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B‐B Cell Interactions in the Spontaneous Activation of B Cells in Autoimmune NZB Mice
Author(s) -
Saito Kazuyoshi,
Tanaka Yoshiya,
Ota Toshiyuki,
Eto Sumiya,
Yamashita Uki
Publication year - 1991
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1991.tb01607.x
Subject(s) - antibody , b cell , biology , in vitro , microbiology and biotechnology , antigen , stimulation , immunology , endocrinology , biochemistry
We analyzed the mechanism of spontaneous B cell activation in lupus mice by using anticlass‐II antibody in vitro. The in vitro culture of B cells from old NZB mice markedly produced Ig without any stimulation, while B cells from NZW mice did not. The addition of anticlass‐II antibody (anti‐Ia d antibody) to the culture inhibited Ig production of NZB B cells in a concentration‐dependent manner. On the other hand, the addition of anticlass‐I antibody (anti‐H‐2D d antibody) and anticlass‐II antibody with different specificity (anti‐Ia k ) gave no effect on the Ig production of NZB B cells. When mitomycin C‐treated B cells were added to in vitro culture of responder B cells as a stimulator, Ig production of responder B cells was enhanced in a concentration‐dependent manner. However, the enhancing effect of the stimulator B cells was abrogated by the pretreatment with anticlass‐II antibody. The stimulator B‐cell activity to NZB B cells was marked in NZB B cells, moderate in NZB/W F 1 B cells, and weak in NZW B cells. Furthermore, the stimulator B‐cell activity with regard to NZB B cells was marked in old female NZB B cells, moderate in old male NZB B cells, and weak in young NZB B cells. The expression of class II antigens on the surface of old female NZB B cells was significantly higher than that of old male NZB and young NZB B cells. These results suggest that in lupus mice the spontaneous B‐cell activation is induced by an abnormal B‐B cell interaction mediated by class II antigens.