EXPRESSION OF CYTOKINE RECEPTORS IN THE PLACENTA IN TERM AND PRETERM LABOR

Elevated uterine concentrations of interleukin-1 beta (IL-1 beta), int erleukin-6 (IL-6) and tumour-necrosis factor-alpha (TNF-alpha) are sus pected to cause increased prostaglandin release from gestational tissu es, out little information is available about the expression pattern o f cytokine receptors in these tissues. In this study, cytokine recepto r positive cells in frozen tissue sections of placentae (n=70) and fet al membranes (n=50) were identified by immunohistological staining wit h monoclonal antibodies specific for IL-6 receptor, TNF receptors I an d II, and IL-1 receptor I. Both subunits of the IL-6 receptor (gp130 a nd gp80) as well as TNF receptors I and II were expressed by fetal end othelial cells within placental villi, while IL-l-receptor I was detec ted exclusively in stromal cells of the maternal decidua. The IL-1 rec eptor I and TNF receptors I and II were expressed in both uterine quie sence and labour, irrespective of gestational age. Immunoreactivity of the gp130 subunit of the IL-6 receptor was found also throughout preg nancy, while the appearence of the gp80 subunit correlated with the pr esence of term and preterm labour. In case of preterm labour, expressi on of the gp80 subunit was predominantly detected in the absence of in trauterine infection. Therefore, it is concluded that the de novo expr ession of the gp80 subunit and consequently the appearance of entire I L-6 receptors in the placenta is associated with spontaneously occurri ng labour at term and also with preterm occurring labour in the absenc e of inrauterine infection. (C) 1998 W. B. Saunders Company Ltd.