Pathogenesis of influenza A (H5N1) virus-induced viral pneumonia in the rhesus macaque / 中国人兽共患病学报

ABSTRACT

At present ,the mechanism of highly pathogenic avian influenza H5N1 virus causing human infection or death is still not fully clear .In order to better understand the pathogenesis of the disease ,the rhesus macaques were infected with H5N1 virus (AF148678/ACGoose/Guangdong/11961H5N1) .We analyzed the clinical symptoms ,characteristics of the virus invades body ,pathological changes ,and immune response to discuss the pathogenesis of viral pneumonia induced by H 5N1 virus infection from the early time to the recovery time .The rhesus macaques were infected with H5N1 virus through nasal .Clinical signs were assessed daily ,and major organs and blood were collected for detection of blood routine analysis ,viruses were isola-ted and titrated from organs ,and pathologic and immunohistochemical were also conducted .As a result ,the rhesus macaques in-fected with H5N1 virus experienced fever ,dyspnea ,and anorexia .The respiratory tract was the major target of the virus and the virus could not replicate in organs outside the respiratory tract .Positive staining cells by immunohistochemistry were bronchial epithelial cells and alveolar macrophages .Rhesus macaques experienced temporary severe pneumonia after 1-3 days ,mainly be-cause of neutrophils infiltration ;gradual recovery 6 days later ,mainly with macrophage infiltration ;lung tissue presented recov-ery state after 14 days ,mainly with T lymphocytes infiltration .Finally ,we concluded that the predilection of the H 5N1 virus to infect the lower airway suggests that it may be a limiting factor in human-to-human transmissibility of the H5N1 virus .The pathogenesis may include virus invasion ,replication and immune injury .