Immunological microenvironments in the human vagina and cervix: mediators of cellular immunity are concentrated in the cervical transformation zone

Seminal fluid and fertility in women

Seminal fluid is often viewed as simply a vehicle to carry sperm to fertilize the oocyte, but a more complex function in influencing female reproductive physiology is now evident. Remarkably, seminal fluid contains soluble and exosome-born signaling agents that interact with the female reproductive tract to prime the immune response, with consequences for fertility and pregnancy outcome. Experiments in rodent models demonstrate a key role for seminal fluid in enabling robust embryo implantation and optimal placental development. In particular, seminal fluid promotes leukocyte recruitment and generation of regulatory T cells, which facilitate embryo implantation by suppressing inflammation, assisting uterine vascular adaptation, and sustaining tolerance of fetal antigens. There is emerging evidence of comparable effects in women, where seminal fluid provokes an adaptive immune response in the cervical tissues after contact at intercourse, and spermatozoa accessing the higher tract potentially affect the endometrium directly. These biological responses may have clinical significance, explaining why [1] intercourse in IVF ET cycles improves the likelihood of pregnancy, [2] inflammatory disorders of gestation are more common in women who conceive after limited exposure to seminal fluid of the prospective father, and [3] preeclampsia incidence is elevated after use of donor oocytes or donor sperm where prior contact with conceptus alloantigens has not occurred. It will be important to define the mechanisms through which seminal fluid interacts with female reproductive tissues, to provide knowledge that may assist in preconception planning and infertility treatment.

The reproductive cycle is a pathogenic determinant during gonococcal pelvic inflammatory disease in mice

Women with asymptomatic Neisseria gonorrhoeae infection are at risk of developing pelvic inflammatory disease (PID) if the bacteria ascend from the endocervix into the uterus and oviducts. Factors that affect disease severity, ranging from mild discomfort to severe inflammation, pain, and infertility, remain elusive. Herein we perform direct transcervical inoculation of N. gonorrhoeae into the uterus of mice to establish an infection that leads to PID. Profoundly different disease outcomes were apparent at different stages of the reproductive cycle. Mice that were infected during the diestrus stage of the reproductive cycle displayed extensive gonococcal penetration into the submucosa, severe inflammation, and clinical signs reflecting discomfort. Meanwhile, infection during the intervening estrus stage showed only modest effects. Furthermore, a gonococcal-specific humoral response was only elicited following the penetrative upper genital tract (UGT) infection during diestrus but not estrus. Strikingly, the potential for antibodies to contribute to protection during re-infection also depends upon the reproductive stage, as antigonococcal antibodies within the genital tract were markedly higher when mice were in diestrus. Combined, this work establishes a robust new model reflecting gonococcal PID in humans and reveals how the reproductive cycle determines the pathogenic outcome of gonococcal infections of the UGT.

IL-36γ Augments Host Defense and Immune Responses in Human Female Reproductive Tract Epithelial Cells

IL-36γ is a proinflamatory cytokine which belongs to the IL-1 family of cytokines. It is expressed in the skin and by epithelial cells (ECs) lining lung and gut tissue. We used human 3-D organotypic cells, that recapitulate either in vivo human vaginal or cervical tissue, to explore the possible role of IL-36γ in host defense against pathogens in the human female reproductive tract (FRT). EC were exposed to compounds derived from virus or bacterial sources and induction and regulation of IL-36γ and its receptor was determined. Polyinosinic-polycytidylic acid (poly I:C), flagellin, and synthetic lipoprotein (FSL-1) significantly induced expression of IL-36γ in a dose-dependent manner, and appeared to be TLR-dependent. Recombinant IL-36γ treatment resulted in self-amplification of IL-36γ and its receptor (IL-36R) via increased gene expression, and promoted other inflammatory signaling pathways. This is the first report to demonstrate that the IL-36 receptor and IL-36γ are present in the human FRT EC and that they are differentially induced by microbial products at this site. We conclude that IL-36γ is a driver for epithelial and immune activation following microbial insult and, as such, may play a critical role in host defense in the FRT.

Comparison of Follicular and Luteal Phase Mucosal Markers of HIV Susceptibility in Healthy Women

The purpose of this study was to evaluate differences in vaginal immune cell populations, vaginal tissue gene expression, antimicrobial activity of the cervicovaginal (CV) lavage (CVL), vaginal flora, and p24 antigen production from CV tissues after ex vivo human immunodeficiency virus (HIV) infection between follicular (FOL) and luteal (LUT) phases of the menstrual cycle. CV tissue biopsies, CV secretions, and blood samples were obtained as part of two longitudinal clinical trials of healthy women (CONRAD D11-119 and A12-124 studies). Participants (n = 39) were HIV-seronegative women not using exogenous hormone supplementation, with normal menstrual cycles, who were screened to exclude sexually transmitted and reproductive tract infections. Serum levels of estradiol and progesterone were significantly higher in the LUT versus the FOL phase of the menstrual cycle. Controlling for race, reported contraceptive use/sexual practices, and clinical trial, we found no differences in vaginal tissue immune cell populations and activation status, transcriptomes, inhibition of HIV, herpes simplex virus type 2 and Escherichia coli by the CVL, vaginal pH or Nugent score, or production of p24 antigen after ex vivo infection by HIV-1BaL between CV samples obtained in the FOL phase versus the LUT phase of the menstrual cycle. There were no significant correlations between serum estradiol and progesterone levels and CV endpoints. The hypothesis that the LUT phase of the menstrual cycle represents a more vulnerable stage for mucosal infection with HIV was not supported by data from samples obtained from the lower genital tract (ectocervix and vagina) from these two clinical trials.

