in asthma.

    PubMed

    Kon, O M; Sihra, B S; Loh, L C; Barkans, J; Compton, C H; Barnes, N C; Larché, M; Kay, A B

    2001-07-01

    CD4+ T-cells are likely to be involved as a source of pro-inflammatory cytokines in asthma. This study assessed the effects of an infusion of keliximab (IDEC CE9.1), an anti-CD4+ monoclonal antibody, on peripheral blood CD4+ T-cells in corticosteroid-dependent asthmatics. Three cohorts of patients (termed C0.5: n=6, C1.5: n=5, and C3.0: n=5) received a single infusion of 0.5, 1.5 or 3.0 mg x kg(-1), respectively, with a fourth receiving placebo (Cpl: n=6), and were followed-up for 4 weeks. By flow cytometry in peripheral blood, pre- and postinfusion assessment was made of: a) CD4 and CD8 counts and mean fluorescence; b) CD25, human leukocyte antigen-DR (HLA-DR), CD45RO and CD45RA expression on CD4+ T-cells; and c) interferon (IFN)-gamma, interleukin (IL)-4 and IL-5 expression in CD4+ T-cells. Keliximab's in vitro effects on allergen-specific peripheral blood mononuclear cells (PBMC) proliferation in atopic asthmatics were also evaluated. There was a significant increase in lung function (peak expiratory flow rate) in the C3.0 group. Following infusion in C0.5, C1.5 and C3.0 but not Cpl: 1) the CD4, but not CD8 count was significantly decreased; 2) there was total loss of Leu3a staining; 3) there were significant reductions in the mean fluorescence of OKT4 binding; and 4) there were significant reductions in the numbers of CD25, HLA-DR, CD45RO and CD45RA/CD4+ cells. There were no changes in CD4+ cell expression of IFN-gamma, IL-4 or IL-5. Keliximab caused a significant reduction in T-cell proliferation as compared to a control monoclonal antibody. Keliximab, as an anti-CD4 monoclonal antibody, leads to a transient reduction in the number of CD4+ T-cells and modulation of CD4+ receptor expression in severe asthmatics. The effects of keliximab may be mediated through a decrease in CD4+ surface expression and T-lymphocyte numbers, in addition to a reduction in allergen-induced proliferation.

  9. MHCII-independent CD4+ T cells protect injured CNS neurons via IL-4

    PubMed Central

    Walsh, James T.; Hendrix, Sven; Boato, Francesco; Smirnov, Igor; Zheng, Jingjing; Lukens, John R.; Gadani, Sachin; Hechler, Daniel; Gölz, Greta; Rosenberger, Karen; Kammertöns, Thomas; Vogt, Johannes; Vogelaar, Christina; Siffrin, Volker; Radjavi, Ali; Fernandez-Castaneda, Anthony; Gaultier, Alban; Gold, Ralf; Kanneganti, Thirumala-Devi; Nitsch, Robert; Zipp, Frauke; Kipnis, Jonathan

    2015-01-01

    A body of experimental evidence suggests that T cells mediate neuroprotection following CNS injury; however, the antigen specificity of these T cells and how they mediate neuroprotection are unknown. Here, we have provided evidence that T cell–mediated neuroprotection after CNS injury can occur independently of major histocompatibility class II (MHCII) signaling to T cell receptors (TCRs). Using two murine models of CNS injury, we determined that damage-associated molecular mediators that originate from injured CNS tissue induce a population of neuroprotective, IL-4–producing T cells in an antigen-independent fashion. Compared with wild-type mice, IL-4–deficient animals had decreased functional recovery following CNS injury; however, transfer of CD4+ T cells from wild-type mice, but not from IL-4–deficient mice, enhanced neuronal survival. Using a culture-based system, we determined that T cell–derived IL-4 protects and induces recovery of injured neurons by activation of neuronal IL-4 receptors, which potentiated neurotrophin signaling via the AKT and MAPK pathways. Together, these findings demonstrate that damage-associated molecules from the injured CNS induce a neuroprotective T cell response that is independent of MHCII/TCR interactions and is MyD88 dependent. Moreover, our results indicate that IL-4 mediates neuroprotection and recovery of the injured CNS and suggest that strategies to enhance IL-4–producing CD4+ T cells have potential to attenuate axonal damage in the course of CNS injury in trauma, inflammation, or neurodegeneration. PMID:25607842

  10. Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses

    PubMed Central

    Provine, Nicholas M.; Badamchi-Zadeh, Alexander; Bricault, Christine A.; Penaloza-MacMaster, Pablo; Larocca, Rafael A.; Borducchi, Erica N.; Seaman, Michael S.

    2016-01-01

    ABSTRACT We have recently demonstrated that CD4+ T cell help is required at the time of adenovirus (Ad) vector immunization for the development of functional CD8+ T cell responses, but the temporal requirement for CD4+ T cell help for the induction of antibody responses remains unclear. Here we demonstrate that induction of antibody responses in C57BL/6 mice can occur at a time displaced from the time of Ad vector immunization by depletion of CD4+ T cells. Transient depletion of CD4+ T cells at the time of immunization delays the development of antigen-specific antibody responses but does not permanently impair their development or induce tolerance against the transgene. Upon CD4+ T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals. These delayed antibody responses exhibit no functional defects with regard to isotype, functional avidity, expansion after boosting immunization, or the capacity to neutralize a simian immunodeficiency virus (SIV) Env-expressing pseudovirus. The development of this delayed transgene-specific antibody response is temporally linked to the expansion of de novo antigen-specific CD4+ T cell responses, which develop after transient depletion of CD4+ T cells. These data demonstrate that functional vaccine-elicited antibody responses can be induced even if CD4+ T cell help is provided at a time markedly separated from the time of vaccination. IMPORTANCE CD4+ T cells have a critical role in providing positive help signals to B cells, which promote robust antibody responses. The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen. Here we demonstrate that, in contrast to the current model that the absence of CD4+ T cell help at priming results in long-term antibody nonresponsiveness, antibody responses can be induced by adenovirus vector immunization or alum

  11. Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution.

    PubMed

    Zeng, Ming; Paiardini, Mirko; Engram, Jessica C; Beilman, Greg J; Chipman, Jeffrey G; Schacker, Timothy W; Silvestri, Guido; Haase, Ashley T

    2012-08-30

    Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1-infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution.

  12. Tumor-infiltrating HLA-matched CD4(+) T cells retargeted against Hodgkin and Reed-Sternberg cells.

    PubMed

    Rengstl, Benjamin; Schmid, Frederike; Weiser, Christian; Döring, Claudia; Heinrich, Tim; Warner, Kathrin; Becker, Petra S A; Wistinghausen, Robin; Kameh-Var, Sima; Werling, Eva; Billmeier, Arne; Seidl, Christian; Hartmann, Sylvia; Abken, Hinrich; Küppers, Ralf; Hansmann, Martin-Leo; Newrzela, Sebastian

    2016-06-01

    Hodgkin lymphoma (HL) presents with a unique histologic pattern. Pathognomonic Hodgkin and Reed-Sternberg (HRS) cells usually account for less than 1% of the tumor and are embedded in a reactive infiltrate mainly comprised of CD4(+) T cells. HRS cells induce an immunosuppressive microenvironment and thereby escape antitumor immunity. To investigate the impact of interactions between HRS cells and T cells, we performed long-term co-culture studies that were further translated into a xenograft model. Surprisingly, we revealed a strong antitumor potential of allogeneic CD4(+) T cells against HL cell lines. HRS and CD4(+) T cells interact by adhesion complexes similar to immunological synapses. Tumor-cell killing was likely based on the recognition of allogeneic major histocompatibility complex class II (MHC-II) receptor, while CD4(+) T cells from MHC-II compatible donors did not develop any antitumor potential in case of HL cell line L428. However, gene expression profiling (GEP) of co-cultured HRS cells as well as tumor infiltration of matched CD4(+) T cells indicated cellular interactions. Moreover, matched CD4(+) T cells could be activated to kill CD30(+) HRS cells when redirected with a CD30-specific chimeric antigen receptor. Our work gives novel insights into the crosstalk between HRS and CD4(+) T cells, suggesting the latter as potent effector cells in the adoptive cell therapy of HL.

  13. Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution

    PubMed Central

    Zeng, Ming; Paiardini, Mirko; Engram, Jessica C.; Beilman, Greg J.; Chipman, Jeffrey G.; Schacker, Timothy W.; Silvestri, Guido

    2012-01-01

    Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1–infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution. PMID:22613799

  14. Tumor-infiltrating HLA-matched CD4(+) T cells retargeted against Hodgkin and Reed-Sternberg cells.

    PubMed

    Rengstl, Benjamin; Schmid, Frederike; Weiser, Christian; Döring, Claudia; Heinrich, Tim; Warner, Kathrin; Becker, Petra S A; Wistinghausen, Robin; Kameh-Var, Sima; Werling, Eva; Billmeier, Arne; Seidl, Christian; Hartmann, Sylvia; Abken, Hinrich; Küppers, Ralf; Hansmann, Martin-Leo; Newrzela, Sebastian

    2016-06-01

    Hodgkin lymphoma (HL) presents with a unique histologic pattern. Pathognomonic Hodgkin and Reed-Sternberg (HRS) cells usually account for less than 1% of the tumor and are embedded in a reactive infiltrate mainly comprised of CD4(+) T cells. HRS cells induce an immunosuppressive microenvironment and thereby escape antitumor immunity. To investigate the impact of interactions between HRS cells and T cells, we performed long-term co-culture studies that were further translated into a xenograft model. Surprisingly, we revealed a strong antitumor potential of allogeneic CD4(+) T cells against HL cell lines. HRS and CD4(+) T cells interact by adhesion complexes similar to immunological synapses. Tumor-cell killing was likely based on the recognition of allogeneic major histocompatibility complex class II (MHC-II) receptor, while CD4(+) T cells from MHC-II compatible donors did not develop any antitumor potential in case of HL cell line L428. However, gene expression profiling (GEP) of co-cultured HRS cells as well as tumor infiltration of matched CD4(+) T cells indicated cellular interactions. Moreover, matched CD4(+) T cells could be activated to kill CD30(+) HRS cells when redirected with a CD30-specific chimeric antigen receptor. Our work gives novel insights into the crosstalk between HRS and CD4(+) T cells, suggesting the latter as potent effector cells in the adoptive cell therapy of HL. PMID:27471632

  15. New candidates for CD4 T cell pathogenicity in experimental neuroinflammation and multiple sclerosis.

    PubMed

    Hoppmann, Nicola; Graetz, Christiane; Paterka, Magdalena; Poisa-Beiro, Laura; Larochelle, Catherine; Hasan, Maruf; Lill, Christina M; Zipp, Frauke; Siffrin, Volker

    2015-04-01

    Multiple sclerosis is a chronic autoimmune demyelinating disease of the central nervous system, which is thought to be triggered by environmental factors in genetically susceptible individuals leading to activation of autoreactive T lymphocytes. Large multi-centre genome-wide association studies have identified multiple genetic risk loci in multiple sclerosis. In this study, we investigated T cell transcriptomic changes in experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. We correlated these findings with the multiple sclerosis risk genes postulated by the most recent Immunochip analysis and found that multiple sclerosis susceptibility genes were significantly regulated in experimental autoimmune encephalomyelitis. Our data indicate that nine distinct genes associated with multiple sclerosis risk, Bach2, Il2ra, Irf8, Mertk, Odf3b, Plek, Rgs1, Slc30a7 and Thada, can be confirmed to be differentially regulated in pathogenic CD4(+) T cells. During the effector phase within the inflamed CNS, CD4(+) T cells undergo comprehensive transformation and we identified key transcription factors and signalling networks involved in this process. The transformation was linked to metabolic changes with the involvement of liver X receptor/retinoid X receptor signalling and cholesterol biosynthesis, which might control the T cell effector function in the central nervous system. Thus, our study confirms the involvement of multiple sclerosis risk genes in the pathophysiology of the animal model and sheds light on additional disease-relevant inflammatory networks.

  16. Murine autoimmune hearing loss mediated by CD4+ T cells specific for inner ear peptides.

    PubMed

    Solares, C Arturo; Edling, Andrea E; Johnson, Justin M; Baek, Moo-Jin; Hirose, Keiko; Hughes, Gordon B; Tuohy, Vincent K

    2004-04-01

    Autoimmune sensorineural hearing loss (ASNHL) is characterized typically by bilateral, rapidly progressive hearing loss that responds therapeutically to corticosteroid treatment. Despite its name, data implicating autoimmunity in the etiopathogenesis of ASNHL have been limited, and targeted self-antigens have not been identified. In the current study we show that the inner ear-specific proteins cochlin and beta-tectorin are capable of targeting experimental autoimmune hearing loss (EAHL) in mice. Five weeks after immunization of SWXJ mice with either Coch 131-150 or beta-tectorin 71-90, auditory brainstem responses (ABR) showed significant hearing loss at all frequencies tested. Flow cytometry analysis showed that each peptide selectively activated CD4(+) T cells with a proinflammatory Th1-like phenotype. T cell mediation of EAHL was determined by showing significantly increased ABR thresholds 6 weeks after adoptive transfer of peptide-activated CD4(+) T cells into naive SWXJ recipients. Immunocytochemical analysis showed that leukocytic infiltration of inner ear tissues coincided with onset of hearing loss. Our study provides a contemporary mouse model for clarifying our understanding of ASNHL and facilitating the development of novel effective treatments for this clinical entity. Moreover, our data provide experimental confirmation that ASNHL may be a T cell-mediated organ-specific autoimmune disorder of the inner ear.

  17. Vγ9Vδ2 T-Cell Polyfunctionality Is Differently Modulated in HAART-Treated HIV Patients according to CD4 T-Cell Count

    PubMed Central

    Casetti, Rita; De Simone, Gabriele; Sacchi, Alessandra; Rinaldi, Alessandra; Viola, Domenico; Agrati, Chiara; Bordoni, Veronica; Cimini, Eleonora; Tumino, Nicola; Besi, Francesca; Martini, Federico

    2015-01-01

    Alteration of γδ T-cell distribution and function in peripheral blood is among the earliest defects during HIV-infection. We asked whether the polyfunctional response could also be affected, and how this impairment could be associated to CD4 T-cell count. To this aim, we performed a cross-sectional study on HIV-infected individuals. In order to evaluate the polyfunctional-Vγ9Vδ2 T-cell response after phosphoantigen-stimulation, we assessed the cytokine/chemokine production and cytotoxicity by flow-cytometry in HAART-treated-HIV+ persons and healthy-donors. During HIV-infection Vγ9Vδ2-polyfunctional response quality is affected, since several Vγ9Vδ2 T-cell subsets resulted significantly lower in HIV+ patients in respect to healthy donors. Interestingly, we found a weak positive correlation between Vγ9Vδ2 T-cell-response and CD4 T-cell counts. By dividing the HIV+ patients according to CD4 T-cell count, we found that Low-CD4 patients expressed a lower number of two Vγ9Vδ2 T-cell subsets expressing MIP-1β in different combinations with other molecules (CD107a/IFNγ) in respect to High-CD4 individuals. Our results show that the Vγ9Vδ2 T-cell-response quality in Low-CD4 patients is specifically affected, suggesting a direct link between innate Vγ9Vδ2 T-cells and CD4 T-cell count. These findings suggest that Vγ9Vδ2 T-cell quality may be indirectly influenced by HAART therapy and could be included in a new therapeutical strategy which would perform an important role in fighting HIV infection. PMID:26161861

  18. Vγ9Vδ2 T-Cell Polyfunctionality Is Differently Modulated in HAART-Treated HIV Patients according to CD4 T-Cell Count.

    PubMed

    Casetti, Rita; De Simone, Gabriele; Sacchi, Alessandra; Rinaldi, Alessandra; Viola, Domenico; Agrati, Chiara; Bordoni, Veronica; Cimini, Eleonora; Tumino, Nicola; Besi, Francesca; Martini, Federico

    2015-01-01

    Alteration of γδ T-cell distribution and function in peripheral blood is among the earliest defects during HIV-infection. We asked whether the polyfunctional response could also be affected, and how this impairment could be associated to CD4 T-cell count. To this aim, we performed a cross-sectional study on HIV-infected individuals. In order to evaluate the polyfunctional-Vγ9Vδ2 T-cell response after phosphoantigen-stimulation, we assessed the cytokine/chemokine production and cytotoxicity by flow-cytometry in HAART-treated-HIV+ persons and healthy-donors. During HIV-infection Vγ9Vδ2-polyfunctional response quality is affected, since several Vγ9Vδ2 T-cell subsets resulted significantly lower in HIV+ patients in respect to healthy donors. Interestingly, we found a weak positive correlation between Vγ9Vδ2 T-cell-response and CD4 T-cell counts. By dividing the HIV+ patients according to CD4 T-cell count, we found that Low-CD4 patients expressed a lower number of two Vγ9Vδ2 T-cell subsets expressing MIP-1β in different combinations with other molecules (CD107a/IFNγ) in respect to High-CD4 individuals. Our results show that the Vγ9Vδ2 T-cell-response quality in Low-CD4 patients is specifically affected, suggesting a direct link between innate Vγ9Vδ2 T-cells and CD4 T-cell count. These findings suggest that Vγ9Vδ2 T-cell quality may be indirectly influenced by HAART therapy and could be included in a new therapeutical strategy which would perform an important role in fighting HIV infection.

  19. TLR2 engagement on CD4(+) T cells enhances effector functions and protective responses to Mycobacterium tuberculosis.

    PubMed

    Reba, Scott M; Li, Qing; Onwuzulike, Sophia; Ding, Xuedong; Karim, Ahmad F; Hernandez, Yeritza; Fulton, Scott A; Harding, Clifford V; Lancioni, Christina L; Nagy, Nancy; Rodriguez, Myriam E; Wearsch, Pamela A; Rojas, Roxana E

    2014-05-01

    We have previously demonstrated that mycobacterial lipoproteins engage TLR2 on human CD4(+) T cells and upregulate TCR-triggered IFN-γ secretion and cell proliferation in vitro. Here we examined the role of CD4(+) T-cell-expressed TLR2 in Mycobacterium tuberculosis (MTB) Ag-specific T-cell priming and in protection against MTB infection in vivo. Like their human counterparts, mouse CD4(+) T cells express TLR2 and respond to TLR2 costimulation in vitro. This Th1-like response was observed in the context of both polyclonal and Ag-specific TCR stimulation. To evaluate the role of T-cell TLR2 in priming of CD4(+) T cells in vivo, naive MTB Ag85B-specific TCR transgenic CD4(+) T cells (P25 TCR-Tg) were adoptively transferred into Tlr2(-/-) recipient C57BL/6 mice that were then immunized with Ag85B and with or without TLR2 ligand Pam3 Cys-SKKKK. TLR2 engagement during priming resulted in increased numbers of IFN-γ-secreting P25 TCR-Tg T cells 1 week after immunization. P25 TCR-Tg T cells stimulated in vitro via TCR and TLR2 conferred more protection than T cells stimulated via TCR alone when adoptively transferred before MTB infection. Our findings indicate that TLR2 engagement on CD4(+) T cells increases MTB Ag-specific responses and may contribute to protection against MTB infection.

  20. CD4(+)B220(+)TCRγδ(+) T cells produce IL-17 in lupus-prone MRL/lpr mice.

    PubMed

    Qiu, Feng; Li, Tingting; Zhang, Kui; Wan, Jun; Qi, Xiaokun

    2016-09-01

    Systemic lupus erythematosus is an autoimmune disease with comprehensive immune cell disorders. Recent studies suggested that pro-inflammatory cytokine IL-17 plays important role in lupus, leaving the cellular sources and their pathogenic and physiologic characters largely unknown. In the current study, by using lupus-prone MRL/lpr mice, we demonstrated that Th17 response prevails in lupus disease regarding significantly accumulated serum IL-17, increased IL-17-producing splenocytes, and elevated phospho-STAT3 in CD4(+) T cells. Intracellular staining revealed that unusual CD4(+)B220(+) T cells are major IL-17-producing cells, whereas conventional CD4(+)B220(-) T cells are major IFN-γ-producing cells. Subsequent studies showed that CD4(+)B220(+) cells contains both αβ and γδ T cells in the spleen and thymus of MRL/lpr mice. Further study showed that around 60% of γδ T cells in MRL/lpr mice co-express both B220 and CD4 on their surface, and are the major RORγt(+) cells in MRL/lpr mice. Finally, CD4(+)B220(+) T cells alone do not proliferate, but could enhance the proliferation and IFN-γ-production of conventional CD4(+)B220(-) T cells. Our findings suggest the pathogenic role of unusual CD4(+)B220(+) T cells in lupus disease in MRL/lpr mice according to their IL-17-producing ability and stimulatory function for conventional CD4(+)B220(-) T cells. PMID:27235595

  1. Vitamin D Actions on CD4(+) T Cells in Autoimmune Disease.

    PubMed

    Hayes, Colleen Elizabeth; Hubler, Shane L; Moore, Jerott R; Barta, Lauren E; Praska, Corinne E; Nashold, Faye E

    2015-01-01

    This review summarizes and integrates research on vitamin D and CD4(+) T-lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene-environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4(+) T-cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4(+) T lymphocytes is summarized to support the thesis that calcitriol is sunlight's main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data are summarized to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3(+)CD4(+) T-regulatory cell and CD4(+) T-regulatory cell type 1 (Tr1) cell functions, and a Th1-Tr1 switch. The proposed Th1-Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell-cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, unanswered questions and potentially informative future research directions are highlighted to speed delivery of etiology-based strategies to reduce autoimmune disease.

  2. Vitamin D Actions on CD4+ T Cells in Autoimmune Disease

    PubMed Central

    Hayes, Colleen Elizabeth; Hubler, Shane L.; Moore, Jerott R.; Barta, Lauren E.; Praska, Corinne E.; Nashold, Faye E.

    2015-01-01

    This review summarizes and integrates research on vitamin D and CD4+ T-lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene–environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4+ T-cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4+ T lymphocytes is summarized to support the thesis that calcitriol is sunlight’s main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data are summarized to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3+CD4+ T-regulatory cell and CD4+ T-regulatory cell type 1 (Tr1) cell functions, and a Th1–Tr1 switch. The proposed Th1–Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell–cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, unanswered questions and potentially informative future research directions are highlighted to speed delivery of etiology-based strategies to reduce autoimmune disease. PMID:25852682

  3. Non-Canonical Notch Signaling Drives Activation and Differentiation of Peripheral CD4+ T Cells

    PubMed Central

    Dongre, Anushka; Surampudi, Lalitha; Lawlor, Rebecca G.; Fauq, Abdul H.; Miele, Lucio; Golde, Todd E.; Minter, Lisa M.; Osborne, Barbara A.

    2014-01-01

    Cleavage of the Notch receptor via a γ-secretase, results in the release of the active intra-cellular domain of Notch that migrates to the nucleus and interacts with RBP-Jκ, resulting in the activation of downstream target genes. This canonical Notch signaling pathway has been documented to influence T cell development and function. However, the mechanistic details underlying this process remain obscure. In addition to RBP-Jκ, the intra-cellular domain of Notch also interacts with other proteins in the cytoplasm and nucleus, giving rise to the possibility of an alternate, RBP-Jκ independent Notch pathway. However, the contribution of such RBP-Jκ independent, “non-canonical” Notch signaling in regulating peripheral T cell responses is unknown. In this report, we specifically demonstrate the requirement of Notch1 for regulating signal strength and signaling events distal to the T cell receptor in peripheral CD4+ T cells. By using mice with a conditional deletion in Notch1 or RBP-Jκ, we show that Notch1 regulates activation and proliferation of CD4+ T cells independently of RBP-Jκ. Furthermore, differentiation to TH1 and iTreg lineages although Notch dependent, is RBP-Jκ independent. Our striking observations demonstrate that many of the cell-intrinsic functions of Notch occur independently of RBP-Jκ. Such non-canonical regulation of these processes likely occurs through NF-κ B. This reveals a previously unknown, novel role of non-canonical Notch signaling in regulating peripheral T cell responses. PMID:24611064

  4. Tolerance is established in polyclonal CD4(+) T cells by distinct mechanisms, according to self-peptide expression patterns.

    PubMed

    Malhotra, Deepali; Linehan, Jonathan L; Dileepan, Thamotharampillai; Lee, You Jeong; Purtha, Whitney E; Lu, Jennifer V; Nelson, Ryan W; Fife, Brian T; Orr, Harry T; Anderson, Mark S; Hogquist, Kristin A; Jenkins, Marc K

    2016-02-01

    Studies of repertoires of mouse monoclonal CD4(+) T cells have revealed several mechanisms of self-tolerance; however, which mechanisms operate in normal repertoires is unclear. Here we studied polyclonal CD4(+) T cells specific for green fluorescent protein expressed in various organs, which allowed us to determine the effects of specific expression patterns on the same epitope-specific T cells. Peptides presented uniformly by thymic antigen-presenting cells were tolerated by clonal deletion, whereas peptides excluded from the thymus were ignored. Peptides with limited thymic expression induced partial clonal deletion and impaired effector T cell potential but enhanced regulatory T cell potential. These mechanisms were also active for T cell populations specific for endogenously expressed self antigens. Thus, the immunotolerance of polyclonal CD4(+) T cells was maintained by distinct mechanisms, according to self-peptide expression patterns. PMID:26726812

  5. CD4 on CD8+ T cells directly enhances effector function and is a target for HIV infection

    NASA Astrophysics Data System (ADS)

    Kitchen, Scott G.; Jones, Nicole R.; Laforge, Stuart; Whitmire, Jason K.; Vu, Bien-Aimee; Galic, Zoran; Brooks, David G.; Brown, Stephen J.; Kitchen, Christina M. R.; Zack, Jerome A.

