Cytochrome P450 26A1 regulates the clusters and killing activity of NK cells during the peri-implantation period.

Cytochrome P450 26A1 (CYP26A1) plays a vital role in early pregnancy in mice. Our previous studies have found that CYP26A1 affects embryo implantation by modulating natural killer (NK) cells, and that there is a novel population of CYP26A1+ NK cells in the uteri of pregnant mice. The aim of this study was to investigate the effects of CYP26A1 on the subsets and killing activity of NK cells. Through single-cell RNA sequencing (scRNA-seq), we identified four NK cell subsets in the uterus, namely, conventional NK (cNK), tissue-resident NK (trNK) 1 and 2, and proliferating trNK (trNKp). The two most variable subpopulations after uterine knockdown of CYP26A1 were trNKp and trNK2 cells. CYP26A1 knockdown significantly downregulated the expression of the NK cell function-related genes Cd44, Cd160, Vegfc, and Slamf6 in trNK2 cells, and Klra17 and Ogn in trNKp cells. Both RNA-seq and cytotoxicity assays confirmed that CYP26A1+ NK cells had low cytotoxicity. These results indicate that CYP26A1 may affect the immune microenvironment at the maternal-foetal interface by regulating the activity of NK cells.

A novel Cytochrome P450 26A1 expressing NK cell subset at the mouse maternal-foetal interface.

Cyp26a1 had important roles in mouse embryo implantation and was highly expressed in some of NK cells at the human maternal-foetal interface in early pregnancy. However, the regulatory effect of Cyp26a1 on NK cells remains poorly understood. Through qPCR and flow cytometric assays, we found that Cyp26a1 was expressed by mouse uterine NK cells but not spleen NK cells during the peri-implantation period and there was a group of NK cells that highly expressed Cyp26a1, that is Cyp26a1+ NK cell subset. single cell-population transcriptome sequencing on Cyp26a1+ NK and Cyp26a1- NK cell subsets was performed. We found that there were 3957 differentially expressed genes in the Cyp26a1+ NK cell subset with a cut-off of fold change ≥2 and FDR < 0.01, 2509 genes were up-regulated and 1448 genes were down-regulated in Cyp26a1+ NK cell subset. Moreover, cytokine-cytokine receptor interaction signalling pathway and natural killer cell-mediated cytotoxicity signalling pathway were enriched according to KEGG pathway enrichment analysis. We further found that the expression of Gzma and Klrg1 was significantly increased and Fcgr4 was significantly decreased when inhibiting Cyp26a1. Our experimental results show that there is a novel NK cell subset of Cyp26a1+ NK cells in mouse uterus and Cyp26a1 can regulate the gene expression of Gzma, Klrg1 and Fcgr4 in the Cyp26a1+ NK cells.

Cytochrome P450 26A1 modulates uterine dendritic cells in mice early pregnancy.

Cytochrome P450 26A1 (CYP26A1) plays important roles in the mice peri-implantation period. Inhibiting its expression or function leads to pregnancy failure. However, little is known about the underlying mechanisms involved, especially the relationship between CYP26A1 and immune cells. In this study, using Cyp26a1-specific antisense morpholigos (Cyp26a1-MO) knockdown mice model and pCR3.1-Cyp26a1 vaccine mice model, we found that the number of uterine CD45+ CD11c+ MHCIIlo-hi F4/80- dendritic cells (DCs) was significantly decreased in the treated mice. The percentage of mature DCs (CD86hi ) was obviously lower and the percentage of immature DCs (CD86lo ) was remarkably higher in uterine DCs in the treatment group than that of the control group. Further experiments found that ID2, a transcription factor associated with DCs development, and CD86, a DC mature marker molecule, were both significantly reduced in mice uteri in the treated group. In vitro, ID2 and CD86 also decreased in bone marrow-derived DCs under Cyp26a1-MO treatment. These findings provide novel information that CYP26A1 might affect the embryo implantation via modulating the differentiation and maturation of uterine DCs.

Cytochrome P450 26A1 modulates natural killer cells in mouse early pregnancy.

