Rotavirus VP6 nanospheres improved systemic and mucosal immune responses to particulate antigens comparably to alum, but did not enhance responses to the short peptide M2e.
Does Rotavirus inner capsid VP6 act as an adjuvant to improve immune responses to co-administered particulate antigens in immunized mice?
Rotavirus VP6 nanospheres act as an effective adjuvant for particulate antigens, enhancing mucosal and T cell responses superior to alum, but are ineffective for non-particulate short peptides.
Novel adjuvants present a concern for adverse effects, generating a need for alternatives. Rotavirus inner capsid VP6 protein could be considered a potential candidate, due to its ability to self-assemble into highly immunogenic nanospheres and nanotubes. These nanostructures exhibit immunostimulatory properties, which resemble those of traditional adjuvants, promoting the uptake and immunogenicity of the co-administered antigens. We have previously elucidated an adjuvant effect of VP6 on co-delivered norovirus and coxsackievirus B1 virus-like particles, increasing humoral and cellular responses and sparing the dose of co-delivered antigens. This study explored an immunostimulatory effect of VP6 nanospheres on smaller antigens, P particles formed by protruding domain of a norovirus capsid protein and a short peptide, extracellular matrix protein (M2e) of influenza A virus. VP6 exhibited a notable improving impact on immune responses induced by P particles in immunized mice, including systemic and mucosal antibody and T cell responses. The adjuvant effect of VP6 nanospheres was comparable to the effect of alum, except for induction of superior mucosal and T cell responses when P particles were co-administered with VP6. However, unlike alum, VP6 did not influence M2e-specific immune responses, suggesting that the adjuvant effect of VP6 is dependent on the particulate nature of the co-administered antigen.
Heinimäki et al. (Tue,) reported a other. Rotavirus inner capsid VP6 nanospheres vs. Alum was evaluated on Systemic and mucosal antibody and T cell responses. Rotavirus VP6 nanospheres improved systemic and mucosal immune responses to particulate antigens comparably to alum, but did not enhance responses to the short peptide M2e.