Interleukin 2 is a proliferative signal for B cells from autoimmune mice.
T cells from murine lupus strains manifest complex defects in interleukin 2 (IL 2) production and receptor expression. The capacity of B cells from such mice to utilize IL 2 as a growth factor has not been previously reported and is examined herein. Anti-Thy-1.2 plus complement-treated spleen cells from 6-8-week-old autoimmune MRL-lpr/lpr mice and from age and sex-matched immunologically normal CBA/J mice were cultured with lipopolysaccharide (LPS) for 36 h and analyzed for the expression of IL 2 receptors using the monoclonal antibody 7D4. The percentage of B cells expressing IL 2 receptors was comparable in MRL-lpr/lpr and CBA/J mice. In contrast to those from CBA/J, BALB/c and (BALB/c X NZW)F1 mice, LPS-stimulated B cells from MRL-lpr/lpr and from (NZB X NZW)F1 mice were capable of proliferating in response to IL 2. Fractionation of MRL-lpr/lpr B cells using Percoll gradient density separation demonstrated that the IL 2-responsive population consisted predominantly of large cells. In addition, unfractionated B cells from MRL-lpr/lpr mice were found to be substantially more responsive to IL 2 than those from CBA/J and BALB/c mice following activation with anti-immunoglobulin plus LPS. The hyper-responsiveness to IL 2 may be a consequence of the state of activation of autoimmune B cells and is of potential importance in the pathogenesis of systemic lupus erythematosus.
D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D006133:Growth Substances / Q000032:analysis; D007136:Immunoglobulins / Q000276:immunology; D007376:Interleukin-2; D015847:Interleukin-4; D008070:Lipopolysaccharides / Q000494:pharmacology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008222:Lymphokines / Q000032:analysis; D051379:Mice; D008815:Mice, Inbred Strains; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins / Q000494:pharmacology
D001323:Autoantibodies; D006133:Growth Substances; D007136:Immunoglobulins; D007376:Interleukin-2; D008070:Lipopolysaccharides; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D015847:Interleukin-4