Zhu J, Meinersmann R J, Hiett K L, Evans D L
Poultry Microbiological Safety Research Unit, Russell Agricultural Research Center, U.S. Department of Agriculture, Agricultural Research Service, Athens, GA 30604.
Curr Microbiol. 1999 Apr;38(4):244-9. doi: 10.1007/pl00006795.
Campylobacter jejuni is a significant cause of food-borne diseases in humans. The bacterium is considered a commensal organism in chickens, and it can heavily colonize chickens without causing inflammation. Poultry may be the major reservoir for the human infection in developed countries. Here we show that an outer-membrane protein extract prepared from the bacteria caused apoptosis of chicken lymphocytes detected in vitro with the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay that preferentially labels individual apoptotic cells. Blood- and spleen-lymphocytes from different-aged chickens displayed a significantly greater percentage of apoptotic cells after culture with the outer-membrane proteins from C. jejuni than controls treated with phosphate-buffered saline, chicken ovalbumin, or outer-membrane proteins prepared from E. coli strain BL21. The C. jejuni extract also produced apoptosis of chicken lymphoblastoid tumor cell lines. Apoptosis was blocked by pretreating the extract with proteinase K or antiserum against outer-membrane proteins. The results suggest that C. jejuni may be capable of achieving immune avoidance in chickens by causing apoptosis of lymphocytes.
空肠弯曲菌是人类食源性疾病的一个重要病因。该细菌被认为是鸡体内的共生生物，它能够在鸡体内大量定殖而不引发炎症。在发达国家，家禽可能是人类感染的主要宿主。在此我们表明，从该细菌制备的外膜蛋白提取物在体外通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（该方法优先标记单个凋亡细胞）检测到可导致鸡淋巴细胞凋亡。与用磷酸盐缓冲盐水、鸡卵清蛋白或从大肠杆菌BL21菌株制备的外膜蛋白处理的对照组相比，来自不同年龄鸡的血液和脾脏淋巴细胞在用空肠弯曲菌外膜蛋白培养后显示出明显更高比例的凋亡细胞。空肠弯曲菌提取物还可导致鸡淋巴母细胞肿瘤细胞系发生凋亡。用蛋白酶K或抗外膜蛋白抗血清预处理提取物可阻断凋亡。结果表明，空肠弯曲菌可能能够通过导致淋巴细胞凋亡在鸡体内实现免疫逃避。