Critical Review: Mechanisms of HIV Transmission in Depo-Provera Users: The Likely Role of Hypoestrogenism

Almost half of new HIV infections worldwide occur in women, and vaginal intercourse is the most common mode of transmission. Accumulating evidence suggests that depot medroxyprogesterone acetate may increase HIV transmission, but little is known about the underlying mechanisms. We propose that hypoestrogenism in depot medroxyprogesterone acetate may contribute to increased HIV transmission. We present supportive evidence and propose potential interventions to prevent or treat vaginal hypoestrogenism using vaginal estrogens.

Expression Profile of Human Fc Receptors in Mucosal Tissue: Implications for Antibody-Dependent Cellular Effector Functions Targeting HIV-1 Transmission

The majority of new Human Immunodeficiency Virus (HIV)-1 infections are acquired via sexual transmission at mucosal surfaces. Partial efficacy (31.2%) of the Thai RV144 HIV-1 vaccine trial has been correlated with Antibody-dependent Cellular Cytotoxicity (ADCC) mediated by non-neutralizing antibodies targeting the V1V2 region of the HIV-1 envelope. This has led to speculation that ADCC and other antibody-dependent cellular effector functions might provide an important defense against mucosal acquisition of HIV-1 infection. However, the ability of antibody-dependent cellular effector mechanisms to impact on early mucosal transmission events will depend on a variety of parameters including effector cell type, frequency, the class of Fc-Receptor (FcR) expressed, the number of FcR per cell and the glycoslyation pattern of the induced antibodies. In this study, we characterize and compare the frequency and phenotype of IgG (CD16 [FcγRIII], CD32 [FcγRII] and CD64 [FcγRI]) and IgA (CD89 [FcαR]) receptor expression on effector cells within male and female genital mucosal tissue, colorectal tissue and red blood cell-lysed whole blood. The frequency of FcR expression on CD14+ monocytic cells, myeloid dendritic cells and natural killer cells were similar across the three mucosal tissue compartments, but significantly lower when compared to the FcR expression profile of effector cells isolated from whole blood, with many cells negative for all FcRs. Of the three tissues tested, penile tissue had the highest percentage of FcR positive effector cells. Immunofluorescent staining was used to determine the location of CD14+, CD11c+ and CD56+ cells within the three mucosal tissues. We show that the majority of effector cells across the different mucosal locations reside within the subepithelial lamina propria. The potential implication of the observed FcR expression patterns on the effectiveness of FcR-dependent cellular effector functions to impact on the initial events in mucosal transmission and dissemination warrants further mechanistic studies.

Blocking CXCL9 Decreases HIV-1 Replication and Enhances the Activity of Prophylactic Antiretrovirals in Human Cervical Tissues

OBJECTIVES

The interferon-gamma-induced chemokine CXCL9 is expressed in a wide range of inflammatory conditions including those affecting the female genital tract. CXCL9 promotes immune cell recruitment, activation, and proliferation. The role of CXCL9 in modulating HIV-1 infection of cervicovaginal tissues, a main portal of viral entry, however, has not been established. We report a link between CXCL9 and HIV-1 replication in human cervical tissues and propose CXCL9 as a potential target to enhance the anti-HIV-1 activity of prophylactic antiretrovirals.

DESIGN

Using ex vivo infection of human cervical tissues as a model of mucosal HIV-1 acquisition, we described the effect of CXCL9 neutralization on HIV-1 gene expression and mucosal CD4 T-cell activation. The anti-HIV-1 activity of tenofovir, the leading mucosal pre-exposure prophylactic microbicide, alone or in combination with CXCL9 neutralization was also studied.

METHODS

HIV-1 replication was evaluated by p24 ELISA. HIV-1 DNA and RNA, and CD4, CCR5, and CD38 transcription were evaluated by quantitative real-time polymerase chain reaction. Frequency of activated cervical CD4 T cells was quantified using fluorescence-activated cell sorting.

RESULTS

Antibody blocking of CXCL9 reduced HIV-1 replication by decreasing mucosal CD4 T-cell activation. CXCL9 neutralization in combination with suboptimal concentrations of tenofovir, possibly present in the cervicovaginal tissues of women using the drug inconsistently, demonstrated an earlier and greater decrease in HIV-1 replication compared with tissues treated with tenofovir alone.

CONCLUSIONS

CXCL9 neutralization reduces HIV-1 replication and may be an effective target to enhance the efficacy of prophylactic antiretrovirals.

ART influences HIV persistence in the female reproductive tract and cervicovaginal secretions

The recently completed HIV prevention trials network study 052 is a landmark collaboration demonstrating that HIV transmission in discordant couples can be dramatically reduced by treating the infected individual with antiretroviral therapy (ART). However, the cellular and virological events that occur in the female reproductive tract (FRT) during ART that result in such a drastic decrease in transmission were not studied and remain unknown. Here, we implemented an in vivo model of ART in BM/liver/thymus (BLT) humanized mice in order to better understand the ability of ART to prevent secondary HIV transmission. We demonstrated that the entire FRT of BLT mice is reconstituted with human CD4+ cells that are shed into cervicovaginal secretions (CVS). A high percentage of the CD4+ T cells in the FRT and CVS expressed CCR5 and therefore are potential HIV target cells. Infection with HIV increased the numbers of CD4+ and CD8+ T cells in CVS of BLT mice. Furthermore, HIV was present in CVS during infection. Finally, we evaluated the effect of ART on HIV levels in the FRT and CVS and demonstrated that ART can efficiently suppress cell-free HIV-RNA in CVS, despite residual levels of HIV-RNA+ cells in both the FRT and CVS.

