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Sample records for central memory cd4

  1. Hoxb4 Overexpression in CD4 Memory Phenotype T Cells Increases the Central Memory Population upon Homeostatic Proliferation

    PubMed Central

    Fournier, Marilaine; Labrecque, Nathalie; Bijl, Janet J.

    2013-01-01

    Memory T cell populations allow a rapid immune response to pathogens that have been previously encountered and thus form the basis of success in vaccinations. However, the molecular pathways underlying the development and maintenance of these cells are only starting to be unveiled. Memory T cells have the capacity to self renew as do hematopoietic stem cells, and overlapping gene expression profiles suggested that these cells might use the same self-renewal pathways. The transcription factor Hoxb4 has been shown to promote self-renewal divisions of hematopoietic stem cells resulting in an expansion of these cells. In this study we investigated whether overexpression of Hoxb4 could provide an advantage to CD4 memory phenotype T cells in engrafting the niche of T cell deficient mice following adoptive transfer. Competitive transplantation experiments demonstrated that CD4 memory phenotype T cells derived from mice transgenic for Hoxb4 contributed overall less to the repopulation of the lymphoid organs than wild type CD4 memory phenotype T cells after two months. These proportions were relatively maintained following serial transplantation in secondary and tertiary mice. Interestingly, a significantly higher percentage of the Hoxb4 CD4 memory phenotype T cell population expressed the CD62L and Ly6C surface markers, characteristic for central memory T cells, after homeostatic proliferation. Thus Hoxb4 favours the maintenance and increase of the CD4 central memory phenotype T cell population. These cells are more stem cell like and might eventually lead to an advantage of Hoxb4 T cells after subjecting the cells to additional rounds of proliferation. PMID:24324706

  2. Effector and Central Memory Poly-Functional CD4+ and CD8+ T Cells are Boosted upon ZOSTAVAX® Vaccination

    PubMed Central

    Sei, Janet J.; Cox, Kara S.; Dubey, Sheri A.; Antonello, Joseph M.; Krah, David L.; Casimiro, Danilo R.; Vora, Kalpit A.

    2015-01-01

    ZOSTAVAX® is a live attenuated varicella-zoster virus (VZV) vaccine that is licensed for the protection of individuals ≥50 years against shingles and its most common complication, postherpetic neuralgia. While IFNγ responses increase upon vaccination, the quality of the T cell response has not been elucidated. By using polychromatic flow cytometry, we characterized the breadth, magnitude, and quality of ex vivo CD4+ and CD8+ T cell responses induced 3–4 weeks after ZOSTAVAX vaccination of healthy adults. We show, for the first time that the highest frequencies of VZV-specific CD4+ T cells were poly-functional CD154+IFNγ+IL-2+TNFα+ cells, which were boosted upon vaccination. The CD4+ T cells were broadly reactive to several VZV proteins, with immediate early (IE) 63 ranking the highest among them in the fold rise of poly-functional cells, followed by IE62, gB, open reading frame (ORF) 9, and gE. We identified a novel poly-functional ORF9-specific CD8+ T cell population in 62% of the subjects, and these were boosted upon vaccination. Poly-functional CD4+ and CD8+ T cells produced significantly higher levels of IFNγ, IL-2, and TNFα compared to mono-functional cells. After vaccination, a boost in the expression of IFNγ by poly-functional IE63- and ORF9-specific CD4+ T cells and IFNγ, IL-2, and TNFα by ORF9-specific poly-functional CD8+ T cells was observed. Responding poly-functional T cells exhibited both effector (CCR7−CD45RA−CD45RO+), and central (CCR7+CD45RA−CD45RO+) memory phenotypes, which expressed comparable levels of cytokines. Altogether, our studies demonstrate that a boost in memory poly-functional CD4+ T cells and ORF9-specific CD8+ T cells may contribute toward ZOSTAVAX efficacy. PMID:26579128

  3. Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells

    PubMed Central

    Li Causi, Eleonora; Parikh, Suraj C.; Chudley, Lindsey; Layfield, David M.; Ottensmeier, Christian H.; Stevenson, Freda K.; Di Genova, Gianfranco

    2015-01-01

    CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines. PMID:26332995

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Memory CD4 T cells in influenza.

    PubMed

    Zens, Kyra D; Farber, Donna L

    2015-01-01

    Influenza A virus is a significant cause of morbidity and mortality worldwide, particularly among young children and the elderly. Current vaccines induce neutralizing antibody responses directed toward highly variable viral surface proteins, resulting in limited heterosubtypic protection to new viral serotypes. By contrast, memory CD4 T cells recognize conserved viral proteins and are cross-reactive to multiple influenza strains. In humans, virus-specific memory CD4 T cells were found to be the protective correlate in human influenza challenge studies, suggesting their key role in protective immunity. In mouse models, memory CD4 T cells can mediate protective responses to secondary influenza infection independent of B cells or CD8 T cells, and can influence innate immune responses. Importantly, a newly defined, tissue-resident CD4 memory population has been demonstrated to be retained in lung tissue and promote optimal protective responses to an influenza infection. Here, we review the current state of results regarding the generation of memory CD4 T cells following primary influenza infection, mechanisms for their enhanced efficacy in protection from secondary challenge including their phenotype, localization, and function in the context of both mouse models and human infection. We also discuss the generation of memory CD4 T cells in response to influenza vaccines and its future implications for vaccinology. PMID:25005927

  7. Human cerebrospinal fluid central memory CD4+ T cells: Evidence for trafficking through choroid plexus and meninges via P-selectin

    PubMed Central

    Kivisäkk, Pia; Mahad, Don J.; Callahan, Melissa K.; Trebst, Corinna; Tucky, Barbara; Wei, Tao; Wu, Lijun; Baekkevold, Espen S.; Lassmann, Hans; Staugaitis, Susan M.; Campbell, James J.; Ransohoff, Richard M.

    2003-01-01

    Cerebrospinal fluid (CSF) from healthy individuals contains between 1,000 and 3,000 leukocytes per ml. Little is known about trafficking patterns of leukocytes between the systemic circulation and the noninflamed CNS. In the current study, we characterized the surface phenotype of CSF cells and defined the expression of selected adhesion molecules on vasculature in the choroid plexus, the subarachnoid space surrounding the cerebral cortex, and the cerebral parenchyma. Using multicolor flow cytometry, we found that CSF cells predominantly consisted of CD4+/CD45RA-/CD27+/CD69+-activated central memory T cells expressing high levels of CCR7 and L-selectin. CD3+ T cells were present in the choroid plexus stroma in autopsy CNS tissue sections from individuals who died without known neurological disorders. P- and E-selectin immunoreactivity was detected in large venules in the choroid plexus and subarachnoid space, but not in parenchymal microvessels. CD4+ T cells in the CSF expressed high levels of P-selectin glycoprotein ligand 1, and a subpopulation of circulating CD4+ T cells displayed P-selectin binding activity. Intercellular adhesion molecule 1, but not vascular cell adhesion molecule 1 or mucosal addressin cell adhesion molecule 1, was expressed in choroid plexus and subarachnoid space vessels. Based on these findings, we propose that T cells are recruited to the CSF through interactions between P-selectin/P-selectin ligands and intercellular adhesion molecule 1/lymphocyte function-associated antigen 1 in choroid plexus and subarachnoid space venules. These results support the overall hypothesis that activated memory T cells enter CSF directly from the systemic circulation and monitor the subarachnoid space, retaining the capacity to either initiate local immune reactions or return to secondary lymphoid organs. PMID:12829791

  8. IL-21-Induced MHC Class II+ NK Cells Promote the Expansion of Human Uncommitted CD4+ Central Memory T Cells in a Macrophage Migration Inhibitory Factor-Dependent Manner.

    PubMed

    Loyon, Romain; Picard, Emilie; Mauvais, Olivier; Queiroz, Lise; Mougey, Virginie; Pallandre, Jean-René; Galaine, Jeanne; Mercier-Letondal, Patricia; Kellerman, Guillaume; Chaput, Nathalie; Wijdenes, John; Adotévi, Olivier; Ferrand, Christophe; Romero, Pedro; Godet, Yann; Borg, Christophe

    2016-07-01

    NK cells are critical for innate immunity-mediated protection. The main roles of NK cells rely on their cytotoxic functions or depend on the tuning of Th1 adaptive immunity by IFN-γ. However, the precise influence of inflammatory cytokines on NK cell and CD4 T lymphocyte interactions was never investigated. In this study, we provide evidence that IL-21, a cytokine produced during chronic inflammation or infectious diseases, promotes the differentiation of a specific subset of NK cells coexpressing CD86 and HLA-DR and lacking NKp44. More importantly, IL-21-propagated HLA-DR(+) NK cells produce macrophage migration inhibitory factor and provide costimulatory signaling during naive CD4(+) T cell priming inducing the differentiation of uncommitted central memory T cells. Central memory T cells expanded in the presence of HLA-DR(+) NK cells are CXCR3(+)CCR6(-)CCR4(-)CXCR5(-) and produce IL-2, as well as low levels of TNF-α. Costimulation of CD4(+) T cells by HLA-DR(+) NK cells prevents the acquisition of effector memory phenotype induced by IL-2. Moreover, we identified this population of NK HLA-DR(+) macrophage migration inhibitory factor(+) cells in inflammatory human appendix. Collectively, these results demonstrate a novel function for IL-21 in tuning NK and CD4(+) T cell interactions promoting a specific expansion of central memory lymphocytes. PMID:27233967

  9. Development and Function of Protective and Pathologic Memory CD4 T Cells

    PubMed Central

    Jaigirdar, Shafqat Ahrar; MacLeod, Megan K. L.

    2015-01-01

    Immunological memory is one of the defining features of the adaptive immune system. As key orchestrators and mediators of immunity, CD4 T cells are central to the vast majority of adaptive immune responses. Generated following an immune response, memory CD4 T cells retain pertinent information about their activation environment enabling them to make rapid effector responses upon reactivation. These responses can either benefit the host by hastening the control of pathogens or cause damaging immunopathology. Here, we will discuss the diversity of the memory CD4 T cell pool, the signals that influence the transition of activated T cells into that pool, and highlight how activation requirements differ between naïve and memory CD4 T cells. A greater understanding of these factors has the potential to aid the design of more effective vaccines and to improve regulation of pathologic CD4 T cells, such as in the context of autoimmunity and allergy. PMID:26441961

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

    NASA Astrophysics Data System (ADS)

    Shedlock, Devon J.; Shen, Hao

    2003-04-01

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

  11. Repressive Effect of Primary Virus Replication on Superinfection Correlated with Gut-Derived Central Memory CD4+ T Cells in SHIV-Infected Chinese Rhesus Macaques

    PubMed Central

    Xiong, Jing; Wang, Wei; Jiang, Hong; Chen, Ting; Wu, Fangxin; Liu, Kejian; Su, Aihua; Ju, Bin; Chen, Zhiwei; Couto, Marcelo A.; Wei, Qiang; Qin, Chuan

    2013-01-01

    A possible mechanism of susceptibility to superinfection with simian-human immunodeficiency virus (SHIV)-1157ipd3N4 was explored in twelve SHIVSF162P3-infected Chinese rhesus macaques. Based on the kinetics of viral replication for the second infecting virus following SHIV-1157ipd3N4 inoculation, the monkeys were divided into two groups: those relatively resistant to superinfection (SIR) and those relatively sensitive to superinfection (SIS). We found that superinfection-resistant macaques had high primary viremia, whereas superinfection-sensitive macaques had low primary viremia, suggesting that primary SHIVSF162P3 infection with a high viral-replication level would repress superinfection with a heterologous SHIV-1157ipd3N4. Although no correlation of protection against superinfection with virus-specific CD4+ T cell or CD8+ T cell immune responses from gut was observed prior to superinfection, superinfection susceptibility was strongly correlated with CD4+ Tcm cells from gut both prior to the second infecting virus inoculation and on day 7 after superinfection, but not with CD4+ Tem cells from gut or with CD4+ Tcm cells from peripheral blood and lymph node. These results point to the important roles of gut-derived CD4+ Tcm cells for the study of the mechanisms of protection against superinfection and the evaluation of the safety and efficacy of vaccines and therapies against acquired immune deficiency syndrome (AIDS). PMID:24023734

  12. Coordinated Changes in DNA Methylation in Antigen-Specific Memory CD4 T Cells

    PubMed Central

    Ogoshi, Katsumi; Sasaki, Atsushi; Abe, Jun; Qu, Wei; Nakatani, Yoichiro; Ahsan, Budrul; Oshima, Kenshiro; Shand, Francis H. W.; Ametani, Akio; Suzuki, Yutaka; Kaneko, Shuichi; Wada, Takashi; Hattori, Masahira; Sugano, Sumio; Morishita, Shinichi; Matsushima, Kouji

    2013-01-01

    Memory CD4+ T cells are central regulators of both humoral and cellular immune responses. T cell differentiation results in specific changes in chromatin structure and DNA methylation of cytokine genes. Although the methylation status of a limited number of gene loci in T cells has been examined, the genome-wide DNA methylation status of memory CD4+ T cells remains unexplored. To further elucidate the molecular signature of memory T cells, we conducted methylome and transcriptome analyses of memory CD4+ T cells generated using T cells from TCR-transgenic mice. The resulting genome-wide DNA methylation profile revealed 1144 differentially methylated regions (DMRs) across the murine genome during the process of T cell differentiation, 552 of which were associated with gene loci. Interestingly, the majority of these DMRs were located in introns. These DMRs included genes such as CXCR6, Tbox21, Chsy1, and Cish, which are associated with cytokine production, homing to bone marrow, and immune responses. Methylation changes in memory T cells exposed to specific Ag appeared to regulate enhancer activity rather than promoter activity of immunologically relevant genes. In addition, methylation profiles differed between memory T cell subsets, demonstrating a link between T cell methylation status and T cell differentiation. By comparing DMRs between naive and Ag-specific memory T cells, this study provides new insights into the functional status of memory T cells. PMID:23509353

  13. Tolerance induction in memory CD4 T cells requires two rounds of antigen-specific activation.

    PubMed

    David, Alexandria; Crawford, Frances; Garside, Paul; Kappler, John W; Marrack, Philippa; MacLeod, Megan

    2014-05-27

    A major goal for immunotherapy is to tolerize the immune cells that coordinate tissue damage in autoimmune and alloantigen responses. CD4 T cells play a central role in many of these conditions and improved antigen-specific regulation or removal of these cells could revolutionize current treatments. A confounding factor is that little is known about whether and how tolerance is induced in memory CD4 T cells. We used MHC class II tetramers to track and analyze a population of endogenous antigen-specific memory CD4 T cells exposed to soluble peptide in the absence of adjuvant. We found that such memory T cells proliferated and reentered the memory pool apparently unperturbed by the incomplete activation signals provided by the peptide. Upon further restimulation in vivo, CD4 memory T cells that had been previously exposed to peptide proliferated, provided help to primary responding B cells, and migrated to inflamed sites. However, these reactivated memory cells failed to survive. The reduction in T-cell number was marked by low expression of the antiapoptotic molecule B cell lymphoma 2 (Bcl2) and increased expression of activated caspase molecules. Consequently, these cells failed to sustain a delayed-type hypersensitivity response. Moreover, following two separate exposures to soluble antigen, no T-cell recall response and no helper activity for B cells could be detected. These results suggest that the induction of tolerance in memory CD4 T cells is possible but that deletion and permanent removal of the antigen-specific T cells requires reactivation following exposure to the tolerogenic antigen. PMID:24821788

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

    PubMed Central

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

    2006-01-01

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

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

    PubMed

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

    2015-11-16

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2007-01-01

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

  18. Polarization diversity of human CD4+ stem cell memory T cells.

    PubMed

    Takeshita, Masaru; Suzuki, Katsuya; Kassai, Yoshiaki; Takiguchi, Maiko; Nakayama, Yusuke; Otomo, Yuki; Morita, Rimpei; Miyazaki, Takahiro; Yoshimura, Akihiko; Takeuchi, Tsutomu

    2015-07-01

    T cells are considered to develop through three stages, from naïve T (Tn) into central memory T (Tcm) and finally into effector memory T (Tem). Among the subsets of Tn, stem cell memory T (Tscm) were recently found to be the least developed memory subset. While this subset was revealed to possess self-reproducibility and multipotentiality, little is known about the relationship between development and polarity. We conducted transcriptome analysis of human CD4(+) T subsets and found that Tscm was a clearly distinct subset, located between Tn and Tcm. Surface antigen analysis and differentiation assay showed that the flexibility of polarity and the cytokine production progressively changed as the differentiation of CD4(+) T cells advanced. Interestingly, we found that most cells of the CD45RO(-)CCR7(+)CCR6(+) subset, hitherto considered the naïve precursor of Th17, were in fact Tscm. These findings may advance our understanding of the highly heterogeneous human helper T cells. PMID:25931384

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

    NASA Astrophysics Data System (ADS)

    Sun, Joseph C.; Bevan, Michael J.

    2003-04-01

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

  20. Memory CD4 T cells emerge from effector T-cell progenitors.

    PubMed

    Harrington, Laurie E; Janowski, Karen M; Oliver, James R; Zajac, Allan J; Weaver, Casey T

    2008-03-20

    A hallmark of adaptive immunity is the generation of memory T cells that confer long-lived, antigen-specific protection against repeat challenges by pathogens. Understanding the mechanisms by which memory T cells arise is important for rational vaccination strategies and improved therapeutic interventions for chronic infections and autoimmune disorders. The large clonal expansion of CD8 T cells in response to some infections has made the development of CD8 T-cell memory more amenable to study, giving rise to a model of memory cell differentiation in which a fraction of fully competent effector T cells transition into long-lived memory T cells. Delineation of CD4 T-cell memory development has proved more difficult as a result of limitations on tracking the smaller populations of CD4 effector T cells generated during a pathogenic challenge, complicating efforts to determine whether CD4 memory T cells are direct descendants of effector T cells or whether they develop by alternative pathways. Here, using two complementary cytokine reporter mouse models to identify interferon (IFN)-gamma-positive effector T cells and track their fate, we show that the lineage relationship between effector and memory CD4 T cells resembles that for CD8 T cells responding to the same pathogen. We find that, in parallel with effector CD8 T cells, IFN-gamma-positive effector CD4 T cells give rise to long-lived memory T cells capable of anamnestic responses to antigenic rechallenge. PMID:18322463

  1. The Majority of HIV Type 1 DNA in Circulating CD4+ T Lymphocytes Is Present in Non-Gut-Homing Resting Memory CD4+ T Cells

    PubMed Central

    Xu, Yin; Bailey, Michelle; Seddiki, Nabila; Suzuki, Kazuo; Murray, John M.; Gao, Yuan; Yan, Celine; Cooper, David A.; Kelleher, Anthony D.; Koelsch, Kersten K.; Zaunders, John

    2013-01-01

    Abstract Memory CD4+ T lymphocytes in peripheral blood that express integrins α4ß7 preferentially recirculate through gut-associated lymphoid tissue (GALT), a proposed site of significant HIV-1 replication. Tregs and activated CD4+ T cells in GALT could also be particularly susceptible to infection. We therefore hypothesized that infection of these subsets of memory CD4+ T cells may contribute disproportionately to the HIV-1 reservoir. A cross-sectional study of CD4+ T cell subsets of memory CD45RO+ cells in peripheral blood mononuclear cells (PBMCs) was conducted using leukapheresis from eight subjects with untreated chronic HIV-1 infection. Real-time polymerase chain reaction (PCR) was used to quantify total and integrated HIV-1 DNA levels from memory CD4+ T cells sorted into integrin β7+ vs. β7−, CD25+CD127low Treg vs. CD127high, and activated CD38+ vs. CD38−. More than 80% of total HIV-1 DNA was found to reside in the integrin β7-negative non-gut-homing subset of CD45RO+ memory CD4+ T cells. Less than 10% was found in highly purified Tregs or CD38+ activated memory cells. Similarly, integrated HIV-1 DNA copies were found to be more abundant in resting non-gut-homing memory CD4+ T cells (76%) than in their activated counterparts (23%). Our investigations showed that the majority of both total and integrated HIV-1 DNA was found within non-gut-homing resting CD4+ T cells. PMID:23971972

  2. Temporal requirements for B cells in the establishment of CD4 T cell memory.

    PubMed

    Mollo, Sarah B; Zajac, Allan J; Harrington, Laurie E

    2013-12-15

    CD4 T cell memory generation is shaped by a number of factors, including the strength and duration of TCR signaling, as well as the priming environment, all of which can be modified by B cells. Studies using B cell-deficient mice indicate B cells play a critical role in generating effector and memory CD4 T cells; however, when and how B cells are acting to promote these responses has not yet been ascertained. In this study, we use anti-CD20 Ab depletion of B cells at different times following Listeria monocytogenes infection to show that B cells are necessary for the induction of optimal CD4 T cell memory, but not for the transition and maintenance of this population. Importantly, the prerequisite of B cells early postinfection is partially dependent on their expression of MHC class II. B cells are not only required during the priming phase, but also necessary for the initiation of robust secondary responses by memory CD4 T cells. Interestingly, the requirement during the recall response is independent of B cell Ag presentation. Overall, these studies demonstrate the temporally and functionally distinct roles for B cells in regulating CD4 T cell responses. PMID:24218454

  3. New Insights into the Generation of CD4 Memory May Shape Future Vaccine Strategies for Influenza.

    PubMed

    Devarajan, Priyadharshini; Bautista, Bianca; Vong, Allen M; McKinstry, Karl Kai; Strutt, Tara M; Swain, Susan L

    2016-01-01

    Influenza viral evolution presents a formidable challenge to vaccination due to the virus' ability to rapidly mutate to evade immune responses. Live influenza infections generate large and diverse CD4 effector T cell responses that yield highly protective, long-lasting CD4 T cell memory that can target conserved viral epitopes. We review advances in our understanding of mechanisms involved in generating CD4 T cell responses against the influenza A virus (IAV), focusing on specialized follicular helper (TFH) and CD4 cytotoxic (ThCTL) effector subsets and on CD4 T cell memory. We also discuss two recent findings in context of enhancing vaccine responses. First, helper T cells require priming with APC secreting high levels of IL-6. Second, the transition of IAV-generated effectors to memory depends on IL-2, costimulation and antigen signals, just before effectors reach peak numbers, defined as the "memory checkpoint." The need for these signals during the checkpoint could explain why many current influenza vaccines are poorly effective and elicit poor cellular immunity. We suggest that CD4 memory generation can be enhanced by re-vaccinating at this time. Our best hope lies in a universal vaccine that will not need to be formulated yearly against seasonal antigenically novel influenza strains and will also be protective against a pandemic strain. We suggest a vaccine approach that elicits a powerful T cell response, by initially inducing high levels of APC activation and later providing antigen at the memory checkpoint, may take us a step closer to such a universal influenza vaccine. PMID:27148257

  4. New Insights into the Generation of CD4 Memory May Shape Future Vaccine Strategies for Influenza

    PubMed Central

    Devarajan, Priyadharshini; Bautista, Bianca; Vong, Allen M.; McKinstry, Karl Kai; Strutt, Tara M.; Swain, Susan L.

    2016-01-01

    Influenza viral evolution presents a formidable challenge to vaccination due to the virus’ ability to rapidly mutate to evade immune responses. Live influenza infections generate large and diverse CD4 effector T cell responses that yield highly protective, long-lasting CD4 T cell memory that can target conserved viral epitopes. We review advances in our understanding of mechanisms involved in generating CD4 T cell responses against the influenza A virus (IAV), focusing on specialized follicular helper (TFH) and CD4 cytotoxic (ThCTL) effector subsets and on CD4 T cell memory. We also discuss two recent findings in context of enhancing vaccine responses. First, helper T cells require priming with APC secreting high levels of IL-6. Second, the transition of IAV-generated effectors to memory depends on IL-2, costimulation and antigen signals, just before effectors reach peak numbers, defined as the “memory checkpoint.” The need for these signals during the checkpoint could explain why many current influenza vaccines are poorly effective and elicit poor cellular immunity. We suggest that CD4 memory generation can be enhanced by re-vaccinating at this time. Our best hope lies in a universal vaccine that will not need to be formulated yearly against seasonal antigenically novel influenza strains and will also be protective against a pandemic strain. We suggest a vaccine approach that elicits a powerful T cell response, by initially inducing high levels of APC activation and later providing antigen at the memory checkpoint, may take us a step closer to such a universal influenza vaccine. PMID:27148257

  5. Oligoclonal CD4+ T Cells Promote Host Memory Immune Responses to Zwitterionic Polysaccharide of Streptococcus pneumoniae▿

    PubMed Central

    Groneck, Laura; Schrama, David; Fabri, Mario; Stephen, Tom Li; Harms, Fabian; Meemboor, Sonja; Hafke, Helena; Bessler, Martina; Becker, Jürgen C.; Kalka-Moll, Wiltrud M.

    2009-01-01

    Zwitterionic polysaccharides of the normal flora bacteria represent a novel class of antigens in that they correct systemic CD4+ T-cell deficiencies and direct lymphoid organogenesis during colonization of the host. Presentation of these polysaccharides to CD4+ T cells depends on major histocompatibility complex class II- and DM-dependent retrograde transport from lysosomes to the cell surface. Yet the phenotype and clonality of the immune response to the polysaccharide in the mature host immune system have not been studied. Using the zwitterionic capsular polysaccharide Sp1 of Streptococcus pneumoniae, a transient member of the bacterial flora, in an experimental mouse model of cellular immunity, we demonstrated the accumulation of TH1- and TH17-polarized CD4+ CD44high CD62low CD25− memory T cells. Subcutaneous immunization with Sp1 resulted in an increase of serum immunoglobulin G (IgG), predominantly of the IgG1 subclass, and suggested the presence of a humoral memory response to the polysaccharide. CD4+ T cells stimulated with polysaccharide in vitro and in vivo showed a nonrestricted pattern for the T-cell receptor (TCR) β-chain variable region, as demonstrated by semiquantitative reverse transcription-PCR and flow cytometry. Clonotype mapping of in vivo and in vitro polysaccharide-activated CD4+ T cells revealed clonotypic TCR transcripts. Taken together, the data show the induction of clonal expansion of CD4+ T cells by polysaccharides of commensal bacteria. Cellular and humoral memory host responses imply the ability of these polysaccharides to mediate the expansion of T cells via recognition within the CDR3 region of the TCR. PMID:19546196

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-01-01

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

  8. Airway Memory CD4(+) T Cells Mediate Protective Immunity against Emerging Respiratory Coronaviruses.

    PubMed

    Zhao, Jincun; Zhao, Jingxian; Mangalam, Ashutosh K; Channappanavar, Rudragouda; Fett, Craig; Meyerholz, David K; Agnihothram, Sudhakar; Baric, Ralph S; David, Chella S; Perlman, Stanley

    2016-06-21

    Two zoonotic coronaviruses (CoVs)-SARS-CoV and MERS-CoV-have crossed species to cause severe human respiratory disease. Here, we showed that induction of airway memory CD4(+) T cells specific for a conserved epitope shared by SARS-CoV and MERS-CoV is a potential strategy for developing pan-coronavirus vaccines. Airway memory CD4(+) T cells differed phenotypically and functionally from lung-derived cells and were crucial for protection against both CoVs in mice. Protection was dependent on interferon-γ and required early induction of robust innate and virus-specific CD8(+) T cell responses. The conserved epitope was also recognized in SARS-CoV- and MERS-CoV-infected human leukocyte antigen DR2 and DR3 transgenic mice, indicating potential relevance in human populations. Additionally, this epitope was cross-protective between human and bat CoVs, the progenitors for many human CoVs. Vaccine strategies that induce airway memory CD4(+) T cells targeting conserved epitopes might have broad applicability in the context of new CoVs and other respiratory virus outbreaks. PMID:27287409

  9. Persistent BCG bacilli perpetuate CD4 T effector memory and optimal protection against tuberculosis.

    PubMed

    Kaveh, Daryan A; Carmen Garcia-Pelayo, M; Hogarth, Philip J

    2014-12-01

    Tuberculosis (TB) remains one of the most important infectious diseases of man and animals, and the only available vaccine (BCG) requires urgent replacement or improvement. To facilitate this, the protective mechanisms induced by BCG require further understanding. As a live attenuated vaccine, persistence of BCG bacilli in the host may be a crucial mechanism. We have investigated the long term persistence of BCG following vaccination and the influence on the induced immune response and protection, using an established murine model. We sought to establish whether previously identified BCG-specific CD4 TEM cells represent genuine long-lived memory cells of a relatively high frequency, or are a consequence of continual priming by chronically persistent BCG vaccine bacilli. By clearing persistent bacilli, we have compared immune responses (spleen and lung CD4: cytokine producing T effector/TEM; TCR-specific) and BCG-induced protection, in the presence and absence of these persisting vaccine bacilli. Viable BCG bacilli persisted for at least 16 months post-vaccination, associated with specific CD4 T effector/TEM and tetramer-specific responses. Clearing these bacilli abrogated all BCG-specific CD4 T cells whilst only reducing protection by 1log10. BCG may induce two additive mechanisms of immunity: (i) dependant on the presence of viable bacilli and TEM; and (ii) independent of these factors. These data have crucial implications on the rational generation of replacement TB vaccines, and the interpretation of BCG induced immunity in animal models. PMID:25444816

  10. Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

    PubMed Central

    Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

    2015-01-01

    Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

  11. Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells.

    PubMed

    Chatterjee, Soumya; Clark, Carolyn E; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B

    2015-03-15

    Exaggerated CD4(+) T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper 1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis. To assess the dynamics of Ag-specific memory T cell compartments in the context of filarial infection, we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial-infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial Ag (BmA) or with the M. tuberculosis-specific Ag culture filtrate protein-10 (CFP-10). Our data demonstrated that the Inf group had a marked increase in BmA-specific CD4(+)IL-4(+) cells (median net frequency compared with baseline [Fo] = 0.09% versus 0.01%; p = 0.038) but also to CFP-10 (Fo = 0.16% versus 0.007%; p = 0.04) and staphylococcal enterotoxin B (Fo = 0.49% versus 0.26%; p = 0.04). The Inf subjects showed a BmA-specific expansion of CD4(+)CD45RO(+)IL-4(+) producing central memory (TCM, CD45RO(+)CCR7(+)CD27(+); Fo = 1.1% versus 0.5%; p = 0.04) as well as effector memory (TEM, CD45RO(+)CCR7(-)CD27(-); Fo = 1.5% versus 0.2%; p = 0.03) with a similar but nonsignificant response to CFP-10. In addition, there was expansion of CD4(+)IL-4(+)CD45RA(+)CCR7(+)CD27(+) (naive-like) in Inf individuals compared with Uninf subjects. Among Inf subjects with definitive latent tuberculosis, there were no differences in frequencies of IL-4-producing cells within any of the memory compartments compared with the Uninf group. Our data suggest that filarial infection induces Ag-specific, exaggerated IL-4 responses in distinct T cell memory compartments to M. tuberculosis-specific Ags, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to M. tuberculosis. PMID:25667413

  12. The Immune-Metabolic Basis of Effector Memory CD4+ T Cell Function under Hypoxic Conditions.

    PubMed

    Dimeloe, Sarah; Mehling, Matthias; Frick, Corina; Loeliger, Jordan; Bantug, Glenn R; Sauder, Ursula; Fischer, Marco; Belle, Réka; Develioglu, Leyla; Tay, Savaş; Langenkamp, Anja; Hess, Christoph

    2016-01-01

    Effector memory (EM) CD4(+) T cells recirculate between normoxic blood and hypoxic tissues to screen for cognate Ag. How mitochondria of these cells, shuttling between normoxia and hypoxia, maintain bioenergetic efficiency and stably uphold antiapoptotic features is unknown. In this study, we found that human EM CD4(+) T cells had greater spare respiratory capacity (SRC) than did naive counterparts, which was immediately accessed under hypoxia. Consequently, hypoxic EM cells maintained ATP levels, survived and migrated better than did hypoxic naive cells, and hypoxia did not impair their capacity to produce IFN-γ. EM CD4(+) T cells also had more abundant cytosolic GAPDH and increased glycolytic reserve. In contrast to SRC, glycolytic reserve was not tapped under hypoxic conditions, and, under hypoxia, glucose metabolism contributed similarly to ATP production in naive and EM cells. However, both under normoxic and hypoxic conditions, glucose was critical for EM CD4(+) T cell survival. Mechanistically, in the absence of glycolysis, mitochondrial membrane potential (ΔΨm) of EM cells declined and intrinsic apoptosis was triggered. Restoring pyruvate levels, the end product of glycolysis, preserved ΔΨm and prevented apoptosis. Furthermore, reconstitution of reactive oxygen species (ROS), whose production depends on ΔΨm, also rescued viability, whereas scavenging mitochondrial ROS exacerbated apoptosis. Rapid access of SRC in hypoxia, linked with built-in, oxygen-resistant glycolytic reserve that functionally insulates ΔΨm and mitochondrial ROS production from oxygen tension changes, provides an immune-metabolic basis supporting survival, migration, and function of EM CD4(+) T cells in normoxic and hypoxic conditions. PMID:26621861

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

    PubMed Central

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

    2015-01-01

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

  14. Generation of a universal CD4 memory T cell recall peptide effective in humans, mice and non-human primates.

    PubMed

    Fraser, Christopher C; Altreuter, David H; Ilyinskii, Petr; Pittet, Lynnelle; LaMothe, Robert A; Keegan, Mark; Johnston, Lloyd; Kishimoto, Takashi Kei

    2014-05-19

    CD4T cells play a key role in humoral immunity by providing help to B cells, enabling effective antibody class switching and affinity maturation. Some vaccines may generate a poor response due to a lack of effective MHC class II epitopes, resulting in ineffective helper T cell activation and recall and consequently poor humoral immunity. It may be beneficial to provide a CD4T cell helper peptide with a vaccine particularly in the case of a poorly immunogenic antigen. Such a T cell helper peptide must be promiscuous in its ability to bind a broad range of MHC class II alleles due to broad allelic variation in the human population. We designed a chimeric MHC class II peptide (TpD) with epitopes from tetanus toxoid and diphtheria toxoid, separated by an internal cathepsin cleavage site. TpD was capable of inducing a memory recall response in peripheral blood mononuclear cells from 20/20 human donors. T cells responding to TpD showed a central memory phenotype. Immunization of mice with a synthetic nicotine nanoparticle vaccine containing TpD showed that the peptide was required for robust antibody production and resulted in a long term CD4 memory T cell recall response. As a pre-clinical model two non-human primate species, rhesus macaques and cynomolgus monkeys, were immunized with a nicotine nanoparticle vaccine and evaluated for an anti-nicotine antibody response and TpD specific memory T cells. We found that 4/4 rhesus monkeys had both sustained antibody production and TpD memory T cells for the duration of the experiment (119 days). In addition 30/30 cynomolgus monkeys dosed with nicotine vaccine nanoparticles showed dose-dependent antibody generation and T cell recall response compared to saline injected controls. In summary we have developed a potent universal memory T cell helper peptide (TpD) that is active in vitro in human PBMCs and in vivo in mice and non-human primates. PMID:24583006

  15. Virus-specific CD4+ memory phenotype T cells are abundant in unexposed adults

    PubMed Central

    Su, Laura F.; Kidd, Brian A.; Han, Arnold; Kotzin, Jonathan J.; Davis, Mark M.

    2013-01-01

    While T cell memory is generally thought to require direct antigen exposure, we find an abundance of memory phenotype cells (20–90%, averaging over 50%) of CD4+ T cells specific for viral antigens in adults that have never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. This contrasts with newborns where the same T cell receptor (TCR) specificities are almost entirely naïve, which may explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens and in support of this we find extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and the expansion of one of these following influenza vaccination. Thus the presence of these memory phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments. PMID:23395677

  16. Superantigen-induced CD4 Memory T Cell Anergy. I. Staphylococcal Enterotoxin B Induces Fyn-mediated Negative Signaling1

    PubMed Central

    Watson, Andrew R. O.; Janik, David K.; Lee, William T.

    2012-01-01

    Memory CD4 T cells must provide robust protection for an organism while still maintaining self-tolerance. Superantigens reveal a memory cell-specific regulatory pathway, by which signaling through the TCR can lead to clonal tolerance (anergy). Here we show that the src kinase Fyn is a critical regulator of anergy in murine memory CD4 T cells induced by the bacterial superantigen staphylococcal enterotoxin B (SEB). Exposure to SEB results in impaired TCR signaling due to failed CD3/ZAP-70 complex formation. Further, signal transduction through the TCR remains similarly blocked when anergic memory cells are subsequently exposed to agonist peptide antigen. Pharmacological inhibition or genetic elimination of Fyn kinase reverses memory cell anergy, resulting in SEB-induced cell proliferation. The mechanism underlying impaired TCR signaling and subsequent memory cell anergy must involve a Fyn signaling pathway given that the suppression of Fyn activity restores CD3/ZAP-70 complex formation and TCR proximal signaling. PMID:22386537

  17. Most microbe-specific naïve CD4⁺ T cells produce memory cells during infection.

    PubMed

    Tubo, Noah J; Fife, Brian T; Pagan, Antonio J; Kotov, Dmitri I; Goldberg, Michael F; Jenkins, Marc K

    2016-01-29

    Infection elicits CD4(+) memory T lymphocytes that participate in protective immunity. Although memory cells are the progeny of naïve T cells, it is unclear that all naïve cells from a polyclonal repertoire have memory cell potential. Using a single-cell adoptive transfer and spleen biopsy method, we found that in mice, essentially all microbe-specific naïve cells produced memory cells during infection. Different clonal memory cell populations had different B cell or macrophage helper compositions that matched effector cell populations generated much earlier in the response. Thus, each microbe-specific naïve CD4(+) T cell produces a distinctive ratio of effector cell types early in the immune response that is maintained as some cells in the clonal population become memory cells. PMID:26823430

  18. Oral vaccination with lipid-formulated BCG induces a long-lived, multifunctional CD4(+) T cell memory immune response.

    PubMed

    Ancelet, Lindsay R; Aldwell, Frank E; Rich, Fenella J; Kirman, Joanna R

    2012-01-01

    Oral delivery of BCG in a lipid formulation (Liporale™-BCG) targets delivery of viable bacilli to the mesenteric lymph nodes and confers protection against an aerosol Mycobacterium tuberculosis challenge. The magnitude, quality and duration of the effector and memory immune response induced by Liporale™-BCG vaccination is unknown. Therefore, we compared the effector and memory CD4(+) T cell response in the spleen and lungs of mice vaccinated with Liporale™-BCG to the response induced by subcutaneous BCG vaccination. Liporale™-BCG vaccination induced a long-lived CD4(+) T cell response, evident by the detection of effector CD4(+) T cells in the lungs and a significant increase in the number of Ag85B tetramer-specific CD4(+) T cells in the spleen up to 30 weeks post vaccination. Moreover, following polyclonal stimulation, Liporale™-BCG vaccination, but not s.c. BCG vaccination, induced a significant increase in both the percentage of CD4(+) T cells in the lungs capable of producing IFNγ and the number of multifunctional CD4(+) T cells in the lungs at 30 weeks post vaccination. These results demonstrate that orally delivered Liporale™-BCG vaccine induces a long-lived multifunctional immune response, and could therefore represent a practical and effective means of delivering novel BCG-based TB vaccines. PMID:23049885

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

    PubMed Central

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

    2016-01-01

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

  20. Memory programming in CD8+ T-cell differentiation is intrinsic and is not determined by CD4 help

    PubMed Central

    Kim, Juhyun; Jeong Ryu, Su; Oh, Keunhee; Ju, Ji-Min; Yeong Jeon, Ji; Nam, Giri; Lee, Dong-Sup; Kim, Hang-Rae; Young Kim, Joo; Chang, Jun; Sproule, Thomas; Choi, Kyungho; Roopenian, Derry; Young Choi, Eun

    2015-01-01

    CD8+ T cells activated without CD4+ T-cell help are impaired in memory expansion. To understand the underlying cellular mechanism, here we track the dynamics of helper-deficient CD8+ T-cell response to a minor histocompatibility antigen by phenotypic and in vivo imaging analyses. Helper-deficient CD8+ T cells show reduced burst expansion, rapid peripheral egress, delayed antigen clearance and continuous activation, and are eventually exhausted. Contrary to the general consensus that CD4 help encodes memory programmes in CD8+ T cells and helper-deficient CD8+ T cells are abortive, these cells can differentiate into effectors and memory precursors. Importantly, accelerating antigen clearance or simply increasing the burst effector size enables generation of memory cells by CD8+ T cells, regardless of CD4 help. These results suggest that the memory programme is CD8+ T-cell-intrinsic, and provide insight into the role of CD4 help in CD8+ T-cell responses. PMID:26272364

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

    PubMed Central

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

    2013-01-01

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

  2. Programmed death 1 regulates memory phenotype CD4 T cell accumulation, inhibits expansion of the effector memory phenotype subset and modulates production of effector cytokines.

    PubMed

    Charlton, Joanna J; Tsoukatou, Debbie; Mamalaki, Clio; Chatzidakis, Ioannis

    2015-01-01

    Memory phenotype CD4 T cells are found in normal mice and arise through response to environmental antigens or homeostatic mechanisms. The factors that regulate the homeostasis of memory phenotype CD4 cells are not clear. In the present study we demonstrate that there is a marked accumulation of memory phenotype CD4 cells, specifically of the effector memory (T(EM)) phenotype, in lymphoid organs and tissues of mice deficient for the negative co-stimulatory receptor programmed death 1 (PD-1). This can be correlated with decreased apoptosis but not with enhanced homeostatic turnover potential of these cells. PD-1 ablation increased the frequency of memory phenotype CD4 IFN-γ producers but decreased the respective frequency of IL-17A-producing cells. In particular, IFN-γ producers were more abundant but IL-17A producing cells were more scarce among PD-1 KO T(EM)-phenotype cells relative to WT. Transfer of peripheral naïve CD4 T cells suggested that accumulated PD-1 KO T(EM)-phenotype cells are of peripheral and not of thymic origin. This accumulation effect was mediated by CD4 cell-intrinsic mechanisms as shown by mixed bone marrow chimera experiments. Naïve PD-1 KO CD4 T cells gave rise to higher numbers of TEM-phenotype lymphopenia-induced proliferation memory cells. In conclusion, we provide evidence that PD-1 has an important role in determining the composition and functional aspects of memory phenotype CD4 T cell pool. PMID:25803808

  3. The Role of CD4 T Cell Memory in Generating Protective Immunity to Novel and Potentially Pandemic Strains of Influenza

    PubMed Central

    DiPiazza, Anthony; Richards, Katherine A.; Knowlden, Zackery A. G.; Nayak, Jennifer L.; Sant, Andrea J.

    2016-01-01

    Recent events have made it clear that potentially pandemic strains of influenza regularly pose a threat to human populations. Therefore, it is essential that we develop better strategies to enhance vaccine design and evaluation to predict those that will be poor responders to vaccination and to identify those that are at particular risk of disease-associated complications following infection. Animal models have revealed the discrete functions that CD4 T cells play in developing immune response and to influenza immunity. However, humans have a complex immunological history with influenza through periodic infection and vaccination with seasonal variants, leading to the establishment of heterogeneous memory populations of CD4 T cells that participate in subsequent responses. The continual evolution of the influenza-specific CD4 T cell repertoire involves both specificity and function and overlays other restrictions on CD4 T cell activity derived from viral antigen handling and MHC class II:peptide epitope display. Together, these complexities in the influenza-specific CD4 T cell repertoire constitute a formidable obstacle to predicting protective immune response to potentially pandemic strains of influenza and in devising optimal vaccine strategies to potentiate these responses. We suggest that more precise efforts to identify and enumerate both the positive and negative contributors within the CD4 T cell compartment will aid significantly in the achievement of these goals. PMID:26834750

  4. CD4 memory T cells develop and acquire functional competence by sequential cognate interactions and stepwise gene regulation.

    PubMed

    Kaji, Tomohiro; Hijikata, Atsushi; Ishige, Akiko; Kitami, Toshimori; Watanabe, Takashi; Ohara, Osamu; Yanaka, Noriyuki; Okada, Mariko; Shimoda, Michiko; Taniguchi, Masaru; Takemori, Toshitada

    2016-06-01

    Memory CD4(+) T cells promote protective humoral immunity; however, how memory T cells acquire this activity remains unclear. This study demonstrates that CD4(+) T cells develop into antigen-specific memory T cells that can promote the terminal differentiation of memory B cells far more effectively than their naive T-cell counterparts. Memory T cell development requires the transcription factor B-cell lymphoma 6 (Bcl6), which is known to direct T-follicular helper (Tfh) cell differentiation. However, unlike Tfh cells, memory T cell development did not require germinal center B cells. Curiously, memory T cells that develop in the absence of cognate B cells cannot promote memory B-cell recall responses and this defect was accompanied by down-regulation of genes associated with homeostasis and activation and up-regulation of genes inhibitory for T-cell responses. Although memory T cells display phenotypic and genetic signatures distinct from Tfh cells, both had in common the expression of a group of genes associated with metabolic pathways. This gene expression profile was not shared to any great extent with naive T cells and was not influenced by the absence of cognate B cells during memory T cell development. These results suggest that memory T cell development is programmed by stepwise expression of gatekeeper genes through serial interactions with different types of antigen-presenting cells, first licensing the memory lineage pathway and subsequently facilitating the functional development of memory T cells. Finally, we identified Gdpd3 as a candidate genetic marker for memory T cells. PMID:26714588

  5. Expression of CD39 by human peripheral blood CD4+CD25+ T cells denotes a regulatory memory phenotype

    PubMed Central

    Dwyer, Karen M.; Hanidziar, Dusan; Putheti, Prabhakar; Hill, Prue A; Pommey, Sandra; McRae, Jennifer L; Winterhalter, Adam; Doherty, Glen; Deaglio, Silvia; Koulmanda, Maria; Gao, Wenda; Robson, Simon C.; Strom, Terry B.

    2010-01-01

    We have shown that CD39 and CD73 are co-expressed on the surface of murine CD4+Foxp3+ regulatory T cells (Treg) and generate extracellular adenosine, contributing to Treg immunosuppressive activity. We now describe that CD39, independently of CD73, is expressed by a subset of blood derived human CD4+CD25+CD127lo T regulatory cells (Treg), defined by robust expression of Foxp3. A further distinct population of CD4+CD39+ T lymphocytes can be identified, which do not express CD25 and FoxP3 and exhibit the memory effector cellular phenotype. Differential expression of CD25 and CD39 on circulating CD4+ T cells distinguishes between Treg and pathogenic cellular populations that secrete pro-inflammatory cytokines such as IFNγ and IL-17. These latter cell populations are increased, with a concomitant decrease in the CD4+CD25+CD39+ Tregs, in the peripheral blood of patients with renal allograft rejection. We conclude that the ectonucleotidase CD39 is a useful and dynamic lymphocytes surface marker that can be used to identify different peripheral blood T cell populations to allow tracking of these in health and disease, as in renal allograft rejection. PMID:20977632

  6. Antiviral Innate Immune Activation in HIV-Infected Adults Negatively Affects H1/IC31-Induced Vaccine-Specific Memory CD4+ T Cells.

    PubMed

    Lenz, Nicole; Schindler, Tobias; Kagina, Benjamin M; Zhang, Jitao David; Lukindo, Tedson; Mpina, Maxmillian; Bang, Peter; Kromann, Ingrid; Hoff, Søren T; Andersen, Peter; Reither, Klaus; Churchyard, Gavin J; Certa, Ulrich; Daubenberger, Claudia A

    2015-07-01

    Tuberculosis (TB) remains a global health problem, with vaccination being a necessary strategy for disease containment and elimination. A TB vaccine should be safe and immunogenic as well as efficacious in all affected populations, including HIV-infected individuals. We investigated the induction and maintenance of vaccine-induced memory CD4(+) T cells following vaccination with the subunit vaccine H1/IC31. H1/IC31 was inoculated twice on study days 0 and 56 among HIV-infected adults with CD4(+) lymphocyte counts of >350 cells/mm(3). Whole venous blood stimulation was conducted with the H1 protein, and memory CD4(+) T cells were analyzed using intracellular cytokine staining and polychromatic flow cytometry. We identified high responders, intermediate responders, and nonresponders based on detection of interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) expressing central (TCM) and effector memory CD4(+) T cells (TEM) 182 days after the first immunization. Amplicon-based transcript quantification using next-generation sequencing was performed to identify differentially expressed genes that correlated with vaccine-induced immune responses. Genes implicated in resolution of inflammation discriminated the responders from the nonresponders 3 days after the first inoculation. The volunteers with higher expression levels of genes involved in antiviral innate immunity at baseline showed impaired H1-specific TCM and TEM maintenance 6 months after vaccination. Our study showed that in HIV-infected volunteers, expression levels of genes involved in the antiviral innate immune response affected long-term maintenance of H1/IC31 vaccine-induced cellular immunity. (The clinical trial was registered in the Pan African Clinical Trials Registry [PACTR] with the identifier PACTR201105000289276.). PMID:25924764

  7. Antiviral Innate Immune Activation in HIV-Infected Adults Negatively Affects H1/IC31-Induced Vaccine-Specific Memory CD4+ T Cells

    PubMed Central

    Lenz, Nicole; Schindler, Tobias; Kagina, Benjamin M.; Zhang, Jitao David; Lukindo, Tedson; Mpina, Maxmillian; Bang, Peter; Kromann, Ingrid; Hoff, Søren T.; Andersen, Peter; Reither, Klaus; Churchyard, Gavin J.; Certa, Ulrich

    2015-01-01

    Tuberculosis (TB) remains a global health problem, with vaccination being a necessary strategy for disease containment and elimination. A TB vaccine should be safe and immunogenic as well as efficacious in all affected populations, including HIV-infected individuals. We investigated the induction and maintenance of vaccine-induced memory CD4+ T cells following vaccination with the subunit vaccine H1/IC31. H1/IC31 was inoculated twice on study days 0 and 56 among HIV-infected adults with CD4+ lymphocyte counts of >350 cells/mm3. Whole venous blood stimulation was conducted with the H1 protein, and memory CD4+ T cells were analyzed using intracellular cytokine staining and polychromatic flow cytometry. We identified high responders, intermediate responders, and nonresponders based on detection of interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) expressing central (TCM) and effector memory CD4+ T cells (TEM) 182 days after the first immunization. Amplicon-based transcript quantification using next-generation sequencing was performed to identify differentially expressed genes that correlated with vaccine-induced immune responses. Genes implicated in resolution of inflammation discriminated the responders from the nonresponders 3 days after the first inoculation. The volunteers with higher expression levels of genes involved in antiviral innate immunity at baseline showed impaired H1-specific TCM and TEM maintenance 6 months after vaccination. Our study showed that in HIV-infected volunteers, expression levels of genes involved in the antiviral innate immune response affected long-term maintenance of H1/IC31 vaccine-induced cellular immunity. (The clinical trial was registered in the Pan African Clinical Trials Registry [PACTR] with the identifier PACTR201105000289276.) PMID:25924764

  8. β1 INTEGRIN IS CRITICAL FOR THE MAINTENANCE OF ANTIGEN-SPECIFIC CD4 T CELLS IN THE BONE MARROW BUT NOT LONG-TERM IMMUNOLOGICAL MEMORY1

    PubMed Central

    DeNucci, Christopher C.; Shimizu, Yoji

    2011-01-01

    The long-term maintenance of memory CD4 T cells promotes protective immunity against future pathogen re-infection. As a site rich in survival cytokines, the bone marrow is proposed to be a critical niche for the survival of memory CD4 T cells. We demonstrate that endogenous, polyclonal Ag-specific CD4 T cells rapidly enter and are recovered long-term from the bone marrow following intravenous infection with Listeria monocytogenes. β1 integrin-deficient CD4 T cells also populate the bone marrow early following an infection, but their numbers in this site rapidly decline. This decline was not caused by increased death of T cells lacking β1 integrin but rather by reduced retention in the bone marrow after the primary immune response. The loss of memory CD4 T cells from the bone marrow does not lead to a loss of the predominant source of memory CD4 T cells in the spleen or the ability to mount a memory response. Thus, β1 integrin-dependent maintenance of memory CD4 T cells in the bone marrow is not required for long-term CD4 T cell memory. PMID:21357540

  9. Anergy in CD4 Memory T Lymphocytes: II. Abrogation of TCR-induced Formation of Membrane Signaling Complexes1

    PubMed Central

    Lee, William T.; Prasad, Aparna; Watson, Andrew R. O.

    2012-01-01

    Memory and naive CD4 T cells have unique regulatory pathways for self/non-self discrimination. A memory cell specific regulatory pathway was revealed using superantigens to trigger the TCR. Upon stimulation by bacterial superantigens, like staphylococcal enterotoxin B (SEB), TCR proximal signaling is impaired leading to clonal tolerance (anergy). In the present report, we show that memory cell anergy results from the sequestration of the protein tyrosine kinase ZAP-70 away from the TCR/CD3ζ chain. During SEB-induced signaling, ZAP-70 is excluded from both detergent-resistant membrane microdomains and the immunological synapse, thus blocking downstream signaling. We also show that the mechanism underlying memory cell anergy must involve Fyn kinase, given that the suppression of Fyn activity restores the movement of ZAP-70 to the immunological synapse, TCR proximal signaling, and cell proliferation. Thus, toleragens, including microbial toxins, may modulate memory responses by targeting the organizational structure of memory cell signaling complexes. PMID:22663768

  10. Peripheral and central neuronal ATF3 precedes CD4+ T-cell infiltration in EAE.

    PubMed

    Frezel, Noémie; Sohet, Fabien; Daneman, Richard; Basbaum, Allan I; Braz, Joao M

    2016-09-01

    Experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis produced by immunization with myelin oligodendrocyte glycoprotein (MOG) and adjuvants, results from profound T-cell mediated CNS demyelination. EAE is characterized by progressive, ascending motor dysfunction and symptoms of ongoing pain and hypersensitivity, in some cases preceding or concomitant with the motor deficits. In this regard, the EAE model mimics major features of multiple sclerosis, where a central neuropathic pain state is common. Although the latter condition is presumed to arise from a CNS loss of inhibitory controls secondary to the demyelination, dysfunction of sensory neurons may also contribute. Based on our previous studies that demonstrated the utility of monitoring expression of activating transcription factor 3 (ATF3), a sensitive marker of injured sensory neurons, here we followed both ATF3 and CD4+ T cells invasion of sensory ganglia (as well as the CNS) at different stages of the EAE model. We found that ATF3 is induced in peripheral sensory ganglia and brainstem well before the appearance of motor deficits. Unexpectedly, the ATF3 induction always preceded T cell infiltration, typically in adjacent, but non-overlapping regions. Surprisingly, control administration of the pertussis toxin and/or Complete Freund's adjuvants, without MOG, induced ATF3 in sensory neurons. In contrast, T cell infiltration only occurred with MOG. Taken together, our results suggest that the clinical manifestations in the EAE result not only from central demyelination but also from neuronal stress and subsequent pathophysiology of sensory neurons. PMID:27343802

  11. Circulating CXCR5+CD4+ T Follicular-Like Helper Cell and Memory B Cell Responses to Human Papillomavirus Vaccines

    PubMed Central

    Matsui, Ken; Adelsberger, Joseph W.; Kemp, Troy J.; Baseler, Michael W.; Ledgerwood, Julie E.; Pinto, Ligia A.

    2015-01-01

    Through the interaction of T follicular helper (Tfh) cells and B cells, efficacious vaccines can generate high-affinity, pathogen-neutralizing antibodies, and memory B cells. Using CXCR5, CXCR3, CCR6, CCR7, PD1, and ICOS as markers, Tfh-like cells can be identified in the circulation and be classified into three functionally distinct subsets that are PD1+ICOS+, PD1+ ICOS-, or PD1-ICOS-. We used these markers to identify different subsets of CXCR5+CD4+ Tfh-like cells in response to highly immunogenic and efficacious vaccines for human papillomaviruses (HPV): Cervarix and Gardasil. In this small study, we used PBMC samples from 11 Gardasil recipients, and 8 Cervarix recipients from the Vaccine Research Center 902 Study to examine the induction of circulating Tfh-like cells and IgD-CD38HiCD27+ memory B cells by flow cytometry. PD1+ICOS+ CXCR3+CCR6-CXCR5+CD4+ (Tfh1-like) cells were induced and peaked on Day (D) 7 post-first vaccination, but not as much on D7 post-third vaccination. We also observed a trend toward increase in PD1+ICOS+ CXCR3-CCR6-CXCR5+CD4+ (Tfh2-like) cells for both vaccines, and PD1+ICOS+ CXCR3-CCR6+CXCR5+CD4+ (Tfh17-like) subset was induced by Cervarix post-first vaccination. There were also minimal changes in the other cellular subsets. In addition, Cervarix recipients had more memory B cells post-first vaccination than did Gardasil recipients at D14 and D30. We found frequencies of memory B cells at D30 correlated with anti-HPV16 and 18 antibody titers from D30, and the induction levels of memory B cells at D30 and PD1+ICOS+Tfh1-like cells at D7 post-first vaccination correlated for Cervarix. Our study showed that induction of circulating CXCR5+CD4+ Tfh-like subsets can be detected following immunization with HPV vaccines, and potentially be useful as a marker of immunogenicity of vaccines. However, further investigations should be extended to different cohorts with larger sample size to better understand the functions of these T cells, as well as

  12. A NOVEL 78-KDA FATTY ACYL-COA SYNTHETASE (ACS1) OF BABESIA BOVIS STIMULATES MEMORY CD4+ T LYMPHOCYTE RESPONSES IN B. BOVIS-IMMUNE CATTLE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antigen-specific CD4+ T lymphocyte responses contribute to protective immunity against Babesia bovis, however the antigens that induce these responses remain largely unknown. A proteomic approach was used to identify novel B. bovis antigens recognized by memory CD4+ T cells from immune cattle. Fract...

  13. Immunophenotyping of rheumatoid arthritis reveals a linkage between HLA-DRB1 genotype, CXCR4 expression on memory CD4+ T cells, and disease activity

    PubMed Central

    Nagafuchi, Yasuo; Shoda, Hirofumi; Sumitomo, Shuji; Nakachi, Shinichiro; Kato, Rika; Tsuchida, Yumi; Tsuchiya, Haruka; Sakurai, Keiichi; Hanata, Norio; Tateishi, Shoko; Kanda, Hiroko; Ishigaki, Kazuyoshi; Okada, Yukinori; Suzuki, Akari; Kochi, Yuta; Fujio, Keishi; Yamamoto, Kazuhiko

    2016-01-01

    Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that leads to destructive arthritis. Although the HLA class II locus is the strongest genetic risk factor for rheumatoid arthritis, the relationship between HLA class II alleles and lymphocyte activation remains unclear. We performed immunophenotyping of peripheral blood mononuclear cells on 91 HLA-DRB1-genotyped RA patients and 110 healthy donors. The frequency of memory CXCR4+CD4+ T cells, and not Th1 and Th17 cells, was significantly associated with disease severity by multiple linear regression analysis. RA patients with one or more susceptible HLA-DR haplotypes (shared epitope: SE) displayed a significantly higher frequency of memory CXCR4+CD4+ T cells. Moreover, the frequency of memory CXCR4+CD4+ T cells significantly correlated with the expression level of HLA-DR on B cells, which was elevated in RA patients with SE. In vitro analysis and transcriptomic pathway analysis suggested that the interaction between HLA-DR and T cell receptors is an important regulator of memory CXCR4+CD4+ T cells. Clinically, a higher frequency of memory CXCR4+CD4+ T cells predicted a better response to CTLA4-Ig. Memory CXCR4+CD4+ T cells may serve as a powerful biomarker for unraveling the linkage between HLA-DRB1 genotype and disease activity in RA. PMID:27385284

  14. Cytomegalovirus-infected human endothelial cells can stimulate allogeneic CD4+ memory T cells by releasing antigenic exosomes1

    PubMed Central

    Walker, Jason D.; Maier, Cheryl L.; Pober, Jordan S.

    2008-01-01

    Human CMV infection is controlled by T cell-mediated immunity and in immunosuppressed transplant patients it is associated with acute allograft rejection as well as chronic allograft vasculopathy. CMV infects endothelial cells (EC) and it is thought that CMV-specific host immune responses to infected allograft EC contribute to rejection. In vitro, CD4+ T cells from CMV-positive donors (but not CMV-negative donors) are readily activated by CMV-infected allogeneic EC, although it is unclear how allogeneic CMV-infected EC activate self-class II MHC-restricted memory CD4+ T cells. In this study we confirm that purified CD4+ T cells from CMV+ donors are activated by allogeneic CMV-infected EC, but find that the response is dependent upon co-purified APC expressing class II MHC that are autologous to the T cells. The transfer of CMV antigens from infected EC to APC can be mediated by EC-derived exosome-like particles. These results provide a mechanism by which CMV can exacerbate allograft rejection, and suggest a novel function of EC-derived exosomes that could contribute in a more general manner to immune surveillance. PMID:19155503

  15. Requirement for CD4+ T Lymphocytes in Host Resistance against Cryptococcus neoformans in the Central Nervous System of Immunized Mice

    PubMed Central

    Buchanan, Kent L.; Doyle, Hester A.

    2000-01-01

    The importance of cell-mediated immunity (CMI) and CD4+ T lymphocytes in host resistance against Cryptococcus neoformans is well documented and is exemplified by the high susceptibility to progressive infection with this pathogen of AIDS patients with reduced CD4+ T-cell numbers. Although much has been learned about the role of CMI in the clearance of C. neoformans from the lungs and other internal organs, less is known about the protective mechanisms in the brain, the organ most frequently involved with a fatal outcome of cryptococcosis. We hypothesized that host resistance mechanisms against C. neoformans in the central nervous system (CNS) were similar to those outside the CNS (i.e., gamma interferon [IFN-γ], CD4+ T cells, and others). To test this hypothesis, we used a murine model of cryptococcal meningitis whereby cryptococci are introduced directly into the CNS. In experiments where mice were immunized to mount an anticryptococcal CMI response, our results indicate that immunization induced protective mechanisms that could be detected in the CNS by inhibition of the growth of viable yeast cells. Flow cytometric analyses of leukocytes in brain and spinal cord homogenates revealed that T lymphocytes, macrophages, and neutrophils accumulated in C. neoformans-infected brains of immune mice. In vivo depletion of CD4+ T cells, but not CD8+ T cells, resulted in significantly reduced leukocyte accumulation in the brains of immune mice. Furthermore, depletion of CD4+ T cells or neutralization of IFN-γ exacerbated CNS infection in immune mice, suggesting a critical role for CMI mechanisms in acquired protection in the CNS. PMID:10639404

  16. The cortical actin determines different susceptibility of naïve and memory CD4+ T cells to HIV-1 cell-to-cell transmission and infection.

    PubMed

    Permanyer, Marc; Pauls, Eduardo; Badia, Roger; Esté, José A; Ballana, Ester

    2013-01-01

    Memory CD4+ T cells are preferentially infected by HIV-1 compared to naïve cells. HIV-1 fusion and entry is a dynamic process in which the cytoskeleton plays an important role by allowing virion internalization and uncoating. Here, we evaluate the role of the cortical actin in cell-to-cell transfer of virus antigens and infection of target CD4+ T cells. Using different actin remodeling compounds we demonstrate that efficiency of HIV-internalization was proportional to the actin polymerization of the target cell. Naïve (CD45RA+) and memory (CD45RA-) CD4+ T cells could be phenotypically differentiated by the degree of cortical actin density and their capacity to capture virus. Thus, the higher cortical actin density of memory CD4+ T cells was associated to increased efficiency of HIV-antigen internalization and the establishment of a productive infection. Conversely, the lower cortical actin density in naïve CD4+ T cells restricted viral antigen transfer and consequently HIV-1 infection. In conclusion, the cortical actin density differentially affects the susceptibility to HIV-1 infection in naïve and memory CD4+ T cells by modulating the efficiency of HIV antigen internalization. PMID:24244453

  17. Gut environment-induced intraepithelial autoreactive CD4+ T cells suppress central nervous system autoimmunity via LAG-3

    PubMed Central

    Kadowaki, Atsushi; Miyake, Sachiko; Saga, Ryoko; Chiba, Asako; Mochizuki, Hideki; Yamamura, Takashi

    2016-01-01

    The gut environment has been found to significantly influence autoimmune diseases such as multiple sclerosis; however, immune cell mechanisms are unclear. Here we show that the gut epithelium of myelin oligodendrocyte glycoprotein(35-55)-specific T-cell receptor transgenic mice contains environmental stimuli-induced intraepithelial lymphocytes (IELs) that inhibit experimental autoimmune encephalomyelitis on transfer. These cells express surface markers phenotypical of ‘induced' IELs, have a TH17-like profile and infiltrate the central nervous system (CNS). They constitutively express Ctla4 and Tgfb1 and markedly upregulate Lag3 expression in the CNS, thereby inhibiting inflammation. We also demonstrate the suppressive capability of CD4+ IELs with alternative antigen specificities, their proliferation in response to gut-derived antigens and contribution of the microbiota and dietary aryl hydrocarbon receptor ligands to their induction. Thus, the gut environment favours the generation of autoreactive CD4+ T cells with unique regulatory functions, potentially important for preventing CNS autoimmunity. PMID:27198196

  18. Gut environment-induced intraepithelial autoreactive CD4(+) T cells suppress central nervous system autoimmunity via LAG-3.

