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Sample records for helper integration site-1

  1. T helper 17 cells may drive neuroprogression in major depressive disorder: Proposal of an integrative model.

    PubMed

    Slyepchenko, Anastasiya; Maes, Michael; Köhler, Cristiano A; Anderson, George; Quevedo, João; Alves, Gilberto S; Berk, Michael; Fernandes, Brisa S; Carvalho, André F

    2016-05-01

    The exact pathophysiology of major depressive disorder (MDD) remains elusive. The monoamine theory, which hypothesizes that MDD emerges as a result of dysfunctional serotonergic, dopaminergic and noradrenergic pathways, has guided the therapy of this illness for several decades. More recently, the involvement of activated immune, oxidative and nitrosative stress pathways and of decreased levels of neurotrophic factors has provided emerging insights regarding the pathophysiology of MDD, leading to integrated theories emphasizing the complex interplay of these mechanisms that could lead to neuroprogression. In this review, we propose an integrative model suggesting that T helper 17 (Th17) cells play a pivotal role in the pathophysiology of MDD through (i) microglial activation, (ii) interactions with oxidative and nitrosative stress, (iii) increases of autoantibody production and the propensity for autoimmunity, (iv) disruption of the blood-brain barrier, and (v) dysregulation of the gut mucosa and microbiota. The clinical and research implications of this model are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Helper Hats

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2010-01-01

    Special clothing is worn by "community helpers" such as police officers, nurses, firefighters, cafeteria workers, dentists, and waste management workers as they do their jobs. The special clothing allows workers to be safe. Therefore, exploring how hats help community workers do their jobs can be a way to introduce the idea of how the shape or…

  3. Acute myeloid leukemia with monosomy 7, ectopic virus integration site-1 overexpression and central diabetes insipidus: A case report.

    PubMed

    Ma, Hongbing; Yang, Jing; Xiang, Bing; Jia, Yongqian

    2015-06-01

    Central diabetes insipidus (DI) is a rare complication in patients with acute myeloid leukemia (AML), typically occurring in patients with abnormalities of chromosomes 3 or 7. The association between AML with monosomy 7 and DI has been described in a number of studies; however, DI has been rarely reported in cases of ectopic virus integration site-1 (EVI1)-positive AML with monosomy 7. The current study reports a case of AML with monosomy 7 and EVI1 overexpression, with central DI as the initial symptom. The patient was an 18-year-old female who presented with polyuria and polydipsia. Bone marrow aspiration revealed 83.5% myeloperoxidase-positive blasts without trilineage myelodysplasia. The karyotype was 45,XX,-7, and the patient presented monosomy 7 and EVI1 overexpression (-7/EVI1(+)) without 3q aberration. Treatment with induction therapy was unsuccessful. To the best of our knowledge, this is the second case of DI-AML with -7/EVI1(+) and without a 3q aberration. The possible mechanisms associated with EVI1, monosomy 7 and DI were investigated.

  4. Correction of chromosomal mutation and random integration in embryonic stem cells with helper-dependent adenoviral vectors.

    PubMed

    Ohbayashi, Fumi; Balamotis, Michael A; Kishimoto, Atsuhiro; Aizawa, Emi; Diaz, Arturo; Hasty, Paul; Graham, Frank L; Caskey, C Thomas; Mitani, Kohnosuke

    2005-09-20

    For gene therapy of inherited diseases, targeted integration/gene repair through homologous recombination (HR) between exogenous and chromosomal DNA would be an ideal strategy to avoid potentially serious problems of random integration such as cellular transformation and gene silencing. Efficient sequence-specific modification of chromosomes by HR would also advance both biological studies and therapeutic applications of a variety of stem cells. Toward these goals, we developed an improved strategy of adenoviral vector (AdV)-mediated HR and examined its ability to correct an insertional mutation in the hypoxanthine phosphoribosyl transferase (Hprt) locus in male mouse ES cells. The efficiency of HR was compared between four types of AdVs that contained various lengths of homologies at the Hprt locus and with various multiplicities of infections. The frequency of HR with helper-dependent AdVs (HD AdVs) with an 18.6-kb homology reached 0.2% per transduced cell at a multiplicity of infection of 10 genomes per cell. Detection of random integration at DNA levels by PCR revealed extremely high efficiency of 5% per cell. We also isolated and characterized chromosomal sites where HD AdVs integrated in a random manner. In contrast to retroviral, lentiviral, and adeno-associated viral vectors, which tend to integrate into genes, the integration sites of AdV was distributed randomly inside and outside genes. These findings suggest that HR mediated by HD AdVs is efficient and relatively safe and might be a new viable option for ex vivo gene therapy as well as a tool for chromosomal manipulation of a variety of stem cells.

  5. Expression and survival significance of B-cell-specific Moloney murine leukemia virus integration site 1 and matrix metalloproteinase-9 in non-small-cell lung cancer

    PubMed Central

    Mu, Mingkui; Song, Yang; Zhang, Bin

    2016-01-01

    One of the main challenges in lung cancer research is identifying patients at high risk of progression and metastasis following surgical resection. In the present study, the prognostic significance of B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) and matrix metalloproteinase-9 (MMP9) in non-small-cell lung cancer (NSCLC) was evaluated. BMI1 and MMP9 expression in tumors from 132 surgical NSCLC patients [squamous cell carcinoma (SCC), n=79; and adenocarcinoma (AD), n=53] was evaluated by immunohistochemistry. The clinical significance was determined using multivariate Cox regression analysis, Kaplan-Meier curves and the log-rank test. High BMI1 expression was more frequent in SCC compared with that in AD (P=0.015). Comparisons between the expression of BMI1 and that of other known biological markers revealed that the expression of BMI1 was correlated with that of MMP9 (χ2=4.241, P=0.039) in SCC. Although an association was not identified between high BMI1 expression and overall survival (OS) in NSCLC or AD, high BMI1 expression was an unfavorable predictor of survival in SCC according to the survival curves (P=0.038). In addition, combined high BMI1 and MMP9 expression levels were significantly correlated with SCC nodal/distant metastasis (χ2=6.392, P=0.014). Multivariate Cox proportional model analysis demonstrated that this combined marker was an independent prognostic indicator of OS in SCC (P=0.025; hazard ratio = 12.963; 95% confidence interval: 1.142–7.637). Therefore, this study demonstrated that combined BMI1 and MMP9 expression may be used as a marker for the progression and metastasis of SCC. These results may aid in the elucidation of the potential mechanism underlying the involvement of BMI1 and MMP9 in tissue-specific SCC progression. PMID:27900059

  6. The product of the human AHI-1 (Abelson helper integration site) gene: experimental in vitro data point to its involvement in tumor cell invasion.

    PubMed

    Bozzuto, Giuseppina; Molinari, Agnese

    2017-01-01

    Each of the steps involved in invasion of tumors requires specific molecular program in which the modulation of adhesive and migratory properties of disseminating cells plays an essential role. The improvement in the knowledge of these mechanisms can lead to discovery of new target candidates in drug development. In this study we focused attention on the product of the human AHI-1 (Abelson helper integration site) gene Jouberin (Jbn). In particular, we explore by in vitro invasion assay, AHI-1 knockdown and electron microscopy, if Jbn is involved in the signaling machinery that regulates tumor invasion. To this purpose tumor cells of different histological derivation (brain, breast, skin) were employed. We found that Jbn expression correlates with the proliferation, invasive potential and invasion strategy of the tested tumor cells, and that its downregulation reduces their capability of migrating and invading the extracellular matrix. The results obtained in this study for the first time point to Jbn as a new candidate involved in the invasion process of tumor cells, and as potential molecular target in anticancer therapy.

  7. T helper cell cytotoxicity

    SciTech Connect

    Penna, A.; Glasebrook, A.

    1986-03-01

    It has recently been shown that helper T cells (Lyt2/sup -/, L3T4/sup +/) can express cytolytic activity when activated by antigen (Ag). The authors have studied the phenomenon of T helper cell cytotoxicity using cloned lines of Ag-reactive T cells and T hybrids. Cytotoxicity was determined by coculture of T cells with /sup 51/Cr-labelled Ag presenting cells (APC) and/or non-APC (bystander cells). A high frequency of Ag-specific L3T4/sup +/ T cell clones (> 90%) and hybrids (> 50%) were found to be cytotoxic. Cytotoxicity as determined by /sup 51/Cr release was maximal at 20 hr with little or no cytotoxicity detectable at 6 hr. Target cells, either APC or bystander cells, were killed provided the T cells were stimulated by Ag. Not all of the B cells used as APC were susceptible targets even if able to promote bystander killing. Monoclonal antibodies directed against L3T4, LFA-1 and T cell receptor molecules were able to block the cytotoxicity indicating a requirement for specific activation of the T cells. Cyclosporin A (CsA) reduced the cytotoxic activity of helper T hybrids and clones, while it did not affect the cytotoxic activity of Lyt2/sup +/, L3T4/sup -/ cytolytic T cell (CTL) clones. The delayed expression of cytotoxic activity, the lysis of bystander cells and inhibition by CsA suggest that the cytolytic mechanism is mediated by a soluble factor and different from the cytolytic mechanism of CTL. The phenomenon of cytotoxic T helper cells may be relevant to suppression of B cell immune responses in vivo.

  8. B cell helper assays.

    PubMed

    Abrignani, Sergio; Tonti, Elena; Casorati, Giulia; Dellabona, Paolo

    2009-01-01

    Activation, proliferation and differentiation of naïve B lymphocytes into memory B cells and plasma cells requires engagement of the B cell receptor (BCR) coupled to T-cell help (1, 2). T cells deliver help in cognate fashion when they are activated upon recognition of specific MHC-peptide complexes presented by B cells. T cells can also deliver help in a non-cognate or bystander fashion, when they do not find specific MHC-peptide complexes on B cells and are activated by alternative mechanisms. T-cell dependent activation of B cells can be studied in vitro by experimental models called "B cell helper assays" that are based on the co-culture of B cells with activated T cells. These assays allow to decipher the molecular bases for productive T-dependent B cell responses. We show here examples of B cell helper assays in vitro, which can be reproduced with any subset of T lymphocytes that displays the appropriate helper signals.

  9. Community health workers: examining the Helper Therapy principle.

    PubMed

    Roman, L A; Lindsay, J K; Moore, J S; Shoemaker, A L

    1999-04-01

    A community approach to the integration of health and social services for low-income pregnant women is being addressed through Community Integrated Service System (CISS) initiatives of the Maternal Child Health Bureau. This particular CISS program model was designed to enable low-income mothers to function in a Community Health Worker (CHW) role providing social support for at-risk pregnant women. Using Riessman's notion of "helper therapy," the model was also developed to enhance the potential for CHWs to gain helper benefits. The purpose of this exploratory study was to describe perceived helper benefits and stressors associated with the CHW role and to examine the usefulness of an instrument developed to assess benefits and stressors. The study findings revealed that the majority of CHWs perceived helper benefits that included positive feelings about self, a sense of belonging, valuable work experience, and access to health information and skills through training or contact with program staff. Stressors such as feeling inadequate to help, however, were associated with the helper role for some CHWs. Preliminary analysis of the Helper's Perception Measure indicated that it may be an effective measure and should be tested with a larger sample of CHWs.

  10. 30 CFR 56.7009 - Drill helpers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Drill helpers. 56.7009 Section 56.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7009 Drill helpers. If a drill helper assists the drill operator during movement of a drill...

  11. 30 CFR 57.7009 - Drill helpers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Drill helpers. 57.7009 Section 57.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7009 Drill helpers. If a drill helper assists the drill operator during movement...

  12. 30 CFR 56.7009 - Drill helpers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Drill helpers. 56.7009 Section 56.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7009 Drill helpers. If a drill helper assists the drill operator during movement of a drill...

  13. 30 CFR 56.7009 - Drill helpers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Drill helpers. 56.7009 Section 56.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7009 Drill helpers. If a drill helper assists the drill operator during movement of a drill...

  14. 30 CFR 56.7009 - Drill helpers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drill helpers. 56.7009 Section 56.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7009 Drill helpers. If a drill helper assists the drill operator during movement of a drill...

  15. 30 CFR 57.7009 - Drill helpers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drill helpers. 57.7009 Section 57.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7009 Drill helpers. If a drill helper assists the drill operator during movement...

  16. 30 CFR 57.7009 - Drill helpers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Drill helpers. 57.7009 Section 57.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7009 Drill helpers. If a drill helper assists the drill operator during movement...

  17. 30 CFR 57.7009 - Drill helpers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Drill helpers. 57.7009 Section 57.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7009 Drill helpers. If a drill helper assists the drill operator during movement...

  18. 30 CFR 56.7009 - Drill helpers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Drill helpers. 56.7009 Section 56.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7009 Drill helpers. If a drill helper assists the drill operator during movement of a drill...

  19. 30 CFR 57.7009 - Drill helpers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Drill helpers. 57.7009 Section 57.7009 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7009 Drill helpers. If a drill helper assists the drill operator during movement...

  20. Peer Helpers in Hungary: A Qualitative Analysis

    ERIC Educational Resources Information Center

    Racz, Jozsef; Lacko, Zsuzsa

    2008-01-01

    Hungary is a country in transition that has no real tradition of peer helping. A qualitative study was carried out involving 13 peer helpers of two kinds (a) age-based peers, and (b) way-of-life-based peers (fellow helpers). The motivations for and the processes of becoming a peer helper were analyzed. Results showed the largest difference being…

  1. Peer Helpers in Hungary: A Qualitative Analysis

    ERIC Educational Resources Information Center

    Racz, Jozsef; Lacko, Zsuzsa

    2008-01-01

    Hungary is a country in transition that has no real tradition of peer helping. A qualitative study was carried out involving 13 peer helpers of two kinds (a) age-based peers, and (b) way-of-life-based peers (fellow helpers). The motivations for and the processes of becoming a peer helper were analyzed. Results showed the largest difference being…

  2. General pathologist-helper: The new medical app about general pathology.

    PubMed

    Fernández-Vega, Iván

    2015-01-01

    Smartphone applications (apps) have become increasingly prevalent in medicine. Due to most pathologists, pathology trainees, technicians, and medical students use smartphones; apps can be a different way for general pathology education. "General pathologist-helper (GP-HELPER)" is a novel app developed as a reference tool in general pathology and especially for general pathologists, developed for Android and iOS platforms. "GP-HELPER," was created using Mobincube website platform. This tool also integrates "FORUM GP-HELPER," an external website created using Miarroba website (http://forum-gp-helper.mboards.com) and "COMMUNITY GP-HELPER" a multichannel chat created using Chatango website platform. The application was released in July 2015, and it is been periodically updated since then. The app has permanent information (offline data) about different pathology protocols (TNM latest edition, protocols regarding management of tumors of unknown primary origin, and flowcharts for some of the most difficult tumors to diagnose) and a database with more than 5000 immunohistochemistry results from different tumors. Online data have links to more than 1100 reference pathology video lectures, 250 antibodies information, more than 70 pathology association websites, 46 pathology providers, and 78 outstanding pathology journal websites. Besides this information, the app has two interactive places such as "FORUM GP-HELPER" and "COMMUNITY GP-HELPER" that let users to stay in touch everywhere and every time. Expert consult section is also available. "GP-HELPER" pretends to integrate offline and online data about pathology with two interactive external places in order to represent a reference tool for general pathologists and associate members.

  3. Vector and Helper Genome Rearrangements Occur During Production of Helper-Dependent Adenoviral Vectors

    PubMed Central

    Ahn, Miwon; Gamble, Aisha; Witting, Scott R.; Magrisso, Jack; Surendran, Sneha; Obici, Silvana

    2013-01-01

    Abstract Helper-dependent adenoviral vectors (HD Ad) hold extreme promise for gene therapy of human diseases. All viral genes are deleted in HD Ad vectors, and therefore, the presence of a helper virus is required for their production. Current methods to minimize helper contamination in large-scale preparations rely on the use of the Cre/loxP system. The inclusion of loxP sites flanking the packaging signal results in its excision in the presence of Cre recombinase, preventing helper genome encapsidation. It is well established that the level of Cre recombinase activity is important in determining the degree of helper contamination. However, there is little information on other mechanisms that could also play an important role. We have generated several HD Ad vectors containing a rapalog-inducible system to regulate transgene expression, or LacZ under the control of the elongation factor 1 α promoter. Large-scale production of these vectors resulted in abundant helper contamination. Viral DNA analysis revealed the presence of rearrangements between vector and helper genomes. The rearrangements involved a helper DNA molecule with a fragment of the left arm of the HD Ad vector, including its ITR, packaging signal, and some stuffer sequence. Overall, our data suggest that helper DNA molecules that accumulate after Cre recombinase activity are prone to rearrangements, resulting in helper genomes that have incorporated a packaging signal from the vector. Helper particles with rearranged genomes have a growth advantage. This study identifies a novel mechanism leading to helper contamination during helper-dependent adenoviral vector production. PMID:23249343

  4. Programming perpetual T helper cell plasticity.

    PubMed

    Rowell, Emily; Wilson, Christopher B

    2009-01-16

    In this issue of Immunity,Lee et al. (2009) and Wei et al. (2009) each investigate the stability of T helper cell lineages and find that commitment to these fates is more plastic than previously appreciated.

  5. Doing Good: Counseling and the "Helper's High."

    ERIC Educational Resources Information Center

    Kottler, Jeffrey A.

    1994-01-01

    In support of a previous article entitled "Counseling Endorphins" (CG 546 741), the author addresses the nature of altruism and the "helper's high" as they affect what counselors do with their clients and their lives. (JPS)

  6. Doing Good: Counseling and the "Helper's High."

    ERIC Educational Resources Information Center

    Kottler, Jeffrey A.

    1994-01-01

    In support of a previous article entitled "Counseling Endorphins" (CG 546 741), the author addresses the nature of altruism and the "helper's high" as they affect what counselors do with their clients and their lives. (JPS)

  7. Pharmacoimmunodynamics of Methylprednisolone: Trafficking of Helper T Lymphocytes

    PubMed Central

    Fisher, Lynn E.; Ludwig, Elizabeth A.; Jusko, William J.

    2014-01-01

    A two-compartment closed model was used to characterize the cell trafficking behavior of helper T cells in response to various single doses of methylprednisolone. Steroids are assumed to inhibit the circadian-determined cell return from extravascular sites to blood in a classic inhibitory pattern reflected by an IC50. The rate of cell efflux from tissues is modeled with a cosine function having a period of 24 hr and a maximum at about 1 AM. Nonlinear least-squares regression employing differential equations was used to analyze helper T-cell data from three human studies from our laboratory. The IC50 value of methylprednisolone of 12–19 ng/ml approximates receptor KD values. Simulations were performed to demonstrate the log-linear role of steroid dose or AUC on the integral of effect of helper T cells over a wide range of methylprednisolone doses. This pharmacodynamic model allows flexibility for characterizing any type of steroid dosing regimen and is relevent in describing complex response data for corticosteroid immunosuppressive effects PMID:1479558

  8. Microbiome Helper: a Custom and Streamlined Workflow for Microbiome Research

    PubMed Central

    Comeau, André M.; Douglas, Gavin M.

    2017-01-01

    ABSTRACT Sequence-based approaches to study microbiomes, such as 16S rRNA gene sequencing and metagenomics, are uncovering associations between microbial taxa and a myriad of factors. A drawback of these approaches is that the necessary sequencing library preparation and bioinformatic analyses are complicated and continuously changing, which can be a barrier for researchers new to the field. We present three essential components to conducting a microbiome experiment from start to finish: first, a simplified and step-by-step custom gene sequencing protocol that requires limited lab equipment, is cost-effective, and has been thoroughly tested and utilized on various sample types; second, a series of scripts to integrate various commonly used bioinformatic tools that is available as a standalone installation or as a single downloadable virtual image; and third, a set of bioinformatic workflows and tutorials to provide step-by-step guidance and education for those new to the microbiome field. This resource will provide the foundations for those newly entering the microbiome field and will provide much-needed guidance and best practices to ensure that quality microbiome research is undertaken. All protocols, scripts, workflows, tutorials, and virtual images are freely available through the Microbiome Helper website (https://github.com/mlangill/microbiome_helper/wiki). IMPORTANCE As the microbiome field continues to grow, a multitude of researchers are learning how to conduct proper microbiome experiments. We outline here a streamlined and custom approach to processing samples from detailed sequencing library construction to step-by-step bioinformatic standard operating procedures. This allows for rapid and reliable microbiome analysis, allowing researchers to focus more on their experiment design and results. Our sequencing protocols, bioinformatic tutorials, and bundled software are freely available through Microbiome Helper. As the microbiome research field continues

  9. Cost minimization by helpers in cooperative vertebrates.

    PubMed

    Russell, A F; Sharpe, L L; Brotherton, P N M; Clutton-Brock, T H

    2003-03-18

    When parents invest heavily in reproduction they commonly suffer significant energetic costs. Parents reduce the long-term fitness implications of these costs through increased foraging and reduced reproductive investment in the future. Similar behavioral modifications might be expected among helpers in societies of cooperative vertebrates, in which helping is associated with energetic costs. By using multivariate analyses and experiments, we show that in cooperative meerkats, Suricata suricatta, helping is associated with substantial short-term growth costs but limited long-term fitness costs. This association forms because individual contributions to cooperation are initially condition dependent, and, because when helpers invest heavily in cooperation, they increase their foraging rate during the subsequent nonbreeding period and reduce their level of cooperative investment in the subsequent reproductive period. These results provide a unique demonstration that despite significant short-term costs, helpers, like breeders, are able to reduce the fitness consequences of these costs through behavioral modifications.

  10. Cost minimization by helpers in cooperative vertebrates

    PubMed Central

    Russell, A. F.; Sharpe, L. L.; Brotherton, P. N. M.; Clutton-Brock, T. H.

    2003-01-01

    When parents invest heavily in reproduction they commonly suffer significant energetic costs. Parents reduce the long-term fitness implications of these costs through increased foraging and reduced reproductive investment in the future. Similar behavioral modifications might be expected among helpers in societies of cooperative vertebrates, in which helping is associated with energetic costs. By using multivariate analyses and experiments, we show that in cooperative meerkats, Suricata suricatta, helping is associated with substantial short-term growth costs but limited long-term fitness costs. This association forms because individual contributions to cooperation are initially condition dependent, and, because when helpers invest heavily in cooperation, they increase their foraging rate during the subsequent nonbreeding period and reduce their level of cooperative investment in the subsequent reproductive period. These results provide a unique demonstration that despite significant short-term costs, helpers, like breeders, are able to reduce the fitness consequences of these costs through behavioral modifications. PMID:12629209

  11. Using Peer Helpers for Tuberculosis Prevention.

    ERIC Educational Resources Information Center

    McCue, Maureen; Afifi, Larry Anna

    1996-01-01

    Describes a peer helper program initiated by the University of Iowa Student Health Services to prevent active tuberculosis development among foreign national students. Before instituting the program, compliance with tuberculosis prevention efforts for those students was less than 5%. Since the peer program was instituted, compliance has risen to…

  12. Conflict Resolution and Mediation for Peer Helpers.

    ERIC Educational Resources Information Center

    Sorenson, Don L.

    This book explores conflict resolution strategies and presents a systematic approach to mediation for peer helpers. The first part examines conflict resolution. Internal and external sources of conflict are considered. Irritations, inappropriate expectations, and unknown sources of external conflict are examined. A section on looking inside…

  13. Bricklayer's Helper. Coordinator's Guide. Individualized Study Guide.

    ERIC Educational Resources Information Center

    Barnes, Bill

    This individualized, competency-based study guide is designed to assist teacher-coordinators supervising cooperative education programs for bricklayer's helpers in providing students with general information for immediate reinforcement on the job and developing an understanding of the job prior to employment. A progress chart is provided to allow…

  14. Using Peer Helpers for Tuberculosis Prevention.

    ERIC Educational Resources Information Center

    McCue, Maureen; Afifi, Larry Anna

    1996-01-01

    Describes a peer helper program initiated by the University of Iowa Student Health Services to prevent active tuberculosis development among foreign national students. Before instituting the program, compliance with tuberculosis prevention efforts for those students was less than 5%. Since the peer program was instituted, compliance has risen to…

  15. Electrician's Helper. Coordinator's Guide. Individualized Study Guide.

    ERIC Educational Resources Information Center

    Stotts, Danny

    This guide is designed to assist teacher-coordinators supervising cooperative education programs for electrician's helpers in helping students complete a set of individualized, competency-based training activities dealing with electricity and electrical circuits and equipment. The first part of the manual includes a progress chart, a study guide…

  16. T follicular helper cell diversity and plasticity.

    PubMed

    Cannons, Jennifer L; Lu, Kristina T; Schwartzberg, Pamela L

    2013-05-01

    CD4(+) T helper (Th) cells play an instrumental role in orchestrating adaptive immune responses to invading pathogens through their ability to differentiate into specialized effector subsets. Part of this customized response requires the development of T follicular helper (Tfh) cells, which provide help to B cells for the generation of germinal centers (GCs) and long-term protective humoral responses. Although initially viewed as terminally differentiated, we now recognize that Th cell subsets, including Tfh cells, display substantial flexibility and overlap in their characteristics. In this review, we highlight advances in our understanding of Tfh cell development, cytokine production, and the potential plasticity that allows Tfh cells to possess characteristics of other effector Th cell populations. Published by Elsevier Ltd.

  17. Beyond Helper Phage: Using "Helper Cells" to Select Peptide Affinity Ligands

    PubMed Central

    Shou, Yulin; Schmidt, Emily N.; Paavola, Chad D.; Naranjo, Leslie; Bemdich, Sara; Swanson, Basil I.; Bradbury, Andrew R. M.; Martinez, Jennifer S.

    2016-01-01

    Peptides are important affinity ligands for microscopy, biosensing, and targeted delivery. However, because they can have low affinity for their targets, their selection from large naïve libraries can be challenging. When selecting peptidic ligands from display libraries, it is important to: 1) ensure efficient display; 2) maximize the ability to select high affinity ligands; and 3) minimize the effect of the display context on binding. The “helper cell” packaging system has been described as a tool to produce filamentous phage particles based on phagemid constructs with varying display levels, while remaining free of helper phage contamination. Here we report on the first use of this system for peptide display, including the systematic characterization and optimization of helper cells, their inefficient use in antibody display and their use in creating and selecting from a set of phage display peptide libraries. Our libraries were analyzed with unprecedented precision by standard or deep sequencing, and shown to be superior in quality than commercial gold standards. Using our helper cell libraries, we have obtained ligands recognizing Yersinia pestis surface antigen F1V and L-glutamine-binding periplasmic protein QBP. In the latter case, unlike any of the peptide library selections described so far, we used a combination of phage and yeast display to select intriguing peptide ligands. Based on the success of our selections we believe that peptide libraries obtained with helper cells are not only suitable, but preferable to traditional phage display libraries for selection of peptidic ligands. PMID:27626637

  18. General pathologist-helper: The new medical app about general pathology

    PubMed Central

    Fernández-Vega, Iván

    2015-01-01

    Introduction: Smartphone applications (apps) have become increasingly prevalent in medicine. Due to most pathologists, pathology trainees, technicians, and medical students use smartphones; apps can be a different way for general pathology education. “General pathologist-helper (GP-HELPER)” is a novel app developed as a reference tool in general pathology and especially for general pathologists, developed for Android and iOS platforms. Materials and Methods: “GP-HELPER,” was created using Mobincube website platform. This tool also integrates “FORUM GP-HELPER,” an external website created using Miarroba website (http://forum-gp-helper.mboards.com) and “COMMUNITY GP-HELPER” a multichannel chat created using Chatango website platform. Results: The application was released in July 2015, and it is been periodically updated since then. The app has permanent information (offline data) about different pathology protocols (TNM latest edition, protocols regarding management of tumors of unknown primary origin, and flowcharts for some of the most difficult tumors to diagnose) and a database with more than 5000 immunohistochemistry results from different tumors. Online data have links to more than 1100 reference pathology video lectures, 250 antibodies information, more than 70 pathology association websites, 46 pathology providers, and 78 outstanding pathology journal websites. Besides this information, the app has two interactive places such as “FORUM GP-HELPER” and “COMMUNITY GP-HELPER” that let users to stay in touch everywhere and every time. Expert consult section is also available. Conclusions: “GP-HELPER” pretends to integrate offline and online data about pathology with two interactive external places in order to represent a reference tool for general pathologists and associate members. PMID:26730351

  19. A Web-based home helper support system.

    PubMed

    Ogawa, H; Yonezawa, Y; Maki, H; Hahn, A W; Caldwell, W M

    2001-01-01

    A web-based "Home Helper" support system has been developed for improving scheduling and record keeping efficiency and for eliminating unnecessary travel. This support system consists of a wireless internet mobile phone for each "Home Helper" and a server at the main office. After each visit, the Home Helpers send their care reports via the mobile phone to the office server. This server computer then creates the "filings" automatically and in appropriate format for insurance and government use.

  20. A job analysis of care helpers.

    PubMed

    Shin, Su Jin; Choi, Kyung-Sook; Jeong, Seungeun; Kim, Seulgee; Park, Hyeung-Keun; Seok, Jae Eun

    2012-01-01

    The aim of this study was to examine the roles of care helpers through job analysis. To do this, this study used the Developing A Curriculum Method (DACUM) to classify job content and a multi-dimensional study design was applied to identify roles and create a job description by looking into the appropriateness, significance, frequency, and difficulty of job content as identified through workshops and cross-sectional surveys conducted for appropriateness verification. A total of 418 care helpers working in nursing facilities and community senior service facilities across the country were surveyed. The collected data were analyzed using PASW 18.0 software. Six duties and 18 tasks were identified based on the job model. Most tasks were found to be "important task", scoring 4.0 points or above. Physical care duties, elimination care, position changing and movement assistance, feeding assistance, and safety care were identified as high frequency tasks. The most difficult tasks were emergency prevention, early detection, and speedy reporting. A summary of the job of care helpers is providing physical, emotional, housekeeping, and daily activity assistance to elderly patients with problems in independently undertaking daily activities due to physical or mental causes in long-term care facilities or at the client's home. The results of this study suggest a task-focused examination, optimizing the content of the current standard teaching materials authorized by the Ministry of Health and Welfare while supplementing some content which was identified as task elements but not included in the current teaching materials and fully reflecting the actual frequency and difficulty of tasks.

  1. A job analysis of care helpers

    PubMed Central

    Choi, Kyung-Sook; Jeong, Seungeun; Kim, Seulgee; Park, Hyeung-Keun; Seok, Jae Eun

    2012-01-01

    The aim of this study was to examine the roles of care helpers through job analysis. To do this, this study used the Developing A Curriculum Method (DACUM) to classify job content and a multi-dimensional study design was applied to identify roles and create a job description by looking into the appropriateness, significance, frequency, and difficulty of job content as identified through workshops and cross-sectional surveys conducted for appropriateness verification. A total of 418 care helpers working in nursing facilities and community senior service facilities across the country were surveyed. The collected data were analyzed using PASW 18.0 software. Six duties and 18 tasks were identified based on the job model. Most tasks were found to be "important task", scoring 4.0 points or above. Physical care duties, elimination care, position changing and movement assistance, feeding assistance, and safety care were identified as high frequency tasks. The most difficult tasks were emergency prevention, early detection, and speedy reporting. A summary of the job of care helpers is providing physical, emotional, housekeeping, and daily activity assistance to elderly patients with problems in independently undertaking daily activities due to physical or mental causes in long-term care facilities or at the client's home. The results of this study suggest a task-focused examination, optimizing the content of the current standard teaching materials authorized by the Ministry of Health and Welfare while supplementing some content which was identified as task elements but not included in the current teaching materials and fully reflecting the actual frequency and difficulty of tasks. PMID:22323929

  2. Strategic growth decisions in helper cichlids.

    PubMed Central

    Heg, Dik; Bender, Nicole; Hamilton, Ian

    2004-01-01

    Recently, it has been shown that group-living subordinate clownfish Amphiprion percula increase their growth rate after acquiring the dominant breeder male position in the group. Evidence was found for strategic growth adjustments of subordinate fishes depending on the threat of eviction, i.e. subordinates adjust their growth rates so they remain smaller than the dominant fish and thereby limit the threat of being expelled from the territory. However, it is impossible to exclude several alternative factors that potentially could have influenced the observed changes in growth, owing to the nature of that experiment (removing the second-ranking fish--the breeder male--caused the third-ranking fish to change sex to become breeder male and change rank). We studied strategic growth decisions in the group-living Lake Tanganyika cichlid Neolamprologus pulcher under controlled laboratory conditions with ad libitum food availability. First, we show that male breeders grow faster than subordinate male helpers of the same initial size and confirm that N. pulcher shows status-dependent growth. Second, we improved on the experimental design by not removing the dominant breeder male in the group; instead we replaced the breeder male with a new breeder male in a full factorial design and measured growth of the subordinate male helpers is a function of the size difference with the old and the new breeder male. As predicted, male helpers showed strategic growth adjustments, i.e. growing faster when the size difference with the breeder male is large. Strategic growth adjustments were less pronounced than status-dependent growth adjustments. PMID:15801617

  3. Regulatory mechanisms of helper T cell differentiation

    PubMed Central

    Pappu, Bhanu P.; Angkasekwinai, Pornpimon; Dong, Chen

    2008-01-01

    Interleukin 17 (IL-17) family consists of six cytokines in mammals. Among them, IL-17 and IL-17F are expressed by a novel subset of CD4+ helper T (Th) cells and play critical function in inflammation and autoimmunity. On the other hand, IL-17E, also called IL-25, has been associated with allergic responses. Here we summarize recent work by us as well as other investigators in understanding the regulation and function of these three cytokines. From these studies, IL-17 family cytokines may serve as novel targets for pharmaceutical intervention of immune and inflammatory diseases. PMID:18280574

  4. Beyond helper phage: Using "helper cells" to select peptide affinity ligands

    DOE PAGES

    Phipps, Mary Lisa; Lillo, Antoinetta M.; Shou, Yulin; ...

    2016-09-14

    Peptides are important affinity ligands for microscopy, biosensing, and targeted delivery. However, because they can have low affinity for their targets, their selection from large naïve libraries can be challenging. When selecting peptidic ligands from display libraries, it is important to: 1) ensure efficient display; 2) maximize the ability to select high affinity ligands; and 3) minimize the effect of the display context on binding. The “helper cell” packaging system has been described as a tool to produce filamentous phage particles based on phagemid constructs with varying display levels, while remaining free of helper phage contamination. Here we report onmore » the first use of this system for peptide display, including the systematic characterization and optimization of helper cells, their inefficient use in antibody display and their use in creating and selecting from a set of phage display peptide libraries. Our libraries were analyzed with unprecedented precision by standard or deep sequencing, and shown to be superior in quality than commercial gold standards. Using our helper cell libraries, we have obtained ligands recognizing Yersinia pestis surface antigen F1V and L-glutamine-binding periplasmic protein QBP. In the latter case, unlike any of the peptide library selections described so far, we used a combination of phage and yeast display to select intriguing peptide ligands. Here, based on the success of our selections we believe that peptide libraries obtained with helper cells are not only suitable, but preferable to traditional phage display libraries for selection of peptidic ligands.« less

  5. Construction of a helper cell line for avian reticuloendotheliosis virus cloning vectors

    SciTech Connect

    Watanabe, S.; Temin, H.M.

    1983-12-01

    The authors wished to construct cell lines that supply the gene products of gag, pol, and env for the growth of replication-defective reticuloendotheliosis retrovirus vectors without production of the helper virus. To do this, first they located by S1 mapping the donor and acceptor splice sites of reticuloendotheliosis virus strain A. The donor splice site is ca. 850 base pairs from the 5' end of proviral DNA. It is close to or overlaps the encapsidation sequences for viral RNA. The splice acceptor site is ca. 5.6 kilobase pairs from the 5' end of proviral DNA. Therefore, the encapsidation sequences and the donor splice site were removed from viral DNA to give expression of the gag and pol genes without virus production. The promoter in the long terminal repeat was fused to a site near the first ATG codon of the env gene, thereby deleting the encapsidation sequences and the gag and pol genes to give expression of the env gene without virus production. The permissive canine cell line D17 was transfected with the two modified viral DNAs. Two cell clones that contain both modified viral DNAs support the production of replication-defective spleen necrosis virus-thymidine kinase recombinant retrovirus vectors without the production of helper virus. To prevent recombination, the vector contains deletions that overlap with deletions in the integrated helper virus DNAs. This helper cell-vector system will be useful to derive infectious recombinant virus stocks of high titer (over 10/sup 5/ thymidine kinase transforming units per ml) which are able to infect avian, rat, and dog cells without the aid of helper virus.

  6. Role of Natural Helpers in Preventing Child Abuse and Neglect.

    ERIC Educational Resources Information Center

    Ballew, Julius R.

    1985-01-01

    Examines social isolation and the use of informal helping networks of families (N=130) at risk for child abuse or neglect. Preventive service workers' (N=13) responses to a natural helper survey revealed that friends, relatives, and neighbors are potential helpers for such families and are effective in resolving problems they address. (NRB)

  7. Managing Stress and Burnout among Helpers in Rural Areas.

    ERIC Educational Resources Information Center

    Reed, John C.

    Individuals who work in the helping professions (physicians, counselors, nurses, pastors, and social workers) often work with individuals in stressful crisis situations. In addition to working in high stress situations, helpers in rural areas also suffer from isolation from support networks and peers that are available to urban helpers. This…

  8. Welder's Helper. Coordinator's Guide. Individualized Study Guide. General Metal Trades.

    ERIC Educational Resources Information Center

    Dean, James W.

    This guide provides information to enable coordinators to direct learning activities for students using an individualized study guide on being a welder's helper. The study material is designed for students enrolled in cooperative part-time training and employed, or desiring to be employed, as welders' helpers. Contents include a sample progress…

  9. Welder's Helper. Coordinator's Guide. Individualized Study Guide. General Metal Trades.

    ERIC Educational Resources Information Center

    Dean, James W.

    This guide provides information to enable coordinators to direct learning activities for students using an individualized study guide on being a welder's helper. The study material is designed for students enrolled in cooperative part-time training and employed, or desiring to be employed, as welders' helpers. Contents include a sample progress…

  10. Crisis Intervention Strategies for School-Based Helpers. Second Edition.

    ERIC Educational Resources Information Center

    Fairchild, Thomas N., Ed.

    School-based helpers are helping professionals who work within educational settings and whose training and primary responsibility is to promote the mental health of students. Few resource materials provide these helpers with needed information and practical strategies--this text tries to meet that need. The 12 chapters here cover a wide range of…

  11. SPARK Peer Helper Program, 1993-94. OER Report.

    ERIC Educational Resources Information Center

    Goldberg, Phyllis

    The Peer Helper Program was administered by Substance Prevention, Abuse Rehabilitation, and Knowledge (SPARK). Since its beginning in 1971, SPARK has addressed issues such as drug use, teenage pregnancy, HIV/AIDS, sexual abuse and other forms of violence. The Peer Helper Program was designed to train students in the skills required to assist peers…

  12. IL-1 and T Helper Immune Responses

    PubMed Central

    Santarlasci, Veronica; Cosmi, Lorenzo; Maggi, Laura; Liotta, Francesco; Annunziato, Francesco

    2013-01-01

    CD4 T cells play a critical role in mediating adaptive immunity to a variety of pathogens as well as in tumor immunity. If not adequately regulated, CD4 T cells can be also involved in autoimmunity, asthma, and allergic responses. During TCR activation in a particular cytokine milieu, naïve CD4 T cells may differentiate into one of several lineages of T helper (Th) cells, including Th1, Th2, and Th17, as defined by their pattern of cytokine production and function. IL-1, the prototypic proinflammatory cytokine, has been shown to influence growth and differentiation of immunocompetent lymphocytes. The differential expression of IL-1RI on human CD4 T cell subsets confers distinct capacities to acquire specific effector functions. In this review, we summarize the role of IL-1 on CD4 T cells, in terms of differentiation, activation, and maintenance or survival. PMID:23874332

  13. Helpers increase the reproductive potential of offspring in cooperative meerkats.

    PubMed

    Russell, A F; Young, A J; Spong, G; Jordan, N R; Clutton-Brock, T H

    2007-02-22

    In both animal and human societies, individuals may forego personal reproduction and provide care to the offspring of others. Studies aimed at investigating the adaptive nature of such cooperative breeding systems in vertebrates typically calculate helper 'fitness' from relationships of helper numbers and offspring survival to independence. The aim of this study is to use observations and supplemental feeding experiments in cooperatively breeding meerkats, Suricata suricatta, to investigate whether helpers influence the long-term reproductive potential of offspring during adulthood. We show that helpers have a significant and positive influence on the probability that offspring gain direct reproductive success in their lifetimes. This effect arises because helpers both reduce the age at which offspring begin to reproduce as subordinates and increase the probability that they will compete successfully for alpha rank. Supplemental feeding experiments confirm the causality of these results. Our results suggest that one can neither discount the significance of helper effects when none is found nor necessarily estimate accurately the fitness benefit that helpers accrue, unless their effects on offspring are considered in the long term.

  14. Helpers increase the reproductive potential of offspring in cooperative meerkats

    PubMed Central

    Russell, A.F; Young, A.J; Spong, G; Jordan, N.R; Clutton-Brock, T.H

    2006-01-01

    In both animal and human societies, individuals may forego personal reproduction and provide care to the offspring of others. Studies aimed at investigating the adaptive nature of such cooperative breeding systems in vertebrates typically calculate helper ‘fitness’ from relationships of helper numbers and offspring survival to independence. The aim of this study is to use observations and supplemental feeding experiments in cooperatively breeding meerkats, Suricata suricatta, to investigate whether helpers influence the long-term reproductive potential of offspring during adulthood. We show that helpers have a significant and positive influence on the probability that offspring gain direct reproductive success in their lifetimes. This effect arises because helpers both reduce the age at which offspring begin to reproduce as subordinates and increase the probability that they will compete successfully for alpha rank. Supplemental feeding experiments confirm the causality of these results. Our results suggest that one can neither discount the significance of helper effects when none is found nor necessarily estimate accurately the fitness benefit that helpers accrue, unless their effects on offspring are considered in the long term. PMID:17476771

  15. A new typology of home-care helpers.

    PubMed

    Porter, Eileen J; Ganong, Lawrence H; Drew, Nancy; Lanes, Tracy I

    2004-12-01

    The formal-informal dichotomy of home care, which has been a theoretical framework in quantitative and qualitative research, might not be descriptive of older persons' views about their home-care providers. This qualitative study explores the perspectives of older women about the characteristics of their home-care providers. Three interviews were conducted with each of 25 women (aged 80-94 years) during the first 4 months of participation in a 3-year phenomenological study. The women described their helpers. We differentiated helper types on the basis of the nature of the help, and we explored variations in compensation arrangements. We delineated a new typology of home-care helpers: regular helpers, on-call helpers, can-will doers, and mainstays. When home-care helpers are categorized by type of assistance provided, the potential value of their efforts is more evident. The association of formal care with paid help and informal care with nonpaid help limits the effectiveness of the dichotomy as a basis for home-care-payment policies. The new home-care-helper typology cuts across the dimensions of the dichotomy, providing an alternative theoretical framework for further research.

  16. A Comparative Analysis of Trained and Untrained Helpers' Communication Behaviors in Response to Crisis.

    ERIC Educational Resources Information Center

    DeWine, Sue; Miller, Larry D.

    A study was designed to compare the verbal responses of trained and untrained helpers confronted with the same crisis situation. The subjects were 24 trained graduate helpers, 24 untrained graduate helpers, and 24 untrained undergraduate helpers. Each subject was paired with an actor in one of the following conditions: male actor with male…

  17. Effects of helpers on juvenile development and survival in meerkats.

    PubMed

    Clutton-Brock, T H; Russell, A F; Sharpe, L L; Brotherton, P N; McIlrath, G M; White, S; Cameron, E Z

    2001-09-28

    Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups.

  18. 14. BRIDGE TENDER ALBERT REEVES (RIGHT) AND YOUTHFUL HELPER (WALLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. BRIDGE TENDER ALBERT REEVES (RIGHT) AND YOUTHFUL HELPER (WALLY HALES), HANDLING HUGE 'KEY' TO WIND OPEN THE CENTER SWING SPAN. - Maurice River Pratt Through-Truss Swing Bridge, Spanning Maurice River, Mauricetown, Cumberland County, NJ

  19. Herpesviruses provide helper functions for avian adeno-associated parvovirus.

    PubMed

    Bauer, H J; Monreal, G

    1986-01-01

    The avian herpesviruses infectious laryngotracheitis virus (ILTV) and herpesvirus of turkeys (HVT), as well as the mammalian herpesvirus pseudorabies virus (PRV) were able to provide complete helper activity for the production of infectious avian adeno-associated virus (AAAV) in chicken cells. The presence of AAAV in the infected chicken cell reduced the multiplication of HVT. ILTV or PRV, however, were not affected if used as helper viruses. Infectious AAAV was determined by an indirect immunofluorescence assay and infectious herpesvirus by plaque assays.

  20. Transcriptional and epigenetic networks that drive helper T cell identities

    PubMed Central

    Shih, Han-Yu; Sciumè, Giuseppe; Poholek, Amanda C; Vahedi, Golnaz; Hirahara, Kiyoshi; Villarino, Alejandro V; Bonelli, Michael; Bosselut, Remy; Kanno, Yuka; Muljo, Stefan A; O’Shea, John J.

    2014-01-01

    The discovery of the specification of CD4+ helper T cells to discrete effector “lineages” represented a watershed event in conceptualizing mechanisms of host defense and immunoregulation. However, our appreciation for the actual complexity of helper T cell subsets continues unabated. Just as the Sami language of Scandinavia has 1000 different words for reindeer, the range of fates available for a CD4+ T cell is numerous and may be underestimated. Added to the crowded scene for helper T cell subsets is the continuously growing family of innate lymphoid cells (ILCs), endowed with common effector responses and the previously defined “master regulators” for CD4+ helper T cell subsets are also shared by ILC subsets. Within the context of this extraordinary complexity are concomitant advances in the understanding of transcriptomes and epigenomes. So what do terms like “lineage commitment” and helper T cell “specification” mean in the early 21st century? How do we put all of this together in a coherent conceptual framework? It would be arrogant to assume that we have a sophisticated enough understanding to seriously answer these questions. Instead, we will review the current status of the flexibility of helper T cell responses in relation to their genetic regulatory networks and epigenetic landscapes. Recent data have provided major surprises as to what master regulators can or cannot do, how they interact with other transcription factors and impact global genome-wide changes and how all these factors come together to influence helper cell function. PMID:25123275

  1. Variation in helper effort among cooperatively breeding bird species is consistent with Hamilton's Rule.

    PubMed

    Green, Jonathan P; Freckleton, Robert P; Hatchwell, Ben J

    2016-08-24

    Investment by helpers in cooperative breeding systems is extremely variable among species, but this variation is currently unexplained. Inclusive fitness theory predicts that, all else being equal, cooperative investment should correlate positively with the relatedness of helpers to the recipients of their care. We test this prediction in a comparative analysis of helper investment in 36 cooperatively breeding bird species. We show that species-specific helper contributions to cooperative brood care increase as the mean relatedness between helpers and recipients increases. Helper contributions are also related to the sex ratio of helpers, but neither group size nor the proportion of nests with helpers influence helper effort. Our findings support the hypothesis that variation in helping behaviour among cooperatively breeding birds is consistent with Hamilton's rule, indicating a key role for kin selection in the evolution of cooperative investment in social birds.

  2. Variation in helper effort among cooperatively breeding bird species is consistent with Hamilton's Rule

    PubMed Central

    Green, Jonathan P.; Freckleton, Robert P.; Hatchwell, Ben J.

    2016-01-01

    Investment by helpers in cooperative breeding systems is extremely variable among species, but this variation is currently unexplained. Inclusive fitness theory predicts that, all else being equal, cooperative investment should correlate positively with the relatedness of helpers to the recipients of their care. We test this prediction in a comparative analysis of helper investment in 36 cooperatively breeding bird species. We show that species-specific helper contributions to cooperative brood care increase as the mean relatedness between helpers and recipients increases. Helper contributions are also related to the sex ratio of helpers, but neither group size nor the proportion of nests with helpers influence helper effort. Our findings support the hypothesis that variation in helping behaviour among cooperatively breeding birds is consistent with Hamilton's rule, indicating a key role for kin selection in the evolution of cooperative investment in social birds. PMID:27554604

  3. Helper-dependent vs. helper-independent CTL responses in HIV infection: implications for drug therapy and resistance.

    PubMed

    Wodarz, D

    2001-12-07

    Clinical data from HIV-infected patients, as well as theoretical studies, suggest that CTL responses in the presence and absence of CD4 cell help are qualitatively different. In the presence of help, CTL responses are maintained despite very low antigenic loads and control the infection in the long term. In the absence of specific helper cell responses, CTL require high antigenic loads to be maintained, are short lived at low levels of antigen, and do not control the infection in the long term. This paper describes mathematical models analysing the dynamics of helper-dependent and helper-independent CTL in HIV infection with special focus on the dynamics during drug therapy in chronic infection. Theory suggests that a fast rate of virus spread results in high degrees of helper cell impairment which promotes the development of helper-independent CTL responses and compromised immunological control. In agreement with clinical findings, the model suggests that upon start of therapy, there is a transient increase in the level of CTL, followed by a decline to low levels once virus load has been significantly suppressed. According to the model, the presence of helper-independent CTL can promote the establishment of a helper-dependent memory response. Interestingly, this gives rise to the prediction that a relatively early stop of therapy, before the level of CTL has fallen below a threshold, can promote improved immunological control. Issues concerning the timing and duration of treatment are discussed. The CTL kinetics during drug therapy also provide new insights into the principles underlying the emergence of drug-resistant strains during the course of treatment. Copyright 2001 Academic Press.

  4. T follicular helper cell programming by cytokine-mediated events.

    PubMed

    Read, Kaitlin A; Powell, Michael D; Oestreich, Kenneth J

    2016-11-01

    CD4(+) T cells, or T helper cells, are critical mediators and coordinators of adaptive immunity. Unique effector T helper cell populations have been identified that perform distinct functions in response to pathogenic infection. The T follicular helper (Tfh) cells are one such subset, which has been identified as the primary T-cell population responsible for interacting with B cells to promote effective antibody-mediated immune responses. Since their initial description at the turn of the century, and subsequent classification as a distinct T helper cell subset, there has been substantial interest in elucidating the regulatory mechanisms that govern Tfh cell formation. The collective insight from this body of work has demonstrated that Tfh cell differentiation is a complex and multistage process regulated by a litany of cell-intrinsic and cell-extrinsic factors. As with the development of the other recognized T helper cell subsets, specific cytokines exercise prominent roles in both the positive and negative regulation of Tfh cell development. However, the exact composition of, and stage-specific requirements for, these environmental factors in the governance of Tfh cell differentiation remain incompletely understood. In this review, we summarize what is known regarding the role of cytokines in both the promotion and inhibition of Tfh cell differentiation and function. © 2016 John Wiley & Sons Ltd.

  5. Development of a size-restricted pIX-deleted helper virus for amplification of helper-dependent adenovirus vectors.

    PubMed

    Sargent, K L; Ng, P; Evelegh, C; Graham, F L; Parks, R J

    2004-03-01

    Helper-dependent adenovirus vectors (hdAd), which are deleted of all viral protein-coding sequences, can mediate long-term expression of a therapeutic transgene and lead to life-long, phenotypic correction in animal models of genetic disease. Here, we describe a new system for the generation of hdAd, which utilizes the DNA size restrictions imposed on an Ad virion deleted of protein IX (pIX): such virions are reported to package up to only approximately 35 kb of viral DNA. A pIX(-) helper virus (approximately 37.3 kb) was easily grown on complementing 293pIX cells. Upon infection of noncomplementing cells, this virus was not capable of forming infectious virions, but provided replicative and packaging functions for propagation of a 30-kb hdAd. The pIX(-) helper virus was effective in amplifying an hdAd and, in combination with Cre-mediated excision in the viral-packaging signal, resulted in a 1000-fold reduction in helper virus contamination in hdAd stocks compared to Cre/lox alone, as determined by plaque assay. However, through slot blot analysis of DNA isolated from virions, we determined that the ratio of hdAd to helper DNA was 500:1, similar to the ratio observed when using Cre/lox alone. Surprisingly, a large amount of the 37.3-kb helper DNA was being packaged into the pIX-deleted virions, but these virions were incapable of establishing productive infections in plaque assays, for reasons which are still unclear. Nevertheless, the pIX(-) hdAd generated in this system infected cells and expressed a transgene at levels similar to those obtained with a pIX(+) hdAd. These data suggest that, although further studies are necessary to characterize the nature of the defective helper virions formed in this system, deletion of pIX from the helper virus genome does provide an effective method to prevent recovery of functional helper virus during hdAd amplification.

  6. Characterization of a human antigen specific helper factor

    SciTech Connect

    Richardson, B.

    1986-03-01

    While antigen (Ag) specific helper factors have been characterized in mice, similar molecules have not been identified in humans. To characterize human antigen specific helper molecules, an IL-2 dependent tetanus toxoid (T.T.) reactive T cell line was fused with a 6-thioguanine resistant CEM line, and hybrids selected in medium containing hypoxanthine and azaserine. Hybrids were screened by culturing the cells with /sup 35/S-Met then reacting the supernatants with T.T. or hepatitis vaccine immobilized on nitrocellulose. One hybrid, TT6BA-O, was identified which secreted a Met-containing molecule which bound T.T. but not hepatitis vaccine. Supernatants from TT6BA-O, but not the parent CEM line, when added to autologous peripheral blood mononuclear cells (PBMC's) stimulated secretion of T.T. specific antibodies (Abs). Specificity controls demonstrated that TT6BA-O supernatant did not induce antibodies to diphtheria toxoid, hepatitis vaccine or pneumococcal polysaccharide, and total immunoglobulin (lg) synthesis was minimally increased. In contrast, pokeweed mitogen stimulated significant lg synthesis as well as Ab's to pneumococcal polysaccharide and T.T. TT6BA-O supernatant induced anti-T.T.Ab's in autologous PBMC's but not PBMC's from 3 unrelated donors, suggesting that the activity of the helper factor is restricted, possibly by the MHC. The molecular weight of the helper factor was estimated at 100,000-150,000 by Sephacryl S-300 chromatography. Finally, the helper factor could be demonstrated to bind and elute from sephorose-immobilized T.T. and anti-DR antisera, but not anti-lg antisera or the T40/25 monoclonal antibody, which binds a nonpolymorphic determinant on the human T cell receptor. These results demonstrate that human Ag specific helper factors exist, bind antigen and bear class II MHC determinants.

  7. 29 CFR 570.52 - Occupations of motor-vehicle driver and outside helper (Order 2).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Occupations of motor-vehicle driver and outside helper... Health or Well-Being § 570.52 Occupations of motor-vehicle driver and outside helper (Order 2). (a... motor-vehicle driver and outside helper on any public road, highway, in or about any mine...

  8. 29 CFR 570.52 - Occupations of motor-vehicle driver and outside helper (Order 2).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Occupations of motor-vehicle driver and outside helper... Health or Well-Being § 570.52 Occupations of motor-vehicle driver and outside helper (Order 2). (a... motor-vehicle driver and outside helper on any public road, highway, in or about any mine...

  9. 29 CFR 570.52 - Occupations of motor-vehicle driver and outside helper (Order 2).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Occupations of motor-vehicle driver and outside helper... Health or Well-Being § 570.52 Occupations of motor-vehicle driver and outside helper (Order 2). (a... motor-vehicle driver and outside helper on any public road, highway, in or about any mine...

  10. Family Caregiving or Caregiving Alone: Who Helps the Helper?

    ERIC Educational Resources Information Center

    Sims-Gould, Joanie; Martin-Matthews, Anne

    2007-01-01

    This study advances the understanding of family caregiving by examining the relationship between adult children caregivers and their helpers. Specifically, it focuses on examining "who helps whom" and extends analyses beyond the dyadic focus of caregiving in later life. The focus on helping and caregiving addresses the variety of…

  11. Communicating bad news: a model for emergency mental health helpers.

    PubMed

    Nardi, Thomas J; Keefe-Cooperman, Kathleen

    2006-01-01

    This article addresses the concerns of the messenger/helper who must convey tragic news to individuals and families. It offers a model to be used as a guide to ease the stress on both the deliverer and receiver of bad news. The model uses the mnemonic, PEWTER (Prepare, Evaluate, Warn, Tell, Emotional Response, Regroup), to represent the six components of the communication process.

  12. 15. BRIDGE TENDER ALBERT REEVES OF MAURICETOWN AND HELPER WALLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. BRIDGE TENDER ALBERT REEVES OF MAURICETOWN AND HELPER WALLY HALES HOLDING HUGE KEY ABOVE HOLE IN DECK OF CENTER SWING SPAN TO REVEAL KEY BASETHE KEY IS SET UPON A MALE FITTING USED TO OPEN THE SPAN - Maurice River Pratt Through-Truss Swing Bridge, Spanning Maurice River, Mauricetown, Cumberland County, NJ

  13. Natural Helpers: A Study of Primary Caregivers among Migrant Women.

    ERIC Educational Resources Information Center

    Greenfield, Wilma L.

    Natural helpers exist even among the most oppressed populations in this country, particularly migrant women, and recognition of their helping networks can give professional caregivers access to a resource that is often more adaptive, more efficient, and more humane than many static, impersonal, and obsolete human service bureaucracies. Migrant…

  14. 49 CFR 232.219 - Double heading and helper service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER... a train, a visual inspection shall be made of each helper locomotive brake system to determine that the brake system operates as intended in response to a 20-psi reduction initiated from the controlling...

  15. 49 CFR 232.219 - Double heading and helper service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER... a train, a visual inspection shall be made of each helper locomotive brake system to determine that the brake system operates as intended in response to a 20-psi reduction initiated from the controlling...

  16. 49 CFR 232.219 - Double heading and helper service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER... a train, a visual inspection shall be made of each helper locomotive brake system to determine that the brake system operates as intended in response to a 20-psi reduction initiated from the controlling...

  17. Supervising Helpers Who Work with the Trauma of Sexual Abuse

    ERIC Educational Resources Information Center

    Etherington, Kim

    2009-01-01

    This paper contributes to the ongoing discussion in this journal about counsellors' experiences of vicarious traumatisation (Sexton, 1999; Dunkley & Whelan, 2006a, b). It builds on my previous paper (Etherington, 2000a) that focused on the role of supervision in moderating the potential impact on helpers, and on the helping relationship, of…

  18. A fine romance: T follicular helper cells and B cells.

    PubMed

    King, Cecile

    2011-06-24

    T follicular helper (Tfh) cells help B cells to generate affinity-matured antibodies. Three papers in this issue of Immunity (Choi et al., 2011; Kerfoot et al., 2011; Kitano et al., 2011) provide information about the reciprocal relationship between B cells and Tfh cells.

  19. HEATER'S HELPER OPERATING PUSHER. HOT BILLETS ON CONVEYOR MOVE TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HEATER'S HELPER OPERATING PUSHER. HOT BILLETS ON CONVEYOR MOVE TO OPENING AT THE HEAD OF THE 12" MILL. PUSHER (ELECTRICALLY OPERATED) MOVES BILLETS INTO READY POSITION FOR 12" MILL. - Cambria Iron Company, Gautier Works, 12" Mill, Clinton Street & Little Conemaugh River, Johnstown, Cambria County, PA

  20. [Helper viruses of adeno-associated virus type 4 replication].

    PubMed

    Dreĭzin, R S; Zhuravel', T F; Shalunova, N V; Klenova, A V; Zolotarskaia, E E

    1979-01-01

    In replication of adeno-associated virus type 4 (AAV-4) the helper function may be performed by a non-defective virus from the same group of parvoviruses (Kilham virus). The synthesis of AAV-4 antigen was observed in a pig embryo kidney cell line, SPEV, chronically infected with Kilham virus, strain RV-13, 45--52 passages. A one-day-old SPEV-Kilham culture was infected with AAV-4. The AAV-4 antigen was detected by immunofluorescence at 6, 8, 12, 18 hours, 2, 3, 4, and 5 days after inoculation. During the first 2--4 days after inoculation the AAV-4 antigen was found in the nucleus and perinuclear zone, later in the cytoplasm. A "new" helper virus for AAV-4 replication has been found: simiancytomegalovirus in human embryo fibroblast cell culture permissive for the helper virus. In the systems where AAV-4 replicates, its antigen can be detected in the nucleus and perinuclear zone by IF. AAV-4 did not replicate in a system insensitive to the helper virus or under non-permissive conditions: at the time, the AAV-4 antigen localized only in the cell cytoplasm was detected.

  1. Peer helpers' struggles to care for "others" who inject drugs.

    PubMed

    Dechman, Margaret Kathleen

    2015-05-01

    Users who access needle exchanges are sometimes recruited to act as secondary distributors in an effort to reach a broader range of individuals who inject drugs. Although evaluations have demonstrated the efficiency of such approaches, more recent research has begun to uncover particular challenges associated with assuming these intermediary roles. This article provides insights drawn from four focus-group sessions with 17 volunteers, termed natural helpers, who have between 1 and 14 years experience acting as secondary distributors for an Atlantic Canadian needle exchange. From the perspective of the natural helpers involved in this research, medical professionals consider those who inject drugs to be undeserving of the care accorded to more "responsible" patients. As a consequence of such disenfranchisement, natural helpers find themselves drawn into many forms of informal "doctoring" that extend far beyond their official roles as secondary distribution agents. In addition to providing syringes, training new users in safe injection procedures and promoting the use of sterile equipment, natural helpers try to dissuade people from starting to inject, act as first responders for overdoses, test drug potency, administer first aid, share prescription drugs such as antibiotics, offer temporary housing, counsel on emotional/psychological issues, and support those who are striving to reduce their drug consumption. The practices that have arisen in response to the distancing from professional health care experienced by those who inject drugs pose serious dilemmas and risks for not only users and natural helpers but also the general public. Copyright © 2015 The Author. Published by Elsevier B.V. All rights reserved.

  2. From interleukin-23 to T-helper 17 cells: human T-helper cell differentiation revisited

    PubMed Central

    Boniface, Katia; Blom, Bianca; Liu, Yong-Jun; Malefyt, René de Waal

    2013-01-01

    Summary Protracted inflammation leading to dysregulation of effector T-cell responses represents a common feature of a wide range of autoimmune diseases. The interleukin-12 (IL-12)/T-helper 1 (Th1) pathway was thought to be responsible for the pathogenesis of multiple chronic inflammatory diseases, including psoriasis, inflammatory bowel disease, arthritis, or multiple sclerosis, mainly through their production of interferon-γ and its effects on macrophage activation and chemokine production. However, this initial concept of T-cell-mediated chronic inflammation required an adjustment with the discovery of an IL-12-related cytokine, designated IL-23. IL-23 was rapidly recognized for its involvement in the establishment of chronic inflammation and in the development of a Th cell subset producing IL-17, designated Th17, which is distinct from the previously reported Th1 and Th2 populations. This review aims to describe the characterization of IL-23 and its receptor, its biological activities, as well as its involvement in the development of human Th17 cells and autoimmunity. PMID:19161421

  3. Development of natural helper characteristic scale (NHCS): an instrument for identifying natural helpers for health area in Thai context.

    PubMed

    Neelapaichit, Nareemarn; Tanasugarn, Chanuantong; Wattanasomboon, Paranee; Chansatitporn, Natkamol

    2013-12-01

    Volunteerism in health through cadres of village health volunteers (VHV) has been common since the "health for all" campaign. At present, with political support, the VHV receives monthly financial support, and this creates a conflict of interest and competition among the VHV groups. Therefore, a tool to identify the VHV who has natural helper characteristics, a voluntary mind set and a readiness to help is needed. The purpose of the present study was to develop and test the quality of the natural helper characteristic scale (NHCS). The present study used a multi-methods design to identify natural helper characteristic constructs in the Thai public health context by interviewing community leaders and public health professionals who have experience in working with natural helpers successfully. Suggested constructs have been validated with key informants using telephone interview to confirm the common constructs before reconfirmation with factor analysis and reliability statistical test. Qualitative data indicated 3 constructs is commonly found and statistically tested by exploratory factor analysis revealed a 30-item with a five-factor solution (altruism, role recognition, openness to new experiences, family readiness, and social acceptance) that accounted for 62.24% of the variance. The finding of confirmatory factor analysis indicated that the 5-factor model with 24 items demonstrated acceptable fit indicated a good fit to the data (2 = 439.91; df = 217 (p < 0.001); chi2/ df = 2.02; RMSEA = 0.05; GFI = 0.90; and, CFI = 0.96). Cronbach's alpha coefficients of the total scale's Cronbach's alpha was 0.94. The NHCS demonstrated evidence of the content and construct validity, and adequate internal consistency reliability. The NHCS can be used for identifying natural helpers in working for the health programs.

  4. Regulation of Human Helper T Cell Subset Differentiation by Cytokines

    PubMed Central

    Schmitt, Nathalie; Ueno, Hideki

    2015-01-01

    Since the discovery of Th1 and Th2 cells in the late 80’s, the family of effector CD4+ helper T (Th) cell subsets has expanded. The differentiation of naïve CD4+ T cells is largely determined when they interact with dendritic cells in lymphoid organs, and cytokines play a major role in the regulation of Th differentiation in the early stages. Recent studies show that the developmental mechanism of certain Th subsets is not fully shared between mice and humans. Here we will review recent discoveries on the roles of cytokines in the regulation of Th differentiation in humans, and discuss the differences between mice and humans in the developmental mechanisms of several Th subsets, including Th17 cells and T follicular helper (Tfh) cells. We propose that the differentiation of human Th subsets is largely regulated by the three cytokines, IL-12, IL-23, and TGF-β. PMID:25879814

  5. Implementation of an Economical Parking Helper Device Using Ultrasound Sensors

    NASA Astrophysics Data System (ADS)

    Jamil, Tariq

    2010-06-01

    Every motorist dreams of a car that will take the stress out of parking by finding a suitable space and then maneuvers itself into the space with minimal assistance from the driver. This paper describes a parking helper device using ultrasound sensors, mounted on the car, to monitor both sides of the street for a suitable parking space, and when a large enough parking space is detected, the helper instructs the driver to stop the car and guides him/her via a display screen and voice about steering maneuvers which will ultimately result in the car being properly parked in the given parking space. Ultrasound sensors mounted on the front and rear bumpers of the car will ensure that a safe distance is maintained to other vehicles and objects and the driver will need to operate only the accelerator and the brake pedals. A warning signal sounds if the vehicle gets too close to other objects in the parking space.

  6. Alcoholics Anonymous-Related Helping and the Helper Therapy Principle

    PubMed Central

    Pagano, Maria E.; Post, Stephen G.; Johnson, Shannon M.

    2012-01-01

    The helper therapy principle (HTP) observes the helper’s health benefits derived from helping another with a shared malady. The HTP is embodied by the program of Alcoholics Anonymous as a method to diminish egocentrism as a root cause of addiction. This article reviews recent evidence of the HTP in alcohol populations, extends to populations with chronic conditions beyond addiction, and concludes with new directions of empirical inquiry. PMID:23525280

  7. Site-1 protease, a novel metabolic target for glioblastoma.

    PubMed

    Caruana, Beth T; Skoric, Aleksandra; Brown, Andrew J; Lutze-Mann, Louise H

    2017-08-26

    Sterol regulatory element binding proteins (SREBPs) are transcriptional regulators of lipids which promote glioblastoma growth. Here, we investigate the effect of inhibiting expression of SREBP target genes in human glioblastoma cells. This was achieved by using PF-429242 to inhibit site-1 protease (S1P), an enzyme required for SREBP activation. Treatment with PF-429242 decreased glioblastoma cell viability, induced apoptosis and downregulated steroid, isoprenoid and unsaturated fatty acid biosynthetic pathways. Several pro-inflammatory genes were upregulated. Collectively, these results demonstrate the potential of S1P as a target for glioblastoma therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Convergent evolution of pathogenicity islands in helper cos phage interference

    PubMed Central

    Manning, Keith A.; Dokland, Terje; Marina, Alberto

    2016-01-01

    Staphylococcus aureus pathogenicity islands (SaPIs) are phage satellites that exploit the life cycle of their helper phages for their own benefit. Most SaPIs are packaged by their helper phages using a headful (pac) packaging mechanism. These SaPIs interfere with pac phage reproduction through a variety of strategies, including the redirection of phage capsid assembly to form small capsids, a process that depends on the expression of the SaPI-encoded cpmA and cpmB genes. Another SaPI subfamily is induced and packaged by cos-type phages, and although these cos SaPIs also block the life cycle of their inducing phages, the basis for this mechanism of interference remains to be deciphered. Here we have identified and characterized one mechanism by which the SaPIs interfere with cos phage reproduction. This mechanism depends on a SaPI-encoded gene, ccm, which encodes a protein involved in the production of small isometric capsids, compared with the prolate helper phage capsids. As the Ccm and CpmAB proteins are completely unrelated in sequence, this strategy represents a fascinating example of convergent evolution. Moreover, this result also indicates that the production of SaPI-sized particles is a widespread strategy of phage interference conserved during SaPI evolution. This article is part of the themed issue ‘The new bacteriology’. PMID:27672154

  9. Do "helpers at the nest" increase their parents' reproductive success?

    PubMed

    Crognier, E; Baali, A; Hilali, M K

    2001-01-01

    "Helpers at the nest," usually offspring of a preceding litter who contribute by feeding the young to increase the reproductive success of a breeding pair, are known in many species of birds and mammals. Although similar behaviors were described by ethnological observations in several human societies, there is a lack of data on their existence and role. This study of 794 reproductive life histories of post-menopausal Berber women of Southern Morocco aims to provide such information. Results show that the presence of "probable helpers" in the household is related to higher fertility scores and is associated with improved survival of offspring to sexual maturity. In contrast to sparse observations from other human societies, there is no indication that child caretaking would be specific to eldest daughters. Although the association between offspring survival and helping patterns seems highly probable, there is no confirmation that child caretaking per se is the relevant variable. Contrary to nonhuman helpers at the nest, workloads of children range from housekeeping to light agricultural tasks, and are not focused on assisting younger siblings. The improvement of reproductive success is probably the result of multiple interactions, among which the network of kinship would play a role at both the levels of economy and reciprocal assistance.

  10. Follicular helper T cell in immunity and autoimmunity

    PubMed Central

    Mesquita, D.; Cruvinel, W.M.; Resende, L.S.; Mesquita, F.V.; Silva, N.P.; Câmara, N.O.S.; Andrade, L.E.C.

    2016-01-01

    The traditional concept that effector T helper (Th) responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17) and the follicular helper T cells (Tfh). These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R), the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases. PMID:27096200

  11. T-Helper Cytokine Profiles in Patients with Kawasaki Disease.

    PubMed

    Lee, Sang Bum; Kim, Young Hyun; Hyun, Myung Chul; Kim, Yeo Hyang; Kim, Hee Sun; Lee, Young Hwan

    2015-11-01

    Kawasaki disease is an acute systemic vasculitis of which pathogenesis suspected is caused by immune dysregulation. The goal of this study is to evaluate the activation pattern of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) in patients with Kawasaki disease. Prospective study of 60 patients (male 36, female 24) with diagnosis of Kawasaki disease were enrolled. One hundred and eighty blood samples from these patients were collected according to the different clinical stages {before initial intravenous immunoglobulin (IVIG), 5 days after initial IVIG, 2 months after initial IVIG}. The plasma level of Th1 cytokines; interferon-gamma (IFN-γ) & interleukin (IL)-2 and Th2 cytokines; IL-4 & IL-10 were measured by enzyme-liked immunosorbent assay. In all patients, the plasma level of Th1 cytokines (IFN-γ, IL-2) and Th2 cytokines (IL-4 and IL-10) were markedly elevated during the acute stage of Kawasaki disease. Since then, the plasma level of all these cytokines decreased significantly along with the process of clinical stages. Regardless of the existence of coronary artery lesion or no response to initial IVIG treatment, there were no significant differences between them. These data suggest that both Th1 and Th2 cells may be activated simultaneously during the acute stage of Kawasaki disease. Further studies are therefore required to establish the difference of activation pattern of T helper cells between Kawasaki disease and other inflammatory diseases.

  12. Convergent evolution of pathogenicity islands in helper cos phage interference.

    PubMed

    Carpena, Nuria; Manning, Keith A; Dokland, Terje; Marina, Alberto; Penadés, José R

    2016-11-05

    Staphylococcus aureus pathogenicity islands (SaPIs) are phage satellites that exploit the life cycle of their helper phages for their own benefit. Most SaPIs are packaged by their helper phages using a headful (pac) packaging mechanism. These SaPIs interfere with pac phage reproduction through a variety of strategies, including the redirection of phage capsid assembly to form small capsids, a process that depends on the expression of the SaPI-encoded cpmA and cpmB genes. Another SaPI subfamily is induced and packaged by cos-type phages, and although these cos SaPIs also block the life cycle of their inducing phages, the basis for this mechanism of interference remains to be deciphered. Here we have identified and characterized one mechanism by which the SaPIs interfere with cos phage reproduction. This mechanism depends on a SaPI-encoded gene, ccm, which encodes a protein involved in the production of small isometric capsids, compared with the prolate helper phage capsids. As the Ccm and CpmAB proteins are completely unrelated in sequence, this strategy represents a fascinating example of convergent evolution. Moreover, this result also indicates that the production of SaPI-sized particles is a widespread strategy of phage interference conserved during SaPI evolution.This article is part of the themed issue 'The new bacteriology'.

  13. Resource Allocation Planning Helper (RALPH): Lessons learned

    NASA Technical Reports Server (NTRS)

    Durham, Ralph; Reilly, Norman B.; Springer, Joe B.

    1990-01-01

    The current task of Resource Allocation Process includes the planning and apportionment of JPL's Ground Data System composed of the Deep Space Network and Mission Control and Computing Center facilities. The addition of the data driven, rule based planning system, RALPH, has expanded the planning horizon from 8 weeks to 10 years and has resulted in large labor savings. Use of the system has also resulted in important improvements in science return through enhanced resource utilization. In addition, RALPH has been instrumental in supporting rapid turn around for an increased volume of special what if studies. The status of RALPH is briefly reviewed and important lessons learned from the creation of an highly functional design team are focused on through an evolutionary design and implementation period in which an AI shell was selected, prototyped, and ultimately abandoned, and through the fundamental changes to the very process that spawned the tool kit. Principal topics include proper integration of software tools within the planning environment, transition from prototype to delivered to delivered software, changes in the planning methodology as a result of evolving software capabilities and creation of the ability to develop and process generic requirements to allow planning flexibility.

