Sileghem M R, Flynn J N, Saya R, Williams D J
International Laboratory for Research on Animal Diseases (ILRAD), Nairobi, Kenya.
Vet Immunol Immunopathol. 1993 Jul;37(2):123-34. doi: 10.1016/0165-2427(93)90060-h.
Bovine macrophages and monocytes were cultured in vitro and analyzed for their capacity to secrete co-stimulatory cytokines. To this end, the culture medium was titrated on suboptimally stimulated murine thymocytes. A low residual release by normal monocytes was noted which usually remained below the detection limit of the assay. These cells could be induced to secrete high titres following activation with bacterial lipopolysaccharide. When harvested from animals infected with Trypanosoma congolense, the cells released high titres spontaneously. This increase in co-stimulatory cytokine secretion was noted in both peripheral blood monocytes and splenic macrophages and was amplified by addition of indomethacin. The activation was transient, and the titres had dropped to pre-infection values at the end of the experiment. At that time, the monocytes were, however, still able to respond to external stimuli. Addition of neutralizing anti-transforming growth factor beta antibodies did not influence the thymocyte co-stimulatory activity of the supernatants. High levels of co-stimulatory cytokine secretion were noted with monocytes from both the susceptible Boran breed and the tolerant N'Dama breed. Early in infection, at Day 10 post infection, the production by the N'Dama monocytes was 16 times higher than the production by the Boran monocytes. Later in the infection, the titres were similar in both breeds.
牛巨噬细胞和单核细胞在体外培养，并分析它们分泌共刺激细胞因子的能力。为此，将培养基在次优刺激的小鼠胸腺细胞上进行滴定。正常单核细胞的残余释放量较低，通常保持在检测限以下。用细菌脂多糖激活后，这些细胞可被诱导分泌高滴度的细胞因子。从感染刚果锥虫的动物体内收获的细胞会自发释放高滴度的细胞因子。在外周血单核细胞和脾巨噬细胞中均观察到共刺激细胞因子分泌的增加，并且通过添加吲哚美辛可使其增强。这种激活是短暂的，在实验结束时滴度已降至感染前的值。然而，此时单核细胞仍能够对外界刺激作出反应。添加中和性抗转化生长因子β抗体并不影响上清液对胸腺细胞的共刺激活性。在易感的博拉牛品种和耐受的恩达马牛品种的单核细胞中均观察到高水平的共刺激细胞因子分泌。在感染早期，即感染后第10天，恩达马单核细胞的产量比博拉单核细胞的产量高16倍。在感染后期，两个品种的滴度相似。