    PubMed

    Kadowaki, Atsushi; Miyake, Sachiko; Saga, Ryoko; Chiba, Asako; Mochizuki, Hideki; Yamamura, Takashi

    2016-01-01

    The gut environment has been found to significantly influence autoimmune diseases such as multiple sclerosis; however, immune cell mechanisms are unclear. Here we show that the gut epithelium of myelin oligodendrocyte glycoprotein(35-55)-specific T-cell receptor transgenic mice contains environmental stimuli-induced intraepithelial lymphocytes (IELs) that inhibit experimental autoimmune encephalomyelitis on transfer. These cells express surface markers phenotypical of 'induced' IELs, have a TH17-like profile and infiltrate the central nervous system (CNS). They constitutively express Ctla4 and Tgfb1 and markedly upregulate Lag3 expression in the CNS, thereby inhibiting inflammation. We also demonstrate the suppressive capability of CD4(+) IELs with alternative antigen specificities, their proliferation in response to gut-derived antigens and contribution of the microbiota and dietary aryl hydrocarbon receptor ligands to their induction. Thus, the gut environment favours the generation of autoreactive CD4(+) T cells with unique regulatory functions, potentially important for preventing CNS autoimmunity. PMID:27198196

  19. CD4 T cells with effector memory phenotype and function develop in the sterile environment of the fetus.

    PubMed

    Zhang, Xiaoming; Mozeleski, Brian; Lemoine, Sebastien; Dériaud, Edith; Lim, Annick; Zhivaki, Dania; Azria, Elie; Le Ray, Camille; Roguet, Gwenaelle; Launay, Odile; Vanet, Anne; Leclerc, Claude; Lo-Man, Richard

    2014-05-28

    The T cell compartment is considered to be naïve and dedicated to the development of tolerance during fetal development. We have identified and characterized a population of fetally developed CD4 T cells with an effector memory phenotype (TEM), which are present in cord blood. This population is polyclonal and has phenotypic features similar to those of conventional adult memory T cells, such as CD45RO expression. These cells express low levels of CD25 but are distinct from regulatory T cells because they lack Foxp3 expression. After T cell receptor activation, neonatal TEM cells readily produced tumor necrosis factor-α (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF). We also detected interferon-γ (IFN-γ)-producing T helper 1 (TH1) cells and interleukin-4 (IL-4)/IL-13-producing TH2-like cells, but not IL-17-producing cells. We used chemokine receptor expression patterns to divide this TEM population into different subsets and identified distinct transcriptional programs using whole-genome microarray analysis. IFN-γ was found in CXCR3(+) TEM cells, whereas IL-4 was found in both CXCR3(+) TEM cells and CCR4(+) TEM cells. CCR6(+) TEM cells displayed a genetic signature that corresponded to TH17 cells but failed to produce IL-17A. However, the TH17 function of TEM cells was observed in the presence of IL-1β and IL-23. In summary, in the absence of reported pathology or any major infectious history, T cells with a memory-like phenotype develop in an environment thought to be sterile during fetal development and display a large variety of inflammatory effector functions associated with CD4 TH cells at birth. PMID:24871133

  20. CD4+CD25+ regulatory T cells in the small intestinal lamina propria show an effector/memory phenotype.

    PubMed

    Guo, Zijin; Jang, Myoung Ho; Otani, Kazuhiro; Bai, Zhongbin; Umemoto, Eiji; Matsumoto, Masanori; Nishiyama, Mika; Yamasaki, Mikako; Ueha, Satoshi; Matsushima, Kouji; Hirata, Takako; Miyasaka, Masayuki

    2008-03-01

    CD4(+)CD25(+) regulatory T cells (Tregs) have been implicated in the suppression of pathogenic responses to both self- and non-self-antigens in the intestine. However, their precise properties and functions in the gut, as well as the molecular basis of their recruitment to the gut, are poorly understood. Here, we found that most of the CD4(+)CD25(+) T cells in the small intestinal lamina propria (LP) express Foxp3 and exhibit an 'effector/memory' phenotype, CD44(hi)CD45RB(lo)CD62L(-), whereas only a minority of the Foxp3(+)CD4(+)CD25(+) T cells in the spleen and mesenteric lymph nodes showed this phenotype. The Tregs in the small intestinal LP (LP-Tregs) expressed higher levels of CCR4 and CCR9 and a substantially lower level of CCR7 than the Tregs in the spleen. In vitro, the LP-Tregs showed chemotaxis to CCL25/thymus-expressed chemokine. In addition, they showed efficient chemotaxis to the CCR4 ligands, CCL17/thymus and activation-regulated chemokine and CCL22/macrophage-derived chemokine, which are abundantly expressed by dendritic cells (DCs) in the small intestinal LP. In vivo, approximately 50% of the LP-Tregs were closely associated or in direct contact with LP-DCs. These findings demonstrate that LP-Tregs are phenotypically and functionally unique and raise the possibility that they are retained in the small intestinal LP through the action of CCL17 and CCL22, which are locally produced by LP-DCs. PMID:18184698

  1. Impaired CD4+ and T-helper 17 cell memory response to Streptococcus pneumoniae is associated with elevated glucose and percent glycated hemoglobin A1c in Mexican Americans with type 2 diabetes mellitus.

    PubMed

    Martinez, Perla J; Mathews, Christine; Actor, Jeffrey K; Hwang, Shen-An; Brown, Eric L; De Santiago, Heather K; Fisher Hoch, Susan P; McCormick, Joseph B; Mirza, Shaper

    2014-01-01

    Individuals with type 2 diabetes are significantly more susceptible to pneumococcal infections than healthy individuals of the same age. Increased susceptibility is the result of impairments in both innate and adaptive immune systems. Given the central role of T-helper 17 (Th17) and T-regulatory (Treg) cells in pneumococcal infection and their altered phenotype in diabetes, this study was designed to analyze the Th17 and Treg cell responses to a whole heat-killed capsular type 2 strain of Streptococcus pneumoniae. Patients with diabetes demonstrated a lower frequency of total CD+T-cells, which showed a significant inverse association with elevated fasting blood glucose. Measurement of specific subsets indicated that those with diabetes had, low intracellular levels of interleukin (IL)-17, and lower pathogen-specific memory CD4+ and IL-17+ cell numbers. No significant difference was observed in the frequency of CD4+ and Th17 cells between those with and without diabetes. However, stratification of data by obesity indicated a significant increase in frequency of CD4+ and Th17 cells in obese individuals with diabetes compared with nonobese individual with diabetes. The memory CD+T-cell response was associated inversely with both fasting blood glucose and percent glycated hemoglobin A1c. This study demonstrated that those with type 2 diabetes have a diminished pathogen-specific memory CD4+ and Th17 response, and low percentages of CD+T-cells in response to S. pneumoniae stimulation. PMID:23927943

  2. Broadly targeted human cytomegalovirus-specific CD4+ and CD8+ T cells dominate the memory compartments of exposed subjects.

    PubMed

    Sylwester, Andrew W; Mitchell, Bridget L; Edgar, John B; Taormina, Cara; Pelte, Christian; Ruchti, Franziska; Sleath, Paul R; Grabstein, Kenneth H; Hosken, Nancy A; Kern, Florian; Nelson, Jay A; Picker, Louis J

    2005-09-01

    Human cytomegalovirus (HCMV) infections of immunocompetent hosts are characterized by a dynamic, life-long interaction in which host immune responses, particularly of T cells, restrain viral replication and prevent disease but do not eliminate the virus or preclude transmission. Because HCMV is among the largest and most complex of known viruses, the T cell resources committed to maintaining this balance have never been characterized completely. Here, using cytokine flow cytometry and 13,687 overlapping 15mer peptides comprising 213 HCMV open reading frames (ORFs), we found that 151 HCMV ORFs were immunogenic for CD4(+) and/or CD8(+) T cells, and that ORF immunogenicity was influenced only modestly by ORF expression kinetics and function. We further documented that total HCMV-specific T cell responses in seropositive subjects were enormous, comprising on average approximately 10% of both the CD4(+) and CD8(+) memory compartments in blood, whereas cross-reactive recognition of HCMV proteins in seronegative individuals was limited to CD8(+) T cells and was rare. These data provide the first glimpse of the total human T cell response to a complex infectious agent and will provide insight into the rules governing immunodominance and cross-reactivity in complex viral infections of humans. PMID:16147978

  3. Broadly targeted human cytomegalovirus-specific CD4+ and CD8+ T cells dominate the memory compartments of exposed subjects

    PubMed Central

    Sylwester, Andrew W.; Mitchell, Bridget L.; Edgar, John B.; Taormina, Cara; Pelte, Christian; Ruchti, Franziska; Sleath, Paul R.; Grabstein, Kenneth H.; Hosken, Nancy A.; Kern, Florian; Nelson, Jay A.; Picker, Louis J.

    2005-01-01

    Human cytomegalovirus (HCMV) infections of immunocompetent hosts are characterized by a dynamic, life-long interaction in which host immune responses, particularly of T cells, restrain viral replication and prevent disease but do not eliminate the virus or preclude transmission. Because HCMV is among the largest and most complex of known viruses, the T cell resources committed to maintaining this balance have never been characterized completely. Here, using cytokine flow cytometry and 13,687 overlapping 15mer peptides comprising 213 HCMV open reading frames (ORFs), we found that 151 HCMV ORFs were immunogenic for CD4+ and/or CD8+ T cells, and that ORF immunogenicity was influenced only modestly by ORF expression kinetics and function. We further documented that total HCMV-specific T cell responses in seropositive subjects were enormous, comprising on average ∼10% of both the CD4+ and CD8+ memory compartments in blood, whereas cross-reactive recognition of HCMV proteins in seronegative individuals was limited to CD8+ T cells and was rare. These data provide the first glimpse of the total human T cell response to a complex infectious agent and will provide insight into the rules governing immunodominance and cross-reactivity in complex viral infections of humans. PMID:16147978

  4. Polarized granzyme release is required for antigen-driven transendothelial migration of human effector memory CD4 T cells

    PubMed Central

    Manes, Thomas D.; Pober, Jordan S.

    2014-01-01

    Human effector memory (EM) CD4 T cells may transmigrate across endothelial cell (EC) monolayers either in response to inflammatory chemokines or in response to TCR recognition of antigen presented on the surface of the EC. The kinetics, morphologic manifestations, and molecular requirements of chemokine- and TCR-driven transendothelial migration (TEM) differ significantly. Here we report that while the MTOC and cytosolic granules follow the nucleus across the endothelium in a uropod during chemokine-driven TEM, MTOC reorientation to the contact region between the T cell and the EC, accompanied by dynein-driven transport of granzyme-containing granules to and exocytosis at the contact region, are early events in TCR-driven but not chemokine-driven TEM. Inhibitors of either granule function or of granzyme proteolytic activity can arrest TCR-driven TEM, implying a requirement for granule discharge in the process. In the final stages of TCR-driven TEM, the MTOC precedes, rather than follows, the nucleus across the endothelium. Thus TCR-driven TEM of EM CD4 T cells appears to be a novel process that more closely resembles immune synapse formation than it does conventional chemotaxis. PMID:25367116

  5. High-throughput sequencing reveals restricted TCR Vβ usage and public TCRβ clonotypes among pancreatic lymph node memory CD4(+) T cells and their involvement in autoimmune diabetes.

    PubMed

    Marrero, Idania; Aguilera, Carlos; Hamm, David E; Quinn, Anthony; Kumar, Vipin

    2016-06-01

    Islet-reactive memory CD4(+) T cells are an essential feature of type 1 diabetes (T1D) as they are involved in both spontaneous disease and in its recurrence after islet transplantation. Expansion and enrichment of memory T cells have also been shown in the peripheral blood of diabetic patients. Here, using high-throughput sequencing, we investigated the clonal diversity of the TCRβ repertoire of memory CD4(+) T cells in the pancreatic lymph nodes (PaLN) of non-obese diabetic (NOD) mice and examined their clonal overlap with islet-infiltrating memory CD4T cells. Both prediabetic and diabetic NOD mice exhibited a restricted TCRβ repertoire dominated by clones expressing TRBV13-2, TRBV13-1 or TRBV5 gene segments. There is a limited degree of TCRβ overlap between the memory CD4 repertoire of PaLN and pancreas as well as between the prediabetic and diabetic group. However, public TCRβ clonotypes were identified across several individual animals, some of them with sequences similar to the TCRs from the islet-reactive T cells suggesting their antigen-driven expansion. Moreover, the majority of the public clonotypes expressed TRBV13-2 (Vβ8.2) gene segment. Nasal vaccination with an immunodominat peptide derived from the TCR Vβ8.2 chain led to protection from diabetes, suggesting a critical role for Vβ8.2(+) CD4(+) memory T cells in T1D. These results suggest that memory CD4(+) T cells bearing limited dominant TRBV genes contribute to the autoimmune diabetes and can be potentially targeted for intervention in diabetes. Furthermore, our results have important implications for the identification of public T cell clonotypes as potential novel targets for immune manipulation in human T1D. PMID:27161799

  6. Central Muscarinic Cholinergic Activation Alters Interaction between Splenic Dendritic Cell and CD4+CD25- T Cells in Experimental Colitis

    PubMed Central

    Pavlov, Valentin A.; Tracey, Kevin J.; Khafipour, Ehsan; Ghia, Jean-Eric

    2014-01-01

    Background The cholinergic anti-inflammatory pathway (CAP) is based on vagus nerve (VN) activity that regulates macrophage and dendritic cell responses in the spleen through alpha-7 nicotinic acetylcholine receptor (a7nAChR) signaling. Inflammatory bowel disease (IBD) patients present dysautonomia with decreased vagus nerve activity, dendritic cell and T cell over-activation. The aim of this study was to investigate whether central activation of the CAP alters the function of dendritic cells (DCs) and sequential CD4+/CD25−T cell activation in the context of experimental colitis. Methods The dinitrobenzene sulfonic acid model of experimental colitis in C57BL/6 mice was used. Central, intracerebroventricular infusion of the M1 muscarinic acetylcholine receptor agonist McN-A-343 was used to activate CAP and vagus nerve and/or splenic nerve transection were performed. In addition, the role of α7nAChR signaling and the NF-kB pathway was studied. Serum amyloid protein (SAP)-A, colonic tissue cytokines, IL-12p70 and IL-23 in isolated splenic DCs, and cytokines levels in DC-CD4+CD25−T cell co-culture were determined. Results McN-A-343 treatment reduced colonic inflammation associated with decreased pro-inflammatory Th1/Th17 colonic and splenic cytokine secretion. Splenic DCs cytokine release was modulated through α7nAChR and the NF-kB signaling pathways. Cholinergic activation resulted in decreased CD4+CD25−T cell priming. The anti-inflammatory efficacy of central cholinergic activation was abolished in mice with vagotomy or splenic neurectomy. Conclusions Suppression of splenic immune cell activation and altered interaction between DCs and T cells are important aspects of the beneficial effect of brain activation of the CAP in experimental colitis. These findings may lead to improved therapeutic strategies in the treatment of IBD. PMID:25295619

  7. Identifying the target cell in primary simian immunodeficiency virus (SIV) infection: highly activated memory CD4(+) T cells are rapidly eliminated in early SIV infection in vivo.

    PubMed

    Veazey, R S; Tham, I C; Mansfield, K G; DeMaria, M; Forand, A E; Shvetz, D E; Chalifoux, L V; Sehgal, P K; Lackner, A A

    2000-01-01

    It has recently been shown that rapid and profound CD4(+) T-cell depletion occurs almost exclusively within the intestinal tract of simian immunodeficiency virus (SIV)-infected macaques within days of infection. Here we demonstrate (by three- and four-color flow cytometry) that this depletion is specific to a definable subset of CD4(+) T cells, namely, those having both a highly and/or acutely activated (CD69(+) CD38(+) HLA-DR(+)) and memory (CD45RA(-) Leu8(-)) phenotype. Moreover, we demonstrate that this subset of helper T cells is found primarily within the intestinal lamina propria. Viral tropism for this particular cell type (which has been previously suggested by various studies in vitro) could explain why profound CD4(+) T-cell depletion occurs in the intestine and not in peripheral lymphoid tissues in early SIV infection. Furthermore, we demonstrate that an acute loss of this specific subset of activated memory CD4(+) T cells may also be detected in peripheral blood and lymph nodes in early SIV infection. However, since this particular cell type is present in such small numbers in circulation, its loss does not significantly affect total CD4(+) T cell counts. This finding suggests that SIV and, presumably, human immunodeficiency virus specifically infect, replicate in, and eliminate definable subsets of CD4(+) T cells in vivo. PMID:10590091

  8. CD40L+ CD4+ memory T cells migrate in a CD62P-dependent fashion into reactive lymph nodes and license dendritic cells for T cell priming

    PubMed Central

    Martín-Fontecha, Alfonso; Baumjohann, Dirk; Guarda, Greta; Reboldi, Andrea; Hons, Miroslav; Lanzavecchia, Antonio; Sallusto, Federica

    2008-01-01

    There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4+ effector memory T (TEM) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4+ TEM cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4+ TEM cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4+ TEM cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that TEM cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity. PMID:18838544

  9. Decreased TNF-α synthesis by macrophages restricts cutaneous immunosurveillance by memory CD4+ T cells during aging

    PubMed Central

    Agius, Elaine; Lacy, Katie E.; Vukmanovic-Stejic, Milica; Jagger, Ann L.; Papageorgiou, Anna-Pia; Hall, Sue; Reed, John R.; Curnow, S. John; Fuentes-Duculan, Judilyn; Buckley, Christopher D.; Salmon, Mike; Taams, Leonie S.; Krueger, James; Greenwood, John; Klein, Nigel; Rustin, Malcolm H.A.

    2009-01-01

    Immunity declines during aging, however the mechanisms involved in this decline are not known. In this study, we show that cutaneous delayed type hypersensitivity (DTH) responses to recall antigens are significantly decreased in older individuals. However, this is not related to CC chemokine receptor 4, cutaneous lymphocyte-associated antigen, or CD11a expression by CD4+ T cells or their physical capacity for migration. Instead, there is defective activation of dermal blood vessels in older subject that results from decreased TNF-α secretion by macrophages. This prevents memory T cell entry into the skin after antigen challenge. However, isolated cutaneous macrophages from these subjects can be induced to secrete TNF-α after stimulation with Toll-like receptor (TLR) 1/2 or TLR 4 ligands in vitro, indicating that the defect is reversible. The decreased conditioning of tissue microenvironments by macrophage-derived cytokines may therefore lead to defective immunosurveillance by memory T cells. This may be a predisposing factor for the development of malignancy and infection in the skin during aging. PMID:19667063

  10. Human Infant Memory B Cell and CD4+ T Cell Responses to HibMenCY-TT Glyco-Conjugate Vaccine

    PubMed Central

    Fuery, Angela; Richmond, Peter C.; Currie, Andrew J.

    2015-01-01

    Carrier-specific T cell and polysaccharide-specific B cell memory responses are not well characterised in infants following glyco-conjugate vaccination. We aimed to determine if the number of Meningococcal (Men) C- and Y- specific memory B cells and; number and quality of Tetanus Toxoid (TT) carrier-specific memory CD4+ T cells are associated with polysaccharide-specific IgG post HibMenCY-TT vaccination. Healthy infants received HibMenCY-TT vaccine at 2, 4 and 6 months with a booster at 12 months. Peripheral blood mononuclear cells were isolated and polysaccharide-specific memory B cells enumerated using ELISpot. TT-specific memory CD4+ T cells were detected and phenotyped based on CD154 expression and intracellular TNF-α, IL-2 and IFN-γ expression following stimulation. Functional polysaccharide-specific IgG titres were measured using the serum bactericidal activity (SBA) assay. Polysaccharide-specific Men C- but not Men Y- specific memory B cell frequencies pre-boost (12 months) were significantly associated with post-boost (13 months) SBA titres. Regression analysis showed no association between memory B cell frequencies post-priming (at 6 or 7 months) and SBA at 12 months or 13 months. TT-specific CD4+ T cells were detected at frequencies between 0.001 and 0.112 as a percentage of CD3+ T cells, but their numbers were not associated with SBA titres. There were significant negative associations between SBA titres at M13 and cytokine expression at M7 and M12. Conclusion: Induction of persistent polysaccharide-specific memory B cells prior to boosting is an important determinant of secondary IgG responses in infants. However, polysaccharide-specific functional IgG responses appear to be independent of the number and quality of circulating carrier-specific CD4+ T cells after priming. PMID:26191794

  11. The Expression of Functional Vpx during Pathogenic SIVmac Infections of Rhesus Macaques Suppresses SAMHD1 in CD4+ Memory T Cells

    PubMed Central

    Brenchley, Jason M.; Acharya, Priyamvada; Miyagi, Eri; Plishka, Ronald J.; Buckler-White, Alicia; Kwong, Peter D.; Nishimura, Yoshiaki; Strebel, Klaus; Martin, Malcolm A.

    2015-01-01

    For nearly 20 years, the principal biological function of the HIV-2/SIV Vpx gene has been thought to be required for optimal virus replication in myeloid cells. Mechanistically, this Vpx activity was recently reported to involve the degradation of Sterile Alpha Motif and HD domain-containing protein 1 (SAMHD1) in this cell lineage. Here we show that when macaques were inoculated with either the T cell tropic SIVmac239 or the macrophage tropic SIVmac316 carrying a Vpx point mutation that abrogates the recruitment of DCAF1 and the ensuing degradation of endogenous SAMHD1 in cultured CD4+ T cells, virus acquisition, progeny virion production in memory CD4+ T cells during acute infection, and the maintenance of set-point viremia were greatly attenuated. Revertant viruses emerging in two animals exhibited an augmented replication phenotype in memory CD4+ T lymphocytes both in vitro and in vivo, which was associated with reduced levels of endogenous SAMHD1. These results indicate that a critical role of Vpx in vivo is to promote the degradation of SAMHD1 in memory CD4+ T lymphocytes, thereby generating high levels of plasma viremia and the induction of immunodeficiency. PMID:25996507

  12. CD4+ T Cell Help Guides Formation of CD103+ Lung-Resident Memory CD8+ T Cells during Influenza Viral Infection

    PubMed Central

    Laidlaw, Brian J.; Zhang, Nianzhi; Marshall, Heather D.; Staron, Mathew M.; Guan, Tianxia; Hu, Yinghong; Cauley, Linda S.; Craft, Joe; Kaech, Susan M.

    2014-01-01

    SUMMARY Tissue-resident memory T (Trm) cells provide enhanced protection against infection at mucosal sites. Here we found that CD4+ T cells are important for the formation of functional lung-resident CD8+ T cells after influenza virus infection. In the absence of CD4+ T cells, CD8+ T cells displayed reduced expression of CD103 (Itgae), were mislocalized away from airway epithelia, and demonstrated an impaired ability to recruit CD8+ T cells to the lung air-ways upon heterosubtypic challenge. CD4+ T cell-derived interferon-γ was necessary for generating lung-resident CD103+ CD8+ Trm CD8 T cells. Furthermore, expression of the transcription factor T-bet was increased in “unhelped” lung Trm cells, and a reduction in T-bet rescued CD103 expression in the absence of CD4+ T cell help. Thus, CD4+ T cell-dependent signals are important to limit expression of T-bet and allow for the development of CD103+ CD8+ Trm cells in the lung airways following respiratory infection. PMID:25308332

  13. CD8 T cell memory recall is enhanced by novel direct interactions with CD4 T cells enabled by MHC class II transferred from APCs.

    PubMed

    Romagnoli, Pablo A; Premenko-Lanier, Mary F; Loria, Gilbert D; Altman, John D

    2013-01-01

    Protection against many intracellular pathogens is provided by CD8 T cells, which are thought to need CD4 T cell help to develop into effective memory CD8 T cells. Because murine CD8 T cells do not transcribe MHC class II (MHC-II) genes, several models have proposed antigen presenting cells (APCs) as intermediaries required for CD4 T cells to deliver their help to CD8 T cells. Here, we demonstrate the presence of MHC-II molecules on activated murine CD8 T cells in vitro as well as in vivo. These MHC-II molecules are acquired via trogocytosis by CD8 T cells from their activating APCs, particularly CD11c positive dendritic cells (DCs). Transferred MHC-II molecules on activated murine CD8 T cells were functionally competent in stimulating specific indicator CD4 T cells. CD8 T cells that were "helped" in vitro and subsequently allowed to rest in vivo showed enhanced recall responses upon challenge compared to "helpless" CD8 T cells; in contrast, no differences were seen upon immediate challenge. These data indicate that direct CD8:CD4 T cell interactions may significantly contribute to help for CD8 T cells. Furthermore, this mechanism may enable CD8 T cells to communicate with different subsets of interacting CD4 T cells that could modulate immune responses. PMID:23441229

  14. Expression of Cutaneous Lymphocyte–Associated Antigen and E-selectin Ligand by Circulating Human Memory CD4+ T Lymphocytes Specific for Herpes Simplex Virus Type 2

    PubMed Central

    González, Julio C.; Kwok, William W.; Wald, Anna; McClurkan, Christopher L.; Huang, Jay; Koelle, David M.

    2005-01-01

    Virus-specific memory T lymphocytes traffic to sites of viral infection. Herpes simplex virus (HSV) type 2–specific CD4+ and CD8+ T lymphocytes differ with regard to their homing kinetics to infected tissues. We studied the expression of cutaneous lymphocyte–associated antigen (CLA) and E-selectin ligand (ESL) by HSV-2–specific CD4+ T lymphocytes. Virus-reactive T lymphocytes were identified ex vivo by CD154 or interferon-γ up-regulation. We detected selective expression of CLA by HSV-2–reactive CD4+ T lymphocytes, but at levels lower than those we previously observed for CD8+ T lymphocytes. Short-term HSV-2–reactive CD4+ lines generated from peripheral-blood mononuclear cells preferentially express CLA, compared with cytomegalovirus- or influenza-specific cells. CLA is expressed by HSV-2–reactive cells that are initially CLA negative before restimulation. Short-term culture-expanded HSV-2–specific CD4+ T lymphocytes also selectively express ESL. These findings have implications for the optimization of vaccines for HSV and other cutaneous pathogens. PMID:15609235

  15. Nuclear PKC-θ facilitates rapid transcriptional responses in human memory CD4+ T cells through p65 and H2B phosphorylation

    PubMed Central

    Li, Jasmine; Hardy, Kristine; Phetsouphanh, Chan; Tu, Wen Juan; Sutcliffe, Elissa L.; McCuaig, Robert; Sutton, Christopher R.; Zafar, Anjum; Munier, C. Mee Ling; Zaunders, John J.; Xu, Yin; Theodoratos, Angelo; Tan, Abel; Lim, Pek Siew; Knaute, Tobias; Masch, Antonia; Zerweck, Johannes; Brezar, Vedran; Milburn, Peter J.; Dunn, Jenny; Casarotto, Marco G.; Turner, Stephen J.; Seddiki, Nabila; Kelleher, Anthony D.

    2016-01-01

    ABSTRACT Memory T cells are characterized by their rapid transcriptional programs upon re-stimulation. This transcriptional memory response is facilitated by permissive chromatin, but exactly how the permissive epigenetic landscape in memory T cells integrates incoming stimulatory signals remains poorly understood. By genome-wide ChIP-sequencing ex vivo human CD4+ T cells, here, we show that the signaling enzyme, protein kinase C theta (PKC-θ) directly relays stimulatory signals to chromatin by binding to transcriptional-memory-responsive genes to induce transcriptional activation. Flanked by permissive histone modifications, these PKC-enriched regions are significantly enriched with NF-κB motifs in ex vivo bulk and vaccinia-responsive human memory CD4+ T cells. Within the nucleus, PKC-θ catalytic activity maintains the Ser536 phosphorylation on the p65 subunit of NF-κB (also known as RelA) and can directly influence chromatin accessibility at transcriptional memory genes by regulating H2B deposition through Ser32 phosphorylation. Furthermore, using a cytoplasm-restricted PKC-θ mutant, we highlight that chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit transcriptional memory responses in human memory T cells. PMID:27149922

  16. Nuclear PKC-θ facilitates rapid transcriptional responses in human memory CD4+ T cells through p65 and H2B phosphorylation.

    PubMed

    Li, Jasmine; Hardy, Kristine; Phetsouphanh, Chan; Tu, Wen Juan; Sutcliffe, Elissa L; McCuaig, Robert; Sutton, Christopher R; Zafar, Anjum; Munier, C Mee Ling; Zaunders, John J; Xu, Yin; Theodoratos, Angelo; Tan, Abel; Lim, Pek Siew; Knaute, Tobias; Masch, Antonia; Zerweck, Johannes; Brezar, Vedran; Milburn, Peter J; Dunn, Jenny; Casarotto, Marco G; Turner, Stephen J; Seddiki, Nabila; Kelleher, Anthony D; Rao, Sudha

    2016-06-15

    Memory T cells are characterized by their rapid transcriptional programs upon re-stimulation. This transcriptional memory response is facilitated by permissive chromatin, but exactly how the permissive epigenetic landscape in memory T cells integrates incoming stimulatory signals remains poorly understood. By genome-wide ChIP-sequencing ex vivo human CD4(+) T cells, here, we show that the signaling enzyme, protein kinase C theta (PKC-θ) directly relays stimulatory signals to chromatin by binding to transcriptional-memory-responsive genes to induce transcriptional activation. Flanked by permissive histone modifications, these PKC-enriched regions are significantly enriched with NF-κB motifs in ex vivo bulk and vaccinia-responsive human memory CD4(+) T cells. Within the nucleus, PKC-θ catalytic activity maintains the Ser536 phosphorylation on the p65 subunit of NF-κB (also known as RelA) and can directly influence chromatin accessibility at transcriptional memory genes by regulating H2B deposition through Ser32 phosphorylation. Furthermore, using a cytoplasm-restricted PKC-θ mutant, we highlight that chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit transcriptional memory responses in human memory T cells. PMID:27149922

  17. Artificial antigen-presenting cells expressing HLA class II molecules as an effective tool for amplifying human specific memory CD4(+) T cells.

    PubMed

    Garnier, Anthony; Hamieh, Mohamad; Drouet, Aurélie; Leprince, Jérôme; Vivien, Denis; Frébourg, Thierry; Le Mauff, Brigitte; Latouche, Jean-Baptiste; Toutirais, Olivier

    2016-08-01

    Owing to their multiple immune functions, CD4(+) T cells are of major interest for immunotherapy in chronic viral infections and cancer, as well as for severe autoimmune diseases and transplantation. Therefore, standardized methods allowing rapid generation of a large number of CD4(+) T cells for adoptive immunotherapy are still awaited. We constructed stable artificial antigen-presenting cells (AAPCs) derived from mouse fibroblasts. They were genetically modified to express human leukocyte antigen (HLA)-DR molecules and the human accessory molecules B7.1, Intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-3 (LFA-3). AAPCs expressing HLA-DR1, HLA-DR15 or HLA-DR51 molecules and loaded with peptides derived from influenza hemagglutinin (HA), myelin basic protein (MBP) or factor VIII, respectively, activated specific CD4(+) T-cell clones more effectively than Epstein-Barr virus (EBV)-transformed B cells. We also showed that AAPCs were able to take up and process whole Ag proteins, and present epitopes to specific T cells. In primary cultures, AAPCs loaded with HA peptide allowed generation of specific Th1 lymphocytes from healthy donors as demonstrated by tetramer and intracellular cytokine staining. Although AAPCs were less effective than autologous peripheral blood mononuclear cells (PBMCs) to stimulate CD4(+) T cells in primary culture, AAPCs were more potent to reactivate and expand memory Th1 cells in a strictly Ag-dependent manner. As the availability of autologous APCs is limited, the AAPC system represents a stable and reliable tool to achieve clinically relevant numbers of CD4(+) T cells for adoptive immunotherapy. For fundamental research in immunology, AAPCs are also useful to decipher mechanisms involved in the development of human CD4 T-cell responses. PMID:26924643

  18. Human CD4+ effector T lymphocytes generated upon TCR engagement with self-peptides respond defectively to IL-7 in their transition to memory cells

    PubMed Central

    González-Pérez, Gabriela; Segovia, Norma C; Rivas-Carvalho, Amaranta; Reyes, Diana P; Torres-Aguilar, Honorio; Aguilar-Ruiz, Sergio R; Irles, Claudine; Soldevila, Gloria; Sánchez-Torres, Carmen

    2013-01-01

    The peripheral repertoire of CD4+ T lymphocytes contains autoreactive cells that remain tolerant through several mechanisms. However, nonspecific CD4+ T cells can be activated in physiological conditions as in the course of an ongoing immune response, and their outcome is not yet fully understood. Here, we investigate the fate of human naive CD4+ lymphocytes activated by dendritic cells (DCs) presenting endogenous self-peptides in comparison with lymphocytes involved in alloresponses. We generated memory cells (Tmem) from primary effectors activated with mature autologous DCs plus interleukin (IL)-2 (Tmauto), simulating the circumstances of an active immune response, or allogeneic DCs (Tmallo). Tmem were generated from effector cells that were rested in the absence of antigenic stimuli, with or without IL-7. Tmem were less activated than effectors (demonstrated by CD25 downregulation) particularly with IL-7, suggesting that this cytokine may favour the transition to quiescence. Tmauto and Tmallo showed an effector memory phenotype, and responded similarly to polyclonal and antigen-specific stimuli. Biochemically, IL-7-treated Tmallo were closely related to conventional memory lymphocytes based on Erk-1/2 activation, whereas Tmauto were more similar to effectors. Autologous effectors exhibited lower responses to IL-7 than allogeneic cells, which were reflected in their reduced proliferation and higher cell death. This was not related to IL-7 receptor expression but rather to signalling deficiencies, according to STAT5 activation These results suggest that ineffective responses to IL-7 could impair the transition to memory cells of naive CD4+ T lymphocytes recognizing self-peptides in the setting of strong costimulation. PMID:23454917

  19. Decreased Naive and Increased Memory CD4+ T Cells Are Associated with Subclinical Atherosclerosis: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Olson, Nels C.; Doyle, Margaret F.; Jenny, Nancy Swords; Huber, Sally A.; Psaty, Bruce M.; Kronmal, Richard A.; Tracy, Russell P.

    2013-01-01

    Background Adaptive immunity has been implicated in atherosclerosis in animal models and small clinical studies. Whether chronic immune activation is associated with atherosclerosis in otherwise healthy individuals remains underexplored. We hypothesized that activation of adaptive immune responses, as reflected by higher proportions of circulating CD4+ memory cells and lower proportions of naive cells, would be associated with subclinical atherosclerosis. Methods and Findings We examined cross-sectional relationships of circulating CD4+ naive and memory T cells with biomarkers of inflammation, serologies, and subclinical atherosclerosis in 912 participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Circulating CD4+ naive cells were higher in women than men and decreased with age (all p-values <0.0001). European-Americans had higher levels of naive cells and lower levels of memory cells compared with African-Americans and Hispanic-Americans (all p-values ≤0.0005). Lower naive/higher memory cells were associated with interleukin-6 levels. In multivariate models, cytomegalovirus (CMV) and H. Pylori titers were strongly associated with higher memory and lower naive cells (all p-values <0.05). Higher memory cells were associated with coronary artery calcification (CAC) level in the overall population [β-Coefficient (95% confidence interval (CI))  = 0.20 (0.03, 0.37)]. Memory and naive (inversely) cells were associated with common carotid artery intimal media thickness (CC IMT) in European-Americans [memory: β =  0.02 (0.006, 0.04); naive: β = −0.02 (−0.004, −0.03)]. Conclusions These results demonstrate that the degree of chronic adaptive immune activation is associated with both CAC and CC IMT in otherwise healthy individuals, consistent with the known role of CD4+ T cells, and with innate immunity (inflammation), in atherosclerosis. These data are also consistent with the hypothesis that immunosenescence accelerates chronic diseases by

  20. Circulating CXCR5⁺CD4⁺ T Follicular-Like Helper Cell and Memory B Cell Responses to Human Papillomavirus Vaccines.

    PubMed

    Matsui, Ken; Adelsberger, Joseph W; Kemp, Troy J; Baseler, Michael W; Ledgerwood, Julie E; Pinto, Ligia A

    2015-01-01

    Through the interaction of T follicular helper (Tfh) cells and B cells, efficacious vaccines can generate high-affinity, pathogen-neutralizing antibodies, and memory B cells. Using CXCR5, CXCR3, CCR6, CCR7, PD1, and ICOS as markers, Tfh-like cells can be identified in the circulation and be classified into three functionally distinct subsets that are PD1+ICOS+, PD1+ ICOS-, or PD1-ICOS-. We used these markers to identify different subsets of CXCR5+CD4+ Tfh-like cells in response to highly immunogenic and efficacious vaccines for human papillomaviruses (HPV): Cervarix and Gardasil. In this small study, we used PBMC samples from 11 Gardasil recipients, and 8 Cervarix recipients from the Vaccine Research Center 902 Study to examine the induction of circulating Tfh-like cells and IgD-CD38HiCD27+ memory B cells by flow cytometry. PD1+ICOS+ CXCR3+CCR6-CXCR5+CD4+ (Tfh1-like) cells were induced and peaked on Day (D) 7 post-first vaccination, but not as much on D7 post-third vaccination. We also observed a trend toward increase in PD1+ICOS+ CXCR3-CCR6-CXCR5+CD4+ (Tfh2-like) cells for both vaccines, and PD1+ICOS+ CXCR3-CCR6+CXCR5+CD4+ (Tfh17-like) subset was induced by Cervarix post-first vaccination. There were also minimal changes in the other cellular subsets. In addition, Cervarix recipients had more memory B cells post-first vaccination than did Gardasil recipients at D14 and D30. We found frequencies of memory B cells at D30 correlated with anti-HPV16 and 18 antibody titers from D30, and the induction levels of memory B cells at D30 and PD1+ICOS+Tfh1-like cells at D7 post-first vaccination correlated for Cervarix. Our study showed that induction of circulating CXCR5+CD4+ Tfh-like subsets can be detected following immunization with HPV vaccines, and potentially be useful as a marker of immunogenicity of vaccines. However, further investigations should be extended to different cohorts with larger sample size to better understand the functions of these T cells, as well as

  1. Overexpression of Foxn1 attenuates age-associated thymic involution and prevents the expansion of peripheral CD4 memory T cells

    PubMed Central

    Zook, Erin C.; Krishack, Paulette A.; Zhang, Shubin; Zeleznik-Le, Nancy J.; Firulli, Anthony B.; Witte, Pamela L.

    2011-01-01

    The forkhead box n1 (Foxn1) transcription factor is essential for thymic organogenesis during embryonic development; however, a functional role of Foxn1 in the postnatal thymus is less well understood. We developed Foxn1 transgenic mice (Foxn1Tg), in which overexpression of Foxn1 is driven by the human keratin-14 promoter. Expression of the Foxn1 transgene increased the endogenous Foxn1 levels. In aged mice, overexpression of Foxn1 in the thymus attenuated the decline in thymocyte numbers, prevented the decline in frequency of early thymic progenitors, and generated a higher number of signal joint TCR excised circle. Histologic studies revealed that structural alterations associated with thymic involution were diminished in aged Foxn1 Tg. Total numbers of EpCAM+ MHC II+ and MHC IIhi thymic epithelial cells were higher in young and old Foxn1Tg and more EpCAM+ MHC IIhi TEC expressed Ki-67 in aged Foxn1Tg compared with WT. Furthermore, Foxn1Tg displayed a significant reduction in the expansion of splenic CD4+ memory compartments and attenuated the decline in CD4+ and CD8+ naive compartments. Our data indicate that manipulation of Foxn1 expression in the thymus ameliorates thymopoiesis in aged mice and offer a strategy to combat the age-associated decline in naive T-cell production and CD4 naive/memory ratios in the elderly. PMID:21908422

  2. Control of viremia and maintenance of intestinal CD4(+) memory T cells in SHIV(162P3) infected macaques after pathogenic SIV(MAC251) challenge.

    PubMed

    Pahar, Bapi; Lackner, Andrew A; Piatak, Michael; Lifson, Jeffrey D; Wang, Xiaolei; Das, Arpita; Ling, Binhua; Montefiori, David C; Veazey, Ronald S

    2009-05-10

    Recent HIV vaccine failures have prompted calls for more preclinical vaccine testing in non-human primates. However, similar to HIV infection of humans, developing a vaccine that protects macaques from infection following pathogenic SIV(MAC251) challenge has proven difficult, and current vaccine candidates at best, only reduce viral loads after infection. Here we demonstrate that prior infection with a chimeric simian-human immunodeficiency virus (SHIV) containing an HIV envelope gene confers protection against intravenous infection with the heterologous, highly pathogenic SIV(MAC251) in rhesus macaques. Although definitive immune correlates of protection were not identified, preservation and/or restoration of intestinal CD4(+) memory T cells were associated with protection from challenge and control of viremia. These results suggest that protection against pathogenic lentiviral infection or disease progression is indeed possible, and may correlate with preservation of mucosal CD4(+) T cells. PMID:19298994

  3. Intracellular expression of interleukin-4 and interferon-γ by a Mycobacterium tuberculosis antigen-stimulated CD4+ CD57+ T-cell subpopulation with memory phenotype in tuberculosis patients

    PubMed Central

    Jiménez-Martínez, Maria C; Linares, Marisela; Báez, Renata; Montaño, Luis F; Martínez-Cairo, Salvador; Gorocica, Patricia; Chávez, Raúl; Zenteno, Edgar; Lascurain, Ricardo

    2004-01-01

    In some chronic pathological conditions, antigen persistence activates and expands the CD4+ CD57+ T-cell subset. The host immune response against tuberculosis infection is maintained through the continuous presence of antigen-stimulated effector/memory helper T cells. To determine whether CD4+ CD57+ T cells were also expanded in human tuberculosis, we analysed (by flow cytometry) the phenotype of peripheral blood CD4+ T cells from 30 tuberculosis patients and 30 healthy controls. We observed a significant increase in the CD4+ CD57+ T-cell subset in tuberculosis patients in comparison to healthy controls (P < 0.001). Most CD4+ CD57+ T cells exhibited a CD28− CD45RO+ CD62L− phenotype, which is associated with memory cells. In vitro, a higher number of antigen-stimulated CD4+ CD57+ T cells produced intracellular interferon-γ and interleukin-4 compared with antigen-stimulated CD4+ CD57− T cells (P < 0.001). These findings suggest that the majority of CD4+ CD57+ T cells correspond to a phenotype of activated memory T cells. PMID:14678204

  4. Central tolerance spares the private high-avidity CD4(+) T-cell repertoire specific for an islet antigen in NOD mice.

    PubMed

    Serre, Laurent; Fazilleau, Nicolas; Guerder, Sylvie

    2015-07-01

    Although central tolerance induces the deletion of most autoreactive T cells, some autoreactive T cells escape thymic censorship. Whether potentially harmful autoreactive T cells present distinct TCRαβ features remains unclear. Here, we analyzed the TCRαβ repertoire of CD4(+) T cells specific for the S100β protein, an islet antigen associated with type 1 diabetes. We found that diabetes-resistant NOD mice deficient for thymus specific serine protease (TSSP), a protease that impairs class II antigen presentation by thymic stromal cells, were hyporesponsive to the immunodominant S100β1-15 epitope, as compared to wild-type NOD mice, due to intrathymic negative selection. In both TSSP-deficient and wild-type NOD mice, the TCRαβ repertoire of S100β-specific CD4(+) T cells though diverse showed a specific bias for dominant TCRα rearrangements with limited CDR3α diversity. These dominant TCRα chains were public since they were found in all mice. They were of intermediate- to low-avidity. In contrast, high-avidity T cells expressed unique TCRs specific to each individual (private TCRs) and were only found in wild-type NOD mice. Hence, in NOD mice, the autoreactive CD4(+) T-cell compartment has two major components, a dominant and public low-avidity TCRα repertoire and a private high-avidity CD4(+) T-cell repertoire; the latter is deleted by re-enforced negative selection. PMID:25884569

  5. Defective T cell Receptor-mediated Signal Transduction in Memory CD4 T Lymphocytes Exposed to Superantigen or anti-T cell Receptor Antibodies

    PubMed Central

    Watson, Andrew R.O.; Lee, William T.

    2007-01-01

    Lymphocytes must promote protective immune responses while still maintaining self-tolerance. Stimulation through the T cell receptor (TCR1) can lead to distinct responses in naive and memory CD4 T cells. Whereas peptide antigen stimulates both naive and memory T cells, soluble anti-CD3 antibodies and bacterial superantigens stimulate only naive T cells to proliferate and secrete cytokines. Further, superantigens, like staphylococcal enterotoxin B (SEB), cause memory T cells to become anergic while soluble anti-CD3 does not. In the present report we show that signal transduction through the TCR is impaired in memory cells exposed to either anti-CD3 or SEB. A block in signaling leads to impaired activation of the kinase ZAP-70 so that downstream signals and cell proliferation do not occur. We further show that the signaling defect is unique to each agent. In anti-CD3-treated memory T cells, the src kinase Lck is only transiently activated and does not phosphorylate and activate ZAP-70. In SEB-treated memory T cells, ZAP-70 does not interact with the TCR/CD3 complex to become accessible to Lck. Finally, we provide evidence that alternative signaling pathways are initiated in SEB-treated memory cells. Altered signaling, indicated by an elevation in activity of the src kinase Fyn, may be responsible for memory cell anergy caused by SEB. Thus, differentiation of naive T cells into memory cells is accompanied by alterations in TCR-mediated signaling that can promote heightened recall immunity or specific tolerance. PMID:17083922

  6. ERβ in CD4+ T Cells Is Crucial for Ligand-Mediated Suppression of Central Nervous System Autoimmunity.

    PubMed

    Aggelakopoulou, Maria; Kourepini, Evangelia; Paschalidis, Nikolaos; Panoutsakopoulou, Vily

    2016-06-15

    The development of therapies for multiple sclerosis targeting pathogenic T cell responses remains imperative. Previous studies have shown that estrogen receptor (ER) β ligands could inhibit experimental autoimmune encephalomyelitis. However, the effects of ERβ-specific ligands on human or murine pathogenic immune cells, such as Th17, were not investigated. In this article, we show that the synthetic ERβ-specific ligand 4-(2-phenyl-5,7-bis[trifluoromethyl]pyrazolo[1,5-a]pyrimidin-3-yl)phenol (PHTPP) reversed established paralysis and CNS inflammation, characterized by a dramatic suppression of pathogenic Th responses as well as induction of IL-10-producing regulatory CD4(+) T cell subsets in vivo. Moreover, administration of PHTPP in symptomatic mice induced regulatory CD4(+) T cells that were suppressive in vivo. PHTPP-mediated experimental autoimmune encephalomyelitis amelioration was canceled in mice with ERβ-deficient CD4(+) T cells only, indicating that expression of ERβ by these cells is crucial for the observed therapeutic effect. Importantly, synthetic ERβ-specific ligands acting directly on CD4(+) T cells suppressed human and mouse Th17 cells, downregulating Th17 cell signature gene expression and expanding IL-10-producing T cells among them. TGF-β1 and aryl hydrocarbon receptor activation enhanced the ERβ ligand-mediated expansion of IL-10-producing T cells among Th17 cells. In addition, these ERβ-specific ligands promoted the induction and maintenance of Foxp3(+) T regulatory cells, as well as their in vitro suppressive function. Thus, ERβ-specific ligands targeting pathogenic Th17 cells and inducing functional regulatory cells represent a promising subset of therapeutic agents for multiple sclerosis. PMID:27183630

  7. Cellular and molecular requirements for the recall of IL-4-producing memory CD4(+)CD45RO(+)CD27(-) T cells during protection induced by attenuated Plasmodium falciparum sporozoites.

    PubMed

    Palmer, Dupeh R; Krzych, Urszula

    2002-03-01

    The requirements for maintenance of antigen (Ag)-specific memory T cells in protection to malaria is poorly understood. We have previously demonstrated a recall of IL-4-producing memory CD4(+)CD45RO(+) T cells with parasitized red blood cells (pRBC) in persons protected by radiation-attenuated Plasmodium falciparum sporozoites (gamma-spz). Using the CD27 marker, we have now identified two subsets of CD4(+)CD45RO(+) T cells: CD4(+)CD45RO(+)CD27(+) T cells representing an early memory and CD4(+)CD45RO(+)CD27() T cells representing a terminally differentiated memory cells. A small subset of CD4(+)CD45RO(+)CD27(-) T cells also expressed CD70, the CD27 ligand. The addition of anti-CD70 monoclonal antibody (mAb) to pRBC-stimulated cultures significantly inhibited the conversion of CD27(+) to CD27(-) subset without profoundly affecting IL-4 production. In contrast, the inclusion of anti-CD27 mAb in parallel cultures abrogated IL-4 production without interfering with conscription of T cells into the CD27(-) T cell set. We propose that the persistence of memory CD4(+) T cells depends on Ag-driven conscription of a mature memory phenotype through co-ligation of CD27 and CD70 expressed, respectively, on CD27(+) and CD27(-) T cells. Hence, protracted protection in malaria depends in part on memory CD4(+) T cells that require specific Ag presumably from the repositories of liver-and blood-stage antigens and the delivery of a second signal from the CD27:CD70 interaction. PMID:11857339

  8. Opioid growth factor and low-dose naltrexone impair central nervous system infiltration by CD4 + T lymphocytes in established experimental autoimmune encephalomyelitis, a model of multiple sclerosis.

    PubMed

    Hammer, Leslie A; Waldner, Hanspeter; Zagon, Ian S; McLaughlin, Patricia J

    2016-01-01

    Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS), characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is the animal model widely utilized to study MS. EAE is mediated by CD4(+) T cells and can be induced in EAE-susceptible mice through immunization with a myelin antigen, such as proteolipid protein 139-151 (PLP139-151) in SJL mice. In this PLP-induced EAE model, autoreactive CD4(+) T cells migrate from peripheral tissues into the CNS where they are reactivated resulting in CNS damage. Th1 and Th17 cells produce the pro-inflammatory cytokines IFNγ and IL-17, respectively, that have been shown to have pathogenic roles in EAE and MS. Anti-inflammatory Th2, IL-4 secreting cells, have been indicated to inhibit EAE exacerbation. However, given the inflammatory environment of EAE, Th2 effector cells are outnumbered by Th1/Th17 cells. Regulatory CD4(+) T cells suppress immune reactions and have been demonstrated to be dysfunctional in MS patients. Opioid growth factor (OGF), chemically termed [Met(5)]-enkephalin, is a negative growth factor that interacts with the OGF receptor. The OGF-OGFr axis can be activated through exogenous administration of OGF or a low dosage of naltrexone (LDN), an opioid antagonist. We have previously demonstrated that modulation of the OGF-OGFr axis results in alleviation from relapse-remitting EAE, and that CNS-infiltrating CD3(+) T cells are diminished with exogenous OGF or intermittent blockade with LDN administration. In this paper, we aimed to determine whether OGF or LDN alter the Th effector responses of CD4(+) T lymphocytes within the CNS in established EAE. We report in these studies that the numbers of CD4(+) T lymphocytes in the CNS of EAE mice are decreased following treatment with OGF for five days but not LDN. However, modulation of the OGF-OGFr axis did not result in changes to CD4(+) Th effector cell responses

  9. A pilot study showing associations between frequency of CD4(+) memory cell subsets at diagnosis and duration of partial remission in type 1 diabetes.

    PubMed

    Moya, Rosita; Robertson, Hannah Kathryn; Payne, Dawson; Narsale, Aditi; Koziol, Jim; Davies, Joanna Davida

    2016-05-01

    In some patients with type 1 diabetes the dose of insulin required to achieve euglycemia is substantially reduced soon after diagnosis. This partial remission is associated with β-cell function and good glucose control. The purpose of this study was to assess whether frequencies of CD4(+) T cell subsets in children newly diagnosed with type 1 diabetes are associated with length of partial remission. We found that the frequency of CD4(+) memory cells, activated Treg cells and CD25(+) cells that express a high density of the IL-7 receptor, CD127 (CD127(hi)) are strongly associated with length of partial remission. Prediction of length of remission via Cox regression is significantly enhanced when CD25(+) CD127(hi) cell frequency is combined with either Insulin Dependent Adjusted A1c (IDAA1c), or glycosylated hemoglobin (HbA1c), or C-peptide levels at diagnosis. CD25(+) CD127(hi) cells do not express Foxp3, LAG-3 and CD49b, indicating that they are neither Treg nor Tr1 cells. PMID:27114212

  10. Impaired selective cytokine production by CD4(+) T cells in Common Variable Immunodeficiency associated with the absence of memory B cells.

    PubMed

    Berrón-Ruiz, Laura; López-Herrera, Gabriela; Vargas-Hernández, Alexander; Santos-Argumedo, Leopoldo; López-Macías, Constantino; Isibasi, Armando; Segura-Méndez, Nora Hilda; Bonifaz, Laura

    2016-05-01

    Common Variable Immunodeficiency (CVID) is a primary immunodeficiency characterized by B cell dysfunction and decreased serum immunoglobulin. CVID patients are classified by the absence or presence of memory B cells. In addition, T cell defects have been demonstrated in only a proportion of CVID patients. The aim of this study was to evaluate the function of CD4(+) T cells from CVID patients and its association with memory B cells. Patients were classified according to their Freiburg groups: group Ia and Ib, with decreased switched memory B cells (<0.4 of PBL), and group II, with normal B cell subsets. Their T cell function was evaluated after stimulation. We observed normal and even increased CD4(+) T cell proliferation in group Ia (p=0.0277). The proliferation positively correlated with the clinical severity score (r=0.4796). We observed lower levels of IL-17A and IL-10 in group Ia (p=0.0177, 0.0109) and Ib (p=0.0009, 0.0084) patients. Group Ib patients also had low levels of IL-13 and IL-9 (p=0.0169, 0.010). Group II patients had similar cytokine production to that of the controls. BAFFR expression was reduced in groups Ia (p=0.0001) and Ib (p=0.0002) and showed an inverse correlation with the severity score (p=0.0262; r=0.5371). ICOS expression was reduced in group Ia (p=0.0364), and PD-1 was increased in group Ib (p=0.0432) patients. This study shows a selective impairment in cytokine production in group Ia patients, which was more extensive than in group Ib patients. The impairment was associated with BAFFR expression in B cells, with ICOS and PD-1 in T cells and, remarkably, with the absence of memory B cells and with the disease severity. Our results suggest that the evaluation of cytokine expression by T cells in combination with the study of B cell memory could be important for understand the pathogenesis of CVID patients. PMID:27057998

  11. T cell immunity. Functional heterogeneity of human memory CD4⁺ T cell clones primed by pathogens or vaccines.

    PubMed

    Becattini, Simone; Latorre, Daniela; Mele, Federico; Foglierini, Mathilde; De Gregorio, Corinne; Cassotta, Antonino; Fernandez, Blanca; Kelderman, Sander; Schumacher, Ton N; Corti, Davide; Lanzavecchia, Antonio; Sallusto, Federica

    2015-01-23

    Distinct types of CD4(+) T cells protect the host against different classes of pathogens. However, it is unclear whether a given pathogen induces a single type of polarized T cell. By combining antigenic stimulation and T cell receptor deep sequencing, we found that human pathogen- and vaccine-specific T helper 1 (T(H)1), T(H)2, and T(H)17 memory cells have different frequencies but comparable diversity and comprise not only clones polarized toward a single fate, but also clones whose progeny have acquired multiple fates. Single naïve T cells primed by a pathogen in vitro could also give rise to multiple fates. Our results unravel an unexpected degree of interclonal and intraclonal functional heterogeneity of the human T cell response and suggest that polarized responses result from preferential expansion rather than priming. PMID:25477212

  12. The sterile and tolerogenic fetal niche does not restrict the generation of CD4 T memory cells

    PubMed Central

    2015-01-01

    T-cell activation requires a sequence of signals derived from co-stimulatory receptors and from immunogens that may or may not be of infectious origin. This scenario provides the threshold of inflammatory stimulus needed for the induction of antigen-specific T cell responses. One of the dogmas of immunology stipulates that the activation of T lymphocytes is prevented in immunosuppressed or tolerogenic environments. However, it was shown recently that a healthy uterine environment that is considered sterile, therefore not exposed to infection, is capable of generating T memory cells with the capacity to differentiate lineage-specific inflammatory effector T-cell responses. The implications of this finding are discussed in this editorial. PMID:25992363

  13. Stress-activated Dendritic Cells (DC) Induce Dual Interleukin (IL)-15- and IL1β-mediated Pathways, Which May Elicit CD4+ Memory T Cells and Interferon (IFN)-stimulated Genes.

    PubMed

    Wang, Yufei; Lavender, Paul; Watson, Julie; Arno, Matthew; Lehner, Thomas

    2015-06-19

    The prevailing evidence suggests that immunological memory does not require antigenic re-stimulation but is maintained by low level tonic stimulation. We examined the hypothesis that stress agents contribute to tonic cellular activation and maintain immunological memory. Stimulation of monocyte-derived dendritic cells (DC) with stress agents elicits reactive oxygen species and HSP70. NFκB is activated, which up-regulates membrane-associated (ma) IL-15, caspase-1 and IL-1β. Co-culture of stress-treated DC with mononuclear cells activates IL-15 and IL-1β receptors on CD4(+) T cells, eliciting CD40L, proliferation, and up-regulation of CD45RO(+) memory T cells. The transcription factors Tbet(high) and RORγt are up-regulated, whereas FoxP3 is down-regulated, resulting in enhanced Th1 and Th17 expression and the corresponding cytokines. The interaction between maIL-15 expressed by DC and IL-15R on CD4(+) T cells results in one pathway and the corresponding cells expressing IL-1β and IL1βR as a second pathway. Importantly, inhibition studies with IL-15 antibodies and IL-1βR inhibitor suggest that both pathways may be required for optimum CD4(+) CD45RO(+) memory T cell expression. Type 1 IFN expression in splenic CD11c DC of stress-treated mice demonstrated a significant increase of IFN-α in CD11c CD317(+) and CD8α(+) DC. Analysis of RNA in human CD4(+) memory T cells showed up-regulation of type 1 IFN-stimulated genes and inhibition with histone methyltransferase inhibitor. We suggest the paradigm that stress-induced tonic stimulation might be responsible for the robust persistence of the immune response in vaccination and that epigenetic changes are involved in maintaining CD4(+) T cell memory. PMID:25907558

  14. Stress-activated Dendritic Cells (DC) Induce Dual Interleukin (IL)-15- and IL1β-mediated Pathways, Which May Elicit CD4+ Memory T Cells and Interferon (IFN)-stimulated Genes*

    PubMed Central

    Wang, Yufei; Lavender, Paul; Watson, Julie; Arno, Matthew; Lehner, Thomas

    2015-01-01

    The prevailing evidence suggests that immunological memory does not require antigenic re-stimulation but is maintained by low level tonic stimulation. We examined the hypothesis that stress agents contribute to tonic cellular activation and maintain immunological memory. Stimulation of monocyte-derived dendritic cells (DC) with stress agents elicits reactive oxygen species and HSP70. NFκB is activated, which up-regulates membrane-associated (ma) IL-15, caspase-1 and IL-1β. Co-culture of stress-treated DC with mononuclear cells activates IL-15 and IL-1β receptors on CD4+ T cells, eliciting CD40L, proliferation, and up-regulation of CD45RO+ memory T cells. The transcription factors Tbethigh and RORγt are up-regulated, whereas FoxP3 is down-regulated, resulting in enhanced Th1 and Th17 expression and the corresponding cytokines. The interaction between maIL-15 expressed by DC and IL-15R on CD4+ T cells results in one pathway and the corresponding cells expressing IL-1β and IL1βR as a second pathway. Importantly, inhibition studies with IL-15 antibodies and IL-1βR inhibitor suggest that both pathways may be required for optimum CD4+ CD45RO+ memory T cell expression. Type 1 IFN expression in splenic CD11c DC of stress-treated mice demonstrated a significant increase of IFN-α in CD11c CD317+ and CD8α+ DC. Analysis of RNA in human CD4+ memory T cells showed up-regulation of type 1 IFN-stimulated genes and inhibition with histone methyltransferase inhibitor. We suggest the paradigm that stress-induced tonic stimulation might be responsible for the robust persistence of the immune response in vaccination and that epigenetic changes are involved in maintaining CD4+ T cell memory. PMID:25907558

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

    PubMed

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

    2016-03-01

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

  16. reChIP-seq reveals widespread bivalency of H3K4me3 and H3K27me3 in CD4(+) memory T cells.

    PubMed

    Kinkley, Sarah; Helmuth, Johannes; Polansky, Julia K; Dunkel, Ilona; Gasparoni, Gilles; Fröhler, Sebastian; Chen, Wei; Walter, Jörn; Hamann, Alf; Chung, Ho-Ryun

    2016-01-01

    The combinatorial action of co-localizing chromatin modifications and regulators determines chromatin structure and function. However, identifying co-localizing chromatin features in a high-throughput manner remains a technical challenge. Here we describe a novel reChIP-seq approach and tailored bioinformatic analysis tool, normR that allows for the sequential enrichment and detection of co-localizing DNA-associated proteins in an unbiased and genome-wide manner. We illustrate the utility of the reChIP-seq method and normR by identifying H3K4me3 or H3K27me3 bivalently modified nucleosomes in primary human CD4(+) memory T cells. We unravel widespread bivalency at hypomethylated CpG-islands coinciding with inactive promoters of developmental regulators. reChIP-seq additionally uncovered heterogeneous bivalency in the population, which was undetectable by intersecting H3K4me3 and H3K27me3 ChIP-seq tracks. Finally, we provide evidence that bivalency is established and stabilized by an interplay between the genome and epigenome. Our reChIP-seq approach augments conventional ChIP-seq and is broadly applicable to unravel combinatorial modes of action. PMID:27530917

  17. reChIP-seq reveals widespread bivalency of H3K4me3 and H3K27me3 in CD4+ memory T cells

    PubMed Central

    Kinkley, Sarah; Helmuth, Johannes; Polansky, Julia K.; Dunkel, Ilona; Gasparoni, Gilles; Fröhler, Sebastian; Chen, Wei; Walter, Jörn; Hamann, Alf; Chung, Ho-Ryun

    2016-01-01

    The combinatorial action of co-localizing chromatin modifications and regulators determines chromatin structure and function. However, identifying co-localizing chromatin features in a high-throughput manner remains a technical challenge. Here we describe a novel reChIP-seq approach and tailored bioinformatic analysis tool, normR that allows for the sequential enrichment and detection of co-localizing DNA-associated proteins in an unbiased and genome-wide manner. We illustrate the utility of the reChIP-seq method and normR by identifying H3K4me3 or H3K27me3 bivalently modified nucleosomes in primary human CD4+ memory T cells. We unravel widespread bivalency at hypomethylated CpG-islands coinciding with inactive promoters of developmental regulators. reChIP-seq additionally uncovered heterogeneous bivalency in the population, which was undetectable by intersecting H3K4me3 and H3K27me3 ChIP-seq tracks. Finally, we provide evidence that bivalency is established and stabilized by an interplay between the genome and epigenome. Our reChIP-seq approach augments conventional ChIP-seq and is broadly applicable to unravel combinatorial modes of action. PMID:27530917

  18. Recombinant Bivalent Fusion Protein rVE Induces CD4+ and CD8+ T-Cell Mediated Memory Immune Response for Protection Against Yersinia enterocolitica Infection

    PubMed Central

    Singh, Amit K.; Kingston, Joseph J.; Gupta, Shishir K.; Batra, Harsh V.

    2015-01-01

    Studies investigating the correlates of immune protection against Yersinia infection have established that both humoral and cell mediated immune responses are required for the comprehensive protection. In our previous study, we established that the bivalent fusion protein (rVE) comprising immunologically active regions of Y. pestis LcrV (100–270 aa) and YopE (50–213 aa) proteins conferred complete passive and active protection against lethal Y. enterocolitica 8081 challenge. In the present study, cohort of BALB/c mice immunized with rVE or its component proteins rV, rE were assessed for cell mediated immune responses and memory immune protection against Y. enterocolitica 8081. rVE immunization resulted in extensive proliferation of both CD4 and CD8 T cell subsets; significantly high antibody titer with balanced IgG1: IgG2a/IgG2b isotypes (1:1 ratio) and up-regulation of both Th1 (TNF-α, IFN-γ, IL-2, and IL-12) and Th2 (IL-4) cytokines. On the other hand, rV immunization resulted in Th2 biased IgG response (11:1 ratio) and proliferation of CD4+ T-cell; rE group of mice exhibited considerably lower serum antibody titer with predominant Th1 response (1:3 ratio) and CD8+ T-cell proliferation. Comprehensive protection with superior survival (100%) was observed among rVE immunized mice when compared to the significantly lower survival rates among rE (37.5%) and rV (25%) groups when IP challenged with Y. enterocolitica 8081 after 120 days of immunization. Findings in this and our earlier studies define the bivalent fusion protein rVE as a potent candidate vaccine molecule with the capability to concurrently stimulate humoral and cell mediated immune responses and a proof of concept for developing efficient subunit vaccines against Gram negative facultative intracellular bacterial pathogens. PMID:26733956

  19. Distributed trace using central performance counter memory

    DOEpatents

    Satterfield, David L; Sexton, James C

    2013-10-22

    A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

  20. Distributed trace using central performance counter memory

    DOEpatents

    Satterfield, David L.; Sexton, James C.

    2013-01-22

    A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

  1. Migration of CD8+ T Cells into the Central Nervous System Gives Rise to Highly Potent Anti-HIV CD4dimCD8bright T Cells in a Wnt Signaling-Dependent Manner.

