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Sample records for central memory cd4

  1. A transcriptome-based model of central memory CD4 T cell death in HIV infection.

    PubMed

    Olvera-García, Gustavo; Aguilar-García, Tania; Gutiérrez-Jasso, Fany; Imaz-Rosshandler, Iván; Rangel-Escareño, Claudia; Orozco, Lorena; Aguilar-Delfín, Irma; Vázquez-Pérez, Joel A; Zúñiga, Joaquín; Pérez-Patrigeon, Santiago; Espinosa, Enrique

    2016-11-22

    Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state. Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log2 Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses. Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1β, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection. Our

  2. Frequency of beryllium-specific, central memory CD4+ T cells in blood determines proliferative response

    PubMed Central

    Fontenot, Andrew P.; Palmer, Brent E.; Sullivan, Andrew K.; Joslin, Fenneke G.; Wilson, Cara C.; Maier, Lisa A.; Newman, Lee S.; Kotzin, Brian L.

    2005-01-01

    Beryllium exposure can lead to the development of beryllium-specific CD4+ T cells and chronic beryllium disease (CBD), which is characterized by the presence of lung granulomas and a CD4+ T cell alveolitis. Studies have documented the presence of proliferating and cytokine-secreting CD4+ T cells in blood of CBD patients after beryllium stimulation. However, some patients were noted to have cytokine-secreting CD4+ T cells in blood in the absence of beryllium-induced proliferation, and overall, the correlation between the 2 types of responses was poor. We hypothesized that the relative proportion of memory T cell subsets determined antigen-specific proliferation. In most CBD patients, the majority of beryllium-specific CD4+ T cells in blood expressed an effector memory T cell maturation phenotype. However, the ability of blood cells to proliferate in the presence of beryllium strongly correlated with the fraction expressing a central memory T cell phenotype. In addition, we found a direct correlation between the percentage of beryllium-specific CD4+ TEM cells in blood and T cell lymphocytosis in the lung. Together, these findings indicate that the functional capability of antigen-specific CD4+ T cells is determined by the relative proportion of memory T cell subsets, which may reflect internal organ involvement. PMID:16151531

  3. Human CD4+ central and effector memory T cells produce IL-21: effect on cytokine-driven proliferation of CD4+ T cell subsets.

    PubMed

    Onoda, Tadashi; Rahman, Mizanur; Nara, Hidetoshi; Araki, Akemi; Makabe, Koki; Tsumoto, Kouhei; Kumagai, Izumi; Kudo, Toshio; Ishii, Naoto; Tanaka, Nobuyuki; Sugamura, Kazuo; Hayasaka, Kiyoshi; Asao, Hironobu

    2007-10-01

    IL-21 regulates certain functions of T cells, B cells, NK cells and dendritic cells. Although activated CD4(+) T cells produce IL-21, data identifying the specific CD4(+) T cell subsets that produce IL-21 are conflicting. In a previous study, mouse IL-21 message was detected in T(H)2, whereas human IL-21 (hIL-21) message was found in both T(H)1 and follicular helper T cells. To identify the IL-21-secreting cell populations in human, we established a hybridoma cell line producing an anti-hIL-21 mAb. Intracellular hIL-21-staining experiments showed that hIL-21 was mainly expressed in activated CD4(+) central memory T cells and in activated CD4(+) effector memory T cells, but not in activated CD4(+) naive T cells. Moreover, IL-21 was produced upon activation by some IFN-gamma-producing T(H)1-polarized cells and some IL-17-producing T(H)17-polarized cells, but not by IL-4-producing T(H)2-polarized cells. These results suggest that specific CD4(+) T cell populations produce IL-21. In the functional analysis, we found that IL-21 significantly enhanced the cytokine-driven proliferation of CD4(+) helper T cells synergistically with IL-7 and IL-15 without T cell activation stimuli. Taken together, IL-21 produced from CD4(+) memory T cells may have a supportive role in the maintenance of CD4(+) T cell subsets.

  4. Central memory CD4+ T cells are preferential targets of double infection by HIV-1.

    PubMed

    Haqqani, Aiman A; Marek, Samantha L; Kumar, Jagadish; Davenport, Miles; Wang, Heng; Tilton, John C

    2015-11-11

    Template switching between two distinct HIV-1 RNA genomes during reverse transcription gives rise to recombinant viruses that greatly expand the genetic diversity of HIV-1 and have adverse implications for drug resistance, immune escape, and vaccine design. Virions with two distinct genomes are produced exclusively from cells infected with two or more viruses, or 'doubly infected' cells. Previous studies have revealed higher than expected frequencies of doubly infected cells compared to frequencies based on chance alone, suggesting non-random enhancement of double infection. We investigated double infection of unstimulated primary CD4+ T cells using reporter viruses carrying genes for different fluorescent proteins, EGFP and mCherry, combined with sophisticated modeling techniques based on Poisson distribution. Additionally, through the use of multiparameter flow cytometry we examined the susceptibility of naïve and memory subsets of CD4+ T cells to double infection by HIV. Using our double infection system, we confirm non-random enhancement of multiple infection events. Double infection of CD4+ T cells was not found to be a consequence of suboptimal provirus expression rescued by Tat in trans-as has been reported in cell lines-but rather due to a heterogeneous cell population in which only a fraction of primary peripheral blood CD4+ T cells are susceptible to HIV infection regardless of viral titer. Intriguingly, double infection of CD4+ T cells occurred preferentially in memory CD4+ T cells-particularly the central memory (TCM) subset-but was not a consequence of SAMHD1-mediated restriction of HIV infection in naïve cells. These findings reveal that double infection in primary CD4+ T cells is primarily a consequences of cellular heterogeneity and not rescue of suboptimal provirus expression by Tat in trans. Additionally, we report a previously unappreciated phenomenon of enhanced double infection within primary TCM cells and suggest that these long-lived cells

  5. 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

  6. Establishment and Reversal of HIV-1 Latency in Naive and Central Memory CD4+ T Cells In Vitro

    PubMed Central

    Zerbato, Jennifer M.; Serrao, Erik; Lenzi, Gina; Kim, Baek; Ambrose, Zandrea; Watkins, Simon C.; Engelman, Alan N.

    2016-01-01

    ABSTRACT The latent HIV-1 reservoir primarily resides in resting CD4+ T cells which are a heterogeneous population composed of both naive (TN) and memory cells. In HIV-1-infected individuals, viral DNA has been detected in both naive and memory CD4+ T cell subsets although the frequency of HIV-1 DNA is typically higher in memory cells, particularly in the central memory (TCM) cell subset. TN and TCM cells are distinct cell populations distinguished by many phenotypic and physiological differences. In this study, we used a primary cell model of HIV-1 latency that utilizes direct infection of highly purified TN and TCM cells to address differences in the establishment and reversal of HIV-1 latency. Consistent with what is seen in vivo, we found that HIV-1 infected TN cells less efficiently than TCM cells. However, when the infected TN cells were treated with latency-reversing agents, including anti-CD3/CD28 antibodies, phorbol myristate acetate/phytohemagglutinin, and prostratin, as much (if not more) extracellular virion-associated HIV-1 RNA was produced per infected TN cell as per infected TCM cell. There were no major differences in the genomic distribution of HIV-1 integration sites between TN and TCM cells that accounted for these observed differences. We observed decay of the latent HIV-1 cells in both T cell subsets after exposure to each of the latency-reversing agents. Collectively, these data highlight significant differences in the establishment and reversal of HIV-1 latency in TN and TCM CD4+ T cells and suggest that each subset should be independently studied in preclinical and clinical studies. IMPORTANCE The latent HIV-1 reservoir is frequently described as residing within resting memory CD4+ T cells. This is largely due to the consistent finding that memory CD4+ T cells, specifically the central (TCM) and transitional memory compartments, harbor the highest levels of HIV-1 DNA in individuals on suppressive therapy. This has yielded little research

  7. 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

  8. Central memory CD4 cells are an early indicator of immune reconstitution in HIV/AIDS patients with anti-retroviral treatment.

    PubMed

    Hua, Wei; Jiao, Yanmei; Zhang, Hongwei; Zhang, Tong; Chen, Dexi; Zhang, Yonghong; Chen, Xinyue; Wu, Hao

    2012-01-01

    The number of central memory cells among the CD4+ T cells and the of activation of CD8+ T cells is believed to be a better indicator of immune restoration in patients on antiretroviral therapy (ART) than the absolute numbers of CD4(+) and CD8+ T cells alone. In the current study, we investigated the changes in the CD4(+) T cell subsets and their association with immune reconstitution and immune activation at early stages of ART. A prospective study was performed in 21 asymptomatic treatment-naive HIV-infected patients with CD4(+) T cells less than 350 cells/μl. Blood samples were evaluated at base line, and at 2, 4, 8 and 12 weeks' post antiretroviral therapy (ART). A biphasic increase of CD4(+) T cells, central memory CD4 cells (CD4 CM) and CD4 naïve cells were observed after ART, with a rapid increase before week 4. Change in CD4 CM at week 4 positively correlated with the change in CD4(+) T cells at weeks 12 post ART, and negatively correlated with the change in CD8(+)CD38(+) T cells at weeks 12 post ART. We conclude that CD4 CM cells are a major contributor to early immune reconstitution in treatment-naive HIV-infected patients with delayed ART, and might be an early indicator for immune reconstitution.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  11. Increased ex vivo cell death of central memory CD4 T cells in treated HIV infected individuals with unsatisfactory immune recovery.

    PubMed

    Massanella, Marta; Gómez-Mora, Elisabet; Carrillo, Jorge; Curriu, Marta; Ouchi, Dan; Puig, Jordi; Negredo, Eugènia; Cabrera, Cecilia; Clotet, Bonaventura; Blanco, Julià

    2015-07-17

    High levels of ex vivo CD4 T-cell death and the accumulation of highly differentiated and/or immunosenescent T cells have been associated with poor CD4 T-cell recovery in treated HIV-infected individuals. However, the relationship between cell death and T-cell differentiation is still unclear. We have analyzed cell death, immunosenescence and differentiation parameters in HAART-treated subjects (VL <50 copies/mL for more than 2 years) with CD4 T-cell count <350 cells/μL (immunodiscordant, n = 23) or >400 cells/μL (immunoconcordant, n = 33). We included 11 healthy individuals as reference. As expected, suboptimal CD4 T-cell recovery was associated with low frequencies of naïve cells, high frequencies of transitional and effector memory cells and a subsequent low ratio of central/transitional memory cells in the CD4 compartment. These alterations correlated with spontaneous CD4 T-cell death. A deeper analysis of cell death in CD4 T-cell subsets showed increased cell death in memory cells of immunodiscordant individuals, mainly affecting central memory cells. Immunosenescence was also higher in immunodiscordant individuals albeit unrelated to cell death. The CD8 compartment was similar in both HIV-infected groups, except for an underrepresentation of naïve cells in immunodiscordant individuals. Immunodiscordant individuals show alterations in memory CD4 T-cell differentiation associated with a short ex vivo lifespan of central memory cells and an in vivo low central/transitional memory cell ratio. These alterations may contribute to poor CD4 T-cell repopulation.

  12. CXCR5 expressing human central memory CD4 T cells and their relevance for humoral immune responses.

    PubMed

    Chevalier, Nina; Jarrossay, David; Ho, Edwin; Avery, Danielle T; Ma, Cindy S; Yu, Di; Sallusto, Federica; Tangye, Stuart G; Mackay, Charles R

    2011-05-15

    High expression of CXCR5 is one of the defining hallmarks of T follicular helper cells (T(FH)), a CD4 Th cell subset that promotes germinal center reactions and the selection and affinity maturation of B cells. CXCR5 is also expressed on 20-25% of peripheral blood human central memory CD4 T cells (T(CM)), although the definitive function of these cells is not fully understood. The constitutive expression of CXCR5 on T(FH) cells and a fraction of circulating T(CM) suggests that CXCR5(+) T(CM) may represent a specialized subset of memory-type T(FH) cells programmed for homing to follicles and providing B cell help. To verify this assumption, we analyzed this cell population and show its specialized function in supporting humoral immune responses. Compared with their CXCR5(-) T(CM) counterparts, CXCR5(+) T(CM) expressed high levels of the chemokine CXCL13 and efficiently induced plasma cell differentiation and Ig secretion. We found that the distinct B cell helper qualities of CXCR5(+) T(CM) were mainly due to high ICOS expression and pronounced responsiveness to ICOS ligand costimulation together with large IL-10 secretion. Furthermore, B cell helper attributes of CXCR5(+) T(CM) were almost exclusively acquired on cognate interaction with B cells, but not with dendritic cells. This implies that a preferential recruitment of circulating CXCR5(+) T(CM) to CXCL13-rich B cell follicles is required for the promotion of a quick and efficient protective secondary humoral immune response. Taken together, we propose that CXCR5(+) T(CM) represent a distinct memory cell subset specialized in supporting Ab-mediated immune responses.

  13. ICOS is required for the generation of both central and effector CD4(+) memory T-cell populations following acute bacterial infection.

    PubMed

    Marriott, Clare L; Carlesso, Gianluca; Herbst, Ronald; Withers, David R

    2015-06-01

    Interactions between ICOS and ICOS ligand (ICOSL) are essential for the development of T follicular helper (Tfh) cells and thus the formation and maintenance of GC reactions. Given the conflicting reports on the requirement of other CD4(+) T-cell populations for ICOS signals, we have employed a range of in vivo approaches to dissect requirements for ICOS signals in mice during an endogenous CD4(+) T-cell response and contrasted this with CD28 signals. Genetic absence of ICOSL only modestly reduced the total number of antigen-specific CD4(+) T cells at the peak of the primary response, but resulted in a severely diminished number of both T central memory and T effector memory cells. Treatment with blocking anti-ICOS mAb during the primary response recapitulated these effects and caused a more substantial reduction than blocking CD28 signals with CTLA4Ig. During the memory phase of the response further signals through ICOS or CD28 were not required for survival. However, upon secondary challenge only Tfh cell expansion remained heavily ICOS-dependent, while CD28 signals were required for optimal expansion of all subsets. These data demonstrate the importance of ICOS signals specifically for memory CD4(+) T-cell formation, while highlighting the potential of therapeutically targeting this pathway.

  14. Reactivation of latent HIV-1 in central memory CD4⁺ T cells through TLR-1/2 stimulation.

    PubMed

    Novis, Camille L; Archin, Nancie M; Buzon, Maria J; Verdin, Eric; Round, June L; Lichterfeld, Mathias; Margolis, David M; Planelles, Vicente; Bosque, Alberto

    2013-10-24

    Toll-like receptors (TLRs) are crucial for recognition of pathogen-associated molecular patterns by cells of the innate immune system. TLRs are present and functional in CD4⁺ T cells. Memory CD4⁺ T cells, predominantly central memory cells (TCM), constitute the main reservoir of latent HIV-1. However, how TLR ligands affect the quiescence of latent HIV within central memory CD4⁺ T cells has not been studied. We evaluated the ability of a broad panel of TLR agonists to reactivate latent HIV-1. The TLR-1/2 agonist Pam3CSK4 leads to viral reactivation of quiescent HIV in a model of latency based on cultured TCM and in resting CD4⁺ T cells isolated from aviremic patients. In addition, we investigated the signaling pathway associated with Pam3CSK4 involved in HIV-1 reactivation. We show that the transcription factors NFκB, NFAT and AP-1 cooperate to induce viral reactivation downstream of TLR-1/2 stimulation. Furthermore, increasing levels of cyclin T1 is not required for TLR-mediated viral reactivation, but induction of viral expression requires activated pTEFb. Finally, Pam3CSK4 reactivates latent HIV-1 in the absence of T cell activation or proliferation, in contrast to antigen stimulation. Our findings suggest that the signaling through TLR-1/2 pathway via Pam3CSK4 or other reagents should be explored as an anti-latency strategy either alone or in combination with other anti-latency drugs.

  15. Protective Immunity Induced with the RTS,S/AS Vaccine Is Associated with IL-2 and TNF-α Producing Effector and Central Memory CD4+ T Cells

    PubMed Central

    Rein, Lisa E.; Moris, Philippe; Janssens, Michel; Ofori-Anyinam, Opokua; Cohen, Joe; Kester, Kent E.; Heppner, D. Gray; Krzych, Urszula

    2011-01-01

    A phase 2a RTS,S/AS malaria vaccine trial, conducted previously at the Walter Reed Army Institute of Research, conferred sterile immunity against a primary challenge with infectious sporozoites in 40% of the 80 subjects enrolled in the study. The frequency of Plasmodium falciparum circumsporozoite protein (CSP)-specific CD4+ T cells was significantly higher in protected subjects as compared to non-protected subjects. Intrigued by these unique vaccine-related correlates of protection, in the present study we asked whether RTS,S also induced effector/effector memory (TE/EM) and/or central memory (TCM) CD4+ T cells and whether one or both of these sub-populations is the primary source of cytokine production. We showed for the first time that PBMC from malaria-non-exposed RTS,S-immunized subjects contain both TE/EM and TCM cells that generate strong IL-2 responses following re-stimulation in vitro with CSP peptides. Moreover, both the frequencies and the total numbers of IL-2-producing CD4+ TE/EM cells and of CD4+ TCM cells from protected subjects were significantly higher than those from non-protected subjects. We also demonstrated for the first time that there is a strong association between the frequency of CSP peptide-reactive CD4+ T cells producing IL-2 and the titers of CSP-specific antibodies in the same individual, suggesting that IL-2 may be acting as a growth factor for follicular Th cells and/or B cells. The frequencies of CSP peptide-reactive, TNF-α-producing CD4+ TE/EM cells and of CD4+ TE/EM cells secreting both IL-2 and TNF-α were also shown to be higher in protected vs. non-protected individuals. We have, therefore, demonstrated that in addition to TNF-α, IL-2 is also a significant contributing factor to RTS,S/AS vaccine induced immunity and that both TE/EM and TCM cells are major producers of IL-2. PMID:21779319

  16. Divergent CD4+ T memory stem cell dynamics in pathogenic and nonpathogenic simian immunodeficiency virus infections.

    PubMed

    Cartwright, Emily K; McGary, Colleen S; Cervasi, Barbara; Micci, Luca; Lawson, Benton; Elliott, Sarah T C; Collman, Ronald G; Bosinger, Steven E; Paiardini, Mirko; Vanderford, Thomas H; Chahroudi, Ann; Silvestri, Guido

    2014-05-15

    Recent studies have identified a subset of memory T cells with stem cell-like properties (T(SCM)) that include increased longevity and proliferative potential. In this study, we examined the dynamics of CD4(+) T(SCM) during pathogenic SIV infection of rhesus macaques (RM) and nonpathogenic SIV infection of sooty mangabeys (SM). Whereas SIV-infected RM show selective numeric preservation of CD4(+) T(SCM), SIV infection induced a complex perturbation of these cells defined by depletion of CD4(+)CCR5(+) T(SCM), increased rates of CD4(+) T(SCM) proliferation, and high levels of direct virus infection. The increased rates of CD4(+) T(SCM) proliferation in SIV-infected RM correlated inversely with the levels of central memory CD4(+) T cells. In contrast, nonpathogenic SIV infection of SM evidenced preservation of both CD4(+) T(SCM) and CD4(+) central memory T cells, with normal levels of CD4(+) T(SCM) proliferation, and lack of selective depletion of CD4(+)CCR5(+) T(SCM). Importantly, SIV DNA was below the detectable limit in CD4(+) T(SCM) from 8 of 10 SIV-infected SM. We propose that increased proliferation and infection of CD4(+) T(SCM) may contribute to the pathogenesis of SIV infection in RM.

  17. Immune memory in CD4+ CD45RA+ T cells.

    PubMed Central

    Richards, D; Chapman, M D; Sasama, J; Lee, T H; Kemeny, D M

    1997-01-01

    This study addresses the question of whether human peripheral CD4+ CD45RA+ T cells possess antigen-specific immune memory. CD4+ CD45RA+ T cells were isolated by a combination of positive and negative selection. Putative CD4+ CD45RA+ cells expressed CD45RA (98.9%) and contained < 0.1% CD4+ CD45RO+ and < 0.5% CD4+ CD45RA+ CD45RO+ cells. Putative CD45RO+ cells expressed CD45RO (90%) and contained 9% CD45RA+ CD45RO+ and < 0.1% CD4+ CD45RA+ cells. The responder frequency of Dermatophagoides pteronyssinus-stimulated CD4+ CD45RA+ and CD4+ CD45RO+ T cells was determined in two atopic donors and found to be 1:11,314 and 1:8031 for CD4+ CD45RA+ and 1:1463 and 1:1408 for CD4+ CD45RO+ T cells. The responder frequencies of CD4+ CD45RA+ and CD4+ CD45RO+ T cells from two non-atopic, but exposed, donors were 1:78031 and 1:176,903 for CD4+ CD45RA+ and 1:9136 and 1:13,136 for CD4+ CD45RO+ T cells. T cells specific for D. pteronyssinus were cloned at limiting dilution following 10 days of bulk culture with D. pteronyssinus antigen. Sixty-eight clones were obtained from CD4+ CD45RO+ and 24 from CD4+ CD45RA+ T cells. All clones were CD3+ CD4+ CD45RO+ and proliferated in response to D. pteronyssinus antigens. Of 40 clones tested, none responded to Tubercule bacillus purified protein derivative (PPD). No difference was seen in the pattern of interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) producing clones derived from CD4+ CD45RA+ and CD4+ CD45RO+ precursors, although freshly isolated and polyclonally activated CD4+ CD45RA+ T cells produced 20-30-fold lower levels of IL-4 and IFN-gamma than their CD4+ CD45RO+ counterparts. Sixty per cent of the clones used the same pool of V beta genes. These data support the hypothesis that immune memory resides in CD4+ CD45RA+ as well as CD4+ CD45RO+ T cells during the chronic immune response to inhaled antigen. PMID:9301520

  18. Transcriptomic Analysis Implicates the p53 Signaling Pathway in the Establishment of HIV-1 Latency in Central Memory CD4 T Cells in an In Vitro Model.

    PubMed

    White, Cory H; Moesker, Bastiaan; Beliakova-Bethell, Nadejda; Martins, Laura J; Spina, Celsa A; Margolis, David M; Richman, Douglas D; Planelles, Vicente; Bosque, Alberto; Woelk, Christopher H

    2016-11-01

    The search for an HIV-1 cure has been greatly hindered by the presence of a viral reservoir that persists despite antiretroviral therapy (ART). Studies of HIV-1 latency in vivo are also complicated by the low proportion of latently infected cells in HIV-1 infected individuals. A number of models of HIV-1 latency have been developed to examine the signaling pathways and viral determinants of latency and reactivation. A primary cell model of HIV-1 latency, which incorporates the generation of primary central memory CD4 T cells (TCM), full-length virus infection (HIVNL4-3) and ART to suppress virus replication, was used to investigate the establishment of HIV latency using RNA-Seq. Initially, an investigation of host and viral gene expression in the resting and activated states of this model indicated that the resting condition was reflective of a latent state. Then, a comparison of the host transcriptome between the uninfected and latently infected conditions of this model identified 826 differentially expressed genes, many of which were related to p53 signaling. Inhibition of the transcriptional activity of p53 by pifithrin-α during HIV-1 infection reduced the ability of HIV-1 to be reactivated from its latent state by an unknown mechanism. In conclusion, this model may be used to screen latency reversing agents utilized in shock and kill approaches to cure HIV, to search for cellular markers of latency, and to understand the mechanisms by which HIV-1 establishes latency.

  19. Transcriptomic Analysis Implicates the p53 Signaling Pathway in the Establishment of HIV-1 Latency in Central Memory CD4 T Cells in an In Vitro Model

    PubMed Central

    White, Cory H.; Moesker, Bastiaan; Beliakova-Bethell, Nadejda; Martins, Laura J.; Richman, Douglas D.; Planelles, Vicente; Woelk, Christopher H.

    2016-01-01

    The search for an HIV-1 cure has been greatly hindered by the presence of a viral reservoir that persists despite antiretroviral therapy (ART). Studies of HIV-1 latency in vivo are also complicated by the low proportion of latently infected cells in HIV-1 infected individuals. A number of models of HIV-1 latency have been developed to examine the signaling pathways and viral determinants of latency and reactivation. A primary cell model of HIV-1 latency, which incorporates the generation of primary central memory CD4 T cells (TCM), full-length virus infection (HIVNL4-3) and ART to suppress virus replication, was used to investigate the establishment of HIV latency using RNA-Seq. Initially, an investigation of host and viral gene expression in the resting and activated states of this model indicated that the resting condition was reflective of a latent state. Then, a comparison of the host transcriptome between the uninfected and latently infected conditions of this model identified 826 differentially expressed genes, many of which were related to p53 signaling. Inhibition of the transcriptional activity of p53 by pifithrin-α during HIV-1 infection reduced the ability of HIV-1 to be reactivated from its latent state by an unknown mechanism. In conclusion, this model may be used to screen latency reversing agents utilized in shock and kill approaches to cure HIV, to search for cellular markers of latency, and to understand the mechanisms by which HIV-1 establishes latency. PMID:27898737

  20. Priming of CD4+ T cells and development of CD4+ T cell memory; lessons for malaria.

    PubMed

    Stephens, R; Langhorne, J

    2006-01-01

    CD4 T cells play a central role in the immune response to malaria. They are required to help B cells produce the antibody that is essential for parasite clearance. They also produce cytokines that amplify the phagocytic and parasitocidal response of the innate immune system, as well as dampening this response later on to limit immunopathology. Therefore, understanding the mechanisms by which T helper cells are activated and the requirements for development of specific, and effective, T cell memory and immunity is essential in the quest for a malaria vaccine. In this paper on the CD4 session of the Immunology of Malaria Infections meeting, we summarize discussions of CD4 cell priming and memory in malaria and in vaccination and outline critical future lines of investigation. B. Stockinger and M.K. Jenkins proposed cutting edge experimental systems to study basic T cell biology in malaria. Critical parameters in T cell activation include the cell types involved, the route of infection and the timing and location and cell types involved in antigen presentation. A new generation of vaccines that induce CD4 T cell activation and memory are being developed with new adjuvants. Studies of T cell memory focus on differentiation and factors involved in maintenance of antigen specific T cells and control of the size of that population. To improve detection of T cell memory in the field, efforts will have to be made to distinguish antigen-specific responses from cytokine driven responses.

  1. Preferential expansion of human virus-specific multifunctional central memory T cells by partial targeting of the IL-2 receptor signaling pathway: the key role of CD4+ T cells.

    PubMed

    Schmueck, Michael; Fischer, Annika M; Hammoud, Ben; Brestrich, Gordon; Fuehrer, Henrike; Luu, Si-Hong; Mueller, Karin; Babel, Nina; Volk, Hans-Dieter; Reinke, Petra

    2012-05-15

    Effector memory T cells are effective in controlling acute infections, but central memory T cells play a key role in long-lasting protection against viruses and tumors. In vivo/in vitro challenge by Ag commonly supports the generation of effector memory T cells with limited longevity. To our knowledge, this study demonstrates for the first time in the human system and under rechallenge conditions that targeting IL-2R by partial mammalian target of rapamycin inhibition or blocking IL-2Rα enriches human CD4(+)/CD8(+) central memory T cells within the virus-specific T cell product associated with enhanced functionality (i.e., multicytokine secretors, including IL-2; enhanced CD137 and CD107a expression on CD8(+) and CD4(+) T cells, respectively; and killing infected target cells). Remarkably, the effects on CD8(+) T cells are mainly mediated via the enhancement of CD4(+) T cell function. The data reveal new insights into the role of CD4(+) T cell support for the quality of CD8(+) T cell memory, even under rechallenge conditions. Moreover, our method offers a new approach to improve the long-lasting efficacy of adoptive T cell therapy in patients.

  2. Increased Stability and Limited Proliferation of CD4+ Central Memory T Cells Differentiate Nonprogressive Simian Immunodeficiency Virus (SIV) Infection of Sooty Mangabeys from Progressive SIV Infection of Rhesus Macaques

    PubMed Central

    McGary, Colleen S.; Cervasi, Barbara; Chahroudi, Ann; Micci, Luca; Taaffe, Jessica; Meeker, Tracy; Silvestri, Guido; Davenport, Miles P.

    2014-01-01

    ABSTRACT Depletion of CD4+ central memory T (TCM) cells dictates the tempo of progression to AIDS in simian immunodeficiency virus (SIV)-infected rhesus macaques (RMs) both in the natural history of infection and in the context of vaccination. CD4+ TCM cells of sooty mangabeys (SMs), a natural host for SIV in which infection is nonpathogenic, are less susceptible to SIV infection than CD4+ TCM cells of RMs. Whether this relative protection from infection translates into increased stability of CD4+ TCM cells in natural versus nonnatural hosts has not yet been determined. Here we compared, both cross-sectionally and longitudinally, the levels of CD4+ TCM cells in a large cohort of SMs and RMs and the association between CD4+ TCM levels and the main virologic and immunologic markers of disease progression. Consistent with their lower susceptibility to infection, CD4+ TCM cells of SIV-infected SMs are lost with kinetics 20 times slower than those of SIV-infected RMs. Remarkably, the estimated length of time of SIV infection needed for CD4+ TCM cells to fall to half of their initial levels is <16 months for RMs but >17 years for SMs. Furthermore, the fraction of proliferating CD4+ TCM cells is significantly lower in SIV-infected SMs than in SIV-infected RMs, and the extent of CD4+ TCM cell proliferation is associated positively with CD4+ T cell levels in SIV-infected SMs but negatively with CD4+ T cell levels in SIV-infected RMs. Collectively, these findings identify increased stability and maintenance of the prohomeostatic role of CD4+ TCM cells as features distinguishing nonprogressive from progressive SIV infections and support the hypothesis of a direct mechanistic link between the loss of CD4+ TCM cells and disease progression. IMPORTANCE Comparison of the immunologic effects of simian immunodeficiency virus (SIV) infection on rhesus macaques (RMs), a species characterized by progression to AIDS, and natural host sooty mangabeys (SMs), a species which remains AIDS

  3. 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

  4. Endothelial cell-T lymphocyte interactions: IP[corrected]-10 stimulates rapid transendothelial migration of human effector but not central memory CD4+ T cells. Requirements for shear stress and adhesion molecules.

    PubMed

    Manes, Thomas D; Pober, Jordan S; Kluger, Martin S

    2006-07-15

    The chemokine interferon (IFN)-gamma-inducible protein of 10 kDa (IP-10; CXCL10) has been implicated in recruitment of T cells into rejecting allografts yet appears ineffective at stimulating human peripheral blood CD4 T cells to transmigrate across tumor necrosis factor (TNF)-treated human endothelial cell (EC) monolayers in vitro. The same cells rapidly (within 15 min) transmigrate across TNF-treated EC monolayers overlaid with stromal cell-derived factor-1 alpha (SDF-1 alpha) and subjected to shear stress. The effector memory subset within the CD4 T cell population, defined as CD45RO, CD62L and CCR7, which constitutes less than 10% of total CD4 T cells, does respond to IP-10 but requires enrichment to be observed in this model. Central memory T cells do not respond to IP-10. Transendothelial migration of effector memory CD4 T cells requires TNF-pretreatment of the EC monolayer and application of venular shear force during the assay. TNF treatment of ECs may be effectively replaced by transduction of vascular cell adhesion molecule-1 or intercellular adhesion molecule-1 but not E-selectin.

  5. CD4 T-Cell Memory Generation and Maintenance

    PubMed Central

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

    2014-01-01

    Immunologic memory is the adaptive immune system's powerful ability to remember a previous antigen encounter and react with accelerated vigor upon antigen re-exposure. It provides durable protection against reinfection with pathogens and is the foundation for vaccine-induced immunity. Unlike the relatively restricted immunologic purview of memory B cells and CD8 T cells, the field of CD4 T-cell memory must account for multiple distinct lineages with diverse effector functions, the issue of lineage commitment and plasticity, and the variable distribution of memory cells within each lineage. Here, we discuss the evidence for lineage-specific CD4 T-cell memory and summarize the known factors contributing to memory-cell generation, plasticity, and long-term maintenance. PMID:24940912

  6. CD4 T-cell memory generation and maintenance.

    PubMed

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

    2014-01-01

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

  7. Persistent expansion of CD4+ effector memory T cells in Wegener's granulomatosis.

    PubMed

    Abdulahad, W H; van der Geld, Y M; Stegeman, C A; Kallenberg, C G M

    2006-09-01

    In order to test the hypothesis that Wegener's granulomatosis (WG) is associated with an ongoing immune effector response, even in remission, we examined the distribution of peripheral naive and memory T-lymphocytes in this disease, and analyzed the function-related phenotypes of the memory T-cell population. Peripheral blood mononuclear cells (PBMCs) were freshly isolated from WG-patients in remission (R-WG, n=40), active WG-patients (A-WG, n=17), and age-matched healthy controls (HCs, n=21). Expression of CD4, CD8, CD45RO, CCR7, interleukin (IL)-18Ralpha, ST2L, and FoxP3 were determined by four-color flow cytometric analysis. CD45RO and CCR7 were used for distinction between naive and memory T cells, IL-18Ralpha, ST2L, and FoxP3 for the assessment of Type1, Type2, and regulatory T-cells, respectively. In R-WG, the CD4+CD45RO+CCR7- effector memory T-cell subpopulation (TEM) was relatively increased, whereas the CD4+CD45RO-CCR7+ naive T-cell population (TNaive) was decreased as compared to HC. The distribution of naive and memory CD8+T cells did not differ between R-WG, A-WG, and HC, nor did CD4+CD45RO+CCR7+ central memory T cells (TCM). In contrast to HC, the percentage of CD4+TNaive cells in R-WG correlated negatively with age, whereas CD4+TEM cells showed a positive correlation. In R-WG, a skewing towards Type2 T cells was observed in CD4+TEM cells. No differences were detected in FoxP3+CD4+TEM cells between R-WG and A-WG, whereas the FoxP3-CD4+TEM cells were increased in R-WG and decreased in A-WG as compared to HC. Collectively, peripheral blood homeostasis of CD4+T cells is disturbed in R-WG with the persistent expansion of non-regulatory CD4+TEM cells. These cells might be involved in relapse and may constitute a target for therapy.

  8. A colitogenic memory CD4+ T cell population mediates gastrointestinal graft-versus-host disease

    PubMed Central

    Zhou, Vivian; Agle, Kimberle; Chen, Xiao; Beres, Amy; Komorowski, Richard; Belle, Ludovic; Taylor, Carolyn; Zhu, Fenlu; Haribhai, Dipica; Williams, Calvin B.; Verbsky, James; Blumenschein, Wendy; Sadekova, Svetlana; Bowman, Eddie; Ballantyne, Christie; Weaver, Casey; Serody, David A.; Vincent, Benjamin; Serody, Jonathan; Cua, Daniel J.; Drobyski, William R.

    2016-01-01

    Damage to the gastrointestinal tract is a major cause of morbidity and mortality in graft-versus-host disease (GVHD) and is attributable to T cell–mediated inflammation. In this work, we identified a unique CD4+ T cell population that constitutively expresses the β2 integrin CD11c and displays a biased central memory phenotype and memory T cell transcriptional profile, innate-like properties, and increased expression of the gut-homing molecules α4β7 and CCR9. Using several complementary murine GVHD models, we determined that adoptive transfer and early accumulation of β2 integrin–expressing CD4+ T cells in the gastrointestinal tract initiated Th1-mediated proinflammatory cytokine production, augmented pathological damage in the colon, and increased mortality. The pathogenic effect of this CD4+ T cell population critically depended on coexpression of the IL-23 receptor, which was required for maximal inflammatory effects. Non–Foxp3-expressing CD4+ T cells produced IL-10, which regulated colonic inflammation and attenuated lethality in the absence of functional CD4+Foxp3+ T cells. Thus, the coordinate expression of CD11c and the IL-23 receptor defines an IL-10–regulated, colitogenic memory CD4+ T cell subset that is poised to initiate inflammation when there is loss of tolerance and breakdown of mucosal barriers. PMID:27500496

  9. Peripheral T Follicular Helper Cells Are the Major HIV Reservoir within Central Memory CD4 T Cells in Peripheral Blood from Chronically HIV-Infected Individuals on Combination Antiretroviral Therapy

    PubMed Central

    Pallikkuth, Suresh; Sharkey, Mark; Babic, Dunja Z.; Gupta, Sachin; Stone, Geoffrey W.; Fischl, Margaret A.; Stevenson, Mario

    2015-01-01

    ABSTRACT In this study, we examined the peripheral blood (PB) central memory (TCM) CD4+ T cell subsets designated peripheral T follicular helper cells (pTfh cells) and non-pTfh cells to assess HIV permissiveness and persistence. Purified pTfh and non-pTfh cells from healthy HIV-negative donors were tested for HIV permissiveness using green fluorescent protein (GFP)-expressing HIV-1NL4-3/Ba-L, followed by viral reactivation using beads coated with anti-CD3/anti-CD28 monoclonal antibodies. The role of pTfh cells in HIV persistence was analyzed in 12 chronically HIV-1 infected patients before and 48 weeks after initiation of raltegravir-containing combination antiretroviral therapy (cART). Total cellular HIV-1 DNA and episomes containing two copies of the viral long terminal repeat (2LTR circles) were analyzed in using droplet digital PCR in the purified pTfh and non-pTfh cells. Activation-inducible HIV p24 expression was determined by flow cytometry. Results indicate that pTfh cells, in particular PD1+ pTfh cells, showed greater permissiveness for HIV infection than non-pTfh cells. At week 48 on cART, HIV DNA levels were unchanged from pre-cART levels, although a significant decrease in 2LTR circles was observed in both cell subsets. Inducible HIV p24 expression was higher in pTfh cells than in non-pTfh cells, with the highest frequencies in the PD1+ CXCR3− pTfh cell subset. Frequencies of HLADR+ CD38+ activated CD4 T cells correlated with 2LTR circles in pTfh and non-pTfh cells at both time points and with p24+ cells at entry. In conclusion, among CD4 TCM cells in PB of aviremic patients on cART, pTfh cells, in particular the PD1+ CXCR3− subset, constitute a major HIV reservoir that is sustained by ongoing residual immune activation. The inducible HIV p24 assay is useful for monitoring HIV reservoirs in defined CD4 T cell subsets. IMPORTANCE Identification of the type and nature of the cellular compartments of circulating HIV reservoirs is important for

  10. 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

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

    PubMed

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

    2014-02-10

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

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

    PubMed Central

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

    2014-01-01

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

  13. Longitudinal changes in CD4(+) T-cell memory responses induced by BCG vaccination of newborns.

    PubMed

    Soares, Andreia P; Kwong Chung, Cheong K C; Choice, Terry; Hughes, E Jane; Jacobs, Gail; van Rensburg, Esme Janse; Khomba, Gloria; de Kock, Marwou; Lerumo, Lesedi; Makhethe, Lebohang; Maneli, Mbulelo H; Pienaar, Bernadette; Smit, Erica; Tena-Coki, Nontobeko G; van Wyk, Leandre; Boom, W Henry; Kaplan, Gilla; Scriba, Thomas J; Hanekom, Willem A

    2013-04-01

    Improved vaccination strategies against tuberculosis are needed, such as approaches to boost immunity induced by the current vaccine, BCG. Design of these strategies has been hampered by a lack of knowledge of the kinetics of the human host response induced by neonatal BCG vaccination. Furthermore, the functional and phenotypic attributes of BCG-induced long-lived memory T-cell responses remain unclear. We assessed the longitudinal CD4 T-cell response following BCG vaccination of human newborns. The kinetics, function, and phenotype of these cells were measured using flow cytometric whole-blood assays. We showed that the BCG-specific CD4 T-cell response peaked 6-10 weeks after vaccination and gradually waned over the first year of life. Highly activated T-helper 1 cells, predominantly expressing interferon γ, tumor necrosis factor α, and/or interleukin 2, were present at the peak response. Following contraction, BCG-specific CD4 T cells expressed high levels of Bcl-2 and displayed a predominant CD45RACCR7 central memory phenotype. However, cytokine and cytotoxic marker expression by these cells was more characteristic of effector memory cells. Our findings suggest that boosting of BCG-primed CD4 T cells with heterologous tuberculosis vaccines may be best after 14 weeks of age, once an established memory response has developed.

  14. Longitudinal Changes in CD4+ T-Cell Memory Responses Induced by BCG Vaccination of Newborns

    PubMed Central

    Soares, Andreia P.; Kwong Chung, Cheong K. C.; Choice, Terry; Hughes, E. Jane; Jacobs, Gail; van Rensburg, Esme Janse; Khomba, Gloria; de Kock, Marwou; Lerumo, Lesedi; Makhethe, Lebohang; Maneli, Mbulelo H.; Pienaar, Bernadette; Smit, Erica; Tena-Coki, Nontobeko G.; van Wyk, Leandre; Boom, W. Henry; Kaplan, Gilla; Scriba, Thomas J.; Hanekom, Willem A.

    2013-01-01

    Background. Improved vaccination strategies against tuberculosis are needed, such as approaches to boost immunity induced by the current vaccine, BCG. Design of these strategies has been hampered by a lack of knowledge of the kinetics of the human host response induced by neonatal BCG vaccination. Furthermore, the functional and phenotypic attributes of BCG-induced long-lived memory T-cell responses remain unclear. Methods. We assessed the longitudinal CD4+ T-cell response following BCG vaccination of human newborns. The kinetics, function, and phenotype of these cells were measured using flow cytometric whole-blood assays. Results. We showed that the BCG-specific CD4+ T-cell response peaked 6–10 weeks after vaccination and gradually waned over the first year of life. Highly activated T-helper 1 cells, predominantly expressing interferon γ, tumor necrosis factor α, and/or interleukin 2, were present at the peak response. Following contraction, BCG-specific CD4+ T cells expressed high levels of Bcl-2 and displayed a predominant CD45RA–CCR7+ central memory phenotype. However, cytokine and cytotoxic marker expression by these cells was more characteristic of effector memory cells. Conclusions. Our findings suggest that boosting of BCG-primed CD4+ T cells with heterologous tuberculosis vaccines may be best after 14 weeks of age, once an established memory response has developed. PMID:23293360

  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. © 2015 Shakya et al.

  16. Initiation of Antiretroviral Therapy Restores CD4+ T Memory Stem Cell Homeostasis in Simian Immunodeficiency Virus-Infected Macaques.

    PubMed

    Cartwright, Emily K; Palesch, David; Mavigner, Maud; Paiardini, Mirko; Chahroudi, Ann; Silvestri, Guido

    2016-08-01

    Treatment of human immunodeficiency virus (HIV) infection with antiretroviral therapy (ART) has significantly improved prognosis. Unfortunately, interruption of ART almost invariably results in viral rebound, attributed to a pool of long-lived, latently infected cells. Based on their longevity and proliferative potential, CD4(+) T memory stem cells (TSCM) have been proposed as an important site of HIV persistence. In a previous study, we found that in simian immunodeficiency virus (SIV)-infected rhesus macaques (RM), CD4(+) TSCM are preserved in number but show (i) a decrease in the frequency of CCR5(+) cells, (ii) an expansion of the fraction of proliferating Ki-67(+) cells, and (iii) high levels of SIV DNA. To understand the impact of ART on both CD4(+) TSCM homeostasis and virus persistence, we conducted a longitudinal analysis of these cells in the blood and lymph nodes of 25 SIV-infected RM. We found that ART induced a significant restoration of CD4(+) CCR5(+) TSCM both in blood and in lymph nodes and a reduction in the fraction of proliferating CD4(+) Ki-67(+) TSCM in blood (but not lymph nodes). Importantly, we found that the level of SIV DNA in CD4(+) transitional memory (TTM) and effector memory (TEM) T cells declined ∼100-fold after ART in both blood and lymph nodes, while the level of SIV DNA in CD4(+) TSCM and central memory T cells (TCM-) did not significantly change. These data suggest that ART is effective at partially restoring CD4(+) TSCM homeostasis, and the observed stable level of virus in TSCM supports the hypothesis that these cells are a critical contributor to SIV persistence. Understanding the roles of various CD4(+) T cell memory subsets in immune homeostasis and HIV/SIV persistence during antiretroviral therapy (ART) is critical to effectively treat and cure HIV infection. T memory stem cells (TSCM) are a unique memory T cell subset with enhanced self-renewal capacity and the ability to differentiate into other memory T cell subsets

  17. Differential T cell receptor-mediated signaling in naive and memory CD4 T cells.

    PubMed

    Farber, D L; Acuto, O; Bottomly, K

    1997-08-01

    Naive and memory CD4 T cells differ in cell surface phenotype, function, activation requirements, and modes of regulation. To investigate the molecular bases for the dichotomies between naive and memory CD4 T cells and to understand how the T cell receptor (TCR) directs diverse functional outcomes, we investigated proximal signaling events triggered through the TCR/CD3 complex in naive and memory CD4 T cell subsets isolated on the basis of CD45 isoform expression. Naive CD4 T cells signal through TCR/CD3 similar to unseparated CD4 T cells, producing multiple tyrosine-phosphorylated protein species overall and phosphorylating the T cell-specific ZAP-70 tyrosine kinase which is recruited to the CD3zeta subunit of the TCR. Memory CD4 T cells, however, exhibit a unique pattern of signaling through TCR/CD3. Following stimulation through TCR/CD3, memory CD4 T cells produce fewer species of tyrosine-phosphorylated substrates and fail to phosphorylate ZAP-70, yet unphosphorylated ZAP-70 can associate with the TCR/CD3 complex. Moreover, a 26/28-kDa phosphorylated doublet is associated with CD3zeta in resting and activated memory but not in naive CD4 T cells. Despite these differences in the phosphorylation of ZAP-70 and CD3-associated proteins, the ZAP-70-related kinase, p72syk, exhibits similar phosphorylation in naive and memory T cell subsets, suggesting that this kinase could function in place of ZAP-70 in memory CD4 T cells. These results indicate that proximal signals are differentially coupled to the TCR in naive versus memory CD4 T cells, potentially leading to distinct downstream signaling events and ultimately to the diverse functions elicited by these two CD4 T cell subsets.

  18. IL-10 is excluded from the functional cytokine memory of human CD4+ memory T lymphocytes.

    PubMed

    Dong, Jun; Ivascu, Claudia; Chang, Hyun-Dong; Wu, Peihua; Angeli, Roberta; Maggi, Laura; Eckhardt, Florian; Tykocinski, Lars; Haefliger, Carolina; Möwes, Beate; Sieper, Jochen; Radbruch, Andreas; Annunziato, Francesco; Thiel, Andreas

    2007-08-15

    Epigenetic modifications, including DNA methylation, profoundly influence gene expression of CD4(+) Th-specific cells thereby shaping memory Th cell function. We demonstrate here a correlation between a lacking fixed potential of human memory Th cells to re-express the immunoregulatory cytokine gene IL10 and its DNA methylation status. Memory Th cells secreting IL-10 or IFN-gamma were directly isolated ex vivo from peripheral blood of healthy volunteers, and the DNA methylation status of IL10 and IFNG was assessed. Limited difference in methylation was found for the IL10 gene locus in IL-10-secreting Th cells, as compared with Th cells not secreting IL-10 isolated directly ex vivo or from in vitro-established human Th1 and Th2 clones. In contrast, in IFN-gamma(+) memory Th cells the promoter of the IFNG gene was hypomethylated, as compared with IFN-gamma-nonsecreting memory Th cells. In accordance with the lack of epigenetic memory, almost 90% of ex vivo-isolated IL-10-secreting Th cells lacked a functional memory for IL-10 re-expression after restimulation. Our data indicate that IL10 does not become epigenetically marked in human memory Th cells unlike effector cytokine genes such as IFNG. The exclusion of IL-10, but not effector cytokines, from the functional memory of human CD4(+) T lymphocytes ex vivo may reflect the need for appropriate regulation of IL-10 secretion, due to its potent immunoregulatory potential.

  19. Modulation of CD4+ T Helper Cell Memory Responses in the Human Skin.

    PubMed

    Padovan, Elisabetta

    2017-01-01

    Immunological memory is defined as the capacity to mount faster and more effective immune responses against antigenic challenges that have been previously encountered by the host. CD4+ T helper (Th) cells play central roles in the establishment of immunological memory as they assist the functions of other leukocytes. Th cells express polarized cytokine profiles and distinct migratory and seeding capacities, but also retain a certain functional plasticity that allows them to modulate their proliferation, activity, and homing behaviour upon need. Thus, in healthy individuals, T cell immunomodulation fulfils the task of eliciting protective immune responses where they are needed. At times, however, Th plasticity can lead to collateral tissue damage and progression to autoimmune diseases or, conversely, incapacity to reject malignant tissues and clear chronic infections. Furthermore, common immune players and molecular pathways of diseases can lead to different outcomes in different individuals. A mechanistic understanding of those pathways is therefore crucial for developing precise and curative medical interventions. Here, I focus on the skin microenvironment and comprehensively describe some of the cellular and molecular determinants of CD4+ T cell memory responses in homeostatic and pathological conditions. In discussing the cellular network orchestrating cutaneous immunity, I comprehensively describe the bidirectional interaction of skin antigen-presenting cells and mononuclear phagocytes with Th17 lymphocytes, and examine how the outcome of this interaction is influenced by endogenous skin molecules, including sodium salts and neuropeptides. © 2017 S. Karger AG, Basel.

  20. Expression of CD8alpha identifies a distinct subset of effector memory CD4+ T lymphocytes.

    PubMed

    Macchia, Iole; Gauduin, Marie-Claire; Kaur, Amitinder; Johnson, R Paul

    2006-10-01

    Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8alphaalpha homodimer, while the minor population was CD4lo CD8hi and expressed the CD8alphabeta heterodimer. The majority of CD4hi CD8alphalo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7- CD28- HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8alphalo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8alphalo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8alphalo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8alpha represent an effector/memory subset of CD4+ T cells and that this cell population can be depleted during the course of SIV infection.

  1. Proportions of CD4+ memory T cells are altered in individuals chronically infected with Schistosoma haematobium

    PubMed Central

    Nausch, Norman; Bourke, Claire D.; Appleby, Laura J.; Rujeni, Nadine; Lantz, Olivier; Trottein, François; Midzi, Nicholas; Mduluza, Takafira; Mutapi, Francisca

    2012-01-01

    Characterisation of protective helminth acquired immunity in humans or experimental models has focused on effector responses with little work conducted on memory responses. Here we show for the first time, that human helminth infection is associated with altered proportions of the CD4+ memory T cells, with an associated alteration of TH1 responses. The reduced CD4+ memory T cell proportions are associated with a significantly lower ratio of schistosome-specific IgE/IgG4 (marker for resistance to infection/re-infection) in uninfected older people. Helminth infection does not affect the CD8+ memory T cell pool. Furthermore, we show for the first time in a helminth infection that the CD4+ memory T cell proportions decline following curative anti-helminthic treatment despite increased CD4+ memory cell replication. Reduced accumulation of the CD4+ memory T cells in schistosome-infected people has implications for the development of natural or vaccine induced schistosome-specific protective immunity as well as for unrelated pathogens. PMID:22737405

  2. Memory CD4+ T cells induce innate responses independently of pathogen.

    PubMed

    Strutt, Tara M; McKinstry, K Kai; Dibble, John P; Winchell, Caylin; Kuang, Yi; Curtis, Jonathan D; Huston, Gail; Dutton, Richard W; Swain, Susan L

    2010-05-01

    Inflammation induced by recognition of pathogen-associated molecular patterns markedly affects subsequent adaptive responses. We asked whether the adaptive immune system can also affect the character and magnitude of innate inflammatory responses. We found that the response of memory, but not naive, CD4(+) T cells enhances production of multiple innate inflammatory cytokines and chemokines (IICs) in the lung and that, during influenza infection, this leads to early control of virus. Memory CD4(+) T cell-induced IICs and viral control require cognate antigen recognition and are optimal when memory cells are either T helper type 1 (T(H)1) or T(H)17 polarized but are independent of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) production and do not require activation of conserved pathogen recognition pathways. This represents a previously undescribed mechanism by which memory CD4(+) T cells induce an early innate response that enhances immune protection against pathogens.

  3. Memory CD4 T cell subsets are kinetically heterogeneous and replenished from naive T cells at high levels

    PubMed Central

    Gossel, Graeme; Hogan, Thea; Cownden, Daniel

    2017-01-01

    Characterising the longevity of immunological memory requires establishing the rules underlying the renewal and death of peripheral T cells. However, we lack knowledge of the population structure and how self-renewal and de novo influx contribute to the maintenance of memory compartments. Here, we characterise the kinetics and structure of murine CD4 T cell memory subsets by measuring the rates of influx of new cells and using detailed timecourses of DNA labelling that also distinguish the behaviour of recently divided and quiescent cells. We find that both effector and central memory CD4 T cells comprise subpopulations with highly divergent rates of turnover, and show that inflows of new cells sourced from the naive pool strongly impact estimates of memory cell lifetimes and division rates. We also demonstrate that the maintenance of CD4 T cell memory subsets in healthy mice is unexpectedly and strikingly reliant on this replenishment. DOI: http://dx.doi.org/10.7554/eLife.23013.001 PMID:28282024

  4. Apoptotic cell-treated dendritic cells induce immune tolerance by specifically inhibiting development of CD4⁺ effector memory T cells.

