Natural infection of captive cynomolgus monkeys (Macaca fascicularis) with hepatitis E virus genotype 4

Markers of antroponotic viral infections in vervet monkeys arrived from their natural habitat (Tanzania)

INTRODUCTION

Various human viruses have been identified in wild monkeys and in captive primates. Cases of transmission of viruses from wild monkeys to humans and vice versa are known. The aim of this study was to identify markers of anthroponotic viral infections in vervet monkeys (Chlorocebus pygerythrus) arrived from their natural habitat (Tanzania).

MATERIALS AND METHODS

Fecal samples (n = 56) and blood serum samples (n = 75) obtained from 75 animals, respectively, on days 10 and 23 after admission to the primate center, were tested for the markers of anthroponotic viral infections (Ebola virus, Marburg virus, lymphocytic choriomeningitis, hepatitis C virus, herpes simplex virus (HSV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), parainfluenza types 1 and 3, intestinal adenoviruses, rotaviruses) by enzyme immunoassay (ELISA) and polymerase chain reaction (PCR).

RESULTS AND DISCUSSION

Among the examined animals, markers of 6 out of 11 tested viral infections were identified. Detection rates of IgG antibodies to HSV-1,2 (15.9%) and CMV (15.9%) were two times as low as IgG antibodies to EBV (31.8%). Among the markers of respiratory viral infections, IgG antibodies to parainfluenza virus type 1 were found (6.8%). 14.3% of the animals had rotavirus antigen, and 94% had simian adenovirus DNA. Markers of hemorrhagic fevers Ebola, Marburg, LCM, hepatitis C, and type 3 parainfluenza were not detected.

CONCLUSION

When importing monkeys from different regions of the world, an expanded screening for viral infections is needed considering the epidemiological situation both in the country of importation and in the country of destination.

[Enteral viral hepatitis in monkeys]

Within the last decade, a large number of viruses genetically related to human hepatitis viruses have been identified in different animal species, including monkeys. Numerous viruses related to human hepatitis A virus (HAV, Picornaviridae: Hepatovirus: Hepatovirus A) were detected in various mammalian species in 2015-2018, predominantly in bats and rodents, but also in shrews, seals and marsupials. Zoonotic hepatitis E virus (HEV, Hepeviridae: Orthohepevirus: Orthohepevirus A) genotypes have been found in wild boars, deer, camels, and rabbits, as well as in non human primates. In addition, viruses that are genetically close to HEV have been described in bats, ferrets, rodents, birds, and fish. Nevertheless, monkeys remain important laboratory animals in HAV and HEV research. The study of spontaneous and experimental infection in these animals is an invaluable source of information about the biology and pathogenesis of these viruses and continues to be an indispensable tool for vaccine and drug testing. The purpose of this literature review was to summarize and analyze published data on the circulation of HAV and HEV among wild and captive primates, as well as the results of experimental studies of HAV and HEV infections in monkeys.

Identifying Circular RNAs in HepG2 Expressing Genotype IV Swine Hepatitis E Virus ORF3 Via Whole Genome Sequencing