  14. T Helper1/T Helper2 Cells and Resistance/Susceptibility to Leishmania Infection: Is This Paradigm Still Relevant?

    PubMed Central

    Alexander, James; Brombacher, Frank

    2012-01-01

    Work in large part on Leishmania major in the 1980s identified two distinct apparently counter-regulatory CD4+ T cell populations, T helper (h)1 and Th2, that controlled resistance/susceptibility to infection respectively. However, the generation of IL-4−/− mice in the 1990s questioned the paramount role of this Th2 archetypal cytokine in the non-healing response to Leishmania infection. The more recent characterization of CD4+ T cell regulatory populations and further effector CD4+ T helper populations, Th17, Th9, and T follicular (f)h cells as well as the acknowledged plasticity in T helper cell function has further added to the complexity of host pathogen interactions. These interactions are complicated by the multiplicity of cells that respond to CD4+ T cell subset signatory cytokines, as well as the diversity of Leishmania species that are often subject to significantly different immune-regulatory controls. In this article we review current knowledge with regard to the role of CD4+ T cells and their products during Leishmania infection. In particular we update on our studies using conditional IL-4Rα gene-deficient mice that have allowed dissection of the cell interplay dictating the disease outcomes of the major Leishmania species infecting humans. PMID:22566961

  15. Helper Response to Experimentally Manipulated Predation Risk in the Cooperatively Breeding Cichlid Neolamprologus pulcher

    PubMed Central

    Heg, Dik; Taborsky, Michael

    2010-01-01

    Background We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: ‘pay-to-stay’ PS, ‘risk avoidance’ RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy. Methodology/Principal Findings Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, ‘punishment’ by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS). Conclusions/Significance We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were

  16. [Examination of physical and psychological health conditions and the influence factors of home helpers].

    PubMed

    Ashitomi, Ikuya

    2005-12-01

    The primary aim of this study was to examine the physical and psychological health conditions and the influence factors of home helpers. The secondary aim was to suggest a stress management system for home helpers. Self-report questionnaires were distributed to 1147 home helpers who were with home health care agencies in Kitakyushu-city. Responses from 979 home helpers were received, yielding a response rate of 85.5%. A total of 967 home helpers (excluding 12 male home helpers) were used for analysis. The Japanese version of the General Health Questionnaire 28 (GHQ-28) was used to measure the physical and psychological health conditions of the home helpers. In addition, as an influence factor, stress coping was measured by the Lazarus-type Stress Coping Inventory (SCI). Home helpers also filled out the Ego Aptitude Scale (EAS) as a personality measure. Furthermore, the subjects were asked questions about individual background factors, including age, marital status, working hours, years working as a home helper, type of home helper, job satisfaction, job continuation and awareness of stress. The data were analyzed using the Statistical Package for the Social Sciences (SPSS 11.5 J). The groups of full-time or part-time home helpers showed GHQ-28 total scores of 6.86 +/- 5.48 and 5.21 +/- 4.97 (Mean +/- SD): part-time home helpers had significantly higher scores than full-time home helpers. The GHQ-28 measure indicated that about 20% of home helpers had physical and psychological symptoms, and about 4% had mid-level depressive symptoms. About half of the subjects were aware of stress. There were significant negative correlations between GHQ-28 total scores and age. Also, there was a statistically significant relation between GHQ-28 and job satisfaction, awareness of stress, type of stress coping and individual personality. Furthermore, there was a statistically significant relation between GHQ-28 and the confrontive coping type, positive reappraisal of SCI, and

  17. SU-E-T-218: The IHE-RO Helper Tool: Demonstrating the Connectivity Issues Solved by IHE-RO.

    PubMed

    Kapoor, Rishabh; Yeung, Daniel; Kumar, Sabari Ajay; Alex, Daley; Kapur, Priyanka; Palta, Jatinder

    2012-06-01

    To develop a Web-based application (IHE-RO Helper) to allow comprehensive review of the interconnectivity and interoperability of various radiotherapy devices established through testing sanctioned by the Integrating Healthcare Enterprise-Radiation Oncology (IHE-RO). IHE-RO is an initiative sponsored by ASTRO to improve the way computer based systems in radiation oncology share information using well-defined data exchange standards (DICOM / HL7). At the IHE-RO Connectathon events over the last 4 years, 11 vendors with 14 different products have successfully tested and identified solutions to connectivity problems in treatment planning, simulation and delivery. Because the test results are highly technical, the interconnectivity issues amongst the RT devices may get overlooked by the end users. The IHE-RO helper tool is designed to operate in simple clinical terms with queries and presentations organized based on treatment techniques and clinical features that are familiar to the practitioners. For example, if you are planning to purchase a treatment planning system capable of generating plans (e.g. Stereotactic treatments) and are concerned whether the TPS can successfully transfer such data to your treatment management system (TMS) and subsequently to your treatment delivery system (TDS), the IHE-RO Helper can identify the connectivity requirements and list vendors that have successfully passed an IHE-RO Connectathon and validated their solution to the specific requirements. The IHE-RO helper tool provides a graphical and textual user interface to effectively demonstrate the solved interconnectivity problems between TPS, TMS and TDS. A report is also provided that explains the interconnectivity problems and its solutions. The IHE-RO helper is an effective tool to clearly identify vendor products that are IHE-RO compliant, thereby encourages vendor participation in testing and validation. Such a tool will be invaluable in procurement of new equipment to ensure a

  18. T-Helper Cytokine Profiles in Patients with Kawasaki Disease

    PubMed Central

    Lee, Sang Bum; Kim, Young Hyun; Hyun, Myung Chul; Kim, Yeo Hyang; Kim, Hee Sun

    2015-01-01

    Background and Objectives Kawasaki disease is an acute systemic vasculitis of which pathogenesis suspected is caused by immune dysregulation. The goal of this study is to evaluate the activation pattern of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) in patients with Kawasaki disease. Subjects and Methods Prospective study of 60 patients (male 36, female 24) with diagnosis of Kawasaki disease were enrolled. One hundred and eighty blood samples from these patients were collected according to the different clinical stages {before initial intravenous immunoglobulin (IVIG), 5 days after initial IVIG, 2 months after initial IVIG}. The plasma level of Th1 cytokines; interferon-gamma (IFN-γ) & interleukin (IL)-2 and Th2 cytokines; IL-4 & IL-10 were measured by enzyme-liked immunosorbent assay. Results In all patients, the plasma level of Th1 cytokines (IFN-γ, IL-2) and Th2 cytokines (IL-4 and IL-10) were markedly elevated during the acute stage of Kawasaki disease. Since then, the plasma level of all these cytokines decreased significantly along with the process of clinical stages. Regardless of the existence of coronary artery lesion or no response to initial IVIG treatment, there were no significant differences between them. Conclusion These data suggest that both Th1 and Th2 cells may be activated simultaneously during the acute stage of Kawasaki disease. Further studies are therefore required to establish the difference of activation pattern of T helper cells between Kawasaki disease and other inflammatory diseases. PMID:26617655

  19. Transcriptional and epigenetic regulation of T-helper lineage specification

    PubMed Central

    Tripathi, Subhash K; Lahesmaa, Riitta

    2014-01-01

    Combined with TCR stimuli, extracellular cytokine signals initiate the differentiation of naive CD4+ T cells into specialized effector T-helper (Th) and regulatory T (Treg) cell subsets. The lineage specification and commitment process occurs through the combinatorial action of multiple transcription factors (TFs) and epigenetic mechanisms that drive lineage-specific gene expression programs. In this article, we review recent studies on the transcriptional and epigenetic regulation of distinct Th cell lineages. Moreover, we review current study linking immune disease-associated single-nucleotide polymorphisms with distal regulatory elements and their potential role in the disease etiology. PMID:25123277

  20. Antagonistic effect of helpers on breeding male and female survival in a cooperatively breeding bird

    PubMed Central

    Paquet, Matthieu; Doutrelant, Claire; Hatchwell, Ben J; Spottiswoode, Claire N; Covas, Rita

    2015-01-01

    1. Cooperatively breeding species are typically long lived and hence, according to theory, are expected to maximize their lifetime reproductive success through maximizing survival. Under these circumstances, the presence of helpers could be used to lighten the effort of current reproduction for parents to achieve higher survival. 2. In addition, individuals of different sexes and ages may follow different strategies, but whether male and female breeders and individuals of different ages benefit differently from the presence of helpers has often been overlooked. Moreover, only one study that investigated the relationship between parental survival and the presence of helpers used capture–mark–recapture analyses (CMR). These methods are important since they allow us to account for the non-detection of individuals that are alive in the population but not detected, and thus, the effects on survival and recapture probability to be disentangled. 3. Here, we used multi-event CMR methods to investigate whether the number of helpers was associated with an increase in survival probability for male and female breeders of different ages in the sociable weaver Philetairus socius. In this species, both sexes reduce their feeding rate in the presence of helpers. We therefore predicted that the presence of helpers should increase the breeders' survival in both sexes, especially early in life when individuals potentially have more future breeding opportunities. In addition, sociable weaver females reduce their investment in eggs in the presence of helpers, so we predicted a stronger effect of helpers on female than male survival. 4. As expected we found that females had a higher survival probability when breeding with more helpers. Unexpectedly, however, male survival probability decreased with increasing number of helpers. This antagonistic effect diminished as the breeders grew older. 5. These results illustrate the complexity of fitness costs and benefits underlying

  1. Emerging concepts in T follicular helper cell responses to malaria.

    PubMed

    Hansen, Diana S; Obeng-Adjei, Nyamekye; Ly, Ann; Ioannidis, Lisa J; Crompton, Peter D

    2017-02-01

    Antibody responses to malaria and candidate malaria vaccines are short-lived in children, leaving them susceptible to repeated malaria episodes. Because T follicular helper (TFH) cells provide critical help to B cells to generate long-lived antibody responses, they have become the focus of recent studies of Plasmodium-infected mice and humans. The emerging data converge on common themes, namely, that malaria-induced TH1 cytokines are associated with the activation of (i) T-like memory TFH cells with impaired B cell helper function, and (ii) pre-TFH cells that acquire Th1-like features (T-bet expression, IFN-γ production), which impede their differentiation into fully functional TFH cells, thus resulting in germinal center dysfunction and suboptimal antibody responses. Deeper knowledge of TFH cells in malaria could illuminate strategies to improve vaccines through modulating TFH cell responses. This review summarizes emerging concepts in TFH cell responses to malaria. Copyright © 2016. Published by Elsevier Ltd.

  2. Early T helper cell programming of gene expression in human.

    PubMed

    Tuomela, Soile; Lahesmaa, Riitta

    2013-11-15

    Molecular mechanisms guiding naïve T helper cell differentiation into functionally specified effector cells are intensively studied. The rapidly growing knowledge is mainly achieved by using mouse cells or disease models. Comparatively exiguous data is gathered from human primary cells although they provide the "ultimate model" for immunology in man, have been exploited in many original studies paving the way for the field, and can be analyzed more easily than ever with the help of modern technology and methods. As usage of mouse models is unavoidable in translational research, parallel human and mouse studies should be performed to assure the relevancy of the hypothesis created during the basic research. In this review, we give an overview on the status of the studies conducted with human primary cells aiming at elucidating the mechanisms instructing the priming of T helper cell subtypes. The special emphasis is given to the recent high-throughput studies. In addition, by comparing the human and mouse studies we intend to point out the regulatory mechanisms and questions which are lacking examination with human primary cells.

  3. Genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens BBc6R8

    SciTech Connect

    Deveau, Aurelie; Grob, Harald; Morin, Emmanuelle; Karpinets, Tatiana V; Utturkar, Sagar M; Mehnaz, Samina; Kurz, Sven; Martin, Francis; Frey-Klett, Pascale; Labbe, Jessy L

    2014-01-01

    We report the draft genome sequence of the mycorrhiza helper bacterium Pseudomonas fluorescens strain BBc6R8 . Several traits which could be involved in the mycorrhiza helper ability of the bacterial strain such as multiple secretion systems, auxin metabolism and phosphate mobilization were evidenced in the genome.

  4. Helper effects on pup lifetime fitness in the cooperatively breeding red wolf (Canis rufus).

    PubMed

    Sparkman, Amanda M; Adams, Jennifer; Beyer, Arthur; Steury, Todd D; Waits, Lisette; Murray, Dennis L

    2011-05-07

    The evolutionary maintenance of cooperative breeding systems is thought to be a function of relative costs and benefits to breeders, helpers and juveniles. Beneficial effects of helpers on early-life survivorship and performance have been established in several species, but lifetime fitness benefits and/or costs of being helped remain unclear, particularly for long-lived species. We tested for effects of helpers on early- and late-life traits in a population of reintroduced red wolves (Canis rufus), while controlling for ecological variables such as home-range size and population density. We found that the presence of helpers in family groups was positively correlated with pup mass and survival at low population density, but negatively correlated with mass/size at high density, with no relation to survival. Interestingly, mass/size differences persisted into adulthood for both sexes. While the presence of helpers did not advance age at first reproduction for pups of either sex, females appeared to garner long-term fitness benefits from helpers through later age at last reproduction, longer reproductive lifespan and a greater number of lifetime reproductive events, which translated to higher lifetime reproductive success. In contrast, males with helpers exhibited diminished lifetime reproductive performance. Our findings suggest that while helper presence may have beneficial short-term effects in some ecological contexts, it may also incur long-term sex-dependent costs with critical ramifications for lifetime fitness.

  5. Helper effects on pup lifetime fitness in the cooperatively breeding red wolf (Canis rufus)

    PubMed Central

    Sparkman, Amanda M.; Adams, Jennifer; Beyer, Arthur; Steury, Todd D.; Waits, Lisette; Murray, Dennis L.

    2011-01-01

    The evolutionary maintenance of cooperative breeding systems is thought to be a function of relative costs and benefits to breeders, helpers and juveniles. Beneficial effects of helpers on early-life survivorship and performance have been established in several species, but lifetime fitness benefits and/or costs of being helped remain unclear, particularly for long-lived species. We tested for effects of helpers on early- and late-life traits in a population of reintroduced red wolves (Canis rufus), while controlling for ecological variables such as home-range size and population density. We found that the presence of helpers in family groups was positively correlated with pup mass and survival at low population density, but negatively correlated with mass/size at high density, with no relation to survival. Interestingly, mass/size differences persisted into adulthood for both sexes. While the presence of helpers did not advance age at first reproduction for pups of either sex, females appeared to garner long-term fitness benefits from helpers through later age at last reproduction, longer reproductive lifespan and a greater number of lifetime reproductive events, which translated to higher lifetime reproductive success. In contrast, males with helpers exhibited diminished lifetime reproductive performance. Our findings suggest that while helper presence may have beneficial short-term effects in some ecological contexts, it may also incur long-term sex-dependent costs with critical ramifications for lifetime fitness. PMID:20961897

  6. Adult helpers increase the recruitment of closely related offspring in the cooperatively breeding rifleman

    PubMed Central

    Briskie, James V.; Hatchwell, Ben J.

    2016-01-01

    Indirect fitness benefits gained through kin-selected helping are widely invoked to explain the evolution of cooperative breeding behavior in birds. However, the impact of helpers on productivity of helped broods can be difficult to determine if the effects are confounded by territory quality or if the benefit of helpers is apparent only in the long term. In riflemen Acanthisitta chloris, helping and group membership are effectively decoupled as adult helpers are individuals that have dispersed from their natal territory and live independently from breeders in “kin neighborhoods.” Nevertheless, helpers direct their care toward close relatives, suggesting that helping provides indirect fitness benefits. The aim of this study was to examine the benefits of helpers to recipient offspring in the rifleman, investigating both short- and long-term effects. The total amount of food delivered to nestlings in helped broods was greater than that received by broods without helpers. This did not result in any short-term increase in nestling mass or nestling body condition nor was there any reduction in length of the nestling period at helped nests. However, helpers were associated with a significant increase in juvenile recruitment, with twice the proportion of fledglings surviving to the next breeding season from helped broods relative to unhelped broods. Thus, helpers gain indirect fitness by improving the survival of kin, and in contrast to a previous study of riflemen, we conclude that kin selection has played a key role in the evolution of cooperative breeding in this species. PMID:28028377

  7. Thymic influence on the T-lymphocyte self MHC repertoire. I. Helper T-lymphocyte precursors.

    PubMed

    Jenski, L J; Belloni, M L; Miller, B A

    1988-01-01

    We measured the frequencies of helper T-cell precursors in spleens of allogeneic thymus-grafted nude mice to determine whether allogeneic thymus engraftment resulted in clonal deletion of helper T-cells reactive to thymic major histocompatibility complex alloantigens, thereby producing tolerance to the thymic alloantigens. C3H thymus-grafted nudes had nearly normal numbers of C3H-reactive helper T-cell precursors, whereas C57BL/6 thymus-grafted nudes had significantly reduced numbers of C57BL/6-reactive helper T-cell precursors. Additional evidence suggested that tolerance was not due to a paucity of helper T-cell precursors: a) there was no correlation between the helper T-cell precursor frequency and the ability to mount cytotoxic responses against the thymic alloantigens, and b) exogenous helper factors did not break cytotoxic T-lymphocyte tolerance to thymic alloantigens. Thus, we conclude that immune tolerance resulting from engraftment of allogeneic thymic tissue is not necessarily due to clonal deletion of specific helper T-cell precursors.

  8. Internal complementarities in the immune system: regulation of the expression of helper T-cell idiotypes.

    PubMed Central

    Martinez, C; Pereira, P; Bernabé, R; Bandeira, A; Larsson, E L; Cazenave, P A; Coutinho, A

    1984-01-01

    More than half of BALB/c helper T lymphocytes specific for 2,4,6-trinitrophenyl (TNP)-modified syngeneic spleen cells are inhibited in their proliferative responses to antigen-presenting cells and in their cooperation with B lymphocytes by monoclonal anti-idiotypic antibodies directed to a TNP-binding BALB/c myeloma protein (MOPC 460). This inhibition is specific for anti-TNP-self helper cells of BALB/c origin and is controlled by IgCh-linked genes, as it is not observed with CB.20 helper cells of the same specificity. In contrast, anti-TNP-self helper cells prepared from BALB/c mice that were chronically suppressed with anti-mu chain antibodies and possessed no B lymphocytes were not inhibited by anti-idiotypic antibodies. We conclude that the B-cell antibody repertoires contribute to the selection of the (idiotypic) T-helper-cell repertoires. PMID:6235521

  9. Domestic helpers as frontline workers in China's home-based elder care: A systematic review.

    PubMed

    Wang, Jing; Wu, Bei

    2017-01-01

    We conducted a systematic review of the existing empirical studies focusing on Chinese domestic helpers in mainland China and foreign domestic helpers in Hong Kong who provide care for community-dwelling older adults. There are very limited studies specifically focusing on this population. The findings synthesized domestic helpers' characteristics, acknowledged their contributions to elder care in China, and showed multiple challenges facing them, such as issues related to their physical health and emotional well-being, lack of legal rights protection, difficulties of adapting life in the host city, lack of training, and risk of abuse and sexual harassment. Our findings support the need for developing training and educational programs about legal rights protection and cultural competency for domestic helpers and the need to promote domestic helpers' access to health care and social welfare and opportunities for career advancement, and provide respectful working conditions.

  10. Mechanisms Underlying Helper T cell Plasticity: Implications for Immune-mediated Disease

    PubMed Central

    Hirahara, Kiyoshi; Poholek, Amanda; Vahedi, Golnaz; Laurence, Arian; Kanno, Yuka; Milner, Joshua D.; O’Shea, John J.

    2013-01-01

    CD4 helper T cells are critical for proper immune cell homeostasis and host defense, but are also major contributes to immune and inflammatory disease. Arising from a simple, biphasic model of differentiation, Th1 and Th2 cells, a bewildering number of fates seem to possible for helper T cells. To what extent different helper cell subsets maintain their characteristic gene expression profiles or exhibit functional plasticity is a hotly debated topic. In this review, we will discuss how the expression of “signature cytokines” and “master regulator” transcription factors do not neatly conform to a simple T helper paradigm. While this may seem confusing, the good news is that the newly recognized complexity fits better with our understanding of immunopathogenesis. Finally, we will discuss factors include epigenetic regulation and metabolic alterations that contribute to helper cell specific and plasticity. PMID:23622118

  11. Development and characterization of promoterless helper RNAs for the production of alphavirus replicon particle.

    PubMed

    Kamrud, K I; Alterson, K; Custer, M; Dudek, J; Goodman, C; Owens, G; Smith, J F

    2010-07-01

    Alphavirus-based replicon systems are frequently used as preclinical vectors and as antigen discovery tools, and they have recently been assessed in clinical vaccine trials. Typically, alphavirus replicon RNAs are delivered within virus-like replicon particles (VRP) that are produced following transfection of replicon RNA and two helper RNAs into permissive cells in vitro. The non-structural proteins expressed from the replicon RNA amplify the replicon RNA in cis and the helper RNAs in trans, the latter providing the viral structural proteins necessary to package the replicon RNA into VRP. Current helper RNA designs incorporate the alphavirus 26S promoter to direct the transcription of high levels of structural gene mRNAs. We demonstrate here that the 26S promoter is not required on helper RNAs to produce VRP and propose that such promoterless helper RNAs, by design, reduce the probability of generating replication-competent virus that may otherwise result from RNA recombination.

  12. T Follicular Helper Cell Plasticity Shapes Pathogenic T Helper 2 Cell-Mediated Immunity to Inhaled House Dust Mite.

    PubMed

    Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E; Spolski, Rosanne; Leonard, Warren J; León, Beatriz

    2016-02-16

    Exposure to environmental antigens, such as house dust mite (HDM), often leads to T helper 2 (Th2) cell-driven allergic responses. However, the mechanisms underlying the development of these responses are incompletely understood. We found that the initial exposure to HDM did not lead to Th2 cell development but instead promoted the formation of interleukin-4 (IL-4)-committed T follicular helper (Tfh) cells. Following challenge exposure to HDM, Tfh cells differentiated into IL-4 and IL-13 double-producing Th2 cells that accumulated in the lung and recruited eosinophils. B cells were required to expand IL-4-committed Tfh cells during the sensitization phase, but did not directly contribute to disease. Impairment of Tfh cell responses during the sensitization phase or Tfh cell depletion prevented Th2 cell-mediated responses following challenge. Thus, our data demonstrate that Tfh cells are precursors of HDM-specific Th2 cells and reveal an unexpected role of B cells and Tfh cells in the pathogenesis of allergic asthma.

  13. Helper virus-mediated downregulation of transgene expression permits production of recalcitrant helper-dependent adenoviral vector

    PubMed Central

    Palmer, Donna J; Grove, Nathan C; Ng, Philip

    2016-01-01

    Helper-dependent adenoviral vectors (HDAd) that express certain transgene products are impossible to produce because the transgene product is toxic to the producer cells, especially when made in large amounts during vector production. Downregulating transgene expression from the HDAd during vector production is a way to solve this problem. In this report, we show that this can be accomplished by inserting the target sequence for the adenoviral VA RNAI into the 3’ untranslated region of the expression cassette in the HDAd. Thus during vector production, when the producer cells are coinfected with both the helper virus (HV) and the HDAd, the VA RNAI produced by the HV will target the transgene mRNA from the HDAd via the endogenous cellular RNAi pathway. Once the HDAd is produced and purified, transduction of the target cells results in unimpeded transgene expression because of the absence of HV. This simple and universal strategy permits for the robust production of otherwise recalcitrant HDAds. PMID:27331077

  14. Helpers' Self-Assessment Biases Before and after Helping Skills Training.

    PubMed

    Jaeken, Marine; Zech, Emmanuelle; Brison, Céline; Verhofstadt, Lesley L; Van Broeck, Nady; Mikolajczak, Moïra

    2017-01-01

    Several studies have shown that therapists are generally biased concerning their performed helping skills, as compared to judges' ratings. As clients' ratings of therapists' performance are better predictors of psychotherapy effectiveness than judges' ratings, this study examined the validity and effectiveness of a helping skills training program at reducing novice helpers' self-enhancement biases concerning their helping skills, in comparison to their clients' ratings. Helping skills were assessed by three objective measures (a knowledge multiple choice test, a video test and a role play), as well as by a self- and peer-reported questionnaire. In addition, some performed helping skills' correlates (relationship quality, session quality, and helpers' therapeutic attitudes) were assessed both by helpers and their simulated helpees. Seventy-two sophomores in psychology participated to this study, 37 being assigned to a 12-h helping skills training program, and 35 to a control group. Helpers were expected to assess the aforementioned performed helping skills and correlates as being better than their helpees' assessments at pretest, thus revealing a self-enhancement bias. At posttest, we expected that trained helpers would objectively exhibit better helping skills than untrained helpers while beginning to underestimate their performance, thus indexing a self-diminishment bias. In contrast, we hypothesized that untrained helpers would continue to overestimate their performance. Our hypotheses were only partly confirmed but results reflected a skilled-unaware pattern among trainees. Trained helpers went either from a pretest overestimation to a posttest equivalence (performed helping skills and performed therapeutic attitudes), or from a pretest equivalence to a posttest underestimation (performed session quality and performed therapeutic relationship), as compared to helpees' ratings. Results showed that trained helpers improved on all helping skills objective measures

  15. Helpers' Self-Assessment Biases Before and after Helping Skills Training

    PubMed Central

    Jaeken, Marine; Zech, Emmanuelle; Brison, Céline; Verhofstadt, Lesley L.; Van Broeck, Nady; Mikolajczak, Moïra

    2017-01-01

    Several studies have shown that therapists are generally biased concerning their performed helping skills, as compared to judges' ratings. As clients' ratings of therapists' performance are better predictors of psychotherapy effectiveness than judges' ratings, this study examined the validity and effectiveness of a helping skills training program at reducing novice helpers' self-enhancement biases concerning their helping skills, in comparison to their clients' ratings. Helping skills were assessed by three objective measures (a knowledge multiple choice test, a video test and a role play), as well as by a self- and peer-reported questionnaire. In addition, some performed helping skills' correlates (relationship quality, session quality, and helpers' therapeutic attitudes) were assessed both by helpers and their simulated helpees. Seventy-two sophomores in psychology participated to this study, 37 being assigned to a 12-h helping skills training program, and 35 to a control group. Helpers were expected to assess the aforementioned performed helping skills and correlates as being better than their helpees' assessments at pretest, thus revealing a self-enhancement bias. At posttest, we expected that trained helpers would objectively exhibit better helping skills than untrained helpers while beginning to underestimate their performance, thus indexing a self-diminishment bias. In contrast, we hypothesized that untrained helpers would continue to overestimate their performance. Our hypotheses were only partly confirmed but results reflected a skilled-unaware pattern among trainees. Trained helpers went either from a pretest overestimation to a posttest equivalence (performed helping skills and performed therapeutic attitudes), or from a pretest equivalence to a posttest underestimation (performed session quality and performed therapeutic relationship), as compared to helpees' ratings. Results showed that trained helpers improved on all helping skills objective measures

  16. Toxicity associated with repeated administration of first-generation adenovirus vectors does not occur with a helper-dependent vector.

    PubMed Central

    O'Neal, W. K.; Zhou, H.; Morral, N.; Langston, C.; Parks, R. J.; Graham, F. L.; Kochanek, S.; Beaudet, A. L.

    2000-01-01

    BACKGROUND: Certain gene therapy protocols may require multiple administrations of vectors to achieve therapeutic benefit to the patient. This may be especially relevant for vectors such as adenoviral vectors that do not integrate into the host chromosome. Because immunocompetent animal models used for gene transfer studies develop neutralizing antibodies to adenoviral vectors after a single administration, little is known about how repeat administrations of vectors might affect transgene expression and vector toxicity. MATERIALS AND METHODS: We used mice deficient in the membrane spanning region of immunoglobulin (IgM), which do not develop antibodies, to evaluate the effect of repeated intravenous administration of first-generation and helper-dependent adenoviral vectors expressing human alpha 1-antitrypsin (hAAT). The duration and levels of transgene expression were evaluated after repeated administration of vectors. Toxicity was assessed by measuring the level of liver enzymes in the serum and the degrees of hepatocyte hypertrophy and proliferation. RESULTS: We found that previous administration of first-generation adenoviral vectors can alter the response to subsequent doses. These alterations included an increase in transgene expression early (within 1 and 3 days), followed by a rapid drop in expression by day 7. In addition, previous administrations of first-generation vectors led to an increase in toxicity of subsequent doses, as indicated by a rise in liver enzymes and an increase in hepatocyte proliferation. In contrast to first-generation vectors, use of the helper-dependent adenovirus vector, Ad-STK109, which contained no viral coding regions, did not lead to increased toxicity after multiple administrations. CONCLUSIONS: We conclude that the response of the host to adenoviral vectors can be altered after repeated administration, compared with the response after the initial vector dose. In addition, these experiments provide further evidence for the

  17. A nonimmunosuppressive helper virus allows high efficiency induction of B cell lymphomas by reticuloendotheliosis virus strain T.

    PubMed

    Barth, C F; Humphries, E H

    1988-01-01

    We have documented the effect of two nondefective helper viruses, reticuloendotheliosis virus A (REV-A) and chick syncytial virus (CSV) infection on bursal tissue. REV-A infection results in bursal atrophy, destroying both its structural and functional integrity. In contrast, the bursae in CSV-infected chicks, while reduced slightly in size, appear both structurally and functionally normal. REV-A-induced bursal atrophy is not a result of viral replication in the B-lymphocyte as (a) both viruses are capable of inducing, with equal efficiency, the formation of preneoplastic lesions containing proliferating B lymphocytes and (b) it appears that equivalent amounts of viral antigen are expressed in the bursae of chicks infected with either virus. We have examined the phenotype of tumors induced by the replication-defective virus REV-T when replicated by the two different helper viruses, REV-A and CSV. In REV-T(REV-A)-infected chicks, the majority of tumors that develop are negative for IgM expression. In contrast, the majority of tumors induced by REV-T(CSV) infection are IgM+. This finding is confirmed by recovery of IgM- cell lines from REV-T(REV-A)-infected chicks and IgM+ cell lines from REV-T(CSV)-infected chicks. In addition, repopulation studies show that bursal-derived cells that are IgM+ serve as target cells for REV-T(CSV)-induced lymphomas. This study demonstrates, therefore, that REV-T can induce IgM+, B cell lymphomas with high efficiency. We conclude that infections by the helper viruses, REV-A and CSV, differ dramatically in their effects on the composition of the population of cells that serve as targets for REV-T-induced neoplasia.

  18. The Newly Identified T Helper 22 Cells Lodge in Leukemia

    PubMed Central

    Azizi, Gholamreza; Rastegar Pouyani, Mohsen; Navabi, Shadi sadat; Yazdani, Reza; Kiaee, Fatemeh; Mirshafiey, Abbas

    2015-01-01

    Leukemia is a hematological tumor in which the malignant myeloid or lymphoid subsets play a pivotal role. Newly identified T helper cell 22 (Th22) is a subset of CD4+ T cells with distinguished gene expression, function and specific properties apart from other known CD4+ T cell subsets.Th22 cells are characterized by production of a distinct profile of effector cytokines, including interleukin (IL)-22, IL-13, and tumor necrosis factor-α (TNF-α). The levels of Th22 and cytokine IL-22 are increased and positively related to inflammatory and autoimmune disorders. Recently, several studies have reported the changes in frequency and function of Th22 in acute leukemic disorders as AML and ALL. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of leukemic disease. PMID:26261700

  19. Development and function of follicular helper T cells.

    PubMed

    Ise, Wataru

    2015-01-01

    Most currently available vaccines rely on the induction of long-lasting protective humoral immune responses by memory B cells and plasma cells. Antibody responses against most antigens require interactions between antigen-specific B cells and CD4(+) T cells. Follicular helper T cells (TFH cells) are specialized subset of T cells that provide help to B cells and are essential for germinal center formation, affinity maturation, and the development of high-affinity antibodies. TFH-cell differentiation is a multistage process involving B-cell lymphoma 6 and other transcription factors, cytokines, and costimulation through inducible costimulator (ICOS) and several other molecules. This article reviews recent advances in our understanding of TFH cell biology, including their differentiation, transcriptional regulation, and function.

  20. T follicular helper cell differentiation, function, and roles in disease

    PubMed Central

    Crotty, Shane

    2014-01-01

    Summary Follicular helper T (Tfh) cells are specialized providers of T cell help to B cells, and are essential for germinal center formation, affinity maturation, and the development of most high affinity antibodies and memory B cells. Tfh cell differentiation is a multi-stage, multi-factorial process involving B cell lymphoma 6 (Bcl6) and other transcription factors. This article reviews understanding of Tfh cell biology, including their differentiation, migration, transcriptional regulation, and B cell help functions. Tfh cells are critical components of many protective immune responses against pathogens. As such, there is strong interest in harnessing Tfh cells to improve vaccination strategies. Tfh cells also have roles in a range of other diseases, particularly autoimmune diseases. Overall, there have been dramatic advances in this young field, but there is much to be learned about Tfh cell biology in the interest of applying that knowledge to biomedical needs. PMID:25367570

  1. Maternal Effects in Relation to Helper Presence in the Cooperatively Breeding Sociable Weaver

    PubMed Central

    Paquet, Matthieu; Covas, Rita; Chastel, Olivier; Parenteau, Charline; Doutrelant, Claire

    2013-01-01

    In egg laying species, breeding females may adjust the allocation of nutrients or other substances into eggs in order to maximise offspring or maternal fitness. Cooperatively breeding species offer a particularly interesting context in which to study maternal allocation because helpers create predictably improved conditions during offspring development. Some recent studies on cooperative species showed that females assisted by helpers produced smaller eggs, as the additional food brought by the helpers appeared to compensate for this reduction in egg size. However, it remains unclear how common this effect might be. Also currently unknown is whether females change egg composition when assisted by helpers. This effect is predicted by current maternal allocation theory, but has not been previously investigated. We studied egg mass and contents in sociable weavers (Philetairus socius). We found that egg mass decreased with group size, while fledgling mass did not vary, suggesting that helpers may compensate for the reduced investment in eggs. We found no differences in eggs’ carotenoid contents, but females assisted by helpers produced eggs with lower hormonal content, specifically testosterone, androstenedione (A4) and corticosterone levels. Taken together, these results suggest that the environment created by helpers can influence maternal allocation and potentially offspring phenotypes. PMID:23536872

  2. Self-adaptive Worker-Helper Systems with Self-Organized Task Allocation

    NASA Astrophysics Data System (ADS)

    Merkle, Daniel; Middendorf, Martin; Scheidler, Alexander

    In this chapter a self-organized worker helper system is described, which is part of an abstract Organic Computing system (OC system). It consists of normal worker components and helper components, and the workers need some service from time to time in order to continue with their normal work. The service is done by the helpers, which have reconfigurable hardware to perform the different service tasks. The speed of service for a certain task depends on the amount of resources configured for this task. Strategies are presented that can be used by the helpers to decide whether to accept a service task and how to reconfigure themselves. It is also described how the worker helper system can be organized without global knowledge about the type of service requests and the set of available helper components. In order to obtain a decentralized mechanism and to make it suitable for the paradigm of OC a fully decentralized and dynamic clustering algorithm has been combined with a self-organized task allocation system. Empirical results show that the described worker helper system can adapt to dynamic situations with changing probabilities for service, and that decentralized clustering is able to reduce the reconfiguration cost significantly.

  3. Homology Requirements for Efficient, Footprintless Gene Editing at the CFTR Locus in Human iPSCs with Helper-dependent Adenoviral Vectors.

    PubMed

    Palmer, Donna J; Grove, Nathan C; Ing, Jordan; Crane, Ana M; Venken, Koen; Davis, Brian R; Ng, Philip

    2016-01-01

    Helper-dependent adenoviral vectors mediate high efficiency gene editing in induced pluripotent stem cells without needing a designer nuclease thereby avoiding off-target cleavage. Because of their large cloning capacity of 37 kb, helper-dependent adenoviral vectors with long homology arms are used for gene editing. However, this makes vector construction and recombinant analysis difficult. Conversely, insufficient homology may compromise targeting efficiency. Thus, we investigated the effect of homology length on helper-dependent adenoviral vector targeting efficiency at the cystic fibrosis transmembrane conductance regulator locus in induced pluripotent stem cells and found a positive correlation. With 23.8 and 21.4 kb of homology, the frequencies of targeted recombinants were 50-64.6% after positive selection for vector integration, and 97.4-100% after negative selection against random integrations. With 14.8 kb, the frequencies were 26.9-57.1% after positive selection and 87.5-100% after negative selection. With 9.6 kb, the frequencies were 21.4 and 75% after positive and negative selection, respectively. With only 5.6 kb, the frequencies were 5.6-16.7% after positive selection and 50% after negative selection, but these were more than high enough for efficient identification and isolation of targeted clones. Furthermore, we demonstrate helper-dependent adenoviral vector-mediated footprintless correction of cystic fibrosis transmembrane conductance regulator mutations through piggyBac excision of the selectable marker. However, low frequencies (≤ 1 × 10(-3)) necessitated negative selection for piggyBac-excision product isolation.

  4. Homology Requirements for Efficient, Footprintless Gene Editing at the CFTR Locus in Human iPSCs with Helper-dependent Adenoviral Vectors.

    PubMed

    Palmer, Donna J; Grove, Nathan C; Ing, Jordan; Crane, Ana M; Venken, Koen; Davis, Brian R; Ng, Philip

    2016-10-11

    Helper-dependent adenoviral vectors mediate high efficiency gene editing in induced pluripotent stem cells without needing a designer nuclease thereby avoiding off-target cleavage. Because of their large cloning capacity of 37 kb, helper-dependent adenoviral vectors with long homology arms are used for gene editing. However, this makes vector construction and recombinant analysis difficult. Conversely, insufficient homology may compromise targeting efficiency. Thus, we investigated the effect of homology length on helper-dependent adenoviral vector targeting efficiency at the cystic fibrosis transmembrane conductance regulator locus in induced pluripotent stem cells and found a positive correlation. With 23.8 and 21.4 kb of homology, the frequencies of targeted recombinants were 50-64.6% after positive selection for vector integration, and 97.4-100% after negative selection against random integrations. With 14.8 kb, the frequencies were 26.9-57.1% after positive selection and 87.5-100% after negative selection. With 9.6 kb, the frequencies were 21.4 and 75% after positive and negative selection, respectively. With only 5.6 kb, the frequencies were 5.6-16.7% after positive selection and 50% after negative selection, but these were more than high enough for efficient identification and isolation of targeted clones. Furthermore, we demonstrate helper-dependent adenoviral vector-mediated footprintless correction of cystic fibrosis transmembrane conductance regulator mutations through piggyBac excision of the selectable marker. However, low frequencies (≤ 1 × 10(-3)) necessitated negative selection for piggyBac-excision product isolation.

  5. Homology Requirements for Efficient, Footprintless Gene Editing at the CFTR Locus in Human iPSCs with Helper-dependent Adenoviral Vectors

    PubMed Central

    Palmer, Donna J; Grove, Nathan C; Ing, Jordan; Crane, Ana M; Venken, Koen; Davis, Brian R; Ng, Philip

    2016-01-01

    Helper-dependent adenoviral vectors mediate high efficiency gene editing in induced pluripotent stem cells without needing a designer nuclease thereby avoiding off-target cleavage. Because of their large cloning capacity of 37 kb, helper-dependent adenoviral vectors with long homology arms are used for gene editing. However, this makes vector construction and recombinant analysis difficult. Conversely, insufficient homology may compromise targeting efficiency. Thus, we investigated the effect of homology length on helper-dependent adenoviral vector targeting efficiency at the cystic fibrosis transmembrane conductance regulator locus in induced pluripotent stem cells and found a positive correlation. With 23.8 and 21.4 kb of homology, the frequencies of targeted recombinants were 50–64.6% after positive selection for vector integration, and 97.4–100% after negative selection against random integrations. With 14.8 kb, the frequencies were 26.9–57.1% after positive selection and 87.5–100% after negative selection. With 9.6 kb, the frequencies were 21.4 and 75% after positive and negative selection, respectively. With only 5.6 kb, the frequencies were 5.6–16.7% after positive selection and 50% after negative selection, but these were more than high enough for efficient identification and isolation of targeted clones. Furthermore, we demonstrate helper-dependent adenoviral vector-mediated footprintless correction of cystic fibrosis transmembrane conductance regulator mutations through piggyBac excision of the selectable marker. However, low frequencies (≤ 1 × 10−3) necessitated negative selection for piggyBac-excision product isolation. PMID:27727248

  6. BCL6 interacting corepressor contributes to germinal center T follicular helper cell formation and B cell helper function

    PubMed Central

    Yang, Jessica A.; Tubo, Noah J.; Gearhart, Micah D.; Bardwell, Vivian J.; Jenkins, Marc K.

    2015-01-01

    CD4+ germinal center (GC) T follicular helper (GC-Tfh) cells help B cells become long-lived plasma cells and memory cells. The transcriptional repressor BCL6 plays a key role in GC-Tfh formation by inhibiting the expression of genes that promote differentiation into other lineages. We determined whether BCOR, a component of a Polycomb repressive complex that interacts with the BCL6 BTB domain, influences GC-Tfh differentiation. T cell-targeted BCOR deficiency led to a substantial loss of peptide:MHCII-specific GC-Tfh cells following Listeria monocytogenes infection and a 2-fold decrease following immunization with a peptide in CFA. The reduction in GC-Tfh cells was associated with diminished plasma cell and GC B cell formation. Thus, T cell-expressed BCOR is critical for optimal GC-Tfh differentiation and humoral immunity. PMID:25964495

  7. Partial reconstitution of a replication-competent retrovirus in helper cells with partial overlaps between vector and helper cell genomes.

    PubMed

    Martinez, I; Dornburg, R

    1996-04-10

    Contamination of retroviral vector preparations with replication-competent retroviruses is a major safety concern in human gene therapy. These can arise by recombination between retroviral vectors and packaging cell sequences. Recently, we constructed new packaging lines, derived from spleen necrosis virus (SNV) that do not contain overlapping regions of homology between these two components (DSH134G and DSH29B cells). These cell lines were tested for the presence of recombination products and replication-competent viruses in comparison to a similar packaging line (DSN) that contains a partial overlap between vector and viral protein coding regions. No recombination products were detected in DSH cells. However, we found that recombination had occurred in DSN cells, partially reconstituting a provirus-like structure that was capable of being spread, although inefficiently, through an infected cell culture. Our data indicate that even small regions of sequence homology eventually allow homologous recombination between vector and helper cell genomes.

  8. Helper T cell plasticity: Impact of Extrinsic and Intrinsic Signals On Transcriptomes and Epigenomes

    PubMed Central

    Bonelli, Michael; Shih, Han-Yu; Hirahara, Kiyoshi; Singelton, Kentner; Laurence, Arian; Poholek, Amanda; Hand, Tim; Mikami, Yohei; Vahedi, Golnaz; Kanno, Yuka; O'Shea, John J.

    2014-01-01

    CD4+ helper T cells are crucial for autoimmune and infectious diseases; however, the recognition of the many, diverse fates available continues unabated. Precisely what controls specification of helper T cells and preserves phenotypic commitment is currently intensively investigated. In this review, we will discuss the major factors that impact helper T cell fate choice, ranging from cytokines and the microbiome to metabolic control and epigenetic regulation. We will also discuss the technological advances along with the attendant challenges presented by “big data”, which allow the understanding of these processes on comprehensive scales. PMID:24831346

  9. Helper activity by human large granular lymphocytes in in vitro immunoglobulin synthesis.

    PubMed

    Rodriguez, M A; Blanca, I; Baroja, M L; Arama, S; Leon-Ponte, M; Abadi, I; Bianco, N E

    1987-09-01

    In the present study we have examined the effect of human large granular lymphocytes (LGL) from healthy donors on Ig synthesis by autologous B lymphocytes. The results showed that this cell population has a consistent helper activity in pokeweed mitogen-activated cultures even when added at very low numbers. LGL can mediate their effect by secreting soluble helper factors capable of modulating B-cell responses as evidenced by the enhancement of IgG and IgM production by supernatants obtained from LGL cultures. Preincubation with interferon gamma further potentiated the helper activity by LGL.

  10. Incorporating Natural Helpers to Address Service Disparities for Young Children with Conduct Problems

    PubMed Central

    Acevedo-Polakovich, I. David; Niec, Larissa N.; Barnet, Miya L.; Bell, Katrina M.

    2013-01-01

    In response to the high levels of unmet need among historically underserved young children with conduct problems, this paper outlines some of the key issues involved in incorporating natural helpers into the delivery of parenting interventions for the treatment of conduct problems among historically underserved children. Strategies for the selection and training of natural helpers are discussed along with challenges that might be encountered in these processes. Directions for future research are also highlighted. With appropriate selection and training procedures in place, natural helpers may increase the accessibility of services for children and families and foster the reduction of service disparities. PMID:24729649

  11. Helper T cells against tumor-associated antigens (TAA): preferential induction of helper T cell activities involved in anti-TAA cytotoxic T lymphocyte and antibody responses

    SciTech Connect

    Fujiwara, H.; Yoshioka, T.; Shima, J.; Kosugi, A.; Itoh, K.; Hamaoka, T.

    1986-04-01

    This study establishes assay systems for helper T cell activities assisting cytotoxic T lymphocyte (CTL) and antibody responses to tumor-associated antigens (TAA) and demonstrates the existence of TAA that induce preferentially anti-TAA CTL helper and B cell helper T cell activities in two syngeneic tumor models. C3H/HeN mice were immunized to the syngeneic X5563 plasmacytoma or MH135 hepatoma. Spleen cells from these mice were tested for anti-TAA helper T cell activity capable of augmenting anti-trinitrophenyl(TNP) CTL and anti-TNP antibody responses from anti-TNP CTL and B cell precursors (responding cells) by stimulation with TNP-modified X5563 or MH134 tumor cells. The results demonstrate that cultures of responding cells plus 850R X-irradiated tumor-immunized spleen cells (helper cells) failed to enhance anti-TNP CTL or antibody responses when in vitro stimulation was provided by either unmodified tumor cells or TNP-modified syngeneic spleen cells (TNP-self). In contrast, these cultures resulted in appreciable augmentation of anti-TNP CTL or antibody response when stimulated by TNP-modified tumor cells. The results are discussed in the light of cellular mechanisms underlying the preferential anti-TAA immune responses, and the interrelationship between various types of cell functions including CTL- and B cell-help.

  12. H+ stoichiometry of sites 1 + 2 of the respiratory chain of normal and tumor mitochondria.

    PubMed

    Villalobo, A; Alexandre, A; Lehninger, A L

    1984-09-01

    The mechanistic stoichiometry for vectorial H+ ejection coupled to electron transport through energy-conserving segments 1 + 2 was determined on cyanide-inhibited mitochondria from rat liver, rat heart, and Ehrlich ascites tumor cells, and on rat liver mitoplasts with ferricyanide or ferricytochrome c as electron acceptors. K+ (+ valinomycin) and Ca2+ were employed as permeant cations. Three different methods were employed. In the first, known pulses of ferricyanide were added, and the total H+ ejected was determined with a glass electrode. Such measurements gave H+/2e-values exceeding 7.0 for both normal and tumor mitochondria with beta-hydroxybutyrate and other NAD-linked substrates; uptake of Ca2+ was also measured and gave the expected q+/2e-ratios. The second type of measurement was initiated by addition of ferricytochrome c to rat liver mitoplasts, with H+ ejection monitored with the glass electrode and ferricytochrome c reduction by dual-wavelength spectrophotometry; the H+/2e-ratios generally exceeded 7.0. In the third type of measurement, mixing and dilution artifacts were eliminated by oxidizing ferrocytochrome c in situ with a small amount of ferricyanide. H+/2e-ratios for rat liver mitoplasts oxidizing beta-hydroxybutyrate consistently approached or exceeded 7.5. Over 150 measurements made under a variety of conditions gave observed H+/2e-ejection ratios significantly exceeding 7.0, which correlated closely with H+/2e-measurements on sites 1 + 2 + 3, sites 2 + 3, and site 2. Factors leading to the deficit of the observed ratios from the integral value 8 for sites 1 + 2 were discussed.

  13. Tailored Immune Responses: Novel Effector Helper T Cell Subsets in Protective Immunity

    PubMed Central

    Kara, Ervin E.; Comerford, Iain; Fenix, Kevin A.; Bastow, Cameron R.; Gregor, Carly E.; McKenzie, Duncan R.; McColl, Shaun R.

    2014-01-01

    Differentiation of naïve CD4+ cells into functionally distinct effector helper T cell subsets, characterised by distinct “cytokine signatures,” is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the TH1/TH2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered. PMID:24586147

  14. Roles of community helpers in using the Medicare Part D benefit

    PubMed Central

    Hensley, Melissa A.

    2013-01-01

    Objectives To examine the experiences of low-income Part D beneficiaries with mental illness and their use of community helpers to access prescription medicines. Methods Individual semi-structured interviews were conducted with 26 Medicare beneficiaries with mental illness in community settings. The transcripts were analyzed for content related to community help-seeking and attitudes toward family and professional helpers. Results Medicare Part D beneficiaries with mental illness used the assistance of community helpers extensively. Pharmacists, nurses, community mental health case managers, and family members assisted beneficiaries with understanding their benefit plans and interpreting paperwork from plans and government agencies. Community helpers also assisted with tasks related to medication adherence. Mental health consumers appreciated the help that they received from family members and professionals. Conclusion This group of Medicare beneficiaries would have experienced difficulty in using their benefits and obtaining their medication without considerable help from professionals and family members in the community. PMID:21317520

  15. Identification of novel helper epitope peptides of Survivin cancer-associated antigen applicable to developing helper/killer-hybrid epitope long peptide cancer vaccine.

    PubMed

    Ohtake, Junya; Ohkuri, Takayuki; Togashi, Yuji; Kitamura, Hidemitsu; Okuno, Kiyotaka; Nishimura, Takashi

    2014-09-01

    We identified novel helper epitope peptides of Survivin cancer antigen, which are presented to both HLA-DRB1*01:01 and DQB1*06:01. The helper epitope also contained three distinct Survivin-killer epitopes presented to HLA-A*02:01 and A*24:02. This 19 amino-acids epitope peptide (SU18) induced weak responses of Survivin-specific CD4(+) and CD8(+) T cells though it contained both helper and killer epitopes. To enhance the vaccine efficacy, we synthesized a long peptide by conjugating SU18 peptide and another DR53-restricted helper epitope peptide (SU22; 12 amino-acids) using glycine-linker. We designated this artificial 40 amino-acids long peptide containing two helper and three killer epitopes as Survivin-helper/killer-hybrid epitope long peptide (Survivin-H/K-HELP). Survivin-H/K-HELP allowed superior activation of IFN-γ-producing CD4(+) Th1 cells and CD8(+) Tc1 cells compared with the mixture of its component peptides (SU18 and SU22) in the presence of OK-432-treated monocyte-derived DC (Mo-DC). Survivin-H/K-HELP-pulsed Mo-DC pretreated with OK-432 also exhibited sustained antigen-presentation capability of stimulating Survivin-specific Th1 cells compared with Mo-DC pulsed with a mixture of SU18 and SU22 short peptides. Moreover, we demonstrated that Survivin-H/K-HELP induced a complete response in a breast cancer patient with the induction of cellular and humoral immune responses. Thus, we believe that an artificially synthesized Survivin-H/K-HELP will become an innovative cancer vaccine.

  16. Ambivalent helpers and unhealthy choices: public health practitioners' narratives of Indigenous ill-health.

    PubMed

    Kowal, Emma; Paradies, Yin

    2005-03-01

    Public health practitioners in Australian indigenous health work in a complex political environment. Public health training is limited in providing them with conceptual tools needed to unpack the postcolonial nexus of 'fourth-world' health. A workshop was designed by the authors to facilitate critical reflection on how the concepts of race and culture are used in constructions of indigenous ill-health. It was attended by researchers, students, clinicians and bureaucrats working in public health in northern Australia. A thematic analysis of the workshop minutes provided insight into public health practitioners' narratives of Indigenous ill-health. The major themes that emerged included tension between structure and agency and between sameness and difference, and ambivalence surrounding the 'helper' identity of public health practitioners. We suggest that these narratives can be understood as attempts to maintain the moral integrity of both Indigenous people and practitioners. This task is necessitated by the specter of cultural relativism intrinsic to contemporary liberal discourses of multiculturalism that attempt to reconcile the universal rights of the citizen with the special rights of minority groups. We argue that the concepts of self-determination and neocolonialism mark the spaces where universal and particular discourses overlap and clash. Practitioners who seek to escape neocolonialism must inhabit only the discursive space of public health congruent with self-determination, leaving them in a bind common to many postcolonial situations. They must relieve the ill-health of indigenous people without acting upon them; change them without declaring that change is required.

  17. Evaluation of the web-based "home helper" support system using wireless Internet mobile phones.

    PubMed

    Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Sato, Haruhiko; Hahn, Allen W; Caldwell, W Morton

    2002-01-01

    In Japan, Home Helpers provide the home welfare and care services such as cooking, bathing, washing, cleaning, shopping, etc. Last year, we developed the web-based Home Helper support system using wireless Internet mobile phones for improving scheduling and record keeping efficiency and for eliminating unnecessary travel. We have evaluated by questionnaire whether the system can be easily operated. All in all, the system has performed satisfactorily and is in functional use daily.

  18. Evaluation of the T helper 17 axis in ankylosing spondylitis.

    PubMed

    Taylan, Ali; Sari, Ismail; Kozaci, Didem L; Yuksel, Arif; Bilge, Safak; Yildiz, Yasar; Sop, Gulten; Coker, Isil; Gunay, Necati; Akkoc, Nurullah

    2012-08-01

    To evaluate the T helper 17 (Th17) axis and its relation to tumor necrosis factor (TNF) alpha blockage and disease activity in ankylosing spondylitis (AS). The study included 127 AS patients (100M/27F) and 38 (27M/11F) controls. Spinal mobility was assessed by the bath ankylosing spondylitis metrology index (BASMI). Patients were also evaluated with the bath ankylosing spondylitis functional (BASFI) and bath ankylosing spondylitis disease activity index. Cytokines including IL-6, IL-12, TGF-β, IL-17A, and IL-23 were measured in serum sample using commercially available ELISA kits. Cytokines including IL-6, IL-12, TGF-β, IL-17, and IL-23 were significantly higher in the AS patients than the controls (P < 0.05). The Th-17-related cytokines were not different between patients treated with anti-TNF and conventional therapies (P > 0.05). Cytokines were also similar between patients with active and inactive disease (P > 0.05). On correlation analysis, IL-17 was correlated with IL-23 and IL-12 (P < 0.05) and IL-23 showed correlations with IL-12 and BASMI (P < 0.05). We found serum levels of Th-17-related cytokines to be significantly increased in the sera of AS patients. Disease activity and treatment type did not affect the level of these cytokines.

  19. Lazy group members are substitute helpers in carrion crows

    PubMed Central

    Baglione, Vittorio; Canestrari, Daniela; Chiarati, Elisa; Vera, Ruben; Marcos, Jose M.

    2010-01-01

    In many cooperatively breeding societies, helping effort varies greatly among group members, raising the question of why dominant individuals tolerate lazy subordinates. In groups of carrion crows Corvus corone corone, helpers at the nest increase breeders' reproductive success, but chick provisioning is unevenly distributed among non-breeders, with a gradient that ranges from individuals that work as much as the breeders to others that completely refrain from visiting the nest. Here we show that lazy non-breeders represent an insurance workforce that fully compensates for a reduction in the provisioning effort of another group member, avoiding a decrease in reproductive success. When we temporarily impaired a carer, decreasing its nest attendance, the laziest non-breeders increased their provisioning rate and individuals that initially refrained from visiting the nest started helping. Breeders, in contrast, did not increase chick provisioning. This shows that lazy non-breeders can buffer a sudden unfavourable circumstance and suggests that group stability relies on the potential contribution of group members in addition to their current effort. PMID:20519217

  20. Lazy group members are substitute helpers in carrion crows.

    PubMed

    Baglione, Vittorio; Canestrari, Daniela; Chiarati, Elisa; Vera, Ruben; Marcos, Jose M

    2010-11-07

    In many cooperatively breeding societies, helping effort varies greatly among group members, raising the question of why dominant individuals tolerate lazy subordinates. In groups of carrion crows Corvus corone corone, helpers at the nest increase breeders' reproductive success, but chick provisioning is unevenly distributed among non-breeders, with a gradient that ranges from individuals that work as much as the breeders to others that completely refrain from visiting the nest. Here we show that lazy non-breeders represent an insurance workforce that fully compensates for a reduction in the provisioning effort of another group member, avoiding a decrease in reproductive success. When we temporarily impaired a carer, decreasing its nest attendance, the laziest non-breeders increased their provisioning rate and individuals that initially refrained from visiting the nest started helping. Breeders, in contrast, did not increase chick provisioning. This shows that lazy non-breeders can buffer a sudden unfavourable circumstance and suggests that group stability relies on the potential contribution of group members in addition to their current effort.

  1. T helper cell activation and human retroviral pathogenesis.

    PubMed Central

    Copeland, K F; Heeney, J L

    1996-01-01

    T helper (Th) cells are of central importance in regulating many critical immune effector mechanisms. The profile of cytokines produced by Th cells correlates with the type of effector cells induced during the immune response to foreign antigen. Th1 cells induce the cell-mediated immune response, while Th2 cells drive antibody production. Th cells are the preferential targets of human retroviruses. Infections with human T-cell leukemia virus (HTLV) or human immunodeficiency virus (HIV) result in the expansion of Th cells by the action of HTLV (adult T-cell leukemia) or the progressive loss of T cells by the action of HIV (AIDS). Both retrovirus infections impart a high-level activation state in the host immune cells as well as systemically. However, diverging responses to this activation state have contrasting effects on the Th-cell population. In HIV infection, Th-cell loss has been attributed to several mechanisms, including a selective elimination of cells by apoptosis. The induction of apoptosis in HIV infection is complex, with many different pathways able to induce cell death. In contrast, infection of Th cells with HTLV-1 affords the cell a protective advantage against apoptosis. This advantage may allow the cell to escape immune surveillance, providing the opportunity for the development of Th-cell cancer. In this review, we will discuss the impact of Th-cell activation and general immune activation on human retrovirus expression with a focus upon Th-cell function and the progression to disease. PMID:8987361

  2. User manual for SPLASH (Single Panel Lamp and Shroud Helper).

    SciTech Connect

    Larsen, Marvin Elwood

    2006-02-01

    The radiant heat test facility develops test sets providing well-characterized thermal environments, often representing fires. Many of the components and procedures have become standardized to such an extent that the development of a specialized design tool to determine optimal configurations for radiant heat experiments was appropriate. SPLASH (Single Panel Lamp and Shroud Helper) is that tool. SPLASH is implemented as a user-friendly, Windows-based program that allows a designer to describe a test setup in terms of parameters such as number of lamps, power, position, and separation distance. This document is a user manual for that software. Any incidental descriptions of theory are only for the purpose of defining the model inputs. The theory for the underlying model is described in SAND2005-2947 (Ref. [1]). SPLASH provides a graphical user interface to define lamp panel and shroud designs parametrically, solves the resulting radiation enclosure problem for up to 2500 surfaces, and provides post-processing to facilitate understanding and documentation of analyzed designs.

  3. In vitro and in vivo characterization of microRNA-targeted alphavirus replicon and helper RNAs.

    PubMed

    Kamrud, Kurt I; Coffield, V McNeil; Owens, Gary; Goodman, Christin; Alterson, Kim; Custer, Max; Murphy, Michael A; Lewis, Whitney; Timberlake, Sarah; Wansley, Elizabeth K; Berglund, Peter; Smith, Jonathan

    2010-08-01

    Alphavirus-based replicon vector systems (family Togaviridae) have been developed as expression vectors with demonstrated potential in vaccine development against both infectious diseases and cancer. The single-cycle nature of virus-like replicon particles (VRP), generated by supplying the structural proteins from separate replicable helper RNAs, is an attractive safety component of these systems. MicroRNAs (miRNAs) have emerged as important cellular RNA regulation elements. Recently, miRNAs have been employed as a mechanism to attenuate or restrict cellular tropism of replication-competent viruses, such as oncolytic adenoviruses, vesicular stomatitis virus, and picornaviruses as well as nonreplicating lentiviral and adenoviral vectors. Here, we describe the incorporation of miRNA-specific target sequences into replicable alphavirus helper RNAs that are used in trans to provide the structural proteins required for VRP production. VRP were found to be efficiently produced using miRNA-targeted helper RNAs if miRNA-specific inhibitors were introduced into cells during VRP production. In the absence of such inhibitors, cellular miRNAs were capable of downregulating helper RNA replication in vitro. When miRNA targets were incorporated into a replicon RNA, cellular miRNAs were capable of downregulating replicon RNA replication upon delivery of VRP into animals, demonstrating activity in vivo. These data provide the first example of miRNA-specific repression of alphavirus replicon and helper RNA replication and demonstrate the feasibility of miRNA targeting of expression vector helper functions that are provided in trans.

  4. Predation risk is an ecological constraint for helper dispersal in a cooperatively breeding cichlid.

    PubMed Central

    Heg, Dik; Bachar, Zina; Brouwer, Lyanne; Taborsky, Michael

    2004-01-01

    Environmental conditions are thought to be responsible for the extent and benefits of cooperative breeding in many animal societies, but experimental tests are scarce. We manipulated predator pressure in the cooperatively breeding cichlid Neolamprologus pulcher in Lake Tanganyika, where predators have been suggested to influence helper and breeder survival, helper dispersal and group reproductive success. We varied the type and intensity of predation by releasing medium, large, or no predators inside large underwater cages enclosing two or three group territories. Helper and breeder survival, helper dispersal and group reproductive success decreased from the control, to the medium- and large-predator treatments. These effects were modified by helper body size and the number of adults protecting the group from predators, supporting the 'group augmentation hypothesis'. Predators forced helpers to stay closer to, and spend more time inside, protective shelters. The results demonstrate the importance of predators for group living in this species, and support the 'ecological constraints hypothesis' of cooperative breeding, in the sense that subordinates stay at home rather than leave and breed independently under the risk of predation. PMID:15556889

  5. A novel subset of helper T cells promotes immune responses by secreting GM-CSF

    PubMed Central

    Zhang, J; Roberts, A I; Liu, C; Ren, G; Xu, G; Zhang, L; Devadas, S; Shi, Yufang

    2013-01-01

    Helper T cells are crucial for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte macrophage-colony-stimulating factor (GM-CSF). By depleting major cytokines during the differentiation of CD4+ T cells in vitro, we derived cells that were found to produce large amounts of GM-CSF, but little of the cytokines produced by other helper T subsets. By their secretion of GM-CSF, this novel subset of helper T cells (which we have termed ThGM cells) promoted the production of cytokines by other T-cell subtypes, including type 1 helper T cell (Th1), type 2 helper T cell (Th2), type 1 cytotoxic T cell (Tc1), type 2 cytotoxic T cell (Tc2), and naive T cells, as evidenced by the fact that antibody neutralization of GM-CSF abolished this effect. ThGM cells were found to be highly prone to activation-induced cell death (AICD). Inhibitors of TRAIL or granzymes could not block AICD in ThGM cells, whereas inhibition of FasL/Fas interaction partially rescued ThGM cells from AICD. Thus, ThGM cells are a novel subpopulation of T helper cells that produce abundant GM-CSF, exhibit exquisite susceptibility to apoptosis, and therefore play a pivotal role in the regulation of the early stages of immune responses. PMID:24076588

  6. Predation risk is an ecological constraint for helper dispersal in a cooperatively breeding cichlid.

    PubMed

    Heg, Dik; Bachar, Zina; Brouwer, Lyanne; Taborsky, Michael

    2004-11-22

    Environmental conditions are thought to be responsible for the extent and benefits of cooperative breeding in many animal societies, but experimental tests are scarce. We manipulated predator pressure in the cooperatively breeding cichlid Neolamprologus pulcher in Lake Tanganyika, where predators have been suggested to influence helper and breeder survival, helper dispersal and group reproductive success. We varied the type and intensity of predation by releasing medium, large, or no predators inside large underwater cages enclosing two or three group territories. Helper and breeder survival, helper dispersal and group reproductive success decreased from the control, to the medium- and large-predator treatments. These effects were modified by helper body size and the number of adults protecting the group from predators, supporting the 'group augmentation hypothesis'. Predators forced helpers to stay closer to, and spend more time inside, protective shelters. The results demonstrate the importance of predators for group living in this species, and support the 'ecological constraints hypothesis' of cooperative breeding, in the sense that subordinates stay at home rather than leave and breed independently under the risk of predation.

  7. Helper T Cell Responses to Respiratory Viruses in the Lung: Development, Virus Suppression, and Pathogenesis.

    PubMed

    Miyauchi, Kosuke

    The lung is an important line of defense that is exposed to respiratory infectious pathogens, including viruses. Lung epithelial cells and/or alveolar macrophages are initially targeted by respiratory viruses. Once respiratory viruses invade the cells of the lung, innate immunity is activated to inhibit viral replication. Innate immune signaling also activates virus-specific adaptive immune responses. The helper T cells play pivotal roles in the humoral and cellular adaptive immune responses. Helper T cells are categorized into several distinct subsets (e.g., TH1, TH2, TFH, TH17, and Treg), differentiated by their corresponding signature cytokine production profiles. Helper T cells migrate into the airways and the lung after respiratory virus infections. The behavior of the helper T cells differs with each respiratory virus-in some cases, the response is beneficial; in other cases, it is harmful. Here, the general mechanisms underlying helper T cell responses to viral infections are summarized, and functions and reactions of the helper T cells against some respiratory viral infections are discussed. In influenza virus infections, TH1 cells, which regulate the cytotoxic T lymphocytes and IgG2 responses, are efficiently activated. TFH cells required for highly specific and memory humoral responses are also activated on influenza infections. In infections with respiratory syncytial virus and rhinovirus, TH2 cells develop in the lung and contribute to pathogenesis. In many cases, Treg cells inhibit excessive virus-specific T cell responses that can contribute to viral pathogenicity.

  8. Cre Levels Limit Packaging Signal Excision Efficiency in the Cre/loxP Helper-Dependent Adenoviral Vector System

    PubMed Central

    Ng, Philip; Evelegh, Carole; Cummings, Derek; Graham, Frank L.

    2002-01-01

    Helper-dependent (HD) adenovirus vectors devoid of all viral coding sequences have a large cloning capacity and provide long-term transgene expression in vivo with negligible toxicity, making them attractive vectors for gene therapy. Currently, the most efficient means of producing HD vectors involves coinfecting 293 cells expressing Cre with the HD vector and a helper virus bearing a packaging signal flanked by loxP sites. Cre-mediated packaging signal excision renders the helper virus genome unpackageable but still able to replicate and provide helper functions for HD vector propagation. Typically, helper virus contamination is ≤1% pre- and ≤0.1% postpurification by CsCl banding. While these contamination levels are low, further reduction is desirable. However, this objective has not been realized since the Cre/loxP system was first developed. This lack of progress is due, at least in part, to our lack of understanding of the origins of the contaminating helper virus, thus rendering its reduction or elimination difficult to achieve. This study was designed to investigate the possible sources of contaminating helper virus persisting during HD vector amplification. The results revealed that Cre is limiting in helper virus-infected Cre-expressing 293 cells, thereby permitting helper viruses to escape packaging signal excision and propagate. The results of this study should provide a foundation for developing rational strategies to further reduce or possibly eliminate the contaminating helper virus. PMID:11932383

  9. Tbet Deficiency Causes T Helper Cell Dependent Airways Eosinophilia and Mucus Hypersecretion in Response to Rhinovirus Infection

    PubMed Central

    Glanville, Nicholas; Schröder, Armin; Walton, Ross P.; Johnston, Sebastian L.

    2016-01-01

    Current understanding of adaptive immune, particularly T cell, responses to human rhinoviruses (RV) is limited. Memory T cells are thought to be of a primarily T helper 1 type, but both T helper 1 and T helper 2 memory cells have been described, and heightened T helper 2/ lessened T helper 1 responses have been associated with increased RV-induced asthma exacerbation severity. We examined the contribution of T helper 1 cells to RV-induced airways inflammation using mice deficient in the transcription factor T-Box Expressed In T Cells (Tbet), a critical controller of T helper 1 cell differentiation. Using flow cytometry we showed that Tbet deficient mice lacked the T helper 1 response of wild type mice and instead developed mixed T helper 2/T helper 17 responses to RV infection, evidenced by increased numbers of GATA binding protein 3 (GATA-3) and RAR-related orphan receptor gamma t (RORγt), and interleukin-13 and interleukin-17A expressing CD4+ T cells in the lung. Forkhead box P3 (FOXP3) and interleukin-10 expressing T cell numbers were unaffected. Tbet deficient mice also displayed deficiencies in lung Natural Killer, Natural Killer T cell and γδT cell responses, and serum neutralising antibody responses. Tbet deficient mice exhibited pronounced airways eosinophilia and mucus production in response to RV infection that, by utilising a CD4+ cell depleting antibody, were found to be T helper cell dependent. RV induction of T helper 2 and T helper 17 responses may therefore have an important role in directly driving features of allergic airways disease such as eosinophilia and mucus hypersecretion during asthma exacerbations. PMID:27683080

  10. [Integrity].

    PubMed

    Gómez Rodríguez, Rafael Ángel

    2014-01-01

    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  11. Artemisinin analogue SM934 attenuate collagen-induced arthritis by suppressing T follicular helper cells and T helper 17 cells

    PubMed Central

    Lin, Ze-Min; Yang, Xiao-Qian; Zhu, Feng-Hua; He, Shi-Jun; Tang, Wei; Zuo, Jian-Ping

    2016-01-01

    SM934 is an artemisinin analogue with immunosuppressive properties and potent therapeutic activity against lupus-like diseases in autoimmune mice. In this report, the therapeutic efficacy and underlying mechanisms of SM934 on rheumatoid arthritis (RA) was investigated using collagen-induced arthritis (CIA) in DBA/1J mice. We demonstrated that SM934 treatment alleviate the severity of arthritis in CIA mice with established manifestations. The therapeutic benefits were associated with ameliorated joint swelling and reduced extent of bone erosion and destruction. Further, administration of SM934 diminished the development of T follicular helper (Tfh) cells and Th17 cells and suppressed the production of pathogenic antibodies, without altering the proportion of germinal center B cells. Ex vivo, SM934 treatment inhibited the bovine type II collagen (CII) induced proliferation and inflammatory cytokines secretion of CII -reactive T cells. In vitro, SM934 impeded the polarization of naïve CD4+ T cells into Tfh cells and the expression of its transcript factor Bcl-6. Moreover, SM934 decreased the IL-21-producing CD4+ T cells and dampened the IL-21 downstream signaling through STAT3. These finding offered the convincing evidence that artemisinin derivative might attenuate RA by simultaneously interfering with the generation of Tfh cells and Th17 cells as well as the subsequent antibody-mediated immune responses. PMID:27897259

  12. The Roles of T Helper 1, T Helper 17 and Regulatory T Cells in the Pathogenesis of Sarcoidosis.

    PubMed

    Mortaz, Esmaeil; Rezayat, Fatemeh; Amani, Davar; Kiani, Arda; Garssen, Johan; Adcock, Ian M; Velayati, Aliakbar

    2016-08-01

    Sarcoidosis is a systemic granulomatous disorder of unidentified etiology, with a heterogeneous clinical presentation. It is characterized by a reduced delayed-type hypersensitivity to tuberculin and common antigens. The balance between Th1, Th17 and Regulatory T(Treg) cells controls T-cell proliferation and activation.The Th17/Treg ratio in the peripheral blood and bronchoalveolar lavage fluidis increased in patients with active sarcoidosis. Amplified IL-17A expression in granulomas and the presence of IL-17A+, IL-17A+IL-4+ and IL-17A+IFN-γ+ memory T helper cells in the circulation and BAL indicate Th17 cell involvement in granuloma induction and/or maintenance in sarcoidosis. Sarcoidosis should therefore be considered as a Th1/Th17 multisystem disorder and anti-IL-17/Th17 approaches that control and reduce IL-17Amay be an option, therefore, for the treatment of sarcoidosis.Here we provide a short overview as to the role of Th17 cells as critical cells in the pathogenesis of sarcoidosis.

  13. T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4+ T cells

    PubMed Central

    Spolski, Rosanne; Robertson, Avril A. B.; Klos, Andreas; Rheinheimer, Claudia; Dutow, Pavel; Woodruff, Trent M.; Yu, Zu Xi; O'Neill, Luke A.; Coll, Rebecca C.; Sher, Alan; Leonard, Warren J.; Köhl, Jörg; Monk, Pete; Cooper, Matthew A.; Arno, Matthew; Afzali, Behdad; Lachmann, Helen J.; Cope, Andrew P.; Mayer-Barber, Katrin D.; Kemper, Claudia

    2016-01-01

    The NLRP3 inflammasome controls interleukin-1β maturation in antigen-presenting cells, but a direct role for NLRP3 in human adaptive immune cells has not been described. We found that the NLRP3 inflammasome assembles in human CD4+ T cells and initiates caspase-1–dependent interleukin-1β secretion, thereby promoting interferon-γ production and T helper 1 (TH1) differentiation in an autocrine fashion. NLRP3 assembly requires intracellular C5 activation and stimulation of C5a receptor 1 (C5aR1), which is negatively regulated by surface-expressed C5aR2. Aberrant NLRP3 activity in T cells affects inflammatory responses in human autoinflammatory disease and in mouse models of inflammation and infection. Our results demonstrate that NLRP3 inflammasome activity is not confined to “innate immune cells” but is an integral component of normal adaptive TH1 responses. PMID:27313051

  14. T helper 1 immunity requires complement-driven NLRP3 inflammasome activity in CD4⁺ T cells.

    PubMed

    Arbore, Giuseppina; West, Erin E; Spolski, Rosanne; Robertson, Avril A B; Klos, Andreas; Rheinheimer, Claudia; Dutow, Pavel; Woodruff, Trent M; Yu, Zu Xi; O'Neill, Luke A; Coll, Rebecca C; Sher, Alan; Leonard, Warren J; Köhl, Jörg; Monk, Pete; Cooper, Matthew A; Arno, Matthew; Afzali, Behdad; Lachmann, Helen J; Cope, Andrew P; Mayer-Barber, Katrin D; Kemper, Claudia

    2016-06-17

    The NLRP3 inflammasome controls interleukin-1β maturation in antigen-presenting cells, but a direct role for NLRP3 in human adaptive immune cells has not been described. We found that the NLRP3 inflammasome assembles in human CD4(+) T cells and initiates caspase-1-dependent interleukin-1β secretion, thereby promoting interferon-γ production and T helper 1 (T(H)1) differentiation in an autocrine fashion. NLRP3 assembly requires intracellular C5 activation and stimulation of C5a receptor 1 (C5aR1), which is negatively regulated by surface-expressed C5aR2. Aberrant NLRP3 activity in T cells affects inflammatory responses in human autoinflammatory disease and in mouse models of inflammation and infection. Our results demonstrate that NLRP3 inflammasome activity is not confined to "innate immune cells" but is an integral component of normal adaptive T(H)1 responses.

