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

Abstract

The molecular backgrounds of the anti-phospholipid syndrome and immunisation against the Rhesus proteolipid antigens are still largely unknown. In the present study, expression of (1) CD1, a major histocompatibility complex class l-like lipid antigen presenting molecule, (2) IL-10, a cytokine promoting induction of clonal anergy, and (3) CD80 and CD86, two T-cell costimulators preventing induction of clonal anergy when present, was investigated in frozen sections of cervix, corpus and the fallopian tube (FT) of 25-day-old BALB/c mice injected with FSH, progesterone or medium and of pregnant mice from each trimester (days 7, 14 and 19). CD1 was expressed by all endometrial epithelial cells. Enhanced immunostaining of the endometrial epithelial cells was observed after FSH treatment, and cervix and FT expressed generally more than the corpus of the uterus. After treatment with medroxy progesterone 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 treatment increased the intensity of the IL-10 immunofluorescence. There were also 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 present study demonstrates definite differences in the expression of both CD1 and IL-10 between the FSH and MPA treated mice, suggesting differences during the oestrous cycle. As IL-10 is expressed more in the secretory phase, it is probably involved in making the endometrium more acceptable for implantation by inducing clonal anergy. This is supported by the absence of CD80 and CD86. These results also suggest that abnormal expression of CD1d during pregnancy may predispose the mother for immunisation against lipid antigens such as membrane phospholipids and Rhesus-antigens.