Cytochrome P450 26A1 (CYP26A1) has a spatiotemporal expression pattern in the uterus, with a significant increase in mRNA and protein levels during peri-implantation. Inhibiting the function or expression of CYP26A1 can cause pregnancy failure, suggesting an important regulatory role of CYP26A1 in the maintenance of pregnancy. However, little is known about the exact mechanism involved. In this study, using a pCR3.1-cyp26a1 plasmid immunization mouse model and a Cyp26a1-MO (Cyp26a1-specific antisense oligos) knockdown mouse model, we report that the number of Dolichos biflorus agglutinin (DBA) lectin-positive uterine natural killer (uNK) cells was reduced in pCR3.1-cyp26a1 plasmid immunized and Cyp26a1-MO-treated mice. In contrast, the percentage of CD3- CD49b+ NK cells in the uteri from the treatment group was significantly higher than that of the control group in both models. Similarly, significantly up-regulated expression of CD49b (a pan-NK cell marker), interferon gamma, CCL2, CCR2 (CCL2 receptor) and CCL3 were detected in the uteri of pCR3.1-cyp26a1- and Cyp26a1-MO-treated mice. Transcriptome analysis suggested that CYP26A1 might regulate NK cells through chemokines. In conclusion, the present data suggest that silencing CYP26A1 expression/function can decrease the number of uNK cells and significantly increase the percentage of CD3- CD49b+ NK cells in the uteri of pregnant mice. These findings provide a new line of evidence correlating the deleterious effects of blocking CYP26A1 in pregnancy with the aberrant regulation of NK cells in the uterus.

Regulation of cyp26a1 on Th17 cells in mouse peri-implantation.

Cytochrome P450 26A1 (cyp26a1) is expressed in the mouse uterus during peri-implantation. The repression of this protein is closely associated with a reduction in implantation sites, suggesting a specific role for cyp26a1 in pregnancy and prompting questions concerning how a metabolic enzyme can generate this distinct outcome. To explore the effective downstream targets of cyp26a1 and confirm if its role in peri-implantation depends on its metabolic substrate RA (retinoic acid), we characterized the changes in the peripheral blood, spleen and uterine implantation sites using the cyp26a1 gene vaccine constructed before. Flow cytometry results showed a significant increase in CD4(+) RORγt(+) Th17 cells in both the peripheral blood and spleen in the experimental group. The expression of RORγt and IL-17 presented the Th17 cells reduction in uterus followed by the suppression of cyp26a1 expression. For greater certainty, cyp26a1 antibody blocking model and RNA interference model were constructed to determine the precise target immune cell group. High performance liquid chromatography results showed a significant increase in uterine at-RA followed by the immunization of cyp26a1 gene vaccine. Both the ascertain by measuring RARα protein levels in peri-implantation uterus after gene vaccine immunization and researches using the specific agonist and antagonist against RARα suggested that RARα may be the main RA receptor for signal transduction. These results provided more evidence for the signal messenger role of RA in cyp26a1 regulation from the other side. Here, we showed that the cyp26a1-regulated Th17 cells are dependent on at-RA signalling, which is delivered through RARα in mouse peri-implantation.

Retinoic acid synthesis and metabolism are concurrent in the mouse uterus during peri-implantation.

