Binding Patterns of Human Norovirus-Like Particles to Buccal and Intestinal Tissues of Gnotobiotic Pigs in Relation to A/H Histo-Blood Group Antigen Expression

Abstract

ABSTRACT Histo-blood group antigen (HBGA) phenotypes have been associated with susceptibility to human noroviruses (HuNoVs). Our aims were: (i) to determine the patterns of A/H HBGA expression in buccal and intestinal tissues of gnotobiotic (Gn) pigs; (ii) to determine if virus-like particles (VLPs) of HuNoV genogroup I (GI) and GII bind to A- or H-type tissues; (iii) to compare A/H expression and VLP binding patterns and confirm their binding specificities by blocking assays; (iv) to develop a hemagglutination inhibition test using buccal cells from live pigs to determine the Gn pig's A/H phenotype and to match viral strains with previously determined HuNoV VLP binding specificities; and (v) to determine the A/H phenotypes and compare these data to the infection outcomes of a previous study of 65 Gn pigs inoculated with HuNoV GII/4 strain HS66 and expressing A and/or H or neither antigen on their buccal and intestinal tissues (S. Cheetham, M. Souza, T. Meulia, S. Grimes, M. G. Han, and L. J. Saif, J. Virol. 80:10372-10381, 2006). We found that the HuNoV GI/GII VLPs of different clusters bound to tissues from four pigs tested (two A + and two H + ). The GI/1 and GII/4 VLPs bound extensively to duodenal and buccal tissues from either A + or H + pigs, but surprisingly, GII/1 and GII/3 VLPs bound minimally to the duodenum of an A + pig. The VLP binding was partially inhibited by A-, H1-, or H2-specific monoclonal antibodies, but was completely blocked by porcine mucin. Comparing the A/H phenotypes of 65 HS66-inoculated Gn pigs from our previous study, we found that significantly more A + and H + pigs (51%) than non-A + and non-H + pigs (12.5%) shed virus. From the 22 convalescent pigs, significantly more A + or H + pigs (66%) than non-A + or H + pigs (25%) seroconverted.