    PubMed

    Richards, Maureen H; Narasipura, Srinivas D; Seaton, Melanie S; Lutgen, Victoria; Al-Harthi, Lena

    2016-01-01

    The role of CD8(+) T cells in HIV control in the brain and the consequences of such control are unclear. Approximately 3% of peripheral CD8(+) T cells dimly express CD4 on their surface. This population is known as CD4(dim)CD8(bright) T cells. We evaluated the role of CD4(dim)CD8(bright) and CD8 single positive T cells in HIV-infected brain using NOD/SCID/IL-2rcγ(-/-) mice reconstituted with human PBMCs (NSG-huPBMC). All three T cell populations (CD4 single positive, CD8 single positive, and CD4(dim)CD8(bright)) were found in NSG-huPBMC mouse brain within 2 wk of infection. Wnts secreted from astrocytes induced CD4(dim)CD8(bright) T cells by 2-fold in vitro. Injection of highly purified CD8 single positive T cells into mouse brain induced CD4(dim)CD8(bright) T cells by 10-fold, which were proliferative and exhibited a terminally differentiated effector memory phenotype. Brain CD4(dim)CD8(bright) T cells from HIV-infected mice exhibited anti-HIV-specific responses, as demonstrated by induction of CD107ab post exposure to HIV peptide-loaded targets. Further, higher frequency of CD4(dim)CD8(bright) T cells (R = -0.62; p ≤ 0.001), but not CD8 single positive T cells (R = -0.24; p ≤ 0.27), negatively correlated with HIV gag mRNA transcripts in HIV-infected NSG-huPBMC brain. Together, these studies indicate that single positive CD8(+) T cells entering the CNS during HIV infection can give rise to CD4(dim)CD8(bright) T cells, likely through a Wnt signaling-dependent manner, and that these cells are associated with potent anti-HIV control in the CNS. Thus, CD4(dim)CD8(bright) T cells are capable of HIV control in the CNS and may offer protection against HIV-associated neurocognitive disorders. PMID:26582945

  2. CD4+ T cells play a critical role in the generation of primary and memory antitumor immune responses elicited by SA-4-1BBL and TAA-based vaccines in mouse tumor models.

    PubMed

    Sharma, Rajesh K; Yolcu, Esma S; Srivastava, Abhishek K; Shirwan, Haval

    2013-01-01

    The role of CD4(+) T cells in the generation of therapeutic primary and memory immune responses in cancer diverse immunotherapy settings remains ambiguous. We herein investigated this issue using two vaccine formulations containing a novel costimulatory molecule, SA-4-1BBL, as adjuvant and HPV E7 or survivin (SVN) as tumor associated antigens (TAAs) in two mouse transplantable tumor models; the TC-1 cervical cancer expressing xenogeneic HPV E7 and 3LL lung carcinoma overexpressing autologous SVN. Single vaccination with optimized SA-4-1BBL/TAA formulations resulted in the eradication of 6-day established TC-1 and 3LL tumors in >70% of mice in both models. The in vivo depletion of CD4(+) T cells one day before tumor challenge resulted in compromised vaccine efficacy in both TC-1 (25%) and 3LL (12.5%) tumor models. In marked contrast, depletion of CD4(+) T cells 5 days post-tumor challenge and one day prior to vaccination did not significantly alter the therapeutic efficacy of these vaccines. However, long-term immunological memory was compromised in the 3LL, but not in TC-1 model as a significant number (85.7%) of tumor free-mice succumbed to tumor growth when rechallenged with 3LL cells 60 days after the initial tumor inoculation. Collectively, these results demonstrate the indispensable role CD4(+) T cells play in the generation of therapeutic primary immune responses elicited by SA-4-1BBL/TAA-based vaccines irrespective of the nature of TAAs and establish the importance of CD4(+) T cells for long-term immune memory against 3LL tumor expressing self-antigen SVN, but not TC-1 expressing xenogeneic viral antigen E7. PMID:24066030

  3. High quality long-term CD4+ and CD8+ effector memory populations stimulated by DNA-LACK/MVA-LACK regimen in Leishmania major BALB/c model of infection.

    PubMed

    Sánchez-Sampedro, Lucas; Gómez, Carmen Elena; Mejías-Pérez, Ernesto; Sorzano, Carlos Oscar S; Esteban, Mariano

    2012-01-01

    Heterologous vaccination based on priming with a plasmid DNA vector and boosting with an attenuated vaccinia virus MVA recombinant, with both vectors expressing the Leishmania infantum LACK antigen (DNA-LACK and MVA-LACK), has shown efficacy conferring protection in murine and canine models against cutaneus and visceral leishmaniasis, but the immune parameters of protection remain ill defined. Here we performed by flow cytometry an in depth analysis of the T cell populations induced in BALB/c mice during the vaccination protocol DNA-LACK/MVA-LACK, as well as after challenge with L. major parasites. In the adaptive response, there is a polyfunctional CD4(+) and CD8(+) T cell activation against LACK antigen. At the memory phase the heterologous vaccination induces high quality LACK-specific long-term CD4(+) and CD8(+) effector memory cells. After parasite challenge, there is a moderate boosting of LACK-specific CD4(+) and CD8(+) T cells. Anti-vector responses were largely CD8(+)-mediated. The immune parameters induced against LACK and triggered by the combined vaccination DNA/MVA protocol, like polyfunctionality of CD4(+) and CD8(+) T cells with an effector phenotype, could be relevant in protection against leishmaniasis. PMID:22715418

  4. A diametric role for OX40 in the response of effector/memory CD4+ T cells and regulatory T cells to alloantigen

    PubMed Central

    Kinnear, Gillian; Wood, Kathryn J.; Fallah-Arani, Farnaz; Jones, Nick D.

    2013-01-01

    OX40 is a member of the TNFR superfamily that has potent costimulatory properties. Although the impact of blockade of the OX40-OX40L pathway has been well documented in models of autoimmune disease, its effect on the rejection of allografts is less well defined. Here we show that the alloantigen-mediated activation of naïve and memory CD4+ T cells results in the induction of OX40 expression and that blockade of OX40-OX40L interactions prevents skin allograft rejection mediated by either subset of T cells. Moreover, a blocking anti-OX40 was found to have no effect on the activation and proliferation of T cells, but rather effector T cells failed to accumulate in peripheral lymph nodes and subsequently migrate to skin allografts. This was found to be the result of an enhanced degree of cell death amongst proliferating effector cells. In clear contrast, blockade of OX40-OX40L interactions at the time of exposure to alloantigen enhanced the ability of regulatory T cells to suppress T cell responses to alloantigen by supporting rather than diminishing regulatory T cell survival. These data show that OX40-OX40L signalling contributes to the evolution of the adaptive immune response to an allograft via the differential control of alloreactive effector and regulatory T cell survival. Moreover, these data serve to further highlight OX40 and OX40L as therapeutic targets to assist the induction of tolerance to allografts and self-antigens. PMID:23817421

  5. Loss of memory CD4+ T-cells in semi-wild mandrills (Mandrillus sphinx) naturally infected with species-specific simian immunodeficiency virus SIVmnd-1.

    PubMed

    Greenwood, Edward J D; Schmidt, Fabian; Liégeois, Florian; Kondova, Ivanela; Herbert, Anaïs; Ngoubangoye, Barthelemy; Rouet, François; Heeney, Jonathan L

    2014-01-01

    Simian immunodeficiency virus (SIV) infection is found in a number of African primate species and is thought to be generally non-pathogenic. However, studies of wild primates are limited to two species, with SIV infection appearing to have a considerably different outcome in each. Further examination of SIV-infected primates exposed to their natural environment is therefore warranted. We performed a large cross-sectional study of a cohort of semi-wild mandrills with naturally occurring SIV infection, including 39 SIV-negative and 33 species-specific SIVmnd-1-infected animals. This study was distinguished from previous reports by considerably greater sample size, examination of exclusively naturally infected animals in semi-wild conditions and consideration of simian T-lymphotropic virus (STLV) status in addition to SIVmnd-1 infection. We found that SIVmnd-1 infection was associated with a significant and progressive loss of memory CD4(+) T-cells. Limited but significant increases in markers of immune activation in the T-cell populations, significant increases in plasma neopterin and changes to B-cell subsets were also observed in SIV-infected animals. However, no increase in plasma soluble CD14 was observed. Histological examination of peripheral lymph nodes suggested that SIVmnd-1 infection was not associated with a significant disruption of the lymph node architecture. Whilst this species has evolved numerous strategies to resist the development of AIDS, significant effects of SIV infection could be observed when examined in a natural environment. STLVmnd-1 infection also had significant effects on some markers relevant to understanding SIV infection and thus should be considered in studies of SIV infection of African primates where present. PMID:24214347

  6. Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor

    SciTech Connect

    Kim, So Yong; Lim, Ju Hyun; Choi, Sung Won; Kim, Miyoung; Kim, Seong-Tae; Kim, Min-Seon; Cho, You Sook; Chun, Eunyoung; Lee, Ki-Young

    2010-04-09

    Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.

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

    PubMed

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

    2016-08-22

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

  8. HIV-1 tropism for the central nervous system: Brain-derived envelope glycoproteins with lower CD4 dependence and reduced sensitivity to a fusion inhibitor

    SciTech Connect

    Martin-Garcia, Julio . E-mail: julio.martin-garcia@drexelmed.edu; Cao, Wei; Varela-Rohena, Angel; Plassmeyer, Matthew L.; Gonzalez-Scarano, Francisco

    2006-03-01

    We previously described envelope glycoproteins of an HIV-1 isolate adapted in vitro for growth in microglia that acquired a highly fusogenic phenotype and lower CD4 dependence, as well as resistance to inhibition by anti-CD4 antibodies. Here, we investigated whether similar phenotypic changes are present in vivo. Envelope clones from the brain and spleen of an HIV-1-infected individual with neurological disease were amplified, cloned, and sequenced. Phylogenetic analysis demonstrated clustering of sequences according to the tissue of origin, as expected. Functional clones were then used in cell-to-cell fusion assays to test for CD4 and co-receptor utilization and for sensitivity to various antibodies and inhibitors. Both brain- and spleen-derived envelope clones mediated fusion in cells expressing both CD4 and CCR5 and brain envelopes also used CCR3 as co-receptor. We found that the brain envelopes had a lower CD4 dependence, since they efficiently mediated fusion in the presence of low levels of CD4 on the target cell membrane, and they were significantly more resistant to blocking by anti-CD4 antibodies than the spleen-derived envelopes. In contrast, we observed no difference in sensitivity to the CCR5 antagonist TAK-779. However, brain-derived envelopes were significantly more resistant than those from spleen to the fusion inhibitor T-1249 and concurrently showed slightly greater fusogenicity. Our results suggest an increased affinity for CD4 of brain-derived envelopes that may have originated from in vivo adaptation to replication in microglial cells. Interestingly, we note the presence of envelopes more resistant to a fusion inhibitor in the brain of an untreated, HIV-1-infected individual.

  9. Recovery of CD4+ T Cells in HIV patients with a stable virologic response to antiretroviral therapy is associated with polymorphisms of interleukin-6 and central major histocompatibility complex genes.

    PubMed

    Fernandez, Sonia; Rosenow, Ann A; James, Ian R; Roberts, Steven G; Nolan, Richard C; French, Martyn A; Price, Patricia

    2006-01-01

    We investigated whether polymorphisms in genes associated with HIV disease progression and/or immune activation affect CD4+ T-cell recovery in HIV patients who began combination antiretroviral therapy (ART) with advanced immunodeficiency and achieved stable control of plasma viremia. Patients with CD4 T-cell counts <300 cells/microL (n = 33) and >400 cells/microL (n = 37) on ART were compared. A multiple case-control logistic regression associated carriage of BAT1(1,2) or interleukin (IL)6-174(2,2) with low CD4 T-cell counts (P = 0.012). BAT1*2 uniquely marks the central major histocompatibility complex region of a conserved haplotype (HLA-A1,B8,BAT1*2,TNFA-308*2,DR3,DQ2). There was no association between alleles carried at CCR5Delta32, CCR5 59029, CCR5 59353, CCR2+190 (V64I), SDF1 3'UTR, IL1A+4845, IL1B+3953, IL4-589, IL10-592, IL10-R1+536, IL10-R1+1112, IL12B 3'UTR, TNFA-308, or TNFA-1031 and CD4 T-cell counts. We suggest that immune activation and/or CD4 T-cell apoptosis in HIV patients on effective ART is influenced by genetic factors. PMID:16340466

  10. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys

    PubMed Central

    Ortiz, Alexandra M.; Carnathan, Diane G.; Yu, Joana; Sheehan, Katherine M.; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H.; Klatt, Nichole R.; Brenchley, Jason M.; Davenport, Miles P.; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2’-bromo-5’-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  11. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys.

    PubMed

    Ortiz, Alexandra M; Carnathan, Diane G; Yu, Joana; Sheehan, Katherine M; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H; Klatt, Nichole R; Brenchley, Jason M; Davenport, Miles P; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2'-bromo-5'-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  12. Kaposi's Sarcoma-associated Herpesvirus K3 and K5 Proteins Block Distinct Steps in Transendothelial Migration of Effector Memory CD4+ T cells by Targeting Different Endothelial Proteins

    PubMed Central

    Manes, Thomas D.; Hoer, Simon; Muller, William A.; Lehner, Paul J.; Pober, Jordan S.

    2010-01-01

    K3 and K5 are Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded E3 ubiquitin ligases that differentially reduce surface expression of various proteins in infected cells. Here we describe their effects on human dermal microvascular endothelial cells (HDMEC), a natural target of KSHV infection. TNF-treated HDMEC transduced to express K5 show reduced capacity to capture effector memory (EM) CD4+ T cells under conditions of venular shear stress. K5 but not K3 transduction significantly reduces ICAM-1 expression and the inhibition of T cell capture was phenocopied by siRNA knockdown of ICAM-1 and by anti-ICAM-1 Ab blocking. Co-transduction with an ICAM-1 truncated construct not subject to K5 ubiquitylation restored EM CD4+ T cell capture. K3 transductants effectively capture EM CD4+ T cells, but fail to support their transendothelial migration (TEM) in response to TCR engagement by superantigen presented by the EC, leaving intact chemokine-dependent TEM. K3 but not K5 transduction significantly reduces PECAM-1 expression and the effect on TCR-induced TEM is phenocopied by siRNA knockdown of PECAM-1 and by anti-PECAM-1 Ab blocking. TCR-dependent TEM was restored in K3 transductants co-transduced to express a mutant of PECAM-1 not subject to K3-induced ubiquitylation. EM CD4+ T cells lack any known PECAM-1 counter receptor, but heterophilic engagement of PECAM-1 may involve glycosaminoglycans, and TCR-induced TEM, but not chemokine-induced TEM, appears to involve a heparan- or chondroitin-like molecule on T cells. These results both identify specific roles of K5 and K3 in immune evasion and further differentiate the processes of inflammatory chemokine- versus TCR-dependent recruitment of human EM CD4+ T cells. PMID:20357254

  13. Idiopathic CD4 Lymphocytopenia

    PubMed Central

    Régent, Alexis; Autran, Brigitte; Carcelain, Guislaine; Cheynier, Rémi; Terrier, Benjamin; Charmeteau-De Muylder, Bénédicte; Krivitzky, Alain; Oksenhendler, Eric; Costedoat-Chalumeau, Nathalie; Hubert, Pascale; Lortholary, Olivier; Dupin, Nicolas; Debré, Patrice; Guillevin, Loïc; Mouthon, Luc

    2014-01-01

    Abstract Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria. We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19–70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14–24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy. In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm3 (range, 4–294); mean CD8: 236/mm3 (range, 1–1293); mean CD19: 113/mm3 (range, 3–547); and mean NK cell count: 122/mm3 (range, 5–416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm3 and NK cell count <100/mm3 were predictors of death. In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency. PMID:24646462

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

    PubMed Central

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

    2014-01-01

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

  15. Progesterone Levels Associate with a Novel Population of CCR5+CD38+ CD4 T Cells Resident in the Genital Mucosa with Lymphoid Trafficking Potential.

    PubMed

    Swaims-Kohlmeier, Alison; Haaland, Richard E; Haddad, Lisa B; Sheth, Anandi N; Evans-Strickfaden, Tammy; Lupo, L Davis; Cordes, Sarah; Aguirre, Alfredo J; Lupoli, Kathryn A; Chen, Cheng-Yen; Ofotukun, Igho; Hart, Clyde E; Kohlmeier, Jacob E

    2016-07-01

    The female genital tract (FGT) provides a means of entry to pathogens, including HIV, yet immune cell populations at this barrier between host and environment are not well defined. We initiated a study of healthy women to characterize resident T cell populations in the lower FGT from lavage and patient-matched peripheral blood to investigate potential mechanisms of HIV sexual transmission. Surprisingly, we observed FGT CD4 T cell populations were primarily CCR7(hi), consistent with a central memory or recirculating memory T cell phenotype. In addition, roughly half of these CCR7(hi) CD4 T cells expressed CD69, consistent with resident memory T cells, whereas the remaining CCR7(hi) CD4 T cells lacked CD69 expression, consistent with recirculating memory CD4 T cells that traffic between peripheral tissues and lymphoid sites. HIV susceptibility markers CCR5 and CD38 were increased on FGT CCR7(hi) CD4 T cells compared with blood, yet migration to the lymphoid homing chemokines CCL19 and CCL21 was maintained. Infection with GFP-HIV showed that FGT CCR7(hi) memory CD4 T cells are susceptible HIV targets, and productive infection of CCR7(hi) memory T cells did not alter chemotaxis to CCL19 and CCL21. Variations of resident CCR7(hi) FGT CD4 T cell populations were detected during the luteal phase of the menstrual cycle, and longitudinal analysis showed the frequency of this population positively correlated to progesterone levels. These data provide evidence women may acquire HIV through local infection of migratory CCR7(hi) CD4 T cells, and progesterone levels predict opportunities for HIV to access these novel target cells. PMID:27233960

  16. Anaplasma marginale infection with persistent high-load bacteremia induces a dysfunctional memory CD4+ T lymphocyte response but sustained high IgG titers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of blood-borne infections is dependent on antigen-specific effector and memory T cells and high-affinity IgG responses. In chronic infections characterized by a high antigen load, it has been shown that antigen-specific T and B cells are vulnerable to downregulation and apoptosis. Anaplasma ...

  17. Identification of PGAM5 as a Mammalian Protein Histidine Phosphatase that Plays a Central Role to Negatively Regulate CD4(+) T Cells.

    PubMed

    Panda, Saswati; Srivastava, Shekhar; Li, Zhai; Vaeth, Martin; Fuhs, Stephen R; Hunter, Tony; Skolnik, Edward Y

    2016-08-01

    Whereas phosphorylation of serine, threonine, and tyrosine is exceedingly well characterized, the role of histidine phosphorylation in mammalian signaling is largely unexplored. Here we show that phosphoglycerate mutase family 5 (PGAM5) functions as a phosphohistidine phosphatase that specifically associates with and dephosphorylates the catalytic histidine on nucleoside diphosphate kinase B (NDPK-B). By dephosphorylating NDPK-B, PGAM5 negatively regulates CD4(+) T cells by inhibiting NDPK-B-mediated histidine phosphorylation and activation of the K(+) channel KCa3.1, which is required for TCR-stimulated Ca(2+) influx and cytokine production. Using recently developed monoclonal antibodies that specifically recognize phosphorylation of nitrogens at the N1 (1-pHis) or N3 (3-pHis) positions of the imidazole ring, we detect for the first time phosphoisoform-specific regulation of histidine-phosphorylated proteins in vivo, and we link these modifications to TCR signaling. These results represent an important step forward in studying the role of histidine phosphorylation in mammalian biology and disease. PMID:27453048

  18. Increased Mucosal CD4+ T Cell Activation in Rhesus Macaques following Vaccination with an Adenoviral Vector

    PubMed Central

    Bukh, Irene; Calcedo, Roberto; Roy, Soumitra; Carnathan, Diane G.; Grant, Rebecca; Qin, Qiuyue; Boyd, Surina; Ratcliffe, Sarah J.; Veeder, Christin L.; Bellamy, Scarlett L.; Betts, Michael R.

    2014-01-01

    ABSTRACT The possibility that vaccination with adenovirus (AdV) vectors increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of HIV acquisition within the Step trial. Modeling this within rhesus macaques is complicated because human adenoviruses, including human adenovirus type 5 (HAdV-5), are not endogenous to macaques. Here, we tested whether vaccination with a rhesus macaque-derived adenoviral vector (simian adenovirus 7 [SAdV-7]) enhances mucosal T cell activation within rhesus macaques. Following intramuscular SAdV-7 vaccination, we observed a pronounced increase in SAdV-7-specific CD4+ T cell responses in peripheral blood and, more dramatically, in rectal mucosa tissue. Vaccination also induced a significant increase in the frequency of activated memory CD4+ T cells in SAdV-7- and HAdV-5-vaccinated animals in the rectal mucosa but not in peripheral blood. These fluctuations within the rectal mucosa were also associated with a pronounced decrease in the relative frequency of naive resting CD4+ T cells. Together, these results indicate that peripheral vaccination with an AdV vector can increase the activation of mucosal CD4+ T cells, potentially providing an experimental model to further evaluate the role of host-vector interactions in increased HIV acquisition after AdV vector vaccination. IMPORTANCE The possibility that vaccination with a human adenovirus 5 vector increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of human immunodeficiency virus (HIV) acquisition within the Step trial. In this study, we tested whether vaccination with a rhesus macaque-derived adenoviral vector in rhesus macaques enhances mucosal CD4+ T cell activation, the main cell target of simian immunodeficiency virus (SIV)/HIV. The results showed that vaccination with an adenoviral vector indeed increases activation of mucosal CD4+ T cells and potentially increases susceptibility to SIV

  19. Treatment with Interleukin-7 Restores Host Defense against Pneumocystis in CD4+ T-Lymphocyte-Depleted Mice

    PubMed Central

    Samuelson, D. R.; Assouline, B.; Morre, M.; Shellito, J. E.

    2015-01-01

    Pneumocystis pneumonia (PCP) is a major cause of morbidity and mortality in patients with HIV infection. CD4+ T lymphocytes are critical for host defense against this infection, but in the absence of CD4+ T lymphocytes, CD8+ T lymphocytes may provide limited host defense. The cytokine interleukin-7 (IL-7) functions to enhance lymphocyte proliferation, survival, and recruitment of immune cells to sites of infection. However, there is little known about the role of IL-7 in PCP or its potential use as an immunotherapeutic agent. We hypothesized that treatment with recombinant human IL-7 (rhIL-7) would augment host defense against Pneumocystis and accelerate pathogen clearance in CD4-depleted mice. Control and CD4-depleted mice were infected with Pneumocystis, and rhIL-7 was administered via intraperitoneal injection. Our studies indicate that endogenous murine IL-7 is part of the normal host response to Pneumocystis murina and that administration of rhIL-7 markedly enhanced clearance of Pneumocystis in CD4-depleted mice. Additionally, we observed increased recruitment of CD8+ T lymphocytes to the lungs and decreased apoptosis of pulmonary CD8+ T lymphocytes in rhIL-7-treated animals compared to those in untreated mice. The antiapoptotic effect of rhIL-7 was associated with increased levels of Bcl-2 protein in T lymphocytes. rhIL-7 immunotherapy in CD4-depleted mice also increased the number of gamma interferon (IFN-γ)-positive CD8+ central memory T lymphocytes in the lungs. We conclude that rhIL-7 has a potent therapeutic effect in the treatment of murine Pneumocystis pneumonia in CD4-depleted mice. This therapeutic effect is mediated through enhanced recruitment of CD8+ T cells and decreased apoptosis of lung T lymphocytes, with a preferential action on central memory CD8+ T lymphocytes. PMID:26483405

  20. Normal adult ramified microglia separated from other central nervous system macrophages by flow cytometric sorting: Phenotypic differences defined and direct ex vivo antigen presentation to myelin basic protein-reactive CD4{sup +} T cells compared

    SciTech Connect

    Ford, A.L.; Goodsall, A.L.; Sedgwick, J.D.

    1995-05-01

    Ramified microglia in the adult central nervous system (CNS) are the principal glial element up-regulating MHC class I and II expression in response to inflammatory events or neuronal damage. A proportion of these cells also express MHC class II constitutively in the normal CNS. The role of microglia as APCs for CD4{sup +} cells extravasating into the CNS remains undefined. In this study, using irradiation bone marrow chimeras in CD45-congenic rats, the phenotype CD45{sup low}CD11b/c{sup +} is shown to identify microglial cells specifically within the CNS. Highly purified populations of microglia and nonmicroglial but CNS-associated macrophages (CD45{sup high}CD11b/c{sup +}) have been obtained directly from the adult CNS, by using flow cytometric sorting. Morphologically, freshly isolated microglia vs other CNS macrophages are quite distinct. Of the two populations recovered from the normal CNS, it is the minority CD45{sup high}CD11 b/c{sup +} transitional macrophage population, and not microglia, that is the effective APC for experimental autoimmune encephalomyelitis-inducing CD4{sup +} myelin basic protein (MBP)-reactive T cells. CD45{sup high}CD11b/c{sup +} CNS macrophages also stimulate MBP-reactive T cells without addition of MBP to culture suggesting presentation of endogenous Ag. This is the first study in which microglia vs other CNS macrophages have been analyzed for APC ability directly from the CNS, with substantial cross-contamination between the two populations eliminated. The heterogeneity of these populations in terms of APC function is clearly demonstrated. Evidence is still lacking that adult CNS microglia have the capacity to interact with and stimulate CD4{sup +} T cells to proliferate or secrete IL-2. 60 refs., 6 figs., 1 tab.

  1. Quantitation of Replication-Competent HIV-1 in Populations of Resting CD4+ T Cells

    PubMed Central

    Soriano-Sarabia, Natalia; Bateson, Rosalie E.; Dahl, Noelle P.; Crooks, Amanda M.; Kuruc, JoAnn D.; Margolis, David M.

    2014-01-01

    ABSTRACT Central memory (TCM) CD4+ T cells are the principal reservoir of latent HIV-1 infection that persists despite durable, successful antiretroviral therapy (ART). In a study that measured HIV DNA in 17 patients and replication-competent HIV in 4 patients, pools of resting and activated transitional memory (TTM) CD4+ T cells were found to be a reservoir for HIV infection. As defective viruses account for the majority of integrated HIV DNA and do not reflect the actual frequency of latent, replication-competent proviral infection, we assessed the specific contribution of resting TTM cells to latent HIV infection. We measured the frequency of replication-competent HIV in purified resting memory cell subpopulations by a limiting-dilution, quantitative viral outgrowth assay (QVOA). HIV was routinely detected within the resting central memory compartment but was infrequently detected within the resting TTM compartment. These observations suggest that prolonged ART may limit persistent latent infection in the TTM compartment. Our results confirm the importance of latent infection within the TCM compartment and again focus attention on these cells as the most important latent viral reservoir. While proliferation may drive expansion of detectable viral genomes in cells, the frequency of replication-competent HIV must be carefully assessed. Latent infection appears to wane within the transitional memory compartment in patients who have sustained successful viral suppression via ART or were treated very early in infection. IMPORTANCE Antiretroviral therapy (ART) has led to a significant decrease in morbidity and mortality among HIV-infected patients. However, HIV integrates into the genome of CD4+ T cells, generating pools of long-lived cells that are reservoirs of latent HIV. Two main subsets of CD4+ T cells, central memory and transitional memory cells, were reported to be major reservoirs of HIV infection. However, this study primarily measured the HIV DNA content

  2. Allergen-Specific CD4(+) T Cells in Human Asthma.

    PubMed

    Ling, Morris F; Luster, Andrew D

    2016-03-01

    In allergic asthma, aeroallergen exposure of sensitized individuals mobilizes robust innate and adaptive airway immune responses, stimulating eosinophilic airway inflammation and the activation and infiltration of allergen-specific CD4(+) T cells into the airways. Allergen-specific CD4(+) T cells are thought to be central players in the asthmatic response as they specifically recognize the allergen and initiate and orchestrate the asthmatic inflammatory response. In this article, we briefly review the role of allergen-specific CD4(+) T cells in the pathogenesis of human allergic airway inflammation in allergic individuals, discuss the use of allergen-major histocompatibility complex class II tetramers to characterize allergen-specific CD4(+) T cells, and highlight current gaps in knowledge and directions for future research pertaining to the role of allergen-specific CD4(+) T cells in human asthma. PMID:27027948

  3. Requirement of CD30 expression on CD4 T cells in the pathogenesis of experimental autoimmune encephalomyelitis.

    PubMed

    Shinoda, Koji; Sun, Xun; Oyamada, Akiko; Yamada, Hisakata; Kira, Jun-Ichi; Yoshikai, Yasunobu

    2016-02-15

    CD30, a member of the tumor necrosis factor receptor superfamily, is expressed preferentially by effector or memory helper T cells. Here we show that experimental autoimmune encephalomyelitis (EAE) is ameliorated with markedly reduced induction of antigen-specific Th1 and Th17 cells in CD30 knockout mice. Passive EAE indicated that CD30 on non-hematopoietic parenchymal cell is not required and mixed bone marrow chimera experiments revealed that CD30 signaling on CD4 T cells amplified the development of antigen-specific and encephalitogenic CD4 T cells. Thus, CD30 expression on CD4 T cells is critically involved in the pathogenesis of central nervous system autoimmunity. PMID:26857493

  4. Effects of Soluble CD4 on Simian Immunodeficiency Virus Infection of CD4-Positive and CD4-Negative Cells

    PubMed Central

    Schenten, Dominik; Marcon, Luisa; Karlsson, Gunilla B.; Parolin, Cristina; Kodama, Toshiaki; Gerard, Norma; Sodroski, Joseph

    1999-01-01

    A soluble form of the CD4 receptor (sCD4) can either enhance or inhibit the infection of cells by simian immunodeficiency virus (SIV) and human immunodeficiency virus. We investigated the basis for these varying effects by studying the entry of three SIV isolates into CD4-positive and CD4-negative cells expressing different chemokine receptors. Infection of CD4-negative cells depended upon the viral envelope glycoproteins and upon the chemokine receptor, with CCR5 and gpr15 being more efficient than STRL33. Likewise, enhancement of infection by sCD4 was observed when CCR5- and gpr15-expressing target cells were used but not when those expressing STRL33 were used. The sCD4-mediated enhancement of virus infection of CD4-negative, CCR5-positive cells was related to the sCD4-induced increase in binding of the viral gp120 envelope glycoprotein to CCR5. Inhibitory effects of sCD4 could largely be explained by competition for virus attachment to cellular CD4 rather than other detrimental effects on virus infectivity (e.g., disruption of the envelope glycoprotein spike). Consistent with this, the sCD4-activated SIV envelope glycoprotein intermediate on the virus was long-lived. Thus, the net effect of sCD4 on SIV infectivity appears to depend upon the degree of enhancement of chemokine receptor binding and upon the efficiency of competition for cellular CD4. PMID:10364284

  5. Mucosal vaccination with attenuated Mycobacterium tuberculosis induces strong central memory responses and protects against tuberculosis

    PubMed Central

    Kaushal, Deepak; Foreman, Taylor W.; Gautam, Uma S.; Alvarez, Xavier; Adekambi, Toidi; Rangel-Moreno, Javier; Golden, Nadia A.; Johnson, Ann-Marie F.; Phillips, Bonnie L.; Ahsan, Muhammad H.; Russell-Lodrigue, Kasi E.; Doyle, Lara A.; Roy, Chad J.; Didier, Peter J.; Blanchard, James L.; Rengarajan, Jyothi; Lackner, Andrew A.; Khader, Shabaana A.; Mehra, Smriti

    2015-01-01

    Tuberculosis (TB) is a global pandaemic, partially due to the failure of vaccination approaches. Novel anti-TB vaccines are therefore urgently required. Here we show that aerosol immunization of macaques with the Mtb mutant in SigH (MtbΔsigH) results in significant recruitment of inducible bronchus-associated lymphoid tissue (iBALT) as well as CD4+ and CD8+ T cells expressing activation and proliferation markers to the lungs. Further, the findings indicate that pulmonary vaccination with MtbΔsigH elicited strong central memory CD4+ and CD8+ T-cell responses in the lung. Vaccination with MtbΔsigH results in significant protection against a lethal TB challenge, as evidenced by an approximately three log reduction in bacterial burdens, significantly diminished clinical manifestations and granulomatous pathology and characterized by the presence of profound iBALT. This highly protective response is virtually absent in unvaccinated and BCG-vaccinated animals after challenge. These results suggest that future TB vaccine candidates can be developed on the basis of MtbΔsigH. PMID:26460802

  6. A rationally designed CD4 analogue inhibits experimental allergic encephalomyelitis

    NASA Astrophysics Data System (ADS)

    Jameson, Bradford A.; McDonnell, James M.; Marini, Joseph C.; Korngold, Robert

    1994-04-01

    EXPERIMENTAL allergic encephalomyelitis (EAE) is an acute inflammatory autoimmune disease of the central nervous system that can be elicited in rodents and is the major animal model for the study of multiple sclerosis (MS)1,2. The pathogenesis of both EAE and MS directly involves the CD4+ helper T-cell subset3-5. Anti-CD4 monoclonal antibodies inhibit the development of EAE in rodents6-9, and are currently being used in human clinical trials for MS. We report here that similar therapeutic effects can be achieved in mice using a small (rationally designed) synthetic analogue of the CD4 protein surface. It greatly inhibits both clinical incidence and severity of EAE with a single injection, but does so without depletion of the CD4+ subset and without the inherent immunogenicity of an antibody. Furthermore, this analogue is capable of exerting its effects on disease even after the onset of symptoms.

  7. ROSTRUM IN MEMORIAL SECTION ALONG CENTRAL DRIVE, WITH BIVOUAC OF ...

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

    ROSTRUM IN MEMORIAL SECTION ALONG CENTRAL DRIVE, WITH BIVOUAC OF THE DEAD MONUMENT AT FAR LEFT. VIEW TO EAST. - Baton Rouge National Cemetery, 220 North 19th Street, Baton Rouge, East Baton Rouge Parish, LA

  8. Early effector cells survive the contraction phase in malaria infection and generate both central and effector memory T cells.

    PubMed

    Opata, Michael M; Carpio, Victor H; Ibitokou, Samad A; Dillon, Brian E; Obiero, Joshua M; Stephens, Robin

    2015-06-01

    CD4 T cells orchestrate immunity against blood-stage malaria. However, a major challenge in designing vaccines to the disease is poor understanding of the requirements for the generation of protective memory T cells (Tmem) from responding effector T cells (Teff) in chronic parasite infection. In this study, we use a transgenic mouse model with T cells specific for the merozoite surface protein (MSP)-1 of Plasmodium chabaudi to show that activated T cells generate three distinct Teff subsets with progressive activation phenotypes. The earliest observed Teff subsets (CD127(-)CD62L(hi)CD27(+)) are less divided than CD62L(lo) Teff and express memory genes. Intermediate (CD62L(lo)CD27(+)) effector subsets include the most multicytokine-producing T cells, whereas fully activated (CD62L(lo)CD27(-)) late effector cells have a terminal Teff phenotype (PD-1(+), Fas(hi), AnnexinV(+)). We show that although IL-2 promotes expansion, it actually slows terminal effector differentiation. Using adoptive transfer, we show that only early Teff survive the contraction phase and generate the terminal late Teff subsets, whereas in uninfected recipients, they become both central and effector Tmem. Furthermore, we show that progression toward full Teff activation is promoted by increased duration of infection, which in the long-term promotes Tem differentiation. Therefore, we have defined markers of progressive activation of CD4 Teff at the peak of malaria infection, including a subset that survives the contraction phase to make Tmem, and show that Ag and cytokine levels during CD4 T cell expansion influence the proportion of activated cells that can survive contraction and generate memory in malaria infection. PMID:25911759

  9. The memory systems of children with (central) auditory disorder.

    PubMed

    Pires, Mayra Monteiro; Mota, Mailce Borges; Pinheiro, Maria Madalena Canina

    2015-01-01

    This study aims to investigate working, declarative, and procedural memory in children with (central) auditory processing disorder who showed poor phonological awareness. Thirty 9- and 10-year-old children participated in the study and were distributed into two groups: a control group consisting of 15 children with typical development, and an experimental group consisting of 15 children with (central) auditory processing disorder who were classified according to three behavioral tests and who showed poor phonological awareness in the CONFIAS test battery. The memory systems were assessed through the adapted tests in the program E-PRIME 2.0. The working memory was assessed by the Working Memory Test Battery for Children (WMTB-C), whereas the declarative memory was assessed by a picture-naming test and the procedural memory was assessed by means of a morphosyntactic processing test. The results showed that, when compared to the control group, children with poor phonological awareness scored lower in the working, declarative, and procedural memory tasks. The results of this study suggest that in children with (central) auditory processing disorder, phonological awareness is associated with the analyzed memory systems. PMID:26398254

  10. A Single HIV-1 Cluster and a Skewed Immune Homeostasis Drive the Early Spread of HIV among Resting CD4+ Cell Subsets within One Month Post-Infection

    PubMed Central

    Avettand-Fenoël, Véronique; Nembot, Georges; Mélard, Adeline; Blanc, Catherine; Lascoux-Combe, Caroline; Slama, Laurence; Allegre, Thierry; Allavena, Clotilde; Yazdanpanah, Yazdan; Duvivier, Claudine; Katlama, Christine; Goujard, Cécile; Seksik, Bao Chau Phung; Leplatois, Anne; Molina, Jean-Michel; Meyer, Laurence; Autran, Brigitte; Rouzioux, Christine

    2013-01-01

    Optimizing therapeutic strategies for an HIV cure requires better understanding the characteristics of early HIV-1 spread among resting CD4+ cells within the first month of primary HIV-1 infection (PHI). We studied the immune distribution, diversity, and inducibility of total HIV-DNA among the following cell subsets: monocytes, peripheral blood activated and resting CD4 T cells, long-lived (naive [TN] and central-memory [TCM]) and short-lived (transitional-memory [TTM] and effector-memory cells [TEM]) resting CD4+T cells from 12 acutely-infected individuals recruited at a median 36 days from infection. Cells were sorted for total HIV-DNA quantification, phylogenetic analysis and inducibility, all studied in relation to activation status and cell signaling. One month post-infection, a single CCR5-restricted viral cluster was massively distributed in all resting CD4+ subsets from 88% subjects, while one subject showed a slight diversity. High levels of total HIV-DNA were measured among TN (median 3.4 log copies/million cells), although 10-fold less (p = 0.0005) than in equally infected TCM (4.5), TTM (4.7) and TEM (4.6) cells. CD3−CD4+ monocytes harbored a low viral burden (median 2.3 log copies/million cells), unlike equally infected resting and activated CD4+ T cells (4.5 log copies/million cells). The skewed repartition of resting CD4 subsets influenced their contribution to the pool of resting infected CD4+T cells, two thirds of which consisted of short-lived TTM and TEM subsets, whereas long-lived TN and TCM subsets contributed the balance. Each resting CD4 subset produced HIV in vitro after stimulation with anti-CD3/anti-CD28+IL-2 with kinetics and magnitude varying according to subset differentiation, while IL-7 preferentially induced virus production from long-lived resting TN cells. In conclusion, within a month of infection, a clonal HIV-1 cluster is massively distributed among resting CD4 T-cell subsets with a flexible inducibility, suggesting that

  11. Characterization of the human CD4 gene promoter: transcription from the CD4 gene core promoter is tissue-specific and is activated by Ets proteins.

    PubMed Central

    Salmon, P; Giovane, A; Wasylyk, B; Klatzmann, D

    1993-01-01

    We analyzed the 5' transcription control sequences of the human CD4 gene. We located the transcription initiation site and showed that the CD4 core promoter (positions -40 to +16) lacks a classical "TATA" or initiator positioning consensus sequence but directs precise and efficient transcription when coupled to the ubiquitously active simian virus 40 enhancer. The transcriptional activity of the CD4 gene promoter correlated with CD4 expression in various cell types. Interestingly, the CD4 core promoter also displayed a tissue-specific transcriptional activity. Within this fragment, three nucleic acid sequences are completely conserved in the murine CD4 gene. One of these sequences contains a perfect ETS consensus sequence. Another ETS consensus sequence is located 1060 nt upstream. Electrophoretic-mobility-shift assays showed that the core promoter ETS motif binds an Ets-related protein specifically expressed at high levels in CD4+ cells. Moreover, in CD4- cells, overexpression of Ets-1 or Ets-2 efficiently and specifically activated transcription from the CD4 promoter and core promoter. These data indicate that Ets transcription factors play a central role in controlling CD4 gene expression, by binding to both a classical remote site and an unusual proximal activator sequence. Images Fig. 2 Fig. 4 PMID:8356078

  12. Identification of novel markers for mouse CD4 T follicular helper cells

    PubMed Central

    Iyer, Smita S.; Latner, Donald R.; Zilliox, Michael J.; McCausland, Megan; Akondy, Rama S.; MacMaster-Penaloza, Pablo; Hale, J. Scott; Ye, Lilin; Mohammed, Ata-Ur-Rasheed; Amara, Rama R.; Ahmed, Rafi

    2013-01-01

    SUMMARY CD4 T-follicular helper cells (TFH) are central for generation of long-term B cell immunity. A defining phenotypic attribute of TFH cells is expression of the chemokine receptor CXCR5, and TFH cells are typically identified by co-expression of CXCR5 together with other markers such as programmed death (PD)-1. Herein we report high-level expression of the nutrient transporter, folate receptor (FR)4 on TFH cells in acute viral infection. Distinct from the expression profile of conventional TFH markers, FR4 was highly expressed by naive CD4 T cells, was down regulated after activation and subsequently re-expressed on TFH cells. Furthermore, FR4 was maintained, albeit at lower levels, on memory TFH cells. Comparative gene expression profiling of FR4hi, versus FR4lo antigen-specific CD4 effector T cells revealed a molecular signature consistent with TFH and TH1 subsets, respectively. Interestingly, genes involved in the purine metabolic pathway, including the ecto-enzyme CD73, were enriched in TFH cells compared to TH1 cells, and phenotypic analysis confirmed expression of CD73 on TFH cells. As there is now considerable interest in developing vaccines that will induce optimal TFH cell responses, the identification of two novel cell surface markers should be useful in characterization and identification of TFH cells following vaccination and infection. PMID:24030473

  13. Analysis of subsets of B cells, Breg, CD4Treg and CD8Treg cells in adult patients with primary selective IgM deficiency

    PubMed Central

    Louis, Ankmalika Gupta; Agrawal, Sudhanshu; Gupta, Sudhir

    2016-01-01

    Primary selective IgM deficiency (SIGMD) is a rare and recently IUIS-recognized primary immunodeficiency disease with increased susceptibility to infections, allergy, and autoimmune diseases. The pathogenesis of selective IgM remains unclear. The objective of the study was to understand the pathogenesis of selective IgM deficiency via a comprehensive analysis of subsets of B cells, naïve and memory subsets of CD4+ and CD8+ T cells, and Breg, CD4Treg, and CD8Treg cells. Twenty adult patients with SIGMD (serum IgM 4 mg/dl-32 mg/dl) and age-and gender-matched healthy controls were studied. Naïve B cells, transitional B cells, marginal zone B cells, germinal center B cells, IgM memory B cells, switched memory B cells, plasmablasts, CD21low B cells, B1 cells, CXCR3+ naive and memory B cells; naïve, central memory, and effector memory subsets of CD4+ and CD8+ T cells, and CD4Treg, CD8Treg and Breg were phenotypically analyzed using multicolor flow cytometry. A significant increase in CD21low, IgM memory B cells, Breg and CD8Treg, and a significant decreased in germinal center B cells, and CXCR3+ naïve and memory B cells were observed in SIGMD. These alterations in subsets of B cells, and Breg and CD8Treg cells may play a role in the pathogenesis of SIGMD. PMID:27168952

  14. Analysis of Populations of Memory T-Helper Cells Expressing CXCR3 and CCR6 Chemokine Receptors in Peripheral Blood of Patients with Chronic Viral Hepatitis C.

    PubMed

    Elezov, D S; Kudryavtsev, I V; Arsent'ev, N A; Basin, V V; Esaulenko, E V; Semenov, A V; Totolyan, A A

    2015-12-01

    Flow cytometry was employed to examine the content of major populations of memory T helper cells and expression of chemokine receptors CXCR3 and CCR6 on their surface in peripheral blood drawn from virtually healthy people and the patients with chronic viral hepatitis C. The following combination of monoclonal antibodies had been used: CD62LFITC/CD45RA-PE/CD3-ECD/CCR6-PC7/CXCR3-APC/CD4-APC-Cy7. In comparison with control group, the patients with chronic hepatitis C had a smaller number of populations of naïve CD4(+) T cells and central memory CD4(+) T cells but a greater number of terminally differentiated effector memory CD4(+) T cells and effector memory CD4(+) T cells. No differences were revealed between CD4(+) T cell populations of both groups in expression of CXCR3 and CCR6 receptors. PMID:26639464

  15. CD4-Specific Designed Ankyrin Repeat Proteins Are Novel Potent HIV Entry Inhibitors with Unique Characteristics

    PubMed Central

    Schweizer, Andreas; Rusert, Peter; Berlinger, Livia; Ruprecht, Claudia R.; Mann, Axel; Corthésy, Stéphanie; Turville, Stuart G.; Aravantinou, Meropi; Fischer, Marek; Robbiani, Melissa; Amstutz, Patrick; Trkola, Alexandra

    2008-01-01

    Here, we describe the generation of a novel type of HIV entry inhibitor using the recently developed Designed Ankyrin Repeat Protein (DARPin) technology. DARPin proteins specific for human CD4 were selected from a DARPin DNA library using ribosome display. Selected pool members interacted specifically with CD4 and competed with gp120 for binding to CD4. DARPin proteins derived in the initial selection series inhibited HIV in a dose-dependent manner, but showed a relatively high variability in their capacity to block replication of patient isolates on primary CD4 T cells. In consequence, a second series of CD4-specific DARPins with improved affinity for CD4 was generated. These 2nd series DARPins potently inhibit infection of genetically divergent (subtype B and C) HIV isolates in the low nanomolar range, independent of coreceptor usage. Importantly, the actions of the CD4 binding DARPins were highly specific: no effect on cell viability or activation, CD4 memory cell function, or interference with CD4-independent virus entry was observed. These novel CD4 targeting molecules described here combine the unique characteristics of DARPins—high physical stability, specificity and low production costs—with the capacity to potently block HIV entry, rendering them promising candidates for microbicide development. PMID:18654624

  16. Memory and Working-with-Memory: A Component Process Model Based on Modules and Central Systems.

    PubMed

    Moscovitch, M

    1992-01-01

    Abstract A neuropsychological model of memory is proposed that incorporates Fodor's (1983) idea of modules and central systems. The model has four essential components: (1) a non-frontal neocortical component that consists of perceptual (and perhaps interpretative semantic) modules that mediate performance on item-specific, implicit tests of memory, (2) a modular medial temporal/hippocampal component that mediates encoding, storage, and retrieval on explicit, episodic tests of memory that are associative/cue dependent, (3) a central system, frontal-lobe component that mediates performance on explicit tests that are strategic and on procedural tests that are rule-bound, and (4) a basal ganglia component that mediates performance on sensorimotor, procedural tests of memory. The usefulness of the modular/central system construct is explored and evidence from studies of normal, amnesic, agnosic, and demented people is provided to support the model. PMID:23964882

  17. Transcriptional Regulatory Networks for CD4 T Cell Differentiation

    PubMed Central

    Zhu, Jinfang

    2015-01-01

    CD4+ T cells play a central role in controlling the adaptive immune response by secreting cytokines to activate target cells. Naïve CD4+ T cells differentiate into at least four subsets, Th1, Th2, Th17, and inducible regulatory T cells, each with unique functions for pathogen elimination. The differentiation of these subsets is induced in response to cytokine stimulation, which is translated into Stat activation, followed by induction of master regulator transcription factors. In addition to these factors, multiple other transcription factors, both subset specific and shared, are also involved in promoting subset differentiation. This review will focus on the network of transcription factors that control CD4+ T cell differentiation. PMID:24839135

  18. Novel Teleost CD4-Bearing Cell Populations Provide Insights into the Evolutionary Origins and Primordial Roles of CD4+ Lymphocytes and CD4+ Macrophages.

    PubMed

    Takizawa, Fumio; Magadan, Susana; Parra, David; Xu, Zhen; Korytář, Tomáš; Boudinot, Pierre; Sunyer, J Oriol

    2016-06-01

    Tetrapods contain a single CD4 coreceptor with four Ig domains that likely arose from a primordial two-domain ancestor. Notably, teleost fish contain two CD4 genes. Like tetrapod CD4, CD4-1 of rainbow trout includes four Ig domains, whereas CD4-2 contains only two. Because CD4-2 is reminiscent of the prototypic two-domain CD4 coreceptor, we hypothesized that by characterizing the cell types bearing CD4-1 and CD4-2, we would shed light into the evolution and primordial roles of CD4-bearing cells. Using newly established mAbs against CD4-1 and CD4-2, we identified two bona-fide CD4(+) T cell populations: a predominant lymphocyte population coexpressing surface CD4-1 and CD4-2 (CD4 double-positive [DP]), and a minor subset expressing only CD4-2 (CD4-2 single-positive [SP]). Although both subsets produced equivalent levels of Th1, Th17, and regulatory T cell cytokines upon bacterial infection, CD4-2 SP lymphocytes were less proliferative and displayed a more restricted TCRβ repertoire. These data suggest that CD4-2 SP cells represent a functionally distinct population and may embody a vestigial CD4(+) T cell subset, the roles of which reflect those of primeval CD4(+) T cells. Importantly, we also describe the first CD4(+) monocyte/macrophage population in a nonmammalian species. Of all myeloid subsets, we found the CD4(+) population to be the most phagocytic, whereas CD4(+) lymphocytes lacked this capacity. This study fills in an important gap in the knowledge of teleost CD4-bearing leukocytes, thus revealing critical insights into the evolutionary origins and primordial roles of CD4(+) lymphocytes and CD4(+) monocytes/macrophages. PMID:27183628

  19. Central and Peripheral Components of Working Memory Storage

    PubMed Central

    Cowan, Nelson; Saults, J. Scott; Blume, Christopher L.

    2014-01-01

    This study re-examines the issue of how much of working memory storage is central, or shared across sensory modalities and verbal and nonverbal codes, and how much is peripheral, or specific to a modality or code. In addition to the exploration of many parameters in 9 new dual-task experiments and re-analysis of some prior evidence, the innovations of the present work compared to previous studies of memory for two stimulus sets include (1) use of a principled set of formulas to estimate the number of items in working memory, and (2) a model to dissociate central components, which are allocated to very different stimulus sets depending on the instructions, from peripheral components, which are used for only one kind of material. We consistently find that the central contribution is smaller than was suggested by Saults and Cowan (2007), and that the peripheral contribution is often much larger when the task does not require the binding of features within an object. Previous capacity estimates are consistent with the sum of central plus peripheral components observed here. We consider the implications of the data as constraints on theories of working memory storage and maintenance. PMID:24867488

  20. CD4+CD25bright T cells in human intestinal lamina propria as regulatory cells.

    PubMed

    Makita, Shin; Kanai, Takanori; Oshima, Shigeru; Uraushihara, Koji; Totsuka, Teruji; Sawada, Taisuke; Nakamura, Tetsuya; Koganei, Kazutaka; Fukushima, Tsuneo; Watanabe, Mamoru

    2004-09-01

    It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only active suppression by regulatory T cells plays an important role in the normal intestinal homeostasis, but also its dysregulation leads to the development of inflammatory bowel disease. In this study, we demonstrate that the CD4(+)CD25(bright) T cells reside in the human intestinal lamina propria (LP) and functionally retain regulatory activities. All human LP CD4(+) T cells regardless of CD25 expression constitutively expressed CTLA-4, glucocorticoid-induced TNFR family-related protein, and Foxp3 and proliferate poorly. Although LP CD4(+)CD25(-) T cells showed an activated and anergic/memory phenotype, they did not retain regulatory activity. In LP CD4(+)CD25(+) T cells, however, cells expressing CD25 at high levels (CD4(+)CD25(bright)) suppressed the proliferation and various cytokine productions of CD4(+)CD25(-) T cells. LP CD4(+)CD25(bright) T cells by themselves produced fewer amounts of IL-2, IFN-gamma, and IL-10. Interestingly, LP CD4(+)CD25(bright) T cells with regulatory T activity were significantly increased in patients with active inflammatory bowel disease. These results suggest that CD4(+)CD25(bright) T cells found in the normal and inflamed intestinal mucosa selectively inhibit the host immune response and therefore may contribute to the intestinal immune homeostasis. PMID:15322172

  1. Visuospatial deficits in schizophrenia: central executive and memory subsystems impairments.

    PubMed

    Leiderman, Eduardo A; Strejilevich, Sergio A

    2004-06-01

    Object and spatial visual working memory are impaired in schizophrenic patients. It is not clear if the impairments reside in each memory subsystem alone or also in the central executive component that coordinates these processes. In order to elucidate which memory component is impaired, we developed a paradigm with single spatial and object working memory tasks and dual ones with two different delays (5 and 30 s). Fifteen schizophrenic patients and 14 control subjects performed these tests. Schizophrenic patients had a poorer performance compared to normal controls in all tasks and in all time delays. Both schizophrenics and controls performed significantly worse in the object task than in the spatial task. The performance was even worse in the dual task compared to the singles ones in schizophrenic patients but not in controls. These data suggest that visuospatial performance deficits in schizophrenia are due to both visuospatial memory subsystems impairments and central executive ones. The pattern of deficits observed points to a codification or evocation deficit and not to a maintenance one. PMID:15099604

  2. Sublingual therapeutic immunization with a polyvalent bacterial preparation in patients with recurrent respiratory infections: immunomodulatory effect on antigen-specific memory CD4+ T cells and impact on clinical outcome

    PubMed Central

    Alecsandru, D; Valor, L; Sánchez-Ramón, S; Gil, J; Carbone, J; Navarro, J; Rodríguez, J J; Rodríguez-Sainz, C; Fernández-Cruz, E

    2011-01-01

    Recurrent respiratory tract infections (RRTIs) are common clinical conditions in individuals with alterations of the immune function. A prospective open pilot study in a cohort of patients with RRTIs has been performed to assess whether sublingual immunization with a polyvalent bacterial vaccine could exert an immunomodulatory effect on the antigen-specific immunological responses and have an impact on the clinical outcome. Seventeen patients with RRTIs were recruited. An oral polyvalent bacterial preparation (Bactek®) was administered to all patients daily for 6 months. Immunological assessment was performed at baseline and at the end of immunization. Immunological measurements included: T cell-specific proliferations of CD3+CD4+ and CD3+CD8+ to Bactek® antigens, total immunoglobulin levels, antibodies to pneumococcal polysaccharide and tetanus toxoid and B, T and natural killer (NK) cell subsets. There was a significant increase in the proliferative capacity of CD3+CD4+ T cells specific to Bactek® antigens at month 6 in comparison to baseline (P < 0·0001). A significant increase in total CD3+ T cells was also observed (P < 0·05). No significant differences were observed between baseline and month 6 in levels of total immunoglobulins, specific antibodies and B, T or NK cell subsets. A significant reduction in the patient's rate of RRTIs was observed compared with 1 year prior to initiation of therapy (P < 0·0001). The results demonstrate that long-term administration of a sublingual polyvalent bacterial preparation in patients with RRTIs exerts an immune stimulating effect on CD4+ T helper cell responses to bacterial antigens which could be associated with clinical benefit. PMID:21391984

  3. Plasticity of human CD4 T cell subsets.

    PubMed

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

    2014-01-01

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

  4. Plasticity of Human CD4 T Cell Subsets

    PubMed Central

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

    2014-01-01

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

  5. CD4 (T-Cell) Tests

    MedlinePlus

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

  6. Expression of CD4 by human megakaryocytes.

    PubMed Central

    Basch, R S; Kouri, Y H; Karpatkin, S

    1990-01-01

    The CD4 antigen, which serves as the receptor for human immunodeficiency virus type 1 (HIV-1) on T cells, has been detected on human megakaryocytes. Recent evidence of impaired thrombopoiesis in HIV-1-related thrombocytopenia suggested that these cells could be directly infected by the virus and prompted a search for a receptor on megakaryocytes of normal subjects that could permit entry of HIV-1. Bone marrow specimens from uninfected normal control subjects were centrifuged over Ficoll-Hypaque (1.077 g/ml) and analyzed by three-color analysis with a flow cytometer utilizing monoclonal antibodies against CD4 and a glycoprotein present on the surface of megakaryocytes and platelets (GPIIb/IIIa; CD41), as well as 7-aminoactinomycin D, a stain for DNA. Cells presumed to be megakaryocytes were identified by having a DNA content greater than tetraploid and staining brightly with anti-CD41. Approximately 0.4% of the nucleated cells of the marrow met these criteria. Twenty-five percent of these megakaryocytes stained as brightly as CD4+ T cells. Several clones of antibody recognizing different epitopes of the CD4 molecule gave similar results. Platelets were CD4-. Staining of megakaryocytes with anti-CD4 was confirmed by direct microscopic examination of Percoll-gradient-enriched megakaryocytes employing two-color (CD4-phycoerythrin and CD41-fluorescein) immunofluorescence analysis and phase-contrast microscopy. The proportion of double-labeled cells among 112 phase-contrast-identifiable megakaryocytes from five bone marrow specimens varied between 20% and 26% with a mean and SD of 22% +/- 2.5%. Thus some human megakaryocytes express CD4 on their surface that should be capable of binding the HIV-1 gp120 envelope protein. This could serve as a portal of entry for HIV-1. Images PMID:2236021

  7. Predicting AIDS-related events using CD4 percentage or CD4 absolute counts

    PubMed Central

    Pirzada, Yasmin; Khuder, Sadik; Donabedian, Haig

    2006-01-01

    Background The extent of immunosuppression and the probability of developing an AIDS-related complication in HIV-infected people is usually measured by the absolute number of CD4 positive T-cells. The percentage of CD4 positive cells is a more easily measured and less variable number. We analyzed sequential CD4 and CD8 numbers, percentages and ratios in 218 of our HIV infected patients to determine the most reliable predictor of an AIDS-related event. Results The CD4 percentage was an unsurpassed predictor of the occurrence of AIDS-related events when all subsets of patients are considered. The CD4 absolute count was the next most reliable, followed by the ratio of CD4/CD8 percentages. The value of CD4 percentage over the CD4 absolute count was seen even after the introduction of highly effective HIV therapy. Conclusion The CD4 percentage is unsurpassed as a parameter for predicting the onset of HIV-related diseases. The extra time and expense of measuring the CD4 absolute count may be unnecessary. PMID:16916461

  8. Immune reconstitution but persistent activation after 48 weeks of antiretroviral therapy in youth with pre-therapy CD4 >350 in ATN 061

    PubMed Central

    Rudy, Bret J.; Kapogiannis, Bill G.; Worrell, Carol; Squires, Kathleen; Bethel, James; Li, Su; Wilson, Craig M.; Agwu, Allison; Emmanuel, Patricia; Price, Georgine; Hudey, Stephanie; Goodenow, Maureen M.; Sleasman, John W.

    2015-01-01

    Measures of immune outcomes in youth who initiate combination antiretroviral therapy (cART) early in HIV infection are limited. Design Adolescent Trials Network 061 examined changes over 48 weeks of cART in T cell subsets and markers of T cell and macrophage activation in subjects with pre-therapy CD4>350. All subjects had optimal viral suppression from weeks 24 through 48. Methods Subjects (n=48) initiated cART with tenofovir/emtricitabine plus ritonavir-boosted atazanavir. Data were collected at baseline and weeks 12, 24, and 48. Trends were compared to uninfected controls. Results Significant increases over 48 weeks were noted in all CD4 populations including total, naïve, central memory (CM), and effector memory RO (EM RO) and effector memory RA (EM RA) while numbers of CM and EMRO CD8 cells declined significantly. By week 48, CD4 naïve cells were similar to controls while CM CD4 cells remained significantly lower and EM RO and EM RA subsets were significantly higher. CD38 and HLA DR expression, both individually and when co-expressed, decreased over 48 weeks of cART on CD8 cells but remained significantly higher than controls at week 48. In contrast, markers of macrophage activation measured by sCD14 and sCD163 in plasma did not change with cART and were significantly higher than controls. Conclusion In youth initiating early cART, CD4 cell reconstitution is robust with decreases in CD8 cells. However CD8 T cell and macrophage activation persists at higher levels than uninfected controls. PMID:25942459

  9. CD4+NKG2D+ T Cells Exhibit Enhanced Migratory and Encephalitogenic Properties in Neuroinflammation

    PubMed Central

    Ruck, Tobias; Bittner, Stefan; Gross, Catharina C.; Breuer, Johanna; Albrecht, Stefanie; Korr, Sabrina; Göbel, Kerstin; Pankratz, Susann; Henschel, Christian M.; Schwab, Nicholas; Staszewski, Ori; Prinz, Marco; Kuhlmann, Tanja

    2013-01-01

    Migration of encephalitogenic CD4+ T lymphocytes across the blood-brain barrier is an essential step in the pathogenesis of multiple sclerosis (MS). We here demonstrate that expression of the co-stimulatory receptor NKG2D defines a subpopulation of CD4+ T cells with elevated levels of markers for migration, activation, and cytolytic capacity especially when derived from MS patients. Furthermore, CD4+NKG2D+ cells produce high levels of proinflammatory IFN-γ and IL-17 upon stimulation. NKG2D promotes the capacity of CD4+NKG2D+ cells to migrate across endothelial cells in an in vitro model of the blood-brain barrier. CD4+NKG2D+ T cells are enriched in the cerebrospinal fluid of MS patients, and a significant number of CD4+ T cells in MS lesions coexpress NKG2D. We further elucidated the role of CD4+NKG2D+ T cells in the mouse system. NKG2D blockade restricted central nervous system migration of T lymphocytes in vivo, leading to a significant decrease in the clinical and pathologic severity of experimental autoimmune encephalomyelitis, an animal model of MS. Blockade of NKG2D reduced killing of cultivated mouse oligodendrocytes by activated CD4+ T cells. Taken together, we identify CD4+NKG2D+ cells as a subpopulation of T helper cells with enhanced migratory, encephalitogenic and cytotoxic properties involved in inflammatory CNS lesion development. PMID:24282598

  10. Chronic Parasitic Infection Maintains High Frequencies of Short-Lived Ly6C+CD4+ Effector T Cells That Are Required for Protection against Re-infection

    PubMed Central

    Peters, Nathan C.; Pagán, Antonio J.; Lawyer, Phillip G.; Hand, Timothy W.; Henrique Roma, Eric; Stamper, Lisa W.; Romano, Audrey; Sacks, David L.

