scholarly journals Persistent Infection with Ebola Virus under Conditions of Partial Immunity

2004 ◽  
Vol 78 (2) ◽  
pp. 958-967 ◽  
Author(s):  
Manisha Gupta ◽  
Siddhartha Mahanty ◽  
Patricia Greer ◽  
Jonathan S. Towner ◽  
Wun-Ju Shieh ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Persistent Infection ◽  
Cd4 T Cells ◽  
Viral Antigen ◽  
Ebola Virus ◽  
Hemorrhagic Fever ◽  
Subcutaneous Infection ◽  
Deficient Mice

ABSTRACT Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed to subcutaneous infection and had high viral antigen titers in tissues, whereas mice deficient in B cells or CD4 T cells cleared infection and survived, suggesting that CD8 T cells, independent of CD4 T cells and antibodies, are critical to protection against subcutaneous Ebola virus infection. B-cell-deficient mice that survived the primary subcutaneous infection (vaccinated mice) transiently depleted or not depleted of CD4 T cells also survived lethal intraperitoneal rechallenge for ≥25 days. However, all vaccinated B-cell-deficient mice depleted of CD8 T cells had high viral antigen titers in tissues following intraperitoneal rechallenge and died within 6 days, suggesting that memory CD8 T cells by themselves can protect mice from early death. Surprisingly, vaccinated B-cell-deficient mice, after initially clearing the infection, were found to have viral antigens in tissues later (day 120 to 150 post-intraperitoneal infection). Furthermore, following intraperitoneal rechallenge, vaccinated B-cell-deficient mice that were transiently depleted of CD4 T cells had high levels of viral antigen in tissues earlier (days 50 to 70) than vaccinated undepleted mice. This demonstrates that under certain immunodeficiency conditions, Ebola virus can persist and that loss of primed CD4 T cells accelerates the course of persistent infections. These data show that CD8 T cells play an important role in protection against acute disease, while both CD4 T cells and antibodies are required for long-term protection, and they provide evidence of persistent infection by Ebola virus suggesting that under certain conditions of immunodeficiency a host can harbor virus for prolonged periods, potentially acting as a reservoir.

Reconstitution of the T Cell Repertoire Following Treatment with Alemtuzumab in Patients with B-Cell Chronic Lymphocytic Leukemia (B-CLL).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2986-2986
Author(s):  
Mohammad R. Rezvany ◽  
Mahmood J. Tehrani ◽  
Claes Karlsson ◽  
Jeanette Lundin ◽  
Hodjattallah Rabbani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Long Term Follow Up

Abstract Background and Methods: B-cell chronic lymphocytic leukemia (B-CLL) occurs as a result of clonal accumulation of functionally abnormal B cells. Alemtuzumab is a humanized monoclonal antibody specific for the CD52 antigen, which is highly expressed on both B-CLL cells and normal lymphocytes, but not on hematopoietic (CD34) stem cells. Alemtuzumab has been shown to effectively deplete the blood and bone marrow of lymphocytes, including CD4 and CD8 T cells, which may lead to profound immunosuppression and make patients more susceptible to infections. We and others have previously shown that the CD4 T cells in B-CLL patients may be clonally distinct from the normal population in that they present a more clonal pattern of the T-cell receptor (TCR) repertoire (Rezvany et al, Blood2003;101:1063–1070). It is therefore of interest to study the T cell repertoire following alemtuzumab administration as well as factors affecting T cell reconstitution following CD52 targeted therapy. In this study, we evaluated in depth the T-cell receptor-beta-variable sequence (TCR BV) in CD4 and CD8 T cells by real-time PCR, before and repeatedly after/during long term follow-up, in 5 B-CLL patients who had received alemtuzumab as first-line therapy (Lundin et al, Blood2002;100:768–773). Also, an analysis was conducted of CDR3 length polymorphism to describe changes in the clonality pattern. Results: A decline in most of BV genes either in CD4 or CD8 T cells was observed shortly after alemtuzumab treatment, which was followed by a gradual increase in most of the BV genes during long-term follow up. CDR3 length polymorphism analysis shortly after treatment revealed an even more highly restricted pattern in CD4 T cells compared to baseline with a shift towards a monoclonal/oligoclonal pattern regardless of increased or decreased BV usage. Furthermore, in the analysis of the clonal spectrum that was expressed shortly after alemtuzumab therapy, the number of peaks was significantly reduced in CD4 (P <0.01) but not in CD8 T cells, which was followed by a gradual increase in diversity towards a polyclonal repertoire during long-term follow up. Conclusions: These results indicate that perturbations in the T cell repertoire following alemtuzumab are complex, and are not reflected by changes in CD4/CD8 T cell numbers only. The restricted CDR3 pattern present prior to therapy became even more restricted after end of treatment, followed by a normalization of CDR3 patterns in CD4 T-cells during long-term follow-up. These results further suggest a regulatory role for T cells in relation to the malignant B cell clone in patients with B-CLL.

