Existence of both IL-1 alpha and beta in normal human amniotic fluid: unique high molecular weight form of IL-1 beta.
We investigated the possible existence of IL-1 in human amniotic fluid (AF). Since AF from most full-term deliveries appeared to contain an inhibitor(s) for thymocyte proliferation, AFs were fractionated by gel filtration prior to IL-1 assay. IL-1 activities eluted in two peaks at positions of 90,000-60,000 MW and 20,000-15,000 MW. Growth inhibitory activity eluted at the position of 70,000-50,000 MW, and its effect appeared to be non-specific because these fractions inhibited the growth of various cell lines. Using isoelectric focusing (IEF) techniques, pI values of 6.8-7.3 for the higher MW IL-1 as well as 4.9-5.5 and 6.7-7.0 for the lower MW IL-1 were obtained. Antibody against human IL-1 alpha partially neutralized the activity of the lower MW IL-1, though it exhibited little effect on the higher MW IL-1. In contrast, antibody against human IL-1 beta almost completely neutralized the activity of the higher MW IL-1 and partially neutralized the activity of the lower MW IL-1. These results suggest that most of the higher MW IL-1 is beta-type, and the lower MW IL-1 is a mixture of alpha and beta-types. IL-1 beta appeared to exist as a complex (combined with AF components) or as an aggregate of the lower MW IL-1 forms. These findings indicate that both IL-1 alpha and IL-1 beta are present in normal human AF from full-term deliveries, though IL-1 beta exists as a higher MW form aggregated with an unknown molecule.
Tamatani
T
T
Department of Microbiology, University of Tsukuba, Ibaraki, Japan.
Tsunoda
H
H
Iwasaki
H
H
Kaneko
M
M
Hashimoto
T
T
Onozaki
K
K
D000653:Amniotic Fluid / Q000276:immunology*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis* / Q000276:immunology; D007526:Isoelectric Point; D008213:Lymphocyte Activation; D008970:Molecular Weight; D011247:Pregnancy; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology
D007375:Interleukin-1