scholarly journals Blockade of LAG-3 in PD-L1-deficient mice enhances clearance of blood stage malaria independent of humoral responses

2020 ◽  
Author(s):  
Raquel Furtado ◽  
Laurent Chorro ◽  
Natalie Zimmerman ◽  
Erik Guillen ◽  
Emily Spaulding ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Blood Parasite ◽  
Blood Parasites ◽  
Inhibitory Receptors ◽  
Chronic Infections ◽  
Helper T Lymphocytes ◽  
Humoral Responses ◽  
Blood Stage Malaria

AbstractT cells expressing high levels of inhibitory receptors such as PD-1 and LAG-3 are a hallmark of chronic infections and cancer. Checkpoint blockade therapies targeting these receptors have been largely validated as promising strategies to restore exhausted T cell functions and clearance of chronic infections and tumors. The inability to develop long-term natural immunity in malaria-infected patients has been proposed to be at least partially accounted for by sustained expression of high levels of inhibitory receptors on T and B lymphocytes. While blockade or lack of PD-1/PD-L1 and/or LAG-3 was reported to promote better clearance of Plasmodium parasites in mice, how exactly these pathways contributes to protection is not known. Herein, using a mouse model of non-lethal P. yoelii (Py) infection, we reveal that the kinetics of blood parasitemia is indistinguishable between PD-1-/-, PD-L1-/- and WT mice. Yet, monoclonal antibody (mAb) blockade of LAG-3 in PD-L1-/- mice promoted accelerated control of blood parasite growth and clearance. We also report that i) the majority of LAG-3+ cells are T cells, ii) selective depletion of CD8+ T cells did not prevent anti-LAG-3-mediated protection, and iii) production of effector cytokines by CD4+ T cells is increased in anti-LAG-3-treated versus control mice. In addition, parasite-specific Ab serum titers and their ability to transfer protection from both groups of mice was comparable and depletion of CD4+ T cells prevented protection. Thus, taken together, these results are consistent with a model in which disruption of PD-L1 and LAG-3 on parasite-specific CD4+ T cells unleashes their ability to effectively clear blood parasites, independently from humoral responses.Author SummaryMalaria, caused by Plasmodium parasites, is a global burden for which an efficacious vaccine is urgently needed. The development of long-term immunity against malaria is unclear, but we know that both T and B (that produce antibodies, Ab) lymphocytes, that are subsets of white blood cells, are required. Studies in mouse models of malaria have suggested that sets of inhibitory receptors, namely LAG-3 and PD-1, expressed on cytotoxic and helper T lymphocytes hamper the development of effective immunity against malaria. Therapeutic blockade of these receptors was reported to enhance blood parasite clearance through the development of more protective parasite-specific helper T lymphocytes and Abs. Herein, we reveal that, while mice genetically deficient for the PD-1 pathway fail to clear blood parasites better than WT counterparts, anti-LAG-3 treatment does. Importantly, we found comparable parasite-specific Ab responses between all mouse groups, and Ab transfers conferred similar protection to newly infected mice. We also show that LAG-3 is mostly expressed on T lymphocytes, and that cytotoxic T lymphocytes are not involved in anti-LAG-3 accelerated clearance of parasites. Our results suggest that LAG-3 blockade acts on helper T lymphocytes to unleash their effector responses and enhance the control of blood-stage malaria, independently from parasite-specific Abs.

scholarly journals Blockade of LAG-3 in PD-L1-Deficient Mice Enhances Clearance of Blood Stage Malaria Independent of Humoral Responses

2021 ◽  
Vol 11 ◽  
Author(s):  
Raquel Furtado ◽  
Laurent Chorro ◽  
Natalie Zimmerman ◽  
Erik Guillen ◽  
Emily Spaulding ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Blood Parasites ◽  
Natural Immunity ◽  
Inhibitory Receptors ◽  
Chronic Infections ◽  
Cell Functions ◽  
Cell Responses ◽  
B Cell Responses ◽  
Humoral Responses

