Human rhinovirus serotypes (HRV) fall into two distinct groups, major and minor, by virtue of their cell receptor-binding ability. In this study minor receptor-binding group viruses are demonstrated to bind directly to cells of the murine immune system, including lymphoid dendritic cells which act as antigen-presenting cells, although they do not produce a productive infection in murine cells. This binding is specific and can be blocked by other serotypes of minor-group HRV. Pre-treatment of HRV 1A, a minor-group virus, with HRV 1A-specific antibodies inhibited the cellular proliferation of murine virus primed T helper cells, whereas antibody treatment of HRV 15, a non-binding major serotype, gave no inhibition. The cell binding ability of minor-group HRV played a role in the overall immunogenicity of this virus group, which was shown to be enhanced compared to the immunogenicity of major-group viruses in mice.