    PubMed

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

    2016-02-01

    CD4(+) memory T cells play an important role in induction of autoimmunity and chronic inflammatory responses; however, regulatory mechanisms of CD4(+) memory T cell-mediated inflammatory responses are poorly understood. Here we show that apoptotic cell-treated dendritic cells inhibit development and differentiation of CD4(+) effector memory T cells in vitro and in vivo. Simultaneously, intravenous transfer of apoptotic T cell-induced tolerogenic dendritic cells can block development of experimental autoimmune encephalomyelitis (EAE), an inflammatory disease of the central nervous system in C57 BL/6J mouse. Our results imply that it is effector memory CD4(+) T cells, not central memory CD4(+) T cells, which play a major role in chronic inflammatory responses in mice with EAE. Intravenous transfer of tolerogenic dendritic cells induced by apoptotic T cells leads to immune tolerance by specifically blocking development of CD4(+) effector memory T cells compared with results of EAE control mice. These results reveal a new mechanism of apoptotic cell-treated dendritic cell-mediated immune tolerance in vivo.

  5. 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.

  6. IL-21 is required for CD4 memory formation in response to viral infection

    PubMed Central

    Yuan, Yuqing; Huang, Xiaopei

    2017-01-01

    IL-21 has been shown to play an important role in the CD8 T cell response during acute and chronic viral infections. However, the role of IL-21 signaling in the CD4 T cell response to viral infection remains incompletely defined. In a model of infection with vaccinia virus, we show that intrinsic IL-21 signaling on CD4 T cells was critical for the formation of memory CD4 T cells in vivo. We further reveal that IL-21 promoted CD4 T cell survival in a mechanism dependent on activation of the STAT1 and STAT3 signaling pathways. In addition, the activation of Akt is also required for IL-21–dependent survival of CD4 T cells in vivo. These results identify a critical role for intrinsic IL-21 signaling in CD4 T cell survival and memory formation in response to viral infection in vivo and may provide insights into the design of effective vaccine strategies. PMID:28405614

  7. HIV-Infected Children Have Elevated Levels of PD-1+ Memory CD4 T Cells With Low Proliferative Capacity and High Inflammatory Cytokine Effector Functions.

    PubMed

    Foldi, Julia; Kozhaya, Lina; McCarty, Bret; Mwamzuka, Mussa; Marshed, Fatma; Ilmet, Tiina; Kilberg, Max; Kravietz, Adam; Ahmed, Aabid; Borkowsky, William; Unutmaz, Derya; Khaitan, Alka

    2017-09-15

    During human immunodeficiency virus (HIV) disease, chronic immune activation leads to T-cell exhaustion. PD-1 identifies "exhausted" CD8 T cells with impaired HIV-specific effector functions, but its role on CD4 T cells and in HIV-infected children is poorly understood. In a Kenyan cohort of vertically HIV-infected children, we measured PD-1+ CD4 T-cell frequencies and phenotype by flow cytometry and their correlation with HIV disease progression and immune activation. Second, in vitro CD4 T-cell proliferative and cytokine responses to HIV-specific and -nonspecific stimuli were assessed with and without PD-1 blockade. HIV-infected children have increased frequencies of PD-1+ memory CD4 T cells that fail to normalize with antiretroviral treatment. These cells are comprised of central and effector memory subsets and correlate with HIV disease progression, measured by viral load, CD4 percentage, CD4:CD8 T-cell ratio, and immune activation. Last, PD-1+ CD4 T cells predict impaired proliferative potential yet preferentially secrete the Th1 and Th17 cytokines interferon-γ and interleukin 17A, and are unresponsive to in vitro PD-1 blockade. This study highlights differences in PD-1+ CD4 T-cell memory phenotype and response to blockade between HIV-infected children and adults, with implications for potential immune checkpoint therapies.

  8. Human memory, but not naive, CD4+ T cells expressing transcription factor T-bet might drive rapid cytokine production.

    PubMed

    Yu, Si-fei; Zhang, Yan-nan; Yang, Bin-yan; Wu, Chang-you

    2014-12-19

    We found that after stimulation for a few hours, memory but not naive CD4(+) T cells produced a large amount of IFN-γ; however, the mechanism of rapid response of memory CD4(+) T cells remains undefined. We compared the expression of transcription factors in resting or activated naive and memory CD4(+) T cells and found that T-bet, but not pSTAT-1 or pSTAT-4, was highly expressed in resting memory CD4(+) T cells and that phenotypic characteristics of T-bet(+)CD4(+) T cells were CD45RA(low)CD62L(low) CCR7(low). After short-term stimulation, purified memory CD4(+) T cells rapidly produced effector cytokines that were closely associated with the pre-existence of T-bet. By contrast, resting naive CD4(+) T cells did not express T-bet, and they produced cytokines only after sustained stimulation. Our further studies indicated that T-bet was expressed in the nuclei of resting memory CD4(+) T cells, which might have important implications for rapid IFN-γ production. Our results indicate that the pre-existence and nuclear mobilization of T-bet in resting memory CD4(+) T cells might be a possible transcriptional mechanism for rapid production of cytokines by human memory CD4(+) T cells.

  9. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions.

    PubMed

    Nascimbeni, Michelina; Shin, Eui-Cheol; Chiriboga, Luis; Kleiner, David E; Rehermann, Barbara

    2004-07-15

    Although an increased frequency of CD4(+)CD8(+) T cells has been observed in the peripheral blood during viral infections, their role, function, and biologic significance are still poorly understood. Here we demonstrate that the circulating CD4(+)CD8(+) T-cell population contains mature effector memory lymphocytes specific for antigens of multiple past, latent, and high-level persistent viral infections. Upon in vitro antigenic challenge, a higher frequency of CD4(+)CD8(+) than single-positive cells displayed a T helper 1/T cytotoxic 1 (Th1/Tc1) cytokine profile and proliferated. Ex vivo, more double-positive than single-positive cells exhibited a differentiated phenotype. Accordingly, their lower T-cell receptor excision circles (TREC) content and shorter telomeres proved they had divided more frequently than single-positive cells. Consistent with expression of the tissue-homing marker CXCR3, CD4(+)CD8(+) T cells were demonstrated in situ at the site of persistent viral infection (ie, in the liver during chronic hepatitis C). Finally, a prospective analysis of hepatitis C virus (HCV) infection in a chimpanzee, the only animal model for HCV infection, showed a close correlation between the frequency of activated CD4(+)CD8(+) T cells and viral kinetics. Collectively, these findings demonstrate that peripheral CD4(+)CD8(+) T cells take part in the adaptive immune response against infectious pathogens and broaden the perception of the T-cell populations involved in antiviral immune responses.

  10. Target organ localization of memory CD4+ T cells in patients with chronic beryllium disease

    PubMed Central

    Fontenot, Andrew P.; Canavera, Scott J.; Gharavi, Laia; Newman, Lee S.; Kotzin, Brian L.

    2002-01-01

    Chronic beryllium disease (CBD) is caused by exposure to beryllium in the workplace, and it remains an important public health concern. Evidence suggests that CD4+ T cells play a critical role in the development of this disease. Using intracellular cytokine staining, we found that the frequency of beryllium-specific CD4+ T cells in the lungs (bronchoalveolar lavage) of 12 CBD patients ranged from 1.4% to 29% (mean 17.8%), and these T cells expressed a Th1-type phenotype in response to beryllium sulfate (BeSO4). Few, if any, beryllium-specific CD8+ T cells were identified. In contrast, the frequency of beryllium-responsive CD4+ T cells in the blood of these subjects ranged from undetectable to 1 in 500. No correlation was observed between the frequency of beryllium-responsive bronchoalveolar lavage (BAL) CD4+ T cells as detected by intracellular staining and lymphocyte proliferation in culture after BeSO4 exposure. Staining for surface marker expression showed that nearly all BAL T cells exhibit an effector memory cell phenotype. These results demonstrate a dramatically high frequency and compartmentalization of antigen-specific effector memory CD4+ cells in the lungs of CBD patients. These studies provide insight into the phenotypic and functional characteristics of antigen-specific T cells invading other inaccessible target organs in human disease. PMID:12438445

  11. Memory CD4+ T cells are suppressed by CD8+ regulatory T cells in vitro and in vivo

    PubMed Central

    Long, Xin; Cheng, Qi; Liang, Huifang; Zhao, Jianping; Wang, Jian; Wang, Wei; Tomlinson, Stephen; Chen, Lin; Atkinson, Carl; Zhang, Bixiang; Chen, Xiaoping; Zhu, Peng

    2017-01-01

    Background: Acute graft rejection mediated by alloreactive memory CD4+ T cells is a major obstacle to transplantation tolerance. It has been reported that CD8+ T regulatory cells (Tregs) have the ability to induce graft tolerance by restraining the function of activated CD4+ T cells, but not including memory T cells. The aim of this study is to elucidate the effect of CD8+ Tregs on alloreactive memory CD4+ T cells. Methods: We detected Qa-1 expression and performed proliferative assay on memory CD4+ T cells. All memory CD4+ T cells were purified from mice receiving skin allografts. We performed inhibitory and cytotoxic assays on CD8+ Tregs, which were isolated from a T cell vaccination mouse model, and IL-2, IL-4, IL-10 and IFN-γ levels were measured in co-culture supernatants by ELISA. To confirm CD8+ Tregs inhibition of memory CD4+ T cells in-vivo, we utilized a murine model of cardiac allograft transplantation. Results: Memory CD4+ T cells mediated acute allograft rejection, and CD8+ Tregs suppressed the proliferation of memory CD4+ T cells. In vitro, memory CD4+ T cells were inhibited and lysed by CD8+ Tregs. There was a positive correlation between IFN-γ levels, and cell lysis rate induced by CD8+ Tregs. In-vivo studies demonstrated CD8+ Tregs prolonged graft survival times, by inhibiting CD4+ memory T cells, through a Qa-1-peptide-TCR pathway. Conclusions: CD8+ Tregs inhibit CD4+ memory T cell-mediated acute murine cardiac allograft rejection, and further prolong graft survival times. These results provide new insights into immune regulation of organ rejection. PMID:28123634

  12. A subset of memory CD4+ helper T lymphocytes identified by expression of Pgp-1

    PubMed Central

    1989-01-01

    The Pgp-1 glycoprotein (Ly-24 antigen) is acquired by mature murine T lymphocytes at the time of primary antigen stimulation Pgp-1 was previously shown to be a useful cell surface marker for distinguishing antigen-specific memory CD8+ T lymphocytes after immunization. Here we demonstrate that this observation extends to CD4+ T lymphocytes. Antigen-specific CD4+ T cells in mice immunized with sperm whale myoglobin or keyhole limpet hemocyanin were contained nearly exclusively in the minor Pgp-1+ subset. PMID:2564418

  13. Memory CD4 T Cells Induce Antibody-Mediated Rejection of Renal Allografts.

    PubMed

    Gorbacheva, Victoria; Fan, Ran; Fairchild, Robert L; Baldwin, William M; Valujskikh, Anna

    2016-11-01

    Despite advances in immunosuppression, antibody-mediated rejection is a serious threat to allograft survival. Alloreactive memory helper T cells can induce potent alloantibody responses and often associate with poor graft outcome. Nevertheless, the ability of memory T cells to elicit well characterized manifestations of antibody-mediated rejection has not been tested. We investigated helper functions of memory CD4 T cells in a mouse model of renal transplantation. Whereas the majority of unsensitized C57Bl/6 recipients spontaneously accepted fully MHC-mismatched A/J renal allografts, recipients containing donor-reactive memory CD4 T cells rapidly lost allograft function. Increased serum creatinine levels, high serum titers of donor-specific alloantibody, minimal T cell infiltration, and intense C4d deposition in the grafts of sensitized recipients fulfilled all diagnostic criteria for acute renal antibody-mediated rejection in humans. IFNγ neutralization did not prevent the renal allograft rejection induced by memory helper T cells, and CD8 T cell depletion at the time of transplantation or depletion of both CD4 and CD8 T cells also did not prevent the renal allograft rejection induced by memory helper T cells starting at day 4 after transplantation. However, B cell depletion inhibited alloantibody generation and significantly extended allograft survival, indicating that donor-specific alloantibodies (not T cells) were the critical effector mechanism of renal allograft rejection induced by memory CD4 T cells. Our studies provide direct evidence that recipient T cell sensitization may result in antibody-mediated rejection of renal allografts and introduce a physiologically relevant animal model with which to investigate mechanisms of antibody-mediated rejection and novel therapeutic approaches for its prevention and treatment. Copyright © 2016 by the American Society of Nephrology.

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

    PubMed

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

    2016-01-15

    Notch signaling has recently emerged as an important regulator of immune responses in autoimmune diseases. The recombination signal-binding protein for immunoglobulin kappa J region (RBPJ) is a transcriptional repressor, but converts into a transcriptional activator upon activation of the canonical Notch pathway. Genome-wide association studies of rheumatoid arthritis (RA) identified a susceptibility locus, rs874040(CC), which implicated the RBPJ gene. Here, chromatin state mapping generated using the chromHMM algorithm reveals strong enhancer regions containing DNase I hypersensitive sites overlapping the rs874040 linkage disequilibrium block in human memory, but not in naïve CD4(+) T cells. The rs874040 overlapping this chromatin state was associated with increased RBPJ expression in stimulated memory CD4(+) T cells from healthy subjects homozygous for the risk allele (CC) compared with memory CD4(+) T cells bearing the protective allele (GG). Transcriptomic analysis of rs874040(CC) memory T cells showed a repression of canonical Notch target genes IL (interleukin)-9, IL-17 and interferon (IFN)γ in the basal state. Interestingly, activation of the Notch pathway using soluble Notch ligand, Jagged2-Fc, induced IL-9 and IL-17A while delta-like 4Fc, another Notch ligand, induced higher IFNγ expression in the rs874040(CC) memory CD4(+) T cells compared with their rs874040(GG) counterparts. In RA, RBPJ expression is elevated in memory T cells from RA patients compared with control subjects, and this was associated with induced inflammatory cytokines IL-9, IL-17A and IFNγ in response to Notch ligation in vitro. These findings demonstrate that the rs874040(CC) allele skews memory T cells toward a pro-inflammatory phenotype involving Notch signaling, thus increasing the susceptibility to develop RA. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    PubMed

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

    2015-02-15

    Memory T cells are primed for rapid responses to Ag; however, the molecular mechanisms responsible for priming remain incompletely defined. CpG methylation in promoters is an epigenetic modification, which regulates gene transcription. Using targeted bisulfite sequencing, we examined methylation of 2100 genes (56,000 CpGs) mapped by deep sequencing of T cell activation in human naive and memory CD4 T cells. Four hundred sixty-six CpGs (132 genes) displayed differential methylation between naive and memory cells. Twenty-one genes exhibited both differential methylation and gene expression before activation, linking promoter DNA methylation states to gene regulation; 6 of 21 genes encode proteins closely studied in T cells, whereas 15 genes represent novel targets for further study. Eighty-four genes demonstrated differential methylation between memory and naive cells that correlated to differential gene expression following activation, of which 39 exhibited reduced methylation in memory cells coupled with increased gene expression upon activation compared with naive cells. These reveal a class of primed genes more rapidly expressed in memory compared with naive cells and putatively regulated by DNA methylation. These findings define a DNA methylation signature unique to memory CD4 T cells that correlates with activation-induced gene expression. Copyright © 2015 by The American Association of Immunologists, Inc.

  16. Defining CD4 T Cell Memory by the Epigenetic Landscape of CpG DNA Methylation

    PubMed Central

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

    2015-01-01

    Memory T cells are primed for rapid responses to antigen; however, the molecular mechanisms responsible for priming remain incompletely defined. CpG methylation in promoters is an epigenetic modification, which regulates gene transcription. Using targeted bisulfite sequencing, we examined methylation of 2100 genes (56,000 CpG) mapped by deep sequencing of T cell activation in human naïve and memory CD4 T cells. 466 CpGs (132 genes) displayed differential methylation between naïve and memory cells. 21 genes exhibited both differential methylation and gene expression before activation, linking promoter DNA methylation states to gene regulation; 6 of 21 genes encode proteins closely studied in T cells, while 15 genes represent novel targets for further study. 84 genes demonstrated differential methylation between memory and naïve cells that correlated to differential gene expression following activation, of which 39 exhibited reduced methylation in memory cells coupled with increased gene expression upon activation compared to naïve cells. These reveal a class of primed genes more rapidly expressed in memory compared to naïve cells and putatively regulated by DNA methylation. These findings define a DNA methylation signature unique to memory CD4 T cells that correlates with activation-induced gene expression. PMID:25576597

  17. Differentiation of distinct long-lived memory CD4 T cells in intestinal tissues after oral Listeria monocytogenes infection.

    PubMed

    Romagnoli, P A; Fu, H H; Qiu, Z; Khairallah, C; Pham, Q M; Puddington, L; Khanna, K M; Lefrançois, L; Sheridan, B S

    2017-03-01

    Mucosal antigen-specific CD4 T-cell responses to intestinal pathogens remain incompletely understood. Here we examined the CD4 T-cell response after oral infection with an internalin A 'murinized' Listeria monocytogenes (Lm). Oral Lm infection induced a robust endogenous listeriolysin O (LLO)-specific CD4 T-cell response with distinct phenotypic and functional characteristics in the intestine. Circulating LLO-specific CD4 T cells transiently expressed the 'gut-homing' integrin α4β7 and accumulated in the intestinal lamina propria and epithelium where they were maintained independent of interleukin (IL)-15. The majority of intestinal LLO-specific CD4 T cells were CD27(-) Ly6C(-) and CD69(+) CD103(-) while the lymphoid LLO-specific CD4 T cells were heterogeneous based on CD27 and Ly6C expression and predominately CD69(-). LLO-specific effector CD4 T cells transitioned into a long-lived memory population that phenotypically resembled their parent effectors and displayed hallmarks of residency. In addition, intestinal effector and memory CD4 T cells showed a predominant polyfunctional Th1 profile producing IFNγ, TNFα, and IL-2 at high levels with minimal but detectable levels of IL-17A. Depletion of CD4 T cells in immunized mice led to elevated bacterial burden after challenge infection highlighting a critical role for memory CD4 T cells in controlling intestinal intracellular pathogens.

  18. Differentiation of distinct long-lived memory CD4 T cells in intestinal tissues after oral Listeria monocytogenes infection

    PubMed Central

    Romagnoli, PA; Fu, HH; Qiu, Z; Khairallah, C; Pham, QM; Puddington, L; Khanna, KM; Lefrançois, L; Sheridan, BS

    2016-01-01

    Mucosal antigen-specific CD4 T cell responses to intestinal pathogens remain incompletely understood. Here we examined the CD4 T cell response after oral infection with an internalin A ‘murinized’ Listeria monocytogenes (Lm). Oral Lm infection induced a robust endogenous listeriolysin O (LLO)-specific CD4 T cell response with distinct phenotypic and functional characteristics in the intestine. Circulating LLO-specific CD4 T cells transiently expressed the ‘gut-homing’ integrin α4β7 and accumulated in the intestinal lamina propria and epithelium where they were maintained independent of IL-15. The majority of intestinal LLO-specific CD4 T cells were CD27− Ly6C− and CD69+ CD103− while the lymphoid LLO-specific CD4 T cells were heterogeneous based on CD27 and Ly6C expression and predominately CD69−. LLO-specific effector CD4 T cells transitioned into a long-lived memory population that phenotypically resembled their parent effectors and displayed hallmarks of residency. In addition, intestinal effector and memory CD4 T cells showed a predominant polyfunctional Th1 profile producing IFNγ, TNFα and IL-2 at high levels with minimal but detectable levels of IL-17A. Depletion of CD4 T cells in immunized mice led to elevated bacterial burden after challenge infection highlighting a critical role for memory CD4 T cells in controlling intestinal intracellular pathogens. PMID:27461178

  19. 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

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

    PubMed

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

    2015-09-16

    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. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. Airway Memory CD4+ T Cells Mediate Protective Immunity against Emerging Respiratory Coronaviruses

    PubMed Central

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

    2016-01-01

    SUMMARY Two zoonotic coronaviruses (CoV), 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 interferon-γ-dependent 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 may have broad applicability in the context of new CoV and other respiratory virus outbreaks. PMID:27287409

  2. Rapid Turnover of Effector–Memory CD4+ T Cells in Healthy Humans

    PubMed Central

    Macallan, Derek C.; Wallace, Diana; Zhang, Yan; de Lara, Catherine; Worth, Andrew T.; Ghattas, Hala; Griffin, George E.; Beverley, Peter C.L.; Tough, David F.

    2004-01-01

    Memory T cells can be divided into central–memory (TCM) and effector–memory (TEM) cells, which differ in their functional properties. Although both subpopulations can persist long term, it is not known whether they are maintained by similar mechanisms. We used in vivo labeling with deuterated glucose to measure the turnover of CD4+ T cells in healthy humans. The CD45R0+CCR7− TEM subpopulation was shown to have a rapid proliferation rate of 4.7% per day compared with 1.5% per day for CD45R0+CCR7+ TCM cells; these values are equivalent to average intermitotic (doubling) times of 15 and 48 d, respectively. In contrast, the CD45RA+CCR7+ naive CD4+ T cell population was found to be much longer lived, being labeled at a rate of only 0.2% per day (corresponding to an intermitotic time of approximately 1 yr). These data indicate that human CD4+ TEM cells constitute a short-lived cell population that requires continuous replenishment in vivo. PMID:15249595

  3. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. 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.

  5. 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

  6. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Kynurenine Reduces Memory CD4 T-Cell Survival by Interfering with Interleukin-2 Signaling Early during HIV-1 Infection.

    PubMed

    Dagenais-Lussier, Xavier; Aounallah, Mouna; Mehraj, Vikram; El-Far, Mohamed; Tremblay, Cecile; Sekaly, Rafick-Pierre; Routy, Jean-Pierre; van Grevenynghe, Julien

    2016-09-01

    Early HIV-1 infection is characterized by enhanced tryptophan catabolism, which contributes to immune suppression and disease progression. However, the mechanism by which kynurenine, a tryptophan-related metabolite, induces immune suppression remains poorly understood. Herein, we show that the increased production of kynurenine correlates with defective interleukin-2 (IL-2) signaling in memory CD4 T cells from HIV-infected subjects. Defective IL-2 signaling in these subjects, which drives reduced protection from Fas-mediated apoptosis, was also associated with memory CD4 T-cell loss. Treatment of memory CD4 T cells with the concentration of kynurenine found in plasma inhibited IL-2 signaling through the production of reactive oxygen species. We further show that IL-2 signaling in memory CD4 T cells is improved by the antioxidant N-acetylcysteine. Early initiation of antiretroviral therapy restored the IL-2 response in memory CD4 T cells by reducing reactive oxygen species and kynurenine production. The study findings provide a kynurenine-dependent mechanism through IL-2 signaling for reduced CD4 T-cell survival, which can be reversed by early treatment initiation in HIV-1 infection. The persistence of functional memory CD4 T cells represents the basis for long-lasting immune protection in individuals after exposure to HIV-1. Unfortunately, primary HIV-1 infection results in the massive loss of these cells within weeks of infection, which is mainly driven by inflammation and massive infection by the virus. These new findings show that the enhanced production of kynurenine, a metabolite related to tryptophan catabolism, also impairs memory CD4 T-cell survival and interferes with IL-2 signaling early during HIV-1 infection. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Kynurenine Reduces Memory CD4 T-Cell Survival by Interfering with Interleukin-2 Signaling Early during HIV-1 Infection

    PubMed Central

    Dagenais-Lussier, Xavier; Aounallah, Mouna; Mehraj, Vikram; El-Far, Mohamed; Tremblay, Cecile; Sekaly, Rafick-Pierre; Routy, Jean-Pierre

    2016-01-01

    ABSTRACT Early HIV-1 infection is characterized by enhanced tryptophan catabolism, which contributes to immune suppression and disease progression. However, the mechanism by which kynurenine, a tryptophan-related metabolite, induces immune suppression remains poorly understood. Herein, we show that the increased production of kynurenine correlates with defective interleukin-2 (IL-2) signaling in memory CD4 T cells from HIV-infected subjects. Defective IL-2 signaling in these subjects, which drives reduced protection from Fas-mediated apoptosis, was also associated with memory CD4 T-cell loss. Treatment of memory CD4 T cells with the concentration of kynurenine found in plasma inhibited IL-2 signaling through the production of reactive oxygen species. We further show that IL-2 signaling in memory CD4 T cells is improved by the antioxidant N-acetylcysteine. Early initiation of antiretroviral therapy restored the IL-2 response in memory CD4 T cells by reducing reactive oxygen species and kynurenine production. The study findings provide a kynurenine-dependent mechanism through IL-2 signaling for reduced CD4 T-cell survival, which can be reversed by early treatment initiation in HIV-1 infection. IMPORTANCE The persistence of functional memory CD4 T cells represents the basis for long-lasting immune protection in individuals after exposure to HIV-1. Unfortunately, primary HIV-1 infection results in the massive loss of these cells within weeks of infection, which is mainly driven by inflammation and massive infection by the virus. These new findings show that the enhanced production of kynurenine, a metabolite related to tryptophan catabolism, also impairs memory CD4 T-cell survival and interferes with IL-2 signaling early during HIV-1 infection. PMID:27356894

  9. Gut memories do not fade: epigenetic regulation of lasting gut homing receptor expression in CD4(+) memory T cells.

    PubMed

    Szilagyi, B A; Triebus, J; Kressler, C; de Almeida, M; Tierling, S; Durek, P; Mardahl, M; Szilagyi, A; Floess, S; Huehn, J; Syrbe, U; Walter, J; Polansky, J K; Hamann, A

    2017-02-15

    The concept of a "topographical memory" in lymphocytes implies a stable expression of homing receptors mediating trafficking of lymphocytes back to the tissue of initial activation. However, a significant plasticity of the gut-homing receptor α4β7 was found in CD8(+) T cells, questioning the concept. We now demonstrate that α4β7 expression in murine CD4(+) memory T cells is, in contrast, imprinted and remains stable in the absence of the inducing factor retinoic acid (RA) or other stimuli from mucosal environments. Repetitive rounds of RA treatment enhanced the stability of de novo induced α4β7. A novel enhancer element in the murine Itga4 locus was identified that showed, correlating to stability, selective DNA demethylation in mucosa-seeking memory cells and methylation-dependent transcriptional activity in a reporter gene assay. This implies that epigenetic mechanisms contribute to the stabilization of α4β7 expression. Analogous DNA methylation patterns could be observed in the human ITGA4 locus, suggesting that its epigenetic regulation is conserved between mice and men. These data prove that mucosa-specific homing mediated by α4β7 is imprinted in CD4(+) memory T cells, reinstating the validity of the concept of "topographical memory" for mucosal tissues, and imply a critical role of epigenetic mechanisms.Mucosal Immunology advance online publication 15 February 2017. doi:10.1038/mi.2017.7.

  10. 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

  11. CD25+ FoxP3+ Memory CD4 T Cells Are Frequent Targets of HIV Infection In Vivo

    PubMed Central

    Pollakis, Georgios; Kuffour, Edmund Osei; Haase, Kerstin; Bauer, Asli; Nadai, Yuka; Podola, Lilli; Clowes, Petra; Schiemann, Matthias; Henkel, Lynette; Hoffmann, Dieter; Joseph, Sarah; Bhuju, Sabin; Maboko, Leonard; Sarfo, Fred Stephen; Eberhardt, Kirsten; Hoelscher, Michael; Feldt, Torsten; Saathoff, Elmar

    2016-01-01

    ABSTRACT Interleukin 2 (IL-2) signaling through the IL-2 receptor alpha chain (CD25) facilitates HIV replication in vitro and facilitates homeostatic proliferation of CD25+ FoxP3+ CD4+ T cells. CD25+ FoxP3+ CD4+ T cells may therefore constitute a suitable subset for HIV infection and plasma virion production. CD25+ FoxP3+ CD4+ T cell frequencies, absolute numbers, and the expression of CCR5 and cell cycle marker Ki67 were studied in peripheral blood from HIV+ and HIV− study volunteers. Different memory CD4+ T cell subsets were then sorted for quantification of cell-associated HIV DNA and phylogenetic analyses of the highly variable EnvV1V3 region in comparison to plasma-derived virus sequences. In HIV+ subjects, 51% (median) of CD25+ FoxP3+ CD4+ T cells expressed the HIV coreceptor CCR5. Very high frequencies of Ki67+ cells were detected in CD25+ FoxP3+ memory CD4+ T cells (median, 27.6%) in comparison to CD25− FoxP3− memory CD4+ T cells (median, 4.1%; P < 0.0001). HIV DNA content was 15-fold higher in CD25+ FoxP3+ memory CD4+ T cells than in CD25− FoxP3− T cells (P = 0.003). EnvV1V3 sequences derived from CD25+ FoxP3+ memory CD4+ T cells did not preferentially cluster with plasma-derived sequences. Quasi-identical cell-plasma sequence pairs were rare, and their proportion decreased with the estimated HIV infection duration. These data suggest that specific cellular characteristics of CD25+ FoxP3+ memory CD4+ T cells might facilitate efficient HIV infection in vivo and passage of HIV DNA to cell progeny in the absence of active viral replication. The contribution of this cell population to plasma virion production remains unclear. IMPORTANCE Despite recent advances in the understanding of AIDS virus pathogenesis, which cell subsets support HIV infection and replication in vivo is incompletely understood. In vitro, the IL-2 signaling pathway and IL-2-dependent cell cycle induction are essential for HIV infection of stimulated T cells. CD25+ FoxP3+ memory

  12. CD25+ FoxP3+ Memory CD4 T Cells Are Frequent Targets of HIV Infection In Vivo.

    PubMed

    Chachage, Mkunde; Pollakis, Georgios; Kuffour, Edmund Osei; Haase, Kerstin; Bauer, Asli; Nadai, Yuka; Podola, Lilli; Clowes, Petra; Schiemann, Matthias; Henkel, Lynette; Hoffmann, Dieter; Joseph, Sarah; Bhuju, Sabin; Maboko, Leonard; Sarfo, Fred Stephen; Eberhardt, Kirsten; Hoelscher, Michael; Feldt, Torsten; Saathoff, Elmar; Geldmacher, Christof

    2016-10-15

    Interleukin 2 (IL-2) signaling through the IL-2 receptor alpha chain (CD25) facilitates HIV replication in vitro and facilitates homeostatic proliferation of CD25(+) FoxP3(+) CD4(+) T cells. CD25(+) FoxP3(+) CD4(+) T cells may therefore constitute a suitable subset for HIV infection and plasma virion production. CD25(+) FoxP3(+) CD4(+) T cell frequencies, absolute numbers, and the expression of CCR5 and cell cycle marker Ki67 were studied in peripheral blood from HIV(+) and HIV(-) study volunteers. Different memory CD4(+) T cell subsets were then sorted for quantification of cell-associated HIV DNA and phylogenetic analyses of the highly variable EnvV1V3 region in comparison to plasma-derived virus sequences. In HIV(+) subjects, 51% (median) of CD25(+) FoxP3(+) CD4(+) T cells expressed the HIV coreceptor CCR5. Very high frequencies of Ki67(+) cells were detected in CD25(+) FoxP3(+) memory CD4(+) T cells (median, 27.6%) in comparison to CD25(-) FoxP3(-) memory CD4(+) T cells (median, 4.1%; P < 0.0001). HIV DNA content was 15-fold higher in CD25(+) FoxP3(+) memory CD4(+) T cells than in CD25(-) FoxP3(-) T cells (P = 0.003). EnvV1V3 sequences derived from CD25(+) FoxP3(+) memory CD4(+) T cells did not preferentially cluster with plasma-derived sequences. Quasi-identical cell-plasma sequence pairs were rare, and their proportion decreased with the estimated HIV infection duration. These data suggest that specific cellular characteristics of CD25(+) FoxP3(+) memory CD4(+) T cells might facilitate efficient HIV infection in vivo and passage of HIV DNA to cell progeny in the absence of active viral replication. The contribution of this cell population to plasma virion production remains unclear. Despite recent advances in the understanding of AIDS virus pathogenesis, which cell subsets support HIV infection and replication in vivo is incompletely understood. In vitro, the IL-2 signaling pathway and IL-2-dependent cell cycle induction are essential for HIV infection of

  13. ICOS and Bcl6-dependent pathways maintain a CD4 T cell population with memory-like properties during tuberculosis.

    PubMed

    Moguche, Albanus O; Shafiani, Shahin; Clemons, Corey; Larson, Ryan P; Dinh, Crystal; Higdon, Lauren E; Cambier, C J; Sissons, James R; Gallegos, Alena M; Fink, Pamela J; Urdahl, Kevin B

    2015-05-04

    Immune control of persistent infection with Mycobacterium tuberculosis (Mtb) requires a sustained pathogen-specific CD4 T cell response; however, the molecular pathways governing the generation and maintenance of Mtb protective CD4 T cells are poorly understood. Using MHCII tetramers, we show that Mtb-specific CD4 T cells are subject to ongoing antigenic stimulation. Despite this chronic stimulation, a subset of PD-1(+) cells is maintained within the lung parenchyma during tuberculosis (TB). When transferred into uninfected animals, these cells persist, mount a robust recall response, and provide superior protection to Mtb rechallenge when compared to terminally differentiated Th1 cells that reside preferentially in the lung-associated vasculature. The PD-1(+) cells share features with memory CD4 T cells in that their generation and maintenance requires intrinsic Bcl6 and intrinsic ICOS expression. Thus, the molecular pathways required to maintain Mtb-specific CD4 T cells during ongoing infection are similar to those that maintain memory CD4 T cells in scenarios of antigen deprivation. These results suggest that vaccination strategies targeting the ICOS and Bcl6 pathways in CD4 T cells may provide new avenues to prevent TB. © 2015 Moguche et al.

  14. ICOS and Bcl6-dependent pathways maintain a CD4 T cell population with memory-like properties during tuberculosis

    PubMed Central

    Moguche, Albanus O.; Shafiani, Shahin; Clemons, Corey; Larson, Ryan P.; Dinh, Crystal; Higdon, Lauren E.; Cambier, C.J.; Sissons, James R.; Gallegos, Alena M.; Fink, Pamela J.

    2015-01-01

    Immune control of persistent infection with Mycobacterium tuberculosis (Mtb) requires a sustained pathogen-specific CD4 T cell response; however, the molecular pathways governing the generation and maintenance of Mtb protective CD4 T cells are poorly understood. Using MHCII tetramers, we show that Mtb-specific CD4 T cells are subject to ongoing antigenic stimulation. Despite this chronic stimulation, a subset of PD-1+ cells is maintained within the lung parenchyma during tuberculosis (TB). When transferred into uninfected animals, these cells persist, mount a robust recall response, and provide superior protection to Mtb rechallenge when compared to terminally differentiated Th1 cells that reside preferentially in the lung-associated vasculature. The PD-1+ cells share features with memory CD4 T cells in that their generation and maintenance requires intrinsic Bcl6 and intrinsic ICOS expression. Thus, the molecular pathways required to maintain Mtb-specific CD4 T cells during ongoing infection are similar to those that maintain memory CD4 T cells in scenarios of antigen deprivation. These results suggest that vaccination strategies targeting the ICOS and Bcl6 pathways in CD4 T cells may provide new avenues to prevent TB. PMID:25918344

  15. Telomerase Is Involved in IL-7-Mediated Differential Survival of Naive and Memory CD4+ T Cells1

    PubMed Central

    Yang, Yinhua; An, Jie; Weng, Nan-ping

    2008-01-01

    IL-7 plays an essential role in T cell maintenance and survival. The survival effect of IL-7 is thought to be mediated through regulation of Bcl2 family proteins. After a comparative analysis of IL-7-induced growth and cell death of human naive and memory CD4+ T cells, we observed that more memory CD4+ T cells underwent cell division and proceeded to apoptosis than naive cells in response to IL-7. However, IL-7-induced expressions of Bcl2 family members (Bcl2, Bcl-xL, Bax, and Bad) were similar between naive and memory cells. Instead, we found that IL-7 induced higher levels of telomerase activity in naive cells than in memory cells, and the levels of IL-7-induced telomerase activity had a significant inverse correlation with cell death in CD4+ T cells. Furthermore, we showed that reducing expression of telomerase reverse transcriptase and telomerase activity significantly increased cell death of IL-7-cultured CD4+ T cells. Together, these findings demonstrate that telomerase is involved in IL-7-mediated differential survival of naive and memory CD4+ T cells. PMID:18322183

  16. The memory phase of the CD4 T-cell response to influenza virus infection maintains its diverse antigen specificity

    PubMed Central

    Richards, Katherine A; Chaves, Francisco A; Sant, Andrea J

    2011-01-01

    A major gap in our understanding of the immune response to pathogens and vaccines is how closely the antigen specificity in the memory phase mimics repertoire that is rapidly expanded upon priming. Understanding the diversity of the CD4 T-cell memory compartment after a primary response to pathogens is hampered by the technical challenges of epitope discovery and suitable models to study primary immune responses. Recently, we have used overlapping synthetic peptides to empirically map most of the specificities present in the primary response to live influenza infection. We found that the CD4 T-cell response can be exceptionally diverse, depending on the allele(s) of MHC class II molecules expressed. In the current study, using a mouse model of primary influenza infection and peptide-specific cytokine EliSpots, we have asked how this broad CD4 T-cell immunodominance hierarchy changes as the immune response contracts and memory is established. Our studies revealed that, for the most part, diversity is maintained, and most specificities, including those for relatively minor epitopes, are preserved in the memory CD4 T-cell compartment. A modest, but reproducible shift in specificity toward haemagglutinin-derived epitopes was observed, raising the possibility that protein or peptide persistence might play a role in the evolution of the memory phase of the CD4 T-cell response. PMID:21517839

  17. Selective Expansion of Memory CD4+ T cells By Mitogenic Human CD28 Generates Inflammatory Cytokines and Regulatory T cells

    PubMed Central

    Singh, Manisha; Basu, Sreemanti; Camell, Christina; Couturier, Jacob; Nudelman, Rodolfo J.; Medina, Miguel A.; Rodgers, John R.; Lewis, Dorothy E.

    2009-01-01

    Co-stimulatory signals are important for development of effector and regulatory T cells. In this case, CD28 signaling is usually considered inert in the absence of signaling through the TCR. By contrast, mitogenic rat CD28 mAbs reportedly expand regulatory T cells without TCR stimulation. We found that a commercially available human CD28 mAb (ANC28) stimulated PBMCs without TCR co-ligation or cross-linking; ANC28 selectively expanded CD4+CD25+FoxP3−(T effector) and CD4+CD25+FoxP3+ (Treg) cells. ANC28 stimulated the CD45RO+ CD4+ (memory) population whereas CD45RA+CD4+ (naïve) cells did not respond. ANC28 also induced inflammatory cytokines. Treg induced by ANC28 retain the Treg phenotype longer than did co-stimulated Treg. Treg induced by ANC28 suppressed CD25− T cells through a contact-dependent mechanism. Purity influenced the response of CD4+CD25+ cells because bead-purified CD4+CD25+ cells (85–90% pure) responded strongly to ANC28, whereas 98% pure FACS-sorted CD4+CD25 bright (T-reg) did not respond. Purified CD4+CD25int cells responded similarly to the bead-purified CD4+CD25+ cells. Thus, pre-activated CD4+ T cells (CD25int) respond to ANC28 rather than Treg (CD25bright). The ability of ANC28 to expand both effectors producing inflammatory cytokines as well as suppressive regulatory T cells might be useful for ex vivo expansion of therapeutic T cells. PMID:18446791

  18. Plasmodium falciparum apical membrane antigen 1 vaccine elicits multifunctional CD4 cytokine-producing and memory T cells.

    PubMed

    Huaman, Maria Cecilia; Mullen, Gregory E D; Long, Carole A; Mahanty, Siddhartha

    2009-08-20

    The Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading vaccine candidate and was tested for safety and immunogenicity in human Phase I Clinical Trials. PBMC from vaccine recipients were analyzed by flow cytometric methods to determine the nature of T-cell responses and AMA1-reactive memory T cells. Both CD4 and CD8 T cells produced a number of cytokines following AMA1 re-stimulation, with IL-5-producing cells at the highest frequency, consistent with a Th2 bias. The relative frequency of multifunctional cells synthesizing Th1 cytokines IFN-gamma, IL-2 and TNF-alpha changed after each vaccination. Interestingly, median fluorescence intensity measurements revealed that cells producing more than one cytokine contributed greater quantities of each cytokine than cell populations that produced each of the cytokines alone. AMA1 vaccination also elicited the development of memory cell populations, and both central and effector memory T cells were identified concurrently after the AMA1 vaccination. The detailed profile of multifunctional T-cell responses to AMA1 presented here will advance our ability to assess the immunogenicity of human malarial vaccines.

  19. Oral Vaccination with Lipid-Formulated BCG Induces a Long-lived, Multifunctional CD4+ T Cell Memory Immune Response

    PubMed Central

    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

  20. Treatment with targeted Vesicular Stomatitis Virus generates therapeutic multifunctional anti-tumor memory CD4 T-cells

    PubMed Central

    Gao, Yanhua; Whitaker-Dowling, Patricia; Griffin, Judith A.; Bergman, Ira

    2011-01-01

    A generally applicable, easy-to-use method of focusing a patient's immune system to eradicate or prevent cancer has been elusive. We are attempting to develop a targeted virus to accomplish these aims. We previously created a recombinant replicating Vesicular Stomatitis Virus that preferentially infected Her2/neu expressing breast cancer cells and showed therapeutic efficacy in an implanted Balb/c mouse tumor model. The current work shows that this therapy generated therapeutic anti-tumor CD4 T-cells against multiple tumor antigens. CD4 T-cells transferred directly from cured donor mice could eradicate established tumors in host mice. T-cells were transferred directly from donor mice and were not stimulated ex vivo. Both tumors that expressed Her2/neu and those that did not were cured by transferred T-cells. Analysis of cytokines secreted by anti-tumor memory CD4 T-cells displayed a multifunctional pattern with high levels of IFNγ, IL-4 and IL-17. Anti-tumor memory CD4 T-cells traveled to the mesenteric lymph nodes and were activated there. Treatment with targeted rrVSV is a potent immune adjuvant that generates therapeutic, multifunctional anti-tumor memory CD4 T-cells that recognize multiple tumor antigens. Immunity elicited by viral therapy is independent of host major histocompatibility complex (MHC) or knowledge of tumor antigens. Virus-induced tumor immunity could have great benefit in the prevention and treatment of tumor metastases. PMID:22240921

  1. 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

  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 Central

    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 (TEM) 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 TEM-phenotype cells relative to WT. Transfer of peripheral naïve CD4 T cells suggested that accumulated PD-1 KO TEM-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

    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.

  4. 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

  5. Epigenomic Profiling of Human CD4(+) T Cells Supports a Linear Differentiation Model and Highlights Molecular Regulators of Memory Development.

    PubMed

    Durek, Pawel; Nordström, Karl; Gasparoni, Gilles; Salhab, Abdulrahman; Kressler, Christopher; de Almeida, Melanie; Bassler, Kevin; Ulas, Thomas; Schmidt, Florian; Xiong, Jieyi; Glažar, Petar; Klironomos, Filippos; Sinha, Anupam; Kinkley, Sarah; Yang, Xinyi; Arrigoni, Laura; Amirabad, Azim Dehghani; Ardakani, Fatemeh Behjati; Feuerbach, Lars; Gorka, Oliver; Ebert, Peter; Müller, Fabian; Li, Na; Frischbutter, Stefan; Schlickeiser, Stephan; Cendon, Carla; Fröhler, Sebastian; Felder, Bärbel; Gasparoni, Nina; Imbusch, Charles D; Hutter, Barbara; Zipprich, Gideon; Tauchmann, Yvonne; Reinke, Simon; Wassilew, Georgi; Hoffmann, Ute; Richter, Andreas S; Sieverling, Lina; Chang, Hyun-Dong; Syrbe, Uta; Kalus, Ulrich; Eils, Jürgen; Brors, Benedikt; Manke, Thomas; Ruland, Jürgen; Lengauer, Thomas; Rajewsky, Nikolaus; Chen, Wei; Dong, Jun; Sawitzki, Birgit; Chung, Ho-Ryun; Rosenstiel, Philip; Schulz, Marcel H; Schultze, Joachim L; Radbruch, Andreas; Walter, Jörn; Hamann, Alf; Polansky, Julia K

    2016-11-15

    The impact of epigenetics on the differentiation of memory T (Tmem) cells is poorly defined. We generated deep epigenomes comprising genome-wide profiles of DNA methylation, histone modifications, DNA accessibility, and coding and non-coding RNA expression in naive, central-, effector-, and terminally differentiated CD45RA(+) CD4(+) Tmem cells from blood and CD69(+) Tmem cells from bone marrow (BM-Tmem). We observed a progressive and proliferation-associated global loss of DNA methylation in heterochromatic parts of the genome during Tmem cell differentiation. Furthermore, distinct gradually changing signatures in the epigenome and the transcriptome supported a linear model of memory development in circulating T cells, while tissue-resident BM-Tmem branched off with a unique epigenetic profile. Integrative analyses identified candidate master regulators of Tmem cell differentiation, including the transcription factor FOXP1. This study highlights the importance of epigenomic changes for Tmem cell biology and demonstrates the value of epigenetic data for the identification of lineage regulators.

  6. Effector CD4 T cell transition to memory requires late cognate interactions that induce autocrine IL-2

    PubMed Central

    McKinstry, K. Kai; Strutt, Tara M.; Bautista, Bianca; Zhang, Wenliang; Kuang, Yi; Cooper, Andrea M.; Swain, Susan L.

    2014-01-01

    It is unclear how CD4 T cell memory formation is regulated following pathogen challenge, and when critical mechanisms act to determine effector T cell fate. Here, we report that following influenza infection most effectors require signals from major histocompatibility complex class II molecules and CD70 during a late window well after initial priming to become memory. During this timeframe, effector cells must produce IL-2 or be exposed to high levels of paracrine or exogenously added IL-2 to survive an otherwise rapid default contraction phase. Late IL-2 promotes survival through acute down regulation of apoptotic pathways in effector T cells and by permanently upregulating their IL-7 receptor expression, enabling IL-7 to sustain them as memory T cells. This new paradigm defines a late checkpoint during the effector phase at which cognate interactions direct CD4 T cell memory generation. PMID:25369785

  7. CD4(+) T cells confer anxiolytic and antidepressant-like effects, but enhance fear memory processes in Rag2(-/-) mice.

    PubMed

    Clark, Sarah M; Soroka, Jennifer A; Song, Chang; Li, Xin; Tonelli, Leonardo H

    2016-05-01

    Accumulating evidence supports a role of T cells in behavioral stress responsiveness. Our laboratory previously reported that lymphocyte deficient Rag2(-/-) mice on a BALB/c background display resilience to maladaptive stress responses when compared with immune competent mice in the predator odor exposure (POE) paradigm, while exhibiting similar behavior in a cued fear-conditioning (FC) paradigm. In the present study, Rag2(-/-) mice on a C57BL/6 background were assessed in the same behavioral paradigms, as well as additional tests of anxiety and depressive-like behavior. Furthermore, the effects of naïve CD4(+ ) T cells were evaluated by adoptive transfer of functional cells from nonstressed, wild-type donors to Rag2(-/-) mice. Consistent with our prior results, Rag2(-/-) mice displayed an attenuated startle response after POE. Nevertheless, reconstitution of Rag2(-/-) mice with CD4(+ ) T cells did not modify startle reactivity. Additionally, in contrast with our previous findings, Rag2(-/-) mice showed attenuated fear responses in the FC paradigm compared to wild-type mice and reconstitution with CD4(+ ) T cells promoted fear learning and memory. Notably, reconstitution with CD4(+ ) T cells had anxiolytic and antidepressant-like effects in Rag2(-/-) mice that had not been previously stressed, but had no effect after POE. Taken together, our results support a role of CD4(+ ) T cells in emotionality, but also indicate that they may promote fear responses by enhancing learning and memory processes.

  8. Memory-like CD8+ and CD4+ T cells cooperate to break peripheral tolerance under lymphopenic conditions.

    PubMed

    Le Saout, Cecile; Mennechet, Sandie; Taylor, Naomi; Hernandez, Javier

    2008-12-09

    The onset of autoimmunity in experimental rodent models and patients frequently correlates with a lymphopenic state. In this condition, the immune system has evolved compensatory homeostatic mechanisms that induce quiescent naive T cells to proliferate and differentiate into memory-like lymphocytes even in the apparent absence of antigenic stimulation. Because memory T cells have less stringent requirements for activation than naive cells, we hypothesized that autoreactive T cells that arrive to secondary lymphoid organs in a lymphopenic environment could differentiate and bypass the mechanisms of peripheral tolerance such as those mediated by self-antigen cross-presentation. Here, we show that lymphopenia-driven proliferation and differentiation of potentially autoreactive CD8(+) T cells into memory-like cells is not sufficient to induce self-reactivity against a pancreatic antigen. Induction of an organ-specific autoimmunity required antigen-specific CD4(+) T cell help. Notably, we found that this function could be accomplished by memory-like CD4(+) T cells generated in vivo through lymphopenia-induced proliferation. These helper cells promoted the further differentiation of memory-like CD8(+) T cells into effectors in response to antigen cross-presentation, resulting in their migration to the tissue of antigen expression where autoimmunity ensued. Thus, the cooperation of self-reactive memory-like CD4(+) and CD8(+) T cells under lymphopenic conditions overcomes cross-tolerance resulting in autoimmunity.

  9. TGF-β inhibits IL-7-induced proliferation in memory but not naive human CD4(+) T cells.

    PubMed

    Nguyen, Thao P; Sieg, Scott F

    2017-08-01

    TGF-β is a potent suppressor of T cell activation and expansion. Although the antiproliferative effects of TGF-β are well characterized in TCR-activated cells, the effects of TGF-β on T cell proliferation driven by homeostatic cytokines, such as IL-7, are poorly defined. In the current study, we found that TGF-β inhibits IL-7-induced proliferation in memory, but not in naive human CD4(+) T cells. TGF-β impaired c-myc induction in all CD4(+) T cell maturation subsets, although the impairment was less sustained in naive CD4(+) T cells. TGF-β had no discernible effect on IL-7R signaling (p-STAT-5, p-Akt, or p-S6) in memory T cells but selectively enhanced p-S6 signaling in naive T cells. The inhibitory effects of TGF-β on memory T cell proliferation were partially overcome by chemical inhibition of GSK-3, which also led to enhanced c-myc expression. These data suggest that TGF-β could play an important role in limiting homeostatic proliferation of memory T cells. Our observations also point toward a novel strategy to subvert TGF-β-mediated inhibition of memory T cells by targeting GSK-3 for inhibition. © Society for Leukocyte Biology.

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

    PubMed Central

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

    2016-01-01

    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

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

    PubMed

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

    2003-09-01

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

  12. Memory CD4+ T cells are required for optimal NK cell effector functions against the opportunistic fungal pathogen Pneumocystis murina.

    PubMed

    Kelly, Michelle N; Zheng, Mingquan; Ruan, Sanbao; Kolls, Jay; D'Souza, Alain; Shellito, Judd E

    2013-01-01

    Little is known about the role of NK cells or their interplay with other immune cells during opportunistic infections. Using our murine model of Pneumocystis pneumonia, we found that loss of NK cells during immunosuppression results in substantial Pneumocystis lung burden. During early infection of C57B/6 CD4(+) T cell-depleted mice, there were significantly fewer NK cells in the lung tissue compared with CD4(+) T cell-intact animals, and the NK cells present demonstrated decreased upregulation of the activation marker NKp46 and production of the effector cytokine, IFN-γ. Furthermore, coincubation studies revealed a significant increase in fungal killing when NK cells were combined with CD4(+) T cells compared with either cell alone, which was coincident with a significant increase in perforin production by NK cells. Finally, however, we found through adoptive transfer that memory CD4(+) T cells are required for significant NK cell upregulation of the activation marker NK group 2D and production of IFN-γ, granzyme B, and perforin during Pneumocystis infection. To the best of our knowledge, this study is the first to demonstrate a role for NK cells in immunity to Pneumocystis pneumonia, as well as to establish a functional relationship between CD4(+) T cells and NK cells in the host response to an opportunistic fungal pathogen.

