Differential Growth Characteristics of Crimean-Congo Hemorrhagic Fever Virus in Kidney Cells of Human and Bovine Origin.

Katalin Földes,Koray Ergünay,Aykut Ozkul,Touraj Aligholipour Farzani

doi:10.3390/v12060685

Katalin Földes, Koray Ergünay + Show 2 more

Open Access

https://doi.org/10.3390/v12060685

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Abstract

Crimean-Congo hemorrhagic fever virus (CCHFV) causes a lethal tick-borne zoonotic disease with severe clinical manifestation in humans but does not produce symptomatic disease in wild or domestic animals. The factors contributing to differential outcomes of infection between species are not yet understood. Since CCHFV is known to have tropism to kidney tissue and cattle play an important role as an amplifying host for CCHFV, in this study, we assessed in vitro cell susceptibility to CCHFV infection in immortalized and primary kidney and adrenal gland cell lines of human and bovine origin. Based on our indirect fluorescent focus assay (IFFA), we suggest a cell-to-cell CCHF viral spread process in bovine kidney cells but not in human cells. Over the course of seven days post-infection (dpi), infected bovine kidney cells are found in restricted islet-like areas. In contrast, three dpi infected human kidney or adrenal cells were noted in areas distant from one another yet progressed to up to 100% infection of the monolayer. Pronounced CCHFV replication, measured by quantitative real-time RT-PCR (qRT-PCR) of both intra- and extracellular viral RNA, was documented only in human kidney cells, supporting restrictive infection in cells of bovine origin. To further investigate the differences, lactate dehydrogenase activity and cytopathic effects were measured at different time points in all mentioned cells. In vitro assays indicated that CCHFV infection affects human and bovine kidney cells differently, where human cell lines seem to be markedly permissive. This is the initial reporting of CCHFV susceptibility and replication patterns in bovine cells and the first report to compare human and animal cell permissiveness in vitro. Further investigations will help to understand the impact of different cell types of various origins on the virus–host interaction.

Highlights

Crimean-Congo hemorrhagic fever virus (CCHFV) causes a tick-borne viral disease with a geographical distribution in certain endemic areas such as eastern and southern Europe, Asia, the Middle-East, and Africa [1]
Cattle have an important role in the zoonotic cycle of CCHFV [8]: agricultural practices involving cattle facilitate human-tick contact; slaughterhouses provide an opportunity for direct contact with the viremic blood of infected animals; particular religious practices involving animal sacrifice can contribute to human exposure risks in endemic regions [9]
CCHFV is prioritized for research and vaccine/antiviral development in the WHO R&D Blueprint, CCHFV is prioritized for research and vaccine/antiviral development in the WHO R&D

Summary

Introduction

Crimean-Congo hemorrhagic fever virus (CCHFV) causes a tick-borne viral disease with a geographical distribution in certain endemic areas such as eastern and southern Europe, Asia, the Middle-East, and Africa [1]. It possesses a high mortality rate (up to 40%), and there is no licensed vaccine available to combat the disease [2]. Ticks serve as a viral vector and reservoir, many animals, such as cattle have been shown to act as natural hosts for CCHFV, while infected humans do not [5,6,7]. Cattle have an important role in the zoonotic cycle of CCHFV [8]: agricultural practices involving cattle facilitate human-tick contact; slaughterhouses provide an opportunity for direct contact with the viremic blood of infected animals; particular religious practices involving animal sacrifice can contribute to human exposure risks in endemic regions [9]

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