B淋巴细胞对卡介苗颗粒性抗原的递呈作用

ANTIGEN PRESENTATION OF HUMAN B LYMPHOCYTES ON BCG PARTICULATE ANTIGEN

作者通过体外试验,将分离纯化的人外周血B细胞先与卡介苗(BCG)共育,成为激发的B细胞,再与建立的对BCG具特异性的T细胞株细胞混合培养,在无单核巨噬细胞存在的情况下,检测B细胞对颗粒性抗原的递呈效应。结果显示,6％的B细胞与BCG共育24小时后,胞浆中可见有BCG菌体,48小时后菌体界限模糊;激发的B细胞能明显地刺激T细胞株出现增殖反应及产生IL-2,但可被氯奎所抑制。表明B细胞对颗粒性抗原有递呈给T细胞,使之有激活作用。

The possibility of human B lymphocytesto process and present BCG particulate anti-gen to BCG specific T cell line was studied.It was found that about 6% of B cells afterincubated with BCG for 24 h, showed BCGbacilli in their cytoplasm, by acid faststain, and became obscure 48 h later. Theseresults demonstrated that human B lympho-cytes could phagocytose, process, and deg-radate BCG particulate antigen. The BCGpulsed B cells acted as antigen presentingcells to BCG specific T cell line. The pro-liferation and IL-2 production of specific Tcell line were significantly enhanced by BCGpulsed B cell stimulation (as shown intable 1). It was evident that BCG antigenwas presented to T cell lines ty B cell. Theactivity of BCG pulsed B cell was time de-pending (table 2). By treating B lymphocy-tes with chloroquine which interferes withnormal lysosome functions could completelyinhibit the proliferation of BCG specific Tcell line when B lymphocytes were pulsedwith BCG or expressate of BCG. The re-sults revealed that B cells must process an-tigen before presenting antigen to T cells.It is concluded that B lymphocytes canphagocytose, process and presentdeterminants of BCG particulate antigento BCG specific T cell line; and thathuman B lymphocytes may play animportant role in the anti-tuberculousimmunity in vivo, at least as antigenpresenting cells. To pursue the study of thisproblem, it is suggested to use B lympho-cytes deficient mice as experimental modelsfor further investigation.