Hyperreactivity of activated B cells to B cell growth factor in patients with systemic lupus erythematosus.
Inasmuch as B cell function is in large part determined by lymphokine-derived accessory signals, we studied the effects of recombinant IL-2 and low-molecular-weight B cell growth factor (BCGF) on peripheral blood B cells activated with Staphylococcus aureus Cowan I to explain the B cell hyperfunction in patients with SLE. When S. aureus Cowan I-activated normal B cells were separated into Tac-antigen (Tac-Ag)+ and Tac-Ag- cells by employing a rosette technique, IL-2 induced only the Tac-Ag+ cells to proliferate, whereas both the Tac-Ag+ and Tac-Ag- cells responded to BCGF. The Tac-Ag+ and Tac-Ag- fractions of activated SLE B cells behaved like respective fractions of activated normal B cells for the pattern of response to these growth factors. It should be pointed out, however, that although the Tac-Ag+ B cells of SLE patients and those of normal controls responded to IL-2 to almost the same degree, both the Tac-Ag+ and Tac-Ag- B cells of SLE patients exhibited markedly enhanced proliferative responses to BCGF. The selectively enhanced responsiveness of a broader range of activated SLE B cells may lead to B cell hyperactivity in this disease.
Ueda
Y
Y
Department of Internal Medicine, Shimane Medical University, Japan.
Sakane
T
T
Tsunematsu
T
T
D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D002474:Cell-Free System; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D007376:Interleukin-2; D010835:Phytohemagglutinins; D015375:Receptors, Interleukin-2; D015847:Interleukin-4