    2004-06-01

    Costimulation of purified CD8+ T lymphocytes induces de novo expression of CD4, suggesting a previously unrecognized function for this molecule in the immune response. Here, we report that the CD4 molecule plays a direct role in CD8+ T cell function by modulating expression of IFN- and Fas ligand, two important CD8+ T cell effector molecules. CD4 expression also allows infection of CD8 cells by HIV, which results in down-regulation of the CD4 molecule and impairs the induction of IFN-, Fas ligand, and the cytotoxic responses of activated CD8+ T cells. Thus, the CD4 molecule plays a direct role in CD8 T cell function, and infection of these cells by HIV provides an additional reservoir for the virus and also may contribute to the immunodeficiency seen in HIV disease.

  6. Regulation of DNA methylation dictates Cd4 expression during the development of helper and cytotoxic T cell lineages.

    PubMed

    Sellars, MacLean; Huh, Jun R; Day, Kenneth; Issuree, Priya D; Galan, Carolina; Gobeil, Stephane; Absher, Devin; Green, Michael R; Littman, Dan R

    2015-07-01

    During development, progenitor cells with binary potential give rise to daughter cells that have distinct functions. Heritable epigenetic mechanisms then lock in gene-expression programs that define lineage identity. Regulation of the gene encoding the T cell-specific coreceptor CD4 in helper and cytotoxic T cells exemplifies this process, with enhancer- and silencer-regulated establishment of epigenetic memory for stable gene expression and repression, respectively. Using a genetic screen, we identified the DNA-methylation machinery as essential for maintaining silencing of Cd4 in the cytotoxic lineage. Furthermore, we found a requirement for the proximal enhancer in mediating the removal of DNA-methylation marks from Cd4, which allowed stable expression of Cd4 in helper T cells. Our findings suggest that stage-specific methylation and demethylation events in Cd4 regulate its heritable expression in response to the distinct signals that dictate lineage 'choice' during T cell development. PMID:26030024

  7. Large-scale in vitro expansion of polyclonal human CD4(+)CD25high regulatory T cells.

    PubMed

    Hoffmann, Petra; Eder, Ruediger; Kunz-Schughart, Leoni A; Andreesen, Reinhard; Edinger, Matthias

    2004-08-01

    CD4(+)CD25+ regulatory T (Treg) cells are pivotal for the maintenance of self-tolerance, and their adoptive transfer gives protection from autoimmune diseases and pathogenic alloresponses after solid organ or bone marrow transplantation in murine model systems. In vitro, human CD4(+)CD25+ Treg cells display phenotypic and functional characteristics similar to those of murine CD4(+)CD25+ Treg cells: namely, hyporesponsiveness to T-cell receptor (TCR) stimulation and suppression of CD25- T cells. Thus far, the detailed characterization and potential clinical application of human CD4(+)CD25+ Treg cells have been hampered by their paucity in peripheral blood and the lack of appropriate expansion protocols. Here we describe the up to 40 000-fold expansion of highly purified human CD4(+)CD25high T cells in vitro through the use of artificial antigen-presenting cells for repeated stimulation via CD3 and CD28 in the presence of high-dose interleukin 2 (IL-2). Expanded CD4(+)CD25high T cells were polyclonal, maintained their phenotype, exceeded the suppressive activity of freshly isolated CD4(+)CD25high T cells, and maintained expression of the lymph node homing receptors L-selectin (CD62L) and CCR7. The ability to rapidly expand human CD4(+)CD25high Treg cells on a large scale will not only facilitate their further exploration but also accelerate their potential clinical application in T cell-mediated diseases and transplantation medicine. PMID:15090447

  8. Dose-Responsive Gene Expression in Suberoylanilide Hydroxamic Acid (SAHA) Treated Resting CD4+ T Cells

    PubMed Central

    Reardon, Brian; Beliakova-Bethell, Nadejda; Spina, Celsa A.; Singhania, Akul; Margolis, David M.; Richman, Douglas R.; Woelk, Christopher H.

    2015-01-01

    Design Persistent latently infected CD4+ T cells represent a major obstacle to HIV eradication. Histone deacetylase inhibitors (HDACis) are a proposed activation therapy. However, off-target effects on expression in host immune cells are poorly understood. We hypothesized that HDACi-modulated genes would be best identified with dose-response analysis. Methods Resting primary CD4+ T cells were treated with 0.34, 1, 3, or 10 μM of the HDACi, SAHA, for 24 hours and subjected to microarray gene expression analysis. Genes with dose-correlated expression were filtered to identify a subset with consistent up or downregulation at each SAHA dose. Histone modifications were characterized in 6 SAHA dose-responsive genes by chromatin immunoprecipitation (ChIP-RT-qPCR). Results A large number of genes were shown to be up (N=657) or downregulated (N=725) by SAHA in a dose-responsive manner (FDR p-value < 0.05, fold change ≥ |2|). Several genes (CTNNAL1, DPEP2, H1F0, IRGM, PHF15, and SELL) are potential in vivo biomarkers of SAHA activity. SAHA dose-responsive genes included transcription factors, HIV restriction factors, histone methyltransferases, and host proteins that interact with HIV. Pathway analysis suggested net downregulation of T cell activation with increasing SAHA dose. Histone acetylation was not correlated with host gene expression, but plausible alternative mechanisms for SAHA-modulated gene expression were identified. Conclusions Numerous genes in CD4+ T cells are modulated by SAHA in a dose-responsive manner, including genes that may negatively influence HIV activation from latency. Our study suggests that SAHA influences gene expression through a confluence of several mechanisms, including histone modification, and altered expression and activity of transcription factors. PMID:26258524

  9. Specific CD4+ T-Cell Reactivity and Cytokine Release in Different Clinical Presentations of Leptospirosis

    PubMed Central

    Moos, Verena; Allers, Kristina; Luge, Enno; Mayer-Scholl, Anne; Nöckler, Karsten; Loddenkemper, Christoph; Jansen, Andreas; Schneider, Thomas

    2015-01-01

    Clinical manifestations of leptospirosis are highly variable: from asymptomatic to severe and potentially fatal. The outcome of the disease is usually determined in the immunological phase, beginning in the second week of symptoms. The underlying mechanisms, predictive factors, and individual immune responses that contribute to clinical variations are not well understood. The aim of this study was to determine the specifics of CD4+ T-cell reactivity and cytokine release after stimulation with leptospiral antigens in patients with leptospirosis of different disease severities (patients with mild and severe symptoms) and in control subjects (with and without proven exposure to Leptospira). Whole-blood specimens were stimulated with Leptospira antigens in vitro. Subsequently, intracellular staining of cytokines was performed, and flow cytometry was used to assess the expression of CD40 ligand (CD40L) and the production of gamma interferon (IFN-γ), interleukin-10 (IL-10), IL-2, and tumor necrosis factor alpha (TNF-α) by CD4+ T cells. The production of inflammatory cytokines such as TNF-α by CD4+ T cells after stimulation with leptospiral antigens was highest in patients with severe disease. In contrast, the ratio of IL-10 production to TNF-α production was higher in exposed subjects than in patients with mild and severe disease. Levels of proinflammatory cytokines such as TNF-α may be useful markers of the severity of the immunological phase of leptospirosis. IL-10 production by T cells after antigen-specific stimulation may indicate a more successful downregulation of the inflammatory response and may contribute to an asymptomatic course of the disease. PMID:26491036

  10. Progressive CD4+ central–memory T cell decline results in CD4+ effector–memory insufficiency and overt disease in chronic SIV infection

    PubMed Central

    Okoye, Afam; Meier-Schellersheim, Martin; Brenchley, Jason M.; Hagen, Shoko I.; Walker, Joshua M.; Rohankhedkar, Mukta; Lum, Richard; Edgar, John B.; Planer, Shannon L.; Legasse, Alfred; Sylwester, Andrew W.; Piatak, Michael; Lifson, Jeffrey D.; Maino, Vernon C.; Sodora, Donald L.; Douek, Daniel C.; Axthelm, Michael K.; Grossman, Zvi; Picker, Louis J.

    2007-01-01

    Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4+ CCR5+ effector–memory T (TEM) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4+ memory T cell proliferation appears to prevent collapse of effector site CD4+ TEM cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4+ TEM cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4+ TEM cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4+ TEM cells from central–memory T (TCM) cell precursors. The instability of effector site CD4+ TEM cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5− CD4+ TCM cells. These data suggest that although CD4+ TEM cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4+ TCM cells. PMID:17724130

  11. PD-1/PD-Ls pathways between CD4(+) T cells and pleural mesothelial cells in human tuberculous pleurisy.

    PubMed

    Yin, Wen; Tong, Zhao-Hui; Cui, Ai; Zhang, Jian-Chu; Ye, Zhi-Jian; Yuan, Ming-Li; Zhou, Qiong; Shi, Huan-Zhong

    2014-03-01

    Programmed death 1 (PD-1), PD-ligand 1 (PD-L1), and PD-L2 have been demonstrated to be involved in tuberculosis immunity, however, the expression and regulation of PD-1/PD-Ls pathways in pleural mesothelial cells (PMCs) and CD4(+) T cells in tuberculous pleural effusion (TPE) have not been investigated. Expression of PD-1 on CD4(+) T cells and expressions of PD-L1 and PD-L2 on PMCs in TPE were determined. The impacts of PD-1/PD-Ls pathways on proliferation, apoptosis, adhesion, and migration of CD4(+) T cells were explored. Concentrations of soluble PD-l, but not of soluble PD-Ls, were much higher in TPE than in serum. Expressions of PD-1 on CD4(+) T cells in TPE were significantly higher than those in blood. Expressions of PD-Ls were much higher on PMCs from TPE when compared with those from transudative effusion. Interferon-γ not only upregulated the expression of PD-1 on CD4(+) T cells, but also upregulated the expressions of PD-Ls on PMCs. Blockage PD-1/PD-Ls pathways abolished the inhibitory effects on proliferation and adhesion activity of CD4(+) T cells induced by PMCs. PD-1/PD-Ls pathways on PMCs inhibited proliferation and adhesion activity of CD4(+) T cells, suggesting that Mycobacterium tuberculosis might exploit PD-1/PD-Ls pathways to evade host cell immune response in human.

  12. Protective CD4 T cells targeting cryptic epitopes of Mycobacterium tuberculosis resist infection-driven terminal differentiation.

    PubMed

    Woodworth, Joshua S; Aagaard, Claus Sindbjerg; Hansen, Paul R; Cassidy, Joseph P; Agger, Else Marie; Andersen, Peter

    2014-04-01

    CD4 T cells are crucial to the control of Mycobacterium tuberculosis infection and are a key component of current vaccine strategies. Conversely, immune-mediated pathology drives disease, and recent evidence suggests that adaptive and innate responses are evolutionarily beneficial to M. tuberculosis. We compare the functionality of CD4 T cell responses mounted against dominant and cryptic epitopes of the M. tuberculosis 6-kDa early secreted Ag (ESAT-6) before and postinfection. Protective T cells against cryptic epitopes not targeted during natural infection were induced by vaccinating mice with a truncated ESAT-6 protein, lacking the dominant epitope. The ability to generate T cells that recognize multiple cryptic epitopes was MHC-haplotype dependent, including increased potential via heterologous MHC class II dimers. Before infection, cryptic epitope-specific T cells displayed enhanced proliferative capacity and delayed cytokine kinetics. After aerosol M. tuberculosis challenge, vaccine-elicited CD4 T cells expanded and recruited to the lung. In chronic infection, dominant epitope-specific T cells developed a terminal differentiated KLRG1(+)/PD-1(lo) surface phenotype that was significantly reduced in the cryptic epitope-specific T cell populations. Dominant epitope-specific T cells in vaccinated animals developed into IFN-γ- and IFN-γ,TNF-α-coproducing effector cells, characteristic of the endogenous response. In contrast, cryptic epitope-specific CD4 T cells maintained significantly greater IFN-γ(+)TNF-α(+)IL-2(+) and TNF-α(+)IL-2(+) memory-associated polyfunctionality and enhanced proliferative capacity. Vaccine-associated IL-17A production by cryptic CD4 T cells was also enhanced, but without increased neutrophilia/pathology. Direct comparison of dominant/cryptic epitope-specific CD4 T cells within covaccinated mice confirmed the superior ability of protective cryptic epitope-specific T cells to resist M. tuberculosis infection-driven T cell

  13. Ndfip-mediated degradation of Jak1 tunes cytokine signalling to limit expansion of CD4+ effector T cells

    PubMed Central

    O'Leary, Claire E.; Riling, Christopher R.; Spruce, Lynn A.; Ding, Hua; Kumar, Suresh; Deng, Guoping; Liu, Yuhong; Seeholzer, Steven H.; Oliver, Paula M.

    2016-01-01

    Nedd4 family E3 ubiquitin ligases have been shown to restrict T-cell function and impact T-cell differentiation. We show here that Ndfip1 and Ndfip2, activators of Nedd4 family ligases, together limit accumulation and function of effector CD4+ T cells. Using a three-part proteomics approach in primary T cells, we identify stabilization of Jak1 in Ndfip1/2-deficient T cells stimulated through the TCR. Jak1 degradation is aborted in activated T cells that lack Ndfips. In wild-type cells, Jak1 degradation lessens CD4+ cell sensitivity to cytokines during TCR stimulation, while in Ndfip-deficient cells cytokine responsiveness persists, promoting increased expansion and survival of pathogenic effector T cells. Thus, Ndfip1/Ndfip2 regulate the cross talk between the T-cell receptor and cytokine signalling pathways to limit inappropriate T-cell responses. PMID:27088444

  14. The role of TRPV1 in the CD4+ T cell-mediated inflammatory response of allergic rhinitis.

    PubMed

    Samivel, Ramachandran; Kim, Dae Woo; Son, Hye Ran; Rhee, Yun-Hee; Kim, Eun Hee; Kim, Ji Hye; Bae, Jun-Sang; Chung, Young-Jun; Chung, Phil-Sang; Raz, Eyal; Mo, Ji-Hun

    2016-01-01

    Transient receptor potential vanilloid 1 (TRPV1), which has been identified as a molecular target for the activation of sensory neurons by various painful stimuli, was reported to regulate the signaling and activation of CD4+ T cells. However, the role of TRPV1 in CD4+ T cell in allergic rhinitis remains poorly understood. In this study, TRPV1 expression was localized in CD4+ T cells. Both knockout and chemical inhibition of TRPV1 suppressed Th2/Th17 cytokine production in CD4 T cells and Jurkat T cells, respectively, and can suppress T cell receptor signaling pathways including NF-κB, MAP kinase, and NFAT. In TRPV1 knockout allergic rhinitis (AR) mice, eosinophil infiltration, Th2/Th17 cytokines in the nasal mucosa, and total and ova-specific IgE levels in serum decreased, compared with wild-type AR mice. The TRPV1 antagonists, BCTC or theobromine, showed similar inhibitory immunologic effects on AR mice models. In addition, the number of TRPV1+/CD4+ inflammatory cells increased in the nasal mucosa of patients with AR, compared with that of control subjects. Thus, TRPV1 activation on CD4+ T cells is involved in T cell receptor signaling, and it could be a novel therapeutic target in AR.

  15. The role of TRPV1 in the CD4+ T cell-mediated inflammatory response of allergic rhinitis

    PubMed Central

    Son, Hye Ran; Rhee, Yun-Hee; Kim, Eun Hee; Kim, Ji Hye; Bae, Jun-Sang; Chung, Young-Jun; Chung, Phil-Sang; Raz, Eyal; Mo, Ji-Hun

    2016-01-01

    Transient receptor potential vanilloid 1 (TRPV1), which has been identified as a molecular target for the activation of sensory neurons by various painful stimuli, was reported to regulate the signaling and activation of CD4+ T cells. However, the role of TRPV1 in CD4+ T cell in allergic rhinitis remains poorly understood. In this study, TRPV1 expression was localized in CD4+ T cells. Both knockout and chemical inhibition of TRPV1 suppressed Th2/Th17 cytokine production in CD4 T cells and Jurkat T cells, respectively, and can suppress T cell receptor signaling pathways including NF-κB, MAP kinase, and NFAT. In TRPV1 knockout allergic rhinitis (AR) mice, eosinophil infiltration, Th2/Th17 cytokines in the nasal mucosa, and total and ova-specific IgE levels in serum decreased, compared with wild-type AR mice. The TRPV1 antagonists, BCTC or theobromine, showed similar inhibitory immunologic effects on AR mice models. In addition, the number of TRPV1+/CD4+ inflammatory cells increased in the nasal mucosa of patients with AR, compared with that of control subjects. Thus, TRPV1 activation on CD4+ T cells is involved in T cell receptor signaling, and it could be a novel therapeutic target in AR. PMID:26700618

  16. Titrating T cell Epitopes within Self-Assembled Vaccines Optimizes CD4+ Helper T Cell and Antibody Outputs

    PubMed Central

    Chen, Jianjun; Verbus, Emily A.; Han, Huifang; Fridman, Arthur; McNeely, Tessie; Collier, Joel H.; Chong, Anita S.

    2014-01-01

    Epitope content plays a critical role in determining T cell and antibody responses to vaccines, biomaterials, and protein therapeutics, but its effects are nonlinear and difficult to isolate. Here, molecular self-assembly was used to build a vaccine with precise control over epitope content, in order to finely tune the magnitude and phenotype of T helper and antibody responses. Self-adjuvanting peptide nanofibers were formed by co-assembling a high-affinity universal CD4+ T cell epitope (PADRE) and a B cell epitope from Staphylococcus aureus at specifiable concentrations. Increasing the PADRE concentration from μM to mM elicited bell-shaped dose-responses that were unique to different T cell populations. Notably, the epitope ratios that maximized T follicular helper and antibody responses differed by an order of magnitude from those that maximized Th1 or Th2 responses. Thus, modular materials assembly provides a means of controlling epitope content and efficiently skewing the adaptive immune response in the absence of exogenous adjuvant; this approach may contribute to the development of improved vaccines and immunotherapies. PMID:24923735

  17. Titrating T-cell epitopes within self-assembled vaccines optimizes CD4+ helper T cell and antibody outputs.

    PubMed

    Pompano, Rebecca R; Chen, Jianjun; Verbus, Emily A; Han, Huifang; Fridman, Arthur; McNeely, Tessie; Collier, Joel H; Chong, Anita S

    2014-11-01

    Epitope content plays a critical role in determining T-cell and antibody responses to vaccines, biomaterials, and protein therapeutics, but its effects are nonlinear and difficult to isolate. Here, molecular self-assembly is used to build a vaccine with precise control over epitope content, in order to finely tune the magnitude and phenotype of T helper and antibody responses. Self-adjuvanting peptide nanofibers are formed by co-assembling a high-affinity universal CD4+ T-cell epitope (PADRE) and a B-cell epitope from Staphylococcus aureus at specifiable concentrations. Increasing the PADRE concentration from micromolar to millimolar elicited bell-shaped dose-responses that are unique to different T-cell populations. Notably, the epitope ratios that maximize T follicular helper and antibody responses differed by an order of magnitude from those that maximized Th1 or Th2 responses. Thus, modular materials assembly provides a means of controlling epitope content and efficiently skewing the adaptive immune response in the absence of exogenous adjuvant; this approach may contribute to the development of improved vaccines and immunotherapies.

  18. Triple infection with HIV-1, HTLV-1 and Strongyloides stercoralis, rendering CD4+ T-cell counts a misleading entity.

    PubMed

    Janssen, Saskia; Rossatanga, Elie G; Jurriaans, Suzanne; ten Berge, Ineke J M; Grobusch, Martin P

    2013-01-01

    We report the case of a Gabonese HIV-patient who presented with haemoptysis, weight loss, fulminant diarrhoea and subsequent ileus and elevated CD4+ T-cell counts. He was diagnosed with Strongyloides stercoralis and human T-lymphotrophic virus type-1 infection. After treatment of the strongyloides hyperinfection syndrome, his CD4+ T-cell counts dropped greatly. The initially elevated CD4+ T-cell counts were misleading to the clinicians with regard to decision-making on antiretroviral therapy initiation. PMID:24152969

  19. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity.

    PubMed

    Martins, Karen A O; Cooper, Christopher L; Stronsky, Sabrina M; Norris, Sarah L W; Kwilas, Steven A; Steffens, Jesse T; Benko, Jacqueline G; van Tongeren, Sean A; Bavari, Sina

    2016-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development. PMID:26870818

  20. The Regulation of CD4(+) T Cell Responses during Protozoan Infections.

    PubMed

    Engwerda, Christian R; Ng, Susanna S; Bunn, Patrick T

    2014-01-01

    CD4(+) T cells are critical for defense against protozoan parasites. Intracellular protozoan parasite infections generally require the development of a Th1 cell response, characterized by the production of IFNγ and TNF that are critical for the generation of microbicidal molecules by phagocytes, as well as the expression of cytokines and cell surface molecules needed to generate cytolytic CD8(+) T cells that can recognize and kill infected host cells. Over the past 25 years, much has been learnt about the molecular and cellular components necessary for the generation of Th1 cell responses, and it has become clear that these responses need to be tightly controlled to prevent disease. However, our understanding of the immunoregulatory mechanisms activated during infection is still not complete. Furthermore, it is apparent that although these mechanisms are critical to prevent inflammation, they can also promote parasite persistence and development of disease. Here, we review how CD4(+) T cells are controlled during protozoan infections and how these regulatory mechanisms can influence parasite growth and disease outcome.

  1. Inflammatory monocytes are potent antitumor effectors controlled by regulatory CD4+ T cells

    PubMed Central

    Pommier, Arnaud; Audemard, Alexandra; Durand, Aurélie; Lengagne, Renée; Delpoux, Arnaud; Martin, Bruno; Douguet, Laetitia; Le Campion, Armelle; Kato, Masashi; Avril, Marie-Françoise; Auffray, Cédric; Lucas, Bruno; Prévost-Blondel, Armelle

    2013-01-01

    The present study evaluates the impact of immune cell populations on metastatic development in a model of spontaneous melanoma [mice expressing the human RET oncogene under the control of the metallothionein promoter (MT/ret mice)]. In this model, cancer cells disseminate early but remain dormant for several weeks. Then, MT/ret mice develop cutaneous metastases and, finally, distant metastases. A total of 35% of MT/ret mice develop a vitiligo, a skin depigmentation attributable to the lysis of normal melanocytes, associated with a delay in tumor progression. Here, we find that regulatory CD4+ T cells accumulate in the skin, the spleen, and tumor-draining lymph nodes of MT/ret mice not developing vitiligo. Regulatory T-cell depletion and IL-10 neutralization led to increased occurrence of vitiligo that correlated with a decreased incidence of melanoma metastases. In contrast, inflammatory monocytes/dendritic cells accumulate in the skin of MT/ret mice with active vitiligo. Moreover, they inhibit tumor cell proliferation in vitro through a reactive oxygen species-dependent mechanism, and both their depletion and reactive oxygen species neutralization in vivo increased tumor cell dissemination. Altogether, our data suggest that regulatory CD4+ T cells favor tumor progression, in part, by inhibiting recruitment and/or differentiation of inflammatory monocytes in the skin. PMID:23878221

  2. Protective cellular retroviral immunity requires both CD4+ and CD8+ immune T cells.

    PubMed Central

    Hom, R C; Finberg, R W; Mullaney, S; Ruprecht, R M

    1991-01-01

    We have found previously that postexposure chemoprophylaxis with 3'-azido-3'-deoxythymidine (also known as zidovudine or AZT) in combination with recombinant human alpha A/D interferon fully protected mice exposed to a lethal dose of Rauscher murine leukemia virus (RLV) against viremia and disease. After cessation of therapy, over 90% of these mice were able to resist rechallenge with live RLV, thus demonstrating an acquired immunity. Adoptive cell transfer of 4 x 10(7) cells from immunized mice fully protected naive recipients from viremia and splenomegaly after RLV challenge. However, when these immune T cells were fractionated into CD4+ and CD8+ subpopulations, only partial protection was found when 4 x 10(7) T cells of either subset were given. Full protection against RLV challenge was seen again when the T-cell subsets from immunized mice were recombined and transferred at the same number into naive mice. We conclude that cellular immunity alone is protective and that both CD4+ and CD8+ cell types are required for conferring full protection against live virus challenge. Images PMID:1898666

  3. Depletion of CD4+ CD25+ Regulatory T Cells Promotes CCL21-Mediated Antitumor Immunity

    PubMed Central

    Zhou, Shuang; Tao, Huihong; Zhen, Zhiwei; Chen, Haixia; Chen, Guolin; Yang, Yaoqin

    2013-01-01

    CCL21 is known to attract dendritic cells (DCs) and T cells that may reverse tumor-mediated immune suppression. The massive infiltration of tumors by regulatory T cells (Tregs) prevents the development of a successful helper immune response. In this study, we investigated whether elimination of CD4+ CD25+ Tregs in the tumor microenvironment using anti-CD25 monoclonal antibodies (mAbs) was capable of enhancing CCL21-mediated antitumor immunity in a mouse hepatocellular carcinoma (HCC) model. We found that CCL21 in combination with anti-CD25 mAbs (PC61) resulted in improved antitumor efficacy and prolonged survival, not only inhibited tumor angiogenesis and cell proliferation, but also led to significant increases in the frequency of CD4+, CD8+ T cells and CD11c+ DCs within the tumor, coincident with marked induction of tumor-specific CD8+ cytotoxic T lymphocytes (CTLs) at the local tumor site. The intratumoral immune responses were accompanied by the enhanced elaboration of IL-12 and IFN-γ, but reduced release of the immunosuppressive mediators IL-10 and TGF-β1. The results indicated that depletion of Tregs in the tumor microenvironment could enhance CCL21-mediated antitumor immunity, and CCL21 combined with anti-CD25 mAbs may be a more effective immunotherapy to promote tumor rejection. PMID:24023916

  4. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity

    PubMed Central

    Martins, Karen A.O.; Cooper, Christopher L.; Stronsky, Sabrina M.; Norris, Sarah L.W.; Kwilas, Steven A.; Steffens, Jesse T.; Benko, Jacqueline G.; van Tongeren, Sean A.; Bavari, Sina

    2015-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development. PMID:26870818

  5. CD4+ T Cells Drive Goblet Cell Depletion during Citrobacter rodentium Infection

    PubMed Central

    Chan, Justin M.; Bhinder, Ganive; Sham, Ho Pan; Ryz, Natasha; Huang, Tina; Bergstrom, Kirk S.

