scholarly journals Cd40-Independent Pathways of T Cell Help for Priming of Cd8+ Cytotoxic T Lymphocytes

2000 ◽  
Vol 191 (3) ◽  
pp. 541-550 ◽  
Author(s):  
Zhengbin Lu ◽  
Lingxian Yuan ◽  
Xianzheng Zhou ◽  
Eduardo Sotomayor ◽  
Hyam I. Levitsky ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Cell Communication ◽  
Cd8 T Cell ◽  
Cd4 Help ◽  
T Cell Help

In many cases, induction of CD8+ CTL responses requires CD4+ T cell help. Recently, it has been shown that a dominant pathway of CD4+ help is via antigen-presenting cell (APC) activation through engagement of CD40 by CD40 ligand on CD4+ T cells. To further study this three cell interaction, we established an in vitro system using dendritic cells (DCs) as APCs and influenza hemagglutinin (HA) class I and II peptide–specific T cell antigen receptor transgenic T cells as cytotoxic T lymphocyte precursors and CD4+ T helper cells, respectively. We found that CD4+ T cells can provide potent help for DCs to activate CD8+ T cells when antigen is provided in the form of either cell lysate, recombinant protein, or synthetic peptides. Surprisingly, this help is completely independent of CD40. Moreover, CD40-independent CD4+ help can be documented in vivo. Finally, we show that CD40-independent T cell help is delivered through both sensitization of DCs and direct CD4+–CD8+ T cell communication via lymphokines. Therefore, we conclude that CD4+ help comprises at least three components: CD40-dependent DC sensitization, CD40-independent DC sensitization, and direct lymphokine-dependent CD4+–CD8+ T cell communication.

scholarly journals Cytotoxic T Lymphocyte–associated Antigen 4 (CTLA-4) Can Regulate Dendritic Cell–induced Activation and Cytotoxicity of CD8+ T Cells Independently of CD4+T Cell Help

1999 ◽  
Vol 189 (7) ◽  
pp. 1157-1162 ◽  
Author(s):  
Kathy D. McCoy ◽  
Ian F. Hermans ◽  
J. Henry Fraser ◽  
Graham Le Gros ◽  
Franca Ronchese
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocyte ◽  
Cd8 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Cd4 T Cell ◽  
Cd4 T Cell Help ◽  
T Cell Help

The mechanisms that regulate the strength and duration of CD8+ cytotoxic T cell activity determine the effectiveness of an antitumor immune response. To better understand the antitumor effects of anti-cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) antibody treatment, we analyzed the effect of CTLA-4 signaling on CD8+ T cells in vitro and in vivo. In vitro, cross-linking of CTLA-4 on purified CD8+ T cells caused decreased proliferative responses to anti-CD3 stimulation and rapid loss of activation marker expression. In vivo, blockade of CTLA-4 by neutralizing anti–CTLA-4 mAb greatly enhanced the accumulation, activation, and cytotoxic activity of CD8+ T cells induced by immunization with Ag on dendritic cells (DC). This enhanced response did not require the expression of MHC class II molecules on DC or the presence of CD4+ T cells. These results demonstrate that CTLA-4 blockade is able to directly enhance the proliferation and activation of specific CD8+ T cells, indicating its potential for tumor immunotherapy even in situations in which CD4+ T cell help is limited or absent.

scholarly journals Immunologic Self-Tolerance Maintained by Cd25+Cd4+Regulatory T Cells Constitutively Expressing Cytotoxic T Lymphocyte–Associated Antigen 4

2000 ◽  
Vol 192 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Takeshi Takahashi ◽  
Tomoyuki Tagami ◽  
Sayuri Yamazaki ◽  
Toshimitsu Uede ◽  
Jun Shimizu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Lymphocyte ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Costimulatory Molecule ◽  
Self Tolerance

This report shows that cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) plays a key role in T cell–mediated dominant immunologic self-tolerance. In vivo blockade of CTLA-4 for a limited period in normal mice leads to spontaneous development of chronic organ-specific autoimmune diseases, which are immunopathologically similar to human counterparts. In normal naive mice, CTLA-4 is constitutively expressed on CD25+CD4+ T cells, which constitute 5–10% of peripheral CD4+ T cells. When the CD25+CD4+ T cells are stimulated via the T cell receptor in vitro, they potently suppress antigen-specific and polyclonal activation and proliferation of other T cells, including CTLA-4–deficient T cells, and blockade of CTLA-4 abrogates the suppression. CD28-deficient CD25+CD4+ T cells can also suppress normal T cells, indicating that CD28 is dispensable for activation of the regulatory T cells. Thus, the CD25+CD4+ regulatory T cell population engaged in dominant self-tolerance may require CTLA-4 but not CD28 as a costimulatory molecule for its functional activation. Furthermore, interference with this role of CTLA-4 suffices to elicit autoimmune disease in otherwise normal animals, presumably through affecting CD25+CD4+ T cell–mediated control of self-reactive T cells. This unique function of CTLA-4 could be exploited to potentiate T cell–mediated immunoregulation, and thereby to induce immunologic tolerance or to control autoimmunity.

