Pregnancy associated hormones modulate the cytokine production but not the phenotype of PBMC-derived human dendritic cells.

OBJECTIVE: Dendritic cells (DC) play a central role in initiating and polarizing immune responses. As effects of pregnancy associated hormones on phenotype and function of DC are unknown, our objective was to test the influence of progesterone, beta-estradiol and betaHCG on immature (iDC) and mature (mDC) DC. STUDY
DESIGN: DC generated from peripheral-blood-monocytes were exposed to different doses of hormones. DC phenotype was determined by FACS-analysis of surface marker expression (CD40, CD86, CD83 and HLA-DR). Modifications in the secretion of cytokines (IL12p70, IL-18, IL-10, IL-6, TNFalpha) and chemokines (MDC, IL-8) were analysed by ELISA. T cell stimulatory capacity of mDC was assessed by mixed lymphocyte reaction.
RESULTS: Incubation with progesterone or estradiol resulted in a significant upregulation of IL-10 production by iDC and mDC. Combinations of progesterone and betaHCG or estradiol respectively induced a significant decrease in production of IL-18 by mDC. No significant changes could be observed in surface marker expression or T cell stimulatory capacity, neither in cultures of DC matured under influence of progesterone, estradiol nor betaHCG.
CONCLUSIONS: PBMC-derived DC seem to be relatively stable against the influence of pregnancy associated hormones apart from particular effects on cytokine production which partly could contribute to the modification of immune responses observed in normal early pregnancy.