Cell mediated cross-reactivity in vivo and in vitro to purified dermatophyte antigen preparations in sensitized guinea pigs.

Guinea pigs were sensitized to either Trichophyton rubrum, Trichophyton mentagrophytes, or Epidermophyton floccosum. Cross-reactivity experiments were performed in vivo and in vitro with purified antigen preparations prepared from the respective dermatophyte according to the ethylene glycol method. All sensitized animals responded with delayed-type skin reactions to all three antigen preparations, although the strongest reactivity observed was to the homologous antigen. Spleen and blood lymphocytes from many (but not all) animals were stimulated by these antigens and the response to the homologous antigen was always more pronounced. The findings indicate the presence of a common group-specific dermatophyte antigen as well as the possibility of species-specific antigens in the experimental system studied.