PGI2 as a regulator of CD4+ subset differentiation and function.

Prostaglandin (PG)I(2) has important regulatory functions on the innate and adaptive immune systems. Recent experimental evidence reveals that PGI(2) modulates the development and function of CD4+ T cells subsets, including Th1, Th2, and Th17 cell responses. In vitro and in vivo studies support that PGI(2) generally has an inhibitory effect on Th1 and Th2 activation, differentiation, and cytokine production. In contrast, PGI(2) seems to enhance Th17-favoring polarization conditions, resulting in Th17 cytokine production. Therefore, PGI(2) may either promote or inhibit individual CD4+ cell subsets and impact adaptive immune responses.