Mickey V. Patel

Sex Hormone Regulation of Innate Immunity in the Female Reproductive Tract: The Role of Epithelial Cells in Balancing Reproductive Potential with Protection against Sexually Transmitted Pathogens

Citation Wira CR, Fahey JV, Ghosh M, Patel MV, Hickey DK, Ochiel DO. Sex hormone regulation of innate immunity in the female reproductive tract: the role of epithelial cells in balancing reproductive potential with protection against sexually transmitted pathogens. Am J Reprod Immunol 2010

Innate and adaptive immunity at mucosal surfaces of the female reproductive tract: stratification and integration of immune protection against the transmission of sexually transmitted infections

This review examines the multiple levels of pre-existing immunity in the upper and lower female reproductive tract. In addition, we highlight the need for further research of innate and adaptive immune protection of mucosal surfaces in the female reproductive tract. Innate mechanisms include the mucus lining, a tight epithelial barrier and the secretion of antimicrobial peptides and cytokines by epithelial and innate immune cells. Stimulation of the innate immune system also serves to bridge the adaptive arm resulting in the generation of pathogen-specific humoral and cell-mediated immunity. Less understood are the multiple components that act in a coordinated way to provide a network of ongoing protection. Innate and adaptive immunity in the human female reproductive tract are influenced by the stage of menstrual cycle and are directly regulated by the sex steroid hormones, progesterone and estradiol. Furthermore, the effect of hormones on immunity is mediated both directly on immune and epithelial cells and indirectly by stimulating growth factor secretion from stromal cells. The goal of this review is to focus on the diverse aspects of the innate and adaptive immune systems that contribute to a unique network of protection throughout the female reproductive tract.

Innate immunity in the human female reproductive tract: endocrine regulation of endogenous antimicrobial protection against HIV and other sexually transmitted infections.

Citation Wira CR, Patel MV, Ghosh M, Mukura L, Fahey JV. Innate immunity in the human female reproductive tract: endocrine regulation of endogenous antimicrobial protection against HIV and other sexually transmitted infections. Am J Reprod Immunol 2011; 65: 196–211

Mucosal Immunity in the Human Female Reproductive Tract

PROBLEM To investigate the mucosal immune system in the cervix and vagina of premenopausal women in terms of immune cells present and cytolytic capacity of mucosal CD3+ T cells in the lower reproductive tract. METHODS Fresh tissue fragments prepared by vibratome sectioning were analyzed for the presence of cells by confocal scanning laser microscopy (CSLM). Isolated reproductive tract cells prepared by enzymatic were analyzed for CD3+ T cell phenotype by FACS analysis and for cytolytic function by an anti-CD3 mAb mediated redirected lysis assay. RESULTS As determined by CSLM, CD3+ cells as well as macrophages and dendritic cells are distributed throughout the lower female reproductive tract in both the epithelium and subepithelial mucosa. It was found that cervical and vaginal tissues from pre- and post-menopausal women contain CD3+ T cells (CTL) that have cytolytic activity, when measured in an antigen non-specific anti-CD3 mAb mediated redirected lysis assay. CONCLUSIONS These results indicate that the lower reproductive tract of women is immuno-competent as judged by the presence of CD3, CD4, CD8, macrophage, and dendritic cells in the endocervix, ectocervix, and vagina of premenopausal and postmenopausal women. Further, these studies demonstrate that CD3+ T cells with cytolytic activity are present in the cervix and vagina during the proliferative and secretory phases of the menstrual cycle and following menopause.

