A Preliminary Study On The Chronic Hepatitis E Virus Infection And Establishment Of Chronic Animal Model

Hepatitis E virus(HEY)is a pathogen causing viral hepatitis and transmitted by the fecal-oral route,which can infect people and animals in different species.HEV infection is an important public health concern in many parts of the world and causing waterborne outbreaks.Hepatitis E is a serious public health problem responsible for over 50%of acute viral hepatitis cases in developing countries.Hepatitis E has been regarded as a kind of acute self－limited disease at early stage,because patients can recover themselves after 3-4 weeks.A large number of clinical studies showed that Immunocompromised people such as organ transplant patients,HIV positive patients and patients with malignant tumor,or ordinary people infected with HEV can develop into chronic hepatitis E infection.However,the pathogenic mechanism of chronic HEV infection is not clear.Therefore,it is an urgent need to understand the pathogenesis of HEV infection that developed into chronic hepatitis.This paper aims to study the pathogenesis of chronic HEV infection and establish the animal model of chronic HEV infection.This work consists of three aspects:(l)explore the mechanism of HEV chronic by using rhesus monkeys chronic HEV infection model;(2)explore effects on chronic HEV infection by mutation of viral genome;(3)establish the chronic HEV infection animal model.(1)Using rhesus monkeys chronic HEV infection model to explore the mechanism of HEV chronic infectionIn the study,the healthy rhesus monkeys inoculated genotype IV HEV(KU356187)strain showed acute HEV infection.Another healthy rhesus monkeys that inoculated genotype IV HEV(KM01)strain were persistent infection.There had been a continuous amino acid mutation in HEV capsid protein in the whole genome sequencing of HEV that lead a chronic infection in rhesus monkeys by comparing with the original strain.(2)Effects on chronic HEV infection by viral genome mutationTo further confirm the interaction relation between the HEV ORF2 successive amino acid mutation and HEV chronic infection,we constructed HEV recombinant strain by knocking out mutant area through reverse genetics technology,and assessed its infectivity in A549 cells.We found that the HEV recombinant strain were successfully constructed and infectious A549 cells effectively.(3)Establishment of the chronic HEV infection animal modelTo elaborate the HEV recombinant strain infectivity,we screened and established a chronic HEV infection animal model in mice.Then we simulated the HEV chronic infection on the animal model successfully.The results indicated that the HEV ORF2 successive amino acid mutation is closely related to HEV chronic infection.The results in this study demonstrated HEV ORF2 successive amino acid mutation of KM01 strain ean lead to ehronic HEV infection,which may be a reason why general population infected by HEV can develop into chronic hepatitis E infection.At the same time,we established a chronic HEV infection animal model in mice.This result provides a strong basis for further studying the pathogenesis of chronic HEV infection and identifying anti-HEV drug.