scholarly journals CD4+ T cells derived from B cell-deficient mice inhibit the establishment of peripheral B cell pools

2000 ◽  
Vol 97 (9) ◽  
pp. 4766-4771 ◽  
Author(s):  
N. Baumgarth ◽  
G. C. Jager ◽  
O. C. Herman ◽  
L. A. Herzenberg ◽  
L. A. Herzenberg
Keyword(s):  
T Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Deficient Mice

scholarly journals Helios Expressing Regulatory T Cells are Correlated with Decreased IL-2 Producing CD8 T Cells and Antibody Diversity in Mozambican Individuals Living Chronically HIV-1

2021 ◽  
Author(s):  
Raquel Matavele Chissumba ◽  
Cacildo Magul ◽  
Rosa Macamo ◽  
Vânia Monteiro ◽  
Maria Enosse ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cell Function ◽  
Antibody Responses ◽  
Virologic Suppression ◽  
Antibody Diversity ◽  
Immune Alterations ◽  
Hiv 1

Abstract Background: Human immunodeficiency virus type 1 (HIV-1) causes impairment of T and B cell responses, which begins during the acute phase of infection and is not completely restored by antiretroviral treatment. Regulatory T cell (Tregs) can improve overall disease outcome by controlling chronic inflammation, but may also suppress beneficial HIV-1 specific immune responses. We analyzed immune alterations, including Tregs, and their clinical significance in Mozambican people living chronically with HIV-1 (PLWH-C). Results: In PLWH-C, the proportion of total Tregs was positively correlated with the proportion of IL-2+CD4 T cells (r=0.647; p=0.032) and IL-2+IFNg+CD8 T cells (r=0.551; p=0.014), while the Helios+Tregs correlated inversely with levels of IL-2+CD8 T cells (r= -0.541; p=0.017). Overall, PLWH-C, with (82%) or without virologic suppression (64%), were seronegative for at least HIV-1 p31, gp160 or p24, and the breadth of antibody responses was positively correlated with proportions of CD38+HLA-DR+CD8 T cells (r=0.620; p=0.012), viral load (r=0.452; p=0.040) and inversely CD4 T cells count (r=-0.481; p=0.027). Analysis of all individuals living HIV-1 showed that the breadth of HIV-1 antibody responses was inversely correlated with the proportion of Helios+Tregs (r=-0.45; p=0.02). Conclusion: Among Mozambican patients living with HIV-1, seronegativity to some HIV-1 proteins is common mostly in virologically suppressed individuals. Low diversity of HIV-specific antibodies is correlated to indicators of disease control during ART. Elevation in the proportion of Helios+Tregs is related to a reduction of CD8 T expressing intracellular IL-2 but may contribute to impairment of B cell function.

scholarly journals LAG3 and PD1 Regulate CD8+ T Cell in Diffuse Large B-cell Lymphoma Patients