  15. The transcription factor Runx3 guards cytotoxic CD8(+) effector T cells against deviation towards follicular helper T cell lineage.

    PubMed

    Shan, Qiang; Zeng, Zhouhao; Xing, Shaojun; Li, Fengyin; Hartwig, Stacey M; Gullicksrud, Jodi A; Kurup, Samarchith P; Van Braeckel-Budimir, Natalija; Su, Yao; Martin, Matthew D; Varga, Steven M; Taniuchi, Ichiro; Harty, John T; Peng, Weiqun; Badovinac, Vladimir P; Xue, Hai-Hui

    2017-08-01

    Activated CD8(+) T cells differentiate into cytotoxic effector (TEFF) cells that eliminate target cells. How TEFF cell identity is established and maintained is not fully understood. We found that Runx3 deficiency limited clonal expansion and impaired upregulation of cytotoxic molecules in TEFF cells. Runx3-deficient CD8(+) TEFF cells aberrantly upregulated genes characteristic of follicular helper T (TFH) cell lineage, including Bcl6, Tcf7 and Cxcr5. Mechanistically, the Runx3-CBFβ transcription factor complex deployed H3K27me3 to Bcl6 and Tcf7 genes to suppress the TFH program. Ablating Tcf7 in Runx3-deficient CD8(+) TEFF cells prevented the upregulation of TFH genes and ameliorated their defective induction of cytotoxic genes. As such, Runx3-mediated Tcf7 repression coordinately enforced acquisition of cytotoxic functions and protected the cytotoxic lineage integrity by preventing TFH-lineage deviation.

  16. Integration

    ERIC Educational Resources Information Center

    Kalyn, Brenda

    2006-01-01

    Integrated learning is an exciting adventure for both teachers and students. It is not uncommon to observe the integration of academic subjects such as math, science, and language arts. However, educators need to recognize that movement experiences in physical education also can be linked to academic curricula and, may even lead the…

  17. Newly identified helper bacteria stimulate ectomycorrhizal formation in Populus

    SciTech Connect

    Labbe, Jessy L.; Weston, David J.; Dunkirk, Nora; Pelletier, Dale A.; Tuskan, Gerald A.

    2014-10-24

    Mycorrhiza helper bacteria (MHB) are known to increase host root colonization by mycorrhizal fungi but the molecular mechanisms and potential tripartite trophic interactions are poorly understood. Through an effort to study Populus microbiome, we isolated 21 Pseudomonas strains from native Populus deltoides roots. These bacterial isolates were characterized and screened for MHB effectiveness on the Populus-Laccaria system. Two other Pseudomonas strains (i.e., Pf-5 and BBc6R8) from existing collections were also included as reference in the screening process. We analyzed Laccaria bicolor S238N growth rate, mycelial architecture and transcriptional changes induced by the contrasting Pseudomonas strains (i.e., inhibitory, neutral and beneficial). We characterized 17 out of the 21 Pseudomonas strains from the Populus rhizosphere with positive effects on L. bicolor S238N growth, as well as on Populus root architecture and colonization by L. bicolor S238N across three Populus species. Four of seven reporter genes, Tra1, Tectonin2, Gcn5 and Cipc1, thought to be specific to the interaction with strain BBc6R8, were induced or repressed while interacting with six (i.e., GM17, GM33, GM41, GM48, Pf-5 and BBc6R8) of the tested Pseudomonas strains. GM41 promoted the highest roots colonization across three Populus species but most notably in P. deltoides, which is otherwise, poorly colonized by L. bicolor. Here we report novel MHB strains isolated from native Populus that improve roots colonization. This tripartite relationship could be exploited in nursery production for target Populus species/genotypes as a means of improving establishment and survival in marginal lands.

  18. Newly identified helper bacteria stimulate ectomycorrhizal formation in Populus

    PubMed Central

    Labbé, Jessy L.; Weston, David J.; Dunkirk, Nora; Pelletier, Dale A.; Tuskan, Gerald A.

    2014-01-01

    Mycorrhiza helper bacteria (MHB) are known to increase host root colonization by mycorrhizal fungi but the molecular mechanisms and potential tripartite interactions are poorly understood. Through an effort to study Populus microbiome, we isolated 21 Pseudomonas strains from native Populus deltoides roots. These bacterial isolates were characterized and screened for MHB effectiveness on the Populus-Laccaria system. Two additional Pseudomonas strains (i.e., Pf-5 and BBc6R8) from existing collections were included for comparative purposes. We analyzed the effect of co-cultivation of these 23 individual Pseudomonas strains on Laccaria bicolor “S238N” growth rate, mycelial architecture and transcriptional changes. Nineteen of the 23 Pseudomonas strains tested had positive effects on L. bicolor S238N growth, as well as on mycelial architecture, with strains GM41 and GM18 having the most significant effect. Four of seven L. bicolor reporter genes, Tra1, Tectonin2, Gcn5, and Cipc1, thought to be regulated during the interaction with MHB strain BBc6R8, were induced or repressed, while interacting with Pseudomonas strains GM17, GM33, GM41, GM48, Pf-5, and BBc6R8. Strain GM41 promoted the highest roots colonization across three Populus species but most notably in P. deltoides, which is otherwise poorly colonized by L. bicolor. Here we report novel MHB strains isolated from native Populus that improve L. bicolor root colonization on Populus. This tripartite relationship could be exploited for Populus species/genotypes nursery production as a means of improving establishment and survival in marginal lands. PMID:25386184

  19. T helper cell cytokine profiles after endurance exercise.

    PubMed

    Kakanis, Michael W; Peake, Jonathan; Brenu, Ekua W; Simmonds, Michael; Gray, Bon; Marshall-Gradisnik, Sonya M

    2014-09-01

    Endurance exercise can cause immunosuppression and increase the risk of upper respiratory illness. The present study examined changes in the secretion of T helper (Th) cell cytokines after endurance exercise. Ten highly trained road cyclists [mean±SEM: age 24.2±1.7 years; height 1.82±0.02 m; body mass 73.8±2.0 kg; peak oxygen uptake 65.9±2.3 mL/(kg•min)] performed 2 h of cycling exercise at 90% of the second ventilatory threshold. Peripheral blood mononuclear cells were isolated and stimulated with phytohemagglutinin. Plasma cortisol concentrations and the concentration of Th1/Th2/Th17 cell cytokines were examined. Data were analyzed using both traditional statistics and magnitude-based inferences. Results revealed a significant decrease in plasma cortisol at 4-24 h postexercise compared with pre-exercise values. Qualitative analysis revealed postexercise changes in concentrations of plasma cortisol, IL-2, TNF, IL-4, IL-6, IL-10, and IL-17A compared with pre-exercise values. A Th1/Th2 shift was evident immediately postexercise. Furthermore, for multiple cytokines, including IL-2 and TNF (Th1), IL-6 and IL-10 (Th2), and IL-17 (Th17), no meaningful change in concentration occurred until more than 4 h postexercise, highlighting the duration of exercise-induced changes in immune function. These results demonstrate the importance of considering "clinically" significant versus statistically significant changes in immune cell function after exercise.

  20. Distinct Regulation of IL-17 in Human Helper T Lymphocytes

    PubMed Central

    Chen, Zhi; Tato, Cristina M.; Muul, Linda; Laurence, Arian; O’Shea, John J.

    2008-01-01

    Objective IL-17 producing helper T cells have been proposed to represent a separate lineage of CD4+ cells, designated Th17 cells, which are regulated by the transcription factor RORγt. However, despite advances in understanding murine Th17 differentiation, a systematic assessment of factors that promote the differentiation of naïve human T cells to Th17 cells has not been reported. This present study was undertaken to assess the effects of cytokines known to promote murine Th17 cells on naïve human CD4+ T cells. Methods Human naïve and memory CD4+ T cells isolated from peripheral blood were activated and cultured with various cytokines. Cytokine production was measured by ELISA and flow cytometry. mRNA was measured by quantitative PCR. Results In response to CD3/CD28 stimulation alone, human memory T cells rapidly produced IL-17, whereas naïve T cells expressed low levels. TGF-β1 and IL-6 upregulated RORγt expression but did not induce Th17 differentiation of naïve CD4+ T cells. However, IL-23 upregulated its own receptor and was an important inducer of IL-17 and IL-22. Conclusion The present data demonstrate the differential regulation of IL-17 and RORγt expression in human CD4+ T cells compared to murine cells. Optimal conditions for the development of IL-17-producing T cells from murine naïve precursors are ineffective in human T cells. Conversely, IL-23 promoted generation of human Th17 cells but was also a very potent inducer of other proinflammatory cytokines. These findings may have important implications in the pathogenesis of human autoimmunity compared to mouse models. PMID:17763419

  1. Newly identified helper bacteria stimulate ectomycorrhizal formation in Populus

    DOE PAGES

    Labbe, Jessy L.; Weston, David J.; Dunkirk, Nora; ...

    2014-10-24

    Mycorrhiza helper bacteria (MHB) are known to increase host root colonization by mycorrhizal fungi but the molecular mechanisms and potential tripartite trophic interactions are poorly understood. Through an effort to study Populus microbiome, we isolated 21 Pseudomonas strains from native Populus deltoides roots. These bacterial isolates were characterized and screened for MHB effectiveness on the Populus-Laccaria system. Two other Pseudomonas strains (i.e., Pf-5 and BBc6R8) from existing collections were also included as reference in the screening process. We analyzed Laccaria bicolor S238N growth rate, mycelial architecture and transcriptional changes induced by the contrasting Pseudomonas strains (i.e., inhibitory, neutral and beneficial).more » We characterized 17 out of the 21 Pseudomonas strains from the Populus rhizosphere with positive effects on L. bicolor S238N growth, as well as on Populus root architecture and colonization by L. bicolor S238N across three Populus species. Four of seven reporter genes, Tra1, Tectonin2, Gcn5 and Cipc1, thought to be specific to the interaction with strain BBc6R8, were induced or repressed while interacting with six (i.e., GM17, GM33, GM41, GM48, Pf-5 and BBc6R8) of the tested Pseudomonas strains. GM41 promoted the highest roots colonization across three Populus species but most notably in P. deltoides, which is otherwise, poorly colonized by L. bicolor. Here we report novel MHB strains isolated from native Populus that improve roots colonization. This tripartite relationship could be exploited in nursery production for target Populus species/genotypes as a means of improving establishment and survival in marginal lands.« less

  2. Reducing the physical work load and strain of personal helpers through clothing redesign.

    PubMed

    Nevala, Nina; Holopainen, Jaana; Kinnunen, Oili; Hänninen, Osmo

    2003-11-01

    This study assessed the effects of redesigning clients' clothing on the physical work load and strain of personal helpers. Five women, aged 18-54 years, who helped persons with physical disabilities were measured at their worksites before and after development of the clothes worn by clients. The physical work load and strain of the helpers' dressing/undressing of clients were determined from their hand and back movements, work time, muscular activity, heart rate (HR), percentage of heart rate range (%HRR), and rating of perceived exertion (RPE). The muscular activity of the right (p=0.05) and left (p=0.02) trapezius muscles, HR (p=0.03), and %HRR (p=0.03) of the helpers were lower when the new outerwear was used in place of traditional outerwear. Four helpers reported lower perceived exertion, and three had shorter work time with the new outerwear. This study showed that redesigning clients' clothing can help reduce the physical work load and strain of personal helpers.

  3. Personal experience in professional narratives: the role of helpers' families in their work with terror victims.

    PubMed

    Shamai, Michal

    2005-06-01

    This article describes research on the narratives of social workers who help terror victims, focusing on the relationship between the helpers' families and their work. Qualitative analysis of three training groups of social workers who are responsible for helping in the event of terror attacks in different parts of Israel, and of three debriefing groups for social workers after terror attacks, reveals that the helpers' families play a role in the narratives constructed by the helpers. Two main themes were identified. The first centers on the interaction between work and the family, and shows that in the situation of a terror attack, the conflict between the two disappears and the family often serves as a support system for the helpers. The second theme refers to the family dimension alone, and focuses on the dichotomy between vitality and loss. The way that family life events affect helpers'professional intervention is described. The findings are discussed in light of Conservation of Resources Theory, the fight-flight response to threat, and the concept of the family as a source of safety and risk taking.

  4. Distinct T helper cell dependence of memory B-cell proliferation versus plasma cell differentiation.

    PubMed

    Zabel, Franziska; Fettelschoss, Antonia; Vogel, Monique; Johansen, Pål; Kündig, Thomas M; Bachmann, Martin F

    2017-03-01

    Several memory B-cell subclasses with distinct functions have been described, of which the most effective is the class-switched (CS) memory B-cell population. We have previously shown, using virus-like particles (VLPs), that the proliferative potential of these CS memory B cells is limited and they fail to re-enter germinal centres (GCs). However, VLP-specific memory B cells quickly differentiated into secondary plasma cells (PCs) with the virtue of elevated antibody production compared with primary PCs. Whereas the induction of VLP(+) memory B cells was strongly dependent on T helper cells, we were wondering whether re-stimulation of VLP(+) memory B cells and their differentiation into secondary PCs would also require T helper cells. Global absence of T helper cells led to strongly impaired memory B cell proliferation and PC differentiation. In contrast, lack of interleukin-21 receptor-dependent follicular T helper cells or CD40 ligand signalling strongly affected proliferation of memory B cells, but differentiation into mature secondary PCs exhibiting increased antibody production was essentially normal. This contrasts with primary B-cell responses, where a strong dependence on CD40 ligand but limited importance of interleukin-21 receptor was seen. Hence, T helper cell dependence differs between primary and secondary B-cell responses as well as between memory B-cell proliferation and PC differentiation.

  5. Definition of herpes simplex virus type 1 helper activities for adeno-associated virus early replication events.

    PubMed

    Alazard-Dany, Nathalie; Nicolas, Armel; Ploquin, Aurélie; Strasser, Regina; Greco, Anna; Epstein, Alberto L; Fraefel, Cornel; Salvetti, Anna

    2009-03-01

    The human parvovirus Adeno-Associated Virus (AAV) type 2 can only replicate in cells co-infected with a helper virus, such as Adenovirus or Herpes Simplex Virus type 1 (HSV-1); whereas, in the absence of a helper virus, it establishes a latent infection. Previous studies demonstrated that the ternary HSV-1 helicase/primase (HP) complex (UL5/8/52) and the single-stranded DNA-Binding Protein (ICP8) were sufficient to induce AAV-2 replication in transfected cells. We independently showed that, in the context of a latent AAV-2 infection, the HSV-1 ICP0 protein was able to activate rep gene expression. The present study was conducted to integrate these observations and to further explore the requirement of other HSV-1 proteins during early AAV replication steps, i.e. rep gene expression and AAV DNA replication. Using a cellular model that mimics AAV latency and composite constructs coding for various sets of HSV-1 genes, we first confirmed the role of ICP0 for rep gene expression and demonstrated a synergistic effect of ICP4 and, to a lesser extent, ICP22. Conversely, ICP27 displayed an inhibitory effect. Second, our analyses showed that the effect of ICP0, ICP4, and ICP22 on rep gene expression was essential for the onset of AAV DNA replication in conjunction with the HP complex and ICP8. Third, and most importantly, we demonstrated that the HSV-1 DNA polymerase complex (UL30/UL42) was critical to enhance AAV DNA replication to a significant level in transfected cells and that its catalytic activity was involved in this process. Altogether, this work represents the first comprehensive study recapitulating the series of early events taking place during HSV-1-induced AAV replication.

  6. Change in the number of informal helpers of frail older persons.

    PubMed Central

    Miller, B; Furner, S E

    1994-01-01

    Little is known of the extent to which helper networks of frail older persons change over time and what factors are associated with change. Few national estimates of the scope of change exist to aid policy planners. This study provides national estimates of changes in the size of the informal helping network of frail elderly by sociodemographic and functional status subgroups of this segment of the population. The data are drawn from the 1982-84 National Long Term Care Survey, which included longitudinal followup of 4,530 respondents living in the community at both times. Bivariate patterns of change over 2 years in the number of informal helpers were analyzed. Sociodemographic factors (sex, age group, and race) of the frail elderly may be more important influences on change in the number of helpers than functional status expressed in terms of their limitations in activities of daily living. PMID:8041861

  7. Essential competencies for the education of nursing assistants and care helpers in elderly care.

    PubMed

    Oeseburg, Barth; Hilberts, Rudi; Roodbol, Petrie F

    2015-10-01

    The Dutch health care system faces huge challenges with regard to the demand on elderly care and the competencies of professionals required to meet this demand. However, a recent study showed that the curricula in vocational education for nursing assistants and care helpers remains inadequate to prepare them for the social and healthcare needs of the elderly. To determine the essential competencies for the initial education of nursing assistants and care helpers in elderly care. First, a draft version of essential competencies for the education of nursing assistants and care helpers in elderly care (N=120) was developed and approved by experts, also members of the project steering committee. Second, a Delphi survey was conducted to determine the essential competencies. The Delphi panel consisted of eleven field experts (teachers/educational developers) working for different vocational education training colleges in the Netherlands. Ten panel members participated in a two-round consensus building process via email. A definitive set of 116 essential competencies for the initial education of nursing assistants and 42 essential competencies for the initial education of care helpers were determined. The competencies in the definitive set are more in line with social and healthcare needs of the elderly like: autonomy, daily functioning prevention of health problems, healthy ageing and wellbeing, involvement of informal care, collaboration between professionals and informal care. The main challenge now is to translate these competencies into educational programmes for vocational education training colleges for care helpers and nursing assistants. Recommendations are made for the implementation of these competencies in the Dutch vocational education training colleges for care helpers and nursing assistants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Associations of Warmth and Control of Filipina Domestic Helpers and Mothers to Hong Kong Kindergarten Children's Social Competence

    ERIC Educational Resources Information Center

    Ip, Hoi Man; Cheung, Sum Kwing; McBride-Chang, Catherine; Chang, Lei

    2008-01-01

    Research Findings: Across 63 Hong Kong families, both Filipina domestic helpers and mothers separately rated their own caregiving style (warmth and control) and kindergarten children's social competence. Results indicated that Filipina helpers rated themselves as higher in warmth than mothers did. In addition, self-rated warmth of both caregivers,…

  9. Helpers benefit offspring in both the short and long-term in the cooperatively breeding banded mongoose.

    PubMed

    Hodge, Sarah J

    2005-12-07

    Helpers in cooperative and communal breeding species are thought to accrue fitness benefits through improving the condition and survival of the offspring that they care for, yet few studies have shown conclusively that helpers benefit the offspring they rear. Using a novel approach to control for potentially confounding group-specific variables, I compare banded mongoose (Mungos mungo) offspring within the same litter that differ in the amount of time they spend with a helper, and hence the amount of care they receive. I show that pups that spend more time in close proximity to a helper are fed more, grow faster and have a higher probability of survival to independence than their littermates. Moreover, high growth rates during development reduce the age at which females breed for the first time, suggesting that helpers can improve the future fecundity of the offspring for which they care. These results provide strong evidence that it is the amount of investment per se that benefits offspring, rather than some correlate such as territory quality, and validate the assumption that helpers improve the reproductive success of breeders, and hence may gain fitness benefits from their actions. Furthermore, the finding that helpers may benefit offspring in the long-term suggests that current studies underestimate the fitness benefits that helpers gain from rearing the offspring of others.

  10. DNA-based methods to prepare helper virus-free herpes amplicon vectors and versatile design of amplicon vector plasmids.

    PubMed

    Kasai, Kazue; Saeki, Yoshinaga

    2006-06-01

    The herpes simplex virus (HSV) amplicon vector is a versatile plasmid-based gene delivery vehicle with a large transgene capacity (up to 150 kb) and the ability to infect a broad range of cell types. The vector system was originally developed by Frenkel and her colleagues in 1980. Ever since, a great deal of effort by various investigators has been directed at minimizing the toxicity associated with the inevitable contamination by helper virus. In 1996, Fraefel and his colleagues successfully devised a cosmid-based packaging system that was free of contamination by helper virus (so-called helper virus-free packaging), which utilized as helper a set of 5 overlapping cosmid clones that covered the entire HSV genome, which lacked the DNA packaging/cleavage signals. With the helper virus-free system, broader applications of the vector became possible. Cloning of the entire HSV genome in bacteria artificial chromosome (BAC) plasmids enabled stable maintenance and propagation of the helper HSV genome in bacteria. It also allowed for the development of BAC-based helper virus-free packaging systems. In this article, we review various versions of DNA-based methods to prepare HSV amplicon vectors free of helper virus contamination. We also examine recent advances in vector design, including methods of vector construction, hybrid amplicon vectors, and the infectious BAC system. Future directions in improving packaging systems and vector designs are discussed.

  11. Instructed subsets or agile swarms: how T-helper cells may adaptively counter uncertainty with variability and plasticity.

    PubMed

    Schrom, Edward C; Graham, Andrea L

    2017-09-16

    Over recent years, extensive phenotypic variability and plasticity have been revealed among the T-helper cells of the mammalian adaptive immune system, even within clonal lineages of identical antigen specificity. This challenges the conventional view that T-helper cells assort into functionally distinct subsets following differential instruction by the innate immune system. We argue that the adaptive value of coping with uncertainty can reconcile the 'instructed subset' framework with T-helper variability and plasticity. However, we also suggest that T-helper cells might better be understood as agile swarms engaged in collective decision-making to promote host fitness. With rigorous testing, the 'agile swarms' framework may illuminate how variable and plastic individual T-helper cells interact to create coherent immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Functional human Th17 clones with WT1-specific helper activity.

    PubMed

    Tachino, Sho; Fujiki, Fumihiro; Oka, Yoshihiro; Tsuboi, Akihiro; Morimoto, Soyoko; Lin, Yu-Hung; Tamanaka, Taichi; Kondo, Kenta; Nakajima, Hiroko; Nishida, Sumiyuki; Hosen, Naoki; Oji, Yusuke; Kumanogoh, Atsushi; Sugiyama, Haruo

    2013-04-01

    Th17 plays important roles in the pathogenesis of various inflammatory and autoimmune diseases. Although the importance of Th17 in tumor immunity has also been suggested, precise roles of tumor-associated antigen-specific Th17 still remain poorly understood, especially in humans. We previously identified WT1332, a 16-mer helper epitope derived from tumor-associated antigen Wilms' tumor gene 1 (WT1) product, and WT1332-specific Th1 clones were established. In the present study, WT1-specific Th17 clones were established by the stimulation of peripheral blood mononuclear cells with the WT1332 helper peptide under human Th17-polarizing conditions. The WT1-specific Th17 clone exhibited the helper function for proliferation of conventional CD4(+) T cells in the antigenic stimulation-specific manner. This is the first report of establishment of functional Th17 clones with both antigen (WT1332) specificity and antigen-specific helper activity. Th17 clones established here and the method to establish antigen-specific Th17 clones should be a useful tool to further analyze the roles of human Th17 in tumor immunity.

  13. Beyond the Reach of Ethics and Equity? Depersonalisation and Dehumanisation in Foreign Domestic Helper Narratives

    ERIC Educational Resources Information Center

    Ladegaard, Hans J.

    2013-01-01

    This paper analyses narratives told by foreign domestic helpers (FDHs) in a Hong Kong church shelter. The narratives provide evidence that FDHs appear to be untouched by the ethics and equity of Hong Kong society. They are denied the rights that apply to other groups: the right to eat, rest and talk; they are humiliated and denigrated, and the…

  14. CD4 T-helper cell cytokine phenotypes and antibody response following tetanus toxoid booster immunization

    USDA-ARS?s Scientific Manuscript database

    Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10+ cells. Eight healthy subjects were given a TT booster vacci...

  15. Natural Helpers as Street Health Workers Among the Black Urban Elderly.

    ERIC Educational Resources Information Center

    Milligan, Sharon; And Others

    1987-01-01

    Analyzed five-year experience of neighborhood-based, volunteer geriatric health outreach program developed by consortium of health and social agencies. Found outreach program enhanced network of natural community helpers through organized program in which Street Health Workers provided support to older adults and families. (Author)

  16. "Helping" versus "Being a Helper": Invoking the Self to Increase Helping in Young Children

    ERIC Educational Resources Information Center

    Bryan, Christopher J.; Master, Allison; Walton, Gregory M.

    2014-01-01

    Can a subtle linguistic cue that invokes the self motivate children to help? In two experiments, 3- to 6-year-old children (N = 149) were exposed to the idea of "being a helper" (noun condition) or "helping" (verb condition). Noun wording fosters the perception that a behavior reflects an identity--the kind of person one is.…

  17. Baker's Helper. DOT No. 313.684-010. Cafeteria Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    This study guide is one of eight individualized units developed for students enrolled in cooperative part-time training and employed in a cafeteria. Each self-paced unit is composed of information about one specific occupation; this unit focuses on the duties of the baker's helper. Materials provided in this guide for coordinator use include a…

  18. Informal Helpers' Responses when Adolescents Tell Them about Dating Violence or Romantic Relationship Problems

    ERIC Educational Resources Information Center

    Weisz, Arlene N.; Tolman, Richard M.; Callahan, Michelle R.; Saunders, Daniel G.; Black, Beverly M.

    2007-01-01

    This study examines the responses of informal helpers to adolescents who disclose dating violence or upsetting but non-violent experiences in their romantic relationships. Based on a survey of 224 Midwestern high school students, the study found that youths were more likely to disclose problems to friends rather than others. A factor analysis of…

  19. "Helping" versus "Being a Helper": Invoking the Self to Increase Helping in Young Children

    ERIC Educational Resources Information Center

    Bryan, Christopher J.; Master, Allison; Walton, Gregory M.

    2014-01-01

    Can a subtle linguistic cue that invokes the self motivate children to help? In two experiments, 3- to 6-year-old children (N = 149) were exposed to the idea of "being a helper" (noun condition) or "helping" (verb condition). Noun wording fosters the perception that a behavior reflects an identity--the kind of person one is.…

  20. When I Grow Up: The Community Helper Resource Book. Grades Pre-K-1.

    ERIC Educational Resources Information Center

    Timmons, Dayle; Rogers, Kerry

    This book is designed to help teachers construct learning centers focusing on the community and community helpers. By using dramatic creative play and simulations, students become more aware of occupations and potential career choices. The career center provides a thematic approach to career education and a foundation for individual and group…

  1. Training Child Care Workers in Denmark: II. Training Family Helpers and Family Day Care Mothers.

    ERIC Educational Resources Information Center

    Wagner, Mary; Wagner, Marsden G.

    This report describes the training of two kinds of paraprofessionals in child care in Denmark: the family helper who has considerable educational background, and the family day care mother for whom there are no educational prerequisites. The funding, the training, and the curriculum design of the paraprofessional programs are discussed. There is…

  2. Prevalence and Duties of Collegiate Human Sexuality Peer Helpers: Results of a National Study

    ERIC Educational Resources Information Center

    Butler, Scott M.; Black, David R.

    2011-01-01

    The purpose of the present study is to assess human sexuality peer helper use among college student health centers nationwide. Results from 358 institutions indicate that 53.9% of centers use peers for educational programming, prevention efforts, and/or counseling initiatives. When adjusting for institutions that sponsor a program (n = 193), the M…

  3. Social Networks and Social Support: Implications for Natural Helper and Community Level Interventions.

    ERIC Educational Resources Information Center

    Israel, Barbara A.

    1985-01-01

    Focuses on the linkage between social support and social networks and health educational programs that involve interventions at the network and community level. Addresses programs enhancing entire networks through natural helpers; and programs strengthening overlapping networks/communities through key opinion and informal leaders who are engaged…

  4. Beyond the Reach of Ethics and Equity? Depersonalisation and Dehumanisation in Foreign Domestic Helper Narratives

    ERIC Educational Resources Information Center

    Ladegaard, Hans J.

    2013-01-01

    This paper analyses narratives told by foreign domestic helpers (FDHs) in a Hong Kong church shelter. The narratives provide evidence that FDHs appear to be untouched by the ethics and equity of Hong Kong society. They are denied the rights that apply to other groups: the right to eat, rest and talk; they are humiliated and denigrated, and the…

  5. CIB1 and CIB2 are HIV-1 helper factors involved in viral entry

    PubMed Central

    Godinho-Santos, Ana; Hance, Allan J.; Gonçalves, João; Mammano, Fabrizio

    2016-01-01

    HIV-1 relies on the host-cell machinery to accomplish its replication cycle, and characterization of these helper factors contributes to a better understanding of HIV-host interactions and can identify potential novel antiviral targets. Here we explored the contribution of CIB2, previously identified by RNAi screening as a potential helper factor, and its homolog, CIB1. Knockdown of either CIB1 or CIB2 strongly impaired viral replication in Jurkat cells and in primary CD4+ T-lymphocytes, identifying these proteins as non-redundant helper factors. Knockdown of CIB1 and CIB2 impaired envelope-mediated viral entry for both for X4- and R5-tropic HIV-1, and both cell-free and cell-associated entry pathways were affected. In contrast, the level of CIB1 and CIB2 expression did not influence cell viability, cell proliferation, receptor-independent viral binding to the cell surface, or later steps in the viral replication cycle. CIB1 and CIB2 knockdown was found to reduce the expression of surface molecules implicated in HIV-1 infection, including CXCR4, CCR5 and integrin α4β7, suggesting at least one mechanism through which these proteins promote viral infection. Thus, this study identifies CIB1 and CIB2 as host helper factors for HIV-1 replication that are required for optimal receptor-mediated viral entry. PMID:27489023

  6. English-Speaking Foreign Domestic Helpers and Students' English Reading Attainment in Hong Kong

    ERIC Educational Resources Information Center

    Tse, Shek Kam; Lam, Raymond Y. H.; Loh, Elizabeth K. Y.; Ip, Olivia K. M.; Lam, Joseph W. I.; Chan, Yiu Man

    2009-01-01

    The English reading comprehension ability of 4,352 Grade 4 Hong Kong students was tested. The students' parents completed questionnaires about home factors, including monthly income, language habitually spoken at home, whether the mother was employed, and whether an English-speaking domestic helper resided there. Analyses revealed statistically…

  7. Cook's Helper. DOT No. 317.687-010. Restaurant Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    Hohhertz, Durwin

    This coordinator's guide for a module on cook's helpers, one of seven individualized units about restaurant occupations, has been developed for students enrolled in cooperative part-time training and employed in a commercial restaurant. Included in the first part of the guide are a progress chart, suggested teaching procedures, answers to the…

  8. Kitchen Helper. DOT No. 318.687-010. Cafeteria Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    This study guide, one of eight individualized units developed for students enrolled in cooperative part-time training and employed in a cafeteria, is composed of information about one specific occupation; this unit focuses on the duties of the kitchen helper. Materials provided in this guide for coordinator use include a student progress chart; a…

  9. Cook's Helper. DOT No. 317.687-010. Cafeteria Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    This study guide, one of eight individualized units developed for students enrolled in cooperative part-time training and employed in a cafeteria, is composed of information about one specific occupation; this unit focuses on the duties of the cook's helper. Materials provided in this guide for coordinator use include a student progress chart; a…

  10. Solutions-Focused Role Play: Its Use in Training Peer Helpers

    ERIC Educational Resources Information Center

    Beale, Andrew V.; Hall, Kimberly R.

    2005-01-01

    Solutions-focused role play provides students with structured opportunities to transfer what they have learned to authentic situations they are likely to encounter as peer helpers. Rather than coming up with a single way to solve a problem, students are encouraged to explore multiple possible solutions. Peer training programs have traditionally…

  11. Exploring the role of Natural Helpers in efforts to address disparities for children with conduct problems

    PubMed Central

    Acevedo-Polakovich, I. David; Niec, Larissa N.; Barnett, Miya L.; Bell, Katrina M.; Aguilar, Gerardo; Vilca, Jeanette; Abbenante-Honold, Emily S.; Christian, Allison S.; Peer, Samuel O.

    2014-01-01

    The incorporation of natural helpers into services has been suggested as an innovative strategy to address disparities for historically underserved children with conduct problems. In order to inform incorporation efforts, this study examined the perceptions of natural helpers serving one U.S. Latina/o community regarding need for services for children with conduct problems, their reactions to a specific parent training intervention, and the training and support needed to deliver this intervention successfully. Participants identified a need for culturally-responsive services for children with conduct problems, and felt that parent training would be appropriate for the families they serve. Participants further identified specific training and support that they would require in order to deliver parent training with fidelity and effectiveness. Findings support the suggestion that natural helpers have the potential to address service disparities among Latina/o children with conduct problems. Recommendations from natural helpers should guide the development of culturally-adapted preventive interventions that help address existing service disparities. PMID:24910488

  12. Baker's Helper. DOT No. 313.684-010. Cafeteria Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    This study guide is one of eight individualized units developed for students enrolled in cooperative part-time training and employed in a cafeteria. Each self-paced unit is composed of information about one specific occupation; this unit focuses on the duties of the baker's helper. Materials provided in this guide for coordinator use include a…

  13. Cook's Helper. DOT No. 317.687-010. Restaurant Occupations. Coordinator's Guide. First Edition.

    ERIC Educational Resources Information Center

    Hohhertz, Durwin

    This coordinator's guide for a module on cook's helpers, one of seven individualized units about restaurant occupations, has been developed for students enrolled in cooperative part-time training and employed in a commercial restaurant. Included in the first part of the guide are a progress chart, suggested teaching procedures, answers to the…

  14. A web-based care-requiring client and Home Helper mutual support system.

    PubMed

    Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Hahn, Allen W; Caldwell, W Morton

    2005-01-01

    For the improved efficiency of home care of the elderly, a web-based system has been developed to enable faster communications between care-requiring clients, their Home Helper and the care manager. Changes to care items, such as cooking, bathing, washing, cleaning and shopping are usually requested by the elderly client over the telephone. However, the care central office often requires 24 hours to process and respond to such spoken requests. The system we have developed consists of Internet client computers with liquid crystal input tablets, wireless Internet Java enabled mobile phones and a central office server that yields almost instant communication. The care clients enter requests on the liquid crystal tablet at their home and then their computer sends these requests to the server at the Home Helper central office. The server automatically creates a new file of the requested items, and then immediately transfers them to the care manager and Home Helper's mobile phone. With this non-vocal and paperless system, the care-requiring clients, who can easily operate the liquid crystal tablet, can very quickly communicate their needed care change requests to their Home Helper.

  15. The role of helper lipids in lipid nanoparticles (LNPs) designed for oligonucleotide delivery.

    PubMed

    Cheng, Xinwei; Lee, Robert J

    2016-04-01

    Lipid nanoparticles (LNPs) have shown promise as delivery vehicles for therapeutic oligonucleotides, including antisense oligos (ONs), siRNA, and microRNA mimics and inhibitors. In addition to a cationic lipid, LNPs are typically composed of helper lipids that contribute to their stability and delivery efficiency. Helper lipids with cone-shape geometry favoring the formation hexagonal II phase, such as dioleoylphosphatidylethanolamine (DOPE), can promote endosomal release of ONs. Meanwhile, cylindrical-shaped lipid phosphatidylcholine can provide greater bilayer stability, which is important for in vivo application of LNPs. Cholesterol is often included as a helper that improves intracellular delivery as well as LNP stability in vivo. Inclusion of a PEGylating lipid can enhance LNP colloidal stability in vitro and circulation time in vivo but may reduce uptake and inhibit endosomal release at the cellular level. This problem can be addressed by choosing reversible PEGylation in which the PEG moiety is gradually released in blood circulation. pH-sensitive anionic helper lipids, such as fatty acids and cholesteryl hemisuccinate (CHEMS), can trigger low-pH-induced changes in LNP surface charge and destabilization that can facilitate endosomal release of ONs. Generally speaking, there is no correlation between LNP activity in vitro and in vivo because of differences in factors limiting the efficiency of delivery. Designing LNPs requires the striking of a proper balance between the need for particle stability, long systemic circulation time, and the need for LNP destabilization inside the target cell to release the oligonucleotide cargo, which requires the proper selection of both the cationic and helper lipids. Customized design and empirical optimization is needed for specific applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Retroviral Transduction of Helper T Cells as a Genetic Approach to Study Mechanisms Controlling their Differentiation and Function

    PubMed Central

    Singh, Yogesh; Garden, Oliver A.; Lang, Florian; Cobb, Bradley S.

    2016-01-01

    Helper T cell development and function must be tightly regulated to induce an appropriate immune response that eliminates specific pathogens yet prevents autoimmunity. Many approaches involving different model organisms have been utilized to understand the mechanisms controlling helper T cell development and function. However, studies using mouse models have proven to be highly informative due to the availability of genetic, cellular, and biochemical systems. One genetic approach in mice used by many labs involves retroviral transduction of primary helper T cells. This is a powerful approach due to its relative ease, making it accessible to almost any laboratory with basic skills in molecular biology and immunology. Therefore, multiple genes in wild type or mutant forms can readily be tested for function in helper T cells to understand their importance and mechanisms of action. We have optimized this approach and describe here the protocols for production of high titer retroviruses, isolation of primary murine helper T cells, and their transduction by retroviruses and differentiation toward the different helper subsets. Finally, the use of this approach is described in uncovering mechanisms utilized by microRNAs (miRNAs) to regulate pathways controlling helper T cell development and function. PMID:27842353

  17. Technical report of biota, FEL Site 1, Lawrence Livermore National Laboratory: Final report

    SciTech Connect

    Taylor, D.W.; Davilla, W.; Orloff, S.

    1986-09-26

    Lawrence Livermore National Laboratory is considering an expansion of laser test facilities adjacent to its existing LLNL Site 300 test location. Construction of a free-electron laser, known as the FEL Project, is being considered on approximately 3900 hectates (10,500 acres) of land. We will refer to this proposed site as FEL Site 1. Knowledge of the flora and vegetation resources of the proposed FEL Site 1 is necessary in order to plan for construction, operation, and possible future expansion of the FEL facility. The purpose of botanical sections of this report is to quantitatively describe the variation of vegetation on FEL Site 1, and to relate the vegetation to potential environmental impacts associated with present operation and possible expansion of site facilities. The primary purpose of the wildlife studies was to determine the presence and status of any endangered, threatened, fully protected, or otherwise sensitive species on FEL Site 1 that might be affected by the proposed FEL project. We directed our studies mainly toward the federally endangered San Joaquin kit fox (Vulpes macrotis mutica), but also toward another 14 special status species that potentially occur on site, including the state threatened Alameda striped racer (Masticophis lateralis euryxanthus).

  18. The name of the helper: a new look at "Rumpelstiltskin".

    PubMed

    Rosegrant, John

    2008-04-01

    The fairy tale of Rumpelstiltskin is studied in conjunction with related tales to provide a fuller understanding of its meaning than previous studies have done. The content of these tales depicts ambivalence about childhood magic and ambivalence about adult reality, which are uneasily resolved by eliminating magic and dwelling in a disenchanted world. Enchantment is retained formally in the telling of the story. To the extent that transference is enchantment, similar conflicts occur during psychoanalysis: is the patient better off adhering to transference or relinquishing it--or can it be integrated with day-to-day experience?

  19. USP21 prevents the generation of T-helper-1-like Treg cells

    PubMed Central

    Li, Yangyang; Lu, Yue; Wang, Shuaiwei; Han, Zhijun; Zhu, Fuxiang; Ni, Yingmeng; Liang, Rui; Zhang, Yan; Leng, Qibin; Wei, Gang; Shi, Guochao; Zhu, Ruihong; Li, Dan; Wang, Haikun; Zheng, Song Guo; Xu, Hongxi; Tsun, Andy; Li, Bin

    2016-01-01

    FOXP3+ Regulatory T (Treg) cells play a key role in the maintenance of immune homeostasis and tolerance. Disruption of Foxp3 expression results in the generation of instable Treg cells and acquisition of effector T-cell-like function. Here we report that the E3 deubiquitinase USP21 prevents the depletion of FOXP3 at the protein level and restricts the generation of T-helper-1-like Treg cells. Mice depleted of Usp21 specifically in Treg cells display immune disorders characterized by spontaneous T-cell activation and excessive T-helper type 1 (Th1) skewing of Treg cells into Th1-like Treg cells. USP21 stabilizes FOXP3 protein by mediating its deubiquitination and maintains the expression of Treg signature genes. Our results demonstrate how USP21 prevents FOXP3 protein depletion and controls Treg lineage stability in vivo. PMID:27857073

  20. T-helper cell intrinsic defects in lupus that break peripheral tolerance to nuclear autoantigens.

    PubMed

    Datta, Syamal K; Zhang, Li; Xu, Luting

    2005-04-01

    Special populations of T helper cells drive B cells to produce IgG class switched, pathogenic autoantibodies in lupus. The major source of antigenic determinants (epitopes) that trigger interactions between lupus T and B cells is nucleosomes of apoptotic cells. These epitopes can be used for antigen-specific therapy of lupus. Secondly, the autoimmune T cells of lupus are sustained because they resist anergy and activation-induced programmed cell death by markedly upregulating cyclooxygenase (COX) 2 along with the antiapoptotic molecule c-FLIP. Only certain COX-2 inhibitors block pathogenic anti-DNA autoantibody production in lupus by causing death of autoimmune T helper cells. Hence COX-2 inhibitors may work independently of their ability to block the enzymatic function of COX-2, and structural peculiarities of these select inhibitors may lead to better drug discovery and design.

  1. Regulation of T Helper Cell Subsets by Cyclooxygenases and Their Metabolites

    PubMed Central

    Li, Hong; Edin, Matthew L.; Gruzdev, Artiom; Cheng, Jennifer; Bradbury, J. Alyce; Graves, Joan P.; DeGraff, Laura M.; Zeldin, Darryl C.

    2013-01-01

    Cyclooxygenases and their metabolites are important regulators of inflammatory responses and play critical roles in regulating the differentiation of T helper cell subsets in inflammatory diseases. In this review, we highlight new information on regulation of T helper cell subsets by cyclooxygenases and their metabolites. Prostanoids influence cytokine production on both antigen presenting cells and T cells to regulate the differentiation of naïve CD4+ T cells to Th1, Th2 and Th17 cell phenotypes. Cyclooxygenases and PGE2 generally exacerbate Th2 and Th17 phenotypes, while suppressing Th1 differentiation. Thus, cycloxygenases may play a critical role in diseases that involve immune cell dysfunction. Targeting of cyclooxygenases and their eicosanoid products may represent a new approach for treatment of inflammatory diseases, tumors and autoimmune disorders. PMID:23201570

  2. USP21 prevents the generation of T-helper-1-like Treg cells.

    PubMed

    Li, Yangyang; Lu, Yue; Wang, Shuaiwei; Han, Zhijun; Zhu, Fuxiang; Ni, Yingmeng; Liang, Rui; Zhang, Yan; Leng, Qibin; Wei, Gang; Shi, Guochao; Zhu, Ruihong; Li, Dan; Wang, Haikun; Zheng, Song Guo; Xu, Hongxi; Tsun, Andy; Li, Bin

    2016-11-18

    FOXP3(+) Regulatory T (Treg) cells play a key role in the maintenance of immune homeostasis and tolerance. Disruption of Foxp3 expression results in the generation of instable Treg cells and acquisition of effector T-cell-like function. Here we report that the E3 deubiquitinase USP21 prevents the depletion of FOXP3 at the protein level and restricts the generation of T-helper-1-like Treg cells. Mice depleted of Usp21 specifically in Treg cells display immune disorders characterized by spontaneous T-cell activation and excessive T-helper type 1 (Th1) skewing of Treg cells into Th1-like Treg cells. USP21 stabilizes FOXP3 protein by mediating its deubiquitination and maintains the expression of Treg signature genes. Our results demonstrate how USP21 prevents FOXP3 protein depletion and controls Treg lineage stability in vivo.

  3. Psychological well-being and social support among elders employed as lay helpers.

    PubMed

    Gammonley, Denise

    2009-01-01

    Impacts on lay helpers of participation in part-time work supporting rural elders with severe mental illness were explored in a group of 17 older adults employed in a demonstration project. Self-rated well-being and social support were assessed over 1 year. Ratings of autonomy and positive relations with others varied over 1 year. Perceptions of the amount of social support provided showed a trend toward improvement at 1 year. Results are considered in the context of role theory and illustrated with an ethnographic case study of the service environment. The lay helper role is a form of productive engagement through paid caregiving, with potential to supplement rural mental health service systems while supporting elders' needs for meaningful civic engagement.

  4. The Biological Functions of T Helper 17 Cell Effector Cytokines in Inflammation

    PubMed Central

    Ouyang, Wenjun; Kolls, Jay K.; Zheng, Yan

    2012-01-01

    T helper 17 (Th17) cells belong to a recently identified T helper subset, in addition to the traditional Th1 and Th2 subsets. These cells are characterized as preferential producers of interleukin-17A (IL-17A), IL-17F, IL-21, and IL-22. Th17 cells and their effector cytokines mediate host defensive mechanisms to various infections, especially extracellular bacteria infections, and are involved in the pathogenesis of many autoimmune diseases. The receptors for IL-17 and IL-22 are broadly expressed on various epithelial tissues. The effector cytokines of Th17 cells, therefore, mediate the crucial crosstalk between immune system and tissues, and play indispensable roles in tissue immunity. PMID:18400188

  5. Monogenic mutations differentially affect the quantity and quality of T follicular helper cells in patients with human primary immunodeficiencies.

    PubMed

    Ma, Cindy S; Wong, Natalie; Rao, Geetha; Avery, Danielle T; Torpy, James; Hambridge, Thomas; Bustamante, Jacinta; Okada, Satoshi; Stoddard, Jennifer L; Deenick, Elissa K; Pelham, Simon J; Payne, Kathryn; Boisson-Dupuis, Stéphanie; Puel, Anne; Kobayashi, Masao; Arkwright, Peter D; Kilic, Sara Sebnem; El Baghdadi, Jamila; Nonoyama, Shigeaki; Minegishi, Yoshiyuki; Mahdaviani, Seyed Alireza; Mansouri, Davood; Bousfiha, Aziz; Blincoe, Annaliesse K; French, Martyn A; Hsu, Peter; Campbell, Dianne E; Stormon, Michael O; Wong, Melanie; Adelstein, Stephen; Smart, Joanne M; Fulcher, David A; Cook, Matthew C; Phan, Tri Giang; Stepensky, Polina; Boztug, Kaan; Kansu, Aydan; İkincioğullari, Aydan; Baumann, Ulrich; Beier, Rita; Roscioli, Tony; Ziegler, John B; Gray, Paul; Picard, Capucine; Grimbacher, Bodo; Warnatz, Klaus; Holland, Steven M; Casanova, Jean-Laurent; Uzel, Gulbu; Tangye, Stuart G

    2015-10-01

    Follicular helper T (TFH) cells underpin T cell-dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS, or BTK. Loss-of-function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS, or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo, as corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1, and IL12RB1 LOF mutations. Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell-induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised

  6. Multiplicity of virus-encoded helper T-cell epitopes expressed on FBL-3 tumor cells.

    PubMed Central

    Iwashiro, M; Kondo, T; Shimizu, T; Yamagishi, H; Takahashi, K; Matsubayashi, Y; Masuda, T; Otaka, A; Fujii, N; Ishimoto, A

    1993-01-01

    To identify retroviral antigenic determinants recognized by CD4+ T helper cells during tumor rejection, we established four noncytolytic, helper-type, CD4+ T-cell clones by limiting dilution cultures of mixed lymphocyte-tumor cultures from mice immune to a Friend virus-induced tumor, FBL-3. Among these, three T helper cell clones were isolated from C57BL/6 mice and the fourth was isolated from a (BALB/c x C57BL/6)F1 mouse. All these clones proliferated in response to the immunizing FBL-3 tumor cells in a major histocompatibility complex class II-restricted manner. Each clone expressed a distinct T-cell receptor with a characteristic combination of alpha and beta chains. The localization of helper T-cell determinants on viral proteins was analyzed with recombinant vaccinia viruses expressing Friend murine leukemia virus (F-MuLV) gag or env genes or shorter fragments of the env gene. Epitopes recognized by these T-cell clones were mapped to at least two distinct portions in the env region of the F-MuLV genome. These epitopes were identified more precisely with synthetic peptides derived from the F-MuLV envelope protein sequence. One of these epitopes was common to Friend and Moloney MuLVs and was located in the N-terminal region of the gp70 glycoprotein at amino acids 122 to 141. The second epitope, which was recognized in the context of hybrid I-Eb/d major histocompatibility complex class II molecule, was located close to the C-terminal end of gp70 at amino acids 462 to 479. In addition, a possible third epitope was located in the N-terminal half of the gp70 sequence and differed from the first epitope in that it was not cross-reactive with the Moloney MuLV envelope protein. PMID:7687300

  7. Pathologically expanded peripheral T helper cell subset drives B cells in rheumatoid arthritis.

    PubMed

    Rao, Deepak A; Gurish, Michael F; Marshall, Jennifer L; Slowikowski, Kamil; Fonseka, Chamith Y; Liu, Yanyan; Donlin, Laura T; Henderson, Lauren A; Wei, Kevin; Mizoguchi, Fumitaka; Teslovich, Nikola C; Weinblatt, Michael E; Massarotti, Elena M; Coblyn, Jonathan S; Helfgott, Simon M; Lee, Yvonne C; Todd, Derrick J; Bykerk, Vivian P; Goodman, Susan M; Pernis, Alessandra B; Ivashkiv, Lionel B; Karlson, Elizabeth W; Nigrovic, Peter A; Filer, Andrew; Buckley, Christopher D; Lederer, James A; Raychaudhuri, Soumya; Brenner, Michael B

    2017-02-01

    CD4(+) T cells are central mediators of autoimmune pathology; however, defining their key effector functions in specific autoimmune diseases remains challenging. Pathogenic CD4(+) T cells within affected tissues may be identified by expression of markers of recent activation. Here we use mass cytometry to analyse activated T cells in joint tissue from patients with rheumatoid arthritis, a chronic immune-mediated arthritis that affects up to 1% of the population. This approach revealed a markedly expanded population of PD-1(hi)CXCR5(-)CD4(+) T cells in synovium of patients with rheumatoid arthritis. However, these cells are not exhausted, despite high PD-1 expression. Rather, using multidimensional cytometry, transcriptomics, and functional assays, we define a population of PD-1(hi)CXCR5(-) 'peripheral helper' T (TPH) cells that express factors enabling B-cell help, including IL-21, CXCL13, ICOS, and MAF. Like PD-1(hi)CXCR5(+) T follicular helper cells, TPH cells induce plasma cell differentiation in vitro through IL-21 secretion and SLAMF5 interaction (refs 3, 4). However, global transcriptomics highlight differences between TPH cells and T follicular helper cells, including altered expression of BCL6 and BLIMP1 and unique expression of chemokine receptors that direct migration to inflamed sites, such as CCR2, CX3CR1, and CCR5, in TPH cells. TPH cells appear to be uniquely poised to promote B-cell responses and antibody production within pathologically inflamed non-lymphoid tissues.

  8. DeltaPhage—a novel helper phage for high-valence pIX phagemid display

    PubMed Central

    Nilssen, Nicolay R.; Frigstad, Terje; Pollmann, Sylvie; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger; Løset, Geir Å.

    2012-01-01

    Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems. PMID:22539265

  9. DeltaPhage--a novel helper phage for high-valence pIX phagemid display.

    PubMed

    Nilssen, Nicolay R; Frigstad, Terje; Pollmann, Sylvie; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger; Løset, Geir Å

    2012-09-01

    Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems.

  10. Elevated prolactin levels immediately precede decisions to babysit by male meerkat helpers.

    PubMed

    Carlson, Anne A; Russell, Andrew F; Young, Andrew J; Jordan, Neil R; McNeilly, Alan S; Parlow, Al F; Clutton-Brock, Tim

    2006-06-01

    Recent studies suggest that decisions to care for the offspring of others in societies of cooperative vertebrates may have a hormonal basis. The crucial question of whether changes in hormone levels immediately precede or merely follow bouts of offspring care, however, remains largely unanswered. Here, we show that in wild groups of cooperatively breeding meerkats, male helpers that decided to babysit for the day had significantly higher levels of prolactin, coupled with lower levels of cortisol, before initiating a babysitting session compared with similarly aged individuals that decided to forage. In addition, these hormonal differences disappeared over the course of the day, suggesting that hormone levels changed in a fundamentally different way in meerkats that babysat versus those that foraged. In contrast, long-term contributions to babysitting were not significantly associated with plasma levels of prolactin, cortisol, or testosterone in individual male helpers. Our results show, for the first time, that elevated levels of prolactin may immediately precede bouts of helping behavior but differ from recent findings on the same study population in which plasma levels of cortisol, but not prolactin, were significantly and positively associated with rates of pup feeding by male helpers. Together, these results lend significant weight to the idea that decisions to help in cooperative vertebrates have a hormonal basis, although different hormones appear to be associated with different types of care.

  11. Induction of cytotoxic T cell precursors in vivo. Role of T helper cells

    PubMed Central

    1983-01-01

    Strain AS rats respond with two populations of cytotoxic T lymphocytes to stimulation in vitro by the major histocompatibility complex (MHC)- incompatible strain HL rat tumor (HL-A2T2). One is specific for MHC alloantigens present on both HL-A2T2 and normal HL targets, the other is tumor specific. The activation of these killer cells requires helper T lymphocytes. The tumor-specific helper cells depend on syngeneic radioresistant accessory cells to present the tumor antigens in an immunogenic form. The appropriate helper-accessory cell interaction results in the production of soluble factors which then induce the maturation of precursor cells into effective killer cells. Studies with a procedure for inducing negative selection of T cells in vivo showed that short-term exposure to HL-A2T2 tumor induced selection only for TH but not cytotoxic T lymphocyte precursors (CTLp). Simultaneous injection of supernatants from concanavalin A-activated spleen cell cultures, however, did produce selection of CTLp. These and other findings suggest that under normal circumstances in vivo, both signals (recognition of antigen and acceptance of maturation factors) are provided in the vicinity of an antigen presenting macrophage-like accessory cell. PMID:6222131

  12. Increased Peripheral Proinflammatory T Helper Subsets Contribute to Cardiovascular Complications in Diabetic Patients

    PubMed Central

    Zhao, Ru-xing; Li, Wen-juan; Lu, Yi-ran; Qin, Jun; Wu, Chuan-long; Tian, Meng; He, Tian-yi; Yi, Shou-nan; Tang, Dong-qi; Sun, Lei; Chen, Li

    2014-01-01

    Background. Coronary atherosclerotic heart disease (CHD) is one of the major concerns in type 2 diabetes (T2D). The systemic chronic inflammation has been postulated to bridge the increased risk of cardiovascular disease and T2D. We formulated that increased peripheral proinflammatory T helper subsets contributed to the development of cardiovascular complications in diabetic patients. Methods. The frequencies of peripheral total CD4+ T helper cells, proinflammatory Th1, Th17, and Th22 subsets were determined by flow cytometry in diabetic patients with or without CHD (n = 42 and 67, resp.). Results. Both peripheral frequencies and total numbers of Th1, Th17, and Th22 cells were further increased in diabetic patients with CHD. Logistic regression and categorical cross-table analysis further confirmed that increased proinflammatory Th subsets, especially Th22, were independent risk factors of cardiovascular complication in diabetes. Elevated Th subsets also correlated with increased CRP levels and the atherogenic index of plasma. Moreover, Th1 frequency and Th22 numbers demonstrated remarkable potential in predicting CHD in diabetes. Conclusions. Increased peripheral proinflammatory T helper subsets act in concert and contribute to the increased prevalence of diabetic cardiovasculopathy. The recently identified Th22 cells might play an independent role in CHD and represent a novel proxy for cardiovascular risks in diabetes. PMID:24803740

  13. Some cytokine profiles of T-helper cells in lesions of advanced periodontitis.

    PubMed

    Berglundh, Tord; Liljenberg, Birgitta; Lindhe, Jan

    2002-08-01

    The aim of the present study was to analyze some cytokine profiles of T-helper cells in periodontitis lesions. 22 adult patients (7 females and 15 males, aged 24-66 years) with advanced and generalized chronic periodontitis were recruited. Clinical and radiographical characteristics of periodontal disease was assessed. From each patient a gingival biopsy was obtained from one randomly selected diseased interproximal site. The soft tissue sample was prepared for immunohistochemical analysis. Double staining was performed to detect cells positive for both the CD4 marker and different cytokines, i.e. interleukin (IL)-2, IL-4, IL-6 and interferon-gamma (IFN-gamma). The lesions in advanced periodontitis contained similar proportions of cells positive for the different cytokine markers examined. In addition, the number of cells expressing cytokine profiles for either T helper-1 (IFN-gamma + IL-2) or T helper-2 (IL-4 + IL-6) was similar. It is suggested that the lesions of periodontitis are regulated by a combined Th-1 and Th-2 function.

  14. Staphylococcal pathogenicity island interference with helper phage reproduction is a paradigm of molecular parasitism.

    PubMed

    Ram, Geeta; Chen, John; Kumar, Krishan; Ross, Hope F; Ubeda, Carles; Damle, Priyadarshan K; Lane, Kristin D; Penadés, José R; Christie, Gail E; Novick, Richard P

    2012-10-02

    Staphylococcal pathogenicity islands (SaPIs) carry superantigen and resistance genes and are extremely widespread in Staphylococcus aureus and in other Gram-positive bacteria. SaPIs represent a major source of intrageneric horizontal gene transfer and a stealth conduit for intergeneric gene transfer; they are phage satellites that exploit the life cycle of their temperate helper phages with elegant precision to enable their rapid replication and promiscuous spread. SaPIs also interfere with helper phage reproduction, blocking plaque formation, sharply reducing burst size and enhancing the survival of host cells following phage infection. Here, we show that SaPIs use several different strategies for phage interference, presumably the result of convergent evolution. One strategy, not described previously in the bacteriophage microcosm, involves a SaPI-encoded protein that directly and specifically interferes with phage DNA packaging by blocking the phage terminase small subunit. Another strategy involves interference with phage reproduction by diversion of the vast majority of virion proteins to the formation of SaPI-specific small infectious particles. Several SaPIs use both of these strategies, and at least one uses neither but possesses a third. Our studies illuminate a key feature of the evolutionary strategy of these mobile genetic elements, in addition to their carriage of important genes-interference with helper phage reproduction, which could ensure their transferability and long-term persistence.

  15. Engineering of weak helper interactions for high-efficiency FRET probes.

    PubMed

    Grünberg, Raik; Burnier, Julia V; Ferrar, Tony; Beltran-Sastre, Violeta; Stricher, François; van der Sloot, Almer M; Garcia-Olivas, Raquel; Mallabiabarrena, Arrate; Sanjuan, Xavier; Zimmermann, Timo; Serrano, Luis

    2013-10-01

    Fluorescence resonance energy transfer (FRET)-based detection of protein interactions is limited by the very narrow range of FRET-permitting distances. We show two different strategies for the rational design of weak helper interactions that co-recruit donor and acceptor fluorophores for a more robust detection of bimolecular FRET: (i) in silico design of electrostatically driven encounter complexes and (ii) fusion of tunable domain-peptide interaction modules based on WW or SH3 domains. We tested each strategy for optimization of FRET between (m)Citrine and mCherry, which do not natively interact. Both approaches yielded comparable and large increases in FRET efficiencies with little or no background. Helper-interaction modules can be fused to any pair of fluorescent proteins and could, we found, enhance FRET between mTFP1 and mCherry as well as between mTurquoise2 and mCitrine. We applied enhanced helper-interaction FRET (hiFRET) probes to study the binding between full-length H-Ras and Raf1 as well as the drug-induced interaction between Raf1 and B-Raf.

  16. Group-size-dependent punishment of idle subordinates in a cooperative breeder where helpers pay to stay

    PubMed Central

    Fischer, Stefan; Zöttl, Markus; Groenewoud, Frank; Taborsky, Barbara

    2014-01-01

    In cooperative breeding systems, dominant breeders sometimes tolerate unrelated individuals even if they inflict costs on the dominants. According to the ‘pay-to-stay’ hypothesis, (i) subordinates can outweigh these costs by providing help and (ii) dominants should be able to enforce help by punishing subordinates that provide insufficient help. This requires that dominants can monitor helping and can recognize group members individually. In a field experiment, we tested whether cooperatively breeding cichlid Neolamprologus pulcher subordinates increase their help after a forced ‘idle’ period, how other group members respond to a previously idle helper, and how helper behaviour and group responses depend on group size. Previously, idle helpers increased their submissiveness and received more aggression than control helpers, suggesting that punishment occurred to enforce help. Subordinates in small groups increased their help more than those in large groups, despite receiving less aggression. When subordinates were temporarily removed, dominants in small groups were more likely to evict returning subordinates. Our results suggest that only in small groups do helpers face a latent threat of punishment by breeders as predicted by the pay-to-stay hypothesis. In large groups, cognitive constraints may prevent breeders from tracking the behaviour of a large number of helpers. PMID:24990673

  17. The Distribution and Abundance of Leaf Litter Arthropods in MOFEP Sites 1, 2, and 3

    Treesearch

    Jan Weaver; Sarah. Heyman

    1997-01-01

    In June 1993, we collected 144 leaf litter samples from 36 plots (4 samples/plot) located in MOFEP forest sites 1, 2 and 3. Half of the plots were placed randomly on northeast-facing stands (ELT 18), and half randomly placed on southwest-facing stands (ELT 17). Arthropods were extracted using Tullgren funnels, and then sorted into morpho-species, counted, and measured...

  18. The influence of flexible management practices on the sharing of experiential knowledge in the workplace: a case study of food service helpers.

    PubMed

    Ledoux, Elise; Cloutier, Esther; Fournier, Pierre-Sébastien

    2012-01-01

    Previous studies have shown that the job knowledge and prudent knowledge of experienced workers constitute a wealth that needs to be shared in workplaces to promote worker integration, job retention and occupational health and safety. It appears, however, that certain management practices undermine this knowledge sharing process. This case study of food service helpers in institutional food service departments is part of a research project aimed at comparing the impact of different work organization methods on knowledge sharing in the workplace on the basis of case studies carried out in several organizations. The results of this case study reveal that by destabilizing and weakening the work teams, flexible management practices create an environment that is not conducive to experiential knowledge sharing.

  19. Expression of Master Regulators of T-cell, Helper T-cell and Follicular Helper T-cell Differentiation in Angioimmunoblastic T-cell Lymphoma.

    PubMed

    Matsumoto, Yosuke; Nagoshi, Hisao; Yoshida, Mihoko; Kato, Seiichi; Kuroda, Junya; Shimura, Kazuho; Kaneko, Hiroto; Horiike, Shigeo; Nakamura, Shigeo; Taniwaki, Masafumi

    2017-09-25

    Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.

  20. Contamination Assessment Report, Site 1-7, Hydrazine Blending and Storage Facility. Version 3.2

    DTIC Science & Technology

    1988-09-01

    1 . LEGEND / h R 6W t!! 6 /J -T IV SKI IN Yl MoUNTAI T 0 / ARPENI. 2 IiI V 0 L- - - - - 1 ,~~~ 2 S SITE 1 -7 / 3 S T- F...facilities were collectively known as Building 757. They consisted of four 24,900-gallon tanks designated HAS-i, HAS- 2 , HAS- 3 , and CS- 1 , and two 19,000...facility. Since that time, the four hydrazine tanks (HAS-l, HAS- 2 , HAS- 3 , and CS- 1 ) and the two unsymmetrical dimethyl hydrazine tanks (US- 1 and US- 2 )

  1. Shifted T Helper Cell Polarization in a Murine Staphylococcus aureus Mastitis Model.

    PubMed

    Zhao, Yanqing; Zhou, Ming; Gao, Yang; Liu, Heyuan; Yang, Wenyu; Yue, Jinhua; Chen, Dekun

    2015-01-01

    Mastitis, one of the most costly diseases in dairy ruminants, is an inflammation of the mammary gland caused by pathogenic infection. The mechanisms of adaptive immunity against pathogens in mastitis have not been fully elucidated. To investigate T helper cell-mediated adaptive immune responses, we established a mastitis model by challenge with an inoculum of 4 × 106 colony-forming units of Staphylococcus aureus in the mammary gland of lactating mice, followed by quantification of bacterial burden and histological analysis. The development of mastitis was accompanied by a significant increase in both Th17 and Th1 cells in the mammary gland. Moreover, the relative expression of genes encoding cytokines and transcription factors involved in the differentiation and function of these T helper cells, including Il17, Rorc, Tgfb, Il1b, Il23, Ifng, Tbx21, and Il12, was greatly elevated in the infected mammary gland. IL-17 is essential for neutrophil recruitment to infected mammary gland via CXC chemokines, whereas the excessive IL-17 production contributes to tissue damage in mastitis. In addition, a shift in T helper cell polarization toward Th2 and Treg cells was observed 5 days post-infection, and the mRNA expression of the anti-inflammatory cytokine Il10 was markedly increased at day 7 post-infection. These results indicate that immune clearance of Staphylococcus aureus in mastitis is facilitated by the enrichment of Th17, Th1 and Th2 cells in the mammary gland mediated by pro-inflammatory cytokine production, which is tightly regulated by Treg cells and the anti-inflammatory cytokine IL-10.

  2. Shifted T Helper Cell Polarization in a Murine Staphylococcus aureus Mastitis Model

    PubMed Central

    Zhao, Yanqing; Zhou, Ming; Gao, Yang; Liu, Heyuan; Yang, Wenyu; Yue, Jinhua; Chen, Dekun

    2015-01-01

    Mastitis, one of the most costly diseases in dairy ruminants, is an inflammation of the mammary gland caused by pathogenic infection. The mechanisms of adaptive immunity against pathogens in mastitis have not been fully elucidated. To investigate T helper cell-mediated adaptive immune responses, we established a mastitis model by challenge with an inoculum of 4 × 106 colony-forming units of Staphylococcus aureus in the mammary gland of lactating mice, followed by quantification of bacterial burden and histological analysis. The development of mastitis was accompanied by a significant increase in both Th17 and Th1 cells in the mammary gland. Moreover, the relative expression of genes encoding cytokines and transcription factors involved in the differentiation and function of these T helper cells, including Il17, Rorc, Tgfb, Il1b, Il23, Ifng, Tbx21, and Il12, was greatly elevated in the infected mammary gland. IL-17 is essential for neutrophil recruitment to infected mammary gland via CXC chemokines, whereas the excessive IL-17 production contributes to tissue damage in mastitis. In addition, a shift in T helper cell polarization toward Th2 and Treg cells was observed 5 days post-infection, and the mRNA expression of the anti-inflammatory cytokine Il10 was markedly increased at day 7 post-infection. These results indicate that immune clearance of Staphylococcus aureus in mastitis is facilitated by the enrichment of Th17, Th1 and Th2 cells in the mammary gland mediated by pro-inflammatory cytokine production, which is tightly regulated by Treg cells and the anti-inflammatory cytokine IL-10. PMID:26230498

  3. CD4 T-helper cell cytokine phenotypes and antibody response following tetanus toxoid booster immunization.

    PubMed

    Livingston, Kimberly A; Jiang, Xiaowen; Stephensen, Charles B

    2013-04-30

    Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10(+) cells. Eight healthy subjects were given a TT booster vaccination. Blood was drawn before, 3, 7, 14, and 28days after vaccination and peripheral blood mononuclear cells (PBMC) were cultured for 7days with TT, negative control (diluent), and a positive control (Staphylococcus enterotoxin B [SEB]). Activation markers (CD25 and CD69) were measured after 44h (n=8), cytokines in supernatant after 3 and 7days, and intracellular cytokine staining (ICS) of proliferated cells (identified by dye dilution) after 7days (n=6). Vaccination increased TT-specific expression of CD25 and CD69 on CD3(+)CD4(+) lymphocytes, and TT-specific proliferation at 7, 14 and 28days post vaccination. Vaccination induced TT-specific Th1 (IFN-γ, TNF-α, and IL-2) Th2 (IL-13, IL-5, and IL-4), Th17 (IL-17A) and IL-10(+) cells as measured by ICS. TT-specific Th1 cells were the most abundant (12-15% of all TT-specific CD4(+) T-cells) while IL10(+) (1.8%) Th17 (1.1%) and Th2 cells (0.2-0.6%) were less abundant. TT-specific cytokine concentrations in PBMC supernatants followed the same pattern where a TT-specific IL-9 response was also seen. In conclusion, TT booster vaccination induced a broad T-helper cell response. This method of evaluating cytokine phenotypes may be useful in examining the impact of nutrition and environmental conditions on the plasticity of T-helper cell memory responses.

  4. When helping helps: autonomous motivation for prosocial behavior and its influence on well-being for the helper and recipient.

    PubMed

    Weinstein, Netta; Ryan, Richard M

    2010-02-01

    Self-determination theory posits that the degree to which a prosocial act is volitional or autonomous predicts its effect on well-being and that psychological need satisfaction mediates this relation. Four studies tested the impact of autonomous and controlled motivation for helping others on well-being and explored effects on other outcomes of helping for both helpers and recipients. Study 1 used a diary method to assess daily relations between prosocial behaviors and helper well-being and tested mediating effects of basic psychological need satisfaction. Study 2 examined the effect of choice on motivation and consequences of autonomous versus controlled helping using an experimental design. Study 3 examined the consequences of autonomous versus controlled helping for both helpers and recipients in a dyadic task. Finally, Study 4 manipulated motivation to predict helper and recipient outcomes. Findings support the idea that autonomous motivation for helping yields benefits for both helper and recipient through greater need satisfaction. Limitations and implications are discussed. Copyright 2009 APA, all rights reserved

  5. Identification of genomic regions of the herpesvirus of turkeys (HVT) with helper activity for avian adeno-associated virus (AAAV).

    PubMed

    Bauer, H J; Schüller, S; Monreal, G; Lindenmaier, W

    1993-03-01

    Herpesvirus of turkeys (HVT) is a potent helper for the defective parvovirus avian adeno-associated virus (AAAV). To study the helper mechanism at the molecular level, we established a complete cosmid library of HVT DNA in a set of seven overlapping clones and transiently cotransfected secondary chicken embryo fibroblast (CEF) cells with AAAV DNA and recombinant cosmids (cBL) (individual as well as in different combinations). Using an AAAV-specific indirect immunofluorescence assay, we identified four regions on the HVT genome, represented by cBL267, cBL27, cBL33, and cBL34, which express helper functions for AAAV. As demonstrated by infection studies with extracts from cotransfected CEF cells, cBL267 promotes productive AAAV growth, while the helper effect induced by cBL27, cBL33, and cBL34 is limited to the synthesis of noninfectious AAAV antigen. In view of the data presented, possible HVT-specific helper mechanisms for AAAV are discussed.

  6. Production of high-titer helper virus-free retroviral vectors by cocultivation of packaging cells with different host ranges.

    PubMed Central

    Lynch, C M; Miller, A D

    1991-01-01

    The titer of retroviral vectors can be increased by cocultivation of retrovirus packaging cells that produce a vector with packaging cells having a different host range. Multiple rounds of infection occur in such cultures, producing an amplification of vector copy number and titer. Production of a vector with a very high titer of over 10(10) CFU per ml of conditioned medium has been reported, although replication-competent helper virus was also present. Since helper-free virus is a requirement for many applications of retroviral vectors, we repeated this procedure with a modified vector and achieved a 2- to 10-fold amplification of vector titer in the absence of helper virus, up to 2 x 10(7) CFU/ml. We have also repeated these experiments with the same vector and methods described previously or have assayed virus from the high-titer vector-producing cell line reported previously and observed maximum titers of 10(8) CFU/ml, invariably accompanied by helper virus. Thus, while amplification of vector titer in the absence of helper virus is possible, some unexplained difference in the assays for virus titer must account for our inability to obtain the exceptionally high vector titers that were reported previously. PMID:2041097

  7. Efficient loading of HLA-DR with a T helper epitope by genetic exchange of CLIP

    PubMed Central

    van Bergen, Jeroen; Schoenberger, Stephen P.; Verreck, Frank; Amons, Reinout; Offringa, Rienk; Koning, Frits

    1997-01-01

    The HLA class II-associated invariant chain (Ii)-derived peptide (CLIP) occupies the peptide binding groove during assembly in the endoplasmic reticulum, travels with HLA class II to endosomal compartments, and is subsequently released to allow binding of antigenic peptides. We investigated whether the exchange of CLIP with a known T helper epitope at the DNA level would lead to efficient loading of this helper epitope onto HLA class II. For this purpose, a versatile Ii-encoding expression vector was created in which CLIP can be replaced with a helper epitope of choice. Upon supertransfection of HLA-DR1-transfected 293 cells with an Ii vector encoding a known T helper epitope (HA307–319), predominantly length variants of this epitope were detected in association with the HLA-DR1 molecules of these cells. Moreover, this transfectant was efficiently recognized by a peptide-specific T helper clone (HA1.7). The results suggest that this type of Ii vector can be used to create potent class II+ cellular vaccines in which defined T cell epitopes are continuously synthesized. PMID:9207120

  8. Utilization of the natural helper model in health promotion targeting African American men.

    PubMed

    Scott, Tiffany N

    2009-12-01

    When compared with other racial and ethnic groups, African American men experience a great number of health disparities. The factors that perpetuate health disparities among African American men are multidimensional and include lack of access to equitable health care, lack of knowledge and limited education about health promoting behaviors, lack of organizational trust and acceptability, the impact of masculinity on health, and psychological factors. This article explores the health promotion needs of African American men and the ability of the natural helper model to address those needs. Further discussion of its use by holistic nurses as a culturally tailored health promotion intervention targeting African American men is presented.

  9. Simian immunodeficiency virus confounds T follicular helper T cells and the germinal centre

    PubMed Central

    Lea-Henry, Tom N.

