Equine immunoglobulin F(ab′) 2 fragments protect mice from Rift Valley fever virus infection

摘要

BackgroundRift Valley fever virus (RVFV) is an emerging arbovirus in Africa and the Arabian Peninsula, in which infection with RVFV poses a serious threat to humans and livestock globally. Approved treatments for RVFV infection, especially for use in humans, have not yet been developed. There is an urgent need for effective drugs to prevent RVFV disease. MethodsIn previous study, we developed RVFV virus like particles (VLPs) expressing the surface glycoproteins Gn and Gc. The morphology was shown to be similar to live RVFV under electron microscopy. In this study, we immunized horses with RVFV VLPs, prepared the immunoglobulin F(ab′)2fragments, and characterized itsin vitroneutralization andin vivoefficacy in mice. ResultsF(ab′)2was found to potently neutralize RVFV in VeroE6 cells, and passive transfer of immunoglobulin F(ab′)2fragments resulting in reduced mortality in RVFV infected mice. ConclusionOur results show that passive immunotherapy with equine immunoglobulin F(ab′)2fragments is a promising strategy to treat RVFV infections.