Estradiol Reduces Susceptibility of CD4 + T Cells and Macrophages to HIV-Infection

The magnitude of the HIV epidemic in women requires urgent efforts to find effective preventive methods. Even though sex hormones have been described to influence HIV infection in epidemiological studies and regulate different immune responses that may affect HIV infection, the direct role that female sex hormones play in altering the susceptibility of target cells to HIV-infection is largely unknown. Here we evaluated the direct effect of 17-β-estradiol (E2) and ethinyl estradiol (EE) in HIV-infection of CD4+ T-cells and macrophages. Purified CD4+ T-cells and monocyte-derived macrophages were generated in vitro from peripheral blood and infected with R5 and X4 viruses. Treatment of CD4+ T-cells and macrophages with E2 prior to viral challenge reduced their susceptibility to HIV infection in a dose-dependent manner. Addition of E2 2 h after viral challenge however did not result in reduced infection. In contrast, EE reduced infection in macrophages to a lesser extent than E2 and had no effect on CD4+ T-cell infection. Reduction of HIV-infection induced by E2 in CD4+ T-cells was not due to CCR5 down-regulation, but was an entry-mediated mechanism since infection with VSV-G pseudotyped HIV was not modified by E2. In macrophages, despite the lack of an effect of E2 on CCR5 expression, E2–treatment reduced viral entry 2 h after challenge and increased MIP-1β secretion. These results demonstrate the direct effect of E2 on susceptibility of HIV-target cells to infection and indicate that inhibition of target cell infection involves cell-entry related mechanisms.

Regulation of Mucosal Immunity in the Female Reproductive Tract: The Role of Sex Hormones in Immune Protection Against Sexually Transmitted Pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against human immunodeficiency virus (HIV) or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the FRT. Working together, these antimicrobials along with mucosal antibodies attack viral, bacterial, and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus, has evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol (E2) and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells, fibroblasts and immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate and adaptive immune systems are under hormonal control, that protection varies with the stage of the menstrual cycle and as such, is dampened during the secretory stage of the cycle to optimize conditions for fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Endocrine control of mucosal immunity in the female reproductive tract: impact of environmental disruptors.

The complexity of the human female reproductive tract (FRT) with its multiple levels of hormonally controlled immune protection has only begun to be understood. Dissecting the functions and roles of the immune system in the FRT is complicated by the differential hormonal regulation of its distinct anatomical structures that vary throughout the menstrual cycle. Although many fundamental mechanisms of steroid regulation of reproductive tract immune function have been determined, the effects of exogenous synthetic steroids or endocrine disruptors on immune function and disease susceptibility in the FRT have yet to be evaluated in detail. There is increasing evidence that environmental or synthetic molecules can alter normal immune function. This review provides an overview of the innate and adaptive immune systems, the current status of immune function in the FRT and the potential risks of environmental or pharmacological molecules that may perturb this system.

Endocrine Regulation of the Mucosal Immune System in the Female Reproductive Tract

Abstract Ovarian sex hormones have a critical role in regulating all aspects of the mucosal immune system of the human and animal female reproductive tract. Consisting of the innate and adaptive immune systems, the upper (fallopian tubes, uterus, and endocervix) and lower (ectocervix and vagina) systems are precisely regulated by estradiol (E 2 ) and progesterone (P 4 ) to optimize conditions for successful pregnancy and protection against sexually transmitted diseases. This review aims to examine the effects of E 2 and P 4 on innate, humoral, and cellular immunity in the reproductive tracts of human and rodent, pointing out unique similarities and differences that exist in terms of immune cell distribution and function, chemokine, cytokine and antimicrobial secretion, immunoglobulin production and transport, and antigen presentation. The studies presented indicate that endocrine control of immune system in the upper and lower reproductive tract is separate and distinct and that immune function at each site must be analyzed in the context of the unique contributions that each makes to procreation and to maternal and fetal protection against potential pathogens.

Innate Immunity in the Vagina (Part I): Estradiol Inhibits HBD2 and Elafin Secretion by Human Vaginal Epithelial Cells

Vaginal epithelial cells (VEC) are the first line of defense against incoming pathogens in the female reproductive tract. Their ability to produce the anti‐HIV molecules elafin and HBD2 under hormonal stimulation is unknown.

Pathogen Recognition in the Human Female Reproductive Tract: Expression of Intracellular Cytosolic Sensors NOD1, NOD2, RIG-1, and MDA5 and response to HIV-1 and Neisseria gonorrhea

Expression patterns and regulation of cytosolic pattern recognition receptors (PRR) NOD‐1, NOD‐2, RIG‐1, and MDA5 have not been elucidated in the human female reproductive tract (FRT).