SARS冠状病毒致多器官感染的在体研究

SARS CORONAVIRUS COULD CAUSE MULTI-ORGAN INFECTION

目的 研究体内SARS冠状病毒(SARS CV)感染的靶细胞 ,为SARS CV致多器官损伤寻找依据。方法 依据SARS CV基因序列 ,合成 3个代表性寡核苷酸探针 ,采用核酸原位杂交和透射电镜观察相结合的方法 ,对 2例严重急性呼吸综合征 (SARS)死亡病例进行系统的SARS CV定位、分布及数量研究。结果 SARS病例多器官组织细胞中观测到SARS CV。肺组织内SARS CV主要位于终末细支气管黏膜上皮 ,Ⅰ、Ⅱ型肺泡上皮 ,部分巨噬细胞和毛细血管内皮细胞及个别淋巴细胞胞质内 ,原位杂交示呈全浆型或包涵体型分布 ,肺组织内平均阳性细胞数为每个 2 0 0倍视野 80± 2 5个 ;电镜下病毒颗粒大小为 10 0～ 15 0nm ,低电子密度核心 ,日晕或花环状包膜 ;肾组织内大约 15 %肾小管上皮细胞呈SARS CV阳性 ,以髓质较多 ,肾上腺组织内少部分实质细胞及窦状毛细血管内皮细胞内呈阳性杂交信号 ;胃、肠黏膜上皮及腺上皮细胞内检测到SARS CV颗粒 ,其中浅表 2 / 3黏膜检出率较高 ;电镜下少数心肌细胞内可见较多SARS CV颗粒 ,原位杂交示阳性心肌细胞呈灶性分布 ;胸、腹腔淋巴结内组织细胞 ,窦内皮细胞及极少数淋巴细胞内见SARS CV ;此外 ,少数睾丸曲细精管上皮及间质细胞内检测到SARS CV。结论 SARS CV在体内存在多种靶细胞 ,SARS CV可致以肺脏为?

Objective To explore the target cells of SARS coronavirus infection in vivo and to provide the evidence of multi organ injuries produced by SARS coronavirus infection. Methods Three biotin labeling oligonucleotide probes were synthesized according to the published gene sequence of SARS coronavirus. The location, distributtion and quantity of SARS coronavirus in 2 autopsy cases of SARS were studied by in situ hybridization and electron microscopic examination. Results SARS coronavirus particles were identified in multiple organs. In lungs, SARS coronaviruses were located predominantly in the cytoplasm of bronchiolar and alveolar epithelial cells, in a part of macrophages and endothelial cells as well as a few infiltrated lymphocytes. In situ hybridization showed that in target cells SARS coronavirus distribution presented a cytoplasmic or inclusive pattern, and the mean number of positive cells in the pulmonary tissue was 80±25 per 200× field. Electron microscopic examination showed that the coronaviral particles were 100～150 nm in diameter, with low density electron cores with halo or garland envelopes. About 15% of renal tubular epithelial cells harbored SARS coronavirus, and a few parenchymal cells and sinusoid capillary endothelial cells of adrenal glands were hybridization positive. In the gastro intestinal tract, SARS coronaviruses were seen in the cytoplasm of mucosal and crypt epithelial cells, mostly in 2/3 of superficial mocosa. Under both electron microscopy and in situ hybridization observation, SARS coronaviruses were found focally distributed in some cardiomyocytes. The SARS coronavirus positive particles were also noted in macrophages/histocytes, sinusoid endothelial cells, as well as a few lymphocytes in thoracic and celiac lymph nodes. In addition, coronavirus particles were also seen in a few testicular epithelial cells and Leydig's cells. Conclusion SARS coronavirus could attack multiple target cells, implicating that SARS might cause multi organ damages, with lungs as the predominant organ of injury.