Swine hepatitis E (SHE) is a new type of zoonotic infectious disease caused by swine hepatitis E virus (SHEV). Open reading frame 3 (ORF3) is a key regulatory and virulent protein of SHEV. Circular RNAs (circRNAs) are a special kind of non-coding RNA molecule, which has a closed ring structure. In this study, to identify the circRNA profile in host cells affected by SHEV ORF3, adenovirus ADV4-ORF3 mediated the overexpression of ORF3 in HepG2 cells, whole genome sequencing was used to investigate the differentially expressed circRNAs, GO and KEGG were performed to enrichment analyze of differentially expressed circRNA-hosting gene, and Targetscan and miRanda softwares were used to analyze the interaction between circRNA and miRNA. The results showed adenovirus successfully mediated the overexpression of ORF3 in HepG2 cells, 1,105 up-regulation circRNAs and 1,556 down-regulation circRNAs were identified in ADV4-ORF3 infection group compared with the control. GO function enrichment analysis of differentially expressed circRNAs-hosting genes classified three main categories (cellular component, biological process and molecular function). KEGG pathway enrichment analysis scatter plot showed the pathway term of top20. The circRNAs with top10 number of BS sites for qRT-PCR validation were selected to confirmed, the results indicated that the up-regulated hsa_circ_0001423 and hsa_circ_0006404, and down-regulated of hsa_circ_0004833 and hsa_circ_0007444 were consistent with the sequencing data. Our findings first preliminarily found that ORF3 protein may affect triglyceride activation (GO:0006642) and riboflavin metabolism (ko00740) in HepG2 cells, which provides a scientific basis for further elucidating the effect of ORF3 on host lipid metabolism and the mechanism of SHEV infection.

[Markers of viral hepatitis E (Hepeviridae, Orthohepevirus, Orthohepevirus A) in the imported Old World monkeys]

INTRODUCTION

Viral hepatitis E is a zooanthroponotic disease that occurs in humans and various animals, including monkeys. It is caused by hepatitis E virus (HEV) (Hepeviridae, Orthohepevirus: Orthohepevirus A), for which 8 genotypes have been described to date. Among them, strains of genotypes 1 and 2 have been isolated from humans, strains of genotypes 3 and 4 from humans and animals, and strains of genotypes 5-8 from animals only. The main threat of the disease is associated with the documented zoonotic transmission of HEV genotypes 3, 4, 7, and 8, to humans through infected meat, blood and milk. Thus, monkeys could be involved in the transmission of HEV.The aim of this work was to study serological and molecular genetic markers of HEV infection in strepsirrhines (Old World monkeys, Cercopithecoidea), imported to the Adler Primate Center from various regions of the world (Tanzania, Vietnam, Mauritius).

MATERIAL AND METHODS

Fecal (n = 224) and blood serum samples (n = 395) from cynomolgus (Macaca fascicularis) and vervet monkeys (Chlorocebus pygerythrus) were examined by the enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS AND DISCUSSION

The data obtained show the high detection rate (51.8%) of IgG antibodies to HEV among 5 groups of cynomolgus monkeys imported from Vietnam, with a predominance of highly reactive sera (84%). High detection rate of IgM antibodies in these animals (10.4%) was observed, with the large number of IgM-reactive sera in one particular group of animals (36.8%). The fact of detection of HEV RNA in two groups of cynomolgus monkeys (11.9% and 5.7%) is of particular importance. All HEV sequences of isolated from monkeys belonged to genotype 4.

CONCLUSION

Our data indicate that monkeys (in particular, cynomolgus monkeys) can serve as a natural reservoir of HEV genotype 4 for humans. This requires an appropriate set of anti-epidemic measures in a number of situations.

In vivo models for studying Hepatitis E virus infection; Updates and applications

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis globally. HEV belongs to the Hepeviridae family and at least five genotypes (gt) infect humans. Several animal species are reservoirs for different HEV strains, and they are the source of infection for humans. Some HEV strains are species specific, but other strains could cross species and infect many hosts. The study of HEV infection and pathogenesis was hampered due to the lack of an in vitro and in vivo robust model system. The cell culture system has been established for certain HEV strains, especially gt3 and 4, but gt1 strains replicate poorly in vitro. To date, animal models are the best tool for studying HEV infection. Non-human primates (NHPs) and pigs are the main animal models used for studying HEV infection, but ethical and financial concerns restrict the use of NHPs in research. Therefore, new small animal models have been developed which help more progress in HEV research. In this review, we give updates on the animal models used for studying HEV infection, focusing on the applicability of each model in studying different HEV infections, cross-species infection, virus-host interaction, evaluation of anti-HEV therapies and testing potential HEV vaccines.