    2016-01-01

    Yamamoto et al. have studied T follicular helper (TFH) and germinal centre (GC) responses after infection of rhesus macaques (RM) infected with simian immunodeficiency virus (SIV). In this study the authors examined the behaviour of TFH, reproducing infection-associated TFH accumulation and their association with the quality of antibody responses against cross-clade viral epitopes. The authors correlate TFH IL4 and CD154 expression with superior antibody responses. Accumulation of TFH was accompanied by aberrant expression of non-TFH transcriptional regulators such as BLIMP1 in TFH, suggesting viral induced abnormalities may affect TFH function. PMID:28149882

  10. Progress and prospects: gene therapy for genetic diseases with helper-dependent adenoviral vectors.

    PubMed

    Brunetti-Pierri, N; Ng, P

    2008-04-01

    Preclinical studies in small and large animal models using helper-dependent adenoviral vectors (HDAds) have generated promising results for the treatment of genetic diseases. However, clinical translation is complicated by the dose-dependent, capsid-mediated acute toxic response following systemic vector injection. With the advancements in vectorology, a better understanding of vector-mediated toxicity, and improved delivery methods, HDAds may emerge as an important vector for gene therapy of genetic diseases and this report highlights recent progress and prospects in this field.

  11. Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells

    PubMed Central

    Sadtler, Kaitlyn; Estrellas, Kenneth; Allen, Brian W.; Wolf, Matthew T.; Fan, Hongni; Tam, Ada J.; Patel, Chirag H.; Luber, Brandon S.; Wang, Hao; Wagner, Kathryn R.; Powell, Jonathan D.; Housseau, Franck; Pardoll, Drew M.

    2016-01-01

    Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4–dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair. PMID:27081073

  12. Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells.

    PubMed

    Sadtler, Kaitlyn; Estrellas, Kenneth; Allen, Brian W; Wolf, Matthew T; Fan, Hongni; Tam, Ada J; Patel, Chirag H; Luber, Brandon S; Wang, Hao; Wagner, Kathryn R; Powell, Jonathan D; Housseau, Franck; Pardoll, Drew M; Elisseeff, Jennifer H

    2016-04-15

    Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4-dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair. Copyright © 2016, American Association for the Advancement of Science.

  13. Effects of a Novel Arginine Methyltransferase Inhibitor on T Helper Cell Cytokine Production

    PubMed Central

    Bonham, Kevin; Hemmers, Saskia; Lim, Yeon-Hee; Hill, Dawn M.; Finn, M.G.; Mowen, Kerri A.

    2010-01-01

    The protein arginine methyltransferase (PRMT) family of enzymes catalyzes the transfer of methyl groups from S-adenosylmethionine to the guanidino nitrogen atom of peptidylarginine to form monomethylarginine or dimethylarginine. We created several less polar analogues of the specific PRMT inhibitor AMI-1, and one such compound was found to have improved PRMT inhibitory activity over the parent molecule. The newly identified PRMT inhibitor modulated T helper cell function and thus may serve as a lead for further inhibitors useful for immune-mediated disease treatment. PMID:20345902

  14. Circulating T helper and T regulatory subsets in untreated early rheumatoid arthritis and healthy control subjects.

    PubMed

    Pandya, Jayesh M; Lundell, Anna-Carin; Hallström, Magnus; Andersson, Kerstin; Nordström, Inger; Rudin, Anna

    2016-10-01

    The pathogenic role and frequency of T cell subtypes in early rheumatoid arthritis are still unclear. We therefore performed a comprehensive analysis of the circulating T cell subtype pattern in patients with untreated early rheumatoid arthritis compared to healthy control subjects. Peripheral blood mononuclear cells were obtained from 26 patients with untreated early rheumatoid arthritis and from with 18 age- and sex-matched healthy control subjects. T helper cell types Th0, Th1, Th2, Th17, and Th1/17 and nonclassic T helper subsets were defined by flow cytometry based on the expression of chemokine receptors CCR4, CCR6, and CXCR3. Regulatory T cells were defined by expression of CD25(+) CD127(low) and also FOXP3 CXCR5(+) cells among regulatory and nonregulatory T cells were defined as T follicular regulatory and T follicular helper cells, respectively. The phenotype of T cell subsets was confirmed by transcription factor and cytokine secretion analyses. Multivariate discriminant analysis showed that patients with untreated early rheumatoid arthritis were segregated from healthy control subjects based on the circulating T cell subset profile. Among the discriminator subsets, CCR4(+)CXCR3(-) (Th2 and Th17), CTLA4(+) and FOXP3(+) subsets were present in significantly higher frequencies, whereas CCR4(-) (Th1/Th17, CCR6(+)CCR4(-)CXCR3(-), and Th1) subsets were present in lower frequencies in patients with untreated early rheumatoid arthritis compared with healthy control subjects. The proportions of Th2 and Th17 subsets associated positively with each other and negatively with the CXCR3(+)/interferon γ-secreting subsets (Th1 and Th1/Th17) in patients with untreated rheumatoid arthritis. The proportions of Th2 cells increased with age in patients with untreated early rheumatoid arthritis and healthy control subjects. The dominance of circulating CCR4(+)CXCR3(-) T helper subsets (Th2 and Th17) in untreated early rheumatoid arthritis point toward a pathogenic role of

  15. Monogenic mutations differentially impact the quantity and quality of T follicular helper cells in human primary immunodeficiencies

    PubMed Central

    Ma, Cindy S; Wong, Natalie; Rao, Geetha; Avery, Danielle T; Torpy, James; Hambridge, Thomas; Bustamante, Jacinta; Okada, Satoshi; Stoddard, Jennifer L; Deenick, Elissa K; Pelham, Simon J; Payne, Katherine; Boisson-Dupuis, Stéphanie; Puel, Anne; Kobayashi, Masao; Arkwright, Peter D; Kilic, Sara Sebnem; Baghdadi, Jamila El; Nonoyama, Shigeaki; Minegishi, Yoshiyuki; Mahdaviani, Seyed Alireza; Mansouri, Davood; Bousfiha, Aziz; Blincoe, Annaliesse K; French, Martyn A; Hsu, Peter; Campbell, Dianne E.; Stormon, Michael O; Wong, Melanie; Adelstein, Stephen; Smart, Joanne M; Fulcher, David A; Cook, Matthew C; Phan, Tri G; Stepensky, Polina; Boztug, Kaan; Kansu, Aydan; Ikincioğullari, Aydan; Baumann, Ulrich; Beier, Rita; Roscioli, Tony; Ziegler, John B; Gray, Paul; Picard, Capucine; Grimbacher, Bodo; Warnatz, Klaus; Holland, Steven M; Casanova, Jean-Laurent; Uzel, Gulbu; Tangye, Stuart G

    2016-01-01

    Background T follicular helper (Tfh) cells underpin T-cell dependent humoral immunity and the success of most vaccines. Tfh cells also contribute to human immune disorders such as autoimmunity, immunodeficiency and malignancy. Understanding the molecular requirements for the generation and function of Tfh cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunological abnormalities. Objective To determine the signaling pathways and cellular interactions required for the development and function of Tfh cells in humans. Methods Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating Tfh (cTfh) cell subsets, memory B cells and serum Ig levels were quantified and functionally assessed in healthy controls as well as patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS or BTK. Results Loss-of function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS or BTK reduced cTfh frequencies. STAT3, IL21/R LOF and STAT1 gain-of function mutations skewed cTfh differentiation towards a phenotype characterized by over-expression of IFNγ and programmed death -1 (PD-1). IFNγ inhibited cTfh function in vitro and in vivo, corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1 and IL12RB1 LOF mutations. Conclusion Specific mutations impact the quantity and quality of cTfh cells, highlighting the need to assess Tfh cells in patients by multiple criteria, including phenotype and function. Furthermore, IFNγ functions in vivo to restrain Tfh-induced B cell differentiation. These findings shed new light on Tfh biology and the integrated signaling pathways required for their generation, maintenance and effector function, and explain compromised humoral immunity in some PIDs. PMID:26162572

  16. Immunodominant regions for T helper-cell sensitization on the human nicotinic receptor alpha subunit in myasthenia gravis.

    PubMed Central

    Protti, M P; Manfredi, A A; Straub, C; Howard, J F; Conti-Tronconi, B M

    1990-01-01

    In myasthenia gravis an autoimmune response against the nicotinic acetylcholine receptor (AChR) occurs. The alpha subunit of the AChR contains both the epitope(s) that dominates the antibody response (main immunogenic region) and epitopes involved in T helper cell sensitization. In this study, overlapping synthetic peptides corresponding to the complete AChR alpha-subunit sequence were used to propagate polyclonal AChR-specific T helper cell lines from four myasthenic patients of different HLA types. Response of the T helper lines to the individual peptides was studied. Four immunodominant sequence segments were identified--i.e., residues 48-67, 101-120, 304-322, and 419-437. These regions did not include residues known to form the main immunogenic region or the cholinergic binding site, and they frequently contained sequence motifs that have been proposed to be related to T-epitope formation. Images PMID:2145582

  17. Holistic systems biology approaches to molecular mechanisms of human helper T cell differentiation to functionally distinct subsets.

    PubMed

    Chen, Z; Lönnberg, T; Lahesmaa, R

    2013-08-01

    Current knowledge of helper T cell differentiation largely relies on data generated from mouse studies. To develop therapeutical strategies combating human diseases, understanding the molecular mechanisms how human naïve T cells differentiate to functionally distinct T helper (Th) subsets as well as studies on human differentiated Th cell subsets is particularly valuable. Systems biology approaches provide a holistic view of the processes of T helper differentiation, enable discovery of new factors and pathways involved and generation of new hypotheses to be tested to improve our understanding of human Th cell differentiation and immune-mediated diseases. Here, we summarize studies where high-throughput systems biology approaches have been exploited to human primary T cells. These studies reveal new factors and signalling pathways influencing T cell differentiation towards distinct subsets, important for immune regulation. Such information provides new insights into T cell biology and into targeting immune system for therapeutic interventions.

  18. In Vitro and In Vivo Characterization of MicroRNA-Targeted Alphavirus Replicon and Helper RNAs ▿ ‡

    PubMed Central

    Kamrud, Kurt I.; Coffield, V. McNeil; Owens, Gary; Goodman, Christin; Alterson, Kim; Custer, Max; Murphy, Michael A.; Lewis, Whitney; Timberlake, Sarah; Wansley, Elizabeth K.; Berglund, Peter; Smith, Jonathan

    2010-01-01

    Alphavirus-based replicon vector systems (family Togaviridae) have been developed as expression vectors with demonstrated potential in vaccine development against both infectious diseases and cancer. The single-cycle nature of virus-like replicon particles (VRP), generated by supplying the structural proteins from separate replicable helper RNAs, is an attractive safety component of these systems. MicroRNAs (miRNAs) have emerged as important cellular RNA regulation elements. Recently, miRNAs have been employed as a mechanism to attenuate or restrict cellular tropism of replication-competent viruses, such as oncolytic adenoviruses, vesicular stomatitis virus, and picornaviruses as well as nonreplicating lentiviral and adenoviral vectors. Here, we describe the incorporation of miRNA-specific target sequences into replicable alphavirus helper RNAs that are used in trans to provide the structural proteins required for VRP production. VRP were found to be efficiently produced using miRNA-targeted helper RNAs if miRNA-specific inhibitors were introduced into cells during VRP production. In the absence of such inhibitors, cellular miRNAs were capable of downregulating helper RNA replication in vitro. When miRNA targets were incorporated into a replicon RNA, cellular miRNAs were capable of downregulating replicon RNA replication upon delivery of VRP into animals, demonstrating activity in vivo. These data provide the first example of miRNA-specific repression of alphavirus replicon and helper RNA replication and demonstrate the feasibility of miRNA targeting of expression vector helper functions that are provided in trans. PMID:20504925

  19. A Chemically Inducible Helper Module for Detecting Protein-Protein Interactions with Tunable Sensitivity Based on KIPPIS.

    PubMed

    Kashima, Daiki; Kawade, Raiji; Nagamune, Teruyuki; Kawahara, Masahiro

    2017-04-13

    As protein-protein interactions (PPIs) play essential roles in regulating their functional consequences in cells, methods to detect PPIs in living cells are desired for correct understanding of intracellular PPIs and pharmaceutical development therefrom. Here we demonstrate a c-kit-based PPI screening (KIPPIS) system in combination with a chemically inducible helper module for detecting PPIs in living mammalian cells. In this system, a mutant of FK506-binding protein 12 (FKBPF36 V) is fused with a protein of interest and the intracellular domain of a receptor tyrosine kinase c-kit. Constitutive expression of two fusion proteins with interacting proteins of interest in interleukin-3 (IL-3)-dependent cells results in dimerization and subsequent activation of the c-kit intracellular domains, which allows cell proliferation in a culture medium devoid of IL-3. A helper ligand, a small synthetic chemical that homodimerizes FKBPF36 V, assists the formation of stable complexes of the fusion proteins and serves as a tuner for sensitivity of the system. Using this system, two model PPIs were successfully detected on the basis of cell proliferation, which was featured by the helper-ligand- and PPI-dependent phosphorylation of the Src family kinases, a hallmark of the c-kit signaling. Notably, the inclusion of the helper module enabled PPI detection with tunable sensitivity. The helper-assisted KIPPIS allows us to configure various affinity thresholds by changing the concentration of the helper ligand, which may be applied to select affinity-matured variants using the advantage of cell proliferation.

  20. Immunometabolic Regulation of Interleukin-17-Producing T Helper Cells: Uncoupling New Targets for Autoimmunity

    PubMed Central

    Binger, Katrina J.; Côrte-Real, Beatriz F.; Kleinewietfeld, Markus

    2017-01-01

    Interleukin-17-producing T helper (Th17) cells are critical for the host defense of bacterial and fungal pathogens and also play a major role in driving pathogenic autoimmune responses. Recent studies have indicated that the generation of Th17 cells from naïve CD4+ T cells is coupled with massive cellular metabolic adaptations, necessary to cope with different energy and metabolite requirements associated with switching from a resting to proliferative state. Furthermore, Th17 cells have to secure these metabolic adaptations when facing nutrient-limiting environments, such as at the sites of inflammation. Accumulating data indicates that this metabolic reprogramming is significantly linked to the differentiation of T helper cells and, particularly, that the metabolic changes of Th17 cells and anti-inflammatory Forkhead box P3+ regulatory T cells are tightly and reciprocally regulated. Thus, a better understanding of these processes could offer potential new targets for therapeutic interventions for autoimmune diseases. In this mini-review, we will highlight some of the recent advances and discoveries in the field, with a particular focus on metabolic demands of Th17 cells and their implications for autoimmunity. PMID:28377767

  1. Properties of satellite tobacco mosaic virus phenotypes expressed in the presence and absence of helper virus.

    PubMed

    Sivanandam, Venkatesh; Mathews, Deborah; Rao, A L N

    2015-09-01

    In this study, we assembled an Agrobacterium-based transient expression system for the ectopic expression of Satellite tobacco mosaic virus (STMV) (+) or (-) transcripts and their biological activity was confirmed when Nicotiana benthamiana plants were co-expressed with helper Tobacco mosaic virus replicase. Characterization of STMV in the presence and absence of its HV revealed: (i) HV-dependent expression of STMV (+) in N. benthamiana, but not in N. tabacum, generated a replication-deficient but translation and encapsidation competent variant lacking the highly conserved 3' 150 nucleotides (nt) (STMVΔ150); (ii) mutational analysis demonstrated that a conserved 3' stem-loop structure in wild type and STMVΔ150 located between nt 874 and 897 is essential for translation of CP; (iii) helper virus-independent expression of CP from wt STMV was competent for the assembly of empty aberrant virion-like particles; whereas, CP translated from STMVΔ150 resulted in disorganized CP aggregates suggesting a role for the 3'tRNA-like structure in STMV assembly.

  2. T Helper 17 Cells in Primary Sjögren’s Syndrome

    PubMed Central

    Matsui, Kiyoshi; Sano, Hajime

    2017-01-01

    Primary Sjögren’s syndrome is an autoimmune disease characterized by diffuse infiltration of lymphocytes into exocrine glands and other tissues. The infiltrating lymphocytes have been identified as subsets of B cells and T cells, including T helper 17 cells, T regulatory cells and follicular helper T cells. The role of these cells in the development of the syndrome is now known, as is their impact on the production of proinflammatory cytokines such as IL-6, IL-17, IL-22 and IL-23. In particular, experimental animal models and patients suggest that a shift in Th17/Treg balance toward the proinflammatory Th17 axis exacerbates primary Sjögren’s syndrome and other autoimmune disorders. Nevertheless, the pathogenesis of the disorder is not yet fully elucidated. This review summarizes the recent advances in therapeutic control of the Treg/Th17 balance, as well as the efficacy of candidate therapeutics against primary Sjögren’s syndrome. PMID:28678161

  3. Asymmetric 1-Alkyl-2-acyl Phosphatidylcholine: a Helper Lipid for Enhanced Non-viral Gene Delivery

    PubMed Central

    Huang, Zhaohua; Li, Weijun; Szoka, Francis C.

    2011-01-01

    Rationally designed asymmetrical alkylacyl phosphatidylcholines (APC) have been synthesized and evaluated as helper lipids for non-viral gene delivery. A long aliphatic chain (C22~C24) was introduced at the 1-position of glycerol backbone, a branched lipid chain (C18) at the 2-position, and a phosphocholine head group at the 3-position. The fusogenicity of APC depends on the length and degree of saturation of the alkyl chain. Cationic lipids were formulated with APC as either lipoplexes or nanolipoparticles, and evaluated for their stability, transfection efficiency, and cytotoxicity. APC mediated high in vitro transfection efficiency, and had low cytotoxicity. Small nanolipoparticles (less than 100 nm) can be obtained with APC by applying as low as 0.1% PEG-lipid. Our study extends the type of helper lipids that are suitable for gene transfer and points the way to improve non-viral nucleic acid delivery system other than the traditional cationic lipids optimization. This work is supported by NIH grant EB003008. PMID:21718766

  4. An efficient and scalable process for helper-dependent adenoviral vector production using polyethylenimine-adenofection.

    PubMed

    Dormond, E; Meneses-Acosta, A; Jacob, D; Durocher, Y; Gilbert, R; Perrier, M; Kamen, A

    2009-02-15

    Safety requirements for adenoviral gene therapy protocols have led to the development of the third generation of vectors commonly called helper-dependent adenoviral vectors (HDVs). HDVs have demonstrated a high therapeutic potential; however, the poor efficiency and reliability of the actual production process hampers further large-scale clinical evaluation of this new vector. The current HDV production methods involve a preliminary rescue step through transfection of adherent cell cultures by an HDV plasmid followed by a helper adenovirus (HV) infection. Amplification by serial co-infection of complementary cells allows an increase in the HDV titer. Using a HEK293 FLP/frt cell system in suspension culture, an alternative protocol to the current transfection/infection procedure was evaluated. In this work, the adenofection uses the HDV plasmid linked to the HV with the help of polyethylenimine (PEI) and has shown to outperform standard protocols by producing higher HDV yield. The influence of complex composition on the HDV production was examined by a statistical design. The optimized adenofection and amplification conditions were successively performed to generate HDV at the 3 L bioreactor scale. Following only two serial co-infection passages, up to 1.44 x 10(8) HDV infectious units/mL of culture were generated, which corresponded to 26% of the total particles produced. This production strategy, realized in cell suspension culture, reduced process duration and therefore the probability of vector recombination by introducing a cost-effective transfection protocol, ensuring production of high-quality vector stock.

  5. Phenotypically distinct helper NK cells are required for gp96-mediated anti-tumor immunity

    PubMed Central

    Sedlacek, Abigail L.; Kinner-Bibeau, Lauren B.; Binder, Robert J.

    2016-01-01

    A number of Heat Shock Proteins (HSPs), in the extracellular environment, are immunogenic. Following cross-presentation of HSP-chaperoned peptides by CD91+ antigen presenting cells (APCs), T cells are primed with specificity for the derivative antigen-bearing cell. Accordingly, tumor-derived HSPs are in clinical trials for cancer immunotherapy. We investigate the role of NK cells in gp96-mediated anti-tumor immune responses given their propensity to lyse tumor cells. We show that gp96-mediated rejection of tumors requires a unique and necessary helper role in NK cells. This helper role occurs during the effector phase of the anti-tumor immune response and is required for T cell and APC function. Gp96 activates NK cells indirectly via APCs to a phenotype distinct from NK cells activated by other mechanisms such as IL-2. While NK cells have both lytic and cytokine producing properties, we show that gp96 selectively activates cytokine production in NK cells, which is important in the HSP anti-tumor immune response, and leaves their cytotoxic capacity unchanged. PMID:27431727

  6. Adapting a natural (lay) helpers model of change for worksite health promotion for women.

    PubMed

    Tessaro, I A; Taylor, S; Belton, L; Campbell, M K; Benedict, S; Kelsey, K; DeVellis, B

    2000-10-01

    Social network interventions that utilize informal systems of helping can be an important strategy for health promotion change. This article describes the development, implementation and evaluation of a natural (lay) helping intervention for health promotion change, specifically designed for women in small rural blue-collar worksites. One hundred and four women in four intervention worksites were recruited as natural helpers, and received health and skill-building education over an 18-month period. Qualitative evaluation showed: (1) two patterns of natural helping for women, i.e. participation due to a specific health concern with either themselves or others in their personal networks, and participation due to a larger sense of the importance of health and prevention; (2) over time natural helpers expanded the diffusion of health promotion information from close network members to co-workers and were more likely to be approached by their co-workers for information; (3) group activities at the worksite, particularly around physical activity, increased over time; and (4) because of time constraints at the workplace, written materials were a major way of spreading information to co-workers. This study shows that women can be recruited and trained to diffuse health promotion information and provide support to co-workers for health behavior change.

  7. Enhanced CCR5+/CCR3+ T helper cell ratio in patients with active cutaneous lupus erythematosus.

    PubMed

    Freutel, S; Gaffal, E; Zahn, S; Bieber, T; Tüting, T; Wenzel, J

    2011-10-01

    Cutaneous lupus erythematosus (CLE) is characterized by enhanced interferon α (IFNα) levels in serum and in tissue. Since IFNα promotes a Th1-biased immune response, we hypothesized that a Th1-associated chemokine receptor profile should be a typical finding in patients with active CLE. Therefore, peripheral blood mononuclear cells were isolated from patients with different CLE subsets (n = 15), healthy controls (n = 13) and patients under immunotherapy with IFNα (n = 7). T helper cells were analysed by flow cytometry for the expression of the chemokines receptor CCR5, indicative for Th1 cells, and of CCR3, indicating Th2. In addition, intracellular levels of the type I IFN-inducible MxA protein were measured. Patients with widespread active CLE skin lesions had a significantly increased expression of CCR5, whereas expression of CCR3 was decreased when compared with healthy controls. MxA expression was significantly enhanced in all investigated CLE subtypes, with the highest levels in patients with widespread skin lesions. The enhanced CCR5/CCR3 ratio closely correlated with the MxA levels in peripheral lymphocytes and with disease activity. Our analyses revealed that active CLE is associated with a systemic type I IFN effect that appears to induce a shift towards a Th1-associated chemokine receptor profile. The CCR5/CCR3 T-helper cell ratio might therefore represent an indirect marker for the disease activity in CLE.

  8. Scalable Memory Registration for High-Performance Networks Using Helper Threads

    SciTech Connect

    Li, Dong; Cameron, Kirk W.; Nikolopoulos, Dimitrios; de Supinski, Bronis R.; Schulz, Martin

    2011-01-01

    Remote DMA (RDMA) enables high performance networks to reduce data copying between an application and the operating system (OS). However RDMA operations in some high performance networks require communication memory explicitly registered with the network adapter and pinned by the OS. Memory registration and pinning limits the flexibility of the memory system and reduces the amount of memory that user processes can allocate. These issues become more significant on multicore platforms, since registered memory demand grows linearly with the number of processor cores. In this paper we propose a new memory registration/deregistration strategy to reduce registered memory on multicore architectures for HPC applications. We hide the cost of dynamic memory management by offloading all dynamic memory registration and deregistration requests to a dedicated memory management helper thread. We investigate design policies and performance implications of the helper thread approach. We evaluate our framework with the NAS parallel benchmarks, for which our registration scheme significantly reduces the registered memory (23.62% on average and up to 49.39%) and avoids memory registration/deregistration costs for reused communication memory. We show that our system enables the execution of problem sizes that could not complete under existing memory registration strategies.

  9. Interleukin-4 production by Follicular Helper T cells requires the conserved Il4 enhancer HS V

    PubMed Central

    Vijayanand, Pandurangan; Seumois, Grégory; Simpson, Laura J.; Abdul-Wajid, Sarah; Baumjohann, Dirk; Panduro, Marisella; Huang, Xiaozhu; Interlandi, Jeneen; Djuretic, Ivana M.; Brown, Daniel R.; Sharpe, Arlene H.; Rao, Anjana; Ansel, K. Mark

    2012-01-01

    SUMMARY Follicular helper T cells (Tfh cells) are the major producers of interleukin-4 (IL-4) in secondary lymphoid organs where humoral immune responses develop. Il4 regulation in Tfh cells appears distinct from the classical T helper 2 (Th2) cell pathway, but the underlying molecular mechanisms remain largely unknown. We found that HS V (also known as CNS2), a 3’ enhancer in the Il4 locus, is essential for IL-4 production by Tfh cells. Mice lacking HS V display marked defects in Th2 humoral immune responses, as evidenced by abrogated IgE and sharply reduced IgG1 production in vivo. In contrast, effector Th2 cells that are involved in tissue responses were far less dependent on HS V. HS V facilitated removal of repressive chromatin marks during Th2 and Tfh cell differentiation, and increased accessibility of the Il4 promoter. Thus Tfh and Th2 cells utilize distinct but overlapping molecular mechanisms to regulate Il4, a finding with important implications for understanding the molecular basis of Th2 mediated allergic diseases. PMID:22326582

  10. trans-2-Aminocyclohexanol-based amphiphiles as highly efficient helper lipids for gene delivery by lipoplexes.

    PubMed

    Zheng, Yu; Liu, Xin; Samoshina, Nataliya M; Samoshin, Vyacheslav V; Franz, Andreas H; Guo, Xin

    2015-12-01

    Lipidic amphiphiles equipped with the trans-2-aminocyclohexanol (TACH) moiety are promising pH-sensitive conformational switches ("flipids") that can trigger a lipid bilayer perturbation in response to increased acidity. Because pH-sensitivity was shown to improve the efficiency of several gene delivery systems, we expected that such flipids could significantly enhance the gene transfection by lipoplexes. Thus a series of novel lipids with various TACH-based head groups and hydrocarbon tails were designed, prepared and incorporated into lipoplexes that contain the cationic lipid 1,2-dioleoyl-3-trimethylammonio-propane (DOTAP) and plasmid DNA encoding a luciferase gene. B16F1 and HeLa cells were transfected with such lipoplexes in both serum-free and serum-containing media. The lipoplexes consisting of TACH-lipids exhibited up to two orders of magnitude better transfection efficiency and yet similar toxicity compared to the ones with the conventional helper lipids 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) or cholesterol. Thus, the TACH-lipids can be used as novel helper lipids for efficient gene transfection with low cytotoxicity.

  11. Increased frequency of circulating follicular helper T cells in patients with rheumatoid arthritis.

    PubMed

    Ma, Jie; Zhu, Chenlu; Ma, Bin; Tian, Jie; Baidoo, Samuel Essien; Mao, Chaoming; Wu, Wei; Chen, Jianguo; Tong, Jia; Yang, Min; Jiao, Zhijun; Xu, Huaxi; Lu, Liwei; Wang, Shengjun

    2012-01-01

    Follicular helper T (Tfh) cells are recognized as a distinct CD4(+) helper T-cell subset, which provides for B-cell activation and production of specific antibody responses, and play a critical role in the development of autoimmune disease. So far, only one study investigated the circulating Tfh cells increased in a subset of SLE patients. Since relatively little is known about the Tfh cells in rheumatoid arthritis (RA) patients, in this study, Tfh-cell frequency, related cytokine IL-21, and transcription factor Bcl-6 were investigated in 53 patients with RA and 31 health controls. Firstly, we found that the frequency of CD4(+)CXCR5(+)ICOS(high) Tfh cells was increased significantly in the peripheral blood of RA patients, compared with that in healthy controls. It is known that Tfh cells are critical for directing the development of an antibody response by germinal centers B cells; secondly, we observed that the Tfh-cell frequency is accompanied by the level of anti-CCP antibody in RA patients. Furthermore, expression of Bcl-6 mRNA and plasma IL-21 concentrations in RA patients was increased. Taken together, these findings have shown that the increased frequency of circulating Tfh cells is correlated with elevated levels of anti-CCP antibody, indicating the possible involvement of Tfh cells in the disease progression of RA.

  12. T follicular helper cells differentiate from Th2 cells in response to helminth antigens

    PubMed Central

    Zaretsky, Arielle Glatman; Taylor, Justin J.; King, Irah L.; Marshall, Fraser A.; Mohrs, Markus

    2009-01-01

    The relationship of T follicular helper (TFH) cells to other T helper (Th) subsets is controversial. We find that after helminth infection, or immunization with helminth antigens, reactive lymphoid organs of 4get IL-4/GFP reporter mice contain populations of IL-4/GFP-expressing CD4+ T cells that display the TFH markers CXCR5, PD-1, and ICOS. These TFH cells express the canonical TFH markers BCL6 and IL-21, but also GATA3, the master regulator of Th2 cell differentiation. Consistent with a relationship between Th2 and TFH cells, IL-4 protein production, reported by expression of huCD2 in IL-4 dual reporter (4get/KN2) mice, was a robust marker of TFH cells in LNs responding to helminth antigens. Moreover, the majority of huCD2/IL-4–producing Th cells were found within B cell follicles, consistent with their definition as TFH cells. TFH cell development after immunization failed to occur in mice lacking B cells or CD154. The relationship of TFH cells to the Th2 lineage was confirmed when TFH cells were found to develop from CXCR5− PD-1− IL-4/GFP+ CD4+ T cells after their transfer into naive mice and antigen challenge in vivo. PMID:19380637

  13. Increased Circulating T Follicular Helper Cells Are Inhibited by Rituximab in Neuromyelitis Optica Spectrum Disorder.

    PubMed

    Zhao, Cong; Li, Hong-Zeng; Zhao, Dai-Di; Ma, Chao; Wu, Fang; Bai, Ya-Nan; Zhang, Min; Li, Zhu-Yi; Guo, Jun

    2017-01-01

    Neuromyelitis optica spectrum disorder (NMOSD) is a severe autoimmune disease of the central nervous system. The existence of autoantibody targeting aquaporin-4 (AQP4-Ab) indicates the involvement of humoral immunity in the pathogenesis of this disease. Rituximab (RTX), a monoclonal antibody against CD20, has been used to treat NMOSD by depleting circulating B cells and overall satisfactory outcome has been achieved. Although T follicular helper cells have been proved to regulate B cell activation and antibody production, the role of these cells in NMOSD and the impact of RTX treatment on these cells remain less understood. In this study, we found that frequencies of circulating T follicular helper (cTfh) cells and B cells together with the related cytokines, IL-21 and IL-6, were closely correlated with disease activity of NMOSD. Furthermore, B cell depletion with RTX treatment inhibited the expansion of cTfh cells, and these effects were achieved through eliminating IL-6-producing B cells and blocking the direct contact between cTfh cells and B cells. These findings imply the complicated cross talk between cTfh cells and B cells and may provide a novel therapeutic target for NMOSD.

  14. Increased Circulating T Follicular Helper Cells Are Inhibited by Rituximab in Neuromyelitis Optica Spectrum Disorder

    PubMed Central

    Zhao, Cong; Li, Hong-Zeng; Zhao, Dai-Di; Ma, Chao; Wu, Fang; Bai, Ya-Nan; Zhang, Min; Li, Zhu-Yi; Guo, Jun

    2017-01-01

    Neuromyelitis optica spectrum disorder (NMOSD) is a severe autoimmune disease of the central nervous system. The existence of autoantibody targeting aquaporin-4 (AQP4-Ab) indicates the involvement of humoral immunity in the pathogenesis of this disease. Rituximab (RTX), a monoclonal antibody against CD20, has been used to treat NMOSD by depleting circulating B cells and overall satisfactory outcome has been achieved. Although T follicular helper cells have been proved to regulate B cell activation and antibody production, the role of these cells in NMOSD and the impact of RTX treatment on these cells remain less understood. In this study, we found that frequencies of circulating T follicular helper (cTfh) cells and B cells together with the related cytokines, IL-21 and IL-6, were closely correlated with disease activity of NMOSD. Furthermore, B cell depletion with RTX treatment inhibited the expansion of cTfh cells, and these effects were achieved through eliminating IL-6-producing B cells and blocking the direct contact between cTfh cells and B cells. These findings imply the complicated cross talk between cTfh cells and B cells and may provide a novel therapeutic target for NMOSD. PMID:28360886

  15. Global transcriptome analysis and enhancer landscape of human primary T follicular helper and T effector lymphocytes

    PubMed Central

    Weinstein, Jason S.; Lezon-Geyda, Kimberly; Maksimova, Yelena; Craft, Samuel; Zhang, Yaoping; Su, Mack; Schulz, Vincent P.

    2014-01-01

    T follicular helper (Tfh) cells are a subset of CD4+ T helper cells that migrate into germinal centers and promote B-cell maturation into memory B and plasma cells. Tfh cells are necessary for promotion of protective humoral immunity following pathogen challenge, but when aberrantly regulated, drive pathogenic antibody formation in autoimmunity and undergo neoplastic transformation in angioimmunoblastic T-cell lymphoma and other primary cutaneous T-cell lymphomas. Limited information is available on the expression and regulation of genes in human Tfh cells. Using a fluorescence-activated cell sorting–based strategy, we obtained primary Tfh and non-Tfh T effector cells from tonsils and prepared genome-wide maps of active, intermediate, and poised enhancers determined by chromatin immunoprecipitation–sequencing, with parallel transcriptome analyses determined by RNA sequencing. Tfh cell enhancers were enriched near genes highly expressed in lymphoid cells or involved in lymphoid cell function, with many mapping to sites previously associated with autoimmune disease in genome-wide association studies. A group of active enhancers unique to Tfh cells associated with differentially expressed genes was identified. Fragments from these regions directed expression in reporter gene assays. These data provide a significant resource for studies of T lymphocyte development and differentiation and normal and perturbed Tfh cell function. PMID:25331115

  16. PubstractHelper: A Web-based Text-Mining Tool for Marking Sentences in Abstracts from PubMed Using Multiple User-Defined Keywords.

    PubMed

    Chen, Chou-Cheng; Ho, Chung-Liang

    2014-01-01

    While a huge amount of information about biological literature can be obtained by searching the PubMed database, reading through all the titles and abstracts resulting from such a search for useful information is inefficient. Text mining makes it possible to increase this efficiency. Some websites use text mining to gather information from the PubMed database; however, they are database-oriented, using pre-defined search keywords while lacking a query interface for user-defined search inputs. We present the PubMed Abstract Reading Helper (PubstractHelper) website which combines text mining and reading assistance for an efficient PubMed search. PubstractHelper can accept a maximum of ten groups of keywords, within each group containing up to ten keywords. The principle behind the text-mining function of PubstractHelper is that keywords contained in the same sentence are likely to be related. PubstractHelper highlights sentences with co-occurring keywords in different colors. The user can download the PMID and the abstracts with color markings to be reviewed later. The PubstractHelper website can help users to identify relevant publications based on the presence of related keywords, which should be a handy tool for their research. http://bio.yungyun.com.tw/ATM/PubstractHelper.aspx and http://holab.med.ncku.edu.tw/ATM/PubstractHelper.aspx.

  17. Dog Helper's Guide: Dog Project Group Activities Grades 3-12. 4-H Skills for Life Animal Series. National 4-H Curriculum. BU-08169

    ERIC Educational Resources Information Center

    National 4-H Council, 2005

    2005-01-01

    This final guide in the series is designed to assist in one's role of helper for youth interested in the dog project. These learn-by-doing activities can be adapted for families, classrooms, dog project meetings, after school programs, camps or other settings. In this Helper's Guide, one will find helpful information about characteristics of…

  18. Dog Helper's Guide: Dog Project Group Activities Grades 3-12. 4-H Skills for Life Animal Series. National 4-H Curriculum. BU-08169

    ERIC Educational Resources Information Center

    National 4-H Council, 2005

    2005-01-01

    This final guide in the series is designed to assist in one's role of helper for youth interested in the dog project. These learn-by-doing activities can be adapted for families, classrooms, dog project meetings, after school programs, camps or other settings. In this Helper's Guide, one will find helpful information about characteristics of…

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

    PubMed Central

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

    2015-01-01

    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

  20. The transcription factor T-bet is induced by multiple pathways and prevents an endogenous T helper-2 program during T helper-1 responses

    PubMed Central

    Zhu, Jinfang; Jankovic, Dragana; Oler, Andrew J.; Wei, Gang; Sharma, Suveena; Hu, Gangqing; Guo, Liying; Yagi, Ryoji; Yamane, Hidehiro; Punkosdy, George; Feigenbaum, Lionel; Zhao, Keji; Paul, William E.

    2013-01-01

    SUMMARY T-bet is a critical transcription factor for T helper-1 (Th1) cell differentiation. To study the regulation and functions of T-bet, we developed a T-bet-ZsGreen reporter mouse strain. We determined that interleukin-12 (IL-12) and interferon-γ (IFN-γ) were redundant in inducing T-bet in mice infected with Toxoplasma gondii and that T-bet did not contribute to its own expression when induced by IL-12 and IFN-γ. By contrast, T-bet and the transcription factor Stat4 were critical for IFN-γ production whereas IFN-γ signaling was dispensable for inducing IFN-γ. Loss of T-bet resulted in activation of an endogenous program driving Th2 cell differentiation in cells expressing T-bet-ZsGreen. Genome-wide analyses indicated that T-bet directly induced many Th1 cell-related genes but indirectly suppressed Th2 cell-related genes. Our study revealed redundancy and synergy among several Th1 cell-inducing pathways in regulating the expression of T-bet and IFN-γ, and a critical role of T-bet in suppressing an endogenous Th2 cell-associated program. PMID:23041064

  1. Helping Children to Tell about Sexual Abuse: Guidance for Helpers Rosaleen McElvaney Helping Children to Tell about Sexual Abuse: Guidance for Helpers Jessica Kingsley Publishers 160pp £14.99 9781849057127 1849057125 [Formula: see text].

    PubMed

    2017-09-06

    Written in an easy-to-read style and with useful references to research, this book explores the issue of disclosure of sexual abuse. It follows a child's experience of abuse, describing the challenges of disclosure from the perspectives of the child and an adult helper, then discusses the help needed after disclosure.

  2. Bad Influence?--An Investigation into the Purported Negative Influence of Foreign Domestic Helpers on Children's Second Language English Acquisition

    ERIC Educational Resources Information Center

    Leung, Alex Ho-Cheong

    2012-01-01

    This paper explores the purported negative influence of foreign domestic helpers (FDHs) on child second language acquisition (SLA) by studying Hong Kong Cantonese children's listening ability in second language (L2) English. 31 kindergarten third graders aged 4;6 to 6, and 29 first year secondary students aged 11-14 who have had a Filipino…

  3. The Differentiation of CD4+ T-Helper Cell Subsets in the Context of Helminth Parasite Infection

    PubMed Central

    Bouchery, Tiffany; Kyle, Ryan; Ronchese, Franca; Le Gros, Graham

    2014-01-01

    Helminths are credited with being the major selective force driving the evolution of the so-called “type 2” immune responses in vertebrate animals, with their size and infection strategies presenting unique challenges to the immune system. Originally, type 2 immune responses were defined by the presence and activities of the CD4+ T-helper 2 subset producing the canonical cytokines IL-4, IL-5, and IL-13. This picture is now being challenged by the discovery of a more complex pattern of CD4+ T-helper cell subsets that appear during infection, including Tregs, Th17, Tfh, and more recently, Th22, Th9, and ThGM. In addition, a clearer view of the mechanisms by which helminths and their products selectively prime the CD4+ T-cell subsets is emerging. In this review, we have focused on recent data concerning the selective priming, differentiation, and functional role of CD4+ T-helper cell subsets in the context of helminth infection. We argue for a re-evaluation of the original Th2 paradigm and discuss how the observed plasticity of the T-helper subsets may enable the parasitized host to achieve an appropriate compromise between elimination, tissue repair, containment, and pathology. PMID:25360134

  4. Examining Live-In Foreign Domestic Helpers as a Coping Resource for Family Caregivers of People With Dementia in Singapore.

    PubMed

    Basnyat, Iccha; Chang, Leanne

    2017-09-01

    In Singapore, the responsibility of caring for persons with dementia falls on family members who cope with a long-term caregiver burden, depending on available support resources. Hiring foreign domestic workers to alleviate caregiver burden becomes a prevalent coping strategy that caregivers adopt. This strategy allows caregivers to provide home care as part of fulfilling family obligations while managing the caregiver burden. This study aimed to investigate primary caregivers' relationship with hired support and its impact on coping with caregiver burden. Twenty in-depth interviews were conducted with primary caregivers who hired live-in domestic helpers to take care of their family members with dementia. The findings revealed that caregivers perceived the normative obligations to provide home care to family members with dementia. They sought support from domestic helpers to cope with physical and mental burnout, disruption of normal routines, and avoidance of financial strain. A mutual-support relationship was built between caregivers and domestic helpers through trust and interdependence. The presence of domestic helpers as a coping resource reveals the positive outcomes of problem-, emotional-, and diversion-focused coping. This study illustrates that coping strategies are employed in different ways depending on the needs of caregivers, access to infrastructure, cultural expectations, and available resources.

  5. The Role of Foreign Domestic Helpers in Hong Kong Chinese Children's English and Chinese Skills: A Longitudinal Study

    ERIC Educational Resources Information Center

    Dulay, Katrina May; Tong, Xiuhong; McBride, Catherine

    2017-01-01

    We investigated the influence of nonparental caregivers, such as foreign domestic helpers (FDH), on the home language spoken to the child and its implications for vocabulary and word reading development in Cantonese- and English-speaking bilingual children. Using data collected from ages 5 to 9, we analyzed Chinese vocabulary, Chinese character…

  6. The Postoperative Immunosuppressive Phenotypes of Peripheral T Helper Cells Are Associated with Poor Prognosis of Breast Cancer Patients.

    PubMed

    Fu, Ganglan; Miao, Liping; Wang, Meng; Guo, MingYan; Wang, Chengli; Ji, Fengtao; Cao, Minghui

    2017-10-01

    T helper cells play essential roles in anti-tumor immune response. However, the postoperative changes of peripheral T cell subsets and their clinical significance in breast cancer patients remain largely unknown. We evaluated the perioperative changes of T lymphocyte subsets in invasive breast cancer (IBC) patients and breast fibroadenoma (BF) patients preoperatively (preop) and 6, 24, 72 hours postoperatively (POH6, POH24, and POH72). Proportions of CD3, CD4, CD8, T helper (Th) 1, Th2, Th17 cells, regulatory T cells (Treg), and CD4(+)/CD8(+), Th1/Th2 ratio were detected by flow cytometry. Changes in T helper cell quantity were correlated to clinicopathological parameters. Furthermore, we explored the association between the perioperative variations of T cell subsets and disease-free survival (DFS) of IBC patients. In IBC patients, Th1 cells diminished while Tregs elevated in postoperative 72 hours in the peripheral blood. In contrast, no significant perioperative changes of T cell subsets were observed in BF patients. Postoperative lower Th1 cells at POH 72 of IBC patients were correlated with greater tumor burden, HER2 positive and Ki67 positive. The increased Tregs at POH 72 of IBC patients were correlated with larger tumor size and HER2 positive. Th1 cell decline and Treg increment were both associated with shorter DFS in IBC patients. The variations of peripheral T helper cell subsets showed postoperative immunosuppression and were associated with poor prognosis in IBC patients.

  7. Effects of a Peer Helping Training Program on Helping Skills and Self-Growth of Peer Helpers

    ERIC Educational Resources Information Center

    Aladag, Mine; Tezer, Esin

    2009-01-01

    The purpose of this study was to develop a peer helping training program for university students in Turkey and to examine its effectiveness in improving the helping skills and self-growth of peer helpers. A pre-test, post-test, follow-up-test experimental design, involving a treatment and control group, was carried out with a total sample of 31…

  8. Helping effort increases with relatedness in bell miners, but ‘unrelated’ helpers of both sexes still provide substantial care

    PubMed Central

    Wright, Jonathan; McDonald, Paul G.; te Marvelde, Luc; Kazem, Anahita J. N.; Bishop, Charles M.

    2010-01-01

    Indirect fitness benefits from kin selection can explain why non-breeding individuals help raise the young of relatives. However, the evolution of helping by non-relatives requires direct fitness benefits, for example via group augmentation. Here, we examine nest visit rates, load sizes and prey types delivered by breeding pairs and their helpers in the cooperatively breeding bell miner (Manorina melanophrys). In this system, males remain in their natal colony while young females typically disperse, and helpers of both sexes often assist at multiple nests concurrently. We found extremely clear evidence for the expected effect of genetic relatedness on individual helping effort per nest within colonies. This positive incremental effect of kinship was facultative—i.e. largely the result of within-individual variation in helping effort. Surprisingly, no sex differences were detectable in any aspect of helping, and even non-relatives provided substantial aid. Helpers and breeders of both sexes regulated their provisioning effort by responding visit-by-visit to changes in nestling begging. Helping behaviour in bell miners therefore appears consistent with adaptive cooperative investment in the brood, and kin-selected care by relatives. Similar investment by ‘unrelated’ helpers of both sexes argues against direct fitness benefits, but is perhaps explained by kin selection at the colony level. PMID:19846458

  9. More Water, Madam? An ESL Curriculum for Service Helpers in Full-Service and Fast-Food Restaurants.

    ERIC Educational Resources Information Center

    Cwach, Marlin Day; Gravely, Mary Liles

    This document, which was developed as a cooperative effort between the business and education communities in Denver, presents an English-as-a-second-language curriculum for service helpers in full-service and fast food restaurants. The curriculum consists of five lessons targeted toward high intermediate to advanced nonnative speakers who work in…

  10. A requirement for physical linkage between determinants recognized by helper molecules and cytotoxic T cell precursors in the induction of cytotoxic T cell responses.

    PubMed

    Krowka, J F; Singh, B; Fotedar, A; Mosmann, T; Giedlin, M A; Pilarski, L M

    1986-05-15

    It has long been understood that both antibody and delayed-type hypersensitivity responses are induced through collaborative events in which the determinants recognized by the precursor cells must be physically linked to the determinants recognized by the helper. Although it is clear that the generation of memory cytotoxic T lymphocyte precursors (CTLp) involves linked recognition of determinants, the induction of CTL responses has been viewed as being dependent upon interleukin 2 (IL 2), which could be provided by a helper cell, but independent of requirements for antigen bridging. In this work, we have designed a system that lacks exogenous IL 2 by using as our source of help, antigen-specific helper molecules derived from helper T cells. These soluble helper molecules are uncontaminated by IL 2 and unlike a helper cell, are unable to produce IL 2. Helper molecules specific for chicken red blood cells (Crbc) and for a synthetic polypeptide, poly 18, were tested. Thymocyte responders require a source of help to respond to alloantigens intrinsically expressed on the surface of adherent stimulator cells. To analyze the mechanism whereby the helper molecules acted, we used a system involving recognition of haptenic and carrier determinants that were physically linked by virtue of being located on the same cell surface (intra-structural linkage). Adherent stimulator cells were pulsed with Crbc or poly 18 so that the alloantigens recognized by the thymocyte CTLp (intrinsically expressed class I) were either linked or unlinked to the carrier determinants (Crbc or poly 18) presented by the adherent cells and recognized by the helper molecules. Both types of helper molecule were shown to be antigen-specific in crisscross experiments. The helper molecules specific for Crbc were able to induce the thymocyte CTLp only when both hapten and carrier were present on the same stimulator cell surface. Because we were not able to detect a requirement for H-2-restricted recognition

  11. Bypass of carrier-induced epitope-specific suppression using a T-helper epitope.

    PubMed Central

    Sad, S; Rao, K; Arora, R; Talwar, G P; Raghupathy, R

    1992-01-01

    A gonadotropin-releasing hormone (GnRH)-based vaccine is being developed as a method for non-surgical immunotherapy as immunization with this vaccine results in atrophy of the prostate. This vaccine, a conjugate of GnRH and diphtheria toxoid (DT), provides a unique hapten-carrier system for investigating the influence of carrier presensitization on antibody responses to self haptens. In a recent communication we showed that preimmunization with carriers diphtheria toxoid and tetanus toxoid results in a strain-dependent inhibition of anti-GnRH responses in mice and that T cells from carrier-presensitized mice are responsible for anti-haptenic suppression. In the present report we describe a strategy for bypassing DT-induced epitopic suppression using a T-helper epitope from DT. PMID:1383134

  12. Unrelated helpers in a primitively eusocial wasp: is helping tailored towards direct fitness?

    PubMed

    Leadbeater, Ellouise; Carruthers, Jonathan M; Green, Jonathan P; van Heusden, Jasper; Field, Jeremy

    2010-08-06

    The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests.

  13. Unrelated Helpers in a Primitively Eusocial Wasp: Is Helping Tailored Towards Direct Fitness?

    PubMed Central

    Leadbeater, Ellouise; Carruthers, Jonathan M.; Green, Jonathan P.; van Heusden, Jasper; Field, Jeremy

    2010-01-01

    The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests. PMID:20700463

  14. Molecular profiling of T-helper immune genes during dengue virus infection

    PubMed Central

    Chen, Jincheng; Ng, Mary Mah Lee; Chu, Justin Jang Hann

    2008-01-01

    In this study, we provide a comprehensive molecular profiling of the involvement of T- helper (Th) genes during dengue virus infection of different cell types. The Th gene profiles of three human cell types (monocytes, T-cells and hepatocytes) were analyzed simultaneously via array-based RT-PCR upon infection with dengue virus. Differential regulation of 41 Th genes was identified and of which 20 of those genes may contribute to immuno-pathogenesis of dengue virus infection by regulating inflammation, thrombocytopenia and vascular permeability. Among the strongly up-regulated genes were the RANTES, CC-CKR3, IRF4, CLEC2C, IL-6 and TLR6, which are potent inducer of inflammation and vascular permeability. Profiling genes obtained from this study may serve as potential biomarkers and the modulation of Th immune responses during dengue virus infection has important implications in disease outcome. PMID:19117515

  15. Autoreactive helper T cells alleviate the need for intrinsic TLR signaling in autoreactive B cell activation

    PubMed Central

    Giles, Josephine R.; Neves, Adriana Turqueti; Marshak-Rothstein, Ann; Shlomchik, Mark J.

    2017-01-01

    T cells play a significant role in the pathogenesis of systemic autoimmune diseases, including systemic lupus erythematosus; however, there is relatively little information on the nature and specificity of autoreactive T cells. Identifying such cells has been technically difficult because they are likely to be rare and low affinity. Here, we report a method for identifying autoreactive T cell clones that recognize proteins contained in autoantibody immune complexes, providing direct evidence that functional autoreactive helper T cells exist in the periphery of normal mice. These T cells significantly enhanced autoreactive B cell proliferation and altered B cell differentiation in vivo. Most importantly, these autoreactive T cells were able to rescue many aspects of the TLR-deficient AM14 (anti-IgG2a rheumatoid factor) B cell response, suggesting that TLR requirements can be bypassed. This result has implications for the efficacy of TLR-targeted therapy in the treatment of ongoing disease. PMID:28239656

  16. Follicular helper T cells progressively differentiate to regulate the germinal center response

    PubMed Central

    Licona-Limón, Paula; Esplugues, Enric; Flavell, Richard; Craft, Joe

    2016-01-01

    Germinal center (GC) B cells undergo affinity selection, dependent upon interactions with CD4+ follicular helper T (TFH) cells. We demonstrate that TFH cells progressed through transcriptionally and functionally distinct stages, providing differential signals for GC regulation. They initially localized proximally to mutating B cells, secreted IL-21, induced expression of the transcription factor Bcl-6 and selected high affinity B cell clones. As the GC response evolved, TFH cells extinguished IL-21 and switched to IL-4 production, showed robust CD40 ligand expression and promoted the development of antibody-secreting B cells via upregulation of the transcription factor Blimp-1. Thus, TFH cells in the B cell follicle progressively differentiated through stages of localization, cytokine production and surface ligand expression to fine-tune of the GC reaction. PMID:27573866

  17. T follicular helper and T follicular regulatory cells have different TCR specificity

    PubMed Central

    Maceiras, Ana Raquel; Almeida, Silvia Cristina Paiva; Mariotti-Ferrandiz, Encarnita; Chaara, Wahiba; Jebbawi, Fadi; Six, Adrien; Hori, Shohei; Klatzmann, David; Faro, Jose; Graca, Luis

    2017-01-01

    Immunization leads to the formation of germinal centres (GCs) that contain both T follicular helper (Tfh) and T follicular regulatory (Tfr) cells. Whether T-cell receptor (TCR) specificity defines the differential functions of Tfh and Tfr cells is unclear. Here we show that antigen-specific T cells after immunization are preferentially recruited to the GC to become Tfh cells, but not Tfr cells. Tfh cells, but not Tfr cells, also proliferate efficiently on restimulation with the same immunizing antigen in vitro. Ex vivo TCR repertoire analysis shows that immunization induces oligoclonal expansion of Tfh cells. By contrast, the Tfr pool has a TCR repertoire that more closely resembles that of regulatory T (Treg) cells. Our data thus indicate that the GC Tfh and Tfr pools are generated from distinct TCR repertoires, with Tfh cells expressing antigen-responsive TCRs to promote antibody responses, and Tfr cells expressing potentially autoreactive TCRs to suppress autoimmunity. PMID:28429709

  18. The Potential Role of T Helper Cell 22 and IL-22 in Immunopathogenesis of Multiple Sclerosis

    PubMed Central

    Fard, Nazanin Arjomand; Azizi, Gholamreza

    2016-01-01

    Multiple sclerosis is a complex disease with many different immune cells involved in its pathogenesis. Newly identified T helper cell 22 (Th22) is a subset of CD4+ T cells with specific properties apart from other known CD4+ T cell subsets with distinguished function and gene expression. Th22 cells are characterized by production of a distinct profile of effector cytokines, including interleukin (IL)-22, IL-13, and tumor necrosis factor-α (TNF- α). The frequency of Th22 and related cytokine IL-22 are increased in various autoimmune diseases. Recently, several studies have reported the changes in frequency and function of Th22 in multiple sclerosis. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of multiple sclerosis disease. PMID:27672486

  19. TCR ITAM multiplicity is required for the generation of follicular helper T-cells.

    PubMed

    Hwang, SuJin; Palin, Amy C; Li, LiQi; Song, Ki-Duk; Lee, Jan; Herz, Jasmin; Tubo, Noah; Chu, Hamlet; Pepper, Marion; Lesourne, Renaud; Zvezdova, Ekaterina; Pinkhasov, Julia; Jenkins, Marc K; McGavern, Dorian; Love, Paul E

    2015-05-11

    The T-cell antigen receptor (TCR) complex contains 10 copies of a di-tyrosine Immunoreceptor-Tyrosine-based-Activation-Motif (ITAM) that initiates TCR signalling by recruiting protein tyrosine kinases. ITAM multiplicity amplifies TCR signals, but the importance of this capability for T-cell responses remains undefined. Most TCR ITAMs (6 of 10) are contributed by the CD3ζ subunits. We generated 'knock-in' mice that express non-signalling CD3ζ chains in lieu of wild-type CD3ζ. Here we demonstrate that ITAM multiplicity is important for the development of innate-like T-cells and follicular helper T-cells, events that are known to require strong/sustained TCR-ligand interactions, but is not essential for 'general' T-cell responses including proliferation and cytokine production or for the generation of a diverse antigen-reactive TCR repertoire.

  20. B–helper neutrophils stimulate immunoglobulin diversification and production in the marginal zone of the spleen

    PubMed Central

    Puga, Irene; Cols, Montserrat; Barra, Carolina M.; He, Bing; Cassis, Linda; Gentile, Maurizio; Comerma, Laura; Chorny, Alejo; Shan, Meimei; Xu, Weifeng; Magri, Giuliana; Knowles, Daniel M.; Tam, Wayne; Chiu, April; Bussel, James B; Serrano, Sergi; Lorente, José Antonio; Bellosillo, Beatriz; Lloreta, Josep; Juanpere, Nuria; Alameda, Francesc; Baró, Teresa; de Heredia, Cristina Díaz; Torán, Núria; Català, Albert; Torrebadell, Montserrat; Fortuny, Claudia; Cusi, Victoria; Carreras, Carmen; Diaz, George A.; Blander, J. Magarian; Farber, Claire-Michèle; Silvestri, Guido; Cunningham-Rundles, Charlotte; Calvillo, Michaela; Dufour, Carlo; Notarangelo, Lucia Dora; Lougaris, Vassilios; Plebani, Alessandro; Casanova, Jean-Laurent; Ganal, Stephanie C.; Diefenbach, Andreas; Aróstegui, Juan Ignacio; Juan, Manel; Yagüe, Jordi; Mahlaoui, Nizar; Donadieu, Jean; Chen, Kang; Cerutti, Andrea

    2011-01-01

    Neutrophils utilize immunoglobulins (Igs) to clear antigen, but their role in Ig production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T-independent Ig responses to circulating antigen. Neutrophils colonized peri-MZ areas after post-natal mucosal colonization by microbes and enhanced their B-helper function upon receiving reprogramming signals from splenic sinusoidal endothelial cells, including interleukin 10 (IL-10). Splenic neutrophils induced Ig class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism involving the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and less preimmune Igs to T-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial Ig defense by interacting with MZ B cells. PMID:22197976

  1. Memory B cells contribute to rapid Bcl6 expression by memory follicular helper T cells.

    PubMed

    Ise, Wataru; Inoue, Takeshi; McLachlan, James B; Kometani, Kohei; Kubo, Masato; Okada, Takaharu; Kurosaki, Tomohiro

    2014-08-12

    In primary humoral responses, B-cell lymphoma 6 (Bcl6) is a master regulator of follicular helper T (TFH) cell differentiation; however, its activation mechanisms and role in memory responses remain unclear. Here we demonstrate that survival of CXCR5(+) TFH memory cells, and thus subsequent recall antibody response, require Bcl6 expression. Furthermore, we show that, upon rechallenge with soluble antigen Bcl6 in memory TFH cells is rapidly induced in a dendritic cell-independent manner and that peptide:class II complexes (pMHC) on cognate memory B cells significantly contribute to this induction. Given the previous evidence that antigen-specific B cells residing in the follicles acquire antigens within minutes of injection, our results suggest that memory B cells present antigens to the cognate TFH memory cells, thereby contributing to rapid Bcl6 reexpression and differentiation of the TFH memory cells during humoral memory responses.

  2. Follicular regulatory T cells impair follicular T helper cells in HIV and SIV infection

    PubMed Central

    Miles, Brodie; Miller, Shannon M.; Folkvord, Joy M.; Kimball, Abigail; Chamanian, Mastooreh; Meditz, Amie L.; Arends, Tessa; McCarter, Martin D.; Levy, David N.; Rakasz, Eva G.; Skinner, Pamela J.; Connick, Elizabeth

    2015-01-01

    Human and simian immunodeficiency viruses (HIV and SIV) exploit follicular lymphoid regions by establishing high levels of viral replication and dysregulating humoral immunity. Follicular regulatory T cells (TFR) are a recently characterized subset of lymphocytes that influence the germinal centre response through interactions with follicular helper T cells (TFH). Here, utilizing both human and rhesus macaque models, we show the impact of HIV and SIV infection on TFR number and function. We find that TFR proportionately and numerically expand during infection through mechanisms involving viral entry and replication, TGF-β signalling, low apoptosis rates and the presence of regulatory dendritic cells. Further, TFR exhibit elevated regulatory phenotypes and impair TFH functions during HIV infection. Thus, TFR contribute to inefficient germinal centre responses and inhibit HIV and SIV clearance. PMID:26482032

  3. Athymic (nude) mice fail to delete functional self-reactive helper T cells.

    PubMed

    Caulfield, M J; Stanko, D; Isaak, D D

    1993-09-01

    We have examined the thymic requirement for the antibody response to a foreign antigen coupled to self erythrocytes. We find that self erythrocytes mediate thymus-independent, carrier specific help for the antibody response to the pneumococcal cell wall polysaccharide antigen, PnC. Thus, athymic nude mice gave a high primary antibody plaque-forming cell (PFC) response to PnC-mouse RBC but a low response to PnC coupled to sheep or burro RBC. The meager response to PnC coupled to foreign RBCs could not be attributed to antigenic competition since the response to the carrier (burro RBC) was < 100 PFC per spleen. Reconstitution of nude mice with splenic T cells from euthymic mice enhanced rather than suppressed the antibody response to PnC-mouse RBC. The results document that in the absence of thymic deletion, functional self-reactive helper cells persist in the nude mouse.

  4. ICAMs support B cell interactions with T follicular helper cells and promote clonal selection.

    PubMed

    Zaretsky, Irina; Atrakchi, Ofir; Mazor, Roei D; Stoler-Barak, Liat; Biram, Adi; Feigelson, Sara W; Gitlin, Alexander D; Engelhardt, Britta; Shulman, Ziv

    2017-09-22

    The germinal center (GC) reaction begins with a diverse and expanded group of B cell clones bearing a wide range of antibody affinities. During GC colonization, B cells engage in long-lasting interactions with T follicular helper (Tfh) cells, a process that depends on antigen uptake and antigen presentation to the Tfh cells. How long-lasting T-B interactions and B cell clonal expansion are regulated by antigen presentation remains unclear. Here, we use in vivo B cell competition models and intravital imaging to examine the adhesive mechanisms governing B cell selection for GC colonization. We find that intercellular adhesion molecule 1 (ICAM-1) and ICAM-2 on B cells are essential for long-lasting cognate Tfh-B cell interactions and efficient selection of low-affinity B cell clones for proliferative clonal expansion. Thus, B cell ICAMs promote efficient antibody immune response by enhancement of T cell help to cognate B cells. © 2017 Zaretsky et al.

  5. Capicua deficiency induces autoimmunity and promotes follicular helper T cell differentiation via derepression of ETV5

    PubMed Central

    Park, Sungjun; Lee, Seungwon; Lee, Choong-Gu; Park, Guk Yeol; Hong, Hyebeen; Lee, Jeon-Soo; Kim, Young Min; Lee, Sung Bae; Hwang, Daehee; Choi, Youn Soo; Fryer, John D.; Im, Sin-Hyeog; Lee, Seung-Woo; Lee, Yoontae

    2017-01-01

    High-affinity antibody production through the germinal centre (GC) response is a pivotal process in adaptive immunity. Abnormal development of follicular helper T (TFH) cells can induce the GC response to self-antigens, subsequently leading to autoimmunity. Here we show the transcriptional repressor Capicua/CIC maintains peripheral immune tolerance by suppressing aberrant activation of adaptive immunity. CIC deficiency induces excessive development of TFH cells and GC responses in a T-cell-intrinsic manner. ETV5 expression is derepressed in Cic null TFH cells and knockdown of Etv5 suppresses the enhanced TFH cell differentiation in Cic-deficient CD4+ T cells, suggesting that Etv5 is a critical CIC target gene in TFH cell differentiation. Furthermore, we identify Maf as a downstream target of the CIC–ETV5 axis in this process. These data demonstrate that CIC maintains T-cell homeostasis and negatively regulates TFH cell development and autoimmunity. PMID:28855737

  6. Follicular Helper T (Tfh) Cells in Autoimmune Diseases and Allograft Rejection

    PubMed Central

    Jeon, Yun-Hui

    2016-01-01

    Production of high affinity antibodies for antigens is a critical component for the immune system to fight off infectious pathogens. However, it could be detrimental to our body when the antigens that B cells recognize are of self-origin. Follicular helper T, or Tfh, cells are required for the generation of germinal center reactions, where high affinity antibody-producing B cells and memory B cells predominantly develop. As such, Tfh cells are considered as targets to prevent B cells from producing high affinity antibodies against self-antigens, when high affinity autoantibodies are responsible for immunopathologies in autoimmune disorders. This review article provides an overview of current understanding of Tfh cells and discusses it in the context of animal models of autoimmune diseases and allograft rejections for generation of novel therapeutic interventions. PMID:27574501

  7. The role of T helper type 17 cells in inflammatory arthritis

    PubMed Central

    Sarkar, S; Cooney, L A; Fox, D A

    2010-01-01

    While T cells have been implicated in the pathogenesis of inflammatory arthritis for more than three decades, the focus on the T helper type 17 (Th17) subset of CD4 T cells and their secreted cytokines, such as interleukin (IL)-17, is much more recent. Proinflammatory actions of IL-17 were first identified in the 1990s, but the delineation of a distinct Th17 subset in late 2005 has sparked great interest in the role of these cells in a broad range of immune-mediated diseases. This review summarizes current understanding of the role of Th17 cells and their products in both animal models of inflammatory arthritis and human immune-driven arthritides. PMID:19758374

  8. Analysis of the autoproteolytic activity of the recombinant helper component proteinase from zucchini yellow mosaic virus.

    PubMed

    Boonrod, Kajohn; Füllgrabe, Marc W; Krczal, Gabi; Wassenegger, Michael

    2011-10-01

    The multifunctional helper component proteinase (HC-Pro) of potyviruses contains an autoproteolytic function that, together with the protein 1 (P1) and NIa proteinase, processes the polyprotein into mature proteins. In this study, we analysed the autoproteolytic active domain of zucchini yellow mosaic virus (ZYMV) HC-Pro. Several Escherichia coli-expressed MBP:HC-Pro:GFP mutants containing deletions or point mutations at either the N- or C-terminus of the HC-Pro protein were examined. Our results showed that amino acids essential for the proteolytic activity of ZYMV HC-Pro are distinct from those of the tobacco etch virus HC-Pro, although the amino acid sequences in the proteolytic active domain are conserved among potyviruses.

  9. Filling in the helper-gap: the intentions of frail older widows.

    PubMed

    Porter, Eileen J; Ganong, Lawrence H

    2005-01-01

    Despite marked interest in continuity of care and transitions experienced by older persons, there is little information available about the intentions of older women regarding changes that occur in their support networks. This article reports the findings of a descriptive phenomenological study of older widows' experience of home care and describes the experiences of 10 women who lost a key helper during the 3-year study. Compared with theories of continuity of care or transition, the findings are in keeping with the focus of nonequilibrium systems theory: bringing order out of disorder. Findings imply the need for holistic nursing interventions with older women who hope to continue living alone for as long as possible.

  10. Moderate Aerobic Exercise Alters Migration Patterns of Antigen Specific T helper Cells within an Asthmatic Lung

    PubMed Central

    Dugger, Kari J.; Chrisman, Taylor; Jones, Ben; Chastain, Parker; Watson, Kacie; Estell, Kim; Zinn, Kurt; Schwiebert, Lisa

    2013-01-01

    Studies show that an escalation in both incidence and severity of allergic asthmatic symptoms can largely be due to increased sedentary lifestyles. In addition, moderate aerobic exercise has been shown to reduce the severity of asthma; albeit by an unknown mechanism. Studies do implicate the re-distribution of T helper (Th) cells as a means of moderate aerobic exercise altering an immune response. We have previously reported that exercise decreases T helper 2 (Th2) responses within the lungs of an ovalbumin (OVA)-sensitized murine allergic asthma model. Therefore, we hypothesized that exercise alters the migration of OVA-specific Th cells in an OVA-challenged lung. To test this hypothesis, wild type mice received OVA-specific Th cells expressing a luciferase-reporter construct and were OVA-sensitized and exercised. OVA-specific Th cell migration was decreased in OVA-challenged lungs of exercised mice when compared to their sedentary controls. Surface expression levels of lung-homing chemokine receptors, CCR4 and CCR8, on Th cells and their cognate lung-homing chemokine gradients revealed no difference between exercised and sedentary OVA-sensitized mice. However, transwell migration experiments demonstrated that lung-derived Th cells from exercised OVA-sensitized mice exhibited decreased migratory function versus controls. These data suggest that Th cells from exercised mice are less responsive to lung-homing chemokines. Together, these studies show that moderate aerobic exercise training can reduce the accumulation of antigen-specific Th cell migration into an asthmatic lung by decreasing chemokine receptor responsiveness. PMID:23928286

  11. Decreased PD-1 positive blood follicular helper T cells in patients with psoriasis.

    PubMed

    Shin, Dongyun; Kim, Dae Suk; Kim, Sung Hee; Je, Jung Hwan; Kim, Hee Ju; Young Kim, Do; Kim, Soo Min; Lee, Min-Geol

    2016-10-01

    Follicular helper T (Tfh) cells are recently characterized subset of helper T cells, which are initially found in the germinal centers of B cell follicles. The major role of Tfh cells is helping B cell activation and antibody production during humoral immunity. Recently, blood Tfh cells were shown to be associated with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, bullous pemphigoid and psoriasis. There is only one study which investigated Tfh cells in psoriasis patients. Therefore, in this study, we evaluated and analyzed blood Tfh cells in Korean patients with psoriasis. A total of 28 psoriasis patients and 16 healthy controls were enrolled. The frequency and absolute number of CXCR5(+)PD-1(+) Tfh cells were decreased in patients with psoriasis compared to healthy controls. CD4(+)CXCR5(+) T cells and CXCR5(+)ICOS(+) Tfh cells did not show differences. The frequency and absolute number of CXCR5(+)PD-1(+) Tfh cells in psoriasis patients negatively correlated with erythrocyte sedimentation rate and positively correlated with disease duration. The absolute number of CXCR5(+)ICOS(+) Tfh cells also showed positive correlation with disease duration. However, the subpopulations of Tfh cells did not correlate with Psoriasis Area and Severity Index. Serum interleukin-21 level was significantly increased in psoriasis patients compared to healthy controls, however, its level did not correlate with clinical and experimental parameters of psoriasis patients. These findings suggest the decreased function of Tfh cells in psoriasis, which could result in attenuated B cell immune responses in the pathogenesis of psoriasis. However, further investigations are necessary to confirm the function of Tfh cells in psoriasis vulgaris.

  12. Differentiation of human B lymphocyte subpopulations induced by an alloreactive helper T-cell clone

    SciTech Connect

    Anderson, S.J.; Hummell, D.S.; Lawton, A.R.

    1988-07-01

    We have used cloned alloreactive helper T cells to determine if direct T cell-B cell interaction can induce differentiation of human peripheral blood B cells which do not respond to pokeweed mitogen (PWM). T-cell clone 2F8 was derived from a one-way mixed lymphocyte reaction. 2F8 cells are T3+T4+T8-IL-2R+ and proliferate in response to irradiated stimulator cells, but not autologous cells, in the absence of exogenous interleukin-2. 2F8 cells provide allospecific help for polyclonal proliferation and differentiation of B cells in the absence of any other stimulus. The magnitude of this response is comparable to that of the response of the same B cells to PWM and fresh autologous T cells. 2F8 cells could also provide nonspecific help for unrelated donor B cells in the presence of PWM, with no requirement for costimulation by irradiated stimulator cells. Allospecific stimulation of B cells was completely inhibited by antibodies to class II major histocompatibility complex (MHC) framework determinants and was abrogated by 1000-rad irradiation. Cloned 2F8 T cells stimulated differentiation of both small, high-density B cells and larger B cells, generating up to 30% plasma cells with either fraction. B cells forming rosettes with mouse erythrocytes were also induced to differentiate by the helper T cell clone. As found previously, neither small, high-density B cells nor mouse rosette+ B cells responded well to PWM. Direct interaction with allospecific T cells induces differentiation of a broader spectrum of B cells than soluble growth and differentiation factors in conjunction with polyclonal activators such as PWM and protein A containing staphylococci.

  13. Altered Memory Circulating T Follicular Helper-B Cell Interaction in Early Acute HIV Infection

    PubMed Central

    Muir, Roshell; Metcalf, Talibah; Tardif, Virginie; Takata, Hiroshi; Phanuphak, Nittaya; Kroon, Eugene; Colby, Donn J.; Trichavaroj, Rapee; Valcour, Victor; Robb, Merlin L.; Michael, Nelson L.; Ananworanich, Jintanat; Trautmann, Lydie; Haddad, Elias K.

    2016-01-01

    The RV254 cohort of HIV-infected very early acute (4thG stage 1 and 2) (stage 1/2) and late acute (4thG stage 3) (stage 3) individuals was used to study T helper- B cell responses in acute HIV infection and the impact of early antiretroviral treatment (ART) on T and B cell function. To investigate this, the function of circulating T follicular helper cells (cTfh) from this cohort was examined, and cTfh and memory B cell populations were phenotyped. Impaired cTfh cell function was observed in individuals treated in stage 3 when compared to stage 1/2. The cTfh/B cell cocultures showed lower B cell survival and IgG secretion at stage 3 compared to stage 1/2. This coincided with lower IL-10 and increased RANTES and TNF-α suggesting a role for inflammation in altering cTfh and B cell responses. Elevated plasma viral load in stage 3 was found to correlate with decreased cTfh-mediated B cell IgG production indicating a role for increased viremia in cTfh impairment and dysfunctional humoral response. Phenotypic perturbations were also evident in the mature B cell compartment, most notably a decrease in resting memory B cells in stage 3 compared to stage 1/2, coinciding with higher viremia. Our coculture assay also suggested that intrinsic memory B cell defects could contribute to the impaired response despite at a lower level. Overall, cTfh-mediated B cell responses are significantly altered in stage 3 compared to stage 1/2, coinciding with increased inflammation and a reduction in memory B cells. These data suggest that early ART for acutely HIV infected individuals could prevent immune dysregulation while preserving cTfh function and B cell memory. PMID:27463374

  14. Determinants of job satisfaction in foreign domestic helpers caring for people with dementia in Hong Kong.

    PubMed

    Bai, Xue; Kwok, Timothy C Y; Chan, Natalie Y T; Ho, Florence K Y

    2013-09-01

    The job satisfaction of live-in foreign domestic helpers (FDHs) may influence their caring motivation and the quality of care they provide, which may in turn affect the health status of care recipients. This study identifies the factors affecting job satisfaction of FDHs caring for people with dementia in Hong Kong, focusing especially on the role of FDHs' adaptation status, job self-efficacy and care recipients' situation. A total of 152 FDHs taking care of people with dementia were recruited from 6 day care centres for elderly people in Hong Kong when they attended with their care recipients. Data were collected from February to August 2011 and the response rate was 95%. Participants completed questionnaires which included measures of care recipients' dementia severity and disruptive behaviours, FDHs' demographic factors, personal adaptation status, caregiving self-efficacy and job satisfaction. Hierarchical regression analysis was conducted to analyse the data. The results showed that longer stay in Hong Kong, better fluency in Cantonese (local dialect), greater satisfaction in living conditions, higher caregiving self-efficacy and less disruptive behaviour of care recipients were independently associated with stronger job satisfaction in FDHs looking after people with dementia. On the basis of these findings, we would suggest that employers should consider helpers who have been in Hong Kong for a longer period of time and speak fluent Cantonese, and have previous experience of taking care of people with dementia. In addition, FDHs caring for people with dementia may benefit from carer training which improves their self-efficacy in dementia care.

