Autoimmune MRL/lpr mice sera contain IgG with interleukin 3-like activity.
The spleen cells, thymocytes, and bone marrow cells of autoimmune MRL/MP-lpr/lpr (MRL/lpr) mice do not constitutively produce interleukin 3 (IL-3), but these mice had IL-3-like activity in their sera. MRL/lpr sera supported the growth of the IL-3-dependent cell lines FDC-P2 and DA-1 but not the growth of IL-2-dependent T-572 cells. This IL-3-like activity increased with age. Biochemical analysis of the MRL/lpr sera by anion-exchange chromatography, gel filtration on a Superose 12 column, the binding to protein-A and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the serum factor with the IL-3-like activity was not IL-3 itself but was associated with IgG. Flow cytometric analysis also showed that the serum level of the Ig capable of binding FDC-P2 cells was high in MRL/lpr but not in MRL/+ mice. We suggest that IL-3 is not responsible for lymphoid hyperplasia, contrary to a previous report; rather auto-antibodies directed toward the IL-3 receptor may act pathogenically in MRL/lpr mice.
Ohta
Y
Y
Nippon Roche Research Center, Kanagawa, Japan.
Tamura
S
S
Tezuka
E
E
Sugawara
M
M
Imai
S
S
Tanaka
H
H
D000375:Aging; D000818:Animals; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology* / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D007106:Immune Sera / Q000494:pharmacology; D007074:Immunoglobulin G / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis; D007377:Interleukin-3 / Q000096:biosynthesis / Q000502:physiology*; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains / Q000235:genetics / Q000276:immunology*
D007106:Immune Sera; D007074:Immunoglobulin G; D007376:Interleukin-2; D007377:Interleukin-3