scholarly journals CD8+γδ T cells are more frequent in CMV seropositive bone marrow grafts and display phenotype of an adaptive immune response

immuneACCESS ◽  
2019 ◽  
Author(s):  
A Gaballa ◽  
LCM Arruda ◽  
E Radestad ◽  
M Uhlin
2011 ◽  
Vol 79 (10) ◽  
pp. 3940-3946 ◽  
Author(s):  
Cuixia Shi ◽  
Bikash Sahay ◽  
Jennifer Q. Russell ◽  
Karen A. Fortner ◽  
Nicholas Hardin ◽  
...  

ABSTRACTLittle is known regarding the function of γδ T cells, although they accumulate at sites of inflammation in infections and autoimmune disorders. We previously observed that γδ T cellsin vitroare activated byBorrelia burgdorferiin a TLR2-dependent manner. We now observe that the activated γδ T cells can in turn stimulate dendritic cellsin vitroto produce cytokines and chemokines that are important for the adaptive immune response. This suggested thatin vivoγδ T cells may assist in activating the adaptive immune response. We examined this possibilityin vivoand observed that γδ T cells are activated and expand in number duringBorreliainfection, and this was reduced in the absence of TLR2. Furthermore, in the absence of γδ T cells, there was a significantly blunted response of adaptive immunity, as reflected in reduced expansion of T and B cells and reduced serum levels of anti-Borreliaantibodies, cytokines, and chemokines. This paralleled a greaterBorreliaburden in γδ-deficient mice as well as more cardiac inflammation. These findings are consistent with a model of γδ T cells functioning to promote the adaptive immune response during infection.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ahmed Gaballa ◽  
Lucas C. M. Arruda ◽  
Emelie Rådestad ◽  
Michael Uhlin

The role of gamma delta (γδ) T cells in human cytomegalovirus (HCMV) immune surveillance has been the focus of research interest for years. Recent reports have shown a substantial clonal proliferation of γδ T cells in response to HCMV, shedding light on the adaptive immune response of γδ T cells. Nevertheless, most efforts have focused on Vδ2negγδ T cell subset while less attention has been given to investigate other less common γδ T cell subsets. In this regard, a distinct subpopulation of γδ T cells that expresses the CD8 coreceptor (CD8+γδ T cells) has not been thoroughly explored. Whether it is implicated in HCMV response and its ability to generate adaptive response has not been thoroughly investigated. In this study, we combined flow cytometry and immune sequencing of the TCR γ-chain (TRG) to analyze in-depth bone marrow (BM) graft γδ T cells from CMV seropositive (CMV+) and CMV seronegative (CMV-) donors. We showed that the frequency of CD8+γδ T cells was significantly higher in CMV+ grafts compared to CMV- grafts (P<0.001). Further characterization revealed that CD8+γδ T cells from CMV+ grafts express Vγ9- and preferentially differentiated from a naive to terminal effector memory phenotype (CD27low/-CD45RO-). In line with these findings, TRG immune sequencing revealed clonal focusing and reduced usage of the Vγ9/JP gene segment in a CMV+ graft. Furthermore, CD8+γδ T cells showed an enhanced response to TCR/CD3 and cytokine stimulation in contrast to CD8-γδ T cells. We conclude that γδ T cells in BM grafts are reshaped by donor CMV serostatus and highlight the potential adaptive role of CD8+γδ T cells in HCMV immune response.


Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1317-1324 ◽  
Author(s):  
Vincent Pitard ◽  
David Roumanes ◽  
Xavier Lafarge ◽  
Lionel Couzi ◽  
Isabelle Garrigue ◽  
...  

Abstract The ability of human γδ T cells to develop immunologic memory is still a matter of debate. We previously demonstrated the involvement of Vδ2− γδ T lymphocytes in the response of immunosuppressed organ recipients to cytomegalovirus (CMV). Here, we demonstrate their ability to mount an adaptive immune response to CMV in immunocompetent subjects. Vδ2− γδ T-cell peripheral blood numbers, repertoire restriction, and cytotoxicity against CMV-infected fibroblasts were markedly increased in CMV-seropositive, compared with CMV-seronegative, healthy persons. Whereas Vδ2− γδ T cells were found as naive cells in CMV− patients, they virtually all exhibited the cytotoxic effector/memory phenotype in CMV+ patients, which is also observed in transplanted patients challenged with CMV. This long-term complete remodeling of the Vδ2− γδ T-cell population by CMV predicts their ability to exhibit an adaptive anti-CMV immune response. Consistent with this, we observed that the secondary response to CMV was associated with a faster γδ T-cell expansion and a better resolution of infection than the primary response. In conclusion, the increased level of effector-memory Vδ2− γδ T cells in the peripheral blood is a specific signature of an adaptive immune response to CMV infection of both immunocompetent and immunosuppressed patients.


2019 ◽  
Vol 80 (12) ◽  
pp. 999-1005 ◽  
Author(s):  
Barbara Misme-Aucouturier ◽  
Adel Touahri ◽  
Marjorie Albassier ◽  
Francine Jotereau ◽  
Patrice Le Pape ◽  
...  

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1027
Author(s):  
Nima Taefehshokr ◽  
Sina Taefehshokr ◽  
Bryan Heit

The current coronavirus disease 2019 (COVID-19) pandemic, a disease caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), was first identified in December 2019 in China, and has led to thousands of mortalities globally each day. While the innate immune response serves as the first line of defense, viral clearance requires activation of adaptive immunity, which employs B and T cells to provide sanitizing immunity. SARS-CoV-2 has a potent arsenal of mechanisms used to counter this adaptive immune response through processes, such as T cells depletion and T cell exhaustion. These phenomena are most often observed in severe SARS-CoV-2 patients, pointing towards a link between T cell function and disease severity. Moreover, neutralizing antibody titers and memory B cell responses may be short lived in many SARS-CoV-2 patients, potentially exposing these patients to re-infection. In this review, we discuss our current understanding of B and T cells immune responses and activity in SARS-CoV-2 pathogenesis.


2007 ◽  
Vol 205 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Andrea J. Wolf ◽  
Ludovic Desvignes ◽  
Beth Linas ◽  
Niaz Banaiee ◽  
Toshiki Tamura ◽  
...  

The onset of the adaptive immune response to Mycobacterium tuberculosis is delayed compared with that of other infections or immunization, and allows the bacterial population in the lungs to expand markedly during the preimmune phase of infection. We used adoptive transfer of M. tuberculosis Ag85B-specific CD4+ T cells to determine that the delayed adaptive response is caused by a delay in initial activation of CD4+ T cells, which occurs earliest in the local lung-draining mediastinal lymph node. We also found that initial activation of Ag85B-specific T cells depends on production of antigen by bacteria in the lymph node, despite the presence of 100-fold more bacteria in the lungs. Although dendritic cells have been found to transport M. tuberculosis from the lungs to the local lymph node, airway administration of LPS did not accelerate transport of bacteria to the lymph node and did not accelerate activation of Ag85B-specific T cells. These results indicate that delayed initial activation of CD4+ T cells in tuberculosis is caused by the presence of the bacteria in a compartment that cannot be mobilized from the lungs to the lymph node, where initial T cell activation occurs.


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