  15. Immunogenic Consensus Sequence T helper Epitopes for a Pan-Burkholderia Biodefense Vaccine

    PubMed Central

    De Groot, Anne S.; Ardito, Matthew; Moise, Leonard; Gustafson, Eric A.; Spero, Denice; Tejada, Gloria; Martin, William

    2014-01-01

    Background Biodefense vaccines against Category B bioterror agents Burkholderia pseudomallei (BPM) and Burkholderia mallei (BM) are needed, as they are both easily accessible to terrorists and have strong weaponization potential. Burkholderia cepaciae (BC), a related pathogen, causes chronic lung infections in cystic fibrosis patients. Since BPM, BM and BC are all intracellular bacteria, they are excellent targets for T cell-based vaccines. However, the sheer volume of available genomic data requires the aid of immunoinformatics for vaccine design. Using EpiMatrix, ClustiMer and EpiAssembler, a set of immunoinformatic vaccine design tools, we screened the 31 available Burkholderia genomes and performed initial tests of our selections that are candidates for an epitope-based multi-pathogen vaccine against Burkholderia species. Results Immunoinformatics analysis of 31 Burkholderia genomes yielded 350,004 9-mer candidate vaccine peptides of which 133,469 had perfect conservation across the 10 BM genomes, 175,722 had perfect conservation across the 11 BPM genomes and 40,813 had perfect conservation across the 10 BC genomes. Further screening with EpiMatrix yielded 54,010 high-scoring Class II epitopes; these were assembled into 2,880 longer highly conserved ‘immunogenic consensus sequence’ T helper epitopes. 100% of the peptides bound to at least one HLA class II allele in vitro, 92.7% bound to at least two alleles, 82.9% to three, and 75.6% of the binding results were consistent with the immunoinformatics analysis. Conclusions Our results show it is possible to rapidly identify promiscuous T helper epitopes conserved across multiple Burkholderia species and test their binding to HLA ligands in vitro. The next step in our process will be to test the epitopes ex vivo using peripheral leukocytes from BC, BPM infected humans and for immunogenicity in human HLA transgenic mice. We expect that this approach will lead to development of a licensable, pan

  16. Mathematical model for HIV dynamics in HIV-specific helper cells

    NASA Astrophysics Data System (ADS)

    Pinto, Carla M. A.; Carvalho, Ana

    2014-03-01

    In this paper we study a delay mathematical model for the dynamics of HIV in HIV-specific CD4 + T helper cells. We modify the model presented by Roy and Wodarz in 2012, where the HIV dynamics is studied, considering a single CD4 + T cell population. Non-specific helper cells are included as alternative target cell population, to account for macrophages and dendritic cells. In this paper, we include two types of delay: (1) a latent period between the time target cells are contacted by the virus particles and the time the virions enter the cells and; (2) virus production period for new virions to be produced within and released from the infected cells. We compute the reproduction number of the model, R0, and the local stability of the disease free equilibrium and of the endemic equilibrium. We find that for values of R0<1, the model approaches asymptotically the disease free equilibrium. For values of R0>1, the model approximates asymptotically the endemic equilibrium. We observe numerically the phenomenon of backward bifurcation for values of R0⪅1. This statement will be proved in future work. We also vary the values of the latent period and the production period of infected cells and free virus. We conclude that increasing these values translates in a decrease of the reproduction number. Thus, a good strategy to control the HIV virus should focus on drugs to prolong the latent period and/or slow down the virus production. These results suggest that the model is mathematically and epidemiologically well-posed.

  17. STAT6 regulates natural helper cell proliferation during lung inflammation initiated by Alternaria

    PubMed Central

    Khorram, Naseem; Chang, Jinny E.; Kim, Hee-Kyoo; Rosenthal, Peter; Croft, Michael; Broide, David H.

    2012-01-01

    Asthma exacerbations can be caused by a number of factors, including the fungal allergen Alternaria, which is specifically associated with severe and near-fatal attacks. The mechanisms that trigger lung responses are unclear and might vary between allergens. A comparison between Alternaria, Aspergillus, Candida, and house dust mite, all allergens in humans, showed that only Alternaria promoted immediate innate airway eosinophilia within 12 h of inhalation in nonsensitized mice. Alternaria, but not the other allergens, induced a rapid increase in airway levels of IL-33, accompanied by IL-33 receptor (IL-33R)-positive natural helper cell (NHC) production of IL-5 and IL-13. NHCs in the lung and bone marrow constitutively expressed transcription factors [GATA-3 and E26 transformation-specific sequence-1 (ETS-1)] that could allow for rapid induction of T helper type 2 (Th2) cytokines. Lung NHC numbers and proliferation (%Ki-67), but not IL-5 or GATA-3 expression, were significantly reduced in STAT6-deficient mice 3 days after one challenge with Alternaria. Alternaria induced NHC expression of the EGF receptor ligand amphiregulin (partially dependent on STAT6), as well as EGF receptor signaling in the airway epithelium. Finally, human peripheral blood NHCs (CRTH2+CD127+ lineage-negative lymphocytes) from allergic individuals highly expressed GATA-3 and ETS-1, similar to lung NHCs in mice. In summary, Alternaria-induced lung NHC proliferation and expression of amphiregulin are regulated by STAT6. In addition, NHCs in mouse and humans are primed to express Th2 cytokines through constitutive expression of GATA-3 and ETS-1. Thus several transcription factor pathways (STAT6, GATA-3, and ETS-1) may contribute to NHC proliferation and Th2-type responses in Alternaria-induced asthma. PMID:22865552

  18. New insights into the immunopathogenesis of systemic lupus erythematosus: the role of T follicular helper cells.

    PubMed

    Ma, Huijuan; Wan, Suigui; Xia, Changqing

    2014-01-01

    To review the development of T follicular helper (TFH) cells and their role in systemic lupus erythematosus (SLE) pathogenesis, the effect of dendritic cells (DCs) on TFH cells in SLE, as well as the potential use of TFH cells as a new therapeutic target in clinical practice. The data used in this review were retrieved mainly from the PubMed database (1989-2013). The terms used in the literature search were "T follicular helper cells," "systemic lupus erythematosus," and "dendritic cells." Relevant publications about the TFH cells development, the interaction between the TFH cells and the DCs, and the clinical applications of TFH cells were identified, retrieved, and reviewed. TFH cells, a novel distinct CD4+ T cell subset, are specialized in providing help to B cells in the formation of germinal centers (GCs) and long-term protective humoral immune responses. The development of TFH cells from naïve CD4+ T cell is a multistep process. As the pivot of immunoregulation, DCs are indispensable for TFH cells generation. In addition to receptor-ligand interactions between TFH cells and DCs, the cytokines secreted by DCs are also necessary for TFH cell generation. TFH cell dysregulation has been implicated in the development of SLE. More evidence from animal models of SLE and SLE patients suggests that TFH cells are necessary for pathogenic autoantibody production. Therefore, therapeutically targeting TFH cells can be a promising approach to treat antibody-mediated autoimmune diseases including SLE. TFH cells play a critical role in the pathogenesis of SLE, making them attractive therapeutic targets in clinical practice.

  19. Effect of adoptive transfer of cloned Actinobacillus actinomycetemcomitans-specific T helper cells on periodontal disease.

    PubMed Central

    Yamashita, K; Eastcott, J W; Taubman, M A; Smith, D J; Cox, D S

    1991-01-01

    Previously we isolated several Actinobacillus actinomycetemcomitans-specific T-cell clones from the spleens and lymph nodes of immunized Rowett rats. These clones were characterized as W3/13+, W3/25+, OX8-, and OX22-, suggesting a T helper (Th) phenotype. In the current experiments, 10(6) cells from a single A. actinomycetemcomitans-specific clone (A3) were adoptively transferred to a group (AaTh; n = 13) of normal heterozygous rats (rnu/+) at 28 days of age. A second group received no T cells (AaNT; n = 15), and a third group also received no T cells (NAaNT, n = 11). Beginning 1 day after transfer, the first and second groups were infected orally with A. actinomycetemcomitans for 5 consecutive days. The presence of infection was confirmed immediately after challenge and after 5 months, when the experiments were ended. Significantly higher numbers of lymphocytes were recovered from the gingival tissues of the first group than from those of either of the other groups. Also, this group showed significantly elevated (P less than 0.01) serum immunoglobulin G and immunoglobulin M antibody to A. actinomycetemcomitans in an enzyme-linked immunosorbent assay when compared with both other groups. Bone loss was significantly lower (P less than 0.01) in recipients of A. actinomycetemcomitans-specific cloned cells when compared with the other infected group and was approximately equal to the bone loss of the uninfected group. These results are consistent with the hypothesis that T-cell regulation can affect periodontal disease. In this regulation, T helper cells appear to interfere with periodontal bone loss. PMID:1825991

  20. Inclusion of the helper lipid dioleoyl-phosphatidylethanolamine in solid lipid nanoparticles inhibits their transfection efficiency.

    PubMed

    de Jesus, Marcelo B; Radaic, Allan; Hinrichs, Wouter L J; Ferreira, Carmen V; de Paula, Eneida; Hoekstra, Dick; Zuhorn, Inge S

    2014-02-01

    Solid lipid nanoparticles (SLNs) are a promising system for the delivery of lipophilic and hydrophilic drugs. They consist of a solid lipid core that is stabilized by a layer of surfactants. By the incorporation of cationic lipids in the formulation, positively charged SLNs can be generated, that are suitable carriers for nucleic acids (DNA, siRNA). Considering the beneficial effect of helper lipids on the transfection efficiency with cationic liposomes, the effect of the helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) on transfection with cationic lipid-containing solid lipid nanoparticles was investigated in PC3 prostate cancer cells. The inclusion of DOPE in SLN formulations, instead of promoted, strongly inhibited SLN transfection efficiency, by frustrating the accommodation of DNA by the particles, as was revealed by biochemical analysis. SLNs devoid of DOPE maintained a homogenous size distribution of approximately 150 nm following lipoplex assembly and cellular delivery, and showed transfection efficiency comparable to that of Lipofectamine 2000' (LF2k). Moreover, the SLNs maintain their high transfection efficiency after lyophilization and long-term storage (1-2 years), an important asset for biomedical applications. There is even the possibility to lyophilize the SLN carrier together with its DNA cargo, which represents an interesting pharmaceutical advantage of the SLN formulations over LF2k. These results reflect marked differences between the physicochemical properties of cationic liposomes and SLNs, the latter requiring more critical lipid-depending properties for effective 'packaging' of DNA but displaying a higher storage stability than cationic lipid based carriers like LF2k.

  1. Abnormalities of follicular helper T-cell number and function in Wiskott-Aldrich syndrome

    PubMed Central

    Zhang, Xuan; Dai, Rongxin; Li, Wenyan; Zhao, Hongyi; Zhang, Yongjie; Zhou, Lina; Du, Hongqiang; Luo, Guangjin; Wu, Junfeng; Niu, Linlin; An, Yunfei; Zhang, Zhiyong; Ding, Yuan; Song, Wenxia; Liu, Chaohong

    2016-01-01

    Wiskott-Aldrich syndrome protein (WASp) is a hematopoietic-specific regulator of actin nucleation. Wiskott-Aldrich syndrome (WAS) patients show immunodeficiencies, most of which have been attributed to defective T-cell functions. T follicular helper (Tfh) cells are the major CD4+ T-cell subset with specialized B-cell helper capabilities. Aberrant Tfh cells activities are involved in immunopathologies such as autoimmunity, immunodeficiencies, and lymphomas. We found that in WAS patients, the number of circulating Tfh cells was significantly reduced due to reduced proliferation and increased apoptosis, and Tfh cells were Th2 and Th17 polarized. The expression of inducible costimulator (ICOS) in circulating Tfh cells was higher in WAS patients than in controls. BCL6 expression was decreased in total CD4+ T and Tfh cells of WAS patients. Mirroring the results in patients, the frequency of Tfh cells in WAS knockout (KO) mice was decreased, as was the frequency of BCL6+ Tfh cells, but the frequency of ICOS+ Tfh cells was increased. Using WAS chimera mice, we found that the number of ICOS+ Tfh cells was decreased in WAS chimera mice, indicating that the increase in ICOS+ Tfh cells in WAS KO mice was cell extrinsic. The data from in vivo CD4+ naive T-cell adoptive transfer mice as well as in vitro coculture of naive B and Tfh cells showed that the defective function of WASp-deficient Tfh cells was T-cell intrinsic. Consistent findings in both WAS patients and WAS KO mice suggested an essential role for WASp in the development and memory response of Tfh cells and that WASp deficiency causes a deficient differentiation defect in Tfh cells by downregulating the transcription level of BCL6. PMID:27170596

  2. Dysfunction of irradiated thymus for the development of helper T cells

    SciTech Connect

    Amagai, T.; Kina, T.; Hirokawa, K.; Nishikawa, S.; Imanishi, J.; Katsura, Y.

    1987-07-15

    The development of cytotoxic T cells and helper T cells in an intact or irradiated thymus was investigated. C57BL/6 (H-2b, Thy-1.2) mice were whole body-irradiated, or were irradiated with shielding over either the thymus or right leg and tail, and were transferred with 1.5 X 10(7) bone marrow cells from B10.Thy-1.1 mice (H-2b, Thy-1.1). At various days after reconstitution, thymus cells from the recipient mice were harvested and a peanut agglutinin low-binding population was isolated. This population was further treated with anti-Thy-1.2 plus complement to remove host-derived cells and was assayed for the frequency of cytotoxic T cell precursors (CTLp) and for the activity of helper T cells (Th). In the thymus of thymus-shielded and irradiated mice, Th activity reached normal control level by day 25, whereas CTLp frequency remained at a very low level during these days. In the thymus of whole body-irradiated mice, generation of CTLp was highly accelerated while that of Th was retarded, the period required for reconstitution being 25 days and more than 42 days for CTLp and Th, respectively. Preferential development of CTLp was also seen in right leg- and tail-shielded (L-T-shielded) and irradiated recipients. Histological observation indicated that Ia+ nonlymphoid cells were well preserved in the thymus of thymus-shielded and irradiated recipients, whereas in L-T-shielded and irradiated recipients, such cells in the medulla were markedly reduced in number. These results suggest strongly that the generation of Th but not CTLp is dependent on radiosensitive thymic component(s), and that such components may represent Ia+ cells themselves in the medulla or some microenvironment related to Ia+ cells.

  3. Effects of Sustained Sleep Restriction on Mitogen-Stimulated Cytokines, Chemokines and T Helper 1/ T Helper 2 Balance in Humans

    PubMed Central

    Axelsson, John; Rehman, Javaid-ur; Akerstedt, Torbjorn; Ekman, Rolf; Miller, Gregory E.; Höglund, Caroline Olgart; Lekander, Mats

    2013-01-01

    Background Recent studies suggest that acute sleep deprivation disrupts cellular immune responses by shifting T helper (Th) cell activity towards a Th2 cytokine profile. Since little is known about more long-term effects, we investigated how five days of sleep restriction would affect pro-inflammatory, chemotactic, Th1- and Th2 cytokine secretion. Methods Nine healthy males participated in an experimental sleep protocol with two baseline sleep-wake cycles (sleep 23.00 – 07.00 h) followed by 5 days with restricted sleep (03.00 – 07.00 h). On the second baseline day and on the fifth day with restricted sleep, samples were drawn every third hour for determination of cytokines/chemokines (tumor necrosis factor alpha (TNF-α), interleukin (IL) -1β, IL-2, IL-4 and monocyte chemoattractant protein-1 (MCP-1)) after in vitro stimulation of whole blood samples with the mitogen phytohemagglutinin (PHA). Also leukocyte numbers, mononuclear cells and cortisol were analysed. Results 5-days of sleep restriction affected PHA-induced immune responses in several ways. There was a general decrease of IL-2 production (p<.05). A shift in Th1/Th2 cytokine balance was also evident, as determined by a decrease in IL2/IL4 ratio. No other main effects of restricted sleep were shown. Two significant interactions showed that restricted sleep resulted in increased TNF-α and MCP-1 in the late evening and early night hours (p’s<.05). In addition, all variables varied across the 24 h day. Conclusions 5-days of sleep restriction is characterized by a shift towards Th2 activity (i.e. lower 1L-2/IL-4 ratio) which is similar to the effects of acute sleep deprivation and psychological stress. This may have implications for people suffering from conditions characterized by excessive Th2 activity like in allergic disease, such as asthma, for whom restricted sleep could have negative consequences. PMID:24349251

  4. Molecular control of CD4(+) T cell lineage plasticity and integrity.

    PubMed

    Ellmeier, Wilfried

    2015-10-01

    CD4(+) helper T cells and CD8(+) cytotoxic T cells form the two major subsets of peripheral T lymphocytes. Helper T cells fulfill crucial roles in the activation and coordination of the immune response, while cytotoxic T cells kill virus-infected or tumor cells. Recent data suggest that the lineage identify of helper T cells is not fixed and that CD4(+) T cells under certain physiological conditions can be reprogrammed to express CD8 lineage genes and to develop into intestinal intraepithelial CD4(+) cytotoxic T lymphocytes that lack the expression of the key helper T cell lineage commitment factor ThPOK. Moreover, the analysis of mice with a conditional deletion of the transcription factor ThPOK or the histone deacetylases HDAC1 and HDAC2 indicated that CD8 lineage genes are actively repressed in CD4(+) T cells in order to maintain the lineage integrity of helper T cells. In this review I summarize recent studies that indicate plasticity of CD4(+) T cells towards a CTL program and that demonstrate that ThPOK and HDAC1-HDAC2 are part of a transcriptional regulatory circuit that counteracts the activity of the transcription factor Runx3 to maintain CD4(+) T cell lineage integrity. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Recombinant expression, purification, and kinetic and inhibitor characterisation of human site-1-protease.

    PubMed

    Bodvard, Kristofer; Mohlin, Johanna; Knecht, Wolfgang

    2007-02-01

    Human site-1-protease (S1P, MEROPS S08.8063), also widely known as subtilisin/kexin isozyme 1 (SKI-1), is a membrane bound subtilisin-related serine protease, that belongs to a group of nine mammalian proprotein convertases. Among these proteases, S1P displays unique substrate specificity, by showing preferred cleavage after non-basic amino acids. S1P plays a key role in a proteolytic pathway that controls the cholesterol content of membranes, cells and blood. S1P also participates in the activation of viral coat glycoproteins of the lassa virus, the lympocytic choriomeningitis virus and the crimean congo hemorrhagic fever virus. We expressed recombinant human S1P using the baculovirus expression vector system and characterized the highly purified enzyme. Featuring a new chromogenic substrate (Acetyl-Arg-Arg-Leu-Leu-p-nitroanilide) we show that the enzymatic activity of S1P is not calcium dependent, but can be modulated by a variety of mono- and divalent cations. S1P displayed pronounced positive cooperativity with a substrate derived from the viral coat glycoprotein of the lassa virus. The screening of a limited number of protease inhibitors showed that S1P was not inhibited by specific inhibitors of other proprotein convertases or by Pefabloc SC (4-(2-aminoethyl) benzene sulphonyl fluoride, AEBSF). We found 3,4-dichloroisocoumarin (DCI) to be a potent slow binding inhibitor of human S1P, with a K(iapp) = 6.8 microM, thus representing a new small molecule inhibitor of S1P. These findings show that S1P differs significantly from other proprotein convertases with respect to kinetics, co-factor requirement and inhibition.

  6. DNaseI hypersensitive sites 1, 2 and 3 of the human beta-globin dominant control region direct position-independent expression.

    PubMed Central

    Fraser, P; Hurst, J; Collis, P; Grosveld, F

    1990-01-01

    The human beta-globin dominant control region (DCR) which flanks the multigene beta-globin locus directs high level, site of integration independent, copy number dependent expression on a linked human beta-globin gene in transgenic mice and stably transfected mouse erythroleukemia (MEL) cells. We have assayed each of the individual DNaseI hypersensitive regions present in the full 15kb DCR for position independence and copy number dependence of a linked beta-globin gene in transgenic mice. The results show that at least three of the individual DNaseI hypersensitive site regions (sites 1, 2 and 3), though expressing at lower levels than the full DCR, are capable of position independent, copy number dependent expression. Site 2 alone directs the highest level of expression of the single site constructs, producing nearly 70% of the level of the full DCR. Sites 1 and 3 each provide 30% of the full activity. Deletion of either site 2 or 3 from the complete set significantly reduces the level of expression, but does not effect position independence or copy number dependence. This demonstrates that sites 2 and 3 are required for full expression and suggests that all the sites are required for the full expression of even a single gene from this multigene locus. Images PMID:2362805

  7. Large scale transcriptome analysis reveals interplay between development of forest trees and a beneficial mycorrhiza helper bacterium.

    PubMed

    Kurth, Florence; Feldhahn, Lasse; Bönn, Markus; Herrmann, Sylvie; Buscot, François; Tarkka, Mika T

    2015-09-02

    Pedunculate oak, Quercus robur is an abundant forest tree species that hosts a large and diverse community of beneficial ectomycorrhizal fungi (EMFs), whereby ectomycorrhiza (EM) formation is stimulated by mycorrhiza helper bacteria such as Streptomyces sp. AcH 505. Oaks typically grow rhythmically, with alternating root flushes (RFs) and shoot flushes (SFs). We explored the poorly understood mechanisms by which oaks integrate signals induced by their beneficial microbes and endogenous rhythmic growth at the level of gene expression. To this end, we compared transcript profiles of oak microcuttings at RF and SF during interactions with AcH 505 alone and in combination with the basidiomycetous EMF Piloderma croceum. The local root and distal leaf responses to the microorganisms differed substantially. More genes involved in the recognition of bacteria and fungi, defence and cell wall remodelling related transcription factors (TFs) were differentially expressed in the roots than in the leaves of oaks. In addition, interaction with AcH 505 and P. croceum affected the expression of a higher number of genes during SF than during RF, including AcH 505 elicited defence response, which was attenuated by co-inoculation with P. croceum in the roots during SF. Genes encoding leucine-rich receptor-like kinases (LRR-RLKs) and proteins (LRR-RLPs), LRR containing defence response regulators, TFs from bZIP, ERF and WRKY families, xyloglucan cell wall transglycolases/hydrolases and exordium proteins were differentially expressed in both roots and leaves of plants treated with AcH 505. Only few genes, including specific RLKs and TFs, were induced in both AcH 505 and co-inoculation treatments. Treatment with AcH 505 induces and maintains the expression levels of signalling genes encoding candidate receptor protein kinases and TFs and leads to differential expression of cell wall modification related genes in pedunculate oak microcuttings. Local gene expression response to AcH 505

  8. Females increase reproductive investment in response to helper-mediated improvements in allo-feeding, nest survival, nestling provisioning and post-fledging survival in the Karoo scrub-robin Cercotrichas coryphaeus

    USGS Publications Warehouse

    Lloyd, P.; Andrew, Taylor W.; Du Plessis, M.A.; Martin, T.E.

    2009-01-01

    In many cooperatively-breeding species, the presence of one or more helpers improves the reproductive performance of the breeding pair receiving help. Helper contributions can take many different forms, including allo-feeding, offspring provisioning, and offspring guarding or defence. Yet, most studies have focussed on single forms of helper contribution, particularly offspring provisioning, and few have evaluated the relative importance of a broader range of helper contributions to group reproductive performance. We examined helper contributions to multiple components of breeding performance in the Karoo scrub-robin Cercotrichas coryphaeus, a facultative cooperative breeder. We also tested a prediction of increased female investment in reproduction when helpers improve conditions for rearing young. Helpers assisted the breeding male in allo-feeding the incubating female, increasing allo-feeding rates. Greater allo-feeding correlated with greater female nest attentiveness during incubation. Nest predation was substantially lower among pairs breeding with a helper, resulting in a 74% increase in the probability of nest survival. Helper contributions to offspring provisioning increased nestling feeding rates, resulting in a reduced incidence of nestling starvation and increased nestling mass. Nestling mass had a strong, positive effect on post-fledging survival. Controlling for female age and habitat effects, annual production of fledged young was 130% greater among pairs breeding with a helper, and was influenced most strongly by helper correlates with nest survival, despite important helper effects on offspring provisioning. Females breeding with a helper increased clutch size, supporting the prediction of increased female investment in reproduction in response to helper benefits. ?? 2009 J. Avian Biol.

  9. How germinal centers evolve broadly neutralizing antibodies: the breadth of the follicular helper T cell response.

    PubMed

    De Boer, Rob J; Perelson, Alan S

    2017-09-06

    Many HIV-1 infected patients evolve broadly neutralizing antibodies (bnAbs). This evolutionary process typically takes several years, and is poorly understood as selection taking place in germinal centers occurs on the basis of antibody affinity. B cells with the highest affinity receptors tend to acquire the most antigen from the FDC network, and present the highest density of cognate peptides to follicular helper T cells (Tfh), which provide survival signals to the B cell. BnAbs are therefore only expected to evolve when the B cell lineage evolving breadth is consistently capturing and presenting more peptides to Tfh cells than other lineages of more specific B cells. Here we develop mathematical models of Tfh in germinal centers to explicitly define the mechanisms of selection in this complex evolutionary process.Our results suggest that broadly reactive B cells presenting a high density of pMHC are readily outcompeted by B cells responding to lineages of HIV-1 that transiently dominate the within host viral population. Conversely, if broadly reactive B cells acquire a large variety of several HIV-1 proteins from the FDC network and present a high diversity of several pMHC, they be rescued by a large fraction of the Tfh repertoire in the germinal center. Under such circumstances the evolution of bnAbs is much more consistent. Increasing the magnitude of the Tfh response, or the breadth of the Tfh repertoire, both markedly facilitate the evolution of bnAbs. Because both can be increased by vaccination with several HIV-1 proteins, this calls for experiments testing.Importance Many HIV-infected patients slowly evolve antibodies that can neutralize a large variety of viruses. Such "broadly neutralizing antibodies" (bnAbs) could in the future become therapeutic agents. BnAbs appear very late and patients are typically not protected by them. At the moment we fail to understand why this takes so long, and how the immune system selects for broadly neutralizing capacity

  10. Independence, Security, and the intergenerational social contract: home-helper services and elder care in rural Japan.

    PubMed

    Traphagan, John W

    2003-01-01

    For several years, demographic trends and changing ideas about responsibilities for elder care in Japan have contributed to the desire, or need, for families to seek out new care approaches. This article focuses on one alternative to traditional approaches to caring for elder family members--the home-helper program that is available through the Japanese long-term care insurance program. Using ethnographic data collected in northern Japan, it will be argued that the home-helper program forms a compensatory elder care system that is intended to augment family-provided care and social support, rather than to promote independent living. This compensatory approach to elder care is based upon an intergenerational social contract in which it is assumed that some degree of dependence on family members is both an expected and preferred outcome of growing old.

  11. Mother's little helpers: What we know (and don't know) about cooperative infant care in callitrichines.

    PubMed

    Erb, Wendy M; Porter, Leila M

    2017-01-01

    Since Darwin (), scientists have been puzzled by how behaviors that impose fitness costs on helpers while benefiting their competitors could evolve through natural selection. Hamilton's () theory of inclusive fitness provided an explanation by showing how cooperative behaviors could be adaptive if directed at closely related kin. Recent studies, however, have begun to question whether kin selection is sufficient to explain cooperative behavior in some species (Bergmüller, Johnstone, Russell, & Bshary, ). Many researchers have instead emphasized the importance of direct fitness benefits for helpers in the evolution of cooperative breeding systems. Furthermore, individuals can vary in who, when, and how much they help, and the factors that affect this variation are poorly understood (Cockburn, ; Heinsohn, ). Cooperative breeders thus provide excellent models for the study of evolutionary theories of cooperation and conflict (Cant, ).

  12. Hamster embryo cells transformed by herpes simplex virus: reactions with adeno-associated satellite virus (AAV) and its adenovirus helpers.

    PubMed

    Mayor, H D; Jordan, L E; Gorman, C

    1977-01-01

    We have studied the reactions of hamster embryo cells transformed by ultraviolet-inactivated herpes simplex type 2 (333-8-9 T cells) to infections with adeno-associated satellite virus (AAV) and its adenovirus helpers. Resident HSV structural antigens were not detectable in early or late passage of 333-8-9 T cells. AAV structural antigens were not detected in these cells unless the cells were coinfected with a helper adenovirus. In early passage 333-8-9 T cells were permissive to infections with simian adenovirus SV15 whereas normal hamster cell line LSH was nonpermissive. In some late passages of 333-8-9 T cells infections with SV15 adenovirus led to the production of viruslike particles whose morphology was identical with reoviruses.

  13. The positive bystander effect: passive bystanders increase helping in situations with high expected negative consequences for the helper.

    PubMed

    Fischer, Peter; Greitemeyer, Tobias

    2013-01-01

    The present field study investigated the interplay between the presence of a passive bystander (not present versus present) in a simulated bike theft and expected negative consequences (low versus high) in predicting intervention behavior when no physical victim is present. It was found that an additional bystander increases individual intervention in situations where the expected negative consequences for the helper in case of intervention were high (i.e., when the bike thief looks fierce) compared to situations where the expected negative consequences for the helper were low (i.e., when the bike thief does not look fierce). In contrast, no such effect for high vs. low expected negative consequences was observed when no additional bystander observed the critical situation. The results are discussed in light of previous laboratory findings on expected negative consequences and bystander intervention.

  14. T-helper cell responses to HIV envelope peptides in cord blood: protection against intrapartum and breast-feeding transmission.

    PubMed

    Kuhn, L; Coutsoudis, A; Moodley, D; Trabattoni, D; Mngqundaniso, N; Shearer, G M; Clerici, M; Coovadia, H M; Stein, Z

    2001-01-05

    Acquired HIV-specific cell-mediated immune responses have been observed in exposed-uninfected individuals, and it has been inferred, but not demonstrated, that these responses constitute a part of natural protective immunity to HIV. This inference was tested prospectively in the natural exposure setting of maternal-infant HIV transmission in a predominantly breast-fed population. Cord blood from infants of HIV-seropositive women in Durban, South Africa, were tested for in vitro reactivity to a cocktail of HIV envelope peptides (Env) using a bioassay measuring interleukin-2 production in a murine cell line. Infants were followed with repeat HIV RNA tests up to 18 months of age to establish which ones acquired HIV-infection. T-helper cell responses to Env were detected in 33 out of 86 (38%) cord blood samples from infants of HIV-seropositive women and in none of nine samples from seronegative women (P = 0.02). Among infants of HIV-seropositive mothers, three out of 33 with T-helper responses to Env were already infected before delivery (HIV RNA positive on the day of birth), two were lost to follow-up, and none of the others (out of 28) were found to be HIV infected on subsequent tests. In comparison, six out of 53 infants unresponsive to Env were infected before delivery, and eight out of 47 (17%) of the others were found to have acquired HIV infection intrapartum or post-partum through breast-feeding (P = 0.02). T-helper cell responses to HIV envelope peptides were detected in more than one-third of newborns of HIV-infected women; no new infections were acquired by these infants at the time of delivery or post-natally through breast-feeding if these T-helper cell responses were detected in cord blood.

  15. The role of social environment on parental care: offspring benefit more from the presence of female than male helpers.

    PubMed

    Brouwer, Lyanne; van de Pol, Martijn; Cockburn, Andrew

    2014-03-01

    Investment in offspring depends on the costs and benefits to the carer, which can vary with sex and social status. Investment also depends on the effort of others by allowing for compensation (load-lightening), with biparental care studies showing that this depends on the state and type of the other carer. By contrast, studies on cooperative breeders have solely focussed on the effects of group size rather than its composition (i.e. social environment). Here we propose and provide the first test of the 'Social Environment' hypothesis, that is, how the characteristics (here the sex) of other helpers present in the group affect parental care and how this in turn affects offspring fitness in cooperatively breeding red-winged fairy-wrens (Malurus elegans). Breeders provisioned nestlings at a higher rate than helpers, but there was no sex difference in provisioning rate. Compensation to increasing group size varied little with sex and status, but strongly depended on social environment. All group members reduced their provisioning rates in response to an increasing number of male (load-lightening), but not female helpers (additive care). As a result, nestlings received more food and grew faster in the presence of female helpers. The increased nestling growth did convey a fitness advantage due to a higher post-fledging survival to adulthood. Our study provides the first evidence that parental care can depend on social environment. This could be an important overlooked aspect to explain variation in parental care in cooperative breeders in general and in particular the enormous variation between the sexes, which we reveal in a literature overview.

  16. Mutations in the helper component protease gene of zucchini yellow mosaic virus affect its ability to mediate aphid transmissibility.

    PubMed

    Huet, H; Gal-On, A; Meir, E; Lecoq, H; Raccah, B

    1994-06-01

    The nucleotide sequence of the helper component protease (HC-Pro) genes of three zucchini yellow mosaic virus (ZYMV) strains has been compared with that of a helper-deficient strain of ZYMV-HC. The comparisons revealed three unique deduced amino acid differences. Two of these mutations were located in regions which are conserved in other potyviruses. The role of these mutations in aphid transmissibility was examined by exchanging DNA fragments of part of the deficient HC-Pro gene with the respective section within the gene of the infectious full-length clone of the aphid-transmissible ZYMV. The first exchange included two of the three mutations, the first coding for a change from Asp to Gly (in a non-conserved region) and the second coding for a change from Arg to Ile [within the Phe-Arg-Asp-Lys (FRNK) conserved box]. This exchange resulted in a reduced transmission (20.6% for the mutated virus compared with 57.4% in the normal ZYMV when acquired from plants and 37.2% compared with 83.1%, respectively, when acquired from membranes). The second exchange incorporated a single mutation [conferring a change from Thr to Ala within the Pro-Thr-Lys (PTK) conserved box]. This single mutation resulted in almost total loss of HC activity in aphid transmission both from plants and from membranes. The Lys residue in the conserved Lys-Ile-Thr-Cys (KITC) box, which is related to loss of HC activity in potato virus Y, tobacco vein mottling virus and in the Michigan strain of ZYMV, is unchanged in the helper-deficient ZYMV. It is therefore proposed that more than one site in HC-Pro may be functionally related to aphid transmissibility. The possible reasons for the role of these mutations in helper activity in aphid transmission of ZYMV are discussed.

  17. T-Helper 17 Cells in Psoriatic Plaques and Additional Genetic Links between IL-23 and Psoriasis

    PubMed Central

    Blauvelt, Andrew

    2010-01-01

    T-helper 17 (Th17) cells are a newly appreciated T-cell subset, distinct from both Th1 and Th2 cells, that have been implicated in the pathogenesis of psoriasis and other autoimmune inflammatory diseases (Figure 1) (Fitch et al., 2007; Kastelein et al., 2007). IL-23 stimulates survival and proliferation of Th17 cells and thus serves as a key master cytokine regulator for these diseases. PMID:18408745

  18. Helpers at the nest improve late-life offspring performance: evidence from a long-term study and a cross-foster experiment.

    PubMed

    Brouwer, Lyanne; Richardson, David S; Komdeur, Jan

    2012-01-01

    Conditions during an individual's rearing period can have far reaching consequences for its survival and reproduction later in life. Conditions typically vary due to variation in parental quality and/or the environment, but in cooperative breeders the presence of helpers adds an important component to this. Determining the causal effect of helpers on offspring fitness is difficult, since high-quality breeders or territories are likely to produce high-quality offspring, but are also more likely to have helpers because of past reproductive success. This problem is best resolved by comparing the effect of both helping and non-helping subordinates on offspring fitness, however species in which both type of subordinates commonly occur are rare. We used multi-state capture-recapture models on 20 years of data to investigate the effect of rearing conditions on survival and recruitment in the cooperatively breeding Seychelles warbler (Acrocephalus sechellensis), with both helping and non-helping subordinates. The number of helpers in the rearing territory, but not territory quality, group- or brood size, was positively associated with survival of offspring in their first year, and later in life. This was not a result of group size itself since the number of non-helpers was not associated with offspring survival. Furthermore, a nestling cross-foster experiment showed that the number of helpers on the pre-foster territory was not associated with offspring survival, indicating that offspring from territories with helpers do not differ in (genetic) quality. Our results suggest that the presence of helpers not only increase survival of offspring in their first year of life, but also subsequent adult survival, and therefore have important fitness consequences later in life. This means that when calculating the fitness benefits of helping not only short-term but also the late-life benefits have to be taken into account to fully understand the evolution of cooperative breeding.

  19. Supernatant from a cloned helper T cell stimulates resting B cells to express transferrin and IL-2 receptors.

    PubMed

    Diu, A; Leclercq, L; Dautry-Varsat, A; Theze, J

    1987-07-01

    We describe the properties of the supernatant from a murine cloned helper T cell (clone 52.3) which is able to polyclonally activate most resting B cells in the absence of any additional stimulus. We hypothesize that an activity which we call BCAF (B-cell-activating factor(s] exists in our supernatant which can activate resting B cells alone or in conjunction with other lymphokines. In the present report, we investigate changes in the surface antigen pattern induced on resting B cells by BCAF-containing supernatant. Analysis of the cells by flow cytometry shows that transferrin receptor and IL-2 receptor expression increase on a large fraction of B cells after 2 days of activation by the T-helper-cell clone supernatant. Monoclonal anti-transferrin receptor antibody inhibits cell division but does not affect blastogenesis, while IL-2 has no effect in our experimental system. Our present results confirm that BCAF-containing supernatants can act on most resting B cells and replace helper T cells in inducing B-cell activation and proliferation.

  20. Iron oxide nanoparticles suppressed T helper 1 cell-mediated immunity in a murine model of delayed-type hypersensitivity

    PubMed Central

    Shen, Chien-Chang; Liang, Hong-Jen; Wang, Chia-Chi; Liao, Mei-Hsiu; Jan, Tong-Rong

    2012-01-01

    Background It was recently reported that iron oxide nanoparticles attenuated antigen-specific humoral responses and T cell cytokine expression in ovalbumin-sensitized mice. It is presently unclear whether iron oxide nanoparticles influence T helper 1 cell-mediated immunity. The present study aimed to investigate the effect of iron oxide nanoparticles on delayed-type hypersensitivity (DTH), whose pathophysiology requires the participation of T helper 1 cells and macrophages. Methods DTH was elicited by a subcutaneous challenge with ovalbumin to the footpads of mice sensitized with ovalbumin. Iron oxide nanoparticles (0.2–10 mg iron/kg) were administered intravenously 1 hour prior to ovalbumin sensitization. Local inflammatory responses were examined by footpad swelling and histological analysis. The expression of cytokines by splenocytes was measured by enzyme-linked immunosorbent assay. Results Administration of iron oxide nanoparticles, in a dose-dependent fashion, significantly attenuated inflammatory reactions associated with DTH, including the footpad swelling, the infiltration of T cells and macrophages, and the expression of interferon-γ, interleukin-6, and tumor necrosis factor-α in the inflammatory site. Iron oxide nanoparticles also demonstrated a suppressive effect on ovalbumin-stimulated production of interferon-γ by splenocytes and the phagocytic activity of splenic CD11b+ cells. Conclusion These results demonstrated that a single dose of iron oxide nanoparticles attenuated DTH reactions by suppressing the infiltration and functional activity of T helper 1 cells and macrophages in response to antigen stimulation. PMID:22701318

  1. Location and Survival of Mycorrhiza Helper Pseudomonas fluorescens during Establishment of Ectomycorrhizal Symbiosis between Laccaria bicolor and Douglas Fir

    PubMed Central

    Frey-Klett, P.; Pierrat, J. C.; Garbaye, J.

    1997-01-01

    The mycorrhiza helper bacterium Pseudomonas fluorescens BBc6, isolated from a Laccaria bicolor sporocarp, consistently promotes L. bicolor-Douglas fir (Pseudotsuga menziesii) ectomycorrhizal formation, even with low doses of bacterial inoculum. In order to describe this phenomenon more accurately, we have looked at the location and survival of the introduced bacterial strain in the soil and in the rhizosphere during the establishment of mycorrhizal symbiosis in glasshouse and nursery experiments. Bacterial populations were quantified with a spontaneous, stable, rifampin-resistant mutant, BBc6R8, which phenotypically conformed to the parental strain. BBc6R8 populations declined rapidly, reaching the detection limit after 19 weeks, and did not increase either when L. bicolor sporocarps were forming in autumn or when Douglas fir roots resumed growing in spring. BBc6R8 was neither an endophyte nor a rhizobacterium. Furthermore, it was not particularly associated with either mycorrhizas of Douglas fir-L. bicolor or L. bicolor sporocarps. Surprisingly, a significant mycorrhiza helper effect was observed when the inoculated BBc6R8 population had dropped as low as 30 CFU g of dry matter(sup-1) in the soil. This study raises questions concerning the bacterial concentration in the soil which is effective for promotion of mycorrhizal establishment and the timing of the bacterial effect. It allows us to develop working hypotheses, which can be tested experimentally, to identify the mechanisms of the mycorrhiza helper effect. PMID:16535478

  2. Dominant female meerkats do not use aggression to elevate work rates of helpers in response to increased brood demand

    PubMed Central

    Santema, Peter; Clutton-Brock, Tim

    2012-01-01

    In cooperatively breeding animals, in which nonbreeding subordinates assist in rearing offspring born to dominants, breeders and helpers may be in conflict over their respective contributions to offspring care and selection may favour breeders that use aggression to elevate the work rates of helpers. We tested the prediction that dominant female meerkats, Suricata suricatta, should increase aggression towards subordinates when the need for help is higher, by playing back recordings of pup begging calls to simulate increased need for help. Second, we tested the prediction that dominants should reduce aggression when subordinates help more, by playing back recordings of feeding calls to simulate elevated pup provisioning rates by subordinates. Neither of the two playback experiments affected rates of aggressive interactions between breeding females and helpers. Instead, breeding females increased their own level of pup provisioning in response to increased pup begging. Hence, our results do not support a role of aggression in regulating helping behaviour in meerkats, but suggest that pup provisioning can be explained by direct and/or indirect benefits derived from helping. As yet, firm evidence that breeders use aggression to promote helping by subordinates in cooperative animal societies remains elusive. PMID:22505769

  3. Preschoolers' social and moral judgments of third-party helpers and hinderers align with infants' social evaluations.

    PubMed

    Van de Vondervoort, Julia W; Hamlin, J Kiley

    2017-12-01

    Two experiments explored preschoolers' social preferences and moral judgments of prosocial and antisocial others. In Experiment 1, 3- to 5-year-olds (N=74) observed helping and hindering scenarios previously used to explore sociomoral evaluation in preverbal infants. Whereas 3-year-olds in Experiment 1 did not reliably distinguish between the helper and hinderer when reporting social preferences or moral judgments, both 4- and 5-year-olds preferred the helper, judged the helper to be "nicer" than the hinderer, selectively allocated punishment to the hinderer, and were able to justify their punishment allocations. A simplified procedure and the addition of comprehension questions in Experiment 2 (N=24) improved 3-year-olds' performance, suggestive that their performance in Experiment 1 was likely due to processing or memory difficulties rather than an inability to engage in explicit social and moral evaluation. These studies reveal that young children readily interpret helping and hindering scenarios as socially and morally relevant. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Mycorrhization between Cistus ladanifer L. and Boletus edulis Bull is enhanced by the mycorrhiza helper bacteria Pseudomonas fluorescens Migula.

    PubMed

    Mediavilla, Olaya; Olaizola, Jaime; Santos-del-Blanco, Luis; Oria-de-Rueda, Juan Andrés; Martín-Pinto, Pablo

    2016-02-01

    Boletus edulis Bull. is one of the most economically and gastronomically valuable fungi worldwide. Sporocarp production normally occurs when symbiotically associated with a number of tree species in stands over 40 years old, but it has also been reported in 3-year-old Cistus ladanifer L. shrubs. Efforts toward the domestication of B. edulis have thus focused on successfully generating C. ladanifer seedlings associated with B. edulis under controlled conditions. Microorganisms have an important role mediating mycorrhizal symbiosis, such as some bacteria species which enhance mycorrhiza formation (mycorrhiza helper bacteria). Thus, in this study, we explored the effect that mycorrhiza helper bacteria have on the efficiency and intensity of the ectomycorrhizal symbiosis between C. ladanifer and B. edulis. The aim of this work was to optimize an in vitro protocol for the mycorrhizal synthesis of B. edulis with C. ladanifer by testing the effects of fungal culture time and coinoculation with the helper bacteria Pseudomonas fluorescens Migula. The results confirmed successful mycorrhizal synthesis between C. ladanifer and B. edulis. Coinoculation of B. edulis with P. fluorescens doubled within-plant mycorrhization levels although it did not result in an increased number of seedlings colonized with B. edulis mycorrhizae. B. edulis mycelium culture time also increased mycorrhization levels but not the presence of mycorrhizae. These findings bring us closer to controlled B. edulis sporocarp production in plantations.

  5. MicroRNA-Containing T-Regulatory-Cell-Derived Exosomes Suppress Pathogenic T Helper 1 Cells

    PubMed Central

    Okoye, Isobel S.; Coomes, Stephanie M.; Pelly, Victoria S.; Czieso, Stephanie; Papayannopoulos, Venizelos; Tolmachova, Tanya; Seabra, Miguel C.; Wilson, Mark S.

    2014-01-01

    Summary Foxp3+ T regulatory (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely. Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of intercellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T-cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg-cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg-cell-mediated suppression mediated by miRNA-containing exosomes. PMID:25035954

  6. Small molecule RORγt antagonists inhibit T helper 17 cell transcriptional network by divergent mechanisms

    PubMed Central

    Xiao, Sheng; Yosef, Nir; Yang, Jianfei; Wang, Yonghui; Zhou, Ling; Zhu, Chen; Wu, Chuan; Baloglu, Erkan; Schmidt, Darby; Ramesh, Radha; Lobera, Mercedes; Sundrud, Mark S.; Tsai, Pei-Yun; Xiang, Zhijun; Wang, Jinsong; Xu, Yan; Lin, Xichen; Kretschmer, Karsten; Rahl, Peter B.; Young, Richard A.; Zhong, Zhong; Hafler, David A.; Regev, Aviv; Ghosh, Shomir; Marson, Alexander; Kuchroo, Vijay K.

    2014-01-01

    We identified three RORγt-specific inhibitors that suppress T helper 17 (Th17) cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding in the presence and absence of drug with corresponding whole-genome transcriptome sequencing. RORγt acts both as a direct activator of Th17 cell signature genes and as a direct repressor of signature genes from other T-cell lineages, with the strongest transcriptional effects on cis-regulatory sites containing the RORα binding motif. RORγt is central in a densely interconnected regulatory network that shapes the balance of T-cell differentiation. The three inhibitors identified here modulated the RORγt-dependent transcriptional network to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity. PMID:24745332

  7. Activated Circulating T Follicular Helper Cells Are Associated with Disease Severity in Patients with Psoriasis

    PubMed Central

    Wang, Ying; Yang, Haoyu; Yuan, Weichang; Ren, Jingyi

    2016-01-01

    Circulating T follicular helper (cTfh) cells are known to be involved in numerous immune-mediated diseases, but their pathological role in psoriasis is less fully investigated. Herein, we aimed to identify whether cTfh cells contributed to the pathogenesis of psoriasis. The frequency and function of cTfh cells were compared between patients with psoriasis vulgaris and healthy controls, and the infiltration of Tfh cells was detected between lesional and nonlesional skin tissues of psoriasis patients. Moreover, the dynamic change of cTfh cells before and after acitretin treatment was evaluated. Our results showed both increased frequency and activation (indicated by higher expression of ICOS, PD-1, HLA-DR, and Ki-67 and increased production of IL-21, IL-17, and IFN-γ) of cTfh cells in psoriasis patients. Compared with nonlesional skin tissues of psoriasis patients, the number of infiltrated Tfh cells was significantly increased in psoriasis lesions. In addition, positive correlations between the percentage of cTfh, functional markers on cTfh cells in peripheral blood and disease severity were noted. Furthermore, the frequency of cTfh cells and the levels of cytokines secreted by cTfh cells were all significantly decreased after 1-month treatment. PMID:27774460

  8. T regulatory (Treg) and T helper 17 (Th17) lymphocytes in thyroid autoimmunity.

    PubMed

    González-Amaro, Roberto; Marazuela, Mónica

    2016-04-01

    Different immune cell subsets have a relevant role in the pathogenesis of and tissue damage seen in autoimmune thyroid diseases (AITD), including T regulatory (Treg) lymphocytes and T helper (Th) 17 cells. There are several types of CD4+ Treg cells (Foxp3+, CD69+, Tr1), which are able to prevent the appearance of autoimmune diseases, down regulating the immune response and the inflammatory phenomenon. However, despite their presence in peripheral blood and thyroid tissue from patients with AITD, these cells are apparently unable to put down the autoimmune process. Moreover, many reports indicate the involvement of Th17 cells in chronic inflammatory diseases, including AITD. Nevertheless, it is now evident that these lymphocytes show a remarkable plasticity, giving rise to anti-inflammatory (including Treg lymphocytes) and pro-inflammatory cell subtypes. Nowadays, both Treg and Th17 cells must be considered as key elements in the pathogenesis of AITD as well as plausible potential targets for the next generation of therapeutic options of this condition.

  9. T1/ST2 promotes T helper 2 cell activation and polyfunctionality in bronchopulmonary mycosis.

    PubMed

    Piehler, D; Grahnert, A; Eschke, M; Richter, T; Köhler, G; Stenzel, W; Alber, G

    2013-03-01

    Interleukin (IL)-33 enhances T helper (Th)2 immunity via its receptor T1/ST2. Infection with the yeast-like pathogen Cryptococcus neoformans is usually controlled by a Th1-mediated immune response. The mechanisms responsible for nonprotective Th2 immunity leading to allergic inflammation in pulmonary cryptococcosis are still not fully understood. Using a murine pulmonary model of C. neoformans infection, we report that T1/ST2 expression correlates with the intensity of Th2 activation, as demonstrated by the expression of CD25 and CD44 and downregulation of CD62L. Antigen-specific T1/ST2(+) Th cells are the primary source of the Th2 cytokines IL-5 and IL-13 as compared with wild-type T1/ST2(-) Th cells or Th cells from T1/ST2(-/-) mice. In addition, T1/ST2(+) Th cells almost exclusively contain bi- and trifunctional Th2 cytokine-producing Th cells compared with T1/ST2(-) Th cells or Th cells from T1/ST2(-/-) mice. Finally, T1/ST2-driven Th2 development resulted in defective pulmonary fungal control. These data demonstrate that T1/ST2 directs Th2 cell activation and polyfunctionality in allergic bronchopulmonary mycosis.

  10. The route to pathologies in chronic inflammatory diseases characterized by T helper type 2 immune cells

    PubMed Central

    Jovanovic, K; Siebeck, M; Gropp, R

    2014-01-01

    T helper type 2 (Th2)-characterized inflammatory responses are highly dynamic processes initiated by epithelial cell damage resulting in remodelling of the tissue architecture to prevent further harm caused by a dysfunctional epithelial barrier or migrating parasites. This process is a temporal and spatial response which requires communication between immobile cells such as epithelial, endothelial, fibroblast and muscle cells and the highly mobile cells of the innate and adaptive immunity. It is further characterized by a high cellular plasticity that enables the cells to adapt to a specific inflammatory milieu. Incipiently, this milieu is shaped by cytokines released from epithelial cells, which stimulate Th2, innate lymphoid and invariant natural killer (NK) T cells to secrete Th2 cytokines and to activate dendritic cells which results in the further differentiation of Th2 cells. This milieu promotes wound-healing processes which are beneficial in parasitic infections or toxin exposure but account for increasingly dysfunctional vital organs, such as the lung in the case of asthma and the colon in ulcerative colitis. A better understanding of the dynamics underlying relapses and remissions might lead ultimately to improved therapeutics for chronic inflammatory diseases adapted to individual needs and to different phases of the inflammation. PMID:24981014

  11. The role of mycorrhization helper bacteria in the establishment and action of ectomycorrhizae associations

    PubMed Central

    Rigamonte, Tatiana Alves; Pylro, Victor Satler; Duarte, Gabriela Frois

    2010-01-01

    More than 95 % short roots of most terrestrial plants are colonized by mycorrhizal fungi as soon as they emerge in the upper soil profiles. The establishment of mycorrhizal association involves profound morphological and physiological changes in root and fungus. It is affected by other rhizospheric microorganisms, specifically by the bacteria. Bacteria may have developed mechanisms of selective interaction with surrounding microorganisms, with neutral or positive effects on mycorrhizal associations, but negative effect on root pathogens in general. Because of the beneficial effect of bacteria on mycorrhizae, the concept of Mycorrhization Helper Bacteria (MHB) was created. Five main actions of MHB on mycorrhizae were proposed: in the receptivity of root to the mycobiont, in root-fungus recognition, in fungal growth, in the modification of rhizospheric soil and in the germination of fungal propagules. MHB appear to develop a gradation of specificity for the mycobiont, but little or no specificity for the host plant in symbiosis. One of the main groups of MHB is the fluorescent Pseudomonas, well represented in diversity and cell density studies of mycorrhizal associations. This review covers the activity of MHB in the establishment of ectomycorrhizae, taking as model the effects of Pseudomonas sp. described in scientific literature. PMID:24031563

  12. Carrier Subunit of Plasma Membrane Transporter Is Required for Oxidative Folding of Its Helper Subunit*

    PubMed Central

    Rius, Mònica; Chillarón, Josep

    2012-01-01

    We study the amino acid transport system b0,+ as a model for folding, assembly, and early traffic of membrane protein complexes. System b0,+ is made of two disulfide-linked membrane subunits: the carrier, b0,+ amino acid transporter (b0,+AT), a polytopic protein, and the helper, related to b0,+ amino acid transporter (rBAT), a type II glycoprotein. rBAT ectodomain mutants display folding/trafficking defects that lead to type I cystinuria. Here we show that, in the presence of b0,+AT, three disulfides were formed in the rBAT ectodomain. Disulfides Cys-242-Cys-273 and Cys-571-Cys-666 were essential for biogenesis. Cys-673-Cys-685 was dispensable, but the single mutants C673S, and C685S showed compromised stability and trafficking. Cys-242-Cys-273 likely was the first disulfide to form, and unpaired Cys-242 or Cys-273 disrupted oxidative folding. Strikingly, unassembled rBAT was found as an ensemble of different redox species, mainly monomeric. The ensemble did not change upon inhibition of rBAT degradation. Overall, these results indicated a b0,+AT-dependent oxidative folding of the rBAT ectodomain, with the initial and probably cotranslational formation of Cys-242-Cys-273, followed by the oxidation of Cys-571-Cys-666 and Cys-673-Cys-685, that was completed posttranslationally. PMID:22493502

  13. Carrier subunit of plasma membrane transporter is required for oxidative folding of its helper subunit.

    PubMed

    Rius, Mònica; Chillarón, Josep

    2012-05-25

    We study the amino acid transport system b(0,+) as a model for folding, assembly, and early traffic of membrane protein complexes. System b(0,+) is made of two disulfide-linked membrane subunits: the carrier, b(0,+) amino acid transporter (b(0,+)AT), a polytopic protein, and the helper, related to b(0,+) amino acid transporter (rBAT), a type II glycoprotein. rBAT ectodomain mutants display folding/trafficking defects that lead to type I cystinuria. Here we show that, in the presence of b(0,+)AT, three disulfides were formed in the rBAT ectodomain. Disulfides Cys-242-Cys-273 and Cys-571-Cys-666 were essential for biogenesis. Cys-673-Cys-685 was dispensable, but the single mutants C673S, and C685S showed compromised stability and trafficking. Cys-242-Cys-273 likely was the first disulfide to form, and unpaired Cys-242 or Cys-273 disrupted oxidative folding. Strikingly, unassembled rBAT was found as an ensemble of different redox species, mainly monomeric. The ensemble did not change upon inhibition of rBAT degradation. Overall, these results indicated a b(0,+)AT-dependent oxidative folding of the rBAT ectodomain, with the initial and probably cotranslational formation of Cys-242-Cys-273, followed by the oxidation of Cys-571-Cys-666 and Cys-673-Cys-685, that was completed posttranslationally.

  14. Altered helper Tcell-mediated immune responses in male mice conceived through in vitro fertilization.

    PubMed

    Karimi, Hiwa; Mahdavi, Pooya; Fakhari, Shohreh; Faryabi, Mohammad Reza; Esmaeili, Parisa; Banafshi, Omid; Mohammadi, Ebrahim; Fathi, Fardin; Mokarizadeh, Aram

    2017-03-08

    A study using a mouse IVF model was conducted to examine the hypothesis that in vitro fertilization (IVF) treatment may lead to immune alteration in the offspring. Phagocytic activity and lymphocyte proliferative responses to mitogen, alloantigen, and purified protein derivative (PPD) of Mycobacterium bovis were investigated in the splenocytes of BCG-treated male mice conceived by IVF or natural conception. Intracellular expression of T-bet and GATA3 in helper T-cell population were examined in both groups. Moreover, the serum levels of IFN-γ and IL-4 along with BCG-specific levels of IgG1 and IgG2a were assessed by ELISA. In comparison with naturally-conceived mice, PPD-specific proliferative response and T-bet/GATA3 ratio were significantly decreased in IVF-conceived mice. Moreover, IVF-conceived mice exhibited marked decreases in IFN-γ/IL-4 and IgG2a/IgG1 ratios. Results indicate that in comparison with male mice conceived by natural conception, IVF counterparts exhibit less efficient immune responses against BCG through further promotion of Th2 responses.

  15. Treatment of osteoarthritis using a helper-dependent adenoviral vector retargeted to chondrocytes

    PubMed Central

    Ruan, Merry ZC; Cerullo, Vincenzo; Cela, Racel; Clarke, Chris; Lundgren-Akerlund, Evy; Barry, Michael A; Lee, Brendan HL

    2016-01-01

    Osteoarthritis (OA) is a joint disease characterized by degeneration of the articular cartilage, subchondral bone remodeling, and secondary inflammation. It is among the top three causes of chronic disability, and currently there are no treatment options to prevent disease progression. The localized nature of OA makes it an ideal candidate for gene and cell therapy. However, gene and cell therapy of OA is impeded by inefficient gene transduction of chondrocytes. In this study, we developed a broadly applicable system that retargets cell surface receptors by conjugating antibodies to the capsid of helper-dependent adenoviral vectors (HDVs). Specifically, we applied this system to retarget chondrocytes by conjugating an HDV to an α-10 integrin monoclonal antibody (a10mab). We show that a10mab-conjugated HDV (a10mabHDV)-infected chondrocytes efficiently in vitro and in vivo while detargeting other cell types. The therapeutic index of an intra-articular injection of 10mabHDV-expressing proteoglycan 4 (PRG4) into a murine model of post-traumatic OA was 10-fold higher than with standard HDV. Moreover, we show that PRG4 overexpression from articular, superficial zone chondrocytes is effective for chondroprotection in postinjury OA and that α-10 integrin is an effective protein for chondrocyte targeting. PMID:27626040

  16. B cell depleting therapy regulates splenic and circulating T follicular helper cells in immune thrombocytopenia.

    PubMed

    Audia, Sylvain; Rossato, Marzia; Trad, Malika; Samson, Maxime; Santegoets, Kim; Gautheron, Alexandrine; Bekker, Cornelis; Facy, Olivier; Cheynel, Nicolas; Ortega-Deballon, Pablo; Boulin, Mathieu; Berthier, Sabine; Leguy-Seguin, Vanessa; Martin, Laurent; Ciudad, Marion; Janikashvili, Nona; Saas, Philippe; Radstake, Timothy; Bonnotte, Bernard

    2017-02-01

    B cells are involved in immune thrombocytopenia (ITP) pathophysiology by producing antiplatelet auto-antibodies. However more than a half of ITP patients do not respond to B cell depletion induced by rituximab (RTX). The persistence of splenic T follicular helper cells (TFH) that we demonstrated to be expanded during ITP and to support B cell differentiation and antiplatelet antibody-production may participate to RTX inefficiency. Whereas it is well established that the survival of TFH depends on B cells in animal models, nothing is known in humans yet. To determine the effect of B cell depletion on human TFH, we quantified B cells and TFH in the spleen and in the blood from ITP patients treated or not with RTX. We showed that B cell depletion led to a dramatic decrease in splenic TFH and in CXCL13 and IL-21, two cytokines predominantly produced by TFH. The absolute count of circulating TFH and serum CXCL13 also decreased after RTX treatment, whatever the therapeutic response. Therefore, we showed that the maintenance of TFH required B cells and that TFH are not involved in the inefficiency of RTX in ITP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Divergence of helper, cytotoxic, and regulatory T cells in the decidua from miscarriage.

    PubMed

    Ebina, Yasuhiko; Shimada, Shigeki; Deguchi, Masashi; Maesawa, Yoko; Iijima, Norifumi; Yamada, Hideto

    2016-09-01

    The aim of this prospective study was to evaluate phenotypic differences of helper T (Th), cytotoxic T (Tc), and regulatory T (Treg) cells in the deciduae of missed miscarriage with a normal chromosome karyotype of a fetus (MN) and missed miscarriage with an abnormal chromosome karyotype of a fetus (MA). The decidua of 19 MN and 28 MA was obtained. Additionally, the decidua of 15 induced abortion (IA) and the endometrium of 19 non-pregnant women (EM) were obtained. IFN-γ(+) , IL-17(+) , CD25(high) Foxp3(+) cells in CD4(+) (Th) cells, and IFN-γ(+) cells in CD8(+) (Tc) cells were evaluated by flow cytometry. The percentages of IFN-γ(+) Tc and CD4(+) CD25(high) Foxp3(+) (Treg) cells in MN were significantly increased as compared with MA and IA. The percentage of IFN-γ(+) Th in MN was increased as compared with IA. Activation of IFN-γ(+) Tc and Treg cells in the decidua might be associated with the pathophysiology underlying MN. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Differentiation and recruitment of IL-22-producing helper T cells in lgA nephropathy

    PubMed Central

    Xiao, Chenggen; Zhou, Qiaoling; Li, Xiaozhao; Li, Hui; Meng, Ting; Zhong, Yong; Pu, Jiaxi; Zhu, Mengyuan; Xu, Yan; Gan, Lu; Sun, Hong; Xiao, Ping

    2016-01-01

    IL-22-producing helper T cells (Th22 cells) have been reported to be involved in lgA nephropathy. However, the mechanisms underlying the differentiation and immune regulation of Th22 cells in lgA nephropathy remain unknown. To elucidate the mechanisms by which Th22 cells differentiate and are recruited into the kidney in lgA nephropathy, the distribution of Th22 cells in both the kidney and blood was determined. Additionally, the impacts of proinflammatory cytokines and antigen presentation in the kidney on Th22 cell differentiation were explored. Specifically, the chemoattractant activities of chemokines produced by the kidney for Th22 cells were investigated. Th22 cells were significantly higher both in the kidney and in the blood in lgA nephropathy mice. IL-1β, IL-6, IL-21 and/or TNF-a promoted Th22 cells differentiation from CD4+ T cells. It was observed that kidneys undergoing lgA nephropathy expressed CCL20, CCL22 and CCL27, and kidney supernatants were chemotactic for Th22 cells. This activity was partially blocked by anti-CCL20, anti-CCL22, and anti-CCL27 antibodies, which also potentially improved renal lesions simultaneously. The overrepresentation of Th22 cells in lgAN may be attributable to the actions of kidney chemokines and cytokines. Our data suggest a collaborative loop between the kidney and Th22 cells in lgA nephropathy. PMID:27725866

  19. T Helper Subsets, Peripheral Plasticity, and the Acute Phase Protein, α1-Antitrypsin

    PubMed Central

    Baranovski, Boris M.; Freixo-Lima, Gabriella S.; Lewis, Eli C.; Rider, Peleg

    2015-01-01

    The traditional model of T helper differentiation describes the naïve T cell as choosing one of several subsets upon stimulation and an added reciprocal inhibition aimed at maintaining the chosen subset. However, to date, evidence is mounting to support the presence of subset plasticity. This is, presumably, aimed at fine-tuning adaptive immune responses according to local signals. Reprograming of cell phenotype is made possible by changes in activation of master transcription factors, employing epigenetic modifications that preserve a flexible mode, permitting a shift between activation and silencing of genes. The acute phase response represents an example of peripheral changes that are critical in modulating T cell responses. α1-antitrypsin (AAT) belongs to the acute phase responses and has recently surfaced as a tolerogenic agent in the context of adaptive immune responses. Nonetheless, AAT does not inhibit T cell responses, nor does it shutdown inflammation per se; rather, it appears that AAT targets non-T cell immunocytes towards changing the cytokine environment of T cells, thus promoting a regulatory T cell profile. The present review focuses on this intriguing two-way communication between innate and adaptive entities, a crosstalk that holds important implications on potential therapies for a multitude of immune disorders. PMID:26583093

  20. Thimerosal compromises human dendritic cell maturation, IL-12 production, chemokine release, and T-helper polarization.

    PubMed

    Loison, Emily; Gougeon, Marie-Lise

    2014-01-01

    Thimerosal is a preservative used in multidose vials of vaccine formulations to prevent bacterial and fungal contamination. We recently reported that nanomolar concentrations of thimerosal induce cell cycle arrest of human T cells activated via the TCR and inhibition of proinflammatory cytokine production, thus interfering with T-cell functions. Given the essential role of dendritic cells (DCs) in T-cell polarization and vaccine immunity, we studied the influence of non-toxic concentrations of thimerosal on DC maturation and functions. Ex-vivo exposure of human monocyte-derived DCs to nanomolar concentrations of thimerosal prevented LPS-induced DC maturation, as evidenced by the inhibition of morphological changes and a decreased expression of the maturation markers CD86 and HLA-DR. In addition thimerosal dampened their proinflammatory response, in particular the production of the Th1 polarizing cytokine IL-12, as well as TNF-α and IL-6. DC-dependent T helper polarization was altered, leading to a decreased production of IFN-γ IP10 and GM-CSF and increased levels of IL-8, IL-9, and MIP-1α. Although multi-dose vials of vaccines containing thimerosal remain important for vaccine delivery, our results alert about the ex-vivo immunomodulatory effects of thimerosal on DCs, a key player for the induction of an adaptive response.

  1. Identification of FAM111A as an SV40 Host Range Restriction and Adenovirus Helper Factor

    PubMed Central

    Padi, Megha; Korkhin, Anna; James, Robert L.; Adelmant, Guillaume; Yoon, Rosa; Guo, Luxuan; Berrios, Christian; Zhang, Ying; Calderwood, Michael A.; Velmurgan, Soundarapandian; Cheng, Jingwei; Marto, Jarrod A.; Hill, David E.; Cusick, Michael E.; Vidal, Marc; Florens, Laurence; Washburn, Michael P.; Litovchick, Larisa; DeCaprio, James A.

    2012-01-01

    The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT. PMID:23093934

  2. Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model.

    PubMed

    Simão, D; Pinto, C; Fernandes, P; Peddie, C J; Piersanti, S; Collinson, L M; Salinas, S; Saggio, I; Schiavo, G; Kremer, E J; Brito, C; Alves, P M

    2016-01-01

    Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in preclinical tests. For clinical translation, in-depth preclinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, whereas human adenovirus type 5 (HAdV5) showed increased tropism toward glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity.

  3. An improved helper phage system for efficient isolation of specific antibody molecules in phage display.

    PubMed

    Baek, Hyunjung; Suk, Kyoung-ho; Kim, Yong-hwan; Cha, Sanghoon

    2002-03-01

    Phage display technology has been applied in many fields of biological and medical sciences to study molecular interactions and especially in the generation of monoclonal antibodies of human origin. However, extremely low display level of antibody molecules on the surface of phage is an intrinsic problem of a phagemid-based display system resulting in low success rate of isolating specific binding molecules. We show here that display of single-chain antibody fragment (scFv) generated with pIGT3 phagemid can be increased dramatically by using a genetically modified Ex-phage. Ex-phage has a mutant pIII gene that produces a functional wild-type pIII in suppressing Escherichia coli strains but does not make any pIII in non-suppressing E.coli strains. Packaging phagemids encoding antibody-pIII fusion in F+ non-suppressing E.coli strains with Ex-phage enhanced the display level of antibody fragments on the surfaces of recombinant phage particles resulting in an increase of antigen-binding reactivity >100-fold compared to packaging with M13KO7 helper phage. Thus, the Ex-phage and pIGT3 phagemid vector provides a system for the efficient enrichment of specific binding antibodies from a phage display library and, thereby, increases the chance of obtaining more diverse antibodies specific for target antigens.

  4. T Helper 17/Regulatory T Cell Balance and Experimental Models of Peritoneal Dialysis-Induced Damage

    PubMed Central

    Liappas, Georgios; Gónzalez-Mateo, Guadalupe Tirma; Majano, Pedro; Sánchez- Tomero, José Antonio; Ruiz-Ortega, Marta; Martín, Pilar; Sanchez-Díaz, Raquel; Selgas, Rafael; López-Cabrera, Manuel; Aguilera Peralta, Abelardo

    2015-01-01

    Fibrosis is a general complication in many diseases. It is the main complication during peritoneal dialysis (PD) treatment, a therapy for renal failure disease. Local inflammation and mesothelial to mesenchymal transition (MMT) are well known key phenomena in peritoneal damage during PD. New data suggest that, in the peritoneal cavity, inflammatory changes may be regulated at least in part by a delicate balance between T helper 17 and regulatory T cells. This paper briefly reviews the implication of the Th17/Treg-axis in fibrotic diseases. Moreover, it compares current evidences described in PD animal experimental models, indicating a loss of Th17/Treg balance (Th17 predominance) leading to peritoneal damage during PD. In addition, considering the new clinical and animal experimental data, new therapeutic strategies to reduce the Th17 response and increase the regulatory T response are proposed. Thus, future goals should be to develop new clinical biomarkers to reverse this immune misbalance and reduce peritoneal fibrosis in PD. PMID:26064907

  5. Modulation of CD4+ T Helper Cell Memory Responses in the Human Skin.

    PubMed

    Padovan, Elisabetta

    2017-01-01

    Immunological memory is defined as the capacity to mount faster and more effective immune responses against antigenic challenges that have been previously encountered by the host. CD4+ T helper (Th) cells play central roles in the establishment of immunological memory as they assist the functions of other leukocytes. Th cells express polarized cytokine profiles and distinct migratory and seeding capacities, but also retain a certain functional plasticity that allows them to modulate their proliferation, activity, and homing behaviour upon need. Thus, in healthy individuals, T cell immunomodulation fulfils the task of eliciting protective immune responses where they are needed. At times, however, Th plasticity can lead to collateral tissue damage and progression to autoimmune diseases or, conversely, incapacity to reject malignant tissues and clear chronic infections. Furthermore, common immune players and molecular pathways of diseases can lead to different outcomes in different individuals. A mechanistic understanding of those pathways is therefore crucial for developing precise and curative medical interventions. Here, I focus on the skin microenvironment and comprehensively describe some of the cellular and molecular determinants of CD4+ T cell memory responses in homeostatic and pathological conditions. In discussing the cellular network orchestrating cutaneous immunity, I comprehensively describe the bidirectional interaction of skin antigen-presenting cells and mononuclear phagocytes with Th17 lymphocytes, and examine how the outcome of this interaction is influenced by endogenous skin molecules, including sodium salts and neuropeptides. © 2017 S. Karger AG, Basel.

  6. Adenoidal follicular T helper cells provide stronger B-cell help than those from tonsils.

    PubMed

    Morris, Matthew C; Kozara, Kevin; Salamone, Frank; Benoit, Margo; Pichichero, Michael E

    2016-02-01

    The tonsils and adenoids are secondary lymphoid organs, where antigen processing and immune cell development occur to control bacterial colonization and infection in the upper respiratory tract. Both organs are abundant in follicular T helper cells (TFH), a subset of T cells specialized for promoting B-cell development. There are no prior studies on differences between the immune cells of the tonsils and adenoids and whether the cells function differently. In vitro assays to assess cell phenotype of tonsils and adenoids from young children (median age = 40 months). Mononuclear cells from tonsils and adenoids were cultured with or without 1 µg/mL Staphylococcus enterotoxin B (SEB) for 4 days. Cell phenotype and function were assessed by flow cytometry and multiplex enzyme-linked immunosorbent assay. We found that in resting adenoids, TFH expressed higher CXCR5 and inducible costimulator but lower PD-1 than those from the tonsils, and that adenoidal B cells expressed higher CD27. Upon polyclonal stimulation with SEB, both TFH and B cells from the adenoids proliferated to a greater extent, and culture supernatants contained higher levels of interleukin 21. We conclude that the cells of the adenoid are disposed toward the provision of more robust B-cell help than the tonsils. NA. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  7. Adenoidal follicular T helper cells provide stronger B cell help than those from tonsils

    PubMed Central

    Morris, Matthew C.; Kozara, Kevin; Salamone, Frank; Benoit, Margo; Pichichero, Michael E.

