Effect of TAP-SSL5 fusion protein on binding of activated platelets to hu-man lymphocytes / 中国病理生理杂志

ABSTRACT

AIM: To study the effect of tick anticoagulant peptide-staphylococcal superantigen like protein 5 (TAP-SSL5), an anti-inflammatory and anticoagulant fusion protein , on the binding of activated platelets to human lym-phocytes.METHODS:Human periphery lymphocytes were isolated by magnetic activated cell sorting (MACS).The toxic-ity of TAP-SSL5 on the viability of Jurkat cell was assessed by CCK-8 assay.Flow cytometry was applied to detect the ex-pression of CD162 (PSGL-1) on the Jurkat cells (human peripheral blood leukemia T lymphocyte cell line ) and the inhibi-tory effect of TAP-SSL5 on the binding of mouse anti-human CD162 monoclonal antibody (KPL-1) to Jurkat cells.Platelets were activated by ADP at concentration of 20μmol/L, the binding rates of activated platelets to Jurkat cells or human lym-phocytes were assayed by flow cytometry .RESULTS:The concentration of TAP-SSL5 below 30 mg/L didn’ t affect the vi-ability of Jurkat cells .TAP-SSL5 at 10 mg/L competitively inhibited KPL-1 binding to Jurkat cells .The binding rates of activated platelets to Jurkat cells or lymphocytes were (11.86 ±4.49)% and (8.32 ±1.00)%, respectively, which de-creased to (6.73 ±2.71)%and (5.51 ±0.70)%after the Jurkat cells and lymphocytes were pre-incubated with 10 mg/L TAP-SSL5 (P <0.05).CONCLUSION:TAP-SSL5 binds to PSGL-1 expressed on lymphocyte surface and directly in-hibits the binding of activated platelets to human lymphocytes , which may be one of the anti-inflammatory mechanisms of TAP-SSL5.