    2014-01-01

    In contrast to the ability of long-lived CD8+ memory T cells to mediate protection against systemic viral infections, the relationship between CD4+ T cell memory and acquired resistance against infectious pathogens remains poorly defined. This is especially true for T helper 1 (Th1) concomitant immunity, in which protection against reinfection coincides with a persisting primary infection. In these situations, pre-existing effector CD4 T cells generated by ongoing chronic infection, not memory cells, may be essential for protection against reinfection. We present a systematic study of the tissue homing properties, functionality, and life span of subsets of memory and effector CD4 T cells activated in the setting of chronic Leishmania major infection in resistant C57Bl/6 mice. We found that pre-existing, CD44+CD62L−T-bet+Ly6C+ effector (TEFF) cells that are short-lived in the absence of infection and are not derived from memory cells reactivated by secondary challenge, mediate concomitant immunity. Upon adoptive transfer and challenge, non-dividing Ly6C+ TEFF cells preferentially homed to the skin, released IFN-γ, and conferred protection as compared to CD44+CD62L−Ly6C− effector memory or CD44+CD62L+Ly6C− central memory cells. During chronic infection, Ly6C+ TEFF cells were maintained at high frequencies via reactivation of TCM and the TEFF themselves. The lack of effective vaccines for many chronic diseases may be because protection against infectious challenge requires the maintenance of pre-existing TEFF cells, and is therefore not amenable to conventional, memory inducing, vaccination strategies. PMID:25473946

  11. Idiopathic CD4 lymphocytopenia with sensorimotor polyneuropathy.

    PubMed

    Puri, Vinod; Duggal, Ashish Kumar; Chaudhry, Neera

    2016-01-01

    A, 21-years-old, male, presented with acute onset, gradually progressive, predominantly distal, symmetrical weakness of both upper and lower limbs with arreflexia. He had impaired sensations in glove and stocking distribution with distal gradient. He was found to have absolute CD4 + cell count of 188 cells/μL, absolute CD8 cell count, 532 cells/μL and CD4: CD8 ratio of 0.35. Electrophysiology revealed reduced to absent CMAP amplitude as well as SNAPs in various nerves of upper and lower limbs, along with normal conduction velocity and normal F wave latencies. Pattern evoked visual potentials were prolonged, on both sides, P100 being 130 ms, on right and 108 ms, on left side. In the follow up of 2 years, he showed spontaneous but gradual clinical improvement but his electrophysiological parameters as well as CD 4+ cells count did not show any significant improvement. PMID:27570393

  12. Idiopathic CD4 lymphocytopenia with sensorimotor polyneuropathy

    PubMed Central

    Puri, Vinod; Duggal, Ashish Kumar; Chaudhry, Neera

    2016-01-01

    A, 21-years-old, male, presented with acute onset, gradually progressive, predominantly distal, symmetrical weakness of both upper and lower limbs with arreflexia. He had impaired sensations in glove and stocking distribution with distal gradient. He was found to have absolute CD4 + cell count of 188 cells/μL, absolute CD8 cell count, 532 cells/μL and CD4: CD8 ratio of 0.35. Electrophysiology revealed reduced to absent CMAP amplitude as well as SNAPs in various nerves of upper and lower limbs, along with normal conduction velocity and normal F wave latencies. Pattern evoked visual potentials were prolonged, on both sides, P100 being 130 ms, on right and 108 ms, on left side. In the follow up of 2 years, he showed spontaneous but gradual clinical improvement but his electrophysiological parameters as well as CD 4+ cells count did not show any significant improvement. PMID:27570393

  13. Pathogenic CD4 T cells in type 1 diabetes recognize epitopes formed by peptide fusion.

    PubMed

    Delong, Thomas; Wiles, Timothy A; Baker, Rocky L; Bradley, Brenda; Barbour, Gene; Reisdorph, Richard; Armstrong, Michael; Powell, Roger L; Reisdorph, Nichole; Kumar, Nitesh; Elso, Colleen M; DeNicola, Megan; Bottino, Rita; Powers, Alvin C; Harlan, David M; Kent, Sally C; Mannering, Stuart I; Haskins, Kathryn

    2016-02-12

    T cell-mediated destruction of insulin-producing β cells in the pancreas causes type 1 diabetes (T1D). CD4 T cell responses play a central role in β cell destruction, but the identity of the epitopes recognized by pathogenic CD4 T cells remains unknown. We found that diabetes-inducing CD4 T cell clones isolated from nonobese diabetic mice recognize epitopes formed by covalent cross-linking of proinsulin peptides to other peptides present in β cell secretory granules. These hybrid insulin peptides (HIPs) are antigenic for CD4 T cells and can be detected by mass spectrometry in β cells. CD4 T cells from the residual pancreatic islets of two organ donors who had T1D also recognize HIPs. Autoreactive T cells targeting hybrid peptides may explain how immune tolerance is broken in T1D. PMID:26912858

  14. Emerging technologies for point-of-care CD4 T-lymphocyte counting

    PubMed Central

    Boyle, David S.; Hawkins, Kenneth R.; Steele, Matthew S.; Singhal, Mitra; Cheng, Xuanhong

    2012-01-01

    A CD4 T-lymphocyte count determines eligibility for antiretroviral therapy (ART) with patients recently diagnosed with HIV and also monitors the efficacy of ART treatment thereafter. ART slows the progression of HIV to AIDS. In the developing world, CD4 tests are often performed in centralized laboratories, typically in urban areas. The expansion of ART programs into rural areas has created a need for rapid CD4 counting as logistical barriers can delay the timely dissemination of test results and affect patient care through delay in intervention or loss of follow-up care. CD4 measurement at the point-of-care (POC) in rural areas could help facilitating ART and monitoring of treatment. This review highlights recent technology developments with applications towards determining CD4 counts at the POC. PMID:21798607

  15. TGF-β induces the differentiation of human CXCL13-producing CD4(+) T cells.

    PubMed

    Kobayashi, Shio; Watanabe, Takeshi; Suzuki, Ryo; Furu, Moritoshi; Ito, Hiromu; Ito, Juichi; Matsuda, Shuichi; Yoshitomi, Hiroyuki

    2016-02-01

    In the ectopic lymphoid-like structures present in chronic inflammatory conditions such as rheumatoid arthritis, a subset of human effector memory CD4(+) T cells that lacks features of follicular helper T (Tfh) cells produces CXCL13. Here, we report that TGF-β induces the differentiation of human CXCL13-producing CD4(+) T cells from naïve CD4(+) T cells. The TGF-β-induced CXCL13-producing CD4(+) T cells do not express CXCR5, B-cell lymphoma 6 (BCL6), and other Tfh-cell markers. Furthermore, expression levels of CD25 (IL-2Rα) in CXCL13-producing CD4(+) T cells are significantly lower than those in FoxP3(+) in vitro induced Treg cells. Consistent with this, neutralization of IL-2 and knockdown of STAT5 clearly upregulate CXCL13 production by CD4(+) T cells, while downregulating the expression of FoxP3. Furthermore, overexpression of FoxP3 in naïve CD4(+) T cells downregulates CXCL13 production, and knockdown of FoxP3 fails to inhibit the differentiation of CXCL13-producing CD4(+) T cells. As reported in rheumatoid arthritis, proinflammatory cytokines enhance secondary CXCL13 production from reactivated CXCL13-producing CD4(+) T cells. Our findings demonstrate that CXCL13-producing CD4(+) T cells lacking Tfh-cell features differentiate via TGF-β signaling but not via FoxP3, and exert their function in IL-2-limited but TGF-β-rich and proinflammatory cytokine-rich inflammatory conditions. PMID:26541894

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  18. Chimeric antigen receptor-modified T cells derived from defined CD8+ and CD4+ subsets confer superior antitumor reactivity in vivo

    PubMed Central

    Sommermeyer, Daniel; Hudecek, Michael; Kosasih, Paula L.; Gogishvili, Tea; Maloney, David G.; Turtle, Cameron J.; Riddell, Stanley R.

    2016-01-01

    Adoptive T-cell therapy with gene-modified T-cells expressing a tumor-reactive T-cell receptor (TCR) or chimeric antigen receptor (CAR) is a rapidly growing field of translational medicine and has shown success in the treatment of B-cell malignancies and solid tumors. In all reported trials, patients have received T-cell products comprised of random compositions of CD4+ and CD8+ naïve and memory T-cells, meaning that each patient received a different therapeutic agent. This variation might have influenced the efficacy of T-cell therapy, and complicates comparison of outcomes between different patients and across trials. We analyzed CD19 CAR-expressing effector T-cells derived from different subsets (CD4+/CD8+ naïve, central memory, effector memory). T-cells derived from each of the subsets were efficiently transduced and expanded, but showed clear differences in effector function and proliferation in vitro and in vivo. Combining the most potent CD4+ and CD8+ CAR-expressing subsets resulted in synergistic antitumor effects in vivo. We show that CAR-T-cell products generated from defined T-cell subsets can provide uniform potency compared with products derived from unselected T-cells that vary in phenotypic composition. These findings have important implications for the formulation of T-cell products for adoptive therapies. PMID:26369987

  19. Effects of interleukin-2 therapy on the proliferation and differentiation of CD4/CD25 positive and CD4/CD25 negative cells in HIV+ patients.

    PubMed

    Caggiari, L; Zanussi, S; D'Andrea, M; Bortolin, M T; Crepaldi, C; Caffau, C; Paoli, P D

    2001-01-01

    Interleukin-2 has been widely used in HIV-1+ subjects as an immunoactivating agent. In this study, we investigated cytokine production, Ki67 antigen expression and the modulation of the surface phenotype of the CD4/CD25+ subset as compared to the reciprocal CD4/CD25- subset in IL-2-treated HIV+ patients. Our findings suggest that CD4 T cells are heterogeneous in responding to IL-2, because CD4/CD25+ cells sharply increased their "memory" phenotype, their Ki67 antigen expression and were the main in vivo targets for IL-2-dependent proliferation during therapy, while the percentages of IFN-gamma+ (terminally differentiated) cells remained unchanged at the end of therapy. Conversely, the CD4+/CD25- subpopulation showed an expansion of differentiated cells and a slight increase in the proliferation rate. The use of anti-retroviral therapy alone (HAART) reduced the proliferation and increased the differentiation of both CD4 subsets. Our data suggest that IL-2 has a moderate capacity to activate resting T cells in vivo and is probably unable to boost HIV-1 from latency to the replicative state. PMID:11566623

  20. Simian immunodeficiency virus selectively infects proliferating CD4+ T cells in neonatal rhesus macaques

    PubMed Central

    Wang, Xiaolei; Xu, Huanbin; Pahar, Bapi; Alvarez, Xavier; Green, Linda C.; Dufour, Jason; Moroney-Rasmussen, Terri; Lackner, Andrew A.

    2010-01-01

    Infants infected with HIV have a more severe course of disease and persistently higher viral loads than HIV-infected adults. However, the underlying pathogenesis of this exacerbation remains obscure. Here we compared the rate of CD4+ and CD8+ T-cell proliferation in intestinal and systemic lymphoid tissues of neonatal and adult rhesus macaques, and of normal and age-matched simian immunodeficiency virus (SIV)–infected neonates. The results demonstrate infant primates have much greater rates of CD4+ T-cell proliferation than adult macaques, and that these proliferating, recently “activated” CD4+ T cells are infected in intestinal and other lymphoid tissues of neonates, resulting in selective depletion of proliferating CD4+ T cells in acute infection. This depletion is accompanied by a marked increase in CD8+ T-cell activation and production, particularly in the intestinal tract. The data indicate intestinal CD4+ T cells of infant primates have a markedly accelerated rate of proliferation and maturation resulting in more rapid and sustained production of optimal target cells (activated memory CD4+ T cells), which may explain the sustained “peak” viremia characteristic of pediatric HIV infection. Eventual failure of CD4+ T-cell turnover in intestinal tissues may indicate a poorer prognosis for HIV-infected infants. PMID:20716768

  1. Elevated expression of T-bet in mycobacterial antigen-specific CD4(+) T cells from patients with tuberculosis.

    PubMed

    Yang, Bingfen; Zhai, Fei; Jiang, Jing; Wang, Xinjing; Cao, Zhihong; Cheng, Xiaoxing

    2015-01-01

    T-bet is a T-box transcriptional factor that controls the differentiation and effector functions of CD4 T cells. In this study, we studied the role of T-bet in regulating CD4(+) T cell immunity against tuberculosis (TB). T-bet expression in Mycobacterium tuberculosis antigen-specific CD4(+) T cells was significantly higher in patients with active TB than in individuals with latent TB infection (p<0.0001). Comparison of T-bet expression in TCM and TEM subsets showed that CD4(+)T-bet(+)M. tuberculosis antigen-specific CD4(+) T cells had significantly lower frequency of TCM (p=0.003) and higher frequency of TEM (p=0.003) than CD4(+)T-bet(-) cells. The expression of PD-1 in antigen-specific CD4(+) T cells was significantly higher in patients with TB than in individuals with latent TB infection (p=0.006). CD4(+)CD154(+)T-bet(+) T cells had significantly higher expression of PD-1 than CD4(+)CD154(+)T-bet(-) T cells (p=0.0028). It is concluded that T-bet expression might be associated with differentiation into effector memory cells and PD-1 expression in mycobacterial antigen-specific CD4(+) T cells. PMID:26302932

  2. Heterogeneity of Human CD4(+) T Cells Against Microbes.

    PubMed

    Sallusto, Federica

    2016-05-20

    CD4(+) T helper (Th) cells play a central role in the adaptive immune response by providing help to B cells and cytotoxic T cells and by releasing different types of cytokines in tissues to mediate protection against a wide range of pathogenic microorganisms. These functions are performed by different types of Th cells endowed with distinct migratory capacities and effector functions. Here we discuss how studies of the human T cell response to microbes have advanced our understanding of Th cell functional heterogeneity, in particular with the discovery of a distinct Th1 subset involved in the response to Mycobacteria and the characterization of two types of Th17 cells specific for extracellular bacteria or fungi. We also review new approaches to dissect at the clonal level the human CD4(+) T cell response induced by pathogens or vaccines that have revealed an unexpected degree of intraclonal diversification and propose a progressive and selective model of CD4(+) T cell differentiation. PMID:27168241

  3. CD4 T Cell Responses in Latent and Chronic Viral Infections

    PubMed Central

    Walton, Senta; Mandaric, Sanja; Oxenius, Annette

    2013-01-01

    The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

  4. Molecular characterization of woodchuck CD4 (wCD4) and production of a depletion monoclonal antibody against wCD4.

    PubMed

    Yang, Yinke; Zhang, Xiaoyong; Zhang, Chunyan; Tao, Yuanqing; Fan, Wei; Wang, Zhongdong; Wang, Hu; Lu, Mengji; Yang, Dongliang; Fiedler, Melanie; Wang, Baoju

    2013-11-01

    CD4 T cells play an important role in the immune response against hepatitis B virus (HBV) infection. Woodchucks represent an excellent animal model to study HBV infection. In this study, we characterized the cDNA sequence of woodchuck CD4 (wCD4). The deduced wCD4 protein has four extracellular immunoglobulin-like domains comparable to the other mammalian CD4 molecules. The important extracellular cysteine residues and the intracellular tyrosine protein kinase-binding site of wCD4 are also conserved. The deduced wCD4 protein shows 53-63% identity with the counterparts of other mammalians. Phylogenetic analysis indicates that wCD4 is closely related with the counterparts of primates. Two polyclonal antibodies (pAbs) and four monoclonal Abs (mAbs) against wCD4 were produced. Two pAbs and one mAbs (G2) were found to effectively suppress ConA induced proliferation in vitro. Anti-wCD4 mAb G2 depleted 60% of CD4 cells from healthy woodchucks, while the remaining CD4 cells responded well to ConA stimulation. This work provides a basis for studying CD4 T cell mediated immune responses against HBV infection in the woodchuck model. PMID:23685260

  5. Altered Responses to Homeostatic Cytokines in Patients with Idiopathic CD4 Lymphocytopenia

    PubMed Central

    Mouthon, Luc; Landires, Ivan; Rohrlich, Pierre; Pestre, Vincent; Thèze, Jacques; Lortholary, Olivier; Chakrabarti, Lisa A.

    2013-01-01

    Idiopathic CD4 lymphocytopenia (ICL) is a rare immune deficiency characterized by a protracted CD4+ T cell loss of unknown etiology and by the occurrence of opportunistic infections similar to those seen in AIDS. We investigated whether a defect in responses to cytokines that control CD4+ T cell homeostasis could play a role in ICL. Immunophenotype and signaling responses to interleukin-7 (IL-7), IL-2, and thymic stromal lymphopoietin (TSLP) were analyzed by flow cytometry in CD4+ T cells from 15 ICL patients and 15 healthy blood donors. The induction of phospho-STAT5 after IL-7 stimulation was decreased in memory CD4+ T cells of some ICL patients, which correlated with a decreased expression of the IL-7Rα receptor chain (R = 0.74, p<0.005) and with lower CD4+ T cell counts (R = 0.69, p<0.005). IL-2 responses were also impaired, both in the Treg and conventional memory subsets. Decreased IL-2 responses correlated with decreased IL-7 responses (R = 0.75, p<0.005), pointing to combined defects that may significantly perturb CD4+ T cell homeostasis in a subset of ICL patients. Unexpectedly, responses to the IL-7-related cytokine TSLP were increased in ICL patients, while they remained barely detectable in healthy controls. TSLP responses correlated inversely with IL-7 responses (R = −0.41; p<0.05), suggesting a cross-regulation between the two cytokine systems. In conclusion, IL-7 and IL-2 signaling are impaired in ICL, which may account for the loss of CD4+ T cell homeostasis. Increased TSLP responses point to a compensatory homeostatic mechanism that may mitigate defects in γc cytokine responses. PMID:23383227

  6. CD4-independent infection of human neural cells by human immunodeficiency virus type 1.

    PubMed Central

    Harouse, J M; Kunsch, C; Hartle, H T; Laughlin, M A; Hoxie, J A; Wigdahl, B; Gonzalez-Scarano, F

    1989-01-01

    A number of studies have indicated that central nervous system-derived cells can be infected with human immunodeficiency virus type 1 (HIV-1). To determine whether CD4, the receptor for HIV-1 in lymphoid cells, was responsible for infection of neural cells, we characterized infectable human central nervous system tumor lines and primary fetal neural cells and did not detect either CD4 protein or mRNA. We then attempted to block infection with anti-CD4 antibodies known to block infection of lymphoid cells; we noted no effect on any of these cultured cells. The results indicate that CD4 is not the receptor for HIV-1 infection of the glioblastoma line U373-MG, medulloblastoma line MED 217, or primary human fetal neural cells. Images PMID:2786088

  7. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    SciTech Connect

    Chen, Weizao; Feng, Yang; Wang, Yanping; Zhu, Zhongyu; Dimitrov, Dimiter S.

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  8. Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties

    PubMed Central

    Matharu, G. S.; Mittal, S.; Pynsent, P. B.; Buckley, C. D.; Revell, M. P.

    2016-01-01

    Objectives T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty. Methods In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry. Results The percentages of CD4+ T-cell subtypes in PB were not different between groups. The CD4+ T-cells in the SF of MoM hips showed a completely different distribution of phenotypes compared with that found in the PB in the same patients, including significantly decreased CD4+ T-central memory cells (p < 0.05) and increased T-effector memory cells (p < 0.0001) in the SF. Inducible co-stimulator (ICOS) was the only co-stimulatory molecule with different expression on CD4+ CD28+ cells between groups. In PB, ICOS expression was increased in MoM (p < 0.001) and MoP (p < 0.05) cases compared with the controls. In SF, ICOS expression was increased in MoM hips compared with MoP hips (p < 0.05). Conclusions Increased expression of ICOS on CD4+ T-cells in PB and SF of patients with failed arthroplasties suggests that these cells are activated and involved in generating immune responses. Variations in ICOS expression between MoM and MoP hips may indicate different modes of arthroplasty failure. Cite this article: Professor P. A. Revell. Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties. Bone Joint Res 2016;5:52–60

  9. Tuberculosis Therapy Modifies the Cytokine Profile, Maturation State, and Expression of Inhibitory Molecules on Mycobacterium tuberculosis-Specific CD4+ T-Cells

    PubMed Central

    Saharia, Kapil K.; Petrovas, Constantinos; Ferrando-Martinez, Sara; Leal, Manuel; Luque, Rafael; Ive, Prudence; Luetkemeyer, Anne; Havlir, Diane; Koup, Richard A.

    2016-01-01

    Background Little is known about the expression of inhibitory molecules cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed-death-1 (PD-1) on Mycobacterium tuberculosis (Mtb)-specific CD4 T-cells and how their expression is impacted by TB treatment. Methods Cryopreserved PBMCs from HIV-TB co-infected and TB mono-infected patients with untreated and treated tuberculosis (TB) disease were stimulated for six hours with PPD and stained. Using polychromatic flow cytometry, we characterized the differentiation state, cytokine profile, and inhibitory molecule expression on PPD-specific CD4 T-cells. Results In our HIV-TB co-infected cohort, TB treatment increased the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+IL-2+TNF-α+ and IFN-γ+IL-2+ (p = 0.0004 and p = 0.0002, respectively) while decreasing the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+MIP1-β+TNF-α+ and IFN-γ+MIP1-β+. The proportion of PPD-specific CD4 T-cells expressing an effector memory phenotype decreased (63.6% vs 51.6%, p = 0.0015) while the proportion expressing a central memory phenotype increased (7.8% vs. 21.7%, p = 0.001) following TB treatment. TB treatment reduced the proportion of PPD-specific CD4 T-cells expressing CTLA-4 (72.4% vs. 44.3%, p = 0.0005) and PD-1 (34.5% vs. 29.2%, p = 0.03). Similar trends were noted in our TB mono-infected cohort. Conclusion TB treatment alters the functional profile of Mtb-specific CD4 T-cells reflecting shifts towards a less differentiated maturational profile and decreases PD-1 and CTLA-4 expression. These could serve as markers of reduced mycobacterial burden. Further study is warranted. PMID:27367521

  10. IL-21 is a central memory T cell-associated cytokine that inhibits the generation of pathogenic Th1/17 effector cells.

    PubMed

    Kastirr, Ilko; Maglie, Stefano; Paroni, Moira; Alfen, Johanna Sophie; Nizzoli, Giulia; Sugliano, Elisa; Crosti, Maria-Cristina; Moro, Monica; Steckel, Bodo; Steinfelder, Svenja; Stölzel, Katharina; Romagnani, Chiara; Botti, Fiorenzo; Caprioli, Flavio; Pagani, Massimilliano; Abrignani, Sergio; Geginat, Jens

    2014-10-01

    IL-21 promotes Th17 differentiation, and Th17 cells that upregulate T-bet, IFN-γ, and GM-CSF drive experimental autoimmune diseases in mice. Anti-IL-21 treatment of autoimmune patients is therefore a therapeutic option, but the role of IL-21 in human T cell differentiation is incompletely understood. IL-21 was produced at high levels by human CD4(+) central memory T cells, suggesting that it is associated with early T cell differentiation. Consistently, it was inhibited by forced expression of T-bet or RORC2, the lineage-defining transcription factors of Th1 and Th17 effector cells, respectively. Although IL-21 was efficiently induced by IL-12 in naive CD4(+) T cells, it inhibited the generation of Th1 effector cells in a negative feedback loop. IL-21 was also induced by IL-6 and promoted Th17 differentiation, but it was not absolutely required. Importantly, however, IL-21 promoted IL-10 secretion but inhibited IFN-γ and GM-CSF production in developing Th17 cells, and consequently prevented the generation of polyfunctional Th1/17 effector cells. Moreover, in Th17 memory cells, IL-21 selectively inhibited T-bet upregulation and GM-CSF production. In summary, IL-21 is a central memory T cell-associated cytokine that promotes Th17 differentiation and IL-10 production, but inhibits the generation of potentially pathogenic Th1/17 effector cells. These findings shed new light on the role of IL-21 in T cell differentiation, and have relevant implications for anti-IL-21 therapy of autoimmune diseases. PMID:25172491

  11. The future role of CD4 cell count for monitoring antiretroviral therapy.

    PubMed

    Ford, Nathan; Meintjes, Graeme; Pozniak, Anton; Bygrave, Helen; Hill, Andrew; Peter, Trevor; Davies, Mary-Ann; Grinsztejn, Beatriz; Calmy, Alexandra; Kumarasamy, N; Phanuphak, Praphan; deBeaudrap, Pierre; Vitoria, Marco; Doherty, Meg; Stevens, Wendy; Siberry, George K

    2015-02-01

    For more than two decades, CD4 cell count measurements have been central to understanding HIV disease progression, making important clinical decisions, and monitoring the response to antiretroviral therapy (ART). In well resourced settings, the monitoring of patients on ART has been supported by routine virological monitoring. Viral load monitoring was recommended by WHO in 2013 guidelines as the preferred way to monitor people on ART, and efforts are underway to scale up access in resource-limited settings. Recent studies suggest that in situations where viral load is available and patients are virologically suppressed, long-term CD4 monitoring adds little value and stopping CD4 monitoring will have major cost savings. CD4 cell counts will continue to play an important part in initial decisions around ART initiation and clinical management, particularly for patients presenting late to care, and for treatment monitoring where viral load monitoring is restricted. However, in settings where both CD4 cell counts and viral load testing are routinely available, countries should consider reducing the frequency of CD4 cell counts or not doing routine CD4 monitoring for patients who are stable on ART. PMID:25467647

  12. 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

  13. The Story of CD4+CD28− T Cells Revisited: Solved or Still Ongoing?

    PubMed Central

    Maly, Kathrin

    2015-01-01

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

  14. Human CD141+ DCs induce CD4+ T cells to produce type 2 cytokines1

    PubMed Central

    Yu, Chun I; Becker, Christian; Metang, Patrick; Marches, Florentina; Wang, Yuanyuan; Toshiyuki, Hori; Banchereau, Jacques; Merad, Miriam; Palucka, Karolina

    2014-01-01

    Dendritic cells (DCs) play the central role in the priming of naïve T cells and the differentiation of unique effector T cells. Here, using lung tissues and blood from both humans and humanized mice, we analyzed the response of human CD1c+ and CD141+ DC subsets to live-attenuated influenza virus (LAIV). Specifically, we analyzed the type of CD4+ T cell immunity elicited by LAIV-exposed DCs. Both DC subsets induce proliferation of allogeneic naïve CD4+ T cells with capacity to secrete IFN-γ. However, CD141+ DCs are uniquely able to induce the differentiation of IL-4 and IL-13 producing CD4+ T cells. CD141+ DCs induce IL-4 and IL-13 secreting CD4+ T cells through OX40L. Thus, CD141+ DCs demonstrate remarkable plasticity in guiding adaptive immune responses. PMID:25246496

  15. Quantification of Cells with Specific Phenotypes I: Determination of CD4+ Cell Count Per Microliter in Reconstituted Lyophilized Human PBMC Prelabeled with Anti-CD4 FITC Antibody

    PubMed Central

    Stebbings, Richard; Wang, Lili; Sutherland, Janet; Kammel, Martin; Gaigalas, Adolfas K; John, Manuela; Roemer, Bodo; Kuhne, Maren; Schneider, Rudolf J; Braun, Michael; Engel, Andrea; Dikshit, Dinesh K; Abbasi, Fatima; Marti, Gerald E; Paola Sassi, Maria; Revel, Laura; Kim, Sook-Kyung; Baradez, Marc-Olivier; Lekishvili, Tamara; Marshall, Damian; Whitby, Liam; Jing, Wang; Ost, Volker; Vonsky, Maxim; Neukammer, Jörg

    2015-01-01

    A surface-labeled lyophilized lymphocyte (sLL) preparation has been developed using human peripheral blood mononuclear cells prelabeled with a fluorescein isothiocyanate conjugated anti-CD4 monoclonal antibody. The sLL preparation is intended to be used as a reference material for CD4+ cell counting including the development of higher order reference measurement procedures and has been evaluated in the pilot study CCQM-P102. This study was conducted across 16 laboratories from eight countries to assess the ability of participants to quantify the CD4+ cell count of this reference material and to document cross-laboratory variability plus associated measurement uncertainties. Twelve different flow cytometer platforms were evaluated using a standard protocol that included calibration beads used to obtain quantitative measurements of CD4+ T cell counts. There was good overall cross-platform and counting method agreement with a grand mean of the laboratory calculated means of (301.7 ± 4.9) μL−1 CD4+ cells. Excluding outliers, greater than 90% of participant data agreed within ±15%. A major contribution to variation of sLL CD4+ cell counts was tube to tube variation of the calibration beads, amounting to an uncertainty of 3.6%. Variation due to preparative steps equated to an uncertainty of 2.6%. There was no reduction in variability when data files were centrally reanalyzed. Remaining variation was attributed to instrument specific differences. CD4+ cell counts obtained in CCQM-P102 are in excellent agreement and show the robustness of both the measurements and the data analysis and hence the suitability of sLL as a reference material for interlaboratory comparisons and external quality assessment. © 2015 The Authors. Published by Wiley Periodicals, Inc. PMID:25655255

  16. Quantification of cells with specific phenotypes I: determination of CD4+ cell count per microliter in reconstituted lyophilized human PBMC prelabeled with anti-CD4 FITC antibody.

    PubMed

    Stebbings, Richard; Wang, Lili; Sutherland, Janet; Kammel, Martin; Gaigalas, Adolfas K; John, Manuela; Roemer, Bodo; Kuhne, Maren; Schneider, Rudolf J; Braun, Michael; Engel, Andrea; Dikshit, Dinesh K; Abbasi, Fatima; Marti, Gerald E; Sassi, Maria Paola; Revel, Laura; Kim, Sook-Kyung; Baradez, Marc-Olivier; Lekishvili, Tamara; Marshall, Damian; Whitby, Liam; Jing, Wang; Ost, Volker; Vonsky, Maxim; Neukammer, Jörg

    2015-03-01

    A surface-labeled lyophilized lymphocyte (sLL) preparation has been developed using human peripheral blood mononuclear cells prelabeled with a fluorescein isothiocyanate conjugated anti-CD4 monoclonal antibody. The sLL preparation is intended to be used as a reference material for CD4+ cell counting including the development of higher order reference measurement procedures and has been evaluated in the pilot study CCQM-P102. This study was conducted across 16 laboratories from eight countries to assess the ability of participants to quantify the CD4+ cell count of this reference material and to document cross-laboratory variability plus associated measurement uncertainties. Twelve different flow cytometer platforms were evaluated using a standard protocol that included calibration beads used to obtain quantitative measurements of CD4+ T cell counts. There was good overall cross-platform and counting method agreement with a grand mean of the laboratory calculated means of (301.7 ± 4.9) μL(-1) CD4+ cells. Excluding outliers, greater than 90% of participant data agreed within ±15%. A major contribution to variation of sLL CD4+ cell counts was tube to tube variation of the calibration beads, amounting to an uncertainty of 3.6%. Variation due to preparative steps equated to an uncertainty of 2.6%. There was no reduction in variability when data files were centrally reanalyzed. Remaining variation was attributed to instrument specific differences. CD4+ cell counts obtained in CCQM-P102 are in excellent agreement and show the robustness of both the measurements and the data analysis and hence the suitability of sLL as a reference material for interlaboratory comparisons and external quality assessment. PMID:25655255

  17. Clinical-scale selection and viral transduction of human naïve and central memory CD8+ T cells for adoptive cell therapy of cancer patients.

    PubMed

    Casati, Anna; Varghaei-Nahvi, Azam; Feldman, Steven Alexander; Assenmacher, Mario; Rosenberg, Steven Aaron; Dudley, Mark Edward; Scheffold, Alexander

    2013-10-01

    The adoptive transfer of lymphocytes genetically engineered to express tumor-specific antigen receptors is a potent strategy to treat cancer patients. T lymphocyte subsets, such as naïve or central memory T cells, selected in vitro prior to genetic engineering have been extensively investigated in preclinical mouse models, where they demonstrated improved therapeutic efficacy. However, so far, this is challenging to realize in the clinical setting, since good manufacturing practices (GMP) procedures for complex cell sorting and genetic manipulation are limited. To be able to directly compare the immunological attributes and therapeutic efficacy of naïve (T(N)) and central memory (T(CM)) CD8(+) T cells, we investigated clinical-scale procedures for their parallel selection and in vitro manipulation. We also evaluated currently available GMP-grade reagents for stimulation of T cell subsets, including a new type of anti-CD3/anti-CD28 nanomatrix. An optimized protocol was established for the isolation of both CD8(+) T(N) cells (CD4(-)CD62L(+)CD45RA(+)) and CD8(+) T(CM) (CD4(-)CD62L(+)CD45RA(-)) from a single patient. The highly enriched T cell subsets can be efficiently transduced and expanded to large cell numbers, sufficient for clinical applications and equivalent to or better than current cell and gene therapy approaches with unselected lymphocyte populations. The GMP protocols for selection of T(N) and T(CM) we reported here will be the basis for clinical trials analyzing safety, in vivo persistence and clinical efficacy in cancer patients and will help to generate a more reliable and efficacious cellular product. PMID:23903715

  18. Dynamics of CCR5 Expression by CD4+ T Cells in Lymphoid Tissues during Simian Immunodeficiency Virus Infection

    PubMed Central

    Veazey, Ronald S.; Mansfield, Keith G.; Tham, Irene C.; Carville, Angela C.; Shvetz, Daniel E.; Forand, Amy E.; Lackner, Andrew A.

    2000-01-01

    Early viral replication and profound CD4+ T-cell depletion occur preferentially in intestinal tissues of macaques infected with simian immunodeficiency virus (SIV). Here we show that a much higher percentage of CD4+ T cells in the intestine express CCR5 compared with those found in the peripheral blood, spleen, or lymph nodes. In addition, the selectivity and extent of the CD4+ T-cell loss in SIV infection may depend upon these cells coexpressing CCR5 and having a “memory” phenotype (CD45RA−). Following intravenous infection with SIVmac251, memory CD4+ CCR5+ T cells were selectively eliminated within 14 days in all major lymphoid tissues (intestine, spleen, and lymph nodes). However, the effect on CD4+ T-cell numbers was most profound in the intestine, where cells of this phenotype predominate. The CD4+ T cells that remain after 14 days of infection lacked CCR5 and/or were naive (CD45RA+). Furthermore, when animals in the terminal stages of SIV infection (with AIDS) were examined, virtually no CCR5-expressing CD4+ T cells were found in lymphoid tissues, and all of the remaining CD4+ T cells were naive and coexpressed CXCR4. These findings suggest that chemokine receptor usage determines which cells are targeted for SIV infection and elimination in vivo. PMID:11069995

  19. Canine CD4+CD8+ double positive T cells in peripheral blood have features of activated T cells.

    PubMed

    Bismarck, Doris; Schütze, Nicole; Moore, Peter; Büttner, Mathias; Alber, Gottfried; Buttlar, Heiner v

    2012-10-15

    In dogs a CD4(+)CD8(+) double positive T cell subpopulation exists that has not been phenotypically defined yet. We demonstrate that canine CD4(+)CD8(+) T cells are mature CD1a(-) and TCRαβ(+) T cells. To analyse the activation potential of CD4(+)CD8(+) T cells, PBMC from dogs vaccinated against canine distemper virus (CDV) were re-stimulated with CDV. Upon antigen-specific stimulation, the CD4(+)CD8(+) T cell fraction increases and consists nearly exclusively of proliferated cells. Similarly, other features of activated effector/memory T cells such as up-regulation of CD25 and MHC-II as well as down-regulation of CD62L (L-selectin) were observed in CD4(+)CD8(+) T cells after stimulation. Canine CD4(+)CD8(+) T cells are less abundant, but more heterogeneous than porcine ones, comprising a small proportion expressing the β chain of CD8 in addition to the CD8α chain, like human CD4(+)CD8(+) T cells. In summary, this analysis provides the basis for functional characterisation of the in vivo relevance of CD4(+)CD8(+) T cells in T-cell mediated immunity. PMID:22789871

  20. Pathogenic CD4 T cells in type 1 diabetes recognize epitopes formed by peptide fusion

    PubMed Central

    Delong, Thomas; Wiles, Timothy A.; Baker, Rocky L.; Bradley, Brenda; Barbour, Gene; Reisdorph, Richard; Kumar, Nitesh; Elso, Colleen M.; Armstrong, Michael; Powell, Roger L.; Reisdorph, Nichole; DeNicola, Megan; Bottino, Rita; Powers, Alvin C.; Harlan, David M.; Kent, Sally C.; Mannering, Stuart I.; Haskins, Kathryn

    2016-01-01

    Type 1 diabetes (T1D) is caused by T cell mediated destruction of the insulin-producing β cells. CD4 T cell responses play a central role in β-cell destruction but the identity of the epitopes recognized by pathogenic CD4 T cells remains unknown. To address this we used a panel of diabetes triggering CD4 T cell clones isolated from non-obese diabetic (NOD) mice. Here we show that these pathogenic CD4 T cells target peptide ligands that are formed by covalent crosslinking of proinsulin peptides to other peptides present in β-cell secretory granules. These hybrid insulin peptides (HIPs) are highly antigenic for CD4 T cells and can be detected by mass spectrometry in β-cells. CD4 T cells from the residual pancreatic islets of two organ donors who had T1D also recognize HIPs. The discovery that autoreactive T cells target hybrid peptides may explain how immune tolerance is broken in T1D. PMID:26912858

  1. MHC class II tetramer analyses in AE37-vaccinated prostate cancer patients reveal vaccine-specific polyfunctional and long-lasting CD4(+) T-cells.

    PubMed

    Anastasopoulou, Eleftheria A; Voutsas, Ioannis F; Papamichail, Michael; Baxevanis, Constantin N; Perez, Sonia A

    2016-07-01

    Realizing the basis for generating long-lasting clinical responses in cancer patients after therapeutic vaccinations provides the means to further ameliorate clinical efficacy. Peptide cancer vaccines stimulating CD4(+) T helper cells are often promising for inducing immunological memory and persistent CD8(+) cytotoxic T cell responses. Recent reports from our clinical trial with the AE37 vaccine, which is a HER2 hybrid polypeptide, documented its efficacy to induce CD4(+) T cell immunity, which was associated with clinical improvements preferentially among HLA-DRB1*11(+) prostate cancer patients. Here, we performed in-depth investigation of the CD4(+) T cell response against the AE37 vaccine. We used the DR11/AE37 tetramer in combination with multicolor flow cytometry to identify and characterize AE37-specific CD4(+) T cells regarding memory and Tregs phenotype in HLA-DRB1*11(+) vaccinated patients. To verify vaccine-specific immunological memory in vivo, we also assessed AE37-specific CD4(+) T cells in defined CD4(+) memory subsets by cell sorting. Finally, vaccine-induced AE37-specific CD4(+) T cells were assessed regarding their functional profile. AE37-specific memory CD4(+) T cells could be detected in peptide-stimulated cultures from prostate cancer patients following vaccination even 4 y post-vaccination. The vast majority of vaccine-induced AE37-specific CD4(+) T cells exhibited a multifunctional, mostly Th1 cytokine signature, with the potential of granzyme B production. In contrast, we found relatively low frequencies of Tregs among AE37-specific CD4(+) T cells. This is the first report on the identification of vaccine-induced HER2-specific multifunctional long-lasting CD4(+) T cells in vaccinated prostate cancer patients. PMID:27622033

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

    PubMed

    Iijima, Norifumi; Iwasaki, Akiko

    2016-05-26

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

  3. CD4-binding site alterations in CCR5-using HIV-1 envelopes influencing gp120-CD4 interactions and fusogenicity

    SciTech Connect

    Sterjovski, Jasminka; Churchill, Melissa J.; Roche, Michael; Ellett, Anne; Farrugia, William; Wesselingh, Steven L.; Cunningham, Anthony L.; Ramsland, Paul A.; Gorry, Paul R.

    2011-02-20

    CD4-binding site (CD4bs) alterations in gp120 contribute to different pathophysiological phenotypes of CCR5-using (R5) HIV-1 strains, but the potential structural basis is unknown. Here, we characterized functionally diverse R5 envelope (Env) clones (n = 16) to elucidate potential structural alterations within the gp120 CD4bs that influence Env function. Initially, we showed that the magnitude of gp120-CD4-binding correlates with increased fusogenicity and reduced CD4 dependence. Analysis of three-dimensional gp120 structural models revealed two CD4bs variants, D279 and N362, that were associated with reduced CD4 dependence. Further structural analysis showed that a wider aperture of the predicted CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop, was associated with amino acid alterations within V5 and correlated with increased gp120-CD4 binding and increased fusogenicity. Our results provide evidence that the gp120 V5 loop may alter CD4bs conformation and contribute to increased gp120-CD4 interactions and Env fusogenicity.

  4. Analysis of purine metabolic enzymes in human CD4 Leu 8- and CD4 Leu 8+ lymphocyte subpopulations.

    PubMed

    Fernandez-Mejia, C; Polmar, S H; Peralta-Zaragoza, O; Madrid-Marina, V

    1993-02-01

    1. Specific activities of adenosine deaminase, purine nucleoside phosphorylase, adenosine kinase, 5'-nucleotidase, S-adenosyl-L-homocysteine hydrolase, AMP deaminase, adenine phosphoribosyl transferase, and hypoxanthine phosphoribosyl transferase were analyzed in human CD4 T-lymphocyte subsets. 2. CD4 Leu 8- (helper/inducer) and CD4 Leu 8+ (suppressor/inducer) subpopulations were obtained by panning or fluorescence activated cell sorting techniques using specific monoclonal antibodies. 3. A 45% decrease of 5'-NT AMP activity in the CD4 Leu 8- cells (suppressor/inducer) compared with CD4 total cell population. 4. No statistical significant differences in enzyme activity were found between the subsets analyzed in other purine enzymes. 5. These results suggest that the distribution of purine metabolic enzymes is homogeneous in CD4 Leu 8- and CD4 Leu 8+ T-lymphocyte subpopulations. PMID:8444317

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  7. CRTAM determines the CD4+ cytotoxic T lymphocyte lineage

    PubMed Central

    Takeuchi, Arata; Badr, Mohamed El Sherif Gadelhaq; Miyauchi, Kosuke; Ishihara, Chitose; Onishi, Reiko; Guo, Zijin; Sasaki, Yoshiteru; Ike, Hiroshi; Takumi, Akiko; Tsuji, Noriko M.; Murakami, Yoshinori; Katakai, Tomoya; Kubo, Masato

    2016-01-01

    Naive T cells differentiate into various effector T cells, including CD4+ helper T cell subsets and CD8+ cytotoxic T cells (CTL). Although cytotoxic CD4+ T cells (CD4+CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4+ T cells that express class I–restricted T cell–associated molecule (CRTAM) upon activation possesses the characteristics of both CD4+ and CD8+ T cells. CRTAM+ CD4+ T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM+ T cells are the precursor of CD4+CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4+CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM+ T cells traffic to mucosal tissues and inflammatory sites and developed into CD4+CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4+CTL through the induction of Eomes and CTL-related gene. PMID:26694968

  8. CEMETERY CENTRAL PLAZA, SHOWING ROSTRUM AT RIGHT BACK¬GROUND AND MEMORIAL ...

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

    CEMETERY CENTRAL PLAZA, SHOWING ROSTRUM AT RIGHT BACK¬GROUND AND MEMORIAL TO PURSUERS OF LINCOLN’S ASSASSIN AT LEFT FORE¬GROUND. VIEW TO SOUTHWEST. - Alexandria National Cemetery, 1450 Wilkes Street, Alexandria, Independent City, VA

  9. Canine CD4(+)CD8(+) double-positive T cells can develop from CD4(+) and CD8(+) T cells.

    PubMed

    Bismarck, Doris; Moore, Peter F; Alber, Gottfried; von Buttlar, Heiner

    2014-12-15

    For a long time the expression of the CD4 and CD8 receptor on peripheral blood T cells was thought to be mutually exclusive. However, in canine peripheral blood, similar to other species as swine or human for example, mature CD4(+)CD8(+) double-positive (dp) T cells exist which simultaneously express both surface receptors and have features of activated T cells. Canine CD4(+)CD8(+)dp T cells are heterogeneous and can be divided into three subpopulations by their intensity of CD4 and CD8α expression: CD4(bright)CD8α(bright), CD4(dim)CD8α(bright) and CD4(dim)CD8α(dim). The number of CD4(+)CD8α(+)dp T cells increases after in vitro stimulation of canine peripheral blood mononuclear cells (PBMC) raising the question of their progenitor(s). Thus, the aim of our study was to characterize the progenitor(s) of canine CD4(+)CD8α(+)dp T cells. By cell tracing experiments we identified both CD4(+) single-positive (sp) and also CD8α(+)sp T cells as progenitors of canine CD4(+)CD8α(+)dp T cells after in vitro stimulation. CD4(+)sp T cells almost exclusively upregulate a CD8αα homodimer, whereas CD8α(+)sp T cells can become CD4(+)CD8αβ(+) or CD4(+)CD8αα(+). Even in the absence of other cells, highly purified CD4(+)sp T cells can become double-positive upon in vitro stimulation, whereas highly purified CD8α(+)sp T cells fail to do so. However, CD8α(+)sp T cells can additionally express CD4 when stimulated in the presence of CD4(-)CD8α(-) double-negative (dn) cells or more efficiently when stimulated in the presence of CD4(+)sp T cells. Soluble factors secreted by CD4(+)sp T cells are sufficient for the upregulation of CD4 on CD8α(+)sp T cells, but direct cell-cell contact between CD4(+)sp and CD8α(+)sp T cells is more efficient. mRNA analysis shows that additional CD4 expression on CD8α(+)sp T cells results from de novo synthesis. Thus, uptake of soluble CD4 or trogocytosis is less likely as mechanism for generation of canine double-positive T cells. CD4(+)CD

  10. Neuropharmacology of memory consolidation and reconsolidation: Insights on central cholinergic mechanisms.

    PubMed

    Blake, M G; Krawczyk, M C; Baratti, C M; Boccia, M M

    2014-01-01

    Central cholinergic system is critically involved in all known memory processes. Endogenous acetylcholine release by cholinergic neurons is necessary for modulation of acquisition, encoding, consolidation, reconsolidation, extinction, retrieval and expression. Experiments from our laboratory are mainly focused on elucidating the mechanisms by which acetylcholine modulates memory processes. Blockade of hippocampal alpha-7-nicotinic receptors (α7-nAChRs) with the antagonist methyllycaconitine impairs memory reconsolidation. However, the administration of a α7-nAChR agonist (choline) produce a paradoxical modulation, causing memory enhancement in mice trained with a weak footshock, but memory impairment in animals trained with a strong footshock. All these effects are long-lasting, and depend on the age of the memory trace. This review summarizes and discusses some of our recent findings, particularly regarding the involvement of α7-nAChRs on memory reconsolidation. PMID:24819880

  11. Effect of standard tuberculosis treatment on naive, memory and regulatory T-cell homeostasis in tuberculosis-diabetes co-morbidity.

    PubMed

    Kumar, Nathella P; Moideen, Kadar; Viswanathan, Vijay; Kornfeld, Hardy; Babu, Subash

    2016-09-01

    Perturbations in CD4(+) and CD8(+) T-cell phenotype and function are hallmarks of tuberculosis-diabetes co-morbidity. However, their contribution to the pathogenesis of this co-morbidity and the effect of anti-tuberculosis treatment on the phenotype of the T-cell subsets is poorly understood. In this study, we examined the frequency of different T-cell subsets in individuals with pulmonary tuberculosis (PTB) with diabetes mellitus (DM) or without coincident diabetes mellitus (NDM) before, during and after completion of anti-tuberculosis chemotherapy. PTB-DM is characterized by heightened frequencies of central memory CD4(+) and CD8(+) T cells and diminished frequencies of naive, effector memory and/or effector CD4(+) and CD8(+) T cells at baseline and after 2 months of treatment but not following treatment completion in comparison with PTB-NDM. Central memory CD4(+) and CD8(+) T-cell frequencies exhibited a positive correlation with fasting blood glucose and glycated haemoglobin A1c levels, whereas the frequencies of naive and effector memory or effector CD4(+) and CD8(+) T cells exhibited a negative correlation. However, the frequencies of CD4(+) and CD8(+) T-cell subsets in individuals with PTB exhibited no significant relationship with bacterial burdens. Finally, although minor alterations in the T-cell subset compartment were observed at 2 months of treatment, significantly decreased frequencies of central memory and significantly enhanced frequencies of naive CD4(+) and CD8(+) T cells were observed at the completion of treatment. Our data reveal a profound effect of coexistent diabetes on the altered frequencies of central memory, effector memory and naive T cells and its normalization following therapy. PMID:27289086

  12. The effect of CD4 receptor downregulation and its downstream signaling molecules on HIV-1 latency

    SciTech Connect

    Kim, Kyung-Chang; Kim, Hyeon Guk; Roh, Tae-Young; Park, Jihwan; Jung, Kyung-Min; Lee, Joo-Shil; Choi, Sang-Yun; Kim, Sung Soon; Choi, Byeong-Sun

    2011-01-14

    Research highlights: {yields} CD4 receptors were downregulated on the surface of HIV-1 latently infected cells. {yields} CD4 downstream signaling molecules were suppressed in HIV-1 latently infected cells. {yields} HIV-1 progeny can be reactivated by induction of T-cell activation signal molecules. {yields} H3K4me3 and H3K9ac were highly enriched in CD4 downstream signaling molecules. {yields} HIV-1 latency can be maintained by the reduction of downstream signaling molecules. -- Abstract: HIV-1 can establish a latent infection in memory CD4 + T cells to evade the host immune response. CD4 molecules can act not only as the HIV-1 receptor for entry but also as the trigger in an intracellular signaling cascade for T-cell activation and proliferation via protein tyrosine kinases. Novel chronic HIV-1-infected A3.01-derived (NCHA) cells were used to examine the involvement of CD4 downstream signaling in HIV-1 latency. CD4 receptors in NCHA cells were dramatically downregulated on its surface but were slightly decreased in whole-cell lysates. The expression levels of CD4 downstream signaling molecules, including P56{sup Lck}, ZAP-70, LAT, and c-Jun, were sharply decreased in NCHA cells. The lowered histone modifications of H3K4me3 and H3K9ac correlated with the downregulation of P56{sup Lck}, ZAP-70, and LAT in NCHA cells. AP-1 binding activity was also reduced in NCHA cells. LAT and c-Jun suppressed in NCHA cells were highly induced after PMA treatment. In epigenetic analysis, other signal transduction molecules which are associated with active and/or latent HIV-1 infection showed normal states in HIV-1 latently infected cells compared to A3.01 cells. In conclusion, we demonstrated that the HIV-1 latent state is sustained by the reduction of downstream signaling molecules via the downregulation of CD4 and the attenuated activity of transcription factor as AP-1. The HIV-1 latency model via T-cell deactivation may provide some clues for the development of the new

  13. In Vivo Identification and Characterization of CD4+ Cytotoxic T Cells Induced by Virulent Brucella abortus Infection

    PubMed Central

    Martirosyan, Anna; Von Bargen, Kristine; Arce Gorvel, Vilma; Zhao, Weidong; Hanniffy, Sean; Bonnardel, Johnny; Méresse, Stéphane; Gorvel, Jean-Pierre

    2013-01-01

    CD4+ T cells display a variety of helper functions necessary for an efficient adaptive immune response against bacterial invaders. This work reports the in vivo identification and characterization of murine cytotoxic CD4+ T cells (CD4+ CTL) during Brucella abortus infection. These CD4+ CTLs express granzyme B and exhibit immunophenotypic features consistent with fully differentiated T cells. They express CD25, CD44, CD62L ,CD43 molecules at their surface and produce IFN-γ. Moreover, these cells express neither the co-stimulatory molecule CD27 nor the memory T cell marker CD127. We show here that CD4+ CTLs are capable of cytolytic action against Brucella-infected antigen presenting cells (APC) but not against Mycobacterium-infected APC. Cytotoxic CD4+ T cell population appears at early stages of the infection concomitantly with high levels of IFN-γ and granzyme B expression. CD4+ CTLs represent a so far uncharacterized immune cell sub-type triggered by early immune responses upon Brucella abortus infection. PMID:24367519

  14. In vivo identification and characterization of CD4⁺ cytotoxic T cells induced by virulent Brucella abortus infection.

    PubMed

    Martirosyan, Anna; Von Bargen, Kristine; Arce Gorvel, Vilma; Zhao, Weidong; Hanniffy, Sean; Bonnardel, Johnny; Méresse, Stéphane; Gorvel, Jean-Pierre

    2013-01-01

    CD4(+) T cells display a variety of helper functions necessary for an efficient adaptive immune response against bacterial invaders. This work reports the in vivo identification and characterization of murine cytotoxic CD4(+) T cells (CD4(+) CTL) during Brucella abortus infection. These CD4(+) CTLs express granzyme B and exhibit immunophenotypic features consistent with fully differentiated T cells. They express CD25, CD44, CD62L ,CD43 molecules at their surface and produce IFN-γ. Moreover, these cells express neither the co-stimulatory molecule CD27 nor the memory T cell marker CD127. We show here that CD4(+) CTLs are capable of cytolytic action against Brucella-infected antigen presenting cells (APC) but not against Mycobacterium-infected APC. Cytotoxic CD4(+) T cell population appears at early stages of the infection concomitantly with high levels of IFN-γ and granzyme B expression. CD4(+) CTLs represent a so far uncharacterized immune cell sub-type triggered by early immune responses upon Brucella abortus infection. PMID:24367519

  15. The effect of timing of antiretroviral therapy on CD4+ T-cell reconstitution in the intestine of HIV-infected patients.

    PubMed

    Allers, K; Puyskens, A; Epple, H-J; Schürmann, D; Hofmann, J; Moos, V; Schneider, T

    2016-01-01

    Whether and to what extent gut mucosal CD4(+) T cells of HIV-infected patients can be restored by combination antiretroviral therapy (cART) is not yet fully resolved. We studied absolute numbers, differentiation, and activation of mucosal CD4(+) T cells at different stages of HIV infection and assessed the effect of timing of cART initiation on this cell population. Mucosal CD4(+) T-cell numbers were severely reduced at all stages of chronic infection, but normal in patients with acute infection. In patients with initiation of cART during chronic HIV infection, mucosal CD4(+) T cells restored to less than half of the numbers in controls. However, in patients who initiated cART during acute HIV infection, mucosal CD4(+) T-cell numbers were fully preserved and markers of microbial translocation and inflammation reversed to normal. The proportion of mucosal effector memory CD4(+) T cells normalized only if cART was initiated at >350 CD4(+) T cells per μl blood but not with delayed treatment. In conclusion, mucosal CD4(+) T-cell numbers can be preserved if cART is initiated in acute HIV infection. In chronically HIV-infected patients, early cART improves mucosal CD4(+) T-cell differentiation but cannot prevent the persistent lack of total CD4(+) T cells. PMID:26129649

  16. Brain antigen-reactive CD4+ T cells are sufficient to support learning behavior in mice with limited T cell repertoire

    PubMed Central

    Radjavi, Ali; Smirnov, Igor; Kipnis, Jonathan

    2013-01-01

    Numerous methods of T cell depletion lead to impairment of learning and memory function in mice. While adoptive transfer of whole splenocytes rescues learning behavior impairments, the precise sub-population and antigenic specificity of the T cells mediating the rescue remains unknown. Using several transgenic mouse models in combination with adoptive transfers, we demonstrate the necessity of an antigen-specific CD4+ T cell compartment in normal spatial learning and memory, as measured by the Morris water maze (MWM). Moreover, transfer of a monoclonal T cell population reactive to the central nervous system (CNS) antigen, myelin oligodendrocyte glycoprotein (MOG), was sufficient to improve cognitive task performance in otherwise impaired OTII mice, raising the possibility that the antigen-specificity requirement of pro-cognitive T cells may be directed against CNS-derived self-antigens. PMID:24012647

  17. Heterologous vaccination against human tuberculosis modulates antigen-specific CD4+ T-cell function.

    PubMed

    Dintwe, One B; Day, Cheryl L; Smit, Erica; Nemes, Elisa; Gray, Clive; Tameris, Michele; McShane, Helen; Mahomed, Hassan; Hanekom, Willem A; Scriba, Thomas J

    2013-09-01

    Heterologous prime-boost strategies hold promise for vaccination against tuberculosis. However, the T-cell characteristics required for protection are not known. We proposed that boost vaccines should induce long-lived functional and phenotypic changes to T cells primed by Bacille Calmette Guerin (BCG) and/or natural exposure to mycobacteria. We characterized changes among specific CD4(+) T cells after vaccination with the MVA85A vaccine in adults, adolescents, and children. CD4(+) T cells identified with Ag85A peptide-bearing HLA class II tetramers were characterized by flow cytometry. We also measured proliferative potential and cytokine expression of Ag85A-specific CD4(+) T cells. During the effector phase, MVA85A-induced specific CD4(+) T cells coexpressed IFN-γ and IL-2, skin homing integrins, and the activation marker CD38. This was followed by contraction and a transition to predominantly IL-2-expressing, CD45RA(-) CCR7(+) CD27(+) or CD45RA(+) CCR7(+) CD27(+) specific CD4(+) T cells. These surface phenotypes were similar to Ag85A-specific T cells prior to MVA85A. However, functional differences were observed postvaccination: specific proliferative capacity was markedly higher after 6-12 months than before vaccination. Our data suggest that MVA85A vaccination may modulate Ag85A-specific CD4(+) T-cell function, resulting in greater recall potential. Importantly, surface phenotypes commonly used as proxies for memory T-cell function did not associate with functional effects of vaccination. PMID:23737382

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

    PubMed Central

    Elsner, Rebecca A.; Hastey, Christine J.

    2014-01-01

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

  19. Low SAMHD1 expression following T-cell activation and proliferation renders CD4+ T cells susceptible to HIV-1

    PubMed Central

    Ruffin, Nicolas; Brezar, Vedran; Ayinde, Diana; Lefebvre, Cécile; Wiesch, Julian Schulze Zur; van Lunzen, Jan; Bockhorn, Maximilian; Schwartz, Olivier; Hocini, Hakim; Lelievre, Jean-Daniel; Banchereau, Jacques; Levy, Yves; Seddiki, Nabila

    2015-01-01

    Objectives: HIV-1 replication depends on the state of cell activation and division. It is established that SAMHD1 restricts HIV-1 infection of resting CD4+ T cells. The modulation of SAMHD1 expression during T-cell activation and proliferation, however, remains unclear, as well as a role for SAMHD1 during HIV-1 pathogenesis. Methods: SAMHD1 expression was assessed in CD4+ T cells after their activation and in-vitro HIV-1 infection. We performed phenotype analyzes using flow cytometry on CD4+ T cells from peripheral blood and lymph nodes from cohorts of HIV-1-infected individuals under antiretroviral treatment or not, and controls. Results: We show that SAMHD1 expression decreased during CD4+ T-cell proliferation in association with an increased susceptibility to in-vitro HIV-1 infection. Additionally, circulating memory CD4+ T cells are enriched in cells with low levels of SAMHD1. These SAMHD1low cells are highly differentiated, exhibit a large proportion of Ki67+ cycling cells and are enriched in T-helper 17 cells. Importantly, memory SAMHD1low cells were depleted from peripheral blood of HIV-infected individuals. We also found that follicular helper T cells present in secondary lymphoid organs lacked the expression of SAMHD1, which was accompanied by a higher susceptibility to HIV-1 infection in vitro. Conclusion: We demonstrate that SAMHD1 expression is decreased during CD4+ T-cell activation and proliferation. Also, CD4+ T-cell subsets known to be more susceptible to HIV-1 infection, for example, T-helper 17 and follicular helper T cells, display lower levels of SAMHD1. These results pin point a role for SAMHD1 expression in HIV-1 infection and the concomitant depletion of CD4+ T cells. PMID:25715102

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

    PubMed Central

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

    2015-01-01

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

  1. HIV-specific regulatory T cells are associated with higher CD4 cell counts in primary infection

    PubMed Central

    Kared, Hassen; Lelièvre, Jean-Daniel; Donkova-Petrini, Vladimira; Aouba, Albertine; Melica, Giovanna; Balbo, Michèle; Weiss, Laurence; Lévy, Yves

    2008-01-01

    Objective Expansion of Regulatory T (Treg) cells has been described in chronically HIV-infected subjects. We investigated whether HIV-suppressive Treg could be detected during primary HIV infection (PHI). Methods Seventeen patients diagnosed early after PHI (median: 13 days; 1–55) were studied. Median CD4 cell count was 480 cells/μl (33–1306) and plasma HIV RNA levels ranged between 3.3 to 5.7 log10 cp/mL. Suppressive capacity of blood purified CD4+CD25+ was evaluated in a co-culture assay. Fox-p3, IL-2 and IL-10 were quantified by RT-PCR and intra-cellular staining of ex vivo and activated CD4+CD25high T cells. Results The frequency of CD4+CD127lowCD25high T cells among CD4 T cells was lower in PHI compared to chronic patients (n=19). They exhibited a phenotype of memory T cells and expressed constitutively FoxP3. Similarly to chronic patients, Treg from PHI patients inhibited the proliferation of PPD and HIV p24 activated CD4+CD25− T cells. CD4+CD25high T cells from PHI patients responded specifically to p24 stimulation by expressing IL-10. In untreated PHI patients, the frequency, as well as HIV-specific activity of Treg decreased during a 24-month follow up. A positive correlation between percentages of Treg and both CD4 cell counts and the magnitude of p24-specific suppressive activity at diagnosis of PHI was found. Conclusions Our data showed that HIV drives Treg since PHI and that these cells persist throughout the course of the infection. A correlation between the frequency of Treg and CD4 T cell counts suggest that these cells may impact on the immune activation set point at PHI diagnosis. PMID:19005268

  2. Administration of interleukin-7 increases CD4 T cells in idiopathic CD4 lymphocytopenia.

    PubMed

    Sheikh, Virginia; Porter, Brian O; DerSimonian, Rebecca; Kovacs, Stephen B; Thompson, William L; Perez-Diez, Ainhoa; Freeman, Alexandra F; Roby, Gregg; Mican, JoAnn; Pau, Alice; Rupert, Adam; Adelsberger, Joseph; Higgins, Jeanette; Bourgeois, Jeffrey S; Jensen, Stig M R; Morcock, David R; Burbelo, Peter D; Osnos, Leah; Maric, Irina; Natarajan, Ven; Croughs, Therese; Yao, Michael D; Estes, Jacob D; Sereti, Irini

    2016-02-25

    Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL. We performed an open-label phase 1/2A dose-escalation trial of 3 subcutaneous doses of recombinant human IL-7 (rhIL-7) per week in patients with ICL who were at risk of disease progression. The primary objectives of the study were to assess safety and the immunomodulatory effects of rhIL-7 in ICL patients. Injection site reactions were the most frequently reported adverse events. One patient experienced a hypersensitivity reaction and developed non-neutralizing anti-IL-7 antibodies. Patients with autoimmune diseases that required systemic therapy at screening were excluded from the study; however, 1 participant developed systemic lupus erythematosus while on study and was excluded from further rhIL-7 dosing. Quantitatively, rhIL-7 led to an increase in the number of circulating CD4 and CD8 T cells and tissue-resident CD3 T cells in the gut mucosa and bone marrow. Functionally, these T cells were capable of producing cytokines after mitogenic stimulation. rhIL-7 was well tolerated at biologically active doses and may represent a promising therapeutic intervention in ICL. This trial was registered at www.clinicaltrials.gov as #NCT00839436. PMID:26675348

  3. Central Nervous Insulin Signaling in Sleep-Associated Memory Formation and Neuroendocrine Regulation

    PubMed Central

    Feld, Gordon B; Wilhem, Ines; Benedict, Christian; Rüdel, Benjamin; Klameth, Corinna; Born, Jan; Hallschmid, Manfred

    2016-01-01

    The neurochemical underpinnings of sleep's contribution to the establishment and maintenance of memory traces are largely unexplored. Considering that intranasal insulin administration to the CNS improves memory functions in healthy and memory-impaired humans, we tested whether brain insulin signaling and sleep interact to enhance memory consolidation in healthy participants. We investigated the effect of intranasal insulin on sleep-associated neurophysiological and neuroendocrine parameters and memory consolidation in 16 men and 16 women (aged 18–30 years), who learned a declarative word-pair task and a procedural finger sequence tapping task in the evening before intranasal insulin (160 IU) or placebo administration and 8 h of nocturnal sleep. On the subsequent evening, they learned interfering word-pairs and a new finger sequence before retrieving the original memories. Insulin increased growth hormone concentrations in the first night-half and EEG delta power during the second 90 min of non-rapid-eye-movement sleep. Insulin treatment impaired the acquisition of new contents in both the declarative and procedural memory systems on the next day, whereas retrieval of original memories was unchanged. Results indicate that sleep-associated memory consolidation is not a primary mediator of insulin's acute memory-improving effect, but that the peptide acts on mechanisms that diminish the subsequent encoding of novel information. Thus, by inhibiting processes of active forgetting during sleep, central nervous insulin might reduce the interfering influence of encoding new information. PMID:26448203

  4. Central Nervous Insulin Signaling in Sleep-Associated Memory Formation and Neuroendocrine Regulation.

    PubMed

    Feld, Gordon B; Wilhem, Ines; Benedict, Christian; Rüdel, Benjamin; Klameth, Corinna; Born, Jan; Hallschmid, Manfred

    2016-05-01

    The neurochemical underpinnings of sleep's contribution to the establishment and maintenance of memory traces are largely unexplored. Considering that intranasal insulin administration to the CNS improves memory functions in healthy and memory-impaired humans, we tested whether brain insulin signaling and sleep interact to enhance memory consolidation in healthy participants. We investigated the effect of intranasal insulin on sleep-associated neurophysiological and neuroendocrine parameters and memory consolidation in 16 men and 16 women (aged 18-30 years), who learned a declarative word-pair task and a procedural finger sequence tapping task in the evening before intranasal insulin (160 IU) or placebo administration and 8 h of nocturnal sleep. On the subsequent evening, they learned interfering word-pairs and a new finger sequence before retrieving the original memories. Insulin increased growth hormone concentrations in the first night-half and EEG delta power during the second 90 min of non-rapid-eye-movement sleep. Insulin treatment impaired the acquisition of new contents in both the declarative and procedural memory systems on the next day, whereas retrieval of original memories was unchanged. Results indicate that sleep-associated memory consolidation is not a primary mediator of insulin's acute memory-improving effect, but that the peptide acts on mechanisms that diminish the subsequent encoding of novel information. Thus, by inhibiting processes of active forgetting during sleep, central nervous insulin might reduce the interfering influence of encoding new information. PMID:26448203

  5. Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation.

    PubMed

    Busquets-Garcia, Arnau; Gomis-González, Maria; Srivastava, Raj Kamal; Cutando, Laura; Ortega-Alvaro, Antonio; Ruehle, Sabine; Remmers, Floortje; Bindila, Laura; Bellocchio, Luigi; Marsicano, Giovanni; Lutz, Beat; Maldonado, Rafael; Ozaita, Andrés

    2016-08-30

    Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation. Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved. Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH(+) cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation. Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders. PMID:27528659

  6. Specific central memory T cells in the bone marrow of patients immunized against tyrosinase peptides.

    PubMed

    Letsch, Anne; Keilholz, Ulrich; Kern, Florian; Asemissen, Anne Marie; Thiel, Eckhard; Scheibenbogen, Carmen

    2006-01-01

    The goal of vaccination against tumors is the induction of effector T cells mediating tumor destruction and memory T cells providing long-term immunity. Several previous studies in patients vaccinated with major histocompatibility complex (MHC) class I peptides failed to show induction of central memory T cells, which are considered important to provide long-term memory. This study examined the subset composition and function of specific T cells generated by immunization with MHC class I binding tyrosinase peptides in combination with the adjuvants granulocyte-macrophage colony-stimulating factor and keyhole limpet hemocyanin in peripheral blood (PB) and bone marrow (BM) of melanoma patients. Most of the tyrosinase-specific T cells in PB had a CD45RA(+)CCR7(-) effector phenotype. In contrast to this, a large subset of tyrosinase-specific T cells in BM were memory T cells, including CD45RA(+)CCR7(-) central and CD45RA(-)CCR7(-) effector memory T cells. BM tyrosinase-specific T cells were functional, because they produced interferon-gamma and had a high proliferative potential. This study suggests that peptide vaccination can generate a fully functional memory T-cell response characterized by central and effector memory phenotypes, proliferative potential, and BM tropism. PMID:16531820

  7. Impact of sepsis on CD4 T cell immunity

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  9. Memory in myasthenia gravis: neuropsychological tests of central cholinergic function before and after effective immunologic treatment.

