Liew F Y, Howard J G, Hale C
J Immunol. 1984 Jan;132(1):456-61.
Protective immunity against fatal L. tropica infection in genetically vulnerable BALB/c mice can be induced by prophylactic immunization with irradiated promastigotes even when heat-killed. Such immunity is adoptively transferable transiently into intact or durably into sub-lethally irradiated (200 or 550 rad) syngeneic recipients by splenic T but not B cells. The effector T cells are of the Lyt-1+2- phenotype, devoid of demonstrable cytotoxic activity. The immune splenic T cell population expresses specific helper activity for antibody synthesis. A causal role for helper T cells in this capacity, however, seems unlikely, because it was shown in the accompanying paper that antibody does not determine the protective immunity against L. tropica. The immunized donors show no detectable cutaneous DTH or its early memory recall in response to live or killed promastigotes or a soluble L. tropica antigen preparation. Spleen, lymph node, and peritoneal exudate cells from protectively immunized donors similarly fail to transfer DTH locally or systemically. These cells also lack demonstrable suppressive activity against the expression or induction of DTH to L. tropica. Thus, protection against L. tropica induced by prophylactic i.v. immunization with irradiated promastigotes appears to be conferred by Lyt-1+2- T cells that are distinguishable from T cells mediating either both DTH and T help, or cytotoxicity.
即使是热灭活的辐照前鞭毛体，对基因易感性BALB/c小鼠的致命热带利什曼原虫感染也可通过预防性免疫诱导产生保护性免疫。这种免疫可通过脾脏T细胞而非B细胞短暂地过继转移至完整的同基因受体，或持久地过继转移至亚致死剂量辐照（200或550拉德）的同基因受体。效应T细胞为Lyt-1+2-表型，无明显细胞毒性活性。免疫脾脏T细胞群体表达针对抗体合成的特异性辅助活性。然而，辅助性T细胞在此功能中起因果作用的可能性似乎不大，因为在随附论文中表明抗体并不决定对热带利什曼原虫的保护性免疫。免疫供体对活的或灭活的前鞭毛体或可溶性热带利什曼原虫抗体制剂无可检测到的皮肤迟发型超敏反应（DTH）或其早期记忆回忆反应。来自保护性免疫供体的脾脏、淋巴结和腹腔渗出细胞同样无法局部或全身转移DTH。这些细胞也缺乏对热带利什曼原虫DTH表达或诱导的明显抑制活性。因此，通过静脉注射辐照前鞭毛体进行预防性免疫诱导的对热带利什曼原虫的保护似乎是由Lyt-1+2- T细胞介导的，这些T细胞不同于介导DTH和T辅助或细胞毒性的T细胞。
