伊氏锥虫弱毒株免疫家兔的T细胞应答反应

T-lymphocyte Response of Rabbits Immunized with an Attenuat-ed Strain of T. evansi

以ANAE染色法和~3H-TdR掺入的淋巴细胞转化试验,测定了伊氏锥虫弱毒株免疫家兔的T细胞动态变化.结果,免疫兔外周血T细胞增殖反应在免疫后第24d达到高峰,ANAE阳性细胞百分率这72.65%,对照组仅为41.2%;约1周后,出现抑制性T细胞,其增殖反应也明显减弱,最后完全被抑制.而外源性白细胞介素2的加入,可解除这种免疫抑制.攻虫后,特异性T细胞应答反应未再出现强烈的回忆反应,但伊氏锥虫弱毒株免疫家兔获得9/12的保护.因此,T细胞在这种抗锥虫免疫中,没有起到主导作用.

Twelve rabbits were successively,immunized with an attenuared strain of T. evansi and challenged with virulent trypanosomas later. During the experimental period, the responses of peripheral blood T-lymphocyte were assayed with ANAE staining method and blastoge-nesis in vitro by measuring C[3H] thymidine uptake. The proliferative response of peripheral blood T-cell of immunized rabbits reached its peak on days 24 after immunization. The percentage of ANAE-positive lymphocyte of immunized rabbits was 72. 4, whereas it was only about 41. 2 in controls. It was found that the suppressed T -cells occurred in peripheral blood on days 31, and thus the proliferative response was significantly suppressed and eventually abolished. However, the immunosuppression can be lifted by introducing the exogeneous interleukin Ⅰ. There was no active anamnestic response after challenge ,but 9 out of 12 immunized rabbits have been prevented from virulent trypanosoma infection. It is probable that T-cells do not play a key role in antitry-panosoma immunity.