2. |
- Arruda, Lucas C. M., et al.
(author)
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Impact of gamma delta T cells on clinical outcome of hematopoietic stem cell transplantation : systematic review and meta-analysis
- 2019
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 3:21, s. 3436-3448
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Research review (peer-reviewed)abstract
- Allogeneic hematopoietic stem cell transplantation (HSCT) using alpha beta T-/B-cell-depleted grafts recently emerged as a transplant strategy and highlighted the potential role of gamma delta T cells on HSCT outcomes. Our aim was to scrutinize available evidence of gamma delta T-cell impact on relapse, infections, survival, and acute graft-versus-host disease (aGVHD). We performed a systematic review and meta-analysis of studies assessing gamma delta T cells in HSCT. We searched PubMed, Web of Science, Scopus, and conference abstracts from inception to March 2019 for relevant studies. We included all studies that assessed gamma delta T cells associated with HSCT. Data were extracted independently by 2 investigators based on strict selection criteria. A random-effects model was used to pool outcomes across studies. Primary outcome was disease relapse. We also assessed infections, survival, and aGVHD incidence. The review was registered with PROSPERO (CRD42019133344). Our search returned 2412 studies, of which 11 (919 patients) were eligible for meta-analysis. Median follow-up was 30 months (interquartile range, 22-32). High gamma delta T-cell values after HSCT were associated with less disease relapse (risk ratio [RR], 0.58; 95% confidence interval [95% CI], 0.40-0.84; P = .004; I-2 = 0%), fewer viral infections (RR, 0.59; 95% CI, 0.43-0.82; P < .002; I-2 = 0%) and higher overall (HR, 0.28; 95% CI, 0.18-0.44; P < .00001; I-2 = 0%) and disease-free survivals (HR 0.29; 95% CI, 0.18-0.48; P < .00001; I-2 = 0%). We found no association between high gd T-cell values and aGVHD incidence (RR, 0.72; 95% CI, 0.41-1.27; P = .26; I-2 = 0%). In conclusion, high gd T cells after HSCT is associated with a favorable clinical outcome but not with aGVHD development, suggesting that gd T cells have a significant effect on the success of HSCT. This study was registered with PROSPERO as #CRD42019133344.
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3. |
- Gaballa, Ahmed, et al.
(author)
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CD8(+)gamma delta T Cells Are More Frequent in CMV Seropositive Bone Marrow Grafts and Display Phenotype of an Adaptive Immune Response
- 2019
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In: STEM CELLS INTERNATIONAL. - : HINDAWI LTD. - 1687-966X .- 1687-9678. ; 2019
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Journal article (peer-reviewed)abstract
- The role of gamma delta (gamma delta) 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 gamma delta T cells in response to HCMV, shedding light on the adaptive immune response of gamma delta T cells. Nevertheless, most efforts have focused on V delta 2(neg)gamma delta T cell subset while less attention has been given to investigate other less common gamma delta T cell subsets. In this regard, a distinct subpopulation of gamma delta T cells that expresses the CD8 coreceptor (CD8(+)gamma delta 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 gamma-chain (TRG) to analyze in-depth bone marrow (BM) graft gamma delta T cells from CMV seropositive (CMV+) and CMV seronegative (CMV-) donors. We showed that the frequency of CD8(+)gamma delta T cells was significantly higher in CMV+ grafts compared to CMV- grafts (P<0.001). Further characterization revealed that CD8(+)gamma delta T cells from CMV+ grafts express V gamma 9(-) and preferentially differentiated from a naive to terminal effector memory phenotype (CD27(low/-)CD45RO(-)). In line with these findings, TRG immune sequencing revealed clonal focusing and reduced usage of the V gamma 9/JP gene segment in a CMV+ graft. Furthermore, CD8(+)gamma delta T cells showed an enhanced response to TCR/CD3 and cytokine stimulation in contrast to CD8(-)gamma delta T cells. We conclude that gamma delta T cells in BM grafts are reshaped by donor CMV serostatus and highlight the potential adaptive role of CD8(+)gamma delta T cells in HCMV immune response.
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