T cells expressing high levels of inhibitory receptors such as PD-1 and LAG-3 are a hallmark of chronic infections and cancer. Checkpoint blockade therapies targeting these receptors have been largely validated as promising strategies to restore exhausted T cell functions and clearance of chronic infections and tumors. The inability to develop long-term natural immunity in malaria-infected patients has been proposed to be at least partially accounted for by sustained expression of high levels of inhibitory receptors on T and B lymphocytes. While blockade or lack of PD-1/PD-L1 and/or LAG-3 was reported to promote better clearance of Plasmodium parasites in various mouse models, how exactly blockade of these pathways contributes to enhanced protection is not known. Herein, using the mouse model of non-lethal P. yoelii (Py) infection, we reveal that the kinetics of blood parasitemia as well as CD4+ T follicular helper (TFH) and germinal center (GC) B cell responses are indistinguishable between PD-1-/-, PD-L1-/- and WT mice. Yet, we also report that monoclonal antibody (mAb) blockade of LAG-3 in PD-L1-/- mice promotes accelerated control of blood parasite growth and clearance, consistent with prior therapeutic blockade experiments. However, neither CD4+ TFH and GC B cell responses, nor parasite-specific Ab serum titers and capacity to transfer protection differed. We also found that i) the majority of LAG-3+ cells are T cells, ii) selective depletion of CD4+ but not CD8+ T cells prevents anti-LAG-3-mediated protection, and iii) production of effector cytokines by CD4+ T cells is increased in anti-LAG-3-treated versus control mice. Thus, taken together, these results are consistent with a model in which blockade and/or deficiency of PD-L1 and LAG-3 on parasite-specific CD4+ T cells unleashes their ability to effectively clear blood parasites, independently from humoral responses.

scholarly journals Mice lacking Programmed cell death-1 show a role for CD8+ T cells in long-term immunity against blood-stage malaria

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Joshua M. Horne-Debets ◽  
Deshapriya S. Karunarathne ◽  
Rebecca J. Faleiro ◽  
Chek Meng Poh ◽  
Laurent Renia ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Cd8 T Cells ◽  
Blood Stage ◽  
Programmed Cell Death 1 ◽  
Blood Stage Malaria

Behavior of helper T lymphocytes in cyclosporine-mediated long-term graft acceptance in the rat

1985 ◽  
Vol 93 (1) ◽  
pp. 168-177 ◽  
Author(s):  
J.W. Kupiec-Weglinski ◽  
C.D. Heidecke ◽  
J.L. Araujo ◽  
M. Abbud-Filho ◽  
E. Towpik ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Helper T Lymphocytes

Cyclophosphamide induces type I interferon and augments the number of CD44hi T lymphocytes in mice: implications for strategies of chemoimmunotherapy of cancer

Blood ◽  
2000 ◽  
Vol 95 (6) ◽  
pp. 2024-2030 ◽  
Author(s):  
Giovanna Schiavoni ◽  
Fabrizio Mattei ◽  
Tiziana Di Pucchio ◽  
Stefano M. Santini ◽  
Laura Bracci ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Adoptive Immunotherapy ◽  
Messenger Rna ◽  
Type I ◽  
Type I Ifn ◽  
Term Survival ◽  
Spleen Lymphocytes

Abstract In a previous study, we reported that a single injection of cyclophosphamide (CTX) in tumor-bearing mice resulted in tumor eradication when the animals were subsequently injected with tumor-sensitized lymphocytes. Notably, CTX acted by inducing bystander effects on T cells, and the response to the combined CTX/adoptive immunotherapy regimen was inhibited in mice treated with antibodies to mouse interferon (IFN)–/β. In the present study, we have investigated whether CTX induced the expression of type I IFN, and we have characterized the CTX effects on the phenotype of T cells in normal mice. CTX injection resulted in an accumulation of type I IFN messenger RNA in the spleen of inoculated mice, at 24 to 48 hours, that was associated with IFN detection in the majority of the animals. CTX also enhanced the expression of the Ly-6C on spleen lymphocytes. This enhancement was inhibited in mice treated with anti–type I IFN antibodies. Moreover, CTX induced a long-lasting increase in in vivo lymphocyte proliferation and in the percentage of CD44hiCD4+ and CD44hiCD8+T lymphocytes. These results demonstrate that CTX is an inducer of type I IFN in vivo and enhances the number of T cells exhibiting the CD44hi memory phenotype. Since type I IFN has been recently recognized as the important cytokine for the in vivo expansion and long-term survival of memory T cells, we suggest that induction of this cytokine may explain at least part of the immunomodulatory effects observed after CTX treatment. Finally, these findings provide a new rationale for combined treatments with CTX and adoptive immunotherapy in cancer patients.