  13. Clinical, Immunological and Treatment-Related Factors Associated with Normalised CD4+/CD8+ T-Cell Ratio: Effect of Naïve and Memory T-Cell Subsets

    PubMed Central

    Tinago, Willard; Coghlan, Elizabeth; Macken, Alan; McAndrews, Julie; Doak, Brenda; Prior-Fuller, Charlotte; Lambert, John S.; Sheehan, Gerard J.; Mallon, Patrick W. G.

    2014-01-01

    Background Although effective antiretroviral therapy(ART) increases CD4+ T-cell count, responses to ART vary considerably and only a minority of patients normalise their CD4+/CD8+ ratio. Although retention of naïve CD4+ T-cells is thought to predict better immune responses, relationships between CD4+ and CD8+ T-cell subsets and CD4+/CD8+ ratio have not been well described. Methods A cross-sectional study in a cohort of ambulatory HIV+ patients. We used flow cytometry on fresh blood to determine expanded CD4+ and CD8+ T-cell subsets; CD45RO+CD62L+(central memory), CD45RO+CD62L-(effector memory) and CD45RO-CD62L+(naïve) alongside routine T-cell subsets(absolute, percentage CD4+ and CD8+ counts), HIVRNA and collected demographic and treatment data. Relationship between CD4+/CD8+ T-cell ratio and expanded T-cell subsets was determined using linear regression analysis. Results are median[IQR] and regression coefficients unless stated. Results We recruited 190 subjects, age 42(36–48) years, 65% male, 65.3% Caucasian, 91% on ART(52.6% on protease inhibitors), 78.4% with HIVRNA<40cps/ml and median ART duration 6.8(2.6–10.2) years. Nadir and current CD4+ counts were 200(112–309) and 465(335–607) cells/mm3 respectively. Median CD4+/CD8+ ratio was 0.6(0.4–1.0), with 26.3% of subjects achieving CD4+/CD8+ ratio>1. Of the expanded CD4+ T-cell subsets, 27.3(18.0–38.3)% were naïve, 36.8(29.0–40.0)% central memory and 27.4(20.0–38.5)% effector memory. Of the CD8+ T-cells subsets, 16.5(10.2–25.5)% were naïve, 19.9(12.7–26.6)% central memory and 41.0(31.8–52.5)% effector memory. In the multivariable adjusted analysis, total cumulative-ART exposure(+0.15,p = 0.007), higher nadir CD4+ count(+0.011,p<0.001) and higher %CD8+ naive T-cells(+0.0085,p<0.001) were associated with higher CD4+/CD8+ ratio, higher absolute CD8+ T-cell(-0.0044,p<0.001) and higher %CD4+ effector memory T-cells(-0.004,p = 0.0036) were associated with lower CD4+/CD8+ ratio. Those

  14. Brief Report: CD14brightCD16- monocytes and sCD14 level negatively associate with CD4-memory T-cell frequency and predict HCV-decline on therapy.

    PubMed

    Judge, Chelsey J; Sandberg, Johan K; Funderburg, Nicholas T; Sherman, Kenneth E; Butt, Adeel A; Kang, Minhee; Landay, Alan L; Lederman, Michael M; Anthony, Donald D

    2016-11-01

    During HIV+ hepatitis C virus (HCV)+ coinfection CD14CD16 monocytes produce soluble immune-activation markers that predict disease progression and poor response to interferon (IFN)-α treatment. We evaluated relationships among immune activation, monocyte phenotype, CD4-memory T cells, and HCV-, cytomegalovirus-, and cytomegalovirus/Epstein-Barr virus/influenza-specific IFN-γ-response before and during IFN-α treatment. Effector-memory and central-memory CD4 T-cell frequencies were lower in HCV+ HIV+ donors than in uninfected donors and correlated negatively with HCV level, CD14CD16 monocytes, and plasma sCD14. sCD14 and CD14CD16 monocytes negatively correlated with IFN-α-dependent HCV decline. CD4 effector-memory T cells positively associated with cytomegalovirus/Epstein-Barr virus/influenza(CEF)-specific IFN-γ response, while sCD14 negatively associated with both CD4 effector-memory T cells and CEF-specific IFN-γ response. These data support a role for memory-CD4 T cells in HCV containment and link immune activation and CD14CD16-monocyte frequency to the failure of IFN-dependent HCV clearance.

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

    PubMed Central

    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

  16. 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.). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. β1 integrin is critical for the maintenance of antigen-specific CD4 T cells in the bone marrow but not long-term immunological memory.

    PubMed

    DeNucci, Christopher C; Shimizu, Yoji

    2011-04-01

    The long-term maintenance of memory CD4 T cells promotes protective immunity against future pathogen reinfection. 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 i.v. infection with Listeria monocytogenes. β(1) 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 β(1) 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, β(1) integrin-dependent maintenance of memory CD4 T cells in the bone marrow is not required for long-term CD4 T cell memory.

  18. 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

  19. Cycling Memory CD4+ T Cells in HIV Disease Have a Diverse T Cell Receptor Repertoire and a Phenotype Consistent with Bystander Activation

    PubMed Central

    Jiang, Wei; Younes, Souheil-Antoine; Funderburg, Nicholas T.; Mudd, Joseph C.; Espinosa, Enrique; Davenport, Miles P.; Babineau, Denise C.; Sieg, Scott F.

    2014-01-01

    ABSTRACT The mechanisms of increased memory CD4+ T cell cycling in HIV disease are incompletely understood but have been linked to antigen stimulation, homeostatic signals, or exposure to microbial products and the inflammatory cytokines that they induce. We examined the phenotype and Vβ family distribution in cycling memory CD4+ T cells among 52 healthy and 59 HIV-positive (HIV+) donors. Cycling memory CD4+ T cells were proportionally more frequent in subjects with HIV infection than in controls, more often expressed CD38 and PD-1, and less frequently expressed OX40 and intracellular CD40L. OX40 expression on memory CD4+ T cells was induced in vitro by anti-CD3, interleukin-2 (IL-2), IL-7, or IL-15 but not by Toll-like receptor ligands. In HIV+ donors, memory CD4+ T cell cycling was directly related to plasma lipopolysaccharide (LPS) levels, to plasma HIV RNA levels, and to memory CD8+ T cell cycling and was inversely related to peripheral blood CD4+ T cell counts but not to the levels of IL-2, IL-7, or IL-15, while in HIV-negative donors, memory CD4+ T cell cycling was related to IL-7 levels and negatively related to the plasma levels of LPS. In both controls and HIV+ donors, cycling memory CD4+ T cells had a broad distribution of Vβ families comparable to that of noncycling cells. Increased memory CD4+ T cell cycling in HIV disease is reflective of generalized immune activation and not driven primarily by cognate peptide stimulation or exposure to common gamma-chain cytokines. This cycling may be a consequence of exposure to microbial products, to plasma viremia, or, otherwise, to proinflammatory cytokines. IMPORTANCE This work provides evidence that the increased memory CD4+ T cell cycling in HIV infection is not a result of cognate peptide recognition but, rather, is more likely related to the inflammatory environment of HIV infection. PMID:24522925

  20. Distinct Effector Memory CD4+ T Cell Signatures in Latent Mycobacterium tuberculosis Infection, BCG Vaccination and Clinically Resolved Tuberculosis

    PubMed Central

    Adekambi, Toidi; Ibegbu, Chris C.; Kalokhe, Ameeta S.; Yu, Tianwei; Ray, Susan M.; Rengarajan, Jyothi

    2012-01-01

    Two billion people worldwide are estimated to be latently infected with Mycobacterium tuberculosis (Mtb) and are at risk for developing active tuberculosis since Mtb can reactivate to cause TB disease in immune-compromised hosts. Individuals with latent Mtb infection (LTBI) and BCG-vaccinated individuals who are uninfected with Mtb, harbor antigen-specific memory CD4+ T cells. However, the differences between long-lived memory CD4+ T cells induced by latent Mtb infection (LTBI) versus BCG vaccination are unclear. In this study, we characterized the immune phenotype and functionality of antigen-specific memory CD4+ T cells in healthy BCG-vaccinated individuals who were either infected (LTBI) or uninfected (BCG) with Mtb. Individuals were classified into LTBI and BCG groups based on IFN-γ ELISPOT using cell wall antigens and ESAT-6/CFP-10 peptides. We show that LTBI individuals harbored high frequencies of late-stage differentiated (CD45RA−CD27−) antigen-specific effector memory CD4+ T cells that expressed PD-1. In contrast, BCG individuals had primarily early-stage (CD45RA−CD27+) cells with low PD-1 expression. CD27+ and CD27− as well as PD-1+ and PD-1− antigen-specific subsets were polyfunctional, suggesting that loss of CD27 expression and up-regulation of PD-1 did not compromise their capacity to produce IFN-γ, TNF-α and IL-2. PD-1 was preferentially expressed on CD27− antigen-specific CD4+ T cells, indicating that PD-1 is associated with the stage of differentiation. Using statistical models, we determined that CD27 and PD-1 predicted LTBI versus BCG status in healthy individuals and distinguished LTBI individuals from those who had clinically resolved Mtb infection after anti-tuberculosis treatment. This study shows that CD4+ memory responses induced by latent Mtb infection, BCG vaccination and clinically resolved Mtb infection are immunologically distinct. Our data suggest that differentiation into CD27−PD-1+ subsets in LTBI is driven by Mtb

  1. Direct ex vivo analysis of human CD4(+) memory T cell activation requirements at the single clonotype level.

    PubMed

    Bitmansour, Arlene D; Douek, Daniel C; Maino, Vernon C; Picker, Louis J

    2002-08-01

    CD4(+) memory T cells continuously integrate signals transmitted through the TCR and costimulatory molecules, only responding when the intensity of such signals exceeds an intrinsic activation threshold. Recent data suggest that these activation thresholds can be regulated independently of TCR specificity, and that threshold tuning may constitute a major mechanism for controlling T cell effector activity. In this work we take advantage of the profound clonotypic hierarchies of the large human CD4(+) T cell response to CMV to study activation thresholds of fresh (unexpanded) memory T cells at the clonotypic level. We identified dominant responses to CMV matrix determinants mediated by single TCRB sequences within particular TCR-Vbeta families. The specific response characteristics of these single, Ag-specific, TCRB-defined clonotypes could be unequivocally determined in fresh PBMC preparations by cytokine flow cytometry with gating on the appropriate Vbeta family. These analyses revealed 1) optimal peptides capable of eliciting specific responses by themselves at doses as low as 2 pg/ml, with each log increase in dose eliciting ever-increasing frequencies of responding cells over a 4- to 5-log range; 2) significant augmentation of response frequencies at all submaximal peptide doses by CD28- and CD49d-mediated costimulation; 3) differential dose response and costimulatory characteristics for IFN-gamma and IL-2 responses; and 4) no association of activation requirements with the CD27-defined CD4(+) T cell memory differentiation pathway. Taken together these data confirm that triggering heterogeneity exists within individual CD4(+) memory T cell clonotypes in vivo and demonstrate that such single clonotypes can manifest qualitatively different functional responses depending on epitope dose and relative levels of costimulation.

  2. CD4+ memory stem cells are infected by HIV-1 in a manner regulated in part by SAMHD1 expression.

    PubMed

    Tabler, Caroline O; Lucera, Mark B; Haqqani, Aiman A; McDonald, David J; Migueles, Stephen A; Connors, Mark; Tilton, John C

    2014-05-01

    CD4(+) and CD8(+) memory T cells with stem cell-like properties (T(SCM) cells) have been identified in mice, humans, and nonhuman primates and are being investigated for antitumor and antiviral vaccines and immunotherapies. Whether CD4(+) T(SCM) cells are infected by human immunodeficiency virus (HIV) was investigated by using a combination HIV reporter virus system in vitro and by direct staining for HIV p24 antigen ex vivo. A proportion of T(SCM) cells were found to express the HIV coreceptors CCR5 and CXCR4 and were infected by HIV both in vitro and in vivo. Analysis of viral outcome following fusion using the combination reporter virus system revealed that T(SCM) cells can become productively or latently infected, although the vast majority of T(SCM) cells are abortively infected. Knockdown of the HIV restriction factor SAMHD1 using Vpx-containing simian immunodeficiency virus (SIV) virion-like particles enhanced the productive infection of T(SCM) cells, indicating that SAMHD1 contributes to abortive infection in these cells. These results demonstrate that CD4(+) T(SCM) cells are targets for HIV infection, that they become productively or latently infected at low levels, and that SAMHD1 expression promotes abortive infection of this important memory cell subset. Here we demonstrate the susceptibility of CD4(+) memory stem cells (T(SCM) cells) to infection by HIV in vitro and in vivo, provide an in-depth analysis of coreceptor expression, demonstrate the infection of naïve and memory CD4(+) T cell subsets with both CCR5- and CXCR4-tropic HIV, and also perform outcome analysis to calculate the percentage of cells that are productively, latently, or abortively infected. Through these outcome studies, we determined that the vast majority of T(SCM) cells are abortively infected by HIV, and we demonstrate that knockdown of SAMHD1 significantly increases the frequency of infection of this CD4(+) T cell subset, indicating that SAMHD1 is an active restriction factor in

  3. Retention of Ag-specific memory CD4(+) T cells in the draining lymph node indicates lymphoid tissue resident memory populations.

    PubMed

    Marriott, Clare L; Dutton, Emma E; Tomura, Michio; Withers, David R

    2017-05-01

    Several different memory T-cell populations have now been described based upon surface receptor expression and migratory capabilities. Here we have assessed murine endogenous memory CD4(+) T cells generated within a draining lymph node and their subsequent migration to other secondary lymphoid tissues. Having established a model response targeting a specific peripheral lymph node, we temporally labelled all the cells within draining lymph node using photoconversion. Tracking of photoconverted and non-photoconverted Ag-specific CD4(+) T cells revealed the rapid establishment of a circulating memory population in all lymph nodes within days of immunisation. Strikingly, a resident memory CD4(+) T cell population became established in the draining lymph node and persisted for several months in the absence of detectable migration to other lymphoid tissue. These cells most closely resembled effector memory T cells, usually associated with circulation through non-lymphoid tissue, but here, these cells were retained in the draining lymph node. These data indicate that lymphoid tissue resident memory CD4(+) T-cell populations are generated in peripheral lymph nodes following immunisation. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Differing requirements for CCR4, E-selectin, and α4β1 for the migration of memory CD4 and activated T cells to dermal inflammation.

    PubMed

    Gehad, Ahmed; Al-Banna, Nadia A; Vaci, Maria; Issekutz, Andrew C; Mohan, Karkada; Latta, Markus; Issekutz, Thomas B

    2012-07-01

    CCR4 on T cells is suggested to mediate skin homing in mice. Our objective was to determine the interaction of CCR4, E-selectin ligand (ESL), and α(4)β(1) on memory and activated T cells in recruitment to dermal inflammation. mAbs to rat CCR4 were developed. CCR4 was on 5-21% of memory CD4 cells, and 20% were also ESL(+). Anti-TCR-activated CD4 and CD8 cells were 40-55% CCR4(+), and ∼75% of both CCR4(+) and CCR4(-) cells were ESL(+). CCR4(+) memory CD4 cells migrated 4- to 7-fold more to dermal inflammation induced by IFN-γ, TNF, TLR agonists, and delayed-type hypersensitivity than CCR4(-) cells. CCR4(+) activated CD4 cells migrated only 5-50% more than CCR4(-) cells to these sites. E-selectin blockade inhibited ∼60% of CCR4(+) activated CD4 cell migration but was less effective on memory cells where α(4)β(1) was more important. Anti-α(4)β(1) also inhibited CCR4(-) activated CD4 cells more than CCR4(+) cells. Anti-E-selectin reduced activated CD8 more than CD4 cell migration. These findings modify our understanding of CCR4, ESL, α(4)β(1), and dermal tropism. There is no strict relationship between CCR4 and ESL for skin homing of CD4 cells, because the activation state and inflammatory stimulus are critical determinants. Dermal homing memory CD4 cells express CCR4 and depend more on α(4)β(1) than ESL. Activated CD4 cells do not require CCR4, but CCR4(+) cells are more dependent on ESL than on α(4)β(1), and CCR4(-) cells preferentially use α(4)β(1). The differentiation from activated to memory CD4 cells increases the dependence on CCR4 for skin homing and decreases the requirement for ESL.

  5. Neutrophils acquire the capacity for antigen presentation to memory CD4(+) T cells in vitro and ex vivo.

    PubMed

    Vono, Maria; Lin, Ang; Norrby-Teglund, Anna; Koup, Richard A; Liang, Frank; Loré, Karin

    2017-04-06

    Neutrophils are critical cells of the innate immune system and rapidly respond to tissue injury and infection. Increasing evidence also indicates that neutrophils have versatile functions in contributing to adaptive immunity by internalizing and transporting antigen and influencing antigen-specific responses. Here, we demonstrate that freshly isolated human neutrophils can function as antigen-presenting cells (APCs) to memory CD4(+) T cells. Neutrophils pulsed with the cognate antigens cytomegalovirus pp65 or influenza hemagglutinin were able to present the antigens to autologous antigen-specific CD4(+) T cells in a major histocompatibility complex class II (MHC-II; HLA-DR)-dependent manner. Although myeloid dendritic cells and monocytes showed superior presenting ability, neutrophils consistently displayed antigen presentation capability. Upregulation of HLA-DR on neutrophils required the presence of the antigen-specific or activated T cells whereas exposure to innate stimuli such as Toll-like receptor ligands was not sufficient. Neutrophils sorted from vaccine-draining lymph nodes from rhesus macaques also showed expression of HLA-DR and were capable of presenting vaccine antigen to autologous antigen-specific memory CD4(+) T cells ex vivo. Altogether, the data demonstrate that neutrophils can adapt a function as APCs and, in combination with their abundance in the immune system, may have a significant role in regulating antigen-specific T-cell responses.

  6. Allospecific CD4+ Effector Memory T Cells Do Not Induce Graft-versus-Host Disease in Mice

    PubMed Central

    Zhang, Ping; Wu, Jieying; Deoliveira, Divino; Chao, Nelson J.; Chen, Benny J.

    2012-01-01

    We studied whether allospecific CD4+ effector memory T cells (TEM) could induce graft-versus-host disease (GVHD) using a novel GVHD model solely induced by CD4+ T cell receptor transgenic TEa cells. Allospecific TEM generated in a lymphopenic host bore a typical memory phenotype. Moreover, these cells were able to elicit a faster and more effective proliferative response upon challenge with alloantigen in vitro and to mediate “second-set” skin graft rejection in vivo. However, these allospecific TEM were unable to induce GVHD. Allospecific TEM recipients became tolerant to alloantigen as a result of clonal deletion. Even though allospecific TEM were able to respond to alloantigen initially, the expansion of these cells and inflammatory cytokine production during GVHD were dramatically decreased. The inability of allospecific TEM to sustain the alloresponse may be a result of enhanced activation induced cell death. These observations provide insights into how allospecific CD4+ TEM respond to alloantigen during GVHD and underscore the fundamental differences of alloresponses mediated by allospecific TEM in graft rejection and GVHD settings. PMID:22809867

  7. The Acquisition of a Memory Phenotype by Murine CD4+ T Cells Is Accompanied by a Loss in Their Capacity to Increase Intracellular Calcium

    PubMed Central

    Hertogh-Huijbregts, Anita

    1992-01-01

    During the process of aging, the fraction of CD4+ T Cells with a naive phenotype, that is, Pgp-1- CD45RBHighMEL-14+, decreases in favor of CD4+ T memory cells. Total CD4+ T cells from aged mice displayed a diminished calcium response to anti-CD3 and even ionomycin as compared to the cells from young mice, and this was related to the changed composition of the CD4+ T-cell population. Regardless the age of the donor mice, naive CD4+ T cells effectively increased intracellular calcium, whereas memory CD4+ T cells were impaired in this regard. In addition, a heterogeneity in the differentiation stage of the naive CD4+ T cells was shown by the observation that calcium mobilization in naive CD4+ T cells from young mice was more profound than that in their aged counterparts. These data thus indicate that during the acquisition of a memory phenotype, murine CD4+ T cells lose the capacity to increase intracellular calcium, which in turn may be responsible for the decreased level of IL-2 production by these cells. PMID:1364177

  8. Restoration of CD4+ responses to co-pathogens in HIV-infected individuals on antiretroviral therapy is dependent on T cell memory phenotype

    PubMed Central

    Soares, Andreia P.; Masson, Lindi; Werner, Lise; Garrett, Nigel J.; Samsunder, Natasha; Karim, Quarraisha Abdool; Karim, Salim S. Abdool; Burgers, Wendy A.

    2015-01-01

    Antiretroviral therapy (ART) induces rapid suppression of viral replication and a progressive replenishment of CD4+ T cells in HIV-infected individuals. However, the effect of ART on restoring pre-existing memory CD4+ T cells specific for common co-pathogens is still unclear. To better understand the dynamics of antigen-specific CD4+ T cells during ART, we assessed the frequency, functional capacity and memory profile of CD4+ T cells specific for Mycobacterium tuberculosis (Mtb) and cytomegalovirus (CMV) in 15 HIV-infected individuals before and one year after ART initiation. After ART initiation, the frequency of Mtb-specific CD4+ T cells showed little change, while CMV-specific CD4+ T cells were significantly lower (p=0.003). There was no difference in the polyfunctional or memory profile of antigen-specific CD4+ T cells before and after ART. The replenishment of antigen-specific CD4+ T cells correlated with the memory differentiation profile of these cells prior to ART. Pathogen-specific CD4+ T cells exhibiting a late differentiated profile (CD45RO+CD27−) had a lower capacity to replenish (p=0.019, r=−0.5) compared to cells with an early differentiated profile (CD45RO+CD27+; p=0.04, r=0.45). In conclusion, restoration of co-pathogen-specific memory CD4+ T cells during treated HIV infection is related to their memory phenotype, where early differentiated cells (such as most Mtb-specific cells) have a higher replenishment capacity compared to late differentiated cells (such as most CMV-specific cells). These data identify an important, hitherto unrecognized, factor that may limit restoration of co-pathogen immunity in HIV-infected individuals on ART. PMID:26195814

  9. Restoration of CD4+ Responses to Copathogens in HIV-Infected Individuals on Antiretroviral Therapy Is Dependent on T Cell Memory Phenotype.

    PubMed

    Riou, Catherine; Tanko, Ramla F; Soares, Andreia P; Masson, Lindi; Werner, Lise; Garrett, Nigel J; Samsunder, Natasha; Karim, Quarraisha Abdool; Karim, Salim S Abdool; Burgers, Wendy A

    2015-09-01

    Antiretroviral therapy (ART) induces rapid suppression of viral replication and a progressive replenishment of CD4(+) T cells in HIV-infected individuals. However, the effect of ART on restoring pre-existing memory CD4(+) T cells specific for common copathogens is still unclear. To better understand the dynamics of Ag-specific CD4(+) T cells during ART, we assessed the frequency, functional capacity, and memory profile of CD4(+) T cells specific for Mycobacterium tuberculosis and CMV in 15 HIV-infected individuals before and 1 y after ART initiation. After ART initiation, the frequency of M. tuberculosis-specific CD4(+) T cells showed little change, whereas CMV-specific CD4(+) T cells were significantly lower (p = 0.003). There was no difference in the polyfunctional or memory profile of Ag-specific CD4(+) T cells before and after ART. The replenishment of Ag-specific CD4(+) T cells correlated with the memory differentiation profile of these cells prior to ART. Pathogen-specific CD4(+) T cells exhibiting a late differentiated profile (CD45RO(+)CD27(-)) had a lower capacity to replenish (p = 0.019; r = -0.5) compared with cells with an early differentiated profile (CD45RO(+)CD27(+); p = 0.04; r = 0.45). In conclusion, restoration of copathogen-specific memory CD4(+) T cells during treated HIV infection is related to their memory phenotype, in which early differentiated cells (such as most M. tuberculosis-specific cells) have a higher replenishment capacity compared with late differentiated cells (such as most CMV-specific cells). These data identify an important, hitherto unrecognized, factor that may limit restoration of copathogen immunity in HIV-infected individuals on ART. Copyright © 2015 by The American Association of Immunologists, Inc.

  10. Sustained interactions between T cell receptors and antigens promote the differentiation of CD4memory T cells.

    PubMed

    Kim, Chulwoo; Wilson, Theodore; Fischer, Kael F; Williams, Matthew A

    2013-09-19

    During CD4⁺ T cell activation, T cell receptor (TCR) signals impact T cell fate, including recruitment, expansion, differentiation, trafficking, and survival. To determine the impact of TCR signals on the fate decision of activated CD4⁺ T cells to become end-stage effector or long-lived memory T helper 1 (Th1) cells, we devised a deep-sequencing-based approach that allowed us to track the evolution of TCR repertoires after acute infection. The transition of effector Th1 cells into the memory pool was associated with a significant decrease in repertoire diversity, and the major histocompatibility complex (MHC) class II tetramer off rate, but not tetramer avidity, was a key predictive factor in the representation of individual clonal T cell populations at the memory stage. We conclude that stable and sustained interactions with antigens during the development of Th1 responses to acute infection are a determinative factor in promoting the differentiation of Th1 memory cells.

  11. Triptolide inhibits CD4(+) memory T cell-mediated acute rejection and prolongs cardiac allograft survival in mice.

    PubMed

    Qiu, Shuiwei; Lv, Dingliang

    2017-10-01

    There have been numerous investigations into the immunosuppressive effects of triptolide; however, its inhibitory effects on memory T cells remain to be elucidated. Using a cluster of differentiation (CD)4(+) memory T-cell transfer model, the aim of the present study was to determine the inhibitory effects of triptolide on CD4(+) memory T cell-mediated acute rejection and to determine the potential underlying mechanisms. At 4 weeks after skin transplantation, mouse cervical heart transplantation was performed following the transfer of CD4(+) memory T cells. Mice were divided into two groups: A Control [normal saline, 30 ml/kg/day; intraperitoneal injection (ip)] and a triptolide group (triptolide, 3 mg/kg/day; ip). Graft survival, pathological examination and the corresponding International Society for Heart & Lung Transplantation (ISHLT) scores were assessed 5 days following heart transplantation, and levels of interleukin (IL)-2, interferon-γ (IFN-γ), IL-10 and transforming growth factor β1 (TGF-β1) in cardiac grafts and peripheral blood were assessed using reverse transcription-quantitative polymerase chain reaction and ELISA. The duration of cardiac graft survival in the triptolide group was significantly increased compared with the control group (14.3±0.4 vs. 5.3±0.2 days; P<0.001). Further pathological examinations revealed that the infiltration of inflammatory cells and myocardial damage in the cardiac grafts was notably reduced by triptolide, and the corresponding ISHLT scores in the triptolide group were significantly lower than those of the control group (grade 2.08±0.15 vs. 3.67±0.17; P<0.001). In addition, triptolide was able to significantly reduce IL-2 and IFN-γ secretion (P<0.01), significantly increase TGF-β1 secretion in the cardiac grafts and peripheral blood (P<0.01) and increase IL-10 secretion in the cardiac grafts. Therefore, the present study suggests that triptolide inhibits CD4(+) memory T cell-mediated acute rejection and

  12. Loss of multi-epitope specificity in memory CD4(+) T cell responses to B. pertussis with age.

    PubMed

    Han, Wanda G H; van Twillert, Inonge; Poelen, Martien C M; Helm, Kina; van de Kassteele, Jan; Verheij, Theo J M; Versteegh, Florens G A; Boog, Claire J P; van Els, Cécile A C M

    2013-01-01

    Pertussis is still occurring in highly vaccinated populations, affecting individuals of all ages. Long-lived Th1 CD4(+) T cells are essential for protective immunity against pertussis. For better understanding of the limited immunological memory to Bordetella pertussis, we used a panel of Pertactin and Pertussis toxin specific peptides to interrogate CD4(+) T cell responses at the epitope level in a unique cohort of symptomatic pertussis patients of different ages, at various time intervals after infection. Our study showed that pertussis epitope-specific T cell responses contained Th1 and Th2 components irrespective of the epitope studied, time after infection, or age. In contrast, the breadth of the pertussis-directed CD4(+) T cell response seemed dependent on age and closeness to infection. Multi-epitope specificity long-term after infection was lost in older age groups. Detailed knowledge on pertussis specific immune mechanisms and their insufficiencies is important for understanding resurgence of pertussis in highly vaccinated populations.

  13. Circulating naive and memory CD4+ T cells and metabolic syndrome in patients with systemic lupus erythematosus: data from a primarily Mestizo population.

    PubMed

    Ugarte-Gil, Manuel F; Sánchez-Zúñiga, César; Gamboa-Cárdenas, Rocío V; Aliaga-Zamudio, Madeley; Zevallos, Francisco; Tineo-Pozo, Giannina; Cucho-Venegas, Jorge M; Mosqueira-Riveros, Ana; Perich-Campos, Risto A; Alfaro-Lozano, José L; Medina, Mariela; Rodríguez-Bellido, Zoila; Alarcón, Graciela S; Pastor-Asurza, Cesar A

    2015-07-01

    The aim of this study was to determine whether the proportions of naive and memory CD4(+) T cell are independently associated with the metabolic syndrome (MetS) in patients with SLE. This cross-sectional study was conducted in SLE patients seen at our rheumatology department between September 2013 and April 2014. CD4(+) T cell subpopulations were examined by flow cytometry. The association of MetS and CD4(+) T cell subpopulations was examined by Mann-Whitney U-test and by multivariable analysis, adjusting for all possible confounding variables. One hundred and seventeen patients were evaluated. Their mean age was 44.6 years (S.D. 12.6), 109 (93.2%) were female and all patients were Mestizo (mixed Caucasian and Amerindian ancestry). Fifty-two patients (44.4%) presented with MetS. Disease duration was 7.6 years (S.D. 6.8). The percentage of naive CD4(+) T cells was 25.0 (S.D. 12.7) and memory CD4(+) T cells was 66.7 (S.D. 13.2) and the memory:naive CD4(+) T cell ratio was 4.3 (S.D. 5.6). In multivariable analysis, the percentage of naive CD4(+) T cells was negatively associated with the presence of MetS [odds ratio (OR) 0.959 (95% CI 0.923, 0.997), P = 0.033], whereas the percentage of memory CD4(+)T cells and the memory:naive CD4(+) T cell ratio were positively associated with its presence [OR 1.040 (95% CI 1.003, 1.078), P = 0.031 and OR 1.238 (95% CI 1.041, 1.472), P = 0.016, respectively]. In the SLE patients studied, a lower percentage of naive CD4(+) T cells, a higher percentage of memory CD4(+) T cells and the memory:naive CD4(+) T cell ratio were independently associated with the presence of MetS. This association could reflect the impact of immunosenescence among SLE patients with cardiovascular morbidity. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Peripheral human CD4(+)CD8(+) T lymphocytes exhibit a memory phenotype and enhanced responses to IL-2, IL-7 and IL-15.

    PubMed

    Clénet, Marie-Laure; Gagnon, François; Moratalla, Ana Carmena; Viel, Emilie C; Arbour, Nathalie

    2017-09-14

    CD4(+)CD8(+) T lymphocytes account for 1-2% of circulating human T lymphocytes, but their frequency is augmented in several diseases. The phenotypic and functional properties of these T lymphocytes are still ill-defined. We performed an ex vivo characterization of CD4(+)CD8(+) T lymphocytes from the blood of healthy individuals. We observed that CD4(+)CD8(+) T lymphocytes exhibit several characteristics associated with memory T lymphocytes including the expression of chemokine receptors (e.g. CCR7, CXCR3, CCR6) and activation markers (e.g. CD57, CD95). Moreover, we showed that a greater proportion of CD4(+)CD8(+) T lymphocytes have an enhanced capacity to produce cytokines (IFNγ, TNFα, IL-2, IL-4, IL-17A) and lytic enzymes (perforin, granzyme B) compared to CD4(+) and/or CD8(+) T lymphocytes. Finally, we assessed the impact of three key cytokines in T cell biology on these cells. We observed that IL-2, IL-7 and IL-15 triggered STAT5 phosphorylation in a greater proportion of CD4(+)CD8(+) T lymphocytes compared to CD4 and CD8 counterparts. We demonstrate that CD4(+)CD8(+) T lymphocytes from healthy donors exhibit a phenotypic profile associated with memory T lymphocytes, an increased capacity to produce cytokines and lytic enzymes, and a higher proportion of cells responding to key cytokines implicated in T cell survival, homeostasis and activation.

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

    PubMed

    Manes, Thomas D; Pober, Jordan S

    2014-12-15

    Human effector memory CD4 T cells may transmigrate across endothelial cell (EC) monolayers either in response to inflammatory chemokines or in response to TCR recognition of Ag presented on the surface of the EC. The kinetics, morphologic manifestations, and molecular requirements of chemokine- and TCR-driven transendothelial migration (TEM) differ significantly. In this study, we report that, whereas the microtubule organizing center (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 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 effector memory CD4 T cells appears to be a novel process that more closely resembles immune synapse formation than it does conventional chemotaxis.

  16. CD4 and CD8 T cells participate in the immune memory response against Vaccinia virus after a previous natural infection☆

    PubMed Central

    Medeiros-Silva, Daniela Carla; dos Santos Moreira-Silva, Eduardo Augusto; Assis Silva Gomes, Juliana de; da Fonseca, Flávio Guimarães; Correa-Oliveira, Rodrigo

    2013-01-01

    The present study evaluates the immune response of memory CD4+ and CD8+ T cells from patients following a natural Vaccinia virus (VACV) infection. A total of 42 individuals were involved in the study being: 22 previously infected individuals (vaccinated or not against smallpox) and 20 non-infected individuals (vaccinated or not). A short-term in vitro stimulation with UV-inactivated VACV of whole blood cells was performed. Our study showed that previously infected individuals have a lower percentage of CD4+ T cells expressing lymph-node homing receptors (CD4+CD62L+CCR7+) and higher percentage of memory CD4+ T cells subsets (CD4+CD45ROHigh) when compared with non-infected subjects, after in vitro viral stimulation. We also showed that infected individuals presented higher percentages of CD4+ and CD8+ memory T lymphocytes expressing IFN-γ when compared to non-infected individuals. We verified that the percentage of CD4+ and CD8+ T memory cells expressing TNF-α was higher in infected and non-infected vaccinated subjects when compared with non-infected unvaccinated individual. We also observed that previously infected individuals have higher percentages of CD8+ T cells expressing lymph-node homing receptors (CCR7+ and CD62L+) and that the memory T cells expressing IFN-γ and TNF-α were at higher percentages in the whole blood cells from infected and non-infected vaccinated individuals, when compared to unvaccinated non-infected subjects. Thus, our findings suggest that CD4+ and CD8+ T cells are involved in the immune memory response against Vaccinia virus natural infection. PMID:24600565

  17. Prostaglandin E2 and IL-23 plus IL-1β differentially regulate the Th1/Th17 immune response of human CD161(+) CD4(+) memory T cells.

    PubMed

    Barrie, Arthur; Khare, Anupriya; Henkel, Matthew; Zhang, Yingze; Barmada, M Michael; Duerr, Richard; Ray, Anuradha

    2011-08-01

    Prostaglandin E2 (PGE2), interleukin (IL)-23, and IL-1beta (β) propagate inflammatory bowel disease (IBD) by enhancing the development and function of IL-17 producing CD4(+) T helper (Th17) cells. CD4(+) T cells that express the C-type lectin-like receptor CD161 have been proposed to be the physiologic pool of circulating Th17 cells implicated in IBD. We sought to understand how PGE2, alone and in combination with IL-23 and IL-1β, modulate human peripheral CD161(+) CD4(+) memory T cells. We found that CD161(+) cells comprise a significant proportion of human peripheral CD4(+) memory T cells. PGE2 and IL-23 plus IL-1β synergistically induced early IL-17A secretion from CD161(+) CD4(+) memory T cells and the selective enrichment of IL-17A(+) CD161(+) CD4(+) memory T cells in culture. Conversely, IL-23 plus IL-1β partially opposed the PGE2-mediated repression of early interferon gamma (IFN-γ) secretion from CD161(+) cells, as well as the PGE2-mediated depletion of IFN-γ(+) CD161(+) cells. Our results suggest that PGE2 and IL-23 plus IL-1β induce the Th17 immune response preferentially in CD161(+) CD4(+) memory T cells, while divergently regulating their ability to express IFN-γ. We hypothesize that Th17-mediated chronic inflammation in IBD depends on the net response of CD161(+) CD4(+) memory T cells to both PGE2 and IL-23 plus IL-1β. © 2011 Wiley Periodicals, Inc.

  18. TCR stimulation without co-stimulatory signals induces expression of "tolerogenic" genes in memory CD4 T cells but does not compromise cell proliferation.

    PubMed

    Xie, Aini; Zheng, Xiong; Khattar, Mithun; Schroder, Paul; Stepkowski, Stanislaw; Xia, Jiahong; Chen, Wenhao

    2015-02-01

    Memory T cells resist co-stimulatory blockade and present a unique therapeutic challenge in transplantation and autoimmune diseases. Herein, we determined whether memory T cells express less "tolerogenic" genes than naïve T cells to reinforce a proliferative response under the deprivation of co-stimulatory signals. The expression of ∼40 tolerogenic genes in memory and naïve CD4(+) T cells was thus assessed during an in vitro TCR stimulation without co-stimulation. Briefly, upon TCR stimulation with an anti-CD3 mAb alone, memory CD4(+) T cells exhibited more proliferation than naïve CD4(+) T cells. To our surprise, at 24h upon anti-CD3 mAb stimulation, memory CD4(+) T cells expressed more than a 5-fold higher level of the transcription factor Egr2 and a 20-fold higher level of the transmembrane E3 ubiquitin ligase GRAIL than those in naïve T cells. Hence, the high-level expression of tolerogenic genes, Egr2 and GRAIL, in memory CD4(+) T cells does not prevent cell proliferation. Importantly, anti-CD3 mAb-stimulated memory CD4(+) T cells expressed high protein/gene levels of phosphorylated STAT5, Nedd4, Bcl-2, and Bcl-XL. Therefore, co-stimulation-independent proliferation of memory CD4(+) T cells may be due to elevated expression of molecules that support cell proliferation and survival, but not lack of tolerogenic molecules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Persistence of integrated HIV DNA in CXCR3+CCR6+ memory CD4+ T-cells in HIV-infected individuals on antiretroviral therapy

    PubMed Central

    Khoury, Gabriela; Anderson, Jenny L; Fromentin, Rémi; Hartogensis, Wendy; Smith, Miranda Z; Bacchetti, Peter; Hecht, Frederick M; Chomont, Nicolas; Cameron, Paul U; Deeks, Steven G; Lewin, Sharon R

    2016-01-01

    Background HIV latent infection can be established in vitro by treating resting CD4+ T-cells with chemokines (CK) that bind to chemokine receptors (CKR), CCR7, CXCR3 and CCR6, highly expressed on T-cells. Objective To determine if CKR identify CD4+ T-cells enriched for HIV in HIV-infected individuals receiving suppressive antiretroviral therapy (ART). Design A cross-sectional study of CKR expression and HIV persistence in blood from HIV-infected individuals on suppressive ART for >3 years (n=48). A subset of 20 individuals underwent leukapheresis and sorting of specific CD4+ T-cell subsets. Methods We used flow cytometry to quantify CCR5, CCR6, CXCR3 and CXCR5 expression on CD4+ T-cells. HIV persistence was quantified using real time PCR to detect total, integrated HIV DNA, 2-LTR circles and cell-associated HIV RNA in total CD4+ T-cells from blood or sorted T-cell subsets. Associations between CKR and HIV persistence in CD4+ T-cells in blood were determined using regression models and adjusted for current and nadir CD4+ T-cell counts. Results The frequency of cells harbouring integrated HIV DNA was inversely associated with current CD4+ T-cell count and positively associated with CCR5+ CD4+ T-cells, CXCR3+CCR6+ and CXCR3+CCR6- expression on total memory CD4+ T-cells (p<0.001, 0.048, 0.015 and 0.016 respectively). CXCR3+CCR6+ CM CD4+ T-cells contained the highest amount of integrated HIV DNA compared to all T-cell subsets examined (p=0.001). Conclusion CXCR3 and CCR6 co-expression defines a subset of CD4+ T-cells that are preferentially enriched for HIV DNA in HIV-infected individuals on ART. PMID:26807971

  20. Role of CD25+ CD4+ T cells in acute and persistent coronavirus infection of the central nervous system

    PubMed Central

    de Aquino, Maria Teresa P.; Puntambekar, Shweta S.; Savarin, Carine; Bergmann, Cornelia C.; Phares, Timothy W.; Hinton, David R.; Stohlman, Stephen A.

    2014-01-01

    The influence of CD25+CD4+ regulatory T cells (Treg) on acute and chronic viral infection of the central nervous system (CNS) was examined using a glial tropic murine coronavirus. Treg in the CNS were highest during initial T cell mediated virus control, decreased and then remained relatively stable during persistence. Anti-CD25 treatment did not affect CNS recruitment of inflammatory cells. Viral control was initially delayed; however, neither the kinetics of viral control nor viral persistence were affected. By contrast, the absence of Treg during the acute phase resulted in increased demyelination during viral persistence. These data suggest that CNS inflammation, progression of viral control and viral persistence are relatively independent of CD25+CD4+ Treg. However, their absence during acute infection alters the ability of the host to limit tissue damage. PMID:24210105

  1. Role of CD25(+) CD4(+) T cells in acute and persistent coronavirus infection of the central nervous system.

    PubMed

    de Aquino, Maria Teresa P; Puntambekar, Shweta S; Savarin, Carine; Bergmann, Cornelia C; Phares, Timothy W; Hinton, David R; Stohlman, Stephen A

    2013-12-01

    The influence of CD25(+)CD4(+) regulatory T cells (Treg) on acute and chronic viral infection of the central nervous system (CNS) was examined using a glial tropic murine coronavirus. Treg in the CNS were highest during initial T cell mediated virus control, decreased and then remained relatively stable during persistence. Anti-CD25 treatment did not affect CNS recruitment of inflammatory cells. Viral control was initially delayed; however, neither the kinetics of viral control nor viral persistence were affected. By contrast, the absence of Treg during the acute phase resulted in increased demyelination during viral persistence. These data suggest that CNS inflammation, progression of viral control and viral persistence are relatively independent of CD25(+)CD4(+) Treg. However, their absence during acute infection alters the ability of the host to limit tissue damage. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Preferential replication of HIV-1 in the CD45RO memory cell subset of primary CD4 lymphocytes in vitro.

    PubMed Central

    Spina, C A; Prince, H E; Richman, D D

    1997-01-01

    The ability of HIV-1 to establish an infection and replicate to high copy number in CD4 lymphocytes is dependent on both the activation state of the cell and virus-encoded regulatory proteins that modulate viral gene expression. To study these required virus-cell interactions, we have used an in vitro cell model of acute HIV infection of quiescent, primary CD4 lymphocytes and subsequent induction of T cell activation and virus replication by lectin or CD3 receptor cross-linking. Experiments were done to determine if the capacity of HIV to establish infection and complete replication was impacted by the maturational state of the CD4 cell target or the specific signal induction pathway engaged during activation. Primary CD4 cells were FACS-sorted into the major phenotypic subsets representative of memory (CD45RO) and naive (CD45RA) cells. Levels of virus replication were compared between infection with wild-type NL4-3 virus and an isogenic mutant containing a deletion in nef regulatory gene. PHA mitogen stimulation was compared with anti-CD3, with and without anti-CD28 costimulation, for induction of cell proliferation and virus replication. In both infected and uninfected cells, the RA cell subset exhibited significantly greater response to CD3/CD28 stimulation than did the RO cell subset. In contrast, the majority of virus replication occurred consistently in the RO cell subset. Deletion of HIV nef function caused a severe reduction in viral replication, especially in the RA naive cell subset after CD3 induction. PCR analysis of viral DNA formation, during infection of quiescent cells, demonstrated that the observed differences in HIV replication capacity between RO and RA cell subsets were not due to inherent differences in cell susceptibility to infection. Our results indicate that HIV replication is enhanced selectively in CD45RO memory phenotype cells through the probable contribution of specialized cellular factors which are produced during CD3-initiated

  3. B cell activating factor (BAFF) and a proliferation inducing ligand (APRIL) mediate CD40-independent help by memory CD4 T cells.

    PubMed

    Gorbacheva, V; Ayasoufi, K; Fan, R; Baldwin, W M; Valujskikh, A

    2015-02-01

    Donor-reactive memory T cells undermine organ transplant survival and are poorly controlled by immunosuppression or costimulatory blockade. Memory CD4 T cells provide CD40-independent help for the generation of donor-reactive effector CD8 T cells and alloantibodies (alloAbs) that rapidly mediate allograft rejection. The goal of this study was to investigate the role of B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) in alloresponses driven by memory CD4 T cells. The short-term neutralization of BAFF alone or BAFF plus APRIL synergized with anti-CD154 mAb to prolong heart allograft survival in recipients containing donor-reactive memory CD4 T cells. The prolongation was associated with reduction in antidonor alloAb responses and with inhibited reactivation and helper functions of memory CD4 T cells. Additional depletion of CD8 T cells did not enhance the prolonged allograft survival suggesting that donor-reactive alloAbs mediate late graft rejection in these recipients. This is the first report that targeting the BAFF cytokine network inhibits both humoral and cellular immune responses induced by memory CD4 T cells. Our results suggest that reagents neutralizing BAFF and APRIL may be used to enhance the efficacy of CD40/CD154 costimulatory blockade and improve allograft survival in T cell-sensitized recipients. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

  4. 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. Copyright © 2014, American Association for the Advancement of Science.

  5. Significant Differences in Antigen-induced Transendothelial Migration of Human CD8 and CD4 T Effector Memory Cells

    PubMed Central

    Manes, Thomas D.; Pober, Jordan S.

    2016-01-01

    Objective Circulating human T effector memory cell (TEM) recognition of non-self MHC molecules on allograft endothelial cells (EC) can initiate graft rejection despite elimination of professional antigen presenting cells necessary for naïve T cell activation. Our prior studies of CD4 TEM have established that engagement of the T cell receptor (TCR) not only activates T cells but also triggers transendothelial migration (TEM) by a process that is distinct from that induced by activating chemokine receptors (CR) on T cells, being slower, requiring microtubule organizing center (MTOC)-directed cytolytic granule polarization to and release from the leading edge of the T cell, and requiring engagement of proteins of the EC lateral border recycling compartment (LBRC). While CD4 TEM may contribute to acute allograft rejection, the primary effectors are alloreactive CD8 TEM. Whether and how TCR engagement affects TEM of human CD8 TEM is unknown. Approach and Results We modeled TEM of CD8 TEM across cultured human microvascular EC engineered to present superantigen under conditions of venular shear stress in vitro in a flow chamber. Here we report that TCR engagement can also induce TEM of this population that similarly differs from CR-driven TEM with regard to kinetics, morphological manifestations, and MTOC dynamics as with CD4 TEM. However, CD8 TEM do not require either cytolytic granule release or interactions with proteins of the LBRC. Conclusions These results imply that therapeutic strategies designed to inhibit TCR-driven recruitment based on targeting granule release or components of the LBRC will not affect CD8 TEM and are unlikely to block acute rejection in the clinic. PMID:27444200

  6. CD28 is required for induction and maintenance of immunological memory in toxin-reactive CD4+ T cells in vivo.

    PubMed

    Fukada, Kenji; Koyanagi, Madoka; Arimura, Yutaka; Ogiuchi, Hideki; Uchiyama, Takehiko; Yagi, Junji

    2005-12-01

    We previously reported that Vbeta3+ CD4+ T cells maintained a protracted expansion, with the phenotypes of memory Th2 cells, for 30 days in C57BL/6 (B6) mice implanted with SEA-containing mini-osmotic pumps. In the present study, we followed the fate of Vbeta3+ CD4+ T cells in CD28-/- mice. Vbeta3+ CD4+ T cells increased to a degree similar to that of B6 Vbeta3+ CD4+ T cells until day 10 after implantation, then declined rapidly reaching the control level by 28 days. Remaining Vbeta3+ CD4+ T cells at that time did not exhibit memory phenotypes nor Th2-deviated responses. The rapid drop in Vbeta3+ CD4+ T cells in CD28-/- mice was attributable to upregulated induction of apoptosis owing to marginal inductions of Bcl-2 and Bcl-xL. Collectively, these data indicate CD28 to play critical roles in the generation and maintenance of SEA-reactive CD4+ T cells in vivo.

  7. Short-Lived Antigen Recognition but Not Viral Infection at a Defined Checkpoint Programs Effector CD4 T Cells To Become Protective Memory.

    PubMed

    Bautista, Bianca L; Devarajan, Priyadharshini; McKinstry, K Kai; Strutt, Tara M; Vong, Allen M; Jones, Michael C; Kuang, Yi; Mott, Daniel; Swain, Susan L

    2016-11-15

    Although memory CD4 T cells are critical for effective immunity to pathogens, the mechanisms underlying their generation are still poorly defined. We find that following murine influenza infection, most effector CD4 T cells undergo apoptosis unless they encounter cognate Ag at a defined stage near the peak of effector generation. Ag recognition at this memory checkpoint blocks default apoptosis and programs their transition to long-lived memory. Strikingly, we find that viral infection is not required, because memory formation can be restored by the addition of short-lived, Ag-pulsed APC at this checkpoint. The resulting memory CD4 T cells express an enhanced memory phenotype, have increased cytokine production, and provide protection against lethal influenza infection. Finally, we find that memory CD4 T cell formation following cold-adapted influenza vaccination is boosted when Ag is administered during this checkpoint. These findings imply that persistence of viral Ag presentation into the effector phase is the key factor that determines the efficiency of memory generation. We also suggest that administering Ag at this checkpoint may improve vaccine efficacy. Copyright © 2016 by The American Association of Immunologists, Inc.

  8. Dexamethasone and Monophosphoryl Lipid A-Modulated Dendritic Cells Promote Antigen-Specific Tolerogenic Properties on Naive and Memory CD4+ T Cells

    PubMed Central

    Maggi, Jaxaira; Schinnerling, Katina; Pesce, Bárbara; Hilkens, Catharien M.; Catalán, Diego; Aguillón, Juan C.

    2016-01-01

    Tolerogenic dendritic cells (DCs) are a promising tool to control T cell-mediated autoimmunity. Here, we evaluate the ability of dexamethasone-modulated and monophosphoryl lipid A (MPLA)-activated DCs [MPLA-tolerogenic DCs (tDCs)] to exert immunomodulatory effects on naive and memory CD4+ T cells in an antigen-specific manner. For this purpose, MPLA-tDCs were loaded with purified protein derivative (PPD) as antigen and co-cultured with autologous naive or memory CD4+ T cells. Lymphocytes were re-challenged with autologous PPD-pulsed mature DCs (mDCs), evaluating proliferation and cytokine production by flow cytometry. On primed-naive CD4+ T cells, the expression of regulatory T cell markers was evaluated and their suppressive ability was assessed in autologous co-cultures with CD4+ effector T cells and PPD-pulsed mDCs. We detected that memory CD4+ T cells primed by MPLA-tDCs presented reduced proliferation and proinflammatory cytokine expression in response to PPD and were refractory to subsequent stimulation. Naive CD4+ T cells were instructed by MPLA-tDCs to be hyporesponsive to antigen-specific restimulation and to suppress the induction of T helper cell type 1 and 17 responses. In conclusion, MPLA-tDCs are able to modulate antigen-specific responses of both naive and memory CD4+ T cells and might be a promising strategy to “turn off” self-reactive CD4+ effector T cells in autoimmunity. PMID:27698654

  9. Human CD4+ CD25hi Foxp3+ regulatory T cells are derived by rapid turnover of memory populations in vivo

    PubMed Central

    Vukmanovic-Stejic, Milica; Zhang, Yan; Cook, Joanne E.; Fletcher, Jean M.; McQuaid, Arthur; Masters, Joanne E.; Rustin, Malcolm H.A.; Taams, Leonie S.; Beverley, Peter C.L.; Macallan, Derek C.; Akbar, Arne N.

    2006-01-01

    While memory T cells are maintained by continuous turnover, it is not clear how human regulatory CD4+CD45RO+CD25hi Foxp3+ T lymphocyte populations persist throughout life. We therefore used deuterium labeling of cycling cells in vivo to determine whether these cells could be replenished by proliferation. We found that CD4+CD45RO+Foxp3+CD25hi T lymphocytes were highly proliferative, with a doubling time of 8 days, compared with memory CD4+CD45RO+Foxp3–CD25– (24 days) or naive CD4+CD45RA+Foxp3–CD25– populations (199 days). However, the regulatory population was susceptible to apoptosis and had critically short telomeres and low telomerase activity. It was therefore unlikely to be self regenerating. These data are consistent with continuous production from another population source. We found extremely close TCR clonal homology between regulatory and memory CD4+ T cells. Furthermore, antigen-related expansions within certain TCR Vβ families were associated with parallel numerical increases of CD4+CD45RO+CD25hiFoxp3+ Tregs with the same Vβ usage. It is therefore unlikely that all human CD4+CD25+Foxp3+ Tregs are generated as a separate functional lineage in the thymus. Instead, our data suggest that a proportion of this regulatory population is generated from rapidly dividing, highly differentiated memory CD4+ T cells; this has considerable implications for the therapeutic manipulation of these cells in vivo. PMID:16955142

  10. Replicative fitness of transmitted HIV-1 drives acute immune activation, proviral load in memory CD4+ T cells, and disease progression.

