Development of a monoclonal antibody specifically recognizing a linear epitope on the E1 protein of Getah virus.

Getah virus (GETV) is a mosquito-borne alphavirus that can cause disease outbreaks in domesticated mammals. The E1 protein of GETV plays a crucial role in mediating the fusion of viruses and host cells. In this study, the recombinant GETV E1 protein was expressed and administered to BALB/c mice. Hybridoma cells secreting a monoclonal antibody (mAb) 7D4-2 against E1 protein were subsequently obtained using a cell fusion protocol between SP2/0 cells and splenocytes. The reactivity of mAb 7D4-2 with GETV was confirmed through Western blot analysis and indirect immunofluorescence assay (IFA). A precise B cell linear epitope, 281-DIPDTAF-287, was identified using Western blot analysis with the produced mAb 7D4-2 by constructing and expressing a series of truncated His-fused E1 proteins. Conservation analysis indicated that this epitope is highly conserved in Group III strains of GETV, but exhibits an amino acid difference (T285S) compared to Group I, Group II, and Group IV. Cross-reactivity analysis by Western blot demonstrated that the B-cell epitope containing the mutation could be recognized by mAb 7D4-2. The ability of mAb 7D4-2 to recognize the epitope carrying the T285S mutation was further confirmed using an infectious clone of GETV. This study enhances the understanding of the biological characteristics of the E1 protein and will facilitate the future development of diagnostic tests for GETV.