    2015-01-01

    Objectives The tonsils and adenoids are secondary lymphoid organs, where antigen processing and immune cell development occurs to control bacterial colonization and infection in the upper respiratory tract. Both organs are abundant in follicular T helper cells (TFH), a subset of T cells specialized for promoting B cell development. There are no prior studies on differences between the immune cells of the tonsils and adenoids and whether the cells function differently. Study design In vitro assays to assess cell phenotype of tonsils and adenoids from young children (median age 40 months). Methods Mononuclear cells from tonsils and adenoids were cultured with or without 1 μg/mL Staphylococcus enterotoxin B (SEB) for 4 days. Cell phenotype and function were assessed by flow cytometry and multiplex ELISA. Results We found that in resting adenoids, TFH expressed higher CXCR5 and ICOS but lower PD-1 than those from the tonsils, and that adenoidal B cells expressed higher CD27. Upon polyclonal stimulation with SEB, both TFH and B cells from the adenoids proliferated to a greater extent, and culture supernatants contained higher levels of IL-21. Conclusion We conclude that the cells of the adenoid are disposed toward the provision of more robust B cell help than the tonsils. PMID:26511445

  8. De novo fatty acid synthesis controls the fate between regulatory T and T helper 17 cells.

    PubMed

    Berod, Luciana; Friedrich, Christin; Nandan, Amrita; Freitag, Jenny; Hagemann, Stefanie; Harmrolfs, Kirsten; Sandouk, Aline; Hesse, Christina; Castro, Carla N; Bähre, Heike; Tschirner, Sarah K; Gorinski, Nataliya; Gohmert, Melanie; Mayer, Christian T; Huehn, Jochen; Ponimaskin, Evgeni; Abraham, Wolf-Rainer; Müller, Rolf; Lochner, Matthias; Sparwasser, Tim

    2014-11-01

    Interleukin-17 (IL-17)-secreting T cells of the T helper 17 (TH17) lineage play a pathogenic role in multiple inflammatory and autoimmune conditions and thus represent a highly attractive target for therapeutic intervention. We report that inhibition of acetyl-CoA carboxylase 1 (ACC1) restrains the formation of human and mouse TH17 cells and promotes the development of anti-inflammatory Foxp3(+) regulatory T (Treg) cells. We show that TH17 cells, but not Treg cells, depend on ACC1-mediated de novo fatty acid synthesis and the underlying glycolytic-lipogenic metabolic pathway for their development. Although TH17 cells use this pathway to produce phospholipids for cellular membranes, Treg cells readily take up exogenous fatty acids for this purpose. Notably, pharmacologic inhibition or T cell-specific deletion of ACC1 not only blocks de novo fatty acid synthesis but also interferes with the metabolic flux of glucose-derived carbon via glycolysis and the tricarboxylic acid cycle. In vivo, treatment with the ACC-specific inhibitor soraphen A or T cell-specific deletion of ACC1 in mice attenuates TH17 cell-mediated autoimmune disease. Our results indicate fundamental differences between TH17 cells and Treg cells regarding their dependency on ACC1-mediated de novo fatty acid synthesis, which might be exploited as a new strategy for metabolic immune modulation of TH17 cell-mediated inflammatory diseases.

  9. Innate Functions of Immunoglobulin M Lessen Liver Gene Transfer with Helper-Dependent Adenovirus

    PubMed Central

    Unzu, Carmen; Morales-Kastresana, Aizea; Sampedro, Ana; Serrano-Mendioroz, Irantzu; Azpilikueta, Arantza; Ochoa, María Carmen; Dubrot, Juan; Martínez-Ansó, Eduardo

    2014-01-01

    The immune system poses obstacles to viral vectors, even in the first administration to preimmunized hosts. We have observed that the livers of B cell-deficient mice were more effectively transduced by a helper-dependent adenovirus serotype-5 (HDA) vector than those of WT mice. This effect was T-cell independent as shown in athymic mice. Passive transfer of the serum from adenovirus-naïve WT to Rag1KO mice resulted in a reduction in gene transfer that was traced to IgM purified from serum of adenovirus-naïve mice. To ascribe the gene transfer inhibition activity to either adenoviral antigen-specific or antigen-unspecific functions of IgM, we used a monoclonal IgM antibody of unrelated specificity. Both the polyclonal and the irrelevant monoclonal IgM inhibited gene transfer by the HDA vector to either cultured hepatocellular carcinoma cells or to the liver of mice in vivo. Adsorption of polyclonal or monoclonal IgMs to viral capsids was revealed by ELISAs on adenovirus-coated plates. These observations indicate the existence of an inborn IgM mechanism deployed against a prevalent virus to reduce early post-infection viremia. In conclusion, innate IgM binding to adenovirus serotype-5 capsids restrains gene-transfer and offers a mechanism to be targeted for optimization of vector dosage in gene therapy with HDA vectors. PMID:24465560

  10. How T follicular helper cells and the germinal centre response change with age.

    PubMed

    Linterman, Michelle A

    2014-01-01

    Normal ageing is accompanied by a decline in the function of the immune system that causes an increased susceptibility to infections and an impaired response to vaccination in older individuals. This results in an increased disease burden in the aged population, even with good immunisation programmes in place. The decreased response to vaccination is partly due to the diminution of the germinal centre response with age, caused by impaired T-cell help to B cells. Within the germinal centre, T-cell help is provided by a specialised subset of CD4(+) T cells; T follicular helper (Tfh) cells. Tfh cells provide survival and selection signals to germinal centre B cells, allowing them to egress from the germinal centre and become long-live plasma cells or memory B cells, and provide life-long protection against subsequent infection. This review will discuss the cellular and molecular changes in both Tfh cells and germinal centre B cells that occur with advancing age, which result in a smaller germinal centre response and a less effective response to immunisation.

  11. PPARγ negatively regulates T cell activation to prevent follicular helper T cells and germinal center formation.

    PubMed

    Park, Hong-Jai; Kim, Do-Hyun; Choi, Jin-Young; Kim, Won-Ju; Kim, Ji Yun; Senejani, Alireza G; Hwang, Soo Seok; Kim, Lark Kyun; Tobiasova, Zuzana; Lee, Gap Ryol; Craft, Joseph; Bothwell, Alfred L M; Choi, Je-Min

    2014-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that regulates lipid and glucose metabolism. Although studies of PPARγ ligands have demonstrated its regulatory functions in inflammation and adaptive immunity, its intrinsic role in T cells and autoimmunity has yet to be fully elucidated. Here we used CD4-PPARγKO mice to investigate PPARγ-deficient T cells, which were hyper-reactive to produce higher levels of cytokines and exhibited greater proliferation than wild type T cells with increased ERK and AKT phosphorylation. Diminished expression of IκBα, Sirt1, and Foxo1, which are inhibitors of NF-κB, was observed in PPARγ-deficient T cells that were prone to produce all the signature cytokines under Th1, Th2, Th17, and Th9 skewing condition. Interestingly, 1-year-old CD4-PPARγKO mice spontaneously developed moderate autoimmune phenotype by increased activated T cells, follicular helper T cells (TFH cells) and germinal center B cells with glomerular inflammation and enhanced autoantibody production. Sheep red blood cell immunization more induced TFH cells and germinal centers in CD4-PPARγKO mice and the T cells showed increased of Bcl-6 and IL-21 expression suggesting its regulatory role in germinal center reaction. Collectively, these results suggest that PPARγ has a regulatory role for TFH cells and germinal center reaction to prevent autoimmunity.

  12. Two-photon microscopy for imaging germinal centers and T follicular helper cells.

    PubMed

    Clatworthy, Menna R

    2015-01-01

    One of the principle features of immune cells is their dynamic nature. Lymphocytes circulate in the blood between secondary lymphoid organs and tissues in an effort to maximize the likelihood of a rapid and appropriate immune response to invading pathogens and tissue damage. Conventional experimental techniques such as histology and flow cytometry have greatly increased our understanding of immune cells, but in the last decade, two-photon microscopy has revolutionized our ability to interrogate the dynamic behavior of immune cells, a facet so critical to their function. Two-photon microscopy relies on the excitation of fluorophores by simultaneous application of two photons of longer wavelength light. This allows a greater depth of imaging with minimal photodamage. Thus, living tissues can be imaged, including immune cells in lymph nodes. This technique has been used to interrogate the events occurring in a germinal center response and the interactions between cells in the germinal center, including T follicular helper cells (Tfh), germinal center B cells, and follicular dendritic cells (FDC). Herein, a method is described by which the interactions between Tfh and B cells within a germinal center in a popliteal lymph node can be imaged in a live mouse.

  13. A mycorrhiza helper bacterium enhances ectomycorrhizal and endomycorrhizal symbiosis of Australian Acacia species.

    PubMed

    Duponnois, R; Plenchette, C

    2003-04-01

    The aims of this study were to test the effects of a mycorrhiza helper bacterium (MHB), Pseudomonas monteilii strain HR13 on the mycorrhization of (1) an Australian Acacia, A. holosericea, by several ectomycorrhizal fungi or one endomycorrhizal fungus Glomus intraradices, and (2) several Australian Acacia species by Pisolithus alba strain IR100 under glasshouse conditions. Bacterial inoculant HR13 significantly promoted ectomycorrhizal colonization for all the Acacia species, from 45.8% ( A. mangium) to 70.3% ( A. auriculiformis). A stimulating effect of HR13 on the ectomycorrhizal establishment was recorded with all the fungal isolates (strains of Pisolithus and Scleroderma). The same effect of bacteria on the frequency of endomycorrhizal colonization of A. holosericea seedlings by G. intraradices with vesicles and hyphae frequencies was recorded. The stimulation of saprophytic fungal growth by MHB is usually the main mechanism that could explain this bacterial effect on mycorrhizal establishment. MHB could stimulate the production of phenolic compounds such as hypaphorine and increase the aggressiveness of the fungal symbiont. However, no significant effect of MHB on fungal growth was recorded with Scleroderma isolates under axenic conditions but positive bacterial effects were observed with Pisolithus strains. From a practical viewpoint, it appears that MHB could stimulate the mycorrhizal colonization of Australian Acacia species with ectomycorrhizal or endomycorrhizal fungi, and could also facilitate controlled mycorrhization in nursery practices where Acacia species are grown for forestation purposes.

  14. Highly efficient retinal gene delivery with helper-dependent adenoviral vectors

    PubMed Central

    Lam, Simon; Cao, Huibi; Wu, Jing; Duan, Rongqi; Hu, Jim

    2015-01-01

    There have been significant advancements in the field of retinal gene therapy in the past several years. In particular, therapeutic efficacy has been achieved in three separate human clinical trials conducted to assess the ability of adeno-associated viruses (AAV) to treat of a type of Leber’s congenital amaurosis caused by RPE65 mutations. However, despite the success of retinal gene therapy with AAV, challenges remain for delivering large therapeutic genes or genes requiring long DNA regulatory elements for controlling their expression. For example, Stargardt’s disease, a form of juvenile macular degeneration, is caused by defects in ABCA4, a gene that is too large to be packaged in AAV. Therefore, we investigated the ability of helper dependent adenovirus (HD-Ad) to deliver genes to the retina as it has a much larger transgene capacity. Using an EGFP reporter, our results showed that HD-Ad can transduce the entire retinal epithelium of a mouse using a dose of only 1 × 105 infectious units and maintain transgene expression for at least 4 months. The results demonstrate that HD-Ad has the potential to be an effective vector for the gene therapy of the retina. PMID:26161435

  15. Combinatorial treatment with oncolytic adenovirus and helper-dependent adenovirus augments adenoviral cancer gene therapy

    PubMed Central

    Farzad, Lisa; Cerullo, Vincenzo; Yagyu, Shigeki; Bertin, Terry; Hemminki, Akseli; Rooney, Cliona; Lee, Brendan; Suzuki, Masataka

    2014-01-01

    Oncolytic adenoviruses (Onc.Ads) produce significant antitumor effects but as single agents they rarely eliminate tumors. Investigators have therefore incorporated sequences into these vectors that encode immunomodulatory molecules to enhance antitumor immunity. Successful implementation of this strategy requires multiple tumor immune inhibitory mechanisms to be overcome, and insertion of the corresponding multiple functional genes reduces the titer and replication of Onc.Ads, compromising their direct ant-tumor effects. By contrast, helper-dependent (HD) Ads are devoid of viral coding sequences, allowing inclusion of multiple transgenes. HDAds, however, lack replicative capacity. Since HDAds encode the adenoviral packaging signal, we hypothesized that the coadministration of Onc.Ad with HDAd would allow to be amplified and packaged during replication of Onc.Ad in transduced cancer cells. This combination could provide immunostimulation without losing oncolytic activity. We now show that coinfection of Onc.Ad with HDAd subsequently replicates HDAd vector DNA in trans in human cancer cell lines in vitro and in vivo, amplifying the transgenes the HDAd encode. This combinatorial treatment significantly suppresses the tumor growth compared to treatment with a single agent in an immunocompetent mouse model. Hence, combinatorial treatment of Onc.Ad with HDAd should overcome the inherent limitations of each agent and provide a highly immunogenic oncolytic therapy. PMID:27119096

  16. Helper-dependent adenoviral vectors for liver-directed gene therapy of primary hyperoxaluria type 1

    PubMed Central

    Castello, Raffaele; Borzone, Roberta; D’Aria, Stefania; Annunziata, Patrizia; Piccolo, Pasquale; Brunetti-Pierri, Nicola

    2015-01-01

    Primary hyperoxaluria type 1 (PH1) is an inborn error of liver metabolism due to deficiency of the peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT) which catalyzes conversion of glyoxylate into glycine. AGT deficiency results in overproduction of oxalate which ultimately leads to end-stage renal disease and death. Organ transplantation as either preemptive liver transplantation or combined liver/kidney transplantation is the only available therapy to prevent disease progression. Gene therapy is an attractive option to provide an alternative treatment for PH1. Towards this goal, we investigated helper-dependent adenoviral (HDAd) vectors for liver-directed gene therapy of PH1. Compared to saline controls, AGT-deficient mice injected with an HDAd encoding the AGT under the control of a liver-specific promoter showed a significant reduction of hyperoxaluria and less increase of urinary oxalate following challenge with Ethylene Glycol (EG), a precursor of glyoxylate. These studies may thus pave the way to clinical application of HDAd for PH1 gene therapy. PMID:26609667

  17. Long-distance movement factor: a transport function of the potyvirus helper component proteinase.

    PubMed Central

    Cronin, S; Verchot, J; Haldeman-Cahill, R; Schaad, M C; Carrington, J C

    1995-01-01

    Transport of viruses from cell to cell in plants typically involves one or more viral proteins that supply dedicated movement functions. Transport from leaf to leaf through phloem, or long-distance transport, is a poorly understood process with requirements differing from those of cell-to-cell movement. Through genetic analysis of tobacco etch virus (TEV; potyvirus group), a novel long-distance movement factor was identified that facilitates vascular-associated movement in tobacco. A mutation in the central region of the helper component proteinase (HC-Pro), a TEV-encoded protein with previously described activities in aphid-mediated transmission and polyprotein processing, inactivated long-distance movement. This mutant virus exhibited only minor defects in genome amplification and cell-to-cell movement functions. In situ histochemical analysis revealed that the mutant was capable of infecting mesophyll, bundle sheath, and phloem cells within inoculated leaves, suggesting that the long-distance movement block was associated with entry into or exit from sieve elements. The long-distance movement defect was specifically complemented by HC-Pro supplied in trans by a transgenic host. The data indicate that HC-Pro functions in one or more steps unique to long-distance transport. PMID:7780307

  18. Interference of cephalosporins with immune response: effects of cefonicid on human T-helper cells.

    PubMed

    Villa, M L; Armelloni, S; Ferrario, E; Ottaviani, F; Clerici, M

    1991-01-01

    To determine the immunosuppressive effect(s) of cephalosporin cefonicid (CEFO) on human T-helper cells (Th), we exposed human peripheral blood mononuclear cells (PBMC) to various concentrations of CEFO during in vitro stimulation with a panel of T-lymphocyte stimulators that activate different Th/antigen presenting cell (APC) pathways. We evaluated the proliferation and IL-2 production induced by influenza virus (FLU), allogeneic lymphocytes (ALLO), xenogeneic mouse splenocytes (XENO) or phytohemagglutinin (PHA). The proliferative responses to FLU and XENO were much more depressed by CEFO than those to ALLO or PHA. After 7 days of culture with the highest dose of CEFO tested (200 mg/l) the stimulation index (stimulated/unstimulated culture) was near to 0 in FLU and XENO treated cultures, indicating that the response against these antigens was completely abrogated. The responses to ALLO and PHA were also impaired, but not abrogated (stimulation index greater than 1). Since FLU and XENO utilize the CD4+ Th/self-APC pathway our data suggested that this pathway was extremely sensitive to CEFO-induced inhibition both when the response requires memory Th cells (FLU) and virgin Th cells (XENO). The incubation with CEFO (200 mg/l) reduced the IL-2 production by XENO, FLU and ALLO to less than 20% of control cultures, while paradoxically increases to 120% the production by PHA.

  19. TGF-β receptor maintains CD4 T helper cell identity during chronic viral infections

    PubMed Central

    Lewis, Gavin M.; Wehrens, Ellen J.; Labarta-Bajo, Lara; Streeck, Hendrik; Zuniga, Elina I.

    2016-01-01

    Suppression of CD8 and CD4 T cells is a hallmark in chronic viral infections, including hepatitis C and HIV. While multiple pathways are known to inhibit CD8 T cells, the host molecules that restrict CD4 T cell responses are less understood. Here, we used inducible and CD4 T cell–specific deletion of the gene encoding the TGF-β receptor during chronic lymphocytic choriomeningitis virus infection in mice, and determined that TGF-β signaling restricted proliferation and terminal differentiation of antiviral CD4 T cells. TGF-β signaling also inhibited a cytotoxic program that includes granzymes and perforin expression at both early and late stages of infection in vivo and repressed the transcription factor eomesodermin. Overexpression of eomesodermin was sufficient to recapitulate in great part the phenotype of TGF-β receptor–deficient CD4 T cells, while SMAD4 was necessary for CD4 T cell accumulation and differentiation. TGF-β signaling also restricted accumulation and differentiation of CD4 T cells and reduced the expression of cytotoxic molecules in mice and humans infected with other persistent viruses. These data uncovered an eomesodermin-driven CD4 T cell program that is continuously suppressed by TGF-β signaling. During chronic viral infection, this program limits CD4 T cell responses while maintaining CD4 T helper cell identity. PMID:27599295

  20. T helper cell polarisation as a measure of the maturation of the immune response.

    PubMed Central

    Cameron, Scott B; Stolte, Ellen H; Chow, Anthony W; Savelkoul, Huub F J

    2003-01-01

    BACKGROUND: T helper cell polarisation is important under chronic immune stimulatory conditions and drives the type of the evolving immune response. Mice treated with superantigens in vivo display strong effects on Th subset differentiation. The aim of the study was to detect the intrinsic capacity of T cells to polarise under various ex vivo conditions. METHODS: Purified CD4+ T cells obtained from super-antigen-treated mice were cultured under Th polarising conditions in vitro. By combining intracellular cytokine staining and subsequent flow cytometric analysis with quantitative cytokine measurements in culture supernatants by enzyme-linked immunosorbent assay (ELISA), the differential Th polarising capacity of the treatment can be detected in a qualitative and quantitative manner. RESULTS AND CONCLUSIONS: BALB/c mice were shown to be biased to develop strong Th2 polarised immune responses using Th0 stimulation of purified CD4+ T cells from phosphate-buffered saline-treated mice. Nevertheless, our analysis methodology convincingly showed that even in these mice, Toxic Shock Syndrome Toxin-1 treatment in vivo resulted in a significantly stronger Th1 polarising effect than control treatment. Our results indicate that populations of Th cells can be assessed individually for their differential Th1 or Th2 maturation capacity in vivo by analysing robust in vitro polarisation cultures combined with intracellular cytokine staining and ELISA. PMID:14760935

  1. Basic science for the clinician 28: T-helper cell subtypes.

    PubMed

    Sigal, Leonard H

    2004-08-01

    The immune response is finely tuned to the various invaders that may cause damage and disease. There is an innate immune system and an acquired immune response, but there is much overlap and recruitment across these lines of demarcation. Broadly speaking, there are cellular immune responses (cellular effectors that identify intracellular pathogens and damage and kill the affected cell) and humoral (B cells become plasma cells which make antibodies to bind extracellular pathogens and their products) that draw upon both systems. At the pivotal point, where decisions are made whether to mount a primarily cellular or a humoral response are T-helper cells (CD4). As you may have read, CD4 cells come in at least 2 subtypes: TH1 cells predispose to the development of a primarily cellular responses and TH2 predispose to humoral responses. Not very complicated, but worthy of some discussion to look at the cytokines produced, the changes these cytokines evince, and how the balances (dare I say yin and yang) keep us healthy but also may get us into trouble!

  2. CD4 T Follicular Helper Cells and HIV Infection: Friends or Enemies?

    PubMed Central

    Moukambi, Félicien; Rodrigues, Vasco; Fortier, Yasmina; Rabezanahary, Henintsoa; Borde, Chloé; Krust, Bernard; Andreani, Guadalupe; Silvestre, Ricardo; Petrovas, Constantinos; Laforge, Mireille; Estaquier, Jérôme

    2017-01-01

    Follicular T helper (Tfh) cells, a subset of CD4 T lymphocytes, are essential for memory B cell activation, survival, and differentiation and assist B cells in the production of antigen-specific antibodies. Work performed in recent years pointed out the importance of Tfh cells in the context of HIV and SIV infections. The importance of tissue distribution of Tfh is also an important point since their frequency differs between peripheral blood and lymph nodes compared to the spleen, the primary organ for B cell activation, and differentiation. Our recent observations indicated an early and profound loss of splenic Tfh cells. The role of transcriptional activator and repressor factors that control Tfh differentiation is also discussed in the context of HIV/SIV infection. Because Tfh cells are important for B cell differentiation and antibody production, accelerating the Tfh responses early during HIV/SIV infection could be promising as novel immunotherapeutic approach or alternative vaccine strategies. However, because Tfh cells are infected during the HIV/SIV infection and represent a reservoir, this may interfere with HIV vaccine strategy. Thus, Tfh represent the good and bad guys during HIV infection. PMID:28265271

  3. IL-12 receptor β1 deficiency alters in vivo T follicular helper cell response in humans

    PubMed Central

    Bustamante, Jacinta; Bourdery, Laure; Bentebibel, Salah Eddine; Boisson-Dupuis, Stephanie; Hamlin, Fran; Tran, Mau V.; Blankenship, Derek; Pascual, Virginia; Savino, Daniel A.; Banchereau, Jacques; Casanova, Jean-Laurent

    2013-01-01

    Antibody responses represent a key immune protection mechanism. T follicular helper (Tfh) cells are the major CD4+ T-cell subset that provides help to B cells to generate an antibody response. Tfh cells together with B cells form germinal centers (GCs), the site where high-affinity B cells are selected and differentiate into either memory B cells or long-lived plasma cells. We show here that interleukin-12 receptor β1 (IL-12Rβ1)–mediated signaling is important for in vivo Tfh response in humans. Although not prone to B cell-deficient–associated infections, subjects lacking functional IL-12Rβ1, a receptor for IL-12 and IL-23, displayed substantially less circulating memory Tfh and memory B cells than control subjects. GC formation in lymph nodes was also impaired in IL-12Rβ1–deficient subjects. Consistently, the avidity of tetanus toxoid–specific serum antibodies was substantially lower in these subjects than in age-matched controls. Tfh cells in tonsils from control individuals displayed the active form of signal transducer and activator of transcription 4 (STAT4), demonstrating that IL-12 is also acting on Tfh cells in GCs. Thus, our study shows that the IL-12–STAT4 axis is associated with the development and the functions of Tfh cells in vivo in humans. PMID:23476048

  4. Viral persistence redirects CD4 T cell differentiation toward T follicular helper cells

    PubMed Central

    Fahey, Laura M.; Wilson, Elizabeth B.; Elsaesser, Heidi; Fistonich, Chris D.; McGavern, Dorian B.

    2011-01-01

    CD4 T cell responses are crucial to prevent and control viral infection; however, virus-specific CD4 T cell activity is considered to be rapidly lost during many persistent viral infections. This is largely caused by the fact that during viral persistence CD4 T cells do not produce the classical Th1 cytokines associated with control of acute viral infections. Considering that CD4 T cell help is critical for both CD8 T cell and B cell functions, it is unclear how CD4 T cells can lose responsiveness but continue to sustain long-term control of persistent viral replication. We now demonstrate that CD4 T cell function is not extinguished as a result of viral persistence. Instead, viral persistence and prolonged T cell receptor stimulation progressively redirects CD4 T cell development away from the Th1 response induced during an acute infection toward T follicular helper cells. Importantly, this sustained CD4 T cell functionality is critical to maintain immunity and ultimately aid in the control of persistent viral infection. PMID:21536743

  5. Follicular T helper cells and humoral reactivity in kidney transplant patients

    PubMed Central

    de Graav, G N; Dieterich, M; Hesselink, D A; Boer, K; Clahsen-van Groningen, M C; Kraaijeveld, R; Litjens, N H R; Bouamar, R; Vanderlocht, J; Tilanus, M; Houba, I; Boonstra, A; Roelen, D L; Claas, F H J; Betjes, M G H; Weimar, W; Baan, C C

    2015-01-01

    Memory B cells play a pivotal role in alloreactivity in kidney transplantation. Follicular T helper (Tfh) cells play an important role in the differentiation of B cells into immunoglobulin-producing plasmablasts [through interleukin (IL)-21]. It is unclear to what extent this T cell subset regulates humoral alloreactivity in kidney transplant patients, therefore we investigated the absolute numbers and function of peripheral Tfh cells (CD4POSCXCR5POS T cells) in patients before and after transplantation. In addition, we studied their relationship with the presence of donor-specific anti-human leucocyte antigen (HLA) antibodies (DSA), and the presence of Tfh cells in rejection biopsies. After transplantation peripheral Tfh cell numbers remained stable, while their IL-21-producing capacity decreased under immunosuppression. When isolated after transplantation, peripheral Tfh cells still had the capacity to induce B cell differentiation and immunoglobulin production, which could be inhibited by an IL-21-receptor-antagonist. After transplantation the quantity of Tfh cells was the highest in patients with pre-existent DSA. In kidney biopsies taken during rejection, Tfh cells co-localized with B cells and immunoglobulins in follicular-like structures. Our data on Tfh cells in kidney transplantation demonstrate that Tfh cells may mediate humoral alloreactivity, which is also seen in the immunosuppressed milieu. PMID:25557528

  6. Control of T helper cell differentiation through cytokine receptor inclusion in the immunological synapse.

    PubMed

    Maldonado, Roberto A; Soriano, Michelle A; Perdomo, L Carolina; Sigrist, Kirsten; Irvine, Darrell J; Decker, Thomas; Glimcher, Laurie H

    2009-04-13

    The antigen recognition interface formed by T helper precursors (Thps) and antigen-presenting cells (APCs), called the immunological synapse (IS), includes receptors and signaling molecules necessary for Thp activation and differentiation. We have recently shown that recruitment of the interferon-gamma receptor (IFNGR) into the IS correlates with the capacity of Thps to differentiate into Th1 effector cells, an event regulated by signaling through the functionally opposing receptor to interleukin-4 (IL4R). Here, we show that, similar to IFN-gamma ligation, TCR stimuli induce the translocation of signal transducer and activator of transcription 1 (STAT1) to IFNGR1-rich regions of the membrane. Unexpectedly, STAT1 is preferentially expressed, is constitutively serine (727) phosphorylated in Thp, and is recruited to the IS and the nucleus upon TCR signaling. IL4R engagement controls this process by interfering with both STAT1 recruitment and nuclear translocation. We also show that in cells with deficient Th1 or constitutive Th2 differentiation, the IL4R is recruited to the IS. This observation suggest that the IL4R is retained outside the IS, similar to the exclusion of IFNGR from the IS during IL4R signaling. This study provides new mechanistic cues for the regulation of lineage commitment by mutual immobilization of functionally antagonistic membrane receptors.

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

    PubMed

    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

    2013-07-01

    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.

  8. 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

  9. Dominance of the CD4+ T helper cell response during acute resolving hepatitis A virus infection

    PubMed Central

    Zhou, Yan; Callendret, Benoît; Xu, Dan; Brasky, Kathleen M.; Feng, Zongdi; Hensley, Lucinda L.; Guedj, Jeremie; Perelson, Alan S.; Lemon, Stanley M.; Lanford, Robert E.

    2012-01-01

    Hepatitis A virus (HAV) infection typically resolves within 4–7 wk but symptomatic relapse occurs in up to 20% of cases. Immune mechanisms that terminate acute HAV infection, and prevent a relapse of virus replication and liver disease, are unknown. Here, patterns of T cell immunity, virus replication, and hepatocellular injury were studied in two HAV-infected chimpanzees. HAV-specific CD8+ T cells were either not detected in the blood or failed to display effector function until after viremia and hepatitis began to subside. The function of CD8+ T cells improved slowly as the cells acquired a memory phenotype but was largely restricted to production of IFN-γ. In contrast, CD4+ T cells produced multiple cytokines when viremia first declined. Moreover, only CD4+ T cells responded during a transient resurgence of fecal HAV shedding. This helper response then contracted slowly over several months as HAV genomes were eliminated from liver. The findings indicate a dominant role for CD4+ T cells in the termination of HAV infection and, possibly, surveillance of an intrahepatic reservoir of HAV genomes that decays slowly. Rapid contraction or failure to sustain such a CD4+ T cell response after resolution of symptoms could increase the risk of relapsing hepatitis A. PMID:22753925

  10. Tle4 regulates epigenetic silencing of gamma interferon expression during effector T helper cell tolerance.

    PubMed

    Bandyopadhyay, Sanmay; Valdor, Rut; Macian, Fernando

    2014-01-01

    In response to suboptimal activation, T cells become hyporesponsive, with a severely reduced capacity to proliferate and produce cytokines upon reencounter with antigen. Chromatin analysis of T cells made tolerant by use of different in vitro and in vivo approaches reveals that the expression of gamma interferon (IFN-γ) is epigenetically silenced in anergic effector TH1 cells. In those T cells, calcium signaling triggers the expression of Tle4, a member of the Groucho family of corepressors, which is then recruited to a distal regulatory element in the Ifng locus and causes the establishment of repressive epigenetic marks at the Ifng gene regulatory elements. Consequently, impaired Tle4 activity results in a markedly reduced capacity to inhibit IFN-γ production in tolerized T cells. We propose that Blimp1-dependent recruitment of Tle4 to the Ifng locus causes epigenetic silencing of the expression of the Ifng gene in anergic TH1 cells. These results define a novel function of Groucho family corepressors in peripheral T cells and demonstrate that specific mechanisms are activated in tolerant T helper cells to directly repress expression of effector cytokines, supporting the hypothesis that stable epigenetic imprinting contributes to the maintenance of the tolerance-associated hyporesponsive phenotype in T cells.

  11. Helper-dependent adenoviral vectors for liver-directed gene therapy of primary hyperoxaluria type 1.

    PubMed

    Castello, R; Borzone, R; D'Aria, S; Annunziata, P; Piccolo, P; Brunetti-Pierri, N

    2016-02-01

    Primary hyperoxaluria type 1 (PH1) is an inborn error of liver metabolism due to deficiency of the peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT), which catalyzes conversion of glyoxylate into glycine. AGT deficiency results in overproduction of oxalate that ultimately leads to end-stage renal disease and death. Organ transplantation as either preemptive liver transplantation or combined liver/kidney transplantation is the only available therapy to prevent disease progression. Gene therapy is an attractive option to provide an alternative treatment for PH1. Toward this goal, we investigated helper-dependent adenoviral (HDAd) vectors for liver-directed gene therapy of PH1. Compared with saline controls, AGT-deficient mice injected with an HDAd encoding the AGT under the control of a liver-specific promoter showed a significant reduction of hyperoxaluria and less increase of urinary oxalate following challenge with ethylene glycol, a precursor of glyoxylate. These studies may thus pave the way to clinical application of HDAd for PH1 gene therapy.

  12. T Helper 1–Inducing Adjuvant Protects against Experimental Paracoccidioidomycosis

    PubMed Central

    de Oliveira, Leandro Licursi; Coltri, Kely Cristine; Cardoso, Cristina Ribeiro Barros; Roque-Barreira, Maria-Cristina; Panunto-Castelo, Ademilson

    2008-01-01

    Immunostimulatory therapy is a promising approach to improving the treatment of systemic fungal infections such as paracoccidioidomycosis (PCM), whose drug therapy is usually prolonged and associated with toxic side effects and relapses. The current study was undertaken to determine if the injection of a T helper (Th) 1–stimulating adjuvant in P. brasiliensis–infected mice could have a beneficial effect on the course of experimental PCM. For this purpose, mice were infected and treated with complete Freund's adjuvant (CFA), a well-established Th1 experimental inductor, or incomplete Freund's adjuvant (IFA - control group) on day 20 postinfection. Four weeks after treatment, the CFA-treated mice presented a mild infection in the lungs characterized by absence of epithelioid cell granulomas and yeast cells, whereas the control mice presented multiple sites of focal epithelioid granulomas with lymphomonocytic halos circumscribing a high number of viable and nonviable yeast cells. In addition, CFA administration induced a 2.4 log reduction (>99%) in the fungal burden when compared to the control group, and led to an improvement of immune response, reversing the immunosuppression observed in the control group. The immunotherapy with Th1-inducing adjuvant, approved to be used in humans, might be a valuable tool in the treatment of PCM and potentially useful to improve the clinical cure rate in humans. PMID:18335066

  13. AIRE expressing marginal zone dendritic cells balances adaptive immunity and T-follicular helper cell recruitment.

    PubMed

    Lindmark, Evelina; Chen, Yunying; Georgoudaki, Anna-Maria; Dudziak, Diana; Lindh, Emma; Adams, William C; Loré, Karin; Winqvist, Ola; Chambers, Benedict J; Karlsson, Mikael C I

    2013-05-01

    Autoimmune polyendocrine syndrome Type I (APS I) results in multiple endocrine organ destruction and is caused by mutations in the Autoimmune regulator gene (AIRE). In the thymic stroma, cells expressing the AIRE gene dictate T cell education and central tolerance. Although this function is the most studied, AIRE is also expressed in the periphery in DCs and stromal cells. Still, how AIRE regulated transcription modifies cell behaviour in the periphery is largely unknown. Here we show that AIRE is specifically expressed by 33D1(+) DCs and dictates the fate of antibody secreting cell movement within the spleen. We also found that AIRE expressing 33D1(+) DCs expresses self-antigens as exemplified by the hallmark gene insulin. Also, as evidence for a regulatory function, absence of Aire in 33D1(+) DCs led to reduced levels of the chemokine CXCL12 and increased co-stimulatory properties. This resulted in altered activation and recruitment of T-follicular helper cells and germinal centre B cells. The altered balance leads to a change of the early response to a T cell-dependent antigen in Aire(-/-) mice. These findings add to the understanding of how specific DC subtypes regulate the early responses during T cell-dependent antibody responses within the spleen and further define the role of AIRE in the periphery as regulator of self-antigen expression and lymphocyte migration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Role of distinct CD4(+) T helper subset in pathogenesis of oral lichen planus.

    PubMed

    Wang, Hui; Zhang, Dunfang; Han, Qi; Zhao, Xin; Zeng, Xin; Xu, Yi; Sun, Zheng; Chen, Qianming

    2016-07-01

    Oral lichen planus (OLP) is one of the most common chronic inflammatory oral mucosal diseases with T-cell-mediated immune pathogenesis. In subepithelial and lamina propria of OLP local lesions, the presence of CD4(+) T helper (CD4(+) Th) cells appeared as the major lymphocytes. These CD4(+) T lymphocytes can differentiate into distinct Th cell types such as Th1, Th2, Treg, Th17, Th22, Th9, and Tfh within the context of certain cytokines environment. Growing evidence indicated that Th1/Th2 imbalance may greatly participate into the cytokine network of OLP immunopathology. In addition, Th1/Th2 imbalance can be regulated by the Treg subset and also greatly influenced by the emerging novel CD4(+) Th subset Th17. Furthermore, the presence of novel subsets Th22, Th9 and Tfh in OLP patients is yet to be clarified. All these Th subsets and their specific cytokines may play a critical role in determining the character, extent and duration of immune responses in OLP pathogenesis. Therefore, we review the roles of distinct CD4(+) Th subsets and their signature cytokines in determining disease severity and susceptibility of OLP and also reveal the novel therapeutic strategies based on T lymphocytes subsets in OLP treatment. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Thimerosal compromises human dendritic cell maturation, IL-12 production, chemokine release, and T-helper polarization

    PubMed Central

    Loison, Emily; Gougeon, Marie-Lise

    2014-01-01

    Thimerosal is a preservative used in multidose vials of vaccine formulations to prevent bacterial and fungal contamination. We recently reported that nanomolar concentrations of thimerosal induce cell cycle arrest of human T cells activated via the TCR and inhibition of proinflammatory cytokine production, thus interfering with T-cell functions. Given the essential role of dendritic cells (DCs) in T-cell polarization and vaccine immunity, we studied the influence of non-toxic concentrations of thimerosal on DC maturation and functions. Ex-vivo exposure of human monocyte-derived DCs to nanomolar concentrations of thimerosal prevented LPS-induced DC maturation, as evidenced by the inhibition of morphological changes and a decreased expression of the maturation markers CD86 and HLA-DR. In addition thimerosal dampened their proinflammatory response, in particular the production of the Th1 polarizing cytokine IL-12, as well as TNF-α and IL-6. DC-dependent T helper polarization was altered, leading to a decreased production of IFN-γ IP10 and GM-CSF and increased levels of IL-8, IL-9, and MIP-1α. Although multi-dose vials of vaccines containing thimerosal remain important for vaccine delivery, our results alert about the ex-vivo immunomodulatory effects of thimerosal on DCs, a key player for the induction of an adaptive response PMID:25424939

  16. Autoimmune memory T helper 17 cell function and expansion are dependent on interleukin-23.

    PubMed

    Haines, Christopher J; Chen, Yi; Blumenschein, Wendy M; Jain, Renu; Chang, Charlie; Joyce-Shaikh, Barbara; Porth, Katherine; Boniface, Katia; Mattson, Jeanine; Basham, Beth; Anderton, Stephen M; McClanahan, Terrill K; Sadekova, Svetlana; Cua, Daniel J; McGeachy, Mandy J

    2013-05-30

    Interleukin-23 (IL-23) is essential for the differentiation of pathogenic effector T helper 17 (Th17) cells, but its role in memory Th17 cell responses is unclear. Using the experimental autoimmune encephalomyelitis (EAE) model, we report that memory Th17 cells rapidly expanded in response to rechallenge and migrated to the CNS in high numbers, resulting in earlier onset and increased severity of clinical disease. Memory Th17 cells were generated from IL-17+ and RORγt+ precursors, and the stability of the Th17 cell phenotype depended on the amount of time allowed for the primary response. IL-23 was required for this enhanced recall response. IL-23 receptor blockade did not directly impact IL-17 production, but did impair the subsequent proliferation and generation of effectors coexpressing the Th1 cell-specific transcription factor T-bet. In addition, many genes required for cell-cycle progression were downregulated in Th17 cells that lacked IL-23 signaling, showing that a major mechanism for IL-23 in primary and memory Th17 cell responses operates via regulation of proliferation-associated pathways.

  17. The T helper type 17/regulatory T cell paradigm in pregnancy.

    PubMed

    Figueiredo, Ana Sofia; Schumacher, Anne

    2016-05-01

    T helper type 17 (Th17) and regulatory T (Treg) cells are active players in the establishment of tolerance and defence. These attributes of the immune system enmesh to guarantee the right level of protection. The healthy immune system, on the one hand, recognizes and eliminates dangerous non-self pathogens and, on the other hand, protects the healthy self. However, there are circumstances where this fine balance is disrupted. In fact, in situations such as in pregnancy, the foreign fetal antigens challenge the maternal immune system and Treg cells will dominate Th17 cells to guarantee fetal survival. In other situations such as autoimmunity, where the Th17 responses are often overwhelming, the immune system shifts towards an inflammatory profile and attacks the healthy tissue from the self. Interestingly, autoimmune patients have meliorating symptoms during pregnancy. This connects with the antagonist role of Th17 and Treg cells, and their specific profiles during these two immune challenging situations. In this review, we put into perspective the Th17/Treg ratio during pregnancy and autoimmunity, as well as in pregnant women with autoimmune conditions. We further review existing systems biology approaches that study specific mechanisms of these immune cells using mathematical modelling and we point out possible future directions of investigation. Understanding what maintains or disrupts the balance between these two opponent yet reciprocal cells in healthy physiological settings, sheds light into the development of innovative pharmacological approaches to fight pregnancy loss and autoimmunity.

  18. Short Peptide Vaccine Induces CD4+ T Helper Cells in Patients with Different Solid Cancers.

    PubMed

    Gross, Stefanie; Lennerz, Volker; Gallerani, Elisa; Mach, Nicolas; Böhm, Steffen; Hess, Dagmar; von Boehmer, Lotta; Knuth, Alexander; Ochsenbein, Adrian; Gnad-Vogt, Ulrike; Forssmann, Ulf; Woelfel, Thomas; Kaempgen, Eckhart

    2016-01-01

    Previous cancer vaccination trials often aimed to activate CD8(+) cytotoxic T-cell (CTL) responses with short (8-10mer) peptides and targeted CD4(+) helper T cells (TH) with HLA class II-binding longer peptides (12-16 mer) that were derived from tumor antigens. Accordingly, a study of immunomonitoring focused on the detection of CTL responses to the short, and TH responses to the long, peptides. The possible induction of concurrent TH responses to short peptides was widely neglected. In a recent phase I vaccination trial, 53 patients with different solid cancers were vaccinated with EMD640744, a cocktail of five survivin-derived short (9- or 10-mer) peptides in Montanide ISA 51VG. We monitored 49 patients and found strong CD8(+) T-cell responses in 63% of the patients. In addition, we unexpectedly found CD4(+) TH cell responses against at least two of the five short peptides in 61% (23/38) of the patients analyzed. The two peptides were recognized by HLA-DP4- and HLA-DR-restricted TH1 cells. Some short peptide-reactive (sp)CD4 T cells showed high functional avidity. Here, we show that a short peptide vaccine is able to activate a specific CD4(+) T-cell repertoire in many patients, facilitating a strong combined CD4(+)/CD8(+) T-cell response.

  19. From idealistic helper to enterprising learner: critical reflections on personal development through experiences from Afghanistan.

    PubMed

    Wickford, Jenny; Rosberg, Susanne

    2012-05-01

    There is little written about the cultural, social, and ethical challenges encountered by physiotherapists engaging in development work. This article takes a critical perspective on what it means to engage in development work as an expatriate physiotherapist, through a self-critical reflection on experiences from Afghanistan. The field notes from an ethnographic study of a development project conducted in Afghanistan were analysed to explore the transformative process of personal and professional development of the development worker. The critical reflective process entailed a change in meaning perspective, described as a shift from the position of an Idealistic Helper to an Enterprising Learner. Of importance in this process were "disorienting dilemmas" that challenged personal perceptions. Critical reflection over such dilemmas led to deeper understanding facilitating the process of change. The essential lesson learned is that the baseline for understanding others is an understanding of one's own meaning perspectives and manner of participation in relation to others and their context. The insights gained have implications for physiotherapists working in development contexts, for other development workers, and for physiotherapists working with patients in clinical practice in a nondevelopment context. Exploring how to collaborate in development contexts could be done using reflective groups with expatriate and local physiotherapists and/or patients. This could lead to greater understanding of oneself, each other, and the local context.

  20. The Peptide Specificity of the Endogenous T Follicular Helper Cell Repertoire Generated after Protein Immunization

    PubMed Central

    Leddon, Scott A.; Sant, Andrea J.

    2012-01-01

    T follicular helper (Tfh) cells potentiate high-affinity, class-switched antibody responses, the predominant correlate of protection from vaccines. Despite intense interest in understanding both the generation and effector functions of this lineage, little is known about the epitope specificity of Tfh cells generated during polyclonal responses. To date, studies of peptide-specific Tfh cells have relied on either the transfer of TcR transgenic cells or use of peptide∶MHC class II tetramers and antibodies to stain TcR and follow limited peptide specificities. In order to comprehensively evaluate polyclonal responses generated from the natural endogenous TcR repertoire, we developed a sorting strategy to separate Tfh cells from non-Tfh cells and found that their epitope-specific responses could be tracked with cytokine-specific ELISPOT assays. The immunodominance hierarchies of Tfh and non-Tfh cells generated in response to immunization with several unrelated protein antigens were remarkably similar. Additionally, increasing the kinetic stability of peptide-MHC class II complexes enhanced the priming of both Tfh and conventional CD4 T cells. These findings may provide us with a strategy to rationally and selectively modulate epitope-specific Tfh responses. By understanding the parameters that control epitope-specific priming, vaccines may be tailored to enhance or focus Tfh responses to facilitate optimal B cell responses. PMID:23077537

  1. Attenuation of AMPK signaling by ROQUIN promotes T follicular helper cell formation

    PubMed Central

    Ramiscal, Roybel R; Parish, Ian A; Lee-Young, Robert S; Babon, Jeffrey J; Blagih, Julianna; Pratama, Alvin; Martin, Jaime; Hawley, Naomi; Cappello, Jean Y; Nieto, Pablo F; Ellyard, Julia I; Kershaw, Nadia J; Sweet, Rebecca A; Goodnow, Christopher C; Jones, Russell G; Febbraio, Mark A; Vinuesa, Carola G; Athanasopoulos, Vicki

    2015-01-01

    T follicular helper cells (Tfh) are critical for the longevity and quality of antibody-mediated protection against infection. Yet few signaling pathways have been identified to be unique solely to Tfh development. ROQUIN is a post-transcriptional repressor of T cells, acting through its ROQ domain to destabilize mRNA targets important for Th1, Th17, and Tfh biology. Here, we report that ROQUIN has a paradoxical function on Tfh differentiation mediated by its RING domain: mice with a T cell-specific deletion of the ROQUIN RING domain have unchanged Th1, Th2, Th17, and Tregs during a T-dependent response but show a profoundly defective antigen-specific Tfh compartment. ROQUIN RING signaling directly antagonized the catalytic α1 subunit of adenosine monophosphate-activated protein kinase (AMPK), a central stress-responsive regulator of cellular metabolism and mTOR signaling, which is known to facilitate T-dependent humoral immunity. We therefore unexpectedly uncover a ROQUIN–AMPK metabolic signaling nexus essential for selectively promoting Tfh responses. DOI: http://dx.doi.org/10.7554/eLife.08698.001 PMID:26496200

  2. Interleukin-17A negatively regulates lymphangiogenesis in T helper 17 cell-mediated inflammation.

    PubMed

    Park, H J; Yuk, C M; Shin, K; Lee, S-H

    2017-09-20

    During inflammation lymphatic vessels (LVs) are enlarged and their density is increased to facilitate the migration of activated immune cells and antigens. However, after antigen clearance, the expanded LVs shrink to maintain homeostasis. Here we show that interleukin (IL)-17A, secreted from T helper type 17 (TH17) cells, is a negative regulator of lymphangiogenesis during the resolution phase of TH17-mediated immune responses. Moreover, IL-17A suppresses the expression of major lymphatic markers in lymphatic endothelial cells and decreases in vitro LV formation. To investigate the role of IL-17A in vivo, we utilized a cholera toxin-mediated inflammation model and identified inflammation and resolution phases based on the numbers of recruited immune cells. IL-17A, markedly produced by TH17 cells even after the peak of inflammation, was found to participate in the negative regulation of LV formation. Moreover, blockade of IL-17A resulted in not only increased density of LVs in tissues but also their enhanced function. Taken together, these findings improve the current understanding of the relationship between LVs and inflammatory cytokines in pathologic conditions.Mucosal Immunology advance online publication 20 September 2017; doi:10.1038/mi.2017.76.

  3. Human T helper type 1 dichotomy: origin, phenotype and biological activities

    PubMed Central

    Annunziato, Francesco; Cosmi, Lorenzo; Liotta, Francesco; Maggi, Enrico; Romagnani, Sergio

    2015-01-01

    The great variety of pathogens present in the environment has obliged the immune system to evolve different mechanisms for tailored and maximally protective responses. Initially, two major types of CD4+ T helper (Th) effector cells were identified, and named as type 1 (Th1) and type 2 (Th2) cells because of the different cytokines they produce. More recently, a third type of CD4+ Th effectors has been identified and named as Th17 cells. Th17 cells, however, have been found to exhibit high plasticity because they rapidly shift into the Th1 phenotype in the inflammatory sites. Therefore, in these sites there is usually a dichotomous mixture of classic and non-classic (Th17-derived) Th1 cells. In humans, non-classic Th1 cells express CD161, as well as the retinoic acid orphan receptor C, interleukin-17 receptor E (IL-17RE), IL-1RI, CCR6, and IL-4-induced gene 1 and Tob-1, which are all virtually absent from classic Th1 cells. The possibility to distinguish between these two cell subsets may allow the opportunity to better establish their respective pathogenic role in different chronic inflammatory disorders. In this review, we discuss the different origin, the distinctive phenotypic features and the major biological activities of classic and non-classic Th1 cells. PMID:25284714

  4. Interleukin-22 Promotes T Helper 1 (Th1)/Th17 Immunity in Chlamydial Lung Infection

    PubMed Central

    Peng, Ying; Gao, Xiaoling; Yang, Jie; Shekhar, Sudhanshu; Wang, Shuhe; Fan, Yijun; Zhao, Weiming; Yang, Xi

    2014-01-01

    The role of interleukin-22 (IL-22) in intracellular bacterial infections is a controversial issue, although the contribution of this cytokine to host defense against extracellular bacterial pathogens has been well established. In this study, we focused on an intra-cellular bacterium, Chlamydia, and evaluated the production and function of IL-22 in host defense against chlamydial lung infection using a mouse model. We found that Chlamydia muridarum infection elicited quick IL-22 responses in the lung, which increased during infection and were reduced when bacterial loads decreased. More importantly, blockade of endogenous IL-22 using neutralizing anti-IL-22 monoclonal antibodies (mAb) resulted in more severe disease in the mice, leading to significantly higher weight loss and bacterial growth and much more severe pathological changes than treatment with isotype control antibody. Immunological analyses identified significantly lower T helper 1 (Th1) and Th17 responses in the IL-22–neutralized mice. In contrast, intranasal administration of exogenous IL-22 significantly enhanced protection following chlamydial lung infection, which was associated with a significant increase of Th17 response. The data demonstrate that IL-22 is a critical cytokine, mediating host defense against chlamydial lung infection and coordinating the function of distinct Th-cell subsets, particularly Th1 and Th17, in the process. PMID:24531835

  5. CD301b+ dendritic cells suppress T follicular helper cells and antibody responses to protein antigens

    PubMed Central

    Kumamoto, Yosuke; Hirai, Toshiro; Wong, Patrick W; Kaplan, Daniel H; Iwasaki, Akiko

    2016-01-01

    Strong antibody response is considered a hallmark of a successful vaccine. While dendritic cells (DCs) are important for T follicular helper (Tfh) cell priming, how this process is regulated in vivo is unclear. We show here that the depletion of CD301b+ DCs specifically enhanced the development of Tfh cells, germinal center B cells and antibody responses against protein antigens. Exaggerated antibody responses in mice depleted of CD301b+ DCs occurred in the absence of any adjuvants, and resulting antibodies had broader specificity and higher affinity to the immunogen. CD301b+ DCs express high levels of PD-1 ligands, PD-L1 and PD-L2. Blocking PD-1 or PD-L1 during priming in wild-type mice partially mimicked the phenotype of CD301b+ DC-depleted animals, suggesting their role in Tfh suppression. Transient depletion of CD301b+ DC results in the generation of autoreactive IgG responses. These results revealed a novel regulatory mechanism and a key role of CD301b+ DCs in blocking autoantibody generation. DOI: http://dx.doi.org/10.7554/eLife.17979.001 PMID:27657168

  6. Expansion of circulating follicular T helper cells associates with disease severity in childhood atopic dermatitis.

    PubMed

    Szabó, Krisztina; Gáspár, Krisztián; Dajnoki, Zsolt; Papp, Gábor; Fábos, Beáta; Szegedi, Andrea; Zeher, Margit

    2017-09-01

    Follicular helper T (TFH) cells play crucial role in B-cell differentiation and antibody production. Although, atopic dermatitis (AD) is often associated with increased serum IgE levels, B-cell mediated responses have not been studied thoroughly. The aim of our study was to investigate the proportion of TFH-like cells in the disease. Twelve children and 17 adults with AD as well as 14 healthy controls were enrolled in the study. The frequency of CD4(+)CXCR5(+)ICOS(+)PD-1(+) TFH-like cells and their IL-21 cytokine production were determined by flow cytometry. Immunohistochemical analysis was performed on skin biopsy specimens from AD patients for the detection of TFH markers. The percentages and absolute numbers of circulating TFH-like cells were significantly increased in children with AD compared to adult patients and healthy controls. IL-21 cytokine production of TFH-like cells was also elevated and showed a strong positive correlation with paediatric patients' SCORAD index. The expression of TFH-specific markers showed only a non-specific scattered pattern in skin biopsy specimens. This is the first study to demonstrate that TFH-like cells expanded in the peripheral blood of children with AD compared to adults. These results reinforce the importance of further investigations on TFH-like cells in different phenotypes and endotypes of AD. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  7. Social genetic and social environment effects on parental and helper care in a cooperatively breeding bird.

    PubMed

    Adams, Mark James; Robinson, Matthew R; Mannarelli, Maria-Elena; Hatchwell, Ben J

    2015-07-07

    Phenotypes expressed in a social context are not only a function of the individual, but can also be shaped by the phenotypes of social partners. These social effects may play a major role in the evolution of cooperative breeding if social partners differ in the quality of care they provide and if individual carers adjust their effort in relation to that of other carers. When applying social effects models to wild study systems, it is also important to explore sources of individual plasticity that could masquerade as social effects. We studied offspring provisioning rates of parents and helpers in a wild population of long-tailed tits Aegithalos caudatus using a quantitative genetic framework to identify these social effects and partition them into genetic, permanent environment and current environment components. Controlling for other effects, individuals were consistent in their provisioning effort at a given nest, but adjusted their effort based on who was in their social group, indicating the presence of social effects. However, these social effects differed between years and social contexts, indicating a current environment effect, rather than indicating a genetic or permanent environment effect. While this study reveals the importance of examining environmental and genetic sources of social effects, the framework we present is entirely general, enabling a greater understanding of potentially important social effects within any ecological population.

  8. Bob1 limits cellular frequency of T‐follicular helper cells

    PubMed Central

    Yamashita, Keiji; Kawata, Koji; Matsumiya, Hiroshi; Kamekura, Ryuta; Jitsukawa, Sumito; Nagaya, Tomonori; Ogasawara, Noriko; Takano, Ken‐ichi; Kubo, Terufumi; Kimura, Sachiko; Shigehara, Katsunori; Himi, Tetsuo

    2016-01-01

    T follicular helper (Tfh) cells are involved in specific humoral immunity at initial and recall phases. The fact that the transcription repressors B‐cell lymphoma‐6 and Blimp‐1 determine lineages of Tfh cells and other types of effector CD4+ T cells, respectively, suggests that there are unique mechanisms to establish Tfh‐cell identity. In this study, we found that Tfh cells preferentially express the transcriptional coactivator Bob1. Bob1 of Tfh cells was dispensable for the expression of B‐cell lymphoma‐6 and the functional property of the cells for B cell help. However, upon initial immunization of foreign antigens, the percentages of Tfh cells in Bob1−/− mice were much higher than those in wild‐type (WT) mice. In addition, expansion of Tfh cells within Bob1−/−CD4+ T cells transferred into WT mice revealed that the high frequency of Tfh cells was caused by a T‐cell‐intrinsic mechanism. These findings were further supported by the results of in vitro studies demonstrating that Bob1−/− Tfh cells had greater proliferative activity in response to stimuli by CD3/CD28 monoclonal antibody and were also refractory to CD3‐induced cell death in comparison to WT Tfh cells. These results suggest that Tfh cells harbor a Bob1‐related mechanism to restrict numerical frequency against stimulation of TCRs. PMID:27080143

  9. TSLP-activated dendritic cells induce human T follicular helper cell differentiation through OX40-ligand.

    PubMed

    Pattarini, Lucia; Trichot, Coline; Bogiatzi, Sofia; Grandclaudon, Maximilien; Meller, Stephan; Keuylian, Zela; Durand, Melanie; Volpe, Elisabetta; Madonna, Stefania; Cavani, Andrea; Chiricozzi, Andrea; Romanelli, Marco; Hori, Toshiyuki; Hovnanian, Alain; Homey, Bernhard; Soumelis, Vassili

    2017-05-01

    T follicular helper cells (Tfh) are important regulators of humoral responses. Human Tfh polarization pathways have been thus far associated with Th1 and Th17 polarization pathways. How human Tfh cells differentiate in Th2-skewed environments is unknown. We show that thymic stromal lymphopoietin (TSLP)-activated dendritic cells (DCs) promote human Tfh differentiation from naive CD4 T cells. We identified a novel population, distinct from Th2 cells, expressing IL-21 and TNF, suggestive of inflammatory cells. TSLP-induced T cells expressed CXCR5, CXCL13, ICOS, PD1, BCL6, BTLA, and SAP, among other Tfh markers. Functionally, TSLP-DC-polarized T cells induced IgE secretion by memory B cells, and this depended on IL-4Rα. TSLP-activated DCs stimulated circulating memory Tfh cells to produce IL-21 and CXCL13. Mechanistically, TSLP-induced Tfh differentiation depended on OX40-ligand, but not on ICOS-ligand. Our results delineate a pathway of human Tfh differentiation in Th2 environments. © 2017 Pattarini et al.

  10. The role of costimulatory molecules in directing the functional differentiation of alloreactive T helper cells.

    PubMed

    Magee, C N; Boenisch, O; Najafian, N

    2012-10-01

    Costimulatory molecules are a heterogenous group of cell surface molecules that act to amplify or counteract the initial activating signals provided to T cells from the T cell receptor following its interaction with an antigen/major histocompatibility complex, thereby influencing T cell differentiation and fate. Although costimulation was previously thought to be indispensable for T cell activation at all stages of development, it is now known that the requirements for costimulation, and the costimulatory molecules involved, vary according to the stage of T cell differentiation. The ability to influence T cell fate is of paramount interest in the field of transplantation as we seek therapeutic options that inhibit detrimental alloimmune responses whilst simultaneously promoting allograft tolerance. As with many immune mechanisms, there is a degree of functional overlap between certain costimulatory molecules, whereas some have diametrically opposite effects on different T cell subsets despite sharing common ligands. This is a critical point when considering these molecules as therapeutic targets in transplantation, as blockade of a costimulatory pathway, although desirable in itself, may prevent the ligation of an essential regulatory coinhibitory molecule. This review discusses the T helper cell lineages pertinent to transplantation and the costimulatory molecules involved in their differentiation. © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.

  11. Innate functions of immunoglobulin M lessen liver gene transfer with helper-dependent adenovirus.

    PubMed

    Unzu, Carmen; Melero, Ignacio; Morales-Kastresana, Aizea; Sampedro, Ana; Serrano-Mendioroz, Irantzu; Azpilikueta, Arantza; Ochoa, María Carmen; Dubrot, Juan; Martínez-Ansó, Eduardo; Fontanellas, Antonio

    2014-01-01

    The immune system poses obstacles to viral vectors, even in the first administration to preimmunized hosts. We have observed that the livers of B cell-deficient mice were more effectively transduced by a helper-dependent adenovirus serotype-5 (HDA) vector than those of WT mice. This effect was T-cell independent as shown in athymic mice. Passive transfer of the serum from adenovirus-naïve WT to Rag1KO mice resulted in a reduction in gene transfer that was traced to IgM purified from serum of adenovirus-naïve mice. To ascribe the gene transfer inhibition activity to either adenoviral antigen-specific or antigen-unspecific functions of IgM, we used a monoclonal IgM antibody of unrelated specificity. Both the polyclonal and the irrelevant monoclonal IgM inhibited gene transfer by the HDA vector to either cultured hepatocellular carcinoma cells or to the liver of mice in vivo. Adsorption of polyclonal or monoclonal IgMs to viral capsids was revealed by ELISAs on adenovirus-coated plates. These observations indicate the existence of an inborn IgM mechanism deployed against a prevalent virus to reduce early post-infection viremia. In conclusion, innate IgM binding to adenovirus serotype-5 capsids restrains gene-transfer and offers a mechanism to be targeted for optimization of vector dosage in gene therapy with HDA vectors.

  12. Influence of helper T cells on the expression of a murine intrastrain crossreactive idiotype.

    PubMed Central

    Hathcock, K S; Gurish, M F; Nisonoff, A; Conger, J D; Hodes, R J

    1986-01-01

    The requirement for idiotype-specific helper T (Th) cells in the generation of a major intrastrain crossreactive idiotype was investigated. This idiotype, designated CRIA, is associated with a large proportion of anti-p-azobenzenearsonate (anti-Ar) antibodies in A/J mice. Secondary in vitro responses were studied. Using carrier-primed heterogeneous Th-cell populations, it was found that CRIA expression is determined by the mouse strain that provides the responding B cells and is independent of the strain of the Th cells functioning in vitro. Thus, A/J or A.BY (Ighe) B-plus-accessory-cell populations, primed in vivo to keyhole limpet hemocyanin-Ar (KLH-Ar), generated CRIA-dominant responses in vitro in the presence of KLH-Ar regardless of whether the KLH-primed Th cells were derived from CRIA+ strains (A/J or A.BY, Ighe) or CRIA- strains (B10.A or C57BL/10, Ighb). Further, when major histocompatibility complex-restricted, KLH-specific Th-cell clones were used, the CRIA dominance of the Ar-specific responses was again determined by the strain providing B plus accessory cells. Similar levels of expression of CRIA in Ar-specific antibodies were generated in the presence of heterogeneous or cloned Th cells. The results suggest that there is no absolute requirement for idiotype-specific Th cells in generating an Ar-specific secondary antibody response in vitro. PMID:2934739

  13. T-helper 17 cells: the driving force of psoriasis and psoriatic arthritis.

    PubMed

    Yoo, In Seol; Lee, Jeung Hoon; Song, Seung Tak; Kim, Jin Hyun; Lee, Hyun Ji; Kang, Seong Wook

    2012-12-01

    There is growing evidence that two recently recognized, unique subsets of CD4(+) T-cells, T-helper 17 cells (Th17) and CD4(+) CD25(+) regulatory T-cells (Treg), may play important roles in the pathogenesis of psoriasis. This study sought to investigate the relationship between Th17 cells and psoriasis or psoriatic arthritis (PsA). Peripheral blood CD4(+) T-cells were isolated from 47 patients with psoriasis and 47 controls, and were cultured under various stimulatory conditions. The Th17 cells and regulatory Treg cells were detected by flow cytometry. Plasma interleukin (IL)-17 was measured by enzyme-linked immunosorbent assay. The proportion of Th17 and Treg cells from peripheral blood mononuclear cells showed no difference between patients with psoriasis and controls. However, psoriasis and PsA patients demonstrated a higher proportion of induced Th17 cells, which was correlated with psoriasis area severity index score. The level of plasma IL-17A in psoriasis was higher than that in controls. Th17 cells may play important roles in the pathogenesis of psoriasis and psoriatic arthritis. © 2012 The Authors International Journal of Rheumatic Diseases © 2012 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  14. Pathogenic T helper type 17 cells contribute to type 1 diabetes independently of interleukin-22.

    PubMed

    Bellemore, S M; Nikoopour, E; Krougly, O; Lee-Chan, E; Fouser, L A; Singh, B

    2016-03-01

    We have shown that pathogenic T helper type 17 (Th17) cells differentiated from naive CD4(+) T cells of BDC2·5 T cell receptor transgenic non-obese diabetic (NOD) mice by interleukin (IL)-23 plus IL-6 produce IL-17, IL-22 and induce type 1 diabetes (T1D). Neutralizing interferon (IFN)-γ during the polarization process leads to a significant increase in IL-22 production by these Th17 cells. We also isolated IL-22-producing Th17 cells from the pancreas of wild-type diabetic NOD mice. IL-27 also blocked IL-22 production from diabetogenic Th17 cells. To determine the functional role of IL-22 produced by pathogenic Th17 cells in T1D we neutralized IL-22 in vivo by using anti-IL-22 monoclonal antibody. We found that blocking IL-22 did not alter significantly adoptive transfer of disease by pathogenic Th17 cells. Therefore, IL-22 is not required for T1D pathogenesis. The IL-22Rα receptor for IL-22 however, increased in the pancreas of NOD mice during disease progression and based upon our and other studies we suggest that IL-22 may have a regenerative and protective role in the pancreatic islets. © 2015 British Society for Immunology.

  15. Theory and experimental validation of SPLASH (Single Panel Lamp and Shroud Helper).

    SciTech Connect

    Larsen, Marvin Elwood; Porter, Jason M.

    2005-06-01

    The radiant heat test facility develops test sets providing well-characterized thermal environments, often representing fires. Many of the components and procedures have become standardized to such an extent that the development of a specialized design tool was appropriate. SPLASH (Single Panel Lamp and Shroud Helper) is that tool. SPLASH is implemented as a user-friendly program that allows a designer to describe a test setup in terms of parameters such as lamp number, power, position, and separation distance. Thermal radiation is the dominant mechanism of heat transfer and the SPLASH model solves a radiation enclosure problem to estimate temperature distributions in a shroud providing the boundary condition of interest. Irradiance distribution on a specified viewing plane is also estimated. This document provides the theoretical development for the underlying model. A series of tests were conducted to characterize SPLASH's ability to analyze lamp and shroud systems. The comparison suggests that SPLASH succeeds as a design tool. Simplifications made to keep the model tractable are demonstrated to result in estimates that are only approximately as uncertain as many of the properties and characteristics of the operating environment.

  16. Follicular Helper CD4+ T Cells in Human Neuroautoimmune Diseases and Their Animal Models.

    PubMed

    Fan, Xueli; Lin, Chenhong; Han, Jinming; Jiang, Xinmei; Zhu, Jie; Jin, Tao

    2015-01-01

    Follicular helper CD4(+) T (TFH) cells play a fundamental role in humoral immunity deriving from their ability to provide help for germinal center (GC) formation, B cell differentiation into plasma cells and memory cells, and antibody production in secondary lymphoid tissues. TFH cells can be identified by a combination of markers, including the chemokine receptor CXCR5, costimulatory molecules ICOS and PD-1, transcription repressor Bcl-6, and cytokine IL-21. It is difficult and impossible to get access to secondary lymphoid tissues in humans, so studies are usually performed with human peripheral blood samples as circulating counterparts of tissue TFH cells. A balance of TFH cell generation and function is critical for protective antibody response, whereas overactivation of TFH cells or overexpression of TFH-associated molecules may result in autoimmune diseases. Emerging data have shown that TFH cells and TFH-associated molecules may be involved in the pathogenesis of neuroautoimmune diseases including multiple sclerosis (MS), neuromyelitis optica (NMO)/neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). This review summarizes the features of TFH cells, including their development, function, and roles as well as TFH-associated molecules in neuroautoimmune diseases and their animal models.

  17. T Helper 17 Cells Interplay with CD4+CD25highFoxp3+ Tregs in Regulation of Inflammations and Autoimmune Diseases

    PubMed Central

    Mai, Jietang; Wang, Hong; Yang#, Xiao-Feng

    2010-01-01

    Interleukin-17 (IL-17)-secreting T helper 17 cells (Th17) are a recently identified CD4+ T helper subset that has been implicated in various inflammatory and autoimmune diseases. Th17, along with CD4+CD25high Foxp3+ regulatory T cells (Tregs) and other newly emergent T helper subsets, Th9 and Tfh, have expanded the Th1-Th2 paradigm. Although this newly proposed six-subset paradigm significantly improved our understanding on the differentiation of CD4+ T helper cell subsets and the regulation of T helper cells in inflammation and autoimmunity, many questions remain to be answered. In this overview, we will briefly review the following issues: a) Old Th1-Th2 paradigm versus new multi-subset paradigm; b) Structural features of IL-17 family cytokines; c) Th17 cells; d) Effects of IL-17 on various cell types and tissues; e) IL-17 receptor and signaling pathways; f) Th17-mediated inflammations; and g) Protective mechanisms of IL-17 in infections. Lastly, we will look into the interaction of Th17 and Treg in autoimmune diseases and inflammation: Th17 cells interplay with Tregs. Regulation of autoimmunity and inflammation lies in the interplays of the different T helper subsets, therefore, better understanding of these subsets’ interactions with one another would greatly improve our approaches in developing therapy to combat inflammatory and autoimmune diseases. PMID:20515737

  18. [Effects of helper protein P20 from Bacillus thuringiensis on Vip3A expression].

    PubMed

    Shi, Yong-xia; Yuan, Mei-jin; Chen, Jian-wu; Sun, Fan; Pang, Yi

    2006-02-01

    Insecticidal crystal proteins (ICPs) produced in Bacillus thuringiensis accumulate as crystalline inclusions that represent up to 30% of total dry weight the cell produces. The mechanisms of in vivo crystallization of these insecticidal proteins remain interests, yet unclear. A 20-kDa protein (P20), the product of the third open reading frame of cry11A operon in B. thuringiensis subsp. israelensis has been defined to be an important molecular chaperone (helper protein) for forming Cyt1A crystal and enhancing Cry11A expression. The novel vegetative insecticidal proteins (VIPs) are secreted outside the cell of B. thuringiensis during mid-logarithmic growth. VIP3A shows activity against many lepidopteran insect larvae in a different mechanism from that of ICPs. To investigate the influence of helper protein P20 on Vip3A production and its insecticidal activity, P20 was coexpressed with Vip3A protein in B. thuringiensis and the yields and insecticidal toxicity of Vip3A were also analyzed. The recombinant plasmid pHVP20 was constructed by inserting a 5.4kb foreign fragment containing both vip3A gene and p20 gene into the shuttle vector pHT3101. The plasmid pHPT3 only containing vip3A gene was used as control. pHVP20 and pHPT3 were transformed into the B. thuringiensis acrystalliferous strain CryB not containing vip3A gene by electroporation. The obtained B. thuringiensis transformants were CryB(pHVP20) and CryB(pHPT3) respectively. Western blot showed that Vip3A protein reached its maximum yield after 48h of CryB (pHVP20) growth and remained high expression level during the sporulation. The maximum yield of Vip3A protein in CryB (pHVP20) was about 1.5 fold as compared with that in CryB(pHPT3) by the mean of ImageMaster VDS software. It is considered that P20 might combine with the native Vip3A protein during the sporulation, stabilize Vip3A and protect Vip3A from unspecific full proteolysis. Bioassay showed that the cell pellets of CryB (pHVP20) and CryB(pHPT3

  19. Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection.

    PubMed

    Cubas, Rafael; van Grevenynghe, Julien; Wills, Saintedym; Kardava, Lela; Santich, Brian H; Buckner, Clarisa M; Muir, Roshell; Tardif, Virginie; Nichols, Carmen; Procopio, Francesco; He, Zhong; Metcalf, Talibah; Ghneim, Khader; Locci, Michela; Ancuta, Petronella; Routy, Jean-Pierre; Trautmann, Lydie; Li, Yuxing; McDermott, Adrian B; Koup, Rick A; Petrovas, Constantinos; Migueles, Steven A; Connors, Mark; Tomaras, Georgia D; Moir, Susan; Crotty, Shane; Haddad, Elias K

    2015-12-15

    Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2-responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART.

  20. Development of T follicular helper cells and their role in disease and immune system.

    PubMed

    Eivazi, Sadegh; Bagheri, Salman; Hashemzadeh, Mohammad Sadegh; Ghalavand, Majdedin; Qamsari, Elmira Safaie; Dorostkar, Ruhollah; Yasemi, Maryam

    2016-12-01

    The T follicular helper cells (TFH) are a subset of CD4+ T cells specialized to regulate antibody responses. The production of these cells is associated with the dendritic cells (DCs) and B cells. TFH cells help B cells form germinal centers (GC) differentiate into memory and plasma cells (antibody-secreting cells) as humoral responses. In addition, there is strong evidence that TFH cells play a pivotal role in the development of long-lived humoral immunity. Molecular factors such as transcription factors, surface receptors, cytokine and micro RNAs are involved in the formation of TFH cells. Such TFH cells are diagnosed by transcription factor (BCL-6), surface marker expression (including CXCR5, PD-1, ICOS and CD40L) and a unique cytokine production pattern (such as IL-21 and IL-6). Memory TFH cells, accompanied by memory B cells, are known to be formed during antibody responses. It is now clear that the precise control of TFH cells is critically important for both inducing the optimal affinity maturation of antibody responses and preventing self-reactivity. Exclusive controls of TFH cell function and production are essential for human health. However, it is important to note that excessive activities may lead to autoimmune diseases, while reduced activity often results in immunodeficiency. It has also been shown that TFH cells are associated with cancers such as angioimmunoblastic T-cell lymphoma (AITL), follicular T-cell lymphoma (FTCL) and nonspecific Peripheral T-cell lymphomas (PTCLs). The biology of TFH cells, including their differentiation and transcriptional regulation will be described in the present review. Some of The developments of these cells in immunodeficiency diseases, autoimmunity and cancer will also be taken into account.

