共刺激信号对脐血淋巴细胞增殖反应及PLCγ1表达的影响

The effect of co-stimulation signals on the proliferative response and PLCγ1 expression of the lymphocytes in cord blood

目的探讨新生儿出生时淋巴细胞功能低下的可能环节。方法给予成人外周血和脐血淋巴细胞共刺激(抗CD3、抗CD28单抗)和跨膜刺激(phorbolmyristateacetate,PMA和ionomycin,IM)后,应用犤3H犦-TdR掺入法检测淋巴细胞增殖反应;WesternBlot法检测淋巴细胞磷脂酶Cγ1(phospholipaseCγ1,PLCγ1)的表达。结果抗CD3+抗CD28单抗共刺激后,脐血淋巴细胞的增殖反应明显增强;PMA+IM跨膜刺激后,脐血淋巴细胞增殖反应的改善更接近于成人。给予抗CD3+抗CD28单抗共刺激后,脐血淋巴细胞PLCγ1的表达低于成人外周血;刺激前后脐血淋巴细胞PLCγ1表达差异无显著性,而成人外周血淋巴细胞PLCγ1表达则有显著增加。结论脐血淋巴细胞活化的下游途径可以发挥更接近于成人的作用,推测其功能障碍可能主要在于淋巴细胞活化的早期阶段。

To explore the possible mechanism of the transient dysfunction of lymphocytes in neonates.Methods Lymphocytes from adult peripheral blood and neonatal cord blood were stimulated with co-stimulators(anti-CD3,anti-CD28 monoclonal antibody) and phorbol myristate acetate (PMA) and ionomycin (IM).The proliferation of lymphocytes was assayed with 3H-TdR method. Western Blot was applied to examine the PLCγ1 expression of the lymphocytes.Results The proliferation of lymphocytes from neonatal cord blood increased significantly in response to stimulation with anti-CD3 plus anti-CD28 monoclonal antibody but still lower in neonates than that in adults.The proliferation of lymphocytes in neonatal cord blood improved with PMA plus IM co-stimulation and approached to that of adult.Whereas the PLCγ1 expression level was lower in cord blood lymphocytes than that of adult after giving anti-CD3 plus anti-CD28 monoclonal antibody.In comparison with non-stimulated groups,significant difference was observed in cord blood lymphocytes;but the expression level of PLCγ1 in adult peripheral blood lymphocytes markedly increased.Conclusions This study indicated that the downstream pathway of lymphocyte activation possibly approaches to the adult's level,suggesting that,the transient dysfunction of the cord blood lymphocytes may mainly occurred in the early stage of the activation.