FcγRIII discriminates between 2 subsets of Vγ9Vδ2 effector cells with different responses and activation pathways

Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1801-1807 ◽  
Author(s):  
Daniela F. Angelini ◽  
Giovanna Borsellino ◽  
Mary Poupot ◽  
Adamo Diamantini ◽  
Rémy Poupot ◽  
...  

Abstract Upon recognition of nonpeptidic phosphoantigens, human Vδ2 T lymphocytes enter a lineage differentiation pattern that determines the generation of memory cells with a range of effector functions. Here, we show that within the effector memory Vδ2 population, 2 distinct and complementary subsets with regard to phenotype, mode of activation, and type of responses can be identified: Vδ2 TEMh cells, which express high levels of chemokine receptors, but low levels of perforin and of natural killer receptors (NKRs) and which produce large amounts of interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) in response to T-cell receptor (TCR)–specific stimulation by phosphoantigens; and Vδ2TEMRA cells, which constitutively express several NKRs, high amounts of perforin, but low levels of chemokine receptors and of IFN-γ. These NK-like cells are refractory to phosphoantigen but respond to activation via FcγRIII (CD16) and are highly active against tumoral target cells. Thus, circulating Vδ2T lymphocytes comprise 2 functionally diverse subsets of effector memory cells that may be discriminated on the basis of CD16 expression.

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1420
Author(s):  
Jagoda Siemaszko ◽  
Aleksandra Marzec-Przyszlak ◽  
Katarzyna Bogunia-Kubik

Natural Killer (NK) cells are natural cytotoxic, effector cells of the innate immune system. They can recognize transformed or infected cells. NK cells are armed with a set of activating and inhibitory receptors which are able to bind to their ligands on target cells. The right balance between expression and activation of those receptors is fundamental for the proper functionality of NK cells. One of the best known activating receptors is NKG2D, a member of the CD94/NKG2 family. Due to a specific NKG2D binding with its eight different ligands, which are overexpressed in transformed, infected and stressed cells, NK cells are able to recognize and attack their targets. The NKG2D receptor has an enormous significance in various, autoimmune diseases, viral and bacterial infections as well as for transplantation outcomes and complications. This review focuses on the NKG2D receptor, the mechanism of its action, clinical relevance of its gene polymorphisms and a potential application in various clinical settings.


Blood ◽  
2004 ◽  
Vol 103 (8) ◽  
pp. 3065-3072 ◽  
Author(s):  
Michael R. Verneris ◽  
Mobin Karami ◽  
Jeanette Baker ◽  
Anishka Jayaswal ◽  
Robert S. Negrin

Abstract Activating and expanding T cells using T-cell receptor (TCR) cross-linking antibodies and interleukin 2 (IL-2) results in potent cytotoxic effector cells capable of recognizing a broad range of malignant cell targets, including autologous leukemic cells. The mechanism of target cell recognition has previously been unknown. Recent studies show that ligation of NKG2D on natural killer (NK) cells directly induces cytotoxicity, whereas on T cells it costimulates TCR signaling. Here we demonstrate that NKG2D expression is up-regulated upon activation and expansion of human CD8+ T cells. Antibody blocking, redirected cytolysis, and small interfering RNA (siRNA) studies using purified CD8+ T cells demonstrate that cytotoxicity against malignant target cells occurs through NKG2D-mediated recognition and signaling and not through the TCR. Activated and expanded CD8+ T cells develop cytotoxicity after 10 to 14 days of culture, coincident with the expression of the adapter protein DAP10. T cells activated and expanded in low (30 U/mL) and high (300 U/mL) concentrations of IL-2 both up-regulated NKG2D expression equally, but only cells cultured in high-dose IL-2 expressed DAP10 and were cytotoxic. Collectively these results establish that NKG2D triggering accounts for the majority of major histocompatibility complex (MHC)–unrestricted cytotoxicity of activated and expanded CD8+ T cells, likely through DAP10-mediated signaling. (Blood. 2004;103: 3065-3072)


2020 ◽  
Vol 22 (5) ◽  
pp. 837-846
Author(s):  
E. A. Blinova ◽  
A. V. Kolerova ◽  
V. E. Balyasnikov ◽  
V. A. Kozlov