Vitamin A (retinol) and its active metabolite, retinoic acid (RA), serve dual roles in the female reproductive tract. Cytochrome P450 26A1 (Cyp26a1), an RA-metabolizing enzyme, is involved in mammalian early pregnancy. In order to investigate the role of RA synthesis and metabolism during embryo implantation, we first investigated the spatiotemporal expression of RA-signal in the mouse uterus during the peri-implantation period. RA-signal-related molecules, including binding proteins, synthesizing enzymes, catabolizing enzymes and receptors, were all expressed in the mouse uterus during embryo implantation. The locations of the RA synthetic system (Aldh1a1, Aldh1a2, CRBP1) and catabolizing enzyme (Cyp26a1) were distinctive in the mouse uterus during the peri-implantation period. Aldh1a1 was located in the gland epithelium, whereas Aldh1a2 and CRBP1 were located in the stroma and Cyp26a1 was expressed in the luminal and glandular epithelium. These results demonstrate that RA synthesis occurs in the stroma, whereas RA metabolism takes place in the endometrial epithelium. When endometrial epithelial cells were isolated on day 4.5 of pregnancy and treated with E(2) (17beta-estradiol) or a combination of E(2) and progesterone, all-trans-RA (10 µM) significantly down-regulated the expression of LIF, HB-EF and CSF-1 in these cells in vitro. Taken together, these results suggest that the accumulation of RA in the stroma during mouse embryo implantation has an inhibitory effect on the expression of the three implantation-essential genes, LIF, HB-EGF and CSF-1. Therefore, the expression of Cyp26a1 in luminal and glandular epithelium might block the adverse effect of RA in order to promote successful embryo implantation.

Cytochrome P450 26A1 Modulates the Polarization of Uterine Macrophages During the Peri-Implantation Period.

Uterine M1/M2 macrophages activation states undergo dynamic changes throughout pregnancy, and inappropriate macrophages polarization can cause adverse pregnancy outcomes, especially during the peri-implantation period. Our previous studies have confirmed that Cytochrome P450 26A1 (CYP26A1) can affect embryo implantation by regulating uterine NK cells and DCs. The aim of this study was to investigate whether CYP26A1 regulates the polarization of uterine macrophages in early pregnancy. Here, we observed that Cyp26a1 was significantly upregulated in M1 as compared with M2 of uterine macrophages, Raw264.7 and iBMDM. Knockdown of CYP26A1 in mice uterine significantly decreased the number of embryo implantation sites and the proportion of CD45+F4/80+CD206 - M1-like uterine macrophages. Primary uterine macrophages treated with anti-CYP26A1 antibody expressed significantly lower levels of M1 markers Nos2, Il1b, Il6 and Tnf-a. In CYP26A1 knockout Raw264.7 cells, the protein levels of M1 markers TNF-α, IL-6 and CD86 were significantly decreased as compared with the wild type cells. Moreover, CYP26A1 deficiency decreased the ability to produce nitric oxide and increased the phagocytosis capacity of Raw264.7 cells under M1 stimulation state. The re-introduction of CYP26A1 partially reversed the polarization levels of M1 in CYP26A1 knockout Raw264.7 cells. CYP26A1 may regulate the polarization of uterine macrophages to M1 through Stap1 and Slc7a2. In summary, these results indicate that CYP26A1 plays a significant role in macrophage polarization, and knockdown of CYP26A1 can cause insufficient M1 polarization during the peri-implantation period, which has adverse effects on blastocyst implantation.

Retinoic acid-metabolizing enzyme cytochrome P450 26a1 (cyp26a1) is essential for implantation: functional study of its role in early pregnancy.

Vitamin A (VA) is required for normal fetal development and successful pregnancy. Excessive VA intake during pregnancy may lead to adverse maternal and fetal effects. Cytochrome P450 26A1 (cyp26a1), a retinoic acid (RA)-metabolizing enzyme, is involved in VA metabolism. It has been shown that cyp26a1 is expressed in female reproductive tract, especially in uterus. In order to investigate the role of cyp26a1 during pregnancy, we constructed a recombinant plasmid DNA vaccine encoding cyp26a1 protein and immunized mice with the plasmid. Compared to control groups, the pregnancy rate of the cyp26a1 plasmid-immunized mice were significantly decreased (P < 0.01). Further results showed that both cyp26a1 mRNA and protein were specifically induced in the uterus during implantation period and localized in the uterine luminal epithelium. Importantly, the number of implantation sites was also significantly reduced (P < 0.05) after the uterine injection of cyp26a1-specific antisense oligos or anti-cyp26a1 antibody on day 3 of pregnancy. Accordingly, the expression of RA-related cellular retinoic acid binding protein 1 and tissue transglutaminase was markedly increased (P < 0.05) in the uterine luminal epithelium after intrauterine injection treatments. These data demonstrate that uterine cyp26a1 activity is important for the maintenance of pregnancy, especially during the process of blastocyst implantation.

