Antibody-dependent anti-cytomegalovirus activity of human γδ T cells expressing CD16 (FcγRIIIa)

Blood ◽  
2012 ◽  
Vol 119 (6) ◽  
pp. 1418-1427 ◽  
Author(s):  
Lionel Couzi ◽  
Vincent Pitard ◽  
Xavier Sicard ◽  
Isabelle Garrigue ◽  
Omar Hawchar ◽  
...  

Abstract Human cytomegalovirus (HCMV) infection is an important cause of morbidity and mortality in transplant recipients. Long-term protective immunity against HCMV requires both sustained specific T-cell response and neutralizing IgG production, but the interplay between these effector arms remains poorly defined. We previously demonstrated that γδ T cells play a substantial role as anti-HCMV T-cell effectors. The observation that CD16 (FcγRIIIA) was specifically expressed by the majority of HCMV-induced γδ T cells prompted us to investigate their cooperation with anti-HCMV IgG. We found that CD16 could stimulate γδ T cells independently of T-cell receptor (TCR) engagement and provide them with an intrinsic antibody-dependent cell-mediated cytotoxic (ADCC) potential. Although CD16+γδ T cells did not mediate ADCC against HCMV-infected cells, in accordance with the low level of anti-HCMV IgGs recognizing infected cells, they produced IFNγ when incubated with IgG-opsonized virions. This CD16-induced IFNγ production was greatly enhanced by IL12 and IFNα, 2 cytokines produced during HCMV infection, and conferred to γδ T cells the ability to inhibit HCMV multiplication in vitro. Taken together, these data identify a new antiviral function for γδ T cells through cooperation with anti-HCMV IgG that could contribute to surveillance of HCMV reactivation in transplant recipients.

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3693-3701 ◽  
Author(s):  
Marlène Brandes ◽  
Katharina Willimann ◽  
Alois B. Lang ◽  
Ki-Hoan Nam ◽  
Chenggang Jin ◽  
...  

Abstractγδ T cells are inadequately defined both in terms of their migration potential and contribution to antimicrobial immunity. Here, we have examined the migration profile of human blood γδ T cells and related cell lines and correlated these findings with their distribution in secondary lymphoid tissues and their function in B-cell cocultures. We find that resting γδ T cells are characterized by an inflammatory migration program similar to cells of the innate immune system. However, T-cell receptor (TCR) triggering resulted in the rapid but transient induction of a lymph node (LN)-homing program, as evidenced by functional CCR7 expression and concomitant reduction in expression and function of CCR5 and, to a lesser degree, CCR2. Moreover, the LN-homing program was reflected by the presence of γδ T cells in gastrointestinal lymphoid tissues, notably in clusters within germinal centers of B-cell follicles. In line with these findings, VγVδ-TCR triggering resulted in prominent expression of essential B-cell costimulatory molecules, including CD40L, OX40, CD70, and ICOS. Furthermore, γδ T cells were shown to provide potent B-cell help during in vitro antibody production. Collectively, our findings agree with a role for γδ T cells in humoral immunity during the early phase of antimicrobial responses. (Blood. 2003; 102:3693-3701)


2010 ◽  
Vol 91 (8) ◽  
pp. 2040-2048 ◽  
Author(s):  
Siok-Keen Tey ◽  
Felicia Goodrum ◽  
Rajiv Khanna

Recent studies have shown that long-term persistence of human cytomegalovirus (HCMV) in mononuclear cells of myeloid lineage is dependent on the UL138 open reading frame, which promotes latent infection. Although T-cell recognition of protein antigens from all stages of lytic HCMV infection is well established, it is not clear whether proteins expressed during latent HCMV infection can also be recognized. This study conducted an analysis of T-cell response towards proteins associated with HCMV latency. Ex vivo analysis of T cells from healthy virus carriers revealed a dominant CD8+ T-cell response to the latency-associated pUL138 protein, which recognized a non-canonical 13 aa epitope in association with HLA-B*3501. These pUL138-specific T cells displayed a range of memory phenotypes that were in general less differentiated than that previously described in T cells specific for HCMV lytic antigens. Antigen-presentation assays revealed that endogenous pUL138 could be presented efficiently by HCMV-infected cells. However, T-cell recognition of pUL138 was dependent on newly synthesized protein, with little presentation from stable, long-lived protein. These data demonstrate that T cells targeting latency-associated protein products exist, although HCMV may limit the presentation of latent proteins, thereby restricting T-cell recognition of latently infected cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5087-5087
Author(s):  
Franco Locatelli ◽  
Daniele Lilleri ◽  
Laura Lozza ◽  
Giovanna Giorgiani ◽  
Piero De Stefano ◽  
...  

