A Th2 chemokine, TARC, produced by trophoblasts and endometrial gland cells, regulates the infiltration of CCR4+ T lymphocytes into human decidua at early pregnancy.

Problem: A chemokine receptor, CCR4 preferentially expressed on type 2 helper T (Th2-type) cells, and its ligand, thymus and activation regulated chemokine--(TARC/CCL)--play important roles in the recruitment of Th2-type cells. We examined the distribution of CCR4 expressing CD4+ and CD8+-T cells in human decidua at early pregnancy, and localized TARC in the decidual tissue and chorionic tissue.

Method Of Study: Decidual tissue was obtained by legal abortion.

Prostaglandin D2 and reproduction.

This review highlights recent studies investigating the role of prostaglandin (PG)D2 in reproduction. PGD2 induces sleep, allergic responses, inhibition of platelet aggregation, and relaxation of vascular and non-vascular smooth muscle, and has some roles in reproduction. Two types of PGD2 synthase are known.

Interleukin 2 receptor gamma chain (gamma(c)) knockout mice show less regularity in estrous cycle but achieve normal pregnancy without fetal compromise.

Problem: Implication of cytokines in pregnancy suggested but remains to be established. We studied the effect of cytokines on reproductive functions such as ovulation and pregnancy, with mutant mice lacking interleukin 2 receptor gamma (IL-2Rgamma), the so-called common gamma chain (gamma(c)), which is shared among receptors for multiple cytokines such as IL-2, IL-4, IL-7, IL-9 and IL-15.

Method Of Study: Regularities of estrous cycles were observed by vaginal smear.

Distributions of endometrial NK cells, B cells, T cells, and Th2/Tc2 cells fail to predict pregnancy outcome following recurrent abortion.

Problem: To evaluate the ability of immunophenotypes of endometrial leukocytes from patients with histories of recurrent abortion to predict outcome of subsequent pregnancy.

Methods Of Study: Seventeen women with two successive spontaneous abortions with normal karyotype in the conceptus and 15 women with male-factor infertility were studied. Subsequent pregnancy outcomes in 17 recurrent abortion patients were noted; 11 had live birth, while six aborted in the first trimester.

Accumulation of CRTH2-positive T-helper 2 and T-cytotoxic 2 cells at implantation sites of human decidua in a prostaglandin D(2)-mediated manner.

T-helper (Th) 2-type cytokines predominate in decidua, plausibly accounting for protection of a semiallograft, the embryo and placenta, from attack by the maternal immune system. However, localization of Th2 and T-cytotoxic (Tc) 2 cells in decidua has not been reported, presumably because of the difficulty in detecting intracellular cytokines in tissues. Here, by staining tissues for a novel surface maker of Th2/Tc2, the chemoattractant receptor-homologous molecule CRTH2, which is expressed on Th2 cells, we show that CRTH2(+) Th2 cells and CRTH2(+) Tc2 cells are significantly increased at the materno-fetal interface (implantation site) in decidua.