Replication of Hepatitis E Virus (HEV) in Primary Human-Derived Monocytes and Macrophages In Vitro

Ibrahim M Sayed; Mohamed Ismail Seddik; Marwa A Gaber; Saber H Saber; Sahar A Mandour; Mohamed A El-Mokhtar

doi:10.3390/vaccines8020239

Replication of Hepatitis E Virus (HEV) in Primary Human-Derived Monocytes and Macrophages In Vitro

Vaccines (Basel). 2020 May 21;8(2):239. doi: 10.3390/vaccines8020239.

Authors

Ibrahim M Sayed^{1

2}, Mohamed Ismail Seddik³, Marwa A Gaber⁴, Saber H Saber⁵, Sahar A Mandour⁶, Mohamed A El-Mokhtar¹

Affiliations

¹ Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt.
² Department of Pathology, School of Medicine, University of California, San Diego, CA 92093, USA.
³ Department of Clinical Pathology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt.
⁴ Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Assiut 71515, Egypt.
⁵ Laboratory of Molecular Cell Biology, Department of Zoology, Faculty of Science, Assiut University, Assiut 71515, Egypt.
⁶ Department of Microbiology and Immunology, Faculty of Pharmacy, Deraya University, Minia 11566, Egypt.

Abstract

HEV is the most causative agent of acute viral hepatitis globally. HEV causes acute, chronic, and extrahepatic manifestations. Chronic HEV infection develops in immunocompromised patients such as organ transplant patients, HIV-infected patients, and leukemic patients. The source of chronic HEV infection is not known. Also, the source of extrahepatic manifestations associated with HEV infection is still unclear. Hepatotropic viruses such as HCV and HBV replicate in peripheral blood mononuclear cells (PBMCs) and these cells become a source of chronic reactivation of the infections in allograft organ transplant patients. Herein, we reported that PBMCs and bone marrow-derived macrophages (BMDMs), isolated from healthy donors (n = 3), are susceptible to HEV in vitro. Human monocytes (HMOs), human macrophages (HMACs), and human BMDMs were challenged with HEV-1 and HEV-3 viruses. HEV RNA was measured by qPCR, the marker of the intermediate replicative form (ds-RNA) was assessed by immunofluorescence, and HEV capsid protein was assessed by flow cytometry and ELISA. HEV infection was successfully established in primary HMOs, HMACs, and human BMDMs, but not in the corresponding cells of murine origin. Intermediate replicative form (ds RNA) was detected in HMOs and HMACs challenged with HEV. The HEV load was increased over time, and the HEV capsid protein was detected intracellularly in the HEV-infected cells and accumulated extracellularly over time, confirming that HEV completes the life cycle inside these cells. The HEV particles produced from the infected BMDMs were infectious to naive HMOs in vitro. The HEV viral load was comparable in HEV-1- and HEV-3-infected cells, but HEV-1 induced more inflammatory responses. In conclusion, HMOs, HMACs, and human BMDMs are permissive to HEV infection and these cells could be the source of chronic and recurrent infection, especially in immunocompromised patients. Replication of HEV in human BMDMs could be related to hematological disorders associated with extrahepatic manifestations.

Keywords: HEV infection; PBMCs; bone marrow; capsid protein; chronic; ds-RNA; extrahepatic; hematological disorders; immune response.

Grants and funding

30208/Science and Technology Development Fund