    2013-01-01

    Both idiopathic and infectious forms of colitis disrupt normal intestinal epithelial cell (IEC) proliferation and differentiation, although the mechanisms involved remain unclear. Recently, we demonstrated that infection by the attaching and effacing murine pathogen Citrobacter rodentium leads to a significant reduction in colonic goblet cell numbers (goblet cell depletion). This pathology depends on T and/or B cells, as Rag1−/− mice do not suffer this depletion during infection, instead suffering high mortality rates. To address the immune mechanisms involved, we reconstituted Rag−/− mice with either CD4+ or CD8+ T cells. Both T cell subsets increased Rag1−/− mouse survival during infection, with mice that received CD8+ T cells developing colonic ulcers but not goblet cell depletion. In contrast, mice that received CD4+ T cells showed goblet cell depletion in concert with exaggerated IEC proliferation. To define the possible involvement of T cell-derived cytokines, we infected gamma interferon receptor gene knockout (IFN-γR−/−) mice and wild-type mice given interleukin 17A (IL-17A) neutralizing antibodies and found that IFN-γ signaling was required for both goblet cell depletion and increased IEC proliferation. Immunostaining revealed that C. rodentium cells preferentially localized to nonhyperplastic crypts containing numerous goblet cells, whereas hyperplastic, goblet cell-depleted crypts appeared protected from infection. To address whether goblet cell depletion benefits the C. rodentium-infected host, we increased goblet cell numbers using the γ-secretase inhibitor dibenzazepine (DBZ), which resulted in greatly increased pathogen burdens and mortality rates. These results demonstrate that goblet cell depletion reflects host immunomodulation of IEC homeostasis and reflects a novel host defense mechanism against mucosal-adherent pathogens. PMID:24101690

  6. Increased frequencies of CD4+CD25high regulatory T cells in acute dengue infection

    PubMed Central

    Lühn, Kerstin; Simmons, Cameron P.; Moran, Edward; Dung, Nguyen Thi Phuong; Chau, Tran Nguyen Bich; Quyen, Nguyen Than Ha; Thao, Le Thi Thu; Van Ngoc, Tran; Dung, Nguyen Minh; Wills, Bridget; Farrar, Jeremy; McMichael, Andrew J.; Dong, Tao; Rowland-Jones, Sarah

    2007-01-01

    Dengue virus infection is an increasingly important tropical disease, causing 100 million cases each year. Symptoms range from mild febrile illness to severe hemorrhagic fever. The pathogenesis is incompletely understood, but immunopathology is thought to play a part, with antibody-dependent enhancement and massive immune activation of T cells and monocytes/macrophages leading to a disproportionate production of proinflammatory cytokines. We sought to investigate whether a defective population of regulatory T cells (T reg cells) could be contributing to immunopathology in severe dengue disease. CD4+CD25highFoxP3+ T reg cells of patients with acute dengue infection of different severities showed a conventional phenotype. Unexpectedly, their capacity to suppress T cell proliferation and to secrete interleukin-10 was not altered. Moreover, T reg cells suppressed the production of vasoactive cytokines after dengue-specific stimulation. Furthermore, T reg cell frequencies and also T reg cell/effector T cell ratios were increased in patients with acute infection. A strong indication that a relative rise of T reg cell/effector T cell ratios is beneficial for disease outcome comes from patients with mild disease in which this ratio is significantly increased (P < 0.0001) in contrast to severe cases (P = 0.2145). We conclude that although T reg cells expand and function normally in acute dengue infection, their relative frequencies are insufficient to control the immunopathology of severe disease. PMID:17452519

  7. CD4+CD25hiFOXP3+ Cells in Cord Blood of Neonates Born from Filaria Infected Mother Are Negatively Associated with CD4+Tbet+ and CD4+RORγt+ T Cells

    PubMed Central

    Zettlmeissl, Eva; van der Vlugt, Luciën E. P. M.; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G.; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

    2014-01-01

    Background Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. Methodology Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC) were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. Results No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = −0.242, P = 0.002; B = −0.178, P = 0.013 respectively). Conclusion Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check. PMID:25531674

  8. The Role of CD4 and CD8 T Cells in Human Cutaneous Leishmaniasis.

    PubMed

    da Silva Santos, Claire; Brodskyn, Cláudia Ida

    2014-01-01

    Leishmaniasis, caused by infection with parasites of the Leishmania genus, affects millions of individuals worldwide. This disease displays distinct clinical manifestations ranging from self-healing skin lesions to severe tissue damage. The control of Leishmania infection is dependent on cellular immune mechanisms, and evidence has shown that CD4 and CD8 T lymphocytes play different roles in the outcome of leishmaniasis. Although the presence of CD4 T cells is important for controlling parasite growth, the results in the literature suggest that the inflammatory response elicited by these cells could contribute to the pathogenesis of lesions. However, recent studies on CD8 T lymphocytes show that these cells are mainly involved in tissue damage through cytotoxic mechanisms. In this review, we focus on the recent advances in the study of the human adaptive immunological response in the pathogenesis of tegumentary leishmaniasis.

  9. Quantifying susceptibility of CD4+ stem memory T-cells to infection by laboratory adapted and clinical HIV-1 strains.

    PubMed

    Flynn, Jacqueline K; Paukovics, Geza; Cashin, Kieran; Borm, Katharina; Ellett, Anne; Roche, Michael; Jakobsen, Martin R; Churchill, Melissa J; Gorry, Paul R

    2014-02-10

    CD4+ T cells are principal targets for human immunodeficiency virus type 1 (HIV-1) infection. CD4+ T cell subsets are heterogeneous cell populations, divided by functional and phenotypic differences into naïve and memory T cells. The memory CD4+ T cells are further segregated into central, effector and transitional memory cell subsets by functional, phenotypic and homeostatic characteristics. Defining the distribution of HIV-1 infection in different T cell subsets is important, as this can play a role in determining the size and composition of the viral reservoir. Both central memory and transitional memory CD4+ T cells have been described as long-lived viral reservoirs for HIV. Recently, the newly described stem memory T cell subset has also been implicated as a long-lived HIV reservoir. Using green fluorescent protein (GFP) reporter strains of HIV-1 and multi parameter flow cytometry, we developed an assay to simultaneously quantify the susceptibility of stem memory (TSCM), central memory, effector memory, transitional memory and naïve CD4+ T cell subsets, to HIV-1 infection in vitro. We show that TSCM are susceptible to infection with laboratory adapted and clinical HIV-1 strains. Our system facilitates the quantitation of HIV-1 infection in alternative T cell subsets by CCR5- and CXCR4-using viruses across different HIV-1 subtypes, and will be useful for studies of HIV-1 pathogenesis and viral reservoirs.

  10. Quantifying Susceptibility of CD4+ Stem Memory T-Cells to Infection by Laboratory Adapted and Clinical HIV-1 Strains

    PubMed Central

    Flynn, Jacqueline K.; Paukovics, Geza; Cashin, Kieran; Borm, Katharina; Ellett, Anne; Roche, Michael; Jakobsen, Martin R.; Churchill, Melissa J.; Gorry, Paul R.

    2014-01-01

    CD4+ T cells are principal targets for human immunodeficiency virus type 1 (HIV-1) infection. CD4+ T cell subsets are heterogeneous cell populations, divided by functional and phenotypic differences into naïve and memory T cells. The memory CD4+ T cells are further segregated into central, effector and transitional memory cell subsets by functional, phenotypic and homeostatic characteristics. Defining the distribution of HIV-1 infection in different T cell subsets is important, as this can play a role in determining the size and composition of the viral reservoir. Both central memory and transitional memory CD4+ T cells have been described as long-lived viral reservoirs for HIV. Recently, the newly described stem memory T cell subset has also been implicated as a long-lived HIV reservoir. Using green fluorescent protein (GFP) reporter strains of HIV-1 and multi parameter flow cytometry, we developed an assay to simultaneously quantify the susceptibility of stem memory (TSCM), central memory, effector memory, transitional memory and naïve CD4+ T cell subsets, to HIV-1 infection in vitro. We show that TSCM are susceptible to infection with laboratory adapted and clinical HIV-1 strains. Our system facilitates the quantitation of HIV-1 infection in alternative T cell subsets by CCR5- and CXCR4-using viruses across different HIV-1 subtypes, and will be useful for studies of HIV-1 pathogenesis and viral reservoirs. PMID:24517971

  11. Bystander stimulation of activated CD4+ T cells of unrelated specificity following a booster vaccination with tetanus toxoid.

    PubMed

    Di Genova, Gianfranco; Savelyeva, Natalia; Suchacki, Amy; Thirdborough, Stephen M; Stevenson, Freda K

    2010-04-01

    Antigen-specific CD4(+) T cells are central to natural and vaccine-induced immunity. An ongoing antigen-specific T-cell response can, however, influence surrounding T cells with unrelated antigen specificities. We previously observed this bystander effect in healthy human subjects following recall vaccination with tetanus toxoid (TT). Since this interplay could be important for maintenance of memory, we have moved to a mouse model for further analysis. We investigated whether boosting memory CD4(+) T cells against TT in vivo would influence injected CD4(+) TCR transgenic T cells (OT-II) specific for an unrelated OVA peptide. If OT-II cells were pre-activated with OVA peptide in vitro, these cells showed a bystander proliferative response during the ongoing parallel TT-specific response. Bystander proliferation was dependent on boosting of the TT-specific memory response in the recipients, with no effect in naive mice. Bystander stimulation was also proportional to the strength of the TT-specific memory T-cell response. T cells activated in vitro displayed functional receptors for IL-2 and IL-7, suggesting these as potential mediators. This crosstalk between a stimulated CD4(+) memory T-cell response and CD4(+) T cells activated by an unrelated antigen could be important in human subjects continually buffeted by environmental antigens.

  12. A specific CD4 epitope bound by tregalizumab mediates activation of regulatory T cells by a unique signaling pathway.

    PubMed

    Helling, Bianca; König, Martin; Dälken, Benjamin; Engling, Andre; Krömer, Wolfgang; Heim, Katharina; Wallmeier, Holger; Haas, Jürgen; Wildemann, Brigitte; Fritz, Brigitte; Jonuleit, Helmut; Kubach, Jan; Dingermann, Theodor; Radeke, Heinfried H; Osterroth, Frank; Uherek, Christoph; Czeloth, Niklas; Schüttrumpf, Jörg

    2015-04-01

    CD4(+)CD25(+) regulatory T cells (Tregs) represent a specialized subpopulation of T cells, which are essential for maintaining peripheral tolerance and preventing autoimmunity. The immunomodulatory effects of Tregs depend on their activation status. Here we show that, in contrast to conventional anti-CD4 monoclonal antibodies (mAbs), the humanized CD4-specific monoclonal antibody tregalizumab (BT-061) is able to selectively activate the suppressive properties of Tregs in vitro. BT-061 activates Tregs by binding to CD4 and activation of signaling downstream pathways. The specific functionality of BT-061 may be explained by the recognition of a unique, conformational epitope on domain 2 of the CD4 molecule that is not recognized by other anti-CD4 mAbs. We found that, due to this special epitope binding, BT-061 induces a unique phosphorylation of T-cell receptor complex-associated signaling molecules. This is sufficient to activate the function of Tregs without activating effector T cells. Furthermore, BT-061 does not induce the release of pro-inflammatory cytokines. These results demonstrate that BT-061 stimulation via the CD4 receptor is able to induce T-cell receptor-independent activation of Tregs. Selective activation of Tregs via CD4 is a promising approach for the treatment of autoimmune diseases where insufficient Treg activity has been described. Clinical investigation of this new approach is currently ongoing. PMID:25512343

  13. Immunodominant CD4+ T-Cell Responses to Influenza A Virus in Healthy Individuals Focus on Matrix 1 and Nucleoprotein

    PubMed Central

    Chen, Li; Zanker, Damien; Xiao, Kun; Wu, Chao; Zou, Quanming

    2014-01-01

    ABSTRACT Antigen-specific CD4+ T cells are essential for effective virus-specific host responses, with recent human challenge studies (in volunteers) establishing their importance for influenza A virus (IAV)-specific immunity. However, while many IAV CD4+ T cell epitopes have been identified, few are known to stimulate immunodominant CD4+ T cell responses. Moreover, much remains unclear concerning the major antigen(s) responded to by the human CD4+ T cells and the extents and magnitudes of these responses. We initiated a systematic screen of immunodominant CD4+ T cell responses to IAV in healthy individuals. Using in vitro expanded-multispecificity IAV-specific T cell lines and individual IAV protein antigens produced by recombinant vaccinia viruses, we found that the internal matrix protein 1 (M1) and nucleoprotein (NP) were the immunodominant targets of CD4+ T cell responses. Ten epitopes derived from M1 and NP were definitively characterized. Furthermore, epitope sequence conservation analysis established that immunodominance correlated with an increased frequency of mutations, reflecting the fact that these prominent epitopes are under greater selective pressure. Such evidence that particular CD4+ T cells are important for protection/recovery is of value for the development of novel IAV vaccines and for our understanding of different profiles of susceptibility to these major pathogens. IMPORTANCE Influenza virus causes half a million deaths annually. CD4+ T cell responses have been shown to be important for protection against influenza and for recovery. CD4+ T cell responses are also critical for efficient CD8+ T cell response and antibody response. As immunodominant T cells generally play a more important role, characterizing these immunodominant responses is critical for influenza vaccine development. We show here that the internal matrix protein 1 (M1) and nucleoprotein (NP), rather than the surface proteins reported previously, are the immunodominant

  14. Chemokine Transfer by Liver Sinusoidal Endothelial Cells Contributes to the Recruitment of CD4+ T Cells into the Murine Liver.

    PubMed

    Neumann, Katrin; Erben, Ulrike; Kruse, Nils; Wechsung, Katja; Schumann, Michael; Klugewitz, Katja; Scheffold, Alexander; Kühl, Anja A

    2015-01-01

    Leukocyte adhesion and transmigration are central features governing immune surveillance and inflammatory reactions in body tissues. Within the liver sinusoids, chemokines initiate the first crucial step of T-cell migration into the hepatic tissue. We studied molecular mechanisms involved in endothelial chemokine supply during hepatic immune surveillance and liver inflammation and their impact on the recruitment of CD4(+) T cells into the liver. In the murine model of Concanavalin A-induced T cell-mediated hepatitis, we showed that hepatic expression of the inflammatory CXC chemokine ligands (CXCL)9 and CXCL10 strongly increased whereas homeostatic CXCL12 significantly decreased. Consistently, CD4(+) T cells expressing the CXC chemokine receptor (CXCR)3 accumulated within the inflamed liver tissue. In histology, CXCL9 was associated with liver sinusoidal endothelial cells (LSEC) which represent the first contact site for T-cell immigration into the liver. LSEC actively transferred basolaterally internalized CXCL12, CXCL9 and CXCL10 via clathrin-coated vesicles to CD4(+) T cells leading to enhanced transmigration of CXCR4(+) total CD4(+) T cells and CXCR3(+) effector/memory CD4(+) T cells, respectively in vitro. LSEC-expressed CXCR4 mediated CXCL12 transport and blockage of endothelial CXCR4 inhibited CXCL12-dependent CD4(+) T-cell transmigration. In contrast, CXCR3 was not involved in the endothelial transport of its ligands CXCL9 and CXCL10. The clathrin-specific inhibitor chlorpromazine blocked endothelial chemokine internalization and CD4(+) T-cell transmigration in vitro as well as migration of CD4(+) T cells into the inflamed liver in vivo. Moreover, hepatic accumulation of CXCR3(+) CD4(+) T cells during T cell-mediated hepatitis was strongly reduced after administration of chlorpromazine. These data demonstrate that LSEC actively provide perivascularly expressed homeostatic and inflammatory chemokines by CXCR4- and clathrin-dependent intracellular transport

  15. CD8α+ Dendritic cells prime TCR-peptide-reactive regulatory CD4+FOXP3− T cells

    PubMed Central

    Smith, Trevor R. F.; Maricic, Igor; Ria, Francesco; Schneider, Susan; Kumar, Vipin

    2011-01-01

    Summary CD4+ T cells with immune regulatory function can be either FOXP3+ or FOXP3−. We have previously shown that priming of naturally occurring TCR-peptide-reactive regulatory CD4+FOXP3− T cells (Treg) specifically controls Vβ8.2+CD4+ T cells mediating experimental autoimmune encephalomyelitis (EAE). However, the mechanism by which these Treg are primed to recognize their cognate antigenic determinant, which is derived from the TCRVβ8.2-chain, is not known. In this study we show that antigen presenting cells (APC) derived from splenocytes of naïve mice are able to stimulate cloned CD4+ Treg in the absence of exogenous antigen, and their stimulation capacity is augmented during EAE. Among the APC populations DC were the most efficient in stimulating the Treg. Stimulation of CD4+ Treg was dependent upon processing and presentation of TCR peptides from ingested Vβ8.2TCR+ CD4+ T cells. Additionally, dendritic cells pulsed with TCR peptide or apoptotic Vβ8.2+ T cells are able to prime Treg in vivo and mediate protection from disease in a CD8-dependent fashion. These data highlight a novel mechanism for the priming of CD4+ Treg by CD8α+ DC, and suggest a pathway that can be exploited to prime antigen-specific regulation of T cell-mediated inflammatory disease. PMID:20394075

  16. An increased frequency of autoantibody-inducing CD4+ T cells in pre-diseased lupus-prone mice.

    PubMed

    Busser, Brian W; Cancro, Michael P; Laufer, Terri M

    2004-07-01

    Pathogenic autoantibody production in murine models of lupus is dependent on autoreactive CD4+ helper T cells. However, the mechanisms which permit the selection and maintenance of this autoantibody-inducing CD4+ T-cell repertoire are currently unknown. We hypothesized that the peripheral CD4+ T-cell repertoire of lupus-prone mice was enriched with autoantibody-inducing specificities. To test this, we utilized the splenic focus assay to determine if pre-diseased lupus-prone (NZB x NZW)F(1) mice have an elevated frequency of autoreactive CD4+ T lymphocytes capable of supporting autoantibody production. The splenic focus limiting dilution assay permits anti-nuclear antibodies to be generated from contact-dependent T-B interactions in vitro. We show that young, pre-diseased lupus-prone mice have an elevated frequency of autoantibody-inducing CD4+ T cells. Interestingly, these autoantibody-inducing CD4+ T-cell responses are also present in the thymus. Therefore, an elevated frequency of autoantibody-inducing CD4+ T cells predisposes lupus-prone mice to the development of autoantibodies.

  17. Influence of phthiocerol dimycocerosate on CD4(+) T cell priming and persistence during Mycobacterium tuberculosis infection.

    PubMed

    Pinto, Rachel; Nambiar, Jonathan K; Leotta, Lisa; Counoupas, Claudio; Britton, Warwick J; Triccas, James A

    2016-07-01

    The characterisation of mycobacterial factors that influence or modulate the host immune response may aid the development of more efficacious TB vaccines. We have previously reported that Mycobacterium tuberculosis deficient in export of Phthiocerol Dimycocerosates (DIM) (MT103(ΔdrrC)) is more attenuated than wild type M. tuberculosis and provides sustained protective immunity compared to the existing BCG vaccine. Here we sought to define the correlates of immunity associated with DIM deficiency by assessing the impact of MT103(ΔdrrC) delivery on antigen presenting cell (APC) function and the generation of CD4(+) T cell antigen-specific immunity. MT103(ΔdrrC) was a potent activator of bone marrow derived dendritic cells, inducing significantly greater expression of CD86 and IL-12p40 compared to BCG or the MT103 parental strain. This translated to an increased ability to initiate early in vivo priming of antigen-specific CD4(+) T cells compared to BCG with enhanced release of IFN-γ and TNF upon antigen-restimulation. The heightened immunity induced by MT103(ΔdrrC) correlated with greater persistence within the spleen compared to BCG, however both MT103(ΔdrrC) and BCG were undetectable in the lung at 70 days post-vaccination. In immunodeficient RAG (-/-) mice, MT103(ΔdrrC) was less virulent than the parental MT103 strain, yet MT103(ΔdrrC) infected mice succumbed more rapidly compared to BCG-infected animals. These results suggest that DIM translocation plays a role in APC stimulation and CD4(+) T cell activation during M. tuberculosis infection and highlights the potential of DIM-deficient strains as novel TB vaccine candidates. PMID:27450001

  18. Communication between Human Dendritic Cell Subsets in Tuberculosis: Requirements for Naive CD4+ T Cell Stimulation

    PubMed Central

    Lozza, Laura; Farinacci, Maura; Bechtle, Marina; Stäber, Manuela; Zedler, Ulrike; Baiocchini, Andrea; del Nonno, Franca; Kaufmann, Stefan H. E.

    2014-01-01

    Human primary dendritic cells (DCs) are heterogeneous by phenotype, function, and tissue localization and distinct from inflammatory monocyte-derived DCs. Current information regarding the susceptibility and functional role of primary human DC subsets to Mycobacterium tuberculosis (Mtb) infection is limited. Here, we dissect the response of different primary DC subsets to Mtb infection. Myeloid CD11c+ cells and pDCs (C-type lectin 4C+ cells) were located in human lymph nodes (LNs) of tuberculosis (TB) patients by histochemistry. Rare CD141hi DCs (C-type lectin 9A+ cells) were also identified. Infection with live Mtb revealed a higher responsiveness of myeloid CD1c+ DCs compared to CD141hi DCs and pDCs. CD1c+ DCs produced interleukin (IL)-6, tumor necrosis factor α, and IL-1β but not IL-12p70, a cytokine important for Th1 activation and host defenses against Mtb. Yet, CD1c+ DCs were able to activate autologous naïve CD4+ T cells. By combining cell purification with fluorescence-activated cell sorting and gene expression profiling on rare cell populations, we detected in responding CD4+ T cells, genes related to effector-cytolytic functions and transcription factors associated with Th1, Th17, and Treg polarization, suggesting multifunctional properties in our experimental conditions. Finally, immunohistologic analyses revealed contact between CD11c+ cells and pDCs in LNs of TB patients and in vitro data suggest that cooperation between Mtb-infected CD1c+ DCs and pDCs favors stimulation of CD4+ T cells. PMID:25071784

  19. Overrepresentation of IL-10-Expressing B Cells Suppresses Cytotoxic CD4+ T Cell Activity in HBV-Induced Hepatocellular Carcinoma

    PubMed Central

    Tan, Hongwu; Zhu, Zun-Qiang; Zhang, Zhang-Yun; Zhao, Ludong

    2016-01-01

    Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis and low five-year survival rate. A strong and effective CD4+ T cell-mediated cytotoxicity was associated with better survival and low recurrence rate in HCC, but the regulatory mechanism that controls CD4+ T cell cytotoxicity in HCC patients is not fully examined. Given that IL-10-expressing B cells could suppress the inflammation of cytotoxic CD8+ T cells, T helper 1 (Th1) cells and Th17 cells, while promoting regulatory T (Treg) cell differentiation, we examined the role of IL-10-expressing B cells in HBV-related HCC patients. We found that compared to healthy controls, HCC patients exhibited significantly higher frequencies of IL-10-expressing B cells, which were negatively correlated with the frequencies of granzyme A, granzyme B, and perforin expressing CD4+ T cells. Surface molecule Tim-1 was preferentially expressed on IL-10-expressing B cells. Therefore, we separated total B cells into Tim-1+ and Tim-1- B cells. CD4+ T cells incubated with Tim-1+ B cells exhibited significantly reduced levels of granzyme A, granzyme B and perforin expression, compared to the CD4+ T cells incubated with Tim-1- B cells. Antagonizing IL-10 in culture rescued CD4+ T cell cytotoxicity. Compared to that in peripheral blood, the level of IL-10-expressing B cells were further upregulated in resected tumor, while the level of CD4+ cytotoxic T cells was downregulated. The negative correlations between IL-10-expressing B cells and CD4+ cytotoxic T cells were also observed in tumor-infiltrating cells. Together, our data revealed an additional antitumor mechanism mediated by IL-10-expressing B cells. PMID:27136203

  20. Computational Analysis of the Model Describing HIV Infection of CD4+T Cells

    PubMed Central

    Atangana, Abdon

    2014-01-01

    An analysis of the model underpinning the description of the spread of HIV infection of CD4+T cells is examined in detail in this work. Investigations of the disease free and endemic equilibrium are done using the method of Jacobian matrix. An iteration technique, namely, the homotopy decomposition method (HDM), is implemented to give an approximate solution of nonlinear ordinary differential equation systems. The technique is described and illustrated with numerical examples. The approximated solution obtained via HDM is compared with those obtained via other methods to prove the trustworthiness of HDM. Moreover, the lessening and simplicity in calculations furnish HDM with a broader applicability. PMID:25136605

  1. Circulating rotavirus-specific T cells have a poor functional profile

    SciTech Connect

    Parra, Miguel; Herrera, Daniel; Jácome, María Fernanda; Mesa, Martha C.; Rodríguez, Luz-Stella; Guzmán, Carolina; Angel, Juana; Franco, Manuel A.

    2014-11-15

    Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ{sup +} cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2 – unlike rIL-12 or DGKα-i – increased the frequencies of RV-CD4 TNF-α{sup +}, CD4 IFN-γ{sup +}, and CD8 IFN-γ{sup +} cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2. - Highlights: • The quality and magnitude of circulating RV-T cell responses are relatively poor. • Circulating RV-CD4 T cells are enriched in monofunctional IFN-γ+ cells. • Treatment with rIL-2 increased the frequencies of cytokine secreting RV-T cells.