Vulvovaginal candidiasis: Epidemiology, microbiology and risk factors

Vulvovaginal candidiasis (VVC) is an infection caused by Candida species that affects millions of women every year. Although Candida albicans is the main cause of VVC, the identification of non-Candida albicans Candida (NCAC) species, especially Candida glabrata, as the cause of this infection, appears to be increasing. The development of VVC is usually attributed to the disturbance of the balance between Candida vaginal colonization and host environment by physiological or nonphysiological changes. Several host-related and behavioral risk factors have been proposed as predisposing factors for VVC. Host-related factors include pregnancy, hormone replacement, uncontrolled diabetes, immunosuppression, antibiotics, glucocorticoids use and genetic predispositions. Behavioral risk factors include use of oral contraceptives, intrauterine device, spermicides and condoms and some habits of hygiene, clothing and sexual practices. Despite a growing list of recognized risk factors, much remains to be elucidated as the role of host versus microorganisms, in inducing VVC and its recurrence. Thus, this review provides information about the current state of knowledge on the risk factors that predispose to VVC, also including a revision of the epidemiology and microbiology of VVC, as well as of Candida virulence factors associated with vaginal pathogenicity.

Drug transporters in tissues and cells relevant to sexual transmission of HIV: Implications for drug delivery

Efflux and uptake transporters of drugs are key regulators of the pharmacokinetics of many antiretroviral drugs. A growing body of literature has revealed the expression and functionality of multiple transporters in female genital tract (FGT), colorectal tissue, and immune cells. Drug transporters could play a significant role in the efficacy of preventative strategies for HIV-1 acquisition. Pre-exposure prophylaxis (PrEP) is a promising strategy, which utilizes topically (vaginally or rectally), orally or other systemically administered antiretroviral drugs to prevent the sexual transmission of HIV to receptive partners. The drug concentration in the receptive mucosal tissues and target immune cells for HIV is critical for PrEP effectiveness. Hence, there is an emerging interest in utilizing transporter information to explain tissue disposition patterns of PrEP drugs, to interpret inter-individual variability in PrEP drug pharmacokinetics and effectiveness, and to improve tissue drug exposure through modulation of the cervicovaginal, colorectal, or immune cell transporters. In this review, the existing literature on transporter expression, functionality and regulation in the transmission-related tissues and cells is summarized. In addition, the relevance of transporter function for drug delivery and strategies that could exploit transporters for increased drug concentration at target locales is discussed. The overall goal is to facilitate an understanding of drug transporters for PrEP optimization.

Evaluation of T, B and natural killer lymphocyte in the cervical stroma of HIV-positive and negative patients with cervical intraepithelial neoplasia

Cervical intraepithelial neoplasias (CIN) are closely associated with oncogenic subtypes of the human papillomavirus (HPV). In the presence of this virus, it is known that the activation or suppression of immune system is the key to the development, progression and/or regression of cervical lesions. Therefore, the objective of this study is to compare the local immune response among HIV-seropositive and seronegative patients with cervical intraepithelial neoplasia regarding the expression of T lymphocytes (CD3+, CD4+ and CD8+), B lymphocytes (CD20+) and natural killers cells (CD56+) in the cervical stroma. A cross-sectional study of paraffin blocks containing cervical tissue after conization by the Loop Electrosurgical Excision Procedure (LEEP) from 47 HIV-seropositive and 38 seronegative patients with CIN. Cervical stroma immunohistochemistry was performed in the CIN area. The Fisher's exact test was used for the statistical analysis. When HIV-seropositive and seronegative women were compared, the seropositive women had a higher count of CD8+ T lymphocytes (52.1% versus 28.9%, P<0.04). Considering CIN degree (CIN 1 and CIN 2/3), the HIV-seronegative patients with CIN 1 had a low count of CD20+B-lymphocytes (7.1%) in comparison with CIN 1 HIV seropositive and with CIN 2/3 HIV-seronegative patients, respectively 50% (P<0.018) and 54.5% (P<0.0048). The HIV infection and degree of CIN influenced the cytotoxic lymphocytes inducing an increase in the number of cells high count of CD20+ lymphocytes with CIN 1.

Relationship Between Genital Drug Concentrations and Cervical Cellular Immune Activation and Reconstitution in HIV-1-Infected Women on a Raltegravir Versus a Boosted Atazanavir Regimen

Determinants of HIV-infected women's genital tract mucosal immune health are not well understood. Because raltegravir (RAL) achieves relatively higher genital tract concentrations than ritonavir-boosted atazanavir (ATV), we examined whether an RAL-based regimen is associated with improved cervical immune reconstitution and less activation in HIV(+) women compared to an ATV-based regimen. Peripheral blood, cervical brushings, cervical-vaginal lavage (CVL), and cervical biopsies were collected from HIV(+) women on tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) and either RAL (n=14) or ATV (n=19) with CD4(+) T cells>300 cells/mm(3) and HIV RNA<48 copies/ml. HLA-DR(+)CD38(+) T cells were measured in blood and cervical cells using flow cytometry, CD4(+) and CD8(+) T cells were quantified in cervical biopsies by immunofluorescent analysis, and HIV RNA (VL), ATV, and RAL concentrations were measured in CVL. In a linear regression model of log(CVL concentration) versus both log(plasma concentration) and treatment group, the RAL CVL level was 519% (95% CI: 133, 1,525%) higher than for ATV (p<0.001). Genital tract VL was undetectable in 90% of subjects and did not differ by regimen. There were no significant differences between groups in terms of cervical %HLA-DR(+)CD38(+)CD4(+) or CD8(+) T cells, CD4(+) or CD8(+) T cells/mm(2), or CD4:CD8 ratio. After adjusting for treatment time and group, the CVL:plasma drug ratio was not associated with the cervical CD4:CD8 ratio or immune activation (p>0.6). Despite significantly higher genital tract penetration of RAL compared to ATV, there were no significant differences in cervical immune activation or reconstitution between women on these regimens, suggesting both drug regimens achieve adequate genital tract levels to suppress virus replication.

