Development of anti-Crimean-Congo hemorrhagic fever virus Gc and NP-specific ELISA for detection of antibodies in domestic animal sera

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is a priority emerging disease. CCHF, caused by the CCHF virus (CCHFV), can lead to hemorrhagic fever in humans with severe cases often having fatal outcomes. CCHFV is maintained within a tick-vertebrate-tick cycle, which includes domestic animals. Domestic animals infected with CCHFV do not show clinical signs of the disease and the presence of antibodies in the serum can provide evidence of their exposure to the virus. Current serological tests are specific to either one CCHFV antigen or the whole virus antigen. Here, we present the development of two in-house ELISAs for the detection of serum IgG that is specific for two different CCHFV antigens: glycoprotein Gc (CCHFV Gc) and nucleoprotein (CCHFV NP). We demonstrate that these two assays were able to detect anti-CCHFV Gc-specific and anti-CCHFV NP-specific IgG in sheep from endemic CCHFV areas with high specificity, providing new insight into the heterogeneity of the immune response induced by natural infection with CCHFV in domestic animals.

Establishment of two serological methods for detecting IgG and neutralizing antibodies against Crimean-Congo hemorrhagic fever virus glycoprotein

“…GP is a dominant protein that causes IgG and neutralizing antibodies, and more and more researchers have realized the role of GP in the detection of antibodies. Recently, some ELISAs based on GP and NP have been published, such as a multiplex assay for simultaneous detection of antibodies against CCHFV NP and glycoproteins (G N ectodomain and GP38) in ruminants ( Hoste et al, 2023 ), an ELISA (Rec-ELISA) based on a purified recombinant nucleocapsid protein (rNP) and mucin-like variable domain (rMLD) for detection of antibodies in CCHF-suspected patient sera ( Gulce-Iz et al., 2021 ), and a Gc and NP-specific ELISA for detection of antibodies in domestic animal sera ( Belij-Rammerstorfer et al., 2022 ). However, this sophisticated approach is hardly feasible in a normal lab.…”