Activating T regulatory cells for tolerance in early pregnancy - the contribution of seminal fluid.
ABSTRACT A state of active tolerance mediated by T regulatory (Treg) cells must be functional from the time of embryo implantation to prevent the conceptus from maternal immune attack. Male seminal fluid and ovarian steroid hormones are implicated in regulating the size and suppressive function of the Treg cell pool during the peri-implantation phase of early pregnancy. Evidence that antigens and cytokine signals in seminal fluid regulate the maternal immune response includes the following: (1) the Treg cell-inducing cytokine TGFbeta and male alloantigens are present in seminal fluid; (2) seminal fluid delivery at coitus is sufficient to induce a state of active immune tolerance to paternal alloantigen, even in the absence of conceptus tissue; (3) female dendritic cells can cross-present seminal fluid antigens to activate both CD8(+) and CD4(+) T cells, and (4) mating events deficient in either sperm or seminal plasma result in diminished CD4(+) CD25(+) Foxp3(+) Treg cell populations at the time of embryo implantation. Ongoing studies indicate that the cytokine environment during priming to male seminal fluid antigens influences the phenotype of responding T cells, and impacts fetal survival in later gestation. Collectively, these observations implicate factors in the peri-conceptual environment of both male and female origin as important determinants of maternal immune tolerance. Defining the mechanisms controlling tolerance induction will be helpful for developing new therapies for immune-mediated pathologies of pregnancy such as miscarriage and pre-eclampsia.
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ABSTRACT: Cervical cancer is a chronic inflammatory disease of multifactorial etiology usually presenting in sexually active women. Exposure of neoplastic cervical epithelial cells to seminal plasma (SP) has been shown to promote the growth of cancer cells in vitro and tumors in vivo by inducing the expression of inflammatory mediators including pro-inflammatory cytokines. IL-1alpha is a pleotropic pro-inflammatory cytokine induced in several human cancers and has been associated with virulent tumor phenotype and poorer prognosis. Here we investigated the expression of IL-1alpha in cervical cancer, the role of SP in the regulation of IL-1alpha in neoplastic cervical epithelial cells and the molecular mechanism underlying this regulation. Methods and results: Real-time quantitative RT-PCR confirmed the elevated expression of IL-1alpha mRNA in cervical squamous cell carcinoma and adenocarcinoma tissue explants, compared with normal cervix. Using immunohistochemistry, IL-1alpha was localized to the neoplastically transformed squamous, columnar and glandular epithelium in all cases of squamous cell carcinoma and adenocarcinomas explants studied. We found that SP induced the expression of IL-alpha in both normal and neoplastic cervical tissue explants. Employing HeLa (adenocarcinoma) cell line as a model system we identified PGE2 and EGF as possible ligands responsible for SP-mediated induction of IL-1alpha in these neoplastic cells. In addition, we showed that SP activates EP2/EGFR/PI3kinase-Akt signaling to induce IL-1alpha mRNA and protein expression. Furthermore, we demonstrate that in normal cervical tissue explants the induction of IL-1alpha by SP is via the activation of EP2/EGFR/PI3 kinase-Akt signaling. Conclusion SP-mediated induction of IL-1alpha in normal and neoplastic cervical epithelial cells suggests that SP may promote cervical inflammation as well as progression of cervical cancer in sexually active women.Journal of Molecular Signalling. 08/2014;
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ABSTRACT: Abstract While the main reproduction aim of semen is the transport of spermatozoa to the female genital tract, seminal plasma is a complex fluid that also carries a broad array of immunologically active molecules. Seminal plasma has been shown to contain a diverse array of anti-inflammatory and pro-inflammatory soluble mediators that regulate immune responses within the female reproductive tract than can facilitate fertilization. Since the natural inflammatory response to semen deposition in the female genital tract may result in recruitment of activated HIV target cells into the female genital mucosa, we discuss the constituents of semen that may increase the risk for HIV infection in women.Viral immunology 05/2014; · 1.78 Impact Factor
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ABSTRACT: Semen deposition results in modulated immunity and an inflammatory response of the genital mucosa, which promotes conditions facilitating conception and pregnancy. These semen-induced alterations in the female reproductive tract can also have implications for the sexual transmission of viral infections such as HIV-1. Semen is not only a vector for HIV-1 but also a carrier for pro- and antiviral factors. Semen induces significant mucosal changes upregulating gene, and transcription factors leading to recruitment and activation of HIV target cells, stimulation of HIV replication and potentiation of Toll-like receptor responses. Although more research is needed to clearly elucidate the resulting collective effects of all these factors, semen modulation of the cervicovaginal microenvironment and immune system appears to lead, through multiple mechanisms, to mucosal changes facilitating viral entry and replication, likely resulting in enhanced susceptibility to acquire HIV-1 infection.American Journal Of Reproductive Immunology 04/2014; · 3.32 Impact Factor