    PubMed

    Claiborne, Daniel T; Prince, Jessica L; Scully, Eileen; Macharia, Gladys; Micci, Luca; Lawson, Benton; Kopycinski, Jakub; Deymier, Martin J; Vanderford, Thomas H; Nganou-Makamdop, Krystelle; Ende, Zachary; Brooks, Kelsie; Tang, Jianming; Yu, Tianwei; Lakhi, Shabir; Kilembe, William; Silvestri, Guido; Douek, Daniel; Goepfert, Paul A; Price, Matthew A; Allen, Susan A; Paiardini, Mirko; Altfeld, Marcus; Gilmour, Jill; Hunter, Eric

    2015-03-24

    HIV-1 infection is characterized by varying degrees of chronic immune activation and disruption of T-cell homeostasis, which impact the rate of disease progression. A deeper understanding of the factors that influence HIV-1-induced immunopathology and subsequent CD4(+) T-cell decline is critical to strategies aimed at controlling or eliminating the virus. In an analysis of 127 acutely infected Zambians, we demonstrate a dramatic and early impact of viral replicative capacity (vRC) on HIV-1 immunopathogenesis that is independent of viral load (VL). Individuals infected with high-RC viruses exhibit a distinct inflammatory cytokine profile as well as significantly elevated T-cell activation, proliferation, and CD8(+) T-cell exhaustion, during the earliest months of infection. Moreover, the vRC of the transmitted virus is positively correlated with the magnitude of viral burden in naive and central memory CD4(+) T-cell populations, raising the possibility that transmitted viral phenotypes may influence the size of the initial latent viral reservoir. Taken together, these findings support an unprecedented role for the replicative fitness of the founder virus, independent of host protective genes and VL, in influencing multiple facets of HIV-1-related immunopathology, and that a greater focus on this parameter could provide novel approaches to clinical interventions.

  11. Subsets of Memory CD4+ T Cell and Bactericidal Antibody Response to Neisseria meningitidis Serogroup C after Immunization of HIV-Infected Children and Adolescents

    PubMed Central

    Milagres, Lucimar G.; Costa, Priscilla R.; Silva, Giselle P.; Carvalho, Karina I.; Pereira-Manfro, Wânia F.; Ferreira, Bianca; Barreto, Daniella M.; Frota, Ana Cristina C.; Hofer, Cristina B.; Kallas, Esper G.

    2014-01-01

    Meningococcal disease is endemic in Brazil, with periodic outbreaks and case fatality rates reach as high as 18 to 20% of cases. Conjugate vaccines against meningococci are immunogenic in healthy children. However, we have previously shown a poor bactericidal antibody response to a Men C conjugate vaccine in Brazilian HIV-infected children and adolescents after a single vaccine administration. The goal of the present work was to investigate associations between bactericidal antibody response induced by MenC vaccine and the frequency and activation profile (expression of CD38, HLA-DR and CCR5 molecules) of total CD4+ memory T cell sub-populations in HIV-1-infected children and adolescents. Responders to vaccination against MenC had a predominance (about 44%) of CD4+ TINTERMEDIATE subset followed by TTRANSITIONAL memory subset (23 to 26%). Importantly, CD4+ TINT frequency was positively associated with bactericidal antibody response induced by vaccination. The positive correlation persisted despite the observation that the frequency TINT CD38+HLA-DR+ was higher in responders. In contrast, CD4+ TCENTRAL MEMORY (TCM) subset negatively correlated with bactericidal antibodies. In conclusion, these data indicate that less differentiated CD+ T cells, like TCM may be constantly differentiating into intermediate and later differentiated CD4+ T cell subsets. These include CD4 TINT subset which showed a positive association with bactericidal antibodies. PMID:25532028

  12. 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

  13. 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 Central

    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

  14. Dopaminergic Receptors on CD4+ T Naive and Memory Lymphocytes Correlate with Motor Impairment in Patients with Parkinson’s Disease

    PubMed Central

    Kustrimovic, Natasa; Rasini, Emanuela; Legnaro, Massimiliano; Bombelli, Raffaella; Aleksic, Iva; Blandini, Fabio; Comi, Cristoforo; Mauri, Marco; Minafra, Brigida; Riboldazzi, Giulio; Sanchez-Guajardo, Vanesa; Marino, Franca; Cosentino, Marco

    2016-01-01

    Parkinson’s disease (PD) is characterized by loss of dopaminergic neurons in substantia nigra pars compacta, α-synuclein (α-syn)-rich intraneuronal inclusions (Lewy bodies), and microglial activation. Emerging evidence suggests that CD4+ T lymphocytes contribute to neuroinflammation in PD. Since the mainstay of PD treatment is dopaminergic substitution therapy and dopamine is an established transmitter connecting nervous and immune systems, we examined CD4+ T naive and memory lymphocytes in PD patients and in healthy subjects (HS), with specific regard to dopaminergic receptor (DR) expression. In addition, the in vitro effects of α-syn were assessed on CD4+ T naive and memory cells. Results showed extensive association between DR expression in T lymphocytes and motor dysfunction, as assessed by UPDRS Part III score. In total and CD4+ T naive cells expression of D1-like DR decrease, while in T memory cells D2-like DR increase with increasing score. In vitro, α-syn increased CD4+ T memory cells, possibly to a different extent in PD patients and in HS, and affected DR expression with cell subset-specific patterns. The present results support the involvement of peripheral adaptive immunity in PD, and may contribute to develop novel immunotherapies for PD, as well as to better use of current dopaminergic antiparkinson drugs. PMID:27652978

  15. Identification of Caucasian CD4 T cell epitopes on the circumsporozoite protein of Plasmodium vivax. T cell memory.

    PubMed

    Bilsborough, J; Carlisle, M; Good, M F

    1993-07-15

    We have identified a population of Caucasians with a defined past history of infection with Plasmodium vivax malaria. Using purified synthetic peptides overlapping the sequence of the circumsporozoite protein, we determined the percentage of individuals whose T cells proliferated or secreted IFN-gamma in response to peptide stimulation, for both this population and a population of nonmalaria-exposed control individuals. A number of peptides were recognized by both groups, but 11 peptides were uniquely recognized by the exposed population, and thus represented malaria-specific T cell epitopes. CD4 T cells were found to be responsible for the proliferative response. Humans last exposed to vivax sporozoites as long ago as 49 yr responded as well or better to these malaria-specific epitopes as individuals exposed within the previous month. Since such malaria-induced memory response may not be a feature of Plasmodium falciparum infections, and since P. falciparum does not have a persisting hypnozoite stage, our data argue that the persistence of T cell memory to vivax epitopes may result from antigenic persistence in the liver.

  16. High-Throughput Sequencing of Islet-Infiltrating Memory CD4+ T Cells Reveals a Similar Pattern of TCR Vβ Usage in Prediabetic and Diabetic NOD Mice

    PubMed Central

    Marrero, Idania; Hamm, David E.; Davies, Joanna D.

    2013-01-01

    Autoreactive memory CD4+ T cells play a critical role in the development of type 1 diabetes, but it is not yet known how the clonotypic composition and TCRβ repertoire of the memory CD4+ T cell compartment changes during the transition from prediabetes to diabetes. In this study, we used high-throughput sequencing to analyze the TCRβ repertoire of sorted islet-infiltrating memory CD4+CD44high T cells in 10-week-old prediabetic and recently diabetic NOD mice. We show that most clonotypes of islet-infiltrating CD4+CD44high T cells were rare, but high-frequency clonotypes were significantly more common in diabetic than in prediabetic mice. Moreover, although the CD4+CD44high TCRβ repertoires were highly diverse at both stages of disease development, dominant use of TRBV1 (Vβ2), TRBV13-3 (Vβ8.1), and TRBV19 (Vβ6) was evident in both prediabetic and diabetic mice. Our findings strongly suggest that therapeutic targeting of cells specifically expressing the dominant TCRβ might reduce pancreatic infiltration in prediabetic mice and attenuate the progression to diabetes. PMID:24146886

  17. Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1

    PubMed Central

    Benlahrech, Adel; Harris, Julian; Meiser, Andrea; Papagatsias, Timos; Hornig, Julia; Hayes, Peter; Lieber, Andre; Athanasopoulos, Takis; Bachy, Veronique; Csomor, Eszter; Daniels, Rod; Fisher, Kerry; Gotch, Frances; Seymour, Len; Logan, Karen; Barbagallo, Romina; Klavinskis, Linda; Dickson, George; Patterson, Steven

    2009-01-01

    In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing α4β7 integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-γ production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition. PMID:19918060

  18. Decreased Numbers of CD4+ Naive and Effector Memory T Cells, and CD8+ Naïve T Cells, are Associated with Trichloroethylene Exposure

    PubMed Central

    Hosgood, H. Dean; Zhang, Luoping; Tang, Xiaojiang; Vermeulen, Roel; Qiu, Chuangyi; Shen, Min; Smith, Martyn T.; Ge, Yichen; Ji, Zhiying; Xiong, Jun; He, Jian; Reiss, Boris; Liu, Songwang; Xie, Yuxuan; Guo, Weihong; Galvan, Noe; Li, Laiyu; Hao, Zhenyue; Rothman, Nathaniel; Huang, Hanlin; Lan, Qing

    2012-01-01

    Trichloroethylene (TCE) is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE’s carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE’s early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4+ T cells, CD8+ T cells, natural killer cells, and B cells) were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors, and/or lymphocyte survival. To explore which T lymphocyte subsets are affected in the same study population, we investigated the effect of TCE exposure on the numbers of CD4+ naïve and memory T cells, CD8+ naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4+ and CD8+ naïve T cell counts were about 8% (p = 0.056) and 17% (p = 0.0002) lower, respectively, among exposed workers. CD4+ effector memory T cell counts were decreased by about 20% among TCE-exposed workers compared to controls (p = 0.001). The selective targeting of TCE on CD8+ naive and possibly CD4+ naive T cells, and CD4+ effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure. PMID:22649769

  19. CD40-independent help by memory CD4 T cells induces pathogenic alloantibody but does not lead to long-lasting humoral immunity

    PubMed Central

    Fan, Ran; Yu, Hong; Valujskikh, Anna

    2014-01-01

    CD40/CD154 interactions are essential for productive antibody responses to T-dependent antigens. Memory CD4 T cells express accelerated helper functions and are less dependent on costimulation when compared to naïve T cells. Here we report that donor-reactive memory CD4 T cells can deliver help to CD40-deficient B cells and induce high titers of IgG alloantibodies that contribute to heart allograft rejection in CD40−/− heart recipients. While cognate interactions between memory helper T cells and B cells are crucial for CD40-independent help, this process is not accompanied by germinal center formation and occurs despite ICOS blockade. Consistent with the extrafollicular nature of T/B cell interactions, CD40-independent help fails to maintain stable levels of serum alloantibody and induce differentiation of long-lived plasma cells and memory B cells. In summary, our data suggest that while CD40-independent help by memory CD4 T cells is sufficient to induce high levels of pathogenic alloantibody, it does not sustain long-lasting anti-donor humoral immunity and B cell memory responses. This information may guide the future use of CD40/CD154 targeting therapies in transplant recipients containing donor-reactive memory T cells. PMID:24102790

  20. Obesity-Induced Metabolic Stress Leads to Biased Effector Memory CD4(+) T Cell Differentiation via PI3K p110δ-Akt-Mediated Signals.

    PubMed

    Mauro, Claudio; Smith, Joanne; Cucchi, Danilo; Coe, David; Fu, Hongmei; Bonacina, Fabrizia; Baragetti, Andrea; Cermenati, Gaia; Caruso, Donatella; Mitro, Nico; Catapano, Alberico L; Ammirati, Enrico; Longhi, Maria P; Okkenhaug, Klaus; Norata, Giuseppe D; Marelli-Berg, Federica M

    2017-03-07

    Low-grade systemic inflammation associated to obesity leads to cardiovascular complications, caused partly by infiltration of adipose and vascular tissue by effector T cells. The signals leading to T cell differentiation and tissue infiltration during obesity are poorly understood. We tested whether saturated fatty acid-induced metabolic stress affects differentiation and trafficking patterns of CD4(+) T cells. Memory CD4(+) T cells primed in high-fat diet-fed donors preferentially migrated to non-lymphoid, inflammatory sites, independent of the metabolic status of the hosts. This was due to biased CD4(+) T cell differentiation into CD44(hi)-CCR7(lo)-CD62L(lo)-CXCR3(+)-LFA1(+) effector memory-like T cells upon priming in high-fat diet-fed animals. Similar phenotype was observed in obese subjects in a cohort of free-living people. This developmental bias was independent of any crosstalk between CD4(+) T cells and dendritic cells and was mediated via direct exposure of CD4(+) T cells to palmitate, leading to increased activation of a PI3K p110δ-Akt-dependent pathway upon priming.

  1. 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

  2. TCR-driven transendothelial migration of human effector memory CD4 T cells involves Vav, Rac, and myosin IIA.

    PubMed

    Manes, Thomas D; Pober, Jordan S

    2013-04-01

    Human effector memory (EM) CD4 T cells may be recruited from the blood into a site of inflammation in response either to inflammatory chemokines displayed on or specific Ag presented by venular endothelial cells (ECs), designated as chemokine-driven or TCR-driven transendothelial migration (TEM), respectively. We have previously described differences in the morphological appearance of transmigrating T cells as well as in the molecules that mediate T cell-EC interactions distinguishing these two pathways. In this study, we report that TCR-driven TEM requires ZAP-70-dependent activation of a pathway involving Vav, Rac, and myosin IIA. Chemokine-driven TEM also uses ZAP-70, albeit in a quantitatively and spatially different manner of activation, and is independent of Vav, Rac, and mysosin IIA, depending instead on an as-yet unidentified GTP exchange factor that activates Cdc42. The differential use of small Rho family GTPases to activate the cytoskeleton is consistent with the morphological differences observed in T cells that undergo TEM in response to these distinct recruitment signals.

  3. Enhancing alloreactivity does not restore GVHD induction but augments skin graft rejection by CD4 effector memory T cells

    PubMed Central

    Anderson, Britt E; Tang, Anita L; Wang, Ying; Froicu, Monica; Rothstein, David; McNiff, Jennifer M; Demetris, Anthony J; Farber, Donna L; Shlomchik, Warren D; Shlomchik, Mark J

    2012-01-01

    Graft-vs.-host disease (GVHD) caused by donor T cells attacking recipient tissues is a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation (alloSCT). Studies have shown that effector memory T cells (TEM) do not cause GVHD but are capable of immune functions post-transplant, including graft-vs.-leukemia (GVL) effects, but the reasons for this are unclear. In mice, the TEM pool may have a less-diverse T cell receptor (TCR) repertoire than TN with fewer alloreactive clones. We therefore tested whether enhancing the alloreactivity of TEM would restore their ability to cause GVHD. In an MHC-matched system, alloreactive TEM were created by transferring GVHD effector cells into syngeneic recipients and allowing conversion to TEM. Upon retransfer to freshly transplanted recipients, these cells caused only mild GVHD. Similarly, in an MHC-mismatched system, TEM with a proven increased precursor frequency of alloreactive clones only caused limited GVHD. Nonetheless these same cells mounted strong in vitro alloresponses and caused rapid skin graft rejection. TEM created from CD4 cells that had undergone lymphopenia-induced proliferation also caused only mild GVHD. Our findings establish that conversion to TEM significantly reduces GVHD potency, even in cells with a substantially enhanced alloreactive repertoire. PMID:21660940

  4. Effect of memory CD4(+) T cells' signal transducer and activator of transcription (STATs) functional shift on cytokine-releasing properties in asthma.

    PubMed

    Chen, Zhihong; Pan, Jue; Jia, Yi; Li, Dandan; Min, Zhihui; Su, Xiaoqiong; Yuan, Honglei; Shen, Geng; Cao, Shengxuan; Zhu, Lei; Wang, Xiangdong

    2017-02-01

    Recent data have demonstrated that long-lived memory T cells are present in the human lung and can play significant roles in the pathogenesis of specific allergic and autoimmune diseases. However, most evidence has been obtained from mouse studies, and the potential roles of memory T cells in human allergic diseases, such as asthma, remain largely unknown. Thirty-three asthmatics, 26 chronic obstructive pulmonary disease (COPD) patients, and 22 healthy volunteers were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) were isolated from the peripheral blood, and cell surface staining (CD4, CD45RO, CRTH2, CD62L, and CCR7) was performed for the detection of memory CD4(+) T cells in blood. After stimulation with interleukin-27 (IL-27) or IL-4 for 15 min, the STAT1/STAT6 phosphorylation of memory CD4(+) T cells was measured separately by flow cytometric techniques. The cytokine-releasing profiles after 6 days of culture under neutralization, TH2, TH2 + lipopolysaccharide (LPS), and TH2 + house dust mite (HDM) conditions were detected by intracellular protein (IL-5, IL-17, and interferon (IFN)-γ) staining. Correlation analyses between the profile of memory CD4(+) T cells and clinical characteristics of asthma were performed. The number of circulating memory CD4(+) T (CD4(+) Tm) cells in asthmatics was increased compared with that in the healthy subjects (48 ± 5.7 % vs. 32 ± 4.1 %, p < 0.05). Compared with COPD and healthy subjects, the phosphorylation of signal transducer and activator of transcription 1 (STAT1-py) was impaired in asthmatics, whereas the phosphorylation of signal transducer and activator of transcription 6 (STAT6-py) was slightly enhanced. This imbalance of STAT1-py/STAT6-py was attributed to TH2 memory cells but not non-TH2 memory cells in blood. The cytokine-releasing profiles of asthmatics was unique, specifically IL-5(high), IL-17(high), and IFN-r(low), compared with those of COPD patients and healthy subjects. The

  5. A major population of mucosal memory CD4+ T cells, coexpressing IL-18Rα and DR3, display innate lymphocyte functionality.

    PubMed

    Holmkvist, P; Roepstorff, K; Uronen-Hansson, H; Sandén, C; Gudjonsson, S; Patschan, O; Grip, O; Marsal, J; Schmidtchen, A; Hornum, L; Erjefält, J S; Håkansson, K; Agace, W W

    2015-05-01

    Mucosal tissues contain large numbers of memory CD4(+) T cells that, through T-cell receptor-dependent interactions with antigen-presenting cells, are believed to have a key role in barrier defense and maintenance of tissue integrity. Here we identify a major subset of memory CD4(+) T cells at barrier surfaces that coexpress interleukin-18 receptor alpha (IL-18Rα) and death receptor-3 (DR3), and display innate lymphocyte functionality. The cytokines IL-15 or the DR3 ligand tumor necrosis factor (TNF)-like cytokine 1A (TL1a) induced memory IL-18Rα(+)DR3(+)CD4(+) T cells to produce interferon-γ, TNF-α, IL-6, IL-5, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-22 in the presence of IL-12/IL-18. TL1a synergized with IL-15 to enhance this response, while suppressing IL-15-induced IL-10 production. TL1a- and IL-15-mediated cytokine induction required the presence of IL-18, whereas induction of IL-5, IL-13, GM-CSF, and IL-22 was IL-12 independent. IL-18Rα(+)DR3(+)CD4(+) T cells with similar functionality were present in human skin, nasal polyps, and, in particular, the intestine, where in chronic inflammation they localized with IL-18-producing cells in lymphoid aggregates. Collectively, these results suggest that human memory IL-18Rα(+)DR3(+) CD4(+) T cells may contribute to antigen-independent innate responses at barrier surfaces.

  6. A major population of mucosal memory CD4+ T cells, coexpressing IL-18Rα and DR3, display innate lymphocyte functionality

    PubMed Central

    Holmkvist, P; Roepstorff, K; Uronen-Hansson, H; Sandén, C; Gudjonsson, S; Patschan, O; Grip, O; Marsal, J; Schmidtchen, A; Hornum, L; Erjefält, J S; Håkansson, K; Agace, W W

    2015-01-01

    Mucosal tissues contain large numbers of memory CD4+ T cells that, through T-cell receptor-dependent interactions with antigen-presenting cells, are believed to have a key role in barrier defense and maintenance of tissue integrity. Here we identify a major subset of memory CD4+ T cells at barrier surfaces that coexpress interleukin-18 receptor alpha (IL-18Rα) and death receptor-3 (DR3), and display innate lymphocyte functionality. The cytokines IL-15 or the DR3 ligand tumor necrosis factor (TNF)-like cytokine 1A (TL1a) induced memory IL-18Rα+DR3+CD4+ T cells to produce interferon-γ, TNF-α, IL-6, IL-5, IL-13, granulocyte–macrophage colony-stimulating factor (GM-CSF), and IL-22 in the presence of IL-12/IL-18. TL1a synergized with IL-15 to enhance this response, while suppressing IL-15-induced IL-10 production. TL1a- and IL-15-mediated cytokine induction required the presence of IL-18, whereas induction of IL-5, IL-13, GM-CSF, and IL-22 was IL-12 independent. IL-18Rα+DR3+CD4+ T cells with similar functionality were present in human skin, nasal polyps, and, in particular, the intestine, where in chronic inflammation they localized with IL-18-producing cells in lymphoid aggregates. Collectively, these results suggest that human memory IL-18Rα+DR3+ CD4+ T cells may contribute to antigen-independent innate responses at barrier surfaces. PMID:25269704

  7. CD4(+) memory T cells retain surface expression of CD31 independently of thymic function in patients with lymphoproliferative disorders following autologous hematopoietic stem-cell transplantation.

    PubMed

    Batorov, Egor V; Tikhonova, Marina A; Kryuchkova, Irina V; Sergeevicheva, Vera V; Sizikova, Svetlana A; Ushakova, Galina Y; Batorova, Dariya S; Gilevich, Andrey V; Ostanin, Alexander A; Shevela, Ekaterina Y; Chernykh, Elena R

    2017-03-14

    High-dose chemotherapy with autologous hematopoietic stem-cell transplantation (AHSCT) causes severe and long-lasting immunodeficiency in patients with lymphoproliferative disorders. The thymus begins to restore the T-cell repertoire approximately from the sixth month post-transplant. We assessed the dynamics of post-transplant recovery of CD4(+)CD45RA(+)CD31(+) T cells, "recent thymic emigrants" (RTEs), and a poorly described subtype of CD4(+)CD45RA(-)CD31(+) T cells in 90 patients with lymphoproliferative disorders following high-dose chemotherapy with AHSCT. Relative and absolute counts of CD4(+)CD31(+) naïve and memory T cells were evaluated before AHSCT, at the day of engraftment, and 6- and 12-month post-transplant. The pre-transplant count of CD4(+)CD45RA(+)CD31(+) T cells was lower than in healthy controls, and did not reach donors' values during the 12-month period. The pre-transplant number of CD4(+)CD45RA(-)CD31(+) T cells was higher than in healthy controls and was restored rapidly following AHSCT. Post-transplant mediastinal radiotherapy reduced counts of RTEs and elongated recovery period. Non-thymic tissue irradiation did not reduce this subset. The obtained data indicate that homeostatic proliferation may decrease the significance of CD31 expression on CD4(+)CD45RA(+) T cells as a marker of RTEs, and suggest that evaluation of RTEs recovery by flow cytometry requires an accurate gating strategy to exclude CD31(+) memory T cells.

  8. 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. © 2016. Published by The Company of Biologists Ltd.

  9. 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

  10. Virus-specific CD4+ and CD8+ cytotoxic T-cell responses and long-term T-cell memory in individuals vaccinated against polio.

    PubMed

    Wahid, Rahnuma; Cannon, Martin J; Chow, Marie

    2005-05-01

    The presence of poliovirus (PV)-specific CD4(+) T cells in individuals vaccinated against polio has been shown, but CD8(+) T-cell responses have not been described. Here, we functionally characterize the CD4(+) T-cell response and show for the first time that dendritic cells and macrophages can stimulate PV-specific CD8(+) T-cell responses in vitro from vaccinees. Both CD4(+) T and CD8(+) T cells secrete gamma interferon in response to PV antigens and are cytotoxic via the perforin/granzyme B-mediated pathway. Furthermore, the T cells also recognize and kill Sabin 1 vaccine-infected targets. The macrophage-stimulated CD4(+) T and CD8(+) T cells most likely represent memory T cells that persist for long periods in vaccinated individuals. Thus, immunity to PV vaccination involves not only an effective neutralizing antibody titer but also long-term CD4(+) and CD8(+) cytotoxic T-cell responses.

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

    PubMed Central

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

    2015-01-01

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

  12. Simultaneous activation of viral antigen-specific memory CD4+ and CD8+ T-cells using mRNA-electroporated CD40-activated autologous B-cells.

    PubMed

    Van den Bosch, Glenn A; Van Gulck, Ellen; Ponsaerts, Peter; Nijs, Griet; Lenjou, Marc; Apers, Ludwig; Kint, Ilse; Heyndrickx, Leo; Vanham, Guido; Van Bockstaele, Dirk R; Berneman, Zwi N; Van Tendeloo, Viggo F I

    2006-01-01

    Recently, it has become obvious that not only CD8 T-cells, but also CD4 T-helper cells are required for the induction of an effective, long-lasting cellular immune response. In view of the clinical importance of cytomegalovirus (CMV) and human immunodeficiency virus (HIV) infection, we developed 2 strategies to simultaneously reactivate viral antigen-specific memory CD4 and CD8 T-cells of CMV-seropositive and HIV-seropositive subjects using mRNA-electroporated autologous CD40-activated B cells. In the setting of HIV, we provide evidence that CD40-activated B cells can be cultured from HAART-naive HIV-1 seropositive patients. These cells not only express and secrete the HIV p24 antigen after electroporation with codon-optimized HIV-1 gag mRNA, but can also be used to in vitro reactivate Gag antigen-specific interferon-gamma-producing CD4 and CD8 autologous T-cells. For the CMV-specific approach, we applied mRNA coding for the pp65 protein coupled to the lysosomal-associated membrane protein-1 to transfect CD40-activated B cells to induce CMV antigen-specific CD4 and CD8 T-cells. More detailed analysis of the activated interferon-gamma-producing CMV pp65 tetramer positive CD8 T-cells revealed an effector memory phenotype with the capacity to produce interleukin-2. Our findings clearly show that the concomitant activation of both CD4 and CD8 (memory) T-cells using mRNA-electroporated CD40-B cells is feasible in CMV and HIV-1-seropositive persons, which indicates the potential value of this approach for application in cellular immunotherapy of infectious diseases.

  13. Altered T-bet dominance in IFN-γ-decoupled CD4+ T cells with attenuated cytokine storm and preserved memory in influenza.

    PubMed

    Dutta, Avijit; Miaw, Shi-Chuen; Yu, Jhang-Sian; Chen, Tse-Ching; Lin, Chun-Yen; Lin, Yung-Chang; Chang, Chia-Shiang; He, Yueh-Chia; Chuang, Sheng-Hao; Yen, Ming-I; Huang, Ching-Tai

    2013-04-15

    Cytokine storm has been postulated as one of the major causes of mortality in patients with severe respiratory viral infections such as influenza. With the help of an influenza Ag- specific mouse experimental system, we report that CD4(+) T cells contribute effector cytokines leading to lung inflammation in acute influenza. Although virus can no longer be detected from tissues 14 d postinfection, virus-derived Ag continues to drive a CD4(+) T cell response after viral clearance. Ag-specific CD4(+) T cells proliferate and evolve into memory CD4(+) T cells efficiently, but the production of effector cytokines is seriously hampered during this phase. This decoupling of proliferation and effector cytokine production doesn't appear in conjunction with increased suppression by regulatory T cells or decreased induction of transcription factors. Rather, GATA-3 and ROR-γt levels are elevated when compared with cells that have effector cytokine production. T-bet dominance over GATA-3 and ROR-γt decreases with the disarmament of effector cytokine production. Importantly, upon reinfection, these decoupled cells produce elevated levels of IFN-γ and were effective in virus eradication. These results provide a mechanism through altered T-bet dominance to dampen the cytokine storm without impeding the generation of memory T cells in influenza virus infection.

  14. Accelerated In Vivo Proliferation of Memory Phenotype CD4+ T-cells in Human HIV-1 Infection Irrespective of Viral Chemokine Co-receptor Tropism

    PubMed Central

    Zhang, Yan; de Lara, Catherine; Worth, Andrew; Hegedus, Andrea; Laamanen, Karoliina; Beverley, Peter; Macallan, Derek

    2013-01-01

    CD4+ T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i) that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5+ cells, and (ii) that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4+ compartment. To test these hypotheses we measured in vivo turnover rates of CD4+ T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p) and disappearance (d*) rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143–569 cells/ul) participated. CCR5-expression defined a CD4+ subpopulation of predominantly CD45R0+ memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5+ vs CCR5−; healthy controls; P<0.01). Conversely, CXCR4 expression defined CD4+ T-cells (predominantly CD45RA+ naive cells) with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5+CD45R0+CD4+ memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05), naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9) or X4-tropic (n = 4). Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively). Our data are most consistent with models in which CD4+ T-cell loss is primarily driven by non-specific immune activation. PMID:23637601

  15. CD4 T Helper Cells Instruct Lymphopenia-Induced Memory-Like CD8 T Cells for Control of Acute LCMV Infection

    PubMed Central

    Schmitt, Michaela E. R.; Sitte, Selina; Voehringer, David

    2016-01-01

    Lymphopenic conditions lead to expansion of memory-like T cells (TML), which develop from naïve T cells by spontaneous proliferation. TML cells are often increased in the elderly population, AIDS patients, and patients recovering from radio- or chemotherapy. At present, it is unclear whether TML cells can efficiently respond to foreign antigen and participate in antiviral immunity. To address this question, we analyzed the immune response during acute low-dose infection with lymphocytic choriomeningitis virus-WE in T cell lymphopenic CD4Cre/R-diphtheria toxin alpha (DTA) mice in which most peripheral T cells show a TML phenotype. On day 8 after infection, the total number of effector T cells and polyfunctional IFN-γ and TNF-α producing CD8 T cells were three- to fivefold reduced in CD4Cre/R-DTA mice as compared to controls. Viral clearance and the humoral immune response were severely impaired in CD4Cre/R-DTA mice although CTLs efficiently killed transferred target cells in vivo. Transfer of naïve CD4 T cells but not anti-PD-L1 blockade restored the expansion of antigen-specific polyfunctional CD8 T cells and resulted in lower viral titers. This finding indicates that under lymphopenic conditions endogenous CD4 TML cell lack the capacity to promote expansion of CTLs. However, CD8 TML cells retain sufficient functional plasticity to participate in antiviral immunity in the presence of appropriate help by fully functional CD4 T cells. This capacity might be exploited to develop treatments for improvement of CD8 T cell functions under various clinical settings of lymphopenia. PMID:28066432

  16. NK cells require antigen-specific memory CD4+ T cells to mediate superior effector functions during HSV-2 recall responses in vitro.

    PubMed

    Chen, Branson; Lee, Amanda J; Chew, Marianne V; Ashkar, Ali A

    2016-12-14

    Natural killer (NK) cells have an important role in mounting protective innate responses against genital herpes simplex virus type 2 (HSV-2) infections. However their role as effectors in adaptive immune responses against HSV-2 is unclear. Here, we demonstrate that NK cells from C57BL/6 mice in an ex vivo splenocyte culture produce significantly more interferon γ (IFN-γ) upon re-exposure to HSV-2 antigens in a mouse model of genital HSV-2 immunization. We find that naïve NK cells do not require any prior stimulation or priming to be activated to produce IFN-γ. Our results demonstrate that HSV-2-experienced CD4(+) T cells have a crucial role in coordinating NK cell activation and that their presence during HSV-2 antigen presentation is required to activate NK cells in this model of secondary immune response. We also examined the requirement of cell-to-cell contacts for both CD4(+) T cells and NK cells. NK cells are dependent on direct interactions with other HSV-2-experienced splenocytes, and CD4(+) T cells need to be in close proximity to NK cells to activate them. This study revealed that NK cells do not exhibit any memory toward HSV-2 antigens and, in fact, require specific interactions with HSV-2-experienced CD4(+) T cells to produce IFN-γ.

  17. Human Blood CD1c(+) Dendritic Cells Promote Th1 and Th17 Effector Function in Memory CD4(+) T Cells.

    PubMed

    Leal Rojas, Ingrid M; Mok, Wai-Hong; Pearson, Frances E; Minoda, Yoshihito; Kenna, Tony J; Barnard, Ross T; Radford, Kristen J

    2017-01-01

    Dendritic cells (DC) initiate the differentiation of CD4(+) helper T cells into effector cells including Th1 and Th17 responses that play an important role in inflammation and autoimmune disease pathogenesis. In mice, Th1 and Th17 responses are regulated by different conventional (c) DC subsets, with cDC1 being the main producers of IL-12p70 and inducers of Th1 responses, while cDC2 produce IL-23 to promote Th17 responses. The role that human DC subsets play in memory CD4(+) T cell activation is not known. This study investigated production of Th1 promoting cytokine IL-12p70, and Th17 promoting cytokines, IL-1β, IL-6, and IL-23, by human blood monocytes, CD1c(+) DC, CD141(+) DC, and plasmacytoid DC and examined their ability to induce Th1 and Th17 responses in memory CD4(+) T cells. Human CD1c(+) DC produced IL-12p70, IL-1β, IL-6, and IL-23 in response to R848 combined with LPS or poly I:C. CD141(+) DC were also capable of producing IL-12p70 and IL-23 but were not as proficient as CD1c(+) DC. Activated CD1c(+) DC were endowed with the capacity to promote both Th1 and Th17 effector function in memory CD4(+) T cells, characterized by high production of interferon-γ, IL-17A, IL-17F, IL-21, and IL-22. These findings support a role for CD1c(+) DC in autoimmune inflammation where Th1/Th17 responses play an important role in disease pathogenesis.

  18. Reduced Memory CD4+ T-Cell Generation in the Circulation of Young Children May Contribute to the Otitis-Prone Condition

    PubMed Central

    Sharma, Sharad K.; Casey, Janet R.

    2011-01-01

    Background. An explanation for the immunologic dysfunction that causes children to be prone to repeated episodes of acute otitis media (AOM) has long been sought. Poor antibody response has been associated with the otitis-prone condition; however, there is no precise mechanistic explanation for this condition. Methods. Non–otitis-prone and otitis-prone children with AOM or nasopharyngeal (NP) colonization caused by either Streptococcus pneumoniae or Haemophilus influenzae were compared for pathogen-specific CD4+ T-helper memory responses by stimulating peripheral blood mononuclear cells using 6 vaccine candidate S. pneumoniae and 3 H. influenzae protein antigens. Samples were analyzed by multi-parameter flow cytometry. Results. Significantly reduced percentages of functional CD45RALow memory CD4+ T cells producing specific cytokines (interferon γ, interleukin [IL]–2, IL-4 and IL-17a) were observed in otitis-prone children following AOM and NP colonization with either S. pneumoniae or H. influenzae. Immunoglobulin (Ig) G responses to the studied protein antigens were reduced, which suggests that antigen-specific B-cell function may be compromised as a result of poor T-cell help. Staphylococcal enterotoxin B stimulated similar cytokine patterns in memory CD4+T cells in both groups of children. Conclusions. Otitis-prone children have suboptimal circulating functional T-helper memory and reduced IgG responses to S. pneumoniae or H. influenzae after colonization and after AOM; this immune dysfunction causes susceptibility to recurrent AOM infections. PMID:21791667

  19. Activated Memory CD4+ T Helper Cells Repopulate the Intestine Early following Antiretroviral Therapy of Simian Immunodeficiency Virus-Infected Rhesus Macaques but Exhibit a Decreased Potential To Produce Interleukin-2

    PubMed Central

    Mattapallil, Joseph J.; Smit-McBride, Zeljka; Dailey, Peter; Dandekar, Satya

    1999-01-01

    Using the simian immunodeficiency virus (SIV)-infected rhesus macaque model, we performed a longitudinal study to determine the effect of antiretroviral therapy on the phenotype and functional potential of CD4+ T cells repopulating intestinal mucosa in human immunodeficiency virus infection. Severe depletion of CD4+ and CD4+ CD8+ T cells occurred in the intestinal mucosa during primary SIV infection. The majority of these cells were of activated memory phenotype. Phosphonate 9-[2-(phosphomethoxypropyl]adenine (PMPA) treatment led to a moderate suppression of intestinal viral loads and repopulation of intestinal mucosa by predominantly activated memory CD4+ T-helper cells. This repopulation was independent of the level of viral suppression. Compared to preinfection values, the frequency of naive CD4+ T cells increased following PMPA therapy, suggesting that new CD4+ T cells were repopulating the intestinal mucosa. Repopulation by CD4+ CD8+ T cells was not observed in either jejunum or colon lamina propria. The majority of CD4+ T cells repopulating the intestinal mucosa following PMPA therapy were CD29hi and CD11ahi. A subset of repopulating intestinal CD4+ T cells expressed Ki-67 antigen, indicating that local proliferation may play a role in the repopulation process. Although the majority of repopulating CD4+ T cells in the intestinal mucosa were functionally capable of providing B- and T-cell help, as evidenced by their expression of CD28, these CD4+ T cells were found to have a reduced capacity to produce interleukin-2 (IL-2) compared to the potential of CD4+ T cells prior to SIV infection. Persistent viral infection may play a role in suppressing the potential of repopulating CD4+ T cells to produce IL-2. Hence, successful antiretroviral therapy should aim at complete suppression of viral loads in mucosal lymphoid tissues, such as intestinal mucosa. PMID:10400763

  20. 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

  1. Antigen presentation by B cells guides programing of memory CD4(+) T-cell responses to a TLR4-agonist containing vaccine in mice.

    PubMed

    Dubois Cauwelaert, Natasha; Baldwin, Susan L; Orr, Mark T; Desbien, Anthony L; Gage, Emily; Hofmeyer, Kimberly A; Coler, Rhea N

    2016-12-01

    The contribution of B cells to immunity against many infectious diseases is unquestionably important and well characterized. Here, we sought to determine the role of B cells in the induction of T-helper 1 (TH 1) CD4(+) T cells upon vaccination with a tuberculosis (TB) antigen combined with a TLR4 agonist. We used B-cell deficient mice (μMT(-/-) ), tetramer-positive CD4(+) T cells, markers of memory "precursor" effector cells (MPECs), and T-cell adoptive transfers and demonstrated that the early antigen-specific cytokine-producing TH 1 responses are unaffected in the absence of B cells, however MPEC induction is strongly impaired resulting in a deficiency of the memory TH 1 response in μMT(-/-) mice. We further show that antigen-presentation by B cells is necessary for their role in MPEC generation using B-cell adoptive transfers from wt or MHC class II knock-out mice into μMT(-/-) mice. Our study challenges the view that B-cell deficiency exclusively alters the TH 1 response at memory time-points. Collectively, our results provide new insights on the multifaceted roles of B cells that will have a high impact on vaccine development against several pathogens including those requiring TH 1 cell-mediated immunity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Increase of circulating α4β7(+) conventional memory CD4 and regulatory T cells in patients with common variable immunodeficiency (CVID).

    PubMed

    de Melo, Karina Mescouto; Unger, Susanne; Keller, Baerbel; Gutenberger, Sylvia; Stumpf, Ina; Goldacker, Sigune; Warnatz, Klaus

    2017-07-01

    This study investigated whether circulating α4β7(+) expressing T cells could serve as a potential marker for gastrointestinal (GI) disease activity in patients with CVID. The analysis of α4β7(+) T cells in the peripheral blood of 36 patients and 22 healthy donors (HD) revealed increased percentages of α4β7(+) conventional memory CD4 T cells and Tregs, but not among CD8 T-cell populations in patients with CVID compared to HD. No differences between patients with and without chronic or acute GI symptoms were observed. EUROClass smB- and 21lo patients, had higher percentages of α4β7(+) memory CD4 T cells compared to HD and smB+ or 21norm patients, respectively. In summary, the detection of α4β7(+) T cells in the peripheral blood did not correlate with active or chronic gastrointestinal disease. The increase of these cells in smB- and 21lo patients adds another piece to the immune dysregulation observed in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Loss of Naïve Cells Accompanies Memory CD4+ T-Cell Depletion during Long-Term Progression to AIDS in Simian Immunodeficiency Virus-Infected Macaques▿

    PubMed Central

    Nishimura, Yoshiaki; Igarashi, Tatsuhiko; Buckler-White, Alicia; Buckler, Charles; Imamichi, Hiromi; Goeken, Robert M.; Lee, Wendy R.; Lafont, Bernard A. P.; Byrum, Russ; Lane, H. Clifford; Hirsch, Vanessa M.; Martin, Malcolm A.

    2007-01-01

    Human immunodeficiency virus and simian immunodeficiency virus (SIV) induce a slow progressive disease, characterized by the massive loss of memory CD4+ T cells during the acute infection followed by a recovery phase in which virus replication is partially controlled. However, because the initial injury is so severe and virus production persists, the immune system eventually collapses and a symptomatic fatal disease invariably occurs. We have assessed CD4+ T-cell dynamics and disease progression in 12 SIV-infected rhesus monkeys for nearly 2 years. Three macaques exhibiting a rapid progressor phenotype experienced rapid and irreversible loss of memory, but not naïve, CD4+ T lymphocytes from peripheral blood and secondary lymphoid tissues and died within the first 6 months of virus inoculation. In contrast, SIV-infected conventional progressor animals sustained marked but incomplete depletions of memory CD4+ T cells and continuous activation/proliferation of this T-lymphocyte subset. This was associated with a profound loss of naïve CD4+ T cells from peripheral blood and secondary lymphoid tissues, which declined at rates that correlated with disease progression. These data suggest that the persistent loss of memory CD4+T cells, which are being eliminated by direct virus killing and activation-induced cell death, requires the continuous differentiation of naïve into memory CD4+ T cells. This unrelenting replenishment process eventually leads to the exhaustion of the naïve CD4+T-cell pool and the development of disease. PMID:17093193

  4. 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

  5. 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 Central

    Hammer, Leslie A; Waldner, Hanspeter; Zagon, Ian S

    2015-01-01

    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 [Met5]-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 in the CNS of

  6. 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.

  7. 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.

  8. Increased Effector Memory Insulin-Specific CD4(+)T-cells Correlate with Insulin Autoantibodies in Recent-Onset Type 1 Diabetic Patients.

    PubMed

    Spanier, Justin A; Sahli, Nathanael L; Wilson, Joseph C; Martinov, Tijana; Dileepan, Thamotharampillai; Burrack, Adam L; Finger, Erik B; Blazar, Bruce R; Michels, Aaron W; Moran, Antoinette; Jenkins, Marc K; Fife, Brian T

    2017-08-25

    Type 1 diabetes (T1D) results from T-cell mediated destruction of insulin producing beta cells. Insulin represents a key self-antigen in disease pathogenesis as recent studies identified proinsulin responding T-cells from inflamed pancreatic islets of recent onset T1D organ donors. These cells respond to an insulin B chain epitope presented by human leukocyte antigen (HLA) DQ8 molecule associated with high T1D risk. It is now critical to understand insulin specific T-cell frequency and phenotype in peripheral blood. We constructed fluorescent insulinB10-23:DQ8 tetramers, stained peripheral blood lymphocytes directly ex vivo, and show DQ8(+) T1D patients have increased tetramer(+) CD4(+) T-cells compared to HLA-matched non-diabetic controls. Patients with a shorter disease duration had higher frequencies of insulin-reactive CD4(+)T-cells with the majority of these cells being antigen experienced. We also demonstrate that the number of insulin tetramer(+) effector memory cells directly correlated with insulin antibody titers, suggesting insulin-specific T and B-cell interactions. Notably, one of four controls with tetramer(+) cells was a first-degree relative having insulin-specific cells with an effector memory phenotype, potentially representing an early marker of T-cell autoimmunity. Our results suggest that studying insulinB10-23:DQ8 reactive T-cell frequency and phenotype may provide a biomarker of disease activity in T1D patients and those at-risk. © 2017 by the American Diabetes Association.

  9. Potent CD4+ T cell-associated antitumor memory responses induced by trifunctional bispecific antibodies in combination with immune checkpoint inhibition

    PubMed Central

    Deppisch, Nina; Ruf, Peter; Eißler, Nina; Lindhofer, Horst; Mocikat, Ralph

    2017-01-01

    Combinatorial approaches of immunotherapy hold great promise for the treatment of malignant disease. Here, we examined the potential of combining an immune checkpoint inhibitor and trifunctional bispecific antibodies (trAbs) in a preclinical melanoma mouse model using surrogate antibodies of Ipilimumab and Catumaxomab, both of which have already been approved for clinical use. The specific binding arms of trAbs redirect T cells to tumor cells and trigger direct cytotoxicity, while the Fc region activates accessory cells eventually giving rise to a long-lasting immunologic memory. We show here that T cells redirected to tumor cells by trAbs strongly upregulate CTLA-4 expression in vitro and in vivo. This suggested that blocking of CTLA-4 in combination with trAb treatment enhances T-cell activation in a tumor-selective manner. However, when mice were challenged with melanoma cells and subsequently treated with antibodies, there was only a moderate beneficial effect of the combinatorial approach in vivo with regard to direct tumor destruction in comparison to trAb therapy alone. By contrast, a significantly improved vaccination effect was obtained by CTLA-4 blocking during trAb-dependent immunization. This resulted in enhanced rejection of melanoma cells given after pre-immunization. The improved immunologic memory induced by the combinatorial approach correlated with an increased humoral antitumor response as measured in the sera and an expansion of CD4+ memory T cells found in the spleens. PMID:27966460

  10. Differential Regulation of Self-reactive CD4+ T Cells in Cervical Lymph Nodes and Central Nervous System during Viral Encephalomyelitis

    PubMed Central

    Savarin, Carine; Bergmann, Cornelia C.; Hinton, David R.; Stohlman, Stephen A.

    2016-01-01

    Viral infections have long been implicated as triggers of autoimmune diseases, including multiple sclerosis (MS), a central nervous system (CNS) inflammatory demyelinating disorder. Epitope spreading, molecular mimicry, cryptic antigen, and bystander activation have been implicated as mechanisms responsible for activating self-reactive (SR) immune cells, ultimately leading to organ-specific autoimmune disease. Taking advantage of coronavirus JHM strain of mouse hepatitis virus (JHMV)-induced demyelination, this study demonstrates that the host also mounts counteractive measures to specifically limit expansion of endogenous SR T cells. In this model, immune-mediated demyelination is associated with induction of SR T cells after viral control. However, their decline during persisting infection, despite ongoing demyelination, suggests an active control mechanism. Antigen-specific IL-10-secreting CD4+ T cells (Tr1) and Foxp3+ regulatory T cells (Tregs), both known to control autoimmunity and induced following JHMV infection, were assessed for their relative in vivo suppressive function of SR T cells. Ablation of Foxp3+ Tregs in chronically infected DEREG mice significantly increased SR CD4+ T cells within cervical lymph nodes (CLN), albeit without affecting their numbers or activation within the CNS compared to controls. In contrast, infected IL-27 receptor deficient (IL-27R−/−) mice, characterized by a drastic reduction of Tr1 cells, revealed that SR CD4+ T cells in CLN remained unchanged but were specifically increased within the CNS. These results suggest that distinct Treg subsets limit SR T cells in the draining lymph nodes and CNS to maximize suppression of SR T-cell-mediated autoimmune pathology. The JHMV model is thus valuable to decipher tissue-specific mechanisms preventing autoimmunity. PMID:27708643

  11. Differential Regulation of Self-reactive CD4(+) T Cells in Cervical Lymph Nodes and Central Nervous System during Viral Encephalomyelitis.

    PubMed

    Savarin, Carine; Bergmann, Cornelia C; Hinton, David R; Stohlman, Stephen A

    2016-01-01

    Viral infections have long been implicated as triggers of autoimmune diseases, including multiple sclerosis (MS), a central nervous system (CNS) inflammatory demyelinating disorder. Epitope spreading, molecular mimicry, cryptic antigen, and bystander activation have been implicated as mechanisms responsible for activating self-reactive (SR) immune cells, ultimately leading to organ-specific autoimmune disease. Taking advantage of coronavirus JHM strain of mouse hepatitis virus (JHMV)-induced demyelination, this study demonstrates that the host also mounts counteractive measures to specifically limit expansion of endogenous SR T cells. In this model, immune-mediated demyelination is associated with induction of SR T cells after viral control. However, their decline during persisting infection, despite ongoing demyelination, suggests an active control mechanism. Antigen-specific IL-10-secreting CD4(+) T cells (Tr1) and Foxp3(+) regulatory T cells (Tregs), both known to control autoimmunity and induced following JHMV infection, were assessed for their relative in vivo suppressive function of SR T cells. Ablation of Foxp3(+) Tregs in chronically infected DEREG mice significantly increased SR CD4(+) T cells within cervical lymph nodes (CLN), albeit without affecting their numbers or activation within the CNS compared to controls. In contrast, infected IL-27 receptor deficient (IL-27R(-/-)) mice, characterized by a drastic reduction of Tr1 cells, revealed that SR CD4(+) T cells in CLN remained unchanged but were specifically increased within the CNS. These results suggest that distinct Treg subsets limit SR T cells in the draining lymph nodes and CNS to maximize suppression of SR T-cell-mediated autoimmune pathology. The JHMV model is thus valuable to decipher tissue-specific mechanisms preventing autoimmunity.

  12. IFN-γ-producing CD4+ T cells promote generation of protective germinal center-derived IgM+ B cell memory against Salmonella Typhi.

    PubMed

    Perez-Shibayama, Christian; Gil-Cruz, Cristina; Pastelin-Palacios, Rodolfo; Cervantes-Barragan, Luisa; Hisaki, Emiliano; Chai, Qian; Onder, Lucas; Scandella, Elke; Regen, Tommy; Waisman, Ari; Isibasi, Armando; Lopez-Macias, Constantino; Ludewig, Burkhard

    2014-06-01

    Abs play a significant role in protection against the intracellular bacterium Salmonella Typhi. In this article, we investigated how long-term protective IgM responses can be elicited by a S. Typhi outer-membrane protein C- and F-based subunit vaccine (porins). We found that repeated Ag exposure promoted a CD4(+) T cell-dependent germinal center reaction that generated mutated IgM-producing B cells and was accompanied by a strong expansion of IFN-γ-secreting T follicular helper cells. Genetic ablation of individual cytokine receptors revealed that both IFN-γ and IL-17 are required for optimal germinal center reactions and production of porin-specific memory IgM(+) B cells. However, more profound reduction of porin-specific IgM B cell responses in the absence of IFN-γR signaling indicated that this cytokine plays a dominant role. Importantly, mutated IgM mAbs against porins exhibited bactericidal capacity and efficiently augmented S. Typhi clearance. In conclusion, repeated vaccination with S. Typhi porins programs type I T follicular helper cell responses that contribute to the diversification of B cell memory and promote the generation of protective IgM Abs.

  13. Cross-reactive memory CD4+ T cells alter the CD8+ T-cell response to heterologous secondary dengue virus infections in mice in a sequence-specific manner.

    PubMed

    Beaumier, Coreen M; Rothman, Alan L

    2009-06-01

    Secondary dengue virus (DENV) infection is a major factor contributing to the risk for severe disease, an effect that depends upon the sequence of infection with different DENV serotypes. We previously reported sequence-dependent effects of secondary DENV infection on CD8+ T-cell responses in mice. To further evaluate the effect of infection sequence, we analyzed DENV-specific CD4+ T-cell responses and their relationship to the CD8+ T-cell response. Serotype cross-reactivity of CD4+ T-cell responses also depended upon the sequence of serotypes in this model. Furthermore, adoptive transfer of memory CD4+ T cells altered the response of memory CD8+ T cells to secondary infection. These data demonstrate the interaction of different components of the T-cell response in determining the immunological outcome of secondary DENV infection.

