Spontaneous increase of plasma-like cells with high GANP expression in the extrafollicular region of lymphoid organs of autoimmune-prone mice.
Autoimmune-prone mice bear a hyper-active B cell population generated spontaneously in peripheral lymphoid organs. Expression of beta RNA-primase GANP was shown to be an activation marker in lymphoid follicle germinal center (GC) B cells after immunization with T cell-dependent antigen (TD-Ag) in normal mice. In this study, we examined the expression of GANP in lymphoid tissues of autoimmune-prone mice. GANP expression was up-regulated in GC-B cells after stimulation with TD-Ags; however, highly GANP-positive (GANP(hi)) cells were also observed in lymph nodes of non-immunized MRL/lpr mice. GANP(hi)cells in lymph nodes as well as in spleens of the different autoimmune-prone strains, MRL/lpr, NZB, (NZBxNZW)F1 and BXSB, gradually increased with age. This population was detected only in small numbers in the red pulp region of the spleen after immunization with TD-Ag in normal C57BL/6 and BALB/c mice. GANP(hi)cells had a B220(-)IgM(+)Syndecan-1(+)phenotype, but were negative for PAS-staining and bromo-deoxyuridine incorporation. These results demonstrate that GANP(hi)plasma-like cells appear in lymph nodes of autoimmune mice during aging, suggesting that the new plasma cell population might be generated after hyper-activation of B cells during the course of autoimmune disease.
Fujimura
Satoru
S
Department of Immunology, Kumamoto University School of Medicine, 2-2-1, Honjo, Kumamoto 860-0811, Japan.
Kuwahara
Kazuhiko
K
Ezaki
Taichi
T
Tomita
Kimio
K
Hirose
Sachiko
S
Sakaguchi
Nobuo
N
D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology / Q000378:metabolism; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D005260:Female; D018858:Germinal Center / Q000276:immunology / Q000378:metabolism; D007114:Immunization; D008213:Lymphocyte Activation; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D019463:Mice, Inbred MRL lpr; D008815:Mice, Inbred Strains; D008817:Mice, Mutant Strains; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010950:Plasma Cells / Q000276:immunology* / Q000378:metabolism*; D013997:Time Factors
D000941:Antigens; C481510:GANP protein, mouse; D009687:Nuclear Proteins; D010750:Phosphoproteins