[Increased catabolism of antigen and enhanced recruitment of antigen-sensitive cells by activation of macrophages with a bacterial phospholipid extract (EBP) (author's transl)].
Intravenous (IV) infection of a bacterial phospholipid extract (EBP) 24 H before IV immunization of mice with sheep red blood cells has modified the specific immune response. A decrease of the response evaluated by the number of rosette-forming cells was observed after the larger doses of EBP. This effect appeared secondarily to an increased catabolism of antigen. Infection of a medium sized dose of EBP directly into the portal vein induced a decreased response by enhancing antigen phogocytosis by liver macrophages. The same amount of EBP injected IV into a systemic vein increased the immune response. An enhanced phagocytosis by macrophages which do not act in the immune response appeared likely after the larger stimulation. Irradiated spleen cells when transferred into naive recipients showed a decreased immunogenicity when obtained from mice injected with antigen and previously treated by the larger doses of EBP. On the other hand, after treatment of mice with low of medium sized doses of EBP, the immune response was increased. Twice the number of rosette-forming cells was observed in treated mice on days 3, 4 and 5 after immunization. The number of B rosette-forming cells appeared higher than the T rosettes following this treatment. This effect appeared secondarily to an increased recruitment of precursor cells. Transfer into naive irradiated recipients of treated spleen cells mixed with antigen was without effect. On the contrary, an enhanced number of rosette-forming cells was detected after transfer of normal spleen cells into irradiated and EBP-treated recipients. This enhancement of response appeared to be produced by more efficient recruitment of precursor cells as demonstrated by an increased frequency of antibody-forming cells in an in vivo limiting dilution technique.
D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D004306:Dose-Response Relationship, Immunologic; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007275:Injections, Intravenous; D007700:Kinetics; D008089:Listeria monocytogenes / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010743:Phospholipids / Q000494:pharmacology*; D011169:Portal Vein; D012397:Rosette Formation; D013997:Time Factors
D000941:Antigens; D010743:Phospholipids
Catabolisme accru de l'antigène et augmentation du recrutement des cellules sensibles à l'antigène par activation des macrophages avec un extrait bactérien phospholipidique (EBP).