  1. T-helper 1 immunoreaction influences survival in muscle-invasive bladder cancer: proof of concept

    PubMed Central

    Ingels, Alexandre; Sanchez Salas, Rafael E.; Ravery, Vincent; Fromont-Hankard, Gaëlle; Validire, Pierre; Patard, Jean-Jacques; Pignot, Géraldine; Prapotnich, Dominique; Olivier, Fabien; Galiano, Marc; Barret, Eric; Rozet, Francois; Weber, Nina; Cathelineau, Xavier

    2014-01-01

    Objective To define immunoscore in bladder cancer studying T helper 1 (Th1) immunoreaction. To define a cancer-specific survival model based on Th1 cells infiltration. Methods A total of 252 patients underwent primary transurethral resection of bladder tumour at our Institution. A retrospective review of a selected cohort with pT1 and muscle-invasive bladder cancer (MIBC) lesions was performed. Pathology blocks were marked with CD3 and CD8 antibodies. Immune cells density in stromal reaction (SR) was measured on five distinct high-power field (HPF) by two dedicated uro-pathologist blinded for patients’ evolution. Statistics Student test or non-parametric Wilcoxon test as appropriate to compare means between two groups. Receiver operating characteristics (ROC) curve to define markers threshold. Cox model to assess survival’s predictors. Results Ten pT1 and 20 MIBC consecutive cases were analysed. Median follow-up was 33.4 months. Immunohistological analysis for pT1 lesions featured limited SR. For MIBC, the mean density of lymphocytes in the SR was of 105/HPF (CD3) and 86/HPF (CD8). Survivors harboured higher lymphocytes densities versus non survivors (CD3: p = 0.0319; CD8: p = 0.0279). CD3 (p = 0.034) and CD8 (p = 0.034) lymphocytes densities were independently associated with cancer-specific survival on Cox model analyses. The retrospective design and small size of cohorts are the study limitations. Conclusions High CD3 and CD8 lymphocytes SR densities are associated with better cancer-specific survival for MIBC. Th1 reaction against the tumour seems to be protective for bladder cancer. Further evaluation is warranted. PMID:25525464

  2. Interleukin-9 over-expression and T helper 9 polarization in systemic sclerosis patients.

    PubMed

    Guggino, G; Lo Pizzo, M; Di Liberto, D; Rizzo, A; Cipriani, P; Ruscitti, P; Candore, G; Gambino, C M; Sireci, G; Dieli, F; Giacomelli, R; Triolo, G; Ciccia, F

    2017-11-01

    T helper 9 (Th9) cells and interleukin (IL)-9 are involved in the pathogenesis of several autoimmune diseases. The exact role of IL-9 and Th9 cells in patients with systemic sclerosis (SSc) have not yet been studied adequately. IL-9, IL-9R, transcription factor PU.1 (PU.1), IL-4, thymic stromal lymphopoietin (TSLP) and transforming growth factor (TGF)-β expression were assessed in skin and kidney biopsies of SSc patients and healthy controls (HC) by immunohistochemistry (IHC). The cellular source of IL-9 was also analysed by confocal microscopy analysis. Peripheral IL-9-producing cells were also studied by flow cytometry. The functional relevance of IL-9 increased expression in SSc was also investigated. Our results demonstrated a strong expression of IL-9, IL-9R, IL-4, TSLP and TGF-β in skin tissues of patients with both limited and diffuse SSc. IL-9 expression was observed mainly in the context of skin infiltrating mononuclear cells and keratinizing squamous epithelium. IL-9 over-expression was also observed in renal biopsies of patients with SSc. IL-9 producing cells in the skin were identified as Th9 cells. Similarly, Th9 cells were expanded and were the major source of IL-9 among SSc peripheral blood mononuclear cells (PBMC), their percentage being correlated directly with the modified Rodnan skin score. Infiltrating mononuclear cells, mast cells and neutrophils expressed IL-9R. In in-vitro studies stimulation with rIL-9 significantly induced NET (neutrophil extracellular traps) release by dying cells (NETosis) in neutrophils, expansion of mast cells and increase of anti-systemic scleroderma 70 (Scl70) production by B cells. Our findings suggest that Th9 cells and IL-9 could be implicated in the pathogenesis of SSc. © 2017 British Society for Immunology.

  3. An evaluation of three-dimensional sensors for the extravehicular activity helper/retreiver

    NASA Technical Reports Server (NTRS)

    Magee, Michael

    1993-01-01

    The Extravehicular Activity Retriever/Helper (EVAHR) is a robotic device currently under development at the NASA Johnson Space Center that is designed to fetch objects or to assist in retrieving an astronaut who may have become inadvertently de-tethered. The EVAHR will be required to exhibit a high degree of intelligent autonomous operation and will base much of its reasoning upon information obtained from one or more three-dimensional sensors that it will carry and control. At the highest level of visual cognition and reasoning, the EVAHR will be required to detect objects, recognize them, and estimate their spatial orientation and location. The recognition phase and estimation of spatial pose will depend on the ability of the vision system to reliably extract geometric features of the objects such as whether the surface topologies observed are planar or curved and the spatial relationships between the component surfaces. In order to achieve these tasks, accurate sensing of the operational environment and objects in the environment will therefore be critical. The qualitative and quantitative results of empirical studies of three sensors that are capable of providing three-dimensional information to the EVAHR, but using completely different hardware approaches are documented. The first of these devices is a phase shift laser with an effective operating range (ambiguity interval) of approximately 15 meters. The second sensor is a laser triangulation system designed to operate at much closer range and to provide higher resolution images. The third sensor is a dual camera stereo imaging system from which range images can also be obtained. The remainder of the report characterizes the strengths and weaknesses of each of these systems relative to quality of data extracted and how different object characteristics affect sensor operation.

  4. Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model

    PubMed Central

    Simão, Daniel; Pinto, Catarina; Fernandes, Paulo; Peddie, Christopher J.; Piersanti, Stefania; Collinson, Lucy M.; Salinas, Sara; Saggio, Isabella; Schiavo, Giampietro; Kremer, Eric J.; Brito, Catarina; Alves, Paula M.

    2017-01-01

    Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in pre-clinical tests. For clinical translation, in-depth pre-clinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, while human adenovirus type 5 (HAdV5) showed increased tropism towards glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity. PMID:26181626

  5. Do Helper T Cell Subtypes in Lymphocytic Thyroiditis Play a Role in the Antitumor Effect?

    PubMed Central

    Yang, Seok Woo; Kang, Seong-Ho; Kim, Kyung Rae; Choi, In Hong; Chang, Hang Seok; Oh, Young Lyun; Hong, Soon Won

    2016-01-01

    Background Papillary thyroid carcinoma (PTC) is frequently accompanied by lymphocytic thyroiditis (LT). Some reports claim that Hashimoto’s thyroiditis (the clinical form of LT) enhances the likelihood of PTC; however, others suggest that LT has antitumor activity. This study was aimed to find out the relationship between the patterns of helper T cell (Th) cytokines in thyroid tissue of PTC with or without LT and the clinicopathological manifestation of PTC. Methods Fresh surgical samples of PTC with (13 cases) or without (10 cases) LT were used. The prognostic parameters (tumor size, extra-thyroidal extension of PTC, and lymph node metastasis) were analyzed. The mRNA levels of two subtypes of Th cytokines, Th1 (tumor necrosis factor α [TNF-α], interferon γ [IFN-γ ], and interleukin [IL] 2) and Th2 (IL-4 and IL-10), were analyzed. Because most PTC cases were microcarcinomas and recent cases without clinical follow-up, negative or faint p27 immunoreactivity was used as a surrogate marker for lymph node metastasis. Results PTC with LT cases showed significantly higher expression of TNF-α (p = .043), IFN-γ (p < .010), IL-4 (p = .015) than those without LT cases. Although the data were not statistically significant, all analyzed cytokines (except for IL-4) were highly expressed in the cases with higher expression of p27 surrogate marker. Conclusions These results indicate that mixed Th1 (TNF-α, IFN-γ , and IL-2) and Th2 (IL-10) immunity might play a role in the antitumor effect in terms of lymph node metastasis. PMID:27681413

  6. T helper 17 cells play a critical pathogenic role in lung cancer

    PubMed Central

    Chang, Seon Hee; Mirabolfathinejad, Seyedeh Golsar; Katta, Harshadadevi; Cumpian, Amber M.; Gong, Lei; Caetano, Mauricio S.; Moghaddam, Seyed Javad; Dong, Chen

    2014-01-01

    Lung cancer development is associated with extensive pulmonary inflammation. In addition, the linkage between chronic obstructive pulmonary disease (COPD) and lung cancer has been demonstrated in population-based studies. IL-17–producing CD4 helper T cells (Th17 cells) play a critical role in promoting chronic tissue inflammation. Although Th17 cells are found in human COPD and lung cancer, their role is not understood. We have thus used a mouse model of lung cancer, in which an oncogenic form of K-ras (K-rasG12D), frequently found in human lung cancer, is restrictedly expressed in lung epithelial cells [via Clara cell secretory protein (CCSPcre)]. In this model, Th17 and Treg but not Th1 cells were found enriched at the tumor tissues. When CCSPcre/K-rasG12D mice were weekly challenged with a lysate of nontypeable Haemophilus influenza (NTHi), which induces COPD-type inflammation and accelerates the tumor growth, they showed greatly enhanced Th17 cell infiltration in the lung tissues. Lack of IL-17, but not IL-17F, resulted in a significant reduction in lung tumor numbers in CCSPcre/K-rasG12D mice and also those treated with NTHi. Absence of IL-17 not only resulted in reduction of tumor cell proliferation and angiogenesis, but also decreased the expression of proinflammatory mediators and reduced recruitment of myeloid cells. Depletion of Gr-1+CD11b+ myeloid cells in CCSPcre/K-rasG12D mice suppressed tumor growth in lung, indicating Gr-1+CD11b+ myeloid cells recruited by IL-17 play a protumor role. Taken together, our data demonstrate a critical role for Th17 cell-mediated inflammation in lung tumorigenesis and suggest a novel way for prevention and treatment of this disease. PMID:24706787

  7. Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection

    PubMed Central

    Cubas, Rafael; van Grevenynghe, Julien; Wills, Saintedym; Kardava, Lela; Santich, Brian H.; Buckner, Clarisa M.; Muir, Roshell; Tardif, Virginie; Nichols, Carmen; Procopio, Francesco; He, Zhong; Metcalf, Talibah; Ghneim, Khader; Locci, Michela; Ancuta, Petronella; Routy, Jean-Pierre; Trautmann, Lydie; Li, Yuxing; McDermott, Adrian B.; Koup, Rick A.; Petrovas, Constantinos; Migueles, Steven A.; Connors, Mark; Tomaras, Georgia D.; Moir, Susan; Crotty, Shane

    2015-01-01

    Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2–responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART. PMID:26546609

  8. PEGylation of bacteriophages increases blood circulation time and reduces T‐helper type 1 immune response

    PubMed Central

    Kim, Kwang‐Pyo; Cha, Jeong‐Dan; Jang, Eun‐Hye; Klumpp, Jochen; Hagens, Steven; Hardt, Wolf‐Dietrich; Lee, Kyung‐Yeol; Loessner, Martin J.

    2008-01-01

    Summary The increasing occurrence of antibiotic‐resistant pathogens is of growing concern, and must be counteracted by alternative antimicrobial treatments. Bacteriophages represent the natural enemies of bacteria. However, the strong immune response following application of phages and rapid clearance from the blood stream are hurdles which need to be overcome. Towards our goal to render phages less immunogenic and prolong blood circulation time, we have chemically modified intact bacteriophages by conjugation of the non‐immunogenic polymer monomethoxy‐polyethylene glycol (mPEG) to virus proteins. As a proof of concept, we have used two different polyvalent and strictly virulent phages of the Myoviridae, representing typical candidates for therapeutical approaches: Felix‐O1 (infects Salmonella) and A511 (infects Listeria). Loss of phage infectivity after PEGylation was found to be proportional to the degree of modification, and could be conveniently controlled by adjusting the PEG concentration. When injected into naïve mice, PEGylated phages showed a strong increase in circulation half‐life, whereas challenge of immunized mice did not reveal a significant difference. Our results suggest that the prolonged half‐life is due to decreased susceptibility to innate immunity as well as avoidance of cellular defence mechanisms. PEGylated viruses elicited significantly reduced levels of T‐helper type 1‐associated cytokine release (IFN‐γ and IL‐6), in both naïve and immunized mice. This is the first study demonstrating that PEGylation can increases survival of infective phage by delaying immune responses, and indicates that this approach can increase efficacy of bacteriophage therapy. PMID:21261844

  9. Increased circulating T‑helper 22 cells in patients with dilated cardiomyopathy.

    PubMed

    Kong, Qing; Li, Xiaomo; Wu, Weifeng; Yang, Fan; Liu, Yanli; Lai, Wenyin; Pan, Xiaofen; Gao, Mengsha; Xue, Yimin

    2014-07-01

    Recently, the newly determined interleukin (IL)‑22‑producing T-helper (Th) 22 cell has been implicated to be involved in the pathogenesis of autoimmune diseases. However, its role in the pathogenesis of dilated cardiomyopathy (DCM) has yet to be elucidated. A total of 30 patients with DCM and 30 healthy controls were enrolled in the present study. The levels of Th22, Th17 and Th1 cells in the peripheral blood were analyzed by flow cytometry. Levels of plasma IL‑22 and autoantibody adenine nucleotide translocator (ANT) were assessed using the ELISA. The key transcription factor of Th22, aryl hydrocarbon receptor (AHR), was assessed using quantitative polymerase chain reaction. Additionally, clinical data on the brain natriuretic peptide (BNP), C‑reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were collected. In comparison with those in the control group, significantly elevated levels of Th22, Th17 and Th1 cells were detected in patients with DCM (all P<0.01). Similarly, elevated mRNA levels of peripheral AHR were detected in patients with DCM. The percentage of Th22 cells was higher in ANT‑positive compared with ANT‑negative patients with DCM. The levels of BNP and CRP, but not ESR, showed a significant positive correlation with those of Th22 cells. With regard to the concentrations of plasma IL‑22, no statistical difference was found between patients with DCM and the healthy controls, nor did it demonstrate a statistical correlation with the percentage of Th22 cells. In conclusion, the present study showed that patients with DCM, particularly those of the ANT autoantibody positive subjects, exhibit elevated levels of peripheral Th22 cells, indicating that a Th22 immune response may be implicated in the pathogenesis of DCM.

  10. Pancreatic Transduction by Helper-Dependent Adenoviral Vectors via Intraductal Delivery

    PubMed Central

    Morró, Meritxell; Teichenne, Joan; Jimenez, Veronica; Kratzer, Ramona; Marletta, Serena; Maggioni, Luca; Mallol, Cristina; Ruberte, Jesus; Kochanek, Stefan; Bosch, Fatima

    2014-01-01

    Abstract Pancreatic gene transfer could be useful to treat several diseases, such as diabetes mellitus, cystic fibrosis, chronic pancreatitis, or pancreatic cancer. Helper-dependent adenoviral vectors (HDAds) are promising tools for gene therapy because of their large cloning capacity, high levels of transgene expression, and long-term persistence in immunocompetent animals. Nevertheless, the ability of HDAds to transduce the pancreas in vivo has not been investigated yet. Here, we have generated HDAds carrying pancreas-specific expression cassettes, that is, driven either by the elastase or insulin promoter, using a novel and convenient plasmid family and homologous recombination in bacteria. These HDAds were delivered to the pancreas of immunocompetent mice via intrapancreatic duct injection. HDAds, encoding a CMV-GFP reporter cassette, were able to transduce acinar and islet cells, but transgene expression was lost 15 days postinjection in correlation with severe lymphocytic infiltration. When HDAds encoding GFP under the control of the specific elastase promoter were used, expression was detected in acinar cells, but similarly, the expression almost disappeared 30 days postinjection and lymphocytic infiltration was also observed. In contrast, long-term transgene expression (>8 months) was achieved with HDAds carrying the insulin promoter and the secretable alkaline phosphatase as the reporter gene. Notably, transduction of the liver, the preferred target for adenovirus, was minimal by this route of delivery. These data indicate that HDAds could be used for pancreatic gene therapy but that selection of the expression cassette is of critical importance to achieve long-term expression of the transgene in this tissue. PMID:25046147

  11. Chitin recognition via chitotriosidase promotes pathologic type-2 helper T cell responses to cryptococcal infection.

    PubMed

    Wiesner, Darin L; Specht, Charles A; Lee, Chrono K; Smith, Kyle D; Mukaremera, Liliane; Lee, S Thera; Lee, Chun G; Elias, Jack A; Nielsen, Judith N; Boulware, David R; Bohjanen, Paul R; Jenkins, Marc K; Levitz, Stuart M; Nielsen, Kirsten

    2015-03-01

    Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection.

  12. Impaired Phenotype and Function of T Follicular Helper Cells in HIV-1-Infected Children Receiving ART.

    PubMed

    Bekele, Yonas; Amu, Sylvie; Bobosha, Kidist; Lantto, Rebecka; Nilsson, Anna; Endale, Birtukan; Gebre, Meseret; Aseffa, Abraham; Rethi, Bence; Howe, Rawleigh; Chiodi, Francesca

    2015-07-01

    T follicular helper (Tfh) cells are important components in development of specific humoral immune responses; whether the number and biology of Tfh cells is impaired in HIV-1-infected children is not yet studied.The frequency, phenotype, and function of Tfh cells and B cells were determined in blood of HIV-1-infected children receiving antiretroviral therapy (ART) and age-matched controls. Flow cytometry was used to characterize the frequency of Tfh cells and B cell subsets. Cytokine expression was measured after in vitro activation of Tfh cells.A reduced frequency of memory Tfh cells (P < 0.001) was identified in HIV-1-infected children and, on these cells, a reduced expression of programmed death-1 (PD-1) and inducible T cell costimulator (ICOS) (P < 0.001 and P < 0.01). Upon activation, the capacity of Tfh cells to express IL-4, an important cytokine for B cell function, was impaired in HIV-1-infected children.B cell subpopulations in HIV-1-infected children displayed significant differences from the control group: the frequency of resting memory (RM) B cells was reduced (P < 0.01) whereas the frequency of exhausted memory B cells increased (P < 0.001). Interestingly, the decline of RM cells correlated with the reduction of memory Tfh cells (P = 0.02).Our study shows that function and phenotype of Tfh cells, pivotal cells for establishment of adaptive B cell responses, are impaired during HIV-1 infection in children. A consistent reduction of memory Tfh cells is associated with declined frequencies of RM B cells, creating a novel link between dysfunctional features of these cell types, major players in establishment of humoral immunity.

  13. Bcl6 and Maf cooperate to instruct human follicular helper CD4 T cell differentiation.

    PubMed

    Kroenke, Mark A; Eto, Danelle; Locci, Michela; Cho, Michael; Davidson, Terence; Haddad, Elias K; Crotty, Shane

    2012-04-15

    Follicular helper CD4 T (Tfh) cells provide B cells with signals that are important for the generation of high-affinity Abs and immunological memory and, therefore, are critical for the protective immunity elicited by most human vaccines. Transcriptional regulators of human Tfh cell differentiation are poorly understood. In this article, we demonstrate that Bcl6 controls specific gene modules for human Tfh cell differentiation. The introduction of Bcl6 expression in primary human CD4 T cells resulted in the regulation of a core set of migration genes that enable trafficking to germinal centers: CXCR4, CXCR5, CCR7, and EBI2. Bcl6 expression also induced a module of protein expression critical for T-B interactions, including SAP, CD40L, PD-1, ICOS, and CXCL13. This constitutes direct evidence for Bcl6 control of most of these functions and includes three genes known to be loci of severe human genetic immunodeficiencies (CD40L, SH2D1A, and ICOS). Introduction of Bcl6 did not alter the expression of IL-21 or IL-4, the primary cytokines of human Tfh cells. We show in this article that introduction of Maf (c-Maf) does induce the capacity to express IL-21. Surprisingly, Maf also induced CXCR5 expression. Coexpression of Bcl6 and Maf revealed that Bcl6 and Maf cooperate in the induction of CXCR4, PD-1, and ICOS. Altogether, these findings reveal that Bcl6 and Maf collaborate to orchestrate a suite of genes that define core characteristics of human Tfh cell biology.

  14. Nucleosomal peptide epitopes for nephritis-inducing T helper cells of murine lupus

    PubMed Central

    1996-01-01

    Nucleosome-specific T helper (Th) cells provide major histocompatibility complex class II-restricted, cognate help to nephritogenic antinuclear autoantibody-producing B cells in lupus. However, the lupus Th cells do not respond when components of the nucleosome, such as free DNA or histones, are individually presented by antigen-presenting cells. Thus critical peptide epitopes for the pathogenic Th cells are probably protected during uptake and processing of the native nucleosome particle as a whole. Therefore, herein we tested 145 overlapping peptides spanning all four core histones in the nucleosome. We localized three regions in core histones, one in H2B at amino acid position 10-33 (H2B(10-33)), and two in H4, at position 16- 39 (H4(16-39)) and position 71-94 (H4(71-94)), that contained the peptide epitopes recognized by the pathogenic autoantibody-inducing Th cells of lupus. The peptide autoepitopes also triggered the pathogenic Th cells of (SWR x NZB)F1 lupus mice in vivo to induce the development of severe lupus nephritis. The nucleosomal autoepitopes stimulated the production of Th1-type cytokines, consistent with immunoglobulin IgG2a, IgG2b, and IgG3 being the isotypes of nephritogenic autoantibodies induced in the lupus mice. Interestingly, the Th cell epitopes overlapped with regions in histones that contain B cell epitopes targeted by autoantibodies, as well as the sites where histones contact with DNA in the nucleosome. Identification of the disease-relevant autoepitopes in nucleosomes will help in understanding how the pathogenic Th cells of spontaneous systemic lupus erythematosus emerge, and potentially lead to the development of peptide-based tolerogenic therapy for this major autoimmune disease. PMID:8676066

  15. Germinal Center B Cell Depletion Diminishes CD4+ Follicular T Helper Cells in Autoimmune Mice

    PubMed Central

    Yusuf, Isharat; Stern, Jessica; McCaughtry, Tom M.; Gallagher, Sandra; Sun, Hong; Gao, Changshou; Tedder, Thomas; Carlesso, Gianluca; Carter, Laura; Herbst, Ronald; Wang, Yue

    2014-01-01

    Background Continuous support from follicular CD4+ T helper (Tfh) cells drives germinal center (GC) responses, which last for several weeks to produce high affinity memory B cells and plasma cells. In autoimmune Sle1 and NZB/W F1 mice, elevated numbers of Tfh cells persist, promoting the expansion of self-reactive B cells. Expansion of circulating Tfh like cells have also been described in several autoimmune diseases. Although, the signals required for Tfh differentiation have now been well described, the mechanisms that sustain the maintenance of fully differentiated Tfh are less understood. Recent data demonstrate a role for GC B cells for Tfh maintenance after protein immunization. Methods and Finding Given the pathogenic role Tfh play in autoimmune disease, we explored whether B cells are required for maintenance of autoreactive Tfh. Our data suggest that the number of mature autoreactive Tfh cells is controlled by GC B cells. Depletion of B cells in Sle1 autoimmune mice leads to a dramatic reduction in Tfh cells. In NZB/W F1 autoimmune mice, similar to the SRBC immunization model, GC B cells support the maintenance of mature Tfh, which is dependent mainly on ICOS. The CD28-associated pathway is dispensable for Tfh maintenance in SRBC immunized mice, but is required in the spontaneous NZB/W F1 model. Conclusion These data suggest that mature Tfh cells require signals from GC B cells to sustain their optimal numbers and function in both autoimmune and immunization models. Thus, immunotherapies targeting B cells in autoimmune disease may affect pathogenic Tfh cells. PMID:25101629

  16. Melatonin reduces inflammatory response in peripheral T helper lymphocytes from relapsing-remitting multiple sclerosis patients.

    PubMed

    Álvarez-Sánchez, Nuria; Cruz-Chamorro, Ivan; Díaz-Sánchez, María; Sarmiento-Soto, Helia; Medrano-Campillo, Pablo; Martínez-López, Alicia; Lardone, Patricia Judith; Guerrero, Juan Miguel; Carrillo-Vico, Antonio

    2017-08-09

    Multiple sclerosis (MS) is a neuroinflammatory disease of the central nervous system in which the immune system plays a central role. In particular, effector populations such as T helper (Th) 1, Th9, Th17 and Th22 cells are involved in disease development, whereas T regulatory cells (Tregs) are associated with the resolution of the disease. Melatonin levels are impaired in MS patients, and exogenous melatonin ameliorates the disease in MS animal models by modulating the Th1/Th17/Treg responses and also improves quality of life and several symptoms in MS patients. However, no study has examined melatonin's effect on T cells from relapsing-remitting MS (RR-MS) patients. Therefore, the objectives of the present study were to evaluate the effects of the in vitro administration of melatonin to peripheral blood mononuclear cells (PBMCs) from 64 RR-MS patients and 64 sex- and age-matched healthy subjects on Th1, Th9, Th17, Th22 and Treg responses and to analyze the expression of the melatonin effector/receptor system in these cells. Melatonin decreased Th1 and Th22 responses in patients, whereas it did not affect the Th17 and Treg subsets. Melatonin also promoted skewing toward a more protective cytokine microenvironment, as shown by an increased anti-inflammatory/Th1 ratio. Furthermore, for the first time, we describe the overexpression of the melatonin effector/receptor system in PBMCs from MS patients; this alteration might be relevant to the disease because acetylserotonin O-methyltransferase expression significantly correlates with disease progression and T effector/regulatory responses in patients. Therefore, our data suggest that melatonin may be an effective treatment for MS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. CD4 T Follicular Helper and Regulatory Cell Dynamics and Function in HIV Infection

    PubMed Central

    Miles, Brodie; Miller, Shannon M.; Connick, Elizabeth

    2016-01-01

    T follicular helper cells (TFH) are a specialized subset of CD4 T cells that reside in B cell follicles and promote B cell maturation into plasma cells and long-lived memory B cells. During chronic infection prior to the development of AIDS, HIV-1 (HIV) replication is largely concentrated in TFH. Paradoxically, TFH numbers are increased in early and midstages of disease, thereby promoting HIV replication and disease progression. Despite increased TFH numbers, numerous defects in humoral immunity are detected in HIV-infected individuals, including dysregulation of B cell maturation, impaired somatic hypermutation, and low quality of antibody production despite hypergammaglobulinemia. Clinically, these defects are manifested by increased vulnerability to bacterial infections and impaired vaccine responses, neither of which is fully reversed by antiretroviral therapy (ART). Deficits in TFH function, including reduced HIV-specific IL-21 production and low levels of co-stimulatory receptor expression, have been linked to these immune impairments. Impairments in TFH likely contribute as well to the ability of HIV to persist and evade humoral immunity, particularly the inability to develop broadly neutralizing antibodies. In addition to direct infection of TFH, other mechanisms that have been linked to TFH deficits in HIV infection include upregulation of PD-L1 on germinal center B cells and augmented follicular regulatory T cell responses. Challenges to development of strategies to enhance TFH function in HIV infection include lack of an established phenotype for memory TFH as well as limited understanding of the relationship between peripheral TFH and lymphoid tissue TFH. Interventions to augment TFH function in HIV-infected individuals could enhance immune reconstitution during ART and potentially augment cure strategies. PMID:28082992

  18. Structure of the Autocatalytic Cysteine Protease Domain of Potyvirus Helper-component Proteinase*

    PubMed Central

    Guo, Bihong; Lin, Jinzhong; Ye, Keqiong

    2011-01-01

    The helper-component proteinase (HC-Pro) of potyvirus is involved in polyprotein processing, aphid transmission, and suppression of antiviral RNA silencing. There is no high resolution structure reported for any part of HC-Pro, hindering mechanistic understanding of its multiple functions. We have determined the crystal structure of the cysteine protease domain of HC-Pro from turnip mosaic virus at 2.0 Å resolution. As a protease, HC-Pro only cleaves a Gly-Gly dipeptide at its own C terminus. The structure represents a postcleavage state in which the cleaved C terminus remains tightly bound at the active site cleft to prevent trans activity. The structure adopts a compact α/β-fold, which differs from papain-like cysteine proteases and shows weak similarity to nsP2 protease from Venezuelan equine encephalitis alphavirus. Nevertheless, the catalytic cysteine and histidine residues constitute an active site that is highly similar to these in papain-like and nsP2 proteases. HC-Pro recognizes a consensus sequence YXVGG around the cleavage site between the two glycine residues. The structure delineates the sequence specificity at sites P1–P4. Structural modeling and covariation analysis across the Potyviridae family suggest a tryptophan residue accounting for the glycine specificity at site P1′. Moreover, a surface of the protease domain is conserved in potyvirus but not in other genera of the Potyviridae family, likely due to extra functional constrain. The structure provides insight into the catalysis mechanism, cis-acting mode, cleavage site specificity, and other functions of the HC-Pro protease domain. PMID:21543324

  19. Hybrid T-Helper Cells: Stabilizing the Moderate Center in a Polarized System

    PubMed Central

    Huang, Sui

    2013-01-01

    Polarization of cell phenotypes, a common strategy to achieve cell type diversity in metazoa, results from binary cell-fate decisions in the branching pedigree of development. Such “either-or” fate decisions are controlled by two opposing cell fate-determining transcription factors. Each of the two distinct “master regulators” promotes differentiation of its respective sister lineage. But they also suppress one other, leading to their mutually exclusive expression in the two ensuing lineages. Thus, promiscuous coexistence of the antagonist regulators in the same cell, the hallmark of the common “undecided” progenitor of two sister lineages, is considered unstable. This antagonism ensures robust polarization into two discretely distinct cell types. But now the immune system's T-helper (Th) cells and their two canonical subtypes, Th1 and Th2 cells, tell a different story, as revealed in three papers recently published in PLOS Biology. The intermediate state that co-expresses the two opposing master regulators of the Th1 and Th2 subtypes, T-bet and Gata3, is highly stable and is not necessarily an undecided precursor. Instead, the Th1/Th2 hybrid cell is a robust new type with properties of both Th1 and Th2 cells. These hybrid cells are functionally active and possess the benefit of moderation: self-limitation of effector T cell function to prevent excessive inflammation, a permanent risk in host defense that can cause tissue damage or autoimmunity. Gene regulatory network analysis suggests that stabilization of the intermediate center in a polarizing system can be achieved by minor tweaking of the architecture of the mutual suppression gene circuit, and thus is a design option readily available to evolution. PMID:23976879

  20. Elevated Urinary T Helper 1 Chemokine Levels in Newly Diagnosed Hypertensive Obese Children

    PubMed Central

    Övünç Hacıhamdioğlu, Duygu; Zeybek, Cengiz; Gök, Faysal; Pekel, Aysel; Muşabak, Uğur

    2015-01-01

    Objective: Increasing evidence suggests that T helper (Th) cells play a significant role in the pathogenesis of hypertension. The aim of this study was to evaluate the effect of obesity and anti-hypertensive treatment on urinary Th1 chemokines. Methods: The study groups consisted of three types of patients: hypertensive obese, healthy, and non-hypertensive obese. Pre-treatment and post-treatment samples of the hypertensive obese group and one sample from the other two groups were evaluated for urinary chemokine: regulated on activation, normal T cell expressed and secreted (RANTES), interferon-gamma-inducible protein 10 (IP10), and monokine induced by interferon-gamma (MIG). In the hypertensive obese group, urine microalbumin: creatinine ratio was examined before and after treatment. We recommended lifestyle changes to all patients. Captopril was started in those who could not be controlled with lifestyle changes and those who had stage 2 hypertension. Results: Twenty-four hypertensive obese (mean age 13.1), 27 healthy (mean age 11.2) and 22 non-hypertensive obese (mean age 11.5) children were investigated. The pre-treatment urine albumin: creatinine ratio was positively correlated with pre-treatment MIG levels (r=0.41, p<0.05). RANTES was significantly higher in the pre-treatment hypertensive and non-hypertensive obese group than in the controls. The urinary IP10 and MIG levels were higher in the pre-treatment hypertensive obese group than in the non-hypertensive obese. Comparison of the pre- and post-treatment values indicated significant decreases in RANTES, IP10, and MIG levels in the hypertensive obese group (p<0.05). Conclusion: Th1 cells could be activated in obese hypertensive children before the onset of clinical indicators of target organ damage. Urinary RANTES seemed to be affected by both hypertension and obesity, and urinary IP10 and MIG seemed to be affected predominantly by hypertension. PMID:26831550

  1. Changes in Follicular Helper T Cells in Idiopathic Thrombocytopenic Purpura Patients

    PubMed Central

    Xie, Jue; Cui, Dawei; Liu, Yan; Jin, Jie; Tong, Hongyan; Wang, Lei; Ruan, Guoxiang; Lu, Yun; Yuan, Huiming

    2015-01-01

    Background: Idiopathic thrombocytopenic purpura (ITP) is a primary autoimmune disease with a decreased platelet count caused by platelet destruction mediated mainly by platelet antibodies. T follicular helper (TFH) cells have demonstrated important roles in autoimmune diseases. The aim of this study is to explore the might role of TFH cells in the patients of ITP. Methods: Twenty-three ITP patients and 12 healthy controls (HC) were enrolled in this study. The frequency of circulating TFH cells in both the patients and HC was analyzed by flow cytometry. Serum interleukin (IL)-21 and IL-6 levels were measured using ELISA, and platelet antibodies were tested using a solid phase technique. Additionally, IL-21, IL-6, Bcl-6 and c-Maf mRNA expressions in peripheral blood mononuclear cells (PBMCs) were detected using real-time PCR. Results: The percentages of circulating CXCR5+ CD4+TFH cells with ICOShigh or PD-1high expression were significantly higher in the ITP patients than in the HC. Moreover, the frequencies of circulating CXCR5+ CD4+TFH cells with inducible costimulator (ICOS)high or programmed death-1 (PD-1)high expression were notably higher in ITP with platelet-antibody-positive ( ITP (+) ) patients than in ITP with platelet-antibody-negative ( ITP (-) ) patients and HC, as were the serum IL-21 and IL-6 levels (significant). Moreover, a positive correlation was found between the CXCR5+CD4+TFH cells with ICOShigh or PD-1high expression and the serum IL-21 levels of ITP (+) patients. Additionally, the mRNA expression levels of IL-21, IL-6, Bcl-6 and c-Maf were significantly increased in ITP patients, especially in ITP (+) patients. Conclusions: This study demonstrated TFH cells and effector molecules might play an important role in the pathogenesis of ITP, which are possible therapeutic targets in ITP patients. PMID:25561904

  2. Notch Signaling Regulates Circulating T Helper 22 Cells in Patients with Chronic Hepatitis C.

    PubMed

    Jiang, Ben-Chun; Liu, Xin; Liu, Xiao-Hong; Li, Zhen-Sheng-Nan; Zhu, Guang-Ze

    2017-04-14

    Notch signaling enhanced the response of interleukin (IL)-22-producing CD4(+) T cells that were defined as T helper 22 (Th22) cells, and Notch-aryl hydrocarbon receptor (AhR)-IL-22 axis fine-tuned inflammatory response. Previous studies have demonstrated that both Notch signaling and Th22 cells took part in the pathogenesis of chronic hepatitis C virus (HCV) infection. Thus, in this study, we aimed at examining the regulatory role of Notch signaling in Th22 cells in HCV infection. A total of 59 patients with chronic hepatitis C and 22 normal controls (NCs) were enrolled in this study. The percentage of Th22 cells and mRNA expression of related transcriptional factors and cytokines were analyzed in response to γ-secretase inhibitor. Th22 cell frequency was significantly elevated in chronic hepatitis C in comparison with that in NCs. Inhibition of Notch signaling downregulated HCV-specific Th22 cells and IL-22 production, which was accompanied by the reduction of AhR and modulatory cytokines (IL-6 and tumor necrosis factor-α). Moreover, the suppression of Notch signaling also decreased the IL-22-mediated antimicrobial response in both normal and HCV-infected HepG2 cells/Huh7.5 cells. This process was also accompanied by the depression of signal transducers and activators of transcription 3 signaling. In conclusion, the current results suggested that Notch signaling acted as a critical pathway in determining the response to IL-22 in chronic hepatitis C. Thus, Notch-Th22 axis might be considered a new therapeutic target for HCV-infected patients.

  3. Tim-3 identifies exhausted follicular helper T cells in breast cancer patients.

    PubMed

    Zhu, Shiguang; Lin, Jun; Qiao, Guangdong; Wang, Xingmiao; Xu, Yanping

    2016-09-01

    Breast cancer is the most common cancer diagnosed in women worldwide. Although a series of treatment options have improved the overall 5-year survival rate to 90%, individual responses still vary from patient to patient. New evidence suggested that the infiltration of CXCL13-expressing CD4(+) follicular helper cells (Tfh) in breast tumor predicted better survival. Here, we examined the regulation of Tfh function in breast cancer patients in depth. We found that the frequencies of circulating Tfh cells were not altered in breast cancer patients compared to healthy controls. However, the expression of PD-1 and Tim-3 in Tfh cells was significantly elevated in breast cancer patients. Interestingly, we observed a preferential upregulation of PD-1 in Tim-3(+) Tfh cells compared to Tim-3(-) Tfh cells. Coexpression of PD-1 and Tim-3 is typically a hallmark of functional exhaustion in chronic virus infections and tumor. To examine whether Tim-3(+) identifies exhausted Tfh cells, we stimulated Tfh cells with anti-CD3/CD28, and found that Tim-3(+) T cells expressed reduced frequencies of chemokine CXCL13 and cytokine interleukin 21 (IL-21), and contained fewer proliferating cells, than Tim-3(-) Tfh cells. Compared to those cocultured with Tim-3(-) Tfh cells, naive B cells cocultured with Tim-3(+) Tfh cells resulted in significantly less IgM, IgG and IgA production after 12 day incubation, demonstrating a reduction in Tim-3(+) Tfh-mediated B cell help. Moreover, the frequencies of Tim-3(+) Tfh cells in resected breast tumor were further upregulated than autologous blood, suggesting a participation of Tim-3(+) Tfh cells in tumor physiology. Overall, the data presented here provided new insight in the regulation of Tfh cells in breast cancer patients.

  4. Impaired Phenotype and Function of T Follicular Helper Cells in HIV-1-Infected Children Receiving ART

    PubMed Central

    Bekele, Yonas; Amu, Sylvie; Bobosha, Kidist; Lantto, Rebecka; Nilsson, Anna; Endale, Birtukan; Gebre, Meseret; Aseffa, Abraham; Rethi, Bence; Howe, Rawleigh; Chiodi, Francesca

    2015-01-01

    Abstract T follicular helper (Tfh) cells are important components in development of specific humoral immune responses; whether the number and biology of Tfh cells is impaired in HIV-1-infected children is not yet studied. The frequency, phenotype, and function of Tfh cells and B cells were determined in blood of HIV-1-infected children receiving antiretroviral therapy (ART) and age-matched controls. Flow cytometry was used to characterize the frequency of Tfh cells and B cell subsets. Cytokine expression was measured after in vitro activation of Tfh cells. A reduced frequency of memory Tfh cells (P < 0.001) was identified in HIV-1-infected children and, on these cells, a reduced expression of programmed death-1 (PD-1) and inducible T cell costimulator (ICOS) (P < 0.001 and P < 0.01). Upon activation, the capacity of Tfh cells to express IL-4, an important cytokine for B cell function, was impaired in HIV-1-infected children. B cell subpopulations in HIV-1-infected children displayed significant differences from the control group: the frequency of resting memory (RM) B cells was reduced (P < 0.01) whereas the frequency of exhausted memory B cells increased (P < 0.001). Interestingly, the decline of RM cells correlated with the reduction of memory Tfh cells (P = 0.02). Our study shows that function and phenotype of Tfh cells, pivotal cells for establishment of adaptive B cell responses, are impaired during HIV-1 infection in children. A consistent reduction of memory Tfh cells is associated with declined frequencies of RM B cells, creating a novel link between dysfunctional features of these cell types, major players in establishment of humoral immunity. PMID:26166114

  5. AFP-specific CD4+ Helper T-cell Responses in Healthy Donors and HCC Patients

    PubMed Central

    Evdokimova, Viktoria N.; Liu, Yang; Potter, Douglas M.; Butterfield, Lisa H.

    2013-01-01

    Summary Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and is often diagnosed at an advanced stage. We have investigated α-fetoprotein (AFP) as a tumor-associated antigen for HCC. We identified major histocompatibility complex class I-restricted peptide epitopes derived from AFP and studied CD8+ T-cell responses in vivo and in vitro in ongoing immunotherapy studies. Helper T cells are of critical importance in shaping the immune response; therefore, we investigated the frequency and function of AFP-specific CD4+ T cells in the general population and among HCC patients. CD4+ T-cell responses were assessed by direct ex vivo multicytokine enzyme-linked immunospot assay and by measurement of cytokine levels using a multicytokine assay. Our analysis indicates that healthy donors have very low frequencies of AFP-specific CD4+ T-cell responses, which are of TH1 type, detectable ex vivo. In contrast, these T cells were either reduced or eliminated in HCC patients at advanced stages of disease. To better activate these cells, we compared the stimulatory capacity of both AFP protein-fed and AdVhAFP-engineered dendritic cells (DC). Healthy donors have CD4+ T-cell responses, which were activated in response to AFP protein-fed DC whereas HCC patients do not demonstrate significant responses to AFP protein. AdVhAFP-transduced DC were capable of activating higher frequency TH1 CD4+ responses to AFP in both healthy donors and AFP-positive HCC patients. Importantly, CD4+ T-cell cytokine expression profiles were skewed towards interleukin-2 and interferon-γ production when activated by adenovirally engineered DC, which has therapeutic implications for vaccination efforts. PMID:17457217

  6. CD147 modulates the differentiation of T-helper 17 cells in patients with rheumatoid arthritis.

    PubMed

    Yang, Hui; Wang, Jian; Li, Yu; Yin, Zhen-Jie; Lv, Ting-Ting; Zhu, Ping; Zhang, Yan

    2017-01-01

    The role of CD147 in regulation of rheumatoid arthritis (RA) is not fully elucidated. The aim of this study was to investigate the effect of cell-to-cell contact of activated CD14(+) monocytes with CD4(+) T cells, and the modulatory role of CD147 on T-helper 17 (Th17) cells differentiation in patients with RA. Twenty confirmed active RA patients and twenty normal controls were enrolled. CD4(+) T cells and CD14(+) monocytes were purified by magnetic beads cell sorting. Cells were cultured under different conditions in CD4(+) T cells alone, direct cell-to-cell contact co-culture of CD4(+) and CD14(+) cells, or indirect transwell co-culture of CD4(+) /CD14(+) cells in response to LPS and anti-CD3 stimulation with or without anti-CD147 antibody pretreatments. The proportion of IL-17-producing CD4(+) T cells (defined as Th17 cells) was determined by flow cytometry. The levels of interleukin (IL)-17, IL-6, and IL-1β in the supernatants of cultured cells were measured by ELISA. The optimal condition for in vitro induction of Th17 cells differentiation was co-stimulation with 0.1 μg/mL of LPS and 100 ng/mL of anti-CD3 for 3 days under direct cell-to-cell contact co-culture of CD4(+) and CD14(+) cells. Anti-CD147 antibody reduced the proportion of Th17 cells, and also inhibited the productions of IL-17, IL-6, and IL-1β in PBMC culture from RA patients. The current results revealed that Th17 differentiation required cell-to-cell contact with activated monocytes. CD147 promoted the differentiation of Th17 cells by regulation of cytokine production, which provided the evidence for pathogenesis and potential therapeutic targets for RA.

  7. Follicular Helper T Cells: New Insights Into Mechanisms of Autoimmune Diseases

    PubMed Central

    Zhang, Xin; Ing, Sharon; Fraser, Austin; Chen, Minzi; Khan, Omar; Zakem, Jerald; Davis, William; Quinet, Robert

    2013-01-01

    ABSTRACT Background Autoimmune diseases (such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, etc) are characterized by the production of autoantibodies against one's own cell components, resulting in the dysfunction of normal organs. At present, therapies for autoimmune diseases involve a variety of nonspecific antiinflammatory and immunosuppressive agents with significant side effects. Current studies have suggested that the germinal center (GC) may be the pathogenic hot spot for the production of autoantibodies in autoimmune disease. Events occurring in the GC—such as the selection of high-affinity B cells, proliferation of B cells, and differentiation of B cells into plasma cells—all depend on T cells. Follicular helper T (Tfh) cells are a recently identified T-cell subset, named for their location in GCs. Tfh cells are characterized by their signature transcription factor (B-cell lymphoma 6), surface molecules (CD40 ligand, chemokine [C-X-C] receptor 5, inducible T-cell costimulator, programmed cell death protein-1, etc), and cytokines (interleukin [IL]-21, IL-6, IL-10, etc). Through these signals, Tfh cells help B cells form GCs and drive B cells to differentiate into memory B cells and plasma cells that produce antibodies. However, uncontrolled generation of Tfh cells in the GCs or peripherals could lead to autoimmunity. Recent studies from our group and others have shown that Tfh cells are expanded in the peripheral blood of patients and in the lymphoid tissues of mice with lupus or rheumatoid arthritis and play an important role in promoting pathogenic autoantibody production. Methods In this review, we summarize the latest immunologic findings regarding the characteristics and development of Tfh cells, their relation to other CD4+ T-cell subsets, and the function of Tfh cells in normal immune response and autoimmune diseases. Conclusion A clear understanding of the mechanisms of Tfh cell–mediated immunity and pathology may

  8. Identification of broadly recognized, T helper 1 lymphocyte epitopes in an equine lentivirus

    PubMed Central

    Fraser, Darrilyn G; Oaks, J Lindsay; Brown, Wendy C; McGuire, Travis C

    2002-01-01

    Equine infectious anaemia virus (EIAV) is a horse lentivirus causing lifelong, persistent infection. During acute infection, CD8+ cytotoxic T lymphocytes (CTL) are probably involved in terminating plasma viraemia. However, only a few EIAV CTL epitopes, restricted to fewer horse major histocompatibility complex (MHC) class I alleles, are known. As interferon-γ (IFN-γ)-secreting CD4+, T helper 1 (Th1) lymphocytes promote CTL activity and help maintain memory CTL, identifying broadly recognized EIAV Th1 epitopes would contribute significantly to vaccine strategies seeking to promote strong CTL responses among horses with varying class I haplotypes. To this end, peripheral blood mononuclear cells (PBMC) from 10 MHC disparate, EIAV-infected horses were tested in T-lymphocyte proliferation assays for recognition of peptides from the Gag p26 capsid region and a portion of Pol. Both regions are highly conserved among EIAV isolates, and this Pol region is 51–63% homologueous to other lentiviral Pol proteins. Seven of 10 horses recognized peptide Gag 221–245, and peptides Gag 242–261 and Pol 323–344 were recognized by five and four horses, respectively. Furthermore, the Gag peptides were recognized by two additional horses after resolving their initial plasma viraemia, indicating that these two peptides can be immunodominant early in infection. Gag peptide-responsive PBMC produced only IFN-γ, indicating a Th1 response, while Pol 323–344-responsive PBMC produced IFN-γ both with and without interleukin-4. PBMC from uninfected horses failed to either proliferate or secrete cytokines in response to peptide stimulation. Finally, CD4+ T lymphocytes were required for proliferation responses, as shown by assays using CD4- versus CD8-depleted PBMC. PMID:11918691

  9. Circulating follicular helper T cells presented distinctively different responses toward bacterial antigens in primary biliary cholangitis.

    PubMed

    Zhou, Zun-Qiang; Tong, Da-Nian; Guan, Jiao; Li, Mei-Fang; Feng, Qi-Ming; Zhou, Min-Jie; Zhang, Zheng-Yun

    2017-10-01

    Primary biliary cholangitis (PBC) is a chronic and progressive cholestatic liver disease with unknown causes. The initiation of PBC is associated with bacterial infections and abnormal immune correlates, such as the presence of self-reactive anti-mitochondrial antibodies and shifted balance of T cell subsets. In particular, the CD4(+)CXCR5(+) follicular helper T (Tfh) cells are highly activated in PBC patients and are significantly associated with PBC severity, but the underlying reasons are unknown. In this study, we found that the circulating CD4(+)CXCR5(+) T cells were enriched with the interferon (IFN)-γ-secreting Th1-subtype and the interleukin (IL)-17-secreting Th17-subtype, but not the IL-4-secreting Th2 subtype. We further demonstrated that a host of microbial motifs, including Pam3CSK4, poly(I:C), LPS, imiquimod, and CpG, could significantly stimulate IFN-γ, IL-17, and/or IL-21 from circulating CD4(+)CXCR5(+) T cells in PBC patients, especially in the presence of monocytes and B cells. Whole bacterial cells of Escherichia coli, Novosphingobium aromaticivorans, and Mycobacterium gordonae, could also potently stimulate IFN-γ, IL-17, and/or IL-21 production from circulating CD4(+)CXCR5(+) T cells. But interestingly, while the whole cell could potently stimulate circulating CD4(+)CXCR5(+) T cells from both healthy controls and PBC patients, the cell protein lysate could only potently stimulate circulating CD4(+)CXCR5(+) T cells from PBC patients, but not those from healthy controls, suggesting that circulating CD4(+)CXCR5(+) T cells in PBC patients had distinctive antigen-specificity from those in healthy individuals. Together, these data demonstrated that bacterial antigen stimulation is a potential source of aberrant Tfh cell activation in PBC patients. Copyright © 2017. Published by Elsevier B.V.

  10. Retinoic Acid Attenuates Ileitis by Restoring the Balance between T-Helper 17 and T

    PubMed Central

    Collins, Colm B.; Aherne, Carol M.; Kominsky, Douglas; McNamee, Eóin N.; Lebsack, Matthew D.P.; Eltzschig, Holger; Jedlicka, Paul; Rivera-Nieves, Jesús

    2013-01-01

    Background & Aims Retinoic acid (RA), produced by intestinal epithelial cells (IECs) and dendritic cells (DCs) and regulated by transforming growth factor (TGF)-β, controls the enteric immune response by activating regulatory T (Treg) cells and preventing activation of T-helper (Th)17 cells Methods We studied the roles of RA in mice that overproduce tumor necrosis factor (TNF) and develop chronic ileitis (TNFΔARE mice). We assessed the frequency and function of CD103+ DCs and Th17 and Treg cells by flow cytometry; we measured expression of cytokines and retinaldehyde dehydrogenase (RALDH) enzymes in ileum samples, DCs, and IECs by real-time PCR. We quantified RA by electrochemical analysis and examined the effect of RA supplementation on TNF-induced ileitis using histologic, co-culture, and suppression assays and flow cytometry Results Numbers of CD103+ DCs decreased in the inflamed ilea of mice with chronic disease; RA synthetic machinery (RALDH1,2) was downregulated. Nevertheless, the proportion of CD4+, CD25+, FoxP3+ Treg cells increased, indicating an alternate source for RA. IECs responded to reduced levels of RA by upregulating RALDH3 in vivo and in vitro. Net tissue levels of RA levels remained lower in TNFΔARE than wild-type mice, indicating that epithelial up-regulation of RALDH3 could not maintain adequate concentrations of RA, probably because of loss of IEC mass. RA supplementation significantly attenuated disease by increasing the number and function of CD103+ DCs and Treg cells and reducing Th17 cells Conclusions Reduced levels of RA appear to induce IEC to upregulate synthesis of RA. RA supplementation attenuates ileitis through its effects on CD103+ DCs and Treg and Th17 cells. RA supplementation might used to treat patients with Crohn's disease PMID:22027263

  11. Stress system activity, innate and T helper cytokines, and susceptibility to immune-related diseases.

    PubMed

    Calcagni, Emanuele; Elenkov, Ilia

    2006-06-01

    Associations between stress and health outcomes have now been carefully documented, but the mechanisms by which stress specifically influences disease susceptibility and outcome remain poorly understood. Recent evidence indicates that glucocorticoids (GCs) and catecholamines (CAs), the major stress hormones, inhibit systemically IL-12, TNF-alpha, and INF-gamma, but upregulate IL-10, IL-4, and TGF-beta production. Thus, during an immune and inflammatory response, the activation of the stress system, through induction of a Th2 shift may protect the organism from systemic "overshooting" with T helper lymphocyte 1 (Th1)/proinflammatory cytokines. In certain local responses and under certain conditions, however, stress hormones may actually facilitate inflammation, through induction of IL-1, IL-6, IL-8, IL-18, TNF-alpha, and CRP production, and through activation of the corticotropin-releasing hormone (CRH)/substance P(SP)-histamine axis. Autoimmunity, chronic infections, major depression, and atherosclerosis are characterized by a dysregulation of the pro/anti-inflammatory and Th1/Th2 cytokine balance. Thus, hyperactive or hypoactive stress system, and a dysfunctional neuroendocrine-immune interface associated with abnormalities of the "systemic anti-inflammatory feedback" and/or "hyperactivity" of the local proinflammatory factors may contribute to the pathogenesis of these diseases. Conditions that are associated with significant changes in stress system activity, such as acute or chronic stress, cessation of chronic stress, pregnancy and the postpartum period, or rheumatoid arthritis (RA) through modulation of the systemic or local pro/anti-inflammatory and Th1/Th2 cytokine balance, may suppress or potentiate disease activity and/or progression. Thus, stress hormones-induced inhibition or upregulation of innate and Th cytokine production may represent an important mechanism by which stress affects disease susceptibility, activity, and outcome of various immune

  12. Bcl6 and Maf cooperate to instruct human follicular helper CD4 T cell (Tfh) differentiation

    PubMed Central

    Kroenke, Mark A.; Eto, Danelle; Locci, Michela; Cho, Michael; Davidson, Terence; Haddad, Elias; Crotty, Shane

    2012-01-01

    Follicular helper CD4 T cells (Tfh) provide B cells with signals important for the generation of high-affinity antibodies and immunological memory, and are therefore critical for the protective immunity elicited by most human vaccines. Transcriptional regulators of human Tfh cell differentiation are poorly understood. Here we demonstrate that Bcl6 controls specific gene modules for human Tfh differentiation. The introduction of Bcl6 expression in primary human CD4 T cells resulted in regulation of a core set of migration genes that enable trafficking to germinal centers: CXCR4, CXCR5, CCR7, and EBI2. Bcl6 expression also induced a module of protein expression critical for T:B interactions, including SAP, CD40L, PD-1, ICOS, and CXCL13. This is the first direct evidence for Bcl6 control of most of these functions, and includes three genes known to be loci of severe human genetic immunodeficiencies (CD40L, SH2D1A, ICOS). Introduction of Bcl6 did not alter expression of IL-21 or IL-4, the primary cytokines of human Tfh cells. We show here that introduction of Maf (c-Maf) does induce the capacity to express IL-21. Surprisingly, Maf also induced CXCR5 expression. Co-expression of Bcl6 and Maf together revealed that Bcl6 and Maf cooperate in the induction of CXCR4, PD-1, and ICOS. Altogether, these findings reveal that Bcl6 and Maf collaborate to orchestrate a suite of genes that define core characteristics of human Tfh cell biology. PMID:22427637

  13. Helper role of NK cells during the induction of anticancer responses by dendritic cells.

    PubMed

    Kalinski, Pawel; Giermasz, Adam; Nakamura, Yutaro; Basse, Per; Storkus, Walter J; Kirkwood, John M; Mailliard, Robbie B

    2005-02-01

    Recent reports demonstrate that natural killer (NK) cells and dendritic cells (DC) support each other's activity in a positive feedback. We observed that activated NK cells induce the maturation of DCs into stable type-1 polarized DCs (DC1), characterized by up to 100-fold enhanced ability to produce IL-12p70 in response to subsequent interaction with Th cells. DC1 induction depends on NK cell-produced IFN-gamma and TNF-alpha, with a possible involvement of additional factors. DC1, induced by NK cells or by NK cell-related soluble factors, are stable, resistant to tumor-related suppressive factors, and show strongly enhanced ability to induce Th1 and CTL responses. In analogy to resting T cells, the induction of "helper" function of NK cells relies on a two-signal activation paradigm. While NKG2D-dependent tumor cell recognition is sufficient to induce the cytotoxic "effector" function of NK cells, the induction of "NK cell help" requires additional signals from type-1 IFNs, products of virally-infected cells, or from IL-2. Compared to non-polarized DCs currently-used in clinical trials, DC1s act as superior inducers of anti-cancer CTL responses during in vitro sensitization. The current data provides rationale for the clinical use of DC1s in cancer and chronic infections (such as HIV), as a new generation DC-based vaccines, uniquely combining fully mature DC status with an elevated, rather than "exhausted" ability to produce bioactive IL-12p70. We are currently implementing stage I/II clinical trials, testing the effectiveness of DC1s induced by NK cells or by NK cell-related factors, as therapeutic vaccines against melanoma.

  14. Defining characteristics of classical Hodgkin lymphoma microenvironment T-helper cells

    PubMed Central

    Clear, Andrew; Owen, Andrew; Iqbal, Sameena; Lee, Abigail; Matthews, Janet; Wilson, Andrew; Calaminici, Maria; Gribben, John G.

    2013-01-01

    CD4+ T-helper cells (THs) dominate the classical Hodgkin lymphoma (CHL) microenvironment, but their role is poorly understood. Advances in flow cytometry and immunohistochemistry permit more detailed investigation of this aspect of CHL pathophysiology. To address the hypothesis that the TH-infiltrate, rather than being TH2-enriched, senescent and hypofunctional, is TH1 and activation marker-rich, cytokine-secretory and proliferative, we applied comprehensive flow cytometric immunophenotyping and functional assays of cytokine secretion/proliferation to TH cells from 18 CHL-derived single-cell suspensions (SCSs) compared to reactive lymph nodes (RLNs). CHL-derived TH cells express TH1-associated CXCR3/CCR5 and TNFα/IFNγ/interleukin-2 (IL-2) and less TH2-associated CCR3/CCR4, with no IL-4/IL-13. They lack exhaustion-/suppression-associated PD1, CD57 and terminally differentiated effector memory cells, with more central memory cells, activation-associated partners of Hodgkin Reed Sternberg (HRS) cell-expressed CD30/OX40-L/ICOS-L, and other activation markers. TH cell lines established from CHL and RLN-derived SCSs remain cytokine-secretory. We confirmed and extended these studies using tissue microarray immunohistochemistry (TMA-IHC) from a large CHL tissue bank (n = 122) and demonstrate TH1-associated TBET is abundant in CHL, and TH2-associated CMAF/GATA3 and exhaustion-associated PD1 expressed at significantly lower levels. These molecular insights into the CHL-associated TH offer potential diagnostic, prognostic and pharmacologically modifiable therapeutic targets and do not support the established view of a TH2-enriched, senescent/exhausted, hypofunctional, hypoproliferative infiltrate. PMID:24004665

  15. TIGIT-positive circulating follicular helper T cells display robust B-cell help functions: potential role in sickle cell alloimmunization.

    PubMed

    Godefroy, Emmanuelle; Zhong, Hui; Pham, Petra; Friedman, David; Yazdanbakhsh, Karina

    2015-11-01

    T follicular helper cells are the main CD4(+) T cells specialized in supporting B-cell responses, but their role in driving transfusion-associated alloimmunization is not fully characterized. Reports of T follicular helper subsets displaying various markers and functional activities underscore the need for better characterization/identification of markers with defined functions. Here we show that a previously unidentified subset of human circulating T follicular helper cells expressing TIGIT, the T-cell immunoreceptor with Ig and immunoreceptor tyrosine-based inhibitory domains, exhibit strong B-cell help functions. Compared to the subset lacking the receptor, T follicular helper cells expressing this receptor up-regulated co-stimulatory molecules and produced higher levels of interleukins (IL-21 and IL-4) critical for promoting B-cell activation/differentiation. Furthermore, this subset was more efficient at inducing the differentiation of B cells into plasmablasts and promoting immunoglobulin G production. Blocking antibodies abrogated the B-cell help properties of receptor-expressing T follicular helper cells, consistent with the key role of this molecule in T follicular helper-associated responses. Importantly, in chronically transfused patients with sickle cell anemia, we identified functional differences of this subset between alloimmunized and non-alloimmunized patients. Altogether, these studies suggest that expression of the T-cell immunoreceptor with Ig and immunoreceptor tyro-sine-based inhibitory domains not only represents a novel circulating T follicular helper biomarker, but is also functional and promotes strong B-cell help and ensuing immunoglobulin G production. These findings open the way to defining new diagnostic and therapeutic strategies in modulating humoral responses in alloimmunization, and possibly vaccination, autoimmunity and immune deficiencies. Copyright© Ferrata Storti Foundation.

  16. Probing the Strength of Infants' Preference for Helpers over Hinderers: Two Replication Attempts of Hamlin and Wynn (2011)

    PubMed Central

    Volein, Agnes; Karap, Zsuzsanna; Csibra, Gergely

    2015-01-01

    Several studies indicate that infants prefer individuals who act prosocially over those who act antisocially toward unrelated third parties. In the present study, we focused on a paradigm published by Kiley Hamlin and Karen Wynn in 2011. In this study, infants were habituated to a live puppet show in which a protagonist tried to open a box to retrieve a toy placed inside. The protagonist was either helped by a second puppet (the “Helper”), or hindered by a third puppet (the “Hinderer”). At test, infants were presented with the Helper and the Hinderer, and encouraged to reach for one of them. In the original study, 75% of 9-month-olds selected the Helper, arguably demonstrating a preference for prosocial over antisocial individuals. We conducted two studies with the aim of replicating this result. Each attempt was performed by a different group of experimenters. Study 1 followed the methods of the published study as faithfully as possible. Study 2 introduced slight modifications to the stimuli and the procedure following the guidelines generously provided by Kiley Hamlin and her collaborators. Yet, in our replication attempts, 9-month-olds’ preference for helpers over hinderers did not differ significantly from chance (62.5% and 50%, respectively, in Studies 1 and 2). Two types of factors could explain why our results differed from those of Hamlin and Wynn: minor methodological dissimilarities (in procedure, materials, or the population tested), or the effect size being smaller than originally assumed. We conclude that fine methodological details that are crucial to infants’ success in this task need to be identified to ensure the replicability of the original result. PMID:26565412

  17. Production of High-Titer Recombinant Adeno-Associated Virus Vectors in the Absence of Helper Adenovirus

    PubMed Central

    Xiao, Xiao; Li, Juan; Samulski, Richard Jude

    1998-01-01

    Recently, efficient and long-term in vivo gene transfer by recombinant adeno-associated virus type 2 (rAAV) vectors has been demonstrated in a variety of tissues. Further improvement in vector titer and purity will expedite this in vivo exploration and provide preclinical information required for use in human gene therapy. In an effort to obtain higher titers, we constructed a novel AAV helper plasmid which utilizes translational control of AAV Rep genes (J. Li et al., J. Virol. 71:5236–5243, 1997). To address the issue of purity, in this study we report the first rAAV production method which is completely free of adenovirus (Ad) helper virus. The new production system uses a plasmid construct which contains a mini-Ad genome capable of propagating rAAV in the presence of AAV Rep and Cap genes. This construct is missing some of the early and most of the late Ad genes and is incapable of producing infectious Ad. Transfection of 293 cells with the new mini-Ad helper and AAV packaging plasmids results in high-titer rAAV vectors with yields greater than 1,000 transducing units, or 105 viral particles per cell. When rAAV vectors were produced by using this production scheme and compared to traditional heat-inactivated rAAV preparations in vitro and in vivo, we observed transduction equivalent to or better than normal levels. The complete removal of infectious Ad from AAV production should facilitate a better understanding of immune response to AAV vectors in vivo, eliminate the need for developing replication-competent Ad assays, and provide a more defined reagent for clinical use. PMID:9499080

  18. An Adenovirus Type 5 Mutant with the Preterminal Protein Gene Deleted Efficiently Provides Helper Functions for the Production of Recombinant Adeno-Associated Virus

    PubMed Central

    Maxwell, Ian H.; Maxwell, Francoise; Schaack, Jerome

    1998-01-01

    Production of recombinant adeno-associated virus (rAAV) requires helper functions that have routinely been provided by infection of the producer cells with adenovirus. Complete removal and/or inactivation of progeny adenovirus, present in such rAAV preparations, presents significant difficulty. Here, we report that an adenovirus type 5 (Ad5) mutant with the preterminal protein (pTP) gene deleted can provide helper function for the growth of rAAV. At high multiplicity, Ad5dl308ΔpTP was as efficient as the phenotypically wild-type Ad5dl309 in permitting growth of rAAV. Use of Ad5dl308ΔpTP, which is incapable of replication in the absence of complementation for pTP, as a helper avoids the need to remove contaminating adenovirus infectious activity by heat inactivation or by purification. Comparison of the transducing ability of rAAV generated with either Ad5dl308ΔpTP or Ad5dl309 as a helper demonstrated that the heat inactivation protocol generally used does not remove all of the helper Ad5dl309 function. PMID:9733887

  19. HLA-Dr+ T cells of the Leu 3 (helper) type infiltrate the kidneys of patients with systemic lupus erythematosus.

    PubMed Central

    Caligaris-Cappio, F; Bergui, L; Tesio, L; Ziano, R; Camussi, G

    1985-01-01

    The lineage and distribution of mononuclear cells infiltrating the kidneys of patients with systemic lupus erythematosus (SLE) have been investigated in cryostat tissue sections of biopsies from 11 patients. The use of heterologous antisera and monoclonal antibodies has revealed that: B lymphocytes and plasma cells are virtually absent in SLE kidney specimens; The vast majority of mononuclear cells which infiltrate the interstitium are activated (HLA-Dr+) T cells (Leu 4+) presenting the helper (Leu 3+) phenotype; T cells are absent in the glomeruli, where HLA-Dr+, SIgM-, Leu 4- elements with a macrophage like appearance can be observed. PMID:3156013

  20. Interleukin 23-Helper T Cell 17 Axis as a Treatment Target for Pityriasis Rubra Pilaris.

    PubMed

    Feldmeyer, Laurence; Mylonas, Alessio; Demaria, Olivier; Mennella, Anna; Yawalkar, Nikhil; Laffitte, Emmanuel; Hohl, Daniel; Gilliet, Michel; Conrad, Curdin

    2017-04-01

    Treatment of pityriasis rubra pilaris (PRP) is solely based on its resemblance to psoriasis rather than any knowledge of its pathomechanism. Insight into pathogenic mediators of inflammation is essential for targeted and valid treatment options that could replace previous serendipitous therapeutic approaches in refractory PRP. To determine whether blockade of the interleukin 23-helper T cell 17 (IL-23-TH17) pathway with ustekinumab represents an efficacious and, based on its proinflammatory cytokine profile, targeted treatment option in PRP. In this case report, a patient with PRP received outpatient treatment at a university hospital department of dermatology with ustekinumab according to the dosing regimen approved for psoriasis. Lesional skin biopsy samples were taken from this patient and 2 others with refractory PRP. Messenger RNA (mRNA) expression of proinflammatory innate and T-cell-derived cytokines were measured and compared with skin samples from patients with psoriasis and healthy donors. From 1 patient, lesional skin samples were taken before ustekinumab treatment and 4 and 28 weeks after treatment initiation. Follow-up was completed after 6 months. Subcutaneous ustekinumab, 45 mg, at weeks 0 and 4 and quarterly thereafter. The primary outcome was to determine the changes in expression of proinflammatory innate and T-cell-derived cytokines during ustekinumab therapy. The secondary objective was to evaluate the clinical and histopathologic phenotype in relation to the mRNA expression profile of proinflammatory cytokines. In lesional PRP skin samples from a single patient, upregulated expression levels were found for most proinflammatory innate cytokines, including tumor necrosis factor (TNF), IL-6, IL-12, IL-23, and IL-1β. Among adaptive T-cell cytokines, an increase of TH1 cytokines and, in particular, TH17 cytokines IL-17A, IL-17F, and IL-22 was seen in PRP. The patient with PRP who received ustekinumab showed regression of skin lesions after 2 weeks

  1. The Expression of T-Helper Associated Transcription Factors and Cytokine Genes in Pre-Eclampsia.

    PubMed

    Gharesi-Fard, Behrouz; Mobasher-Nejad, Fatemeh; Nasri, Fatemeh

    2016-12-01

    Pre-eclampsia (PE) is known as a main factor contributing to fetomaternal mortality, which might affect 2-8% of all pregnancies after the twentieth week of gestation. The balance of T helper subsets is essential to sustain a normal pregnancy and preventing fetomaternal complications. To investigate differences in the levels of transcription factors and cytokine gene expression of Th1/Th2/Th17/Treg subsets within decidual and chorionic layers of placentas from 15 PE-afflicted and 15 healthy Iranian women in their third trimester of pregnancy. Using Quantitative real-time PCR (Q-PCR), the expression of T-BET, GATA-3, ROR-ɣt, FOXP3, and cytokines, including IL-1, IL-6, TNF-α, IFN-γ, IL-4, IL-31, IL-17, IL-23, TGF-β1, TGF-β2, TGF-β3, and IL-35 in the placenta were compared at mRNA levels between groups. FOXP3 and GATA-3 were significantly down-regulated, while T-BET was up-regulated in PE deciduae compared to the control group (p<0.0001, p<0.02, and p<0.01, respectively). Concerning the chorionic samples, FOXP3 significantly decreased, while ROR-γt increased in the PE placentas compared to the healthy ones (p<0.0006 and p<0.02, respectively). Besides, most inflammatory cytokines were up-regulated, while anti-inflammatory cytokines were down-regulated in the PE placentas. Additionally, TNF-α/IL-35, IFN-ɣ/IL-35, IL-6/IL-35, and IL-23/IL-35 ratios were significantly higher (p<0.01) and IL-35/IL-17 ratio was significantly lower (p<0.05) in the pre-eclamptic patients compared to the healthy controls. Our results shed more light on the contribution of Th1/Th2/Th17/Treg balance within placenta in the fate of a normal pregnancy. Moreover, regulatory T cells and IL-35 seem to play a notable role in pre-eclampsia.

  2. Follicular Helper T Cells in Peripheral Blood of Patients With Rheumatoid Arthritis.

    PubMed

    Costantino, Alicia Beatriz; Acosta, Cristina Del Valle; Onetti, Laura; Mussano, Eduardo; Cadile, Ignacio Isaac; Ferrero, Paola Virginia

    2016-08-29

    Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by the presence of different autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein antibodies. CD4T cells expressing CXCR5, referred as follicular helper T cells (Tfh), collaborate with B cells to produce antibodies. Differential expression of CXCR3 and CCR6 within CD4(+)CXCR5(+) T cells defines three mayor subsets: CXCR3(+)CCR6(-) (Tfh1), CXCR3(-)CCR6(-) (Tfh2) and CXCR3(-)CCR6(+) (Tfh17). The aim of the study was to assess whether there is an association between the percentage of these cells and RA and whether there is a correlation with disease activity. Twenty-four RA patients, 22 healthy controls (HC) and 16 undifferentiated arthritis (UA) patients were included. Percentage of CD4(+)CXCR5(+) T cells and their subsets were analyzed by flow cytometry. No differences were found in the percentages of CD4(+)CXCR5(+) T cells in the comparison of RA vs HC or RA vs UA patients. Tfh1, Tfh2 and Tfh17 subsets showed no differences either. There was no correlation between CD4(+)CXCR5(+)T cells, Tfh1, Tfh2 and Tfh17, and Disease Activity Score in twenty-eight joints (DAS28) or erythrocyte sedimentation rate. Surprisingly, there was a positive correlation between Tfh17 cells and C-reactive protein. Finally, there was no correlation between CD4(+)CXCR5(+) T cells, or their subsets, and anti-mutated citrullinated vimentin, or between the cells and RF. There were no differences between the percentages of CD4(+)CXCR5(+) T cells and their subsets in peripheral blood of RA patients and the percentages of cells in the control groups. This finding does not rule out a pathogenic role of these cells in the development and activity of RA. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  3. miRNA Signature of Mouse Helper T Cell Hyper-Proliferation

    PubMed Central

    Sommers, Connie L.; Rouquette-Jazdanian, Alexandre K.; Robles, Ana I.; Kortum, Robert L.; Merrill, Robert K.; Li, Wenmei; Nath, Nandan; Wohlfert, Elizabeth; Sixt, Katherine M.; Belkaid, Yasmine; Samelson, Lawrence E.

    2013-01-01

    Helper T cells from a mutant mouse model, LAT Y136F, hyper-proliferate and cause a severe lymphoproliferative disease that kills the mice by six months of age. LAT Y136F mice carry a tyrosine to phenylalanine mutation in the Linker for Activation of T cells (LAT) gene. This mutation leads to a number of changes in T cells that result in altered cytokine production including increased IL-4 production, increased proliferation, and decreased apoptosis. Hyper-proliferation of the mutant T cells contributes to lymphadenopathy, splenomegaly, and multi-organ T cell infiltration. miRNAs are short non-coding RNAs that regulate expression of cohorts of genes. This study investigates which miRNAs are expressed in LAT Y136F T cells and compares these to miRNAs expressed in wild type T cells that are undergoing proliferation in two other settings. The first setting is homeostatic proliferation, which was modeled by adoptive transfer of wild type T cells into T cell-deficient mice. The second setting is proliferation in response to infection, which was modeled by infection of wild type mice with the nematode H. polygyrus. By comparing miRNA expression in these three proliferative states (LAT Y136F hyper-proliferation, homeostatic proliferation and proliferation in response to H. polygyrus infection) to expression in wild type naïve CD4+ T cells, we found miRNAs that were highly regulated in all three proliferative states (miR-21 and miR-146a) and some that were more specific to individual settings of proliferation such as those more specific for LAT Y136F lymphoproliferative disease (miR-669f, miR-155 and miR-466a/b). Future experiments that modulate levels of the miRNAs identified in this study may reveal the roles of these miRNAs in T cell proliferation and/or lymphoproliferative disease. PMID:23825558

  4. T helper 17 cells and related cytokines after allergen inhalation challenge in allergic asthmatics.

    PubMed

    Naji, Nizar; Smith, Steven G; Gauvreau, Gail M; O'Byrne, Paul M

    2014-01-01

    T helper (Th)17 cells may play a role in allergic asthma. This study assessed the effect of allergen inhalation challenge on circulating Th17 cells and related cytokines in allergic asthmatics. Peripheral blood mononuclear cells were collected from 16 atopic asthmatics before and 24 h after allergen challenge, as well as from 10 atopic nonasthmatics and 10 normal controls. Cells were stained for Th17 cytokines and their receptors (IL-17A, IL-17F, IL-21, IL-22, IL-17R, and IL-23R) using flow cytometry. Cytokine concentrations from cell culture supernatants were quantified using a multiplex assay for IL-17A, IL-17F, IL-21, IL-22, and IL-23. At baseline, asthmatics had a higher percentage of circulating Th17 cells (1.2 ± 0.5%) compared to normal controls (0.9 ± 0.66%, p < 0.001) but not compared to atopic nonasthmatics (1.13 ± 0.5%). There was a significant increase in Th17 cells in asthmatics after allergen challenge to 1.55 ± 0.4% (p < 0.05) and a trend toward significance in IL-17R expression from 3.4 ± 4.3 to 6.86 ± 6.84% after allergen challenge (p = 0.06). There was also a significant reduction in IL-21-positive cells following allergen challenge from 3.46 ± 1.85 to 2.33 ± 1.37% (p < 0.001). There were no significant differences in IL-17F, IL-22 and IL-23R expression. The concentration of IL-17A in culture supernatant was significantly higher in asthmatics compared to normal controls and IL-17A significantly increased 24 h after allergen challenge. The increase of Th17 cells and IL-17A in atopic asthma after allergen inhalation challenge suggests a possible role for Th17 in allergen-induced airway responses. © 2014 S. Karger AG, Basel.