Identification of a novel natural regulatory CD8 T-cell subset and analysis of its mechanism of regulation

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3294-3301 ◽  
Author(s):  
Emmanuel Xystrakis ◽  
Anne S. Dejean ◽  
Isabelle Bernard ◽  
Philippe Druet ◽  
Roland Liblau ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Cell Subset ◽  
Interleukin 4 ◽  
Cell Contact

Abstract The immune system contains natural regulatory T cells that control the magnitude of the immune response during physiologic and pathologic conditions. Although this suppressive function was historically attributed to CD8 T cells, most recent reports have focused on natural regulatory CD4 T cells. In the present study, we describe a new subset of natural CD8 regulatory T cells in normal healthy animals. This subset expresses low levels of CD45RC at its surface (CD45RClow); produces mainly interleukin-4 (IL-4), IL-10, and IL-13 cytokines upon in vitro stimulation; expresses Foxp3 and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4); and is not cytotoxic against allogeneic targets. This subset suppresses the proliferation and differentiation of autologous CD4 T cells into type-1 cytokines producing T cells after stimulation with allogeneic accessory cells. We also provide evidence that this regulatory subset mediates its suppression by cell-to-cell contact and not through secretion of suppressive cytokines. Finally, the regulatory activity of CD8 CD45RClow cells is also demonstrated in vivo in a rat model of CD4-dependent graft-versus-host disease. Collectively, these data demonstrate for the first time that freshly isolated rat CD8 CD45RClow T cells contain T cells with regulatory properties, a result that enlarges the general picture of T-cell-mediated regulation. (Blood. 2004;104:3294-3301)

scholarly journals DNAM-1 promotes activation of cytotoxic lymphocytes by nonprofessional antigen-presenting cells and tumors

2008 ◽  
Vol 205 (13) ◽  
pp. 2965-2973 ◽  
Author(s):  
Susan Gilfillan ◽  
Christopher J. Chan ◽  
Marina Cella ◽  
Nicole M. Haynes ◽  
Aaron S. Rapaport ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Adhesion Molecules ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Cd8 T Cell ◽  
Antigen Presenting

Natural killer (NK) cells and CD8 T cells require adhesion molecules for migration, activation, expansion, differentiation, and effector functions. DNAX accessory molecule 1 (DNAM-1), an adhesion molecule belonging to the immunoglobulin superfamily, promotes many of these functions in vitro. However, because NK cells and CD8 T cells express multiple adhesion molecules, it is unclear whether DNAM-1 has a unique function or is effectively redundant in vivo. To address this question, we generated mice lacking DNAM-1 and evaluated DNAM-1–deficient CD8 T cell and NK cell function in vitro and in vivo. Our results demonstrate that CD8 T cells require DNAM-1 for co-stimulation when recognizing antigen presented by nonprofessional antigen-presenting cells; in contrast, DNAM-1 is dispensable when dendritic cells present the antigen. Similarly, NK cells require DNAM-1 for the elimination of tumor cells that are comparatively resistant to NK cell–mediated cytotoxicity caused by the paucity of other NK cell–activating ligands. We conclude that DNAM-1 serves to extend the range of target cells that can activate CD8 T cell and NK cells and, hence, may be essential for immunosurveillance against tumors and/or viruses that evade recognition by other activating or accessory molecules.

