Open AccessThe immunomodulatory activity of human amniotic fluid can be correlated with transforming growth factor‐beta 1 (TGF‐β1) and β2 activity
Author(s) -
LANG A. K.,
SEARLE R. F.
Publication year - 1994
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1994.tb06595.x
Subject(s) - phytohaemagglutinin , antibody , peripheral blood mononuclear cell , transforming growth factor beta , beta (programming language) , growth inhibition , tgf beta signaling pathway , amniotic fluid , medicine , immunology , transforming growth factor , endocrinology , cell growth , andrology , chemistry , biology , fetus , pregnancy , stimulation , in vitro , biochemistry , genetics , computer science , programming language
SUMMARY The role of alphafetoprotein (AFP) in the immunomodulatory activity of amniotic fluids (AE) from normally progressing human pregnancy (weeks 14–16) was investigated. A panel or42 AF (25% v/v) reduced significantly phytohaemagglutinin (PHA)‐induced peripheral blood mononuclear cell (PBMC) proliferation in serum‐free cultures with a mean per cent inhibition of 68·4 ± 5·5%. In contrast, AEP preparations, with one exception (U.AFP), failed to display inhibitory activity. Pretreatment of AF with anti‐TGF‐β1 and β2 antibodies used alone resulted in the mean per cent loss of inhibition of 33·1 ± 3·9% and 52·3 ± 7·5%, respectively. A summative loss of AF‐mediated inhibition was detected when anti‐TGF‐β1 and β2 antibodies were used in combination, but immunomodulation was rarely abolished 100% by this treatment. Anti‐TGE‐β2 antibody treatment, unlike anti‐TGF‐β1 antibody treatment, reversed the inhibitory activity of U.AFP. The amount of TGF‐β1 and β2 contained in human AF was studied by growth inhibition of Mv1 Lu cells. The mean levels of TGF‐β1 and β2 in AF were 11 ± 0·9 U/ml and 2·3 ± 0·4 U/mI, respectively, which corresponds with a mean per cent inhibition of 49 ±4·7%. U.AFP also significantly inhibited Mv1 Lu cell growth. To investigate the mechanism of AF‐mediated inhibition, the effect of AF and AEP on IL‐2 production by concanavalin A (Con A)‐stimulated PBMC blasts was determined by the CTLL‐2 cell bioassay. IL‐2 production was reduced 55·5% in AF‐treated blasts and 61% in U.AEP‐treated blasts compared with controls. Our findings indicate that the immunomodulatory activity of human AF can be correlated with TGE‐β1 and β2 and not with AFP, the inhibitory activity of U.AFP preparation reflecting copurifying TGF‐β2 activity.