scholarly journals Complementary Dendritic Cell–activating Function of CD8+ and CD4+ T Cells

2002 ◽  
Vol 195 (4) ◽  
pp. 473-483 ◽  
Author(s):  
Robbie B. Mailliard ◽  
Shinichi Egawa ◽  
Quan Cai ◽  
Anna Kalinska ◽  
Svetlana N. Bykovskaya ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Class I ◽  
Chronic Infections ◽  
Cd40 Ligation ◽  
Activation Level ◽  
Tnf Α ◽  
Ifn Γ

Dendritic cells (DCs) activated by CD40L-expressing CD4+ T cells act as mediators of “T helper (Th)” signals for CD8+ T lymphocytes, inducing their cytotoxic function and supporting their long-term activity. Here, we show that the optimal activation of DCs, their ability to produce high levels of bioactive interleukin (IL)-12p70 and to induce Th1-type CD4+ T cells, is supported by the complementary DC-activating signals from both CD4+ and CD8+ T cells. Cord blood– or peripheral blood–isolated naive CD8+ T cells do not express CD40L, but, in contrast to naive CD4+ T cells, they are efficient producers of IFN-γ at the earliest stages of the interaction with DCs. Naive CD8+ T cells cooperate with CD40L-expressing naive CD4+ T cells in the induction of IL-12p70 in DCs, promoting the development of primary Th1-type CD4+ T cell responses. Moreover, the recognition of major histocompatibility complex class I–presented epitopes by antigen-specific CD8+ T cells results in the TNF-α– and IFN-γ–dependent increase in the activation level of DCs and in the induction of type-1 polarized mature DCs capable of producing high levels of IL-12p70 upon a subsequent CD40 ligation. The ability of class I–restricted CD8+ T cells to coactivate and polarize DCs may support the induction of Th1-type responses against class I–presented epitopes of intracellular pathogens and contact allergens, and may have therapeutical implications in cancer and chronic infections.

scholarly journals Differential Requirements for T Cells in Viruslike Particle- and Rotavirus-Induced Protective Immunity

2008 ◽  
Vol 82 (6) ◽  
pp. 3135-3138 ◽  
Author(s):  
Sarah E. Blutt ◽  
Kelly L. Warfield ◽  
Mary K. Estes ◽  
Margaret E. Conner
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Protective Immunity ◽  
Short Term ◽  
Correlates Of Protection ◽  
Viruslike Particles ◽  
Term Maintenance ◽  
B And T Lymphocytes

ABSTRACT Correlates of protection from rotavirus infection are controversial. We compared the roles of B and T lymphocytes in protective immunity induced either by intranasally administered nonreplicating viruslike particles or inactivated virus or by orally administered murine rotavirus. We found that protection induced by nonreplicating vaccines requires CD4+ T cells and CD40/CD40L. In contrast, T cells were not required for short-term protective immunity induced by infection, but both T-cell-dependent and -independent mechanisms contributed to long-term maintenance of protection. Our findings indicate that more than one marker of protective immunity exists and that these markers depend on the vaccine that is administered.