BK Polyomavirus–Specific CD8 T-Cell Expansion In Vitro Using 27mer Peptide Antigens for Developing Adoptive T-Cell Transfer and Vaccination

2020 ◽  
Author(s):  
Maud Wilhelm ◽  
Amandeep Kaur ◽  
Marion Wernli ◽  
Hans H Hirsch
Keyword(s):  
T Cells ◽  
T Cell ◽  
Kidney Transplant ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Bk Polyomavirus

Abstract Background BK polyomavirus (BKPyV) remains a significant cause of premature kidney transplant failure. In the absence of effective antivirals, current treatments rely on reducing immunosuppression to regain immune control over BKPyV replication. Increasing BKPyV-specific CD8 T cells correlate with clearance of BKPyV DNAemia in kidney transplant patients. We characterized a novel approach for expanding BKPyV-specific CD8 T cells in vitro using 27mer-long synthetic BKPyV peptides, different types of antigen-presenting cells, and CD4 T cells. Methods Langerhans cells and immature or mature monocyte-derived dendritic cells (Mo-DCs) were generated from peripheral blood mononuclear cells of healthy blood donors, pulsed with synthetic peptide pools consisting of 36 overlapping 27mers (27mP) or 180 15mers (15mP). BKPyV-specific CD8 T-cell responses were assessed by cytokine release assays using 15mP or immunodominant 9mers. Results BKPyV-specific CD8 T cells expanded using 27mP and required mature Mo-DCs (P = .0312) and CD4 T cells (P = .0156) for highest responses. The resulting BKPyV-specific CD8 T cells proliferated, secreted multiple cytokines including interferon γ and tumor necrosis factor α, and were functional (CD107a+/PD1–) and cytotoxic. Conclusions Synthetic 27mP permit expanding BKPyV-specific CD8 T-cell responses when pulsing mature Mo-DCs in presence of CD4 T cells, suggesting novel and safe approaches to vaccination and adoptive T-cell therapies for patients before and after kidney transplantation.

scholarly journals Selective anergy of V beta 8+,CD4+ T cells in Staphylococcus enterotoxin B-primed mice.

1990 ◽  
Vol 172 (4) ◽  
pp. 1065-1070 ◽  
Author(s):  
Y Kawabe ◽  
A Ochi
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Anergy ◽  
Specific Cytotoxicity ◽  
Enterotoxin B ◽  
Staphylococcus Enterotoxin B

The cellular basis of the in vitro and in vivo T cell responses to Staphylococcus enterotoxin B (SEB) has been investigated. The proliferation and cytotoxicity of V beta 8.1,2+,CD4+ and CD8+ T cells were observed in in vitro response to SEB. In primary cytotoxicity assays, CD4+ T cells from control spleens were more active than their CD8+ counterparts, however, in cells derived from SEB-primed mice, CD8+ T cells were dominant in SEB-specific cytotoxicity. In vivo priming with SEB abrogated the response of V beta 8.1,2+,CD4+ T cells despite the fact that these cells exist in significant number. This SEB-specific anergy occurred only in V beta 8.1,2+,CD4+ T cells but not in CD8+ T cells. These findings indicate that the requirement for the induction of antigen-specific anergy is different between CD4+ and CD8+ T cells in post-thymic tolerance, and the existence of coanergic signals for the induction of T cell anergy is suggested.

scholarly journals Phenotypic and Functional Separation of Memory and Effector Human CD8+ T Cells

1997 ◽  
Vol 186 (9) ◽  
pp. 1407-1418 ◽  
Author(s):  
Dörte Hamann ◽  
Paul A. Baars ◽  
Martin H.G. Rep ◽  
Berend Hooibrink ◽  
Susana R. Kerkhof-Garde ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Fas Ligand ◽  
Cytotoxic T Lymphocyte ◽  
Cell Subset ◽  
Cd8 T Cell ◽  
Cytolytic Activity ◽  
T Cell Subset

Human CD8+ memory- and effector-type T cells are poorly defined. We show here that, next to a naive compartment, two discrete primed subpopulations can be found within the circulating human CD8+ T cell subset. First, CD45RA−CD45R0+ cells are reminiscent of memory-type T cells in that they express elevated levels of CD95 (Fas) and the integrin family members CD11a, CD18, CD29, CD49d, and CD49e, compared to naive CD8+ T cells, and are able to secrete not only interleukin (IL) 2 but also interferon γ, tumor necrosis factor α, and IL-4. This subset does not exert cytolytic activity without prior in vitro stimulation but does contain virus-specific cytotoxic T lymphocyte (CTL) precursors. A second primed population is characterized by CD45RA expression with concomitant absence of expression of the costimulatory molecules CD27 and CD28. The CD8+CD45RA+CD27− population contains T cells expressing high levels of CD11a, CD11b, CD18, and CD49d, whereas CD62L (L-selectin) is not expressed. These T cells do not secrete IL-2 or -4 but can produce IFN-γ and TNF-α. In accordance with this finding, cells contained within this subpopulation depend for proliferation on exogenous growth factors such as IL-2 and -15. Interestingly, CD8+CD45RA+CD27− cells parallel effector CTLs, as they abundantly express Fas-ligand mRNA, contain perforin and granzyme B, and have high cytolytic activity without in vitro prestimulation. Based on both phenotypic and functional properties, we conclude that memory- and effector-type T cells can be separated as distinct entities within the human CD8+ T cell subset.