  5. Attenuation of antigen-specific T helper 1 immunity by Neolitsea hiiranensis and its derived terpenoids

    PubMed Central

    Cheng, Yin-Hua; Chen, Ih-Sheng; Lin, Ying-Chi; Tung, Chun-Wei; Chang, Hsun-Shuo

    2016-01-01

    . hiiranensis-derived β-caryophyllene oxide inhibited several aspects of adaptive immune responses, including T-cell differentiation, IFN-γ production, and Th1-assocaited genes. Conclusion As IFN-γ is the key cytokine secreted by T helper-1 cells and plays a pivotal role in Th1 immune responses, our results suggested that the N. hiiranensis and its terpenoids may possess potential therapeutic effects on Th1-mediated immune disorders. PMID:28344896

  6. Extracellular MicroRNA Signature of Human Helper T Cell Subsets in Health and Autoimmunity.

    PubMed

    Torri, Anna; Carpi, Donatella; Bulgheroni, Elisabetta; Crosti, Maria-Cristina; Moro, Monica; Gruarin, Paola; Rossi, Riccardo L; Rossetti, Grazisa; Di Vizio, Dolores; Hoxha, Mirjam; Bollati, Valentina; Gagliani, Cristina; Tacchetti, Carlo; Paroni, Moira; Geginat, Jens; Corti, Laura; Venegoni, Luigia; Berti, Emilio; Pagani, Massimiliano; Matarese, Giuseppe; Abrignani, Sergio; de Candia, Paola

    2017-02-17

    Upon T cell receptor stimulation, CD4(+) T helper (Th) lymphocytes release extracellular vesicles (EVs) containing microRNAs. However, no data are available on whether human CD4(+) T cell subsets release EVs containing different pattern of microRNAs. The present work aimed at filling this gap by assessing the microRNA content in EVs released upon in vitro T cell receptor stimulation of Th1, Th17, and T regulatory (Treg) cells. Our results indicate that EVs released by Treg cells are significantly different compared with those released by the other subsets. In particular, miR-146a-5p, miR-150-5p, and miR-21-5p are enriched, whereas miR-106a-5p, miR-155-5p, and miR-19a-3p are depleted in Treg-derived EVs. The in vitro identified EV-associated microRNA signature was increased in serum of autoimmune patients with psoriasis and returned to healthy levels upon effective treatment with etanercept, a biological drug targeting the TNF pathway and suppressing inflammation. Moreover, Gene Set Enrichment Analysis showed an over-representation of genes relevant for T cell activation, such as CD40L, IRAK1, IRAK2, STAT1, and c-Myb in the list of validated targets of Treg-derived EV miRNAs. At functional level, Treg-derived (but not Th1/Th17-derived) EVs inhibited CD4(+) T cell proliferation and suppressed two relevant targets of miR-146a-5p: STAT1 and IRAK2. In conclusion, our work identified the miRNAs specifically released by different human CD4(+) T cell subsets and started to unveil the potential use of their quantity in human serum to mark the pathological elicitation of these cells in vivo and their biological effect in cell to cell communication during the adaptive immune response. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. The role of macrophages in the generation of T-helper cells. II. The genetic control of the macrophage-T-cell interaction for helper cell induction with soluble antigens

    PubMed Central

    1975-01-01

    Helper cell induction to nonparticle antigens in vitro requires the cooperation of T cells and macrophages, but does not occur if the macrophages are allogenic. The reasons for this were investigated. Malfunction of allogenic macrophages was excluded by cultures with their syngenic T cells; suppressor cell induction was excluded by admixture experiments. Thus, T cells and macrophages only cooperated if they were genetically similar. The genetic locus (loci) involved was mapped. Using congenic lines differing only at the H-2 complex, the genetic control of T-macrophage interaction was localized in the H- 2 region. Mice with intra H-2 recombinants were used to map the T- macrophage interaction locus in the I-A region of the H-2 complex (formerly known as poly-D, L-ala-poly-L-lys. Recombinants were also used to exclude the presence of another T-macrophage locus either the K, I-B, or I-C, SS-Slp, or D regions of the H-2 complex. Genetic restrictions for T-macrophage interaction in helper cell induction was shown in mice of the H-2-k, d, b, q, s genotypes as well as in H-2 recombinants. The possible mechanisms and significance of this genetic restriction are discussed. PMID:1079849

  8. FeynHelpers: Connecting FeynCalc to FIRE and Package-X

    NASA Astrophysics Data System (ADS)

    Shtabovenko, Vladyslav

    2017-09-01

    We present a new interface called FEYNHELPERS that connects FEYNCALC, a MATHEMATICA package for symbolic semi-automatic evaluation of Feynman diagrams and calculations in quantum field theory (QFT) to PACKAGE-X and FIRE. The former provides a library of analytic results for scalar 1-loop integrals with up to 4 legs, while the latter is a general-purpose tool for reduction of multi-loop scalar integrals using Integration-by-Parts (IBP) identities.

  9. Replication-deficient mutant Herpes Simplex Virus-1 targets professional antigen presenting cells and induces efficient CD4+ T helper responses.

    PubMed

    Fiorentini, Simona; Marconi, Peggy; Avolio, Manuela; Marini, Elena; Garrafa, Emirena; Caracciolo, Sonia; Rossi, Daniele; Bozac, Alexandra; Becker, Pablo D; Gentili, Francesca; Facchetti, Fabio; Guzman, Carlos A; Manservigi, Roberto; Caruso, Arnaldo

    2007-07-01

    Both neutralizing antibodies and cytotoxic T-cells are necessary to control a viral infection. However, vigorous T helper responses are essential for their elicitation and maintenance. Here we show that a recombinant replication-deficient Herpes Simplex Virus (HSV)-1 vector encoding the Human Immunodeficiency Virus (HIV)-1 matrix protein p17 (T0-p17) was capable of infecting professional antigen presenting cells (APCs) in vitro and in vivo. The injection of T0-p17 in the mouse dermis generated a strong p17-specific CD4+ T helper response preceding both p17-specific humoral and effector T cell responses. Moreover, we show that T0-p17 infection did not interfere with the endogenous processing of the transgene encoded antigen, since infected APCs were able to evoke a strong recall response in vitro. Our results demonstrate that replication-deficient HSV vectors can be appealing candidates for the development of vaccines able to trigger T helper responses.

  10. HPV-16 E1, E2 and E6 each complement the Ad5 helper gene set, increasing rAAV2 and wt AAV2 production.

    PubMed

    Cao, M; Zhu, H; Bandyopadhyay, S; You, H; Hermonat, P L

    2012-04-01

    Adeno-associated virus type 2 (AAV) is a popular vector for human gene therapy, because of its safety record and ability to express genes long term. Yet large-scale recombinant (r) AAV production remains problematic because of low particle yield. The adenovirus (Ad) and herpes (simplex) virus helper genes for AAV have been widely used and studied, but the helper genes of human papillomavirus (HPV) have not. HPV-16 E1, E2 and E6 help wild-type (wt) AAV productive infection in differentiating keratinocytes, however, HEK293 cells are the standard cell line used for generating rAAV. Here we demonstrate that the three HPV genes were unable to stimulate significant rAAV replication in HEK293 cells when used alone. However, when used in conjunction (complementation) with the standard Ad5 helper gene set, E1, E2 and E6 were each capable of significantly boosting rAAV DNA replication and virus particle yield. Moreover, wt AAV DNA replication and virion yield were also significantly boosted by each HPV gene along with wt Ad5 virus co-infection. Mild-to-moderate changes in rep- and cap-encoded protein levels were evident in the presence of the E1, E2 and E6 genes. Higher wt AAV DNA replication was not matched by similar increases in the levels of rep-encoded protein. Moreover, although rep mRNA was upregulated, cap mRNA was upregulated more. Higher virus yields did correlate most consistently with increased Rep52-, VP3- and VP-related 21/31 kDa species. The observed boost in wt and rAAV production by HPV genes was not unexpected, as the Ad and HPV helper gene sets do not seem to recapitulate each other. These results raise the possibility of generating improved helper gene sets derived from both the Ad and HPV helper gene sets.

  11. HPV-16 E1, E2 and E6 each complement the Ad5 helper gene set, increasing rAAV2 and wt AAV2 production

    PubMed Central

    Cao, M.; Zhu, H.; Bandyopadhyay, S; You, H; Hermonat, P.L.

    2011-01-01

    Adeno-associated virus type 2 (AAV) is a popular vector for human gene therapy, because of its safety record and ability to express genes long term. Yet large scale recombinant (r)AAV production remains problematic due to low particle yield. The adenovirus (Ad) and herpes (simplex) virus (HSV) helper genes for AAV have been widely used and studied, but the helper genes of human papillomavirus (HPV) have not. HPV-16 E1, E2 and E6 help wild type (wt) AAV productive infection in differentiating keratinocytes, however HEK293 cells are the standard cell line used for generating rAAV. Here we demonstrate that the three HPV genes were unable to stimulate significant rAAV replication in HEK293 cells when used alone. However, when used in conjunction (complementation) with the standard Ad5 helper gene set, E1, E2 and E6 were each capable of significantly boosting rAAV DNA replication and virus particle yield. Moreover, wt AAV DNA replication and virion yield were also significantly boosted by each HPV gene along with wt Ad5 virus co-infection. Mild to moderate changes in rep- and cap–encoded protein levels were evident in the presence of the E1, E2 and E6 genes. Higher wt AAV DNA replication was not matched by similar increases in the levels of rep-encoded protein. Moreover, while rep mRNA was up-regulated, cap mRNA was up-regulated more. Higher virus yields did correlate most consistently with increased Rep52, VP3 and VP-related 21/31 kDa species. The observed boost in wt and rAAV production by HPV genes was not unexpected, as the Ad and HPV helper gene sets do not seem to recapitulate each other. These results raise the possibility of generating improved helper gene sets derived from both the Ad and HPV helper gene sets. PMID:21850053

  12. Feasibility of Audio-Computer-Assisted Self-Interviewing With Color-Coding and Helper Assistance (ACASI-H) for Hmong Older Adults.

    PubMed

    Lor, Maichou; Bowers, Barbara J

    2017-08-01

    Many older adult immigrants in the US, including Hmong older adults, have limited English proficiency (LEP), and cannot read or have difficulty reading even in their first language (non-literate [NL]). Little has been done to identify feasible data collection approaches to enable inclusion of LEP or NL populations in research, limiting knowledge about their health. This study's purpose was to test the feasibility of culturally and linguistically adapted audio computer-assisted self-interviewing (ACASI) with color-labeled response categories and helper assistance (ACASI-H) for collection of health data with Hmong older adults. Thirty dyads (older adult and a helper) completed an ACASI-H survey with 13 health questions and a face-to-face debriefing interview. ACASI-H survey completion was video-recorded and reviewed with participants. Video review and debriefing interviews were audio-recorded and transcribed. Directed and conventional content analyses were used to analyze the interviews. All respondents reported that ACASI-H survey questions were consistent with their health experience. They lacked computer experience and found ACASI-H's interface user-friendly. All used the pre-recorded Hmong oral translation except for one, whose helper provided translation. Some Hmong older adults struggled with the color labeling at first, but helpers guided them to use the colors correctly. All dyads liked the color-labeled response categories and confirmed that a helper was necessary during the survey process. Findings support use of oral survey question administration with a technologically competent helper and color-labeled response categories when engaging LEP older adults in health-related data collection. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Enumeration of bacteria from the Clostridium leptum subgroup in human faecal microbiota using Clep1156 16S rRNA probe in combination with helper and competitor oligonucleotides.

    PubMed

    Saunier, Katiana; Rougé, Carole; Lay, Christophe; Rigottier-Gois, Lionel; Doré, Joël

    2005-07-01

    Target site inaccessibility represents a significant problem for fluorescent in situ hybridisation (FISH) of 16S rRNA oligonucleotide probes. For this reason, the Clep1156 probe targeting 16S rRNA of the Clostridium leptum phylogenetic subgroup used for dot blot experiments could not be used until now for FISH. Considering that bacteria from the C. leptum subgroup are very abundant in the human faecal microbiota and may play a significant role in host health, we have used unlabelled helper and competitor oligonucleotides to improve the 16S rRNA in situ accessibility and specificity of the Clep1156 probe and applied this approach to enumerate C. leptum bacteria in this ecosystem. Nine C. leptum target strains and five non-target strains were selected to develop and validate the helper-competitor strategy. Depending on the target strains, the use of helpers enhanced the fluorescence intensity signal of Clep1156 from 0.4-fold to 8.4-fold with a mean value of 3.6-fold, switching this probe from the brightness class V-VI (masked sites) to III-IV (accessible sites). The simultaneous use of helper and competitor oligonucleotides with Clep1156 probe allowed the expected specificity without disturbing in situ accessibility. Quantified by FISH combined with flow cytometry, C. leptum bacteria in human faecal samples (n=22) represented 19 +/- 7% of bacteria on average [4.9-37.5]. We conclude that helper oligonucleotides are very useful to circumvent the problem of target site in situ accessibility, especially when probe design is limited to only one 16S rRNA area and that helpers and competitors may be efficiently combined.

  14. 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.

  15. 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

  16. Intrinsic features of the CD8α(-) dendritic cell subset in inducing functional T follicular helper cells.

    PubMed

    Shin, Changsik; Han, Jae-A; Choi, Bongseo; Cho, Yoon-Kyoung; Do, Yoonkyung; Ryu, Seongho

    2016-04-01

    T follicular helper (Tfh) cells, a true B cell helper, have a critical role in enhancing humoral immune responses. However, the initial differentiation of Tfh cells by dendritic cells (DCs), the most potent antigen presenting cells, has not been clearly understood, particularly in the knowledge of the two major conventional dendritic cell subsets, CD8α(+) DCs or CD8α(-) DCs. Here we demonstrated that the localization of CD8α(-) DCs in the marginal zone (MZ) bridging channels is closely associated with the induction of CXCR5(+)CCR7(low) Tfh cells. We also showed that the major source of IL-6 for inducing Tfh cells is provided from the activated CD4(+) T cells induced by CD8α(-) DCs, and IL-6 directly secreted from the DC subsets seems minor. CD8α(-) DCs were superior in inducing functional Tfh cells over other antigen presenting cells including B cells. We here observed the unknown intrinsic features of the DC subsets, suggesting the potential of utilizing the CD8α(-) DC subset as therapeutic vaccine for the regulation of humoral immune responses.

  17. Expression and purification of a soluble B lymphocyte stimulator mutant modified with the T-helper cell epitope.

    PubMed

    Gao, Huiguang; Fu, Weiling; Li, Rongfen; Chen, Linfeng; Ji, Qing; Zhang, Li; Huang, Gang; He, Fengtian

    2006-10-01

    The DNA encoding soluble B lymphocyte stimulator (134-285 amino acids, sBLyS) mutant with residues 217-224 replaced by two glycines (named msBLyS) was constructed. The sequence encoding a foreign immunodominant T-helper epitope from ovalbumin (OVA) was then coupled to the 5'-end of msBLyS cDNA. After being sequenced, the recombinant DNA was ligated into the prokaryotic expression vector pQE-80L. The recombinant protein was produced in E. coli DH5alpha after induction with IPTG with the yield of more than 40% of total bacterial protein. The recombinant protein was purified with Ni-NTA chromatography and Sepharcryl S200 chromatography to a purity of more than 98%. The BALB/c mice, immunized with the recombinant protein, produced anti-BLyS antibodies at a high level, which indicated that the recombinant BLyS mutant modified with T-helper epitope elicited polyclonal antibodies with cross-reactivity with BLyS in vivo. This recombinant protein may therefore be used as immune inhibitor of BLyS for treating BLyS -associated autoimmune diseases.

  18. Silencing suppressor activity of a begomovirus DNA β encoded protein and its effect on heterologous helper virus replication.

    PubMed

    Eini, Omid; Dogra, Satish C; Dry, Ian B; Randles, John W

    2012-07-01

    DNA β satellites are circular single-stranded molecules associated with some monopartite begomoviruses in the family Geminiviridae. They co-infect with their helper viruses to induce severe disease in economically important crops. The βC1 protein encoded by DNA β is a pathogenicity determinant and has been reported to suppress post-transcriptional gene silencing (PTGS). The βC1 proteins from various DNA β molecules show low levels of amino acid sequence conservation. We show here that the βC1 from DNA β associated with Cotton leaf curl Multan virus (CLCuMV) is a suppressor of systemic PTGS. When this DNA β satellite co-inoculated with a heterologous helper virus, Tomato leaf curl virus (ToLCV), reduced the level of ToLCV siRNA and this was associated with a higher level of virus accumulation in infected tobacco plants. This may be a mechanism by which βC1 protects a heterologous virus from host gene silencing.

  19. Reduced in vitro immune responses of purified human Leu-3 (helper/inducer phenotype) cells after total lymphoid irradiation

    SciTech Connect

    Field, E.H.; Engleman, E.G.; Terrell, C.P.; Strober, S.

    1984-02-01

    Patients treated with total lymphoid irradiation (TLI) for intractible rheumatoid arthritis showed marked decreases in the in vitro proliferative responses of peripheral blood mononuclear cells (PBM) to antigens and mitogens. To determine whether an intrinsic deficit in helper/inducer cell proliferation contributed to decreased responses, cells of the helper/inducer phenotype were purified from the PBM of treated patients by using monoclonal anti-Leu-3 antibody and a modified panning procedure. The purified Leu-3 cells obtained after TLI showed a marked reduction in (/sup 3/H)thymidine incorporation in response to allogeneic lymphocytes, PHA, Con A, and several protein antigens, as compared with that of cells from the same patients obtained before TLI. In addition, the quantity of Leu-3 surface antigen on the panned cells was reduced after TLI. The results suggest that TLI induces prolonged qualitative as well as quantitative changes in circulating Leu-3 T cells. These changes may contribute to the clinical effects of TLI.

  20. The α4 Nicotinic Receptor Promotes CD4+ T-Cell Proliferation and a Helper T-Cell Immune Response

    PubMed Central

    Nordman, Jacob C.; Muldoon, Pretal; Clark, Sarah; Damaj, M. Imad

    2014-01-01

    Smoking is a common addiction and a leading cause of disease. Chronic nicotine exposure is known to activate nicotinic acetylcholine receptors (nAChRs) in immune cells. We demonstrate a novel role for α4 nAChRs in the effect of nicotine on T-cell proliferation and immunity. Using cell-based sorting and proteomic analysis we define an α4 nAChR expressing helper T-cell population (α4+CD3+CD4+) and show that this group of cells is responsive to sustained nicotine exposure. In the circulation, spleen, bone marrow, and thymus, we find that nicotine promotes an increase in CD3+CD4+ cells via its activation of the α4 nAChR and regulation of G protein subunit o, G protein regulated–inducer of neurite outgrowth, and CDC42 signaling within T cells. In particular, nicotine is found to promote a helper T cell 2 adaptive immunologic response within T cells that is absent in α4−/− mice. We thus present a new mechanism of α4 nAChR signaling and immune regulation in T cells, possibly accounting for the effect of smoking on the immune system. PMID:24107512

  1. Interleukin-4 production by follicular helper T cells requires the conserved Il4 enhancer hypersensitivity site V.

    PubMed

    Vijayanand, Pandurangan; Seumois, Grégory; Simpson, Laura J; Abdul-Wajid, Sarah; Baumjohann, Dirk; Panduro, Marisella; Huang, Xiaozhu; Interlandi, Jeneen; Djuretic, Ivana M; Brown, Daniel R; Sharpe, Arlene H; Rao, Anjana; Ansel, K Mark

    2012-02-24

    Follicular helper T cells (Tfh cells) are the major producers of interleukin-4 (IL-4) in secondary lymphoid organs where humoral immune responses develop. Il4 regulation in Tfh cells appears distinct from the classical T helper 2 (Th2) cell pathway, but the underlying molecular mechanisms remain largely unknown. We found that hypersensitivity site V (HS V; also known as CNS2), a 3' enhancer in the Il4 locus, is essential for IL-4 production by Tfh cells. Mice lacking HS V display marked defects in type 2 humoral immune responses, as evidenced by abrogated IgE and sharply reduced IgG1 production in vivo. In contrast, effector Th2 cells that are involved in tissue responses were far less dependent on HS V. HS V facilitated removal of repressive chromatin marks during Th2 and Tfh cell differentiation and increased accessibility of the Il4 promoter. Thus, Tfh and Th2 cells utilize distinct but overlapping molecular mechanisms to regulate Il4, a finding with important implications for understanding the molecular basis of allergic diseases.

  2. Structural and Nonstructural Viral Proteins Are Targets of T-Helper Immune Response against Human Respiratory Syncytial Virus.

    PubMed

    Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Mir, Carmen; Gebe, John A; Admon, Arie; López, Daniel

    2016-06-01

    Proper antiviral humoral and cellular immune responses require previous recognition of viral antigenic peptides that are bound to HLA class II molecules, which are exposed on the surface of antigen-presenting cells. The helper immune response is critical for the control and the clearance of human respiratory syncytial virus (HRSV) infection, a virus with severe health risk in infected pediatric, immunocompromised, and elderly populations. In this study, using a mass spectrometry analysis of complex HLA class II-bound peptide pools that were isolated from large amounts of HRSV-infected cells, 19 naturally processed HLA-DR ligands, most of them included in a complex nested set of peptides, were identified. Both the immunoprevalence and the immunodominance of the HLA class II response to HRSV were focused on one nonstructural (NS1) and two structural (matrix and mainly fusion) proteins of the infective virus. These findings have clear implications for analysis of the helper immune response as well as for antiviral vaccine design.

  3. Whitefly-mediated transmission of cotton leaf curl Multan betasatellite: evidence for betasatellite encapsidation in coat protein of helper begomoviruses.

    PubMed

    Tabein, S; Behjatnia, S A Akbar; Anabestani, A; Izadpanah, K

    2013-01-01

    Cotton leaf curl Multan betasatellite (CLCuMB) is responsible for symptom expression of a devastating disease of cotton in the Indian subcontinent. CLCuMB depends on helper virus replication-associated protein for its replication and on viral coat protein (CP) for its encapsidation. However, no direct evidence of encapsidation of CLCuMB in viral CP has been available. In the present study, non-viruliferous whiteflies were placed on tomato plants that had been agroinoculated with infectious clones of an Iranian isolate of tomato yellow leaf curl virus (TYLCV-[Ab]) and CLCuMB for an acquisition access period of 72 h and then transferred to healthy tomato seedlings at the 3- to 4-leaf stage. Typical symptoms of TYLCV-[Ab] appeared on inoculated seedlings 30-45 days post-inoculation. The presence of TYLCV-[Ab] and CLCuMB DNAs in symptomatic test plants and viruliferous whiteflies was confirmed by PCR analysis using specific primers and DIG Southern blotting. Furthermore, the possibility of CLCuMB DNA encapsidation in TYLCV-[Ab] CP within infected plants was examined by immunocapture PCR. The results showed that CLCuMB DNA was encapsidated in TYLCV-[Ab] CP. Whitefly-mediated transmission of CLCuMB in the presence of helper virus is additional evidence for encapsidation of CLCuMB by TYLCV-[Ab] CP.

  4. Proportions of circulating follicular helper T cells are reduced and correlate with memory B cells in HIV-infected children.

    PubMed

    Muema, Daniel M; Macharia, Gladys N; Olusola, Babatunde A; Hassan, Amin S; Fegan, Greg W; Berkley, James A; Urban, Britta C; Nduati, Eunice W

    2017-01-01

    HIV causes defects in memory B cells in children, but the mechanisms of those defects have not been fully elucidated. One possible mechanism is the lack of T-cell help to B cells during immune reactions. However, few studies have assessed the effect of HIV on follicular helper T cells (TFH cells) in children. In this study, follicular-homing CD4 T cells and memory B cells were assessed in HIV-infected children and compared with children from the community. CXCR5 and CD45RO were used as markers of follicular-homing T cells and memory T cells, respectively. Memory TFH cells were identified as CD3+CD8-CD4+CXCR5+CD45RO+PD1+. Central memory T cells were identified based on CCR7 expression. Relationship between the proportions of follicular-homing CD4 T cells and memory B cells were determined in multivariable regression models. Highly viremic HIV-infected children had lower proportions of memory TFH cells when compared with community control children. In multivariable analyses, high proportions of memory TFH cells were associated with increased percentages of resting memory B cells after adjusting for other covariates. The impact of HIV on follicular helper T cells could influence the accumulation of memory B cells in HIV-infected children.

  5. Increased Frequency of T Follicular Helper Cells and Elevated Interleukin-27 Plasma Levels in Patients with Pemphigus

    PubMed Central

    Schmidt, Thomas; Seipelt, Maria; Tackenberg, Björn; Möbs, Christian; Ghoreschi, Kamran; Hertl, Michael; Eming, Rüdiger

    2016-01-01

    Pemphigus is an autoimmune disease in which IgG auto-antibodies (auto-ab) against the desmosomal cadherins desmoglein (Dsg) 3 and Dsg1 cause loss of epidermal keratinocyte adhesion. Aim of this study was to investigate cytokines derived from antigen-presenting cells (APC) and their relation to CD4+ T cell subpopulations and to the auto-ab response in pemphigus. In this regard, patients with pemphigus were compared to patients with myasthenia gravis (MG), an unrelated auto-ab–mediated autoimmune disease, and healthy controls. In pemphigus and MG, the plasma concentrations of the APC-derived immunomodulatory cytokine IL-27 were highly increased. Strikingly, IL-27 strongly correlated with Dsg-specific IgG auto-ab titers. T helper (Th) 17 cells were augmented in both pemphigus and MG patients while T follicular helper (Tfh) cells, which are essential in providing B cell help, were increased only in pemphigus along with increasing plasma concentrations of IL-21, a cytokine produced by Th17 and Tfh cells. Moreover, we could detect Dsg3-specific autoreactive T cells producing IL-21 upon ex vivo stimulation with Dsg3. These findings suggest that IL-27 and IL-21-producing T cells, are involved in the pathogenesis of pemphigus. The further characterization of IL-21-producing T cells and of the role of IL-27 will lead to a more defined understanding of the auto-ab response in pemphigus. PMID:26872212

  6. A rapid Q-PCR titration protocol for adenovirus and helper-dependent adenovirus vectors that produces biologically relevant results

    PubMed Central

    Gallaher, Sean D.; Berk, Arnold J.

    2013-01-01

    Adenoviruses are employed in the study of cellular processes and as expression vectors used in gene therapy. The success and reproducibility of these studies is dependent in part on having accurate and meaningful titers of replication competent and helper-dependent adenovirus stocks, which is problematic due to the use of varied and divergent titration protocols. Physical titration methods, which quantify the total number of viral particles, are used by many, but are poor at estimating activity. Biological titration methods, such as plaque assays, are more biologically relevant, but are time consuming and not applicable to helper-dependent gene therapy vectors. To address this, a protocol was developed called “infectious genome titration” in which viral DNA is isolated from the nuclei of cells ~3 h post-infection, and then quantified by Q-PCR. This approach ensures that only biologically active virions are counted as part of the titer determination. This approach is rapid, robust, sensitive, reproducible, and applicable to all forms of adenovirus. Unlike other Q-PCR-based methods, titers determined by this protocol are well correlated with biological activity. PMID:23624118

  7. T Regulatory and T Helper 17 Cells in Primary Sjögren's Syndrome: Facts and Perspectives

    PubMed Central

    Alunno, Alessia; Carubbi, Francesco; Bistoni, Onelia; Caterbi, Sara; Bartoloni, Elena; Mirabelli, Giulia; Cannarile, Francesca; Cipriani, Paola; Giacomelli, Roberto; Gerli, Roberto

    2015-01-01

    Historically, primary Sjögren's syndrome (pSS) was thought to be a T helper (h) 1 driven disease due to the predominance of CD4+T lymphocytes and their products in target organs and peripheral blood of patients. In the last decades, the identification of a number of T cell subsets, including Th17, T regulatory (Treg), and follicular helper T cells, challenged this long-standing paradigm and prompted to identify their role in pSS pathogenesis. In addition the impact of abnormal proinflammatory cytokine production, such as IL-6, IL-17, IL-22, and IL-23, has also attracted considerable attention. However, although several studies have been carried out in experimental models and patients with pSS, many aspects concerning the role of Treg cells and IL-17/Th17 cell system in pSS pathogenesis are not fully elucidated. In particular, the role played by different IL-17-producing T cell subsets as well as the effects of pharmacological therapies on Treg/Th17 cell balance represents an intriguing issue. The aim of this review article is to provide an overview of current knowledge on Treg cells and IL-17-producing T cells in pSS pathogenesis. We believe that these insights into pSS pathogenesis may provide the basis for successful therapeutic intervention in this disease. PMID:26060357

  8. Proportions of circulating follicular helper T cells are reduced and correlate with memory B cells in HIV-infected children

    PubMed Central

    Macharia, Gladys N.; Olusola, Babatunde A.; Hassan, Amin S.; Fegan, Greg W.; Berkley, James A.; Urban, Britta C.; Nduati, Eunice W.

    2017-01-01

    Introduction HIV causes defects in memory B cells in children, but the mechanisms of those defects have not been fully elucidated. One possible mechanism is the lack of T-cell help to B cells during immune reactions. However, few studies have assessed the effect of HIV on follicular helper T cells (TFH cells) in children. Methods In this study, follicular-homing CD4 T cells and memory B cells were assessed in HIV-infected children and compared with children from the community. CXCR5 and CD45RO were used as markers of follicular-homing T cells and memory T cells, respectively. Memory TFH cells were identified as CD3+CD8-CD4+CXCR5+CD45RO+PD1+. Central memory T cells were identified based on CCR7 expression. Relationship between the proportions of follicular-homing CD4 T cells and memory B cells were determined in multivariable regression models. Results Highly viremic HIV-infected children had lower proportions of memory TFH cells when compared with community control children. In multivariable analyses, high proportions of memory TFH cells were associated with increased percentages of resting memory B cells after adjusting for other covariates. Conclusion The impact of HIV on follicular helper T cells could influence the accumulation of memory B cells in HIV-infected children. PMID:28445512

  9. Increased Frequency of T Follicular Helper Cells and Elevated Interleukin-27 Plasma Levels in Patients with Pemphigus.

    PubMed

    Hennerici, Tina; Pollmann, Robert; Schmidt, Thomas; Seipelt, Maria; Tackenberg, Björn; Möbs, Christian; Ghoreschi, Kamran; Hertl, Michael; Eming, Rüdiger

    2016-01-01

    Pemphigus is an autoimmune disease in which IgG auto-antibodies (auto-ab) against the desmosomal cadherins desmoglein (Dsg) 3 and Dsg1 cause loss of epidermal keratinocyte adhesion. Aim of this study was to investigate cytokines derived from antigen-presenting cells (APC) and their relation to CD4+ T cell subpopulations and to the auto-ab response in pemphigus. In this regard, patients with pemphigus were compared to patients with myasthenia gravis (MG), an unrelated auto-ab-mediated autoimmune disease, and healthy controls. In pemphigus and MG, the plasma concentrations of the APC-derived immunomodulatory cytokine IL-27 were highly increased. Strikingly, IL-27 strongly correlated with Dsg-specific IgG auto-ab titers. T helper (Th) 17 cells were augmented in both pemphigus and MG patients while T follicular helper (Tfh) cells, which are essential in providing B cell help, were increased only in pemphigus along with increasing plasma concentrations of IL-21, a cytokine produced by Th17 and Tfh cells. Moreover, we could detect Dsg3-specific autoreactive T cells producing IL-21 upon ex vivo stimulation with Dsg3. These findings suggest that IL-27 and IL-21-producing T cells, are involved in the pathogenesis of pemphigus. The further characterization of IL-21-producing T cells and of the role of IL-27 will lead to a more defined understanding of the auto-ab response in pemphigus.

  10. CD26 Expression on T Helper Populations and sCD26 Serum Levels in Patients with Rheumatoid Arthritis

    PubMed Central

    Cordero, Oscar J.; Varela-Calviño, Rubén; López-González, Tania; Calviño-Sampedro, Cristina; Viñuela, Juan E.; Mouriño, Coral; Hernández-Rodríguez, Íñigo; Rodríguez-López, Marina; Aspe de la Iglesia, Bruno; Pego, José María

    2015-01-01

    We studied dipeptidyl peptidase IV (DPP-IV, CD26) expression in different T helper cells and serum soluble DPP-IV/sCD26 levels in rheumatoid arthritis (RA) patients, correlated these with disease activity score (DAS), and examined how they were affected by different therapies, conventional or biological (anti-TNF, anti-CD20 and anti-IL6R or Ig-CTLA4). The percentage of CD4+CD45R0+CD26- cells was greatly reduced in patients (up to 50%) when compared with healthy subjects. Three other subsets of CD4 cells, including a CD26high Th1-associated population, changed variably with therapies. Data from these subsets (frequency and staining density) significantly correlated with DAS28 or DAS28 components but different in each group of patients undergoing the different therapies. Th17 and Th22 subsets were implicated in RA as independent CCR4+ and CCR4- populations each, with distinct CD26 expression, and were targeted with varying efficiency by each therapy. Serum DPP-IV activity rather than sCD26 levels was lower in RA patients compared to healthy donors. DPP-IV and sCD26 serum levels were found related to specific T cell subsets but not to disease activity. We conclude that, according to their CD26 expression, different cell subsets could serve to monitor RA course, and an uncharacterized T helper CD26- subset, not targeted by therapies, should be monitored for early diagnosis. PMID:26177310

  11. Dysbiosis of gut microbiota induced the disorder of helper T cells in influenza virus-infected mice.

    PubMed

    Yu, Bin; Dai, Cong-qi; Chen, Jia; Deng, Li; Wu, Xian-lin; Wu, Sha; Zhao, Chang-lin; Jiang, Zhen-you; Chen, Xiao-yin

    2015-01-01

    It is widely understood that commensal microbiota contributes to the maintenance of intestinal homeostasis through dynamic interactions with a body's immunity. And the immune regulation is important for the influenza vaccine's effectiveness after body injection, however, the mechanism between commensal microbiota and vaccine's effectiveness remains unknown. The impact that individual bacteria species have on the balance of the systemic immune system beyond the local intestinal mucosal tissues also remains less clear, and the related mechanism is still unknown. In this study, through the administration of various antibiotics, we examined the balance of helper T cell subsets in mice after inoculating them with the influenza virus and then, attempted to imitate the clinical practice in which patients are always prescribed with an antibiotic treatment in flu season. The data indicates that the mice in each group present differential immune responses in terms of the makeup of helper T cell subsets, although the Th17 cell activity seems to not be involved in the systemic immune modulation in the mice that are susceptible to the intervention of antibiotic. Th1, Th2, and anti-inflammatory regulatory T cells have been implicated in the contribution to the systemic immune response influenced by the antibiotic-induced dysbiosis. Thus we believe that the normal intestinal flora could maintain the immune balance and inhibit the inflammatory responses, which may be useful for clinical application to take intestinal flora into consideration when influenza vaccination was used.

  12. JAK inhibition induces silencing of T Helper cytokine secretion and a profound reduction in T regulatory cells.

    PubMed

    Keohane, Clodagh; Kordasti, Shahram; Seidl, Thomas; Perez Abellan, Pilar; Thomas, Nicholas S B; Harrison, Claire N; McLornan, Donal P; Mufti, Ghulam J

    2015-10-01

    CD4(+) T cells maintain cancer surveillance and immune tolerance. Chronic inflammation has been proposed as a driver of clonal evolution in myeloproliferative neoplasms (MPN), suggesting that T cells play an important role in their pathogenesis. Treatment with JAK inhibitors (JAKi) results in improvements in MPN-associated constitutional symptoms as well as reductions in splenomegaly. However, effects of JAKi on T cells in MPN are not well established and the baseline immune signature remains unclear. We investigated the frequency and function of CD4(+) T cell subsets in 50 MPN patients at baseline as well as during treatment with either ruxolitinib or fedratinib in a subset. We show that CD4(+)  CD127(low)  CD25(high)  FOXP3(+) T regulatory cells are reduced in MPN patients compared to healthy controls and that this decrease is even more pronounced following JAKi therapy. Moreover, we show that after 6 months of treatment the number of T helper (Th)-17 cells increased. We also describe a functional 'silencing' of T helper cells both in vivo and in vitro and a blockade of pro-inflammatory cytokines from these cells. This profound effect of JAKi on T cell function may underlay augmented rates of atypical infections that have been reported with use of these drugs.

  13. Development of a suspension serum-free helper-dependent adenovirus production system and assessment of co-infection conditions.

    PubMed

    Meneses-Acosta, Angélica; Dormond, Edwige; Jacob, Danielle; Tom, Roseanne; Bernier, Alice; Perret, Sylvie; St-Laurent, Gilles; Durocher, Yves; Gilbert, Rénald; Kamen, Amine

    2008-03-01

    Helper-dependent adenovirus (HDAd), deleted in all viral protein-coding sequences has been designed to reduce immune response and favor long-term expression of therapeutic genes in clinical programs. Its production requires co-infection of E1-complementing cells with helper adenovirus (HAd). Significant progresses have been made in the molecular design of HDAd, but large scale production remains a challenge. In this work, a scalable system for HDAd production is designed and evaluated focusing on the co-infection step. A human embryo kidney 293 (293) derived cell line, the 293SF/FLPe was generated to produce efficiently HDAd while restricting the packaging of HAd. This cell line was adapted to grow in suspension and in serum-free medium. Multiplicity of infection (MOI) of HDAd ranging from 0.1 to 50 was evaluated in presence of HAd at a MOI of 5. Optimal MOIs for HDAd amplification were found in the range of 5-10. HAd contamination was only 1%. These results were validated in a 3 L bioreactor under controlled operating conditions where a higher HDAd yield of 2.6 x 10(9) viral particles (VP)/mL or 3.5 x 10(8) infectious units (IU)/mL of HDAd was obtained.

  14. Avidity of human T cell receptor engineered CD4+ T cells drives T-helper differentiation fate

    PubMed Central

    Adair, Patrick; Kim, Yong Chan; Pratt, Kathleen P.; Scott, David W.

    2016-01-01

    The role of the T cell receptor (TCR) in antigen recognition and activation of T lymphocytes is well established. However, how the TCR affects T-helper differentiation/skewing is less well understood, particularly for human CD4+ (CD4) T cell subsets. Here we investigate the role of TCR specific antigen avidity in differentiation and maintenance of human Th1, Th2 and Th17 subsets. Two human TCRs, both specific for the same peptide antigen but with different avidities, were cloned and expressed in human CD4 T cells. These TCR engineered cells were then stimulated with specific antigen in unskewed and T-helper skewed conditions. We show that TCR avidity can control the percentage of IL-4 and IFN-γ co-expression in unskewed TCR engineered cells, that effector function can be maintained in a TCR avidity-dependent manner in skewed TCR engineered cells, and that increased TCR avidity can accelerate Th1 skewing of TCR engineered cells. PMID:26653006

  15. Structural and Nonstructural Viral Proteins Are Targets of T-Helper Immune Response against Human Respiratory Syncytial Virus*

    PubMed Central

    Barriga, Alejandro; Barnea, Eilon; Mir, Carmen; Gebe, John A.; Admon, Arie

    2016-01-01

    Proper antiviral humoral and cellular immune responses require previous recognition of viral antigenic peptides that are bound to HLA class II molecules, which are exposed on the surface of antigen-presenting cells. The helper immune response is critical for the control and the clearance of human respiratory syncytial virus (HRSV) infection, a virus with severe health risk in infected pediatric, immunocompromised, and elderly populations. In this study, using a mass spectrometry analysis of complex HLA class II-bound peptide pools that were isolated from large amounts of HRSV-infected cells, 19 naturally processed HLA-DR ligands, most of them included in a complex nested set of peptides, were identified. Both the immunoprevalence and the immunodominance of the HLA class II response to HRSV were focused on one nonstructural (NS1) and two structural (matrix and mainly fusion) proteins of the infective virus. These findings have clear implications for analysis of the helper immune response as well as for antiviral vaccine design. PMID:27090790

  16. An inherently bi-functional subset of Foxp3+ T helper cells is controlled by the transcription factor Eos

    PubMed Central

    Sharma, Madhav D.; Huang, Lei; Choi, Jeong-Hyeon; Lee, Eun-Joon; Wilson, James M.; Lemos, Henrique; Pan, Fan; Blazar, Bruce R.; Pardoll, Drew M.; Mellor, Andrew L; Shi, Huidong; Munn, David H.

    2013-01-01

    SUMMARY At sites of inflammation, certain regulatory T cells (Treg cells) can undergo rapid reprogramming into helper-like cells, without loss of the transcription factor Foxp3. We show that reprogramming is controlled by down-regulation of the transcription factor Eos (Ikzf4), an obligate co-repressor for Foxp3. Reprogramming was restricted to a specific subset of “Eoslabile” Treg cells which were present in the thymus and identifiable by characteristic surface markers and DNA methylation. Mice made deficient in this subset became impaired in their ability to provide help for presentation of new antigens to naive T cells. Down-regulation of Eos required the pro-inflammatory cytokine IL-6, and mice lacking IL-6 had impaired development and function of the Eos-labile subset. Conversely, the immunoregulatory enzyme IDO blocked loss of Eos, and prevented the Eos-labile Treg cells from reprogramming. Thus, the Foxp3+ lineage contains a committed subset of Treg cells capable of rapid conversion into biologically important helper cells. PMID:23684987

  17. An inherently bifunctional subset of Foxp3+ T helper cells is controlled by the transcription factor eos.

    PubMed

    Sharma, Madhav D; Huang, Lei; Choi, Jeong-Hyeon; Lee, Eun-Joon; Wilson, James M; Lemos, Henrique; Pan, Fan; Blazar, Bruce R; Pardoll, Drew M; Mellor, Andrew L; Shi, Huidong; Munn, David H

    2013-05-23

    At sites of inflammation, certain regulatory T cells (Treg cells) can undergo rapid reprogramming into helper-like cells without loss of the transcription factor Foxp3. We show that reprogramming is controlled by downregulation of the transcription factor Eos (Ikzf4), an obligate corepressor for Foxp3. Reprogramming was restricted to a specific subset of "Eos-labile" Treg cells that was present in the thymus and identifiable by characteristic surface markers and DNA methylation. Mice made deficient in this subset became impaired in their ability to provide help for presentation of new antigens to naive T cells. Downregulation of Eos required the proinflammatory cytokine interleukin-6 (IL-6), and mice lacking IL-6 had impaired development and function of the Eos-labile subset. Conversely, the immunoregulatory enzyme IDO blocked loss of Eos and prevented the Eos-labile Treg cells from reprogramming. Thus, the Foxp3(+) lineage contains a committed subset of Treg cells capable of rapid conversion into biologically important helper cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. T-helper cell and associated antibody response to synthetic peptides of the E glycoprotein of Murray Valley encephalitis virus.

    PubMed Central

    Mathews, J H; Allan, J E; Roehrig, J T; Brubaker, J R; Uren, M F; Hunt, A R

    1991-01-01

    A battery of 16 synthetic peptides, selected primarily by computer analysis for predicted B- and T-cell epitopes, was prepared from the deduced amino acid sequence of the envelope (E) glycoprotein of Murray Valley encephalitis (MVE) virus. We examined all of the peptides for T-helper (Th)-cell recognition and antibody induction in three strains of mice: C57BL/6, BALB/c, and C3H. Lymphoproliferative and interleukin-2 assays were performed on splenic T cells from mice inoculated with peptides in Freund's incomplete adjuvant or with MVE virus. Several peptides found to contain predicted T-cell epitopes elicited a Th-cell response in at least one strain of mice, usually with a concomitant antibody response. Peptides 145 (amino acids 145 to 169) and 17 (amino acids 356 to 376) were strongly recognized by T cells from all three inbred strains of mice. Peptide 06 (amino acids 230 to 251) primed C57BL/6 mice for Th- and B-cell reactivity with native MVE virus, and T cells from virus-immune mice were stimulated by this peptide. Peptide 06 was recognized by several Th-cell clones prepared from mice immunized with MVE, West Nile, or Kunjin virus. These results indicate that it may be feasible to design synthetic flavivirus peptides that define T-cell epitopes capable of generating a helper cell response for B-cell epitopes involved in protective immunity. PMID:1832722

  19. Prostate-Specific and Tumor-Specific Targeting of an Oncolytic HSV-1 Amplicon/Helper Virus for Prostate Cancer Treatment

    DTIC Science & Technology

    2009-11-01

    Targeting of an Oncolytic HSV - 1 Amplicon/Helper Virus for Prostate Cancer Treatment PRINCIPAL INVESTIGATOR: Cleo Lee CONTRACTING...5a. CONTRACT NUMBER Prostate-Specific and Tumor-Specific Targeting of an Oncolytic HSV - 1 Amplicon/Helper Virus for Prostate Cancer Treatment...untranslated region (3’UTR) of a herpes simplex virus- 1 ( HSV - 1 ) essential viral gene, ICP4, to create CMV-ICP4-143T and CMV-ICP4-145T amplicon viruses. Our

  20. Dose and Hg species determine the T-helper cell activation in murine autoimmunity.

    PubMed

    Havarinasab, Said; Björn, Erik; Ekstrand, Jimmy; Hultman, Per

    2007-01-05

    Inorganic mercury (mercuric chloride--HgCl(2)) induces in mice an autoimmune syndrome (HgIA) with T cell-dependent polyclonal B cell activation and hypergammaglobulinemia, dose- and H-2-dependent production of autoantibodies targeting the 34 kDa nucleolar protein fibrillarin (AFA), and systemic immune-complex deposits. The organic mercury species methylmercury (MeHg) and ethylmercury (EtHg--in the form of thimerosal) induce AFA, while the other manifestations of HgIA seen after treatment with HgCl(2) are present to varying extent. Since these organic Hg species are converted to the autoimmunogen Hg(2+) in the body, their primary autoimmunogen potential is uncertain and the subject of this study. A moderate dose of HgCl(2) (8 mg/L drinking water--internal dose 148 micro gHg/kg body weight [bw]/day) caused the fastest AFA response, while the induction was delayed after higher (25 mg/L) and lower (1.5 and 3 mg/L) doses. The lowest dose of HgCl(2) inducing AFA was 1.5 mg/L drinking water which corresponded to a renal Hg(2+) concentration of 0.53 micro g/g. Using a dose of 8 mg HgCl(2)/L this threshold concentration was reached within 24 h, and a consistent AFA response developed after 8-10 days. The time lag for the immunological part of the reaction leading to a consistent AFA response was therefore 7-9 days. A dose of thimerosal close to the threshold dose for induction of AFA (2 mg/L drinking water--internal dose 118 micro gHg/kg bw per day), caused a renal Hg(2+) concentration of 1.8 micro g/g. The autoimmunogen effect of EtHg might therefore be entirely due to Hg(2+) formed from EtHg in the body. The effect of organic and inorganic Hg species on T-helper type 1 and type 2 cells during induction of AFA was assessed as the presence and titre of AFA of the IgG1 and IgG2a isotype, respectively. EtHg induced a persistent Th1-skewed response irrespectively of the dose and time used. A low daily dose of HgCl(2) (1.5-3 mg/L) caused a Th1-skewed AFA response, while a

  1. Clinical-scale isolation of the total Aspergillus fumigatus-reactive T-helper cell repertoire for adoptive transfer.

    PubMed

    Bacher, Petra; Jochheim-Richter, Andrea; Mockel-Tenbrink, Nadine; Kniemeyer, Olaf; Wingenfeld, Eva; Alex, Regina; Ortigao, Alice; Karpova, Darja; Lehrnbecher, Thomas; Ullmann, Andrew J; Hamprecht, Axel; Cornely, Oliver; Brakhage, Axel A; Assenmacher, Mario; Bonig, Halvard; Scheffold, Alexander

    2015-10-01

    Evidence of the criticality of the adaptive immune response for controlling invasive aspergillosis has been provided. This observation is supported by the fact that invasive aspergillosis, a grave complication of allogeneic stem cell transplantation, occurs long after myeloid reconstitution in patients with low T-cell engraftment and/or on immunosuppressants. Adoptive T-cell transfer might be beneficial, but idiosyncrasies of Aspergillus fumigatus and the anti-Aspergillus immune response render established selection technologies ineffective. We developed a Good Manufacturing Practice (GMP)-compliant protocol for preparation of A. fumigatus-specific CD4+ cells by sequentially depleting regulatory and cytotoxic T cells, activating A. fumigatus-specific T-helper cells with GMP-grade A. fumigatus lysate, and immuno-magnetically isolating them via the transiently up-regulated activation marker, CD137. In 13 full-scale runs, we demonstrate robustness and feasibility of the approach. From 2 × 10(9) peripheral blood mononuclear cells, we isolated 27 × 10(3)-318 × 10(3)Aspergillus-specific T-helper cells. Frequency among total T cells was increased, on average, by 200-fold. Specific studies indicate specificity and functionality: After non-specific in vitro expansion and re-stimulation with different antigens, we observed strong cytokine responses to A. fumigatus and some other fungi including Candida albicans, but none to unrelated antigens. Our technology isolates naturally occurring Aspergillus-specific T-helper cells within 2 days of identifying the clinical indication. Rapid adoptive transfer of Aspergillus-specific T cells may be quite feasible; the clinical benefit remains to be demonstrated. A manufacturing license as an advanced-therapy medicinal product was received and a clinical trial in post-transplantation invasive aspergillosis patients approved. The product is dosed at 5 × 10E3/kg T cells (single intravenous injection), of which at least 10

  2. Multifunctional Double-negative T Cells in Sooty Mangabeys Mediate T-helper Functions Irrespective of SIV Infection

    PubMed Central

    Micci, Luca; Gasper, Melanie A.; Ortiz, Alexandra M.; Else, James; Silvestri, Guido; Paiardini, Mirko; Aitchison, John D.; Sodora, Donald L.

    2013-01-01

    Studying SIV infection of natural host monkey species, such as sooty mangabeys, has provided insights into the immune changes associated with these nonprogressive infections. Mangabeys maintain immune health despite high viremia or the dramatic CD4 T cell depletion that can occur following multitropic SIV infection. Here we evaluate double-negative (DN)(CD3+CD4−CD8−) T cells that are resistant to SIV infection due to a lack of CD4 surface expression, for their potential to fulfill a role as helper T cells. We first determined that DN T cells are polyclonal and predominantly exhibit an effector memory phenotype (CD95+CD62L−). Microarray analysis of TCR (anti-CD3/CD28) stimulated DN T cells indicated that these cells are multifunctional and upregulate genes with marked similarity to CD4 T cells, such as immune genes associated with Th1 (IFNγ), Th2 (IL4, IL5, IL13, CD40L), Th17 (IL17, IL22) and TFH (IL21, ICOS, IL6) function, chemokines such as CXCL9 and CXCL10 and transcription factors known to be actively regulated in CD4 T cells. Multifunctional T-helper cell responses were maintained in DN T cells from uninfected and SIV infected mangabeys and persisted in mangabeys exhibiting SIV mediated CD4 loss. Interestingly, TCR stimulation of DN T cells from SIV infected mangabeys results in a decreased upregulation of IFNγ and increased IL5 and IL13 expression compared to uninfected mangabeys. Evaluation of proliferative capacity of DN T cells in vivo (BrDU labeling) indicated that these cells maintain their ability to proliferate despite SIV infection, and express the homeostatic cytokine receptors CD25 (IL2 receptor) and CD127 (IL7 receptor). This study identifies the potential for a CD4-negative T cell subset that is refractory to SIV infection to perform T-helper functions in mangabeys and suggests that immune therapeutics designed to increase DN T cell function during HIV infection may have beneficial effects for the host immune system. PMID:23825945

  3. Improved blastocyst development of single cow OPU-derived presumptive zygotes by group culture with agarose-embedded helper embryos

    PubMed Central

    2011-01-01

    Background The in vitro culture of presumed zygotes derived from single cow ovum pick-up (OPU) is important for the production of quality blastocysts maintaining pedigree. The aim of the present study was to evaluate the agar chip-embedded helper embryo coculture system for single cow OPU-derived zygotes by assessing embryo quality. Methods Cumulus oocyte complexes (COCs) were collected from Hanwoo cows with high genetic merit twice a week using the ultra-sound guided OPU technique and from slaughterhouse ovaries. The Hanwoo cow COCs and slaughterhouse ovaries were matured in vitro, fertilized in vitro with thawed Hanwoo sperm and cultured for 24 h. The presumed zygotes were subsequently placed in three different culture systems: (1) control OPU (controlOPU) with single cow OPU-derived presumed zygotes (2~8); (2) agar chip-embedded slaughterhouse helper embryo coculture (agarOPU) with ten presumed zygotes including all presumed zygotes from a cow (2~8) and the rest from agar chip-embedded slaughterhouse presumed zygotes (8~2); and (3) slaughterhouse in vitro embryo production (sIVP) with ten slaughterhouse ovary-derived presumed zygotes, each in 50 μL droplets. Day 8 blastocysts were assayed for apoptosis and gene expression using real time PCR. Results The coculture system promoted higher blastocyst development in OPU zygotes compared to control OPU zygotes cultured alone (35.2 vs. 13.9%; P < 0.01). Genes predicted to be involved in implantation failure and/or embryo resorption were down-regulated (P < 0.05) in control OPU zygotes (CD9, 0.4-fold; AKRAB1, 0.3-fold) and in cocultured zygotes (CD9, 0.3-fold; AKRAB1, 0.3-fold) compared to sIVP blastocysts (1.0-fold). Moreover, genes involved in implantation and/or normal calf delivery were up-regulated (P < 0.05 to P < 0.01) in control OPU zygotes (PGSH2, 5.0-fold; TXN, 4.3-fold; PLAU, 1.7-fold) and cocultured zygotes (PGSH2, 14.5-fold; TXN, 3.2-fold; PLAU, 6.8-fold) compared to sIVP (1.0-fold) blastocysts. However

  4. Bell miner provisioning calls are more similar among relatives and are used by helpers at the nest to bias their effort towards kin

    PubMed Central

    McDonald, Paul G.; Wright, Jonathan

    2011-01-01

    Kin selection predicts that helpers in cooperative systems should preferentially aid relatives to maximize fitness. In family-based groups, this can be accomplished simply by assisting all group members. In more complex societies, where large numbers of kin and non-kin regularly interact, more sophisticated kin-recognition mechanisms are needed. Bell miners (Manorina melanophrys) are just such a system where individuals regularly interact with both kin and non-kin within large colonies. Despite this complexity, individual helpers of both sexes facultatively work harder when provisioning the young of closer genetic relatedness. We investigated the mechanism by which such adaptive discrimination occurs by assessing genetic kinship influences on the structure of more than 1900 provisioning vocalizations of 185 miners. These ‘mew’ calls showed a significant, positive linear increase in call similarity with increasing genetic relatedness, most especially in comparisons between male helpers and the breeding male. Furthermore, individual helping effort was more heavily influenced by call similarity to breeding males than to genetic relatedness, as predicted if call similarity is indeed the rule-of-thumb used to discriminate kin in this system. Individual mew call structure appeared to be inflexible and innate, providing an effective mechanism by which helpers can assess their relatedness to any individual. This provides, to our knowledge, the first example of a mechanism for fine-scale kin discrimination in a complex avian society. PMID:21450738

  5. Bell miner provisioning calls are more similar among relatives and are used by helpers at the nest to bias their effort towards kin.

    PubMed

    McDonald, Paul G; Wright, Jonathan

    2011-11-22

    Kin selection predicts that helpers in cooperative systems should preferentially aid relatives to maximize fitness. In family-based groups, this can be accomplished simply by assisting all group members. In more complex societies, where large numbers of kin and non-kin regularly interact, more sophisticated kin-recognition mechanisms are needed. Bell miners (Manorina melanophrys) are just such a system where individuals regularly interact with both kin and non-kin within large colonies. Despite this complexity, individual helpers of both sexes facultatively work harder when provisioning the young of closer genetic relatedness. We investigated the mechanism by which such adaptive discrimination occurs by assessing genetic kinship influences on the structure of more than 1900 provisioning vocalizations of 185 miners. These 'mew' calls showed a significant, positive linear increase in call similarity with increasing genetic relatedness, most especially in comparisons between male helpers and the breeding male. Furthermore, individual helping effort was more heavily influenced by call similarity to breeding males than to genetic relatedness, as predicted if call similarity is indeed the rule-of-thumb used to discriminate kin in this system. Individual mew call structure appeared to be inflexible and innate, providing an effective mechanism by which helpers can assess their relatedness to any individual. This provides, to our knowledge, the first example of a mechanism for fine-scale kin discrimination in a complex avian society.

  6. Anti-tumour necrosis factor treatment increases circulating T helper type 17 cells similarly in different types of inflammatory arthritis.

    PubMed

    Hull, D N; Williams, R O; Pathan, E; Alzabin, S; Abraham, S; Taylor, P C

    2015-09-01

    We investigated changes in circulating T helper type 17 (Th17) cells following anti-tumour necrosis factor (TNF) in rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) patients. Peripheral blood mononuclear cells (PBMC) were isolated from 25 RA, 15 AS and eight PsA patients at baseline 4 and 12 weeks after treatment, and Th17 cell frequencies were analysed using interleukin (IL)-17 enzyme-linked immunospot (ELISPOT) and flow cytometry. A significant increase in IL-17-producing cells was observed by ELISPOT in RA and AS patients at 12 weeks. Flow cytometry confirmed significant increases in CD4(+) IL-17(+) cells at 12 weeks in RA and AS and 4 weeks in PsA patients. Anti-TNF treatment increases circulating Th17 cells in three different diseases. © 2015 British Society for Immunology.

  7. Genomic views of STAT function in CD4+ T helper cell differentiation: new technology brings new insights and new questions

    PubMed Central

    O’Shea, John J; Lahesmaa, Riitta; Vahedi, Golnaz; Laurence, Arian; Kanno, Yuka

    2011-01-01

    Signal transducer and activator of transcription (STAT) proteins are well known for their essential roles in transmitting cytokine-mediated signals and specifying T helper (TH) cell differentiation; however, recent technological advances have led to a new level of understanding of transcription factor action. This work has revealed that STAT proteins have broad and complex roles in gene regulation and epigenetic control, including important roles as functional repressors. However, the challenge remains how to link signal transduction, nucleosome biology and gene regulation. The relevance of tackling this problem is highlighted by genome-wide association studies that link cytokine signalling and STATs to a variety of autoimmune or immune deficiency disorders. Defining exactly how extrinsic signals control the specification and plasticity of TH cells will provide important insights and perhaps therapeutic opportunities in these diseases. PMID:21436836

  8. A novel helper phage for HaloTag-mediated co-display of enzyme and substrate on phage.

    PubMed

    Delespaul, Wouter; Peeters, Yves; Herdewijn, Piet; Robben, Johan

    2015-05-01

    Phage display is an established technique for the molecular evolution of peptides and proteins. For the selection of enzymes based on catalytic activity however, simultaneous coupling of an enzyme and its substrate to the phage surface is required. To facilitate this process of co-display, we developed a new helper phage displaying HaloTag, a modified haloalkane dehalogenase that binds specifically and covalently to functionalized haloalkane ligands. The display of functional HaloTag was demonstrated by capture on streptavidin-coated magnetic beads, after coupling a biotinylated haloalkane ligand, or after on-phage extension of a DNA oligonucleotide primer with a biotinylated nucleotide by phi29 DNA polymerase. We also achieved co-display of HaloTag and phi29 DNA polymerase, thereby opening perspectives for the molecular evolution of this enzyme (and others) towards new substrate specificities.

  9. Critical roles of mTOR Complex 1 and 2 for T follicular helper cell differentiation and germinal center responses.

    PubMed

    Yang, Jialong; Lin, Xingguang; Pan, Yun; Wang, Jinli; Chen, Pengcheng; Huang, Hongxiang; Xue, Hai-Hui; Gao, Jimin; Zhong, Xiao-Ping

    2016-09-30

    T follicular helper (Tfh) cells play critical roles for germinal center responses and effective humoral immunity. We report here that mTOR in CD4 T cells is essential for Tfh differentiation. In Mtor(f/f)-Cd4Cre mice, both constitutive and inducible Tfh differentiation is severely impaired, leading to defective germinal center B cell formation and antibody production. Moreover, both mTORC1 and mTORC2 contribute to Tfh and GC B cell development but may do so via distinct mechanisms. mTORC1 mainly promotes CD4 T cell proliferation to reach the cell divisions necessary for Tfh differentiation, while Rictor/mTORC2 regulates Tfh differentiation by promoting Akt activation and TCF1 expression without grossly influencing T cell proliferation. Together, our results reveal crucial but distinct roles for mTORC1 and mTORC2 in CD4 T cells during Tfh differentiation and germinal center responses.

  10. Improved silencing suppression and enhanced heterologous protein expression are achieved using an engineered viral helper component proteinase.

    PubMed

    Haikonen, T; Rajamäki, M-L; Valkonen, J P T

    2013-11-01

    RNA silencing limits transient expression of heterologous proteins in plants. Co-expression of viral silencing suppressor proteins can increase and prolong protein expression, but highly efficient silencing suppressors may stress plant tissue and be detrimental to protein yields. Little is known whether silencing suppression could be improved without harm to plant tissues. This study reports development of enhanced silencing suppressors by engineering the helper component proteinase (HCpro) of Potato virus A (PVA). Mutations were introduced to a short region of HCpro (positions 330-335 in PVA HCpro), which is hypervariable among potyviruses. Three out of the four HCpro mutants suppressed RNA silencing more efficiently and sustained expression of co-expressed jellyfish green fluorescent protein for a longer time than wild-type HCpro in agroinfiltrated leaves of Nicotiana benthamiana. Leaf tissues remained healthy-looking without any visible signs of stress.

  11. Development of a helper cell-dependent form of peste des petits ruminants virus: a system for making biosafe antigen.

    PubMed

    Baron, Jana; Baron, Michael D

    2015-09-23

    Peste des petits ruminants (PPR) is a viral disease of sheep and goats that is spreading through many countries in the developing world. Work on the virus is often restricted to studies of attenuated vaccine strains or to work in laboratories that have high containment facilities. We have created a helper cell dependent form of PPR virus by removing the entire RNA polymerase gene and complementing it with polymerase made constitutively in a cell line. The resultant L-deleted virus grows efficiently in the L-expressing cell line but not in other cells. Virus made with this system is indistinguishable from normal virus when used in diagnostic assays, and can be grown in normal facilities without the need for high level biocontainment. The L-deleted virus will thus make a positive contribution to the control and study of this important disease.

  12. Pivotal Roles of T-Helper 17-Related Cytokines, IL-17, IL-22, and IL-23, in Inflammatory Diseases

    PubMed Central

    Qu, Ning; Xu, Mingli; Mizoguchi, Izuru; Furusawa, Jun-ichi; Kaneko, Kotaro; Watanabe, Kazunori; Mizuguchi, Junichiro; Itoh, Masahiro; Kawakami, Yutaka; Yoshimoto, Takayuki

    2013-01-01

    T-helper 17 (Th17) cells are characterized by producing interleukin-17 (IL-17, also called IL-17A), IL-17F, IL-21, and IL-22 and potentially TNF-α and IL-6 upon certain stimulation. IL-23, which promotes Th17 cell development, as well as IL-17 and IL-22 produced by the Th17 cells plays essential roles in various inflammatory diseases, such as experimental autoimmune encephalomyelitis, rheumatoid arthritis, colitis, and Concanavalin A-induced hepatitis. In this review, we summarize the characteristics of the functional role of Th17 cells, with particular focus on the Th17 cell-related cytokines such as IL-17, IL-22, and IL-23, in mouse models and human inflammatory diseases. PMID:23956763

  13. T Follicular Helper Cells Promote a Beneficial Gut Ecosystem for Host Metabolic Homeostasis by Sensing Microbiota-Derived Extracellular ATP.

    PubMed

    Perruzza, Lisa; Gargari, Giorgio; Proietti, Michele; Fosso, Bruno; D'Erchia, Anna Maria; Faliti, Caterina Elisa; Rezzonico-Jost, Tanja; Scribano, Daniela; Mauri, Laura; Colombo, Diego; Pellegrini, Giovanni; Moregola, Annalisa; Mooser, Catherine; Pesole, Graziano; Nicoletti, Mauro; Norata, Giuseppe Danilo; Geuking, Markus B; McCoy, Kathy D; Guglielmetti, Simone; Grassi, Fabio

    2017-03-14

    The ATP-gated ionotropic P2X7 receptor regulates T follicular helper (Tfh) cell abundance in the Peyer's patches (PPs) of the small intestine; deletion of P2rx7, encoding for P2X7, in Tfh cells results in enhanced IgA secretion and binding to commensal bacteria. Here, we show that Tfh cell activity is important for generating a diverse bacterial community in the gut and that sensing of microbiota-derived extracellular ATP via P2X7 promotes the generation of a proficient gut ecosystem for metabolic homeostasis. The results of this study indicate that Tfh cells play a role in host-microbiota mutualism beyond protecting the intestinal mucosa by induction of affinity-matured IgA and suggest that extracellular ATP constitutes an inter-kingdom signaling molecule important for selecting a beneficial microbial community for the host via P2X7-mediated regulation of B cell help.

  14. Characterization of the helper proteins for the assembly of tail fibers of coliphages T4 and lambda.

    PubMed Central

    Hashemolhosseini, S; Stierhof, Y D; Hindennach, I; Henning, U

    1996-01-01

    Assembly of tail fibers of coliphage T4 requires the action of helper proteins. In the absence of one of these, protein 38 (p38), p37, constituting the distal part of the long tail fiber, fails to oligomerize. In the absence of the other, p57, p34 (another component of the long tail fiber), p37, and p12 (the subunit of the short tail fiber) remain unassembled. p38 can be replaced by the Tfa (tail fiber assembly) protein (pTfa) of phage lambda, which has the advantage of remaining soluble even when produced in massive amounts. The mechanisms of action of the helpers are unknown. As a first step towards elucidation of these mechanisms, p57 and pTfa have been purified to homogeneity and have been crystallized. The identity of gene 57 (g57), not known with certainty previously, has been established. The 79-residue protein p57 represents a very exotic polypeptide. It is oligomeric and acidic (an excess of nine negative charges). It does not contain Phe, Trp, Tyr, His, Pro, and Cys. Only 25 N-terminal residues were still able to complement a g57 amber mutant, although with a reduced efficiency. In cells overproducing the protein, it assumed a quasi-crystalline structure in the form of highly ordered fibers. They traversed the cells longitudinally (and thus blocked cell division) with a diameter approaching that of the cell and with a hexagonal appearance. The 194-residue pTfa is also acidic (an excess of 13 negative charges) and is likely to be dimeric. PMID:8892827

  15. The capsid protein of satellite Panicum mosaic virus contributes to systemic invasion and interacts with its helper virus.

    PubMed

    Omarov, Rustem T; Qi, Dong; Scholthof, Karen-Beth G

    2005-08-01

    Satellite panicum mosaic virus (SPMV) depends on its helper Panicum mosaic virus (PMV) for replication and spread in host plants. The SPMV RNA encodes a 17-kDa capsid protein (CP) that is essential for formation of its 16-nm virions. The results of this study indicate that in addition to the expression of the full-length SPMV CP from the 5'-proximal AUG start codon, SPMV RNA also expresses a 9.4-kDa C-terminal protein from the third in-frame start codon. Differences in solubility between the full-length protein and its C-terminal product were observed. Subcellular fractionation of infected plant tissues showed that SPMV CP accumulates in the cytosol, cell wall-, and membrane-enriched fractions. However, the 9.4-kDa protein exclusively cofractionated with cell wall- and membrane-enriched fractions. Earlier studies revealed that the 5'-untranslated region (5'-UTR) from nucleotides 63 to 104 was associated with systemic infection in a host-specific manner in millet plants. This study shows that nucleotide deletions and insertions in the 5'-UTR plus simultaneous truncation of the N-terminal part of the CP impaired SPMV spread in foxtail millet, but not in proso millet plants. In contrast, the expression of the full-length version of SPMV CP efficiently compensated the negative effect of the 5'-UTR deletions in foxtail millet. Finally, immunoprecipitation assays revealed the presence of a specific interaction between the capsid proteins of SPMV and its helper virus (PMV). Our findings show that the SPMV CP has several biological functions, including facilitating efficient satellite virus infection and movement in millet plants.

  16. Impact of Chronic HIV/SIV Infection on T Follicular Helper Cell Subsets and Germinal Center Homeostasis

    PubMed Central

    Graff-Dubois, Stéphanie; Rouers, Angeline; Moris, Arnaud

    2016-01-01

    The discovery of broad and potent HIV-1 neutralizing antibodies (bNAbs) has renewed optimism for developing an effective vaccine against HIV-1. The generation of most bNAbs requires multiple rounds of B cell receptor affinity maturation, suggesting a crucial role of follicular helper T (Tfh) cells in their production. However, less than 1% of HIV-infected patients develop bNAbs that arise late in the course of infection, indicating probable Tfh and B cell dysfunctions in this context. Since the last few years, many studies have characterized Tfh cells from lymph nodes and spleen of HIV-infected individuals and SIV-infected macaques. Various lymphoid Tfh cell subsets have been identified, including precursor Tfh (pTfh), germinal center Tfh (GC Tfh), and the regulatory counterpart of Tfh cells, the follicular regulatory T cells. The latter have been reported to play a crucial role in the control of T and B cell crosstalk and GC reactions. More recently, circulating Tfh-like cells (cTfh) have been identified. Meanwhile, advances in single-cell technologies have made possible to analyze the transcriptional profiles of low abundant cells, such as Tfh populations. Using transcriptional signatures, we review here the impact of chronic SIV/HIV infection on Tfh, GC Tfh, pTfh, and cTfh differentiation and helper T cell functions with regard to their capacity to induce efficient B cell maturation. We will explore some hypothesis to explain the increased proportion of Tfh cells reported in chronically infected individuals and the impact on HIV pathogenesis. PMID:27891132

  17. Human T helper cells specific for antigens of typhus group rickettsiae enhance natural killer cell activity in vitro.

    PubMed Central

    Carl, M; Martin, E E; Dasch, G A

    1986-01-01

    The peripheral blood mononuclear cells (PBMC) from 5 individuals immune to typhus group rickettsiae and from 13 nonimmune individuals were stimulated in vitro for 7 days with typhus group rickettsial antigen (TGRA). At the end of day 7, lysis of the natural killer (NK)-susceptible target K562 by these PBMC was determined. As controls, PBMC from both groups of donors were cultured in vitro for 7 days without antigen or were freshly isolated, and lysis of the K562 target was determined. There was no significant difference between the level of NK activity in freshly isolated PBMC from immune and nonimmune donors. PBMC from immune donors which were stimulated with antigen for 7 days exhibited significantly greater NK activity than did the control population, which was cultured for 7 days without antigen. PBMC from immune donors which were stimulated with TGRA demonstrated significantly higher NK activity than the same PBMC stimulated with antigen derived from an antigenically unrelated rickettsia, Coxiella burnetii. There was no significant difference, however, in the level of NK activity of nonimmune antigen-stimulated PBMC compared with that of the same PBMC population cultured without antigen. Most of the antigen-stimulated NK activity was mediated by Leu-11-positive cells as determined by electronic cell sorting. The ability of TGRA to sustain the NK activity of PBMC from immune donors was abolished when the T4/Leu-3-positive population of lymphocytes was eliminated by positive or negative selection prior to antigen stimulation. The ability of TGRA to sustain the NK activity of PBMC from immune donors was also significantly decreased in the presence of antibodies against human interleukin-2. The results suggest that the activity of human NK cells can be sustained in vitro by antigen-specific T helper cells and that the effect of the T helper cell is mediated, at least in part, by interleukin-2. PMID:2945787

  18. T helper/inducer (CD4+) cells prestimulated with PPD induce monocytes to produce interleukin-1 beta.

    PubMed

    Dunlap, N E; Tilden, A B

    1991-06-01

    We obtained peripheral blood mononuclear cells (PBMC) from four healthy, tuberculin purified protein derivative (PPD) reactive donors and cultured these cells in media containing PPD (low dose = 200 ng/ml or high dose = 1 micrograms/ml). Five days after the addition of PPD, T cells were isolated, washed, and added to autologous adherent cell cultures at a 1:1 ratio. Adherent cells were then cultured for 24 h in media only (baseline), media plus lipopolysaccharide (LPS, 2 micrograms/ml; positive control), or media containing the prestimulated T cells. After 24 h, supernatants were harvested and interleukin 1 beta (IL-beta) levels were assayed by radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). The results show that T cells prestimulated with low dose PPD (200 micrograms/ml) did not induce IL-1 production by adherent cells (mean increase over baseline 0.2 +/- 1.3 standard deviation [SD] ng/ml, P = 0.61). However, T cells prestimulated with high dose PPD (1 microgram/ml) did induce adherent cells to secrete IL-1 beta (mean increase over baseline 1.7 +/- 0.62 [SD] ng/ml, P = 0.01), but this induction was abolished when cell-to-cell contact was prevented by use of double well chambers (mean increase over baseline 0.1 +/- 0.36 [SD] ng/ml, P = 0.69). Prestimulated T helper (CD4+) cells were able to induce monocytes to secrete IL-1 beta but prestimulated CD8+ T cells were not. These data suggest that when T helper (CD4+) cells are sufficiently activated they acquire the ability to induce monocytes to secrete IL-1 beta. Cell-to-cell contact between monocytes and T cells is required. This function of activated T cells may be important in the normal cellular immune response.

  19. Mechanisms of Low Dose Radiation-induced T helper Cell Function

    SciTech Connect

    Gridley, Daila S.

    2008-10-31

    Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of “dirty bombs” by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to

  20. Site-1 protease-activated formation of lysosomal targeting motifs is independent of the lipogenic transcription control[S

    PubMed Central

    Klünder, Sarah; Heeren, Jörg; Markmann, Sandra; Santer, René; Braulke, Thomas; Pohl, Sandra

    2015-01-01

    Site-1 protease (S1P) cleaves membrane-bound lipogenic sterol regulatory element-binding proteins (SREBPs) and the α/β-subunit precursor protein of the N-acetylglucosamine-1-phosphotransferase forming mannose 6-phosphate (M6P) targeting markers on lysosomal enzymes. The translocation of SREBPs from the endoplasmic reticulum (ER) to the Golgi-resident S1P depends on the intracellular sterol content, but it is unknown whether the ER exit of the α/β-subunit precursor is regulated. Here, we investigated the effect of cholesterol depletion (atorvastatin treatment) and elevation (LDL overload) on ER-Golgi transport, S1P-mediated cleavage of the α/β-subunit precursor, and the subsequent targeting of lysosomal enzymes along the biosynthetic and endocytic pathway to lysosomes. The data showed that the proteolytic cleavage of the α/β-subunit precursor into mature and enzymatically active subunits does not depend on the cholesterol content. In either treatment, lysosomal enzymes are normally decorated with M6P residues, allowing the proper sorting to lysosomes. In addition, we found that, in fibroblasts of mucolipidosis type II mice and Niemann-Pick type C patients characterized by aberrant cholesterol accumulation, the proteolytic cleavage of the α/β-subunit precursor was not impaired. We conclude that S1P substrate-dependent regulatory mechanisms for lipid synthesis and biogenesis of lysosomes are different. PMID:26108224