IL-7 is a key factor for the survival and maintenance of CD4+ central (Tcm) and effector (Tem) memory cells in the whole body. In many autoimmune diseases, an elevated level of IL-7 is detected in blood serum and at the site of inflammation, thus suggesting participation of this homeostatic factor in the survival of memory T cells, including auto-reactive clones, in inflammatory disorders. The aim of the study was to investigate the mechanisms of maintaining CD4+ memory T cells under normal and inflammatory conditions. We developed an in vitro model of inflammation, based on induction of pro-inflammatory cytokines, and then evaluated the effects of IL-7 upon purified sorted populations of CD4+Tcm and Tem under normal conditions and in vitro inflammatory model. IL-7 treatment promoted maintenance of CD4+Tcm phenotype in all variants of cultures. In the absence of contact with adherent cell fraction, the IL-7-induced proliferation of Tcm and Tem was slightly reduced, both under normal and inflammatory conditions, thus suggesting low sensitivity of memory T cells to contacts with MHC, and, probably, a requirement for additional signals to provide complete stimulation with IL-7. The last suggestion is also supported by data about CD127 and CD132 expression, i.e., in the absence of contact with MHC, the proportion of CD127+CD132+ cells was decreased in both subpopulations of CD4+ memory cells. Upon in vitro cultures, IL-7 contributed to decreased expression of CD127, and increased expression of CD132 on CD4+Tcm and Tem. We have evaluated the CD4+Tcm and Tem populations by affinity of T cell receptor (TCR), using the level of CD5 expression. Т cells with high TCR affinity for self-antigens are known to have higher expression of CD5. In comparison to Tem, the Tcm contained more CD5high cells. In cultures, IL-7 promoted a high level of CD5 expression on Tcm, which was comparable to levels observed in peripheral blood cells. High CD5 expression on Tem was observed after stimulation with IL-7 in the in vitro inflammatory model. In the absence of contact with MHC, the number of CD5high cells decreased among CD4+Tem and Tcm. Thus, CD4+Tcm cells with high affinity for autologous antigens are probably dependent on the presence of homeostatic factors, in particular, IL-7, and contacts with antigen-presenting cells (APCs). Under conditions of inflammation, no changes were revealed in the mechanism of maintaining CD4+Tcm, in contrast to CD4+Tem. Being less dependent on IL-7 under normal conditions, CD4+CD5highTem are accumulated in the presence of IL-7 under in vitro inflammatory conditions.


2013 ◽  
Vol 81 (11) ◽  
pp. 4171-4181 ◽  
Author(s):  
Laura A. Cooney ◽  
Megha Gupta ◽  
Sunil Thomas ◽  
Sebastian Mikolajczak ◽  
Kimberly Y. Choi ◽  
...  

ABSTRACTVaccination with a single dose of genetically attenuated malaria parasites can induce sterile protection against sporozoite challenge in the rodentPlasmodium yoeliimodel. Protection is dependent on CD8+T cells, involves perforin and gamma interferon (IFN-γ), and is correlated with the expansion of effector memory CD8+T cells in the liver. Here, we have further characterized vaccine-induced changes in the CD8+T cell phenotype and demonstrated significant upregulation of CD11c on CD3+CD8b+T cells in the liver, spleen, and peripheral blood. CD11c+CD8+T cells are predominantly CD11ahiCD44hiCD62L−, indicative of antigen-experienced effector cells. Followingin vitrorestimulation with malaria-infected hepatocytes, CD11c+CD8+T cells expressed inflammatory cytokines and cytotoxicity markers, including IFN-γ, tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), perforin, and CD107a. CD11c−CD8+T cells, on the other hand, expressed negligible amounts of all inflammatory cytokines and cytotoxicity markers tested, indicating that CD11c marks multifunctional effector CD8+T cells. Coculture of CD11c+, but not CD11c−, CD8+T cells with sporozoite-infected primary hepatocytes significantly inhibited liver-stage parasite development. Tetramer staining for the immunodominant circumsporozoite protein (CSP)-specific CD8+T cell epitope demonstrated that approximately two-thirds of CSP-specific cells expressed CD11c at the peak of the CD11c+CD8+T cell response, but CD11c expression was lost as the CD8+T cells entered the memory phase. Further analyses showed that CD11c+CD8+T cells are primarily KLRG1+CD127−terminal effectors, whereas all KLRG1−CD127+memory precursor effector cells are CD11c−CD8+T cells. Together, these results suggest that CD11c marks a subset of highly inflammatory, short-lived, antigen-specific effector cells, which may play an important role in eliminating infected hepatocytes.


Science ◽  
2020 ◽  
Vol 368 (6494) ◽  
pp. eaaz7548 ◽  
Author(s):  
Zhiwei Zhou ◽  
Huabin He ◽  
Kun Wang ◽  
Xuyan Shi ◽  
Yupeng Wang ◽  
...  

Cytotoxic lymphocyte–mediated immunity relies on granzymes. Granzymes are thought to kill target cells by inducing apoptosis, although the underlying mechanisms are not fully understood. Here, we report that natural killer cells and cytotoxic T lymphocytes kill gasdermin B (GSDMB)–positive cells through pyroptosis, a form of proinflammatory cell death executed by the gasdermin family of pore-forming proteins. Killing results from the cleavage of GSDMB by lymphocyte-derived granzyme A (GZMA), which unleashes its pore-forming activity. Interferon-γ (IFN-γ) up-regulates GSDMB expression and promotes pyroptosis. GSDMB is highly expressed in certain tissues, particularly digestive tract epithelia, including derived tumors. Introducing GZMA-cleavable GSDMB into mouse cancer cells promotes tumor clearance in mice. This study establishes gasdermin-mediated pyroptosis as a cytotoxic lymphocyte–killing mechanism, which may enhance antitumor immunity.


Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1137-1144 ◽  
Author(s):  
Deepa Hariharan ◽  
Steven D. Douglas ◽  
Benhur Lee ◽  
Jian-Ping Lai ◽  
Donald E. Campbell ◽  
...  

Abstract The C-C chemokine receptors CCR5 and CCR3 are fusion coreceptors for human immunodeficiency virus (HIV) entry into macrophages. The regulation of their expression influences infectivity by HIV. We report here that interferon-γ (IFN-γ) a cytokine that has bidirectional effects on HIV infection of macrophages, significantly upregulated CCR5 and CCR3 cell surface expression in human mononuclear phagocytes isolated from placental cord blood and adult peripheral blood. Monocytes treated with IFN-γ showed increased chemotaxis to the CCR5 ligands macrophage inflammatory protein-1 (MIP-1) and MIP-1β, confirming the functional relevance of IFN-γ–induced CCR5 expression. However, IFN-γ suppressed HIV entry into macrophages. Interestingly, we demonstrated that IFN-γ inhibited cell surface expression of CD4, the major receptor for HIV. This finding may explain the suppressive effect of IFN-γ on HIV entry into macrophages, despite its enhancing effect on the expression of CCR5 and CCR3 by these cells. In addition, IFN-γ–induced secretion of C-C chemokines (RANTES, MIP-1, and MIP-1β) by mononuclear phagocytes may also suppress HIV entry into macrophages. These data provide further evidence for cytokine-mediated regulation of CCR5 expression and are consistent with a novel paradigm in which cytokines regulate HIV infection and leukocyte migration by reciprocal and opposing effects on the expression of CD4 and chemokine receptors.


Blood ◽  
1998 ◽  
Vol 91 (12) ◽  
pp. 4444-4450 ◽  
Author(s):  
Davide Zella ◽  
Oxana Barabitskaja ◽  
Jennifer M. Burns ◽  
Fabio Romerio ◽  
Daniel E. Dunn ◽  
...  

Abstract Chemokine receptors (CR), which can mediate migration of immune cells to the site of inflammation, also function as coreceptors for human immunodeficiency virus (HIV) entry into CD4+ T lymphocytes and antigen-presenting cells. We demonstrate here that interferon-γ (IFN-γ) increases the expression of chemokine receptors CCR1, CCR3, and CCR5 in monocytoid U937 cells as detected by cell surface molecule labeling and mRNA expression, as well as by intracellular calcium mobilization and cell migration in response to specific ligands. The increased expression of these chemokine receptors also results in an enhanced HIV-1 entry into cells. Our data provide evidence for a relationship of cellular pathways that are induced by IFN-γ with those that regulate chemokine receptor expression.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2664-2664
Author(s):  
Aileen M. Cleary ◽  
David B. Lewis

Abstract Human memory CD4+ T cells can be distinguished from antigenically-naïve CD4+ T cells based on their CD45RAlowCD45R0high and CD45RAhighCD45R0low surface phenotypes, respectively. Memory CD4+ T cells from adult peripheral blood can be further divided based on surface expression of the CCR7 chemokine receptor. Th1 memory CD4+ T cells that are CCR7high (putative central memory cells or Tcm) are expected to be preferentially targeted to peripheral lymph nodes where the ligands for CCR7 are expressed in high amounts. These cells have been reported to lack expression of the CCR3 and CCR5 chemokine receptors, which facilitate entry into inflamed tissues, and produce little or no interferon (IFN)-γ after stimulation via the αβ-TCR/CD3 complex. CD45RAlowCD45R0highCCR7low CD4+ T cells account for virtually all IFN-g production by human CD4 T cells after ab-TCR/CD3 stimulation using monoclonal antibodies, and for this reason were termed effector memory cells (Tem). These findings, as well as the observation of shorter telomere lengths for memory CD4+ T cells that are CCR7low compared to those that CCR7high suggest that the Tcm population may be an intermediate between naïve CD4+ T cells and Tem. It has recently been proposed that the level of signal strength and γc containing cytokines play a role in memory T cell generation. However, little is known whether IL-12 or IL-23 are necessary and for this differentiation and/or maintenance. Our laboratory has previously described a patient with IL-12Rβ1 deficiency, which ablates both IL-12 and IL-23 signaling. This patient had a deficiency in Tem number and function, unexpectedly suggesting that IL-12 and/or IL-23 may play a key role in this process. We therefore hypothesized that signaling through IL-12Rβ1 plays a key role in the latter stages of generation and/or maintenance of human memory CD4+ T cells. Preliminary data thus far show CCR7 expression to be slightly decreased on activated Tcm in response to incubation with IL-2 or IL-12 alone, and to a greater extent with IL-2 and IL-12 incubated together. In addition, spontaneous apoptosis of both Tcm and Tem is decreased upon incubation with IL-12. Taken together, these data suggest that IL-12 may play a role in both generation of Tem and maintenance of both Tcm and Tem.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 477-477
Author(s):  
Erica Dander ◽  
Giuseppina Li Pira ◽  
Ettore Biagi ◽  
Fabrizio Manca ◽  
Andrea Biondi ◽  
...  

