Effects of breeding environments on generation and activation of autoreactive B-1 cells in anti-red blood cell autoantibody transgenic mice.
In anti-red blood cell autoantibody transgenic (autoAb Tg) mice almost all B cells are deleted except for B-1 cells in the peritoneal cavity and the gut. About one-half of the auto Ab Tg mice suffer from autoimmune hemolytic anemia (AIHA) in the conventional condition. Oral administration of lipopolysaccharides activates B-1 cells and induces autoimmune symptoms in the Tg mice, suggesting that the autoimmune disease in anti-RBC autoAb Tg mice is triggered by infections. To examine the association of bacterial infections with the generation of B-1 cells and the occurrence of the autoimmune disease, we analyzed anti-RBC autoAb Tg mice bred in germ-free and specific pathogen-free conditions. In germ-free conditions, few peritoneal B-1 cells were detected, while a significant number of peritoneal B-1 cells existed in specific pathogen-free conditions. In both conditions, no mice suffered from AIHA. However, when these Tg mice were transferred to the conventional condition or injected with lipopolysaccharide, peritoneal B-1 cells expanded and some of these mice suffered from AIHA. These results clearly showed that bacterial infections are responsible for both the expansion of B-1 cells and the onset of the autoimmune disease in these Tg mice.
Murakami
M
M
Department of Medical Chemistry, Kyoto University Faculty of Medicine, Sakyo-ku Yoshida, Japan.
Nakajima
K
K
Yamazaki
K
K
Muraguchi
T
T
Serikawa
T
T
Honjo
T
T
D000818:Animals; D001323:Autoantibodies / Q000235:genetics* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D001947:Breeding; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008822:Mice, Transgenic
D001323:Autoantibodies