Role of secretory protease inhibitor SPINK3 in mouse uterus during early pregnancy.

Successful embryo implantation depends on intricate epithelial-stromal cross-talk. However, molecular modulators involved in this cellular communication remain poorly elucidated. Using multiple approaches, we have investigated the spatiotemporal expression and regulation of serine protease inhibitor Kazal type 3 (SPINK3) in mouse uterus during the estrous cycle and early pregnancy. In cycling mice, both SPINK3 mRNA and protein are only expressed during proestrus. In the pregnant mouse, the expression levels of both SPINK3 mRNA and protein increase on days 5-8 and then decline. Spink3 mRNA is expressed exclusively in the uterine glandular epithelium, whereas SPINK3 protein is localized on the surface of both luminal and glandular epithelium and in the decidua. Moreover, SPINK3 in the decidua has been observed in the primary decidual zone on day 6 and the secondary decidual zone on days 7-8; this is tightly associated with the progression of decidualization. SPINK3 has also been found in decidual cells of the artificially decidualized uterine horn but not control horn, whereas Spink3 mRNA localizes in the glands of both horns. The expression of endometrial Spink3 is not regulated by the blastocyst according to its expression pattern during pseudopregnancy and delayed implantation but is induced by progesterone and further augmented by a combination of progesterone and estrogen in ovariectomized mice. Thus, uterine-gland-derived SPINK3, as a new paracrine modulator, might play an important role in embryo implantation through its influence on stromal decidualization in mice.

Retinoic acid metabolizing enzyme CYP26A1 is implicated in rat embryo implantation.

BACKGROUND: The retinoic acid metabolizing enzyme Cyp26a1 plays a pivotal role in vertebrate embryo development. Cyp26a1 was characterized previously as a differentially expressed gene in peri-implantation rat uteri via suppressive subtracted hybridization analysis. However, the role of Cyp26a1 in rat embryo implantation remained elusive. METHODS: The expression of Cyp26a1 in the uteri of early pregnancy, pseudopregnancy and artificial decidualization was detected by northern blotting, real time-PCR, in situ hybridization, western blotting and immunofluorescent staining. The effect of Cyp26a1 on apoptosis of endometrial stromal cells (ESCs) isolated from rat uteri was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and Hoechst staining. Apoptosis-related proteins in ESCs were detected by western blotting. RESULTS: Cyp26a1 showed distinctive expression patterns in embryos and uteri during the peri-implantation period, with a remarkable increase (P < 0.01 versus Days 4-5) in mRNA and protein in the implantation phase (Days 5.5-6.5 of pregnancy). CYP26A1 was specifically localized in glandular epithelium, luminal epithelium and decidua basalis. The level of CYP26A1 protein was significantly increased in uteri of artificial decidualization (P < 0.01 versus control). Forced Cyp26a1 overexpression significantly reduced the sensitivity of ESCs to etoposide-induced apoptosis, with reductions in p53 (P < 0.01) and Fas (P < 0.05) proteins versus control, while in contrast, FasL (P < 0.01) and proliferating cell nuclear antigen (P < 0.05) proteins increased. CONCLUSIONS: Cyp26a1 is spatiotemporally expressed in the uterus during embryo implantation and decidualization. Overexpression of Cyp26a1 attenuates the process of uterine stromal cell apoptosis, probably via down-regulating the expression of p53 and FasL.

Implantation-associated gene-1 (Iag-1): a novel gene involved in the early process of embryonic implantation in rat.

