Masake R A, Morrison W I
Am J Vet Res. 1981 Oct;42(10):1738-46.
Experimental infection of Boran cattle with Trypanosoma vivax resulted in fluctuating parasitemia detectable in peripheral blood which, as the infection progressed, diminished to undetectable levels. In animals necropsied during the initial stages of the infection, trypanosomes were detected in lymph and in the sinuses of the lymph nodes. The lymph nodes and spleen exhibited marked proliferative response which was maximal in animals killed on days 10 and 17 of infection. The response was characterized by an increase in the size and activity of the germinal centers accompanied by increased numbers of large proliferating lymphocytes in the medullary cords and peripheral part of the paracortex of the lymph nodes and in the periarteriolar regions and peripheral follicular areas of the spleen. This was associated with the production of large numbers of plasma cells which were present in the red pulp of the spleen, in the medullary cords of the lymph nodes, and focally in the peripheral paracortical areas of the lymph nodes. By immunofluorescence, many of these plasma cells were found to contain immunoglobulin (Ig) M. There was also increased number of follicles which exhibited granular deposits of IgM and reduction in the areas containing small lymphocytes bearing IgM. During the remainder of the infection and paralleling the decrease in parasitemia, there was gradual reduction in the reactivity of the lymphoid organs. Accompanying the initial proliferative response was a marked increase in plasma concentration of IgM; this decreased to base line during the 3rd week of the infection. The response to phytohemagglutinin, pokeweed mitogen, and lipopolysaccharide of leukocytes obtained from peripheral blood lymph nodes and spleen at intervals during the infection was not significantly different from controls.
用间日锥虫对博拉牛进行实验性感染，导致外周血中可检测到波动的寄生虫血症，随着感染的进展，寄生虫血症降至不可检测水平。在感染初期进行尸检的动物中，在淋巴和淋巴结窦中检测到锥虫。淋巴结和脾脏表现出明显的增殖反应，在感染第10天和第17天处死的动物中反应最为强烈。该反应的特征是生发中心的大小和活性增加，同时淋巴结髓索和副皮质外周部分以及脾脏动脉周围区域和外周滤泡区域中大量增殖淋巴细胞的数量增加。这与大量浆细胞的产生有关，这些浆细胞存在于脾脏红髓、淋巴结髓索以及淋巴结外周副皮质区域的局部。通过免疫荧光法发现，许多这些浆细胞含有免疫球蛋白（Ig）M。滤泡数量也增加，表现出IgM的颗粒状沉积，而含有携带IgM的小淋巴细胞的区域减少。在感染的其余阶段，与寄生虫血症的下降平行，淋巴器官的反应性逐渐降低。伴随最初的增殖反应，血浆中IgM浓度显著增加；在感染第3周时降至基线水平。在感染期间不同时间从外周血、淋巴结和脾脏获取的白细胞对植物血凝素、商陆有丝分裂原和脂多糖的反应与对照组无显著差异。