  2. Retroviral vector expression in TCR transgenic CD4T cells.

    PubMed

    Choi, Youn Soo; Crotty, Shane

    2015-01-01

    The regulation of gene expression is key to understand the function of genes of interest. To explore the biological functions of genes, transgenic knock-in or knockout technologies have served as invaluable tools. While recent advances in molecular biology have introduced new techniques (i.e., CRISPR mediated gene editing) (Cong et al., Science 339(6121):819-823, 2013; Wang et al., Cell 153(4):910-918, 2013) for the generation of transgenic mice in a relatively short period of time, it can still take a long time to test biological hypotheses from scratch to design how to generate knock-in or knockout mice. Here, we describe methods to manipulate gene expression in T cell receptor (TCR) transgenic CD4 T cells, which allow us to investigate gene functions in the study of differentiation pathways of follicular helper T (Tfh) cells.

  3. Donor CD4 T Cell Diversity Determines Virus Reactivation in Patients After HLA-Matched Allogeneic Stem Cell Transplantation

    PubMed Central

    Ritter, J; Seitz, V; Balzer, H; Gary, R; Lenze, D; Moi, S; Pasemann, S; Seegebarth, A; Wurdack, M; Hennig, S; Gerbitz, A; Hummel, M

    2015-01-01

    Delayed reconstitution of the T cell compartment in recipients of allogeneic stem cell grafts is associated with an increase of reactivation of latent viruses. Thereby, the transplanted T cell repertoire appears to be one of the factors that affect T cell reconstitution. Therefore, we studied the T cell receptor beta (TCRβ) gene rearrangements of flow cytometry–sorted CD4+ and CD8+ T cells from the peripheral blood of 23 allogeneic donors before G-CSF administration and on the day of apheresis. For this purpose, TCRβ rearrangements were amplified by multiplex PCR followed by high-throughput amplicon sequencing. Overall, CD4+ T cells displayed a significantly higher TCRβ diversity compared to CD8+ T cells irrespective of G-CSF administration. In line, no significant impact of G-CSF treatment on the TCR Vβ repertoire usage was found. However, correlation of the donor T cell repertoire with clinical outcomes of the recipient revealed that a higher CD4+ TCRβ diversity after G-CSF treatment is associated with lower reactivation of cytomegalovirus and Epstein–Barr virus. By contrast, no protecting correlation was observed for CD8+ T cells. In essence, our deep TCRβ analysis identifies the importance of the CD4+ T cell compartment for the control of latent viruses after allogeneic stem cell transplantation. PMID:25873100

  4. Tumor-Unrelated CD4 T Cell Help Augments CD134 plus CD137 Dual Costimulation Tumor Therapy.

    PubMed

    Mittal, Payal; St Rose, Marie-Clare; Wang, Xi; Ryan, Joseph M; Wasser, Jeffrey S; Vella, Anthony T; Adler, Adam J

    2015-12-15

    The ability of immune-based cancer therapies to elicit beneficial CD8(+) CTLs is limited by tolerance pathways that inactivate tumor-specific CD4 Th cells. A strategy to bypass this problem is to engage tumor-unrelated CD4 Th cells. Thus, CD4 T cells, regardless of their specificity per se, can boost CD8(+) CTL priming as long as the cognate epitopes are linked via presentation on the same dendritic cell. In this study, we assessed the therapeutic impact of engaging tumor-unrelated CD4 T cells during dual costimulation with CD134 plus CD137 that provide help via the above-mentioned classical linked pathway, as well as provide nonlinked help that facilitates CTL function in T cells not directly responding to cognate Ag. We found that engagement of tumor-unrelated CD4 Th cells dramatically boosted the ability of dual costimulation to control the growth of established B16 melanomas. Surprisingly, this effect depended upon a CD134-dependent component that was extrinsic to the tumor-unrelated CD4 T cells, suggesting that the dual costimulated helper cells are themselves helped by a CD134(+) cell(s). Nevertheless, the delivery of therapeutic help tracked with an increased frequency of tumor-infiltrating granzyme B(+) effector CD8 T cells and a reciprocal decrease in Foxp3(+)CD4(+) cell frequency. Notably, the tumor-unrelated CD4 Th cells also infiltrated the tumors, and their deletion several days following initial T cell priming negated their therapeutic impact. Taken together, dual costimulation programs tumor-unrelated CD4 T cells to deliver therapeutic help during both the priming and effector stages of the antitumor response.

  5. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection.

    PubMed

    Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R; Birx, Deborah L; Ratto-Kim, Silvia; Robb, Merlin L; Kim, Jerome H; Michael, Nelson L; Hu, Haitao

    2016-06-01

    Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

  6. HIV-specific regulatory T cells are associated with higher CD4 cell counts in primary infection

    PubMed Central

    Kared, Hassen; Lelièvre, Jean-Daniel; Donkova-Petrini, Vladimira; Aouba, Albertine; Melica, Giovanna; Balbo, Michèle; Weiss, Laurence; Lévy, Yves

    2008-01-01

    Objective Expansion of Regulatory T (Treg) cells has been described in chronically HIV-infected subjects. We investigated whether HIV-suppressive Treg could be detected during primary HIV infection (PHI). Methods Seventeen patients diagnosed early after PHI (median: 13 days; 1–55) were studied. Median CD4 cell count was 480 cells/μl (33–1306) and plasma HIV RNA levels ranged between 3.3 to 5.7 log10 cp/mL. Suppressive capacity of blood purified CD4+CD25+ was evaluated in a co-culture assay. Fox-p3, IL-2 and IL-10 were quantified by RT-PCR and intra-cellular staining of ex vivo and activated CD4+CD25high T cells. Results The frequency of CD4+CD127lowCD25high T cells among CD4 T cells was lower in PHI compared to chronic patients (n=19). They exhibited a phenotype of memory T cells and expressed constitutively FoxP3. Similarly to chronic patients, Treg from PHI patients inhibited the proliferation of PPD and HIV p24 activated CD4+CD25− T cells. CD4+CD25high T cells from PHI patients responded specifically to p24 stimulation by expressing IL-10. In untreated PHI patients, the frequency, as well as HIV-specific activity of Treg decreased during a 24-month follow up. A positive correlation between percentages of Treg and both CD4 cell counts and the magnitude of p24-specific suppressive activity at diagnosis of PHI was found. Conclusions Our data showed that HIV drives Treg since PHI and that these cells persist throughout the course of the infection. A correlation between the frequency of Treg and CD4 T cell counts suggest that these cells may impact on the immune activation set point at PHI diagnosis. PMID:19005268

  7. Functional analysis of highly defined, FACS-isolated populations of human regulatory CD4+ CD25+ T cells.

    PubMed

    Baecher-Allan, Clare; Wolf, Elizabeth; Hafler, David A

    2005-04-01

    The importance of CD4+ CD25+ regulatory T cells (Treg) in maintaining immune homeostasis has been directly demonstrated in vivo by their manipulation in a number of autoimmune disease models in the mouse. In the study of human regulatory cells, we have found that the cells that consistently demonstrate the in vitro regulatory activity most similar to that described for murine cells in vitro are best identified by restricting the isolation of CD25+ CD4 T cells to those cells expressing only the highest levels of CD25, representing approximately 2-3% of total CD4 T cells. Thus, it is the CD4+ CD25high subset that exhibits the in vitro characteristics that are identical to the CD4+ CD25+ regulatory cells initially characterized in mice. Furthermore, the cells expressing medium to low levels of CD25 not only do not exhibit suppressive activity directly ex vivo, but also actually contain a significant proportion of CD62L- CD4 T cells which are believed to be in vivo activated T cells. Due to the inherent difficulties in using CD25 as a marker for the purification of Treg cells, the finding that selection of the CD25high subset of CD4+ CD25+ T cells minimizes the co-isolation of contaminating activated CD4 T cells is important for future studies of these Treg cells in human disease. In order to perform these studies, we first had to establish a highly reproducible 'micro in vitro co-culture' assay system to enable the functional analysis of high-purity, but low-yield regulatory populations derived from FACS sorting. With this system in place, we are poised to dissect the potential heterogeneity of mechanisms employed by highly specific subpopulations of CD4+ CD25+ cells.

  8. Tumor-Unrelated CD4 T Cell Help Augments CD134 plus CD137 Dual Costimulation Tumor Therapy.

    PubMed

    Mittal, Payal; St Rose, Marie-Clare; Wang, Xi; Ryan, Joseph M; Wasser, Jeffrey S; Vella, Anthony T; Adler, Adam J

    2015-12-15

    The ability of immune-based cancer therapies to elicit beneficial CD8(+) CTLs is limited by tolerance pathways that inactivate tumor-specific CD4 Th cells. A strategy to bypass this problem is to engage tumor-unrelated CD4 Th cells. Thus, CD4 T cells, regardless of their specificity per se, can boost CD8(+) CTL priming as long as the cognate epitopes are linked via presentation on the same dendritic cell. In this study, we assessed the therapeutic impact of engaging tumor-unrelated CD4 T cells during dual costimulation with CD134 plus CD137 that provide help via the above-mentioned classical linked pathway, as well as provide nonlinked help that facilitates CTL function in T cells not directly responding to cognate Ag. We found that engagement of tumor-unrelated CD4 Th cells dramatically boosted the ability of dual costimulation to control the growth of established B16 melanomas. Surprisingly, this effect depended upon a CD134-dependent component that was extrinsic to the tumor-unrelated CD4 T cells, suggesting that the dual costimulated helper cells are themselves helped by a CD134(+) cell(s). Nevertheless, the delivery of therapeutic help tracked with an increased frequency of tumor-infiltrating granzyme B(+) effector CD8 T cells and a reciprocal decrease in Foxp3(+)CD4(+) cell frequency. Notably, the tumor-unrelated CD4 Th cells also infiltrated the tumors, and their deletion several days following initial T cell priming negated their therapeutic impact. Taken together, dual costimulation programs tumor-unrelated CD4 T cells to deliver therapeutic help during both the priming and effector stages of the antitumor response. PMID:26561553

  9. CD4 T-Cell Responses in Primary HIV Infection: Interrelationship with Immune Activation and Virus Burden

    PubMed Central

    Chevalier, Mathieu F.; Didier, Céline; Girard, Pierre-Marie; Manea, Maria E.; Campa, Pauline; Barré-Sinoussi, Françoise; Scott-Algara, Daniel; Weiss, Laurence

    2016-01-01

    Early events during primary HIV infection (PHI) are thought to influence disease outcome. Although a growing body of evidence suggests a beneficial role of HIV-specific CD4 help in HIV infection, it is unclear how early viral replication, systemic immune activation, and antiretroviral therapy (ART) may shape CD4 T-cell responses during PHI, and whether HIV-specific CD4 responses contribute to the high immune activation observed in PHI. Twenty-seven patients with early PHI were included in a prospective longitudinal study and 12 of them received ART after enrollment. Fresh peripheral blood mononuclear cells were used for measurement of ex vivo T-cell activation and of cytokine-producing CD4 T-cells following stimulation with PMA/ionomycin or HIV-1-gag-p24 antigen. Patients were segregated based on CD8 T-cell activation level (i.e., % HLA-DR+CD38+ CD8 T-cells) at baseline (BL). Patients with lower immune activation exhibited higher frequency of bulk CD4 T-cells producing IFN-γ or IL-17 and higher effector-to-regulatory cell ratios. No differences were found in HIV-specific CD4 T-cell frequencies. In contrast, segregation of patients based on plasma viral load (pVL) revealed that patients with higher pVL showed higher cytokine-producing HIV-specific CD4 responses. Of note, the frequency of IFN-γ+ HIV-specific CD4 T cells significantly diminished between BL and month 6 only in ART-treated patients. However, early treatment initiation was associated with better maintenance of HIV-specific IFN-γ+ CD4 T-cells. These data suggest that HIV-specific CD4 responses do not fuel systemic T-cell activation and are driven by viral replication but not able to contribute to its control in the early phase of infection. Moreover, our data also suggest a benefit of early treatment for the maintenance of HIV-specific CD4 T-cell help. PMID:27746782

  10. Peripheral and central neuronal ATF3 precedes CD4+ T-cell infiltration in EAE.

    PubMed

    Frezel, Noémie; Sohet, Fabien; Daneman, Richard; Basbaum, Allan I; Braz, Joao M

    2016-09-01

    Experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis produced by immunization with myelin oligodendrocyte glycoprotein (MOG) and adjuvants, results from profound T-cell mediated CNS demyelination. EAE is characterized by progressive, ascending motor dysfunction and symptoms of ongoing pain and hypersensitivity, in some cases preceding or concomitant with the motor deficits. In this regard, the EAE model mimics major features of multiple sclerosis, where a central neuropathic pain state is common. Although the latter condition is presumed to arise from a CNS loss of inhibitory controls secondary to the demyelination, dysfunction of sensory neurons may also contribute. Based on our previous studies that demonstrated the utility of monitoring expression of activating transcription factor 3 (ATF3), a sensitive marker of injured sensory neurons, here we followed both ATF3 and CD4+ T cells invasion of sensory ganglia (as well as the CNS) at different stages of the EAE model. We found that ATF3 is induced in peripheral sensory ganglia and brainstem well before the appearance of motor deficits. Unexpectedly, the ATF3 induction always preceded T cell infiltration, typically in adjacent, but non-overlapping regions. Surprisingly, control administration of the pertussis toxin and/or Complete Freund's adjuvants, without MOG, induced ATF3 in sensory neurons. In contrast, T cell infiltration only occurred with MOG. Taken together, our results suggest that the clinical manifestations in the EAE result not only from central demyelination but also from neuronal stress and subsequent pathophysiology of sensory neurons. PMID:27343802

  11. Virus-specific CD4+ memory phenotype T cells are abundant in unexposed adults

    PubMed Central

    Su, Laura F.; Kidd, Brian A.; Han, Arnold; Kotzin, Jonathan J.; Davis, Mark M.

    2013-01-01

    While T cell memory is generally thought to require direct antigen exposure, we find an abundance of memory phenotype cells (20–90%, averaging over 50%) of CD4+ T cells specific for viral antigens in adults that have never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. This contrasts with newborns where the same T cell receptor (TCR) specificities are almost entirely naïve, which may explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens and in support of this we find extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and the expansion of one of these following influenza vaccination. Thus the presence of these memory phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments. PMID:23395677

  12. Selective Loss of Innate CD4+ Vα24 Natural Killer T Cells in Human Immunodeficiency Virus Infection

    PubMed Central

    Sandberg, Johan K.; Fast, Noam M.; Palacios, Emil H.; Fennelly, Glenn; Dobroszycki, Joanna; Palumbo, Paul; Wiznia, Andrew; Grant, Robert M.; Bhardwaj, Nina; Rosenberg, Michael G.; Nixon, Douglas F.

    2002-01-01

    Vα24 natural killer T (NKT) cells are innate immune cells involved in regulation of immune tolerance, autoimmunity, and tumor immunity. However, the effect of human immunodeficiency virus type 1 (HIV-1) infection on these cells is unknown. Here, we report that the Vα24 NKT cells can be subdivided into CD4+ or CD4− subsets that differ in their expression of the homing receptors CD62L and CD11a. Furthermore, both CD4+ and CD4− NKT cells frequently express both CXCR4 and CCR5 HIV coreceptors. We find that the numbers of NKT cells are reduced in HIV-infected subjects with uncontrolled viremia and marked CD4+ T-cell depletion. The number of CD4+ NKT cells is inversely correlated with HIV load, indicating depletion of this subset. In contrast, CD4− NKT-cell numbers are unaffected in subjects with high viral loads. HIV infection experiments in vitro show preferential depletion of CD4+ NKT cells relative to regular CD4+ T cells, in particular with virus that uses the CCR5 coreceptor. Thus, HIV infection causes a selective loss of CD4+ lymph node homing (CD62L+) NKT cells, with consequent skewing of the NKT-cell compartment to a predominantly CD4− CD62L− phenotype. These data indicate that the key immunoregulatory NKT-cell compartment is compromised in HIV-1-infected patients. PMID:12097565

  13. Effector and Central Memory Poly-Functional CD4+ and CD8+ T Cells are Boosted upon ZOSTAVAX® Vaccination

    PubMed Central

    Sei, Janet J.; Cox, Kara S.; Dubey, Sheri A.; Antonello, Joseph M.; Krah, David L.; Casimiro, Danilo R.; Vora, Kalpit A.

    2015-01-01

    ZOSTAVAX® is a live attenuated varicella-zoster virus (VZV) vaccine that is licensed for the protection of individuals ≥50 years against shingles and its most common complication, postherpetic neuralgia. While IFNγ responses increase upon vaccination, the quality of the T cell response has not been elucidated. By using polychromatic flow cytometry, we characterized the breadth, magnitude, and quality of ex vivo CD4+ and CD8+ T cell responses induced 3–4 weeks after ZOSTAVAX vaccination of healthy adults. We show, for the first time that the highest frequencies of VZV-specific CD4+ T cells were poly-functional CD154+IFNγ+IL-2+TNFα+ cells, which were boosted upon vaccination. The CD4+ T cells were broadly reactive to several VZV proteins, with immediate early (IE) 63 ranking the highest among them in the fold rise of poly-functional cells, followed by IE62, gB, open reading frame (ORF) 9, and gE. We identified a novel poly-functional ORF9-specific CD8+ T cell population in 62% of the subjects, and these were boosted upon vaccination. Poly-functional CD4+ and CD8+ T cells produced significantly higher levels of IFNγ, IL-2, and TNFα compared to mono-functional cells. After vaccination, a boost in the expression of IFNγ by poly-functional IE63- and ORF9-specific CD4+ T cells and IFNγ, IL-2, and TNFα by ORF9-specific poly-functional CD8+ T cells was observed. Responding poly-functional T cells exhibited both effector (CCR7−CD45RA−CD45RO+), and central (CCR7+CD45RA−CD45RO+) memory phenotypes, which expressed comparable levels of cytokines. Altogether, our studies demonstrate that a boost in memory poly-functional CD4+ T cells and ORF9-specific CD8+ T cells may contribute toward ZOSTAVAX efficacy. PMID:26579128

  14. CD4+ T cells with an activated and exhausted phenotype distinguish immunodeficiency during aviremic HIV-2 infection

    PubMed Central

    Buggert, Marcus; Frederiksen, Juliet; Lund, Ole; Betts, Michael R.; Biague, Antonio; Nielsen, Morten; Tauriainen, Johanna; Norrgren, Hans; Medstrand, Patrik; Karlsson, Annika C.; Jansson, Marianne

    2016-01-01

    Objective: HIV type 2 (HIV-2) represents an attenuated form of HIV, in which many infected individuals remain ‘aviremic’ without antiretroviral therapy. However, aviremic HIV-2 disease progression exists, and in the current study, we therefore aimed to examine if specific pathological characteristics of CD4+ T cells are linked to such outcome. Design: HIV-seronegative (n = 25), HIV type 1 (HIV-1) (n = 33), HIV-2 (n = 39, of whom 26 were aviremic), and HIV-1/2 dually (HIV-D) (n = 13)-infected study participants were enrolled from an occupational cohort in Guinea-Bissau. Methods: CD4+ T-cell differentiation, activation, exhaustion, senescence, and transcription factors were assessed by polychromatic flow cytometry. Multidimensional clustering bioinformatic tools were used to identify CD4+ T-cell subpopulations linked to infection type and disease stage. Results: HIV-2-infected individuals had early and late-differentiated CD4+ T-cell clusters with lower activation (CD38+HLA-DR+) and exhaustion programmed death-1 (PD-1) than HIV-1 and HIV-D-infected individuals. We also noted that aviremic HIV-2-infected individuals possessed fewer individuals. CD4+ T cells with pathological signs compared to other HIV-infected groups. Still, compared to HIV-seronegative individuals, aviremic HIV-2-infected individuals had T-bet+ CD4+ T cells that showed elevated immune activation/exhaustion, and particularly the frequencies of PD-1+ cells were associated with a suboptimal percentage of CD4+ T cells. Conclusion: Increased frequencies of CD4+ T cells with an activated/exhausted phenotype correlate with exacerbated immunodeficiency in aviremic HIV-2-infected individuals. Thus, these findings encourage studies on the introduction of antiretroviral therapy also to individuals with aviremic HIV-2 infection. PMID:27525551

  15. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys

    PubMed Central

    Ortiz, Alexandra M.; Carnathan, Diane G.; Yu, Joana; Sheehan, Katherine M.; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H.; Klatt, Nichole R.; Brenchley, Jason M.; Davenport, Miles P.; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2’-bromo-5’-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  16. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys.

    PubMed

    Ortiz, Alexandra M; Carnathan, Diane G; Yu, Joana; Sheehan, Katherine M; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H; Klatt, Nichole R; Brenchley, Jason M; Davenport, Miles P; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2'-bromo-5'-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  17. In Vivo Identification and Characterization of CD4+ Cytotoxic T Cells Induced by Virulent Brucella abortus Infection

    PubMed Central

    Martirosyan, Anna; Von Bargen, Kristine; Arce Gorvel, Vilma; Zhao, Weidong; Hanniffy, Sean; Bonnardel, Johnny; Méresse, Stéphane; Gorvel, Jean-Pierre

    2013-01-01

    CD4+ T cells display a variety of helper functions necessary for an efficient adaptive immune response against bacterial invaders. This work reports the in vivo identification and characterization of murine cytotoxic CD4+ T cells (CD4+ CTL) during Brucella abortus infection. These CD4+ CTLs express granzyme B and exhibit immunophenotypic features consistent with fully differentiated T cells. They express CD25, CD44, CD62L ,CD43 molecules at their surface and produce IFN-γ. Moreover, these cells express neither the co-stimulatory molecule CD27 nor the memory T cell marker CD127. We show here that CD4+ CTLs are capable of cytolytic action against Brucella-infected antigen presenting cells (APC) but not against Mycobacterium-infected APC. Cytotoxic CD4+ T cell population appears at early stages of the infection concomitantly with high levels of IFN-γ and granzyme B expression. CD4+ CTLs represent a so far uncharacterized immune cell sub-type triggered by early immune responses upon Brucella abortus infection. PMID:24367519

  18. Differential Th17 CD4 T-cell depletion in pathogenic and nonpathogenic lentiviral infections

    PubMed Central

    Paiardini, Mirko; Knox, Kenneth S.; Asher, Ava I.; Cervasi, Barbara; Asher, Tedi E.; Scheinberg, Phillip; Price, David A.; Hage, Chadi A.; Kholi, Lisa M.; Khoruts, Alexander; Frank, Ian; Else, James; Schacker, Timothy; Silvestri, Guido

    2008-01-01

    Acute HIV infection is characterized by massive loss of CD4 T cells from the gastrointestinal (GI) tract. Th17 cells are critical in the defense against microbes, particularly at mucosal surfaces. Here we analyzed Th17 cells in the blood, GI tract, and broncheoalveolar lavage of HIV-infected and uninfected humans, and SIV-infected and uninfected sooty mangabeys. We found that (1) human Th17 cells are specific for extracellular bacterial and fungal antigens, but not common viral antigens; (2) Th17 cells are infected by HIV in vivo, but not preferentially so; (3) CD4 T cells in blood of HIV-infected patients are skewed away from a Th17 phenotype toward a Th1 phenotype with cellular maturation; (4) there is significant loss of Th17 cells in the GI tract of HIV-infected patients; (5) Th17 cells are not preferentially lost from the broncheoalveolar lavage of HIV-infected patients; and (6) SIV-infected sooty mangabeys maintain healthy frequencies of Th17 cells in the blood and GI tract. These observations further elucidate the immunodeficiency of HIV disease and may provide a mechanistic basis for the mucosal barrier breakdown that characterizes HIV infection. Finally, these data may help account for the nonprogressive nature of nonpathogenic SIV infection in sooty mangabeys. PMID:18664624

  19. Interleukin-21-Producing CD4(+) T Cells Promote Type 2 Immunity to House Dust Mites.

    PubMed

    Coquet, Jonathan M; Schuijs, Martijn J; Smyth, Mark J; Deswarte, Kim; Beyaert, Rudi; Braun, Harald; Boon, Louis; Karlsson Hedestam, Gunilla B; Nutt, Steven L; Hammad, Hamida; Lambrecht, Bart N

    2015-08-18

    Asthma is a T helper 2 (Th2)-cell-mediated disease; however, recent findings implicate Th17 and innate lymphoid cells also in regulating airway inflammation. Herein, we have demonstrated profound interleukin-21 (IL-21) production after house dust mite (HDM)-driven asthma by using T cell receptor (TCR) transgenic mice reactive to Dermatophagoides pteronyssinus 1 and an IL-21GFP reporter mouse. IL-21-producing cells in the mediastinal lymph node (mLN) bore characteristics of T follicular helper (Tfh) cells, whereas IL-21(+) cells in the lung did not express CXCR5 (a chemokine receptor expressed by Tfh cells) and were distinct from effector Th2 or Th17 cells. Il21r(-/-) mice developed reduced type 2 responses and the IL-21 receptor (IL-21R) enhanced Th2 cell function in a cell-intrinsic manner. Finally, administration of recombinant IL-21 and IL-25 synergistically promoted airway eosinophilia primarily via effects on CD4(+) lymphocytes. This highlights an important Th2-cell-amplifying function of IL-21-producing CD4(+) T cells in allergic airway inflammation.