  14. The human immunodeficiency virus type 1 (HIV-1) CD4 receptor and its central role in promotion of HIV-1 infection.

    PubMed Central

    Bour, S; Geleziunas, R; Wainberg, M A

    1995-01-01

    Interactions between the viral envelope glycoprotein gp120 and the cell surface receptor CD4 are responsible for the entry of human immunodeficiency virus type 1 (HIV-1) into host cells in the vast majority of cases. HIV-1 replication is commonly followed by the disappearance or receptor downmodulation of cell surface CD4. This potentially renders cells nonsusceptible to subsequent infection by HIV-1, as well as by other viruses that use CD4 as a portal of entry. Disappearance of CD4 from the cell surface is mediated by several different viral proteins that act at various stages through the course of the viral life cycle, and it occurs in T-cell lines, peripheral blood CD4+ lymphocytes, and monocytes of both primary and cell line origin. At the cell surface, gp120 itself and in the form of antigen-antibody complexes can trigger cellular pathways leading to CD4 internalization. Intracellularly, the mechanisms leading to CD4 downmodulation by HIV-1 are multiple and complex; these include degradation of CD4 by Vpu, formation of intracellular complexes between CD4 and the envelope precursor gp160, and internalization by the Nef protein. Each of the above doubtless contributes to the ultimate depletion of cell surface CD4, although the relative contribution of each mechanism and the manner in which they interact remain to be definitively established. PMID:7708013

  15. 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

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

    PubMed

    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.

  17. CD4+ Th1 cells promote CD8+ Tc1 cell survival, memory response, tumor localization and therapy by targeted delivery of interleukin 2 via acquired pMHC I complexes.

    PubMed

    Huang, Hui; Hao, Siguo; Li, Fang; Ye, Zhenmin; Yang, Junbao; Xiang, Jim

    2007-02-01

    The cooperative role of CD4+ helper T (Th) cells has been reported for CD8+ cytotoxic T (Tc) cells in tumor eradication. However, its molecular mechanisms have not been well elucidated. We have recently demonstrated that CD4+ Th cells can acquire major histocompatibility complex/peptide I (pMHC I) complexes and costimulatory molecules by dendritic cell (DC) activation, and further stimulate naïve CD8+ T cell proliferation and activation. In this study, we used CD4+ Th1 and CD8+ Tc1 cells derived from ovalbumin (OVA)-specific T cell receptor (TCR) transgenic OT II and OT I mice to study CD4+ Th1 cell's help effects on active CD8+ Tc1 cells and the molecular mechanisms involved in CD8+ Tc1-cell immunotherapy of OVA-expressing EG7 tumors. Our data showed that CD4+ Th1 cells with acquired pMHC I by OVA-pulsed DC (DCOVA) stimulation are capable of prolonging survival and reducing apoptosis formation of active CD8+ Tc1 cells in vitro, and promoting CD8+ Tc1 cell tumor localization and memory responses in vivo by 3-folds. A combined adoptive T-cell therapy of CD8+ Tc1 with CD4+ Th1 cells resulted in regression of well-established EG7 tumors (5 mm in diameter) in all 10/10 mice. The CD4+ Th1's help effect is mediated via the helper cytokine IL-2 specifically targeted to CD8+ Tc1 cells in vivo by acquired pMHC I complexes. Taken together, these results will have important implications for designing adoptive T-cell immunotherapy protocols in treatment of solid tumors.

  18. Key Role of Effector Memory CD4+ T Lymphocytes in a Short-Incubation Heparin-Binding Hemagglutinin Gamma Interferon Release Assay for the Detection of Latent Tuberculosis

    PubMed Central

    Wyndham-Thomas, Chloé; Corbière, Véronique; Dirix, Violette; Smits, Kaatje; Domont, Fanny; Libin, Myriam; Loyens, Marc; Locht, Camille

    2014-01-01

    The treatment of latent tuberculosis infection (LTBI) in target populations is one of the current WHO strategies for preventing active tuberculosis (TB) infection and reducing the Mycobacterium tuberculosis reservoir. Therefore, powerful LTBI screening tools are indispensable. A gamma interferon release assay (IGRA) in response to the stimulation of peripheral blood mononuclear cells by the latency antigen native heparin-binding hemagglutinin (nHBHA-IGRA) has proven its potential for this purpose. We have evaluated its possible optimization through a reduction of incubation time from 96 to 24 h, while compensating for this by adding interleukin 7 (IL-7) to the medium. We have also investigated the phenotypes of the gamma interferon (IFN-γ)-producing cells after both short and long incubation times. One hundred thirty-one nonimmunocompromised patients were recruited from 3 Brussels-based university hospitals. They were divided into 1 of 4 subgroups according to their M. tuberculosis infection status (LTBI, TB infection, undetermined M. tuberculosis infection status, and noninfected controls). The novel 24-h nHBHA-IGRA was performed for all subjects, and a simultaneous 96-h classical HBHA-IGRA was performed for 79 individuals. The results showed a good correlation between the two tests, and the novel 24-h nHBHA-IGRA maintained the principal advantages of the classical test, namely, a high specificity for LTBI diagnosis, an absence of interference of Mycobacterium bovis BCG vaccination during infancy, and a relative discrimination between LTBI and TB infection. Whereas the commercialized IGRAs show a greater sensitivity for recent than for remote M. tuberculosis infections, the 24-h nHBHA-IGRA appears to have comparable diagnostic powers for recent and remote LTBI. The IFN-γ detected by the 24-h nHBHA-IGRA was mainly secreted by effector memory CD4+ T lymphocytes, a finding suggestive of continuous HBHA presentation during latency. PMID:24391135

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

    PubMed Central

    Greenwood, Edward J. D.; Schmidt, Fabian; Liégeois, Florian; Kondova, Ivanela; Herbert, Anaïs; Ngoubangoye, Barthelemy; 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

  20. 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 Central

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

  1. A Brief Chronicle of CD4 as a Biomarker for HIV/AIDS: A Tribute to the Memory of John L. Fahey

    PubMed Central

    Kagan, Jonathan M.; Sanchez, Ana M.; Landay, Alan; Denny, Thomas N.

    2016-01-01

    Foundational cellular immunology research of the 1960s and 1970s, together with the advent of monoclonal antibodies and flow cytometry, provided the knowledge base and the technological capability that enabled the elucidation of the role of CD4 T cells in HIV infection. Research identifying the sources and magnitude of variation in CD4 measurements, standardized reagents and protocols, and the development of clinical flow cytometers all contributed to the feasibility of widespread CD4 testing. Cohort studies and clinical trials provided the context for establishing the utility of CD4 for prognosis in HIV-infected persons, initial assessment of in vivo antiretroviral drug activity, and as a surrogate marker for clinical outcome in antiretroviral therapeutic trials. Even with sensitive HIV viral load measurement, CD4 cell counting is still utilized in determining antiretroviral therapy eligibility and time to initiate therapy. New point of care technologies are helping both to lower the cost of CD4 testing and enable its use in HIV test and treat programs around the world. PMID:27182452

  2. The inositol 5-phosphatase SHIP-1 and adaptors Dok-1 and 2 play central roles in CD4-mediated inhibitory signaling

    PubMed Central

    Waterman, Paul M.; Marschner, Susanne; Brandl, Erin; Cambier, John C.

    2012-01-01

    CD4 functions to enhance the sensitivity of T cells to antigenic peptide/MHC class II. However, if aggregated in isolation, e.g. in the absence of T cell receptor (TCR), CD4 can transduce yet undefined signals that lead to T cell unresponsiveness to antigen and apoptosis. In Human Immunodeficiency Virus-1 (HIV-1) disease, CD4+ T cell loss can result from gp120-induced CD4 signaling in uninfected cells. We show here that CD4 aggregation leads to Lck-dependent phosphorylation of the RasGAP adaptors Downstream of kinase-1/2 (Dok-1/2) and the inositol 5-phosphatase-1 (SHIP-1) and association of the two molecules. Studies using SHIP-1 shRNA, knockout mice and decoy inhibitors further indicate that CD4-mediated inhibition of TCR-mediated T cell activation is SHIP-1 and Dok-1/2 dependent, and involves SHIP-1 hydrolysis of Phosphatidylinositol 3,4,5-trisphosophate (PI(3,4,5)P3) needed for TCR signaling. Our studies provide evidence for a novel mechanism by which ill-timed CD4-mediated signals activated by ligands such as HIV-1 gp120 lead to disarmament of the immune system. PMID:22370159

  3. 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.

  4. 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.

  5. 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.

  6. Distinct CD4 T-cell effects on primary versus recall CD8 T-cell responses during viral encephalomyelitis.

    PubMed

    Hwang, Mihyun; Phares, Timothy W; Hinton, David R; Stohlman, Stephen A; Bergmann, Cornelia C; Min, Booki

    2015-03-01

    CD4 T-cell help is not a universal requirement for effective primary CD8 T cells but is essential to generate memory CD8 T cells capable of recall responses. This study examined how CD4 T cells affect primary and secondary anti-viral CD8 T-cell responses within the central nervous system (CNS) during encephalomyelitis induced by sublethal gliatropic coronavirus. CD4 T-cell depletion before infection did not impair peripheral expansion, interferon-γ production, CNS recruitment or initial CNS effector capacity of virus-specific CD8 T cells ex vivo. Nevertheless, impaired virus control in the absence of CD4 T cells was associated with gradually diminished CNS CD8 T-cell interferon-γ production. Furthermore, within the CD8 T-cell population short-lived effector cells were increased and memory precursor effector cells were significantly decreased, consistent with higher T-cell turnover. Transfer of memory CD8 T cells to reduce viral load in CD4-depleted mice reverted the recipient CNS CD8 T-cell phenotype to that in wild-type control mice. However, memory CD8 T cells primed without CD4 T cells and transferred into infected CD4-sufficient recipients expanded less efficiently and were not sustained in the CNS, contrasting with their helped counterparts. These data suggest that CD4 T cells are dispensable for initial expansion, CNS recruitment and differentiation of primary resident memory CD8 T cells as long as the duration of antigen exposure is limited. By contrast, CD4 T cells are essential to prolong primary CD8 T-cell function in the CNS and imprint memory CD8 T cells for recall responses. © 2014 John Wiley & Sons Ltd.

  7. Distinct CD4 T-cell effects on primary versus recall CD8 T-cell responses during viral encephalomyelitis

    PubMed Central

    Hwang, Mihyun; Phares, Timothy W; Hinton, David R; Stohlman, Stephen A; Bergmann, Cornelia C; Min, Booki

    2015-01-01

    CD4 T-cell help is not a universal requirement for effective primary CD8 T cells but is essential to generate memory CD8 T cells capable of recall responses. This study examined how CD4 T cells affect primary and secondary anti-viral CD8 T-cell responses within the central nervous system (CNS) during encephalomyelitis induced by sublethal gliatropic coronavirus. CD4 T-cell depletion before infection did not impair peripheral expansion, interferon-γ production, CNS recruitment or initial CNS effector capacity of virus-specific CD8 T cells ex vivo. Nevertheless, impaired virus control in the absence of CD4 T cells was associated with gradually diminished CNS CD8 T-cell interferon-γ production. Furthermore, within the CD8 T-cell population short-lived effector cells were increased and memory precursor effector cells were significantly decreased, consistent with higher T-cell turnover. Transfer of memory CD8 T cells to reduce viral load in CD4-depleted mice reverted the recipient CNS CD8 T-cell phenotype to that in wild-type control mice. However, memory CD8 T cells primed without CD4 T cells and transferred into infected CD4-sufficient recipients expanded less efficiently and were not sustained in the CNS, contrasting with their helped counterparts. These data suggest that CD4 T cells are dispensable for initial expansion, CNS recruitment and differentiation of primary resident memory CD8 T cells as long as the duration of antigen exposure is limited. By contrast, CD4 T cells are essential to prolong primary CD8 T-cell function in the CNS and imprint memory CD8 T cells for recall responses. PMID:25187405

  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. B Cells and Programmed Death-Ligand 2 Signaling Are Required for Maximal Interferon-γ Recall Response by Splenic CD4+ Memory T Cells of Mice Vaccinated with Mycobacterium tuberculosis Ag85B

    PubMed Central

    Riccomi, Antonella; Palma, Carla

    2015-01-01

    CD4+ T cells producing interferon-γ are crucial for protection against Mycobacterium tuberculosis infection and are the cornerstone of tuberculosis vaccination and immunological diagnostic assays. Since emerging evidence indicates that B cells can modulate T cell responses to M. tuberculosis infection, we investigated the contribution of B cells in regulating interferon-γ recall response by memory Thelper1 cells specific for Ag85B, a leading candidate for tuberculosis sub-unit vaccines. We found that B cells were able to maximize the reactivation of CD4+ memory T cells and the interferon-γ response against ex vivo antigen recall in spleens of mice vaccinated with Ag85B. B cell-mediated increase of interferon-γ response was particular evident for high interferon-γ producer CD4+ memory T cells, likely because those T cells were required for triggering and amplification of B cell activation. A positive-feedback loop of mutual activation between B cells, not necessarily antigen-experienced but with integral phosphatidylinositol-3 kinase (PI3K) pathway and a peculiar interferon-γ-producing CD4highT cell subset was established. Programed death-ligand 2 (PD-L2), expressed both on B and the highly activated CD4high T cells, contributed to the increase of interferon-γ recall response through a PD1-independent pathway. In B cell-deficient mice, interferon-γ production and activation of Ag85B-specific CD4+ T cells were blunted against ex vivo antigen recall but these responses could be restored by adding B cells. On the other hand, B cells appeared to down-regulate interleukin-22 recall response. Our data point out that nature of antigen presenting cells determines quality and size of T cell cytokine recall responses. Thus, antigen presenting cells, including B cells, deserve to be considered for a better prediction of cytokine responses by peripheral memory T cells specific for M. tuberculosis antigens. We also invite to consider B cells, PD-L2 and PI3K as potential

  10. 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. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Microscopic colitis patients have increased proportions of Ki67(+) proliferating and CD45RO(+) active/memory CD8(+) and CD4(+)8(+) mucosal T cells.

    PubMed

    Kumawat, Ashok Kumar; Strid, Hilja; Elgbratt, Kristina; Tysk, Curt; Bohr, Johan; Hultgren Hörnquist, Elisabeth

    2013-10-01

    Collagenous colitis (CC) and lymphocytic colitis (LC) are chronic inflammatory bowel disorders of unknown etiology. This study investigated phenotypic characteristics of the mucosal lymphocytes in CC and LC. Lamina propria and intraepithelial lymphocytes (LPLs, IELs) isolated from mucosal biopsies from CC (n=7), LC (n=6), as well as LC or CC patients in histopathological remission, (LC-HR) (n=6) and CC-HR (n=4) and non-inflamed controls (n=10) were phenotypically characterized by four-color flow cytometry. The proportions of CD8(+) IELs were increased in CC and LC (p<0.01) compared to controls. Increased proportions of CD45RO(+)CD8(+) IELs and LPLs were observed in LC and even more in CC patients (p<0.01). Both CC (p<0.05) and LC patients had elevated proportions of CD4(+)8(+) IELs and LPLs compared to controls. The proportions of CD45RO(+) cells were increased in CD4(+)8(+) IELs and LPLs (p<0.05) in CC and LC patients compared to controls. Both CC (p<0.05) and LC patients had higher proportions of Ki67(+)CD8(+) IELs and LPLs compared to controls. In contrast, decreased proportions of CD4(+) LPLs were observed in CC and LC as well as CD4(+) IELs in LC compared to controls. Increased proportions of Ki67(+)CD4(+) IELs and LPLs (p<0.05) were observed in CC and LC patients. CC-HR but not LC-HR patients demonstrated normalized proportions of both IELs and LPLs compared to CC and LC patients respectively. LC and CC patients have differences in mucosal lymphocyte subsets, with increased proportions of Ki67(+) and CD45RO(+) CD8(+) and CD4(+)8(+) mucosal T cells. Copyright © 2012 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

  12. Alterations in levels of CD28-/CD8+ suppressor cell precursor and CD45RO+/CD4+ memory T lymphocytes in the peripheral blood of multiple sclerosis patients.

    PubMed Central

    Crucian, B; Dunne, P; Friedman, H; Ragsdale, R; Pross, S; Widen, R

    1995-01-01

    A comprehensive peripheral blood immunophenotype analysis of 16 multiple sclerosis (MS) patients was performed by three-color flow cytometric analysis, and the results were compared with those for age-matched healthy controls. The cell subsets quantified included T cells (CD3+), B cells (CD19+), NK cells (CD56+), CD4+ and CD8+ T cells, cytotoxic (CD28+) and suppressor precursor (CD28-) CD8+ T cells, CD45RA+ and CD45RO+ T cells (CD4+ and CD8+), and CD5+ T and B cells. Analysis of MS patients' peripheral blood revealed essentially normal levels of total T, B, and NK cells. In agreement with results obtained by other investigators, it was found that MS patients had an increased CD4/CD8 ratio, primarily due to a decrease in CD8+ T cells. MS patients were found to have a significantly decreased level of suppressor precursor (CD28-) CD8+ T cells compared with that of controls but to have normal levels of cytotoxic (CD28+) CD8+ T cells. These data indicate that MS patients do not have a general decrease in CD8+ T cells but that they have a specific decrease in the suppressor precursor subset only and normal levels of cytotoxic CD8+ T cells. MS patients also had a significant increase in memory (CD45RO+) CD4+ T cells and displayed a trend towards a decrease in naive (CD45RA+) T cells in the peripheral blood. PMID:7697540

  13. CD4 T Cell Memory and Antibody Responses Directed against the Pneumococcal Histidine Triad Proteins PhtD and PhtE following Nasopharyngeal Colonization and Immunization and Their Role in Protection against Pneumococcal Colonization in Mice

    PubMed Central

    Khan, M. N.

    2013-01-01

    The present study was undertaken to understand the role of vaccine candidates PhtD and PhtE in pneumococcal nasopharyngeal (NP) colonization, their ability to induce CD4 T cell memory and antibody responses following primary NP colonization, and their contribution to protection against secondary pneumococcal colonization in mice. The study was also aimed at understanding the potential of immunization with PhtD and PhtE in eliciting qualitative CD4 T cell memory responses and protection against pneumococcal NP colonization in mice. PhtD and PhtE isogenic mutants in a TIGR4 background (TIGR4 ΔPhtD and TIGR4 ΔPhtE) were constructed and found to have a significantly reduced colonization density over time in the nasopharynges of mice compared to those of mice colonized with wild-type TIGR4. Mice with primary colonization by wild-type TIGR4, TIGR4 ΔPhtD, or TIGR4 ΔPhtE were protected against secondary colonization by wild-type TIGR4; nonetheless, the clearance of secondary colonization was slower in mice with primary colonization by either TIGR4 ΔPhtD or TIGR4 ΔPhtE than in mice with primary colonization by wild-type TIGR4. Colonization was found to be an immunizing event for PhtD and PhtE antigens (antibody response); however, we failed to detect any antigen (PhtD or PhtE)-specific CD4 T cell responses in any of the colonized groups of mice. Intranasal immunization with either PhtD or PhtE protein generated robust serum antibody and CD4 Th1-biased immune memory and conferred protection against pneumococcal colonization in mice. We conclude that PhtD and PhtE show promise as components in next-generation pneumococcal vaccine formulations. PMID:23897609

  14. 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

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

    PubMed Central

    Cobb, Dustin A.; Bhadra, Rajarshi

    2016-01-01

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

  16. Naïve subset develops the most important alloreactive response among human CD4+ T lymphocytes in human leukocyte antigen-identical related setting.

    PubMed

    Chérel, Mathilde; Choufi, Bachra; Trauet, Jacques; Cracco, Pascale; Dessaint, Jean-Paul; Yakoub-Agha, Ibrahim; Labalette, Myriam

    2014-06-01

    In longitudinal clinical studies, receiving a high percentage of allogeneic donor-derived CD4(+) CCR7(+) T cells, which include naïve and central memory subsets have been correlated with increased incidence and severity of acute GVHD. Whether naïve and central memory CD4(+) T-cell subsets contribute more or equally to alloimmune responses are still unclear in human. The aim of this study was to investigate in vitro the alloreactive response of purified naïve, central memory, and effector memory CD4(+) T-cell subsets in HLA identical setting. By coculturing monocyte-derived dendritic cells and purified CD4(+) T-cell subsets, from healthy HLA-identical male and female sibling pairs, we found that naïve CD4(+) CCR7(+) CD45RA(+) T cells developed the highest proliferative response upon stimulation by minor histocompatibility antigens and were progressively driven to produce high levels of interferon-γ, tumor necrosis factor, and interleukin-6. Comparatively, the central memory CD4(+) CCR7(+) CD45RA(neg) subset proliferated to a lower extent and produced very low amounts of pro-inflammatory cytokines while the CCR7(neg) effector memory CD4(+) subset was unresponsive. This study demonstrates the superior capacity of naïve CD4(+) T cells to mount a primary alloreactive response as compared to central memory T cells. Their proliferative response associated with a pro-inflammatory differentiation makes them potentially acute GVHD inducers. These in vitro results in line with what we have observed in clinical studies and may also lend support to approaches of partial selective T-cell depletion for GVHD prevention.

  17. 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.

  18. 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

  19. Potent HIV-specific responses are enriched in a unique subset of CD8+ T cells that coexpresses CD4 on its surface.

    PubMed

    Zloza, Andrew; Schenkel, Jason M; Tenorio, Allan R; Martinson, Jeffrey A; Jeziorczak, Paul M; Al-Harthi, Lena

    2009-10-29

    In humans, approximately 3% of peripheral CD8+ T cells coexpress CD4 dimly on their surface and hence are designated as CD4(dim)CD8(bright) T cells. We evaluated the contribution of this CD4(dim)CD8(bright) T-cell population to anti-HIV immunity. We demonstrate that CD4(dim)CD8(bright) T cells generate greater than 55% of CD8+ T-cell antigen recognition and effector response to HIV, as evaluated by multiple parameters for assessing T-cell antiviral immunity, including HIV tetramer recognition, cytokine production, and cytolytic potential. Inhibition of major histocompatibility class II (MHC-II) on target cells or CD4 on CD4(dim)CD8(bright) T cells diminishes their anti-HIV responses, suggesting that CD4 on effector cells and MHC-II on target cells provides an additional arm of contact between effector and target cells which is critical to CD4(dim)CD8(bright) T-cell function. CD4(dim)CD8(bright) T cells also exhibit features that are indicative of central memory T cells. Finally, CD4(dim)CD8(bright) T cells are elevated in blood of HIV+ long-term nonprogressors in comparison to HIV- donors. Collectively, our findings show that CD4(dim)CD8(bright) T cells designate an enriched antiviral subpopulation of CD8+ T cells that should be targeted for therapeutic intervention or evaluation of vaccine efficacy.

  20. Antibody response against Betaferon® in immune tolerant mice: involvement of marginal zone B-cells and CD4+ T-cells and apparent lack of immunological memory.

    PubMed

    Sauerborn, Melody; van Beers, Miranda M C; Jiskoot, Wim; Kijanka, Grzegorz M; Boon, Louis; Schellekens, Huub; Brinks, Vera

    2013-01-01

    The immunological processes underlying immunogenicity of recombinant human therapeutics are poorly understood. Using an immune tolerant mouse model we previously demonstrated that aggregates are a major trigger of the antidrug antibody (ADA) response against recombinant human interferon beta (rhIFNβ) products including Betaferon®, and that immunological memory seems to be lacking after a rechallenge with non-aggregated rhIFNβ. The apparent absence of immunological memory indicates a CD4+ T-cell independent (Tind) immune response underlying ADA formation against Betaferon®. This hypothesis was tested. Using the immune tolerant mouse model we first validated that rechallenge with highly aggregated rhIFNβ (Betaferon®) does not lead to a subsequent fast increase in ADA titers, suggesting a lack of immunological memory. Next we assessed whether Betaferon® could act as Tind antigen by inactivation of marginal zone (MZ) B-cells during treatment. MZ B-cells are major effector cells involved in a Tind immune response. In a following experiment we depleted the mice from CD4+ T-cells to test their involvement in the ADA response against Betaferon®. Inactivation of MZ B-cells at the start of Betaferon® treatment drastically lowered ADA levels, suggesting a Tind immune response. However, persistent depletion of CD4+ T-cells before and during Betaferon® treatment abolished the ADA response in almost all mice. The immune response against rhIFNβ in immune tolerant mice is neither a T-cell independent nor a classical T-cell dependent immune response. Further studies are needed to confirm absence of immunological memory (cells).

  1. Induction of Plasmodium falciparum-Specific CD4+ T Cells and Memory B Cells in Gabonese Children Vaccinated with RTS,S/AS01E and RTS,S/AS02D

    PubMed Central

    Agnandji, Selidji T.; Fendel, Rolf; Mestré, Michaël; Janssens, Michel; Vekemans, Johan; Held, Jana; Gnansounou, Ferdinand; Haertle, Sonja; von Glasenapp, Isabel; Oyakhirome, Sunny; Mewono, Ludovic; Moris, Philippe; Lievens, Marc; Demoitie, Marie-Ange; Dubois, Patrice M.; Villafana, Tonya; Jongert, Erik; Olivier, Aurelie; Cohen, Joe; Esen, Meral; Kremsner, Peter G.; Lell, Bertrand; Mordmüller, Benjamin

    2011-01-01

    The recombinant circumsporozoite protein (CS) based vaccine, RTS,S, confers protection against Plasmodium falciparum infection in controlled challenge trials and in field studies. The RTS,S recombinant antigen has been formulated with two adjuvant systems, AS01 and AS02, which have both been shown to induce strong specific antibody responses and CD4 T cell responses in adults. As infants and young children are particularly susceptible to malaria infection and constitute the main target population for a malaria vaccine, we have evaluated the induction of adaptive immune responses in young children living in malaria endemic regions following vaccination with RTS,S/AS01E and RTS,S/AS02D. Our data show that a CS-specific memory B cell response is induced one month after the second and third vaccine dose and that CS-specific antibodies and memory B cells persist up to 12 months after the last vaccine injection. Both formulations also induced low but significant amounts of CS-specific IL-2+ CD4+ T cells one month after the second and third vaccine dose, upon short-term in vitro stimulation of whole blood cells with peptides covering the entire CS derived sequence in RTS,S. These results provide evidence that both RTS,S/AS01E and RTS,S/AS02D induced adaptive immune responses including antibodies, circulating memory B cells and CD4+ T cells directed against P. falciparum CS protein. Trial Registration ClinicalTrials.gov NCT00307021 PMID:21494604

  2. Short Communication: Low Immune Activation Is Associated with Higher Frequencies of Central Memory T Cell Subset in a Cohort of Indian Long-Term Nonprogressors.

    PubMed

    Saxena, Vandana; Bichare, Shubhangi; Singh, Dharmendra; Ghate, Manisha; Godbole, Sheela; Kulkarni, Smita; Gangakhedkar, Raman; Paranjape, Ramesh; Thakar, Madhuri

    2017-02-01

    Persistent immune activation in human immunodeficiency virus (HIV) infection is responsible for alterations in immune system such as activation, apoptosis, and reduced frequencies. Reduced immune activation is known to be associated with virus control. Limited information is available on the influence of pan-immune activation on memory responses. Hence, we compared the T cell activation and memory profile in HIV-infected individuals exhibiting disease control such as long-term nonprogressors (LTNPs) and progressors. The activated CD4(+) and CD8(+) T cells were significantly lower and the CD4(+) and CD8(+) central memory T cell phenotypes were significantly higher in the LTNPs compared to the progressors. In addition, we observed significant inverse association between the T cell activation and frequencies of central memory T cells. Our findings indicate that patients with absence of disease progression have preserved central memory T cell population associated with lesser immune activation.

  3. Loss of methylation at the IFNG promoter and CNS-1 is associated with the development of functional IFN-γ memory in human CD4(+) T lymphocytes.

    PubMed

    Dong, Jun; Chang, Hyun-Dong; Ivascu, Claudia; Qian, Yu; Rezai, Soheila; Okhrimenko, Anna; Cosmi, Lorenzo; Maggi, Laura; Eckhardt, Florian; Wu, Peihua; Sieper, Joachim; Alexander, Tobias; Annunziato, Francesco; Gossen, Manfred; Li, Jun; Radbruch, Andreas; Thiel, Andreas

    2013-03-01

    Cytokine memory for IFN-γ production by effector/memory Th1 cells plays a key role in both protective and pathological immune responses. To understand the epigenetic mechanism determining the ontogeny of effector/memory Th1 cells characterized by stable effector functions, we identified a T-cell-specific methylation pattern at the IFNG promoter and CNS-1 in ex vivo effector/memory Th1 cells, and investigated methylation dynamics of these regions during the development of effector/memory Th1 cells. During Th1 differentiation, demethylation occurred at both the promoter and CNS-1 regions of IFNG as early as 16 h, and this process was independent of cell proliferation and DNA synthesis. Using an IFN-γ capture assay, we found early IFN-γ-producing cells from 2-day differentiating cultures acquired "permissive" levels of demethylation and developed into effector/memory Th1 cells undergoing progressive demethylation at the IFNG promoter and CNS-1 when induced by IL-12. Methylation levels of these regions in effector/memory Th1 cells of peripheral blood from rheumatoid arthritis patients correlated inversely with reduced frequencies of IFN-γ-producers, coincident with recruitment of effector/memory Th1 cells to the site of inflammation. Thus, after termination of TCR stimulation, IL-12 signaling potentiates the stable functional IFN-γ memory in effector/memory Th1 cells characterized by hypomethylation at the IFNG promoter and CNS-1.

  4. CD4 T cells promote CD8 T cell immunity at the priming and effector site during viral encephalitis.

    PubMed

    Phares, Timothy W; Stohlman, Stephen A; Hwang, Mihyun; Min, Booki; Hinton, David R; Bergmann, Cornelia C

    2012-03-01

    CD4 T cell activation during peripheral infections not only is essential in inducing protective CD8 T cell memory but also promotes CD8 T cell function and survival. However, the contributions of CD4 T cell help to antiviral CD8 T cell immunity during central nervous system (CNS) infection are not well established. Encephalitis induced by the sublethal coronavirus JHMV was used to identify when CD4 T cells regulate CD8 T cell responses following CNS infection. Peripheral expansion of virus-specific CD8 T cells was impaired when CD4 T cells were ablated prior to infection but not at 4 days postinfection. Delayed CD4 T cell depletion abrogated CD4 T cell recruitment to the CNS but only slightly diminished CD8 T cell recruitment. Nevertheless, the absence of CNS CD4 T cells was associated with reduced gamma interferon (IFN-γ) and granzyme B expression by infiltrating CD8 T cells, increased CD8 T cell apoptosis, and impaired control of infectious virus. CD4 T cell depletion subsequent to CD4 T cell CNS migration restored CD8 T cell activity and virus control. Analysis of γc-dependent cytokine expression indicated interleukin-21 (IL-21) as a primary candidate optimizing CD8 T cell activity within the CNS. These results demonstrate that CD4 T cells play critical roles in both enhancing peripheral activation of CD8 T cells and prolonging their antiviral function within the CNS. The data highlight the necessity for temporally and spatially distinct CD4 T cell helper functions in sustaining CD8 T cell activity during CNS infection.

  5. [Phenotypic characteristics of LAP(+) CD4(+) T lymphocytes in colorectal cancer tissues].

    PubMed

    Zhong, W; Jiang, Z Y; Zhong, S B; Zhang, L C; Huang, J H; Zhang, S; Chen, L S; Cao, Y F

    2016-08-01

    To analyze the phenotypic characteristics of LAP(+) CD4(+) T lymphocytes and investigate their molecular mechanisms in colorectal cancer (CRC) microenvironment. Fifty colorectal cancer patients treated in our two hospitals from January 2014 to May 2014 were included in this study. Their tumor tissues and adjacent normal tissues, peripheral blood samples, and peripheral blood samples of 25 healthy donors (HD) were collected to isolate the lymphocytes. The different expressions of CCR7, CD45RA, Foxp3, CTLA-4, CCR4 and CCR5 in LAP(+) CD4(+) T and LAP(-)CD4(+) T lymphocytes were analyzed by flow cytometry (FCM). The FCM assay detected that the percentage of LAP(+) CD4(+) T cells in peripheral blood of the CRC patients were significantly higher than that of HD [(9.44±3.18)% versus (1.49±1.00)%, P<0.001]. In addition, significantly more LAP(+) CD4(+) T cells were also recruited into tumor tissue than those in the tumor-adjacent normal tissue [(11.76±3.74)% versus (3.87±1.64)%, P<0.001]. LAP(+) CD4(+) T cells in the tumor-adjacent normal tissue and peripheral blood of both HDs and CRC patients mainly displayed a central memory phenotype. However, effector memory lymphocytes were predominant in the tumor tissue.In the tumor tissue, the expression of Foxp3 in the LAP(+) CD4(+) T cells was (3.87±1.12)%, significantly lower than that in the LAP(-)CD4(+) T cells (16.70±2.61)%, (P<0.001); the expression of CTLA-4 in the LAP(+) CD4(+) T cells was (36.36±19.14)%, significantly higher than the (19.60±8.91)% in the LAP(-)CD4(+) T cells (P<0.001); the expression of CCR4 in the LAP(+) CD4(+) T cells was (37.72±11.14)%, significantly higher than the (30.06±9.14)% in the LAP(-)CD4(+) T cells (P<0.001); and the expression of CCR5 in the LAP(+) CD4(+) T cells was (18.86±7.10)%, significantly higher than the (13.92±3.31)% in the LAP(-)CD4(+) T cells (P<0.001). LAP(+) CD4(+) T cells with low expression of Foxp3 and high expressions of CTLA-4, CCR4 and CCR5 are tend to be

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  7. 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.

  8. 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

  9. 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

  10. CD4+ T cells memorize obesity and promote weight regain.

    PubMed

    Zou, Jianghuan; Lai, Beibei; Zheng, Mingzhu; Chen, Qin; Jiang, Shujun; Song, Anying; Huang, Zan; Shi, Peiliang; Tu, Xin; Wang, Di; Lu, Linrong; Lin, Zhaoyu; Gao, Xiang

    2017-06-19

    Body weight regain often causes failure of obesity therapies while the underlying mechanism remains largely unknown. In this study, we report that immune cells, especially CD4+ T cells, mediate the 'memory' of previous obese status. In a weight gain-loss-regain model, we found that C57BL/6J mice with an obesity history showed a much faster rate of body weight regain. This obesity memory could last for at least 2 months after previously obese mice were kept at the same body weight as non-obese mice. Surprisingly, such obesity memory was abrogated by dexamethasone treatment, whereas immunodeficient Rag1(-/-) and H2A(-/-) mice failed to establish such memory. Rag1(-/-) mice repossessed the obesity memory when immune cells or CD4+ T cells isolated from previously obese mice were transferred. Furthermore, depletion of CD4+ T cells led to obesity memory ablation. Taken together, we conclude that CD4+ T cells mediate obesity memory and promote weight regain.Cellular &Molecular Immunology advance online publication, 19 June 2017; doi:10.1038/cmi.2017.36.

  11. Potent HIV-specific responses are enriched in a unique subset of CD8+ T cells that coexpresses CD4 on its surface

    PubMed Central

    Zloza, Andrew; Schenkel, Jason M.; Tenorio, Allan R.; Martinson, Jeffrey A.; Jeziorczak, Paul M.

    2009-01-01

    In humans, approximately 3% of peripheral CD8+ T cells coexpress CD4 dimly on their surface and hence are designated as CD4dimCD8bright T cells. We evaluated the contribution of this CD4dimCD8bright T-cell population to anti-HIV immunity. We demonstrate that CD4dimCD8bright T cells generate greater than 55% of CD8+ T-cell antigen recognition and effector response to HIV, as evaluated by multiple parameters for assessing T-cell antiviral immunity, including HIV tetramer recognition, cytokine production, and cytolytic potential. Inhibition of major histocompatibility class II (MHC-II) on target cells or CD4 on CD4dimCD8bright T cells diminishes their anti-HIV responses, suggesting that CD4 on effector cells and MHC-II on target cells provides an additional arm of contact between effector and target cells which is critical to CD4dimCD8bright T-cell function. CD4dimCD8bright T cells also exhibit features that are indicative of central memory T cells. Finally, CD4dimCD8bright T cells are elevated in blood of HIV+ long-term nonprogressors in comparison to HIV− donors. Collectively, our findings show that CD4dimCD8bright T cells designate an enriched antiviral subpopulation of CD8+ T cells that should be targeted for therapeutic intervention or evaluation of vaccine efficacy. PMID:19700667

  12. Characterization of CD4 and CD8 T cells producing IFN-γ in human latent and active tuberculosis.

    PubMed

    Rueda, Cesar M; Marín, Nancy D; García, Luis F; Rojas, Mauricio

    2010-11-01

    Patients with pulmonary tuberculosis (PTB) frequently have reduced IFN-γ production in response to mycobacterial antigens, compared to individuals with latent Mycobacterium tuberculosis infection (LTBi). However, it is not clear whether this reduced responsiveness is restricted to a particular T cell subset. Herein, PBMCs from 26 PTB patients, 30 household contacts (HHCs) of PTB, and 30 tuberculin positive (TST+) healthy subjects not recently exposed to PTB, were stained with CFSE and stimulated non-specific (PPD) for 120 h, and specific (CFP-10/ESAT-6) and latency (HSpX) mycobacterial antigens for 144 h and the percentage of CD4(+) and CD8(+)IFN-γ(+) T cells responding determined by flow cytometry, in addition to their memory phenotype by the CD45RO and CD27 expression. PTB had decreased frequency of both CD4(+) and CD8(+) precursor cells, as well as decreased number of CD4(+)IFN-γ(+) cells in response to all antigens, whereas CD8(+)IFN-γ(+) cells were decreased in response to PPD and ESAT-6, but not to CFP-10 and HSpX. HHCs exhibited the highest precursor frequencies and IFN-γ responses, irrespective of the antigen employed. The CD4(+)/CD8(+) cell ratios showed that in response to PPD CD4(+) precursor and IFN-γ-producer cells are more frequent than their CD8(+) counterparts, and that PTB have a decreased CD4(+)IFN-γ(+)/CD8(+)IFN-γ(+) ratio in response to PPD, CFP-10, and ESAT-6. CD4(+)IFN-γ(+) and CD8(+)IFN-γ(+) cells exhibited a central memory phenotype (CD45RO(+)CD27(+)), irrespective of the group of subjects and the antigen used for stimulation. In conclusion, PTB patients had a decreased percentage of CD4(+) and CD8(+) precursor cells and CD4(+)IFN-γ(+). HHCs exhibited the highest frequency of CD4(+) and CD8(+) precursors and CD4(+)IFN-γ(+)-producing cells.

  13. Comparative evaluation of the CD4+CD8+ and CD4+CD8- lymphocytes in the immune response to porcine rubulavirus.

    PubMed

    Hernández, J; Garfias, Y; Nieto, A; Mercado, C; Montaño, L F; Zenteno, E

    2001-05-30

    The porcine immune system is unique in the expression of CD4+CD8+ (double-positive, DP) lymphocytes. These cells have been associated with immunological memory due to their gradual increase with age, the expression of memory phenotype and their ability to respond to recall viral antigen. This work analyzes the biological function of CD4+CD8- and CD4+CD8+ lymphocytes in the immune response to porcine rubulavirus (PRv). CD4+CD8- cells isolated from pigs 3 weeks after infection with porcine rubulavirus proliferated in response to homologous virus and generated lymphoblasts which were predominantly of the CD4+CD8+ phenotype, whereas stimulation with mitogen induced proliferation but did not switch the phenotype. CD4+CD8- lymphocytes isolated after 10 weeks of infection proliferated in response to phytohemagglutinin (PHA) but did not proliferate in response to homologous virus and did not change their phenotype, whereas CD4+CD8+ lymphocytes proliferated in response to PHA and to viral antigen. The cytokine profile of both lymphocyte populations showed the presence of IL-2 and IL-10 transcripts, quantitation demonstrated that CD4+CD8+ cells expressed mainly IL-10, whereas CD4+CD8- lymphocytes expressed primarily IL-2. Our results show that CD4+CD8- lymphocytes in the early phase of porcine rubulavirus infection can be converted to double-positive cells expressing IL-10 in an antigen-dependent manner, and that CD4+CD8- T-cells late in infection do not acquire CD8.

  14. Skin-resident CD4+ T cells protect against Leishmania major by recruiting and activating inflammatory monocytes.

    PubMed

    Glennie, Nelson D; Volk, Susan W; Scott, Phillip

    2017-04-01

    Tissue-resident memory T cells are required for establishing protective immunity against a variety of different pathogens, although the mechanisms mediating protection by CD4+ resident memory T cells are still being defined. In this study we addressed this issue with a population of protective skin-resident, IFNγ-producing CD4+ memory T cells generated following Leishmania major infection. We previously found that resident memory T cells recruit circulating effector T cells to enhance immunity. Here we show that resident memory CD4+ T cells mediate the delayed-hypersensitivity response observed in immune mice and provide protection without circulating T cells. This protection occurs rapidly after challenge, and requires the recruitment and activation of inflammatory monocytes, which limit parasites by production of both reactive oxygen species and nitric oxide. Overall, these data highlight a novel role for tissue-resident memory cells in recruiting and activating inflammatory monocytes, and underscore the central role that skin-resident T cells play in immunity to cutaneous leishmaniasis.

  15. A flexible model of HIV-1 latency permitting evaluation of many primary CD4 T-cell reservoirs.

    PubMed

    Lassen, Kara G; Hebbeler, Andrew M; Bhattacharyya, Darshana; Lobritz, Michael A; Greene, Warner C

    2012-01-01

    Latently infected cells form the major obstacle to HIV eradication. Studies of HIV latency have been generally hindered by the lack of a robust and rapidly deployable cell model that involves primary human CD4 T lymphocytes. Latently infected cell lines have proven useful, but it is unclear how closely these proliferating cells recapitulate the conditions of viral latency in non-dividing CD4 T lymphocytes in vivo. Current primary lymphocyte models more closely reflect the in vivo state of HIV latency, but they are limited by protracted culture periods and often low cell yields. Additionally, these models are always established in a single latently infected cell type that may not reflect the heterogeneous nature of the latent reservoir. Here we describe a rapid, sensitive, and quantitative primary cell model of HIV-1 latency with replication competent proviruses and multiple reporters to enhance the flexibility of the system. In this model, post-integration HIV-1 latency can be established in all populations of CD4 T cells, and reactivation of latent provirus assessed within 7 days. The kinetics and magnitude of reactivation were evaluated after stimulation with various cytokines, small molecules, and T-cell receptor agonists. Reactivation of latent HIV proviruses was readily detected in the presence of strong activators of NF-κB. Latently infected transitional memory CD4 T cells proved more responsive to these T-cell activators than latently infected central memory cells. These findings reveal potentially important biological differences within the latently infected pool of memory CD4 T cells and describe a flexible primary CD4 T-cell system to evaluate novel antagonists of HIV latency.

  16. A Flexible Model of HIV-1 Latency Permitting Evaluation of Many Primary CD4 T-Cell Reservoirs

    PubMed Central

    Lassen, Kara G.; Hebbeler, Andrew M.; Bhattacharyya, Darshana; Lobritz, Michael A.; Greene, Warner C.

    2012-01-01

    Latently infected cells form the major obstacle to HIV eradication. Studies of HIV latency have been generally hindered by the lack of a robust and rapidly deployable cell model that involves primary human CD4 T lymphocytes. Latently infected cell lines have proven useful, but it is unclear how closely these proliferating cells recapitulate the conditions of viral latency in non-dividing CD4 T lymphocytes in vivo. Current primary lymphocyte models more closely reflect the in vivo state of HIV latency, but they are limited by protracted culture periods and often low cell yields. Additionally, these models are always established in a single latently infected cell type that may not reflect the heterogeneous nature of the latent reservoir. Here we describe a rapid, sensitive, and quantitative primary cell model of HIV-1 latency with replication competent proviruses and multiple reporters to enhance the flexibility of the system. In this model, post-integration HIV-1 latency can be established in all populations of CD4 T cells, and reactivation of latent provirus assessed within 7 days. The kinetics and magnitude of reactivation were evaluated after stimulation with various cytokines, small molecules, and T-cell receptor agonists. Reactivation of latent HIV proviruses was readily detected in the presence of strong activators of NF-κB. Latently infected transitional memory CD4 T cells proved more responsive to these T-cell activators than latently infected central memory cells. These findings reveal potentially important biological differences within the latently infected pool of memory CD4 T cells and describe a flexible primary CD4 T-cell system to evaluate novel antagonists of HIV latency. PMID:22291913

  17. Delineating CD4 dependency of HIV-1: Adaptation to infect low level CD4 expressing target cells widens cellular tropism but severely impacts on envelope functionality

    PubMed Central

    Beauparlant, David; Rusert, Peter; Magnus, Carsten; Weber, Jacqueline; Uhr, Therese; Clapham, Paul R.; Metzner, Karin J.

    2017-01-01

    A hallmark of HIV-1 infection is the continuously declining number of the virus’ predominant target cells, activated CD4+ T cells. With diminishing CD4+ T cell levels, the capacity to utilize alternate cell types and receptors, including cells that express low CD4 receptor levels such as macrophages, thus becomes crucial. To explore evolutionary paths that allow HIV-1 to acquire a wider host cell range by infecting cells with lower CD4 levels, we dissected the evolution of the envelope-CD4 interaction under in vitro culture conditions that mimicked the decline of CD4high target cells, using a prototypic subtype B, R5-tropic strain. Adaptation to CD4low targets proved to severely alter envelope functions including trimer opening as indicated by a higher affinity to CD4 and loss in shielding against neutralizing antibodies. We observed a strikingly decreased infectivity on CD4high target cells, but sustained infectivity on CD4low targets, including macrophages. Intriguingly, the adaptation to CD4low targets altered the kinetic of the entry process, leading to rapid CD4 engagement and an extended transition time between CD4 and CCR5 binding during entry. This phenotype was also observed for certain central nervous system (CNS) derived macrophage-tropic viruses, highlighting that the functional perturbation we defined upon in vitro adaptation to CD4low targets occurs in vivo. Collectively, our findings suggest that CD4low adapted envelopes may exhibit severe deficiencies in entry fitness and shielding early in their evolution. Considering this, adaptation to CD4low targets may preferentially occur in a sheltered and immune-privileged environment such as the CNS to allow fitness restoring compensatory mutations to occur. PMID:28264054

  18. Increased TNF-alpha/IFN-gamma/IL-2 and decreased TNF-alpha/IFN-gamma production by central memory T cells are associated with protective responses against bovine tuberculosis following BCG vaccination

    USDA-ARS?s Scientific Manuscript database

    Central memory T cells (Tcm’s) and polyfunctional CD4 T responses contribute to vaccine-elicited protection with both human and bovine tuberculosis (TB); however, their combined role in protective immunity to TB is unclear. To address this question, we evaluated polyfunctional cytokine responses by ...

  19. Plasmodium vivax infection induces expansion of activated naïve/memory T cells and differentiation into a central memory profile.

    PubMed

    Silva, Ana Luiza Teixeira; Lacerda, Marcus Vinícius; Fujiwara, Ricardo Toshio; Bueno, Lilian Lacerda; Braga, Erika Martins

    2013-11-01

    Immunity to malaria is widely believed to wane in the absence of reinfection, but direct evidence for the presence or absence of durable immunological memory to malaria is limited. Here, we characterized the profile of circulating naïve and memory (including central and effector) CD4⁺ T cells responses of individuals naturally infected by Plasmodium vivax. In the current study, we demonstrated that acute P. vivax infection induces a significant increase in the absolute number of both naïve and memory cells, which were responsible for the production of anti-inflammatory (IL-10) and pro-inflammatory (IFN-γ) cytokines. Finally, we described the profile of memory cell subtypes (T(CM)-CD45RO(high)CCR7⁺ and T(EM)-CD45RO(high)CCR7⁻), as well as the pattern of cell migration based on CD62L selectin expression, demonstrating that P. vivax-infected donors presented with a predominantly central memory cell profile. Our results indicate that the expansion of both naïve and memory T cells, responsible for the production of both pro-inflammatory and regulatory cytokines, which might also contribute to the modulation of immune responses during P. vivax infection.

  20. Cytomegalovirus upregulates expression of CCR5 in central memory cord blood mononuclear cells, which may facilitate in utero HIV type 1 transmission.

    PubMed

    Johnson, Erica L; Howard, Chanie L; Thurman, Joy; Pontiff, Kyle; Johnson, Elan S; Chakraborty, Rana

    2015-01-15

    Administration of combination antiretroviral therapy to human immunodeficiency virus type 1 (HIV-1)-infected pregnant women significantly reduces vertical transmission. In contrast, maternal co-opportunistic infection with primary or reactivated cytomegalovirus (CMV) or other pathogens may facilitate in utero transmission of HIV-1 by activation of cord blood mononuclear cells (CBMCs). Here we examine the targets and mechanisms that affect fetal susceptibility to HIV-1 in utero. Using flow cytometry, we demonstrate that the fraction of CD4(+)CD45RO(+) and CD4(+)CCR5(+) CBMCs is minimal, which may account for the low level of in utero HIV-1 transmission. Unstimulated CD4(+) CBMCs that lack CCR5/CD45RO showed reduced levels of HIV-1 infection. However, upon in vitro stimulation with CMV, CBMCs undergo increased proliferation to upregulate the fraction of T central memory cells and expression of CCR5, which enhances susceptibility to HIV-1 infection in vitro. These data suggest that activation induced by CMV in vivo may alter CCR5 expression in CD4(+) T central memory cells to promote in utero transmission of HIV-1. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. 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.

  2. Jug r 2-reactive CD4(+) T cells have a dominant immune role in walnut allergy.

    PubMed

    Archila, Luis Diego; Jeong, David; Pascal, Mariona; Bartra, Joan; Juan, Manel; Robinson, David; Farrington, Mary L; Kwok, William W

    2015-10-01

    Allergic reactions to walnut can be life-threatening. Although IgE epitopes of walnut have been studied, CD4(+) T cell-specific epitopes for walnut remain uncharacterized. In particular, the relationship of both phenotype and frequency of walnut-specific T cells to the disease have not been examined. We sought to provide a thorough phenotypic analysis for walnut-reactive T cells in allergic and nonallergic subjects, particularly the relationship of phenotypes and frequencies of walnut-specific T cells with the disease. The CD154 upregulation assay was used to examine CD4(+) T-cell reactivity toward the walnut allergens Jug r 1, Jug r 2, and Jug r 3. A tetramer-guided epitope mapping approach was used to identify HLA-restricted CD4(+) T-cell epitopes in Jug r 2. Direct ex vivo staining with peptide-major histocompatibility complex class II tetramers enabled comparison of the frequency and phenotype of Jug r 2-specific CD4(+) T cells between allergic and nonallergic subjects. Jug r 2-specific T-cell clones were also generated, and mRNA transcription factor levels were assessed by using quantitative RT-PCR. Intracellular cytokine staining assays were performed for further phenotypic analyses. Jug r 2 was identified as the major allergen that elicited CD4(+) T-cell responses. Multiple Jug r 2 T-cell epitopes were identified. The majority of these T cells in allergic subjects have a CCR4(+) phenotype. A subset of these T cells express CCR4(+)CCR6(+) irrespective of the asthmatic status of the allergic subjects. Intracellular cytokine staining confirmed these TH2-, TH2/TH17-, and TH17-like heterogenic profiles. Jug r 2-specific T-cell clones from allergic subjects mainly expressed GATA3, nonetheless, a portion of T-cell clones both GATA3 and RAR-related orphan receptor C (RORC) or RORC alone, confirming the presence of TH2, TH2/TH17, and TH17 cells. Jug r 2-specific responses dominate walnut T-cell responses in patients with walnut allergy. Jug r 2 central memory CD4

  3. Chronic exposure to trichloroethylene increases DNA methylation of the Ifng promoter in CD4(+) T cells.

    PubMed

    Gilbert, Kathleen M; Blossom, Sarah J; Erickson, Stephen W; Broadfoot, Brannon; West, Kirk; Bai, Shasha; Li, Jingyun; Cooney, Craig A

    2016-10-17

    CD4(+) T cells in female MRL+/+ mice exposed to solvent and water pollutant trichloroethylene (TCE) skew toward effector/memory CD4(+) T cells, and demonstrate seemingly non-monotonic alterations in IFN-γ production. In the current study we examined the mechanism for this immunotoxicity using effector/memory and naïve CD4(+) T cells isolated every 6 weeks during a 40 week exposure to TCE (0.5mg/ml in drinking water). A time-dependent effect of TCE exposure on both Ifng gene expression and IFN-γ protein production was observed in effector/memory CD4(+) T cells, with an increase after 22 weeks of exposure and a decrease after 40 weeks of exposure. No such effect of TCE was observed in naïve CD4(+) T cells. A cumulative increase in DNA methylation in the CpG sites of the promoter of the Ifng gene was observed in effector/memory, but not naïve, CD4(+) T cells over time. Also unique to the Ifng promoter was an increase in methylation variance in effector/memory compared to naïve CD4(+) T cells. Taken together, the CpG sites of the Ifng promoter in effector/memory CD4(+) T cells were especially sensitive to the effects of TCE exposure, which may help explain the regulatory effect of the chemical on this gene.

