Effects of human anti-IL-1 alpha autoantibodies on receptor binding and biological activities of IL-1.
Immunoglobulin G (IgG) antibodies to interleukin 1 alpha (IL-1 alpha) are frequently found in the sera of healthy human individuals. The effects of these autoantibodies on receptor binding and biological activities of human IL-1 were tested. Using the murine T-lymphocyte line NOB-1, human thyrocytes and human foreskin fibroblasts, the antibodies competitively inhibited the biological activity of human recombinant IL-1 alpha (rIL-1 alpha). The degree of inhibition correlated with 125I-rIL-1 alpha binding to IgG in different immunoglobulin preparations and in individual sera. These antibodies also neutralized the IL-1 activity of isolated membrane fragments and lysates of human blood monocytes activated by lipopolysaccharide. In contrast, the supernatant IL-1 activity was not affected. Stronger inhibition of biological activity and cell binding of 125I-rIL-1 alpha was obtained with NOB-1 cells than with human thyrocytes. The antibodies failed to interfere with the biological activity of rIL-1 beta. It is concluded that IgG autoantibodies of IL-1 alpha in the sera of healthy humans selectively inhibit the biological activity of the soluble and membrane-associated forms of IL-1 alpha in vitro, and that the degree of biological inhibition afforded by these antibodies depends upon the target cell.
Svenson
M
M
Department of Medicine TTA, Diseases M, Rigshopitalet University Hospital, Copenhagen, Denmark.
Hansen
M B
MB
Kayser
L
L
Rasmussen
A K
AK
Reimert
C M
CM
Bendtzen
K
K
D000818:Animals; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D005347:Fibroblasts / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D007375:Interleukin-1 / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology*; D007457:Iodine Radioisotopes; D008221:Lymphoid Tissue / Q000737:chemistry / Q000166:cytology; D051379:Mice; D011971:Receptors, Immunologic / Q000378:metabolism*; D017472:Receptors, Interleukin-1; D013961:Thyroid Gland / Q000737:chemistry / Q000166:cytology
D001323:Autoantibodies; D007375:Interleukin-1; D007457:Iodine Radioisotopes; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1