Modeling influenza virus infection in mature Wistar rats

Abstract

It has now been established that blood vessels are target for influenza, but the mechanism by which the influenza virus affects the cardiovascular system is unknown. The aim – adaptation of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) to mature Wistar rats, as these animals are the main experimental model for studying the pathology of the cardiovascular system. Material and methods. Passage of influenza A virus (IAV) in embryonated chicken eggs, intranasal inoculation of rats with virus-containing material s, production of pulmonary homogenate, determination of IAV titer in embryonated chicken eggs, detection of histological changes in lung and pulmonary vessels. Results. The article presents the results of the adaptation of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) to mature Wistar rats. The infectious titer of the virus in the homogenates of infected rats lungs at the last stage of adaptation was 7.0 lg EID50/ml. Histological studies revealed pronounced changes in the respiratory tract (spasm of bronchioles, submucosal edema, desquamation of ciliated epithelium of bronchioles) and pulmonary vessels (spasm, desquamation and swelling of endotheliocytes, dissociation and swelling of the elastic membrane and media). In order to identify IAV in blood vessels and lung tissues, an immunohistochemical study was performed using monoclonal antibodies to NP antigen of IAV. Conclusion. The data obtained allow us to conclude that the strain of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) was adapted to mature Wistar rats maintaining virulent properties. The infectious titer of the virus at the last stage of adaptation was 7.0 lg EID50/ml. IAV identification is confirmed by immunohistochemical examination.

Influenza A Virus Causes Histopathological Changes and Impairment in Functional Activity of Blood Vessels in Different Vascular Beds

“…In the present study, the experimental influenza virus infection of Wistar rats was conducted for two reasons: (1) the possibility of studying non-lethal influenza infection [21]; (2) rats of this stock are the main animal model of various cardiovascular disorders [22][23][24], which is an essential factor for our further studies.…”

“…In the present study, the experimental influenza virus infection of Wistar rats was conducted for two reasons: (1) the possibility of studying non-lethal influenza infection [21];…”

“…The isolate selection was based on clinical studies of IAV H1N1(pdm09), as a causative agent of hemorrhagic pneumonia [25]. The virus was preliminarily adapted through 9 successive passages through infected lung homogenates of Wistar rats, as described [21]. At the last passage, the infectious activity of influenza virus was 6-7 lg EID 50 /mL and the hemagglutination titer of the virus was 1:1024.…”

“…To study this mechanism, we developed an experimental model of non-lethal influenza virus infection in mature Wistar rats [21]. These laboratory animals are also one of the main experimental models for the study of various cardiovascular disorders [22][23][24].…”

Influenza A(H1N1)pdm09 Virus Aggravates Pathology of Blood Vessels in Wistar Rats with Premorbid Acute Cardiomyopathy

“…The isolate selection was based on clinical studies of Influenza A(H1N1)pdm09 virus, as a causative agent of hemorrhagic pneumonia [ 21 ]. The virus was preliminarily adapted through nine successive passages through infected lung homogenates of Wistar rats, as described in [ 22 ]. At the last passage, the infectious activity of the influenza virus was 6.6 log EID 50 /mL; the hemagglutination titer of the virus was 1:1024.…”