A review of the human vs. porcine female genital tract and associated immune system in the perspective of using minipigs as a model of human genital Chlamydia infection

Sexually transmitted diseases constitute major health issues and their prevention and treatment continue to challenge the health care systems worldwide. Animal models are essential for a deeper understanding of the diseases and the development of safe and protective vaccines. Currently a good predictive non-rodent model is needed for the study of genital chlamydia in women. The pig has become an increasingly popular model for human diseases due to its close similarities to humans. The aim of this review is to compare the porcine and human female genital tract and associated immune system in the perspective of genital Chlamydia infection. The comparison of women and sows has shown that despite some gross anatomical differences, the structures and proportion of layers undergoing cyclic alterations are very similar. Reproductive hormonal cycles are closely related, only showing a slight difference in cycle length and source of luteolysing hormone. The epithelium and functional layers of the endometrium show similar cyclic changes. The immune system in pigs is very similar to that of humans, even though pigs have a higher percentage of CD4(+)/CD8(+) double positive T cells. The genital immune system is also very similar in terms of the cyclic fluctuations in the mucosal antibody levels, but differs slightly regarding immune cell infiltration in the genital mucosa - predominantly due to the influx of neutrophils in the porcine endometrium during estrus. The vaginal flora in Göttingen Minipigs is not dominated by lactobacilli as in humans. The vaginal pH is around 7 in Göttingen Minipigs, compared to the more acidic vaginal pH around 3.5-5 in women. This review reveals important similarities between the human and porcine female reproductive tracts and proposes the pig as an advantageous supplementary model of human genital Chlamydia infection.

Characterization of a Hormone-Responsive Organotypic Human Vaginal Tissue Model: Morphologic and Immunologic Effects

Estrogen and progesterone regulate proliferation and differentiation of epithelial cells in the female genital tract. We investigated the effects of these hormones on reconstructed human organotypic vaginal epithelial tissue models (EpiVaginal). We ascertained that epithelial cells in the tissue models express estrogen and progesterone receptors. Treatment with estradiol-17β (E(2)) significantly increased epithelium thickness and transepithelial electrical resistance (TEER), whereas progesterone (P) treatment resulted in thinning of the epithelium and decreased TEER when compared with untreated controls. Exposure to E(2) increased (1) the expression of the progesterone receptor B (PR-B), (2) accumulation of glycogen in suprabasal cells, (3) epithelial differentiation, and (4) the expression of a number of gene pathways associated with innate immunity, epithelial differentiation, wound healing, and antiviral responses. These findings indicate that EpiVaginal tissues are hormone responsive and can be used to study the role of female reproductive hormones in innate immune responses, microbial infection, and drug delivery in the vaginal mucosa.

Infection of ectocervical tissue and universal targeting of T-cells mediated by primary non-macrophage-tropic and highly macrophage-tropic HIV-1 R5 envelopes

Background

HIV-1 variants carrying non-macrophage-tropic HIV-1 R5 envelopes (Envs) are predominantly transmitted and persist in immune tissue even in AIDS patients who have highly macrophage-tropic variants in the brain. Non-macrophage-tropic R5 Envs require high levels of CD4 for infection contrasting with macrophage-tropic Envs, which can efficiently mediate infection of cells via low CD4. Here, we investigated whether non-macrophage-tropic R5 Envs from the acute stage of infection (including transmitted/founder Env) mediated more efficient infection of ectocervical explant cultures compared to non-macrophage-tropic and highly macrophage-tropic R5 Envs from late disease.

Results

We used Env+ pseudovirions that carried a GFP reporter gene to measure infection of the first cells targeted in ectocervical explant cultures. In straight titrations of Env+ pseudovirus supernatants, mac-tropic R5 Envs from late disease mediated slightly higher infectivities for ectocervical explants although this was not significant. Surprisingly, explant infection by several T/F/acute Envs was lower than for Envs from late disease. However, when infectivity for explants was corrected to account for differences in the overall infectivity of each Env+ pseudovirus (measured on highly permissive HeLa TZM-bl cells), non-mac-tropic early and late disease Env+ pseudoviruses mediated significantly higher infection. This observation suggests that cervical tissue preferentially supports non-mac-tropic Env+ viruses compared to mac-tropic viruses. Finally, we show that T-cells were the main targets for infection regardless of whether explants were stimulated with T-cell or monocyte/macrophage cytokines. There was no evidence of macrophage infection even for pseudovirions carrying highly mac-tropic Envs from brain tissue or for the highly mac-tropic, laboratory strain, BaL, which targeted T-cells in the explant tissue.

Conclusions

Our data support ectocervical tissue as a favorable environment for non-mac-tropic HIV-1 R5 variants and emphasize the role of T-cells as initial targets for infection even for highly mac-tropic variants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0176-2) contains supplementary material, which is available to authorized users.

Gene Expression Profiling of Human Vaginal Cells In Vitro Discriminates Compounds with Pro-Inflammatory and Mucosa-Altering Properties: Novel Biomarkers for Preclinical Testing of HIV Microbicide Candidates

BACKGROUND

Inflammation and immune activation of the cervicovaginal mucosa are considered factors that increase susceptibility to HIV infection. Therefore, it is essential to screen candidate anti-HIV microbicides for potential mucosal immunomodulatory/inflammatory effects prior to further clinical development. The goal of this study was to develop an in vitro method for preclinical evaluation of the inflammatory potential of new candidate microbicides using a microarray gene expression profiling strategy.

