scholarly journals Immediate Cytotoxicity But Not Degranulation Distinguishes Effector and Memory Subsets of CD8+ T Cells

2004 ◽  
Vol 199 (7) ◽  
pp. 925-936 ◽  
Author(s):  
Petra Wolint ◽  
Michael R. Betts ◽  
Richard A. Koup ◽  
Annette Oxenius

CD8+ T cells play a central role in the resolution and containment of viral infections. A key effector function of CD8+ T cells is their cytolytic activity toward infected cells. Here, we studied the regulation of cytolytic activity in naive, effector, and central versus effector memory CD8+ T cells specific for the same glycoprotein-derived epitope of lymphocytic choriomeningitis virus. Our results show that the kinetics of degranulation, assessed by a novel flow cytometric based assay, were identical in effector and both subsets of memory CD8+ T cells, but absent in naive CD8+ T cells. However, immediate cytolytic activity was most pronounced in effector T cells, low in effector memory T cells, and absent in central memory T cells, correlating with the respective levels of cytolytic effector molecules present in lytic granules. These results indicate that an inherent program of degranulation is a feature of antigen-experienced cells as opposed to naive CD8+ T cells and that the ability of CD8+ T cells to induce target cell apoptosis/death is dependent on granule protein content rather than on the act of degranulation itself. Furthermore, these results provide a potential mechanism by which central memory CD8+ T cell–mediated death of antigen-presenting cells within the lymph node is avoided.

2016 ◽  
Vol 213 (13) ◽  
pp. 3057-3073 ◽  
Author(s):  
Shiki Takamura ◽  
Hideki Yagi ◽  
Yoshiyuki Hakata ◽  
Chihiro Motozono ◽  
Sean R. McMaster ◽  
...  

CD8+ tissue-resident memory T cells (TRM cells) reside permanently in nonlymphoid tissues and provide a first line of protection against invading pathogens. However, the precise localization of CD8+ TRM cells in the lung, which physiologically consists of a markedly scant interstitium compared with other mucosa, remains unclear. In this study, we show that lung CD8+ TRM cells localize predominantly in specific niches created at the site of regeneration after tissue injury, whereas peripheral tissue-circulating CD8+ effector memory T cells (TEM cells) are widely but sparsely distributed in unaffected areas. Although CD69 inhibited sphingosine 1–phosphate receptor 1–mediated egress of CD8+ T cells immediately after their recruitment into lung tissues, such inhibition was not required for the retention of cells in the TRM niches. Furthermore, despite rigid segregation of TEM cells from the TRM niche, prime-pull strategy with cognate antigen enabled the conversion from TEM cells to TRM cells by creating de novo TRM niches. Such damage site–specific localization of CD8+ TRM cells may be important for efficient protection against secondary infections by respiratory pathogens.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3242-3242
Author(s):  
Robbert van der Voort ◽  
Claudia Brandao ◽  
Thomas J. Volman ◽  
Viviènne Verweij ◽  
Klaas van Gisbergen ◽  
...  