  20. Role of B70/B7-2 in CD4+ T-cell immune responses induced by dendritic cells.

    PubMed

    Fagnoni, F F; Takamizawa, M; Godfrey, W R; Rivas, A; Azuma, M; Okumura, K; Engleman, E G

    1995-07-01

    Dendritic cells (DC) are potent antigen-presenting cells (APC). However, the molecular basis underlying this activity remains incompletely understood. To address this question, we generated murine monoclonal antibodies (mAb) against human peripheral blood-derived DC. One such antibody, designated IT209, stained differentiated DC and adherent monocytes, but failed to stain freshly isolated peripheral blood mononuclear cells (PBMC). The antigen recognized by IT209 was identified as B70 (B7-2; also recently identified as CD86). Using this mAb we studied the role of B70 in CD4+ T-cell activation by DC in vitro. IT209 partly inhibited the proliferative response of CD4+ T cells to allogeneic DC and to recall antigens, such as tetanus toxoid (TT) and purified protein derivative (PPD) of tuberculin, presented by autologous DC. More importantly, the mAb had a potent inhibitory effect on the primary response of CD4+ T cells to autologous DC pulsed with human immunodeficiency virus (HIV) gp160 or keyhole limpet haemocyanin (KLH). Adherent monocytes, despite their expression of B70, failed to induce T-cell responses to these antigens. IT209-mediated inhibition of CD4+ T-cell responses was equivalent to that produced by anti-CD25 mAb, whereas an anti-CD80 mAb was only marginally inhibitory and did not augment the effect of IT209. These findings indicate that the B70 antigen plays an important role in DC-dependent CD4+ T-cell activation, particularly in the induction of primary CD4+ T-cell responses to soluble antigens. However, since activated monocytes, despite their expression of B70, failed to prime naive T cells to these antigens, our results suggest that additional molecules contribute to the functions of DC in CD4+ T-cell activation.

  1. Expression of PD-1/LAG-3 and cytokine production by CD4(+) T cells during infection with Plasmodium parasites.

    PubMed

    Doe, Henrietta T; Kimura, Daisuke; Miyakoda, Mana; Kimura, Kazumi; Akbari, Masoud; Yui, Katsuyuki

    2016-02-01

    CD4(+) T cells play critical roles in protection against the blood stage of malarial infection; however, their uncontrolled activation can be harmful to the host. In this study, in which rodent models of Plasmodium parasites were used, the expression of inhibitory receptors on activated CD4(+) T cells and their cytokine production was compared with their expression in a bacterial and another protozoan infection. CD4(+) T cells from mice infected with P. yoelii 17XL, P yoelii 17XNL, P. chabaudi, P. vinckei and P. berghei expressed the inhibitory receptors, PD-1 and LAG-3, as early as 6 days after infection, whereas those from either Listeria monocytogenes- or Leishmania major-infected mice did not. In response to T-cell receptor stimulation, CD4(+) T cells from mice infected with all the pathogens under study produced high concentrations of IFN-γ. IL-2 production was reduced in mice infected with Plasmodium species, but not in those infected with Listeria or Leishmania. In vitro blockade of the interaction between PD-1 and its ligands resulted in increased IFN-γ production in response to Plasmodium antigens, implying that PD-1 expressed on activated CD4(+) T cells actively inhibits T cell immune responses. Studies using Myd88(-/-), Trif(-/-) and Irf3(-/-) mice showed that induction of these CD4(+) T cells and their ability to produce cytokines is largely independent of TLR signaling. These studies suggest that expression of the inhibitory receptors PD-1 and LAG-3 on CD4(+) T cells and their reduced IL-2 production are common characteristic features of Plasmodium infection.

  2. Role of B70/B7-2 in CD4+ T-cell immune responses induced by dendritic cells.

    PubMed Central

    Fagnoni, F F; Takamizawa, M; Godfrey, W R; Rivas, A; Azuma, M; Okumura, K; Engleman, E G

    1995-01-01

    Dendritic cells (DC) are potent antigen-presenting cells (APC). However, the molecular basis underlying this activity remains incompletely understood. To address this question, we generated murine monoclonal antibodies (mAb) against human peripheral blood-derived DC. One such antibody, designated IT209, stained differentiated DC and adherent monocytes, but failed to stain freshly isolated peripheral blood mononuclear cells (PBMC). The antigen recognized by IT209 was identified as B70 (B7-2; also recently identified as CD86). Using this mAb we studied the role of B70 in CD4+ T-cell activation by DC in vitro. IT209 partly inhibited the proliferative response of CD4+ T cells to allogeneic DC and to recall antigens, such as tetanus toxoid (TT) and purified protein derivative (PPD) of tuberculin, presented by autologous DC. More importantly, the mAb had a potent inhibitory effect on the primary response of CD4+ T cells to autologous DC pulsed with human immunodeficiency virus (HIV) gp160 or keyhole limpet haemocyanin (KLH). Adherent monocytes, despite their expression of B70, failed to induce T-cell responses to these antigens. IT209-mediated inhibition of CD4+ T-cell responses was equivalent to that produced by anti-CD25 mAb, whereas an anti-CD80 mAb was only marginally inhibitory and did not augment the effect of IT209. These findings indicate that the B70 antigen plays an important role in DC-dependent CD4+ T-cell activation, particularly in the induction of primary CD4+ T-cell responses to soluble antigens. However, since activated monocytes, despite their expression of B70, failed to prime naive T cells to these antigens, our results suggest that additional molecules contribute to the functions of DC in CD4+ T-cell activation. PMID:7558137

  3. 5-Hydroxymethylcytosine Remodeling Precedes Lineage Specification during Differentiation of Human CD4(+) T Cells.

    PubMed

    Nestor, Colm E; Lentini, Antonio; Hägg Nilsson, Cathrine; Gawel, Danuta R; Gustafsson, Mika; Mattson, Lina; Wang, Hui; Rundquist, Olof; Meehan, Richard R; Klocke, Bernward; Seifert, Martin; Hauck, Stefanie M; Laumen, Helmut; Zhang, Huan; Benson, Mikael

    2016-07-12

    5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by the TET family of enzymes as part of a recently discovered active DNA de-methylation pathway. 5hmC plays important roles in regulation of gene expression and differentiation and has been implicated in T cell malignancies and autoimmunity. Here, we report early and widespread 5mC/5hmC remodeling during human CD4(+) T cell differentiation ex vivo at genes and cell-specific enhancers with known T cell function. We observe similar DNA de-methylation in CD4(+) memory T cells in vivo, indicating that early remodeling events persist long term in differentiated cells. Underscoring their important function, 5hmC loci were highly enriched for genetic variants associated with T cell diseases and T-cell-specific chromosomal interactions. Extensive functional validation of 22 risk variants revealed potentially pathogenic mechanisms in diabetes and multiple sclerosis. Our results support 5hmC-mediated DNA de-methylation as a key component of CD4(+) T cell biology in humans, with important implications for gene regulation and lineage commitment.

  4. 5-Hydroxymethylcytosine Remodeling Precedes Lineage Specification during Differentiation of Human CD4(+) T Cells.

    PubMed

    Nestor, Colm E; Lentini, Antonio; Hägg Nilsson, Cathrine; Gawel, Danuta R; Gustafsson, Mika; Mattson, Lina; Wang, Hui; Rundquist, Olof; Meehan, Richard R; Klocke, Bernward; Seifert, Martin; Hauck, Stefanie M; Laumen, Helmut; Zhang, Huan; Benson, Mikael

    2016-07-12

    5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by the TET family of enzymes as part of a recently discovered active DNA de-methylation pathway. 5hmC plays important roles in regulation of gene expression and differentiation and has been implicated in T cell malignancies and autoimmunity. Here, we report early and widespread 5mC/5hmC remodeling during human CD4(+) T cell differentiation ex vivo at genes and cell-specific enhancers with known T cell function. We observe similar DNA de-methylation in CD4(+) memory T cells in vivo, indicating that early remodeling events persist long term in differentiated cells. Underscoring their important function, 5hmC loci were highly enriched for genetic variants associated with T cell diseases and T-cell-specific chromosomal interactions. Extensive functional validation of 22 risk variants revealed potentially pathogenic mechanisms in diabetes and multiple sclerosis. Our results support 5hmC-mediated DNA de-methylation as a key component of CD4(+) T cell biology in humans, with important implications for gene regulation and lineage commitment. PMID:27346350

  5. Quantifying and Predicting the Effect of Exogenous Interleukin-7 on CD4+T Cells in HIV-1 Infection

    PubMed Central

    Prague, Mélanie; Lacabaratz, Christine; Beq, Stéphanie; Jarne, Ana; Croughs, Thérèse; Sekaly, Rafick-Pierre; Lederman, Michael M.; Sereti, Irini; Commenges, Daniel; Lévy, Yves

    2014-01-01

    Exogenous Interleukin-7 (IL-7), in supplement to antiretroviral therapy, leads to a substantial increase of all CD4+ T cell subsets in HIV-1 infected patients. However, the quantitative contribution of the several potential mechanisms of action of IL-7 is unknown. We have performed a mathematical analysis of repeated measurements of total and naive CD4+ T cells and their Ki67 expression from HIV-1 infected patients involved in three phase I/II studies (N = 53 patients). We show that, besides a transient increase of peripheral proliferation, IL-7 exerts additional effects that play a significant role in CD4+ T cell dynamics up to 52 weeks. A decrease of the loss rate of the total CD4+ T cell is the most probable explanation. If this effect could be maintained during repeated administration of IL-7, our simulation study shows that such a strategy may allow maintaining CD4+ T cell counts above 500 cells/µL with 4 cycles or fewer over a period of two years. This in-depth analysis of clinical data revealed the potential for IL-7 to achieve sustained CD4+ T cell restoration with limited IL-7 exposure in HIV-1 infected patients with immune failure despite antiretroviral therapy. PMID:24853554

  6. Establishment of HIV-1 resistance in CD4+ T cells by genome editing using zinc-finger nucleases

    PubMed Central

    Perez, Elena E; Wang, Jianbin; Miller, Jeffrey C; Jouvenot, Yann; Kim, Kenneth A; Liu, Olga; Wang, Nathaniel; Lee, Gary; Bartsevich, Victor V; Lee, Ya-Li; Guschin, Dmitry Y; Rupniewski, Igor; Waite, Adam J; Carpenito, Carmine; Carroll, Richard G; Orange, Jordan S; Urnov, Fyodor D; Rebar, Edward J; Ando, Dale; Gregory, Philip D; Riley, James L; Holmes, Michael C; June, Carl H

    2012-01-01

    Homozygosity for the naturally occurring Δ32 deletion in the HIV co-receptor CCR5 confers resistance to HIV-1 infection. We generated an HIV-resistant genotype de novo using engineered zinc-finger nucleases (ZFNs) to disrupt endogenous CCR5. Transient expression of CCR5 ZFNs permanently and specifically disrupted ~50% of CCR5 alleles in a pool of primary human CD4+ T cells. Genetic disruption of CCR5 provided robust, stable and heritable protection against HIV-1 infection in vitro and in vivo in a NOG model of HIV infection. HIV-1-infected mice engrafted with ZFN-modified CD4+ T cells had lower viral loads and higher CD4+ T-cell counts than mice engrafted with wild-type CD4+ T cells, consistent with the potential to reconstitute immune function in individuals with HIV/AIDS by maintenance of an HIV-resistant CD4+ T-cell population. Thus adoptive transfer of ex vivo expanded CCR5 ZFN–modified autologous CD4+ T cells in HIV patients is an attractive approach for the treatment of HIV-1 infection. PMID:18587387

  7. Oral vaccination with lipid-formulated BCG induces a long-lived, multifunctional CD4(+) T cell memory immune response.

    PubMed

    Ancelet, Lindsay R; Aldwell, Frank E; Rich, Fenella J; Kirman, Joanna R

    2012-01-01

    Oral delivery of BCG in a lipid formulation (Liporale™-BCG) targets delivery of viable bacilli to the mesenteric lymph nodes and confers protection against an aerosol Mycobacterium tuberculosis challenge. The magnitude, quality and duration of the effector and memory immune response induced by Liporale™-BCG vaccination is unknown. Therefore, we compared the effector and memory CD4(+) T cell response in the spleen and lungs of mice vaccinated with Liporale™-BCG to the response induced by subcutaneous BCG vaccination. Liporale™-BCG vaccination induced a long-lived CD4(+) T cell response, evident by the detection of effector CD4(+) T cells in the lungs and a significant increase in the number of Ag85B tetramer-specific CD4(+) T cells in the spleen up to 30 weeks post vaccination. Moreover, following polyclonal stimulation, Liporale™-BCG vaccination, but not s.c. BCG vaccination, induced a significant increase in both the percentage of CD4(+) T cells in the lungs capable of producing IFNγ and the number of multifunctional CD4(+) T cells in the lungs at 30 weeks post vaccination. These results demonstrate that orally delivered Liporale™-BCG vaccine induces a long-lived multifunctional immune response, and could therefore represent a practical and effective means of delivering novel BCG-based TB vaccines. PMID:23049885

  8. Phenotypic differences of CD4(+) T cells in response to red blood cell immunization in transfused sickle cell disease patients.

    PubMed

    Vingert, Benoît; Tamagne, Marie; Habibi, Anoosha; Pakdaman, Sadaf; Ripa, Julie; Elayeb, Rahma; Galacteros, Frédéric; Bierling, Philippe; Ansart-Pirenne, Hélène; Bartolucci, Pablo; Noizat-Pirenne, France

    2015-06-01

    Alloimmunization against red blood cells (RBCs) is the main immunological risk associated with transfusion in patients with sickle cell disease (SCD). However, about 50-70% of SCD patients never get immunized despite frequent transfusion. In murine models, CD4(+) T cells play a key role in RBC alloimmunization. We therefore explored and compared the CD4(+) T-cell phenotypes and functions between a group of SCD patients (n = 11) who never became immunized despite a high transfusion regimen and a group of SCD patients (n = 10) who had become immunized (at least against Kidd antigen b) after a low transfusion regimen. We studied markers of CD4(+) T-cell function, including TLR, that directly control lymphocyte function, and their spontaneous cytokine production. We also tested responders for the cytokine profile in response to Kidd antigen b peptides. Low TLR2/TLR3 expression and, unexpectedly, strong expression of CD40 on CD4(+) T cells were associated with the nonresponder status, whereas spontaneous expression of IL-10 by CD4(+) T cells and weak Tbet expression were associated with the responder status. A Th17 profile was predominant in responders when stimulated by Jb(k) . These findings implicate CD4(+) T cells in alloimmunization in humans and suggest that they may be exploited to differentiate responders from nonresponders.

  9. Antigen-specific and non-specific CD4{sup +} T cell recruitment and proliferation during influenza infection

    SciTech Connect

    Chapman, Timothy J.; Castrucci, Maria R.; Padrick, Ryan C.; Bradley, Linda M.; Topham, David J. . E-mail: david_topham@urmc.rochester.edu

    2005-09-30

    To track epitope-specific CD4{sup +} T cells at a single-cell level during influenza infection, the MHC class II-restricted OVA{sub 323-339} epitope was engineered into the neuraminidase stalk of influenza/A/WSN, creating a surrogate viral antigen. The recombinant virus, influenza A/WSN/OVA{sub II}, replicated well, was cleared normally, and stimulated both wild-type and DO11.10 or OT-II TCR transgenic OVA-specific CD4{sup +} T cells. OVA-specific CD4 T cells proliferated during infection only when the OVA epitope was present. However, previously primed (but not naive) transgenic CD4{sup +} T cells were recruited to the infected lung both in the presence and absence of the OVA{sub 323-339} epitope. These data show that, when primed, CD4{sup +} T cells may traffic to the lung in the absence of antigen, but do not proliferate. These results also document a useful tool for the study of CD4 T cells in influenza infection.

  10. Calnexin induces expansion of antigen-specific CD4+ T cells that confer immunity to fungal ascomycetes via conserved epitopes

    PubMed Central

    Wüthrich, Marcel; Brandhorst, Tristan T.; Sullivan, Thomas D.; Filutowicz, Hanna; Sterkel, Alana; Stewart, Douglas; Li, Mengyi; Lerksuthirat, Tassanee; LeBert, Vanessa; Shen, Zu Ting; Ostroff, Gary; Deepe, George S.; Hung, Chiung Yu; Cole, Garry; Walter, Jennifer A.; Jenkins, Marc K.; Klein, Bruce

    2015-01-01

    Fungal infections remain a threat due to the lack of broad spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown, but conserved antigen. Using transgenic CD4+ T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats induces expansion of calnexin-specific CD4+ T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4+ T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogeneticity and conservation of calnexin make this fungal protein a promising vaccine target. PMID:25800545

  11. Calnexin induces expansion of antigen-specific CD4(+) T cells that confer immunity to fungal ascomycetes via conserved epitopes.

    PubMed

    Wüthrich, Marcel; Brandhorst, Tristan T; Sullivan, Thomas D; Filutowicz, Hanna; Sterkel, Alana; Stewart, Douglas; Li, Mengyi; Lerksuthirat, Tassanee; LeBert, Vanessa; Shen, Zu Ting; Ostroff, Gary; Deepe, George S; Hung, Chiung Yu; Cole, Garry; Walter, Jennifer A; Jenkins, Marc K; Klein, Bruce

    2015-04-01

    Fungal infections remain a threat due to the lack of broad-spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown but conserved antigen. Using transgenic CD4(+) T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae, and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes, including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats, induces expansion of calnexin-specific CD4(+) T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4(+) T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogenicity and conservation of calnexin make this fungal protein a promising vaccine target. PMID:25800545

  12. HIV-1 Expression Within Resting CD4+ T Cells After Multiple Doses of Vorinostat

    PubMed Central

    Archin, Nancy M.; Bateson, Rosalie; Tripathy, Manoj K.; Crooks, Amanda M.; Yang, Kuo-Hsiung; Dahl, Noelle P.; Kearney, Mary F.; Anderson, Elizabeth M.; Coffin, John M.; Strain, Matthew C.; Richman, Douglas D.; Robertson, Kevin R.; Kashuba, Angela D.; Bosch, Ronald J.; Hazuda, Daria J.; Kuruc, Joann D.; Eron, Joseph J.; Margolis, David M.

    2014-01-01

    Background. A single dose of the histone deacetylase inhibitor vorinostat (VOR) up-regulates HIV RNA expression within resting CD4+ T cells of treated, aviremic human immunodeficiency virus (HIV)–positive participants. The ability of multiple exposures to VOR to repeatedly disrupt latency has not been directly measured, to our knowledge. Methods. Five participants in whom resting CD4+ T-cell–associated HIV RNA (rc-RNA) increased after a single dose of VOR agreed to receive daily VOR Monday through Wednesday for 8 weekly cycles. VOR serum levels, peripheral blood mononuclear cell histone acetylation, plasma HIV RNA single-copy assays, rc-RNA, total cellular HIV DNA, and quantitative viral outgrowth assays from resting CD4+ T cells were assayed. Results. VOR was well tolerated, with exposures within expected parameters. However, rc-RNA measured after dose 11 (second dose of cycle 4) or dose 22 (second dose of cycle 8) increased significantly in only 3 of the 5 participants, and the magnitude of the rc-RNA increase was much reduced compared with that after a single dose. Changes in histone acetylation were blunted. Results of quantitative viral outgrowth and other assays were unchanged. Conclusions. Although HIV latency is disrupted by an initial VOR dose, the effect of subsequent doses in this protocol was much reduced. We hypothesize that the global effect of VOR results in a refractory period of ≥24 hours. The optimal schedule for VOR administration is still to be defined. PMID:24620025

  13. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells.

    PubMed

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho; Rodrigues, Maurício M

    2016-06-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  14. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    PubMed Central

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho

    2016-01-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  15. Direct ex vivo detection of HLA-DR3-restricted cytomegalovirus- and Mycobacterium tuberculosis-specific CD4+ T cells.

    PubMed

    Bronke, Corine; Palmer, Nanette M; Westerlaken, Geertje H A; Toebes, Mireille; van Schijndel, Gijs M W; Purwaha, Veenu; van Meijgaarden, Krista E; Schumacher, Ton N M; van Baarle, Debbie; Tesselaar, Kiki; Geluk, Annemieke

    2005-09-01

    In order to detect epitope-specific CD4+ T cells in mycobacterial or viral infections in the context of human class II major histocompatibility complex protein human leukocyte antigen (HLA)-DR3, two HLA-DR3 tetrameric molecules were successfully produced. One contained an immunodominant HLA-DR3-restricted T-cell epitope derived from the 65-kDa heat-shock protein of Mycobacterium tuberculosis, peptide 1-13. For the other tetramer, we used an HLA-DR3-restricted T-cell epitope derived from cytomegalovirus (CMV) pp65 lower matrix protein, peptide 510-522, which induced high levels of interferon (IFN)-gamma-producing CD4+ T cells in three of four HLA-DR3-positive CMV-seropositive individuals up to 0.84% of CD4+ T cells by intracellular cytokine staining. In peripheral blood mononuclear cells from M. tuberculosis-exposed, Mycobacterium bovis bacille Calmette-Guérin (BCG)-vaccinated, or CMV-seropositive individuals, we were able to directly detect with both tetramers epitope-specific T cells up to 0.62% and 0.45% of the CD4+ T-cell population reactive to M. tuberculosis and CMV, respectively. After a 6-day culture with peptide p510-522, the frequency of CMV-specific tetramer-binding T cells was expanded up to 9.90% tetramer+ CFSElow (5,6-carboxyfluorescein diacetate succinimidyl ester) cells within the CD4+ T-cell population, further confirming the specificity of the tetrameric molecules. Thus, HLA-DR3/peptide tetrameric molecules can be used to investigate HLA-DR3-restricted antigen-specific CD4+ T cells in clinical disease or after vaccination.

  16. Importance of B cell co-stimulation in CD4+ T cell differentiation: X-linked agammaglobulinaemia, a human model

    PubMed Central

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-01-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann–Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4+CD45RO+ and CD4+CD45RO+CXCR5+ cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

  17. Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model.

    PubMed

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-06-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans.

  18. Treatment with targeted Vesicular Stomatitis Virus generates therapeutic multifunctional anti-tumor memory CD4 T-cells

    PubMed Central

    Gao, Yanhua; Whitaker-Dowling, Patricia; Griffin, Judith A.; Bergman, Ira

    2011-01-01

    A generally applicable, easy-to-use method of focusing a patient's immune system to eradicate or prevent cancer has been elusive. We are attempting to develop a targeted virus to accomplish these aims. We previously created a recombinant replicating Vesicular Stomatitis Virus that preferentially infected Her2/neu expressing breast cancer cells and showed therapeutic efficacy in an implanted Balb/c mouse tumor model. The current work shows that this therapy generated therapeutic anti-tumor CD4 T-cells against multiple tumor antigens. CD4 T-cells transferred directly from cured donor mice could eradicate established tumors in host mice. T-cells were transferred directly from donor mice and were not stimulated ex vivo. Both tumors that expressed Her2/neu and those that did not were cured by transferred T-cells. Analysis of cytokines secreted by anti-tumor memory CD4 T-cells displayed a multifunctional pattern with high levels of IFNγ, IL-4 and IL-17. Anti-tumor memory CD4 T-cells traveled to the mesenteric lymph nodes and were activated there. Treatment with targeted rrVSV is a potent immune adjuvant that generates therapeutic, multifunctional anti-tumor memory CD4 T-cells that recognize multiple tumor antigens. Immunity elicited by viral therapy is independent of host major histocompatibility complex (MHC) or knowledge of tumor antigens. Virus-induced tumor immunity could have great benefit in the prevention and treatment of tumor metastases. PMID:22240921

  19. CD4+ and CD8+ TCRβ repertoires possess different potentials to generate extraordinarily high-avidity T cells

    PubMed Central

    Nakatsugawa, Munehide; Rahman, Muhammed A.; Yamashita, Yuki; Ochi, Toshiki; Wnuk, Piotr; Tanaka, Shinya; Chamoto, Kenji; Kagoya, Yuki; Saso, Kayoko; Guo, Tingxi; Anczurowski, Mark; Butler, Marcus O.; Hirano, Naoto

    2016-01-01

    Recent high throughput sequencing analysis has revealed that the TCRβ repertoire is largely different between CD8+ and CD4+ T cells. Here, we show that the transduction of SIG35α, the public chain-centric HLA-A*02:01(A2)/MART127–35 TCRα hemichain, conferred A2/MART127–35 reactivity to a substantial subset of both CD8+ and CD4+ T cells regardless of their HLA–A2 positivity. T cells individually reconstituted with SIG35α and different A2/MART127–35 TCRβ genes isolated from CD4+ or CD8+ T cells exhibited a wide range of avidity. Surprisingly, approximately half of the A2/MART127–35 TCRs derived from CD4+ T cells, but none from CD8+ T cells, were stained by A2/MART127–35 monomer and possessed broader cross-reactivity. Our results suggest that the differences in the primary structure of peripheral CD4+ and CD8+ TCRβ repertoire indeed result in the differences in their ability to form extraordinarily high avidity T cells which would otherwise have been deleted by central tolerance. PMID:27030642

  20. Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model.

