Safety and Effectiveness of EBV-specific Cytotoxic T Cells for the Treatment for EBV Lymphomas or Other EBV-associated Malignancies

Author(s):  
Keyword(s):  
T Cells ◽  
2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1341.3-1342
Author(s):  
A. Alshevskaya ◽  
J. Lopatnikova ◽  
J. Zhukova ◽  
F. Kireev ◽  
O. Chumasova ◽  
...  

Background:Previous studies of co-expression profile of receptors to tumor necrosis factor alpha (TNF) in rheumatoid arthritis (RA) have revealed a number of indicators associated with diseases activity with 93% sensitivity and 90% specificity. However, the ratio of receptors to cytokines remains poorly understood. However, the question of therapy effect and its effectiveness in various alteration of cytokine receptors balance remains under investigated.Objectives:To evaluate the dynamics of co-expression and quantitative expression of type 1 and 2 receptors for TNF in the subpopulations of CD3+CD8+ cells associated with changes in disease severity before and after effective basic therapy.Methods:Subanalysis of patients with high disease activity level successfully treated with methotrexate and oral glucocorticoids (n = 9) was performed. As a control group, we used data from 43 healthy donors, comparable by sex and age distribution. Subpopulations of cytotoxic T cells were studied, which were included in the final diagnostic models for differentiating different degrees of severity of RA: naive T cells and memory T cells. The dynamics of changes in the indicators of receptors number and proportion of cells expressing the corresponding receptor were compared.Results:For naïve cytotoxic T cells, the main revealed feature was the relative stability of the number of expressed receptors (both TNFR1 and TNFR2), regardless of the therapy, while this number did not significantly differ from healthy ones for TNFR1 and was significantly lower for TNFR2 (p <0.05 for all three fractions). At the same time, in terms of cell percentage, on the contrary, the therapy led to a change in total proportion of TNFR1 + cells closer to healthy donors indicators, and the proportion of TNFR2 + cells in the opposite direction.For cytotoxic T memory cells, it was demonstrated that after successful treatment a significant increase in the number of type 1 receptors was observed, with a decrease in TNFR1+ cells proportion, while these indicators were close to the values of healthy donors. At the same time, healthy donors were characterized by a significantly higher expression of type 2 receptors in terms of cell density of receptors. It is noteworthy that with successful therapy, a slight increase in the number of TNFR2 was observed with a sharp decrease in the proportion of TNFR2+ cells (p = 0.043).Conclusion:The balance of TNF receptor expression on cells actively involved in immunopathological processes affects both the density distribution of receptors on cells and co-expression in a subpopulation. Effective treatment of RA leads to equalization of the expression profile either by the percentage of cells or by the number of receptors, approaching the indicators of healthy donors, but not simultaneously.Disclosure of Interests:None declared


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.


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