High expression of OX-40, ICOS, and low expression PD-L1 of follicular helper and follicular cytotoxic T cells in chronic lymphocytic leukemia

In this study, peripheral blood mononuclear cells (PBMCs) were isolated from heparinized blood samples by density gradient centrifugation using Ficoll-Paque from 34 CLL patients and 19 healthy subjects. The expression of ICOS, OX-40, and PD-L1 of TFC and TFH cells in CLL patients was investigated by flow cytometry. According to healthy subjects, TFH and TFC cell levels were increased in CLL patients. High-ICOS and low-PD-L1 expression in TFH cells and high OX-40 and ICOS, low-PD-L1 expression in TFC cells of CLL patients compared to healthy subjects. OX-40 expression was positively correlated with TFH and TFC cells levels [R = 0.504, (p = 0.002) andR = 0.316, (p = 0.05)]. Additionally, OX-40 expression of TFH was positively correlated with ICOS expression [R = 0.660, (p <  0.001)] and PD-L1 expression [R = 0.649, (p <  0.001)]. OX-40L, ICOSL, and PD-L1 expression of B cells were elevated in CLL patients compared to healthy subjects. OX-40L expression of B cells was positively correlated with ICOSL expression [R = 0.568, (p = 0.0004)] and PD-L1 expression. Elevated CD4+CXCR5+ TFH and CD8+CXCR5+ TFC cells with high OX-40 and ICOS activator and low-PD-1L inhibitor receptor expression in CLL patients might have a role in the pathogenesis of CLL.
Source: Journal of Hematopathology - Category: Pathology Source Type: research