  4. Does discordancy between the CD4 count and CD4 percentage in HIV-positive individuals influence outcomes on highly active antiretroviral therapy?

    PubMed

    Gompels, Mark; Dunn, David T; Phillips, Andrew; Dooley, Debbie; De Burgh Thomas, Andrew; Anderson, Jane; Post, Frank; Pillay, Deenan; Gazzard, Brian; Hill, Teresa; Johnson, Margaret; Gilson, Richard; Bansi, Loveleen; Easterbrook, Philippa; Fisher, Martin; Walsh, John; Orkin, Chloe; Ainsworth, Jonathan; Leen, Clifford; Sabin, Caroline

    2012-02-15

    The CD4 count and CD4 percentage (CD4%) are both strong predictors of clinical disease progression in human immunodeficiency virus (HIV). Although individuals may show discordancy between their CD4 count and CD4%, the clinical relevance of this is unclear. Discordancy was defined where the CD4% was ≤10th percentile for a selected CD4 count range (referred to as low discordancy), within the central 80% range (concordant), or ≥90th percentile (high discordancy). Regression methods identified factors associated with low and high discordancy in untreated individuals and assessed the impact of discordancy on treatment responses to highly active antiretroviral therapy (HAART). High discordancy was associated with female sex, low viral load, and white ethnicity; low discordancy was associated with black or nonwhite ethnicity, older age, and injection drug use. Clinical event rates were higher in individuals with high discordancy starting HAART, but there was no association with subsequent HIV progression by 6 months after starting HAART. CD4 count increases remained lower, by 20 cells/mm(3), in individuals with low discordancy, and higher, by 27 cells/mm(3), in those with high discordancy. Overall discrepancies between the CD4/CD4% are small, confirming the use of absolute CD4 counts as a monitoring tool.

  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. Expression of CCR7 and CD45RA in CD4+ and CD8+ subsets in cerebrospinal fluid of 134 patients with inflammatory and non-inflammatory neurological diseases

    PubMed Central

    Mullen, Katherine M.; Gocke, Anne R.; Allie, Rameeza; Ntranos, Achilles; Grishkan, Inna V.; Pardo, Carlos; Calabresi, Peter A.

    2012-01-01

    We investigated CD45RA and CCR7 expression in CD4+ and CD8+ subsets of cerebrospinal fluid (CSF) lymphocytes, both immediately ex vivo and after stimulation, from 134 patients with a variety of inflammatory and non-inflammatory neurological diseases. Most inflammatory diseases had a higher CD4+: CD8+ ratio and higher percentage of effector memory T cells (TEM) than non-inflammatory controls, excluding active infection. Moreover, we found that patients with highly elevated cell counts in the CSF tended to have a lower percentage of central memory T cells (TCM) than patients with low or absent pleiocytosis, with a concomitant increase in TEM. We also found that samples with elevated IgG index or presence of oligoclonal bands had a significantly higher CD4+:CD8+ ratio than normal samples, consistent with increased CD4+ help for intrathecal IgG synthesis by B cells. PMID:22633193

  7. WFDC1/ps20 is a novel innate immunomodulatory signature protein of human immunodeficiency virus (HIV)-permissive CD4+ CD45RO+ memory T cells that promotes infection by upregulating CD54 integrin expression and is elevated in HIV type 1 infection.

    PubMed

    Alvarez, R; Reading, J; King, D F L; Hayes, M; Easterbrook, P; Farzaneh, F; Ressler, S; Yang, F; Rowley, D; Vyakarnam, A

    2008-01-01

    Understanding why human immunodeficiency virus (HIV) preferentially infects some CD4(+) CD45RO(+) memory T cells has implications for antiviral immunity and pathogenesis. We report that differential expression of a novel secreted factor, ps20, previously implicated in tissue remodeling, may underlie why some CD4 T cells are preferentially targeted. We show that (i) there is a significant positive correlation between endogenous ps20 mRNA in diverse CD4 T-cell populations and in vitro infection, (ii) a ps20(+) permissive cell can be made less permissive by antibody blockade- or small-interference RNA-mediated knockdown of endogenous ps20, and (iii) conversely, a ps20(low) cell can be more permissive by adding ps20 exogenously or engineering stable ps20 expression by retroviral transduction. ps20 expression is normally detectable in CD4 T cells after in vitro activation and interleukin-2 expansion, and such oligoclonal populations comprise ps20(positive) and ps20(low/negative) isogenic clones at an early differentiation stage (CD45RO(+)/CD25(+)/CD28(+)/CD57(-)). This pattern is altered in chronic HIV infection, where ex vivo CD4(+) CD45RO(+) T cells express elevated ps20. ps20 promoted HIV entry via fusion and augmented CD54 integrin expression; both of these effects were reversed by anti-ps20 antibody. We therefore propose ps20 to be a novel signature of HIV-permissive CD4 T cells that promotes infection in an autocrine and paracrine manner and that HIV has coopted a fundamental role of ps20 in promoting cell adhesion for its benefit. Disrupting the ps20 pathway may therefore provide a novel anti-HIV strategy.

  8. Prime, Shock, and Kill: Priming CD4 T Cells from HIV Patients with a BCL-2 Antagonist before HIV Reactivation Reduces HIV Reservoir Size

    PubMed Central

    Cummins, Nathan W.; Sainski, Amy M.; Dai, Haiming; Natesampillai, Sekar; Pang, Yuan-Ping; Bren, Gary D.; de Araujo Correia, Maria Cristina Miranda; Sampath, Rahul; Rizza, Stacey A.; O'Brien, Daniel; Yao, Joseph D.

    2016-01-01

    ABSTRACT Understanding how some HIV-infected cells resist the cytotoxicity of HIV replication is crucial to enabling HIV cure efforts. HIV killing of CD4 T cells that replicate HIV can involve HIV protease-mediated cleavage of procaspase 8 to generate a fragment (Casp8p41) that directly binds and activates the mitochondrial proapoptotic protein BAK. Here, we demonstrate that Casp8p41 also binds with nanomolar affinity to the antiapoptotic protein Bcl-2, which sequesters Casp8p41 and prevents apoptosis. Further, we show that central memory CD4 T cells (TCM) from HIV-infected individuals have heightened expression of BCL-2 relative to procaspase 8, possibly explaining the persistence of HIV-infected TCM despite generation of Casp8p41. Consistent with this hypothesis, the selective BCL-2 antagonist venetoclax induced minimal killing of uninfected CD4 T cells but markedly increased the death of CD4 T cells and diminished cell-associated HIV DNA when CD4 T cells from antiretroviral therapy (ART)-suppressed HIV patients were induced with αCD3/αCD28 to reactivate HIV ex vivo. Thus, priming CD4 T cells from ART suppressed HIV patients with a BCL-2 antagonist, followed by HIV reactivation, achieves reductions in cell-associated HIV DNA, whereas HIV reactivation alone does not. IMPORTANCE HIV infection is incurable due to a long-lived reservoir of HIV+ memory CD4 T cells, and no clinically relevant interventions have been identified that reduce the number of these HIV DNA-containing cells. Since postintegration HIV replication can result in HIV protease generation of Casp8p41, which activates BAK, causing infected CD4 T cell death, we sought to determine whether this occurs in memory CD4 T cells. Here, we demonstrate that memory CD4 T cells can generate Casp8p41 and yet are intrinsically resistant to death induced by diverse stimuli, including Casp8p41. Furthermore, BCL-2 expression is relatively increased in these cells and directly binds and inhibits Casp8p41's

  9. Regulation of CD4 T cells and their effects on immunopathological inflammation following viral infection.

    PubMed

    Bhattacharyya, Mitra; Madden, Patrick; Henning, Nathan; Gregory, Shana; Aid, Malika; Martinot, Amanda J; Barouch, Dan H; Penaloza-MacMaster, Pablo

    2017-10-01

    CD4 T cells help immune responses, but knowledge of how memory CD4 T cells are regulated and how they regulate adaptive immune responses and induce immunopathology is limited. Using adoptive transfer of virus-specific CD4 T cells, we show that naive CD4 T cells undergo substantial expansion following infection, but can induce lethal T helper type 1-driven inflammation. In contrast, memory CD4 T cells exhibit a biased proliferation of T follicular helper cell subsets and were able to improve adaptive immune responses in the context of minimal tissue damage. Our analyses revealed that type I interferon regulates the expansion of primary CD4 T cells, but does not seem to play a critical role in regulating the expansion of secondary CD4 T cells. Strikingly, blockade of type I interferon abrogated lethal inflammation by primary CD4 T cells following viral infection, despite that this treatment increased the numbers of primary CD4 T-cell responses. Altogether, these data demonstrate important aspects of how primary and secondary CD4 T cells are regulated in vivo, and how they contribute to immune protection and immunopathology. These findings are important for rational vaccine design and for improving adoptive T-cell therapies against persistent antigens. © 2017 John Wiley & Sons Ltd.

  10. [The impact of donor naive and memory T cell subsets on patient outcome following allogeneic stem cell transplantation: relationship between infused donor CD4+/CCR7+ T cell subsets and acute graft-versus-host disease].

    PubMed

    Choufi, B; Thiant, S; Trauet, J; Cliquennois, M; Cherrel, M; Boulanger, F; Coiteux, V; Magro, L; Labalette, M; Yakoub-Agha, I

    2014-06-01

    In a previous prospective study on 62 patients who underwent an HLA-matched allogeneic stem cell transplantation, we have observed that proportion of donor-derived CCR7(+)/CD4(+) T cells in the graft provided a predictive indicator of acute GVHD without interfering on chronic GVHD and relapse rate. Here we present our results on a confirmatory cohort of 137 consecutive patients. Indeed patients who received more than 76% of CCR7(+)/CD4(+) T cells in the graft developed more often acute GVHD be it of low or high grade than those who did not. Determination of the CCR7(+)/CCR7(neg) ratio of CD4(+) T cells in the graft provides a predictive indicator of acute GVHD and could help to define strategies of partial selective T cell depleted transplantation.

  11. 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

  12. 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.

  13. Increased susceptibility of CD4+ T cells from elderly individuals to HIV-1 infection and apoptosis is associated with reduced CD4 and enhanced CXCR4 and FAS surface expression levels.

    PubMed

    Heigele, Anke; Joas, Simone; Regensburger, Kerstin; Kirchhoff, Frank

    2015-10-09

    Elderly HIV-1 infected individuals progress to AIDS more frequently and rapidly than people becoming infected at a young age. To identify possible reasons for these differences in clinical progression, we performed comprehensive phenotypic analyses of CD4+ T cells from uninfected young and elderly individuals, and examined their susceptibility to HIV-1 infection and programmed death. Peripheral blood mononuclear cells (PBMCs) from older people contain an increased percentage of central memory and Th17 CD4+ T cells that are main target cells of HIV-1 and strongly reduced proportions of naïve T cells that are poorly susceptible to HIV-1. Unstimulated T cells from elderly individuals expressed higher levels of activation markers, death receptors, and the viral CXCR4 co-receptor than those from young individuals but responded poorly to stimulation. CD4+ T cells from older individuals were highly susceptible to CXCR4- and CCR5-tropic HIV-1 infection but produced significantly lower quantities of infectious virus than cells from young individuals because they were highly prone to apoptosis and thus presumably had a very short life span. The increased susceptibility of T cells from the elderly to HIV-1 infection correlated directly with CXCR4 and inversely with CD4 expression. The levels of apoptosis correlated with the cell surface expression of FAS but not with the expression of programmed death receptor 1 (PD1) or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Increased levels of activated and highly susceptible HIV-1 target cells, reduced CD4 and enhanced CXCR4 cell surface expression, together with the high susceptibility to FAS-induced programmed cell death may contribute to the rapid CD4+ T cell depletion and accelerated clinical course of infection in elderly HIV-1-infected individuals.

  14. 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

  15. Jug r 2-reactive CD4+ T-cells have a dominant immune role in walnut allergy

    PubMed Central

    Archila, Luis Diego; Jeong, David; Pascal, Mariona; Bartra, Joan; Juan, Manel; Robinson, David; Farrington, Mary L.; Kwok, William.W.

    2015-01-01

    Background Allergic reactions to walnut can be life threatening. While IgE epitopes of walnut have been studied, CD4+ T-cell specific epitopes for walnut remain uncharacterized. Particularly, the relationship of both phenotype and frequency of walnut specific T-cells to the disease have not been examined. Objectives We sought to provide a thorough phenotypic analysis for walnut reactive T-cells in allergic and non-allergic subjects. Particularly, the relationship of phenotypes and frequencies of walnut specific T-cells with the disease. Methods CD154 up-regulation assay was used to examine CD4+ T-cell reactivity towards walnut allergens.Jug r 1, Jug r 2 and Jug r 3. Tetramer-Guided epitope mapping approach was utilized to identify HLA-restricted CD4+ T-cells epitopes in Jug r 2. Direct ex vivo staining with peptide-major histocompatibility complex class II (pMHC-II) tetramers enabled the comparison of frequency and phenotype of Jug r 2-specific CD4+ T-cells between allergic and non-allergic subjects. Jug r 2-specific T-cell-clones were also generated and mRNA transcription factor levels were assessed by RT qPCR. Intracellular cytokine staining (ICS) assays were performed for further phenotypical analyses. Results Jug r 2 was identified as the major allergen that elicited CD4+ T-cell responses. Multiple Jug r 2 T-cell epitopes were identified. The majority of these T-cells in allergic subjects have a CCR4+ TCM (central memory) phenotype. A subset of these T-cells express CCR4+CCR6+ irrespectively of the asthmatic status of the allergic subjects. ICS confirmed these TH2, TH2/TH17 and TH17-like heterogenic profiles. Jug r 2-specific T-cell-clones from allergic subjects mainly expressed GATA3; nonetheless, a portion of T-cell clones expressed either GATA3 and RORC, or RORC, confirming the presence of TH2, TH2/TH17 and TH17 cells. Conclusions Jug r 2 specific responses dominate walnut T-cell responses in subjects with walnut allergy. Jug r 2 central memory CD4+ cells

  16. Toll-like receptor 3 signalling up-regulates expression of the HIV co-receptor G-protein coupled receptor 15 on human CD4+ T cells.

    PubMed

    Kiene, Miriam; Rethi, Bence; Jansson, Marianne; Dillon, Stephanie; Lee, Eric; Lantto, Rebecka; Wilson, Cara; Pöhlmann, Stefan; Chiodi, Francesca

    2014-01-01

    Many HIV-2 and SIV isolates, as well as some HIV-1 strains, can use the orphan 7-transmembrane receptor GPR15 as co-receptor for efficient entry into host cells. GPR15 is expressed on central memory and effector memory CD4(+) T cells in healthy individuals and a subset of these cells is susceptible to HIV-1 and SIV infection. However, it has not been determined whether GPR15 expression is altered in the context of HIV-1 infection. Here, we show that GPR15 expression in CD4(+) T cells is markedly up-regulated in some HIV-1 infected individuals compared to the rest of the infected patients and to healthy controls. Infection of the PM1 T cell line with primary HIV-1 isolates was found to up-regulate GPR15 expression on the infected cells, indicating that viral components can induce GPR15 expression. Up-regulation of GPR15 expression on CD4(+) T cells was induced by activation of Toll-like receptor 3 signalling via TIR-domain-containing adapter-inducing interferon-β (TRIF) and was more prominent on gut-homing compared to lymph node-homing CD4(+) T cells. These results suggest that infection-induced up-regulation of GPR15 expression could increase susceptibility of CD4(+) T cells to HIV infection and target cell availability in the gut in some infected individuals.

  17. Toll-Like Receptor 3 Signalling Up-Regulates Expression of the HIV Co-Receptor G-Protein Coupled Receptor 15 on Human CD4+ T Cells

    PubMed Central

    Kiene, Miriam; Rethi, Bence; Jansson, Marianne; Dillon, Stephanie; Lee, Eric; Lantto, Rebecka; Wilson, Cara; Pöhlmann, Stefan; Chiodi, Francesca

    2014-01-01

    Background Many HIV-2 and SIV isolates, as well as some HIV-1 strains, can use the orphan 7-transmembrane receptor GPR15 as co-receptor for efficient entry into host cells. GPR15 is expressed on central memory and effector memory CD4+ T cells in healthy individuals and a subset of these cells is susceptible to HIV-1 and SIV infection. However, it has not been determined whether GPR15 expression is altered in the context of HIV-1 infection. Results Here, we show that GPR15 expression in CD4+ T cells is markedly up-regulated in some HIV-1 infected individuals compared to the rest of the infected patients and to healthy controls. Infection of the PM1 T cell line with primary HIV-1 isolates was found to up-regulate GPR15 expression on the infected cells, indicating that viral components can induce GPR15 expression. Up-regulation of GPR15 expression on CD4+ T cells was induced by activation of Toll-like receptor 3 signalling via TIR-domain-containing adapter-inducing interferon-β (TRIF) and was more prominent on gut-homing compared to lymph node-homing CD4+ T cells. Conclusion These results suggest that infection-induced up-regulation of GPR15 expression could increase susceptibility of CD4+ T cells to HIV infection and target cell availability in the gut in some infected individuals. PMID:24558379

  18. 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.

  19. Innate-like CD4 T cells selected by thymocytes suppress adaptive immune responses against bacterial infections

    PubMed Central

    Qiao, Yu; Gray, Brian M.; Sofi, Mohammed H.; Bauler, Laura D.; Eaton, Kathryn A.; O'Riordan, Mary X. D.; Chang, Cheong-Hee

    2012-01-01

    We have reported a new innate-like CD4 T cell population that expresses cell surface makers of effector/memory cells and produce Th1 and Th2 cytokines immediately upon activation. Unlike conventional CD4 T cells that are selected by thymic epithelial cells, these CD4 T cells, named T-CD4 T cells, are selected by MHC class II expressing thymocytes. Previously, we showed that the presence of T-CD4 T cells protected mice from airway inflammation suggesting an immune regulatory role of T-CD4 T cells. To further understand the function of T-CD4 T cells, we investigated immune responses mediated by T-CD4 T cells during bacterial infection because the generation of antigen specific CD4 T cells contributes to clearance of infection and for the development of immune memory. The current study shows a suppressive effect of T-CD4 T cells on both CD8 and CD4 T cell-mediated immune responses during Listeria and Helicobacter infections. In the mouse model of Listeria monocytogenes infection, T-CD4 T cells resulted in decreasedfrequency of Listeria-specific CD8 T cells and the killing activity of them. Furthermore, mice with T-CD4 T cells developed poor immune memory, demonstrated by reduced expansion of antigen-specific T cells and high bacterial burden upon re-infection. Similarly, the presence of T-CD4 T cells suppressed the generation of antigen-specific CD4 T cells in Helicobacter pylori infected mice. Thus, our studies reveal a novel function of T-CD4 T cells in suppressing anti-bacterial immunity. PMID:23264931

  20. 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

  1. Novel teleost CD4-bearing cell populations provide insights into the evolutionary origins and primordial roles of CD4+ lymphocytes and CD4+ macrophages

    PubMed Central

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

    2016-01-01

    Tetrapods contain a single CD4 co-receptor with four immunoglobulin 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 immunoglobulin domains while CD4-2 contains only two. Since CD4-2 is reminiscent of the prototypic two-domain CD4 co-receptor, 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 monoclonal antibodies against CD4-1 and CD4-2, we identified two bona fide CD4+ T-cell populations, a predominant lymphocyte population co-expressing surface CD4-1 and CD4-2 (CD4 DP), and a minor subset expressing only CD4-2 (CD4-2 SP). While both subsets produced equivalent levels of Th1, Th17, and Treg 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 non-mammalian species. Of all myeloid subsets, we found the CD4+ population to be the most phagocytic, while 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+ monocyte/macrophages. PMID:27183628

  2. Cloning, expression, and characterization of fugu CD4, the first ectothermic animal CD4.

    PubMed

    Suetake, Hiroaki; Araki, Kyosuke; Suzuki, Yuzuru

    2004-08-01

    We have cloned and sequenced the first ectothermic animal CD4 gene from fugu, Takifugu rubripes, using a public database of the third draft sequence of the fugu genome. The fugu CD4 gene encodes a predicted protein of 463 amino acids containing four extracellular immunoglobulin (Ig)-like domains, a transmembrane region, and a cytoplasmic tail. Fugu CD4 shares low identity of about 15-20% with avian and mammalian CD4 proteins. Unlike avian and mammalian CD4, fugu CD4 lacks the Cys pair of the first Ig-like domain, but has a unique possible disulfide bond in the third domain. These differences suggest that fugu CD4 may have a different structure that could affect binding of major histocompatibility complex class II molecules and subsequent T-cell activation. In the putative fugu cytoplasmic region, the protein tyrosine kinase p56lck binding motif is conserved. The predicted fugu CD4 gene is composed of 12 exons, differing from other CD4 genes, but showing conserved synteny and many conserved sequence motifs in the promoter region. RT-PCR analysis demonstrated that the fugu CD4 gene is expressed predominantly in lymphoid tissues. We also show that fugu CD4 can be expressed on the surface of cells via transfection. Molecular characterization of CD4 in fish provides insights into the evolution of both the CD4 molecule and the immune system.

  3. 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

  4. Enhanced contextual fear memory in central serotonin-deficient mice.

    PubMed

    Dai, Jin-Xia; Han, Hui-Li; Tian, Meng; Cao, Jun; Xiu, Jian-Bo; Song, Ning-Ning; Huang, Ying; Xu, Tian-Le; Ding, Yu-Qiang; Xu, Lin

    2008-08-19

    Central serotonin (5-HT) dysregulation contributes to the susceptibility for mental disorders, including depression, anxiety, and posttraumatic stress disorder, and learning and memory deficits. We report that the formation of hippocampus-dependent spatial memory is compromised, but the acquisition and retrieval of contextual fear memory are enhanced, in central 5-HT-deficient mice. Genetic deletion of serotonin in the brain was achieved by inactivating Lmx1b selectively in the raphe nuclei of the brainstem, resulting in a near-complete loss of 5-HT throughout the brain. These 5-HT-deficient mice exhibited no gross abnormality in brain structures and had normal locomotor activity. Spatial learning in the Morris water maze was unaffected, but the retrieval of spatial memory was impaired. In contrast, contextual fear learning and memory induced by foot-shock conditioning was markedly enhanced, but this enhancement could be prevented by intracerebroventricular administration of 5-HT. Foot shock impaired long-term potentiation and facilitated long-term depression in hippocampal slices in WT mice but had no effect in 5-HT-deficient mice. Furthermore, bath application of 5-HT in 5-HT-deficient mice restored foot shock-induced alterations of hippocampal synaptic plasticity. Thus, central 5-HT regulates hippocampus-dependent contextual fear memory, and 5-HT modulation of hippocampal synaptic plasticity may be the underlying mechanism. The enhanced fear memory in 5-HT-deficient mice supports the notion that 5-HT deficiency confers susceptibility to posttraumatic stress disorder in humans.

  5. Evaluation of immunological cross-reactivity between clade A9 high-risk human papillomavirus types on the basis of E6-Specific CD4+ memory T cell responses.

    PubMed

    van den Hende, Muriel; Redeker, Anke; Kwappenberg, Kitty M C; Franken, Kees L M C; Drijfhout, Jan W; Oostendorp, Jaap; Valentijn, A Rob P M; Fathers, Loraine M; Welters, Marij J P; Melief, Cornelis J M; Kenter, Gemma G; van der Burg, Sjoerd H; Offringa, Rienk

    2010-10-15

    CD4(+) T cell responses against the E6 oncoprotein of human papillomavirus (HPV) type 16 and 5 closely related members of clade A9 (HPV31, 33, 35, 52, and 58) were charted in peripheral blood mononuclear cell cultures from healthy subjects and patients who underwent HPV16 E6/E7-specific vaccination. Initial analyses with overlapping peptide arrays showed that approximately one-half of the responding subjects displayed reactivity against corresponding E6 peptides from >or=2 HPV types. This suggested immunological cross-reactivity and complicated retrospective evaluation of the infection history of the healthy subjects. Importantly, further dissection of the response by means of enriched and clonal T cell cultures (with protein antigen instead of peptides) revealed that CD4(+) T cells that are capable of efficiently reacting against E6 antigen from multiple HPV types are rare and only occur when epitope sequences are highly conserved. Our data indicate that natural and vaccine-induced HPV16 E6-specific CD4(+) T cell responses are unlikely to mediate efficient cross-protection against other clade A9 members.

  6. Effects of MF59 Adjuvant on Induction of Isotype-Switched IgG Antibodies and Protection after Immunization with T-Dependent Influenza Virus Vaccine in the Absence of CD4+ T Cells

    PubMed Central

    Ko, Eun-Ju; Lee, Young-Tae; Kim, Ki-Hye; Jung, Yu-Jin; Lee, Youri; Denning, Timothy L.

    2016-01-01

    ABSTRACT CD4+ T cells play a central role in orchestrating adaptive immunity. To better understand the roles of CD4+ T cells in the effects of adjuvants, we investigated the efficacy of a T-dependent influenza virus split vaccine with MF59 or alum in CD4 knockout (CD4KO) and wild-type (WT) mice. CD4+ T cells were required for the induction of IgG antibody responses to the split vaccine and the effects of alum adjuvant. In contrast, MF59 was found to be highly effective in raising isotype-switched IgG antibodies to a T-dependent influenza virus split vaccine in CD4KO mice or CD4-depleted WT mice equivalent to those in intact WT mice, thus overcoming the deficiency of CD4+ T cells in helping B cells and inducing immunity against influenza virus. Vaccination with the MF59-adjuvanted influenza virus vaccine was able to induce protective CD8+ T cells and long-lived antibody-secreting cells in CD4KO mice. The effects of MF59 adjuvant in CD4KO mice might be associated with uric acid, inflammatory cytokines, and the recruitment of multiple immune cells at the injection site, but their cellularity and phenotypes were different from those in WT mice. These findings suggest a new paradigm of CD4-independent adjuvant mechanisms, providing the rationales to improve vaccine efficacy in infants, the elderly, immunocompromised patients, as well as healthy adults. IMPORTANCE MF59-adjuvanted influenza vaccines were licensed for human vaccination, but the detailed mechanisms are not fully elucidated. CD4+ T cells are required to induce antibody isotype switching and long-term memory responses. In contrast, we discovered that MF59 was highly effective in inducing isotype-switched IgG antibodies and long-term protective immune responses to a T-dependent influenza vaccine independent of CD4+ T cells. These findings are highly significant for the following reasons: (i) MF59 can overcome a defect of CD4+ T cells in inducing protective immunity to vaccination with a T-dependent influenza

  7. Pregnancy persistently affects memory T cell populations.

    PubMed

    Kieffer, Tom E C; Faas, Marijke M; Scherjon, Sicco A; Prins, Jelmer R

    2017-02-01

    Pregnancy is an immune challenge to the maternal immune system. The effects of pregnancy on maternal immunity and particularly on memory T cells during and after pregnancy are not fully known. This observational study aims to show the short term and the long term effects of pregnancy on the constitution, size and activation status of peripheral human memory T-lymphocyte populations. Effector memory (EM) and central memory (CM) T-lymphocytes were analyzed using flow cytometry of peripheral blood from 14 nulligravid, 12 primigravid and 15 parous women that were on average 18 months postpartum. The short term effects were shown by the significantly higher CD4+ EM cell and activated CD4+ memory cell proportions in primigravid women compared to nulligravid women. The persistent effects found in this study were the significantly higher proportions of CD4+ EM, CD4+ CM and activated memory T cells in parous women compared to nulligravid women. In contrast to CD4+ cells, activation status of CD8+ memory cells did not differ between the groups. This study shows that pregnancy persistently affects the pre-pregnancy CD4+ memory cell pool in human peripheral blood. During pregnancy, CD4+ T-lymphocytes might differentiate into EM cells followed by persistent higher proportions of CD4+ CM and EM cells postpartum. The persistent effects of pregnancy on memory T cells found in this study support the hypothesis that memory T cells are generated during pregnancy and that these cells could be involved in the lower complication risks in multiparous pregnancies in humans.

  8. CXCR5+CD4+ follicular helper T cells accumulate in resting human lymph nodes and have superior B cell helper activity.

    PubMed

    Havenith, Simone H C; Remmerswaal, Ester B M; Idu, Mirza M; van Donselaar-van der Pant, Karlijn A M I; van der Bom, Nelly; Bemelman, Fréderike J; van Leeuwen, Ester M M; ten Berge, Ineke J M; van Lier, René A W

    2014-03-01

    Although many relevant immune reactions are initiated in the lymph nodes, this compartment has not been systematically studied in humans. Analyses have been performed on immune cells derived from tonsils, but as this tissue is most often inflamed, generalization of these data is difficult. Here, we analyzed the phenotype and function of the human CD4(+) T-cell subsets and lineages in paired resting lymph node and peripheral blood samples. Naive, central memory cells and effector memory cells as well as Th1, Th2, Th17 and Treg cells were equally represented in both compartments. On the other hand, cytotoxic CD4(+) T cells were strikingly absent in the lymph nodes. CXCR5(+)CD4(+) T cells, representing putative follicular Th (Tfh) cells were over-represented in lymph nodes and expressed higher levels of Tfh markers than their peripheral blood counterparts. Compared with the circulating pool, lymph-node-derived CXCR5(+)CD4(+) T cells were superior in providing help to B cells. Thus, functionally competent Tfh cells accumulate in resting human lymph nodes, providing a swift induction of naive and memory antibody responses upon antigenic challenge.

  9. Apoptotic Effects of Antilymphocyte Globulins on Human Pro-inflammatory CD4+CD28− T-cells

    PubMed Central

    Duftner, Christina; Dejaco, Christian; Hengster, Paul; Bijuklic, Klaudija; Joannidis, Michael; Margreiter, Raimund; Schirmer, Michael

    2012-01-01

    Background Pro-inflammatory, cytotoxic CD4+CD28− T-cells with known defects in apoptosis have been investigated as markers of premature immuno-senescence in various immune-mediated diseases. In this study we evaluated the influence of polyclonal antilymphocyte globulins (ATG-Fresenius, ATG-F) on CD4+CD28− T-cells in vivo and in vitro. Principal Findings Surface and intracellular three colour fluorescence activated cell sorting analyses of peripheral blood mononuclear cells from 16 consecutive transplant recipients and short-term cell lines were performed. In vivo, peripheral levels of CD3+CD4+CD28− T-cells decreased from 3.7±7.1% before to 0±0% six hours after ATG-F application (P = 0.043) in 5 ATG-F treated but not in 11 control patients (2.9±2.9% vs. 3.9±3.0%). In vitro, ATG-F induced apoptosis even in CD4+CD28− T-cells, which was 4.3-times higher than in CD4+CD28+ T-cells. ATG-F evoked apoptosis was partially reversed by the broad-spectrum caspase inhibitor benzyloxycarbonyl (Cbz)-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD-fmk) and prednisolon-21-hydrogensuccinate. ATG-F triggered CD25 expression and production of pro-inflammatory cytokines, and induced down-regulation of the type 1 chemokine receptors CXCR-3, CCR-5, CX3CR-1 and the central memory adhesion molecule CD62L predominately in CD4+CD28− T-cells. Conclusion In summary, in vivo depletion of peripheral CD3+CD4+CD28− T-cells by ATG-F in transplant recipients was paralleled in vitro by ATG-F induced apoptosis. CD25 expression and chemokine receptor down-regulation in CD4+CD28− T-cells only partly explain the underlying mechanism. PMID:22479483

  10. 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

  11. 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.

  12. 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

  13. 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

  14. CD4 CTL, a Cytotoxic Subset of CD4+ T Cells, Their Differentiation and Function

    PubMed Central

    Takeuchi, Arata; Saito, Takashi

    2017-01-01

    CD4+ T cells with cytotoxic activity (CD4 CTL) have been observed in various immune responses. These cells are characterized by their ability to secrete granzyme B and perforin and to kill the target cells in an MHC class II-restricted fashion. Although CD4 CTLs were once thought to be an in vitro artifact associated with long-term culturing, they have since been identified in vivo and shown to play important roles in antiviral and antitumor immunity, as well as in inflammation. Functional characterization of CD4 CTL suggests their potential significance for therapeutic purposes. However, in order to develop effective CD4 CTL therapy it is necessary to understand the differentiation and generation of these cells. Although the mechanisms regulating development of various CD4+ Th subsets have been clarified in terms of the cytokine and transcription factor requirement, the CD4 CTL differentiation mechanism remains elusive. These cells are thought to be most closely related to Th1 cells secreting IFNγ and regulated by eomesodermin and/or T-bet transcription factors for their differentiation. However, our studies and those of others have identified CD4 CTLs within other CD4+ T cell subsets, including naïve T cells. We have identified class I-restricted T cell-associated molecule as a marker of CD4 CTL and, by using this marker, we detected a subset of naïve T cells that have the potential to differentiate into CD4 CTL. CD4 CTL develops at sites of infections as well as inflammation. In this review, we summarize recent findings about the generation of CD4 CTL and propose a model with several differentiation pathways. PMID:28280496

  15. 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

  16. Preserved immune functionality and high CMV-specific T-cell responses in HIV-infected individuals with poor CD4(+) T-cell immune recovery.

    PubMed

    Gómez-Mora, Elisabet; García, Elisabet; Urrea, Victor; Massanella, Marta; Puig, Jordi; Negredo, Eugenia; Clotet, Bonaventura; Blanco, Julià; Cabrera, Cecilia

    2017-09-15

    Poor CD4(+) T-cell recovery after cART has been associated with skewed T-cell maturation, inflammation and immunosenescence; however, T-cell functionality in those individuals has not been fully characterized. In the present study, we assessed T-cell function by assessing cytokine production after polyclonal, CMV and HIV stimulations of T-cells from ART-suppressed HIV-infected individuals with CD4(+) T-cell counts >350 cells/μL (immunoconcordants) or <350 cells/μL (immunodiscordants). A group of HIV-uninfected individuals were also included as controls. Since CMV co-infection significantly affected T-cell maturation and polyfunctionality, only CMV(+) individuals were analyzed. Despite their reduced and skewed CD4(+) T-cell compartment, immunodiscordant individuals showed preserved polyclonal and HIV-specific responses. However, CMV response in immunodiscordant participants was significantly different from immunoconcordant or HIV-seronegative individuals. In immunodiscordant subjects, the magnitude of IFN-γ(+) CD8(+) and IL-2(+) CD4(+) T-cells in response to CMV was higher and differently associated with the CD4(+) T-cell maturation profile., showing an increased frequency of naïve, central memory and EMRA CMV-specific CD4(+) T-cells. In conclusion, CD4(+) and CD8(+) T-cell polyfunctionality was not reduced in immunodiscordant individuals, although heightened CMV-specific immune responses, likely related to subclinical CMV reactivations, may be contributing to the skewed T-cell maturation and the higher risk of clinical progression observed in those individuals.

  17. Cytomegalovirus (CMV) Epitope-Specific CD4(+) T Cells Are Inflated in HIV(+) CMV(+) Subjects.

    PubMed

    Abana, Chike O; Pilkinton, Mark A; Gaudieri, Silvana; Chopra, Abha; McDonnell, Wyatt J; Wanjalla, Celestine; Barnett, Louise; Gangula, Rama; Hager, Cindy; Jung, Dae K; Engelhardt, Brian G; Jagasia, Madan H; Klenerman, Paul; Phillips, Elizabeth J; Koelle, David M; Kalams, Spyros A; Mallal, Simon A

    2017-10-02

    Select CMV epitopes drive life-long CD8(+) T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4(+) T cells specific for human CMV (HCMV) are elevated in HIV(+) HCMV(+) subjects. To determine whether HCMV epitope-specific CD4(+) T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4(+) T cells in coinfected HLA-DR7(+) long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4(+) T cells were inflated among these HIV(+) subjects compared with those from an HIV(-) HCMV(+) HLA-DR7(+) cohort or with HLA-DR7-restricted CD4(+) T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4(+) T cells consisted of effector memory or effector memory-RA(+) subsets with restricted TCRβ usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX3CR1, CD38, or HLA-DR but less often coexpressed CD38(+) and HLA-DR(+) The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4(+) T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease. Copyright © 2017 by The American Association of Immunologists, Inc.

  18. Yellow fever vaccination elicits broad functional CD4+ T cell responses that recognize structural and nonstructural proteins.

    PubMed

    James, Eddie A; LaFond, Rebecca E; Gates, Theresa J; Mai, Duy T; Malhotra, Uma; Kwok, William W

    2013-12-01

    Yellow fever virus (YFV) can induce acute, life-threatening disease that is a significant health burden in areas where yellow fever is endemic, but it is preventable through vaccination. The live attenuated 17D YFV strain induces responses characterized by neutralizing antibodies and strong T cell responses. This vaccine provides an excellent model for studying human immunity. While several studies have characterized YFV-specific antibody and CD8(+) T cell responses, less is known about YFV-specific CD4(+) T cells. Here we characterize the epitope specificity, functional attributes, and dynamics of YFV-specific T cell responses in vaccinated subjects by investigating peripheral blood mononuclear cells by using HLA-DR tetramers. A total of 112 epitopes restricted by seven common HLA-DRB1 alleles were identified. Epitopes were present within all YFV proteins, but the capsid, envelope, NS2a, and NS3 proteins had the highest epitope density. Antibody blocking demonstrated that the majority of YFV-specific T cells were HLA-DR restricted. Therefore, CD4(+) T cell responses could be effectively characterized with HLA-DR tetramers. Ex vivo tetramer analysis revealed that YFV-specific T cells persisted at frequencies ranging from 0 to 100 cells per million that are detectable years after vaccination. Longitudinal analysis indicated that YFV-specific CD4(+) T cells reached peak frequencies, often exceeding 250 cells per million, approximately 2 weeks after vaccination. As frequencies subsequently declined, YFV-specific cells regained CCR7 expression, indicating a shift from effector to central memory. Cells were typically CXCR3 positive, suggesting Th1 polarization, and produced gamma interferon and other cytokines after reactivation in vitro. Therefore, YFV elicits robust early effector CD4(+) T cell responses that contract, forming a detectable memory population.

  19. HIV persists in CCR6+CD4+ T cells from colon and blood during antiretroviral therapy

    PubMed Central

    Gosselin, Annie; Wiche Salinas, Tomas Raul; Planas, Delphine; Wacleche, Vanessa S.; Zhang, Yuwei; Fromentin, Rémi; Chomont, Nicolas; Cohen, Éric A.; Shacklett, Barbara; Mehraj, Vikram; Ghali, Maged P.; Routy, Jean-Pierre; Ancuta, Petronela

    2017-01-01

    Objectives: The objective of this article is to investigate the contribution of colon and blood CD4+ T-cell subsets expressing the chemokine receptor CCR6 to HIV persistence during antiretroviral therapy. Design: Matched sigmoid biopsies and blood samples (n = 13) as well as leukapheresis (n = 20) were collected from chronically HIV-infected individuals receiving antiretroviral therapy. Subsets of CD4+ T cells with distinct differentiation/polarization profiles were identified using surface markers as follows: memory (TM, CD45RA−), central memory (TCM; CD45RA−CCR7+), effector (TEM/TM; CD45RA−CCR7−), Th17 (CCR6+CCR4+), Th1Th17 (CCR6+CXCR3+), Th1 (CCR6−CXCR3+), and Th2 (CCR6−CCR4+). Methods: We used polychromatic flow cytometry for cell sorting, nested real-time PCR for HIV DNA quantification, ELISA and flow cytometry for HIV p24 quantification. HIV reactivation was induced by TCR triggering in the presence/absence of all-trans retinoic acid. Results: Compared with blood, the frequency of CCR6+ TM was higher in the colon. In both colon and blood compartments, CCR6+ TM were significantly enriched in HIV DNA when compared with their CCR6− counterparts (n = 13). In blood, integrated HIV DNA levels were significantly enriched in CCR6+ versus CCR6− TCM of four of five individuals and CCR6+ versus CCR6− TEM of three of five individuals. Among blood TCM, Th17 and Th1Th17 contributed the most to the pool of cells harboring integrated HIV DNA despite their reduced frequency compared with Th2, which were infected the least. HIV reactivation was induced by TCR triggering and/or retinoic acid exposure at higher levels in CCR6+ versus CCR6− TM, TCM, and TEM. Conclusion: CCR6 is a marker for colon and blood CD4+ T cells enriched for replication-competent HIV DNA. Novel eradication strategies should target HIV persistence in CCR6+CD4+ T cells from various anatomic sites. PMID:27835617

  20. TCRαβ+/CD4+ Large Granular Lymphocytosis

    PubMed Central

    Lima, Margarida; Almeida, Julia; dos Anjos Teixeira, Maria; Alguero, Maria del Carmen; Santos, Ana Helena; Balanzategui, Ana; Queirós, Maria Luís; Bárcena, Paloma; Izarra, Antonio; Fonseca, Sónia; Bueno, Clara; Justiça, Benvindo; Gonzalez, Marcos; San Miguel, Jesús F.; Orfao, Alberto

    2003-01-01

    Large granular lymphocyte (LGL) leukemia is a well-recognized disease of mature T-CD8+ or less frequently natural killer cells; in contrast, monoclonal expansions of CD4+ T-LGL have only been sporadically reported in the literature. In the present article we have explored throughout a period of 56 months the incidence of monoclonal expansions of CD4+ T-LGL in a population of 2.2 million inhabitants and analyzed the immunophenotype and the pattern of cytokine production of clonal CD4+ T cells of a series of 34 consecutive cases. Like CD8+ T-LGL leukemias, CD4+ T-LGL leukemia patients have an indolent disease; however, in contrast to CD8+ T-LGL leukemias, they do not show cytopenias and autoimmune phenomena and they frequently have associated neoplasias, which is usually determining the clinical course of the disease. Monoclonal CD4+ T-LGLshowed expression of TCRαβ, variable levels of CD8 (CD8−/+dim) and a homogeneous typical cytotoxic (granzyme B+, CD56+, CD57+, CD11b+/−) and activated/memory T cell (CD2+bright, CD7−/+dim, CD11a+bright, CD28−, CD62L− HLA-DR+) immunophenotype. In addition, they exhibited a Th1 pattern of cytokine production [interferon-γ++, tumor necrosis factor-α++, interleukin (IL-2)−/+, IL-4−, IL-10−, IL-13−]. Phenotypic analysis of the TCR-Vβ repertoire revealed large monoclonal TCR-Vβ expansions; only a restricted number of TCR-Vβ families were represented in the 34 cases analyzed. These findings suggest that monoclonal TCRαβ+/CD4+/NKa+/CD8−/+dim T-LGL represent a subgroup of monoclonal LGL lymphoproliferative disorders different from both CD8+ T-LGL and natural killer cell-type LGL leukemias. Longer follow-up periods are necessary to determine the exact significance of this clonal disorder. PMID:12875995

  1. 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

  2. Cd4As2Br3

    PubMed Central

    Kars, Mohammed; Roisnel, Thierry; Dorcet, Vincent; Rebbah, Allaoua; Otero-Diáz, L. Carlos

    2014-01-01

    Single crystals of Cd4As2Br3 (tetra­cadmium biarsenide tri­bromide) were grown by a chemical transport reaction. The structure is isotypic with the members of the cadmium and mercury pnictidohalides family with general formula M 4 A 2 X 3 (M = Cd, Hg; A = P, As, Sb; X = Cl, Br, I) and contains two independent As atoms on special positions with site symmetry -3 and two independent Cd atoms, of which one is on a special position with site symmetry -3. The Cd4As2Br3 structure consists of AsCd4 tetra­hedra sharing vertices with isolated As2Cd6 octa­hedra that contain As–As dumbbells in the centre of the octahedron. The Br atoms are located in the voids of this three-dimensional arrangement and bridge the different polyhedra through Cd⋯Br contacts. PMID:24764933

  3. 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

  4. Immune Reconstitution but Persistent Activation After 48 Weeks of Antiretroviral Therapy in Youth With Pre-Therapy CD4 >350 in ATN 061.

    PubMed

    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

    2015-05-01

    Measures of immune outcomes in youth who initiate combination antiretroviral therapy (cART) early in HIV infection are limited. 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 cells/mm. All subjects had optimal viral suppression from weeks 24 through 48. 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. Significant increases over 48 weeks were noted in all CD4 populations, including total, naive, central memory (CM), and effector memory RO (EM RO) and effector memory RA (EM RA), whereas numbers of CM and EM RO CD8 cells declined significantly. By week 48, CD4 naive cells were similar to controls, whereas 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. 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.

  5. Molecular signatures distinguish human central memory from effector memory CD8 T cell subsets.

    PubMed

    Willinger, Tim; Freeman, Tom; Hasegawa, Hitoshi; McMichael, Andrew J; Callan, Margaret F C

    2005-11-01

    Memory T cells are heterogeneous in terms of their phenotype and functional properties. We investigated the molecular profiles of human CD8 naive central memory (T(CM)), effector memory (T(EM)), and effector memory RA (T(EMRA)) T cells using gene expression microarrays and phospho-protein-specific intracellular flow cytometry. We demonstrate that T(CM) have a gene expression and cytokine signaling signature that lies between that of naive and T(EM) or T(EMRA) cells, whereas T(EM) and T(EMRA) are closely related. Our data define the molecular basis for the different functional properties of central and effector memory subsets. We show that T(EM) and T(EMRA) cells strongly express genes with known importance in CD8 T cell effector function. In contrast, T(CM) are characterized by high basal and cytokine-induced STAT5 phosphorylation, reflecting their capacity for self-renewal. Altogether, our results distinguish T(CM) and T(EM)/T(EMRA) at the molecular level and are consistent with the concept that T(CM) represent memory stem cells.

  6. 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

  7. 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

  8. CD137 is a Useful Marker for Identifying CD4(+) T Cell Responses to Mycobacterium tuberculosis.

    PubMed

    Yan, Z-H; Zheng, X-F; Yi, L; Wang, J; Wang, X-J; Wei, P-J; Jia, H-Y; Zhou, L-J; Zhao, Y-L; Zhang, H-T

    2017-05-01

    Upregulation of CD137 on recently activated CD8(+) T cells has been used to identify rare viral and tumour antigen-specific T cells from the peripheral blood. We aimed to evaluate the accuracy of CD137 for identifying Mycobacterium tuberculosis (Mtb)-reactive CD4(+) T cells in the peripheral blood of infected individuals by flow cytometry and to investigate the characteristics of these CD137(+) CD4(+) T cells. We initially enrolled 31 active tuberculosis (TB) patients, 31 individuals with latent TB infection (LTBI) and 25 healthy donors. The intracellular CD137 and interferon-γ (IFN-γ) production by CD4(+) T cells was simultaneously detected under unstimulated and CFP10-stimulated (culture filtrate protein 10, a Mtb-specific antigen) conditions. In unstimulated CD4(+) T cells, we found that the CD137 expression in the TB group was significantly higher than that in the LTBI group. Stimulation with CFP10 largely increased the CD4(+) T cell CD137 expression in both the TB and LTBI groups. After CFP10 stimulation, the frequency of CD137(+) CD4(+) T cells was higher than that of IFN-γ(+) CD4(+) T cells in both the TB and LTBI groups. Most of the CFP10-activated IFN-γ-secreting cells were CD137-positive, but only a small fraction of the CD137-positive cells expressed IFN-γ. An additional 20 patients with TB were enrolled to characterize the CD45RO(+) CCR7(+) , CD45RO(+) CCR7(-) and CD45RO(-) subsets in the CD137(+) CD4(+) T cell populations. The Mtb-specific CD137(+) CD4(+) T cells were mainly identified as having an effector memory phenotype. In conclusion, CD137 is a useful marker that can be used for identifying Mtb-reactive CD4(+) T cells by flow cytometry. © 2017 The Foundation for the Scandinavian Journal of Immunology.

  9. Low-dose IL-2 selectively activates subsets of CD4+ Tregs and NK cells

    PubMed Central

    Hirakawa, Masahiro; Matos, Tiago; Liu, Hongye; Koreth, John; Kim, Haesook T.; Paul, Nicole E.; Murase, Kazuyuki; Whangbo, Jennifer; Alho, Ana C.; Nikiforow, Sarah; Cutler, Corey; Ho, Vincent T.; Armand, Philippe; Alyea, Edwin P.; Antin, Joseph H.; Blazar, Bruce R.; Lacerda, Joao F.; Soiffer, Robert J.

    2016-01-01

    CD4+ regulatory T cells (CD4Tregs) play a critical role in the maintenance of immune tolerance and prevention of chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. IL-2 supports the proliferation and survival of CD4Tregs and previous studies have demonstrated that IL-2 induces selective expansion of CD4Tregs and improves clinical manifestations of chronic GVHD. However, mechanisms for selective activation of CD4Tregs and the effects of low-dose IL-2 on other immune cells are not well understood. Using mass cytometry, we demonstrate that low concentrations of IL-2 selectively induce STAT5 phosphorylation in Helios+ CD4Tregs and CD56brightCD16– NK cells in vitro. Preferential activation and expansion of Helios+ CD4Tregs and CD56brightCD16– NK cells was also demonstrated in patients with chronic GVHD receiving low-dose IL-2. With prolonged IL-2 treatment for 48 weeks, phenotypic changes were also observed in Helios– CD4Tregs. The effects of low-dose IL-2 therapy on conventional CD4+ T cells and CD8+ T cells were limited to increased expression of PD-1 on effector memory T cells. These studies reveal the selective effects of low-dose IL-2 therapy on Helios+ CD4Tregs and CD56bright NK cells that constitutively express high-affinity IL-2 receptors as well as the indirect effects of prolonged exposure to low concentrations of IL-2 in vivo. PMID:27812545

  10. Modulation of CD4 by suramin.

    PubMed Central

    Allen, P D; Johnston, D H; Macey, M G; Williams, N S; Newland, A C

    1993-01-01

    Suramin is a polysulphonated compound which can selectively bind to, and inhibit the activity of, a wide range of growth factors. There has been renewed interest recently in suramin as an anti-cancer agent and therefore we have studied its effects on lymphocyte subset populations and recombinant human IL-2 (rhIL-2) activation on lymphocytes in vitro. In the presence of rhIL-2 (1000 U/ml), suramin (200 micrograms/ml) caused a decrease in percentage of cells expressing the predominantly T cell antigen CD3; no change in percentage of cells expressing the T suppressor/cytotoxic subset antigen, CD8; a small rise in those expressing the natural killer cell antigen, CD56; and a large significant fall in those expressing the T helper subset antigen CD4 (48.51% versus 27.97%; P < 0.001). CD4 modulation by suramin was also found on the CD4+ cell lines CEM and MOLT-4. The effect of suramin on rhIL-2-induced activation antigen expression remains equivocal, since a small rise in CD25 expression and small falls in CD71 and HLA-Dr expression were recorded. The modulatory effect of suramin on CD4 expression was not reversible over a 96-h culture period in its continued presence. However, on removal of suramin by extensive washing, recovery of CD4 expression was detected within 24 h. Suramin-induced modulation, but not PMA-induced modulation, could be partially inhibited by preincubation with tyrphostin (12 microM), a tyrosine kinase inhibitor. PMID:8419075

  11. Selection and function of CD4+ T lymphocytes in transgenic mice expressing mutant MHC class II molecules deficient in their interaction with CD4.

    PubMed

    Gilfillan, S; Shen, X; König, R

    1998-12-15

    Interactions of the T cell coreceptors, CD4 and CD8, with MHC molecules participate in regulating thymocyte development and T lymphocyte activation and differentiation to memory T cells. However, the exact roles of these interactions in normal T cell development and function remain unclear. CD4 interacts with class II MHC7 molecules via several noncontiguous regions in both the class II MHC alpha- and beta-chains. We have introduced a double mutation that disrupts interaction with CD4 into the I-A(beta)k gene and used this construct to generate transgenic mice expressing only mutant class II MHC. Although CD4+ thymocytes matured to the single-positive stage in these mice, their frequency was reduced by threefold compared with that of wild-type transgenics. Positive selection of CD4+ T cells in the mutant transgenic mice may have been mediated by TCRs with a higher than usual affinity for class II MHC/Ag complexes. In A(beta)k mutant transgenics, peripheral CD4+ lymphocytes promoted B cell differentiation to plasma cells. These CD4+ T cells also secreted IFN-gamma in response to various stimuli (e.g., protein Ag, bacterial superantigen, and alloantigen), but were deficient in IL-2 secretion. Interactions between CD4 and class II MHC molecules appeared to regulate lymphokine production, with a strong bias toward IFN-gamma and against IL-2 in the absence of these interactions. Our results have implications for the manipulation of T cell-dependent immune responses.

