B1 B cell numbers and antibodies against phosphorylcholine and LPS are increased in IL-6 gene knockout mice.
Peritoneal cavity cells were isolated from IL6-gene knockout (IL6(-/-)) and wild-type mice and stained for expression of IgM, CD5, and CD23. B1 cell (IgM(+)/CD23(-), CD5(+)/IgM(+)) numbers were increased twofold in IL6(-/-) mice compared to normals while IgM(+)/CD23(+) (B2) cell numbers were reduced threefold. Intestinal antibody levels were also determined for both total immunoglobulin and phosphorylcholine (PC)-specific and LPS-specific antibody following oral challenge with attenuated Salmonella typhimurium. Total immunoglobulin levels (IgM, IgG, and IgA) were reduced 60-80% in intestinal secretions of IL6(-/-) mice compared to wild-type controls; however, PC-specific antibody was significantly higher in IL6(-/-) mice. Anti-LPS antibodies were also three- to sevenfold higher in IL6(-/-) mice compared to controls following Salmonella challenge. These data suggest that in IL6(-/-) mice the development of mucosal B2 cells is impaired but that intestinal B1 cells responding to microbial antigens such as PC and LPS develop normally and are fully functional.
Bao
S
S
Discipline of Immunology and Microbiology, University of Newcastle, Callaghan, NSW 2308, Australia.
Husband
A J
AJ
Beagley
K W
KW
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology*; D018956:CD5 Antigens / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D015850:Interleukin-6 / Q000502:physiology*; D008070:Lipopolysaccharides / Q000276:immunology*; D018655:Lymphocyte Count; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010767:Phosphorylcholine / Q000276:immunology*; D017455:Receptors, IgE / Q000032:analysis
D000907:Antibodies, Bacterial; D018956:CD5 Antigens; D007075:Immunoglobulin M; D015850:Interleukin-6; D008070:Lipopolysaccharides; D017455:Receptors, IgE; D010767:Phosphorylcholine