    PubMed

    Glennerster, A; Palace, J; Warburton, D; Oxbury, S; Newsom-Davis, J

    1996-04-01

    There are reports of central cholinergic deficits in myasthenia gravis (MG) describing impaired performance on a variety of tests of memory with varying benefits from plasmapheresis. We tested 11 patients with symptomatic MG at the start of a trial of immunosuppressive treatment (prednisolone plus azathioprine or placebo) and again when in remission. The tests included the Logical Memory and Design Reproduction parts of the Wechsler Memory Scale, the Rey Auditory Verbal Learning Test, Peterson-Peterson task, and an auditory vigilance task. Muscle strength improved significantly over the period of treatment, but overall performance on tests of memory or attention did not. These results fail to substantiate reports of functionally significant and reversible central deficits in myasthenia gravis. PMID:8780106

  10. Characterization of Regulatory T-Cell Markers in CD4+ T Cells of the Upper Airway Mucosa

    PubMed Central

    Ballke, Christina; Gran, Einar; Baekkevold, Espen S.; Jahnsen, Frode L.

    2016-01-01

    CD4+ T regulatory cells (Tregs) comprise a heterogeneous population of cells the regulate immune responses and prevent autoimmunity. Most reports on human Tregs are derived from studies of peripheral blood, although Tregs mainly exert their functions in the periphery. Here we performed a detailed analysis of Tregs in the human upper airway mucosa under non-inflammatory conditions, and found that 10% of all CD4+ T cells expressed the transcription factor FOXP3 and the memory marker CD45RO, as well as high levels of CTLA-4. The majority of FOXP3+CD4+ T cells co-expressed the transcription factor Helios and produced very little cytokines, compatible with being thymus-derived Tregs. FOXP3+Helios-CD4+ T cells were more heterogeneous. A mean of 24% produced the immunomodulatory cytokine IL-10, whereas a large fraction also produced IL-2, IFN-μ or IL-17. A significant population (6%) of FOXP3-negative T cells also produced IL-10, usually in combination with IFN-μ. Together, we found that CD4+ T cells in the upper airways differed functionally from their counterparts in peripheral blood, including higher expression of IL-10. Moreover, our findings suggest that several subsets of CD4+ T cells with functionally distinct regulatory properties reside in the upper airway mucosa which should be taken into account when targeting Tregs for therapy. PMID:26866695

  11. HIV-1 Nef mutations abrogating downregulation of CD4 affect other Nef functions and show reduced pathogenicity in transgenic mice

    SciTech Connect

    Hanna, Zaher . E-mail: Zaher.Hanna@ircm.qc.ca; Priceputu, Elena; Hu, Chunyan; Vincent, Patrick; Jolicoeur, Paul

    2006-03-01

    HIV-1 Nef has the ability to downmodulate CD4 cell surface expression. Several studies have shown that CD4 downregulation is required for efficient virus replication and high infectivity. However, the pathophysiological relevance of this phenomenon in vivo, independently of its role in sustaining high virus loads, remains unclear. We studied the impact of the CD4 downregulation function of Nef on its pathogenesis in vivo, in the absence of viral replication, in the CD4C/HIV transgenic (Tg) mouse model. Two independent Nef mutants (RD35/36AA and D174K), known to abrogate CD4 downregulation, were tested in Tg mice. Flow cytometry analysis showed that downregulation of murine CD4 was severely decreased or abrogated on Tg T cells expressing respectively Nef{sup RD35/36AA} and Nef{sup D174K}. Similarly, the severe depletion of double-positive CD4{sup +}CD8{sup +} and of single-positive CD4{sup +}CD8{sup -} thymocytes, usually observed with Nef{sup Wt}, was not detected in Nef{sup RD35/36AA} and Nef{sup D174K} Tg mice. However, both mutant Tg mice showed a partial depletion of peripheral CD4{sup +} T cells. This was accompanied, as previously reported for Net{sup Wt} Tg mice, by the presence of an activated/memory-like phenotype (CD69{sup +}, CD25{sup +}, CD44{sup +}, CD45RB{sup Low}, CD62{sup Low}) of CD4{sup +} T cells expressing Nef{sup RD35/36AA} and to a lesser extent Nef{sup D174K}. In addition, both mutants retained the ability to block CD4{sup +} T cell proliferation in vitro after anti-CD3 stimulation, but not to enhance apoptosis/death of CD4{sup +} T cells. Therefore, it appears that Nef-mediated CD4 downregulation is associated with thymic defects, but segregates independently of the activated/memory-like phenotype, of the partial depletion and of the impaired in vitro proliferation of peripheral CD4{sup +} T cells. Histopathological assessment revealed the total absence of or decrease severity and frequency of organ AIDS-like diseases (lung, heart and kidney

  12. Failure to Suppress the Expansion of the Activated Cd4 T Cell Population in Interferon γ–Deficient Mice Leads to Exacerbation of Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Chu, Cong-Qiu; Wittmer, Susan; Dalton, Dyana K.

    2000-01-01

    Mice deficient in interferon (IFN)-γ or IFN-γ receptor develop progressive and fatal experimental autoimmune encephalomyelitis (EAE). We demonstrate that CD4 T cells lacking IFN-γ production were required to passively transfer EAE, indicating that they were disease-mediating cells in IFN-γ knockout (KO) mice. IFN-γ KO mice accumulated 10–16-fold more activated CD4 T cells (CD4+CD44hi) than wild-type mice in the central nervous system during EAE. CD4+CD44hi T cells in the spleen and central nervous system of IFN-γ KO mice during EAE showed markedly increased in vivo proliferation and significantly decreased ex vivo apoptosis compared with those of wild-type mice. IFN-γ KO CD4+CD44hi T cells proliferated extensively to antigen restimulation in vitro and accumulated larger numbers of live CD4+ CD44hi T cells. IFN-γ completely suppressed proliferation and significantly induced apoptosis of CD4+CD44hi T cells responding to antigen and hence inhibited accumulation of live, activated CD4 T cells. We thus present novel in vivo and in vitro evidence that IFN-γ may limit the extent of EAE by suppressing expansion of activated CD4 T cells. PMID:10880533

  13. CD4+ T cell activation in multiple sclerosis.

    PubMed

    Verselis, S J; Goust, J M

    1987-02-01

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

  14. POC CD4 Testing Improves Linkage to HIV Care and Timeliness of ART Initiation in a Public Health Approach: A Systematic Review and Meta-Analysis

    PubMed Central

    Vojnov, Lara; Markby, Jessica; Boeke, Caroline; Harris, Lindsay; Ford, Nathan; Peter, Trevor

    2016-01-01

    Background CD4 cell count is an important test in HIV programs for baseline risk assessment, monitoring of ART where viral load is not available, and, in many settings, antiretroviral therapy (ART) initiation decisions. However, access to CD4 testing is limited, in part due to the centralized conventional laboratory network. Point of care (POC) CD4 testing has the potential to address some of the challenges of centralized CD4 testing and delays in delivery of timely testing and ART initiation. We conducted a systematic review and meta-analysis to identify the extent to which POC improves linkages to HIV care and timeliness of ART initiation. Methods We searched two databases and four conference sites between January 2005 and April 2015 for studies reporting test turnaround times, proportion of results returned, and retention associated with the use of point-of-care CD4. Random effects models were used to estimate pooled risk ratios, pooled proportions, and 95% confidence intervals. Results We identified 30 eligible studies, most of which were completed in Africa. Test turnaround times were reduced with the use of POC CD4. The time from HIV diagnosis to CD4 test was reduced from 10.5 days with conventional laboratory-based testing to 0.1 days with POC CD4 testing. Retention along several steps of the treatment initiation cascade was significantly higher with POC CD4 testing, notably from HIV testing to CD4 testing, receipt of results, and pre-CD4 test retention (all p<0.001). Furthermore, retention between CD4 testing and ART initiation increased with POC CD4 testing compared to conventional laboratory-based testing (p = 0.01). We also carried out a non-systematic review of the literature observing that POC CD4 increased the projected life expectancy, was cost-effective, and acceptable. Conclusions POC CD4 technologies reduce the time and increase patient retention along the testing and treatment cascade compared to conventional laboratory-based testing. POC CD4 is

  15. Phase 1 studies of central memory-derived CD19 CAR T-cell therapy following autologous HSCT in patients with B-cell NHL.

    PubMed

    Wang, Xiuli; Popplewell, Leslie L; Wagner, Jamie R; Naranjo, Araceli; Blanchard, M Suzette; Mott, Michelle R; Norris, Adam P; Wong, ChingLam W; Urak, Ryan Z; Chang, Wen-Chung; Khaled, Samer K; Siddiqi, Tanya; Budde, Lihua E; Xu, Jingying; Chang, Brenda; Gidwaney, Nikita; Thomas, Sandra H; Cooper, Laurence J N; Riddell, Stanley R; Brown, Christine E; Jensen, Michael C; Forman, Stephen J

    2016-06-16

    Myeloablative autologous hematopoietic stem cell transplantation (HSCT) is a mainstay of therapy for relapsed intermediate-grade B-cell non-Hodgkin lymphoma (NHL); however, relapse rates are high. In phase 1 studies designed to improve long-term remission rates, we administered adoptive T-cell immunotherapy after HSCT, using ex vivo-expanded autologous central memory-enriched T cells (TCM) transduced with lentivirus expressing CD19-specific chimeric antigen receptors (CARs). We present results from 2 safety/feasibility studies, NHL1 and NHL2, investigating different T-cell populations and CAR constructs. Engineered TCM-derived CD19 CAR T cells were infused 2 days after HSCT at doses of 25 to 200 × 10(6) in a single infusion. In NHL1, 8 patients safely received T-cell products engineered from enriched CD8(+) TCM subsets, expressing a first-generation CD19 CAR containing only the CD3ζ endodomain (CD19R:ζ). Four of 8 patients (50%; 95% confidence interval [CI]: 16-84%) were progression free at both 1 and 2 years. In NHL2, 8 patients safely received T-cell products engineered from enriched CD4(+) and CD8(+) TCM subsets and expressing a second-generation CD19 CAR containing the CD28 and CD3ζ endodomains (CD19R:28ζ). Six of 8 patients (75%; 95% CI: 35-97%) were progression free at 1 year. The CD4(+)/CD8(+) TCM-derived CD19 CAR T cells (NHL2) exhibited improvement in expansion; however, persistence was ≤28 days, similar to that seen by others using CD28 CARs. Neither cytokine release syndrome nor delayed hematopoietic engraftment was observed in either trial. These data demonstrate the safety and feasibility of CD19 CAR TCM therapy after HSCT. Trials were registered at www.clinicaltrials.gov as #NCT01318317 and #NCT01815749. PMID:27118452

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

    PubMed

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

    2016-05-15

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

  17. Longitudinal Requirement for CD4+ T Cell Help for Adenovirus Vector–Elicited CD8+ T Cell Responses

    PubMed Central

    Provine, Nicholas M.; Larocca, Rafael A.; Penaloza-MacMaster, Pablo; Borducchi, Erica N.; McNally, Anna; Parenteau, Lily R.; Kaufman, David R.

    2014-01-01

    Despite the widespread use of replication-incompetent recombinant adenovirus (Ad) vectors as candidate vaccine platforms, the mechanism by which these vectors elicit CD8+ T cell responses remains poorly understood. Our data demonstrate that induction and maintenance of CD8+ T cell responses by Ad vector immunization is longitudinally dependent on CD4+ T cell help for a prolonged period. Depletion of CD4+ T cells in wild type mice within the first 8 d following Ad immunization resulted in dramatically reduced induction of Ag-specific CD8+ T cells, decreased T-bet and eomesodermin expression, impaired KLRG1+ effector differentiation, and atypical expression of the memory markers CD127, CD27, and CD62L. Moreover, these CD8+ T cells failed to protect against a lethal recombinant Listeria monocytogenes challenge. Depletion of CD4+ T cells between weeks 1 and 4 following immunization resulted in increased contraction of memory CD8+ T cells. These data demonstrate a prolonged temporal requirement for CD4+ T cell help for vaccine-elicited CD8+ T cell responses in mice. These findings have important implications in the design of vaccines aimed at eliciting CD8+ T cell responses and may provide insight into the impaired immunogenicity of vaccines in the context of AIDS and other CD4+ T cell immune deficiencies. PMID:24778441

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

    PubMed

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

    2016-03-01

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

  19. Differential Expression of Immune Checkpoint Modulators on In Vitro Primed CD4+ and CD8+ T Cells

    PubMed Central

    Sabins, Nina C.; Harman, Benjamin C.; Barone, Linda R.; Shen, Shixue; Santulli-Marotto, Sandra

    2016-01-01

    PD-1, TIM-3, and LAG-3 are molecules shown to have immune modulatory properties, and although initially classified as indicators of T cell hyporesponsiveness, it has become clear that they are also associated with the normal course of T cell activation. Functional studies have focused mainly on CD8+ T cells during chronic inflammation due to interest in co-opting the cellular immune response to eliminate viral or cancerous threats; however, there remains a relative lack of data regarding the expression of these molecules on CD4+ T cells. Here, we report that expression of the immune checkpoint (IC) molecules PD-1, LAG-3, and TIM-3 are differentially expressed on CD4+ and CD8+ T cells in the allogeneic response resulting from a mixed lymphocyte reaction. In these studies, PD-1 expression is higher on CD4+ T cells compared to CD8+ T cells. In contrast, TIM-3 is expressed at higher levels on CD8+ T cells compared to CD4+ T cells with an apparent reciprocity in that PD-1+ CD4+ T cells are frequently TIM-3lo/−, while TIM-3-expressing CD8+ T cells are largely PD-1lo/−. In addition, there is a decrease in the frequency of TIM-3+ CD4+ cells producing IFN-γ and IL-5 compared to TIM-3+ CD8+ cells. Lastly, the memory T cell phenotype within each IC-expressing subset differs between CD4+ and CD8+ T cells. These findings highlight key differences in IC expression patterns between CD4+ and CD8+ T cells and may allow for more effective therapeutic targeting of these molecules in the future. PMID:27379090

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

    PubMed Central

    Ciabattini, Annalisa; Pettini, Elena; Medaglini, Donata

    2013-01-01

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

  1. Central Auditory Dysfunction in Older People with Memory Impairment or Alzheimer's Dementia

    PubMed Central

    Gates, George A.; Anderson, Melissa L.; Feeney, M. Patrick; McCurry, Susan M.; Larson, Eric B.

    2009-01-01

    Central auditory function is commonly compromised in people with a diagnosis of Alzheimer's disease (AD) and may precede the onset of clinical dementia by several years. Given that screening for AD in its earliest stages might someday be useful for emerging therapies aimed at limiting progression, we inquired whether central auditory testing might be suitable for identifying people at risk for dementia. To address this question, we performed a battery of behavioral central auditory tests in a cohort of 313 older people enrolled in a dementia surveillance research program. The cohort consisted of three groups: controls without memory loss (N=232), targets with mild memory impairment but without dementia (N=64), and targets with a dementia diagnosis (N=17). The auditory tests were the Synthetic Sentence Identification with Ipsilateral Competing Message (SSI), the Dichotic Sentence Identification test (DSI), the Dichotic Digits Test (DDT), and the Pitch Pattern Sequence (PPS) test. Additional control was provided by electrophysiologic testing to assess the integrity of the primary auditory pathways. The mean score on each central auditory test worsened significantly across the three memory groups even after adjusting for age and peripheral hearing status, being poorest in the pAD group and moderately reduced in the memory-impaired group compared to the mean scores in the control group. Heterogeneity of results was noted in all three groups. The electrophysiologic tests did not differ across the three groups. Central auditory function was affected by mild memory impairment. The Dichotic Sentence Identification in the free report mode appears to be the central auditory test most sensitive to the presence of memory impairment. Although central auditory testing requires specialized equipment and training, the objectivity of these tests is appealing. We recommend that comprehensive auditory testing be considered and further evaluated for its potential value as a baseline

  2. The dual role of CD4 T helper cells in the infection dynamics of HIV and their importance for vaccination.

    PubMed

    Altes, H Korthals; Wodarz, D; Jansen, V A A

    2002-02-21

    Given the role of the CD4 T helper cells in the development of memory CTL precursors, it seems beneficial to boost the CD4 T helper response in the context of vaccination against the human immunodeficiency virus (HIV). However, CD4 T cells are also the preferred targets of infection by HIV. Here, we address the question as to whether it is advantageous to stimulate the CD4 T helper cell response, as this will increase the pool of potential target cells of infection. To do so we formulated a mathematical model describing the interactions between virus-infected cells, susceptible cells, HIV-specific CD4 helper T cells, and CTL precursor (CTLp) and effector cells (CTLe). The effect of increased initial CD4 helper and CTLp numbers on the outcome of infection, as well as the effect on viral set point of increased CD4 T helper growth rate, CTL responsiveness and the rate at which CTLp and CTLe are produced were studied. We found that only when the virus has a low basic reproductive number does the number of CTLp and CD4 T helper cells at the moment of infection influence the outcome of infection. In this situation, high initial T helper and CTL numbers can switch the outcome from full-blown infection to virus control. However, this holds for virus with infectivity in a limited range, and current estimates of virus infectivity suggest that it is higher. In that case, only a vaccination protocol that increases CTL responsiveness, ideally in combination with the rate of production of CD4 T helper cells, may offer a solution as it can reduce the viral set point considerably. If brought under a certain level, the viral population might be unable to replicate any further. However, changing these parameters of the immune response is only beneficial when infection is controlled by CTL in the long term. When a CD4 lymphoproliferative response is mounted but the CTL response is not maintained, increasing the CD4 T helper growth rate is deleterious. PMID:11851372

  3. Blind T-cell homeostasis in CD4-deficient mice.

    PubMed

    Adleman, L M; Wofsy, D

    1996-04-01

    Recently, it has been proposed that normal T-cell count is maintained by a homeostatic mechanism which is "blind" to the distinction between CD4+ T cells and CD8+ T cells. Interest in this blind homeostasis hypothesis (BHH) stems in part from its implications regarding the pathogenesis and treatment of HIV infection. In this report, BHH was tested in CD4-deficient mice. We found that as predicted by BHH, despite the absence of CD4+ T cells, CD4-deficient mice maintain normal absolute T-cell counts in the blood and spleen primarily through a marked increase in CD8+ T cells. These findings provide strong new support for BHH. PMID:8601219

  4. Optimal CD4 Count for Initiating HIV Treatment

    PubMed Central

    Ford, Deborah; Walker, A. Sarah; Carpenter, James; Copas, Andrew

    2014-01-01

    Background: In HIV infection, dynamic marginal structural models have estimated the optimal CD4 for treatment initiation to minimize AIDS/death. The impact of CD4 observation frequency and grace periods (permitted delay to initiation) on the optimal regimen has not been investigated nor has the performance of dynamic marginal structural models in moderately sized data sets—two issues that are relevant to many applications. Methods: To determine optimal regimens, we simulated 31,000,000 HIV-infected persons randomized at CD4 500–550 cells/mm3 to regimens “initiate treatment within a grace period following observed CD4 first CD4-dependent treatment initiation. Results: Decreasing the frequency of CD4 measurements from monthly to every 3, 6, and 12 months increased the optimal regimen from a CD4 level of 350 (10-year AIDS-free survival, 0.8657) to 410 (0.8650), 460 (0.8634), and 490 (0.8564), respectively. Under a regimen defined by x = 350 with annual CD4s, 10-year AIDS-free survival dropped to 0.8304. Extending the grace period from 1 to 3 or 6 months, with 3-monthly CD4s, maintained the optimal regimen at 410 for 3 months and increased it to 460 for 6 months. In observational studies with 3-monthly CD4s, the mean (SE) estimated optimal regimen was 402 (76), 424 (66), and 430 (63) with 1-, 3-, and 6-month grace periods; 24%, 15%, and 14% of estimated optimal regimens resulted in >0.5% lower AIDS-free survival compared with the true optimal regimen. Conclusions: The optimal regimen is strongly influenced by CD4 frequency and less by grace period length. Dynamic marginal

  5. HIV exceptionalism, CD4+ cell testing, and conscientious subversion

    PubMed Central

    Jansen, L

    2005-01-01

    In recent years, many states in the United States have passed legislation requiring laboratories to report the names of patients with low CD4 cell counts to their state Departments of Health. This name reporting is an integral part of the growing number of "HIV Reporting and Partner Notification Laws" which have emerged in response to recently revised guidelines suggested by the National Centers for Disease Control (CDC). Name reporting for patients with low CD4 cell counts allows for a more accurate tracking of the natural history of HIV disease. However, given that this test is now considered to be an "indicator" of HIV, should it be subject to the same strict consent required for HIV testing? While the CDC has recommended that each state develop its own consent requirements for CD4 cell testing, most states have continued to rely on the presumed consent standards for CD4 cell testing that were in place before the passage of name reporting statutes. This allows physicians who treat patients who refuse HIV testing to order a CD4 cell blood analysis to gather information that is indicative of their patient's HIV status. This paper examines the ethical and legal issues associated with the practice of "conscientious subversion" as it arises when clinicians use CD4 cell counts as a surrogate for HIV testing. PMID:15923478

  6. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term (i.e., 14 days) cultured IFN-gamma ELISPOT assays measure central memory T cell (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT responses correlate with protection. In other species, Tcm’s pose low activation threshold and a...

  7. Working Memory and Mental Arithmetic: A Case for Dual Central Executive Resources

    ERIC Educational Resources Information Center

    Ketelsen, Kirk; Welsh, Marilyn

    2010-01-01

    The current study was designed to examine the possible existence of two limited-capacity pools of central executive resources: one each for verbal and visuospatial processing. Ninety-one college students (M age = 19.0, SD = 2.2) were administered a verbal working memory task that involved updating numbers in 2-, 3-, and 4-load conditions. The task…

  8. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term (i.e., 14 days) cultured IFN-gamma responses of peripheral blood mononuclear cells are used as a correlate of T cell central memory (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT assays are a correlate of protection. Recent...

  9. Differences in expression of gut-homing receptors on CD4+ T cells in black and white HIV-negative men who have sex with men.

    PubMed

    Kelley, Colleen F; Lai, Lilin; Ibegbu, Chris; Rosenberg, Eli S; Kaur, Surinder; Patel, Kalpana; Mulligan, Mark J; Marconi, Vincent C; Sullivan, Patrick S; Amara, Rama R

    2016-05-15

    HIV incidence rates are higher among black men who have sex with men (BMSM) as compared with MSM of other race/ethnicities in the USA. We found that blood memory CD4 cells from BMSM express higher levels of α4β7, the gut-homing integrin, compared with white MSM. Higher expression of α4β7 on blood CD4 cells correlated with higher percentage of proliferating CD4α4β7 cells in rectal tissue suggesting increased trafficking of potential HIV target cells to rectal mucosa could increase HIV susceptibility among BMSM. PMID:26891038

  10. Spatiotemporally Distinct Interactions with Dendritic Cell Subsets Facilitates CD4+ and CD8+ T Cell Activation to Localized Viral Infection.

    PubMed

    Hor, Jyh Liang; Whitney, Paul G; Zaid, Ali; Brooks, Andrew G; Heath, William R; Mueller, Scott N

    2015-09-15

    The dynamics of when and where CD4(+) T cells provide help for CD8(+) T cell priming and which dendritic cells (DCs) activate CD4(+) T cells in vivo after localized infection are poorly understood. By using a cutaneous herpes simplex virus infection model combined with intravital 2-photon imaging of the draining lymph node (LN) to concurrently visualize pathogen-specific CD4(+) and CD8(+) T cells, we found that early priming of CD4(+) T cells involved clustering with migratory skin DCs. CD8(+) T cells did not interact with migratory DCs and their activation was delayed, requiring later clustering interactions with LN-resident XCR1(+) DCs. CD4(+) T cells interacted with these late CD8(+) T cell clusters on resident XCR1(+) DCs. Together, these data reveal asynchronous T cell activation by distinct DC subsets and highlight the key role of XCR1(+) DCs as the central platform for cytotoxic T lymphocyte activation and the delivery of CD4(+) T cell help. PMID:26297566

  11. NK and CD4+ T cell co-operative immune responses correlate with control of disease in a macaque SIV infection model1

    PubMed Central

    Vargas-Inchaustegui, Diego A.; Xiao, Peng; Tuero, Iskra; Patterson, L. Jean; Robert-Guroff, Marjorie

    2012-01-01

    Control of infectious disease may be accomplished by successful vaccination, or by complex immunologic and genetic factors favoring antigen-specific multicellular immune responses. Using a rhesus macaque model, we evaluated antigen-specific T cell-dependent NK cell immune responses in SIV-infected macaques, designated controlling or non-controlling based on long-term chronic viremia levels, to determine if NK cell effector functions contribute to control of SIV infection. We observed that Gag stimulation of macaque PBMCs induced subset-specific NK cell responses in SIV-controlling, but not non-controlling animals, and that circulatory NK cell responses were dependent on antigen-specific IL-2 production by CD4+ central memory T cells. NK cell activation was blocked by anti-IL-2 neutralizing antibody and by CD4+ T cell depletion which abrogated the Gag-specific responses. Among tissue-resident cells, splenic and circulatory NK cells displayed similar activation profiles, whereas liver and mucosal NK cells displayed a decreased activation profile, similar in SIV controlling and non-controlling macaques. Lack of T cell-dependent NK cell function was rescued in SIV non-controlling macaques through drug-mediated control of viremia. Our results indicate that control of disease progression in SIV controlling macaques is associated with co-operation between antigen-specific CD4+ T cells and NK cell effector function, highlight the importance of such cell-to-cell co-operativity in adaptive immunity and suggest this interaction should be further investigated in HIV vaccine development and other prophylactic vaccine approaches. PMID:22798665

  12. Inhibitors of HIV infection via the cellular CD4 receptor.

    PubMed

    Vermeire, Kurt; Schols, Dominique; Bell, Thomas W

    2006-01-01

    Recent advances in our understanding of cellular and molecular mechanisms of viral penetration of the target cell have provided the basis for novel chemotherapy and prophylaxis of HIV-1 infections. This knowledge has been successfully applied to the development of inhibitors that target discrete steps of the entry process. Interesting approaches for prevention of HIV-1 entry include the use of small-molecule inhibitors, natural ligands and/or monoclonal antibodies that interfere with gp120/CD4 interaction. Other compounds acting by novel mechanisms have recently been identified as anti-HIV agents and seem worthy of further preclinical development. Of particular interest in this regard are cyclotriazadisulfonamide (CADA) compounds, which down-modulate the cellular receptor, CD4. A series of analogues of 9-benzyl-3-methylene-1,5-di-p-toluenesulfonyl-1,5,9-triazacyclododecane (CADA) has been synthesized and tested for CD4 down-modulation and anti-HIV activity. Some derivatives proved to be highly effective in decreasing cellular CD4 and in acting as HIV entry inhibitors. Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies correlating molecular features with potency have been used to produce a computational model. This model can be used to design more potent CD4 down-modulating drugs for HIV therapy and prophylaxis. This review summarizes the results of recent studies relating to inhibitors of HIV infection via CD4 and discusses the therapeutic potential of targeting this cellular receptor. Special attention is given to our own work on small-molecule HIV entry inhibitors endowed with CD4 down-modulating properties. PMID:16611063

  13. Brief Report: L-Selectin (CD62L) Is Downregulated on CD4+ and CD8+ T Lymphocytes of HIV-1-Infected Individuals Naive for ART.

    PubMed

    Vassena, Lia; Giuliani, Erica; Buonomini, Anna R; Malagnino, Vincenzo; Andreoni, Massimo; Doria, Margherita

    2016-08-15

    The expression of L-selectin (CD62L) in HIV-1 infection has not been extensively investigated. Here, we measured CD62L expression on T-cell subsets of HIV-1-infected individuals naive for antiretroviral therapy (ART-naive) or receiving therapy (ART), and seronegative control subjects (HIV-neg). We found reduced frequencies of CD62L cells among CD4 and CD8 T cells from ART-naive as compared with ART and HIV-neg groups, particularly within naive and central memory subsets. CD62L expression on T cells inversely correlated with viral load and rapidly increased after ART initiation. Plasma sCD62L levels did not correlate with CD62L expression, being higher in all HIV-1-infected individuals as compared with HIV-neg subjects. Finally, CD62L downregulation was found associated with the expression of the CD38 activation marker in CD8 T cells, but not in CD4 T cells. We suggest that CD62L downregulation due to unconstrained HIV-1 replication may have important consequences for T-cell circulation and function and for disease progression. PMID:27003497

  14. CD4+ T Cells Expressing PD-1, TIGIT and LAG-3 Contribute to HIV Persistence during ART.

    PubMed

    Fromentin, Rémi; Bakeman, Wendy; Lawani, Mariam B; Khoury, Gabriela; Hartogensis, Wendy; DaFonseca, Sandrina; Killian, Marisela; Epling, Lorrie; Hoh, Rebecca; Sinclair, Elizabeth; Hecht, Frederick M; Bacchetti, Peter; Deeks, Steven G; Lewin, Sharon R; Sékaly, Rafick-Pierre; Chomont, Nicolas

    2016-07-01

    HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals. PMID:27415008

  15. CD4+ T Cells Expressing PD-1, TIGIT and LAG-3 Contribute to HIV Persistence during ART

    PubMed Central

    Fromentin, Rémi; Bakeman, Wendy; Lawani, Mariam B.; Khoury, Gabriela; Hartogensis, Wendy; DaFonseca, Sandrina; Killian, Marisela; Epling, Lorrie; Hoh, Rebecca; Sinclair, Elizabeth; Hecht, Frederick M.; Bacchetti, Peter; Deeks, Steven G.; Lewin, Sharon R.; Sékaly, Rafick-Pierre; Chomont, Nicolas

    2016-01-01

    HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals. PMID:27415008

  16. Expanding Roles for CD4 T Cells and Their Subpopulations in Tumor Immunity and Therapy

    PubMed Central

    Dobrzanski, Mark J.

    2013-01-01

    The importance of CD4 T cells in orchestrating the immune system and their role in inducing effective T cell-mediated therapies for the treatment of patients with select established malignancies are undisputable. Through a complex and balanced array of direct and indirect mechanisms of cellular activation and regulation, this functionally diverse family of lymphocytes can potentially promote tumor eradication, long-term tumor immunity, and aid in establishing and/or rebalancing immune cell homeostasis through interaction with other immune cell populations within the highly dynamic tumor environment. However, recent studies have uncovered additional functions and roles for CD4 T cells, some of which are independent of other lymphocytes, that can not only influence and contribute to tumor immunity but paradoxically promote tumor growth and progression. Here, we review the recent advances in our understanding of the various CD4 T cell lineages and their signature cytokines in disease progression and/or regression. We discuss their direct and indirect mechanistic interplay among themselves and with other responding cells of the antitumor response, their potential roles and abilities for “plasticity” and memory cell generation within the hostile tumor environment, and their potentials in cancer treatment and immunotherapy. PMID:23533029

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

    PubMed Central

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

    2015-01-01

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

  18. 5-Hydroxymethylcytosine Remodeling Precedes Lineage Specification during Differentiation of Human CD4(+) T Cells.

    PubMed

    Nestor, Colm E; Lentini, Antonio; Hägg Nilsson, Cathrine; Gawel, Danuta R; Gustafsson, Mika; Mattson, Lina; Wang, Hui; Rundquist, Olof; Meehan, Richard R; Klocke, Bernward; Seifert, Martin; Hauck, Stefanie M; Laumen, Helmut; Zhang, Huan; Benson, Mikael

    2016-07-12

    5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by the TET family of enzymes as part of a recently discovered active DNA de-methylation pathway. 5hmC plays important roles in regulation of gene expression and differentiation and has been implicated in T cell malignancies and autoimmunity. Here, we report early and widespread 5mC/5hmC remodeling during human CD4(+) T cell differentiation ex vivo at genes and cell-specific enhancers with known T cell function. We observe similar DNA de-methylation in CD4(+) memory T cells in vivo, indicating that early remodeling events persist long term in differentiated cells. Underscoring their important function, 5hmC loci were highly enriched for genetic variants associated with T cell diseases and T-cell-specific chromosomal interactions. Extensive functional validation of 22 risk variants revealed potentially pathogenic mechanisms in diabetes and multiple sclerosis. Our results support 5hmC-mediated DNA de-methylation as a key component of CD4(+) T cell biology in humans, with important implications for gene regulation and lineage commitment. PMID:27346350

  19. CD27 Agonism Plus PD-1 Blockade Recapitulates CD4+ T-cell Help in Therapeutic Anticancer Vaccination.

    PubMed

    Ahrends, Tomasz; Bąbała, Nikolina; Xiao, Yanling; Yagita, Hideo; van Eenennaam, Hans; Borst, Jannie

    2016-05-15

    While showing promise, vaccination strategies to treat cancer require further optimization. Likely barriers to efficacy involve cancer-associated immunosuppression and peripheral tolerance, which limit the generation of effective vaccine-specific cytotoxic T lymphocytes (CTL). Because CD4(+) T cells improve CTL responsiveness, next-generation vaccines include helper epitopes. Here, we demonstrate in mice how CD4(+) T-cell help optimizes the CTL response to a clinically relevant DNA vaccine engineered to combat human papillomavirus-expressing tumors. Inclusion of tumor-unrelated helper epitopes greatly increased CTL priming, effector, and memory T-cell programming. CD4(+) T-cell help optimized the CTL response in all these aspects via CD27/CD70 costimulation. Notably, administration of an agonistic CD27 antibody could largely replace helper epitopes in promoting primary and memory CTL responses, acting directly on CD8(+) T cells. CD27 agonism improved efficacy of the vaccine without helper epitopes, more so than combined PD-1 and CTLA-4 blockade. Combining CD27 agonism with CTLA-4 blockade improved vaccine-induced CTL priming and tumor infiltration, but only combination with PD-1 blockade was effective at eradicating tumors, thereby fully recapitulating the effect of CD4(+) T-cell help on vaccine efficacy. PD-1 blockade alone did not affect CTL priming or tumor infiltration, so these results implied that it cooperated with CD4(+) T-cell help by alleviating immune suppression against CTL in the tumor. Helper epitope inclusion or CD27 agonism did not stimulate regulatory T cells, and vaccine efficacy was also improved by CD27 agonism in the presence of CD4(+) T-cell help. Our findings provide a preclinical rationale to apply CD27 agonist antibodies, either alone or combined with PD-1 blockade, to improve the therapeutic efficacy of cancer vaccines and immunotherapy generally. Cancer Res; 76(10); 2921-31. ©2016 AACR. PMID:27020860

  20. Micropatterning of costimulatory ligands enhances CD4+ T cell function

    PubMed Central

    Shen, Keyue; Thomas, V. Kaye; Dustin, Michael L.; Kam, Lance C.

    2008-01-01

    Spatial organization of signaling complexes is a defining characteristic of the immunological synapse (IS), but its impact on cell communication is unclear. In T cell–APC pairs, more IL-2 is produced when CD28 clusters are segregated from central supramolecular activation cluster (cSMAC)-localized CD3 and into the IS periphery. However, it is not clear in these cellular experiments whether the increased IL-2 is driven by the pattern itself or by upstream events that precipitate the patterns. In this article, we recapitulate key features of physiological synapses using planar costimulation arrays containing antibodies against CD3 and CD28, surrounded by ICAM-1, created by combining multiple rounds of microcontact printing on a single surface. Naïve T cells traverse these arrays, stopping at features of anti-CD3 antibodies and forming a stable synapse. We directly demonstrate that presenting anti-CD28 in the cell periphery, surrounding an anti-CD3 feature, enhances IL-2 secretion by naïve CD4+ T cells compared with having these signals combined in the center of the IS. This increased cytokine production correlates with NF-κB translocation and requires PKB/Akt signaling. The ability to arbitrarily and independently control the locations of anti-CD3 and anti-CD28 offered the opportunity to examine patterns not precisely attainable in cell–cell interfaces. With these patterns, we show that the peripheral presentation of CD28 has a larger impact on IL-2 secretion than CD3 colocalization/segregation. PMID:18505845

  1. Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model.

    PubMed

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-06-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

  2. Importance of B cell co-stimulation in CD4+ T cell differentiation: X-linked agammaglobulinaemia, a human model

    PubMed Central

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-01-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann–Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4+CD45RO+ and CD4+CD45RO+CXCR5+ cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

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

    PubMed

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

    2016-09-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Caza, Tiffany; Landas, Steve

    2015-01-01

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

  6. Control of Experimental Autoimmune Encephalomyelitis by CD4+ Suppressor T Cells: Peripheral versus in situ Immunoregulation

    PubMed Central

    Bynoe, Margaret S.; Bonorino, Paula; Viret, Christophe

    2007-01-01

    The pathogenesis of experimental autoimmune encephalomyelitis (EAE) can be efficiently kept under control by specialized subsets of CD4+ T lymphocytes able to negatively regulate the function of T cells with encephalitogenic potential. A number of observations support a role for such suppressor T cells in controlling early phases of disease development at the level of peripheral lymphoid organs but there is also evidence suggesting immunoregulation within the central nervous system (CNS) microenvironment itself. This review evaluates the sites of regulation based on available data from distinct experimental models. We then discuss these aspects with reference to suppressor CD4+ T cells induced through the epicutaneous application of pure CNS antigens that confer long term protection against EAE. Finally, we give an overview of genes recently discovered to be important in regulation of the immune system that may also prove to be key players in the modulation of EAE and MS. PMID:17900707

  7. Novel autoantigens for diabetogenic CD4 T cells in autoimmune diabetes

    PubMed Central

    Delong, Thomas; Baker, Rocky L; He, Jing; Haskins, Kathryn

    2013-01-01

    Autoreactive CD4 T cells play a central role in the development of type 1 diabetes. The BDC-panel of diabetogenic T cell clones was originally isolated from non-obese diabetic (NOD) mice and has been used to study the role of autoreactive CD4 T cells and T cell autoantigens in the development of diabetes. Recent studies by our group have led to the identification of two new target antigens for clones of this panel. This review describes the proteomic strategy used for antigen identification, the antigens identified, and the potential contribution of post-translational modification to autoantigen generation. In addition, we compare peptide epitopes for the T cell clones and discuss their potential applications in investigating the role of T cell autoantigens in the pathogenesis and regulation of disease. PMID:22971988

  8. Nackt (nkt), a new hair loss mutation of the mouse with associated CD4 deficiency.

    PubMed

    Benavides, F; Giordano, M; Fiette, L; Bueno Brunialti, A L; Martin Palenzuela, N; Vanzulli, S; Baldi, P; Schmidt, R; Dosne Pasqualini, C; Guénet, J

    1999-05-01

    A spontaneous recessive mutation named nackt (symbol: nkt) affecting hair growth and T-cell development was discovered in a moderately inbred stock of mice. Skin lesions were characterized by sparse rough coat, bare patches around the eyes and neck, and a scratching behavior throughout life. Fluorescence-activated cell sorter analysis indicated a deficiency in the CD4(+) 8(-) T-cell subset in the thymus and a marked decrease in CD4(+) T cells in peripheral lymphoid organs. Linkage analysis using a set of molecular markers and an F2 intersubspecific cross indicated that the mutation maps to the central region of mouse chromosome 13, in a region homologous to human chromosome 5q22-q35. PMID:10199917

  9. CD4-independent, CCR5-dependent infection of brain capillary endothelial cells by a neurovirulent simian immunodeficiency virus strain

    PubMed Central

    Edinger, Aimee L.; Mankowski, Joseph L.; Doranz, Benjamin J.; Margulies, Barry J.; Lee, Benhur; Rucker, Joseph; Sharron, Matthew; Hoffman, Trevor L.; Berson, Joanne F.; Zink, M. Christine; Hirsch, Vanessa M.; Clements, Janice E.; Doms, Robert W.

    1997-01-01

    Brain capillary endothelial cells (BCECs) are targets of CD4-independent infection by HIV-1 and simian immunodeficiency virus (SIV) strains in vitro and in vivo. Infection of BCECs may provide a portal of entry for the virus into the central nervous system and could disrupt blood–brain barrier function, contributing to the development of AIDS dementia. We found that rhesus macaque BCECs express chemokine receptors involved in HIV and SIV entry including CCR5, CCR3, CXCR4, and STRL33, but not CCR2b, GPR1, or GPR15. Infection of BCECs by the neurovirulent strain SIV/17E-Fr was completely inhibited by aminooxypentane regulation upon activation, normal T cell expression and secretion in the presence or absence of ligands, but not by eotaxin or antibodies to CD4. We found that the envelope (env) proteins from SIV/17E-Fr and several additional SIV strains mediated cell–cell fusion and virus infection with CD4-negative, CCR5-positive cells. In contrast, fusion with cells expressing the coreceptors STRL33, GPR1, and GPR15 was CD4-dependent. These results show that CCR5 can serve as a primary receptor for SIV in BCECs and suggest a possible CD4-independent mechanism for blood–brain barrier disruption and viral entry into the central nervous system. PMID:9405683

  10. Human bone marrow as a source to generate CMV-specific CD4+ T cells with multifunctional capacity.

    PubMed

    Na, Il-Kang; Letsch, Anne; Guerreiro, Manuel; Bauer, Sandra; Noack, Ines; Geginat, Jens; Reinke, Petra; Loesch, Michael; Kienapfel, Heino; Thiel, Eckhard; Volk, Hans Dieter; Scheibenbogen, Carmen

    2009-01-01

    The bone marrow (BM) is an important compartment for T cell memory. In cytomegalovirus (CMV)-seropositive individuals peripheral blood (PB) CMV-specific T cells constitute a large fraction of PB T cells but are mostly differentiated effector/effector memory T cells with limited survival and proliferative potential. In this study, we performed a comprehensive analysis of the CMV-specific T cell response in BM studying both CD4+ and CD8+ T cell responses against overlapping peptide pools of the CMV proteins pp65 and immediate early protein-1. CMV-specific T cell responses were characterized ex vivo and after in vitro expansion of paired PB/BM samples by multiparameter flow cytometry determining surface phenotype, cytokine profile, and cytotoxic capability. Comparable frequencies of CMV-specific T cells were found in un-manipulated PB and BM. Both total CD4+ and CD8+ T cells could be more rapidly expanded from BM. Expanded BM T cells contained significantly higher frequencies of CMV-specific CD4+ T cells than PB. Furthermore, higher frequencies of specific CD4+ T cells from BM were multifunctional, characterized by simultaneous production of interferon-gamma, tumor necrosis factor, and interleukin-2. Use of BM may thus facilitate more rapid generation of adoptive T cells with enhanced functionality. PMID:19816191

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

    PubMed Central

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

    2016-01-01

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

  12. The ontogeny of naïve and regulatory CD4+ T-cell subsets during the first postnatal year: a cohort study

    PubMed Central

    Collier, Fiona M; Tang, Mimi L K; Martino, David; Saffery, Richard; Carlin, John; Jachno, Kim; Ranganathan, Sarath; Burgner, David; Allen, Katrina J; Vuillermin, Peter; Ponsonby, Anne-Louise

    2015-01-01

    As there is limited knowledge regarding the longitudinal development and early ontogeny of naïve and regulatory CD4+ T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naïve (thymic and central) and regulatory (resting and activated) CD4+ T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 and 12 months of age from a population-derived sample of 130 infants. The proportion of naïve and regulatory CD4+ T-cell populations was determined by flow cytometry, and the thymic and central naïve populations were sorted and their phenotype confirmed by relative expression of T cell-receptor excision circle DNA (TREC). At birth, the majority (94%) of CD4+ T cells were naïve (CD45RA+), and of these, ~80% had a thymic naïve phenotype (CD31+ and high TREC), with the remainder already central naïve cells (CD31− and low TREC). During the first year of life, the naïve CD4+ T cells retained an overall thymic phenotype but decreased steadily. From birth to 6 months of age, the proportion of both resting naïve T regulatory cells (rTreg; CD4+CD45RA+FoxP3+) and activated Treg (aTreg, CD4+CD45RA−FoxP3high) increased markedly. The ratio of thymic to central naïve CD4+ T cells was lower in males throughout the first postnatal year indicating early sexual dimorphism in immune development. This longitudinal study defines proportions of CD4+ T-cell populations during the first year of postnatal life that provide a better understanding of normal immune development. PMID:25859389

  13. Impairment of visual memory for objects in natural scenes by simulated central scotomata.

    PubMed

    Geringswald, Franziska; Porracin, Eleonora; Pollmann, Stefan

    2016-01-01

    Because of the close link between foveal vision and the spatial deployment of attention, typically only objects that have been foveated during scene exploration may form detailed and persistent memory representations. In a recent study on patients suffering from age-related macular degeneration, however, we found surprisingly accurate visual long-term memory for objects in scenes. Normal exploration patterns that the patients had learned to rereference saccade targets to an extrafoveal retinal location. This rereferencing may allow use of an extrafoveal location as a focus of attention for efficient object encoding into long-term memory. Here, we tested this hypothesis in normal-sighted observers with gaze-contingent central scotoma simulations. As these observers were inexperienced in scene exploration with central vision loss and had not developed saccadic rereferencing, we expected deficits in long-term memory for objects. We used the same change detection task as in our patient study, probing sensitivity to object changes after a period of free scene exploration. Change detection performance was significantly reduced for two types of scotoma simulation diminishing foveal and parafoveal vision--a visible gray disc and a more subtle image warping--compared with unimpaired controls, confirming our hypothesis. The impact of a smaller scotoma covering specifically foveal vision was less distinct, leading to a marginally significant decrease of long-term memory performance compared with controls. We conclude that attentive encoding of objects is deficient when central vision is lost as long as successful saccadic rereferencing has not yet developed. PMID:27002551

  14. Th1/17 Polarization of CD4 T Cells Supports HIV-1 Persistence during Antiretroviral Therapy

    PubMed Central

    Sun, Hong; Kim, Dhohyung; Li, Xiaodong; Kiselinova, Maja; Ouyang, Zhengyu; Vandekerckhove, Linos; Shang, Hong; Rosenberg, Eric S.; Yu, Xu G.

    2015-01-01

    ABSTRACT The ability to persist long term in latently infected CD4 T cells represents a characteristic feature of HIV-1 infection and the predominant barrier to efforts aiming at viral eradication and cure. Yet, increasing evidence suggests that only small subsets of CD4 T cells with specific developmental and maturational profiles are able to effectively support HIV-1 long-term persistence. Here, we analyzed how the functional polarization of CD4 T cells shapes and structures the reservoirs of HIV-1-infected cells. We found that CD4 T cells enriched for a Th1/17 polarization had elevated susceptibilities to HIV-1 infection in ex vivo assays, harbored high levels of HIV-1 DNA in persons treated with antiretroviral therapy, and made a disproportionately increased contribution to the viral reservoir relative to their contribution to the CD4 T memory cell pool. Moreover, HIV-1 DNA levels in Th1/17 cells remained stable over many years of antiretroviral therapy, resulting in a progressively increasing contribution of these cells to the viral reservoir, and phylogenetic studies suggested preferential long-term persistence of identical viral sequences during prolonged antiretroviral treatment in this cell compartment. Together, these data suggest that Th1/17 CD4 T cells represent a preferred site for HIV-1 DNA long-term persistence in patients receiving antiretroviral therapy. IMPORTANCE Current antiretroviral therapy is very effective in suppressing active HIV-1 replication but does not fully eliminate virally infected cells. The ability of HIV-1 to persist long term despite suppressive antiretroviral combination therapy represents a perplexing aspect of HIV-1 disease pathogenesis, since most HIV-1 target cells are activated, short-lived CD4 T cells. This study suggests that CD4 T helper cells with Th1/17 polarization have a preferential role as a long-term reservoir for HIV-1 infection during antiretroviral therapy, possibly because these cells may imitate some of the

  15. The central role of heat shock factor 1 in synaptic fidelity and memory consolidation.

    PubMed

    Hooper, Philip L; Durham, Heather D; Török, Zsolt; Hooper, Paul L; Crul, Tim; Vígh, László

    2016-09-01

    Networks of neuronal synapses are the fundamental basis for making and retaining memory. Reduced synapse number and quality correlates with loss of memory in dementia. Heat shock factor 1 (HSF1), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fidelity and function, and in memory consolidation. Support for this thesis is based on these observations: (1) heat shock induces improvements in synapse integrity and memory consolidation; (2) synaptic depolarization activates HSF1; (3) activation of HSF1 alone (independent of the canonical heat shock response) augments formation of essential synaptic elements-neuroligands, vesicle transport, synaptic scaffolding proteins, lipid rafts, synaptic spines, and axodendritic synapses; (4) HSF1 coalesces and activates memory receptors in the post-synaptic dendritic spine; (5) huntingtin or α-synuclein accumulation lowers HSF1 while HSF1 lowers huntingtin and α-synuclein aggregation-a potential vicious cycle; and (6) HSF1 agonists (including physical activity) can improve cognitive function in dementia models. Thus, via direct gene expression of synaptic elements, production of HSPs that assure high protein fidelity, and activation of other neuroprotective signaling pathways, HSF1 agonists could provide breakthrough therapy for dementia-associated disease. PMID:27283588

  16. CD8+ cell depletion of SHIV89.6P-infected macaques induces CD4+ T cell proliferation that contributes to increased viral loads

    PubMed Central

    Mueller, Yvonne M.; Do, Duc H.; Boyer, Jean D.; Kader, Muhamuda; Mattapallil, Joseph J.; Lewis, Mark G.; Weiner, David B.; Katsikis, Peter D.

    2009-01-01

    Previous studies have shown that depletion of CD8+ cells during acute and chronic simian immunodeficiency virus (SIV) infection leads to increased viral replication, morbidity and mortality which have been attributed to loss of CD8+ T cell-mediated control of SIV virus. However, these studies did not exclude that CD8+ cell depletion increased homeostatic proliferation of CD4+ T cells, resulting in increased viral targets and therefore viral rebound. Chronically SHIV89.6P-infected cynomolgus macaques were CD8+ cell-depleted and frequencies, cell numbers and phenotype of CD4+ T cells and viral infection were examined using flow cytometry and quantitative real-time PCR. Frequencies and numbers of Ki-67-expressing CD4+ T cells were increased with CD8+ cell depletion. This proliferation of CD4+ T cells occurred even in animals with no rebound of viral loads. Most of the proliferating cells were effector memory CD4+ T cells. Plasma SHIV RNA copies positively correlated with proliferating CD4+ T cells and SHIV DNA copies in Ki-67+ CD4+ T cells. Although this study does not exclude an important role for virus-specific CD8+ T cells in SIV and SHIV infection, our data suggest that homeostatic proliferation is an important contributor to increases in plasma viremia that follow CD8+ cell depletion. PMID:19786539

  17. Input to verbal working memory: Preattentive construction of the central speech representation.

    PubMed

    Jacobsen, Thomas; Schröger, Erich

    2004-01-01

    Working memory uses central sound representations as an informational basis. The central sound representation is the temporally and feature-integrated mental representation that corresponds to phenomenal perception. It is used in (higher-order) mental operations and stored in long-term memory. In the bottom-up processing path, the central sound representation can be probed at the level of auditory sensory memory with the mismatch negativity (MMN) of the event-related potential. The present paper reviews a newly developed MMN paradigm to tap into the processing of speech sound representations. Preattentive vowel categorization based on F1-F2 formant information occurs in speech sounds and complex tones even under conditions of high variability of the auditory input. However, an additional experiment demonstrated the limits of the preattentive categorization of language-relevant information. It tested whether the system categorizes complex tones containing the F1 and F2 formant components of the vowel /a/ differently than six sounds with nonlanguage-like F1-F2 combinations. From the absence of an MMN in this experiment, it is concluded that no adequate vowel representation was constructed. This shows limitations of the capability of preattentive vowel categorization. PMID:15620224

  18. Effects of human immunodeficiency virus type 1 on CD4 lymphocyte subset activation.

    PubMed

    Masci, A M; Paz, F L; Borriello, A; Cassano, S; Della Pietra, V; Stoiber, H; Matarese, G; Della Ragione, F; Zappacosta, S; Racioppi, L

    1999-06-01

    The pathogenesis of the decline of CD4 lymphocyte counts accompanying the typical course of HIV-1 infection is not completely defined and might be related to a differential susceptibility of naive and memory cells to HIV-1 exposure. Here, we examined the effects induced by heat-inactivated HIV-1 virions on these lymphocyte populations. Exposure of CD45RA naive T cells to inactivated viral particles induced a marked decrease of both mitogenic responses and activation-induced apoptosis. Conversely, the growth of CD45RO cells was less severely restrained. Analysis of intracellular levels of cell cycle regulatory proteins revealed an arrest at the G1/S restriction point of the naive but not memory subset. This effect was associated with alterations in phosphotyrosine profile and with a marked decrease of ERK and NJK kinase activation. Finally, up-regulation of the cAMP-dependent protein kinase A (PKA) activity induced by mitogens was not affected by virus. Altogether, these findings show that interaction of HIV-1 with the T cell surface is sufficient to inhibit the proliferative response of the CD4CD45RA subset by disturbing proximal TCR signaling. This mechanism would affect renewal of naive lymphocytes, contributing in such a way to the impairment of T cell turnover during the course of HIV-1 infection. PMID:10382750

  19. Biomarkers of CD4+ CTL cell Mediated Immunity to Tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The immune responses mediated by interactions between T-lymphocyte subsets and mycobacteria-infected macrophages are critical for control of tuberculosis. In these studies, the bovine model was used to characterize the cytolytic and mycobactericidal CD4+ T cell response induced by BCG vaccination. ...

  20. Isolation and Th17 Differentiation of Naïve CD4 T Lymphocytes

    PubMed Central

    Collins, Erin L.; Lau, Kenneth; Larkin, Joseph

    2013-01-01

    Th17 cells are a distinct subset of T cells that have been found to produce interleukin 17 (IL-17), and differ in function from the other T cell subsets including Th1, Th2, and regulatory T cells. Th17 cells have emerged as a central culprit in overzealous inflammatory immune responses associated with many autoimmune disorders. In this method we purify T lymphocytes from the spleen and lymph nodes of C57BL/6 mice, and stimulate purified CD4+ T cells under control and Th17-inducing environments. The Th17-inducing environment includes stimulation in the presence of anti-CD3 and anti-CD28 antibodies, IL-6, and TGF-β. After incubation for at least 72 hours and for up to five days at 37 °C, cells are subsequently analyzed for the capability to produce IL-17 through flow cytometry, qPCR, and ELISAs. Th17 differentiated CD4+CD25- T cells can be utilized to further elucidate the role that Th17 cells play in the onset and progression of autoimmunity and host defense. Moreover, Th17 differentiation of CD4+CD25- lymphocytes from distinct murine knockout/disease models can contribute to our understanding of cell fate plasticity. PMID:24121559

  1. Infection frequency of dendritic cells and CD4+ T lymphocytes in spleens of human immunodeficiency virus-positive patients.

    PubMed Central

    McIlroy, D; Autran, B; Cheynier, R; Wain-Hobson, S; Clauvel, J P; Oksenhendler, E; Debré, P; Hosmalin, A

    1995-01-01

    Dendritic cells (DC) are specialized antigen-presenting leukocytes that are responsible for the activation of naive as well as memory T lymphocytes. If infected by human immunodeficiency virus (HIV), DC may transfer virus to CD4+ lymphocytes. However, the question of whether DC are infected in vivo is controversial. As HIV infection is more active in secondary lymphoid organs than in blood, infection of splenic DC isolated from HIV-seropositive patients was investigated. Splenic DC were first enriched and characterized by flow cytometry from HIV- donors. After direct isolation, they were negative for monocyte and T- and B-lymphocyte markers, negative for CD1a, but positive for major histocompatibility complex class II and CD4. After in vitro maturation, major histocompatibility complex class II expression increased, while CD4 expression was lost. Extensive purification from the spleens of seven HIV+ patients was performed by fluorescence-activated cell sorting. The frequency of cells harboring HIV DNA in purified populations was quantified by limiting-dilution PCR. Directly isolated DC (average, 1/3,000; range, 1/720 to 1/18,000) were in each patient 10 to 100 times less infected than CD4+ T lymphocytes (average, 1/52; range, 1/17 to 1/190). On average, 1/1,450 (1/320 to 1/6,100) unseparated mononuclear splenocytes (containing 5% CD4+ lymphocytes) harbored HIV DNA. In conclusion, in these HIV+ patient spleens, DC seem to be infected, but HIV-DNA positive CD4+ T lymphocytes accounted for the vast majority of infected mononuclear splenocytes. PMID:7609039

  2. Non-invasive tracking of CD4+ T cells with a paramagnetic and fluorescent nanoparticle in brain ischemia.

    PubMed

    Jin, Wei-Na; Yang, Xiaoxia; Li, Zhiguo; Li, Minshu; Shi, Samuel Xiang-Yu; Wood, Kristofer; Liu, Qingwei; Fu, Ying; Han, Wei; Xu, Yun; Shi, Fu-Dong; Liu, Qiang

    2016-08-01

    Recent studies have demonstrated that lymphocytes play a key role in ischemic brain injury. However, there is still a lack of viable approaches to non-invasively track infiltrating lymphocytes and reveal their key spatiotemporal events in the inflamed central nervous system (CNS). Here we describe an in vivo imaging approach for sequential monitoring of brain-infiltrating CD4(+) T cells in experimental ischemic stroke. We show that magnetic resonance imaging (MRI) or Xenogen imaging combined with labeling of SPIO-Molday ION Rhodamine-B (MIRB) can be used to monitor the dynamics of CD4(+) T cells in a passive transfer model. MIRB-labeled CD4(+) T cells can be longitudinally visualized in the mouse brain and peripheral organs such as the spleen and liver after cerebral ischemia. Immunostaining of tissue sections showed similar kinetics of MIRB-labeled CD4(+) T cells when compared with in vivo observations. Our results demonstrated the use of MIRB coupled with in vivo imaging as a valid method to track CD4(+) T cells in ischemic brain injury. This approach will facilitate future investigations to identify the dynamics and key spatiotemporal events for brain-infiltrating lymphocytes in CNS inflammatory diseases. PMID:26661207

  3. Non-invasive tracking of CD4+ T cells with a paramagnetic and fluorescent nanoparticle in brain ischemia

    PubMed Central

    Jin, Wei-Na; Yang, Xiaoxia; Li, Zhiguo; Li, Minshu; Shi, Samuel Xiang-Yu; Wood, Kristofer; Fu, Ying; Han, Wei; Xu, Yun; Shi, Fu-Dong; Liu, Qiang

    2015-01-01

    Recent studies have demonstrated that lymphocytes play a key role in ischemic brain injury. However, there is still a lack of viable approaches to non-invasively track infiltrating lymphocytes and reveal their key spatiotemporal events in the inflamed central nervous system (CNS). Here we describe an in vivo imaging approach for sequential monitoring of brain-infiltrating CD4+ T cells in experimental ischemic stroke. We show that magnetic resonance imaging (MRI) or Xenogen imaging combined with labeling of SPIO-Molday ION Rhodamine-B (MIRB) can be used to monitor the dynamics of CD4+ T cells in a passive transfer model. MIRB-labeled CD4+ T cells can be longitudinally visualized in the mouse brain and peripheral organs such as the spleen and liver after cerebral ischemia. Immunostaining of tissue sections showed similar kinetics of MIRB-labeled CD4+ T cells when compared with in vivo observations. Our results demonstrated the use of MIRB coupled with in vivo imaging as a valid method to track CD4+ T cells in ischemic brain injury. This approach will facilitate future investigations to identify the dynamics and key spatiotemporal events for brain-infiltrating lymphocytes in CNS inflammatory diseases. PMID:26661207

  4. CD4+ and CD8+ TCRβ repertoires possess different potentials to generate extraordinarily high-avidity T cells

    PubMed Central

    Nakatsugawa, Munehide; Rahman, Muhammed A.; Yamashita, Yuki; Ochi, Toshiki; Wnuk, Piotr; Tanaka, Shinya; Chamoto, Kenji; Kagoya, Yuki; Saso, Kayoko; Guo, Tingxi; Anczurowski, Mark; Butler, Marcus O.; Hirano, Naoto

    2016-01-01

    Recent high throughput sequencing analysis has revealed that the TCRβ repertoire is largely different between CD8+ and CD4+ T cells. Here, we show that the transduction of SIG35α, the public chain-centric HLA-A*02:01(A2)/MART127–35 TCRα hemichain, conferred A2/MART127–35 reactivity to a substantial subset of both CD8+ and CD4+ T cells regardless of their HLA–A2 positivity. T cells individually reconstituted with SIG35α and different A2/MART127–35 TCRβ genes isolated from CD4+ or CD8+ T cells exhibited a wide range of avidity. Surprisingly, approximately half of the A2/MART127–35 TCRs derived from CD4+ T cells, but none from CD8+ T cells, were stained by A2/MART127–35 monomer and possessed broader cross-reactivity. Our results suggest that the differences in the primary structure of peripheral CD4+ and CD8+ TCRβ repertoire indeed result in the differences in their ability to form extraordinarily high avidity T cells which would otherwise have been deleted by central tolerance. PMID:27030642

  5. Long-term control of CMV retinitis in a patient with idiopathic CD4+ T lymphocytopenia.

    PubMed

    Yashiro, Shigeko; Fujino, Yujiro; Tachikawa, Natsuo; Inamochi, Kazuya; Oka, Shinichi

    2013-04-01

    Cytomegalovirus (CMV) retinitis with idiopathic CD4(+) T lymphocytopenia (ICL) is rare and difficult to control. We report a first case for long-term control of CMV retinitis with ICL using interleukin-2 (IL-2) therapy and succeeded in discontinuation of anti-CMV therapy. A 49-year-old Japanese woman was diagnosed with ICL based on low CD4(+) count (72/μl), negative for HIV-1 and -2 antibodies, and absence of any defined immunodeficiency diseases or immunosuppressive therapy. PCR test of the aqueous humor in the right eye was suggestive of CMV retinitis. She was treated with systemic ganciclovir, but after several relapses of CMV retinitis, rhegmatogenous retinal detachment appeared in the right eye and she became blind in that eye. Three years later, she developed CMV retinitis in the left eye. Although she received systemic and focal anti-CMV treatments, the retinitis showed no improvement. Finally, retinal detachment occurred, and she underwent vitrectomy. IL-2 was injected to increase CD4(+) counts. Because of hyperpyrexia, blepharedema, central scotoma, and color anomaly, we changed to low-dose IL-2 therapy with no side effects. Finally, we succeeded in increasing the CD4(+) count to more than 200/μl after discontinuation of low-dose IL-2 therapy. CMV retinitis never recurred after discontinuation of anti-CMV therapy, with good visual acuity of 20/20 in the left eye. She developed blindness of the first affected right eye, whereas the visual acuity of the left eye remains excellent more than 12 years after the onset of CMV retinitis through the combined use of anti-CMV therapy, IL-2 therapy, and vitrectomy. PMID:22935818

  6. Evolution of the CD4 family: teleost fish possess two divergent forms of CD4 in addition to lymphocyte activation gene-3

    USGS Publications Warehouse

    Laing, K.J.; Zou, J.J.; Purcell, M.K.; Phillips, R.; Secombes, C.J.; Hansen, J.D.

    2006-01-01

    The T cell coreceptor CD4 is a transmembrane glycoprotein belonging to the Ig superfamily and is essential for cell-mediated immunity. Two different genes were identified in rainbow trout that resemble mammalian CD4. One (trout CD4) encodes four extracellular Ig domains reminiscent off mammalian CD4, whereas the other (CD4REL) codes for two Ig domains. Structural motifs within the amino acid sequences suggest that the two Ig domains of CD4REL duplicated to generate the four-domain molecule of CD4 and the related gene, lymphocyte activation gene-3. Here we present evidence that both of these molecules in trout are homologous to mammalian CD4 and that teleosts encode an additional CD4 family member, lymphocyte activation gene-3, which is a marker for activated T cells. The syntenic relationships of similar genes in other teleost and non-fish genomes provide evidence for the likely evolution of CD4-related molecules in vertebrates, with CD4REL likely representing the primordial form in fish. Expression of both CD4 genes is highest in the thymus and spleen, and mRNA expression of these genes is limited to surface IgM- lymphocytes, consistent with a role for T cell functionality. Finally, the intracellular regions of both CD4 and CD4REL possess the canonical CXC motif involved in the interaction off CD4 with p56LCK, implying that similar mechanisms for CD4 + T cell activation are present in all vertebrates. Our results therefore raise new questions about T cell development and functionality in lower vertebrates that cannot be answered by current mammalian models and, thus, is of fundamental importance for understanding the evolution of cell-mediated immunity in gnathosomes. Copyright ?? 2006 by The American Association of Immunologists, Inc.

  7. HIV Controller CD4+ T Cells Respond to Minimal Amounts of Gag Antigen Due to High TCR Avidity

    PubMed Central

    Vingert, Benoît; Lambotte, Olivier; Boufassa, Faroudy; Lemaître, Fabrice; Kwok, William W.; Theodorou, Ioannis; Delfraissy, Jean-François; Thèze, Jacques; Chakrabarti, Lisa A.