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

    PubMed

    Sommermeyer, D; Hudecek, M; Kosasih, P L; Gogishvili, T; Maloney, D G; Turtle, C J; Riddell, S R

    2016-02-01

    Adoptive T-cell therapy with gene-modified T cells expressing a tumor-reactive T-cell receptor 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 comprising random compositions of CD4(+) and CD8(+) naive and memory T cells, meaning that each patient received a different therapeutic agent. This variation may 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(+) naive, 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.

  13. ICOS-ligand expression on plasmacytoid dendritic cells supports breast cancer progression by promoting the accumulation of immunosuppressive CD4+ T cells.

    PubMed

    Faget, Julien; Bendriss-Vermare, Nathalie; Gobert, Michael; Durand, Isabelle; Olive, Daniel; Biota, Cathy; Bachelot, Thomas; Treilleux, Isabelle; Goddard-Leon, Sophie; Lavergne, Emilie; Chabaud, Sylvie; Blay, Jean Yves; Caux, Christophe; Ménétrier-Caux, Christine

    2012-12-01

    Human breast tumors are infiltrated by memory CD4(+) T cells along with increased numbers of regulatory T cells (Treg) and plasmacytoid dendritic cells (pDC) that facilitate immune escape and correlate with poor prognosis. Here, we report that inducible costimulatory molecule (ICOS), a T cell costimulatory molecule of the CTLA4/PD1/CD28 family, is expressed mostly by tumor-associated Treg in primary breast tumors. A large proportion of these ICOS(+) Treg were Ki67(+) and this evident proliferative expansion was found to rely on interactions with tumor-associated pDC. Indeed, tumor-associated Treg highly expanded in presence of pDC but failed to proliferate under CD3/CD28 signal. In vitro experiments revealed that the addition of a neutralizing anti-ICOS antibody blocked pDC-induced Treg expansion and interleukin-10 secretion by memory CD4(+) T cells, establishing a pivotal role for ICOS in this process. Supporting these findings, the presence of ICOS(+) cells in clinical specimens of breast cancer correlated with a poor prognosis. Together, our results highlight an important relationship between Treg and pDC in breast tumors, and show that ICOS/ICOS-L interaction is a central event in immunosuppression of tumor-associated memory CD4(+) T cells. These findings strongly rationalize antibody-mediated ICOS blockade as a powerful clinical strategy to correct immune escape and promote therapeutic responses in breast cancer.

  14. 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

  15. Pathological Role of Anti-CD4 Antibodies in HIV-Infected Immunologic Nonresponders Receiving Virus-Suppressive Antiretroviral Therapy.

    PubMed

    Luo, Zhenwu; Li, Zhen; Martin, Lisa; Wan, Zhuang; Meissner, Eric G; Espinosa, Enrique; Wu, Hao; Yu, Xiaocong; Fu, Pingfu; Julia Westerink, Maria Anna; Kilby, J Michael; Wu, Jennifer; Huang, Lei; Heath, Sonya L; Li, Zihai; Jiang, Wei

    2017-07-01

    Increased mortality and morbidity occur among human immunodeficiency virus (HIV)-infected patients in whom CD4+ T-cell counts do not increase despite viral suppression with antiretroviral therapy (ART). Here we identified an underlying mechanism. Significantly elevated plasma levels of anti-CD4 immunoglobulin G (IgG) were found in HIV-positive immunologic nonresponders (ie, HIV-positive individuals with CD4+ T-cell counts of ≤350 cells/μL), compared with levels in HIV-positive immunologic responders (ie, HIV-positive individuals with CD4+ T-cell counts of ≥500 cells/μL) and healthy controls. Higher plasma level of anti-CD4 IgG correlated with blunted CD4+ T-cell recovery. Furthermore, purified anti-CD4 IgG from HIV-positive immunologic nonresponders induced natural killer (NK) cell-dependent CD4+ T-cell cytolysis and apoptosis through antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro. We also found that anti-CD4 IgG-mediated ADCC exerts greater apoptosis of naive CD4+ T cells relative to memory CD4+ T cells. Consistently, increased frequencies of CD107a+ NK cells and profound decreases of naive CD4+ T cells were observed in immunologic nonresponders as compared to responders and healthy controls ex vivo. These data indicate that autoreactive anti-CD4 IgG may play an important role in blunted CD4+ T-cell reconstitution despite effective ART. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  16. Myeloid Dendritic Cells Induce HIV-1 Latency in Non-proliferating CD4+ T Cells

    PubMed Central

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

    2013-01-01

    Latently infected resting CD4+ T cells are a major barrier to HIV cure. Understanding how latency is established, maintained and reversed is critical to identifying novel strategies to eliminate latently infected cells. We demonstrate here that co-culture of resting CD4+ T cells and syngeneic myeloid dendritic cells (mDC) can dramatically increase the frequency of HIV DNA integration and latent HIV infection in non-proliferating memory, but not naïve, CD4+ T cells. Latency was eliminated when cell-to-cell contact was prevented in the mDC-T cell co-cultures and reduced when clustering was minimised in the mDC-T cell co-cultures. Supernatants from infected mDC-T cell co-cultures did not facilitate the establishment of latency, consistent with cell-cell contact and not a soluble factor being critical for mediating latent infection of resting CD4+ T cells. Gene expression in non-proliferating CD4+ T cells, enriched for latent infection, showed significant changes in the expression of genes involved in cellular activation and interferon regulated pathways, including the down-regulation of genes controlling both NF-κB and cell cycle. We conclude that mDC play a key role in the establishment of HIV latency in resting memory CD4+ T cells, which is predominantly mediated through signalling during DC-T cell contact. PMID:24339779

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

    PubMed

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

    2013-01-01

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

  18. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. 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.

  20. 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

  1. Apoptotic depletion of CD4+ T cells in idiopathic CD4+ T lymphocytopenia.

    PubMed Central

    Laurence, J; Mitra, D; Steiner, M; Lynch, D H; Siegal, F P; Staiano-Coico, L

    1996-01-01

    Progressive loss of CD4+ T lymphocytes, accompanied by opportunistic infections characteristic of the acquired immune deficiency syndrome, ahs been reported in the absence of any known etiology. The pathogenesis of this syndrome, a subset of idiopathic CD4+ T lymphocytopenia (ICL), is uncertain. We report that CD4+ T cells from seven of eight ICL patients underwent accelerated programmed cell death, a process facilitated by T cell receptor cross-linking. Apoptosis was associated with enhanced expression of Fas and Fas ligand in unstimulated cell populations, and partially inhibited by soluble anti-Fas mAb. In addition, apoptosis was suppressed by aurintricarboxylic acid, an inhibitor of calcium-dependent endonucleases and proteases, in cells from four of seven patients, The in vivo significance of these findings was supported by three factors: the absence of accelerated apoptosis in persons with stable, physiologic CD4 lymphopenia without clinical immune deficiency; detection of serum antihistone H2B autoantibodies, one consequence of DNA fragmentation, in some patients; and its selectivity, with apoptosis limited to the CD4 population in some, and occurring among CD8+ T cells predominantly in those individuals with marked depletion of both CD4+ T lymphocytes linked to clinical immune suppression have evidence for accelerated T cell apoptosis in vitro that may be pathophysiologic and amenable to therapy with apoptosis inhibitors. PMID:8609222

  2. Increased intratumoral IL-22-producing CD4(+) T cells and Th22 cells correlate with gastric cancer progression and predict poor patient survival.

    PubMed

    Zhuang, Yuan; Peng, Liu-Sheng; Zhao, Yong-Liang; Shi, Yun; Mao, Xu-Hu; Guo, Gang; Chen, Weisan; Liu, Xiao-Fei; Zhang, Jin-Yu; Liu, Tao; Luo, Ping; Yu, Pei-Wu; Zou, Quan-Ming

    2012-11-01

    IL-22-producing CD4(+) T cells (IL-22(+)CD4(+) T cells) and Th22 cells (IL-22(+)IL-17(-)IFN-γ(-)CD4(+) T cells) represent newly discovered T-cell subsets, but their nature, regulation, and clinical relevance in gastric cancer (GC) are presently unknown. In our study, the frequency of IL-22(+)CD4(+) T cells in tumor tissues from 76 GC patients was significantly higher than that in tumor-draining lymph nodes, non-tumor, and peritumoral tissues. Most intratumoral IL-22(+)CD4(+) T cells co-expressed IL-17 and IFN-γ and showed a memory phenotype. Locally enriched IL-22(+)CD4(+) T cells positively correlated with increased CD14(+) monocytes and IL-6 and IL-23 detection ex vivo, and in vitro IL-6 and IL-23 induced the polarization of IL-22(+)CD4(+) T cells in a dose-dependent manner and the polarized IL-22(+)CD4(+) T cells co-expressed of IL-17 and IFN-γ. Moreover, IL-22(+)CD4(+) T-cell subsets (IL-22(+)IL-17(+)CD4(+), IL-22(+)IL-17(-)CD4(+), IL-22(+)IFN-γ(+)CD4(+), IL-22(+)IFN-γ(-)CD4(+), and IL-22(+)IL-17(+)IFN-γ(+)CD4(+) T cells), and Th22 cells were also increased in tumors. Furthermore, higher intratumoral IL-22(+)CD4(+) T-cell percentage and Th22-cell percentage were found in patients with tumor-node-metastasis stage advanced and predicted reduced overall survival. In conclusion, our data indicate that IL-22(+)CD4(+) T cells and Th22 cells are likely important in establishing the tumor microenvironment for GC; increased intratumoral IL-22(+)CD4(+) T cells and Th22 cells are associated with tumor progression and predict poorer patient survival, suggesting that tumor-infiltrating IL-22(+)CD4(+) T cells and Th22 cells may be suitable therapeutic targets in patients with GC.

  3. CD4-Induced Antibodies Promote Association of the HIV-1 Envelope Glycoprotein with CD4-Binding Site Antibodies

    PubMed Central

    Fellinger, Christoph H.; Prasad, Neha R.; Zhou, Amber S.; Kondur, Hema R.; Joshi, Vinita R.; Quinlan, Brian D.; Farzan, Michael

    2016-01-01

    ABSTRACT The HIV-1 envelope glycoprotein (Env) is a trimer of gp120/gp41 heterodimers that mediates viral entry. Env binds cellular CD4, an association which stabilizes a conformation favorable to its subsequent association with a coreceptor, typically CCR5 or CXCR4. The CD4- and coreceptor-binding sites serve as epitopes for two classes of HIV-1-neutralizing antibodies: CD4-binding site (CD4bs) and CD4-induced (CD4i) antibodies, respectively. Here we observed that, at a fixed total concentration, mixtures of the CD4i antibodies (E51 or 412d) and the CD4bs antibody VRC01 neutralized the HIV-1 isolates 89.6, ADA, SG3, and SA32 more efficiently than either antibody alone. We found that E51, and to a lesser extent 412d and 17b, promoted association of four CD4bs antibodies to the Env trimer but not to monomeric gp120. We further demonstrated that the binding of the sulfotyrosine-binding pocket by CCR5mim2-Ig was sufficient for promoting CD4bs antibody binding to Env. Interestingly, the relationship is not reciprocal: CD4bs antibodies were not as efficient as CD4-Ig at promoting E51 or 412d binding to Env trimer. Consistent with these observations, CD4-Ig, but none of the CD4bs antibodies tested, substantially increased HIV-1 infection of a CD4-negative, CCR5-positive cell line. We conclude that the ability of CD4i antibodies to promote VRC01 association with Env trimers accounts for the increase potency of VRC01 and CD4i antibody mixtures. Our data further suggest that potent CD4bs antibodies avoid inducing Env conformations that bind CD4i antibodies or CCR5. IMPORTANCE Potent HIV-1-neutralizing antibodies can prevent viral transmission and suppress an ongoing infection. Here we show that CD4-induced (CD4i) antibodies, which recognize the conserved coreceptor-binding site of the HIV-1 envelope glycoprotein (Env), can increase the association of Env with potent broadly neutralizing antibodies that recognize the CD4-binding site (CD4bs antibodies). We further show that

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

    PubMed Central

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

    2016-01-01

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

  5. In situ depletion of CD4+ T cells in human skin by Zanolimumab.

    PubMed

    Villadsen, L S; Skov, L; Dam, T N; Dagnaes-Hansen, F; Rygaard, J; Schuurman, J; Parren, P W H I; van de Winkel, J G J; Baadsgaard, O

    2007-02-01

    CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis xenograft mouse model. Zanolimumab treatment was shown to induce a significant reduction in the numbers of inflammatory mononuclear cells in upper dermis. This reduction in inflammatory mononuclear cells in situ was primarily due to a significant reduction in the numbers of skin-infiltrating CD4(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody is currently in a phase III clinical trial for CTCL, a disease for which there is no safe and effective treatment available today.

  6. 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

  7. 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

  8. Blockade of the Kv1.3 K+ Channel Enhances BCG Vaccine Efficacy by Expanding Central Memory T Lymphocytes.

    PubMed

    Singh, Dhiraj Kumar; Dwivedi, Ved Prakash; Ranganathan, Anand; Bishai, William R; Van Kaer, Luc; Das, Gobardhan

    2016-11-01

    Tuberculosis is the oldest known infectious disease, yet there is no effective vaccine against adult pulmonary tuberculosis. Emerging evidence indicates that T-helper 1 and T-helper 17 cells play important roles in host protection against tuberculosis. However, tuberculosis vaccine efficacy in mice is critically dependent on the balance between antigen-specific central memory T (Tcm) and effector memory T (Tem) cells. Specifically, a high Tcm/Tem cell ratio is essential for optimal vaccine efficacy. Here, we show that inhibition of Kv1.3, a potassium channel preferentially expressed by Tem cells, by Clofazimine selectively expands Tcm cells during BCG vaccination. Furthermore, mice that received clofazimine after BCG vaccination exhibited significantly enhanced resistance against tuberculosis. This superior activity against tuberculosis could be adoptively transferred to naive, syngeneic mice by CD4(+) T cells. Therefore, clofazimine enhances Tcm cell expansion, which in turn provides improved vaccine efficacy. Thus, Kv1.3 blockade is a promising approach for enhancing the efficacy of the BCG vaccine in humans. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  9. Foxp3-dependent transformation of human primary CD4+ T lymphocytes by the retroviral protein tax.

    PubMed

    Chen, Li; Liu, Dan; Zhang, Yang; Zhang, Huan; Cheng, Hua

    2015-10-23

    The retroviral Tax proteins of human T cell leukemia virus type 1 and 2 (HTLV-1 and -2) are highly homologous viral transactivators. Both viral proteins can immortalize human primary CD4+ memory T cells, but when expressed alone they rarely transform T cells. In the present study, we found that the Tax proteins displayed a differential ability to immortalize human CD4+Foxp3+ T cells with characteristic expression of CTLA-4 and GITR. Because epidermal growth factor receptor (EGFR) was reportedly expressed and activated in a subset of CD4+Foxp3+ T cells, we introduced an activated EGFR into Tax-immortalized CD4+Foxp3+ T cells. We observed that these modified cells were grown independently of exogenous IL-2, correlating with a T cell transformation phenotype. In Tax-immortalized CD4+Foxp3- T cells, ectopic expression of Foxp3 was a prerequisite for Tax transformation of T cells. Accordingly, treatment of the transformed T cells with erlotinib, a selective inhibitor of EGFR, induced degradation of EGFR in lysosome, consequently causing T cell growth inhibition. Further, we identified autophagy as a crucial cellular survival pathway for the transformed T cells. Silencing key autophagy molecules including Beclin1, Atg5 and PI3 kinase class III (PI3KC3) resulted in drastic impairment of T cell growth. Our data, therefore, unveiled a previously unidentified role of Foxp3 in T cell transformation, providing a molecular basis for HTLV-1 transformation of CD4+Foxp3+ T cells.

  10. 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

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

    PubMed

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

    2013-07-01

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

  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. Canine peripheral blood CD4(+)CD8(+) double-positive Tcell subpopulations exhibit distinct Tcell phenotypes and effector functions.

    PubMed

    Rothe, Kathrin; Bismarck, Doris; Büttner, Mathias; Alber, Gottfried; von Buttlar, Heiner

    2017-03-01

    Canine peripheral blood CD4(+)CD8α(+) double-positive (dp) Tcells represent a small population of T lymphocytes that are not only derived from single-positive (sp) CD4(+) but also from CD8(+) Tcells. Dp Tcells can be subdivided in three different subpopulations according to their expression levels of CD4 and CD8α, i.e. the CD4(dim)CD8α(bright), CD4(bright)CD8α(bright), and the CD4(bright)CD8α(dim) subsets. Previously we could show that total canine peripheral CD4(+)CD8α(+) dp Tcells have features of activated Tcells. Here we demonstrate that the individual dp Tcell subsets distinctly differ in their activation status and phenotype. Thus, among the dp Tcell subsets the CD4(dim)CD8α(bright) subpopulation has the lowest and the CD4(bright)CD8α(bright) subset the highest frequency of CD25(+) cells pointing to the CD4(bright)CD8α(bright) subset with the highest activation status. Consistent with that, analysis of CD44 vs. CD62L expression demonstrates that the CD4(bright)CD8α(bright) subset contains the highest frequencies of effector-memory Tcells (TEM). Upon in vitro stimulation, the CD4(bright)CD8α(bright) and CD4(dim)CD8α(bright) dp Tcell subsets show the highest frequencies of IFN-γ producing cells. Expression of granzyme B was found exclusively in the CD4(dim)CD8α(bright) dp Tcell subset indicating cytotoxic potential of this dp Tcell subset. Furthermore, T-bet expression was restricted to the CD4(dim)CD8α(bright) subset, while Foxp3(+) regulatory Tcells were detected in the CD4(bright)CD8α(dim) dp Tcell subset. In conclusion, canine dp Tcells are phenotypically and functionally heterogeneous consistent with the diverse characteristics of their single-positive CD4(+) and CD8(+) Tcell progenitors. The data provide the basis for future in vivo studies to elucidate the role of individual dp Tcell subsets in host defense and/or immune pathological diseases of dogs.

  14. Interaction between the cytoplasmic domains of HIV-1 Vpu and CD4: role of Vpu residues involved in CD4 interaction and in vitro CD4 degradation.

    PubMed

    Margottin, F; Benichou, S; Durand, H; Richard, V; Liu, L X; Gomas, E; Benarous, R

    1996-09-15

    The Vpu and CD4 cytoplasmic domains were found, by using a two-hybrid assay in yeast, to interact in the absence of their membrane anchor domains. Studies on several deletion and point mutants revealed that the overall structure of the Vpu cytoplasmic domain is required for this interaction. The Vpu amino acid residues involved in the interaction with CD4 were identified. Deletion of the C-terminal residues of Vpu, required for CD4 degradation, as well as the double mutation on the casein kinase II phosphorylation sites S52N-S56N, also involved in CD4 degradation, resulted in the loss of interaction with CD4 and in the inability to induce CD4 degradation. These results suggest that the ability of Vpu to mediate the degradation of CD4 is linked to its capacity to physically interact with CD4. However, additional mutagenesis on the S52 site revealed that the interaction between the cytoplasmic domains of Vpu and CD4 is not sufficient for in vitro Vpu-mediated CD4 degradation.

  15. Phenotypic and Functional Profiling of CD4 T Cell Compartment in Distinct Populations of Healthy Adults with Different Antigenic Exposure

    PubMed Central

    Roetynck, Sophie; Olotu, Ally; Simam, Joan; Marsh, Kevin; Stockinger, Brigitta; Urban, Britta; Langhorne, Jean

    2013-01-01

    Background Multiparameter flow cytometry has revealed extensive phenotypic and functional heterogeneity of CD4 T cell responses in mice and humans, emphasizing the importance of assessing multiple aspects of the immune response in correlation with infection or vaccination outcome. The aim of this study was to establish and validate reliable and feasible flow cytometry assays, which will allow us to characterize CD4 T cell population in humans in field studies more fully. Methodology/Principal Findings We developed polychromatic flow cytometry antibody panels for immunophenotyping the major CD4 T cell subsets as well as broadly characterizing the functional profiles of the CD4 T cells in peripheral blood. We then validated these assays by conducting a pilot study comparing CD4 T cell responses in distinct populations of healthy adults living in either rural or urban Kenya. This study revealed that the expression profile of CD4 T cell activation and memory markers differed significantly between African and European donors but was similar amongst African individuals from either rural or urban areas. Adults from rural Kenya had, however, higher frequencies and greater polyfunctionality among cytokine producing CD4 T cells compared to both urban populations, particularly for “Th1” type of response. Finally, endemic exposure to malaria in rural Kenya may have influenced the expansion of few discrete CD4 T cell populations with specific functional signatures. Conclusion/Significance These findings suggest that environmentally driven T cell activation does not drive the dysfunction of CD4 T cells but is rather associated with greater magnitude and quality of CD4 T cell response, indicating that the level or type of microbial exposure and antigenic experience may influence and shape the functionality of CD4 T cell compartment. Our data confirm that it is possible and mandatory to assess multiple functional attributes of CD4 T cell response in the context of infection

  16. Chronic Human Infection with Trypanosoma cruzi Drives CD4+ T Cells to Immune Senescence1

    PubMed Central

    Albareda, María Cecilia; Olivera, Gabriela Carina; Laucella, Susana A.; Alvarez, María Gabriela; Fernandez, Esteban Rodrigo; Lococo, Bruno; Viotti, Rodolfo; Tarleton, Rick L.; Postan, Miriam

    2011-01-01

    Previously we found that the frequency of IFN-γ-producing CD8+ T cells specific for Trypanosoma cruzi inversely correlates with disease severity in chronic human Chagas disease along with low levels of IL-2-secreting CD8+ T cells in all clinical stages. This impairment of the parasite-specific T cell responses was associated with phenotypic features of immune senescence of the CD8+ T cell compartment. These data prompted us to address the question of whether the CD4+ T cell compartment also experiences signs of exhaustion. Thus, we performed a functional and phenotypical characterization of T. cruzi-specific and overall CD4+ T cells in chronically infected subjects with different degrees of cardiac dysfunction. The results show an inverse association between disease severity and the frequency of T. cruzi-specific IFN-γ-producing CD4+ T cells. The high expression of CD27 and CD28 with a relative low expression of CD57 found on CD4+IFN-γ + T cells suggests that the effector T cell pool in chronic T. cruzi infection includes a high proportion of newly recruited T cells, but a low frequency of long-term memory cells. The total CD4+ T cell compartment shows signs of senescence and later stages of differentiation associated with more severe stages of the disease. These findings support the hypothesis that long-term T. cruzi infection in humans might exhaust long-lived memory T cells. PMID:19692645

  17. 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.

  18. 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

  19. Antibody raised against soluble CD4-rgp120 complex recognizes the CD4 moiety and blocks membrane fusion without inhibiting CD4-gp120 binding

    PubMed Central

    1990-01-01

    We studied the humoral response of mice immunized with soluble CD4- rgp120 complex, testing polyclonal and monoclonal antibodies (mAbs) with the aim of identifying molecular changes that take place after the first interaction between human immunodeficiency virus and the cell surface. The antisera had a paradoxically high syncytia-blocking titer associated with anti-CD4 specificity, while their capacity to inhibit CD4-gp120 binding was relatively modest. One of the mAbs produced from these responders blocks syncytia formation but does not inhibit CD4 interaction with gp120. Apparently, this mAb interacts with the CD4 moiety of CD4-gp120 complex and prevents a post-binding event necessary for membrane fusion and viral infection. PMID:2212945

  20. Homeostatically Maintained Resting Naive CD4+ T Cells Resist Latent HIV Reactivation

    PubMed Central

    Tsunetsugu-Yokota, Yasuko; Kobayahi-Ishihara, Mie; Wada, Yamato; Terahara, Kazutaka; Takeyama, Haruko; Kawana-Tachikawa, Ai; Tokunaga, Kenzo; Yamagishi, Makoto; Martinez, Javier P.; Meyerhans, Andreas

    2016-01-01

    Homeostatic proliferation (HSP) is a major mechanism by which long-lived naïve and memory CD4+ T cells are maintained in vivo and suggested to contribute to the persistence of the latent HIV-1 reservoir. However, while many in vitro latency models rely on CD4+ T cells that were initially differentiated via T-cell receptor (TCR) stimulation into memory/effector cells, latent infection of naïve resting CD4+ T cells maintained under HSP conditions has not been fully addressed. Here, we describe an in vitro HSP culture system utilizing the cytokines IL-7 and IL-15 that allows studying latency in naïve resting CD4+ T cells. CD4+ T cells isolated from several healthy donors were infected with HIV pseudotypes expressing GFP and cultured under HSP conditions or TCR conditions as control. Cell proliferation, phenotype, and GFP expression were analyzed by flow cytometry. RNA expression was quantified by qRT-PCR. Under HSP culture conditions, latently HIV-1 infected naïve cells are in part maintained in the non-dividing (= resting) state. Although a few HIV-1 provirus+ cells were present in these resting GFP negative cells, the estimated level of GFP transcripts per infected cell seems to indicate a block at the post-transcriptional level. Interestingly, neither TCR nor the prototypic HDAC inhibitor SAHA were able to reactivate HIV-1 provirus from these cells. This lack of reactivation was not due to methylation of the HIV LTR. These results point to a mechanism of HIV control in HSP-cultured resting naïve CD4+ T cells that may be distinct from that in TCR-stimulated memory/effector T cells. PMID:27990142

  1. CD4 T-Cell Subsets in Malaria: TH1/TH2 Revisited

    PubMed Central

    Perez-Mazliah, Damian; Langhorne, Jean

    2015-01-01

    CD4+ T-cells have been shown to play a central role in immune control of infection with Plasmodium parasites. At the erythrocytic stage of infection, IFN-γ production by CD4+ T-cells and CD4+ T-cell help for the B-cell response are required for control and elimination of infected red blood cells. CD4+ T-cells are also important for controlling Plasmodium pre-erythrocytic stages through the activation of parasite-specific CD8+ T-cells. However, excessive inflammatory responses triggered by the infection have been shown to drive pathology. Early classical experiments demonstrated a biphasic CD4+ T-cell response against erythrocytic stages in mice, in which T helper (Th)1 and antibody-helper CD4+ T-cells appear sequentially during a primary infection. While IFN-γ-producing Th1 cells do play a role in controlling acute infections, and they contribute to acute erythrocytic-stage pathology, it became apparent that a classical Th2 response producing IL-4 is not a critical feature of the CD4+ T-cell response during the chronic phase of infection. Rather, effective CD4+ T-cell help for B-cells, which can occur in the absence of IL-4, is required to control chronic parasitemia. IL-10, important to counterbalance inflammation and associated with protection from inflammatory-mediated severe malaria in both humans and experimental models, was originally considered be produced by CD4+ Th2 cells during infection. We review the interpretations of CD4+ T-cell responses during Plasmodium infection, proposed under the original Th1/Th2 paradigm, in light of more recent advances, including the identification of multifunctional T-cells such as Th1 cells co-expressing IFN-γ and IL-10, the identification of follicular helper T-cells (Tfh) as the predominant CD4+ T helper subset for B-cells, and the recognition of inherent plasticity in the fates of different CD4+ T-cells. PMID:25628621

  2. Adoptive transfer of effector CD8+ T cells derived from central memory cells establishes persistent T cell memory in primates.

    PubMed

    Berger, Carolina; Jensen, Michael C; Lansdorp, Peter M; Gough, Mike; Elliott, Carole; Riddell, Stanley R

    2008-01-01

    The adoptive transfer of antigen-specific T cells that have been expanded ex vivo is being actively pursued to treat infections and malignancy in humans. The T cell populations that are available for adoptive immunotherapy include both effector memory and central memory cells, and these differ in phenotype, function, and homing. The efficacy of adoptive immunotherapy requires that transferred T cells persist in vivo, but identifying T cells that can reproducibly survive in vivo after they have been numerically expanded by in vitro culture has proven difficult. Here we show that in macaques, antigen-specific CD8(+) T cell clones derived from central memory T cells, but not effector memory T cells, persisted long-term in vivo, reacquired phenotypic and functional properties of memory T cells, and occupied memory T cell niches. These results demonstrate that clonally derived CD8+ T cells isolated from central memory T cells are distinct from those derived from effector memory T cells and retain an intrinsic capacity that enables them to survive after adoptive transfer and revert to the memory cell pool. These results could have significant implications for the selection of T cells to expand or to engineer for adoptive immunotherapy of human infections or malignancy.

  3. CD4+ Tregs and immune control

    PubMed Central

    Fehérvari, Zoltán; Sakaguchi, Shimon

    2004-01-01

    Recent years have seen Tregs become a popular subject of immunological research. Abundant experimental data have now confirmed that naturally occurring CD25+CD4+ Tregs in particular play a key role in the maintenance of self tolerance, with their dysfunction leading to severe or even fatal immunopathology. The sphere of influence of Tregs is now known to extend well beyond just the maintenance of immunological tolerance and to impinge on a host of clinically important areas from cancer to infectious diseases. The identification of specific molecular markers in both human and murine immune systems has enabled the unprecedented investigation of these cells and should prove key to ultimately unlocking their clinical potential. PMID:15520849

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

    PubMed

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

    2013-01-01

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

  5. The BD FACSPresto Point of Care CD4 Test Accurately Enumerates CD4+ T Cell Counts

    PubMed Central

    Bwana, Priska; Vojnov, Lara; Adhiambo, Maureen; Akinyi, Catherine; Mwende, Joy; Prescott, Marta; Mwau, Matilu

    2015-01-01

    Objective Currently 50% of ART eligible patients are not yet receiving life-saving antiretroviral therapy (ART). Financial constraints do not allow most developing countries to adopt a universal test and offer ART strategy. Decentralizing CD4+ T cell testing may, therefore, provide greater access to testing, ART, and better patient management. We evaluated the technical performance of a new point-of-care CD4+ T cell technology, the BD FACSPresto, in a field methods comparison study. Methods 264 HIV-positive patients were consecutively enrolled and included in the study. The BD FACSPresto POC CD4+ T cell technology was placed in two rural health care facilities and operated by health care facility staff. We compared paired finger-prick and venous samples using the BD FACSPresto and several existing reference technologies, respectively. Results The BD FACSPresto had a mean bias of 67.29 cells/ul and an r2 of 0.9203 compared to the BD FACSCalibur. At ART eligibility thresholds of 350 and 500 cells/ul, the sensitivity to define treatment eligibility were 81.5% and 77.2% and the specificities were 98.9% and 100%, respectively. Similar results were observed when the BD FACSPresto was compared to the BD FACSCount and Alere Pima. The coefficient of variation (CV) was less than 7% for both the BD FACSCalibur and BD FACSPresto. CD4+ T cell testing by nurses using the BD FACSPresto at rural health care facilities showed high technical similarity to test results generated by laboratory technicians using the BD FACSPresto in a high functioning laboratory. Conclusions The BD FACSPresto performed favorably in the laboratory setting compared to the conventional reference standard technologies; however, the lower sensitivities indicated that up to 20% of patients tested in the field in need of treatment would be missed. The BD FACSPresto is a technology that can allow for greater decentralization and wider access to CD4+ T cell testing and ART. PMID:26720601

  6. Impact of Working Memory Training Targeting the Central Executive on Kindergarteners' Numerical Skills

    ERIC Educational Resources Information Center

    Honoré, Nastasya; Noël, Marie-Pascale

    2017-01-01

    Working memory capacities are associated with mathematical development. Many studies have tried to improve working memory abilities through training. Furthermore, the central executive has been shown to be the component of working memory, which is the most strongly related to numerical and arithmetical skills. Therefore, we developed a training…

  7. HIV viral load levels and CD4+ cell counts of youth in 14 cities.

    PubMed

    Ellen, Jonathan M; Kapogiannis, Bill; Fortenberry, J Dennis; Xu, Jiahong; Willard, Nancy; Duval, Anna; Pace, Jill; Loeb, Jackie; Monte, Dina; Bethel, James

    2014-05-15

    To describe the HIV viral load and CD4 cell counts of youth (12-24 years) in 14 cities from March 2010 through November 2011. Baseline HIV viral load and CD4 cell count data were electronically abstracted in a central location and in an anonymous manner through a random computer-generated coding system without any ability to link codes to individual cases. Among 1409 HIV reported cases, 852 participants had data on both viral load and CD4 cell counts. Of these youth, 34% had CD4 cell counts of 350 or less, 27% had cell counts from 351 to 500, and 39% had CD4 cell counts greater than 500. Youth whose transmission risk was male-to-male sexual contact had higher viral loads compared with youth whose transmission risk was perinatal or heterosexual contact. Greater than 30% of those who reported male-to-male sexual contact had viral loads greater than 50 000 copies, whereas less than 20% of heterosexual contact youth had viral loads greater than 50 000 copies. There were no differences noted in viral load by type of testing site. Most HIV-infected youth have CD4 cell counts and viral load levels associated with high rates of sexual transmission. Untreated, these youth may directly contribute to high rates of ongoing transmission. It is essential that any public health test and treat strategy place a strong emphasis on youth, particularly young MSM.

  8. Correlation of CD4 count, CD4% and HIV viral load with clinical manifestations of HIV in infected Indian children.

    PubMed

    Shah, Ira

    2006-06-01

    To correlate the absolute CD4 count, CD4% and HIV viral load with different clinical manifestations of HIV in antiretroviral-naive children. The paediatric and perinatal HIV clinic in a tertiary care hospital over a period of 4 years, from January 1999 to December 2003. A total of 92 highly active antiretroviral-naive, HIV-1-infected children were enrolled in a cross-sectional study. The clinical manifestations, age, sex and CDC classification of each patient were determined. CD4 count, CD4% and HIV-1 viral load were estimated at presentation and correlated with various clinical manifestations of HIV disease. CD4% was higher in infants (p < 0.001) and lower in children over 5 years of age (p = 0.01). Boys had a higher absolute CD4 count than girls (769 +/- 517 vs 532 +/- 430 cells/mm3, p = 0.02). Patients with lymphadenopathy (n = 43) had a high CD4 count (840 +/- 487 cells/mm3, p = 0.01) whereas patients with HIV cardiomyopathy (n = 4) had low CD4 counts (mean 182 cells/mm3, p = 0.04). In patients with failure to thrive (n = 29), the CD4% was low (14 +/- 9%, p = 0.02) and HIV-1 viral load was high (mean 4.5 x 10(5) copies/ml, p = 0.03). CD4 count, CD4% and HIV viral load did not correlate with the stage of the disease as per the CDC classification. HIV viral load, CD4 cell count and CD4% vary with age and disease complications in HIV-infected children. However, CD4 count, CD4% and viral load did not correlate with CDC classification.

  9. Casp8p41: The Protean Mediator of Death in CD4 T-cells that Replicate HIV

    PubMed Central

    Sampath, Rahul; Cummins, Nathan W.; Badley, Andrew D.

    2016-01-01

    HIV cure is now the focus of intense research after Timothy Ray Brown (the Berlin patient) set the precedent of being the first and only person cured. A major barrier to achieving this goal on a meaningful scale is an elimination of the latent reservoir, which is thought to comprise CD4-positive cells that harbor integrated, replication-competent HIV provirus. These cells do not express viral proteins, are indistinguishable from uninfected CD4 cells, and are thought to be responsible for HIV viral rebound—that occurs within weeks of combination anti retroviral therapy (cART) interruption. Modalities to engineer transcriptional stimulation (reactivation) of this dormant integrated HIV provirus, leading to expression of cytotoxic viral proteins, are thought to be a specific way to eradicate the latently infected CD4 pool and are becoming increasingly relevant in the era of HIV cure. HIV protease is one such protein produced after HIV reactivation that cleaves procaspase-8 to generate a novel protein Casp8p41. Casp8p41 then binds to the BH3 domain of BAK, leading to BAK oligomerization, mitochondrial depolarization, and apoptosis. In central memory T cells (TCMs) from HIV-infected patients, an elevated Bcl-2/procaspase-8 ratio was observed, and Casp8p41 binding to Bcl-2 was associated with a lack of reactivation-induced cell death. This was reversed by priming cells with a specific Bcl-2 antagonist prior to reactivation, resulting in increased cell death and decreased HIV DNA in a Casp8p41-dependent pathway. This review describes the biology, clinical relevance, and implications of Casp8p41 for a potential cure. PMID:27721655

  10. Naf1 Regulates HIV-1 Latency by Suppressing Viral Promoter-Driven Gene Expression in Primary CD4+ T Cells.

    PubMed

    Li, Chuan; Wang, Hai-Bo; Kuang, Wen-Dong; Ren, Xiao-Xin; Song, Shu-Ting; Zhu, Huan-Zhang; Li, Qiang; Xu, Li-Ran; Guo, Hui-Jun; Wu, Li; Wang, Jian-Hua

    2017-01-01

    HIV-1 latency is characterized by reversible silencing of viral transcription driven by the long terminal repeat (LTR) promoter of HIV-1. Cellular and viral factors regulating LTR activity contribute to HIV-1 latency, and certain repressive cellular factors modulate viral transcription silencing. Nef-associated factor 1 (Naf1) is a host nucleocytoplasmic shuttling protein that regulates multiple cellular signaling pathways and HIV-1 production. We recently reported that nuclear Naf1 promoted nuclear export of unspliced HIV-1 gag mRNA, leading to increased Gag production. Here we demonstrate new functions of Naf1 in regulating HIV-1 persistence. We found that Naf1 contributes to the maintenance of HIV-1 latency by inhibiting LTR-driven HIV-1 gene transcription in a nuclear factor kappa B-dependent manner. Interestingly, Naf1 knockdown significantly enhanced viral reactivation in both latently HIV-1-infected Jurkat T cells and primary central memory CD4(+) T cells. Furthermore, Naf1 knockdown in resting CD4(+) T cells from HIV-1-infected individuals treated with antiretroviral therapy significantly increased viral reactivation upon T-cell activation, suggesting an important role of Naf1 in modulating HIV-1 latency in vivo Our findings provide new insights for a better understanding of HIV-1 latency and suggest that inhibition of Naf1 activity to activate latently HIV-1-infected cells may be a potential therapeutic strategy.

  11. 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.

  12. CD4 aptamer-RORγt shRNA chimera inhibits IL-17 synthesis by human CD4(+) T cells.

    PubMed

    Song, Pingfang; Chou, Yuan K; Zhang, Xiaowei; Meza-Romero, Roberto; Yomogida, Kentaro; Benedek, Gil; Chu, Cong-Qiu

    2014-10-03

    Cell type specific delivery of RNAi to T cells has remained to be a challenge. Here we describe an aptamer mediated delivery of shRNA to CD4(+) T cells targeting RORγt to suppress Th17 cells. A cDNA encoding CD4 aptamer and RORγt shRNA was constructed and the chimeric CD4 aptamer-RORγt shRNA (CD4-AshR-RORγt) was generated using in vitro T7 RNA transcription. 2'-F-dCTP and 2'-F-dUTP were incorporated into CD4-AshR-RORγt for RNase resistance. CD4-AshR-RORγt was specifically uptaken by CD4(+) Karpas 299 cells and primary human CD4(+) T cells. The RORγt shRNA moiety of CD4-AshR-RORγt chimera was cleaved and released by Dicer. Furthermore, CD4-AshR-RORγt suppressed RORγt gene expression in Karpas 299 cells and CD4(+) T cells and consequently inhibited Th17 cell differentiation and IL-17 production. These results demonstrate that aptamer-facilitated cell specific delivery of shRNA represents a novel approach for efficient RNAi delivery and is potentially to be developed for therapeutics targeting specific T cells subtypes.

  13. 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.

  14. IL-12 is required for anti-OX40-mediated CD4 T cell survival.

    PubMed

    Ruby, Carl E; Montler, Ryan; Zheng, Rongxui; Shu, Suyu; Weinberg, Andrew D

    2008-02-15

    Engagement of OX40 greatly improves CD4 T cell function and survival. Previously, we showed that both OX40 engagement and CTLA-4 blockade led to enhanced CD4 T cell expansion, but only OX40 signaling increased survival. To identify pathways associated with OX40-mediated survival, the gene expression of Ag-activated CD4 T cells isolated from mice treated with anti-OX40 and -CTLA-4 was compared. This comparison revealed a potential role for IL-12 through increased expression of the IL-12R-signaling subunit (IL-12Rbeta2) on T cells activated 3 days previously with Ag and anti-OX40. The temporal expression of IL-12Rbeta2 on OX40-stimulated CD4 T cells was tightly regulated and peaked approximately 4-6 days after initial activation/expansion, but before the beginning of T cell contraction. IL-12 signaling, during this window of IL-12Rbeta2 expression, was required for enhanced T cell survival and survival was associated with STAT4-specific signaling. The findings from these observations were exploited in several different mouse tumor models where we found that the combination of anti-OX40 and IL-12 showed synergistic therapeutic efficacy. These results may lead to the elucidation of the molecular pathways involved with CD4 T cell survival that contribute to improved memory, and understanding of these pathways could lead to greater efficacy of immune stimulatory Abs in tumor-bearing individuals.

  15. CD4 T Cell Help Is Limiting and Selective during the Primary B Cell Response to Influenza Virus Infection

    PubMed Central

    Alam, Shabnam; Knowlden, Zackery A. G.; Sangster, Mark Y.

    2014-01-01

    Influenza virus vaccination strategies are focused upon the elicitation of protective antibody responses through administration of viral protein through either inactivated virions or live attenuated virus. Often overlooked in this strategy is the CD4 T cell response: how it develops into memory, and how it may support future primary B cell responses to heterologous infection. Through the utilization of a peptide-priming regimen, this study describes a strategy for developing CD4 T cell memory with the capacity to robustly expand in the lung-draining lymph node after live influenza virus infection. Not only were frequencies of antigen-specific CD4 T cells enhanced, but these cells also supported an accelerated primary B cell response to influenza virus-derived protein, evidenced by high anti-nucleoprotein (NP) serum antibody titers early, while there is still active viral replication ongoing in the lung. NP-specific antibody-secreting cells and heightened frequencies of germinal center B cells and follicular T helper cells were also readily detectable in the draining lymph node. Surprisingly, a boosted memory CD4 T cell response was not sufficient to provide intermolecular help for antibody responses. Our study demonstrates that CD4 T cell help is selective and limiting to the primary antibody response to influenza virus infection and that preemptive priming of CD4 T cell help can promote effective and rapid conversion of naive B cells to mature antibody-secreting cells. PMID:24155379

  16. Diagnostic Value of the CD103+CD4+/CD4+ Ratio to Differentiate Sarcoidosis from Other Causes of Lymphocytic Alveolitis.

    PubMed

    Bretagne, Lisa; Diatta, Ibrahima-Dina; Faouzi, Mohamed; Nobile, Antoine; Bongiovanni, Massimo; Nicod, Laurent P; Lazor, Romain

    2016-01-01

    The CD103 integrin is present on CD4+ lymphocytes of the bronchial mucosa, but not on peripheral blood CD4+ lymphocytes. It has been hypothesized that CD4+ lymphocytes in pulmonary sarcoidosis originate from redistribution from the peripheral blood to the lung, and therefore do not bear the CD103 integrin. Some data suggest that a low CD103+ percentage among bronchoalveolar lavage fluid (BALF) CD4+ lymphocytes discriminates between sarcoidosis and other diagnoses. To determine the diagnostic value of BALF CD103+ to identify sarcoidosis among other causes of alveolar lymphocytosis in a large retrospective case series. Among 391 consecutive bronchoalveolar lavages performed at our institution and analyzed by flow cytometry, we identified 207 cases, which were grouped into nine diagnostic categories: sarcoidosis, tuberculosis, non-tuberculous infections, hypersensitivity pneumonitis, non-specific interstitial pneumonia, organizing pneumonia, drug-induced lung diseases, other interstitial lung diseases (ILDs), and other diagnoses. To assess the discriminative value of the CD103+CD4+/CD4+ ratio to distinguish sarcoidosis from other entities, areas under ROC curves (AUC) were calculated. Sarcoidosis patients (n = 53) had significantly lower CD103+CD4+/CD4+ ratios than patients in other diagnostic categories. The AUC was 62% for sarcoidosis compared to all other diagnoses, and 69% for sarcoidosis compared to other ILDs. When combining CD103+CD4+/CD4+ and CD4+/CD8+ ratios, the AUC increased to 76 and 78%, respectively. When applying previously published cut-offs to our population, the AUC varied between 54 and 73%. The CD103+CD4+/CD4+ ratio does not accurately discriminate between sarcoidosis and other causes of lymphocytic alveolitis, neither alone nor in combination with the CD4+/CD8+ ratio, and is not a powerful marker for the diagnosis of sarcoidosis. © 2016 S. Karger AG, Basel.

  17. Virions of primary human immunodeficiency virus type 1 isolates resistant to soluble CD4 (sCD4) neutralization differ in sCD4 binding and glycoprotein gp120 retention from sCD4-sensitive isolates.

    PubMed Central

    Moore, J P; McKeating, J A; Huang, Y X; Ashkenazi, A; Ho, D D

    1992-01-01

    Primary isolates of human immunodeficiency virus type 1 (HIV-1) are much less sensitive to neutralization by soluble CD4 (sCD4) and sCD4-immunoglobulin (Ig) chimeras (CD4-IgG) than are HIV-1 strains adapted to growth in cell culture. We demonstrated that there are significant reductions (10- to 30-fold) in the binding of sCD4 and CD4-IgG to intact virions of five primary isolates compared with sCD4-sensitive, cell culture-adapted isolates RF and IIIB. However, soluble envelope glycoproteins (gp120) derived from the primary isolate virions, directly by detergent solubilization or indirectly by recombinant DNA technology, differed in affinity from RF and IIIB gp120 by only one- to threefold. The reduced binding of sCD4 to these primary isolate virions must therefore be a consequence of the tertiary or quaternary structure of the envelope glycoproteins in their native, oligomeric form on the viral surface. In addition, the rate and extent of sCD4-induced gp120 shedding from these primary isolates was lower than that from RF. We suggest that reduced sCD4 binding and increased gp120 retention together account for the relative resistance of these primary isolates to neutralization by sCD4 and CD4-IgG and that virions of different HIV-1 isolates vary both in the mechanism of sCD4 binding and in subsequent conformational changes in their envelope glycoproteins. PMID:1727487

  18. 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.

  19. 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

  20. 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.

  1. Dynamic Modulation of Expression of Lentiviral Restriction Factors in Primary CD4(+) T Cells following Simian Immunodeficiency Virus Infection.

    PubMed

    Rahmberg, Andrew R; Rajakumar, Premeela A; Billingsley, James M; Johnson, R Paul

    2017-04-01

    Although multiple restriction factors have been shown to inhibit HIV/SIV replication, little is known about their expression in vivo Expression of 45 confirmed and putative HIV/SIV restriction factors was analyzed in CD4(+) T cells from peripheral blood and the jejunum in rhesus macaques, revealing distinct expression patterns in naive and memory subsets. In both peripheral blood and the jejunum, memory CD4(+) T cells expressed higher levels of multiple restriction factors compared to naive cells. However, relative to their expression in peripheral blood CD4(+) T cells, jejunal CCR5(+) CD4(+) T cells exhibited significantly lower expression of multiple restriction factors, including APOBEC3G, MX2, and TRIM25, which may contribute to the exquisite susceptibility of these cells to SIV infection. In vitro stimulation with anti-CD3/CD28 antibodies or type I interferon resulted in upregulation of distinct subsets of multiple restriction factors. After infection of rhesus macaques with SIVmac239, the expression of most confirmed and putative restriction factors substantially increased in all CD4(+) T cell memory subsets at the peak of acute infection. Jejunal CCR5(+) CD4(+) T cells exhibited the highest levels of SIV RNA, corresponding to the lower restriction factor expression in this subset relative to peripheral blood prior to infection. These results illustrate the dynamic modulation of confirmed and putative restriction factor expression by memory differentiation, stimulation, tissue microenvironment and SIV infection and suggest that differential expression of restriction factors may play a key role in modulating the susceptibility of different populations of CD4(+) T cells to lentiviral infection.IMPORTANCE Restriction factors are genes that have evolved to provide intrinsic defense against viruses. HIV and simian immunodeficiency virus (SIV) target CD4(+) T cells. The baseline level of expression in vivo and degree to which expression of restriction factors is

  2. EBV Latency II-derived peptides induce a specific CD4+ cytotoxic T-cell activity and not a CD4+ regulatory T-cell response.

    PubMed

    Moralès, Olivier; Depil, Stéphane; Mrizak, Dhafer; Martin, Nathalie; Ndour, Papa Alioune; Dufosse, Françoise; Miroux, Céline; Coll, Jean; de Launoit, Yvan; Auriault, Claude; Pancre, Véronique; Delhem, Nadira

    2012-04-01

    Epstein-Barr virus (EBV) is associated with several malignant diseases that can be distinguished by their patterns of viral latent gene expression. We developed here an original peptidic approach to favor the induction of a specific CD4+ T-cell response against EBV latency II malignancies (Hodgkin's lymphoma, nasopharyngeal carcinoma, T/NK lymphoma). Previously, we selected 6 peptides derived from EBV nuclear antigen-1, latency membrane proteins (LMP)-1, and LMP-2 highly promiscuous for major histocompatibility complex class II molecules and showed their ability to induce interferon-γ-secreting CD4+ T cells. We confirmed here that all peptides used in cocktail are recognized by human CD4+ memory T cells from healthy donors, inducing a broad T-helper (Th)1 cytokine secretion interferon-γ, interleukin-2. Furthermore, we have generated EBV-specific CD4+ T-cell lines and proved their cytotoxic potential, not only on original models expressing latency II antigens (EBV-transformed T cell or monocyte), but also on lymphoblastoid cell lines expressing latency III antigens (lymphoblastoid cell lines). In addition, granzyme B enzyme-linked immunospot assays suggested that a part of this specific cytotoxic activity could be linked to the granule lytic pathway. Very importantly, we have showed that neither phenotypical changes nor functional activities of CD4+CD25+CD127(low)-regulatory T cells were observed in response to EBV+ peptides, avoiding any risk of aggravation of the preexisting immunosuppressive environment reported in EBV-associated malignancies. In conclusion, our promiscuous peptide cocktail could be used safely in immunotherapeutic approaches against EBV latency II malignancies, mainly to prevent relapse in high-risk patients further to classic treatments.

  3. 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

  4. Quantification of cells with specific phenotypes II: determination of CD4 expression level on reconstituted lyophilized human PBMC labelled with anti-CD4 FITC antibody.

    PubMed

    Wang, L; Stebbings, R; Gaigalas, A K; Sutherland, J; Kammel, M; John, M; Roemer, B; Kuhne, M; Schneider, R J; Braun, M; Engel, A; Dikshit, D; Abbasi, F; Marti, G E; Sassi, M; Revel, L; Kim, S K; Baradez, M; Lekishvili, T; Marshall, D; Whitby, L; Jing, W; Ost, V; Vonsky, M; Neukammer, J

    2015-03-01

    This report focuses on the characterization of CD4 expression level in terms of equivalent number of reference fluorophores (ERF). Twelve different flow cytometer platforms across sixteen laboratories were utilized in this study. As a first step the participants were asked to calibrate the fluorescein isothiocyanate (FITC) channel of each flow cytometer using commercially available calibration standard consisting of five populations of microspheres. Each population had an assigned value of equivalent fluorescein fluorophores (EFF denotes a special case of the generic term ERF with FITC as the reference fluorophore). The EFF values were assigned at the National Institute of Standards and Technology (NIST). A surface-labelled lyophilized cell preparation was provided by the National Institute of Biological Standards and Control (NIBSC), using human peripheral blood mononuclear cells (PBMC) pre-labeled with a FITC conjugated anti-CD4 monoclonal antibody. Three PBMC sample vials, provided to each participant, were used for the CD4 expression analysis. The PBMC are purported to have a fixed number of surface CD4 receptors. On the basis of the microsphere calibration, the EFF value of the PBMC samples was measured to characterize the population average CD4 expression level of the PBMC preparations. Both the results of data analysis performed by each participant and the results of centralized analysis of all participants' raw data are reported. Centralized analysis gave a mean EFF value of 22,300 and an uncertainty of 750, corresponding to 3.3% (level of confidence 68%) of the mean EFF value. The next step will entail the measurement of the ERF values of the lyophilized PBMC stained with labels for other fluorescence channels. The ultimate goal is to show that lyophilized PBMC is a suitable biological reference cell material for multicolor flow cytometry and that it can be used to present multicolor flow cytometry measurements in terms of ABC (antibodies bound per cell

  5. Range of CD4-Bound Conformations of HIV-1 gp120, as Defined Using Conditional CD4-Induced Antibodies

    PubMed Central

    Kaplan, Gilad; Roitburd-Berman, Anna; Lewis, George K.