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ying Liu ◽  
Xinhong Guo ◽  
Lingbo Zhan ◽  
Lei Wang ◽  
Xinyou Wang ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Immune Checkpoints ◽  
Healthy Controls ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Background. Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous lymphoid malignancy. The unsatisfactory outcome for refractory patients has prompted efforts to explore new therapeutic approaches for DLBCL. However, the mechanisms involved in treatment associated with immune checkpoints remain unclear. This study is aimed at investigating the potential roles of programmed cell death protein 1 (PD1) and lymphocyte activation gene 3 (LAG3) in CD8+ T cells for treatment in DLBCL. Methods. Utilizing flow cytometry, we examined the content of T cells, the levels of cytokines, and the expression of PD1 and LAG3 in patients with DLBCL as well as in healthy controls. Levels of cytokines in CD8+ T cells from DLBCL patients before and after treatment were compared by blocking of PD1 and LAG3 in magnetic bead-sorted CD8+ T cells. Results. We found that the proportion of CD4+ T cells and CD8+ T cells was increased in DLBCL patients after treatment. The levels of cytokines trended toward those of healthy controls in treatment. PD1 (+), LAG3 (+), or PD1 (+) LAG3 (+) were all expressed in lower amounts in CD4+ T cells and CD8+ T cells after treatment than in untreated DLBCL patients. In addition, blockade of PD1 and LAG3 in sorted CD8+ T cells markedly inhibited cytokine production in response to treatment. Conclusion. PD1 and LAG3 in CD8+ T cells may be important targets of therapy and play therapeutic role in patients with DLBCL.

Cyclophosphamide Plus Allogeneic CD4+ T Cell Infusion Induces Anti-Lymphoma Immunity Despite Lack of Graft-Versus-Host Disease (GVHD) or Sustained Engraftment.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3063-3063
Author(s):  
Sanju Jalla ◽  
Jie Wang ◽  
Leo Luznik ◽  
Ephraim J. Fuchs
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Cell Leukemia ◽  
B Cell Leukemia ◽  
T Cell Help

Abstract Recent evidence suggests that tumor-bearing animals contain CD8+ T cells that can respond productively to a tumor vaccine, but that these T cells do not respond because of insufficient help from tumor-specific CD4+ T cells, which have either been inactivated or turned into anti-tumor suppressor T cells. We therefore devised a strategy to augment anti-tumor immunity by administering cyclophosphamide (Cy), to eliminate suppressor CD4+ T cells, followed by combining autologous tumor cell vaccination and infusion of partially MHC-mismatched, or haploidentical, CD4+ T cells as a source of T cell help for endogenous CD8+ T cells. Interestingly, the combination of Cy followed by haploidentical T cell infusion, with or without vaccine, induced potent systemic anti-tumor immunity resulting in cure of 40-50% of BALB/c mice harboring the A20 B cell leukemia/lymphoma. Depletion of CD8+ T cells from the infusate abrogated GVHD but did not compromise anti-tumor immunity. Allogeneic donor spleen cells that contained CD8+ T cells engrafted durably and caused lethal GVHD. In contrast, the combination of Cy plus CD8+ T cell-depleted spleen cell infusion induced only transient engraftment, peaking on day 7 and declining to undetectable levels by day 14. In the absence of Cy conditioning, allogeneic donor spleen cell infusions did not induce detectable chimerism beyond day 3. In summary, Cy plus allogeneic CD4+ T cell infusion induces potent anti-tumor immunity in a mouse model of B cell leukemia/lymphoma. Potential mechanisms of the therapeutic effect include direct tumor cytotoxicity by CD4+ T cells or allogeneic CD4+ T cell help for endogenous, tumor-specific CD8+ T cells.

scholarly journals 661 Neoantigen-specific CD4+ T cells in human melanoma have diverse differentiation states and correlate with CD8+ T cell, macrophage, and B cell function

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A689-A689
Author(s):  
Naina Singhi ◽  
Carolyn Shasha ◽  
Sylvia Lee ◽  
Julia Szeto ◽  
Ata Moshiri ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Cd8 T Cells ◽  
Immune Cells ◽  
Tumor Antigen ◽  
Cd4 T Cells ◽  
Viral Antigen ◽  
Tumor Antigens ◽  
Human Melanoma

