Piuvezam M R, Russo D M, Burns J M, Skeiky Y A, Grabstein K H, Reed S G
Seattle Biomedical Research Institute, WA 98109.
J Immunol. 1993 Feb 1;150(3):916-24.
The stimulation of normal human PBMC by Trypanosoma cruzi Ag was analyzed. PBMC showed significant in vitro proliferation in response to parasite lysate (Tct), with stimulation indices ranging from 10 to 400, peaking at 6 to 7 days. The cells stimulated with Tct produced significant levels of IL-2. To determine which cells proliferated in response to Tct, PBMC were separated into T- and B-enriched cell populations. Purified T cells, but not B cells, proliferated strongly to Tct. The T cell response required APC and was processing dependent. T cell lines generated against Tct proliferated in response to parasite lysate only in the presence of autologous APC and produced IL-2, IL-6, and IFN-gamma but not IL-4 in response to PMA plus ionomycin. Although there were a significant number of CD45Ra+ cells, the majority of the cells in these T cell lines were CD45Ro+. The V beta usage of Tct-responding T cells was heterogeneous, with most V beta genes represented among the responding cells. An immunodominant repeat Ag (TcD) and a ribosomal phosphoprotein (P0) of T. cruzi elicited strong proliferative responses in all subjects tested. These data indicate the presence of T cell-stimulatory Ag in Tct, characterized by nonpreferential usage of the V beta gene families. The strong stimulation of normal human PBMC by Tct may contribute to immunologic alterations seen in T. cruzi infection.
分析了克氏锥虫抗原对正常人外周血单核细胞（PBMC）的刺激作用。PBMC对寄生虫裂解物（Tct）有显著的体外增殖反应，刺激指数范围为10至400，在6至7天达到峰值。用Tct刺激的细胞产生了显著水平的白细胞介素-2（IL-2）。为了确定哪些细胞对Tct有增殖反应，将PBMC分离为富含T细胞和B细胞的群体。纯化的T细胞而非B细胞对Tct有强烈增殖反应。T细胞反应需要抗原呈递细胞（APC）且依赖于加工处理。针对Tct产生的T细胞系仅在自体APC存在的情况下对寄生虫裂解物有增殖反应，并在佛波酯（PMA）加离子霉素刺激下产生IL-2、IL-6和干扰素-γ（IFN-γ），但不产生IL-4。尽管有大量CD45Ra+细胞，但这些T细胞系中的大多数细胞是CD45Ro+。对Tct有反应的T细胞的Vβ使用情况是异质性的，大多数Vβ基因在反应细胞中都有表达。克氏锥虫的一种免疫显性重复抗原（TcD）和一种核糖体磷蛋白（P0）在所有测试受试者中都引发了强烈的增殖反应。这些数据表明Tct中存在T细胞刺激抗原，其特征是Vβ基因家族的使用无偏好性。Tct对正常人PBMC的强烈刺激可能导致克氏锥虫感染中出现的免疫改变。