BACKGROUND: In order to study the novel genes related to rat embryonic implantation, a novel implantation-associated gene, Iag-1, was identified and characterized from rat uterus of early pregnancy. Iag-1 was initially derived from suppressive subtracted hybridization of a cDNA library of rat uterus, which was used to analyse differentially expressed genes between the preimplantation and implantation period. METHODS: The full-length cDNA sequence of Iag-1 was cloned from rat uterus on D5.5 of pregnancy by 5'- and 3'-RACE. The expression of Iag-1 in the uterus of early pregnancy, pseudopregnancy, artificial decidualization and activation of delayed implantation was detected by northern blotting, in situ hybridization, western blotting and immunofluorescence. Endometrial stromal cells (ESCs) were isolated from rat uterus. The effect of Iag-1 on ESCs proliferation and apoptosis were determined by MTT assay, TUNEL and Hoechst staining. Apoptosis-related proteins in ESCs were detected by western blotting. RESULTS: Differential patterns of Iag-1 expression were detected in rat embryo and in the uterus during the peri-implantation period. Iag-1 was specifically localized in glandular epithelium and luminal epithelium. In contrast, the expression of Iag-1 was not significantly altered in uterus of pseudopregnancy and artificial decidualization, but was significantly increased in the uterus after activation of delayed implantation. Stable expression of introduced Iag-1 inhibited the proliferation of in vitro-cultured ESCs. Significant apoptosis was also detected in the ESCs overexpressing Iag-1, along with the enhancement of p53 and Bax protein expression. CONCLUSIONS: Overexpression of Iag-1 can inhibit ESCs proliferation and induce ESCs apoptosis, and p53 and Bax may play an important role in the process of Iag-1-induced apoptosis.

[Progress in tumor cell invasion].

Tumor cell invasion and metastasis are the most complicated problems of cancer medicine and cancer biology, and cancer becomes a fatal disease because of cancer cell invasion and metastasis. The mechanisms of invasion and metastasis remain elusive, but tumor cell invasion still is the hotspot of research. This review summarizes the development of researching in tumor cell invasion.

IFN-gamma promotes apoptosis of the uterus and placenta in pregnant rat and human cytotrophoblast cells.

Growth and development of placentas in all pregnancy periods and that of fetuses in late pregnancy were inhibited after administration of interferon-gamma (IFN-gamma). Apoptosis can be detected by TUNEL at the maternal-fetal interface during normal rat pregnancy. Apoptosis locations at the maternal-fetal interface changed according to the period of pregnancy. The results of immunohistochemistry and the DNA ladder assay showed that IFN-gamma could promote the apoptosis levels during the entire pregnancy, but it did not change the apoptosis locations. IFN regulatory factor-1 (IRF-1), FasL, and p53 expressions were modulated by IFN-gamma during the entire pregnancy. In vitro cell proliferation assay indicated that IFN-gamma could inhibit proliferation of human cytotrophoblast cells, and flow assay showed that this effect was mainly due to apoptosis induction. TUNEL and Hoechst staining also showed that IFN-gamma could induce apoptosis of human cytotrophoblast cells. Expression of IRF-1 was induced and expression of active caspase-3 was promoted by IFN-gamma treatment, but IFN-gamma did not affect the expression of IFNGR and p53.

Apoptosis and tumor inhibition induced by human chorionic gonadotropin beta in mouse breast carcinoma.

For many breast cancer patients, human chorionic gonadotropin beta (hCGbeta), which is a subunit of a hormone produced by the trophoblast and is essential for maintaining pregnancy, is expressed in the breast cancer cells. However, the mechanism as to how the CGbeta in cell affects the cancer development is not very clear. Mouse breast carcinoma 4T1 with stably hCGbeta expression (4T1-hCGbeta) was established and transplanted into the Balb/c mouse abdominal mammary gland. hCGbeta suppressed breast cancer cell viability in vitro, and dramatically inhibited tumor growth and attenuated tumor vessel formation in vivo. An 86-88% reduction in tumor volume in animals injected with breast cancer expressing hCGbeta, as opposed to those injected with breast cancer without hCGbeta expression, was observed. The production of p21 was promoted by hCGbeta, whereas the Cdk2 was decreasing. These indicate that p21 signal pathway is involved in this process. Significant apoptosis was also detected in hCGbeta-expressing breast cancer cells as well as the enhancement of Bax protein expression. Moreover, hCGbeta blocked the blood vessels formation by inhibiting the expression of MMP9 and VEGF. Further hormone secretion analyses show that the anti-tumor activity induced by hCGbeta is not related to the endocrine function.