Abstract Abstract 3242 Although the importance of the bone marrow (BM) in hematopoiesis is well known, its function in adaptive immune responses has only recently been acknowledged. Currently it is known that the BM contains fully functional CD4+ and CD8+ T cells that can engage in both primary and secondary immune responses. Interestingly, most of these T cells belong to the memory T cell lineage, identifying the BM as one of the largest memory T cell reservoirs in the body. Since not much is known about the trafficking of BM T cells, we compared the homing phenotype and function of T cell subsets in the BM, blood, spleen and peripheral lymph nodes (pLN). In addition, we determined the expression of chemokine mRNA and protein levels in the BM and other lymphoid organs. We confirmed that at least 80% of the CD4+ and 60% of the CD8+ BM T cells have a memory phenotype, and that most CD4+ T cells belong to the effector memory lineage, while the CD8+ population predominantly consists of central memory T cells. Most BM T cells expressed the chemokine receptor CXCR3, the adhesion molecules P-selectin glycoprotein ligand 1 and VLA-4, and increased levels of CD44 and LFA-1, as compared to T cells from the spleen. In addition, L-selectin was absent from most CD4+ BM T cells, but present on virtually all CD8+ T cells. Notably, the percentage of CXCR3+ T cells within the effector memory and central memory subsets from BM was higher than within the same subsets from pLN. Furthermore, BM contained significant mRNA levels of the CXCR3 ligands CXCL9, CXCL10 and CXCL11. An in vivo migration assay using a mixture of fluorescent-labeled T cells from CXCR3-deficient mice and control mice indicated however that during homeostasis CXCR3 does not play a major role in BM entry or retention. These data suggest that CXCR3 expressed by memory T cells is rather involved in BM exit, than in BM entry. Indeed, we observed that, as compared to control mice, CXCR3−/− mice contained significantly more CD4+ and CD8+ T cells in their BM. Additional in vitro assays demonstrated that CD4+ and CD8+ BM T cells migrated vigorously in response to CXCL9 and CXCL10, generally released in high concentrations during inflammation. Finally, we demonstrate that CXCR3−/− effector/effector memory T cells, but not wild type T cells, accumulate in the BM of mice infected with lymphocytic choriomeningitis virus. Altogether, these data demonstrate that the BM is a major reservoir of memory T cells that employ CXCR3 to quickly respond to chemotactic signals from inflamed tissues. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4805-4805
Author(s):  
Tzu-Yun Kuo ◽  
Aisha Hasan ◽  
Richard J O'Reilly

Abstract Initial clinical trials of adoptive immunotherapy have shown that the efficacy of adoptively transferred T-cells in man is often limited by the failure of cultured T cells, particularly cloned CD8 T cells, to persist in vivo. These studies demonstrated that the transferred T cells induced only transient responses and that persistence of the transferred T-cell clonotypes correlated with disease regression. A previous study suggested that CMV virus-specific CD8 T cell clones derived from central memory T cells (TCM), but not effector memory T cells (TEM), persisted long-term in non-human primates. On the other hand, another study comparing TCM and TEM derived SIV virus specific CD8 T-cell clones that were adoptively transferred in non-human primates demonstrated limited persistence of both TCM and TEM derived transferred T cells, and failed to show any difference between the two cell types. Because of these conflicting data, we have reexamed the persistence of adoptively transferred viral antigen specific T-cells derived from TCM and TEM population. Accordingly, we developed a NOG mouse model for studying the ability of human CMVpp65-specific T cells derived from central memory and effector memory populations to migrate to and accumulate in human tumor xenografts expressing CMVpp65, to alter the growth of these tumors and to persist in the tumors. This model also allows us to test immunomodulating agents and their ability to enhance targeted T-cell accumulations, antitumor activity and persistence. We analyzed CMVpp65-specific CD8 T cells derived from TCM and TEM precursors in vitro and in vivo. To tract the T-cells in vivo, we transduced membrane-bound Gaussia luciferase into TCM and TEM populations and monitored T cell trafficking by in vivo bioluminescence. Contrary to expectation, our results initially showed no differences between TCM and TEM derived CMVpp65-specific T-cell in mice co-treated with IL-2 in the time to accumulation, ultimate level of accumulation, degree of CMVpp65+ tumor regression or T-cell persistence. However, in mice cotreated with IL-15/IL-15Rα complex, both TCM and TEM exhibited more sustained engraftment and more prolonged accumulation in both the targeted tumor and in the marrow. In mice treated with IL-15/IL-15Rα, TCM and TEM derived T cells showed a similar effector memory phenotype and a similar level of regression of tumor growth. Thus, adoptive transfer of CMVpp65 specific TCM or TEM when combined with IL-15/IL-15Rα complex may support better persistence of antigen-specific T-cells following adoptive immunotherapy. Studies comparing IL-15/IL-15Rα complex with IL-15 alone are in progress. Disclosures No relevant conflicts of interest to declare.