    PubMed

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-06-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

  1. Regular tai chi chuan exercise enhances functional mobility and CD4CD25 regulatory T cells

    PubMed Central

    Yeh, S‐H; Chuang, H; Lin, L‐W; Hsiao, C‐Y; Eng, H L

    2006-01-01

    Background The duration and vigour of physical exercise are widely considered to be critical elements that may positively or negatively affect physical health and immune response. Objectives To investigate the effect of a 12 week programme of regular tai chi chuan exercise (TCC) on functional mobility, beliefs about benefits of exercise on physical and psychological health, and immune regulation in middle aged volunteers. Methods This quasi‐experimental research design involving one group with testing before and after the programme was conducted to measure the effect of 12 weeks of TCC exercise in 14 men and 23 women from the normal community. Results Regular TCC exercise had a highly significant positive effect on functional mobility (p  =  0.001) and beliefs about the health benefits of exercise (p  =  0.013) in the 37 participants. Total white blood cell and red blood cell count did not change significantly, but a highly significant (p<0.001) decrease in monocyte count occurred. A significant (p  =  0.05) increase in the ratio of T helper to suppressor cells (CD4:CD8) was found, along with a significant (p  =  0.015) increase in CD4CD25 regulatory T cells. Production of the regulatory T cell mediators transforming growth factor β and interleukin 10 under specific antigen stimulation (varicella zoster virus) was also significantly increased after this exercise programme. Conclusions A 12 week programme of regular TCC exercise enhances functional mobility, personal health expectations, and regulatory T cell function. PMID:16505081

  2. Suppression of CD4+ Effector Responses by Naturally Occurring CD4+ CD25+ Foxp3+ Regulatory T Cells Contributes to Experimental Cerebral Malaria

    PubMed Central

    Blanc, Anne-Laurence; Keswani, Tarun; Gorgette, Olivier; Bandeira, Antonio; Malissen, Bernard; Cazenave, Pierre-André

    2015-01-01

    The role of naturally occurring CD4+ CD25+ Foxp3+ regulatory T cells (nTreg) in the pathogenesis of cerebral malaria (CM), which involves both pathogenic T cell responses and parasite sequestration in the brain, is still unclear. To assess the contribution and dynamics of nTreg during the neuropathogenesis, we unbalanced the ratio between nTreg and naive CD4+ T cells in an attenuated model of Plasmodium berghei ANKA-induced experimental CM (ECM) by using a selective cell enrichment strategy. We found that nTreg adoptive transfer accelerated the onset and increased the severity of CM in syngeneic C57BL/6 (B6) P. berghei ANKA-infected mice without affecting the level of parasitemia. In contrast, naive CD4+ T cell enrichment prevented CM and promoted parasite clearance. Furthermore, early during the infection nTreg expanded in the spleen but did not efficiently migrate to the site of neuroinflammation, suggesting that nTreg exert their pathogenic action early in the spleen by suppressing the protective naive CD4+ T cell response to P. berghei ANKA infection in vivo in both CM-susceptible (B6) and CM-resistant (B6-CD4−/−) mice. However, their sole transfer was not sufficient to restore CM susceptibility in two CM-resistant congenic strains tested. Altogether, these results demonstrate that nTreg are activated and functional during P. berghei ANKA infection and that they contribute to the pathogenesis of CM. They further suggest that nTreg may represent an early target for the modulation of the immune response to malaria. PMID:26553468

  3. Loss of NOX-Derived Superoxide Exacerbates Diabetogenic CD4 T-Cell Effector Responses in Type 1 Diabetes.

    PubMed

    Padgett, Lindsey E; Anderson, Brian; Liu, Chao; Ganini, Douglas; Mason, Ronald P; Piganelli, Jon D; Mathews, Clayton E; Tse, Hubert M

    2015-12-01

    Reactive oxygen species (ROS) play prominent roles in numerous biological systems. While classically expressed by neutrophils and macrophages, CD4 T cells also express NADPH oxidase (NOX), the superoxide-generating multisubunit enzyme. Our laboratory recently demonstrated that superoxide-deficient nonobese diabetic (NOD.Ncf1(m1J)) mice exhibited a delay in type 1 diabetes (T1D) partially due to blunted IFN-γ synthesis by CD4 T cells. For further investigation of the roles of superoxide on CD4 T-cell diabetogenicity, the NOD.BDC-2.5.Ncf1(m1J) (BDC-2.5.Ncf1(m1J)) mouse strain was generated, possessing autoreactive CD4 T cells deficient in NOX-derived superoxide. Unlike NOD.Ncf1(m1J), stimulated BDC-2.5.Ncf1(m1J) CD4 T cells and splenocytes displayed elevated synthesis of Th1 cytokines and chemokines. Superoxide-deficient BDC-2.5 mice developed spontaneous T1D, and CD4 T cells were more diabetogenic upon adoptive transfer into NOD.Rag recipients due to a skewing toward impaired Treg suppression. Exogenous superoxide blunted exacerbated Th1 cytokines and proinflammatory chemokines to approximately wild-type levels, concomitant with reduced IL-12Rβ2 signaling and P-STAT4 (Y693) activation. These results highlight the importance of NOX-derived superoxide in curbing autoreactivity due, in part, to control of Treg function and as a redox-dependent checkpoint of effector T-cell responses. Ultimately, our studies reveal the complexities of free radicals in CD4 T-cell responses.

  4. Expression of S100 Protein in CD4-positive T-cell Lymphomas Is Often Associated With T-cell Prolymphocytic Leukemia.

    PubMed

    Aggarwal, Nidhi; Pongpruttipan, Tawatchai; Patel, Snehal; Bayerl, Michael G; Alkan, Serhan; Nathwani, Bharat; Surti, Urvashi; Kitahara, Sumire; Chinthammitr, Yingyong; Swerdlow, Steven H

    2015-12-01

    S100 T-cell lymphomas are infrequent, and except 1 all have been CD4 negative. On the basis of an index case of CD4 S100 T-cell prolymphocytic leukemia (T-PLL), we studied S100 protein expression in 19 additional T-PLLs and 56 other T-cell lymphomas that are usually CD4, including 15 angioimmunoblastic T-cell lymphomas, 24 anaplastic large cell lymphomas (16 ALK and 8 ALK), 7 mycosis fungoides/Sézary syndrome, and 10 peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). Two additional S100 CD4 PTCL, NOS cases were also reviewed. Thirty percent (6/20) of T-PLLs were S100 compared with 0/56 other T-cell lymphomas with previously unstudied S100 reactivity (40 CD4, 2 CD8, 11 CD4/CD8, 3 unknown) (P=0.0007). There were no significant differences between the S100 and S100 T-PLLs with regard to the male:female ratio (2:1 vs. 1:1), age (71.6±7.7 vs. 65.4±9.3), peripheral blood lymphocyte count (67.2±116.6 vs. 101.1±159.7×10/L), or median survival (463 vs. 578 d, where known). The 2 S100 PTCL, NOS cases occurred in a 7-year-old boy and a 45-year-old woman. Both had involvement of the bone marrow and peripheral blood but were morphologically unlike T-PLL and lacked TCL1 gene rearrangement. These results demonstrate that S100 T-cell lymphomas include a subset that are CD4 and most often, but not exclusively, are T-PLL. Although having diagnostic implications, there were no documented clinical differences between the S100 and S100 T-PLLs. PMID:26379148

  5. Synergistic Communication between CD4+ T Cells and Monocytes Impacts the Cytokine Environment

    PubMed Central

    Schrier, Sarah B.; Hill, Abby S.; Plana, Deborah; Lauffenburger, Douglas A.

    2016-01-01

    Physiological cytokine environments arise from factors produced by diverse cell types in coordinated concert. Understanding the contributions of each cell type in the context of cell-cell communication is important for effectively designing disease modifying interventions. Here, we present multi-plexed measurement of 48 cytokines from a coculture system of primary human CD4+ T cells and monocytes across a spectrum of stimuli and for a range of relative T cell/monocyte compositions, coupled with corresponding measurements from PBMCs and plasma from the same donors. Computational analysis of the resulting data-sets elucidated communication-independent and communication-dependent contributions, including both positive and negative synergies. We find that cytokines in cell supernatants were uncorrelated to those found in plasma. Additionally, as an example of positive synergy, production levels of CXCR3 cytokines IP-10 and MIG, depend non-linearly on both IFNγ and TNFα levels in cross-talk between T cells and monocytes. Overall, this work demonstrates that communication between cell types can significantly impact the consequent cytokine environment, emphasizing the value of mixed cell population studies. PMID:27721433

  6. Cutting edge: identification of autoreactive CD4+ and CD8+ T cell subsets resistant to PD-1 pathway blockade.

    PubMed

    Pauken, Kristen E; Nelson, Christine E; Martinov, Tijana; Spanier, Justin A; Heffernan, James R; Sahli, Nathanael L; Quarnstrom, Clare F; Osum, Kevin C; Schenkel, Jason M; Jenkins, Marc K; Blazar, Bruce R; Vezys, Vaiva; Fife, Brian T

    2015-04-15

    Programmed death-1 (PD-1) promotes T cell tolerance. Despite therapeutically targeting this pathway for chronic infections and tumors, little is known about how different T cell subsets are affected during blockade. We examined PD-1/PD ligand 1 (PD-L1) regulation of self-antigen-specific CD4 and CD8 T cells in autoimmune-susceptible models. PD-L1 blockade increased insulin-specific effector CD4 T cells in type 1 diabetes. However, anergic islet-specific CD4 T cells were resistant to PD-L1 blockade. Additionally, PD-L1 was critical for induction, but not maintenance, of CD8 T cell intestinal tolerance. PD-L1 blockade enhanced functionality of effector T cells, whereas established tolerant or anergic T cells were not dependent on PD-1/PD-L1 signaling to remain unresponsive. This highlights the existence of Ag-experienced T cell subsets that do not rely on PD-1/PD-L1 regulation. These findings illustrate how positive treatment outcomes and autoimmunity development during PD-1/PD-L1 inhibition are linked to the differentiation state of a T cell.

  7. Determination of CD4+ and CD8+ T cells in the peripheral blood of dogs with demodicosis.

    PubMed

    Singh, S K; Dimri, U; Sharma, M C; Sharma, B; Saxena, M

    2010-11-01

    The aim of this study was to evaluate the CD4+/CD8+ ratio in peripheral blood of dogs with localized and generalized demodicosis. Sixteen dogs were examined, 8 with localized and 8 with generalized demodicosis, while 8 healthy dogs were used as controls. Peripheral blood was obtained and CD4+ and CD8+ T cells were determined by flow cytometry. Significantly higher numbers of CD8+ T cells and lower numbers of CD4+ T cells were found in dogs with generalized demodicosis compared to dogs with localized demodicosis and healthy controls. Significantly higher numbers of CD8+ T cells and lower numbers of CD4+ T cells were also found in dogs with localized demodicosis compared to healthy controls. The CD4+/CD8+ ratio was also found to be significantly lower in dogs with generalized demodicosis in comparison with dogs with localized demodicosis and healthy controls. It is concluded that significant alteration in the CD4+/CD8+ ratio may be implicated in the pathogenesis of generalized canine demodicosis.

  8. West Nile virus-specific CD4 T cells exhibit direct anti-viral cytokine secretion and cytotoxicity and are sufficient for antiviral protection

    PubMed Central

    Brien, James D.; Uhrlaub, Jennifer L.; Nikolich-Zugich, Janko

    2012-01-01

    CD4 T cells have been shown to be necessary for the prevention of encephalitis during West Nile virus infection. However, the mechanisms used by antigen-specific CD4 T cells to protect mice from West Nile virus encephalitis remain incompletely understood. Contrary to the belief that CD4 T cells are protective because they merely maintain the CD8 T cell response and improve antibody production, we here provide evidence for the direct anti-viral activity of CD4 T cells which functions to protect the host from WNV encephalitis. In adoptive transfers, naïve CD4 T cells protected a significant number of lethally infected RAG−/− mice, demonstrating the protective effect of CD4 T cells independent of B cells and CD8 T cells. To shed light on the mechanism of this protection, we defined the peptide specificities of the CD4 T cells responding to West Nile virus infection in C57BL/6 (H-2b) mice, and used these peptides to characterize the in vivo function of antiviral CD4 T cells. WNV-specific CD4 T cells produced IFN-γ and IL-2, but also showed potential for in vivo and ex vivo cytotoxicity. Furthermore, peptide vaccination using CD4 epitopes conferred protection against lethal West Nile virus infection in immunocompetent mice. These results demonstrate the role of direct effector function of antigen-specific CD4 T cell in preventing severe West Nile virus disease. PMID:19050276

  9. Epigenetic repression of interleukin 2 expression in senescent CD4+ T cells during chronic HIV type 1 infection.

    PubMed

    Nakayama-Hosoya, Kaori; Ishida, Takaomi; Youngblood, Ben; Nakamura, Hitomi; Hosoya, Noriaki; Koga, Michiko; Koibuchi, Tomohiko; Iwamoto, Aikichi; Kawana-Tachikawa, Ai

    2015-01-01

    The molecular mechanisms for IL2 gene-specific dysregulation during chronic human immunodeficiency virus type 1 (HIV-1) infection are unknown. Here, we investigated the role of DNA methylation in suppressing interleukin 2 (IL-2) expression in memory CD4(+) T cells during chronic HIV-1 infection. We observed that CpG sites in the IL2 promoter of CD4(+) T cells were fully methylated in naive CD4(+) T cells and significantly demethylated in the memory populations. Interestingly, we found that the memory cells that had a terminally differentiated phenotype and expressed CD57 had increased IL2 promoter methylation relative to less differentiated memory cells in healthy individuals. Importantly, early effector memory subsets from HIV-1-infected subjects expressed high levels of CD57 and were highly methylated at the IL2 locus. Furthermore, the increased CD57 expression on memory CD4(+) T cells was inversely correlated with IL-2 production. These data suggest that DNA methylation at the IL2 locus in CD4(+) T cells is coupled to immunosenescence and plays a critical role in the broad dysfunction that occurs in polyclonal T cells during HIV-1 infection.

  10. CD4(+) T cells confer anxiolytic and antidepressant-like effects, but enhance fear memory processes in Rag2(-/-) mice.

    PubMed

    Clark, Sarah M; Soroka, Jennifer A; Song, Chang; Li, Xin; Tonelli, Leonardo H

    2016-05-01

    Accumulating evidence supports a role of T cells in behavioral stress responsiveness. Our laboratory previously reported that lymphocyte deficient Rag2(-/-) mice on a BALB/c background display resilience to maladaptive stress responses when compared with immune competent mice in the predator odor exposure (POE) paradigm, while exhibiting similar behavior in a cued fear-conditioning (FC) paradigm. In the present study, Rag2(-/-) mice on a C57BL/6 background were assessed in the same behavioral paradigms, as well as additional tests of anxiety and depressive-like behavior. Furthermore, the effects of naïve CD4(+ ) T cells were evaluated by adoptive transfer of functional cells from nonstressed, wild-type donors to Rag2(-/-) mice. Consistent with our prior results, Rag2(-/-) mice displayed an attenuated startle response after POE. Nevertheless, reconstitution of Rag2(-/-) mice with CD4(+ ) T cells did not modify startle reactivity. Additionally, in contrast with our previous findings, Rag2(-/-) mice showed attenuated fear responses in the FC paradigm compared to wild-type mice and reconstitution with CD4(+ ) T cells promoted fear learning and memory. Notably, reconstitution with CD4(+ ) T cells had anxiolytic and antidepressant-like effects in Rag2(-/-) mice that had not been previously stressed, but had no effect after POE. Taken together, our results support a role of CD4(+ ) T cells in emotionality, but also indicate that they may promote fear responses by enhancing learning and memory processes.

  11. In Situ Peptide-MHC-II Tetramer Staining of Antigen-Specific CD4+ T Cells in Tissues.

    PubMed

    Dileepan, Thamotharampillai; Kim, Hyeon O; Cleary, P Patrick; Skinner, Pamela J

    2015-01-01

    The invention of peptide-MHC-tetramer technology to label antigen-specific T cells has led to an enhanced understanding of T lymphocyte biology. Here we describe the development of an in situ pMHC-II tetramer staining method to visualize antigen-specific CD4+ T cells in tissues. This method complements other methods developed that similarly use MHC class II reagents to stain antigen-specific CD4+ T cells in situ. In this study, we used group A streptococcus (GAS) expressing a surrogate peptide (2W) to inoculate C57BL/6 mice, and used fresh nasal-associated lymphoid tissues (NALT) in optimizing the in situ staining of 2W:I-Ab specific CD4+ T cells. The results showed 2W:I-Ab tetramer-binding CD4+ T cells in GAS-2W but not GAS infected mice. This method holds promise to be broadly applicable to study the localization, abundance, and phenotype of antigen-specific CD4+ T cells in undisrupted tissues. PMID:26067103

  12. Understanding Factors That Modulate the Establishment of HIV Latency in Resting CD4+ T-Cells In Vitro

    PubMed Central

    Anderson, Jenny L.; Mota, Talia M.; Evans, Vanessa A.; Kumar, Nitasha; Rezaei, Simin D.; Cheong, Karey; Solomon, Ajantha; Wightman, Fiona; Cameron, Paul U.; Lewin, Sharon R.

    2016-01-01

    Developing robust in vitro models of HIV latency is needed to better understand how latency is established, maintained and reversed. In this study, we examined the effects of donor variability, HIV titre and co-receptor usage on establishing HIV latency in vitro using two models of HIV latency. Using the CCL19 model of HIV latency, we found that in up to 50% of donors, CCL19 enhanced latent infection of resting CD4+ T-cells by CXCR4-tropic HIV in the presence of low dose IL-2. Increasing the infectious titre of CXCR4-tropic HIV increased both productive and latent infection of resting CD4+ T-cells. In a different model where myeloid dendritic cells (mDC) were co-cultured with resting CD4+ T-cells, we observed a higher frequency of latently infected cells in vitro than CCL19-treated or unstimulated CD4+ T-cells in the presence of low dose IL-2. In the DC-T-cell model, latency was established with both CCR5- and CXCR4-tropic virus but higher titres of CCR5-tropic virus was required in most donors. The establishment of latency in vitro through direct infection of resting CD4+ T-cells is significantly enhanced by CCL19 and mDC, but the efficiency is dependent on virus titre, co-receptor usage and there is significant donor variability. PMID:27383184

  13. CD4+ T cells defined by their Vβ T cell receptor expression are associated with immunoregulatory profiles and lesion size in human leishmaniasis

    PubMed Central

    Keesen, T S L; Antonelli, L R V; Faria, D R; Guimarães, L H; Bacellar, O; Carvalho, E M; Dutra, W O; Gollob, K J

    2011-01-01

    Leishmaniasis is caused by infection with the protozoan parasite, Leishmania, that parasitizes human cells, and the cellular immune response is essential for controlling infection. In order to measure the host T cell response to Leishmania infection, we have measured the expansion, activation state and functional potential of specific T cells as identified by their T cell receptor Vβ region expression. In a group of cutaneous leishmaniasis (CL) patients, we evaluated these characteristics in nine different T cell subpopulations as identified by their Vβ region expression, before and after specific Leishmania antigen stimulation. Our results show: (1) an increase in CD4+ T cells expressing Vβ 5·2 and Vβ 24 in CL compared to controls; (2) a Leishmania antigen-induced increase in CD4+ T cells expressing Vβ 5·2, 11, 12 and 17; (3) a profile of previous activation of CD4+ Vβ 5·2-, 11- and 24-positive T cells, with higher expression of CD45RO, HLA-DR, interferon-γ, tumour necrosis factor-α and interleukin-10 compared to other Vβ-expressing subpopulations; (4) a positive correlation between higher frequencies of CD4+Vβ5·2+ T cells and larger lesions; and (5) biased homing of CD4+ T cells expressing Vβ 5·2 to the lesion site. Given that CL disease involves a level of pathology (ulcerated lesions) and is often followed by long-lived protection and cure, the identification of specific subpopulations active in this form of disease could allow for the discovery of immunodominant Leishmania antigens important for triggering efficient host responses against the parasite, or identify cell populations most involved in pathology. PMID:21726211

  14. A Combined Omics Approach to Generate the Surface Atlas of Human Naive CD4+ T Cells during Early T-Cell Receptor Activation*

    PubMed Central

    Graessel, Anke; Hauck, Stefanie M.; von Toerne, Christine; Kloppmann, Edda; Goldberg, Tatyana; Koppensteiner, Herwig; Schindler, Michael; Knapp, Bettina; Krause, Linda; Dietz, Katharina; Schmidt-Weber, Carsten B.; Suttner, Kathrin

    2015-01-01

    Naive CD4+ T cells are the common precursors of multiple effector and memory T-cell subsets and possess a high plasticity in terms of differentiation potential. This stem-cell-like character is important for cell therapies aiming at regeneration of specific immunity. Cell surface proteins are crucial for recognition and response to signals mediated by other cells or environmental changes. Knowledge of cell surface proteins of human naive CD4+ T cells and their changes during the early phase of T-cell activation is urgently needed for a guided differentiation of naive T cells and may support the selection of pluripotent cells for cell therapy. Periodate oxidation and aniline-catalyzed oxime ligation technology was applied with subsequent quantitative liquid chromatography-tandem MS to generate a data set describing the surface proteome of primary human naive CD4+ T cells and to monitor dynamic changes during the early phase of activation. This led to the identification of 173 N-glycosylated surface proteins. To independently confirm the proteomic data set and to analyze the cell surface by an alternative technique a systematic phenotypic expression analysis of surface antigens via flow cytometry was performed. This screening expanded the previous data set, resulting in 229 surface proteins, which were expressed on naive unstimulated and activated CD4+ T cells. Furthermore, we generated a surface expression atlas based on transcriptome data, experimental annotation, and predicted subcellular localization, and correlated the proteomics result with this transcriptional data set. This extensive surface atlas provides an overall naive CD4+ T cell surface resource and will enable future studies aiming at a deeper understanding of mechanisms of T-cell biology allowing the identification of novel immune targets usable for the development of therapeutic treatments. PMID:25991687

  15. Identification of CD4+ T-cell epitopes on iron-regulated surface determinant B of Staphylococcus aureus.

    PubMed

    Yu, Simiao; Zhang, Hua; Yao, Di; Liu, Wei; Wang, Xintong; Chen, Xiaoting; Wei, Yuhua; Zhang, Zhenghai; Wang, Jiannan; Yu, Liquan; Sun, Hunan; Wu, Zhijun; Yu, Yongzhong; Song, Baifen; Ma, Jinzhu; Tong, Chunyu; Cui, Yudong

    2015-12-01

    Iron-regulated surface determinant B (IsdB) of Staphylococcus aureus (S. aureus) is a highly conserved surface protein that can induce protective CD4(+) T-cell immune response. A pivotal role of CD4(+) T-cells in effective immunity against S. aureus infection has been proved, but CD4(+) T-cell epitopes on the S. aureus IsdB have not been well identified. In this study, MHC binding assay was firstly used to predict CD4(+) T-cell epitopes on S. aureus IsdB protein, and six peptides were synthesized to validate the probable epitopes. Two novel IsdB CD4(+) T-cell epitopes, P1 (residues 159-178) and P4 (residues 287-306), were for the first time identified using CD4(+) T-cells obtained from IsdB-immunized C57BL/6 (H-2(b)) and BALB/c (H-2(d)) mice spleen based on cell proliferation and cytokines response. The results showed that P1 and P4 emulsified in Freund's adjuvant (FA) induced much higher cell proliferation compared with PBS emulsified in FA. CD4(+) T-cells stimulated with peptides P1 and P4 secreted significantly higher levels of IFN-γ and IL-17A. However, the level of the cytokine IL-4 almost remained unchanged, suggesting that P1 and P4 preferentially elicited polarized Th1-type responses. In addition, BALB/c mice just respond to P4 not P1, while C57BL/6 mice respond to P1 not P4, implying that epitope P1 and P4 were determined as H-2(b) and H-2(d) restricted epitope, respectively. Taken together, our data may provide an explanation of the IsdB-induced protection against S. aureus and highlight the possibility of developing the epitope-based vaccine against the S. aureus.

  16. Neisseria gonorrhoeae enhances HIV-1 infection of primary resting CD4+ T cells through TLR2 activation.

    PubMed

    Ding, Jian; Rapista, Aprille; Teleshova, Natalia; Mosoyan, Goar; Jarvis, Gary A; Klotman, Mary E; Chang, Theresa L

    2010-03-15

    Sexually transmitted infections increase the likelihood of HIV-1 transmission. We investigated the effect of Neisseria gonorrheae (gonococcus [GC]) exposure on HIV replication in primary resting CD4(+) T cells, a major HIV target cell during the early stage of sexual transmission of HIV. GC and TLR2 agonists, such as peptidylglycan (PGN), Pam(3)CSK(4), and Pam(3)C-Lip, a GC-derived synthetic lipopeptide, but not TLR4 agonists including LPS or GC lipooligosaccharide enhanced HIV-1 infection of primary resting CD4(+) T cells after viral entry. Pretreatment of CD4(+) cells with PGN also promoted HIV infection. Anti-TLR2 Abs abolished the HIV enhancing effect of GC and Pam(3)C-Lip, indicating that GC-mediated enhancement of HIV infection of resting CD4(+) T cells was through TLR2. IL-2 was required for TLR2-mediated HIV enhancement. PGN and GC induced cell surface expression of T cell activation markers and HIV coreceptors, CCR5 and CXCR4. The maximal postentry HIV enhancing effect was achieved when PGN was added immediately after viral exposure. Kinetic studies and analysis of HIV DNA products indicated that GC exposure and TLR2 activation enhanced HIV infection at the step of nuclear import. We conclude that GC enhanced HIV infection of primary resting CD4(+) T cells through TLR2 activation, which both increased the susceptibility of primary CD4(+) T cells to HIV infection as well as enhanced HIV-infected CD4(+) T cells at the early stage of HIV life cycle after entry. This study provides a molecular mechanism by which nonulcerative sexually transmitted infections mediate enhancement of HIV infection and has implication for HIV prevention and therapeutics. PMID:20147631

  17. CD4+ T Cells Expressing PD-1, TIGIT and LAG-3 Contribute to HIV Persistence during ART

    PubMed Central

    Fromentin, Rémi; Bakeman, Wendy; Lawani, Mariam B.; Khoury, Gabriela; Hartogensis, Wendy; DaFonseca, Sandrina; Killian, Marisela; Epling, Lorrie; Hoh, Rebecca; Sinclair, Elizabeth; Hecht, Frederick M.; Bacchetti, Peter; Deeks, Steven G.; Lewin, Sharon R.; Sékaly, Rafick-Pierre; Chomont, Nicolas

    2016-01-01

    HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals. PMID:27415008

  18. Interleukin 27R regulates CD4+ T cell phenotype and impacts protective immunity during Mycobacterium tuberculosis infection.

