Efficient production of a lentiviral system for displaying Crimean-Congo hemorrhagic fever virus glycoproteins reveals a broad range of cellular susceptibility and neutralization ability.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease with a mortality rate of up to 50% in humans. To avoid safety concerns associated with the use of live virus in virus neutralization assays and to detect human serum neutralizing antibodies, we prepared lentiviral particles containing the CCHF glycoprotein (lenti-CCHFV-GP). Incorporation of the GP into the lentiviral particle was confirmed by electron microscopy and Western blotting. Lenti-CCHFV-GP was found to be able to infect a wide range of cell lines, including BHK-21, HeLa, HepG2, and AsPC-1 cells. In addition, lenti-CCHFV-GP was successfully used as an alternative to CCHFV for the detection of neutralizing antibodies. Sera collected from CCHF survivors neutralized lenti-CCHFV-GP particles in a dose-dependent manner. Our results suggest that the lenti-CCHFV-GP pseudovirus can be used as a safe tool for neutralization assays in low-containment laboratories.