Effect of interferon-gamma treatment on the expression of interleukin-1beta at the maternal-fetal interface of pregnant rats.

In the present study, the possible mechanisms by which interferon (IFN)-gamma affects pregnancy were investigated using the cytokine network model. The IFN-gamma-induced expression of interleukin (IL)-1beta was examined using western blotting, immunohistochemistry and immunofluorescence. The results showed that IFN-gamma treatment significantly decreased the expression of uterine IL-1beta protein during the preimplantation, post-implantation and mid-gestation periods. The expression of IL-1beta protein was increased after IFN-gamma treatment compared with the control group in late pregnancy. In the placenta, IL-1beta protein levels were significantly increased after IFN-gamma treatment in early and mid-pregnancy. In late pregnancy, IFN-gamma treatment significantly decreased placental IL-1beta protein levels. IL-1beta was mainly expressed in the myometrium, uterine arteries, decidua basalis, trophospongium of the junctional layer and trophoblastic epithelium of the labyrinthine layers. IL-1beta was mainly located in the cytoplasm of in vitro cultured endometrial stromal cells (ESCs). IFN-gamma treatment did not affect the distribution of IL-1beta, only the expression of IL-1beta. The effects of IFN-gamma on the proliferation of ESCs were determined using an MTS (a novel tetrazolium compound) assay. IFN-gamma treatment inhibited the proliferation of ESCs and decreased the weight of the fetus and placenta. These results indicate that exogenous IFN-gamma affects the expression of IL-1beta and inhibits ESC proliferation.

The expression of membrane protein augments the specific responses induced by SARS-CoV nucleocapsid DNA immunization.

Nucleocapsid protein plays a critical role in SARS-CoV pathogenesis, and high-level anti-nucleocapsid antibodies are detected in the patients infected by severe acute respiratory syndrome-associated coronavirus (SARS-CoV). Several studies have shown that there exists an interaction between nucleocapsid (N) and membrane (M) protein. In this paper, we investigate whether the expression of membrane protein can affect the immune responses induced by nucleocapsid DNA immunization. Two recombinant plasmids containing M and N coding sequence were constructed. Moreover, in order to get the antigen for ELISA and in vitro stimulation assay, N protein were expressed and purified from E. coli bacteria. Injection of 20mug of the mixture of pVAX1-M and pVAX1-N into the Balb/c mice could elicit the humoral and cellular responses. The ELISA analysis using the N antigen or inactivated SARS-CoV particles as capture antigen showed that co-injection of SARS-M could enhance N-induced antibody production, especially IgG2a subclass. After lymphocytes were stimulated with 10mug/ml purified N antigen, The CD4+ and CD8+ T cells of N and M plus N group were increased compared with those of control groups, and the M protein could augment the activation of lymphocytes induced by N DNA vaccine. Cytokine ELISA analysis revealed that co-injection of M could enhance the levels of IFN-gamma, IL-2 release induced by N antigen. Further experiments in field mouse also support the claim that membrane protein can augment the N-specific immune responses. Virus challenge test was conducted in BSL3 bio safety laboratory with Brandt's vole SARS-CoV model, and the results indicated that co-immunization of M and N antigens could reduce the mortality and pathological changes in lung from the virus infection.

Effects of IL-1 beta on RT1-A/RT1-DM at the maternal-fetal interface during pregnancy in rats.

Interleukin-1 (IL-1beta) beta and major histocompatibility complex (MHC) play an important role during pregnancy. Expression of non-classical class MHC II RT1-DM antigen and classical class MHC I RT1-A antigen induced by IL-1beta was examined by Northern blotting, Western blotting and immunohistochemistry. IL-1beta treatment significantly increased the expression of RT1-A and RT1-DM in early and mid pregnancy. In late pregnancy, expression of RT1-DM significantly increased in uteri and decreased in placenta. Immunohistochemical studies indicated that, in early pregnancy, RT1-DM protein mainly localized to luminal and glandular uterine epithelium, and RT1-A was present in deciduas basalis, outer layer of luminal epithelium and glandular epithelium. During mid and late pregnancy, RT1-DM was present in maternal blood vessels and syncytiotrophoblast of labyrinthine zone, and RT1-A was present in maternal blood vessels and trophoblastic epithelium of the labyrinthine layers. These findings show that exogenous IL-1beta affects expression of RT1-DM and RT1-A and does not affect the localization of corresponding molecules during pregnancy.

