IMMUNE-RESPONSES TO INDIVIDUAL ROTAVIRUS PROTEINS FOLLOWING HETEROLOGOUS AND HOMOLOGOUS ROTAVIRUS INFECTION IN MICE

Serum and intestinal humoral immune responses to rotavirus proteins VP 2, VP4, VP6, VP7, NSP2, and NSP4 were quantitatively compared in mice infected with a homologous murine rotavirus (EHPw) or a heterologous s imian rotavirus (RRV). Viral protein-specific antibody responses were measured by an immunohistochemistry assay that uses recombinant baculo virus-expressed rotavirus proteins as antigens, In serum, IgG response s to VP6 were dominant and comparable in both RRV- and EHPw-infected g roups, but responses to VP2, VP4, VP7, and NSP2 were higher in RRV inf ection, In feces, IgA responses to VP2, VP4, and VP6 were higher in EH Pw-infected mice, but responses to VP7 and NSP2 were detected only in the RRV-infected group. These findings indicate that immune responses to homologous and heterologous rotavirus infection vary both quantitat ively and qualitatively, Differences in humoral responses may play a r ole in the differences in protection induced following homologous or h eterologous rotavirus infection.