BackgroundTumor-antigen specific CD4+ T cells are crucial for the efficacy of antibodies that block immune checkpoint proteins in mouse tumor models, but their activities in human tumor immunity are less clear. CD8+ T cells infiltrating human tumors, including those specific for tumor antigens, have been studied using single cell profiling techniques and exist in a variety of dysfunctional states. The transcriptional states of tumor-specific CD4+ T cells present in tumors and their potential contributions to the tumor microenvironment are less well understood.MethodsWe used targeted single cell RNA sequencing and matching of T cell receptor (TCR) sequences to identify phenotypic signatures that discriminated tumor antigen- and viral antigen-specific CD4+ T cells infiltrating human melanoma tumors in four patients. The presence of CD4+ T cells with these signatures was correlated with the number and phenotype of other immune cells in the tumor microenvironment in an extended cohort of 20 patients.ResultsWe identified 259 CD4+ T cells representing 40 different TCR clonotypes specific for 13 neoantigens and 108 cells representing 14 TCR clonotypes specific for self-antigens in four melanoma patients. High expression of CXCL13 defined conventional CD4+ T cells that recognize tumor associated neoantigens and self-antigens from bystander and viral antigen-specific CD4+ T cells. Tumor-reactive CD4+ T cells could be subdivided into clusters expressing memory and T follicular helper markers, and those expressing cytolytic markers and IFN-g. In an extended cohort of 20 patients with melanoma, the frequency of CXCL13+ CD4+ T cells in the tumor microenvironment correlated with the presence and proliferation of CD8+ T cells, the presence and maturation of B cells, the activation of interferon responsive genes in tumor associated macrophages, and patient survival. CD4+ T cells with similar transcriptional signatures were identified in data sets from breast and non-small cell lung cancer, suggesting these markers may enrich for tumor-reactive CD4+ T cells in many cancers.ConclusionsThese results identify a subset of tumor infiltrating conventional CD4+ T cells in melanoma that are enriched for reactivity to tumor antigens and exist in multiple phenotypic states. Correlations of the presence of these cells with the frequency and phenotype of other immune cells suggest roles for these tumor antigen-specific CD4+ T cells in providing CD8+ T cell help, driving recruitment and maturation of B cells, and activating macrophages. Isolating such cells based on their unique phenotype and utilizing them for adoptive therapy could alter the tumor microenvironment for therapeutic benefit.Ethics ApprovalAll Patient samples in this study were obtained from patients who signed informed consent in a study approved by the institutional review board of the Fred Hutchinson Cancer Research Center (protocol #2643).

scholarly journals Critical Role of T Cells in PF4/Heparin Antibody Production

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1554-1554
Author(s):  
Yongwei Zheng ◽  
Mei Yu ◽  
Anand Padmanabhan ◽  
Richard H. Aster ◽  
Renren Wen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antibody Production ◽  
Cd4 T Cells ◽  
Wild Type ◽  
Specific Antibodies ◽  
Deficient Mice

Abstract Heparin-induced thrombocytopenia (HIT) is an antibody-mediated disorder that can cause arterial or venous thrombosis/thromboembolism, and platelet factor 4 (PF4)/ heparin-reactive antibodies are essential to the pathogenesis of HIT. Our recent studies have demonstrated that marginal zone (MZ) B cells play a major role in production of PF4/heparin-specific antibodies. However, the role of T cells in production of these pathogenic antibodies is not clear. Here we showed that PF4/heparin complex-induced production of PF4/heparin-specific antibodies was markedly impaired in mice, in which CD4 T cells were depleted by administration of GK1.5 anti-CD4 monoclonal antibody. As expected, the CD4 T cell-depleted mice responded normally to T cell-independent antigen TNP-Ficoll but not T cell-dependent antigen NP-CGG, in agreement with the lack of CD4 T cells in these GK1.5-treated mice. Further, following adoptive transfer of a mixture of wild-type splenic B cells and splenocytes from B cell-deficient μMT mice, T and B cell-deficient Rag1 knockout mice responded to PF4/heparin complex challenge to produce PF4/heparin-specific antibodies. In contrast, Rag1-deficient mice that received a mixture of wild-type splenic B cells and splenocytes from Rag1-deficient mice barely produced PF4/heparin-specific antibodies upon PF4/heparin complex challenge. These data suggest that T cells are required for production of PF4/heparin-specific antibodies. Consistent with this concept, mice with B cells lacking CD40 molecule, a B cell costimulatory molecule that helps T cell-dependent B cell responses, displayed a marked reduction of PF4/heparin-specific antibody production following PF4/heparin complex challenge. Also as expected, mice with CD40-deficient B cells were able to respond to T cell-independent antigen TNP-Ficoll but not T cell-dependent antigen NP-CGG, consistent with the lack of T-cell help in these mice. Taken together, these findings demonstrate that T cells play an essential role in production of PF4/heparin-specific antibodies by MZ B cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals CD4 T Cells Are the Only Lymphocytes Needed To Protect Mice against Rotavirus Shedding after Intranasal Immunization with a Chimeric VP6 Protein and the Adjuvant LT(R192G)

