Immune response modulation by colonization of germfree rats with Propionibacterium acnes.
Propionibacterium acnes (oral and/or parenteral administration) had a modulating effect on antibody-and cell-mediated immune responses of germfree (GF) and monoassociated (MA) rats. In conventionally reared rodents, parenteral injection of killed P. acnes stimulated the splenic plaque-forming cell response to sheep erythrocytes. However, in GF rats and in rats monoassociated with viable P. acnes, parenteral injection of killed P. acnes antigen inhibited the plaque-forming cell response to sheep erythrocytes. When compared with the responses of GF control rats, splenocytes from GF rats parenterally injected with P. acnes antigen had a decreased in vitro blastogenic response to phytohemagglutinin and concanavalin A and  an increased blastogenic response to homologous bacterial antigens. Conversely, a parenteral injection of P. acnes antigen into P. acnes MA rats resulted in an increased splenocyte blastogenic response to phytohemagglutinin and concanavalin A but not to homologous (P. acnes) antigens. Thus the presence or absence of intestinal antigenic stimuli (in MA and GF rats) had a modulating effect on the immune response to a parenteral injection of P. acnes antigen.
D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D005856:Germ-Free Life; D006462:Hemolytic Plaque Technique; D007111:Immunity, Cellular; D007275:Injections, Intravenous; D008213:Lymphocyte Activation; D051379:Mice; D011425:Propionibacterium acnes / Q000276:immunology*; D051381:Rats
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial