Muhktar M M, Timoney J F
Department of Veterinary Microbiology, Immunology and Parasitology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
Res Vet Sci. 1988 Sep;45(2):225-9.
Streptococcus equi infection in horses is characterised by intense infiltration of lymph nodes by polymorphonuclear leucocytes (PMNs) suggesting a potent chemotactic response to the organism or its products. Equine PMNs were separated using Ficoll-Hypaque medium and used in an assay of chemotaxis under agarose to study the components of S equi involved in this response. Results showed that complement-derived chemotactic factors generated by activation of the alternative complement pathway were important in chemotactic responses to S equi. Both whole bacteria and peptidoglycan preparations were potent complement activators, whereas purified M protein was less active. In contrast, S equi culture supernatant protein did not activate complement; instead it directly inhibited migration of PMNs. Moreover, PMNs, when incubated with culture supernatant of a non-haemolytic strain, showed signs of cellular degeneration suggesting the presence of a cytotoxin distinct from haemolysin.
马感染马链球菌的特征是多形核白细胞（PMNs）大量浸润淋巴结，这表明对该病原体或其产物有强烈的趋化反应。使用Ficoll-Hypaque培养基分离马的PMNs，并用于琼脂糖趋化试验，以研究参与该反应的马链球菌成分。结果表明，由替代补体途径激活产生的补体衍生趋化因子在对马链球菌的趋化反应中很重要。全细菌和肽聚糖制剂都是有效的补体激活剂，而纯化的M蛋白活性较低。相比之下，马链球菌培养上清蛋白不激活补体；相反，它直接抑制PMNs的迁移。此外，当PMNs与非溶血菌株的培养上清一起孵育时，显示出细胞变性的迹象，这表明存在一种不同于溶血素的细胞毒素。
