Evidence of conserved epitopes in variable region of VP8* subunit of VP4 protein of rotaviruses of P[8]-1 and P[8]-3 lineages.

Although antibody responses to the human rotavirus VP4 protein have been reported, few studies have analyzed the specificity of these responses to the VP8* subunit. This study investigated antibody responses generated against the variable region of the VP4 protein (VP8* subunit) in children infected with rotavirus genotype P[8]. Recombinant VP8* subunit (rVP8*) and truncations corresponding aa 1-102 (peptide A) and 84-180 (peptide B) of rotavirus strains P[8]-1 and P[8]-3 lineages were expressed in Escherichia coli and examined for antibody reactivity using ELISA and Western blot assays. Sera from infected children had IgG antibodies that reacted with full-length rVP8*, peptide A and B of both lineages, with stronger reactivity observed against peptide B. In addition, anti-strain Wa (P[8]-1) and anti-rVP8* (P[8]-3) rabbit polyclonal antiserum reacted against peptide B sequences of both lineages. These data indicate that the VP8* variable region of rotavirus belonging to P[8]-1 and P[8]-3 lineages have conserved epitopes recognized by antibodies elicited during natural infections.