Abstract We are studying the development of HCMV-specific CD4+ and CD8+ T cell response after allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients. A new technique was developed to simultaneously detect HCMV-specific CD4+ and CD8+ effector T cells using HCMV-infected autologous dendritic cells as stimulators and intracellular staining of IFN-γ production by T cells. This prospective study is based on monthly determination of both HCMV-specific T cell number and in vitro lymphoproliferative response to crude HCMV antigen. Patients are routinely monitored for HCMV infection/reactivation in blood (by determination of either antigenemia or quantitation of viral DNA) and treated according to a strategy of pre-emptive therapy. So far, of 41 patients receiving HSCT from an HLA-identical related donor (n=18), unrelated donor (n=15) or a T cell-depleted HSCT from a haploidentical relative (n=8), 25 patients have reached day +180, while 16 patients completed a follow-up of 90 days. Among the 28 HCMV-seropositive HSCT recipients, 25 developed HCMV-specific CD4+ and CD8+ T-cell response within the first 60 days after transplantation. In these patients, absolute CD4+ T cell count increased over time, but remained lower than that of healthy controls also at later time points. By contrast, CD8+ T cells reached and maintained absolute levels comparable to those of controls already from day +60. At this time, HCMV-specific CD4+ T cell count was comparable to that of controls, while HCMV-specific CD8+ T cell count was higher than that of controls, with no significant change thereafter. On the other hand, in vitro lymphoproliferative response to HCMV antigen was detectable only in about one half of these patients, even at day +180. HCMV infection was detected in blood of 22 of the 25 patients in whom HCMV-specific T cells were present. It was either self-limiting (n=14) or in 8 patients required shorter ganciclovir course (median 7 days, range 5-14) than in the 3 HCMV seropositive patients who developed HCMV infection in the absence of specific immunity (median 67 days, range 42–82, p<0.001). No patient developed HCMV disease or late viral infections. Conversely, HCMV-specific response was detected in only 3/13 HCMV seronegative recipients (none of whom developing detectable HCMV infection in blood). In these patients, both absolute and HCMV-specific T cell counts were lower than those of both controls and HCMV-seropositive HSCT recipients. Our data suggest that effective HCMV-specific T cell immunity can promptly develop after HSCT (regardless of donor type or T-cell depletion of the graft), particularly in seropositive recipients in whom latent virus may be a major antigenic drive for rapid reconstitution of T cell compartment, especially of CD8+ lymphocytes. On the other hand, transfer of memory T cell immunity from seropositive donors to seronegative recipients does not appear to be always sufficient to permit detection of virus-specific lymphocytes in patient’s peripheral blood in the early period after the allograft, possibly also due to the lower chance of in vivo antigen stimulation. The frequent dissociation between IFN-γ production and lymphoproliferative response remains to be explained. Future studies could address modulation of antiviral intervention on the reconstitution of HCMV-specific T cell immune response.


1998 ◽  
Vol 187 (11) ◽  
pp. 1885-1892 ◽  
Author(s):  
Patrick A.J. Haslett ◽  
Laura G. Corral ◽  
Matthew Albert ◽  
Gilla Kaplan

The efficacy of thalidomide (α-phthalimido-glutarimide) therapy in leprosy patients with erythema nodosum leprosum is thought to be due to inhibition of tumor necrosis factor α. In other diseases reported to respond to thalidomide, the mechanism of action of the drug is unclear. We show that thalidomide is a potent costimulator of primary human T cells in vitro, synergizing with stimulation via the T cell receptor complex to increase interleukin 2–mediated T cell proliferation and interferon γ production. The costimulatory effect is greater on the CD8+ than the CD4+ T cell subset. The drug also increases the primary CD8+ cytotoxic T cell response induced by allogeneic dendritic cells in the absence of CD4+ T cells. Therefore, human T cell costimulation can be achieved pharmacologically with thalidomide, and preferentially in the CD8+ T cell subset.


2000 ◽  
Vol 191 (12) ◽  
pp. 2145-2158 ◽  
Author(s):  
Paul J. Egan ◽  
Simon R. Carding

Although γδ T cells are involved in the regulation of inflammation after infection, their precise function is not known. Intraperitoneal infection of T cell receptor (TCR)-δ−/− mice with the intracellular bacterium Listeria monocytogenes resulted in the development of necrotic foci in the livers. In contrast, the peritoneal cavities of infected TCR-δ−/− mice contained an accumulation of low density activated macrophages and a reduced percentage of macrophages undergoing apoptosis. γδ T cell hybridomas derived from mice infected with Listeria were preferentially stimulated by low density macrophages from peritoneal exudates of infected mice. Furthermore, primary splenic γδ T cells isolated from Listeria-infected mice were cytotoxic for low density macrophages in vitro, and cytotoxicity was inhibited in the presence of antibodies to the γδ TCR. These results demonstrate a novel interaction between γδ T cells and activated macrophages in which γδ T cells are stimulated by terminally differentiated macrophages to acquire cytotoxic activity and which, in turn, induce macrophage cell death. This interaction suggests that γδ T cells regulate the inflammatory response to infection with intracellular pathogens by eliminating activated macrophages at the termination of the response.


