REGULATION OF CULTURED HUMAN CHORION CELL CHEMOKINE PRODUCTION BY GROUP-B STREPTOCOCCI AND PURIFIED BACTERIAL PRODUCTS

PROBLEM: To determine if different strains of group B streptococci (GB S) and purified bacterial products regulate chemokine production by cu ltured human chorion cells. METHOD OF STUDY: Primary cultures of human chorion cells were established from placentae isolated from normal wo men at term gestation having repeat cesarean section. Five different s trains of heat-killed GBS were incubated with confluent chorion cells at 10(7) bac teria/ml for 16 hours at 37 degrees C. In separate experi ments, lipoteichoic acid and sialic acid at various concentrations wer e incubated with chorion cells for 16 hours at 37 degrees C. Culture s upernatants were collected and then assayed to determine concentration s of interleukin-8 (IL-8) and macrophage inflammatory protein-1 alpha (MIP-1 alpha) by ELISA. RESULTS: We found that GBS stimulated chorion cell production of MIP-1 alpha in a strain-specific fashion. We also f ound that both lipoteichoic acid and sialic acid stimulated concentrat ion-dependent increases in chorion cell IL-8 production. Chorion cells , however, did not increase MIP-1 alpha production in response to eith er lipoteichoic acid or sialic acid. Two strains of GBS tested induced concentration-dependent increases in both IL-8 and MIP-1 alpha, but b oth stimulated IL-8 production to a greater extent. Similarly, IL-1 be ta also caused chorion cells to produce more IL-8 than MIP-1 alpha. CO NCLUSIONS: Our data are the first to show that CBS and purified bacter ial products can stimulate chemokine production by fetal gestational t issues. We suggest that chorion cells may produce specific types of ch emokines to attract different types of inflammatory cells and thus may participate in the pathophysiology of infection-mediated preterm labo r by directing specific inflammatory responses.