    2016-01-01

    ABSTRACT The HIV envelope binds cellular CD4 and undergoes a range of conformational changes that lead to membrane fusion and delivery of the viral nucleocapsid into the cellular cytoplasm. This binding to CD4 reveals cryptic and highly conserved epitopes, the molecular nature of which is still not fully understood. The atomic structures of CD4 complexed with gp120 core molecules (a form of gp120 in which the V1, V2, and V3 loops and N and C termini have been truncated) have indicated that a hallmark feature of the CD4-bound conformation is the bridging sheet minidomain. Variations in the orientation of the bridging sheet hairpins have been revealed when CD4-liganded gp120 was compared to CD4-unliganded trimeric envelope structures. Hence, there appears to be a number of conformational transitions possible in HIV-1 monomeric gp120 that are affected by CD4 binding. The spectrum of CD4-bound conformations has been interrogated in this study by using a well-characterized panel of conditional, CD4-induced (CD4i) monoclonal antibodies (MAbs) that bind HIV-1 gp120 and its mutations under various conditions. Two distinct CD4i epitopes of the outer domain were studied: the first comprises the bridging sheet, while the second contains elements of the V2 loop. Furthermore, we show that the unliganded extended monomeric core of gp120 (coree) assumes an intermediate CD4i conformation in solution that further undergoes detectable rearrangements upon association with CD4. These discoveries impact both accepted paradigms concerning gp120 structure and the field of HIV immunogen design. IMPORTANCE Elucidation of the conformational transitions that the HIV-1 envelope protein undergoes during the course of entry into CD4+ cells is fundamental to our understanding of HIV biology. The binding of CD4 triggers a range of gp120 structural rearrangements that could present targets for future drug design and development of preventive vaccines. Here we have systematically interrogated and

  6. HIV-1 CD4-induced (CD4i) gp120 epitope vaccines promote B and T-cell responses that contribute to reduced viral loads in rhesus macaques.

    PubMed

    Thomas, Michael A; Tuero, Iskra; Demberg, Thorsten; Vargas-Inchaustegui, Diego A; Musich, Thomas; Xiao, Peng; Venzon, David; LaBranche, Celia; Montefiori, David C; DiPasquale, Janet; Reed, Steven G; DeVico, Anthony; Fouts, Timothy; Lewis, George K; Gallo, Robert C; Robert-Guroff, Marjorie

    2014-12-01

    To target the HIV CD4i envelope epitope, we primed rhesus macaques with replicating Ad-rhFLSC (HIV-1BaLgp120 linked to macaque CD4 D1 and D2), with or without Ad-SIVgag and Ad-SIVnef. Macaques were boosted with rhFLSC protein. Memory T-cells in PBMC, bronchoalveolar lavage and rectal tissue, antibodies with neutralizing and ADCC activity, and Env-specific secretory IgA in rectal secretions were elicited. Although protective neutralizing antibody levels were induced, SHIVSF162P4 acquisition following rectal challenge was not prevented. Rapid declines in serum ADCC activity, Env-specific memory B cells in PBMC and bone marrow, and systemic and mucosal memory T cells were observed immediately post-challenge together with delayed anamnestic responses. Innate immune signaling resulting from persisting Ad replication and the TLR-4 booster adjuvant may have been in conflict and reoriented adaptive immunity. A different adjuvant paired with replicating Ad, or a longer post-prime interval allowing vector clearance before boosting might foster persistent T- and B-cell memory.

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

    PubMed Central

    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

    2016-01-01

    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

  8. Low-dose controlled release of mTOR inhibitors maintains T cell plasticity and promotes central memory T cells.

    PubMed

    Gammon, Joshua M; Gosselin, Emily A; Tostanoski, Lisa H; Chiu, Yu-Chieh; Zeng, Xiangbin; Zeng, Qin; Jewell, Christopher M

    2017-10-10

    An important goal for improving vaccine and immunotherapy technologies is the ability to provide further control over the specific phenotypes of T cells arising from these agents. Along these lines, frequent administration of rapamycin (Rapa), a small molecule inhibitor of the mammalian target of rapamycin (mTOR), exhibits a striking ability to polarize T cells toward central memory phenotypes (TCM), or to suppress immune function, depending on the concentrations and other signals present during administration. TCM exhibit greater plasticity and proliferative capacity than effector memory T cells (TEFF) and, therefore, polarizing vaccine-induced T cells toward TCM is an intriguing strategy to enhance T cell expansion and function against pathogens or tumors. Here we combined biodegradable microparticles encapsulating Rapa (Rapa MPs) with vaccines composed of soluble peptide antigens and molecular adjuvants to test if this approach allows polarization of differentiating T cells toward TCM. We show Rapa MPs modulate DC function, enhancing secretion of inflammatory cytokines at very low doses, and suppressing function at high doses. While Rapa MP treatment reduced - but did not stop - T cell proliferation in both CD4(+) and CD8(+) transgenic T cell co-cultures, the expanding CD8(+) T cells differentiated to higher frequencies of TCM at low doses of MP Rapa MPs. Lastly, we show in mice that local delivery of Rapa MPs to lymph nodes during vaccination either suppresses or enhances T cell function in response to melanoma antigens, depending on the dose of drug in the depots. In particular, at low Rapa MP doses, vaccines increased antigen-specific TCM, resulting in enhanced T cell expansion measured during subsequent booster injections over at least 100days. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Probing the Effect of Force on HIV-1 Receptor CD4

    PubMed Central

    2015-01-01

    Cell-surface proteins are central for the interaction of cells with their surroundings and are also associated with numerous diseases. These molecules are exposed to mechanical forces, but the exact relation between force and the functions and pathologies associated with cell-surface proteins is unclear. An important cell-surface protein is CD4, the primary receptor of HIV-1. Here we show that mechanical force activates conformational and chemical changes on CD4 that may be important during viral attachment. We have used single-molecule force spectroscopy and analysis on HIV-1 infectivity to demonstrate that the mechanical extension of CD4 occurs in a time-dependent manner and correlates with HIV-1 infectivity. We show that Ibalizumab, a monoclonal antibody that blocks HIV-1, prevents the mechanical extension of CD4 domains 1 and 2. Furthermore, we demonstrate that thiol/disulfide exchange in CD4 requires force for exposure of cryptic disulfide bonds. This mechanical perspective provides unprecedented information that can change our understanding on how viruses interact with their hosts. PMID:25299596

  10. Probing the effect of force on HIV-1 receptor CD4.

    PubMed

    Perez-Jimenez, Raul; Alonso-Caballero, Alvaro; Berkovich, Ronen; Franco, David; Chen, Ming-Wei; Richard, Patricia; Badilla, Carmen L; Fernandez, Julio M

    2014-10-28

    Cell-surface proteins are central for the interaction of cells with their surroundings and are also associated with numerous diseases. These molecules are exposed to mechanical forces, but the exact relation between force and the functions and pathologies associated with cell-surface proteins is unclear. An important cell-surface protein is CD4, the primary receptor of HIV-1. Here we show that mechanical force activates conformational and chemical changes on CD4 that may be important during viral attachment. We have used single-molecule force spectroscopy and analysis on HIV-1 infectivity to demonstrate that the mechanical extension of CD4 occurs in a time-dependent manner and correlates with HIV-1 infectivity. We show that Ibalizumab, a monoclonal antibody that blocks HIV-1, prevents the mechanical extension of CD4 domains 1 and 2. Furthermore, we demonstrate that thiol/disulfide exchange in CD4 requires force for exposure of cryptic disulfide bonds. This mechanical perspective provides unprecedented information that can change our understanding on how viruses interact with their hosts.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-08-06

    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.

  13. 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

  14. 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

  15. CD4 cell count and CD4/CD8 ratio increase during rituximab maintenance in granulomatosis with polyangiitis patients

    PubMed Central

    Nossent, Johannes C.

    2016-01-01

    Introduction Rituximab (RTX) is a B cell-depleting agent approved for the treatment of granulomatosis with polyangiitis (GPA). RTX reduces antibody producing precursor plasma cells and inhibits B and T cells interaction. Infections related to T cell immunodeficiency are not infrequent during RTX treatment. Our study investigated CD4 cell count and CD4/CD8 ratio in GPA patients during the first two years of long-term RTX treatment. Methods A single centre cohort study of 35 patients who received median total cumulative dose of cyclophosphamide (CYC) of 15 g and were treated with RTX 2 g followed by retreatment with either 2 g once annually or 1 g biannually. Serum levels of total immunoglobulin (Ig) and lymphocytes subsets were recorded at RTX initiation and at 3, 6, 12, 18 and 24 months. Low CD4 count and inverted CD4/CD8 ratio were defined as CD4 < 0.3 × 109/l and ratio < 1. Results The CD4 cell count and CD4/CD8 ratio decreased slightly following the initial RTX treatment and then increased gradually during maintenance treatment. While the proportion of patients with low CD4 cell count decreased from 43% at baseline to 18% at 24 months, the ratio remained inverted in 40%. Oral daily prednisolone dose at baseline, CYC exposure and the maintenance regimen did not influence the CD4 cell count and ratio. Being older (p = 0.012) and having a higher CRP (p = 0.044) and ESR (p = 0.024) at baseline significantly increased the risk of inverted CD4/CD8 ratio at 24 months. Inverted ratio at baseline associated with lower total Ig levels during the study. Conclusions Overall, the CD4 and CD4/CD8 ratio increased during maintenance RTX therapy in GPA with no discernible impact of other immunosuppressive therapy. However the increase in CD4 was not followed by an increase in the CD4/CD8 ratio, especially in older patients. Inverted CD4/CD8 ratio associated with lower Ig levels, suggesting a more profound B cell depleting effect of RTX with a relative increase in CD8

  16. Immunologic memory in cutaneous leishmaniasis.

    PubMed

    Scott, Phillip

    2005-12-01

    Leishmania major infections induce solid immunity to reinfection. Experimental studies in mice indicate that the CD4+ T cells responsible for this immunity include two populations: parasite-dependent T effector cells and parasite-independent central memory T (Tcm) cells. While there currently is no vaccine for leishmaniasis, the existence of a long-lived population of Tcm cells that does not require the continued presence of live parasites suggests that a vaccine that expands these cells might be efficacious.

  17. Impact of sepsis on CD4 T cell immunity

    PubMed Central

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

    2014-01-01

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

  18. Cytotoxic CD4 T Cells: Differentiation, Function, and Application to Dengue Virus Infection

    PubMed Central

    Tian, Yuan; Sette, Alessandro; Weiskopf, Daniela

    2016-01-01

    Dengue virus (DENV) has spread through most tropical and subtropical areas of the world and represents a serious public health problem. The control of DENV infection has not yet been fully successful due to lack of effective therapeutics or vaccines. Nevertheless, a better understanding of the immune responses against DENV infection may reveal new strategies for eliciting and improving antiviral immunity. T cells provide protective immunity against various viral infections by generating effector cells that cooperate to eliminate antigens and memory cells that can survive for long periods with enhanced abilities to control recurring pathogens. Following activation, CD8 T cells can migrate to sites of infection and kill infected cells, whereas CD4 T cells contribute to the elimination of pathogens by trafficking to infected tissues and providing help to innate immune responses, B cells, as well as CD8 T cells. However, it is now evident that CD4 T cells can also perform cytotoxic functions and induce the apoptosis of target cells. Importantly, accumulating studies demonstrate that cytotoxic CD4 T cells develop following DENV infections and may play a crucial role in protecting the host from severe dengue disease. We review our current understanding of the differentiation and function of cytotoxic CD4 T cells, with a focus on DENV infection, and discuss the potential of harnessing these cells for the prevention and treatment of DENV infection and disease. PMID:28003809

  19. Dominance of the CD4+ T helper cell response during acute resolving hepatitis A virus infection

    PubMed Central

    Zhou, Yan; Callendret, Benoît; Xu, Dan; Brasky, Kathleen M.; Feng, Zongdi; Hensley, Lucinda L.; Guedj, Jeremie; Perelson, Alan S.; Lemon, Stanley M.; Lanford, Robert E.

    2012-01-01

    Hepatitis A virus (HAV) infection typically resolves within 4–7 wk but symptomatic relapse occurs in up to 20% of cases. Immune mechanisms that terminate acute HAV infection, and prevent a relapse of virus replication and liver disease, are unknown. Here, patterns of T cell immunity, virus replication, and hepatocellular injury were studied in two HAV-infected chimpanzees. HAV-specific CD8+ T cells were either not detected in the blood or failed to display effector function until after viremia and hepatitis began to subside. The function of CD8+ T cells improved slowly as the cells acquired a memory phenotype but was largely restricted to production of IFN-γ. In contrast, CD4+ T cells produced multiple cytokines when viremia first declined. Moreover, only CD4+ T cells responded during a transient resurgence of fecal HAV shedding. This helper response then contracted slowly over several months as HAV genomes were eliminated from liver. The findings indicate a dominant role for CD4+ T cells in the termination of HAV infection and, possibly, surveillance of an intrahepatic reservoir of HAV genomes that decays slowly. Rapid contraction or failure to sustain such a CD4+ T cell response after resolution of symptoms could increase the risk of relapsing hepatitis A. PMID:22753925

  20. Cytotoxic CD4 T Cells: Differentiation, Function, and Application to Dengue Virus Infection.

    PubMed

    Tian, Yuan; Sette, Alessandro; Weiskopf, Daniela

    2016-01-01

    Dengue virus (DENV) has spread through most tropical and subtropical areas of the world and represents a serious public health problem. The control of DENV infection has not yet been fully successful due to lack of effective therapeutics or vaccines. Nevertheless, a better understanding of the immune responses against DENV infection may reveal new strategies for eliciting and improving antiviral immunity. T cells provide protective immunity against various viral infections by generating effector cells that cooperate to eliminate antigens and memory cells that can survive for long periods with enhanced abilities to control recurring pathogens. Following activation, CD8 T cells can migrate to sites of infection and kill infected cells, whereas CD4 T cells contribute to the elimination of pathogens by trafficking to infected tissues and providing help to innate immune responses, B cells, as well as CD8 T cells. However, it is now evident that CD4 T cells can also perform cytotoxic functions and induce the apoptosis of target cells. Importantly, accumulating studies demonstrate that cytotoxic CD4 T cells develop following DENV infections and may play a crucial role in protecting the host from severe dengue disease. We review our current understanding of the differentiation and function of cytotoxic CD4 T cells, with a focus on DENV infection, and discuss the potential of harnessing these cells for the prevention and treatment of DENV infection and disease.

  1. Downregulation of CD4+LAP+ and CD4+CD25+ regulatory T cells in acute coronary syndromes.

    PubMed

    Lin, Ying-zhong; Lu, Shan-he; Lu, Zheng-de; Huang, Ying; Shi, Ying; Liu, Ling; Wang, Xiao-yan; Ji, Qing-wei

    2013-01-01

    Regulatory T (Treg) cells play a protective role in atherosclerosis prone models and are related to the onset of acute coronary syndromes (ACS, including non-ST-elevation ACS (NSTEACS) and ST-elevation acute myocardial infarction (STEAMI)). CD4+LAP+ Treg cells are a novel subset of Tregs that have been found to ameliorate atherosclerosis in ApoE(-/-) mice, and these cells also exist in humans. The present study was designed to investigate whether CD4+LAP+ Treg cells are involved in the onset of ACS. The frequencies of CD4+LAP+ and CD4+CD25+ Treg cells were detected using flow cytometric analysis, and the plasma IL-10 and TGF- β 1 levels were measured using an ELISA in 29 stable angina (SA) patients, 30 NSTEACS patients, 27 STEAMI patients, and a control group (30 cases). The results revealed a significant decrease in the frequencies of CD4+LAP+ and CD4+CD25+ Treg cells and in the levels of IL-10 and TGF- β 1 in patients with ACS compared with those in the SA and control groups. The decrease in the frequencies of CD4+LAP+ and CD4+CD25+ Treg cells may play a role in the onset of ACS.

  2. Effector CD4+ T cell expression signatures and immune-mediated disease associated genes.

    PubMed

    Zhang, Wei; Ferguson, John; Ng, Sok Meng; Hui, Ken; Goh, Gerald; Lin, Aiping; Esplugues, Enric; Flavell, Richard A; Abraham, Clara; Zhao, Hongyu; Cho, Judy H

    2012-01-01

    Genome-wide association studies (GWAS) in immune-mediated diseases have identified over 150 associated genomic loci. Many of these loci play a role in T cell responses, and regulation of T cell differentiation plays a critical role in immune-mediated diseases; however, the relationship between implicated disease loci and T cell differentiation is incompletely understood. To further address this relationship, we examined differential gene expression in naïve human CD4+ T cells, as well as in in vitro differentiated Th1, memory Th17-negative and Th17-enriched CD4+ T cells subsets using microarray and RNASeq. We observed a marked enrichment for increased expression in memory CD4+ compared to naïve CD4+ T cells of genes contained among immune-mediated disease loci. Within memory T cells, expression of disease-associated genes was typically increased in Th17-enriched compared to Th17-negative cells. Utilizing RNASeq and promoter methylation studies, we identified a differential regulation pattern for genes solely expressed in Th17 cells (IL17A and CCL20) compared to genes expressed in both Th17 and Th1 cells (IL23R and IL12RB2), where high levels of promoter methylation are correlated to near zero RNASeq levels for IL17A and CCL20. These findings have implications for human Th17 celI plasticity and for the regulation of Th17-Th1 expression signatures. Importantly, utilizing RNASeq we found an abundant isoform of IL23R terminating before the transmembrane domain that was enriched in Th17 cells. In addition to molecular resolution, we find that RNASeq provides significantly improved power to define differential gene expression and identify alternative gene variants relative to microarray analysis. The comprehensive integration of differential gene expression between cell subsets with disease-association signals, and functional pathways provides insight into disease pathogenesis.

  3. The role of central attention in retrieval from visual short-term memory.

    PubMed

    Magen, Hagit

    2017-04-01

    The role of central attention in visual short-term memory (VSTM) encoding and maintenance is well established, yet its role in retrieval has been largely unexplored. This study examined the involvement of central attention in retrieval from VSTM using a dual-task paradigm. Participants performed a color change-detection task. Set size varied between 1 and 3 items, and the memory sample was maintained for either a short or a long delay period. A secondary tone discrimination task was introduced at the end of the delay period, shortly before the appearance of a central probe, and occupied central attention while participants were searching within VSTM representations. Similarly to numerous previous studies, reaction time increased as a function of set size reflecting the occurrence of a capacity-limited memory search. When the color targets were maintained over a short delay, memory was searched for the most part without the involvement of central attention. However, with a longer delay period, the search relied entirely on the operation of central attention. Taken together, this study demonstrates that central attention is involved in retrieval from VSTM, but the extent of its involvement depends on the duration of the delay period. Future studies will determine whether the type of memory search (parallel or serial) carried out during retrieval depends on the nature of the attentional mechanism involved the task.

  4. CD4+ T cell activation in multiple sclerosis.

    PubMed

    Verselis, S J; Goust, J M

    1987-02-01

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

  5. Determinants of HIV-1 CD4-Independent Brain Adaptation.

    PubMed

    Shakirzyanova, Madina; Kong, Xiang-Peng; Cheng-Mayer, Cecilia

    2017-10-01

    HIV-1 is known to adapt to the local environment in its usage of receptors, and it can become CD4 independent in the brain where the receptor is scarce. This adaptation is through amino acid variations, but the patterns of such variation are not yet well understood. Given that infection of long-lived CD4-low and CD4-negative cells in anatomical compartments such as the brain expands cell tropism in vivo and may serve as potential viral reservoirs that pose challenge for HIV eradication, understanding the evolution to CD4 independence and envelope conformation associated with infection in the absence of CD4 will not only broaden our insights into HIV pathogenesis but may guide functional cure strategies as well. We characterize, by site-directed mutagenesis, neutralization assay, and structural analysis, a pair of CD4-dependent (cl2) and CD4-independent (cl20) envelopes concurrently isolated from the cerebral spinal fluid of an SHIV-infected macaque with neurological AIDS and with minimum sequence differences. Residues different between cl2 and cl20 are mapped to the V1V2 and surrounding regions. Mutations of these residues in cl2 increased its CD4 independence in infection, and the effects are cumulative and likely structural. Our data suggested that the determinants of CD4 independence in vivo mapped principally to V1V2 of gp120 that can destabilize the apex of the envelope spike, with an additional change in V4 that abrogated a potential N-linked glycan to facilitate movement of the V1V2 domain and further expose the coreceptor-binding site.

  6. Characterization of a polymorphism of CD4 in miniature swine.

    PubMed

    Sundt, T M; LeGuern, C; Germana, S; Smith, C V; Nakajima, K; Lunney, J K; Sachs, D H

    1992-05-15

    A polymorphism of CD4 in miniature swine has been identified by failure of cells from some animals to react with mAb 74-12-4. The phenotypic, molecular genetic, and functional characteristics of these animals have been defined. Cells from heterozygous animals bear approximately 50% the number of 74-12-4-reactive molecules on their surface as do cells from animals homozygous for the wild type. Animals of both phenotypes demonstrate similar flow cytometric profiles for CD8+ T cells. Northern blot analysis confirms the presence of mRNA for CD4 among PBL of animals failing to stain with 74-12-4. CD4 allelism is confirmed by Southern blot analysis, revealing RFLP. Function of the CD4 subset in vivo, as demonstrated by antibody production against a T cell-dependent Ag, is similar between animals of both phenotypes. Proliferative responses to PHA and alloantigen stimulation by a full haplotype mismatch or a class II mismatch alone are equivalent for animals of both phenotypes. These data suggest that the allelic form of CD4, designated CD4.2 in contrast to the wild-type CD4.1, is capable of performing normally as an accessory molecule in the generation of immune responses. Furthermore, antixenogeneic responses to C57B10.BR were equivalent, suggesting that both CD4 molecular types may be capable of interacting with xenogeneic class II molecules. Although the polymorphism includes differences in exons 3 and 4, regions thought to encode portions of the molecule interacting with MHC class II, these results imply that this naturally occurring CD4 polymorphism does not affect the interaction with class II molecules.

  7. 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. Copyright © 2016 by The American Association of Immunologists, Inc.

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

    PubMed

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

    2012-08-30

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

  9. Isolated cutaneous cryptococcosis in clinically unsuspected idiopathic CD4 lymphocytopenia

    PubMed Central

    Sharma, Divya; Singh, Neha; Kaushal, Seema; Jain, Shyama

    2014-01-01

    Idiopathic CD4 lymphocytopenia first defined in 1992 by the U.S. Centers for Disease Control and Prevention, as the repeated presence of a CD4+ T-lymphocyte count of fewer than 300 cells/cumm or of <20% of total T-cells with no evidence of human immunodeficiency virus (HIV) infection and therapy that might cause depressed CD4 T-cells. Most of the cases present with systemic opportunistic infections. We report a case without risk factors or laboratory evidence of HIV infection, presenting with cutaneous cryptococcal infection, diagnosed on cytology. PMID:25745296

  10. Central load reduces peripheral processing: Evidence from incidental memory of background speech.

    PubMed

    Halin, Niklas; Marsh, John E; Sörqvist, Patrik

    2015-12-01

    Is there a trade-off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n-back task in one of two levels of central/cognitive load (i.e., 1-back or 2-back) in the presence of a to-be-ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n-back task was completed. Memory was poorer in the high central load (2-back) condition in comparison with the low central load (1-back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC) - with a superior ability for attentional engagement - remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing - as indexed by incidental memory of background speech - is constrained when task engagement is high.

  11. Myeloma-like cast nephropathy caused by human recombinant soluble CD4 (sCD4) in monkeys.

    PubMed Central

    Bugelski, P. J.; Solleveld, H. A.; Fong, K. L.; Klinkner, A. M.; Hart, T. K.; Morgan, D. G.

    1992-01-01

    CD4 is the receptor for human immunodeficiency virus (HIV) on lymphocytes and macrophages. Soluble CD4 (sCD4), a recombinant truncated form of CD4, has been shown to inhibit HIV-1 in vitro and is being tested as a therapy for AIDS. Preclinical studies in cynomolgus monkeys revealed a protein cast nephropathy after four daily intravenous doses of 100 mg/kg/day. Renal lesions were not found in monkeys that received 10 mg/kg/day. The renal lesions consisted of proteinaceous tubular casts associated with multinucleate giant cells and neutrophils located in the tubules of the distal nephron. The affected tubules were surrounded by an interstitial mixed inflammatory cell infiltrate. By electron microscopy, the casts were composed of moderately electron dense, paracrystalline material. Immunostaining demonstrated that the casts contained sCD4-derived material and Tamm-Horsfall protein. Moreover, biochemical analysis of urine showed that a portion of sCD4 was excreted as intact protein. Because infection with HIV-1 can be associated with clinically significant nephropathy, these data suggest that renal function should be closely monitored in patients receiving soluble forms of CD4. Images Figure 1 Figure 2 Figure 3 PMID:1546739

  12. Altered regulatory T cell homeostasis in patients with CD4+ lymphopenia following allogeneic hematopoietic stem cell transplantation

    PubMed Central

    Matsuoka, Ken-ichi; Kim, Haesook T.; McDonough, Sean; Bascug, Gregory; Warshauer, Ben; Koreth, John; Cutler, Corey; Ho, Vincent T.; Alyea, Edwin P.; Antin, Joseph H.; Soiffer, Robert J.; Ritz, Jerome

    2010-01-01

    CD4+CD25+Foxp3+ Tregs have an indispensable role in the maintenance of tolerance after allogeneic HSC transplantation (HSCT). Patients with chronic graft-versus-host disease (GVHD) have fewer circulating Tregs, but the mechanisms that lead to this deficiency of Tregs after HSCT are not known. Here, we analyzed reconstitution of Tregs and conventional CD4+ T cells (Tcons) in patients who underwent allogeneic HSCT after myeloablative conditioning. Following transplant, thymic generation of naive Tregs was markedly impaired, and reconstituting Tregs had a predominantly activated/memory phenotype. In response to CD4+ lymphopenia after HSCT, Tregs underwent higher levels of proliferation than Tcons, but Tregs undergoing homeostatic proliferation also showed increased susceptibility to Fas-mediated apoptosis. Prospective monitoring of CD4+ T cell subsets revealed that Tregs rapidly expanded and achieved normal levels by 9 months after HSCT, but Treg levels subsequently declined in patients with prolonged CD4+ lymphopenia. This resulted in a relative deficiency of Tregs, which was associated with a high incidence of extensive chronic GVHD. These studies indicate that CD4+ lymphopenia is a critical factor in Treg homeostasis and that prolonged imbalance of Treg homeostasis after HSCT can result in loss of tolerance and significant clinical disease manifestations. PMID:20389017

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

    PubMed

    Hanna, Zaher; 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(RD35/36AA) and Nef(D174K). Similarly, the severe depletion of double-positive CD4+CD8+ and of single-positive CD4+CD8- thymocytes, usually observed with Nef(Wt), was not detected in Nef(RD35/36AA) and Nef(D174K) Tg mice. However, both mutant Tg mice showed a partial depletion of peripheral CD4+ T cells. This was accompanied, as previously reported for Net(Wt) Tg mice, by the presence of an activated/memory-like phenotype (CD69+, CD25+, CD44+, CD45RB(Low), CD62(Low)) of CD4+ T cells expressing Nef(RD35/36AA) and to a lesser extent Nef(D174K). In addition, both mutants retained the ability to block CD4+ T cell proliferation in vitro after anti-CD3 stimulation, but not to enhance apoptosis/death of CD4+ 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+ T cells. Histopathological assessment revealed the total absence of or decrease severity and frequency of organ AIDS-like diseases (lung, heart and kidney pathologies) in respectively Nef(RD35/36AA) and Nef(D174K) Tg mice, relative to those developing in Nef(Wt) Tg

  14. 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

  15. Extensive CD4 and CD8 T-cell cross-reactivity between alphaherpesviruses1

    PubMed Central

    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.

    2015-01-01

    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 bi-directional cross-reactivity. HSV-specific CD4 T cells recovered from HSV seronegative persons can be partially explained 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, and 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 10-50%. Based on these findings, we hypothesize 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

  16. CD4+ and γδTCR+ T lymphocytes are sources of interleukin-17 in swine.

    PubMed

    Stepanova, Hana; Mensikova, Marketa; Chlebova, Katarina; Faldyna, Martin

    2012-05-01

    In the veterinary field, only limited information is available about interleukin-17A (IL-17), despite the fact that this cytokine plays an important role during pro-inflammatory immune responses and induces the production of chemotactic factors for neutrophils. The aim of this study was to characterize porcine IL-17-producing cells. We tested the cross-reactivity of five anti-human IL-17 monoclonal antibodies because such antibodies against porcine IL-17 are currently unavailable. Whole blood cells (WBCs) were stimulated with phorbol-myristate-acetate (PMA) and ionomycin and subsequently analyzed by flow cytometry. The antibody clone SCPL1362 was found to cross-react with porcine IL-17, whereas the other four antibodies tested did not recognize this cytokine. Using this antibody, we characterized porcine WBC-secreting IL-17 after PMA and ionomycin stimulation. All IL-17-producing WBCs were positive for the T lymphocyte marker CD3. Myeloid cells (CD172α(+)) and B lymphocytes (CD79α(+)) were IL-17 negative. The major subset of IL-17 positive T lymphocytes was the CD4(+) lymphocytes (about 60% of all IL-17 positive WBCs). The remaining IL-17 positive WBCs were γδTCR(+) lymphocytes. CD8 positive and CD8 negative cells were found within both CD4(+) and γδTCR(+) cells producing the cytokine. Moreover, IL-17 positive cells were mostly CD45RA negative, therefore activated cells or memory cells. Flow cytometry data were confirmed using sorted cells. Both sorted CD4(+) and γδTCR(+) cells produced IL-17 at mRNA level after PMA and ionomycin stimulation while double negative CD4(-)γδTCR(-) cells were negative for IL-17. We can conclude that only two subpopulations of porcine WBCs are sources of IL-17 after non-specific stimulation: CD3(+)CD4(+) and CD3(+)γδTCR(+). Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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

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

    PubMed Central

    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

    2016-01-01

    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

  19. 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.

  20. Interleukin-2 Therapy Induces CD4 Downregulation, Which Decreases Circulating CD4 T Cell Counts, in African Green Monkeys

    PubMed Central

    Mudd, Joseph C.; Perkins, Molly R.; DiNapoli, Sarah R.; Hirsch, Vanessa M.

    2016-01-01

    ABSTRACT African green monkeys (AGMs) are natural hosts of simian immunodeficiency virus (SIVAGM). Because these animals do not develop simian AIDS despite maintaining high viral loads, there is considerable interest in determining how these animals have evolved to avoid SIV disease progression. Unlike nonnatural hosts of SIV, adult AGMs maintain low levels of CD4+ T cells at steady states and also have a large population of virus-resistant CD8αα T cells that lack CD4 expression despite maintaining T helper cell functionalities. In recent work, we have shown that homeostatic cytokines can induce CD4 downregulation in AGM T cells in vitro. Through administering therapeutic doses of recombinant human interleukin-2 (IL-2) to AGMs, we show here that this mechanism is operative in vivo. IL-2 therapy induced transient yet robust proliferation in all major T cell subsets. Within the CD4+ T cell population, those that were induced into cycle by IL-2 exhibited characteristics of CD4-to-CD8αα conversion. In all animals receiving IL-2, circulating CD4+ T cell counts and proportions tended to be lower and CD4− CD8αα+ T cell counts tended to be higher. Despite reductions in circulating target cells, the viral load was unaffected over the course of study. IMPORTANCE The data in this study identify that homeostatic cytokines can downregulate CD4 in vivo and, when given therapeutically, can induce AGMs to sustain very low levels of circulating CD4+ T cells without showing signs of immunodeficiency. PMID:27053558

  1. Inferential Costs of Trait Centrality in Impression Formation: Organization in Memory and Misremembering

    PubMed Central

    Nunes, Ludmila D.; Garcia-Marques, Leonel; Ferreira, Mário B.; Ramos, Tânia

    2017-01-01

    An extension of the DRM paradigm was used to study the impact of central traits (Asch, 1946) in impression formation. Traits corresponding to the four clusters of the implicit theory of personality—intellectual, positive and negative; and social, positive and negative (Rosenberg et al., 1968)—were used to develop lists containing several traits of one cluster and one central trait prototypical of the opposite cluster. Participants engaging in impression formation relative to participants engaging in memorization not only produced higher levels of false memories corresponding to the same cluster of the list traits but, under response time pressure at retrieval, also produced more false memories of the cluster corresponding to the central trait. We argue that the importance of central traits stems from their ability to activate their corresponding semantic space within a specialized associative memory structure underlying the implicit theory of personality. PMID:28878708

  2. Inferential Costs of Trait Centrality in Impression Formation: Organization in Memory and Misremembering.

    PubMed

    Nunes, Ludmila D; Garcia-Marques, Leonel; Ferreira, Mário B; Ramos, Tânia

    2017-01-01

    An extension of the DRM paradigm was used to study the impact of central traits (Asch, 1946) in impression formation. Traits corresponding to the four clusters of the implicit theory of personality-intellectual, positive and negative; and social, positive and negative (Rosenberg et al., 1968)-were used to develop lists containing several traits of one cluster and one central trait prototypical of the opposite cluster. Participants engaging in impression formation relative to participants engaging in memorization not only produced higher levels of false memories corresponding to the same cluster of the list traits but, under response time pressure at retrieval, also produced more false memories of the cluster corresponding to the central trait. We argue that the importance of central traits stems from their ability to activate their corresponding semantic space within a specialized associative memory structure underlying the implicit theory of personality.

  3. Modulation of CD4 and CD8 response to QuantiFERON-TB Plus in patients with active tuberculosis and latent tuberculosis infection followed over time during treatment.

    PubMed

    Chiacchio, Teresa; Petruccioli, Elisa; Pepponi, Ilaria; Vanini, Valentina; Gualano, Gina; Cirillo, Daniela; Palmieri, Fabrizio; Ippolito, Giuseppe; Goletti, Delia

    2016-12-01

    Interferon (IFN)-γ release assays (IGRA) are designed for diagnosing tuberculosis (TB) infection. The new IGRA, QuantiFERON-TB Plus (QFT-Plus), is based on the enzyme-linked immunosorbent assay detection of IFN-γ after stimulation with Mycobacterium tuberculosis TB1 and TB2 antigens. TB1 elicits a cellular-mediated immune (CMI) response by CD4 T cells, and TB2 contains peptides recognized by both CD4 and CD8 T cells. The aim of the study is to characterize the CMI to QFT-Plus peptides in active TB and latent TB infection (LTBI) at baseline and during or after specific treatment (follow-up). We enrolled 7 individuals with active TB and 11 individuals with LTBI at baseline and followed them during the treatment, either for active diseases or preventive therapy. Peripheral blood mononuclear cells were stimulated with QFT-Plus antigens (TB1, TB2, and mitogen). Cytokine profile (IFN-γ, tumor necrosis factor-α, interleukin-2) and phenotype (CD45RA, CD27) of CD4 and CD8 T cells were characterized by flow cytometry. All the individuals responded to mitogen. CD4 T-cell responses to TB1 and TB2 were similar in both individuals with active TB and those with LTBI evaluated over time. Differently, we found a higher number of TB2-associated CD8 T-cell responders in individuals with active TB than in those with LTBI. For individuals with active TB, there was no change in the specific response overtime. Differently, in individuals with LTBI, the number of CD8 responders to QFT-Plus antigens increased during preventive treatment (TB1=5/11 [45%], TB2=5/11 [45%]) compared with that at the time of enrolment (TB1=1/11 [9%], TB2=1/11 [9%]). Moreover, we analyzed the effector memory profile of T cells responding to QFT-Plus antigens. The largest component of antigen-specific CD4 T cells (65%) had a central memory (CD45RA-CD27+) phenotype at enrolment and during follow-up. In contrast, specific CD8 T cells, which were analyzed only at follow-up because they were almost absent at

  4. Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

    PubMed

    Heit, Antje; Gebhardt, Friedemann; Lahl, Katharina; Neuenhahn, Michael; Schmitz, Frank; Anderl, Florian; Wagner, Hermann; Sparwasser, Tim; Busch, Dirk H; Kastenmüller, Kathrin

    2008-06-01

    Immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained CD8(+) T cell-mediated protection against intracellular pathogens. Most efforts to improve the CD8(+) T cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. In addition, it has been shown that CD4(+) T cell help during the priming phase contributes to the generation of protective CD8(+) memory T cells. In this report we demonstrate that the depletion of CD4(+) T cells paradoxically enhances long-lasting CD8-mediated protective immunity upon protein vaccination. Functional and genetic in vivo inactivation experiments attribute this enhancement primarily to MHC class II-restricted CD4(+) regulatory T cells (Treg), which appear to physiologically suppress the differentiation process towards long-living effector memory T cells. Since, in functional terms, this suppression by Treg largely exceeds the positive effects of conventional CD4(+) T cell help, even the absence of all CD4(+) T cells or lack of MHC class II-mediated interactions on priming dendritic cells result in enhanced CD8(+) T cell immunogenicity. These findings have important implications for the improvement of vaccines against intracellular pathogens or tumors, especially in patients with highly active Treg.

  5. Seasonal Influenza Can Poise Hosts for CD4 T-Cell Immunity to H7N9 Avian Influenza

    PubMed Central

    Richards, Katherine A.; Nayak, Jennifer; Chaves, Francisco A.; DiPiazza, Anthony; Knowlden, Zackery A. G.; Alam, Shabnam; Treanor, John J.; Sant, Andrea J.

    2015-01-01

    The emergence of avian H7N9 viruses has raised concerns about its pandemic potential and prompted vaccine trials. At present, it is unknown whether there will be sufficient cross-reactive hemagglutinin (HA)–specific CD4 T-cell memory with seasonal influenza to facilitate antibody production to H7 HA. There has also been speculation that H7N9 will have few CD4 T-cell epitopes. In this study, we quantified the potential of seasonal influenza to provide memory CD4 T cells that can cross-reactively recognize H7 HA–derived peptides. These studies have revealed that many humans have substantial H7-reactive CD4 T cells, whereas up to 40% are lacking such reactivity. Correlation studies indicate that CD4 T cells reactive with H7 HA are drawn from reactivity generated from seasonal strains. Overall, our findings suggest that previous exposure of humans to seasonal influenza can poise them to respond to avian H7N9, but this is likely to be uneven across populations. PMID:25492919

  6. 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

  7. Increased TNF-α/IFN-γ/IL-2 and Decreased TNF-α/IFN-γ Production by Central Memory T Cells Are Associated with Protective Responses against Bovine Tuberculosis Following BCG Vaccination

    PubMed Central

    Maggioli, Mayara F.; Palmer, Mitchell V.; Thacker, Tyler C.; Vordermeier, Hans Martin; McGill, Jodi L.; Whelan, Adam O.; Larsen, Michelle H.; Jacobs, William R.; Waters, W. Ray

    2016-01-01

    Central memory T cell (Tcm) and polyfunctional CD4 T cell responses contribute to vaccine-elicited protection with both human and bovine tuberculosis (TB); however, their combined role in protective immunity to TB is unclear. To address this question, we evaluated polyfunctional cytokine responses by CD4 T cell effector/memory populations from bacille Calmette–Guerin (BCG) vaccinated and non-vaccinated calves by flow cytometry prior to and after aerosol challenge with virulent Mycobacterium bovis. Polyfunctional cytokine expression patterns in the response by Tcm, effector memory, and effector T cell subsets were similar between BCG-vaccinated and M. bovis-infected calves, only differing in magnitude (i.e., infected > vaccinated). BCG vaccination, however, did alter the kinetics of the ensuing response to virulent M. bovis infection. Early after challenge (3 weeks post-infection), non-vaccinates had greater antigen-specific interferon-γ (IFN-γ)/tumor necrosis factor-α (TNF-α) and lesser IFN-γ/TNF-α/IL-2 responses by Tcm cells than did vaccinated animals. Importantly, these differences were also associated with mycobacterial burden upon necropsy. Polyfunctional responses to ESAT-6:CFP10 (antigens not synthesized by BCG strains) were detected in memory subsets, as well as in effector cells, as early as 3 weeks after challenge. These findings suggest that cell fate divergence may occur early after antigen priming in the response to bovine TB and that memory and effector T cells may expand concurrently during the initial phase of the immune response. In summary, robust IFN-γ/TNF-α response by Tcm cells is associated with greater mycobacterial burden, while IFN-γ/TNF-α/IL-2 response by Tcm cells are indicative of a protective response to bovine TB. PMID:27799930

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

    PubMed

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

    2016-02-01

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

  9. GM-CSF Production Allows the Identification of Immunoprevalent Antigens Recognized by Human CD4+ T Cells Following Smallpox Vaccination

    PubMed Central

    Judkowski, Valeria; Bunying, Alcinette; Ge, Feng; Appel, Jon R.; Law, Kingyee; Sharma, Atima; Raja- Gabaglia, Claudia; Norori, Patricia; Santos, Radleigh G.; Giulianotti, Marc A.; Slifka, Mark K.; Douek, Daniel C.; Graham, Barney S.; Pinilla, Clemencia

    2011-01-01

    The threat of bioterrorism with smallpox and the broad use of vaccinia vectors for other vaccines have led to the resurgence in the study of vaccinia immunological memory. The importance of the role of CD4+ T cells in the control of vaccinia infection is well known. However, more CD8+ than CD4+ T cell epitopes recognized by human subjects immunized with vaccinia virus have been reported. This could be, in part, due to the fact that most of the studies that have identified human CD4+ specific protein-derived fragments or peptides have used IFN-γ production to evaluate vaccinia specific T cell responses. Based on these findings, we reasoned that analyzing a large panel of cytokines would permit us to generate a more complete analysis of the CD4 T cell responses. The results presented provide clear evidence that TNF-α is an excellent readout of vaccinia specificity and that other cytokines such as GM-CSF can be used to evaluate the reactivity of CD4+ T cells in response to vaccinia antigens. Furthermore, using these cytokines as readout of vaccinia specificity, we present the identification of novel peptides from immunoprevalent vaccinia proteins recognized by CD4+ T cells derived from smallpox vaccinated human subjects. In conclusion, we describe a “T cell–driven” methodology that can be implemented to determine the specificity of the T cell response upon vaccination or infection. Together, the single pathogen in vitro stimulation, the selection of CD4+ T cells specific to the pathogen by limiting dilution, the evaluation of pathogen specificity by detecting multiple cytokines, and the screening of the clones with synthetic combinatorial libraries, constitutes a novel and valuable approach for the elucidation of human CD4+ T cell specificity in response to large pathogens. PMID:21931646

  10. Elevated humoral response to cytomegalovirus in HIV-infected individuals with poor CD4+ T-cell immune recovery.

    PubMed

    Gómez-Mora, Elisabet; Massanella, Marta; García, Elisabet; Giles, David; Bernadó, Marta; Urrea, Victor; Carrillo, Jorge; Ouchi, Dan; Puig, Jordi; Negredo, Eugenia; Clotet, Bonaventura; Blanco, Julià; Cabrera, Cecilia

    2017-01-01

    Some HIV-infected c-ART-suppressed individuals show incomplete CD4+ T-cell recovery, abnormal T-cell activation and higher mortality. One potential source of immune activation could be coinfection with cytomegalovirus (CMV). IgG and IgM levels, immune activation, inflammation and T-cell death in c-ART-suppressed individuals with CD4+ T-cell counts >350 cells/μL (immunoconcordant, n = 133) or <350 cells/μL (immunodiscordant, n = 95) were analyzed to evaluate the effect of CMV humoral response on immune recovery. In total, 27 HIV-uninfected individuals were included as controls. In addition, the presence of CMV IgM antibodies was retrospectively analyzed in 58 immunoconcordant individuals and 66 immunodiscordant individuals. Increased CMV IgG levels were observed in individuals with poor immune reconstitution (p = 0.0002). Increased CMV IgG responses were significantly correlated with lower nadir and absolute CD4+ T-cell counts. In contrast, CMV IgG responses were positively correlated with activation (HLA-DR+) and death markers in CD4+ T-cells and activated memory CD8+ T-cells (CD45RA-CD38+). Longitudinal subanalysis revealed an increased frequency of IgM+ samples in individuals with poor CD4+ T-cell recovery, and an association was observed between retrospective IgM positivity and the current level of IgG. The magnitude of the humoral immune response to CMV is associated with nadir CD4+ T-cell counts, inflammation, immune activation and CD4+ T-cell death, thus suggesting that CMV infection may be a relevant driving force in the increased morbidity/mortality observed in HIV+ individuals with poor CD4+ T-cell recovery.

  11. Inhibition of TGF-β1 Signaling Promotes Central Memory T Cell Differentiation

    PubMed Central

    Takai, Shinji; Schlom, Jeffrey; Tucker, Joanne; Tsang, Kwong Y.; Greiner, John W.

    2013-01-01

    The present study affirmed that isolated CD8+ T cells express mRNA and produce TGF-β following cognate peptide recognition. Blockage of endogenous TGF-β with either a TGF-β-blocking antibody or a small molecule inhibitor of TGF-βRI enhances the generation of CD62Lhigh/CD44high central memory CD8+ T cells accompanied with a robust recall response. Interestingly, the augmentation within the central memory T cell pool occurs in lieu of cellular proliferation or activation, but with the expected increase in the ratio of the Eomes/T-bet transcriptional factors. Yet, the signal transduction pathway(s) seems to be non-canonical, independent of SMAD or mTOR signaling. Enhancement of central memory generation by TGF-β blockade is also confirmed in human PBMCs. The findings underscore the role(s) that autocrine TGF-β plays in T cell homeostasis and, in particular, the balance of effector/memory and central/memory T cells. These results may provide a rationale to targeting TGF-β signaling to enhance antigen-specific CD8+ T cell memory against a lethal infection or cancer. PMID:23904158

  12. 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

  13. Cyclotriazadisulfonamides: promising new CD4-targeted anti-HIV drugs.

    PubMed

    Vermeire, Kurt; Schols, Dominique

    2005-08-01

    It is imperative to continue efforts to identify novel effective therapies that can assist in containing the spread of HIV. Recently acquired knowledge about the HIV entry process points to new strategies to block viral entry. For most HIV strains, the successful infection of their target cells is mainly dependent on the presence of the CD4 surface molecule, which serves as the primary virus receptor. The attachment of the viral envelope to this cellular CD4 receptor can be considered as an ideal target with multiple windows of opportunity for therapeutic intervention. Therefore, drugs that interfere with the CD4 receptor, and thus inhibit viral entry, may be promising agents for the treatment of AIDS. The CD4-targeted HIV entry inhibitors cyclotriazadisulfonamides represent a novel class of small molecule antiviral agents with a unique mode of action. The lead compound, CADA, specifically interacts with the cellular CD4 receptor and is active against a wide variety of HIV strains at submicromolar levels when evaluated in different cell-types such as T cells, monocytes and dendritic cells. Moreover, a strict correlation has been demonstrated between anti-HIV activity and CD4 interaction of about 20 different CADA analogues. In addition, CADA acted synergistically in combination with all other FDA-approved anti-HIV drugs as well as with compounds that target the main HIV co-receptors. In this article, the characteristics of cyclotriazadisulfonamide compounds are presented and the possible application of CADA as a microbicide is also discussed.

  14. Decentralization of CD4 testing in resource-limited settings: 7 years of experience in six African countries.

    PubMed

    Marinucci, F; Medina-Moreno, S; Paterniti, A D; Wattleworth, M; Redfield, R R

    2011-05-01

    Improving access to CD4 testing in resource-limited settings can be achieved through both centralized and decentralized testing networks. Decentralized testing models are more suitable for countries where the HIV epidemic affects a large portion of rural populations. Timely access to accurate CD4 results is crucial at the primary level of the health system. For the past 7 years, the Institute of Human Virology of the University of Maryland School of Medicine has implemented a flexible and sustainable three-phase model: (1) site assessment and improvement, (2) appropriate technology selection with capacity building through practical training and laboratory mentoring, and (3) quality management system strengthening and monitoring, to support accessibility to reliable CD4 counting at the point of service. CD4 testing capacity was established in 122 of 229 (53%) laboratories supported in Nigeria, Uganda, Kenya, Zambia, Tanzania, and Rwanda. Among those in rural settings, 46% (69/151) had CD4 testing available at site level, with a functioning flow cytometer installed at 28% (8/29) and 50% (61/122) of level 1 and level 2 sites, respectively. To strengthen local capacity, a total of 1,152 laboratory technicians were trained through 188 training sessions provided both on-site and at central locations. The overall quality of CD4 total testing procedure was assessed at 76% (92/121) of the laboratories, with 25% (23/92), 34% (31/92), and 33% (30/92) of them reporting excellent, good, and satisfactory performance. Balancing country-specific factors with the location of the clinic, number of patients, and the expected workload, was crucial in adapting this flexible model for decentralizing CD4 testing. The close collaboration with local governments and private vendors was key to successfully expanding access to CD4 testing within the framework of HIV care and treatment programs and for the sustainability of medical laboratories in resource-limited settings.

  15. Abortive HIV Infection Mediates CD4 T-Cell Depletion and Inflammation in Human Lymphoid Tissue

    PubMed Central

    Doitsh, Gilad; Cavrois, Marielle; Lassen, Kara G.; Zepeda, Orlando; Yang, Zhiyuan; Santiago, Mario L.; Hebbeler, Andrew M.; Greene, Warner C.

    2010-01-01

    Summary The mechanism by which CD4 T-cells are depleted in HIV-infected hosts remains poorly understood. In ex vivo cultures of human tonsil tissue, CD4 T cells undergo a pronounced cytopathic response following HIV infection. Strikingly, >95% of these dying cells are not productively infected but instead correspond to bystander cells. We now show that the death of these “bystander” cells involves abortive HIV infection. Inhibitors blocking HIV entry or early steps of reverse transcription prevent CD4 T-cell death while inhibition of later events in viral life cycle does not. We propose that the nonpermissive state exhibited by the majority of resting CD4 tonsil T-cells leads to accumulation of incomplete reverse transcripts. These cytoplasmic nucleic acids activate a host defense program that elicits a coordinated proapoptotic and proinflammatory response involving caspase-3 and caspase-1 activation. While this response likely evolved to protect the host, it centrally contributes to the immunopathogenic effects of HIV. PMID:21111238

  16. Abortive HIV infection mediates CD4 T cell depletion and inflammation in human lymphoid tissue.

    PubMed

    Doitsh, Gilad; Cavrois, Marielle; Lassen, Kara G; Zepeda, Orlando; Yang, Zhiyuan; Santiago, Mario L; Hebbeler, Andrew M; Greene, Warner C

    2010-11-24

    The mechanism by which CD4 T cells are depleted in HIV-infected hosts remains poorly understood. In ex vivo cultures of human tonsil tissue, CD4 T cells undergo a pronounced cytopathic response following HIV infection. Strikingly, >95% of these dying cells are not productively infected but instead correspond to bystander cells. We now show that the death of these "bystander" cells involves abortive HIV infection. Inhibitors blocking HIV entry or early steps of reverse transcription prevent CD4 T cell death while inhibition of later events in the viral life cycle does not. We demonstrate that the nonpermissive state exhibited by the majority of resting CD4 tonsil T cells leads to accumulation of incomplete reverse transcripts. These cytoplasmic nucleic acids activate a host defense program that elicits a coordinated proapoptotic and proinflammatory response involving caspase-3 and caspase-1 activation. While this response likely evolved to protect the host, it centrally contributes to the immunopathogenic effects of HIV. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. High frequency of central memory regulatory T cells allows detection of liver recipients at risk of early acute rejection within the first month after transplantation.

    PubMed

    Boix-Giner, Francisco; Millan, Olga; San Segundo, David; Muñoz-Cacho, Pedro; Mancebo, Esther; Llorente, Santiago; Rafael-Valdivia, Lourdes; Rimola, Antoni; Fábrega, Emilio; Mrowiec, Anna; Allende, Luis; Minguela, Alfredo; Bolarín, Jose M; Paz-Artal, Estela; López-Hoyos, Marcos; Brunet, Mercé; Muro, Manuel

    2016-02-01

    Several studies have analyzed the potential of T regulatory cells (Treg cells) as biomarkers of acute rejection (AR). The aim of the present multicenter study was to correlate the percentage of peripheral Treg cells in liver graft recipients drawn at baseline up to 12 months after transplantation with the presence of AR. The percentage of central memory (cm) Treg cells (CD4(+)CD25(high)CD45RO(+)CD62L(+)) was monitored at pre-transplant and at 1 and 2 weeks, and 1, 2, 3 and 6 months and 1 year post-transplantation. The same validation standard operating procedures were used in all participating centers. Fifteen patients developed AR (23.4%). Hepatitis C virus recurrence was observed in 16 recipients, who displayed low peripheral blood cmTreg levels compared with patients who did not. A steady increase of cmTregs was observed during the first month after transplantation with statistically significant differences between AR and non-AR patients. The high frequency of memory Treg cells allowed us to monitor rejection episodes during the first month post-transplantation. On the basis of