    2010-01-01

    HIV controllers are rare individuals who spontaneously control HIV replication in the absence of antiretroviral treatment. Emerging evidence indicates that HIV control is mediated through very active cellular immune responses, though how such responses can persist over time without immune exhaustion is not yet understood. To investigate the nature of memory CD4+ T cells responsible for long-term anti-HIV responses, we characterized the growth kinetics, Vβ repertoire, and avidity for antigen of patient-derived primary CD4+ T cell lines. Specific cell lines were obtained at a high rate for both HIV controllers (16/17) and efficiently treated patients (19/20) in response to the immunodominant Gag293 peptide. However, lines from controllers showed faster growth kinetics than those of treated patients. After normalizing for growth rates, IFN-γ responses directed against the immunodominant Gag293 peptide showed higher functional avidity in HIV controllers, indicating differentiation into highly efficient effector cells. In contrast, responses to Gag161, Gag263, or CMV peptides did not differ between groups. Gag293-specific CD4+ T cells were characterized by a diverse Vβ repertoire, suggesting that multiple clones contributed to the high avidity CD4+ T cell population in controllers. The high functional avidity of the Gag293-specific response could be explained by a high avidity interaction between the TCR and the peptide-MHC complex, as demonstrated by MHC class II tetramer binding. Thus, HIV controllers harbor a pool of memory CD4+ T cells with the intrinsic ability to recognize minimal amounts of Gag antigen, which may explain how they maintain an active antiviral response in the face of very low viremia. PMID:20195518

  8. Evaluation of oral Lanzhou lamb rotavirus vaccine via passive transfusion with CD4(+)/CD8(+) T lymphocytes.

    PubMed

    Du, Jialiang; Lan, Zhiling; Liu, Yueyue; Liu, Yan; Yu, Qingchuan; Li, Yanchao; Guo, Tai

    2016-06-01

    Lanzhou Lamb derived Rotavirus (RV) Vaccine (namely LLR) for children is only used in China. Since there were no reports on evaluation of LLR, even the data of phase IV clinical trial, we proceed the evaluation of LLR through focusing on T-cell to investigate whether LLR could induce the potential function involving in protection as a vaccine. Four groups of nude mice were transfused with CD4(+)/CD8(+) T-cells isolated from LLR-immunized (primed) and LLR-unimmunized (naïve) mice via intraperitonea (i.p.) respectively. Consequently, the adoption mice were challenged with mice-origin wild rotavirus EDIM (Epizootic Diarrhea of Infant Mice) by intragastric administration. Series of fecal/serum samples were collected and viral shedding, then serum IgA/IgG and secreted IgA were assayed. Compared to the mice transfused with T lymphocytes from naïve mice, the nude mice transfused with CD4(+) T lymphocytes from primed mice induce fecal and serum IgA increasing more rapidly, and have a shorter duration of virus shedding too. Whereas, no significant difference in virus clearance was found between the mice transfused with CD8(+) T lymphocytes isolated from primed and naïve mice. Therefore, we cleared the distinct roles of transfused CD4(+)/CD8(+) T lymphocytes for rotavirus clearance in nude mice, that the viral clearance conducted by CD4(+) T lymphocytes. Meanwhile, it has ability to help induction of LLR specific immunogenicity. Comparing with the transfusion of cell from primed and naïve mice, LLR can induce CD4(+) T lymphocytes memory which is a potential index to reflect the immunogenicity and protection, while CD8(+) T lymphocytes remove rotavirus by CTL with little memory ability. PMID:27025573

  9. Optimizing Immunization Strategies for the Induction of Antigen-Specific CD4 and CD8 T Cell Responses for Protection against Intracellular Parasites.

    PubMed

    Hofmeyer, Kimberly A; Duthie, Malcolm S; Laurance, John D; Favila, Michelle A; Van Hoeven, Neal; Coler, Rhea N; Reed, Steven G

    2016-09-01

    Immunization strategies that generate either CD4 or CD8 T cell responses are relatively well described, but less is known with regard to optimizing regimens to induce both CD4 and CD8 memory T cells. Considering the importance of both CD4 and CD8 T cells in the control of intracellular pathogens such as Leishmania donovani, we wanted to identify vaccines that could raise both CD4 and CD8 T cell responses and determine how to configure immunization strategies to generate the best combined protective T cell response. We examined responses generated against the Leishmania vaccine antigen F3 following its administration in either recombinant form with the Toll-like receptor 4 (TLR4) agonist-containing adjuvant formulation GLA-SE (F3+GLA-SE) or as a gene product delivered in an adenoviral vector (Ad5-F3). Homologous immunization strategies using only F3+GLA-SE or Ad5-F3 preferentially generated either CD4 or CD8 T cells, respectively. In contrast, heterologous strategies generated both antigen-specific CD4 and CD8 T cells. Administration of F3+GLA-SE before Ad5-F3 generated the greatest combined CD4 and CD8 responses. Cytotoxic CD8 T cell responses were highest when Th1 cells were generated prior to their induction by Ad5-F3. Finally, a single immunization with a combination of F3+GLA-SE mixed with Ad5-F3 was found to be sufficient to provide protection against experimental L. donovani infection. Taken together, our data delineate immunization regimens that induce antigen-specific CD4 and CD8 T cell memory responses, and identify a single immunization strategy that could be used to rapidly provide protection against intracellular pathogens in regions where access to health care is limited or sporadic. PMID:27466350

  10. CD4 deficits and Disease Course Acceleration can be driven by a collapse of the CD8 response in SIV-infected Rhesus Macaques

    PubMed Central

    Marcondes, Maria Cecilia G.; Sopper, Sieghart; Sauermann, Ulrike; Burdo, Tricia H.; Watry, Debbie; Zandonatti, Michelle; Fox, Howard S.

    2008-01-01

    Objectives Defects in memory CD4+ T cells correlate with development of AIDS in SIV-infected monkeys, but the early events leading to these deficits are unknown. We explored the role of SIV-specific and CD8 cells in the determination of CD4 failure and rapid disease course. Design and Methods Using MamuA*01-restricted Gag and Tat epitope tetramers, we compared the kinetics of specific response in animals with regular (REG) and rapid (RAP) progression. Expression of memory, activation and proliferation markers were examined on the global CD8 pool, as well as on CD4 T cells in those animals. In vivo CD8 depletion in non-MamuA*01 animals was used to investigate CD8 collapse as a leading event on disease progression and CD4 deficits. Results In animals with a rapid disease course, an initial development of SIV-specific CTL is followed by collapse accompanied by global changes in CD8 cells, and occurs in synchrony with the characteristic CD4 deficiencies. Antibody-mediated depletion of CD8 cells early after SIV infection induces similar changes in the CD4 cells and rapid development of AIDS. Conclusions CD8 collapse at acute time points may result in uncontrolled viral load and development of a defective and insufficient CD4 population. Our results indicate that early breakdown in CD8 cells leads to CD4 deficits and rapid progression to AIDS, and suggest that therapeutic approaches should aim at strengthening CD8 T cells early after viral infection. PMID:18614867

  11. Central Engine Memory of Gamma-Ray Bursts and Soft Gamma-Ray Repeaters

    NASA Astrophysics Data System (ADS)

    Zhang, Bin-Bin; Zhang, Bing; Castro-Tirado, Alberto J.

    2016-04-01

    Gamma-ray bursts (GRBs) are bursts of γ-rays generated from relativistic jets launched from catastrophic events such as massive star core collapse or binary compact star coalescence. Previous studies suggested that GRB emission is erratic, with no noticeable memory in the central engine. Here we report a discovery that similar light curve patterns exist within individual bursts for at least some GRBs. Applying the Dynamic Time Warping method, we show that similarity of light curve patterns between pulses of a single burst or between the light curves of a GRB and its X-ray flare can be identified. This suggests that the central engine of at least some GRBs carries “memory” of its activities. We also show that the same technique can identify memory-like emission episodes in the flaring emission in soft gamma-ray repeaters (SGRs), which are believed to be Galactic, highly magnetized neutron stars named magnetars. Such a phenomenon challenges the standard black hole central engine models for GRBs, and suggest a common physical mechanism behind GRBs and SGRs, which points toward a magnetar central engine of GRBs.

  12. Influence of clitoria ternatea extracts on memory and central cholinergic activity in rats.

    PubMed

    Taranalli, A D; Cheeramkuzhy, T C

    2000-01-01

    Clitoria ternatea , commonly known as Shankpushpi, is widely used in the traditional Indian system of medicine as a brain tonic and is believed to promote memory and intelligence. We examined the effectiveness of alcoholic extracts of aerial and root parts of C. ternatea at 300 and 500 mg/kg doses orally in rats in attenuating electroshock-induced amnesia. Extracts at 300 mg/kg dose produced significant memory retention, and the root parts were found to be more effective. In order to delineate the possible mechanism through which C. ternatea elicits the anti-amnesic effects, we studied its influence on central cholinergic activity by estimating the acetylcholine content of the whole brain and acetylcholinesterase activity at different regions of the rat brain, viz., cerebral cortex, midbrain, medulla oblongata and cerebellum. Our results suggest that C. ternatea extracts increase rat brain acetylcholine content and acetyl cholinesterase a ctivity in a similar fashion to the standard cerebro protective drug Pyritinol. PMID:21214440

  13. Comparative analysis of CD4-4B4 and CD4-2H4 lymphocyte subpopulations in HIV negative homosexual, HIV seropositive and healthy subjects.

    PubMed

    Vuillier, F; Lapresle, C; Dighiero, G

    1988-01-01

    A comparative analysis of subsets (4B4 and 2H4) within the CD4 lymphocyte subpopulation was made by double marker analysis among 23 healthy heterosexual, 16 healthy HIV seronegative high-risk homosexuals and 82 HIV seropositive subjects. Data show that the significant increase in CD4 lymphocytes observed among seronegative homosexuals corresponds mainly to an increase in CD4-4B4 positive cells while CD4-2H4 subset levels remain comparable to healthy heterosexual controls. A decrease both in CD4-4B4 and CD4-2H4, parallel to a decrease in CD4 subpopulation, was observed in asymptomatic seropositive carriers (SPC) and patients with ARC syndrome (AIDS-related complex) or AIDS (acquired immunodeficiency syndrome). Interestingly, an absolute decrease in CD4 subpopulation in patients with asymptomatic lymph node enlargement (LAS), is chiefly accounted for by a decrease in CD4-4B4 subset. The values of CD4-2H4 subset are significantly higher than those observed for SPC patients and are close to the normal values. These observations are of interest, as no differences between SPC and LAS patients could be detected when CD3, CD4 and CD8 subpopulations were studied. PMID:2964959

  14. Cell-intrinsic gp130 Signaling on CD4+ T cells Shapes Long-lasting Antiviral Immunity

    PubMed Central

    Harker, James A.; Wong, Kurt A.; Dolgoter, Aleksandr; Zuniga, Elina I.

    2015-01-01

    The interleukin-6 (IL-6) cytokine family utilizes the common signal transduction molecule gp130, which can mediate a diverse range of outcomes. To clarify the role of gp130 signaling in vivo during acute viral infection we infected Cd4-cre Il6stfl/fl mice, in which gp130 is conditionally ablated in T cells, with acute lymphocytic choriomeningitis virus (LCMV). We found that by day 12, but not at day 8, post infection the number of virus specific CD4+ T cells was reduced in the absence of gp130, and this was sustained for up to 2 months post infection. Additionally gp130 deficient TFH had lower expression of Maf, IL-21 and ICOS and this was accompanied by a reduction in the proportion of germinal center B cells and plasmablasts. Remarkably, two months post-infection the proportion of IgG2a/c+ memory B cells and the systemic levels of LCMV-specific IgG2 Abs were dramatically decreased, while there was a corresponding increase in IgG1+ memory B cells and virus-specific IgG1 Abs. In the same animals Gp130 deficient virus specific CD8+ T cells showed a reduced proportion of memory cells, which expressed lower levels of Tcf7, and displayed diminished recall responses on secondary infection. Mixed bone marrow chimeras revealed that the aforementioned gp130 effects on CD4+ T cells were cell-intrinsic. Overall our data show that gp130 signaling in T cells influences the quantity and quality of long lasting CD4+ T cell responses as well as CD8+ T cell and antibody mediated immunity after acute viral infection. PMID:26085685

  15. Distinct Translational Control in CD4+ T Cell Subsets

    PubMed Central

    Yurchenko, Ekaterina; Zheng, Lei; Gandin, Valentina; Topisirovic, Ivan; Li, Shui; Wagner, Carston R.; Sonenberg, Nahum; Piccirillo, Ciriaco A.

    2013-01-01

    Regulatory T cells expressing the transcription factor Foxp3 play indispensable roles for the induction and maintenance of immunological self-tolerance and immune homeostasis. Genome-wide mRNA expression studies have defined canonical signatures of T cell subsets. Changes in steady-state mRNA levels, however, often do not reflect those of corresponding proteins due to post-transcriptional mechanisms including mRNA translation. Here, we unveil a unique translational signature, contrasting CD4+Foxp3+ regulatory T (TFoxp3+) and CD4+Foxp3− non-regulatory T (TFoxp3−) cells, which imprints subset-specific protein expression. We further show that translation of eukaryotic translation initiation factor 4E (eIF4E) is induced during T cell activation and, in turn, regulates translation of cell cycle related mRNAs and proliferation in both TFoxp3− and TFoxp3+ cells. Unexpectedly, eIF4E also affects Foxp3 expression and thereby lineage identity. Thus, mRNA–specific translational control directs both common and distinct cellular processes in CD4+ T cell subsets. PMID:23658533

  16. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  17. CD4+ and CD8+ T Cell Activation Are Associated with HIV DNA in Resting CD4+ T Cells

    PubMed Central

    Cockerham, Leslie R.; Siliciano, Janet D.; Sinclair, Elizabeth; O'Doherty, Una; Palmer, Sarah; Yukl, Steven A.; Strain, Matt C.; Chomont, Nicolas; Hecht, Frederick M.; Siliciano, Robert F.; Richman, Douglas D.; Deeks, Steven G.

    2014-01-01

    The association between the host immune environment and the size of the HIV reservoir during effective antiretroviral therapy is not clear. Progress has also been limited by the lack of a well-accepted assay for quantifying HIV during therapy. We examined the association between multiple measurements of HIV and T cell activation (as defined by markers including CD38, HLA-DR, CCR5 and PD-1) in 30 antiretroviral-treated HIV-infected adults. We found a consistent association between the frequency of CD4+ and CD8+ T cells expressing HLA-DR and the frequency of resting CD4+ T cells containing HIV DNA. This study highlights the need to further examine this relationship and to better characterize the biology of markers commonly used in HIV studies. These results may also have implications for reactivation strategies. PMID:25340755

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

    PubMed

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

    2016-03-01

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

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

    PubMed Central

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

    2016-01-01

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

  20. Cytomegalovirus-Associated CD4(+) CD28(null) Cells in NKG2D-Dependent Glomerular Endothelial Injury and Kidney Allograft Dysfunction.

    PubMed

    Shabir, S; Smith, H; Kaul, B; Pachnio, A; Jham, S; Kuravi, S; Ball, S; Chand, S; Moss, P; Harper, L; Borrows, R

    2016-04-01

    Emerging data suggest that expansion of a circulating population of atypical, cytotoxic CD4(+) T cells lacking costimulatory CD28 (CD4(+) CD28(null) cells) is associated with latent cytomegalovirus (CMV) infection. The purpose of the current study was to increase the understanding of the relevance of these cells in 100 unselected kidney transplant recipients followed prospectively for a median of 54 months. Multicolor flow cytometry of peripheral blood mononuclear cells before transplantation and serially posttransplantation was undertaken. CD4(+) CD28(null) cells were found predominantly in CMV-seropositive patients and expanded in the posttransplantation period. These cells were predominantly effector-memory phenotype and expressed markers of endothelial homing (CX3CR1) and cytotoxicity (NKG2D and perforin). Isolated CD4(+) CD27(-) CD28(null) cells proliferated in response to peripheral blood mononuclear cells previously exposed to CMV-derived (but not HLA-derived) antigens and following such priming incubation with glomerular endothelium resulted in signs of endothelial damage and apoptosis (release of fractalkine and von Willebrand factor; increased caspase 3 expression). This effect was mitigated by NKG2D-blocking antibody. Increased CD4(+) CD28(null) cell frequencies were associated with delayed graft function and lower estimated glomerular filtration rate at end follow-up. This study suggests an important role for this atypical cytotoxic CD4(+) CD28(null) cell subset in kidney transplantation and points to strategies that may minimize the impact on clinical outcomes. PMID:26603521

  1. CD4+ CCR5+ and CD4+ CCR3+ lymphocyte subset and monocyte apoptosis in patients with acute visceral leishmaniasis

    PubMed Central

    Potestio, Marcella; D'Agostino, Pietro; Romano, Giuseppina Colonna; Milano, Salvatore; Ferlazzo, Viviana; Aquino, Alessandra; Di Bella, Gloria; Caruso, Rosalba; Gambino, Giuseppe; Vitale, Giustina; Mansueto, Serafino; Cillari, Enrico

    2004-01-01

    The potential involvement of apoptosis in the pathogenesis of visceral leishmaniasis (VL) was examined by studying spontaneous and Leishmania antigen (LAg)-induced apoptosis using cryopreserved peripheral blood mononuclear cells (PBMC) of Sicilian patients with VL. Results indicate that monocytes and T lymphocytes from acute VL patients show a significantly higher level of apoptosis compared with that observed in healed subjects. The percentage of apoptotic cells was higher in monocytes than in T lymphocytes. T cells involved in programmed cell death (PCD) were mainly of the CD4+ phenotype. In particular, the T helper 1-type (Th1) subset, as evaluated by chemokine receptor-5 (CCR5) expression, is involved in this process. Cell death in Th1-type uses a CD95-mediated mechanism. Furthermore, Th1-type CCR5+ cells are prone to cell suicide in an autocrine or paracrine way, as attested by enhanced expression of CD95L in acute VL patients. The reduction in Th1-type cells by apoptosis was confirmed by the decrease in interferon-γ secretion. In conclusion, apoptosis of monocytes, CD4+ and CD4+ CCR5+ T cells could be involved in the failure of cell mediated immunity that is responsible for severe immune-depression in VL. PMID:15379987

  2. A monoclonal antibody to CD4 domain 2 blocks soluble CD4-induced conformational changes in the envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) and HIV-1 infection of CD4+ cells.

    PubMed Central

    Moore, J P; Sattentau, Q J; Klasse, P J; Burkly, L C

    1992-01-01

    The murine monoclonal antibody (MAb) 5A8, which is reactive with domain 2 of CD4, blocks human immunodeficiency virus type 1 (HIV-1) infection and syncytium formation of CD4+ cells (L. C. Burkly, D. Olson, R. Shapiro, G. Winkler, J. J. Rosa, D. W. Thomas, C. Williams, and P. Chisholm, J. Immunol., in press). Here we show that, in contrast to the CD4 domain 1 MAb 6H10, 5A8 and its Fab fragment do not block soluble CD4 (sCD4) binding to virions, whereas they do inhibit sCD4-induced exposure of cryptic epitopes on gp41 and dissociation of gp120 from virions. Two other MAbs, OKT4 and L120, which are reactive with domains 3 and 4 of CD4, have little or no effect on HIV-1 infection, syncytium formation, or sCD4-induced conformational changes in the envelope glycoproteins. The mechanisms of action of 5A8 and 6H10 can be further distinguished in syncytium inhibition assays: 6H10 blocks competitively, while 5A8 does not. We opine that 5A8 blocks HIV-1 infection and fusion by interfering with conformational changes in gp120/gp41 and/or CD4 that are necessary for virus-cell fusion. Images PMID:1378510

  3. Role of CD4+, CD8+ and double negative T-cells in the protection of SCID/beige mice against respiratory challenge with Rhodococcus equi.

    PubMed Central

    Ross, T L; Balson, G A; Miners, J S; Smith, G D; Shewen, P E; Prescott, J F; Yager, J A

    1996-01-01

    To evaluate the contributions of T-lymphocyte subsets in pulmonary immunity against Rhodococcus equi, C.B-17 SCID/beige mice were adoptively transferred with splenic lymphocytes from congenic BALB/c mice previously infected with R. equi. Spleen cells were enriched for either CD4+ or CD8+ populations before inoculation, Flow cytometry showed that each enriched population contained less than 0.5% cross contamination. Groups of adoptively transferred SCID/beige mice were sacrificed 6 and 13 d after intranasal infection with R. equi. Bacterial clearance was measured in the lungs, liver and spleen. Lesion development was assessed by gross and histopathological score and the fate of transferred cells assessed by flow cytometry and by immunohistochemistry. SCID/beige mice receiving either CD4+ or CD8+ T-cells were able to clear the infection better than control mice. On d 6 post-infection, bacterial numbers were significantly lower in the lungs of CD4+ transferred mice as compared to CD8+ mice. By d 13, both groups had cleared R. equi from all organs. CD4+ cells were however identified in the lung and spleen of CD8+ recipients at d 13 making conclusions about the role of CD8+ cells in R. equi clearance impossible. By contrast, no significant increases in CD8+ lymphocytes were observed in the organs of CD4+ recipients. All mice developed suppurative bronchopneumonia but lesions were most severe in the CD4+ group. Immunohistochemistry and flow cytometry confirmed that CD4+ and CD8+ cells had migrated to the lungs of adoptively transferred mice. Serum antibody against R, equi was not detected by ELISA in the recipients. SCID/beige mice receiving CD4-CD8- cells were unable to clear R. equi. The study supports the suggestion that CD4+ cells have a central role in R. equi clearance in mice. Images Figure 2. Figure 5. PMID:8809381

  4. Intracellular distribution of the envelope glycoprotein of human immunodeficiency virus and its role in the production of cytopathic effect in CD4+ and CD4- human cell lines.

    PubMed Central

    Koga, Y; Sasaki, M; Nakamura, K; Kimura, G; Nomoto, K

    1990-01-01

    Human CD4+ and CD4- monocytoid cell lines were transfected with a constructed plasmid that has the envelope gene of human immunodeficiency virus under the transcriptional control of human metallothionein IIA promoter; the transfected cells were then cloned. These CD4+ and CD4- transfectant cell clones, both of which expressed almost the same amount of gp160 after induction with metal ions, were used for ultrastructural analysis of the distribution of the envelope glycoprotein in the cytoplasm. Immunofluorescence microscopy with an anti-envelope glycoprotein monoclonal antibody showed localized distribution of gp160 in the CD4+ cell clone and diffuse distribution of gp160 in the CD4- cell clone. These observations were substantiated by immunoelectron microscopy, in which the aggregated form of gp160 was observed in the cytoplasm of CD4+ cells but was scarce in that of CD4- cells. A notable finding was that the sites corresponding to the nuclear pores were occupied with aggregates of gp160 in CD4+ cells, exhibiting cytopathic effects. Both freeze-fracture and transmission electron microscopy also showed abnormal morphology around the nuclear pores and perinuclear space. These results support the possibility that such gp160 complexes accumulated around the nuclear pores primarily disturb the transportation of many molecules between the nucleus and the cytoplasm, resulting in a cytopathic effect in the CD4+ cell clone. Images PMID:2204721

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  7. CD4+ and CD8+ T-Cell Responses to Latent Antigen EBNA-1 and Lytic Antigen BZLF-1 during Persistent Lymphocryptovirus Infection of Rhesus Macaques

    PubMed Central

    Leskowitz, R. M.; Zhou, X. Y.; Villinger, F.; Fogg, M. H.; Kaur, A.; Lieberman, P. M.; Wang, F.

    2013-01-01

    Epstein-Barr virus (EBV) infection leads to lifelong viral persistence through its latency in B cells. EBV-specific T cells control reactivations and prevent the development of EBV-associated malignancies in most healthy carriers, but infection can sometimes cause chronic disease and malignant transformation. Epstein-Barr nuclear antigen 1 (EBNA-1) is the only viral protein consistently expressed during all forms of latency and in all EBV-associated malignancies and is a promising target for a therapeutic vaccine. Here, we studied the EBNA-1-specific immune response using the EBV-homologous rhesus lymphocryptovirus (rhLCV) infection in rhesus macaques. We assessed the frequency, phenotype, and cytokine production profiles of rhLCV EBNA-1 (rhEBNA-1)-specific T cells in 15 rhesus macaques and compared them to the lytic antigen of rhLCV BZLF-1 (rhBZLF-1). We were able to detect rhEBNA-1-specific CD4+ and/or CD8+ T cells in 14 of the 15 animals screened. In comparison, all 15 animals had detectable rhBZLF-1 responses. Most peptide-specific CD4+ T cells exhibited a resting phenotype of central memory (TCM), while peptide-specific CD8+ T cells showed a more activated phenotype, belonging mainly to the effector cell subset. By comparing our results to the human EBV immune response, we demonstrate that the rhLCV model is a valid system for studying chronic EBV infection and for the preclinical development of therapeutic vaccines. PMID:23698300

  8. Chimpanzees Immunized with Recombinant Soluble CD4 Develop Anti-Self CD4 Antibody Responses with Anti-Human Immunodeficiency Virus Activity

    NASA Astrophysics Data System (ADS)

    Watanabe, Mamoru; Boyson, Jonathan E.; Lord, Carol I.; Letvin, Norman L.

    1992-06-01

    In view of the efficiency with which human immunodeficiency virus replication can be blocked in vitro with anti-CD4 antibodies, the elicitation of an anti-CD4 antibody response through active immunization might represent a useful therapeutic strategy for AIDS. Here we demonstrate that immunization of chimpanzees with recombinant soluble human CD4 elicited an anti-CD4 antibody response. The elicited antibody bound self CD4 on digitonin-treated but not freshly isolated lymphocytes. Nevertheless, this antibody blocked human immunodeficiency virus replication in chimpanzee and human lymphocytes. These observations suggest that immunization with recombinant soluble CD4 from human immunodeficiency virus-infected humans may be feasible and therapeutically beneficial.

  9. Emergence of CD4 Independence Envelopes and Astrocyte Infection in R5 Simian-Human Immunodeficiency Virus Model of Encephalitis

    PubMed Central

    Zhuang, Ke; Leda, Ana Rachel; Tsai, Lily; Knight, Heather; Harbison, Carole; Gettie, Agegnehu; Blanchard, James; Westmoreland, Susan

    2014-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection in the central nervous system (CNS) is characterized by replication in macrophages or brain microglia that express low levels of the CD4 receptor and is the cause of HIV-associated dementia and related cognitive and motor disorders that affect 20 to 30% of treatment-naive patients with AIDS. Independent viral envelope evolution in the brain has been reported, with the need for robust replication in resident CD4low cells, as well as CD4-negative cells, such as astrocytes, proposed as a major selective pressure. We previously reported giant-cell encephalitis in subtype B and C R5 simian-human immunodeficiency virus (SHIV)-infected macaques (SHIV-induced encephalitis [SHIVE]) that experienced very high chronic viral loads and progressed rapidly to AIDS, with varying degrees of macrophage or microglia infection and activation of these immune cells, as well as astrocytes, in the CNS. In this study, we characterized envelopes (Env) amplified from the brains of subtype B and C R5 SHIVE macaques. We obtained data in support of an association between severe neuropathological changes, robust macrophage and microglia infection, and evolution to CD4 independence. Moreover, the degree of Env CD4 independence appeared to correlate with the extent of astrocyte infection in vivo. These findings further our knowledge of the CNS viral population phenotypes that are associated with the severity of HIV/SHIV-induced neurological injury and improve our understanding of the mechanism of HIV-1 cellular tropism and persistence in the brain. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) infection of astrocytes in the brain has been suggested to be important in HIV persistence and neuropathogenesis but has not been definitively demonstrated in an animal model of HIV-induced encephalitis (HIVE). Here, we describe a new nonhuman primate (NHP) model of R5 simian-human immunodeficiency virus (SHIV)-induced encephalitis

  10. The CD4 and CD3δε Cytosolic Juxtamembrane Regions Are Proximal within a Compact TCR-CD3-pMHC-CD4 Macrocomplex.

    PubMed

    Glassman, Caleb R; Parrish, Heather L; Deshpande, Neha R; Kuhns, Michael S

    2016-06-01

    TCRs relay information about peptides embedded within MHC molecules (pMHC) to the ITAMs of the associated CD3γε, CD3δε, and CD3ζζ signaling modules. CD4 then recruits the Src kinase p56(Lck) (Lck) to the TCR-CD3 complex to phosphorylate the ITAMs, initiate intracellular signaling, and drive CD4(+) T cell fate decisions. Whereas the six ITAMs of CD3ζζ are key determinants of T cell development, activation, and the execution of effector functions, multiple models predict that CD4 recruits Lck proximal to the four ITAMs of the CD3 heterodimers. We tested these models by placing FRET probes at the cytosolic juxtamembrane regions of CD4 and the CD3 subunits to evaluate their relationship upon pMHC engagement in mouse cell lines. The data are consistent with a compact assembly in which CD4 is proximal to CD3δε, CD3ζζ resides behind the TCR, and CD3γε is offset from CD3δε. These results advance our understanding of the architecture of the TCR-CD3-pMHC-CD4 macrocomplex and point to regions of high CD4-Lck + ITAM concentrations therein. The findings thus have implications for TCR signaling, as phosphorylation of the CD3 ITAMs by CD4-associated Lck is important for CD4(+) T cell fate decisions. PMID:27183595

  11. Impact of Distinct Poxvirus Infections on the Specificities and Functionalities of CD4+ T Cell Responses

    PubMed Central

    Siciliano, Nicholas A.; Hersperger, Adam R.; Lacuanan, Aimee M.; Xu, Ren-Huan; Sidney, John; Sette, Alessandro; Sigal, Luis J.

    2014-01-01

    ABSTRACT The factors that determine CD4+ T cell (TCD4+) specificities, functional capacity, and memory persistence in response to complex pathogens remain unclear. We explored these parameters in the C57BL/6 mouse through comparison of two highly related (>92% homology) poxviruses: ectromelia virus (ECTV), a natural mouse pathogen, and vaccinia virus (VACV), a heterologous virus that nevertheless elicits potent immune responses. In addition to elucidating several previously unidentified major histocompatibility complex class II (MHC-II)-restricted epitopes, we observed many qualitative and quantitative differences between the TCD4+ repertoires, including responses not elicited by VACV despite complete sequence conservation. In addition, we observed functional heterogeneity between ECTV- and VACV-specific TCD4+ at both a global and individual epitope level, particularly greater expression of the cytolytic marker CD107a from TCD4+ following ECTV infection. Most striking were differences during the late memory phase where, in contrast to ECTV, VACV infection failed to elicit measurable epitope-specific TCD4+ as determined by intracellular cytokine staining. These findings illustrate the strong influence of epitope-extrinsic factors on TCD4+ responses and memory. IMPORTANCE Much of our understanding concerning host-pathogen relationships in the context of poxvirus infections stems from studies of VACV in mice. However, VACV is not a natural mouse pathogen, and therefore, the relevance of results obtained using this model may be limited. Here, we explored the MHC class II-restricted TCD4+ repertoire induced by mousepox (ECTV) infection and the functional profile of the responding epitope-specific TCD4+, comparing these results to those induced by VACV infection under matched conditions. Despite a high degree of homology between the two viruses, we observed distinct specificity and functional profiles of TCD4+ responses at both acute and memory time points, with VACV

  12. Functional aortic stiffness: role of CD4+ T lymphocytes

    PubMed Central

    Majeed, Beenish A.; Eberson, Lance S.; Tawinwung, Supannikar; Larmonier, Nicolas; Secomb, Timothy W.; Larson, Douglas F.

    2015-01-01

    The immune system is suggested to be essential in vascular remodeling and stiffening. To study the dependence upon lymphocytes in vascular stiffening, we compared an angiotensin II-model of vascular stiffening in normal C57BL/6J mice with lymphocyte-deficient RAG 1−/− mice and additionally characterized the component of vascular stiffness due to vasoconstriction vs. vascular remodeling. Chronic angiotensin II increased aortic pulse wave velocity, effective wall stiffness, and effective Young's modulus in C57BL/6J mice by three-fold but caused no change in the RAG 1−/− mice. These functional measurements were supported by aortic morphometric analysis. Adoptive transfer of CD4+ T helper lymphocytes restored the angiotensin II-mediated aortic stiffening in the RAG 1−/− mice. In order to account for the hydraulic vs. material effects of angiotensin II on pulse wave velocity, subcutaneous osmotic pumps were removed after 21 days of angiotensin II-infusion in the WT mice to achieve normotensive values. The pulse wave velocity (PWV) decreased from three- to two-fold above baseline values up to 7 days following pump removal. This study supports the pivotal role of the CD4+ T-lymphocytes in angiotensin II-mediated vascular stiffening and that angiotensin II-mediated aortic stiffening is due to the additive effect of active vascular smooth muscle vasoconstriction and vascular remodeling. PMID:26379554

  13. Inhibition of HIV replication by pokeweed antiviral protein targeted to CD4+ cells by monoclonal antibodies

    NASA Astrophysics Data System (ADS)

    Zarling, Joyce M.; Moran, Patricia A.; Haffar, Omar; Sias, Joan; Richman, Douglas D.; Spina, Celsa A.; Myers, Dorothea E.; Kuebelbeck, Virginia; Ledbetter, Jeffrey A.; Uckun, Fatih M.

    1990-09-01

    FUNCTIONAL impairment and selective depletion of CD4+ T cells, the hallmark of AIDS, are at least partly caused by human immunodeficiency virus (HIV-1) type 1 binding to the CD4 molecule and infecting CD4+ cells1,2. It may, therefore, be of therapeutic value to target an antiviral agent to CD4+ cells to prevent infection and to inhibit HIV-1 production in patients' CD4+ cells which contain proviral DNA3,4. We report here that HIV-1 replication in normal primary CD4+ T cells can be inhibited by pokeweed antiviral protein, a plant protein of relative molecular mass 30,000 (ref. 5), which inhibits replication of certain plant RNA viruses6-8, and of herpes simplex virus, poliovirus and influenza virus9-11. Targeting pokeweed antiviral protein to CD4+ T cells by conjugating it to monoclonal antibodies reactive with CDS, CD7 or CD4 expressed on CD4+ cells, increased its anti-HIV potency up to 1,000-fold. HIV-1 replication is inhibited at picomolar concentrations of conjugates of pokeweed antiviral protein and monoclonal antibodies, which do not inhibit proliferation of normal CD4+ T cells or CD4-dependent responses. These conjugates inhibit HIV-1 protein synthesis and also strongly inhibit HIV-1 production in activated CD4+ T cells from infected patients.

  14. The role of CD4 on mechanical properties of live cell membrane.

    PubMed

    Bui, Van-Chien; Nguyen, Thi-Huong

    2016-01-01

    Although much progress has been made in the characterization and identification of CD4 functions, its role in mechanical properties of cell membrane remains largely unknown. Here an atomic force microscopy (AFM) was used to investigate the roles of CD4 in the elasticity of the leukemic human Jurkat (clone E6-1) cell membranes. Analysis of the approach force curves with Hertz model for a completely elastic soft sample measured on the selected CD4+ and CD4- cells showed that CD4+ cell membrane was softer than CD4- one. To confirm that CD4 plays a role in altering cell elasticity, human embryonic kidney 293T cells were transiently transfected with wild type (wt) CD4 plasmid before being used in AFM nanoindentation experiments. The results also demonstrated CD4- membrane was stiffer than CD4+ one suggesting that CD4 integrated into plasma membrane and altered its mechanical properties. The study gives insights into the role of CD4 on cell membrane mechanical characteristics and might be helpful for development of cell biology and medicine. PMID:26362701

  15. Smad4 represses the generation of memory-precursor effector T cells but is required for the differentiation of central memory T cells

    PubMed Central

    Cao, J; Zhang, X; Wang, Q; Qiu, G; Hou, C; Wang, J; Cheng, Q; Lan, Y; Han, H; Shen, H; Zhang, Y; Yang, X; Shen, B; Zhang, J

    2015-01-01

    The transcriptional regulation underlying the differentiation of CD8+ effector and memory T cells remains elusive. Here, we show that 18-month-old mice lacking the transcription factor Smad4 (homolog 4 of mothers against decapentaplegic, Drosophila), a key intracellular signaling effector for the TGF-β superfamily, in T cells exhibited lower percentages of CD44hiCD8+ T cells. To explore the role of Smad4 in the activation/memory of CD8+ T cells, 6- to 8-week-old mice with or without Smad4 in T cells were challenged with Listeria monocytogenes. Smad4 deficiency did not affect antigen-specific CD8+ T-cell expansion but led to partially impaired cytotoxic function. Less short-lived effector T cells but more memory-precursor effector T cells were generated in the absence of Smad4. Despite that, Smad4 deficiency led to reduced memory CD8+ T-cell responses. Further exploration revealed that the generation of central memory T cells was impaired in the absence of Smad4 and the cells showed survival issue. In mechanism, Smad4 deficiency led to aberrant transcriptional programs in antigen-specific CD8+ T cells. These findings demonstrated an essential role of Smad4 in the control of effector and memory CD8+ T-cell responses to infection. PMID:26583325

  16. Bioenergetics profile of CD4(+) T cells in relapsing remitting multiple sclerosis subjects.

    PubMed

    De Riccardis, Lidia; Rizzello, Antonia; Ferramosca, Alessandra; Urso, Emanuela; De Robertis, Francesca; Danieli, Antonio; Giudetti, Anna Maria; Trianni, Giorgio; Zara, Vincenzo; Maffia, Michele

    2015-05-20

    Multiple sclerosis (MS) is a chronic inflammatory autoimmune demyelinating disease of the central nervous system. There are four clinical forms of MS, the most common of which is characterized by a relapsing remitting course (RRMS). The etiology of MS is unknown, but many studies suggested that genetic, environmental and infectious agents may contribute to the development of this disease. In experimental autoimmune encephalomyelitis (EAE), the animal model for MS, it has been shown that CD4(+) T cells play a key role in MS pathogenesis. In fact, these cells are able to cross the blood-brain barrier and cause axonal damage with neuronal death. T cell activation critically depends on mitochondrial ATP synthesis and reactive oxygen species (ROS) production. Interestingly, lots of studies linked the oxidative damage arising from mitochondrial changes to neurodegenerative disorders, such as MS. Based on these evidences, this work focused on the metabolic reprogramming of CD4(+) T cells in MS subjects, being this cell population directly implicated in pathogenesis of disease, paying attention to mitochondrial function and response to oxidative stress. Such aspects, once clarified, may open new opportunities for a therapeutic metabolic modulation of MS disorder. PMID:25701681

  17. Decreased percentage of CD4+Foxp3+TGF-β+ and increased percentage of CD4+IL-17+ cells in bronchoalveolar lavage of asthmatics

    PubMed Central

    2014-01-01

    Background Asthma is a chronic inflammatory disorder of the airways with the proven role of Th2 cells in its pathogenesis. The role and characteristic of different subsets of CD4+ cells is much less known. Aim The aim of the study was to analyze the incidence of different subsets of CD4+ T cells, in particular different subsets of CD4+ cells with the co-expression of different cytokines. Methods Twenty five stable asthmatic and twelve age-matched control subjects were recruited to the study. Bronchoscopy and bronchoalveolar lavage (BAL) were performed in all study subjects. CD4+ T cells were isolated from BAL fluid by positive magnetic selection. After stimulation simultaneous expression of TGF-β, FoxP3, CD25, IFN-γ, IL-4, TNF-α (set 1); IL-10, FoxP3, CD25, IFN-γ, IL-4, MIP-1β (set 2); IL-17A, IL-8, IFN-γ, IL-4, MIP-1β (set 3) were measured by flow cytometry. Results The percentage of CD4+ cells co-expressing Foxp3 and TGF-β (CD4+Foxp3+TGF-β+ cells) was significantly lower (P = 0.03), whereas the percentage of CD4+IL-17+ cells (P = 0.008), CD4+IL-17+ IFN-γ+ cells (P = 0.047) and CD4+IL-4+ cells (P = 0.01) were significantly increased in asthmatics compared with that seen in healthy subjects. A significantly higher percentage of CD4+Foxp3+ cells from asthma patients expressed IFN-γ (P = 0.01), IL-4 (P = 0.004) and CD25 (P = 0.04), whereas the percentage of CD4+IL-10+ cells expressing Foxp3 was significantly decreased in asthmatics (P = 0.03). FEV1% predicted correlated negatively with the percentage of CD4+IL-17+ cells (r = -0.33; P = 0.046) and positively with CD4+Foxp3+TGF-β+ cells (r = 0.43; P = 0.01). Conclusions Our results suggest that in the airways of chronic asthma patients there is an imbalance between increased numbers of CD4+IL-17+ cells and Th2 cells and decreased number of CD4+Foxp3+TGF-β+. PMID:25132806

  18. Macrophage entry mediated by HIV Envs from brain and lymphoid tissues is determined by the capacity to use low CD4 levels and overall efficiency of fusion

    SciTech Connect

    Thomas, Elaine R.; Dunfee, Rebecca L.; Stanton, Jennifer; Bogdan, Derek; Taylor, Joann; Kunstman, Kevin; Bell, Jeanne E.; Wolinsky, Steven M.; Gabuzda, Dana . E-mail: dana_gabuzda@dfci.harvard.edu

    2007-03-30

    HIV infects macrophages and microglia in the central nervous system (CNS), which express lower levels of CD4 than CD4+ T cells in peripheral blood. To investigate mechanisms of HIV neurotropism, full-length env genes were cloned from autopsy brain and lymphoid tissues from 4 AIDS patients with HIV-associated dementia (HAD). Characterization of 55 functional Env clones demonstrated that Envs with reduced dependence on CD4 for fusion and viral entry are more frequent in brain compared to lymphoid tissue. Envs that mediated efficient entry into macrophages were frequent in brain but were also present in lymphoid tissue. For most Envs, entry into macrophages correlated with overall fusion activity at all levels of CD4 and CCR5. gp160 nucleotide sequences were compartmentalized in brain versus lymphoid tissue within each patient. Proline at position 308 in the V3 loop of gp120 was associated with brain compartmentalization in 3 patients, but mutagenesis studies suggested that P308 alone does not contribute to reduced CD4 dependence or macrophage-tropism. These results suggest that HIV adaptation to replicate in the CNS selects for Envs with reduced CD4 dependence and increased fusion activity. Macrophage-tropic Envs are frequent in brain but are also present in lymphoid tissues of AIDS patients with HAD, and entry into macrophages in the CNS and other tissues is dependent on the ability to use low receptor levels and overall efficiency of fusion.

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

    PubMed

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

    2010-08-15

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

  20. CMV-specific central memory T cells reside in bone marrow.

    PubMed

    Letsch, Anne; Knoedler, Maren; Na, Il-Kang; Kern, Florian; Asemissen, Anne-Marie; Keilholz, Ulrich; Loesch, Michael; Thiel, Eckhard; Volk, Hans-Dieter; Scheibenbogen, Carmen

    2007-11-01

    CMV-specific CD8(+) T cell responses in peripheral blood (PB) are characterized by a preponderance of effector and effector memory T cells. CMV-specific central memory T cells (T(CM)), which are considered crucial in maintaining long-term immunity, are rarely detectable in PB. In this study we have analyzed differentiation and function of CMV pp65-specific CD8(+) T cells in paired samples of human PB and BM using intracellular cytokine and tetramer staining. Overall frequencies of CMV pp65-specific T cells were similar in PB compared to BM; however, CMV-specific CD45RA(-)CCR7(+) T(CM) were almost exclusively detectable in BM, which was not related to a general accumulation of T(CM) in BM. In vitro, CMV-specific T cells could be more efficiently expanded from BM (median 128-fold, n=6) than from PB (median 72-fold, p=0.01). Taken together, these data show that the BM is a compartment harboring CMV-specific T(CM) and underline the concept of the BM as a secondary immune organ. CMV specific BM-derived T(CM) might be a valuable source for generating T cells for adoptive transfer. PMID:17960663

  1. Common clonal origin of central and resident memory T cells following skin immunization

    PubMed Central

    Gaide, Olivier; Emerson, Ryan O.; Jiang, Xiaodong; Gulati, Nicholas; Nizza, Suzanne; Desmarais, Cindy; Robins, Harlan; Krueger, James G.; Clark, Rachael A.; Kupper, Thomas S.

    2015-01-01

    Central memory T (TCM) cells in lymph nodes (LN) and resident memory T (TRM) cells in peripheral tissues play distinct roles in protective immunity1-5. Both are generated after primary infections, but the clonal origin of TRM and TCM cells is unclear. To address this question, mice were immunized through the skin with either a protein antigen, a chemical hapten, or a non-replicating poxvirus. We then analyzed antigen activated T cells from different tissues using high-throughput sequencing (HTS) of the gene (Tcrbv) encoding T cell receptor gene β chain CDR3 region to simultaneously track thousands of unique T cells6. For every abundant TRM clone generated in the skin, an abundant TCM clone bearing the identical TCR was present in lymph nodes (LN). Thus antigen reactive skin TRM and LN TCM clones were derived from a common naive T cell precursor after skin immunization, generating overlapping TCR repertoires. Although they bore the same TCR, TRM mediated rapid contact hypersensitivity (CHS)7 responses in mice, whereas TCM mediated delayed and attenuated responses. Studies in human subjects confirmed the generation of skin TRM in allergic contact dermatitis. Thus, immunization through skin simultaneously generates skin TRM and LN TCM in similar numbers from the same naïve T cells. PMID:25962122

  2. Differential Role of Autophagy in CD4 T Cells and Macrophages during X4 and R5 HIV-1 Infection

    PubMed Central

    Robert-Hebmann, Véronique; Sagnier, Sophie; Robbins, Ian; Sanchez, Françoise; Lafont, Virginie; Biard-Piechaczyk, Martine

    2009-01-01

    Background HIV-1 can infect and replicate in both CD4 T cells and macrophages. In these cell types, HIV-1 entry is mediated by the binding of envelope glycoproteins (gp120 and gp41, Env) to the receptor CD4 and a coreceptor, principally CCR5 or CXCR4, depending on the viral strain (R5 or X4, respectively). Uninfected CD4 T cells undergo X4 Env-mediated autophagy, leading to their apoptosis, a mechanism now recognized as central to immunodeficiency. Methodology/Principal Findings We demonstrate here that autophagy and cell death are also induced in the uninfected CD4 T cells by HIV-1 R5 Env, while autophagy is inhibited in productively X4 or R5-infected CD4 T cells. In contrast, uninfected macrophages, a preserved cell population during HIV-1 infection, do not undergo X4 or R5 Env-mediated autophagy. Autophagosomes, however, are present in macrophages exposed to infectious HIV-1 particles, independently of coreceptor use. Interestingly, we observed two populations of autophagic cells: one highly autophagic and the other weakly autophagic. Surprisingly, viruses could be detected in the weakly autophagic cells but not in the highly autophagic cells. In addition, we show that the triggering of autophagy in macrophages is necessary for viral replication but addition of Bafilomycin A1, which blocks the final stages of autophagy, strongly increases productive infection. Conclusions/Significance Taken together, our data suggest that autophagy plays a complex, but essential, role in HIV pathology by regulating both viral replication and the fate of the target cells. PMID:19492063

  3. Structural Basis for Species Selectivity in the HIV-1 gp120-CD4 Interaction: Restoring Affinity to gp120 in Murine CD4 Mimetic Peptides

    PubMed Central

    Kassler, Kristin; Meier, Julia; Eichler, Jutta; Sticht, Heinrich

    2011-01-01

    The first step of HIV-1 infection involves interaction between the viral glycoprotein gp120 and the human cellular receptor CD4. Inhibition of the gp120-CD4 interaction represents an attractive strategy to block HIV-1 infection. In an attempt to explore the known lack of affinity of murine CD4 to gp120, we have investigated peptides presenting the putative gp120-binding site of murine CD4 (mCD4). Molecular modeling indicates that mCD4 protein cannot bind gp120 due to steric clashes, while the larger conformational flexibility of mCD4 peptides allows an interaction. This finding is confirmed by experimental binding assays, which also evidenced specificity of the peptide-gp120 interaction. Molecular dynamics simulations indicate that the mCD4-peptide stably interacts with gp120 via an intermolecular β-sheet, while an important salt-bridge formed by a C-terminal lysine is lost. Fixation of the C-terminus by introducing a disulfide bridge between the N- and C-termini of the peptide significantly enhanced the affinity to gp120. PMID:22312332

  4. Antileukemia multifunctionality of CD4(+) T cells genetically engineered by HLA class I-restricted and WT1-specific T-cell receptor gene transfer.

    PubMed

    Fujiwara, H; Ochi, T; Ochi, F; Miyazaki, Y; Asai, H; Narita, M; Okamoto, S; Mineno, J; Kuzushima, K; Shiku, H; Yasukawa, M

    2015-12-01

    To develop gene-modified T-cell-based antileukemia adoptive immunotherapy, concomitant administration of CD4(+) and CD8(+) T cells that have been gene modified using identical HLA class I-restricted leukemia antigen-specific T-cell receptor (TCR) gene transfer has not yet been fully investigated. Here, using CD4(+) and CD8(+) T cells that had been gene modified with a retroviral vector expressing HLA-A*24:02-restricted and Wilms' tumor 1 (WT1)-specific TCR-α/β genes and siRNAs for endogenous TCRs (WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells), we examined the utility of this strategy. WT1-siTCR/CD4(+) T cells sufficiently recognized leukemia cells in an HLA class I-restricted manner and provided target-specific Th1 help for WT1-siTCR/CD8(+) T cells. By using a xenografted mouse model, we found that WT1-siTCR/CD4(+) T cells migrated to leukemia sites and subsequently attracted WT1-siTCR/CD8(+) T cells via chemotaxis. Therapy-oriented experiments revealed effective enhancement of leukemia suppression mediated by concomitant administration of WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells. Importantly, this augmented efficacy in the presence of WT1-siTCR/CD4(+) T cells was correlated with longer survival and enhanced formation of memory T cells by WT1-siTCR/CD8(+) T cells. Collectively, our experimental findings strongly suggest that this strategy would be clinically advantageous for the treatment of human leukemia. PMID:26104661

  5. Cytomegalovirus Infection Leads to Development of High Frequencies of Cytotoxic Virus-Specific CD4+ T Cells Targeted to Vascular Endothelium.

    PubMed

    Pachnio, Annette; Ciaurriz, Miriam; Begum, Jusnara; Lal, Neeraj; Zuo, Jianmin; Beggs, Andrew; Moss, Paul

    2016-09-01

    Cytomegalovirus (CMV) infection elicits a very strong and sustained intravascular T cell immune response which may contribute towards development of accelerated immune senescence and vascular disease in older people. Virus-specific CD8+ T cell responses have been investigated extensively through the use of HLA-peptide tetramers but much less is known regarding CMV-specific CD4+ T cells. We used a range of HLA class II-peptide tetramers to investigate the phenotypic and transcriptional profile of CMV-specific CD4+ T cells within healthy donors. We show that such cells comprise an average of 0.45% of the CD4+ T cell pool and can reach up to 24% in some individuals (range 0.01-24%). CMV-specific CD4+ T cells display a highly differentiated effector memory phenotype and express a range of cytokines, dominated by dual TNF-α and IFN-γ expression, although substantial populations which express IL-4 were seen in some donors. Microarray analysis and phenotypic expression revealed a profile of unique features. These include the expression of CX3CR1, which would direct cells towards fractalkine on activated endothelium, and the β2-adrenergic receptor, which could permit rapid response to stress. CMV-specific CD4+ T cells display an intense cytotoxic profile with high level expression of granzyme B and perforin, a pattern which increases further during aging. In addition CMV-specific CD4+ T cells demonstrate strong cytotoxic activity against antigen-loaded target cells when isolated directly ex vivo. PD-1 expression is present on 47% of cells but both the intensity and distribution of the inhibitory receptor is reduced in older people. These findings reveal the marked accumulation and unique phenotype of CMV-specific CD4+ T cells and indicate how such T cells may contribute to the vascular complications associated with CMV in older people. PMID:27606804

  6. Antigen-specific CD4{sup +} effector T cells: Analysis of factors regulating clonal expansion and cytokine production

    SciTech Connect

    Ohnuki, Kazunobu; Watanabe, Yuri; Takahashi, Yusuke; Kobayashi, Sakiko; Watanabe, Shiho; Ogawa, Shuhei; Kotani, Motoko; Kozono, Haruo; Tanabe, Kazunari; Abe, Ryo

    2009-03-20

    In order to fully understand T cell-mediated immunity, the mechanisms that regulate clonal expansion and cytokine production by CD4{sup +} antigen-specific effector T cells in response to a wide range of antigenic stimulation needs clarification. For this purpose, panels of antigen-specific CD4{sup +} T cell clones with different thresholds for antigen-induced proliferation were generated by repeated stimulation with high- or low-dose antigen. Differences in antigen sensitivities did not correlate with expression of TCR, CD4, adhesion or costimulatory molecules. There was no significant difference in antigen-dependent cytokine production by TG40 cells transfected with TCR obtained from either high- or low-dose-responding T cell clones, suggesting that the affinity of TCRs for their ligands is not primary determinant of T cell antigen reactivity. The proliferative responses of all T cell clones to both peptide stimulation and to TCR{beta} crosslinking revealed parallel dose-response curves. These results suggest that the TCR signal strength of effector T cells and threshold of antigen reactivity is determined by an intrinsic property, such as the TCR signalosome and/or intracellular signaling machinery. Finally, the antigen responses of high- and low-peptide-responding T cell clones reveal that clonal expansion and cytokine production of effector T cells occur independently of antigen concentration. Based on these results, the mechanisms underlying selection of high 'avidity' effector and memory T cells in response to pathogen are discussed.

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

    PubMed Central

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

    2014-01-01

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

  8. Expression of the CD4 gene requires a Myb transcription factor.

    PubMed Central

    Siu, G; Wurster, A L; Lipsick, J S; Hedrick, S M

    1992-01-01

    We have analyzed the control of developmental expression of the CD4 gene, which encodes an important recognition molecule and differentiation antigen on T cells. We have determined that the CD4 promoter alone functions at high levels in the CD4+ CD8- mature T cell but not at the early CD4+ CD8+ stage of T-cell development. In addition, the CD4 promoter functions only in T lymphocytes; thus, the stage and tissue specificity of the CD4 gene is mediated in part by its promoter. We have determined that a Myb transcription factor binds to the CD4 promoter and is critical for full promoter function. Thus, Myb plays an important role in the expression of T-cell-specific developmentally regulated genes. Images PMID:1347906

  9. MHC II tetramers visualize human CD4+ T cell responses to Epstein-Barr virus infection and demonstrate atypical kinetics of the nuclear antigen EBNA1 response.

    PubMed

    Long, Heather M; Chagoury, Odette L; Leese, Alison M; Ryan, Gordon B; James, Eddie; Morton, Laura T; Abbott, Rachel J M; Sabbah, Shereen; Kwok, William; Rickinson, Alan B

    2013-05-01

    Virus-specific CD4(+) T cells are key orchestrators of host responses to viral infection yet, compared with their CD8(+) T cell counterparts, remain poorly characterized at the single cell level. Here we use nine MHC II-epitope peptide tetramers to visualize human CD4(+) T cell responses to Epstein-Barr virus (EBV), the causative agent of infectious mononucleosis (IM), a disease associated with large virus-specific CD8(+) T cell responses. We find that, while not approaching virus-specific CD8(+) T cell expansions in magnitude, activated CD4(+) T cells specific for epitopes in the latent antigen EBNA2 and four lytic cycle antigens are detected at high frequencies in acute IM blood. They then fall rapidly to values typical of life-long virus carriage where most tetramer-positive cells display conventional memory markers but some, unexpectedly, revert to a naive-like phenotype. In contrast CD4(+) T cell responses to EBNA1 epitopes are greatly delayed in IM patients, in line with the well-known but hitherto unexplained delay in EBNA1 IgG antibody responses. We present evidence from an in vitro system that may explain these unusual kinetics. Unlike other EBNAs and lytic cycle proteins, EBNA1 is not naturally released from EBV-infected cells as a source of antigen for CD4(+) T cell priming. PMID:23569328

  10. Increased CD4+/CD8+ Double-Positive T Cells in Chronic Chagasic Patients

    PubMed Central

    Giraldo, Nicolas A.; Bolaños, Natalia I.; Cuellar, Adriana; Guzman, Fanny; Uribe, Ana Maria; Bedoya, Astrid; Olaya, Natalia; Cucunubá, Zulma M.; Roa, Nubia; Rosas, Fernando; Velasco, Víctor; Puerta, Concepción J.; González, John M.

    2011-01-01

    Background CD4+/CD8+ double positive (DP) T cells have been described in healthy individuals as well as in patients with autoimmune and chronic infectious diseases. In chronic viral infections, this cell subset has effector memory phenotype and displays antigen specificity. No previous studies of double positive T cells in parasite infections have been carried out. Methodology/Principal Findings Seventeen chronic chagasic patients (7 asymptomatic and 10 symptomatic) and 24 non-infected donors, including 12 healthy and 12 with non-chagasic cardiomyopathy donors were analyzed. Peripheral blood was stained for CD3, CD4, CD8, HLA-DR and CD38, and lymphocytes for intracellular perforin. Antigen specificity was assessed using HLA*A2 tetramers loaded with T. cruzi K1 or influenza virus epitopes. Surface expression of CD107 and intracellular IFN-γ production were determined in K1-specific DP T cells from 11 chagasic donors. Heart tissue from a chronic chagasic patient was stained for both CD8 and CD4 by immunochemistry. Chagasic patients showed higher frequencies of DP T cells (2.1%±0.9) compared with healthy (1.1%±0.5) and non-chagasic cardiomyopathy (1.2%±0.4) donors. DP T cells from Chagasic patients also expressed more HLA-DR, CD38 and perforin and had higher frequencies of T. cruzi K1-specific cells. IFN-γ production in K1-specific cells was higher in asymptomatic patients after polyclonal stimulation, while these cells tended to degranulate more in symptomatic donors. Immunochemistry revealed that double positive T cells infiltrate the cardiac tissue of a chagasic donor. Conclusions Chagasic patients have higher percentages of circulating double positive T cells expressing activation markers, potential effector molecules and greater class I antigenic specificity against T. cruzi. Although K1 tetramer positive DP T cell produced little IFN-γ, they displayed degranulation activity that was increased in symptomatic patients. Moreover, K1-specific DP T cells can

  11. CD4+ T-cell subsets in inflammatory diseases: beyond the Th1/Th2 paradigm.

    PubMed

    Hirahara, Kiyoshi; Nakayama, Toshinori

    2016-04-01

    CD4(+)T cells are crucial for directing appropriate immune responses during host defense and for the pathogenesis of inflammatory diseases. In addition to the classical biphasic model of differentiation of T-helper 1 (Th1) and Th2 cells, unexpected increases in the numbers of CD4(+)T-cell subsets, including Th17, Th9, T follicular-helper (Tfh) and T-regulatory (Treg) cells, have been recognized. In the present review, we focus on how these various T-helper cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. In particular, we focus on multiple sclerosis, psoriasis and asthma as typical model diseases in which multiple T-helper cell subsets have recently been suggested to play a role. We will also discuss various unique sub-populations of T-helper cells that have been identified. First, we will introduce the heterogeneous T-helper cell subsets, which are classified by their simultaneous expression of multiple key transcription factors. We will also introduce different kinds of memory-type Th2 cells, which are involved in the pathogenesis of chronic type-2 immune-related diseases. Finally, we will discuss the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T-helper cell subsets. The latest progress in the study of T-helper cell subsets has forced us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the Th1/Th2 balance. To this end, we propose another model--the pathogenic T-helper population disease-induction model--as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases. PMID:26874355

  12. Processing and Memory of Central versus Peripheral Information as a Function of Reading Goals: Evidence from Eye-Movements

    ERIC Educational Resources Information Center

    Yeari, Menahem; van den Broek, Paul; Oudega, Marja

    2015-01-01

    The present study examined the effect of reading goals on the processing and memory of central and peripheral textual information. Using eye-tracking methodology, we compared the effect of four common reading goals--entertainment, presentation, studying for a close-ended (multiple-choice) questions test, and studying for an open-ended questions…

  13. Working Memory as a Predictor of Written Arithmetical Skills in Children: The Importance of Central Executive Functions

    ERIC Educational Resources Information Center

    Andersson, Ulf

    2008-01-01

    Background: The study was conducted in an attempt to further our understanding of how working memory contributes to written arithmetical skills in children. Aim: The aim was to pinpoint the contribution of different central executive functions and to examine the contribution of the two subcomponents of children's written arithmetical skills.…

  14. The molecular basis of the memory T cell response: differential gene expression and its epigenetic regulation

    PubMed Central

    Weng, Nan-ping; Araki, Yasuto; Subedi, Kalpana

    2015-01-01

    How the immune system remembers a previous encounter with a pathogen and responds more efficiently to a subsequent encounter has been one of the central enigmas for immunologists for over a century. The identification of pathogen-specific memory lymphocytes that arise after an infection provided a cellular basis for immunological memory. But the molecular mechanisms of immunological memory remain only partially understood. The emerging evidence suggests that epigenetic changes have a key role in controlling the distinct transcriptional profiles of memory lymphocytes and thus in shaping their function. In this Review, we summarize the recent progress that has been made in assessing the differential gene expression and chromatin modifications in memory CD4+ and CD8+ T cells, and we present our current understanding of the molecular basis of memory T cell function. PMID:22421787

  15. Tissue-specific expression of human CD4 in transgenic mice.

    PubMed

    Gillespie, F P; Doros, L; Vitale, J; Blackwell, C; Gosselin, J; Snyder, B W; Wadsworth, S C

    1993-05-01

    The gene for the human CD4 glycoprotein, which serves as the receptor for human immunodeficiency virus type 1, along with approximately 23 kb of sequence upstream of the translational start site, was cloned. The ability of 5' flanking sequences to direct tissue-specific expression was tested in cell culture and in transgenic mice. A 5' flanking region of 6 kb was able to direct transcription of the CD4 gene in NIH 3T3 cells but did not result in detectable expression in the murine T-cell line EL4 or in four lines of transgenic mice. A larger 5' flanking region of approximately 23 kb directed high-level CD4 transcription in the murine T-cell line EL4 and in three independent lines of transgenic mice. Human CD4 expression in all tissues analyzed was tightly correlated with murine CD4 expression; the highest levels of human CD4 RNA expression were found in the thymus and spleen, with relatively low levels detected in other tissues. Expression of human CD4 protein in peripheral blood mononuclear cells was examined by flow cytometry in these transgenic animals and found to be restricted to the murine CD4+ subset of lymphocytes. Human CD4 protein, detected with an anti-human CD4 monoclonal antibody, was present on the surface of 45 to 50% of the peripheral blood mononuclear cells from all transgenic lines. PMID:8474453

  16. Crystal Structure of HIV-1 Primary Receptor CD4 i Complex with a Potent Antiviral Antibody

    SciTech Connect

    Freeman, M.M.; Hong, X.; Seaman, M.S.; Rits-Vollock, S.p Kao, C.Y.; Ho, D.D.; Chen, B.

    2010-06-18

    Ibalizumab is a humanized, anti-CD4 monoclonal antibody. It potently blocks HIV-1 infection and targets an epitope in the second domain of CD4 without interfering with immune functions mediated by interaction of CD4 with major histocompatibility complex (MHC) class II molecules. We report here the crystal structure of ibalizumab Fab fragment in complex with the first two domains (D1-D2) of CD4 at 2.2 {angstrom} resolution. Ibalizumab grips CD4 primarily by the BC-loop (residues 121125) of D2, sitting on the opposite side of gp120 and MHC-II binding sites. No major conformational change in CD4 accompanies binding to ibalizumab. Both monovalent and bivalent forms of ibalizumab effectively block viral infection, suggesting that it does not need to crosslink CD4 to exert antiviral activity. While gp120-induced structural rearrangements in CD4 are probably minimal, CD4 structural rigidity is dispensable for ibalizumab inhibition. These results could guide CD4-based immunogen design and lead to a better understanding of HIV-1 entry.

