Relaxin favors the development of activated human T cells into Th1-like effectors

Differentiation of naive CD4(+) helper T (Th) cells into Th1 or Th2 effecte rs, as characterized by their opposite pattern of cytokine production, can be influenced by several factors, including hormones. In this study, we dem onstrate that porcine relaxin, at concentrations ranging from 10(-10) to 10 (-6) M, favors the in vitro development of human antigen-specific T cells i nto Th1 like effecters and enhances both IFN-gamma mRNA expression and IFN- gamma production by established human T cell clones. The promoting effect o f relaxin on the development of IFN-gamma producing cells was not due to a relaxin-induced release of IL-12 and/or IFN-alpha by antigen-presenting cel ls. These results suggest that relaxin may contribute to the regulation of the immune homeostasis during pregnancy ana may also play some role in coun teracting Th2-dominated disorders.