2017 ◽  
Vol 91 (6) ◽  
Author(s):  
Sarah E. Jackson ◽  
George X. Sedikides ◽  
Gavin M. Mason ◽  
Georgina Okecha ◽  
Mark R. Wills

ABSTRACT Human cytomegalovirus (HCMV) infection and periodic reactivation are generally well controlled by the HCMV-specific T cell response in healthy people. While the CD8+ T cell response to HCMV has been extensively studied, the HCMV-specific CD4+ T cell effector response is not as well understood, especially in the context of direct interactions with HCMV-infected cells. We screened the gamma interferon (IFN-γ) and interleukin-10 (IL-10) responses to 6 HCMV peptide pools (pp65, pp71, IE1, IE2, gB, and US3, selected because they were the peptides most frequently responded to in our previous studies) in 84 donors aged 23 to 74 years. The HCMV-specific CD4+ T cell response to pp65, IE1, IE2, and gB was predominantly Th1 biased, with neither the loss nor the accumulation of these responses occurring with increasing age. A larger proportion of donors produced an IL-10 response to pp71 and US3, but the IFN-γ response was still dominant. CD4+ T cells specific to the HCMV proteins studied were predominantly effector memory cells and produced both cytotoxic (CD107a expression) and cytokine (macrophage inflammatory protein 1β secretion) effector responses. Importantly, when we measured the CD4+ T cell response to cytomegalovirus (CMV)-infected dendritic cells in vitro, we observed that the CD4+ T cells produced a range of cytotoxic and secretory effector functions, despite the presence of CMV-encoded immune evasion molecules. CD4+ T cell responses to HCMV-infected dendritic cells were sufficient to control the dissemination of virus in an in vitro assay. Together, the results show that HCMV-specific CD4+ T cell responses, even those from elderly individuals, are highly functional and are directly antiviral. IMPORTANCE Human cytomegalovirus (HCMV) infection is carried for a lifetime and in healthy people is kept under control by the immune system. HCMV has evolved many mechanisms to evade the immune response, possibly explaining why the virus is never eliminated during the host's lifetime. The dysfunction of immune cells associated with the long-term carriage of HCMV has been linked with poor responses to new pathogens and vaccines when people are older. In this study, we investigated the response of a subset of immune cells (CD4+ T cells) to HCMV proteins in healthy donors of all ages, and we demonstrate that the functionality of CD4+ T cells is maintained. We also show that CD4+ T cells produce effector functions in response to HCMV-infected cells and can prevent virus spread. Our work demonstrates that these HCMV-specific immune cells retain many important functions and help to prevent deleterious HCMV disease in healthy older people.


2001 ◽  
Vol 69 (5) ◽  
pp. 3190-3196 ◽  
Author(s):  
Lars Hviid ◽  
Jørgen A. L. Kurtzhals ◽  
Victoria Adabayeri ◽  
Severine Loizon ◽  
Kåre Kemp ◽  
...  

ABSTRACT γδ T cells have variously been implicated in the protection against, and the pathogenesis of, malaria, but few studies have examined the γδ T-cell response to malaria in African children, who suffer the large majority of malaria-associated morbidity and mortality. This is unfortunate, since available data suggest that simple extrapolation of conclusions drawn from studies of nonimmune adults ex vivo and in vitro is not always possible. Here we show that both the frequencies and the absolute numbers of γδ T cells are transiently increased following treatment of Plasmodium falciparum malaria in Ghanaian children and they can constitute 30 to 50% of all T cells shortly after initiation of antimalarial chemotherapy. The bulk of the γδ T cells involved in this perturbation expressed Vδ1 and had a highly activated phenotype. Analysis of the T-cell receptors (TCR) of the Vδ1+ cell population at the peak of their increase showed that all expressed Vγ chains were used, and CDR3 length polymorphism indicated that the expanded Vδ1 population was highly polyclonal. A very high proportion of the Vδ1+ T cells produced gamma interferon, while fewer Vδ1+ cells than the average proportion of all CD3+ cells produced tumor necrosis factor alpha. No interleukin 10 production was detected among TCR-γδ+cells in general or Vδ1+ cells in particular. Taken together, our data point to an immunoregulatory role of the expanded Vδ1+ T-cell population in this group of semi-immuneP. falciparum malaria patients.