  17. Stabilization of HIV-1 gp120-CD4 receptor complex through targeted interchain disulfide exchange.

    PubMed

    Cerutti, Nichole; Mendelow, Barry V; Napier, Grant B; Papathanasopoulos, Maria A; Killick, Mark; Khati, Makobetsa; Stevens, Wendy; Capovilla, Alexio

    2010-08-13

    HIV-1 enters cells via interaction between the trimeric envelope (Env) glycoprotein gp120/gp41 and the host cell surface receptor molecule CD4. The requirement of CD4 for viral entry has rationalized the development of recombinant CD4-based proteins as competitive viral attachment inhibitors and immunotherapeutic agents. In this study, we describe a novel recombinant CD4 protein designed to bind gp120 through a targeted disulfide-exchange mechanism. According to structural models of the gp120-CD4 receptor complex, substitution of Ser(60) on the CD4 domain 1 alpha-helix with Cys positions a thiol in proximity of the gp120 V1/V2 loop disulfide (Cys(126)-Cys(196)), satisfying the stereochemical and geometric conditions for redox exchange between CD4 Cys(60) and gp120 Cys(126), and the consequent formation of an interchain disulfide bond. In this study, we provide experimental evidence for this effect by describing the expression, purification, refolding, receptor binding and antiviral activity analysis of a recombinant two-domain CD4 variant containing the S60C mutation (2dCD4-S60C). We show that 2dCD4-S60C binds HIV-1 gp120 with a significantly higher affinity than wild-type protein under conditions that facilitate disulfide exchange and that this translates into a corresponding increase in the efficacy of CD4-mediated viral entry inhibition. We propose that targeted redox exchange between conserved gp120 disulfides and nucleophilic moieties positioned strategically on CD4 (or CD4-like scaffolds) conceptualizes a new strategy in the development of high affinity HIV-1 Env ligands, with important implications for therapy and vaccine development. More generally, this chalcogen substitution approach provides a general means of stabilizing receptor-ligand complexes where the structural and biophysical conditions for disulfide exchange are satisfied. PMID:20538591

  18. Stabilization of HIV-1 gp120-CD4 Receptor Complex through Targeted Interchain Disulfide Exchange*

    PubMed Central

    Cerutti, Nichole; Mendelow, Barry V.; Napier, Grant B.; Papathanasopoulos, Maria A.; Killick, Mark; Khati, Makobetsa; Stevens, Wendy; Capovilla, Alexio

    2010-01-01

    HIV-1 enters cells via interaction between the trimeric envelope (Env) glycoprotein gp120/gp41 and the host cell surface receptor molecule CD4. The requirement of CD4 for viral entry has rationalized the development of recombinant CD4-based proteins as competitive viral attachment inhibitors and immunotherapeutic agents. In this study, we describe a novel recombinant CD4 protein designed to bind gp120 through a targeted disulfide-exchange mechanism. According to structural models of the gp120-CD4 receptor complex, substitution of Ser60 on the CD4 domain 1 α-helix with Cys positions a thiol in proximity of the gp120 V1/V2 loop disulfide (Cys126–Cys196), satisfying the stereochemical and geometric conditions for redox exchange between CD4 Cys60 and gp120 Cys126, and the consequent formation of an interchain disulfide bond. In this study, we provide experimental evidence for this effect by describing the expression, purification, refolding, receptor binding and antiviral activity analysis of a recombinant two-domain CD4 variant containing the S60C mutation (2dCD4-S60C). We show that 2dCD4-S60C binds HIV-1 gp120 with a significantly higher affinity than wild-type protein under conditions that facilitate disulfide exchange and that this translates into a corresponding increase in the efficacy of CD4-mediated viral entry inhibition. We propose that targeted redox exchange between conserved gp120 disulfides and nucleophilic moieties positioned strategically on CD4 (or CD4-like scaffolds) conceptualizes a new strategy in the development of high affinity HIV-1 Env ligands, with important implications for therapy and vaccine development. More generally, this chalcogen substitution approach provides a general means of stabilizing receptor-ligand complexes where the structural and biophysical conditions for disulfide exchange are satisfied. PMID:20538591

  19. Conformational Rearrangement Within the Soluble Domains of the CD4 Receptor is Ligand-Specific

    SciTech Connect

    Ashish,F.; Juncadella, I.; Garg, R.; Boone, C.; Anguita, J.; Krueger, J.

    2008-01-01

    Ligand binding induces shape changes within the four modular ectodomains (D1-D4) of the CD4 receptor, an important receptor in immune signaling. Small angle x-ray scattering (SAXS) on both a two-domain and a four-domain construct of the soluble CD4 (sCD4) is consistent with known crystal structures demonstrating a bilobal and a semi-extended tetralobal Z conformation in solution, respectively. Detection of conformational changes within sCD4 as a result of ligand binding was followed by SAXS on sCD4 bound to two different glycoprotein ligands: the tick saliva immunosuppressor Salp15 and the HIV-1 envelope protein gp120. Ab initio modeling of these data showed that both Salp15 and gp120 bind to the D1 domain of sCD4 and yet induce drastically different structural rearrangements. Upon binding, Salp15 primarily distorts the characteristic lobal architecture of the sCD4 without significantly altering the semi-extended shape of the sCD4 receptor. In sharp contrast, the interaction of gp120 with sCD4 induces a shape change within sCD4 that can be described as a Z-to-U bi-fold closure of the four domains across its flexible D2-D3 linker. Placement of known crystal structures within the boundaries of the SAXS-derived models suggests that the ligand-induced shape changes could be a result of conformational changes within this D2-D3 linker. Functionally, the observed shape changes in CD4 receptor causes dissociation of lymphocyte kinase from the cytoplasmic domain of Salp15-bound CD4 and facilitates an interaction between the exposed V3 loops of CD4-bound gp120 molecule to the extracellular loops of its co-receptor, a step essential for HIV-1 viral entry.

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

    PubMed Central

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

    2015-01-01

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

  1. Determinants of immunodominance for CD4 T cells.

    PubMed

    Kim, AeRyon; Sadegh-Nasseri, Scheherazade

    2015-06-01

    The term immunodominance was originally defined as a restricted T cell response to a short peptide sequence derived from a given protein. The question of what determines immunodominance has been a longstanding battle for the past two decades. Hundreds of papers have been written on different aspects of epitope selection during antigen processing documenting the complexity of the process. Antigen processing machinery involves several accessory molecules and chaperons coevolved with proteins of Major Histocompatibility Complex (MHC) molecules that each plays its part in epitope selection. These molecules are targeted to specialized vesicular compartments that also accommodate antigen processing enzymes called cathepsins. Within the antigen processing compartments, highly regulated pH gradient and reducing conditions and enzymes necessary for denaturation of the antigens are available and function to optimize processing of antigen and selection of the fittest for transport to the cell membrane and presentation to T cells. Despite the complexity, a cell free reductionist antigen processing system was recently reported that included only few purified proteins, but was shown to process and select physiologically relevant epitopes from full length protein antigens. Due to its minimalist nature the system has been quite helpful in dissecting the factors that contribute to epitope selection during antigen processing. In this review, we would summarize and highlight models that may explain how the dominant epitope may be selected for presentation to CD4(+) helper T cells. PMID:25576665

  2. Production of IL-16 correlates with CD4+ Th1 inflammation and phosphorylation of axonal cytoskeleton in multiple sclerosis lesions

    PubMed Central

    Skundric, Dusanka S; Cai, Juan; Cruikshank, William W; Gveric, Djordje

    2006-01-01

    Background Multiple sclerosis (MS) is a central nervous system-specific autoimmune, demyelinating and neurodegenerative disease. Infiltration of lesions by autoaggressive, myelin-specific CD4+Th1 cells correlates with clinical manifestations of disease. The cytokine IL-16 is a CD4+ T cell-specific chemoattractant that is biased towards CD4+ Th1 cells. IL-16 precursor is constitutively expressed in lymphocytes and during CD4+ T cell activation; active caspase-3 cleaves and releases C-terminal bioactive IL-16. Previously, we used an animal model of MS to demonstrate an important role for IL-16 in regulation of autoimmune inflammation and subsequent axonal damage. This role of IL-16 in MS is largely unexplored. Here we examine the regulation of IL-16 in relation to CD4+ Th1 infiltration and inflammation-related changes of axonal cytoskeleton in MS lesions. Methods We measured relative levels of IL-16, active caspase-3, T-bet, Stat-1 (Tyr 701), and phosphorylated NF(M+H), in brain and spinal cord lesions from MS autopsies, using western blot analysis. We examined samples from 39 MS cases, which included acute, subacute and chronic lesions, as well as adjacent, normal-appearing white and grey matter. All samples were taken from patients with relapsing remitting clinical disease. We employed two-color immunostaining and confocal microscopy to identify phenotypes of IL-16-containing cells in frozen tissue sections from MS lesions. Results We found markedly increased levels of pro- and secreted IL-16 (80 kD and 22 kD, respectively) in MS lesions compared to controls. Levels of IL-16 peaked in acute, diminished in subacute, and were elevated again in chronic active lesions. Compared to lesions, lower but still appreciable IL-6 levels were measured in normal-appearing white matter adjacent to active lesions. Levels of IL-16 corresponded to increases in active-caspase-3, T-bet and phosphorylated Stat-1. In MS lesions, we readily observed IL-16 immunoreactivity confined to

  3. Bystander CD4+ T lymphocytes survive in HIV-infected human lymphoid tissue

    NASA Technical Reports Server (NTRS)

    Grivel, Jean-Charles; Biancotto, Angelique; Ito, Yoshinori; Lima, Rosangela G.; Margolis, Leonid B.

    2003-01-01

    HIV infection is associated with depletion of CD4(+) T cells. The mechanisms of this phenomenon remain to be understood. In particular, it remains controversial whether and to what extent uninfected ("bystander") CD4(+) T cells die in HIV-infected individuals. We address this question using a system of human lymphoid tissue ex vivo. Tissue blocks were inoculated with HIV-1. After productive infection was established, they were treated with the reverse transcriptase inhibitor nevirapine to protect from infection those CD4(+) T cells that had not yet been infected. These CD4(+) T cells residing in HIV-infected tissue are by definition bystanders. Our results demonstrate that after nevirapine application the number of bystander CD4(+) T cells is conserved. Thus, in the context of HIV-infected human lymphoid tissue, productive HIV infection kills infected cells but is not sufficient to cause the death of a significant number of uninfected CD4(+) T cells.

  4. E protein transcription factors are required for the development of CD4(+) lineage T cells.

    PubMed

    Jones-Mason, Mary Elizabeth; Zhao, Xudong; Kappes, Dietmar; Lasorella, Anna; Iavarone, Antonio; Zhuang, Yuan

    2012-03-23

    The double-positive (DP) to single-positive (SP) transition during T cell development is initiated by downregulation of the E protein transcription factors HEB and E2A. Here, we have demonstrated that in addition to regulating the onset of this transition, HEB and E2A also play a separate role in CD4(+) lineage choice. Deletion of HEB and E2A in DP thymocytes specifically blocked the development of CD4(+) lineage T cells. Furthermore, deletion of the E protein inhibitors Id2 and Id3 allowed CD4(+) T cell development but blocked CD8(+) lineage development. Analysis of the CD4(+) lineage transcriptional regulators ThPOK and Gata3 placed HEB and E2A upstream of CD4(+) lineage specification. These studies identify an important role for E proteins in the activation of CD4(+) lineage differentiation as thymocytes undergo the DP to SP transition. PMID:22425249

  5. Antibodies to CD4 in individuals infected with human immunodeficiency virus type 1.

    PubMed Central

    Kowalski, M; Ardman, B; Basiripour, L; Lu, Y C; Blohm, D; Haseltine, W; Sodroski, J

    1989-01-01

    The attachment of human immunodeficiency virus type 1 (HIV-1) to target cells is mediated by a specific interaction between the viral envelope glycoprotein (gp120) and the CD4 receptor. Here we report that approximately 10% of HIV-1-infected individuals produce antibodies that recognize the extracellular portion of the CD4 molecule. Carboxyl-terminal deletions of CD4 that do not affect HIV-1 gp120 binding eliminate recognition of CD4 by patient antisera. In contrast, mutations in the amino-terminal domain of CD4 that attenuate HIV-1 gp120 binding do not diminish CD4 recognition by patient antisera. These results suggest that HIV-1 infection can generate antibodies directed against a region of the viral receptor distinct from the virus-binding domain. Images PMID:2541442

  6. Vaccine-Elicited CD4 T Cells Induce Immunopathology Following Chronic LCMV Infection

    PubMed Central

    Penaloza-MacMaster, Pablo; Barber, Daniel L.; Wherry, E. John; Provine, Nicholas M.; Teigler, Jeffrey E.; Parenteau, Lily; Blackmore, Stephen; Borducchi, Erica N.; Larocca, Rafael A.; Yates, Kathleen B.; Shen, Hao; Haining, W. Nicholas; Sommerstein, Rami; Pinschewer, Daniel D.; Ahmed, Rafi; Barouch, Dan. H.

    2015-01-01

    CD4 T cells promote innate and adaptive immune responses, but how vaccine-elicited CD4 T cells contribute to immune protection remains unclear. Here we evaluated whether induction of virus-specific CD4 T cells by vaccination would protect mice against infection with chronic lymphocytic choriomeningitis virus (LCMV). Immunization with vaccines that selectively induced CD4 T cell responses resulted in catastrophic inflammation and mortality following challenge with a persistent strain of LCMV. Immunopathology required antigen-specific CD4 T cells and was associated with a cytokine storm, generalized inflammation, and multi-organ system failure. Virus-specific CD8 T cells or antibodies abrogated the pathology. These data demonstrate that vaccine-elicited CD4 T cells in the absence of effective antiviral immune responses can trigger lethal immunopathology. PMID:25593185

  7. Working Memory in the Classroom: An Inside Look at the Central Executive.

    PubMed

    Barker, Lauren A

    2016-01-01

    This article provides a review of working memory and its application to educational settings. A discussion of the varying definitions of working memory is presented. Special attention is given to the various multidisciplinary professionals who work with students with working memory deficits, and their unique understanding of the construct. Definitions and theories of working memory are briefly summarized and provide the foundation for understanding practical applications of working memory to assessment and intervention. Although definitions and models of working memory abound, there is limited consensus regarding universally accepted definitions and models. Current research indicates that developing new models of working memory may be an appropriate paradigm shift at this time. The integration of individual practitioner's knowledge regarding academic achievement, working memory and processing speed could provide a foundation for the future development of new working memory models. Future directions for research should aim to explain how tasks and behaviors are supported by the substrates of the cortico-striatal and the cerebro-cerebellar systems. Translation of neurobiological information into educational contexts will be helpful to inform all practitioners' knowledge of working memory constructs. It will also allow for universally accepted definitions and models of working memory to arise and facilitate more effective collaboration between disciplines working in educational setting. PMID:27191215

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  9. ESTABLISHING MEAN CD4+ T CELL VALUES AMONG HEALTHY JAVANESE ADULTS IN INDONESIA.

    PubMed

    Prasetyo, Afiono Agung; Zaini, Khilyat Ulin Nur

    2015-07-01

    The objective of this study was to establish mean CD4+ T cell values among healthy Javanese adults in Indonesia. Two hundred forty-one healthy adults (119 women and 122 men), aged 18-65 years, were enrolled in the study. CD4+ T cells were analyzed by immunophenotyping. The mean absolute CD4+ T cell count was 753.3 ± 270.3 cells/µl (median = 725.0 cells/µl) and the mean CD4+ T cell percentage was 32.6 ± 7.7%, (median = 31.0%). Women had a slightly higher mean absolute CD4+ T cell count and CD4+ T cell percentage (779.1 ± 271.0 cells/ µl; 33.4 ± 8.2%) than men (728.2 ± 268.3 cells/µl; 31.8 ± 7.1%), but the differences were not statistically significant (p = 0.126, p = 0.216, respectively). The mean absolute CD4+ T cell varied significantly by age group (p = 0.002). Sixty-one point seven percent of men studied (37/60) had a CD4+ T cell count less than 500 cells/µl (OR 1.8; 95% CI = 1.001-3.300). Absolute CD4+ T cell counts among Javanese Indonesians varied significantly by age. PMID:26867386

  10. Clinical Evaluation of the BD FACSPresto™ Near-Patient CD4 Counter in Kenya

    PubMed Central

    Angira, Francis; Akoth, Benta; Omolo, Paul; Opollo, Valarie; Bornheimer, Scott; Judge, Kevin; Tilahun, Henok; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement

    2016-01-01

    Background The BD FACSPresto™ Near-Patient CD4 Counter was developed to expand HIV/AIDS management in resource-limited settings. It measures absolute CD4 counts (AbsCD4), percent CD4 (%CD4), and hemoglobin (Hb) from a single drop of capillary or venous blood in approximately 23 minutes, with throughput of 10 samples per hour. We assessed the performance of the BD FACSPresto system, evaluating accuracy, stability, linearity, precision, and reference intervals using capillary and venous blood at KEMRI/CDC HIV-research laboratory, Kisumu, Kenya, and precision and linearity at BD Biosciences, California, USA. Methods For accuracy, venous samples were tested using the BD FACSCalibur™ instrument with BD Tritest™ CD3/CD4/CD45 reagent, BD Trucount™ tubes, and BD Multiset™ software for AbsCD4 and %CD4, and the Sysmex™ KX-21N for Hb. Stability studies evaluated duration of staining (18–120-minute incubation), and effects of venous blood storage <6–24 hours post-draw. A normal cohort was tested for reference intervals. Precision covered multiple days, operators, and instruments. Linearity required mixing two pools of samples, to obtain evenly spaced concentrations for AbsCD4, total lymphocytes, and Hb. Results AbsCD4 and %CD4 venous/capillary (N = 189/ N = 162) accuracy results gave Deming regression slopes within 0.97–1.03 and R2 ≥0.96. For Hb, Deming regression results were R2 ≥0.94 and slope ≥0.94 for both venous and capillary samples. Stability varied within 10% 2 hours after staining and for venous blood stored less than 24 hours. Reference intervals results showed that gender—but not age—differences were statistically significant (p<0.05). Precision results had <3.5% coefficient of variation for AbsCD4, %CD4, and Hb, except for low AbsCD4 samples (<6.8%). Linearity was 42–4,897 cells/μL for AbsCD4, 182–11,704 cells/μL for total lymphocytes, and 2–24 g/dL for Hb. Conclusions The BD FACSPresto system provides accurate, precise clinical

  11. Enhanced HIV-1 neutralization by a CD4-VH3-IgG1 fusion protein

    SciTech Connect

    Meyuhas, Ronit; Noy, Hava; Fishman, Sigal; Margalit, Alon; Montefiori, David C.; Gross, Gideon

    2009-08-21

    HIV-1 gp120 is an alleged B cell superantigen, binding certain VH3+ human antibodies. We reasoned that a CD4-VH3 fusion protein could possess higher affinity for gp120 and improved HIV-1 inhibitory capacity. To test this we produced several human IgG1 immunoligands harboring VH3. Unlike VH3-IgG1 or VH3-CD4-IgG1, CD4-VH3-IgG1 bound gp120 considerably stronger than CD4-IgG1. CD4-VH3-IgG1 exhibited {approx}1.5-2.5-fold increase in neutralization of two T-cell laboratory-adapted strains when compared to CD4-IgG1. CD4-VH3-IgG1 improved neutralization of 7/10 clade B primary isolates or pseudoviruses, exceeding 20-fold for JR-FL and 13-fold for Ba-L. It enhanced neutralization of 4/8 clade C viruses, and had negligible effect on 1/4 clade A pseudoviruses. We attribute this improvement to possible pairing of VH3 with CD4 D1 and stabilization of an Ig Fv-like structure, rather than to superantigen interactions. These novel findings support the current notion that CD4 fusion proteins can act as better HIV-1 entry inhibitors with potential clinical implications.

  12. Multidimensional Clusters of CD4+ T Cell Dysfunction Are Primarily Associated with the CD4/CD8 Ratio in Chronic HIV Infection

    PubMed Central

    Noyan, Kajsa; Nowak, Piotr; Sönnerborg, Anders; Lund, Ole; Karlsson, Annika C.

    2015-01-01

    HIV infection provokes a myriad of pathological effects on the immune system where many markers of CD4+ T cell dysfunction have been identified. However, most studies to date have focused on single/double measurements of immune dysfunction, while the identification of pathological CD4+ T cell clusters that is highly associated to a specific biomarker for HIV disease remain less studied. Here, multi-parametric flow cytometry was used to investigate immune activation, exhaustion, and senescence of diverse maturation phenotypes of CD4+ T cells. The traditional method of manual data analysis was compared to a multidimensional clustering tool, FLOw Clustering with K (FLOCK) in two cohorts of 47 untreated HIV-infected individuals and 21 age and sex matched healthy controls. In order to reduce the subjectivity of FLOCK, we developed an “artificial reference”, using 2% of all CD4+ gated T cells from each of the HIV-infected individuals. Principle component analyses demonstrated that using an artificial reference lead to a better separation of the HIV-infected individuals from the healthy controls as compared to using a single HIV-infected subject as a reference or analyzing data manually. Multiple correlation analyses between laboratory parameters and pathological CD4+ clusters revealed that the CD4/CD8 ratio was the preeminent surrogate marker of CD4+ T cells dysfunction using all three methods. Increased frequencies of an early-differentiated CD4+ T cell cluster with high CD38, HLA-DR and PD-1 expression were best correlated (Rho = -0.80, P value = 1.96×10−11) with HIV disease progression as measured by the CD4/CD8 ratio. The novel approach described here can be used to identify cell clusters that distinguish healthy from HIV infected subjects and is biologically relevant for HIV disease progression. These results further emphasize that a simple measurement of the CD4/CD8 ratio is a useful biomarker for assessment of combined CD4+ T cell dysfunction in chronic HIV

  13. Frequencies of Virus-Specific CD4+ and CD8+ T Lymphocytes Secreting Gamma Interferon after Acute Natural Rotavirus Infection in Children and Adults

    PubMed Central

    Jaimes, María C.; Rojas, Olga Lucía; González, Ana María; Cajiao, Isabela; Charpilienne, Annie; Pothier, Pierre; Kohli, Evelyne; Greenberg, Harry B.; Franco, Manuel A.; Angel, Juana

    2002-01-01

    Human rotavirus-specific CD4+ and CD8+ T-cell responses in peripheral blood lymphocytes were studied using a flow cytometric assay that detects the intracellular accumulation of cytokines after short-term in vitro antigen stimulation. The frequencies of virus-specific T cells that secrete gamma interferon and interleukin-13 (IL-13) were determined in adults and children during the acute or convalescent phase of rotavirus-induced diarrhea, in asymptomatically infected adults and laboratory workers who worked with human stool samples containing rotavirus, and in healthy adults. Significantly higher frequencies of rotavirus-specific interferon gamma-secreting CD8+ and CD4+ T cells, but not IL-13-secreting T cells, were detected in symptomatically infected adults and exposed laboratory workers than in healthy adults and children with acute rotavirus diarrhea. The levels of rotavirus-specific T cells returned to levels found in healthy adults by 32 days after the onset of rotavirus diarrhea in most adult subjects. Children with rotavirus diarrhea had undetectable or very low levels of CD4+ and CD8+ T cells that secrete gamma interferon. Adult cytomegalovirus-seropositive individuals had frequencies of cytomegalovirus-specific T cells that secrete gamma interferon that were approximately 20 times the level of rotavirus-specific T cells. This result suggests that rotavirus is a relatively poor inducer of circulating memory T cells that secrete gamma interferon. The frequencies of gamma interferon-secreting CD4+ and CD8+ T cells and the frequencies of IL-13-secreting CD4+ T cells responding to the T-cell superantigen staphylococcal enterotoxin B (SEB) were lower in children than in adults. In both adults and children, the frequencies of CD4+ cells secreting gamma interferon in response to SEB were higher than the frequencies of cells secreting IL-13. PMID:11967291

  14. CD4+ primary T cells expressing HCV-core protein upregulate Foxp3 and IL-10, suppressing CD4 and CD8 T cells.

    PubMed

    Fernandez-Ponce, Cecilia; Dominguez-Villar, Margarita; Aguado, Enrique; Garcia-Cozar, Francisco

    2014-01-01

    Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127(low)PD-1(high)TIM-3(high) regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein. PMID:24465502

  15. Control of influenza infection is impaired by diminished interferon-γ secretion by CD4 T cells in the lungs of toddler mice.

    PubMed

    Verhoeven, David; Perry, Sheldon; Pryharski, Karin

    2016-07-01

    Respiratory viral infections, such as influenza, can lead to delayed viral clearance in toddlers, possibly exacerbating disease morbidity. We hypothesized that defective CD4 T cells in toddlers may contribute to a failure to clear virus at a similar rate to adults. Thus, we developed a young mouse model to examine potential divergent responses between toddlers and adults. We determined that young mice (toddler mice, 21 d old) were actively generating and recruiting effector/memory T cells, whereas memory populations were firmly established in older, adult mice (8-10 wk old). We infected toddler and adult mice with influenza A/PR8/34 (H1N1) and found young mice had elevated morbidity, as measured by enhanced weight loss and lower partial pressure of oxygen levels, throughout the infection, thus, modeling the higher morbidity observed in children (<2 y old) during infection. Early viral loads were comparable to adult mice, but toddler mice failed to clear virus by 10 d postinfection. This delayed clearance corresponded to poor lung recruitment of CD4 T cells, lower antiviral T cell responses, and lower B cell/antibodies in the lungs. Mechanistically, diminished interferon-γ was detected in the lungs of toddler mice throughout the infection and corresponded to intrinsic, rather than extrinsic, CD4 T cell limitations in interferon-γ transcription. Moreover, defects in interferon-γ production appeared downstream from signal transducer and activator of transcription 4 in the interleukin-12 signaling pathway, suggesting maturational delays different from neonates. Importantly, recombinant interferon-γ supplementation rescued CD4 T cell numbers in the lungs and influenza-specific antibody formation. This study highlights the intrinsic limitations in CD4 T cell effector functions that may arise in toddlers and contribute to disease pathology. PMID:26823488

  16. T inflammatory memory CD8 T cells participate to antiviral response and generate secondary memory cells with an advantage in XCL1 production.

    PubMed

    Jubin, Virginie; Ventre, Erwan; Leverrier, Yann; Djebali, Sophia; Mayol, Katia; Tomkowiak, Martine; Mafille, Julien; Teixeira, Marie; Teoh, Denise Y-L; Lina, Bruno; Walzer, Thierry; Arpin, Christophe; Marvel, Jacqueline

    2012-06-01

    Besides the classically described subsets of memory CD8 T cells generated under infectious conditions, are T inflammatory memory cells generated under sterile priming conditions, such as sensitization to allergens. Although not fully differentiated as pathogen-induced memory cells, they display memory properties that distinguish them from naive CD8 T cells. Given these memory cells are generated in an antigen-specific context that is devoid of pathogen-derived danger signals and CD4 T cell help, we herein questioned whether they maintained their activation and differentiation potential, could be recruited in an immune response directed against a pathogen expressing their cognate antigen and further differentiate in fully competent secondary memory cells. We show that T inflammatory memory cells can indeed take part to the immune response triggered by a viral infection, differentiate into secondary effectors and further generate typical central memory CD8 T cells and effector memory CD8 T cells. Furthermore, the secondary memory cells they generate display a functional advantage over primary memory cells in their capacity to produce TNF-α and the XCL1 chemokine. These results suggest that cross-reactive stimulations and differentiation of cells directed against allergens or self into fully competent pathogen-induced memory cells might have incidences in inflammatory immuno-pathologies. PMID:22528127

  17. Eomesodermin Expression in CD4+ T Cells Restricts Peripheral Foxp3 Induction.

    PubMed

    Lupar, Ekaterina; Brack, Maria; Garnier, Laure; Laffont, Sophie; Rauch, Katharina S; Schachtrup, Kristina; Arnold, Sebastian J; Guéry, Jean-Charles; Izcue, Ana

    2015-11-15

    CD4(+) T cells polarize into effector Th subsets characterized by signature transcription factors and cytokines. Although T-bet drives Th1 responses and represses the alternative Th2, Th17, and Foxp3(+) regulatory T cell fates, the role of the T-bet-related transcription factor eomesodermin (Eomes) in CD4(+) T cells is less well understood. In this study, we analyze the expression and effects of Eomes in mouse CD4(+) T lymphocytes. We find that Eomes is readily expressed in activated CD4(+) Th1 T cells in vivo. Eomes(+) CD4(+) T cells accumulated in old mice, under lymphopenic conditions in a T cell transfer model of colitis, and upon oral Ag administration. However, despite its expression, genetic deletion of Eomes in CD4(+) T cells did not impact on IFN-γ production nor increase Th2 or Th17 responses. In contrast, Eomes deficiency favored the accumulation of Foxp3(+) cells in old mice, after in vivo differentiation of Eomes-deficient naive CD4(+) T cells, and in response to oral Ag in a cell-intrinsic way. Enforced Eomes expression during in vitro regulatory T cell induction also reduced Foxp3 transcription. Likewise, bystander Eomes-deficient CD4(+) T cells were more efficient at protecting from experimental autoimmune encephalitis compared with wild-type CD4(+) T cells. This enhanced capacity of Eomes-deficient CD4(+) T cells to inhibit EAE in trans was associated with an enhanced frequency of Foxp3(+) cells. Our data identify a novel role for Eomes in CD4(+) T cells and indicate that Eomes expression may act by limiting Foxp3 induction, which may contribute to the association of EOMES to susceptibility to multiple sclerosis. PMID:26453746

  18. Immunodominant HIV-1 Cd4+ T Cell Epitopes in Chronic Untreated Clade C HIV-1 Infection

    PubMed Central

    Ramduth, Danni; Day, Cheryl L.; Thobakgale, Christina F.; Mkhwanazi, Nompumelelo P.; de Pierres, Chantal; Reddy, Sharon; van der Stok, Mary; Mncube, Zenele; Nair, Kriebashne; Moodley, Eshia S.; Kaufmann, Daniel E.; Streeck, Hendrik; Coovadia, Hoosen M.; Kiepiela, Photini; Goulder, Philip J. R.; Walker, Bruce D.

    2009-01-01

    Background A dominance of Gag-specific CD8+ T cell responses is significantly associated with a lower viral load in individuals with chronic, untreated clade C human immunodeficiency virus type 1 (HIV-1) infection. This association has not been investigated in terms of Gag-specific CD4+ T cell responses, nor have clade C HIV-1–specific CD4+ T cell epitopes, likely a vital component of an effective global HIV-1 vaccine, been identified. Methodology/Principal Findings Intracellular cytokine staining was conducted on 373 subjects with chronic, untreated clade C infection to assess interferon-gamma (IFN-γ) responses by CD4+ T cells to pooled Gag peptides and to determine their association with viral load and CD4 count. Gag-specific IFN-γ–producing CD4+ T cell responses were detected in 261/373 (70%) subjects, with the Gag responders having a significantly lower viral load and higher CD4 count than those with no detectable Gag response (p<0.0001 for both parameters). To identify individual peptides targeted by HIV-1–specific CD4+ T cells, separate ELISPOT screening was conducted on CD8-depleted PBMCs from 32 chronically infected untreated subjects, using pools of overlapping peptides that spanned the entire HIV-1 clade C consensus sequence, and reconfirmed by flow cytometry to be CD4+ mediated. The ELISPOT screening identified 33 CD4+ peptides targeted by 18/32 patients (56%), with 27 of the 33 peptides located in the Gag region. Although the breadth of the CD4+ responses correlated inversely with viral load (p = 0.015), the magnitude of the response was not significantly associated with viral load. Conclusions/Significance These data indicate that in chronic untreated clade C HIV-1 infection, IFN-γ–secreting Gag-specific CD4+ T cell responses are immunodominant, directed at multiple distinct epitopes, and associated with viral control. PMID:19352428

  19. Auditing National HIV Guidelines and Policies: The United Kingdom CD4 Surveillance Scheme

    PubMed Central

    Brown, Alison E; Kall, Meaghan M; Smith, Ruth D; Yin, Zheng; Hunter, Alan; Hunter, Alan; Delpech, Valerie C

    2012-01-01

    The United Kingdom’s CD4 surveillance scheme monitors CD4 cell counts among HIV patients and is a national resource for HIV surveillance. It has driven public health policy and allowed auditing of national HIV testing, treatment and care guidelines. We demonstrate its utility through four example outputs: median CD4 count at HIV diagnosis; late HIV diagnosis and short-term mortality; the timing of first CD4 count to indicate entry into HIV care; and the proportion of patients with CD4 counts <350 cells/mm3 receiving anti-retroviral therapy (ARV). In 2009, 95% (61,502/64,420) of adults living with diagnosed HIV infection had CD4 counts available. The median CD4 count at diagnosis increased from 276 to 335 cells/mm3 between 2000 and 2009, indicating modest improvements in HIV testing. In 2009, 52% of patients were diagnosed at a late stage of HIV infection (CD4 <350 cells/mm3); these individuals had a ten-fold risk of dying within a year of their diagnosis compared to those diagnosed promptly. In 2008, the national target of performing a CD4 count within 14 days of diagnosis was met for 61% of patients. National treatment guidelines have largely been met with 83% patients with CD4 <350 cells/mm3 receiving ARV. The monitoring of CD4 counts is critical to HIV surveillance in the United Kingdom enabling the close monitoring of efforts to reduce morbidity and mortality associated with late diagnosis and underpins the auditing of policies and guidelines. These routine surveillance outputs can be generated at national and local levels to drive and monitor public health policy and prevention efforts. PMID:23049663

  20. Auditing national HIV guidelines and policies: The United Kingdom CD4 Surveillance Scheme.

    PubMed

    Brown, Alison E; Kall, Meaghan M; Smith, Ruth D; Yin, Zheng; Hunter, Alan; Hunter, Alan; Delpech, Valerie C

    2012-01-01

    The United Kingdom's CD4 surveillance scheme monitors CD4 cell counts among HIV patients and is a national resource for HIV surveillance. It has driven public health policy and allowed auditing of national HIV testing, treatment and care guidelines. WE DEMONSTRATE ITS UTILITY THROUGH FOUR EXAMPLE OUTPUTS: median CD4 count at HIV diagnosis; late HIV diagnosis and short-term mortality; the timing of first CD4 count to indicate entry into HIV care; and the proportion of patients with CD4 counts <350 cells/mm3 receiving anti-retroviral therapy (ARV). In 2009, 95% (61,502/64,420) of adults living with diagnosed HIV infection had CD4 counts available. The median CD4 count at diagnosis increased from 276 to 335 cells/mm3 between 2000 and 2009, indicating modest improvements in HIV testing. In 2009, 52% of patients were diagnosed at a late stage of HIV infection (CD4 <350 cells/mm(3)); these individuals had a ten-fold risk of dying within a year of their diagnosis compared to those diagnosed promptly. In 2008, the national target of performing a CD4 count within 14 days of diagnosis was met for 61% of patients. National treatment guidelines have largely been met with 83% patients with CD4 <350 cells/mm(3) receiving ARV. The monitoring of CD4 counts is critical to HIV surveillance in the United Kingdom enabling the close monitoring of efforts to reduce morbidity and mortality associated with late diagnosis and underpins the auditing of policies and guidelines. These routine surveillance outputs can be generated at national and local levels to drive and monitor public health policy and prevention efforts. PMID:23049663

  1. Follicular Helper CD4+ T Cells in Human Neuroautoimmune Diseases and Their Animal Models

    PubMed Central

    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. PMID:26300592

  2. CD4+ T cell immunity to the Burkholderia pseudomallei ABC transporter LolC in melioidosis

    PubMed Central

    Chu, Karen K.; Tippayawat, Patcharaporn; Walker, Nicola J.; Harding, Sarah V.; Atkins, Helen S.; Maillere, Bernard; Bancroft, Gregory J.; Lertmemongkolchai, Ganjana; Altmann, Daniel M.

    2011-01-01

    Burkholderia pseudomallei (Bp) causes melioidosis, a disease with a wide range of possible outcomes, from seroconversion and dormancy to sepsis and death. This spectrum of host-pathogen interactions poses challenging questions about heterogeneity in immunity to Bp. Models show protection to be dependent on CD4+ cells and IFNγ, but little is known about specific target antigens. Having previously implicated the ABC transporter, LolC, in protective immunity, we here use epitope prediction, HLA binding studies, HLA-transgenic models and studies of T cells from seropositive individuals to characterize HLA-restricted LolC responses. Immunized mice showed long-lasting memory to the protein, while predictive algorithms identified epitopes within LolC that subsequently demonstrated strong HLA class II binding. Immunization of HLA-DR transgenics with LolC stimulated T cell responses to four of these epitopes. Furthermore, responsiveness of HLA-transgenics to LolC revealed a hierarchy supportive of HLA polymorphism-determined differential susceptibility. Seropositive human donors of diverse HLA class II types showed T cell responses to LolC epitopes which are conserved among Burkholderia species including B. cenocepacia, associated with life-threatening cepacia complex in cystic fibrosis patients and B. mallei, which causes glanders. These findings suggest a role for LolC epitopes in multiepitope vaccine design for melioidosis and related diseases. PMID:21182082

  3. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  4. Evaluation of the FACSPresto, a New Point of Care Device for the Enumeration of CD4% and Absolute CD4+ T Cell Counts in HIV Infection

    PubMed Central

    Makadzange, Azure Tariro; Bogezi, Carola; Boyd, Kathryn; Gumbo, Anesu; Mukura, Dorinda; Matubu, Allen; Ndhlovu, Chiratidzo Ellen

    2016-01-01

    Introduction Enumeration of CD4+ T lymphocytes is important for pre-ART disease staging and screening for opportunistic infections, however access to CD4 testing in resource limited settings is poor. Point of care (POC) technologies can facilitate improved access to CD4 testing. We evaluated the analytical performance of a novel POC device the FACSPresto compared to the FACSCalibur as a reference standard and to the PIMA, a POC device in widespread use in sub-Saharan Africa. Method Specimens were obtained from 253 HIV infected adults. Venous blood samples were analyzed on the FACSPresto and the FACSCalibur, in a subset of 41 samples additional analysis was done on the PIMA. Results The absolute CD4 count results obtained on the FACSPresto were comparable to those on the FACSCalibur with low absolute (9.5cells/μl) and relative bias (3.2%). Bias in CD4% values was also low (1.06%) with a relative bias of 4.9%. The sensitivity was lower at a CD4 count threshold of ≤350cells/μl compared with ≤500cells/μl (84.9% vs. 92.8%) resulting in a high upward misclassification rate at low CD4 counts. Specificity at thresholds of ≤350cells/μl and ≤500cells/μl were 96.6% and 96.8% respectively. The PIMA had a high absolute (-68.6cells/μl) and relative bias (-10.5%) when compared with the FACSCalibur. At thresholds of ≤350cells/μl and ≤500cells/μl the sensitivity was 100% and 95.5% respectively; specificity was 85.7% and 84.2% respectively. The coefficients of repeatability were 4.13%, 5.29% and 9.8% respectively. Discussion The analytic performance of the FACSPresto against the reference standard was very good with better agreement and precision than the PIMA. The FACSPresto had comparable sensitivity at a threshold of 500 cells/μl and better specificity than the PIMA. However the FACSPresto showed reduced sensitivity at low CD4 count thresholds. Conclusion The FACSPresto can be reliably used as a POC device for enumerating absolute CD4 count and CD4% values

  5. CD4+CD25+ cells in multiple myeloma related renal impairment

    PubMed Central

    Huang, Hongdong; Luo, Yang; Liang, Yumei; Long, Xi-Dai; Peng, Youming; Liu, Zhihua; Wen, Xiaojun; Jia, Meng; Tian, Ru; Bai, Chengli; Li, Cui; Dong, Xiaoqun

    2015-01-01

    CD4+CD25+ cells are critical regulators in almost all of the animal models of human organ-specific autoimmune diseases, transplant rejection and allergic diseases. We aimed to explore the role of CD4+CD25+ cells in the pathogenesis of multiple myeloma (MM) related renal impairment (RI). Thirty patients with MM related RI and 30 healthy volunteers were studied. The number of CD4+CD25+ cells was examined by flow cytometry. Clinical and laboratory data were collected from each subject. Glomerular injury was assessed by histopathology. Serum IL-2, IL-4 and IL-6 were analyzed by ELISA. CD4+CD25+ cells significantly decreased in MM related RI patients compared to the controls (P<0.05). CD4+CD25+ cell number was negatively associated with blood urea nitrogen (BUN), supernatant IL-4, serum IL-6, monoclonal immunoglobulin and β2-microglobulin, as well as bone marrow plasma cell percentage and proteinuria; whereas positively associated with estimated glomerular filtration rate (eGFR) (all P < 0.05). CD4+CD25+ cells gradually decreased as the Clinic Stage increased. The number of CD4+CD25+ cells reduced in MM related RI patients, and was correlated with disease severity. CD4+CD25+ cells may play an important role in the pathogenesis of MM related RI. PMID:26564056

  6. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection

    PubMed Central

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-01-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection. PMID:22044420

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

    PubMed Central

    Kannan, Arun K.; Kim, Do-Geun

    2015-01-01

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

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

    PubMed

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

    2008-11-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. AFM force measurements of the gp120-sCD4 and gp120 or CD4 antigen-antibody interactions

    SciTech Connect

    Chen, Yong; Zeng, Gucheng; Chen, Sherry Shiyi; Feng, Qian; Chen, Zheng Wei

    2011-04-08

    Highlights: {yields} The unbinding force of sCD4-gp120 interaction was 25.45 {+-} 20.46 pN. {yields} The unbinding force of CD4 antigen-antibody interaction was 51.22 {+-} 34.64 pN. {yields} The unbinding force of gp120 antigen-antibody interaction was 89.87 {+-} 44.63 pN. {yields} The interaction forces between various HIV inhibitors and the target molecules are significantly different. {yields} Functionalizing on AFM tip or substrate of an interaction pair caused different results. -- Abstract: Soluble CD4 (sCD4), anti-CD4 antibody, and anti-gp120 antibody have long been regarded as entry inhibitors in human immunodeficiency virus (HIV) therapy. However, the interactions between these HIV entry inhibitors and corresponding target molecules are still poorly understood. In this study, atomic force microscopy (AFM) was utilized to investigate the interaction forces among them. We found that the unbinding forces of sCD4-gp120 interaction, CD4 antigen-antibody interaction, and gp120 antigen-antibody interaction were 25.45 {+-} 20.46, 51.22 {+-} 34.64, and 89.87 {+-} 44.63 pN, respectively, which may provide important mechanical information for understanding the effects of viral entry inhibitors on HIV infection. Moreover, we found that the functionalization of an interaction pair on AFM tip or substrate significantly influenced the results, implying that we must perform AFM force measurement and analyze the data with more caution.

  12. The 17D-204 Vaccine Strain-Induced Protection against Virulent Yellow Fever Virus Is Mediated by Humoral Immunity and CD4+ but not CD8+ T Cells.

    PubMed

    Watson, Alan M; Lam, L K Metthew; Klimstra, William B; Ryman, Kate D

    2016-07-01

    A gold standard of antiviral vaccination has been the safe and effective live-attenuated 17D-based yellow fever virus (YFV) vaccines. Among more than 500 million vaccinees, only a handful of cases have been reported in which vaccinees developed a virulent wild type YFV infection. This efficacy is presumed to be the result of both neutralizing antibodies and a robust T cell response. However, the particular immune components required for protection against YFV have never been evaluated. An understanding of the immune mechanisms that underlie 17D-based vaccine efficacy is critical to the development of next-generation vaccines against flaviviruses and other pathogens. Here we have addressed this question for the first time using a murine model of disease. Similar to humans, vaccination elicited long-term protection against challenge, characterized by high neutralizing antibody titers and a robust T cell response that formed long-lived memory. Both CD4+ and CD8+ T cells were polyfunctional and cytolytic. Adoptive transfer of immune sera or CD4+ T cells provided partial protection against YFV, but complete protection was achieved by transfer of both immune sera and CD4+ T cells. Thus, robust CD4+ T cell activity may be a critical contributor to protective immunity elicited by highly effective live attenuated vaccines. PMID:27463517

  13. The 17D-204 Vaccine Strain-Induced Protection against Virulent Yellow Fever Virus Is Mediated by Humoral Immunity and CD4+ but not CD8+ T Cells

    PubMed Central

    Lam, L. K. Metthew; Klimstra, William B.

    2016-01-01

    A gold standard of antiviral vaccination has been the safe and effective live-attenuated 17D-based yellow fever virus (YFV) vaccines. Among more than 500 million vaccinees, only a handful of cases have been reported in which vaccinees developed a virulent wild type YFV infection. This efficacy is presumed to be the result of both neutralizing antibodies and a robust T cell response. However, the particular immune components required for protection against YFV have never been evaluated. An understanding of the immune mechanisms that underlie 17D-based vaccine efficacy is critical to the development of next-generation vaccines against flaviviruses and other pathogens. Here we have addressed this question for the first time using a murine model of disease. Similar to humans, vaccination elicited long-term protection against challenge, characterized by high neutralizing antibody titers and a robust T cell response that formed long-lived memory. Both CD4+ and CD8+ T cells were polyfunctional and cytolytic. Adoptive transfer of immune sera or CD4+ T cells provided partial protection against YFV, but complete protection was achieved by transfer of both immune sera and CD4+ T cells. Thus, robust CD4+ T cell activity may be a critical contributor to protective immunity elicited by highly effective live attenuated vaccines. PMID:27463517

  14. Central Adiposity is Negatively Associated with Hippocampal-Dependent Relational Memory among Overweight and Obese Children

    PubMed Central

    Khan, Naiman A.; Baym, Carol L.; Monti, Jim M.; Raine, Lauren B.; Drollette, Eric S.; Scudder, Mark R.; Moore, R. Davis; Kramer, Arthur F.; Hillman, Charles H.; Cohen, Neal J.

    2014-01-01

    Objective To assess associations between adiposity and hippocampal-dependent and hippocampal-independent memory forms among prepubertal children. Study design Prepubertal children (7–9-year-olds, n = 126), classified as non-overweight (<85th %tile BMI-for-age [n = 73]) or overweight/obese (≥85th %tile BMI-for-age [n = 53]), completed relational (hippocampal-dependent) and item (hippocampal-independent) memory tasks, and performance was assessed with both direct (behavioral accuracy) and indirect (preferential disproportionate viewing [PDV]) measures. Adiposity (%whole body fat mass, subcutaneous abdominal adipose tissue, visceral adipose tissue, and total abdominal adipose tissue) was assessed using DXA. Backward regressions identified significant (P <0.05) predictive models of memory performance. Covariates included age, sex, pubertal timing, socioeconomic status, IQ, oxygen consumption (VO2max), and body mass index (BMI) z-score. Results Among overweight/obese children, total abdominal adipose tissue was a significant negative predictor of relational memory behavioral accuracy, and pubertal timing together with socioeconomic status jointly predicted the PDV measure of relational memory. In contrast, among non-overweight children, male sex predicted item memory behavioral accuracy, and a model consisting of socioeconomic status and BMI z-score jointly predicted the PDV measure of relational memory. Conclusions Regional, and not whole body, fat deposition was selectively and negatively associated with hippocampal-dependent relational memory among overweight/obese prepubertal children. PMID:25454939

  15. Dissecting How CD4 T Cells Are Lost During HIV Infection.

    PubMed

    Doitsh, Gilad; Greene, Warner C

    2016-03-01

    Although the replicative life cycle of HIV within CD4 T cells is understood in molecular detail, less is known about how this human retrovirus promotes the loss of CD4 T lymphocytes. It is this cell death process that drives clinical progression to acquired immune deficiency syndrome (AIDS). Recent studies have highlighted how abortive infection of resting and thus nonpermissive CD4 T cells in lymphoid tissues triggers a lethal innate immune response against the incomplete DNA products generated by inefficient viral reverse transcription in these cells. Sensing of these DNA fragments results in pyroptosis, a highly inflammatory form of programmed cell death, that potentially further perpetuates chronic inflammation and immune activation. As discussed here, these studies cast CD4 T cell death during HIV infection in a different light. Further, they identify drug targets that may be exploited to both block CD4 T cell demise and the chronic inflammatory response generated during pyroptosis. PMID:26962940

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

    PubMed Central

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

    2015-01-01

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

  17. T lymphocytes in rat germinal centres belong to an ER3+ subpopulation of CD4+ cells.

    PubMed Central

    Vonderheide, R H; Hunt, S V

    1990-01-01

    Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes. Images Figure 1 PMID:1970805

  18. Tissue adaptation of regulatory and intraepithelial CD4⁺ T cells controls gut inflammation.

    PubMed

    Sujino, Tomohisa; London, Mariya; Hoytema van Konijnenburg, David P; Rendon, Tomiko; Buch, Thorsten; Silva, Hernandez M; Lafaille, Juan J; Reis, Bernardo S; Mucida, Daniel

    2016-06-24

    Foxp3(+) regulatory T cells in peripheral tissues (pT(regs)) are instrumental in limiting inflammatory responses to nonself antigens. Within the intestine, pT(regs) are located primarily in the lamina propria, whereas intraepithelial CD4(+) T cells (CD4(IELs)), which also exhibit anti-inflammatory properties and depend on similar environmental cues, reside in the epithelium. Using intravital microscopy, we show distinct cell dynamics of intestinal T(regs) and CD4(IELs) Upon migration to the epithelium, T(regs) lose Foxp3 and convert to CD4(IELs) in a microbiota-dependent manner, an effect attributed to the loss of the transcription factor ThPOK. Finally, we demonstrate that pT(regs) and CD4(IELs) perform complementary roles in the regulation of intestinal inflammation. These results reveal intratissue specialization of anti-inflammatory T cells shaped by discrete niches of the intestine. PMID:27256884

  19. Alterations during positive selection in the thymus of nackt CD4-deficient mice.

    PubMed

    Nepomnaschy, I; Lombardi, G; Bekinschtein, P; Berguer, P; Francisco, V; de Almeida, J; Buggiano, V; Pasqualini, C D; Piazzon, I

    2000-12-01

    The T-cell repertoire is shaped by the positive and negative selection of immature CD4(+) CD8(+) double positive (DP) thymocytes. Positive selection of DP T cells to the CD4(+) CD8(-) and CD4(-) CD8(+) simple positive (SP) lineages is a multistep process which involves cellular interactions between thymocytes and stromal cells. Mutant nackt (nkt/nkt) mice have been shown to have a deficiency in the CD4(+) CD8(-) T-cell subset both in the thymus and in the periphery. The present report suggests that nkt/nkt mice present alterations in early steps of positive selection because they show decreases in the percentages of CD69(+) and CD5(+) cells within the DP subset. Experiments involving bone marrow transfer and thymic chimeras demonstrate that the thymic epithelium of nkt/nkt mice is involved in the alterations registered during positive selection and dictates the ultimate fate of CD4(+) SP cells. PMID:11119260

  20. Effects of CD4 monitoring frequency on clinical endpoints in clinically stable HIV-infected patients with viral suppression

    PubMed Central

    Ahn, Jin Young; Boettiger, David; Law, Matthew; Kumarasamy, Nagalingeswaran; Yunihastuti, Evy; Chaiwarith, Romanee; Lee, Man Po; Sim, Benedict LH; Oka, Shinichi; Wong, Wingwai; Kamarulzaman, Adeeba; Kantipong, Pacharee; Phanuphak, Praphan; Ng, Oon Tek; Kiertiburanakul, Sasisopin; Zhang, Fujie; Pujari, Sanjay; Ditangco, Rossana; Ratanasuwan, Winai; Merati, Tuti Parwati; Saphonn, Vonthanak; Sohn, Annette H.; Choi, Jun Yong

    2015-01-01

    Background Current treatment guidelines for HIV infection recommend routine CD4+ lymphocyte (CD4) count monitoring in patients with viral suppression. This may have a limited impact on influencing care as clinically meaningful CD4 decline rarely occurs during viral suppression. Methods In a regional HIV observational cohort in the Asia-Pacific, patients with viral suppression (2 consecutive viral loads <400 copies/mL) and a CD4 count ≥200 cells/μL who had CD4 testing 6 monthly were analyzed. Main study endpoints were occurrence of one CD4 count <200 cells/μL (single CD4<200) and two CD4 counts <200 cells/μL within a 6-month period (confirmed CD4<200). A comparison of time to single and confirmed CD4<200 with biannual or annual CD4 assessment was performed by generating a hypothetical group comprised of the same patients with annual CD4 testing by removing every second CD4 count. Results Among 1538 patients, the rate of single CD4<200 was 3.45/100 patient-years, and of confirmed CD4<200 was 0.77/100 patient-years. During 5 years of viral suppression, patients with baseline CD4 200-249 cells/μL were significantly more likely to experience confirmed CD4<200 compared with patients with higher baseline CD4 (hazard ratio 55.47 [95% confidence interval 7.36–418.20], p<0.001 versus baseline CD4 ≥500 cells/μL). Cumulative probabilities of confirmed CD4<200 was also higher in patients with baseline CD4 200-249 cells/μL compared with patients with higher baseline CD4. There was no significant difference in time to confirmed CD4<200 between biannual and annual CD4 measurement (p=0.336). Conclusions Annual CD4 monitoring in virally suppressed HIV patients with a baseline CD4 ≥250 cells/μL may be sufficient for clinical management. PMID:25850606

  1. Dynamic functional modulation of CD4+ T cell recall responses is dependent on the inflammatory environment of the secondary stimulus.

    PubMed

    Kim, Chulwoo; Jay, David C; Williams, Matthew A

    2014-05-01

    The parameters that modulate the functional capacity of secondary Th1 effector cells are poorly understood. In this study, we employ a serial adoptive transfer model system to show that the functional differentiation and secondary memory potential of secondary CD4+ effector T cells are dependent on the inflammatory environment of the secondary challenge. Adoptive transfer of TCR transgenic lymphocytic choriomeningitis virus (LCMV) Glycoprotein-specific SMARTA memory cells into LCMV-immune hosts, followed by secondary challenge with Listeria monocytogenes recombinantly expressing a portion of the LCMV Glycoprotein (Lm-gp61), resulted in the rapid emergence of SMARTA secondary effector cells with heightened functional avidity (as measured by their ability to make IFNγ in response to ex vivo restimulation with decreasing concentrations of peptide), limited contraction after pathogen clearance and stable maintenance secondary memory T cell populations. In contrast, transfer of SMARTA memory cells into naïve hosts prior to secondary Lm-gp61 challenge, which resulted in a more extended infectious period, resulted in poor functional avidity, increased death during the contraction phase and poor maintenance of secondary memory T cell populations. The modulation of functional avidity during the secondary Th1 response was independent of differences in antigen load or persistence. Instead, the inflammatory environment strongly influenced the function of the secondary Th1 response, as inhibition of IL-12 or IFN-I activity respectively reduced or increased the functional avidity of secondary SMARTA effector cells following rechallenge in a naïve secondary hosts. Our findings demonstrate that secondary effector T cells exhibit inflammation-dependent differences in functional avidity and memory potential, and have direct bearing on the design of strategies aimed at boosting memory T cell responses. PMID:24854337

  2. Varicella-zoster virus glycoproteins B and E are major targets of CD4+ and CD8+ T cells reconstituting during zoster after allogeneic transplantation

    PubMed Central

    Kleemann, Patrick; Distler, Eva; Wagner, Eva M.; Thomas, Simone; Klobuch, Sebastian; Aue, Steffi; Schnürer, Elke; Schild, Hansjörg; Theobald, Matthias; Plachter, Bodo; Tenzer, Stefan; Meyer, Ralf G.; Herr, Wolfgang

    2012-01-01

    Background After allogeneic hematopoietic stem-cell transplantation patients are at increased risk for herpes zoster as long as varicella-zoster virus specific T-cell reconstitution is impaired. This study aimed to identify immunodominant varicella-zoster virus antigens that drive recovery of virus-specific T cells after transplantation. Design and Methods Antigens were purified from a varicella-zoster virus infected cell lysate by high-performance liquid chromatography and were identified by quantitative mass spectrometric analysis. To approximate in vivo immunogenicity for memory T cells, antigen preparations were consistently screened with ex vivo PBMC of varicella-zoster virus immune healthy individuals in sensitive interferon-γ ELISpot assays. Candidate virus antigens identified by the approach were genetically expressed in PBMC using electroporation of in vitro transcribed RNA encoding full-length proteins and were then analyzed for recognition by CD4+ and CD8+ memory T cells. Results Varicella-zoster virus encoded glycoproteins B and E, and immediate early protein 62 were identified in immunoreactive lysate material. Predominant CD4+ T-cell reactivity to these proteins was observed in healthy virus carriers. Furthermore, longitudinal screening in allogeneic stem-cell transplantation patients showed strong expansions of memory T cells recognizing glycoproteins B and E after onset of herpes zoster, while immediate early protein 62 reactivity remained moderate. Reactivity to viral glycoproteins boosted by acute zoster was mediated by both CD4+ and CD8+ T cells. Conclusions Our data demonstrate that glycoproteins B and E are major targets of varicella-zoster virus specific CD4+ and CD8+ T-cell reconstitution occurring during herpes zoster after allogeneic stem-cell transplantation. Varicella-zoster virus glycoproteins B and E might form the basis for novel non-hazardous zoster subunit vaccines suitable for immunocompromised transplant patients. PMID:22207687

  3. Using CD4 Percentage and Age to Optimize Pediatric Antiretroviral Therapy Initiation

    PubMed Central

    Warshaw, Meredith G.; Miller, William C.; Castro, Hannah; Fiscus, Susan A.; Harper, Lynda M.; Harrison, Linda J.; Klein, Nigel J.; Lewis, Joanna; Melvin, Ann J.; Tudor-Williams, Gareth; McKinney, Ross E.

    2014-01-01

    BACKGROUND: Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation. METHODS: HIV-1-infected, HAART-naive children in Europe and the Americas were followed from 2002 through 2009 in PENPACT-1. Data from 162 vertically infected children, with at least World Health Organization “mild” immunosuppression and CD4% <10th percentile, were analyzed for improvement to a normal CD4% (≥10th percentile) within 4 years after HAART initiation. Data from 209 vertically infected children, regardless of immune status, were analyzed for CD4% outcomes at 4 years and viral failure within 4 years. RESULTS: Seventy-two percent of baseline immunosuppressed children recovered to normal within 4 years. Compared with “severe” immunosuppression, more children with “mild” immunosuppression (difference 36%, 95% confidence interval [CI]: 22% to 49%) or “advanced” immunosuppression (difference 20.8%, 95% CI: 5.8% to 35.9%) recovered a normal CD4%. For each 5-year increase in baseline age, the proportion of children achieving a normal CD4% declined by 19% (95% CI: 11% to 27%). Combining baseline CD4% and age effects resulted in >90% recovery when initiating HAART with “mild” immunosuppression at any age or “advanced” immunosuppression at age <3 years. Baseline CD4% effects became greater with increasing age (P = .02). At 4 years, most immunologic benefits were still significant but diminished. Viral failure was highest in infancy (56%) and adolescence (63%). CONCLUSIONS: Initiating HAART at higher CD4% and younger ages maximizes potential for immunologic recovery. Guidelines should weigh immunologic benefits against long-term risks. PMID:25266426

  4. The Visual Orientation Memory of "Drosophila" Requires Foraging (PKG) Upstream of Ignorant (RSK2) in Ring Neurons of the Central Complex

    ERIC Educational Resources Information Center

    Kuntz, Sara; Poeck, Burkhard; Sokolowski, Marla B.; Strauss, Roland

    2012-01-01

    Orientation and navigation in a complex environment requires path planning and recall to exert goal-driven behavior. Walking "Drosophila" flies possess a visual orientation memory for attractive targets which is localized in the central complex of the adult brain. Here we show that this type of working memory requires the cGMP-dependent protein…

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

    PubMed

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

    2016-01-01

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

  6. Exploratory assessment of CD4+ T lymphocytes in brown hares (Lepus europeus) using a cross-reactive anti-rabbit CD4 antibody.

    PubMed

    Rütgen, Barbara C; Gerner, Wilhelm; Beiglböck, Christoph; Schaschl, Helmut; Saalmüller, Armin; Suchentrunk, Franz; Essler, Sabine E

    2014-09-15

    In lagomorphs, lymphocyte subset distributions and the importance of CD4(+) T cell levels has so far only been considered in the frame of rabbit disease models. In this study, the first assessment of CD4(+) T lymphocytes in peripheral blood cells in brown hares (Lepus europaeus L., 1758), a further leporid species using a cross-reactive rabbit anti-CD4 antibody in flow cytometry, is presented. In addition, the entire coding region of the hare CD4 gene (1380 bp) coding for a polypeptide of 459 amino acids has been sequenced. Using generalized least squares fitting by maximum likelihood (GLS) test, significantly (p=0.0095) higher CD4(+) T cell frequencies in males than in females and significantly (p=0.0001) higher frequencies for leverets (younger than 2 months of age) than for subadult and adult (older than 7 months of age) individuals were detected. No significant age influence, however, was found for subadult and adult hares. The study is particularly meant to provide a first step in establishing a toolbox for the assessment of the immune response in this leporid species. PMID:25042071

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

    PubMed Central

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

    2016-01-01

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

  8. HIV-1 induces IL-10 production in human monocytes via a CD4-independent pathway.

    PubMed

    Ji, Jiaxiang; Sahu, Gautam K; Braciale, Vivian L; Cloyd, Miles W

    2005-06-01

    In HIV-infected patients, increased levels of IL-10, mainly produced by virally infected monocytes, were reported to be associated with impaired cell-mediated immune responses. In this study, we investigated how HIV-1 induces IL-10 production in human monocytes. We found that CD14(+) monocytes infected by either HIV-1(213) (X4) or HIV-1(BaL) (R5) produced IL-10, IL-6, tumor necrosis factor-alpha (TNF-alpha), and to a lesser extent, IFN-gamma. However, the capacity of HIV-1 to induce these cytokines was not dependent on virus replication since UV-inactivated HIV-1 induced similar levels of these cytokines. In addition, soluble HIV-1 gp160 could induce CD14(+) monocytes to produce IL-10 but at lower levels. Cross-linking CD4 molecules (XLCD4) with anti-CD4 mAbs and goat anti-mouse IgG (GAM) resulted in high levels of IL-6, TNF-alpha and IFN-gamma but no IL-10 production by CD14(+) monocytes. Interestingly, neither anti-CD4 mAbs nor recombinant soluble CD4 (sCD4) receptor could block IL-10 secretion induced by HIV-1(213), HIV-1(BaL) or HIV-1 gp160 in CD14(+) monocytes, whereas anti-CD4 mAb or sCD4 almost completely blocked the secretion of the other cytokines. Furthermore, HIV-1(213) could induce IL-10 mRNA expression in CD14(+) monocytes while XLCD4 by anti-CD4 mAb and GAM failed to do so. As with IL-10 protein levels, HIV-1(213)-induced IL-10 mRNA expression in CD14(+) monocytes could not be inhibited by anti-CD4 mAb or sCD4. Taken together, HIV-1 binding to CD14(+) monocytes can induce CD4-independent IL-10 production at both mRNA and protein levels. This finding suggests that HIV induces the immunosuppressive IL-10 production in monocytes and is not dependent on CD4 molecules and that interference with HIV entry through CD4 molecules may have no impact on counteracting the effects of IL-10 during HIV infection. PMID:15937058

  9. Characterization and clinical relevance of circulating CD4+CD28- T cells in Graves' disease.

    PubMed

    Wang, Fengming; Chen, Lei; Shen, Qiong; Liu, Tong; Jiang, Lian; Gu, Xinhua; Chen, Lujun; Sun, Jing; Liu, Cuiping

    2015-05-01

    During autoimmune disease the fraction of CD4+CD28- T cells in the peripheral blood of has been found to be elevated. In the present study, peripheral blood was collected from 61 patients with Graves' disease (GD) and 30 healthy control participants. Serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin receptor autoantibody (TRAb) were measured and peripheral blood mononuclear cell (PBMC) surface expression of CD4 and CD28 molecules was detected by flow cytometry. CD4+CD28- cells were sorted from six patients undergoing subtotal thyroidectomy and cultured ex vivo. The influence of TSH pretreated thyroid follicular cells on CD4+CD28- cell proliferation was evaluated using the agonist CD40 mAb 5C11, the blocking CD40L mAb 4F1 or B7-1 mAb 4E5 in 3H-TdR assays. Our data showed that the fraction of CD4+CD28- T cells was higher in GD patients than healthy donors (10.21%±8.56% vs. 2.33%±1.94%; P<0.001), and further elevated in 24 of 61 patients with Graves' ophthalmopathy (GO) (7.00±6.57% vs. 15.21±8.96%; P<0.001). A higher proportion of CD4+CD28- cells was detected in patients with degree II or III goiter than those with degree I goiter (11.53±9.18% vs. 6.11±3.97%; P<0.05 and 14.50±10.41% vs. 6.11±3.97%; P<0.01). The percentage of CD4+CD28- T cells correlated positively with serum levels of FT3 (r=0.354, P<0.01) and TRAb (r=0.304, P<0.05), but did not correlate with serum FT4 or TSH. Ex vivo, 5C11 enhanced proliferation of CD4+CD28+ cells (P<0.05), but did not influence the proliferation of CD4+CD28- cells. 4F1 inhibited the proliferation of both CD4+CD28+ (P<0.05) and CD4+CD28- (P<0.01) cells, and 4E5 inhibited proliferation of CD4+CD28+ cells (P<0.05). The elevation in circulating CD4+CD28- cells in GD patients correlates with disease severity and maybe plays an important role in the pathogenesis of GD. PMID:25839128

  10. A single peptide-major histocompatibility complex ligand triggers digital cytokine secretion in CD4(+) T cells.

    PubMed

    Huang, Jun; Brameshuber, Mario; Zeng, Xun; Xie, Jianming; Li, Qi-jing; Chien, Yueh-hsiu; Valitutti, Salvatore; Davis, Mark M

    2013-11-14

    We have developed a single-molecule imaging technique that uses quantum-dot-labeled peptide-major histocompatibility complex (pMHC) ligands to study CD4(+) T cell functional sensitivity. We found that naive T cells, T cell blasts, and memory T cells could all be triggered by a single pMHC to secrete tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) cytokines with a rate of ∼1,000, ∼10,000, and ∼10,000 molecules/min, respectively, and that additional pMHCs did not augment secretion, indicating a digital response pattern. We also found that a single pMHC localized to the immunological synapse induced the slow formation of a long-lasting T cell receptor (TCR) cluster, consistent with a serial engagement mechanism. These data show that scaling up CD4(+) T cell cytokine responses involves increasingly efficient T cell recruitment rather than greater cytokine production per cell. PMID:24120362

  11. Efficient ex vivo analysis of CD4+ T-cell responses using combinatorial HLA class II tetramer staining.

    PubMed

    Uchtenhagen, Hannes; Rims, Cliff; Blahnik, Gabriele; Chow, I-Ting; Kwok, William W; Buckner, Jane H; James, Eddie A

    2016-01-01

    MHC tetramers are an essential tool for characterizing antigen-specific CD4+ T cells. However, their ex vivo analysis is limited by the large sample requirements. Here we demonstrate a combinatorial staining approach that allows simultaneous characterization of multiple specificities to address this challenge. As proof of principle, we analyse CD4+ T-cell responses to the seasonal influenza vaccine, establishing a frequency hierarchy and examining differences in memory and activation status, lineage commitment and cytokine expression. We also observe cross-reactivity between an established epitope and recent variant and provide a means for probing T-cell receptor cross-reactivity. Using cord blood samples, we correlate the adult frequency hierarchy with the naive precursor frequencies. Last, we use our combinatorial staining approach to demonstrate that rheumatoid arthritis patients on therapy can mount effective responses to influenza vaccination. Together, these results demonstrate the utility of combinatorial tetramer staining and suggest that this approach may have broad applicability in human health and disease. PMID:27571776

  12. CD4(+) T-cell help amplifies innate signals for primary CD8(+) T-cell immunity.

    PubMed

    Bedoui, Sammy; Heath, William R; Mueller, Scott N

    2016-07-01

    CD8(+) T cells provide an important component of protection against intracellular infections and cancer. Immune responses by these T cells involve a primary phase of effector expansion and differentiation, followed by a contraction phase leading to memory formation and, if antigen is re-encountered, a secondary expansion phase with more rapid differentiation. Both primary and secondary phases of CD8(+) T-cell immunity have been shown to depend on CD4(+) T-cell help, although during certain infections the primary phase is variable in this requirement. One explanation for such variability relates to the strength of associated inflammatory signals, with weak signals requiring help. Here, we focus on our studies that have dissected the requirements for help in the primary phase of the CTL response to herpes simplex virus, elucidating intricate interactions and communications between CD4(+) T cells, various dendritic cell subsets, and CD8(+) T cells. We place our studies in the context of others and describe a simple model of help where CD40 signaling amplifies innate signals to enable efficient CD8(+) T-cell expansion and differentiation. This model facilitates CTL induction to various different agents, without altering the qualitative innate signals that direct other important arms of immunity. PMID:27319342

  13. Central additive effect of Ginkgo biloba and Rhodiola rosea on psychomotor vigilance task and short-term working memory accuracy

    PubMed Central

    Al-Kuraishy, Hayder M.