METHODS

To this end, we compared transcriptomes of human vaginal cells (Vk2/E6E7) treated with well-characterized pro-inflammatory (PIC) and non-inflammatory (NIC) compounds. PICs included compounds with different mechanisms of action. Gene expression was analyzed using Affymetrix U133 Plus 2 arrays. Data processing was performed using GeneSpring 11.5 (Agilent Technologies, Santa Clara, CA).

RESULTS

Microarraray comparative analysis allowed us to generate a panel of 20 genes that were consistently deregulated by PICs compared to NICs, thus distinguishing between these two groups. Functional analysis mapped 14 of these genes to immune and inflammatory responses. This was confirmed by the fact that PICs induced NFkB pathway activation in Vk2 cells. By testing microbicide candidates previously characterized in clinical trials we demonstrated that the selected PIC-associated genes properly identified compounds with mucosa-altering effects. The discriminatory power of these genes was further demonstrated after culturing vaginal cells with vaginal bacteria. Prevotella bivia, prevalent bacteria in the disturbed microbiota of bacterial vaginosis, induced strong upregulation of seven selected PIC-associated genes, while a commensal Lactobacillus gasseri associated to vaginal health did not cause any changes.

CONCLUSIONS

In vitro evaluation of the immunoinflammatory potential of microbicides using the PIC-associated genes defined in this study could help in the initial screening of candidates prior to entering clinical trials. Additional characterization of these genes can provide further insight into the cervicovaginal immunoinflammatory and mucosal-altering processes that facilitate or limit HIV transmission with implications for the design of prevention strategies.

Preclinical evaluation of the immunomodulatory lymphocyte trafficking drug FTY720 for HIV prevention in the female genital mucosa of macaques

FTY720 has been shown to reduce inflammatory cytokines and immune cells in the genital mucosa of macaques. This pilot study examined the ability of FTY720 to inhibit HIV acquisition. Systemic treatment with FTY720 failed to prevent or delay vaginal SHIV transmission.

Expression of nucleic acid-sensing Toll-like receptors predicts HPV16 clearance associated with an E6-directed cell-mediated response

Toll-like receptors (TLRs), important in rapid clearance of incident human papillomavirus (HPV) infections, may also be important in shaping the adaptive response to persistent infections. We examined here the association between TLR expression and clearance of HPV16 infections following periods of persistence, using longitudinal TLR measurements and a time-to-clearance analysis, as well as the interaction between TLRs and adaptive, cell-mediated responses involved in clearance. TLR2, TLR3, TLR7, TLR8 and TLR9 mRNA expression were measured in cervical cytobrush samples by quantitative PCR. Responses to the HPV16 E6 and E7 oncoproteins were measured by an interferon-γ immunospot assay. Bivariable and multivariable Cox proportional hazard models were used to estimate the effect of TLRs on HPV16 clearance. Higher expression of TLR3 or TLR7 at an HPV16-positive visit was a significant (p ≤ 0.05) predictor of clearance by the following visit, in both unadjusted and adjusted (for smoking and oral contraceptive use) models. In women with, but not those without, a positive response to E6, higher expression of TLR3 (hazard ratio: 1.2 [95% confidence interval: 1.04-1.39], p = 0.012), TLR7 (1.39 [1.14-1.7], p = 0.001), TLR8 (1.37 [1.11-1.69], p = 0.003), or TLR9 (1.53 [1.13-2.08], p = 0.006) was significantly associated with clearance, revealing an important link between innate and adaptive immunity in the control of HPV infections following periods of persistence.

Activation of vestibule-associated lymphoid tissue in localized provoked vulvodynia

OBJECTIVE

Localized provoked vulvodynia (LPV) may have inflammatory etiology. We wanted to find out whether the cell-mediated immune system becomes activated in the vestibular mucosa in LPV.

STUDY DESIGN

This was a controlled cross-sectional study. Vestibular mucosal specimens were obtained from 27 patients with severe LPV and 15 controls. Detailed clinical history of the patients was obtained. For immunohistochemistry, antibodies against CD3 (T cells), CD20 (B cells), IgA (mucosal plasma cells), CD163 (dendritic cells [DCs]), CD68 (macrophages), and CD117 (mast cells) were employed. Mann-Whitney U test and χ(2) test were used for statistical analyses.

RESULTS

More B lymphocytes and mature mucosal IgA-plasma cells were found in patients than in controls (P < .001 and P < .001, respectively). In LPV samples, B and T cells were arranged into germinal centers representing local immune activation. Germinal centers were not seen in controls. Antigen-presenting DCs and macrophages were found both in patients and controls with similar densities. DCs were found to extend their dendrites into the luminal space through an intact epithelium. Similar amounts of mast cells were found evenly scattered throughout the stroma of vestibular mucosa of both patients and controls.

CONCLUSION

We demonstrate here local organized vestibule-associated lymphoid tissue analogous to mucosa-associated lymphoid tissue. Vestibule-associated lymphoid tissue may emerge as a response to local infection or inflammation in LPV.

The role of sex hormones in immune protection of the female reproductive tract

Within the human female reproductive tract (FRT), the challenge of protection against sexually transmitted infections (STIs) is coupled with the need to enable successful reproduction. Oestradiol and progesterone, which are secreted during the menstrual cycle, affect epithelial cells, fibroblasts and immune cells in the FRT to modify their functions and hence the individual's susceptibility to STIs in ways that are unique to specific sites in the FRT. The innate and adaptive immune systems are under hormonal control, and immune protection in the FRT varies with the phase of the menstrual cycle. Immune protection is dampened during the secretory phase of the cycle to optimize conditions for fertilization and pregnancy, which creates a 'window of vulnerability' during which potential pathogens can enter and infect the FRT.