2005 ◽  
Vol 201 (10) ◽  
pp. 1567-1578 ◽  
Author(s):  
Franck Halary ◽  
Vincent Pitard ◽  
Dorota Dlubek ◽  
Roman Krzysiek ◽  
Henri de la Salle ◽  
...  

Long-lasting expansion of Vδ2neg γδ T cells is a hallmark of cytomegalovirus (CMV) infection in kidney transplant recipients. The ligands of these cells and their role remain elusive. To better understand their immune function, we generated γδ T cell clones from several transplanted patients. Numerous patient Vδ1+, Vδ3+, and Vδ5+ γδ T cell clones expressing diverse Vγ chains, but not control Vγ9Vδ2+ T clones, displayed strong reactivity against CMV-infected cells, as shown by their production of tumor necrosis factor-α. Vδ2neg γδ T lymphocytes could also kill CMV-infected targets and limit CMV propagation in vitro. Their anti-CMV reactivity was specific for this virus among herpesviridae and required T cell receptor engagement, but did not involve major histocompatibility complex class I molecules or NKG2D. Vδ2neg γδ T lymphocytes expressed receptors essential for intestinal homing and were strongly activated by intestinal tumor, but not normal, epithelial cell lines. High frequencies of CMV- and tumor-specific Vδ2neg γδ T lymphocytes were found among patients' γδ T cells. In conclusion, Vδ2neg γδ T cells may play a role in protecting against CMV and tumors, probably through mucosal surveillance of cellular stress, and represent a population that is largely functionally distinct from Vγ9Vδ2+ T cells.


2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Weixu Meng ◽  
Aimin Tang ◽  
Xiaohua Ye ◽  
Xun Gui ◽  
Leike Li ◽  
...  

ABSTRACTThe host immune response to human cytomegalovirus (HCMV) is effective against HCMV reactivation from latency, though not sufficient to clear the virus. T cells are primarily responsible for the control of viral reactivation. When the host immune system is compromised, as in transplant recipients with immunosuppression, HCMV reactivation and progressive infection can cause serious morbidity and mortality. Adoptive T cell therapy is effective for the control of HCMV infection in transplant recipients. However, it is a highly personalized therapeutic regimen and is difficult to implement in routine clinical practice. In this study, we explored a bispecific-antibody strategy to direct non-HCMV-specific T cells to recognize and exert effector functions against HCMV-infected cells. Using a knobs-into-holes strategy, we constructed a bispecific antibody in which one arm is specific for CD3 and can trigger T cell activation, while the other arm, specific for HCMV glycoprotein B (gB), recognizes and marks HCMV-infected cells based on the expression of viral gB on their surfaces. We showed that this bispecific antibody was able to redirect T cells with specificity for HCMV-infected cellsin vitro. In the presence of HCMV infection, the engineered antibody was able to activate T cells with no HCMV specificity for cytokine production, proliferation, and the expression of phenotype markers unique to T cell activation. These results suggested the potential of engineered bispecific antibodies, such as the construct described here, as prophylactic or therapeutic agents against HCMV reactivation and infection.


1991 ◽  
Vol 174 (5) ◽  
pp. 957-967 ◽  
Author(s):  
B Gückel ◽  
C Berek ◽  
M Lutz ◽  
P Altevogt ◽  
V Schirrmacher ◽  
...  

The CD2 receptor functions as an adhesion and signal molecule in T cell recognition. Multimeric binding of CD2 on T cells to its physiologic ligand LFA-3 on cognate partner cells in vitro efficiently augments the antigen-specific T cell signal delivered by the T cell receptor/CD3 complex. The precise contribution of the antigen-nonspecific CD2-LFA-3 interactions to T cell immune responses in vivo, however, has been difficult to assess. Here we analyzed the role of CD2 in the murine immune response using a nondepleting anti-CD2 monoclonal antibody that induces a marked, reversible modulation of CD2 expression on murine T and B cells in situ. This modulation is dose and time dependent, specific for CD2, and does not require the Fc portion of the antibody. Anti-CD2 antibodies [rat IgG1 or F(ab')2] significantly inhibit the CD4+ T cell-mediated response to hen egg lysozyme and the cytotoxic CD8+ T cell response to a syngeneic tumor cell line. In both cases, anti-CD2 antibodies are only effective when administered before or within 24 h after antigen priming. The suppression of the antitumor response corresponds to a sixfold reduction of specific cytotoxic T lymphocyte precursor cells and results in the abrogation of protective antitumor immunity. Anti-CD2 antibodies also affect the humoral immune response to oxazolone: the isotype switch from specific IgM to IgG1 antibodies is delayed, whereas the IgM response is unaltered. In addition, a single antibody injection results in sustained polyclonal unresponsiveness of T cells irrespective of antigen priming and CD2 modulation. These results document that CD2-mediated signals induce a state of T cell unresponsiveness in vivo.


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