Expression of antigens involved in the presentation of lipid antigens and induction of clonal anergy in the female reproductive tract

The molecular backgrounds of the anti-phospholipid syndrome and immunisatio n against the Rhesus proteolipid antigens are still largely unknown. In the present study, expression of (1) CD1, a major histocompatibility complex c lass 1-like lipid antigen presenting molecule, (2) IL-10, a cytokine promot ing induction of clonal anergy, and (3) CD80 and CD86, two T-cell costimula tors preventing induction of clonal anergy when present, was investigated i n frozen sections of cervix, corpus and the fallopian tube (FT) of 25-day-o ld BALB/c mice injected with FSH, progesterone or medium and of pregnant mi ce from each trimester (days 7, 14 and 19). CD1 was expressed by all endome trial epithelial cells. Enhanced immunostaining of the endometrial epitheli al cells was observed after FSH treatment, and cervix and FT expressed gene rally more than the corpus of the uterus. After treatment with medroxy prog esterone acetate (MPA), expression of CD1 by the endometrial epithelia was weak. During pregnancy CD1 was absent from the endometrium adjacent to the foetus, but was unaltered in the cervix and FT. IL-10 was expressed by the endometrial glands and also by the endometrial surface epithelium. MPA trea tment increased the intensity of the IL-10 immunofluorescence. There were a lso chains of positive cells between the muscle bundles within the pregnant myometrium. CD80 and CD86 were usually absent from the female reproductive tract, but were occasionally found in the cervix during pregnancy. The pre sent study demonstrates definite differences in the expression of both CD1 and IL-10 between the FSH and MPA treated mice, suggesting differences duri ng the oestrous cycle. As IL-10 is expressed more in the secretory phase, i t is probably involved in making the endometrium more acceptable for implan tation by inducing clonal anergy. This is supported by the absence of CD80 and CD86. These results also suggest that abnormal expression of CD1d durin g pregnancy may predispose the mother for immunisation against lipid antige ns such as membrane phospholipids and Rhesus-antigens. (C) 2000 Elsevier Sc ience Ireland Ltd. All rights reserved.