Seminal fluid and immune adaptation for pregnancy--comparative biology in mammalian species

Seminal fluid delivered to the female reproductive tract at coitus not only promotes the survival and fertilizing capacity of spermatozoa, but also contains potent signalling agents that influence female reproductive physiology to improve the chances of conception and reproductive success. Male to female seminal fluid signalling occurs in rodents, domestic and livestock animals, and all other mammals examined to date. Seminal plasma is instrumental in eliciting the female response, by provision of cytokines and prostaglandins synthesized in the male accessory glands. These agents bind to receptors on target cells in the cervix and uterus, activating changes in gene expression leading to functional adaptations in the female tissues. Sperm also interact with female tract cells, although the molecular basis of this interaction is not yet defined. The consequences are increased sperm survival and fertilization rates, conditioning of the female immune response to tolerate semen and the conceptus, and molecular and cellular changes in the endometrium that facilitate embryo development and implantation. Studies in porcine, equine, bovine, ovine and canine species all show evidence of male-female signalling function for seminal fluid. There are variations between species that relate to their different reproductive strategies and behaviours, particularly the site of seminal fluid deposition and female reproductive tract anatomy. Although the details of the molecular mechanisms require more study, the available data are consistent with both the sperm and plasma fractions of seminal fluid acting in a synergistic fashion to activate inflammation-like responses and downstream female tract changes in each of these species. Insight into the biological function and molecular basis of seminal fluid signalling in the female will inform new interventions and management practices to support optimal reproductive outcomes in domestic, livestock and endangered animal species.

Chemokine-mediated immune responses in the female genital tract mucosa

The genital tract mucosa is the site where sexually transmitted infections gain entry to the host. The immune response at this site is thus critical to provide innate protection against pathogens that are seen for the very first time as well as provide long-term pathogen-specific immunity, which would be required for an effective vaccine against sexually transmitted infection. A finely regulated immune response is therefore required to provide an effective barrier against pathogens without compromising the capacity of the genital tract to allow for successful conception and fetal development. We review recent developments in our understanding of the immune response in the female genital tract to infectious pathogens, using herpes simplex virus-2, human immunodeficiency virus-1 and Chlamydia trachomatis as examples, with a particular focus on the role of chemokines in orchestrating immune cell migration necessary to achieve effective innate and adaptive immune responses in the female genital tract.

Immune cells in the female reproductive tract

The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus in the upper tract. The immune system is significantly influenced by sex steroid hormones, although leukocytes in the reproductive tract lack receptors for estrogen and progesterone. The leukocytes in the reproductive tract are distributed in either an aggregated or a dispersed form in the epithelial layer, lamina propria, and stroma. Even though immune cells are differentially distributed in each organ of the reproductive tract, the predominant immune cells are T cells, macrophages/dendritic cells, natural killer (NK) cells, neutrophils, and mast cells. B cells are rare in the female reproductive tract. NK cells in the endometrium significantly expand in the late secretory phase and further increase their number during early pregnancy. It is evident that NK cells and regulatory T (Treg) cells are extremely important in decidual angiogenesis, trophoblast migration, and immune tolerance during pregnancy. Dysregulation of endometrial/decidual immune cells is strongly related to infertility, miscarriage, and other obstetric complications. Understanding the immune system of the female reproductive tract will significantly contribute to women's health and to success in pregnancy.

Characteristics and quantities of HIV host cells in human genital tract secretions

Human immunodeficiency virus (HIV)-infected leukocytes have been detected in genital secretions from HIV-infected men and women and may play an important role in the sexual transmission of HIV. However, they have been largely overlooked in studies on mechanisms of HIV transmission and in the design and testing of HIV vaccine and microbicide candidates. This article describes the characteristics and quantities of leukocytes in male and female genital secretions under various conditions and also reviews evidence for the involvement of HIV-infected cells in both horizontal and vertical cell-associated HIV transmission. Additional research is needed in this area to better target HIV prevention strategies.

Modeling mucosal cell-associated HIV type 1 transmission in vitro

Human immunodeficiency virus type 1 (HIV-1) can efficiently spread by direct cell-to-cell contact, a mechanism termed cell-associated HIV transmission. By some estimates, cell-associated HIV transmission is 10-1000-fold more effective than cell-free HIV infection. Mucosal cell-associated HIV transmission may occur when HIV-bearing cells in mucosal secretions from an HIV-infected donor transfer virus directly to recipient target cells in or below the mucosal epithelium, or through HIV transcytosis across the mucosal epithelium of a noninfected host. This mechanism may play an important role in the sexual and vertical transmission of HIV-1, yet most in vitro tests of vaccine and microbicide efficacy assess cell-free virus transmission. This article reviews in vitro assays that have been used to model mucosal cell-associated transmission, including microscopy, immune cell cocultures, use of HIV-infected cells in epithelial cell transcytosis assays, and cell-associated infection of mucosal tissue explants. Assays that authentically simulate mucosal cell-associated HIV transmission could provide valuable insight into mechanisms and molecules that can potentially be targeted for HIV prevention, as well as critical models for testing novel HIV prevention strategies for efficacy against cell-associated HIV transmission.

