Requirement of IL-5 for induction of autoimmune hemolytic anemia in anti-red blood cell autoantibody transgenic mice

T Sakiyama, K Ikuta, S Nisitani… - International …, 1999 - academic.oup.com
T Sakiyama, K Ikuta, S Nisitani, K Takatsu, T Honjo
International immunology, 1999academic.oup.com
Abstract IL-5, IL-10 and lipopolysaccharide (LPS) are known to activate B-1 cells in vivo in
normal mice and anti-red blood cell autoantibody transgenic mice (HL mice). To assess the
exact role of IL-5 in proliferation and activation of peritoneal B-1 cells, we analyzed IL-5
receptor α chain-deficient HL (IL-5Rα–/–× HL) mice generated by the cross between IL-5Rα–
/–and HL mice. In IL-5Rα–/–× HL mice, Ig-producing B-1 cells in the peritoneal cavity were
negligible, although the total number of B-1 cells in the peritoneal cavity were as many as …
Abstract
IL-5, IL-10 and lipopolysaccharide (LPS) are known to activate B-1 cells in vivo in normal mice and anti-red blood cell autoantibody transgenic mice (HL mice). To assess the exact role of IL-5 in proliferation and activation of peritoneal B-1 cells, we analyzed IL-5 receptor α chain-deficient HL (IL-5Rα–/– × HL) mice generated by the cross between IL-5Rα–/– and HL mice. In IL-5Rα–/– × HL mice, Ig-producing B-1 cells in the peritoneal cavity were negligible, although the total number of B-1 cells in the peritoneal cavity were as many as 30% of that in HL mice. Moreover, LPS- or IL-10-induced differentiation of B-1 cells into antibody-producing cells was severely impaired in IL-5Rα–/– × HL mice. We also used in vivo 5-bromo-2′-deoxyuridine labeling to estimate the proliferation of B-1 cells in IL-5Rα–/– mice. The absence of IL-5Rα did not affect spontaneous proliferation of peritoneal B-1 cells. However, induced proliferation of peritoreal B-1 cells by oral administration of LPS was markedly impaired in IL-5Rα–/– mice. These results suggest that IL-5 is required for activation-associated proliferation of B-1 cells but not for their spontaneous proliferation and support the idea that IL-5 plays an important role on the induction of autoantibody production from B-1 cells.
Oxford University Press