Akemi Ushijima

Paternal antigen-specific proliferating regulatory T cells are increased in uterine-draining lymph nodes just before implantation and in pregnant uterus just after implantation by seminal plasma-priming in allogeneic mouse pregnancy

Paternal antigen-specific regulatory T (PA-specific Treg) cells play an important role in feto-maternal tolerance. To detect the PA-specific Tregs, female BALB/c mice were mated with male DBA/2 mice. Mls Ia antigen on DBA/2 mice is recognized by the T-cell receptor Vβ6; thus, CD4(+)Foxp3(+)Vβ6(+) cells are recognized as PA-specific Treg cells. CD4(+)CD25(+)Vβ6(+) cells effectively suppressed the allo-reactive proliferation of lymphocytes compared with that of CD4(+)CD25(+)Vβ6(-) cells. Vβ6(+) PA-specific Treg cells expressed CCR4 and CCR5 on their surface. The frequency of Ki67(+) PA-specific Treg cells among Treg cells was significantly increased in draining lymph nodes on day 3.5 post-coitus (pc; 6.8±1.1%, p<0.05) and day 5.5 pc (7.2±1.1%, p<0.05) in allogeneic pregnant mice compared with that in nonpregnant mice (2.7±0.2%). The frequency of Ki67(+) PA-specific Treg cells in the uterus increased significantly after day 5.5 pc in allogeneic pregnant mice compared with that in nonpregnant mice (8.8±2.8% vs. 1.2±1.3%, p<0.05). However, Ki67(-)PA-specific Tregs did not change during pregnancy. To analyze the role of seminal fluid or sperm in Treg expansion, female BALB/c mice were mated with vasectomized DBA/2 male mice (VAS) or seminal vesicle-excised DBA/2 male mice (SVX). The frequency of Ki67(+) PA-specific Treg cells did not increase in draining lymph nodes or uterus in BALB/c×DBA/2 (SVX) allogeneic mating mice. These findings suggest that the priming by seminal fluid is important for the induction of proliferating PA-specific Tregs in uterine-draining lymph nodes just before implantation and pregnant uterus after implantation, resulting in successful implantation and the maintenance of allogeneic pregnancy.

Helios-positive functional regulatory T cells are decreased in decidua of miscarriage cases with normal fetal chromosomal content

Regulatory (Treg) T cells play essential roles in the maintenance of allogeneic pregnancy in mice and humans. Recent data show that Foxp3 expression occurs in both immuno-suppressive Treg and -nonsuppressive effector T (Teff) cells upon activation in humans. Samstein et al. (2012) reported that inducible Treg (iTreg) cells enforce maternal-fetal tolerance in placental mammals. Therefore, we should reanalyze which types of Treg cell play an important role in the maintenance of allogeneic pregnancy. In this study, we studied the frequencies of naïve Treg cells, effector Treg cells, Foxp3(+) Teff cells, Helios(+) naturally occurring Treg (nTreg) cells, and Helios(-) iTreg cells using flow cytometry. The frequencies of effector Treg cells and Foxp3(+) Teff cells among CD4(+)Foxp3(+) cells in the decidua of miscarriage cases with a normal embryo karyotype (n=8) were significantly lower (P=0.0105) and significantly higher (P=0.0258) than those in normally progressing pregnancies (n=11), respectively. However, these frequencies in miscarriages with an abnormal embryo karyotype (n=15) were similar to those in normally progressing pregnancies. The frequencies of these cell populations in the three groups were unchanged in peripheral blood; on the other hand, most of the effector Treg cells in the decidua were Helios(+) nTreg cells and these frequencies were significantly higher than those in peripheral blood, while those among effector Treg and naïve Treg cells in the decidua and peripheral blood were similar among the three groups. These data suggest that decreased Helios(+) effector nTreg might play an important role in the maintenance of pregnancy in humans.

Alpha-7 nicotinic acetylcholine receptor (nAChR) agonist inhibits the development of endometriosis by regulating inflammation

We investigated α‐7 nAchR expression in human peritoneal macrophages and examined whether activation of nAchR might be a new therapy for endometriosis.

Clonally Expanded Decidual Effector Regulatory T Cells Increase in Late Gestation of Normal Pregnancy, but Not in Preeclampsia, in Humans

Background: Regulatory T (Treg) cells are necessary for the maintenance of allogenic pregnancy. However, the repertoire of effector Treg cells at the feto-maternal interface in human pregnancy remains unknown. Our objective was to study T cell receptor (TCR) repertoires of Treg cells during pregnancy compared to normal and complicated pregnancies. Methods:Paired samples of peripheral blood and decidua in induced abortion and miscarriage cases were obtained from consenting patients. CD4+CD25+CD127low/−CD45RA− effector Treg cells were single-cell sorted from mononuclear cells. cDNAs of complementarity determining region 3 (CDR3) in TCRβ were amplified from the single cells by RT-PCR and the sequences were analyzed. The TCRβ repertoires were determined by amino acid and nucleotide sequences. Treg cells were classified into clonally expanded and non-expanded populations by CDR3 sequences. Results: We enrolled nine induced abortion cases in the 1st trimester, 12 cases delivered without complications in the 3rd trimester, 11 miscarriages with abnormal chromosomal karyotyped embryo, seven miscarriages with normal chromosomal karyotyped embryo, and seven cases of preeclampsia [median gestational week (interquartile range): 7 (7–9), 39 (38–40), 9 (8–10), 8 (8–10), and 34 (32–37), respectively]. The frequency of clonally expanded populations of effector Treg cells increased in decidua of 3rd trimester cases compared to 1st trimester cases [4.5% (1.4–10.8%) vs. 20.9% (15.4–28.1%), p < 0.001]. Clonally expanded Treg cells were rarely seen in peripheral blood. The ratio of clonally expanded populations of decidual effector Treg cells in miscarriages with abnormal and normal embryos was not significantly different compared with that in 1st trimester normal pregnancy. Interestingly, clonally expanded populations of effector Treg cells decreased in preeclampsia compared with that in 3rd trimester normal pregnancy [9.3% (4.4–14.5%) vs. 20.9% (15.4–28.1%), p = 0.003]. When repertoires in previous pregnancy and subsequent pregnancy were compared, some portions of the repertoire were shared. Conclusion: TCR repertoires of decidual effector Treg cells are skewed in the 3rd trimester of normal pregnancy. Failure of clonal expansion of populations of decidual effector Treg cells might be related to the development of preeclampsia.

PAI‐1 in granulosa cells is suppressed directly by statin and indirectly by suppressing TGF‐β and TNF‐α in mononuclear cells by insulin‐sensitizing drugs

Plasminogen activator inhibitor‐1 (PAI‐1) is elevated in women with polycystic ovary syndrome (PCOS), but the regulation in granulosa cells (GCs) is unclear.