    2016-01-01

    Aim: The present study investigates the effect of combined treatment with Ginkgo biloba and/or Rhodiola rosea on psychomotor vigilance task (PVT) and short-term working memory accuracy. Subjects and Methods: A total number of 112 volunteers were enrolled to study the effect of G. biloba and R. rosea on PVT and short-term working memory accuracy as compared to placebo effects, the central cognitive effect was assessed by critical flicker-fusion frequency, PVT, and computerized N-back test. Results: Placebo produced no significant effects on all neurocognitive tests measure P > 0.05 in normal healthy volunteers, G. biloba or R. rosea improve PVT and low to moderate working memory accuracy, The combined effect of R. rosea and G. biloba leading to more significant effect on PVT, all levels of short-term working memory accuracy and critical fusion versus flicker P < 0.01, more than of G. biloba or R. rosea when they used alone. Conclusion: The combined effect of R. rosea and G. biloba leading to a more significant effect on cognitive function than either G. biloba or R. rosea when they used alone. PMID:27069717

  14. The effect of working memory load on semantic illusions: what the phonological loop and central executive have to contribute.

    PubMed

    Büttner, Anke Caroline

    2012-01-01

    When asked how many animals of each kind Moses took on the Ark, most people respond with "two" despite the substituted name (Moses for Noah) in the question. Possible explanations for semantic illusions appear to be related to processing limitations such as those of working memory. Indeed, individual working memory capacity has an impact upon how sentences containing substitutions are processed. This experiment examined further the role of working memory in the occurrence of semantic illusions using a dual-task working memory load approach. Participants verified statements while engaging in either articulatory suppression or random number generation. Secondary task type had a significant effect on semantic illusion rate, but only when comparing the control condition to the two dual-task conditions. Furthermore, secondary task performance in the random number generation condition declined, suggesting a tradeoff between tasks. Response time analyses also showed a different pattern of processing across the conditions. The findings suggest that the phonological loop plays a role in representing semantic illusion sentences coherently and in monitoring for details, while the role of the central executive is to assist gist-processing of sentences. This usually efficient strategy leads to error in the case of semantic illusions. PMID:22897231

  15. Identification and Characterization of an Immunogenic Hybrid Epitope Formed by both HIV gp120 and Human CD4 Proteins ▿

    PubMed Central

    Lewis, George K.; Fouts, Timothy R.; Ibrahim, Sani; Taylor, Brian M.; Salkar, Rachita; Guan, Yongjun; Kamin-Lewis, Roberta; DeVico, Anthony L.

    2011-01-01

    Certain antibodies from HIV-infected humans bind conserved transition state (CD4 induced [CD4i]) domains on the HIV envelope glycoprotein, gp120, and demonstrate extreme dependence on the formation of a gp120-human CD4 receptor complex. The epitopes recognized by these antibodies remain undefined although recent crystallographic studies of the anti-CD4i monoclonal antibody (MAb) 21c suggest that contacts with CD4 as well as gp120 might occur. Here, we explore the possibility of hybrid epitopes that demand the collaboration of both gp120 and CD4 residues to enable antibody reactivity. Analyses with a panel of human anti-CD4i MAbs and gp120-CD4 antigens with specific mutations in predicted binding domains revealed one putative hybrid epitope, defined by the human anti-CD4i MAb 19e. In virological and immunological tests, MAb 19e did not bind native or constrained gp120 except in the presence of CD4. This contrasted with other anti-CD4i MAbs, including MAb 21c, which bound unliganded, full-length gp120 held in a constrained conformation. Conversely, MAb 19e exhibited no specific reactivity with free human CD4. Computational modeling of MAb 19e interactions with gp120-CD4 complexes suggested a distinct binding profile involving antibody heavy chain interactions with CD4 and light chain interactions with gp120. In accordance, targeted mutations in CD4 based on this model specifically reduced MAb 19e interactions with stable gp120-CD4 complexes that retained reactivity with other anti-CD4i MAbs. These data represent a rare instance of an antibody response that is specific to a pathogen-host cell protein interaction and underscore the diversity of immunogenic CD4i epitope structures that exist during natural infection. PMID:21994452

  16. Blockade of Human Immunodeficiency Virus Type 1 Production in CD4^+ T Cells by an Intracellular CD4 Expressed Under Control of the Viral Long Terminal Repeat

    NASA Astrophysics Data System (ADS)

    Buonocore, Linda; Rose, John K.

    1993-04-01

    A retroviral vector was constructed in which a gene encoding a mutated soluble CD4 protein that is retained in the endoplasmic reticulum (sCD4-KDEL) is expressed under control of human immunodeficiency virus type 1 (HIV-1) regulatory elements. HIV-1 infection of a human T-cell line transduced with this vector led to induction of sCD4-KDEL synthesis and a block in transport of the HIV envelope protein to the cell surface. There was a complete block to maturation of infectious HIV-1 in the transduced cells, no viral spread, and little or no syncytium formation. Infected cells gradually disappeared from the culture over a period of 2 months. This intracellular trap for HIV has potential application in gene therapy for AIDS.

  17. CD4+ T cell-dependent and CD4+ T cell-independent cytokine-chemokine network changes in the immune responses of HIV-infected individuals.

    PubMed

    Arnold, Kelly B; Szeto, Gregory L; Alter, Galit; Irvine, Darrell J; Lauffenburger, Douglas A

    2015-10-20

    A vital defect in the immune systems of HIV-infected individuals is the loss of CD4(+) T cells, resulting in impaired immune responses. We hypothesized that there were CD4(+) T cell-dependent and CD4(+) T cell-independent alterations in the immune responses of HIV-1(+) individuals. To test this, we analyzed the secretion of cytokines and chemokines from stimulated peripheral blood mononuclear cell (PBMC) populations from HIV(+) donors, healthy donors, and healthy donors with CD4(+) T cells experimentally depleted. Multivariate analyses of 16 cytokines and chemokines at 6 and 72 hours after three stimuli (antibody-coated beads to stimulate T cells and R848 or lipopolysaccharide to stimulate innate immune cells) enabled integrative analysis of secreted profiles. Two major effects in HIV(+) PBMCs were not reproduced upon depletion of CD4(+) T cells in healthy PBMCs: (i) HIV(+) PBMCs maintained T cell-associated secreted profiles after T cell stimulation; (ii) HIV(+) PBMCs showed impaired interferon-γ (IFN-γ) secretion early after innate stimulation. These changes arose from hyperactive T cells and debilitated natural killer (NK) cell, respectively. Modeling and experiments showed that early IFN-γ secretion predicted later differences in secreted profiles in vitro. This effect was recapitulated in healthy PBMCs by blocking the IFN-γ receptor. Thus, we identified a critical deficiency in NK cell responses of HIV-infected individuals, independent of CD4(+) T cell depletion, which directs secreted profiles. Our findings illustrate a broad approach for identifying key disease-associated nodes in a multicellular, multivariate signaling network. PMID:26486173

  18. Intratumoral CD4+CD25+ regulatory T-cell-mediated suppression of infiltrating CD4+ T cells in B-cell non-Hodgkin lymphoma

    PubMed Central

    Yang, Zhi-Zhang; Novak, Anne J.; Stenson, Mary J.; Witzig, Thomas E.; Ansell, Stephen M.

    2006-01-01

    Most non-Hodgkin lymphomas (NHLs) are of B-cell origin, but the tumor tissue can be variably infiltrated with T cells. In the present study, we have identified a subset of CD4+CD25+ T cells with high levels of CTLA-4 and Foxp3 (intratumoral Treg cells) that are overrepresented in biopsy specimens of B-cell NHL (median of 17% in lymphoma biopsies, 12% in inflammatory tonsil, and 6% in tumor-free lymph nodes; P = .001). We found that these CD4+CD25+ T cells suppressed the proliferation and cytokine (IFN-γ and IL-4) production of infiltrating CD4+CD25- T cells in response to PHA stimulation. PD-1 was found to be constitutively and exclusively expressed on a subset of infiltrating CD4+CD25- T cells, and B7-H1 could be induced on intratumoral CD4+CD25+ T cells in B-cell NHL. Anti-B7-H1 antibody or PD-1 fusion protein partly restored the proliferation of infiltrating CD4+CD25- T cells when cocultured with intratumoral Treg cells. Finally, we found that CCL22 secreted by lymphoma B cells is involved in the chemotaxis and migration of intratumoral Treg cells that express CCR4, but not CCR8. Taken together, our results suggest that Treg cells are highly represented in the area of B-cell NHL and that malignant B cells are involved in the recruitment of these cells into the area of lymphoma. PMID:16403912

  19. Gut Mucosal FOXP3+ Regulatory CD4+ T Cells and Nonregulatory CD4+ T Cells Are Differentially Affected by Simian Immunodeficiency Virus Infection in Rhesus Macaques▿

    PubMed Central

    Allers, Kristina; Loddenkemper, Christoph; Hofmann, Jörg; Unbehaun, Anett; Kunkel, Désirée; Moos, Verena; Kaup, Franz-Josef; Stahl-Hennig, Christiane; Sauermann, Ulrike; Epple, Hans-Jörg; Schneider, Thomas

    2010-01-01

    The gastrointestinal tract represents a major site for human and simian immunodeficiency virus (HIV and SIV) replication and CD4+ T-cell depletion. Despite severe depletion of mucosal CD4+ T cells, FOXP3+ regulatory CD4+ T cells (Treg) are highly increased in the gut mucosa of chronically HIV-infected individuals and may contribute to HIV pathogenesis, either by their immunosuppressive function or as a significant target cell population for virus production. Little is known about the susceptibility of mucosal Treg to viral infection and the longitudinal effect of HIV/SIV infection on Treg dynamics. In this study, we determined the level of SIV infection in Treg and nonregulatory CD4+ T cells (non-Treg) isolated from the colon of SIV-infected rhesus macaques. The dynamics of mucosal Treg and alterations in the mucosal CD4+ T-cell pool were examined longitudinally. Our findings indicate that mucosal Treg were less susceptible to productive SIV infection than non-Treg and thus were selectively spared from SIV-mediated cell death. In addition to improved survival, local expansion of Treg by SIV-induced proliferation of the mucosal CD4+ T-cell pool facilitated the accumulation of mucosal Treg during the course of infection. High frequency of mucosal Treg in chronic SIV infection was strongly related to a reduction of perforin-expressing cells. In conclusion, this study suggests that mucosal Treg are less affected by productive SIV infection than non-Treg and therefore spared from depletion. Although SIV production is limited in mucosal Treg, Treg accumulation may indirectly contribute to viral persistence by suppressing antiviral immune responses. PMID:20071575

  20. SAMHD1 restricts HIV-1 infection in resting CD4+ T cells

    PubMed Central

    Baldauf, Hanna-Mari; Pan, Xiaoyu; Erikson, Elina; Schmidt, Sarah; Daddacha, Waaqo; Burggraf, Manja; Schenkova, Kristina; Ambiel, Ina; Wabnitz, Guido; Gramberg, Thomas; Panitz, Sylvia; Flory, Egbert; Landau, Nathaniel R; Sertel, Serkan; Rutsch, Frank; Lasitschka, Felix; Kim, Baek; König, Renate; Fackler, Oliver T; Keppler, Oliver T

    2013-01-01

    Unlike activated CD4+ T cells, resting CD4+ T cells are highly resistant to productive HIV-1 infection1–8. Early after HIV-1 entry, a major block limits reverse transcription of incoming viral genomes. Here we show that the deoxynucleoside triphosphate triphosphohydrolase SAMHD1 prevents reverse transcription of HIV-1 RNA in resting CD4+ T cells. SAMHD1 is abundantly expressed in resting CD4+ T cells circulating in peripheral blood and residing in lymphoid organs. The early restriction to infection in unstimulated CD4+ T cells is overcome by HIV-1 or HIV-2 virions into which viral Vpx is artificially or naturally packaged, respectively, or by addition of exogenous deoxynucleosides. Vpx-mediated proteasomal degradation of SAMHD1 and elevation of intracellular deoxynucleotide pools precede successful infection by Vpx-carrying HIV. Resting CD4+ T cells from healthy donors following SAMHD1 silencing or from a patient with Aicardi-Goutières syndrome homozygous for a nonsense mutation in SAMHD1 were permissive for HIV-1 infection. Thus, SAMHD1 imposes an effective restriction to HIV-1 infection in the large pool of noncycling CD4+ T cells in vivo. Bypassing SAMHD1 was insufficient for the release of viral progeny, implicating other barriers at later stages of HIV replication. Together, these findings may unveil new ways to interfere with the immune evasion and T cell immunopathology of pandemic HIV-1. PMID:22972397

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

    PubMed Central

    2012-01-01

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

  2. CD4(+)CD25(+) T Cells in primary malignant hypertension related kidney injury.

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  4. Predictor for the effect of amino acid composition on CD4+ T cell epitopes preprocessing.

    PubMed

    Hoze, Ehud; Tsaban, Lea; Maman, Yaakov; Louzoun, Yoram

    2013-05-31

    Predictive tools for all levels of CD8+ T cell epitopes processing have reached a maturation level. Good prediction algorithms have been developed for proteasomal cleavage, TAP and MHC class I peptide binding. The same cannot be said of CD4+ T cell epitopes. While multiple algorithms of varying accuracy have been proposed for MHC class II peptide binding, the preprocessing of CD4+ T cell epitopes is still lacking a good prediction algorithm. CD4+ T cell epitopes generation includes several stages, not all which are well-defined. We here group these stages to produce a generic preprocessing stage predictor for the cleavage processes preceding the presentation of epitopes to CD4+ T cell. The predictor is learnt using a combination of in vitro cleavage experiments and observed naturally processed MHC class II binding peptides. The properties of the predictor highlight the effect of different factors on CD4+ T cell epitopes preprocessing. The most important factor emerging from the predictor is the secondary structure of the cleaved region in the protein. The effect of the secondary structure is expected since CD4+ T cell epitopes are not denatured before cleavage. A website developed based on this predictor is available at: http://peptibase.cs.biu.ac.il/PepCleave_cd4/. PMID:23481624

  5. Mannose-Capped Lipoarabinomannan from Mycobacterium tuberculosis Induces CD4+ T Cell Anergy via GRAIL.

    PubMed

    Sande, Obondo J; Karim, Ahmad F; Li, Qing; Ding, Xuedong; Harding, Clifford V; Rojas, Roxana E; Boom, W Henry

    2016-01-15

    Mycobacterium tuberculosis cell wall glycolipid, lipoarabinomannan, can inhibit CD4(+) T cell activation by downregulating the phosphorylation of key proximal TCR signaling molecules: Lck, CD3ζ, ZAP70, and LAT. Inhibition of proximal TCR signaling can result in T cell anergy, in which T cells are inactivated following an Ag encounter, yet remain viable and hyporesponsive. We tested whether mannose-capped lipoarabinomannan (LAM)-induced inhibition of CD4(+) T cell activation resulted in CD4(+) T cell anergy. The presence of LAM during primary stimulation of P25 TCR-transgenic murine CD4(+) T cells with M. tuberculosis Ag85B peptide resulted in decreased proliferation and IL-2 production. P25 TCR-transgenic CD4(+) T cells primed in the presence of LAM also exhibited decreased response upon restimulation with Ag85B. The T cell anergic state persisted after the removal of LAM. Hyporesponsiveness to restimulation was not due to apoptosis, generation of Foxp3-positive regulatory T cells, or inhibitory cytokines. Acquisition of the anergic phenotype correlated with upregulation of gene related to anergy in lymphocytes (GRAIL) protein in CD4(+) T cells. Inhibition of human CD4(+) T cell activation by LAM also was associated with increased GRAIL expression. Small interfering RNA-mediated knockdown of GRAIL before LAM treatment abrogated LAM-induced hyporesponsiveness. In addition, exogenous IL-2 reversed defective proliferation by downregulating GRAIL expression. These results demonstrate that LAM upregulates GRAIL to induce anergy in Ag-reactive CD4(+) T cells. Induction of CD4(+) T cell anergy by LAM may represent one mechanism by which M. tuberculosis evades T cell recognition. PMID:26667170

  6. CD4 lymphocyte dynamics in Tanzanian pulmonary tuberculosis patients with and without hiv co-infection

    PubMed Central

    2012-01-01

    Background The interaction of HIV and tuberculosis (TB) on CD4 levels over time is complex and has been divergently reported. Methods CD4 counts were assessed from time of diagnosis till the end of TB treatment in a cohort of pulmonary TB patients with and without HIV co-infection and compared with cross-sectional data on age- and sex-matched non-TB controls from the same area. Results Of 1,605 study participants, 1,250 were PTB patients and 355 were non-TB controls. At baseline, HIV was associated with 246 (95% CI: 203; 279) cells per μL lower CD4 counts. All PTB patients had 100 cells per μL lower CD4 counts than the healthy controls. The CD4 levels were largely unchanged during a five-month of TB treatment. HIV infected patients not receiving ART at any time and those already on ART at baseline had no increase in CD4 counts after 5 months of TB treatment, whereas those prescribed ART between baseline and 2 months, and between 2 and 5 months increased by 69 (22;117) and 110 (52; 168) CD4 cells per μL after 5 months. Conclusions The increase in circulating CD4 levels observed in PTB in patients is acquired after 2 months of treatment irrespective of HIV status. Initiation of ART is the strongest factor correlated with CD4 increase during TB treatment. Trial registration number Clinical trials.gov: NCT00311298 PMID:22436147

  7. CD4 Enumeration Technologies: A Systematic Review of Test Performance for Determining Eligibility for Antiretroviral Therapy

    PubMed Central

    Peeling, Rosanna W.; Sollis, Kimberly A.; Glover, Sarah; Crowe, Suzanne M.; Landay, Alan L.; Cheng, Ben; Barnett, David; Denny, Thomas N.; Spira, Thomas J.; Stevens, Wendy S.; Crowley, Siobhan; Essajee, Shaffiq; Vitoria, Marco; Ford, Nathan

    2015-01-01

    Background Measurement of CD4+ T-lymphocytes (CD4) is a crucial parameter in the management of HIV patients, particularly in determining eligibility to initiate antiretroviral treatment (ART). A number of technologies exist for CD4 enumeration, with considerable variation in cost, complexity, and operational requirements. We conducted a systematic review of the performance of technologies for CD4 enumeration. Methods and Findings Studies were identified by searching electronic databases MEDLINE and EMBASE using a pre-defined search strategy. Data on test accuracy and precision included bias and limits of agreement with a reference standard, and misclassification probabilities around CD4 thresholds of 200 and 350 cells/μl over a clinically relevant range. The secondary outcome measure was test imprecision, expressed as % coefficient of variation. Thirty-two studies evaluating 15 CD4 technologies were included, of which less than half presented data on bias and misclassification compared to the same reference technology. At CD4 counts <350 cells/μl, bias ranged from -35.2 to +13.1 cells/μl while at counts >350 cells/μl, bias ranged from -70.7 to +47 cells/μl, compared to the BD FACSCount as a reference technology. Misclassification around the threshold of 350 cells/μl ranged from 1-29% for upward classification, resulting in under-treatment, and 7-68% for downward classification resulting in overtreatment. Less than half of these studies reported within laboratory precision or reproducibility of the CD4 values obtained. Conclusions A wide range of bias and percent misclassification around treatment thresholds were reported on the CD4 enumeration technologies included in this review, with few studies reporting assay precision. The lack of standardised methodology on test evaluation, including the use of different reference standards, is a barrier to assessing relative assay performance and could hinder the introduction of new point-of-care assays in countries

  8. Variables in the Quantification of CD4 in Normals and Hairy Cell Leukemia Patients

    PubMed Central

    Wang, Lili; Abbasi, Fatima; Jasper, Gregory A; Kreitman, Robert J; Liewehr, David; Marti, Gerald E.; Stetler-Stevenson, Maryalice

    2010-01-01

    Background Quantitative flow cytometry (QFCM) is being applied in the clinical flow cytometry laboratory. Quantitative normal T-cell CD4 expression represents a biologic standard and quality control agent. However, low levels of CD4 expression were detected in normal T-cells in Hairy Cell Leukemia (HCL) samples. Methods The QuantiBrite System® was used to determine the level of CD4 expression (mean antibody bound per cell, ABC) in fresh and shipped HCL blood and fresh normal donor blood (NDB). The effects of shipping, lysing reagent, cell preparation method and antibody lot were evaluated. Results Shipped HCL specimens (n = 69) had a significantly lower mean CD4 ABC of 38,788 (CV = 9.1%) compared to fresh specimens (n = 105) CD4 value of 40,330 (CV = 8.4%) (p < 0 .05). In NDB, significant differences were seen for fresh versus shipped specimens using the stain/lyse method but not for lyse/stain method. Consistent differences in CD4 ABC based upon antibody lot were observed in fresh HCL and NDB samples. Stain/lyse and lyse/stain methods using NH4Cl lyse were compared in NDB using identical samples and antibodies. The NDB CD4 ABC values obtained with the lyse (NH4Cl )/stain method (45,562, 3.7% CV) were lower than those obtained with the stain/lyse (NH4Cl) method (49,955, 3.3% CV) with p<0.001. Conclusions CD4 expression in HCL patient samples is not inherently different from that observed in NDB and therefore may serve as a biological control in clinical QFCM. Technical variables impact significantly on QFCM of CD4. PMID:20687201

  9. Distribution of CD4 Lymphocyte Cells Among Apparently Healthy HIV Seropositive and Seronegative Populations

    PubMed Central

    Abubakar, Abdulazeez A

    2012-01-01

    Background: CD4 lymphocyte cells are often used as prognostic markers for monitoring the progression of immunosupression such as HIV infection. Aim: This study was conducted to assess the distribution of CD4 lymphocytes among apparently healthy human immunodeficiency virus (HIV) seronegative and seropositive populations in a Nigerian state. Materials and Methods: A total of 1520 apparently healthy subjects aged 18–64 years, composed of 800 males and 720 females attending some selected health institutions in the state, participated in the study. Ten milliliters of blood was collected from each subject; 5 ml of this was used for HIV antibodies sero-typing while the remaining 5 ml was anticoagulated and used for CD4 lymphocytes level determination. Only samples tested positive both with Capillus and Determine HIV test kits were further differentiated into sero-types with a standard diagnostic HIV test kit. The CD4 lymphocyte levels of all the sample were determined; mean CD4 levels of 205.1±0.09 and 287.4±0.3 cells/μl were recorded among females seropositives and seronagatives respectively. Statistical analysis by the Student t-test showed a significant difference in the mean CD4 lymphocyte count by gender. Results: Findings showed a mean CD4 level of 311.7±1.2 cells/μl among seropositive males while 399.3±0.6 cells/μl was recorded among seronegatives (t=5.86). The study also recorded a CD4 lymphocyte range of 232–464 cells/μl among apparently healthy seronegative population in this locality. Conclusion: The findings showed a significantly higher mean CD4 lymphocyte count among adult male HIV seronegatives (χ2=9.22) and seropositives (χ2=15.07) than their female counterparts. Further research work using the automation technique is suggested to confirm this new range for monitoring HIV subjects on antiretroviral therapy. PMID:22454823

  10. A Combined Omics Approach to Generate the Surface Atlas of Human Naive CD4+ T Cells during Early T-Cell Receptor Activation*

    PubMed Central

    Graessel, Anke; Hauck, Stefanie M.; von Toerne, Christine; Kloppmann, Edda; Goldberg, Tatyana; Koppensteiner, Herwig; Schindler, Michael; Knapp, Bettina; Krause, Linda; Dietz, Katharina; Schmidt-Weber, Carsten B.; Suttner, Kathrin

    2015-01-01

    Naive CD4+ T cells are the common precursors of multiple effector and memory T-cell subsets and possess a high plasticity in terms of differentiation potential. This stem-cell-like character is important for cell therapies aiming at regeneration of specific immunity. Cell surface proteins are crucial for recognition and response to signals mediated by other cells or environmental changes. Knowledge of cell surface proteins of human naive CD4+ T cells and their changes during the early phase of T-cell activation is urgently needed for a guided differentiation of naive T cells and may support the selection of pluripotent cells for cell therapy. Periodate oxidation and aniline-catalyzed oxime ligation technology was applied with subsequent quantitative liquid chromatography-tandem MS to generate a data set describing the surface proteome of primary human naive CD4+ T cells and to monitor dynamic changes during the early phase of activation. This led to the identification of 173 N-glycosylated surface proteins. To independently confirm the proteomic data set and to analyze the cell surface by an alternative technique a systematic phenotypic expression analysis of surface antigens via flow cytometry was performed. This screening expanded the previous data set, resulting in 229 surface proteins, which were expressed on naive unstimulated and activated CD4+ T cells. Furthermore, we generated a surface expression atlas based on transcriptome data, experimental annotation, and predicted subcellular localization, and correlated the proteomics result with this transcriptional data set. This extensive surface atlas provides an overall naive CD4+ T cell surface resource and will enable future studies aiming at a deeper understanding of mechanisms of T-cell biology allowing the identification of novel immune targets usable for the development of therapeutic treatments. PMID:25991687

  11. Nod2 Activates NF-kB in CD4+ T Cells but Its Expression Is Dispensable for T Cell-Induced Colitis

    PubMed Central

    Zanello, Galliano; Goethel, Ashleigh; Forster, Katharina; Geddes, Kaoru; Philpott, Dana J.; Croitoru, Kenneth

    2013-01-01

    Although the etiology of Crohn's disease (CD) remains elusive this disease is characterized by T cell activation that leads to chronic inflammation and mucosal damage. A potential role for maladaptation between the intestinal microbiota and the mucosal immune response is suggested by the fact that mutations in the pattern recognition receptor Nod2 are associated with higher risks for developing CD. Although Nod2 deletion in CD4+ T cells has been shown to impair the induction of colitis in the murine T cell transfer model, the analysis of T cell intrinsic Nod2 function in T cell differentiation and T cell-mediated immunity is inconsistent between several studies. In addition, the role of T cell intrinsic Nod2 in regulatory T cell (Treg) development and function during colitis remain to be analyzed. In this study, we show that Nod2 expression is higher in activated/memory CD4+ T cells and its expression was inducible after T cell receptor (TCR) ligation. Nod2 stimulation with muramyl dipeptide (MDP) led to a nuclear accumulation of c-Rel NF-kB subunit. Although functionally active in CD4+ T cells, the deletion of Nod2 did not impair the induction and the prevention of colitis in the T cell transfer model. Moreover, Nod2 deletion did not affect the development of Foxp3+ Treg cells in the spleen of recipient mice and Nod2 deficient CD4 T cells expressing the OVA specific transgenic TCR were able to differentiate in Foxp3+ Treg cells after OVA feeding. In vitro, CD25+ Nod2 deficient T cells suppressed T cell proliferation as well as wild type counter parts and T cell stimulation with MDP did not affect the proliferation and the cytokine secretion of T cells. In conclusion, our data indicate that Nod2 is functional in murine CD4+ T cells but its expression is dispensable for the T cell regulation of colitis. PMID:24324812

  12. Study of antibody repertoires to the CD4 binding site of gp120 of a Chinese HIV-1-infected elite neutralizer, using 454 sequencing and single-cell sorting.

    PubMed

    Li, Dan; Wang, Zheng; Ren, Li; Zhang, Jing; Feng, Guangda; Hong, Kunxue; Hao, Yanling; Qi, Zhi; Liang, Hua; Shao, Yiming

    2016-04-01

    Broadly neutralizing antibodies (NAbs) against the CD4 binding site of HIV gp120 (CD4bs) have provided important information for vaccine design. In this study, we combined deep sequencing and single memory B cell sorting to isolate CD4bs-directed NAbs from a Chinese HIV-1-infected elite neutralizer. We first performed 454 pyrosequencing to capture the IGHV1, IGKV, and IGLV germline gene families. IGHV1-2*02, the heavy chain germline V gene (VH) of the CD4bs-directed bNAb VRC01, was found to have a relatively low somatic mutation rate. When an identity/divergence plot was used to interrogate the 454 sequencing data, no VRC01-like sequences were found within the dataset. We next used a pair of CD4bs-specific probes (RSC3/ΔRSC3) to sort the B cells from this Chinese donor and identified a CD4bs-directed Ab that showed limited neutralization capability. Interestingly, the VH gene of this weak NAb belongs to the IGHV5-51 lineage, with a somatic mutation rate of 7.99 %. Our study thus demonstrates that CD4bs-directed NAbs can be produced by rearrangement from other VH genes, such as IGHV5-51 in this donor, rather than IGHV1-2*02. The 454 sequencing data and NAb obtained from this study will provide useful insights into the CD4bs-directed B-cell response during HIV-1 infection as well as the diversity of neutralizing antibodies. PMID:26671829

  13. Identification of Owl Monkey CD4 Receptors Broadly Compatible with Early-Stage HIV-1 Isolates

    PubMed Central

    Meyerson, Nicholas R.; Sharma, Amit; Wilkerson, Gregory K.

    2015-01-01

    ABSTRACT Most HIV-1 variants isolated from early-stage human infections do not use nonhuman primate versions of the CD4 receptor for cellular entry, or they do so poorly. We and others have previously shown that CD4 has experienced strong natural selection over the course of primate speciation, but it is unclear whether this selection has influenced the functional characteristics of CD4 as an HIV-1 receptor. Surprisingly, we find that selection on CD4 has been most intense in the New World monkeys, animals that have never been found to harbor lentiviruses related to HIV-1. Based on this, we sampled CD4 genetic diversity within populations of individuals from seven different species, including five species of New World monkeys. We found that some, but not all, CD4 alleles found in Spix's owl monkeys (Aotus vociferans) encode functional receptors for early-stage human HIV-1 isolates representing all of the major group M clades (A, B, C, and D). However, only some isolates of HIV-1 subtype C can use the CD4 receptor encoded by permissive Spix's owl monkey alleles. We characterized the prevalence of functional CD4 alleles in a colony of captive Spix's owl monkeys and found that 88% of surveyed individuals are homozygous for permissive CD4 alleles, which encode an asparagine at position 39 of the receptor. We found that the CD4 receptors encoded by two other species of owl monkeys (Aotus azarae and Aotus nancymaae) also serve as functional entry receptors for early-stage isolates of HIV-1. IMPORTANCE Nonhuman primates, particularly macaques, are used for preclinical evaluation of HIV-1 vaccine candidates. However, a significant limitation of the macaque model is the fact that most circulating HIV-1 variants cannot use the macaque CD4 receptor to enter cells and have to be adapted to these species. This is particularly true for viral variants from early stages of infection, which represent the most relevant vaccine targets. In this study, we found that some individuals

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

    NASA Astrophysics Data System (ADS)

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

    1993-05-01

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

  15. Exploiting IL-17-producing CD4+ and CD8+ T cells to improve cancer immunotherapy in the clinic.

    PubMed

    Majchrzak, Kinga; Nelson, Michelle H; Bailey, Stefanie R; Bowers, Jacob S; Yu, Xue-Zhong; Rubinstein, Mark P; Himes, Richard A; Paulos, Chrystal M

    2016-03-01

    Cancer immunotherapy is one the most effective approaches for treating patients with tumors, as it bolsters the generation and persistence of memory T cells. In preclinical work, it has been reported that adoptively transferred CD4+ and CD8+ lymphocytes that secrete IL-17A (i.e., Th17 and Tc17 cells) regress tumors to a greater extent than IFN-γ(+)Th1 or Tc1 cells in vivo. Herein, we review the mechanisms underlying how infused Th17 and Tc17 cells regress established malignancies in clinically relevant mouse models of cancer. We also discuss how unique signaling cues--such as co-stimulatory molecules (ICOS and 41BB), cytokines (IL-12 and IL-23) or pharmaceutical reagents (Akt inhibitors, etc.)--can be exploited to bolster the therapeutic potential of IL-17(+) lymphocytes with an emphasis on using this knowledge to improve next-generation clinical trials for patients with cancer. PMID:26825102

  16. Correspondence of Neutralizing Humoral Immunity and CD4 T Cell Responses in Long Recovered Sudan Virus Survivors.

    PubMed

    Sobarzo, Ariel; Stonier, Spencer W; Herbert, Andrew S; Ochayon, David E; Kuehne, Ana I; Eskira, Yael; Fedida-Metula, Shlomit; Tali, Neta; Lewis, Eli C; Egesa, Moses; Cose, Stephen; Lutwama, Julius Julian; Yavelsky, Victoria; Dye, John M; Lobel, Leslie

    2016-01-01

    Robust humoral and cellular immunity are critical for survival in humans during an ebolavirus infection. However, the interplay between these two arms of immunity is poorly understood. To address this, we examined residual immune responses in survivors of the Sudan virus (SUDV) outbreak in Gulu, Uganda (2000-2001). Cytokine and chemokine expression levels in SUDV stimulated whole blood cultures were assessed by multiplex ELISA and flow cytometry. Antibody and corresponding neutralization titers were also determined. Flow cytometry and multiplex ELISA results demonstrated significantly higher levels of cytokine and chemokine responses in survivors with serological neutralizing activity. This correspondence was not detected in survivors with serum reactivity to SUDV but without neutralization activity. This previously undefined relationship between memory CD4 T cell responses and serological neutralizing capacity in SUDV survivors is key for understanding long lasting immunity in survivors of filovirus infections. PMID:27187443

  17. Correspondence of Neutralizing Humoral Immunity and CD4 T Cell Responses in Long Recovered Sudan Virus Survivors

    PubMed Central

    Sobarzo, Ariel; Stonier, Spencer W.; Herbert, Andrew S.; Ochayon, David E.; Kuehne, Ana I.; Eskira, Yael; Fedida-Metula, Shlomit; Tali, Neta; Lewis, Eli C.; Egesa, Moses; Cose, Stephen; Lutwama, Julius Julian; Yavelsky, Victoria; Dye, John M.; Lobel, Leslie

    2016-01-01

    Robust humoral and cellular immunity are critical for survival in humans during an ebolavirus infection. However, the interplay between these two arms of immunity is poorly understood. To address this, we examined residual immune responses in survivors of the Sudan virus (SUDV) outbreak in Gulu, Uganda (2000–2001). Cytokine and chemokine expression levels in SUDV stimulated whole blood cultures were assessed by multiplex ELISA and flow cytometry. Antibody and corresponding neutralization titers were also determined. Flow cytometry and multiplex ELISA results demonstrated significantly higher levels of cytokine and chemokine responses in survivors with serological neutralizing activity. This correspondence was not detected in survivors with serum reactivity to SUDV but without neutralization activity. This previously undefined relationship between memory CD4 T cell responses and serological neutralizing capacity in SUDV survivors is key for understanding long lasting immunity in survivors of filovirus infections. PMID:27187443

  18. Cross-priming of long lived protective CD8+ T cells against Trypanosoma cruzi infection: importance of a TLR9 agonist and CD4+ T cells.

    PubMed

    de Alencar, Bruna C G; Araújo, Adriano F S; Penido, Marcus L O; Gazzinelli, Ricardo T; Rodrigues, Mauricio M

    2007-08-10

    We recently described that vaccination of mice with a glutathione S transferase fusion protein representing amino acids 261-500 of the Amastigote Surface Protein-2 efficiently cross-primed protective CD8+ T cells against a lethal challenge with the human protozoan parasite Trypanosoma cruzi. In this study, we initially established that this protective immunity was long lived. Subsequently, we studied the importance of TLR9 agonist CpG ODN 1826, TLR4 and CD4+ T cells for the generation of these protective CD8+ T cells. We found that: (i) the TLR9 agonist CpG ODN 1826 improved the efficiency of protective immunity; (ii) TLR4 is not relevant for priming of specific CD8+ T cells; (iii) CD4+ T cells are critical for priming of memory/protective CD8+ T cells. PMID:17629597

  19. Sex-Dependent Effects of Prenatal Stress on Social Memory in Rats: A Role for Differential Expression of Central Vasopressin-1a Receptors.

    PubMed

    Grundwald, N J; Benítez, D P; Brunton, P J

    2016-04-01

    Prenatal stress (PNS) affects a number of traits in the offspring, including stress axis regulation, emotionality and cognition; however, much less is known about the effects of PNS on social memory and the underlying central mechanisms. In the present study, we investigated social preference, social memory under basal and stress conditions and olfactory memory for social and nonsocial odours in the adult offspring of dams exposed to social stress during late pregnancy. Given the key roles that the central oxytocin and vasopressin systems play in facilitating social memory, we further investigated the effects of PNS on the central expression of mRNA for oxytocin (Oxtr) and vasopressin-1a (Avpr1a) receptors. PNS did not affect social preference in either sex; however, social memory was impaired under basal conditions in PNS females but not PNS males. Accordingly, Avpr1a mRNA expression in the lateral septum and bed nucleus of stria terminalis (BNST) was unaltered in males but was significantly lower in PNS females compared to controls. No differences in Oxtr mRNA expression were detected between control and PNS offspring in either sex in any of the brain regions examined. Social memory deficits in PNS females persisted when social odours were used; however, this does not appear to be a result of impaired olfaction because memory for nonsocial odours was similar in control and PNS females. Under acute stress conditions, deficits in social memory were observed in both male and female control offspring; however, PNS males were unaffected. Moreover, acute stress facilitated social memory in PNS females and this was associated with an up-regulation of Avpr1a mRNA in the lateral septum and BNST. Our data support a role for altered signalling via central Avpr1a in PNS-induced sex-dependent changes in social memory and may have implications for understanding the aetiology of neurodevelopmental disorders characterised by social behaviour deficits in humans. PMID:26613552

  20. Costs of HIV+/AIDS at CD4+ counts disease stages based on treatment protocols.

    PubMed

    Gable, C B; Tierce, J C; Simison, D; Ward, D; Motte, K

    1996-08-01

    We report treatment protocols for HIV+/AIDS patients by CD4+ counts (T-lymphocyte cells/mm3: > or = 500, 499-200, 199-50, and < 50) as a tool to provide better definition and to project annual costs (total charges for services) and lifetimes costs for HIV+/AIDS. The treatment protocols, derived from the literature and an HIV+/AIDS Physician Panel, defined the resource use associated with antiretroviral therapy and opportunistic disease prophylaxis and treatment. Resource use costs were derived from the published literature, insurance database, Medicare fee schedules, surveys, and the Physician Panel. At CD4+ counts, the rates of opportunistic diseases were derived from the Physician Panel experience; the mean occupancy times were derived from the literature. The sensitivity analysis indicated stability of the lifetime costs to variation in mean occupancy times, rates of opportunistic diseases, rates of adverse events (AE), and costs. The total annual costs (1995 dollars) of HIV+/AIDS patients ranged from $1,934 (> or = 500), $6,015 (200-499), and $9,031 (50-199), to $25,239 ( < 50). The annual costs of opportunistic diseases are esophageal candidiasis (EC) ($2,194), tuberculosis (TB) ($2,924), cryptococcal meningitis (CM) ($17,264), toxoplasmosis ($17,631), Mycobacterium avium complex (MAC) (+20,153), Non-Hodgkin's lymphoma (NHL) ($22,329), wasting syndrome ($26,676), central nervous system (CNS) lymphoma ($27,333), Pneumocystis carinii pneumonia (PCP) [mild ($3,545), moderate ($4,889), and severe ($32,609)], Kaposi' sarcoma (KS) [mild/moderate ($5,902), and severe ($10,744)], and cytomegalovirus (CMV) retinitis ($100,337). The projected lifetime costs of HIV+/AIDS are $94,726 (annual costs $7,645). Our lower lifetime costs as compared with recent estimates may be due to including resources only for HIV+/AIDS-related treatment and not for non-HIV+/AIDS conditions, as well as reduced resource use resulting from more efficient diagnostic and therapeutic techniques

  1. CD4+FOXP3+ Regulatory T Cells Exhibit Impaired Ability to Suppress Effector T Cell Proliferation in Patients with Turner Syndrome

    PubMed Central

    Lee, Young Ah; Kim, Hang-Rae; Lee, Jeong Seon; Jung, Hae Woon; Kim, Hwa Young; Lee, Gyung Min; Lee, Jieun; Sim, Ji Hyun; Oh, Sae Jin; Chung, Doo Hyun; Shin, Choong Ho; Yang, Sei Won

    2015-01-01

    Objective We investigated whether the frequency, phenotype, and suppressive function of CD4+FOXP3+ regulatory T cells (Tregs) are altered in young TS patients with the 45,X karyotype compared to age-matched controls. Design and Methods Peripheral blood mononuclear cells from young TS patients (n = 24, 17.4–35.9 years) and healthy controls (n = 16) were stained with various Treg markers to characterize their phenotypes. Based on the presence of thyroid autoimmunity, patients were categorized into TS (–) (n = 7) and TS (+) (n = 17). Tregs sorted for CD4+CD25bright were co-cultured with autologous CD4+CD25− target cells in the presence of anti-CD3 and -CD28 antibodies to assess their suppressive function. Results Despite a lower frequency of CD4+ T cells in the TS (-) and TS (+) patients (mean 30.8% and 31.7%, vs. 41.2%; P = 0.003 and P < 0.001, respectively), both groups exhibited a higher frequency of FOXP3+ Tregs among CD4+ T cells compared with controls (means 1.99% and 2.05%, vs. 1.33%; P = 0.029 and P = 0.004, respectively). There were no differences in the expression of CTLA-4 and the frequency of Tregs expressing CXCR3+, and CCR4+CCR6+ among the three groups. However, the ability of Tregs to suppress the in vitro proliferation of autologous CD4+CD25− T cells was significantly impaired in the TS (–) and TS (+) patients compared to controls (P = 0.003 and P = 0.041). Meanwhile, both the TS (–) and TS (+) groups had lower frequencies of naïve cells (P = 0.001 for both) but higher frequencies of effector memory cells (P = 0.004 and P = 0.002) than did the healthy control group. Conclusions The Tregs of the TS patients could not efficiently suppress the proliferation of autologous effector T cells, despite their increased frequency in peripheral CD4+ T cells. PMID:26709833

  2. Humoral immunity and CD4+ Th1 cells are both necessary for a fully protective immune response upon secondary infection with Brucella melitensis.

    PubMed

    Vitry, Marie-Alice; Hanot Mambres, Delphine; De Trez, Carl; Akira, Shizuo; Ryffel, Bernhard; Letesson, Jean-Jacques; Muraille, Eric

    2014-04-15

    Brucella spp are intracellular bacteria that cause brucellosis, one of the most common zoonoses in the world. Given the serious medical consequences of this disease, a safe and effective human vaccine is urgently needed. Efforts to develop this vaccine have been hampered by our lack of understanding of what constitutes a protective memory response against Brucella. In this study, we characterize the cells and signaling pathways implicated in the generation of a protective immune memory response following priming by the injection of heat-killed or live Brucella melitensis 16M. Using a panel of gene-deficient mice, we demonstrated that during a secondary recall response, both the Brucella-specific humoral response and CD4+ Th1 cells must act together to confer protective immunity in the spleen to B. melitensis infection. Humoral protective immunity is induced by the inoculation of both heat-killed and live bacteria, and its development does not require T cells, MyD88/IL-12p35 signaling pathways, or an activation-induced deaminase-mediated isotype switch. In striking contrast, the presence of memory IFN-γ-producing CD4+ Th1 cells requires the administration of live bacteria and functional MyD88/IL-12p35 pathways. In summary, our work identifies several immune markers closely associated with protective immune memory and could help to define a rational strategy to obtain an effective human vaccine against brucellosis. PMID:24646742

  3. Oral immunization with a Salmonella enterica serovar typhi vaccine induces specific circulating mucosa-homing CD4(+) and CD8(+) T cells in humans.

    PubMed

    Lundin, B Samuel; Johansson, Camilla; Svennerholm, Ann-Mari

    2002-10-01

    The kinetics and homing characteristics of T-cell responses in humans after mucosal immunizations have not been well characterized. Therefore, we have investigated the magnitude and duration of such responses as well as the homing receptor expression of antigen-specific peripheral blood T cells by using an oral model vaccine, i.e., the live, attenuated Salmonella enterica serovar Typhi vaccine (Ty21a). Eight volunteers were each given three doses of the vaccine 2 days apart, and blood samples, from which CD4(+) and CD8(+) T cells were selected by the use of magnetic beads, were collected before vaccination and at regular intervals thereafter. To purify the potentially antigen-specific gut-homing T cells, CD45RA(-) integrin beta(7)(+) cells were further sorted by flow cytometry. The sorted cells were then stimulated in vitro with the serovar Typhi vaccine strain, and the proliferation of cells and the cytokine production were measured. Following vaccination, there was a large increase in both the proliferation of and the gamma interferon (IFN-gamma) production by blood T cells stimulated with the vaccine strain. The responses were seen among both CD4(+) and CD8(+) T cells, although the CD8(+) cells produced the largest amounts of IFN-gamma. Peak responses were seen 7 to 14 days after the onset of vaccination. Furthermore, most of the IFN-gamma produced by both CD4(+) and CD8(+) cells emanated from cells with the potential to home to mucosal tissues, as the integrin beta(7)-expressing memory T cells produced around 10-fold more IFN-gamma than the remaining populations. In conclusion, we demonstrate that oral vaccination with a live oral bacterial vaccine induces antigen-specific CD4(+) and CD8(+) memory T cells, almost all of which express the gut-homing integrin beta(7). PMID:12228290

  4. Interleukin-2 Enhances the Regulatory Functions of CD4(+)T Cell-Derived CD4(-)CD8(-) Double Negative T Cells.

    PubMed

    Cong, Min; Liu, Tianhui; Tian, Dan; Guo, Hongbo; Wang, Ping; Liu, Kai; Lin, Jun; Tian, Yue; Shi, Wen; You, Hong; Jia, Jidong; Zhang, Dong

    2016-08-01

    CD4(+) T cells can be converted to CD4(-)CD8(-) double negative T cells (DN T cells) under appropriate conditions, and IL-2 enhanced the conversion. Here, we investigated the effect of IL-2 on the proliferation and function of converted DN T cells in vitro and in vivo. DN T cells were hyporesponsive when restimulated by mature dendritic cells (mDCs), IL-2 completely restored their responsiveness in vitro. In addition, IL-2 increased the resistance of DN T cells to apoptosis in vivo. DN T cells profoundly inhibited the proliferation of CD4(+)CD25(-) T effector cells triggered by mDCs in vitro, and this suppression was further enhanced by IL-2. Adoptively transferring of DN T cells, in combination with IL-2, inhibited the proliferation and enhanced apoptosis of alloreactive CD4(+) T cells, which resulted in significant prolongation of skin allograft survival time. Perforin plays a key role in the enhancement of DN T cells immune regulation by IL-2. In conclusion, we elucidated that IL-2 promoted DN T cell proliferation and suppressive function. The combination of DN T cells and exogenous IL-2 may represent a novel therapy in the clinical setting to prevent allograft rejection and induce immune tolerance. PMID:27135902

  5. CD4-Independent Infection of Astrocytes by Human Immunodeficiency Virus Type 1: Requirement for the Human Mannose Receptor

    PubMed Central

    Liu, Ying; Liu, Hao; Kim, Byung Oh; Gattone, Vincent H.; Li, Jinliang; Nath, Avindra; Blum, Janice; He, Johnny J.

    2004-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection occurs in the central nervous system and causes a variety of neurobehavioral and neuropathological disorders. Both microglia, the residential macrophages in the brain, and astrocytes are susceptible to HIV-1 infection. Unlike microglia that express and utilize CD4 and chemokine coreceptors CCR5 and CCR3 for HIV-1 infection, astrocytes fail to express CD4. Astrocytes express several chemokine coreceptors; however, the involvement of these receptors in astrocyte HIV-1 infection appears to be insignificant. In the present study using an expression cloning strategy, the cDNA for the human mannose receptor (hMR) was found to be essential for CD4-independent HIV-1 infectivity. Ectopic expression of functional hMR rendered U87.MG astrocytic cells susceptible to HIV-1 infection, whereas anti-hMR serum and hMR-specific siRNA blocked HIV-1 infection in human primary astrocytes. In agreement with these findings, hMR bound to HIV-1 virions via the abundant and highly mannosylated sugar moieties of HIV-1 envelope glycoprotein gp120 in a Ca2+-dependent fashion. Moreover, hMR-mediated HIV-1 infection was dependent upon endocytic trafficking as assessed by transmission electron microscopy, as well as inhibition of viral entry by endosomo- and lysosomotropic drugs. Taken together, these results demonstrate the direct involvement of hMR in HIV-1 infection of astrocytes and suggest that HIV-1 interaction with hMR plays an important role in HIV-1 neuropathogenesis. PMID:15047828

  6. Interleukin-7 is required for CD4(+) T cell activation and autoimmune neuroinflammation.

    PubMed

    Lawson, Brian R; Gonzalez-Quintial, Rosana; Eleftheriadis, Theodoros; Farrar, Michael A; Miller, Stephen D; Sauer, Karsten; McGavern, Dorian B; Kono, Dwight H; Baccala, Roberto; Theofilopoulos, Argyrios N

    2015-12-01

    IL-7 is known to be vital for T cell homeostasis but has previously been presumed to be dispensable for TCR-induced activation. Here, we show that IL-7 is critical for the initial activation of CD4(+) T cells in that it provides some of the necessary early signaling components, such as activated STAT5 and Akt. Accordingly, short-term in vivo IL-7Rα blockade inhibited the activation and expansion of autoantigen-specific CD4(+) T cells and, when used to treat experimental autoimmune encephalomyelitis (EAE), prevented and ameliorated disease. Our studies demonstrate that IL-7 signaling is a prerequisite for optimal CD4(+) T cell activation and that IL-7R antagonism may be effective in treating CD4(+) T cell-mediated neuroinflammation and other autoimmune inflammatory conditions. PMID:26319414

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

    PubMed

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

    2016-02-16

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

  8. IL-10-producing CD4+ T cells negatively regulate fucosylation of epithelial cells in the gut

    PubMed Central

    Goto, Yoshiyuki; Lamichhane, Aayam; Kamioka, Mariko; Sato, Shintaro; Honda, Kenya; Kunisawa, Jun; Kiyono, Hiroshi

    2015-01-01

    Fucosylated glycans on the surface of epithelial cells (ECs) regulate intestinal homeostasis by serving as attachment receptors and a nutrient source for some species of bacteria. We show here that epithelial fucosylation in the ileum is negatively regulated by IL-10-producing CD4+ T cells. The number of fucosylated ECs was increased in the ileum of mice lacking T cells, especially those expressing αβ T cell receptor (TCR), CD4, and IL-10. No such effect was observed in mice lacking B cells. Adoptive transfer of αβTCR+ CD4+ T cells from normal mice, but not IL-10-deficient mice, normalized fucosylation of ECs. These findings suggest that IL-10-producing CD4+ T cells contribute to the maintenance of the function of ECs by regulating their fucosylation. PMID:26522513

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

    PubMed Central

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

    2016-01-01

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

  10. The SPL7013 dendrimer destabilizes the HIV-1 gp120-CD4 complex

    NASA Astrophysics Data System (ADS)

    Nandy, Bidisha; Saurabh, Suman; Sahoo, Anil Kumar; Dixit, Narendra M.; Maiti, Prabal K.

    2015-11-01

    The poly (l-lysine)-based SPL7013 dendrimer with naphthalene disulphonate surface groups blocks the entry of HIV-1 into target cells and is in clinical trials for development as a topical microbicide. Its mechanism of action against R5 HIV-1, the HIV-1 variant implicated in transmission across individuals, remains poorly understood. Using docking and fully atomistic MD simulations, we find that SPL7013 binds tightly to R5 gp120 in the gp120-CD4 complex but weakly to gp120 alone. Further, the binding, although to multiple regions of gp120, does not occlude the CD4 binding site on gp120, suggesting that SPL7013 does not prevent the binding of R5 gp120 to CD4. Using MD simulations to compute binding energies of several docked structures, we find that SPL7013 binding to gp120 significantly weakens the gp120-CD4 complex. Finally, we use steered molecular dynamics (SMD) to study the kinetics of the dissociation of the gp120-CD4 complex in the absence of the dendrimer and with the dendrimer bound in each of the several stable configurations to gp120. We find that SPL7013 significantly lowers the force required to rupture the gp120-CD4 complex and accelerates its dissociation. Taken together, our findings suggest that SPL7013 compromises the stability of the R5 gp120-CD4 complex, potentially preventing the accrual of the requisite number of gp120-CD4 complexes across the virus-cell interface, thereby blocking virus entry.The poly (l-lysine)-based SPL7013 dendrimer with naphthalene disulphonate surface groups blocks the entry of HIV-1 into target cells and is in clinical trials for development as a topical microbicide. Its mechanism of action against R5 HIV-1, the HIV-1 variant implicated in transmission across individuals, remains poorly understood. Using docking and fully atomistic MD simulations, we find that SPL7013 binds tightly to R5 gp120 in the gp120-CD4 complex but weakly to gp120 alone. Further, the binding, although to multiple regions of gp120, does not occlude

  11. The Contribution of CD4+CD25+ T-Regulatory-Cells to Immune Suppression in Sepsis

    PubMed Central

    Wisnoski, Nicholas; Chung, Chun-Shiang; Chen, Yaping; Huang, Xin; Ayala, Alfred

    2006-01-01

    Objective Studies have indicated that there is a development of generalized immune dysfunction following septic insult. However, the mechanisms responsible for these changes remain unclear. Recently, accumulating evidence shows that several lymphocyte subpopulations, such as NKT-, CD4+-Th2-T-, CD8+-T-, γδ-T- and CD4+CD25+-T-regulatory cells, are capable of actively contributing to inducing septic immune suppression. Thus, our aim was to investigate the contribution of CD4+CD25+ cells to the immune dysfunction seen in sepsis. To study this, C57BL/6J, C57BL/6-Il6tm1Kopf (IL-6-/-) and -Il10tm1Cgn (IL-10-/-) mice were subjected to cecal ligation and puncture (CLP) or sham operations. 24hr later, blood was collected and splenocytes were isolated with magnetic microbeads and assessed for phenotypic expression of CD4/CD25 by FACS, cell proliferation [presented as Prolifer. Index = (with anti-CD3)/(without anti-CD3)] and immune suppressive capacity by in vitro add-back experiments. The results indicate a marked elevation in CD4+CD25+ cell levels and their Prolif. Index after sepsis in background mice. CD4+CD25− cells from sham and CLP mice proliferated equally. However, co-culture of CD4+CD− with CD4+CD25+ cells suppressed their proliferation in both sham and CLP mice. Alternatively, in vivo depletion of CD25+ cells prior to CLP markedly restored proliferative capacity and Th1 cytokine release, while not altering plasma pro-inflammatory cytokine levels. Subsequently, IL-6-/- and IL-10-/- mice were used to elucidate the possible mediator(s) regulating those changes seen after sepsis. The increase in septic mouse CD4+CD25+ cells was blunted in IL-10-/- mice but not in IL-6-/- mice. Conversely, while the proliferation of CD4+CD25+ cells from septic C57BL/6J and IL6-/- mice increased, it was blunted in IL-10-/- mice. Surprisingly, depletion of CD25+ cells prior to inducing sepsis did not alter septic mortality. Together, these findings suggest that while CD4+CD25+-T

  12. Chagasic Thymic Atrophy Does Not Affect Negative Selection but Results in the Export of Activated CD4+CD8+ T Cells in Severe Forms of Human Disease

    PubMed Central

    Morrot, Alexandre; Terra-Granado, Eugênia; Pérez, Ana Rosa; Silva-Barbosa, Suse Dayse; Milićević, Novica M.; Farias-de-Oliveira, Désio Aurélio; Berbert, Luiz Ricardo; De Meis, Juliana; Takiya, Christina Maeda; Beloscar, Juan; Wang, Xiaoping; Kont, Vivian; Peterson, Pärt; Bottasso, Oscar; Savino, Wilson

    2011-01-01

    Extrathymic CD4+CD8+ double-positive (DP) T cells are increased in some pathophysiological conditions, including infectious diseases. In the murine model of Chagas disease, it has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment and the lymphoid compartment. In the acute phase, this results in a severe atrophy of the organ and early release of DP cells into the periphery. To date, the effect of the changes promoted by the parasite infection on thymic central tolerance has remained elusive. Herein we show that the intrathymic key elements that are necessary to promote the negative selection of thymocytes undergoing maturation during the thymopoiesis remains functional during the acute chagasic thymic atrophy. Intrathymic expression of the autoimmune regulator factor (Aire) and tissue-restricted antigen (TRA) genes is normal. In addition, the expression of the proapoptotic Bim protein in thymocytes was not changed, revealing that the parasite infection-induced thymus atrophy has no effect on these marker genes necessary to promote clonal deletion of T cells. In a chicken egg ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic system, the administration of OVA peptide into infected mice with thymic atrophy promoted OVA-specific thymocyte apoptosis, further indicating normal negative selection process during the infection. Yet, although the intrathymic checkpoints necessary for thymic negative selection are present in the acute phase of Chagas disease, we found that the DP cells released into the periphery acquire an activated phenotype similar to what is described for activated effector or memory single-positive T cells. Most interestingly, we also demonstrate that increased percentages of peripheral blood subset of DP cells exhibiting an activated HLA-DR+ phenotype are associated with severe cardiac forms of human chronic Chagas disease. These cells may contribute to the

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

    PubMed Central

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

    2006-01-01

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

  14. Clinically HIV but negative serology: Think of idiopathic CD4+ lymphocytopenia

    PubMed Central

    Nagar, Vidya Sanjay; Kadu, Rahul; Chauhan, Shamshersingh Gajendra; Chatterjee, Rudrarpan; Kaushik, Aniruddha; Patel, Deniskumar Vashrambhai; Sood, Ankita

    2016-01-01

    idiopathic CD4+ lymphocytopenia (ICL) is a rare disorder characterized by the presence of depleted CD4 cell line without the presence of HIV infection. Slight male preponderance is noticed and is usually seen in the middle age group. Opportunistic infections are the reason for their discovery and here we describe a case where a man was diagnosed as having Pneumocystis jiroveci pneumonia and oral candidiasis. PMID:27390465

  15. Human plasmacytoid dendritic cells efficiently capture HIV-1 envelope glycoproteins via CD4 for antigen presentation.

    PubMed

    Sandgren, Kerrie J; Smed-Sörensen, Anna; Forsell, Mattias N; Soldemo, Martina; Adams, William C; Liang, Frank; Perbeck, Leif; Koup, Richard A; Wyatt, Richard T; Karlsson Hedestam, Gunilla B; Loré, Karin

    2013-07-01

    Advances in HIV-1 vaccine clinical trials and preclinical research indicate that the virus envelope glycoproteins (Env) are likely to be an essential component of a prophylactic vaccine. Efficient Ag uptake and presentation by dendritic cells (DCs) is important for strong CD4(+) Th cell responses and the development of effective humoral immune responses. In this study, we examined the capacity of distinct primary human DC subsets to internalize and present recombinant Env to CD4(+) T cells. Consistent with their specific receptor expression, skin DCs bound and internalized Env via C-type lectin receptors, whereas blood DC subsets, including CD1c(+) myeloid DCs, CD123(+) plasmacytoid DCs (PDCs), and CD141(+) DCs exhibited a restricted repertoire of C-type lectin receptors and relied on CD4 for uptake of Env. Despite a generally poor capacity for Ag uptake compared with myeloid DCs, the high expression of CD4 on PDCs allowed them to bind and internalize Env very efficiently. CD4-mediated uptake delivered Env to EEA1(+) endosomes that progressed to Lamp1(+) and MHC class II(+) lysosomes where internalized Env was degraded rapidly. Finally, all three blood DC subsets were able to internalize an Env-CMV pp65 fusion protein via CD4 and stimulate pp65-specific CD4(+) T cells. Thus, in the in vitro systems described in this paper, CD4-mediated uptake of Env is a functional pathway leading to Ag presentation, and this may therefore be a mechanism used by blood DCs, including PDCs, for generating immune responses to Env-based vaccines. PMID:23729440

  16. Natural CD4+ T-Cell Responses against Indoleamine 2,3-Dioxygenase

    PubMed Central

    Munir, Shamaila; Larsen, Stine Kiaer; Iversen, Trine Zeeberg; Donia, Marco; Klausen, Tobias Wirenfeldt; Svane, Inge Marie; Straten, Per thor; Andersen, Mads Hald

    2012-01-01

    Background The enzyme indoleamine 2,3-dioxygenase (IDO) contributes to immune tolerance in a variety of settings. In cancer IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it endorses the establishment of peripheral immune tolerance to tumor antigens. Recently, we described cytotoxic CD8+ T-cell reactivity towards IDO-derived peptides. Methods and Findings In the present study, we show that CD4+ helper T cells additionally spontaneously recognize IDO. Hence, we scrutinized the vicinity of the previously described HLA-A*0201-restricted IDO-epitope for CD4+ T-cell epitopes. We demonstrated the presence of naturally occurring IDO-specific CD4+ T cells in cancer patients and to a lesser extent in healthy donors by cytokine release ELISPOT. IDO-reactive CD4+ T cells released IFN-γ, TNF-α, as well as IL-17. We confirm HLA class II-restriction by the addition of HLA class II specific blocking antibodies. In addition, we detected a trend between class I- and class II-restricted IDO responses and detected an association between IDO-specific CD4+ T cells and CD8+ CMV-responses. Finally, we could detect IL-10 releasing IDO-reactive CD4+ T cells. Conclusion IDO is spontaneously recognized by HLA class II-restricted, CD4+ T cells in cancer patients and in healthy individuals. IDO-specific T cells may participate in immune-regulatory networks where the activation of pro-inflammatory IDO-specific CD4+ responses may well overcome or delay the immune suppressive actions of the IDO-protein, which are otherwise a consequence of the early expression of IDO in maturing antigen presenting cells. In contrast, IDO-specific regulatory T cells may enhance IDO-mediated immune suppression. PMID:22539948

  17. The SPL7013 dendrimer destabilizes the HIV-1 gp120-CD4 complex.

    PubMed

    Nandy, Bidisha; Saurabh, Suman; Sahoo, Anil Kumar; Dixit, Narendra M; Maiti, Prabal K

    2015-11-28

    The poly (l-lysine)-based SPL7013 dendrimer with naphthalene disulphonate surface groups blocks the entry of HIV-1 into target cells and is in clinical trials for development as a topical microbicide. Its mechanism of action against R5 HIV-1, the HIV-1 variant implicated in transmission across individuals, remains poorly understood. Using docking and fully atomistic MD simulations, we find that SPL7013 binds tightly to R5 gp120 in the gp120-CD4 complex but weakly to gp120 alone. Further, the binding, although to multiple regions of gp120, does not occlude the CD4 binding site on gp120, suggesting that SPL7013 does not prevent the binding of R5 gp120 to CD4. Using MD simulations to compute binding energies of several docked structures, we find that SPL7013 binding to gp120 significantly weakens the gp120-CD4 complex. Finally, we use steered molecular dynamics (SMD) to study the kinetics of the dissociation of the gp120-CD4 complex in the absence of the dendrimer and with the dendrimer bound in each of the several stable configurations to gp120. We find that SPL7013 significantly lowers the force required to r