Progestin-Containing Contraceptives Alter Expression of Host Defense-Related Genes of the Endometrium and Cervix

Epidemiological studies indicate that progestin-containing contraceptives increase susceptibility to HIV, although the underlying mechanisms involving the upper female reproductive tract are undefined. To determine the effects of depot medroxyprogesterone acetate (DMPA) and the levonorgestrel intrauterine system (LNG-IUS) on gene expression and physiology of human endometrial and cervical transformation zone (TZ), microarray analyses were performed on whole tissue biopsies. In endometrium, activated pathways included leukocyte chemotaxis, attachment, and inflammation in DMPA and LNG-IUS users, and individual genes included pattern recognition receptors, complement components, and other immune mediators. In cervical TZ, progestin treatment altered expression of tissue remodeling and viability but not immune function genes. Together, these results indicate that progestins influence expression of immune-related genes in endometrium relevant to local recruitment of HIV target cells with potential to increase susceptibility and underscore the importance of the upper reproductive tract when assessing the safety of contraceptive products.

Progesterone-based intrauterine device use is associated with a thinner apical layer of the human ectocervical epithelium and a lower ZO-1 mRNA expression

Currently, whether hormonal contraceptives affect male to female human immunodeficiency virus (HIV) transmission is being debated. In this study, we investigated whether the use of progesterone-based intrauterine devices (pIUDs) is associated with a thinning effect on the ectocervical squamous epithelium, down-regulation of epithelial junction proteins, and/or alteration of HIV target cell distribution in the human ectocervix. Ectocervical tissue biopsies from healthy premenopausal volunteers using pIUDs were collected and compared to biopsies obtained from two control groups, namely women using combined oral contraceptives (COCs) or who do not use hormonal contraceptives. In situ staining and image analysis were used to measure epithelial thickness and the presence of HIV receptors in tissue biopsies. Messenger RNA levels of epithelial junction markers were measured by quantitative PCR. The epithelial thickness displayed by women in the pIUD group was similar to those in the COC group, but significantly thinner as compared to women in the no hormonal contraceptive group. The thinner epithelial layer of the pIUD group was specific to the apical layer of the ectocervix. Furthermore, the pIUD group expressed significantly lower levels of the tight junction marker ZO-1 within the epithelium as compared to the COC group. Similar expression levels of HIV receptors and coreceptors CD4, CCR5, DC-SIGN, and Langerin were observed in the three study groups. Thus, women using pIUD displayed a thinner apical layer of the ectocervical epithelium and reduced ZO-1 expression as compared to control groups. These data suggest that pIUD use may weaken the ectocervical epithelial barrier against invading pathogens, including HIV.

Role of Seminal Plasma in Human Female Reproductive Failure: Immunomodulation, Inflammation, and Infections

Human seminal plasma contains factors that can regulate the female immune system and potentially promote reproductive fitness. Adverse effects on fertility and pregnancy may occur when seminal plasma provides insufficient, excessive, or altered signals or when the female partner is incapable of receiving these signals.

Seminal Fluid Signalling in the Female Reproductive Tract: Implications for Reproductive Success and Offspring Health

Carriage of sperm is not the only function of seminal fluid in mammals. Studies in mice show that at conception, seminal fluid interacts with the female reproductive tract to induce responses which influence whether or not pregnancy will occur, and to set in train effects that help shape subsequent fetal development. In particular, seminal fluid initiates female immune adaptation processes required to tolerate male transplantation antigens present in seminal fluid and inherited by the conceptus. A tolerogenic immune environment to facilitate pregnancy depends on regulatory T cells (Treg cells), which recognise male antigens and function to suppress inflammation and immune rejection responses. The female response to seminal fluid stimulates the generation of Treg cells that protect the conceptus from inflammatory damage, to support implantation and placental development. Seminal fluid also elicits molecular and cellular changes in the oviduct and endometrium that directly promote embryo development and implantation competence. The plasma fraction of seminal fluid plays a key role in this process with soluble factors, including TGFB, prostaglandin-E, and TLR4 ligands, demonstrated to contribute to the peri-conception immune environment. Recent studies show that conception in the absence of seminal plasma in mice impairs embryo development and alters fetal development to impact the phenotype of offspring, with adverse effects on adult metabolic function particularly in males. This review summarises our current understanding of the molecular responses to seminal fluid and how this contributes to the establishment of pregnancy, generation of an immune-regulatory environment and programming long-term offspring health.

Medroxyprogesterone Acetate Regulates HIV-1 Uptake and Transcytosis but Not Replication in Primary Genital Epithelial Cells, Resulting in Enhanced T-Cell Infection

Although clinical and experimental evidence indicates that female sex hormones and hormonal contraceptives regulate susceptibility to human immunodeficiency virus type 1 (HIV-1) infection, the underlying mechanism remains unknown. Genital epithelial cells (GECs) are the first cells to encounter HIV during sexual transmission and their interaction with HIV may determine the outcome of exposure. This is the first report that HIV uptake by GECs increased significantly in the presence of the hormonal contraceptive medroxyprogesterone acetate (MPA) and progesterone and that uptake occurred primarily via endocytosis. No productive infection was detected, but endocytosed virus was released into apical and basolateral compartments. Significantly higher viral transcytosis was observed in the presence of MPA. In GEC and T-cell cocultures, maximum viral replication in T cells was observed in the presence of MPA, which also broadly upregulated chemokine production by GECs. These results suggest that MPA may play a significant role in regulating susceptibility to HIV.

The Role of Cationic Polypeptides in Modulating HIV-1 Infection of the Cervicovaginal Mucosa

The mucosa and overlying fluid of the female reproductive tract (FRT) are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa is involved in controlling transmission and infection of HIV-1. Cationic peptides and proteins are the principal innate immune effector molecules of mucosal surfaces, and interact in a combinatorial fashion to modulate HIV-1 infection of the cervix and vagina. While cationic peptides and proteins have historically been categorized as antimicrobial or have other host-benefitting roles, an increasing number of these molecules have been found to augment HIV-1 infection and potentially antagonize host defense. Complex environmental factors such as hormonal fluctuations and/or bacterial and viral co-infections provide additional challenges to both experimentation and interpretation of results. In the context of heterosexual transmission of HIV-1, this review explores how various cationic peptides and proteins participate in modulating host defense against HIV-1 of the cervicovaginal mucosa.