Abstract BACKGROUND: Reactivation of latent CMV in immunocompromised recipients of allogeneic stem cell transplantation remains a major cause of morbidity and mortality. Reconstitution of immunity by CMV specific immunotherapy is an attractive alternative to drugs currently used, which show high toxicity and are sometimes ineffective. It has been demonstrated that CD4 helper T-cell function is crucial for the persistence of in vivo transferred CD8 CMV-specific CTL. Based on this finding, we have explored the feasibility of generating both anti-CMV CD4 and anti-CMV CD8 T-cell lines. METHODS: Dendritic Cells (DC) were generated from donor peripheral blood (PB) monocytes after a 7-day culture in the presence of GM-CSF plus IL-4 and matured with TNF-α, IFN-α, IFN-γ, IL1-β, POLI I:C. Matured-DC were then pulsed with a pool of 50 peptides spanning pp65 and IE1 proteins which are recognised by both CD4 and CD8 T lymphocytes. Donor T cells were stimulated three times at a T cell/DC ratio of 1:6 on day 0, +7 and +14 with mature peptide pulsed-DC. At the end of the culture the specificity of generated T cells was determined as percentage of pentamer-positive cells and intracellular IFN-γ production after incubation with peptide pulsed-DC. Cultured T cells were also analysed for their ability to proliferate in response to peptide pulsed-target cells, to kill them in a standard citotoxicity assay and to migrate in response to inflammatory (CXCL9, CCL3 and CCL5) and constitutive (CXCL12) chemokines. RESULTS: CMV-specific T cell lines were generated from five CMV seropositive donors. In four cases CD4 and CD8 CMV-specific T cell lines were expanded successfully. Cultured T cells expressed CD8 (mean= 70%, range 60–81%) and CD4 (mean= 20%, range 15–28%) and showed a CD45RA- CCR7- Effector Memory phenothype (mean=26%, range 19–30%) or a CD45RA+ CCR7- T Effector Memory RA-Positive phenothype (mean=67%, range 59–77%). An enriched CMV-specific T cell population was observed after staining with pentamers (7–45% pentamer-positive T cells). Furthermore, 90% of CD8+ and 40% of CD4+ T cells expressed high levels of intracytoplasmatic perforin and granzyme. In 4/5 cases tested, cutured T cells showed a cytolitic activity against CD8-peptide pulsed target cells (average lysis=50%, range 40–55%) and to a lesser extent against CD4-peptide pulsed target cells (average lysis=35%, range 30–40%). In addition, cultured T lymphocytes were able to proliferate and to produce intracytoplasmic IFN-γ (average production=50%, range 35–60%) after exposure to peptide-pulsed DC. Finally, Cultured T cells strongly migrated in response to chemokines (CXCL9, CCL3 and CCL5) involved in the recruitment of effector cells during viral infection. DISCUSSION: In conclusion, a great advantage of this method is represented by the possibility to generate anti-CMV CD4+ T cells, which could support in vivo the persistence of re-infused CMV-specific CTL. Moreover, the possibility of generating peptides under GMP conditions would facilitate the translation of this approach into clinical intervention.


2006 ◽  
Vol 203 (4) ◽  
pp. 897-906 ◽  
Author(s):  
Megan MacLeod ◽  
Mark J. Kwakkenbos ◽  
Alison Crawford ◽  
Sheila Brown ◽  
Brigitta Stockinger ◽  
...  

Secondary T cell responses are enhanced because of an expansion in numbers of antigen-specific (memory) cells. Using major histocompatibility complex class II tetramers we have tracked peptide-specific endogenous (non–T cell receptor transgenic) CD4 memory T cells in normal and in costimulation-deficient mice. CD4 memory T cells were detectable after immunization for more than 200 days, although decay was apparent. Memory cells generated in CD40 knockout mice by immunization with peptide-pulsed wild-type dendritic cells survived in the absence of CD40 and proliferated when boosted with peptide (plus adjuvant) in a CD40-independent fashion. However, differentiation of the memory cells into cytokine-producing effector cells did not occur in the absence of CD40. The data indicate that memory cells can be generated without passing through the effector cell stage.


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