Strain differences in lymphocyte responses and in vitro suppressor cell induction between Schistosoma mansoni-infected C57BL/6 and CBA mice.
Splenic lymphocyte blastogenic responses to mitogens and antigens were compared in Schistosoma mansoni-infected C57BL/6 and CBA mice. At 1 and 2 weeks of infection, elevated responses to phytohemagglutinin (PHA) were noted in C57BL/6, but not in CBA cultures. During the same period, elevated responses to lipopolysaccharide were observed in cultures from CBA, but not from C57BL/6 mice. Responses to both mitogens were depressed in both strains later in infection. The magnitude of antigen-specific responses was greater in CBA than in C57BL/6 cultures. A cercarial extract (CE) induced significant suppressor cell activity in normal C57BL/6 cell cultures as assessed by inhibition of syngeneic cell responsiveness to PHA. CE did not induce suppressive activity in CBA cultures. CE-induced suppression was unaffected by adherent cell removal, but was sensitive to anti-Thy 1.2 plus complement treatment. CE also directly inhibited PHA-stimulated C57BL/6 cell cultures, but enhanced cultures of CBA mice. The significance of these findings is discussed in relation to the relative strain differences seen in antigen-specific lymphocyte proliferation and the levels of protection induced after immunization with irradiated cercariae.
D000818:Animals; D000941:Antigens; D000961:Antilymphocyte Serum / Q000494:pharmacology; D003165:Complement System Proteins; D004247:DNA / Q000096:biosynthesis; D000939:Epitopes; D005260:Female; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010835:Phytohemagglutinins / Q000494:pharmacology; D011817:Rabbits; D012552:Schistosomiasis / Q000276:immunology* / Q000469:parasitology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000941:Antigens; D000961:Antilymphocyte Serum; D000939:Epitopes; D008070:Lipopolysaccharides; D010835:Phytohemagglutinins; D003165:Complement System Proteins; D004247:DNA