Pam3CSK4对血小板活化及其TLR2表达的影响

目的 探讨Toll样受体2(TLR2)在血小板激活及免疫方面的作用.方法 取健康人(n=5)全血6 ml,以密度梯度离心法制备洗涤血小板.用1、5、10μg/ml的TLR2激动剂Pam3CSK4(一种合成的细菌脂蛋白)刺激人洗涤血小板,然后测定血小板聚集率,血小板表面蛋白CD62p和TLR2表达的变化.结果 Pam3CSK4以浓度0、1、5和10μg/ml激活血小板:聚集率增加分别为(12.83±2.43)%、(28.32±5.67)%、(52.56±8.54)%、(76.24±11.23)%,P<0.01;血小板表面CD62p表达量增加分别为(11.20±1.67)%、(18.45±2.66)%、(22.45±2.04)%、(29.53±4.08)%,P<0.01.Pam3CSK4在1μg/ml时TLR2表达为(16.85±6.10)%,与对照组(10.81±3.99)%相比差异无统计学意义(P>0.05),在5 μg/ml、10μg/ml时TLR2表达量分别为(21.15±9.90)%和(22.52±9.26)%,与对照组比较差异有统计学意义(P<0.05).结论 细菌脂蛋白Pam3CSK4通过激活TLR2引起血小板聚集、活化,是血小板参与抑制革兰阳性细菌感染的免疫应答机制之一.

The impact of Pan3CSK4 on the platelet activation and the expression of TLR2 on it

Objective To investgate role of TLR2 in the activation, the innate immune and inflammation of human platelets. Methods Human washed platelets were separated from healthy people(n=5) and were stimulated with different concentrations(1μg/ml, 5μg/ml, 10μg/ml) of TLR2 agonistPam3CSK4(a synthetic bacterial lipoproteins). Then the platelet aggregation rate, the expression of CD62p and TLR2 on the platelet surface were measured. Results The platelet aggregation rate were (28.32±5.67)%, (52.56±8.54)% and (76.24±11.23)%, respectively, at concentration of 1μg/ml, 5μg/mland 10μg/ml of Pam3CSK4, more than (12.83±2.43)% at 0μg/ml of it. In addition, the expression of CD62p were (18.45±2.66)%, (22.45±2.04)%, (29.53±4.08)%, respectively at above concentration of Pam3 CSK4, more than (11.20±1.67)% of CD62p at control group(P<0.01). The expression of TLR2 was not significantly increased at a lower concentration of Pam3CSK4(1μg/ml) with (16.85±6.10)% compared with(10.81±3.99)% at the control group. However, it were (21.15±9.90)% and (22.52±9.26)%, respectively, at a higher concentration(5μg/ml, 10μg/ml)more than(10.81±3.99)% at the control group(P<0.05). Conclusion Pam3CSK4 induce aggregation, activation and the up-regulation of TLR2 of platelet by stimulating TLR2 receptor of it. Thereafter, TLR2 play an important role in the innate immune of platelet.