2014 ◽  
Vol 211 (2) ◽  
pp. 345-356 ◽  
Author(s):  
Erin R. Mehlhop-Williams ◽  
Michael J. Bevan

A hallmark of immunological memory is the ability of previously primed T cells to undergo rapid recall responses upon antigen reencounter. Classic work has suggested that memory T cells proliferate in response to lower doses of antigen than naive T cells and with reduced requirements for co-stimulation. In contrast to this premise, we observed that naive but not memory T cells proliferate in vivo in response to limited antigen presentation. To reconcile these observations, we tested the antigen threshold requirement for cell cycle entry in naive and central memory CD8+ T cells. Although both naive and memory T cells detect low dose antigen, only naive T cells activate cell cycle effectors. Direct comparison of TCR signaling on a single cell basis indicated that central memory T cells do not activate Zap70, induce cMyc expression, or degrade p27 in response to antigen levels that activate these functions in naive T cells. The reduced sensitivity of memory T cells may result from both decreased surface TCR expression and increased expression of protein tyrosine phosphatases as compared with naive T cells. Our data describe a novel aspect of memory T cell antigen threshold sensitivity that may critically regulate recall expansion.


2007 ◽  
Vol 75 (6) ◽  
pp. 2708-2716 ◽  
Author(s):  
Jessica Jones-Carson ◽  
Bruce D. McCollister ◽  
Eric T. Clambey ◽  
Andrés Vázquez-Torres

ABSTRACT To better understand the evolution of a systemic memory response to a mucosal pathogen, we monitored antigen-specific OT1 CD8 T-cell responses to a fusion of the SspH2 protein and the peptide SIINFEKL stably expressed from the chromosome of Salmonella enterica and loaded into the class I pathway of antigen presentation of professional phagocytes through the Salmonella pathogenicity island 2 type III secretion system (TTSS). This strategy has revealed that effector memory CD8 T cells with low levels of CD62L expression (CD62Llow) are maintained in systemic sites months after vaccination in response to low-grade infections with Salmonella. However, the CD8 T-cell pool eventually declines. Low numbers of central memory cells surviving after prolonged resting from an antigen encounter can nevertheless reconstitute the systemic effector memory pool in a route-specific recall response to cognate antigens encountered in the gut. Accordingly, populations of CD62Lhigh interleukin-7 receptor-positive progenitor central memory cells grafted into naïve mice expand in response to orally administered Salmonella expressing the chromosomal translational fusion of sspH2 and the sequence encoding the SIINFEKL peptide but fail to proliferate following systemic stimulation. Moreover, populations of systemic memory CD8 T cells restricted to Salmonella in oral vaccines selectively expand in response to cognate antigens presented by cells isolated from mesenteric lymph nodes (MLN). Together, these findings have revealed the imprinting of systemic CD8 central memory T-cell recall responses against enteropathogens by MLN. MLN restriction represents a novel mechanism by which systemic CD8 T-cell immunity is confined to periods of high risk for extraintestinal dissemination.


2007 ◽  
Vol 204 (7) ◽  
pp. 1625-1636 ◽  
Author(s):  
Hirokazu Hikono ◽  
Jacob E. Kohlmeier ◽  
Shiki Takamura ◽  
Susan T. Wittmer ◽  
Alan D. Roberts ◽  
...  

The contributions of different subsets of memory CD8+ T cells to recall responses at mucosal sites of infection are poorly understood. Here, we analyzed the CD8+ T cell recall responses to respiratory virus infection in mice and demonstrate that activation markers, such as CD27 and CD43, define three distinct subpopulations of memory CD8+ T cells that differ in their capacities to mount recall responses. These subpopulations are distinct from effector– and central–memory subsets, coordinately express other markers associated with activation status, including CXCR3, CD127, and killer cell lectin-like receptor G1, and are superior to CD62L in predicting the capacity of memory T cells to mediate recall responses. Furthermore, the capacity of vaccines to elicit these memory T cell subpopulations predicted the efficacy of the recall response. These findings extend our understanding of how recall responses are generated and suggest that activation and migration markers define distinct, and unrelated, characteristics of memory T cells.


