Impact of regulatory T cell therapy on immune cell composition and fetal survival rate in abortion prone mice.

CONTEXT: Implantation of fertilised eggs and survival of a semi-allogenic embryo rely on the interactions between the cells and molecules preparing the uterus. We investigated the effect of regulatory T cell (Treg) therapy on the mechanism of local immune tolerance of mice prone to spontaneous abortion. METHODS: Naive T cells were stimulated in vitro with 17ß-oestradiol (E2), progesterone (P4) and TGF-ß1 for 96h to generate induced Tregs (iTreg). The iTregs were injected into DBA/2-mated pregnant CBA/J female mice (abortion prone model). On day 14 of pregnancy, mice were killed and decidual and placental tissues were collected for cellular composition analysis. RESULTS: Abortion prone mice (PBS treated) showed significantly lower survival rates (P <0.0001), increased CD3+ CD8+ (P <0.05), lower IDO+ (P <0.05) and increased natural killer cells (uNK) cell numbers (P <0.001) in the uterus, as well increased NK cells in the placenta (P <0.05) than in normal pregnant mice (CBA/J×BALB/c). Adoptive transfer of iTregs increased fetal survival in abortion-prone mice (P <0.01) and histopathological evaluation revealed a significantly decreased number of uNK cells in the uterus of TGF-ß1-, E2- and P4-iTregs (P<0.05, P<0.0001 and P<0.05, respectively) than in the PBS treated group. In the placenta, we found significantly lower numbers of uNK cells from TGF-ß1-, E2- and P4-iTregs than in the PBS treated group (P <0.05, P <0.05 and P <0.01, respectively). CONCLUSIONS: We propose that modulation of uterine NK cell activity through immunotherapy using Treg cells should be given more attention as an immunological strategy in the treatment of recurrent miscarriage.

Adoptive cell therapy with induced regulatory T cells normalises the abortion rate in abortion-prone mice.

Ovarian hormones drive invivo generation of regulatory T cells (Tregs) during pregnancy. Little is known about the therapeutic potential of invitro hormone-derived Tregs in pregnancy loss. We investigated the effects of hormone-induced Tregs in a murine model of abortion. CD4+CD25- T cells were isolated from the spleens of CBA/J mice and stimulated with either 17ß-oestradiol (E2), progesterone (P4) or transforming growth factor-ß1 (TGFB1) plus retinoic acid (RA) for 4 days to generate induced Tregs (iTregs). On Days 1-4 of gestation, DBA/2-mated pregnant CBA/J female mice (abortion prone) were injected intravenously with iTregs or Tregs isolated from normal BALB/c-mated pregnant CBA/J mice (np-Tregs). On Day 14, the number of resorbed fetuses was assessed. Serum interferon (IFN)-γ and uterine forkhead box p3 (Foxp3) expression was analysed by ELISA and immunohistochemistry respectively. Using a 3H-thymidine incorporation assay, isolated CD4+CD25+ Tregs induced by the different treatments suppressed the proliferation of CD4+CD25- T cells. Adoptive transfer of iTregs (from all induction groups) significantly decreased fetal resorption in abortion-prone mice. There were no significant changes in serum IFN-γ concentrations after the adoptive transfer of iTregs or np-Tregs. Immunohistochemistry revealed significantly higher Foxp3 expression in gravid uteri from mice injected with np-Tregs and P4-induced iTregs than in the phosphate-buffered saline-treated group. The findings of this study indicate a potential therapeutic benefit of invitro-induced Tregs in patients with recurrent abortion.

Solvent removal of beryllium from surfaces of equipment made of beryllium copper.

Exposure to beryllium compounds, both by inhalation and skin contact, may result in immune sensitization and chronic beryllium disease. The objective of the present research work was to study the feasibility of removing beryllium compounds from the surfaces of devices made of Be-Cu alloy and to estimate the frequency at which the surfaces had to be rubbed in order to evaluate the likelihood that beryllium can be removed from the surfaces by serial wipe sampling at concentrations exceeding the US Department of Energy (DOE) standard limit of 0.2 microg per 100 cm2. The standard limit was exceeded after successive cleanings of moulds and plates made of Be-Cu alloy with solvents such Citranox, an acidic solvent, Alconox, Z-99 and Fantastik, basic solvents, or more neutral solvents such as Luminox and water. Citranox was the best solvent for extracting beryllium from the tested surfaces, while Alconox seemed to be the second best one. In general, warm water, Luminox and Z-99 seemed to be less efficient for extracting Be from all equipment. The results of the present study suggest that Ghost Wipes, when passed across a surface under the firm pressure of an individual's hand, can be used to detect beryllium contamination. However, they seem to show low reliability for quantification. From a safety standpoint in occupational settings, workers should be offered skin protection and respiratory protection if they have to handle devices made of Be-Cu alloy.