Effects of CD70 and CD11a in immune thrombocytopenia patients

Abstract

Introduction: CD70 and CD11a are co-stimulatory molecules that are important for the immune functions of T, B lymphocytes. Over-expressions of CD70 or CD11a cause T cell to be autoreactive.

Objectives: The purpose of this study was to explore the effect of CD70 and CD11a in immune thrombocytopenia (ITP).

Methods: CD70 and CD11a mRNAs and protein expressions in CD4(+) T cells from ITP patients were measured respectively by real-time quantitative-PCR (RT-PCR) and flow cytometry. The apoptosis of T cells, B cells, and platelets in the PBMCs were analyzed by flow cytometry, and secretion of IL-4, IFN-γ, as well as IgG in the reaction supernatant were detected by ELISA. In order to investigate the effects of CD70 and CD11a over-expression on pathogenesis of ITP, anti-CD70, and anti-CD11a mAbs were used to block the signaling pathways.

Results: CD70 and CD11a mRNAs and protein expressions in CD4(+) T cells from ITP patients were significantly higher than healthy controls. In vitro co-culturing of PBMCs with anti-CD70 or anti-CD11a, the apoptosis of T, B lymphocytes were significantly increased but apoptosis of platelets were reduced. Anti-CD11a and anti-CD70 both significantly suppressed the secretion of IFN-γ, while anti-CD11a significantly promoted the secretion of IL-4. There was no significant difference in the healthy group.

Conclusions: CD70 and CD11a facilitate the survival of T, B lymphocytes and indirectly enhance the destruction of platelets in ITP. Blockade of CD70 or CD11a are promising therapeutic approaches for ITP.