2005 ◽  
Vol 202 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Alan D. Roberts ◽  
Kenneth H. Ely ◽  
David L. Woodland

Although the absolute number of memory CD8+ T cells established in the spleen following antigen encounter remains stable for many years, the relative capacity of these cells to mediate recall responses is not known. Here we used a dual adoptive transfer approach to demonstrate a progressive increase in the quality of memory T cell pools in terms of their ability to proliferate and accumulate at effector sites in response to secondary pathogen challenge. This temporal increase in efficacy occurred in CD62Llo (effector memory) and CD62Lhi (central memory) subpopulations, but was most prominent in the CD62Lhi subpopulation. These data indicate that the contribution of effector memory and central memory T cells to the recall response changes substantially over time.


2010 ◽  
Vol 17 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Marcela I. Henao-Tamayo ◽  
Diane J. Ordway ◽  
Scott M. Irwin ◽  
Shaobin Shang ◽  
Crystal Shanley ◽  
...  

ABSTRACT The bacterium Mycobacterium tuberculosis remains one of the world's most successful pathogens, a situation that is aggravated by the fact that the existing vaccine, Mycobacterium bovis BCG, is not effective in adults. As with any vaccine, the purpose of giving BCG vaccination is to establish a long-lived state of memory immunity, but whether this is successfully completely established is still unclear. It is generally accepted that memory T cells can be divided into central and effector memory populations by function and by phenotype; however, the majority of data supporting this division have been generated using transgenic mouse models or mice that have recovered from acute viral infections. Tuberculosis, on the other hand, represents a persistent, chronic state of immunity in which the presence of memory T cells is far less well defined. We show here that mice vaccinated with BCG or chronically infected with M. tuberculosis establish antigen-specific populations of cells within the lungs that predominantly express a cellular phenotype consistent with their being effector or effector memory cells. In contrast, cells with a central memory phenotype exist in much lower numbers in the lungs but can be found in significantly larger numbers in the spleen, where they may represent a potential reservoir. These data suggest that the effector-to-central-memory T-cell transition may well be minimal in these persisting mycobacterial infections, and they support a novel hypothesis that this may explain the fundamental basis of the failure of the BCG vaccine in humans.


2007 ◽  
Vol 180 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Ni Wan ◽  
Hehua Dai ◽  
Tao Wang ◽  
Yolonda Moore ◽  
Xin Xiao Zheng ◽  
...  

2007 ◽  
Vol 204 (9) ◽  
pp. 2015-2021 ◽  
Author(s):  
Andrew M. Intlekofer ◽  
Naofumi Takemoto ◽  
Charlly Kao ◽  
Arnob Banerjee ◽  
Felix Schambach ◽  
...  

Immunity to intracellular pathogens requires dynamic balance between terminal differentiation of short-lived, cytotoxic effector CD8+ T cells and self-renewal of central–memory CD8+ T cells. We now show that T-bet represses transcription of IL-7Rα and drives differentiation of effector and effector–memory CD8+ T cells at the expense of central–memory cells. We also found T-bet to be overexpressed in CD8+ T cells that differentiated in the absence of CD4+ T cell help, a condition that is associated with defective central–memory formation. Finally, deletion of T-bet corrected the abnormal phenotypic and functional properties of “unhelped” memory CD8+ T cells. T-bet, thus, appears to function as a molecular switch between central– and effector–memory cell differentiation. Antagonism of T-bet may, therefore, represent a novel strategy to offset dysfunctional programming of memory CD8+ T cells.


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