scholarly journals In Vivo Detection of Dendritic Cell Antigen Presentation to CD4+ T Cells

1997 ◽  
Vol 185 (12) ◽  
pp. 2133-2141 ◽  
Author(s):  
Elizabeth Ingulli ◽  
Anna Mondino ◽  
Alexander Khoruts ◽  
Marc K. Jenkins
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Delayed Type Hypersensitivity ◽  
Physical Interaction

Although lymphoid dendritic cells (DC) are thought to play an essential role in T cell activation, the initial physical interaction between antigen-bearing DC and antigen-specific T cells has never been directly observed in vivo under conditions where the specificity of the responding T cells for the relevant antigen could be unambiguously assessed. We used confocal microscopy to track the in vivo location of fluorescent dye-labeled DC and naive TCR transgenic CD4+ T cells specific for an OVA peptide–I-Ad complex after adoptive transfer into syngeneic recipients. DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells. In contrast, the OVA peptide-specific T cells formed large clusters around paracortical DC that were pulsed in vitro with the OVA peptide before injection. Interactions were also observed between paracortical DC of the recipient and OVA peptide-specific T cells after administration of intact OVA. Injection of OVA peptide-pulsed DC caused the specific T cells to produce IL-2 in vivo, proliferate, and differentiate into effector cells capable of causing a delayed-type hypersensitivity reaction. Surprisingly, by 48 h after injection, OVA peptide-pulsed, but not unpulsed DC disappeared from the lymph nodes of mice that contained the transferred TCR transgenic population. These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell–rich regions of lymph nodes. This interaction results in T cell activation and disappearance of the DC.

scholarly journals Human memory CD8 T cell effector potential is epigenetically preserved during in vivo homeostasis

2017 ◽  
Vol 214 (6) ◽  
pp. 1593-1606 ◽  
Author(s):  
Hossam A. Abdelsamed ◽  
Ardiana Moustaki ◽  
Yiping Fan ◽  
Pranay Dogra ◽  
Hazem E. Ghoneim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Human Memory ◽  
Memory Cd8 T Cells ◽  
Memory Cd8 T Cell ◽  
Cell Effector

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell–mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (TEM), and longer-lived central memory (TCM) and stem cell memory (TSCM) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7– and IL-15–mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of TCM and TSCM memory cells resulted in phenotypic conversion into TEM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired TEM-associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells.

scholarly journals Bridging channel dendritic cells induce immunity to transfused red blood cells

2016 ◽  
Vol 213 (6) ◽  
pp. 887-896 ◽  
Author(s):  
Samuele Calabro ◽  
Antonia Gallman ◽  
Uthaman Gowthaman ◽  
Dong Liu ◽  
Pei Chen ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Major Complication ◽  
Life Saving ◽  
T Cell Help ◽  
Rbc Transfusion

Red blood cell (RBC) transfusion is a life-saving therapeutic tool. However, a major complication in transfusion recipients is the generation of antibodies against non-ABO alloantigens on donor RBCs, potentially resulting in hemolysis and renal failure. Long-lived antibody responses typically require CD4+ T cell help and, in murine transfusion models, alloimmunization requires a spleen. Yet, it is not known how RBC-derived antigens are presented to naive T cells in the spleen. We sought to answer whether splenic dendritic cells (DCs) were essential for T cell priming to RBC alloantigens. Transient deletion of conventional DCs at the time of transfusion or splenic DC preactivation before RBC transfusion abrogated T and B cell responses to allogeneic RBCs, even though transfused RBCs persisted in the circulation for weeks. Although all splenic DCs phagocytosed RBCs and activated RBC-specific CD4+ T cells in vitro, only bridging channel 33D1+ DCs were required for alloimmunization in vivo. In contrast, deletion of XCR1+CD8+ DCs did not alter the immune response to RBCs. Our work suggests that blocking the function of one DC subset during a narrow window of time during RBC transfusion could potentially prevent the detrimental immune response that occurs in patients who require lifelong RBC transfusion support.

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