Long-term effects of intermittent interleukin 2 therapy in patients with HIV infection: characterization of a novel subset of CD4+/CD25+ T cells

Blood ◽  
2002 ◽  
Vol 100 (6) ◽  
pp. 2159-2167 ◽  
Author(s):  
Irini Sereti ◽  
Hector Martinez-Wilson ◽  
Julia A. Metcalf ◽  
Michael W. Baseler ◽  
Claire W. Hallahan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Hiv Patients ◽  
Activation Markers ◽  
Cd25 Expression ◽  
Cell Counts

The long-term immunologic effects of intermittent interleukin 2 (IL-2) therapy were evaluated in a cross-sectional study by comparing 3 groups: HIV-seronegative volunteers, HIV-infected (HIV+) patients receiving highly active antiretroviral therapy (HAART), and HIV+ patients receiving HAART and intermittent IL-2. Whole-blood immunophenotyping was performed to study expression of the IL-2 receptor chains on T lymphocytes and natural killer cells and to further characterize CD4+/CD25+ T cells. Increased CD25 expression, especially in CD4+ T cells but also in CD8+ T cells, without increases in expression of the β and γ chains of the IL-2 receptor was detected in the IL-2 group. Up to 79% of naive CD4+ T cells (median, 61%) from patients in the IL-2 group expressed CD25, and the number of naive CD4+/CD25+ T cells correlated positively with both the total and naive CD4+ T-cell counts. A discrete population of CD45 double intermediate RA+/RO+CD4+ cells was also preferentially expanded in the IL-2 group, and the number of these cells strongly correlated with the total CD4+ count. Despite increases in CD25 expression, T lymphocytes from patients treated with IL-2 did not have increased expression of early (CD69) or late (CD95) activation markers or evidence of recent proliferation (Ki67). Both CD4+/CD25+ and CD4+/CD25− cells from IL-2–treated HIV+ patients proliferated in response to mitogens, specific antigens, and T-cell-receptor–mediated stimuli. Thus, intermittent administration of IL-2 in HIV+ patients leads to preferential expansion of a unique subset of CD4+ T cells that may represent a critical population in T-cell homeostasis.

scholarly journals Helper T cells for cytotoxic T lymphocytes need not be I region restricted

1982 ◽  
Vol 155 (6) ◽  
pp. 1766-1784 ◽  
Author(s):  
DH Raulet ◽  
MJ Bevan
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Specific Antigen ◽  
Helper T Cells ◽  
Type I ◽  
Histocompatibility Antigens ◽  
Minor Histocompatibility Antigens ◽  
Ctl Responses

We investigated the antigenic requirements for restimulation of H-2- restricted cytolytic T lymphocytes (CTL) in vitro to determine whether H-2 I region-restricted helper T cells are required in these responses. In one set of experiments, we studied the in vitro response of (responder x nonresponder)F(1) female T cells to the male antigen H-Y. We chose to examine this response because it has been suggested that the defect in nonresponder strains is a failure of helper T cells to recognize H-Y in association with nonresponder I region determinants. However, we find that nonresponder male stimulator cells are as effective as F(1) male stimulator cells at inducing H-Y-specific CTL responses. This finding calls into question reports that secondary CTL responses to H-Y are dependent upon the activation of H-Y- specific helper T cells restricted to responder type I region determinants. In a second set of experiments, we examined the requirements for restimulation of H-2-restricted T cells specific for minor-histocompatibility antigens from long-term mixed lymphocyte cultures. These cultures were established by repeatedly restimulating cultures of specific T cells with H- 2-matched stimulator cells expressing foreign minor histocompatibility antigens. We found that H-2D-restricted T ceils, including CTL, could be restimulated with cells that were matched with the responding cells at only the D region genes. This response did not appear to result from positive allogeneic effects or from antigen processing and "representation" by responder type APC that might contaminate the cultures. Thus, we find no evidence for a requirement for I region-restricted helper T cells in these CTL responses. However, helper T cells are required because we find that CTL lines derived by limit-dilution cloning from these long-term MLC are absolutely dependent upon exogenous helper factors for growth. The most simple interpretation of these results is that the helper cells are restricted to H-2 antigens other than I region antigens or to antigens that code outside of the H-2 complex. Finally, we show that factor-dependent CTL lines must recognize their specific antigen to proliferate, even in the presence of exogenous factors. The requirement of activated CTL for antigen to proliferate provides an explanation for how specific CTL can be selectively enriched in MLC by specific antigen stimulation. Furthermore, it is at variance with reports that memory CTL or activated CTL require only interleukin 2 for restimulation.

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