    PubMed

    Torrado, Egidio; Fountain, Jeffrey J; Liao, Mingfeng; Tighe, Michael; Reiley, William W; Lai, Rachel P; Meintjes, Graeme; Pearl, John E; Chen, Xinchun; Zak, Daniel E; Thompson, Ethan G; Aderem, Alan; Ghilardi, Nico; Solache, Alejandra; McKinstry, K Kai; Strutt, Tara M; Wilkinson, Robert J; Swain, Susan L; Cooper, Andrea M

    2015-08-24

    CD4+ T cells mediate protection against Mycobacterium tuberculosis (Mtb); however, the phenotype of protective T cells is undefined, thereby confounding vaccination efforts. IL-27 is highly expressed during human tuberculosis (TB), and absence of IL-27R (Il27ra) specifically on T cells results in increased protection. IL-27R deficiency during chronic Mtb infection does not impact antigen-specific CD4+ T cell number but maintains programmed death-1 (PD-1), CD69, and CD127 expression while reducing T-bet and killer cell lectin-like receptor G1 (KLRG1) expression. Furthermore, T-bet haploinsufficiency results in failure to generate KLRG1+, antigen-specific CD4+ T cells, and in improved protection. T cells in Il27ra(-/-) mice accumulate preferentially in the lung parenchyma within close proximity to Mtb, and antigen-specific CD4+ T cells lacking IL-27R are intrinsically more fit than intact T cells and maintain IL-2 production. Improved fitness of IL-27R-deficient T cells is not associated with increased proliferation but with decreased expression of cell death-associated markers. Therefore, during Mtb infection, IL-27R acts intrinsically on T cells to limit protection and reduce fitness, whereas the IL-27R-deficient environment alters the phenotype and location of T cells. The significant expression of IL-27 in TB and the negative influence of IL-27R on T cell function demonstrate the pathway by which this cytokine/receptor pair is detrimental in TB.

  19. Interleukin 27R regulates CD4+ T cell phenotype and impacts protective immunity during Mycobacterium tuberculosis infection

    PubMed Central

    Torrado, Egidio; Fountain, Jeffrey J.; Liao, Mingfeng; Tighe, Michael; Reiley, William W.; Lai, Rachel P.; Meintjes, Graeme; Pearl, John E.; Chen, Xinchun; Zak, Daniel E.; Thompson, Ethan G.; Aderem, Alan; Ghilardi, Nico; Solache, Alejandra; McKinstry, K. Kai; Strutt, Tara M.; Wilkinson, Robert J.; Swain, Susan L.

    2015-01-01

    CD4+ T cells mediate protection against Mycobacterium tuberculosis (Mtb); however, the phenotype of protective T cells is undefined, thereby confounding vaccination efforts. IL-27 is highly expressed during human tuberculosis (TB), and absence of IL-27R (Il27ra) specifically on T cells results in increased protection. IL-27R deficiency during chronic Mtb infection does not impact antigen-specific CD4+ T cell number but maintains programmed death-1 (PD-1), CD69, and CD127 expression while reducing T-bet and killer cell lectin-like receptor G1 (KLRG1) expression. Furthermore, T-bet haploinsufficiency results in failure to generate KLRG1+, antigen-specific CD4+ T cells, and in improved protection. T cells in Il27ra−/− mice accumulate preferentially in the lung parenchyma within close proximity to Mtb, and antigen-specific CD4+ T cells lacking IL-27R are intrinsically more fit than intact T cells and maintain IL-2 production. Improved fitness of IL-27R–deficient T cells is not associated with increased proliferation but with decreased expression of cell death–associated markers. Therefore, during Mtb infection, IL-27R acts intrinsically on T cells to limit protection and reduce fitness, whereas the IL-27R–deficient environment alters the phenotype and location of T cells. The significant expression of IL-27 in TB and the negative influence of IL-27R on T cell function demonstrate the pathway by which this cytokine/receptor pair is detrimental in TB. PMID:26282876

  20. Hoxb4 Overexpression in CD4 Memory Phenotype T Cells Increases the Central Memory Population upon Homeostatic Proliferation

    PubMed Central

    Fournier, Marilaine; Labrecque, Nathalie; Bijl, Janet J.

    2013-01-01

    Memory T cell populations allow a rapid immune response to pathogens that have been previously encountered and thus form the basis of success in vaccinations. However, the molecular pathways underlying the development and maintenance of these cells are only starting to be unveiled. Memory T cells have the capacity to self renew as do hematopoietic stem cells, and overlapping gene expression profiles suggested that these cells might use the same self-renewal pathways. The transcription factor Hoxb4 has been shown to promote self-renewal divisions of hematopoietic stem cells resulting in an expansion of these cells. In this study we investigated whether overexpression of Hoxb4 could provide an advantage to CD4 memory phenotype T cells in engrafting the niche of T cell deficient mice following adoptive transfer. Competitive transplantation experiments demonstrated that CD4 memory phenotype T cells derived from mice transgenic for Hoxb4 contributed overall less to the repopulation of the lymphoid organs than wild type CD4 memory phenotype T cells after two months. These proportions were relatively maintained following serial transplantation in secondary and tertiary mice. Interestingly, a significantly higher percentage of the Hoxb4 CD4 memory phenotype T cell population expressed the CD62L and Ly6C surface markers, characteristic for central memory T cells, after homeostatic proliferation. Thus Hoxb4 favours the maintenance and increase of the CD4 central memory phenotype T cell population. These cells are more stem cell like and might eventually lead to an advantage of Hoxb4 T cells after subjecting the cells to additional rounds of proliferation. PMID:24324706

  1. T-cell receptor-CD4 physical association in a murine T-cell hybridoma: induction by antigen receptor ligation.

    PubMed Central

    Mittler, R S; Goldman, S J; Spitalny, G L; Burakoff, S J

    1989-01-01

    By employing flow cytometric analysis and fluorescence resonance energy transfer (FRET), we examined the physical relationship between the T-cell receptor-CD3 complex (Ti-CD3) and the CD4 molecule on helper T cells. Through the use of an L3T4-negative murine T-cell hybridoma infectant expressing the human CD4 gene and having antigen specificity for HLA-DR, we show that binding of the Ti-CD3 complex with an anti-CD3 monoclonal antibody induces its redistribution proximal to cell-surface CD4. FRET efficiency was 9.4% on cells labeled with rhodaminated anti-CD3 and fluoresceinated anti-CD4. FRET was found to be temperature dependent, since similarly treated cells held at 4 degrees C displayed a FRET efficiency of less than 1%. Energy transfer was evident within 3 min after warming cells to 37 degrees C. Energy transfer was not detected between Ti-CD3 and the abundantly expressed leukocyte common antigen (CD45). Of greater significance was our observation that hybridomas infected with a truncated CD4 gene lacking the cytoplasmic domain failed to transfer energy despite the fact that CD4 was expressed on the cell surface at levels equivalent to or greater than the wild type. These studies suggest that after crosslinking of the Ti-CD3 on CD4+ T cells, a physical association occurs between the antigen receptor complex and CD4 and that the association is dependent upon the presence of the cytoplasmic domain of CD4. PMID:2530583

  2. Lack of suppressive CD4+CD25+FOXP3+ T cells in advanced stages of primary cutaneous T-cell lymphoma.

    PubMed

    Tiemessen, Machteld M; Mitchell, Tracey J; Hendry, Lisa; Whittaker, Sean J; Taams, Leonie S; John, Susan

    2006-10-01

    Mycosis fungoides and its leukemic variant, Sezary syndrome, are the most common primary cutaneous T-cell lymphomas (CTCLs). In an ex vivo study, we investigated the percentage, phenotype, and suppressive function of CD4+CD25+ regulatory T cells (Tregs) from peripheral blood of CTCL patients. The percentage of Tregs did not differ significantly between patients and controls. Functional assays demonstrated a dichotomy in Treg function: in four out of 10 patients CD4+CD25+ T cells were incapable of suppressing autologous CD4+CD25- T-cell proliferation, whereas suppressive function was intact in the other six patients. Suppressive activity of Tregs inversely correlated with the peripheral blood tumor burden. T-plastin gene expression, used as a Sezary cell marker, confirmed that Sezary cells were heterogeneous for CD25 expression. Mixed lymphocyte reactions demonstrated that CD4+CD25- T cells from patients who lacked functional Tregs were susceptible to suppression by Tregs from healthy controls, and had not become suppressive themselves. Furthermore, we found reduced expression of Foxp3 in the CD4+CD25+ Tregs of these patients relative to the other six CTCL patients and controls. Our findings thus indicate a dysfunction of peripheral Tregs in certain CTCL patients, which correlates with tumor burden.

  3. Lack of Suppressive CD4+CD25+FOXP3+ T Cells in Advanced Stages of Primary Cutaneous T-Cell Lymphoma

    PubMed Central

    Tiemessen, Machteld M.; Mitchell, Tracey J.; Hendry, Lisa; Whittaker, Sean J.; Taams, Leonie S.; John, Susan

    2009-01-01

    Mycosis fungoides and its leukemic variant, Sezary syndrome, are the most common primary cutaneous T-cell lymphomas (CTCLs). In an ex vivo study, we investigated the percentage, phenotype, and suppressive function of CD4+CD25+ regulatory T cells (Tregs) from peripheral blood of CTCL patients. The percentage of Tregs did not differ significantly between patients and controls. Functional assays demonstrated a dichotomy in Treg function: in four out of 10 patients CD4+CD25+ T cells were incapable of suppressing autologous CD4+CD25- T-cell proliferation, whereas suppressive function was intact in the other six patients. Suppressive activity of Tregs inversely correlated with the peripheral blood tumor burden. T-plastin gene expression, used as a Sezary cell marker, confirmed that Sezary cells were heterogeneous for CD25 expression. Mixed lymphocyte reactions demonstrated that CD4+CD25- T cells from patients who lacked functional Tregs were susceptible to suppression by Tregs from healthy controls, and had not become suppressive themselves. Furthermore, we found reduced expression of Foxp3 in the CD4+CD25+ Tregs of these patients relative to the other six CTCL patients and controls. Our findings thus indicate a dysfunction of peripheral Tregs in certain CTCL patients, which correlates with tumor burden. PMID:16741512

  4. A Simple Proteomics-Based Approach to Identification of Immunodominant Antigens from a Complex Pathogen: Application to the CD4 T Cell Response against Human Herpesvirus 6B.

    PubMed

    Becerra-Artiles, Aniuska; Dominguez-Amorocho, Omar; Stern, Lawrence J; Calvo-Calle, J Mauricio

    2015-01-01

    Most of humanity is chronically infected with human herpesvirus 6 (HHV-6), with viral replication controlled at least in part by a poorly characterized CD4 T cell response. Identification of viral epitopes recognized by CD4 T cells is complicated by the large size of the herpesvirus genome and a low frequency of circulating T cells responding to the virus. Here, we present an alternative to classical epitope mapping approaches used to identify major targets of the T cell response to a complex pathogen like HHV-6B. In the approach presented here, extracellular virus preparations or virus-infected cells are fractionated by SDS-PAGE, and eluted fractions are used as source of antigens to study cytokine responses in direct ex vivo T cell activation studies. Fractions inducing significant cytokine responses are analyzed by mass spectrometry to identify viral proteins, and a subset of peptides from these proteins corresponding to predicted HLA-DR binders is tested for IFN-γ production in seropositive donors with diverse HLA haplotypes. Ten HHV-6B viral proteins were identified as immunodominant antigens. The epitope-specific response to HHV-6B virus was complex and variable between individuals. We identified 107 peptides, each recognized by at least one donor, with each donor having a distinctive footprint. Fourteen peptides showed responses in the majority of donors. Responses to these epitopes were validated using in vitro expanded cells and naturally expressed viral proteins. Predicted peptide binding affinities for the eight HLA-DRB1 alleles investigated here correlated only modestly with the observed CD4 T cell responses. Overall, the response to the virus was dominated by peptides from the major capsid protein U57 and major antigenic protein U11, but responses to other proteins including glycoprotein H (U48) and tegument proteins U54 and U14 also were observed. These results provide a means to follow and potentially modulate the CD4 T-cell immune response to HHV-6

  5. Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells.

    PubMed

    Li Causi, Eleonora; Parikh, Suraj C; Chudley, Lindsey; Layfield, David M; Ottensmeier, Christian H; Stevenson, Freda K; Di Genova, Gianfranco

    2015-01-01

    CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines.

  6. Continuous Activation of Autoreactive CD4+ CD25+ Regulatory T Cells in the Steady State

    PubMed Central

    Fisson, Sylvain; Darrasse-Jèze, Guillaume; Litvinova, Elena; Septier, Franck; Klatzmann, David; Liblau, Roland; Salomon, Benoît L.

    2003-01-01

    Despite a growing interest in CD4+ CD25+ regulatory T cells (Treg) that play a major role in self-tolerance and immunoregulation, fundamental parameters of the biology and homeostasis of these cells are poorly known. Here, we show that this population is composed of two Treg subsets that have distinct phenotypes and homeostasis in normal unmanipulated mice. In the steady state, some Treg remain quiescent and have a long lifespan, in the order of months, whereas the other Treg are dividing extensively and express multiple activation markers. After adoptive transfer, tissue-specific Treg rapidly divide and expand preferentially in lymph nodes draining their target self-antigens. These results reveal the existence of a cycling Treg subset composed of autoreactive Treg that are continuously activated by tissue self-antigens. PMID:12939344

  7. Tryptophan biosynthesis protects mycobacteria from CD4 T cell-mediated killing

    PubMed Central

    Zhang, Yanjia J.; Reddy, Manchi C.; Ioerger, Thomas R.; Rothchild, Alissa C.; Dartois, Veronique; Schuster, Brian M.; Trauner, Andrej; Wallis, Deeann; Galaviz, Stacy; Huttenhower, Curtis; Sacchettini, James C.; Behar, Samuel M.; Rubin, Eric J.

    2014-01-01

    Summary Bacteria that cause disease rely on their ability to counteract and overcome host defenses. Here we present a genome-scale study of Mycobacterium tuberculosis (Mtb) that uncovers the bacterial determinants of surviving host immunity, sets of genes we term “counteractomes.” Through this, we find that CD4 T cells attempt to starve Mtb of tryptophan through a mechanism that limits Chlamydia and Leishmania infections. In those cases, tryptophan starvation works well, since those pathogens are natural tryptophan auxotrophs. Mtb, however, can synthesize tryptophan, and thus starvation fails as an Mtb-killing mechanism. We then describe a small molecule inhibitor of Mtb tryptophan synthesis, which turns Mtb into a tryptophan auxotroph and restores the efficacy of a failed host defense. Together, our findings demonstrate that the Mtb determinants for surviving host immunity—Mtb’s immune counteractomes—serve as probes of host immunity, uncovering immune-mediated stresses that can be leveraged for therapeutic discovery. PMID:24315099

  8. Depletion of CD4 T cells enhances immunotherapy for neuroblastoma after syngeneic HSCT but compromises development of antitumor immune memory.

    PubMed

    Jing, Weiqing; Gershan, Jill A; Johnson, Bryon D

    2009-04-30

    High-risk neuroblastoma remains a clinically challenging disease. Here, we report that a multifaceted immunotherapeutic approach including syngeneic hematopoietic stem cell transplantation (HSCT), adoptive transfer of sensitized T cells (from syngeneic donors vaccinated to tumor antigens), and early posttransplantation tumor vaccination can effectively treat mice with established neuroblastoma. Vaccination was an important component of this immunotherapy, as it resulted in enhanced and prolonged tumor-specific CD8 T-cell activity and improved antitumor efficacy. Surprisingly, CD4 cell depletion of mice given sensitized T cells resulted in better tumor-free survival, which was associated with an early increased expansion of CD8 T cells with an effector phenotype, increased numbers of tumor-reactive CD8 T cells, and increased tumor infiltration by CD8 T cells. However, in the absence of CD4 T cells, development of long-term tumor immunity (memory) was severely compromised as reflected by diminished CD8 T-cell recall responses and an inability to resist tumor rechallenge in vivo. Based on these results, a major challenge with this immunotherapeutic approach is how to obtain the ideal initial antitumor response but still preserve antitumor immune memory. These data suggest that identification and selective depletion of immune inhibitory CD4 T cells may be a strategy to enhance early antitumor immunity and induce a long-lasting tumor response after HSCT.

  9. Collaboration between tumor-specific CD4+ T cells and B cells in anti-cancer immunity.

    PubMed

    Guy, Thomas V; Terry, Alexandra M; Bolton, Holly A; Hancock, David G; Zhu, Erhua; Brink, Robert; McGuire, Helen M; Shklovskaya, Elena; Fazekas de St. Groth, Barbara

    2016-05-24

    The role of B cells and antibodies in anti-tumor immunity is controversial, with both positive and negative effects reported in animal models and clinical studies. We developed a murine B16.F10 melanoma model to study the effects of collaboration between tumor-specific CD4+ T cells and B cells on tumor control. By incorporating T cell receptor transgenic T cells and B cell receptor isotype switching B cells, we were able to track the responses of tumor-reactive T and B cells and the development of anti-tumor antibodies in vivo. In the presence of tumor-specific B cells, the number of tumor-reactive CD4+ T cells was reduced in lymphoid tissues and the tumor itself, and this correlated with poor tumor control. B cells had little effect on the Th1 bias of the CD4+ T cell response, and the number of induced FoxP3+ regulatory cells (iTregs) generated from within the original naive CD4+ T cell inoculum was unrelated to the degree of B cell expansion. In response to CD4+ T cell help, B cells produced a range of isotype-switched anti-tumor antibodies, principally IgG1, IgG2a/c and IgG2b. In the absence of CD4+ T cells, B cells responded to agonistic anti-CD40 administration by switching to production of IgG2a/c and, to a lesser extent, IgG1, IgG3, IgA and IgE, which reduced the number of lung metastases after i.v. tumor inoculation but had no effect on the growth of subcutaneous tumors.

  10. Collaboration between tumor-specific CD4+ T cells and B cells in anti-cancer immunity

    PubMed Central

    Guy, Thomas V.; Terry, Alexandra M.; Bolton, Holly A.; Hancock, David G.; Zhu, Erhua; Brink, Robert; McGuire, Helen M.

    2016-01-01

    The role of B cells and antibodies in anti-tumor immunity is controversial, with both positive and negative effects reported in animal models and clinical studies. We developed a murine B16.F10 melanoma model to study the effects of collaboration between tumor-specific CD4+ T cells and B cells on tumor control. By incorporating T cell receptor transgenic T cells and B cell receptor isotype switching B cells, we were able to track the responses of tumor-reactive T and B cells and the development of anti-tumor antibodies in vivo. In the presence of tumor-specific B cells, the number of tumor-reactive CD4+ T cells was reduced in lymphoid tissues and the tumor itself, and this correlated with poor tumor control. B cells had little effect on the Th1 bias of the CD4+ T cell response, and the number of induced FoxP3+ regulatory cells (iTregs) generated from within the original naive CD4+ T cell inoculum was unrelated to the degree of B cell expansion. In response to CD4+ T cell help, B cells produced a range of isotype-switched anti-tumor antibodies, principally IgG1, IgG2a/c and IgG2b. In the absence of CD4+ T cells, B cells responded to agonistic anti-CD40 administration by switching to production of IgG2a/c and, to a lesser extent, IgG1, IgG3, IgA and IgE, which reduced the number of lung metastases after i.v. tumor inoculation but had no effect on the growth of subcutaneous tumors. PMID:27121060

  11. B and CD4+ T cell expression of TLR2 are critical for optimal induction of a T cell-dependent humoral immune response to intact Streptococcus pneumoniae

    PubMed Central

    Vasilevsky, S.; Chattopadhyay, G.; Colino, Jesus; Yeh, T-J; Chen, Q.; Sen, G.; Snapper, C. M.

    2009-01-01

    Summary TLR2−/− mice immunized with Streptococcus pneumoniae (Pn) elicit normal IgM, but defective CD4+ T cell-dependent (TD) type 1 IgG isotype production, associated with a largely intact innate immune response. We studied the TD phosphorylcholine (PC)-specific IgG3 versus the T cell-independent IgM response to Pn to determine whether TLR2 signals directly via the adaptive immune system. Pn-activated TLR2−/− bone marrow dendritic cells (BMDC) have only a modest defect in cytokine secretion, undergo normal maturation, and when transferred into naive WT mice elicit a normal IgM and IgG3 anti-PC response, relative to WT BMDC. Pn synergizes with BCR and TCR signaling for DNA synthesis in purified WT B and CD4+ T cells, respectively, but is defective in cells lacking TLR2. Pn primes TLR2−/− mice for a normal CD4+ T cell IFN-γ recall response. Notably, TLR2−/− B cells transferred into RAG-2−/− mice with WT CD4+ T cells, or TLR2−/− CD4+ T cells transferred into athymic nude mice, each elicit a defective IgG3, in contrast to normal IgM, anti-PC response relative to WT cells. These data are the first to demonstrate a major role for B cell and CD4+ T cell expression of TLR2 for eliciting an anti-bacterial humoral immune response. PMID:19003933

  12. Expansion of cytokine-producing CD4-CD8- T cells associated with abnormal Fas expression and hypereosinophilia

    PubMed Central

    1996-01-01

    The mechanisms of sustained overproduction of eosinophils in the idiopathic hypereosinophilic syndrome and in some human immunodeficiency virus (HIV)-1-infected individuals are largely unknown. We hypothesized that T cells may release soluble products that regulate eosinophilia in these patients, as has been previously shown in bronchial asthma. We identified one patient with idiopathic hypereosinophilic syndrome and one HIV-1-infected individual with associated hypereosinophilia who demonstrated high numbers of CD4-CD8- T cells in peripheral blood. CD4-CD8- T cells from both patients, although highly activated, did not express functional Fas receptors. In one case, the lack of functional Fas receptors was associated with failure of Fas mRNA and protein expression, and in another, expression of a soluble form of the Fas molecule that may have antagonized normal signaling of Fas ligand. In contrast to the recently described lymphoproliferative/autoimmune syndrome, which is characterized by accumulation of CD4-CD8- T cells and mutations within the Fas gene, this study suggests somatic variations in Fas expression and function quite late in life. Both genetic and somatic abnormalities in regulation of the Fas gene are therefore associated with failures to undergo T cell apoptosis. Furthermore, the expanded population of CD4- CD8- T cells from both patients elaborated cytokines with antiapoptotic properties for eosinophils, indicating a major role of these T cells in the development of eosinophilia. Thus, this study demonstrates a sequential dysregulation of apoptosis in different cell types. PMID:8642249

  13. IgE-mediated enhancement of CD4+ T cell responses requires antigen presentation by CD8α− conventional dendritic cells

    PubMed Central

    Ding, Zhoujie; Dahlin, Joakim S.; Xu, Hui; Heyman, Birgitta

    2016-01-01

    IgE, forming an immune complex with small proteins, can enhance the specific antibody and CD4+ T cell responses in vivo. The effects require the presence of CD23 (Fcε-receptor II)+ B cells, which capture IgE-complexed antigens (Ag) in the circulation and transport them to splenic B cell follicles. In addition, also CD11c+ cells, which do not express CD23, are required for IgE-mediated enhancement of T cell responses. This suggests that some type of dendritic cell obtains IgE-Ag complexes from B cells and presents antigenic peptides to T cells. To elucidate the nature of this dendritic cell, mice were immunized with ovalbumin (OVA)-specific IgE and OVA, and different populations of CD11c+ cells, obtained from the spleens four hours after immunization, were tested for their ability to present OVA. CD8α− conventional dendritic cells (cDCs) were much more efficient in inducing specific CD4+ T cell proliferation ex vivo than were CD8α+ cDCs or plasmacytoid dendritic cells. Thus, IgE-Ag complexes administered intravenously are rapidly transported to the spleen by recirculating B cells where they are delivered to CD8α− cDCs which induce proliferation of CD4+ T cells. PMID:27306570

  14. Docosahexaenoic acid reduces suppressive and migratory functions of CD4CD25 regulatory T-cells

    PubMed Central

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-01-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4+CD25+ regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4+CD25− effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-β, and IL-10; nonetheless, this fatty acid increased the expression of p27KIP1 mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease. PMID:19561360

  15. Docosahexaenoic acid reduces suppressive and migratory functions of CD4+CD25+ regulatory T-cells.

    PubMed

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-12-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4(+)CD25(+) regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4(+)CD25(-) effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-beta, and IL-10; nonetheless, this fatty acid increased the expression of p27(KIP1) mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease.

  16. Complement receptor type 1 (CR1/CD35) expressed on activated human CD4+ T cells contributes to generation of regulatory T cells.

    PubMed

    Török, Katalin; Dezső, Balázs; Bencsik, András; Uzonyi, Barbara; Erdei, Anna

    2015-04-01

    The role of complement in the regulation of T cell immunity has been highlighted recently by several groups. We were prompted to reinvestigate the role of complement receptor type 1 (CR1, CD35) [corrected] in human T cells based on our earlier data showing that activated human T cells produce C3 (Torok et al. (2012) [48]) and also by results demonstrating that engagement of Membrane Cofactor Protein (MCP, CD46) induces a switch of anti-CD35-activated [corrected] helper T cells into regulatory T cells (Kemper et al. (2003) [17]). We demonstrate here that co-ligation of CD46 and CD35, [corrected] the two C3b-binding structures present on activated CD4+ human T cells significantly enhances CD25 expression, elevates granzyme B production and synergistically augments cell proliferation. The role of CR1 in the development of the Treg phenotype was further confirmed by demonstrating that its engagement enhances IL-10 production and reduces IFNγ release by the activated CD4+ T cells in the presence of excess IL-2. The functional in vivo relevance of our findings was highlighted by the immunohistochemical staining of tonsils, revealing the presence of CD4/CD35 [corrected] double positive lymphocytes mainly in the inter-follicular regions where direct contact between CD4+ T cells and B lymphocytes occurs. Regarding the in vivo relevance of the complement-dependent generation of regulatory T cells in secondary lymphoid organs we propose a scenario shown in the figure. The depicted process involves the sequential binding of locally produced C3 fragments to CD46 and CD35 [corrected] expressed on activated T cells, which - in the presence of excess IL-2 - leads to the development of Treg cells.

