Bakhiet M, Olsson T, Edlund C, Höjeberg B, Holmberg K, Lorentzen J, Kristensson K
Department of Neurology, Karolinska Institute, Huddinge University Hospital, Sweden.
Scand J Immunol. 1993 Feb;37(2):165-78. doi: 10.1111/j.1365-3083.1993.tb01753.x.
A protein factor that stimulates CD8+ lymphocytes to produce and secrete IFN-gamma has been purified from Trypanosoma brucei brucei (T.b. brucei). This was accomplished by raising monoclonal antibodies (MoAbs) against a fraction of T.b. brucei obtained by gel filtration, which contained high levels of material inducing rat mononuclear cells (MNC) to IFN-gamma production. MoAbs from four hybridomas strongly inhibited trypanosome-induced IFN-gamma production. One of them (MO1) was used for purification of the trypanosome-derived lymphocyte triggering factor (TLTF) by affinity chromatography. SDS electrophoresis of the purified TLTF displayed a band of 42-45 kDa MW. Gel filtration of homogenates of whole parasites yielded several peaks of IFN-gamma-inducing activity with a lowest MW of 41-46 kDa. Bioactivity of all peaks was blocked by MO1, suggesting that a single molecule, or a single epitope of additional molecules, is responsible for the different peaks with IFN-gamma-inducing activity. IFN-gamma released from MNC stimulates T.b. brucei growth. Blocking of TLTF in vitro with MO1 inhibited MNC-supported growth of the parasites. To study the in vivo relevance of TLTF in the course of experimental African trypanosomiasis, MO1 was used to treat rats and mice at different times after infection. Treatments instituted at different time-points after infection suppressed parasite growth, abrogated the IFN-gamma production by splenocytes induced by the infection and prolonged survival of the animals. The data support the hypothesis that TLTF and IFN-gamma have a crucial regulatory function in the parasite-host interactions and that these molecules influence the disease course during experimental African trypanosomiasis.
一种刺激CD8 +淋巴细胞产生和分泌γ干扰素的蛋白质因子已从布氏布氏锥虫（T.b. brucei）中纯化出来。这是通过制备针对经凝胶过滤获得的布氏布氏锥虫部分组分的单克隆抗体（MoAbs）来实现的，该组分含有高水平的可诱导大鼠单核细胞（MNC）产生γ干扰素的物质。来自四个杂交瘤的单克隆抗体强烈抑制锥虫诱导的γ干扰素产生。其中一个（MO1）用于通过亲和色谱法纯化锥虫衍生的淋巴细胞触发因子（TLTF）。纯化的TLTF的SDS电泳显示出一条分子量为42 - 45 kDa的条带。对整个寄生虫匀浆进行凝胶过滤产生了几个诱导γ干扰素活性的峰，其最低分子量为41 - 46 kDa。所有峰的生物活性均被MO1阻断，这表明单个分子或其他分子的单个表位对具有诱导γ干扰素活性的不同峰负责。从MNC释放的γ干扰素刺激布氏布氏锥虫生长。在体外使用MO1阻断TLTF可抑制寄生虫在MNC支持下的生长。为了研究TLTF在实验性非洲锥虫病过程中的体内相关性，在感染后的不同时间使用MO1治疗大鼠和小鼠。在感染后的不同时间点进行治疗可抑制寄生虫生长，消除感染诱导的脾细胞产生的γ干扰素，并延长动物的存活时间。这些数据支持这样的假设，即TLTF和γ干扰素在寄生虫与宿主的相互作用中具有关键的调节功能，并且这些分子在实验性非洲锥虫病期间影响疾病进程。
