Winslow G M, Yager E, Shilo K, Collins D N, Chu F K
Wadsworth Center, New York State Department of Health, Albany, New York 12201-2002, USA.
Infect Immun. 1998 Aug;66(8):3892-9. doi: 10.1128/IAI.66.8.3892-3899.1998.
To determine the basis of susceptibility and resistance to human monocytic ehrlichiosis (HME), immunocompetent and immunocompromised mice were infected with Ehrlichia chaffeensis and bacterial loads were measured by PCR and by immunohistochemistry. Immunocompetent (C. B-17 and C57BL/6) mice cleared the bacteria within 10 days, but immunocompromised SCID and SCID/BEIGE mice developed persistent infection in the spleen, liver, peritoneal cavity, brain, lung, and bone marrow and became moribund within 24 days. Both immunocompromised strains lack T and B lymphocytes, but the SCID/BEIGE strain is also deficient in natural killer (NK) cell function. During advanced stages of disease, the infections were associated with wasting, splenomegaly, lymphadenopathy, liver granulomas and necroses, intravascular coagulation, and granulomatous inflammation. Histochemical and immunohistochemical localization studies confirmed the presence of bacteria in tissues, and viable bacteria were cultured from infected animals. The data reveal that T and/or B cells play an essential role during resistance of immunocompetent mice to infection with E. chaffeensis and demonstrate the utility of immunocompromised mice as an experimental model for the study of HME.
为确定对人单核细胞埃立克体病（HME）易感性和抗性的基础，将免疫活性和免疫受损小鼠感染恰菲埃立克体，并通过聚合酶链反应（PCR）和免疫组织化学法测量细菌载量。免疫活性（C.B-17和C57BL/6）小鼠在10天内清除细菌，但免疫受损的严重联合免疫缺陷（SCID）和SCID/米色小鼠在脾脏、肝脏、腹腔、脑、肺和骨髓中发生持续感染，并在24天内濒死。两种免疫受损品系均缺乏T和B淋巴细胞，但SCID/米色品系在自然杀伤（NK）细胞功能方面也存在缺陷。在疾病晚期，感染与消瘦、脾肿大、淋巴结病、肝肉芽肿和坏死、血管内凝血以及肉芽肿性炎症相关。组织化学和免疫组织化学定位研究证实组织中存在细菌，并且从感染动物中培养出活细菌。数据显示T和/或B细胞在免疫活性小鼠对恰菲埃立克体感染的抗性中发挥重要作用，并证明免疫受损小鼠作为HME研究实验模型的实用性。
