Objective: Our goal was to evaluate the effect of group B streptococci on cytokine and prostaglandin production by amnion cells in vitro.
Study design: Amnion cells from placentas obtained immediately after primary cesarean section were incubated for 48 hours with heat-inactivated group B streptococci at increasing concentrations. Samples for quantification of interleukin-1 beta, interleukin-6, interleukin-8, tumor necrosis factor-alpha, and prostaglandin E2 were collected at 6, 12, 24, and 48 hours.
Results: Basal cytokine production was not demonstrable for any of the cytokines investigated. Incubation of amnion cells with bacterial antigen led to a significant increase in interleukin-6 and interleukin-8 production, whereas secretion of interleukin-1 beta and tumor necrosis factor-alpha was not enhanced. In contrast to cytokines, basal prostaglandin E2 production was measurable but failed to increase after addition of antigen.
Conclusion: Amnion cells can be stimulated to secrete interleukin-6 and interleukin-8 in response to streptococcal antigen. However, this rise in cytokines does not induce an increase in prostaglandin E2. This may be explained by the lack of interleukin-1 and tumor necrosis factor-alpha production, two cytokines that have been shown to activate prostaglandin E2 secretion by amnion cells.