  17. Virologic and immunologic effects of adding maraviroc to suppressive ART in subjects with suboptimal CD4+ T-cell recovery

    PubMed Central

    Cillo, Anthony R.; Hilldorfer, Benedict B.; Lalama, Christina M.; McKinnon, John E.; Coombs, Robert W.; Tenorio, Allan R.; Fox, Lawrence; Gandhi, Rajesh T.; Ribaudo, Heather; Currier, Judith S.; Gulick, Roy M.; Wilkin, Timothy J.; Mellors, John W.

    2015-01-01

    Background Combination antiretroviral therapy (ART) suppresses HIV-1 replication, but does not restore CD4+ T-cell counts in all subjects. To investigate the effects of maraviroc on HIV-1 persistence and the relations between virologic and immunologic parameters in subjects with incomplete CD4+ T-cell recovery, we performed a prospective, open-label pilot trial in which maraviroc was added to a suppressive ART regimen for 24 weeks. Design A5256 was a single-arm trial in which subjects on suppressive ART with incomplete CD4+ T-cell recovery added maraviroc for 24 weeks. Methods We quantified low-level, residual viremia in plasma and total HIV-1 DNA and 2-LTR circles in peripheral blood mononuclear cells before and after maraviroc intensification. We also evaluated markers of CD4+ and CD8+ T-cell immune activation (%CD38+HLA-DR+) and apoptosis (%caspase3+/Bcl-2−). Results No effect of maraviroc was found on the probability of detectable plasma viremia (≥1 copy/mL; n=31, exact McNemar p=1.0) or detectable 2-LTR circles (n=28, p=0.25) or on total HIV-1 DNA (n=28, 90% confidence interval: −0.1, +0.3 log10 copies/106 CD4+ T-cells). Pre-maraviroc HIV-1 DNA levels were inversely related to pre-maraviroc %CD38+HLA-DR+ CD4+ T-cells (Spearman=−0.52, p=0.004), and lower pre-maraviroc HIV-1 DNA levels were associated with larger decreases in %CD38+HLA-DR+ CD4+ T-cells during maraviroc intensification (Spearman=0.44, p=0.018). Conclusions In subjects on suppressive ART with incomplete CD4+ T-cell recovery, maraviroc intensification did not affect measures of HIV-1 persistence but did decrease persistent CD4+ T-cell immune activation especially in subjects with low pre-intensification levels of HIV-1 DNA. PMID:26544577

  18. HIV Skews the Lineage-Defining Transcriptional Profile of Mycobacterium tuberculosis-Specific CD4+ T Cells.

    PubMed

    Riou, Catherine; Strickland, Natalie; Soares, Andreia P; Corleis, Björn; Kwon, Douglas S; Wherry, E John; Wilkinson, Robert J; Burgers, Wendy A

    2016-04-01

    HIV-infected persons are at greater risk of developing tuberculosis (TB) even before profound CD4 loss occurs, suggesting that HIV alters CD4(+) T cell functions capable of containing bacterial replication. An effective immune response to Mycobacterium tuberculosis most likely relies on the development of a balanced CD4 response, in which distinct CD4(+) Th subsets act in synergy to control the infection. To define the diversity of M. tuberculosis-specific CD4(+) Th subsets and determine whether HIV infection impacts such responses, the expression of lineage-defining transcription factors T-bet, Gata3, RORγt, and Foxp3 was measured in M. tuberculosis-specific CD4(+) T cells in HIV-uninfected (n = 20) and HIV-infected individuals (n = 20) with latent TB infection. Our results show that, upon 5-d restimulation in vitro, M. tuberculosis-specific CD4(+) T cells from healthy individuals have the ability to exhibit a broad spectrum of Th subsets, defined by specific patterns of transcription factor coexpression. These transcription factor profiles were skewed in HIV-infected individuals where the proportion of T-bet(high)Foxp3(+) M. tuberculosis-specific CD4(+) T cells was significantly decreased (p = 0.002) compared with HIV-uninfected individuals, a change that correlated inversely with HIV viral load (p = 0.0007) and plasma TNF-α (p = 0.027). Our data demonstrate an important balance in Th subset diversity defined by lineage-defining transcription factor coexpression profiles that is disrupted by HIV infection and suggest a role for HIV in impairing TB immunity by altering the equilibrium of M. tuberculosis-specific CD4(+) Th subsets.

  19. Modulation of Cytokine Secretion Allows CD4 T Cells Secreting IL-10 and IL-17 to Simultaneously Participate in Maintaining Tolerance and Immunity.

    PubMed

    Saito, Kanako; Pignon, Pascale; Ayyoub, Maha; Valmori, Danila

    2015-01-01

    CD4 T cells secreting IL-10 or IL-17 are frequent at mucosal sites, where their equilibrium is important for simultaneously maintaining tolerance and immunity to the resident microbiota. The mode of action of these cells, however, is as yet incompletely understood. In this study, we have combined ex vivo analysis of CD4 T cells producing IL-10 or/and IL-17 with assessment of clonal populations isolated ex vivo using a cytokine catch assay. We found that circulating CD4 T cells secreting IL-10 or/and IL-17 ex vivo include both conventional FOXP3- CD4 T cells and FOXP3+ Helios- Treg. Upon assessment of clonal populations derived from single ex vivo isolated cytokine secreting cells, we found that IL-10 or/and IL-17 secreting cells prevalently secrete one or the other cytokine depending on the type of stimulation, the time after stimulation and the presence of microbial products. Namely, IL-10 secretion by clonal cells was prevalent at early time points after TCR mediated stimulation, was independent of co-stimulation and was increased in the presence of the microbial fermentation product butyrate. In contrast, IL-17 secretion was higher at later time points after TCR mediated stimulation and in the presence of co-stimulatory signals. Taken together, these results provide insights into the mechanisms that, through modulation of cytokine secretion depending on conditions, allow IL-10 and IL-17 producing CD4 T cells to contribute to maintain tolerance to microbes locally, while retaining the ability to participate in protective immune responses at distant sites.

  20. Monocyte-derived macrophages exhibit distinct and more restricted HIV-1 integration site repertoire than CD4(+) T cells.

    PubMed

    Kok, Yik Lim; Vongrad, Valentina; Shilaih, Mohaned; Di Giallonardo, Francesca; Kuster, Herbert; Kouyos, Roger; Günthard, Huldrych F; Metzner, Karin J

    2016-01-01

    The host genetic landscape surrounding integrated HIV-1 has an impact on the fate of the provirus. Studies analysing HIV-1 integration sites in macrophages are scarce. We studied HIV-1 integration site patterns in monocyte-derived macrophages (MDMs) and activated CD4(+) T cells derived from seven antiretroviral therapy (ART)-treated HIV-1-infected individuals whose cells were infected ex vivo with autologous HIV-1 isolated during the acute phase of infection. A total of 1,484 unique HIV-1 integration sites were analysed. Their distribution in the human genome and genetic features, and the effects of HIV-1 integrase polymorphisms on the nucleotide selection specificity at these sites were indistinguishable between the two cell types, and among HIV-1 isolates. However, the repertoires of HIV-1-hosting gene clusters overlapped to a higher extent in MDMs than in CD4(+) T cells. The frequencies of HIV-1 integration events in genes encoding HIV-1-interacting proteins were also different between the two cell types. Lastly, HIV-1-hosting genes linked to clonal expansion of latently HIV-1-infected CD4(+) T cells were over-represented in gene hotspots identified in CD4(+) T cells but not in those identified in MDMs. Taken together, the repertoire of genes targeted by HIV-1 in MDMs is distinct from and more restricted than that of CD4(+) T cells.

  1. Memory CD4+ T cells are required for optimal NK cell effector functions against the opportunistic fungal pathogen Pneumocystis murina.

    PubMed

    Kelly, Michelle N; Zheng, Mingquan; Ruan, Sanbao; Kolls, Jay; D'Souza, Alain; Shellito, Judd E

    2013-01-01

    Little is known about the role of NK cells or their interplay with other immune cells during opportunistic infections. Using our murine model of Pneumocystis pneumonia, we found that loss of NK cells during immunosuppression results in substantial Pneumocystis lung burden. During early infection of C57B/6 CD4(+) T cell-depleted mice, there were significantly fewer NK cells in the lung tissue compared with CD4(+) T cell-intact animals, and the NK cells present demonstrated decreased upregulation of the activation marker NKp46 and production of the effector cytokine, IFN-γ. Furthermore, coincubation studies revealed a significant increase in fungal killing when NK cells were combined with CD4(+) T cells compared with either cell alone, which was coincident with a significant increase in perforin production by NK cells. Finally, however, we found through adoptive transfer that memory CD4(+) T cells are required for significant NK cell upregulation of the activation marker NK group 2D and production of IFN-γ, granzyme B, and perforin during Pneumocystis infection. To the best of our knowledge, this study is the first to demonstrate a role for NK cells in immunity to Pneumocystis pneumonia, as well as to establish a functional relationship between CD4(+) T cells and NK cells in the host response to an opportunistic fungal pathogen.

  2. Monocyte-derived macrophages exhibit distinct and more restricted HIV-1 integration site repertoire than CD4+ T cells

    PubMed Central

    Kok, Yik Lim; Vongrad, Valentina; Shilaih, Mohaned; Di Giallonardo, Francesca; Kuster, Herbert; Kouyos, Roger; Günthard, Huldrych F.; Metzner, Karin J.

    2016-01-01

    The host genetic landscape surrounding integrated HIV-1 has an impact on the fate of the provirus. Studies analysing HIV-1 integration sites in macrophages are scarce. We studied HIV-1 integration site patterns in monocyte-derived macrophages (MDMs) and activated CD4+ T cells derived from seven antiretroviral therapy (ART)-treated HIV-1-infected individuals whose cells were infected ex vivo with autologous HIV-1 isolated during the acute phase of infection. A total of 1,484 unique HIV-1 integration sites were analysed. Their distribution in the human genome and genetic features, and the effects of HIV-1 integrase polymorphisms on the nucleotide selection specificity at these sites were indistinguishable between the two cell types, and among HIV-1 isolates. However, the repertoires of HIV-1-hosting gene clusters overlapped to a higher extent in MDMs than in CD4+ T cells. The frequencies of HIV-1 integration events in genes encoding HIV-1-interacting proteins were also different between the two cell types. Lastly, HIV-1-hosting genes linked to clonal expansion of latently HIV-1-infected CD4+ T cells were over-represented in gene hotspots identified in CD4+ T cells but not in those identified in MDMs. Taken together, the repertoire of genes targeted by HIV-1 in MDMs is distinct from and more restricted than that of CD4+ T cells. PMID:27067385

  3. Dengue virus infection elicits highly polarized CX3CR1+ cytotoxic CD4+ T cells associated with protective immunity.

    PubMed

    Weiskopf, Daniela; Bangs, Derek J; Sidney, John; Kolla, Ravi V; De Silva, Aruna D; de Silva, Aravinda M; Crotty, Shane; Peters, Bjoern; Sette, Alessandro

    2015-08-01

    Dengue virus (DENV) is a rapidly spreading pathogen with unusual pathogenesis, and correlates of protection from severe dengue disease and vaccine efficacy have not yet been established. Although DENV-specific CD8(+) T-cell responses have been extensively studied, the breadth and specificity of CD4(+) T-cell responses remains to be defined. Here we define HLA-restricted CD4(+) T-cell epitopes resulting from natural infection with dengue virus in a hyperepidemic setting. Ex vivo flow-cytometric analysis of DENV-specific CD4(+) T cells revealed that the virus-specific cells were highly polarized, with a strong bias toward a CX3CR1(+) Eomesodermin(+) perforin(+) granzyme B(+) CD45RA(+) CD4 CTL phenotype. Importantly, these cells correlated with a protective HLA DR allele, and we demonstrate that these cells have direct ex vivo DENV-specific cytolytic activity. We speculate that cytotoxic dengue-specific CD4(+) T cells may play a role in the control of dengue infection in vivo, and this immune correlate may be a key target for dengue virus vaccine development. PMID:26195744

  4. Isolation of a new herpes virus from human CD4 sup + T cells

    SciTech Connect

    Frenkel, N.; Schirmer, E.C.; Wyatt, L.S.; Katsafanas, G.; Roffman, E.; Danovich, R.M. ); June, C.H. )

    1990-01-01

    A new human herpes virus has been isolated from CD4{sup +} T cells purified from peripheral blood mononuclear cells of a healthy individual (RK), following incubation of the cells under conditions promoting T-cell activation. The virus could not be recovered from nonactivated cells. Cultures of lymphocytes infected with the RK virus exhibited a cytopathic effect, and electron microscopic analyses revealed a characteristic herpes virus structure. RK virus DNA did not hybridize with large probes derived from herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, and human cytomegalovirus. The genetic relatedness of the RK virus to the recently identified T-lymphotropic human herpes virus 6 (HHV-6) was investigated by restriction enzyme analyses using 21 different enzymes and by blot hydridization analyses using 11 probes derived from two strains of HHV-6 (Z29 and U1102). Whereas the two HHV-6 strains exhibited only limited restriction enzyme polymorphism, cleavage of the RK virus DNA yielded distinct patterns. Of the 11 HHV-6 DNA probes tested, only 6 cross-hybridized with DNA fragments derived from the RK virus. Taken together, the maximal homology amounted to 31 kilobases of the 75 kilobases tested. The authors conclude that the RK virus is distinct from previously characterized human herpesviruses. The authors propose to designate it as the prototype of a new herpes virus, the seventh human herpes virus identified to date.

  5. A Stochastic Model for CD4+ T Cell Proliferation and Dissemination Network in Primary Immune Response

    PubMed Central

    Boianelli, Alessandro; Pettini, Elena; Prota, Gennaro; Medaglini, Donata; Vicino, Antonio

    2015-01-01

    The study of the initial phase of the adaptive immune response after first antigen encounter provides essential information on the magnitude and quality of the immune response. This phase is characterized by proliferation and dissemination of T cells in the lymphoid organs. Modeling and identifying the key features of this phenomenon may provide a useful tool for the analysis and prediction of the effects of immunization. This knowledge can be effectively exploited in vaccinology, where it is of interest to evaluate and compare the responses to different vaccine formulations. The objective of this paper is to construct a stochastic model based on branching process theory, for the dissemination network of antigen-specific CD4+ T cells. The devised model is validated on in vivo animal experimental data. The model presented has been applied to the vaccine immunization context making references to simple proliferation laws that take into account division, death and quiescence, but it can also be applied to any context where it is of interest to study the dynamic evolution of a population. PMID:26301680

  6. Tumor-necrosis factor impairs CD4(+) T cell-mediated immunological control in chronic viral infection.

    PubMed

    Beyer, Marc; Abdullah, Zeinab; Chemnitz, Jens M; Maisel, Daniela; Sander, Jil; Lehmann, Clara; Thabet, Yasser; Shinde, Prashant V; Schmidleithner, Lisa; Köhne, Maren; Trebicka, Jonel; Schierwagen, Robert; Hofmann, Andrea; Popov, Alexey; Lang, Karl S; Oxenius, Annette; Buch, Thorsten; Kurts, Christian; Heikenwalder, Mathias; Fätkenheuer, Gerd; Lang, Philipp A; Hartmann, Pia; Knolle, Percy A; Schultze, Joachim L

    2016-05-01

    Persistent viral infections are characterized by the simultaneous presence of chronic inflammation and T cell dysfunction. In prototypic models of chronicity--infection with human immunodeficiency virus (HIV) or lymphocytic choriomeningitis virus (LCMV)--we used transcriptome-based modeling to reveal that CD4(+) T cells were co-exposed not only to multiple inhibitory signals but also to tumor-necrosis factor (TNF). Blockade of TNF during chronic infection with LCMV abrogated the inhibitory gene-expression signature in CD4(+) T cells, including reduced expression of the inhibitory receptor PD-1, and reconstituted virus-specific immunity, which led to control of infection. Preventing signaling via the TNF receptor selectively in T cells sufficed to induce these effects. Targeted immunological interventions to disrupt the TNF-mediated link between chronic inflammation and T cell dysfunction might therefore lead to therapies to overcome persistent viral infection.

  7. Affinity and dose of TCR engagement yield proportional enhancer and gene activity in CD4+ T cells

    PubMed Central

    Allison, Karmel A; Sajti, Eniko; Collier, Jana G; Gosselin, David; Troutman, Ty Dale; Stone, Erica L; Hedrick, Stephen M; Glass, Christopher K

    2016-01-01

    Affinity and dose of T cell receptor (TCR) interaction with antigens govern the magnitude of CD4+ T cell responses, but questions remain regarding the quantitative translation of TCR engagement into downstream signals. We find that while the response of mouse CD4+ T cells to antigenic stimulation is bimodal, activated cells exhibit analog responses proportional to signal strength. Gene expression output reflects TCR signal strength, providing a signature of T cell activation. Expression changes rely on a pre-established enhancer landscape and quantitative acetylation at AP-1 binding sites. Finally, we show that graded expression of activation genes depends on ERK pathway activation, suggesting that an ERK-AP-1 axis plays an important role in translating TCR signal strength into proportional activation of enhancers and genes essential for T cell function. DOI: http://dx.doi.org/10.7554/eLife.10134.001 PMID:27376549

  8. Loss of CD4+ T Cells in Human Immunodeficiency Virus Type 1-Infected Chimpanzees Is Associated with Increased Lymphocyte Apoptosis

    PubMed Central

    Davis, Ian C.; Girard, Marc; Fultz, Patricia N.

    1998-01-01

    Supportive evidence that apoptosis contributes to loss of CD4+ lymphocytes in human immunodeficiency virus type 1 (HIV-1)-infected humans comes from an apparent lack of abnormal apoptosis in apathogenic lentivirus infections of nonhuman primates, including HIV-1 infection of chimpanzees. Two female chimpanzees were inoculated, one cervically and the other intravenously, with HIV-1 derived from the LAI/LAV-1b strain, which was isolated from a chimpanzee infected with the virus for 8 years. Within 6 weeks of infection, both recipient chimpanzees developed a progressive loss of CD4+ T cells which correlated with persistently high viral burdens and increased levels of CD4+ T-cell apoptosis both in vitro and in vivo. Lymph nodes from both animals also revealed evidence of immune hyperactivation. Intermediate levels of T-cell apoptosis in both peripheral blood and lymph nodes were seen in a third chimpanzee that had been infected with the LAI/LAV-1b strain for 9 years; this animal has maintained depressed CD4/CD8 T-cell ratios for the last 3 years. Similar analyses of cells from 4 uninfected animals and 10 other HIV-1-infected chimpanzees without loss of CD4+ cells revealed no difference in levels of apoptosis in these two control groups. These results demonstrate a correlation between immune hyperactivation, T-cell apoptosis, and chronic loss of CD4+ T cells in HIV-1-infected chimpanzees, providing additional evidence that apoptosis is an important factor in T-cell loss in AIDS. Furthermore, the results show that some HIV-1 strains are pathogenic for chimpanzees and that this species is not inherently resistant to HIV-1-induced disease. PMID:9573225

  9. Pervanadate-induced adhesion of CD4+ T cell to fibronectin is associated with tyrosine phosphorylation of paxillin.

    PubMed

    Miron, S; Kachalsky, S G; Hershkoviz, R; Lider, O

    1997-09-01

    The initial stages of T cell activation involve tyrosine protein kinase-mediated intracellular signaling events. Integrin-mediated adhesion of CD4+ T lymphocytes to extracellular matrix glycoproteins, such as fibronectin, is an activation-dependent process. The involvement of tyrosine protein kinases in the adhesion of CD4+ T cells to fibronectin was examined using pervanadate, a protein-tyrosine phosphatase inhibitor. Pervanadate induced the adhesion of human CD4+ T cells to immobilized fibronectin in a beta1 integrin-mediated fashion, and adhesion was associated with an increase of protein tyrosine phosphorylation. Tyrosine protein kinase inhibitors abrogated both T cell adhesion and intracellular protein tyrosine phosphorylation. Participation of cytoskeletal proteins in the pervanadate-induced T cell adhesion was indicated because cytoskeleton disruption by cytochalasin B inhibited cell adhesion to fibronectin. We demonstrate that the cytoskeletal protein paxillin underwent time-dependent tyrosine phosphorylation simultaneously with pervanadate-induced T cell adhesion to fibronectin. Tyrosine phosphorylation of paxillin was related to cell adhesion, since pretreatment of T cells with cytochalasin B abrogated both adhesion and phosphorylation. This study demonstrates a correlation between activation of protein tyrosine kinases, tyrosine phosphorylation of paxillin, and integrin-mediated T cell adhesion to extracellular matrix glycoproteins. PMID:9307082

  10. Enhancement of CD4(+) T cell response and survival via coexpressed OX40/OX40L in Graves' disease.

    PubMed

    Wang, Qin; Shi, Bi-Min; Xie, Fang; Fu, Zhao-Yang; Chen, Yong-Jing; An, Jing-Nan; Ma, Yu; Liu, Cui-Ping; Zhang, Xue-Kun; Zhang, Xue-Guang

    2016-07-15

    OX40/OX40L pathway plays a very important role in the antigen priming T cells and effector T cells. In the present study, we aimed to examine the involvement of OX40/OX40L pathway in the activation of autoreactive T cells in patients with Grave's disease (GD). We found that OX40 and OX40L were constitutively coexpressed on peripheral CD4(+) T cells from GD patients using flow cytometry analysis. The levels of OX40 and OX40L coexpression on CD4(+) T cells were shown to be correlated with TRAbs. Cell proliferation assay showed that blocking OX40/OX40L signal inhibited T cell proliferation and survival, which suggested that OX40/OX40L could enhance CD4(+) T cell proliferation and maintain their long-term survival in GD by self-enhancing loop of T cell activation independent of APCs. Confocal microscopy and coimmunoprecipitation analysis further revealed that OX40 and OX40L formed a functional complex, which may facilitate signal transduction from OX40L to OX40 and contribute to the pathogenesis of GD. PMID:27107937

  11. Assessment of Bet v 1-specific CD4+ T cell responses in allergic and nonallergic individuals using MHC class II peptide tetramers.

    PubMed

    Van Overtvelt, Laurence; Wambre, Erik; Maillère, Bernard; von Hofe, Eric; Louise, Anne; Balazuc, Anne Marie; Bohle, Barbara; Ebo, Didier; Leboulaire, Christophe; Garcia, Gilles; Moingeon, Philippe

    2008-04-01

    In this study, we used HLA-DRB1*0101, DRB1*0401, and DRB1*1501 peptide tetramers combined with cytokine surface capture assays to characterize CD4(+) T cell responses against the immunodominant T cell epitope (peptide 141-155) from the major birch pollen allergen Bet v 1, in both healthy and allergic individuals. We could detect Bet v 1-specific T cells in the PBMC of 20 birch pollen allergic patients, but also in 9 of 9 healthy individuals tested. Analysis at a single-cell level revealed that allergen-specific CD4(+) T cells from healthy individuals secrete IFN-gamma and IL-10 in response to the allergen, whereas cells from allergic patients are bona fide Th2 cells (producing mostly IL-5, some IL-10, but no IFN-gamma), as corroborated by patterns of cytokines produced by T cell clones. A fraction of Bet v 1-specific cells isolated from healthy, but not allergic, individuals also expresses CTLA-4, glucocorticoid-induced TNF receptor, and Foxp 3, indicating that they represent regulatory T cells. In this model of seasonal exposure to allergen, we also demonstrate the tremendous dynamics of T cell responses in both allergic and nonallergic individuals during the peak pollen season, with an expansion of Bet v 1-specific precursors from 10(-6) to 10(-3) among circulating CD4(+) T lymphocytes. Allergy vaccines should be designed to recapitulate such naturally protective Th1/regulatory T cell responses observed in healthy individuals.

  12. A role for the thermal environment in defining co-stimulation requirements for CD4(+) T cell activation.

    PubMed

    Zynda, Evan R; Grimm, Melissa J; Yuan, Min; Zhong, Lingwen; Mace, Thomas A; Capitano, Maegan; Ostberg, Julie R; Lee, Kelvin P; Pralle, Arnd; Repasky, Elizabeth A

    2015-01-01

    Maintenance of normal core body temperature is vigorously defended by long conserved, neurovascular homeostatic mechanisms that assist in heat dissipation during prolonged, heat generating exercise or exposure to warm environments. Moreover, during febrile episodes, body temperature can be significantly elevated for at least several hours at a time. Thus, as blood cells circulate throughout the body, physiologically relevant variations in surrounding tissue temperature can occur; moreover, shifts in core temperature occur during daily circadian cycles. This study has addressed the fundamental question of whether the threshold of stimulation needed to activate lymphocytes is influenced by temperature increases associated with physiologically relevant increases in temperature. We report that the need for co-stimulation of CD4+ T cells via CD28 ligation for the production of IL-2 is significantly reduced when cells are exposed to fever-range temperature. Moreover, even in the presence of sufficient CD28 ligation, provision of extra heat further increases IL-2 production. Additional in vivo and in vitro data (using both thermal and chemical modulation of membrane fluidity) support the hypothesis that the mechanism by which temperature modulates co-stimulation is linked to increases in membrane fluidity and membrane macromolecular clustering in the plasma membrane. Thermally-regulated changes in plasma membrane organization in response to physiological increases in temperature may assist in the geographical control of lymphocyte activation, i.e., stimulating activation in lymph nodes rather than in cooler surface regions, and further, may temporarily and reversibly enable CD4+ T cells to become more quickly and easily activated during times of infection during fever.

  13. A role for the thermal environment in defining co-stimulation requirements for CD4(+) T cell activation.

    PubMed

    Zynda, Evan R; Grimm, Melissa J; Yuan, Min; Zhong, Lingwen; Mace, Thomas A; Capitano, Maegan; Ostberg, Julie R; Lee, Kelvin P; Pralle, Arnd; Repasky, Elizabeth A

    2015-01-01

    Maintenance of normal core body temperature is vigorously defended by long conserved, neurovascular homeostatic mechanisms that assi