Evaluation of the contraceptive potential of brZPCp vaccine in BALB/c mice: their safety and efficacy.

In this study we have examined the potential ability of Microtus branditi partial ZPC (brZPCp) cDNA sequence (436-1150 nt) as a target for immunocontraception. Immunogenicity studies and fertility trials were performed in BALB/c mice using recombinant construction pCR3.1-brZPC(p). ELISA outcome indicated that antibodies could be generated by immunized mice, and IgG titer was increased compared to the control. Immunohistochemistry outcome indicated that antibodies could recognize native ZP in vivo, which in turn, prevented the binding of sperm to ovulated eggs. Antibodies could also recognize recombinant protein expressed by BL21 in vitro, which was confirmed by SDS-PAGE and Western blot. Fertility rate was reduced by 45% compared to the control immunized with pCR3.1. Meanwhile, there was no incidence of significant ovarian pathology in treated mice. This experiment indicates that this vaccine can elicit the specific antibody which binds exactly to the corresponding ZPC. This construction is proved to be immunogenic, and can reduce fertility without obvious oophoritis. The result in this study suggests a potentially important method for controlling population for its safety and easy production.

The Balance between Conventional DCs and Plasmacytoid DCs Is Pivotal for Immunological Tolerance during Pregnancy in the Mouse.

Dendritic cells (DCs), which can shape their functions depending on the microenvironment, are crucial for the delicate balance of immunity and tolerance during pregnancy. However, the mechanism underlying the microenvironment-educated plasticity of DC differentiation during pregnancy remains largely unclear. Here, we found that the differentiation of conventional DCs (cDCs) and plasmacytoid DCs (pDCs) is regulated in a tissue-specific manner during pregnancy. The ratio of cDCs and pDCs remained constant in the spleen. However, the ratio changed in the para-aortic lymph nodes (LNs), where cDC percentages were significantly reduced concurrent with an increase in pDCs from E8.5 to E16.5. Moreover, the expansion of pDCs and T regulatory (Treg) cells was correlated in the para-aortic LNs, and pDCs had more potential to induce regulatory T cells (Tregs) compared with cDCs (independent of IDO expression). Notably, the balance between cDCs and pDCs is disrupted in IFN-γ-induced abnormal pregnancy, accompanied by lower Treg percentages in the para-aortic LNs and decidua. To further identify the underlying mechanism, we found that elevated IFN-γ can increase the levels of GM-CSF to alter the differentiation of pDCs into cDCs in vivo. Therefore, we provide a novel regulatory mechanism underlying pregnancy-related immune tolerance that involves the balance of DC subsets, which may offer a new target for the prevention of human spontaneous abortion.

Seminal plasma induces inflammation in the uterus through the γδ T/IL-17 pathway.

After insemination, a large number of leukocytes migrate into the uterus, which is accompanied by intense inflammation. However, the details of how seminal plasma interacts with the uterus are still not very clear. Here, we present that neutrophils migrate and accumulate around the uterine epithelium following insemination, which is accompanied by an increase in interleukin (IL) 17A levels. Additionally, we find that γδ T cells are the major source of IL-17A, and the seminal plasma could induce the γδ T cells to secret IL-17A. Blocking IL-17A could reduce the number of neutrophils in the uterus and prevent them from migrating to the epithelium by decreasing the chemokines CXCL1, CXCL2 and CXCL5. Blocking IL-17A did not affect the Th1/Th2 balance but actually diminished the inflammation in the uterus by reducing the expression of IL-1ß and TNF-α. In summary, we found a new mechanism by which seminal plasma could influence the inflammation in the uterus through the γδ T/IL-17 pathway to regulate the expression of various chemokines and cytokines.