Development of an Enzyme-Linked Immunosorbent assay to detect antibodies targeting the recombinant envelope protein 2 of Mayaro virus

Abstract

Mayaro virus (MAYV) is a neglected arthropod-borne virus (arbovirus) antigenically clustered into the Semliki Forest complex group of Alphavirus genus ( Togaviridae family), maintained in an unclear zoonotic cycle involving mosquitoes from Haemagogus genus as the main vector. The genome is constituted of a positive single-stranded RNA of 11.5kb in length, which contains two genes that encode four non-structural (nsP1 - 4) and five structural (C, E3, E2, 6K, and E1) proteins. In the present study, we have developed an ELISA using as antigen the recombinant envelope protein 2 of MAYV produced in E. coli system (rE2-MAYV ELISAs). A panel of 68 human serum samples from arboviral suspected cases were analyzed and titrated for anti-MAYV IgM and IgG antibodies detection. The rE2-MAYV ELISA detected 33.8% (23/68) positive IgG samples, demonstrating 100% sensitivity and 78.95% specificity when compared to MAYV-specific PRNT ₅₀. In addition, the positive MAYV neutralizing samples showed high titers of detection by rE2-MAYV ELISA, suggesting a highly sensitive test. Also, the rE2-MAYV ELISA detected 42.5% (29/68) positive IgM samples, which 13.8% (4/29) presented high avidity interactions to rE2-MAYV. Cross-reactivity was observed to CHIKV-specific murine antibody sample, but not to CHIKV-specific human and other Alphavirus murine antibodies. In short, we have developed a rapid, simple, specific and sensitive MAYV rE2-ELISA and our preliminary results show their potential applicability on diagnosis of MAYV infections.