2002 ◽  
Vol 76 (2) ◽  
pp. 560-568 ◽  
Author(s):  
Monica M. McNeal ◽  
John L. VanCott ◽  
Anthony H. C. Choi ◽  
Matili Basu ◽  
Jason A. Flint ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Vaccine Candidate ◽  
Γδ T Cells ◽  
Mouse Strains ◽  
Virus Shedding ◽  
Intranasal Immunization ◽  
Lymphocyte Populations ◽  
Deficient Mice

ABSTRACT Intranasal immunization of mice with a chimeric VP6 protein and the mucosal adjuvant Escherichia coli heat labile toxin LT(R192G) induces nearly complete protection against murine rotavirus (strain EDIM [epizootic diarrhea of infant mice virus]) shedding for at least 1 year. The aim of this study was to identify the protective lymphocytes elicited by this new vaccine candidate. Immunization of mouse strains lacking one or more lymphocyte populations revealed that protection was dependent on αβ T cells but mice lacking γδ T cells and B cells remained fully protected. Furthermore, depletion of CD8 T cells in immunized B-cell-deficient mice before challenge resulted in no loss of protection, while depletion of CD4 T cells caused complete loss of protection. Therefore, αβ CD4 T cells appeared to be the only lymphocytes required for protection. As confirmation, purified splenic T cells from immunized mice were intraperitoneally injected into Rag-2 mice chronically infected with EDIM. Transfer of 2 × 106 CD8 T cells had no effect on shedding, while transfer of 2 × 105 CD4 T cells fully resolved shedding in 7 days. Interestingly, transfer of naive splenic CD4 T cells also resolved shedding but more time and cells were required. Together, these results establish CD4 T cells as effectors of protection against rotavirus after intranasal immunization of mice with VP6 and LT(R192G).

Differential use of FasL- and perforin-mediated cytolytic mechanisms by T-cell subsets involved in graft-versus-myeloid leukemia responses

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1047-1055 ◽  
Author(s):  
Michael H. Hsieh ◽  
Robert Korngold
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
T Cell Subsets ◽  
Leukemia Cell Line ◽  
Deficient Mice

In graft-versus-leukemia (GVL) responses, the cellular subsets and effector mechanisms responsible for cytotoxicity against leukemic cells in vivo remain poorly characterized. A murine model of syngeneic GVL that features CD4+ and CD8+T-cell responses against the MMB3.19 myeloid leukemia cell line has been previously described. MMB3.19 expresses high levels of functional Fas and tumor necrosis factor (TNF) receptors that do not transduce proapoptotic signals. Through the use of perforin- and Fas ligand (FasL)-deficient mice, it was demonstrated that CD4+ T cells mediate anti-MMB3.19 effects in vivo primarily through the use of FasL and secondarily through perforin mechanisms. Conversely, CD8+ T cells induce GVL effects primarily through the use of perforin and minimally through FasL mechanisms. Although the in vivo observations of CD8+ T cells were reflective of their in vitro cytotoxic T lymphocyte (CTL) activity, for CD4+ T cells, in vitro responses were dominated by the perforin pathway. In addition, the diminished capacity of T cells from perforin- and FasL-deficient mice to lyse MMB3.19 target cells appeared directly related to their deficient cytotoxic functions rather than to defects in activation because these cells were fully capable of mounting proliferative responses to the tumor cells. These findings demonstrate that GVL responses of T-cell subsets can involve preferential use of different cytotoxic mechanisms. In particular, these findings identify a role for both FasL-employing CD4+CTLs and the more novel perforin-utilizing CD4+ T-cell subset in responses against a myeloid leukemia.

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