title: Cell-mediated and humoral immune responses of guinea-pigs to the oral bacterium Actinomyces viscosus.
abstract: Actinomyces viscosus is a Gram-positive facultative rod indigenous to most human mouths. The guinea-pig was evaluated as a model for assessing cellular immune responses to a human strain of A. viscosus. Guinea-pigs, immunized with heat-killed A. viscosus cells or a water-soluble extract from A. viscosus (AVS), were tested for delayed-type hypersensitivity responses to A. viscosus 4 weeks after immunization. A week later, the guinea-pigs were terminated. Lymphocytes from peripheral blood, lymph node and spleen were tested for in-vitro blastogenic responses to heat-killed A. viscosus or the water-soluble extract. Plasma from these guinea-pigs were tested for the presence of precipitating antibodies. Positive in-vivo delayed-type hypersensitivity reactions and antibody responses to AVS occurred only in immunized guinea-pigs. A strong in-vitro blastogenic response to AVS or heat-killed A. viscosus occurred in lymphocytes from immunized guinea-pigs, but a weak response was detected in un-immunized animals. These data suggest that the guinea-pig can be used to evaluate different parameters of the immune response to oral bacteria such as A. viscosus.
mesh_terms: D000190:Actinomyces / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D001439:Bacteroides / Q000276:immunology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006168:Guinea Pigs; D007111:Immunity, Cellular; D007114:Immunization; D008214:Lymphocytes / Q000276:immunology; D013154:Spleen / Q000166:cytology