CD4-positive T-cell recruitment in primary-provoked localized vulvodynia: potential insights into disease triggers

OBJECTIVE

To better understand the potential disease triggers of neurogenic inflammation in provoked localized vulvodynia (PLV), our objective was to determine whether the types of infiltrating lymphocytes were different in vestibular biopsies from women with primary PLV, secondary PLV, and unaffected controls.

METHODS

Secondary retrospective analysis of archived vestibular biopsies from a series of adult premenopausal women with primary PLV (n = 10), secondary PLV (n = 10), and unaffected controls (n = 4) was performed. All study patients had severe entry dyspareunia for more than 1 year. Subjects were excluded if pregnant, or they had a known infection, or history of generalized vulvodynia. Biopsies were performed during the midfollicular phase. Lymphocyte subtypes were highlighted in histologic sections using antibodies against CD3, CD4, and CD8 and scored as the mean number of T-cell subtypes per high-power field. Flow cytometry was also used to test fresh biopsies from a de novo prospective series of primary PLV (n = 4) and unaffected controls (n = 2).

RESULTS

Unaffected control biopsies showed more CD8-positive than CD4-positive T cells, similar to previous reports of the gynecologic tract. In contrast, biopsies from women with primary PLV showed significantly more CD4-positive T cells than those from women with secondary PLV and unaffected controls (p = .003). This observation was further supported by flow cytometry.

CONCLUSIONS

CD4-positive T cells are more numerous in vestibular biopsies from premenopausal women with primary PLV. This may be important because subtypes of CD4-positive T cells are specifically recruited by infectious, allergic, or autoimmune triggers. Future studies distinguishing these subtypes may lead to new insights into this common disease.

How can we design better vaccines to prevent HIV infection in women?

The human immunodeficiency virus (HIV) burden in women continues to increase, and heterosexual contact is now the most common route of infection worldwide. Effective protection of women against HIV-1 infection may require a vaccine specifically targeting mucosal immune responses in the female genital tract (FGT). To achieve this goal, a much better understanding of the immunology of the FGT is needed. Here we review the architecture of the immune system of the FGT, recent studies of potential methods to achieve the goal of mucosal protection in women, including systemic-prime, mucosal-boost, FGT-tropic vectors and immune response altering adjuvants. Advances in other fields that enhance our understanding of female genital immune correlates and the interplay between hormonal and immunological systems may also help to achieve protection of women from HIV infection.

Changes in genital tract immune cell populations after initiation of intrauterine contraception

OBJECTIVE

The primary target cells for the human immunodeficiency virus (HIV) infection in the genital tract are CD4 T cells that express CCR5 on the surface. Alterations in genital tract T cells that express CCR5 could impact HIV acquisition risk. We hypothesized that, when compared with baseline, the use of a hormonal intrauterine device (IUD) would alter HIV target cells (primarily CCR5+ CD4 cells) in the female genital tract more than a nonhormonal IUD.

STUDY DESIGN

Thirty-four healthy HIV-negative women aged 18-40 years who were seeking an IUD for contraception were assigned randomly to receive a levonorgestrel IUD or a copper T380A IUD. A parallel group of 8 control women who did not need contraception was also enrolled. Genital tract mucosal immune cell populations that were collected by cervical cytobrush and endometrial biopsy before and 2 months after IUD placement were analyzed by flow cytometry. Mean differences in cell number and percent that expressed receptors from baseline to follow-up examination were evaluated with the use of paired Student t tests.

RESULTS

Neither IUD altered the number of T cells within the upper and lower genital tracts. Levonorgestrel IUD users had a decrease in T cells that expressed the HIV coreceptor CCR5 in the endometrium and cervix after 2 months of use compared with baseline. There was a decrease in activated endometrial T cells in levonorgestrel IUD users and a decrease in activated cervical T cells in copper IUD users after 2 months of IUD use, compared with baseline.

CONCLUSION

Women who use IUDs have reduced expression of the CCR5 HIV coreceptor on T cells in the endometrium and cervix compared with expression before IUD placement. These findings suggest that susceptibility to HIV infection would not be increased by IUD use.

Mucosal immunity in the female genital tract, HIV/AIDS

Mucosal immunity consists of innate and adaptive immune responses which can be influenced by systemic immunity. Despite having been the subject of intensive studies, it is not fully elucidated what exactly occurs after HIV contact with the female genital tract mucosa. The sexual route is the main route of HIV transmission, with an increased risk of infection in women compared to men. Several characteristics of the female genital tract make it suitable for inoculation, establishment of infection, and systemic spread of the virus, which causes local changes that may favor the development of infections by other pathogens, often called sexually transmitted diseases (STDs). The relationship of these STDs with HIV infection has been widely studied. Here we review the characteristics of mucosal immunity of the female genital tract, its alterations due to HIV/AIDS, and the characteristics of coinfections between HIV/AIDS and the most prevalent STDs.

Methylation patterns of the IFN-γ gene in cervical cancer tissues

OBJECTIVE

To explore the relationship between methylation of interferon gamma (IFN-γ) gene and tumorigenesis in cervical cancer tissues, the biopsy specimens of cervical cancer and cervical intraepithelial neoplasia (CIN) (I-III) patients as well as normal controls were collected and analyzed.

METHODS

The methylation of the IFN-γ gene was verified by using methylation-specific PCR and DNA sequencing analysis, and the expression levels of IFN-γ mRNA were detected using quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR).

RESULTS

The methylation rates of the IFN-γ gene were significantly higher in cervical cancer tissues (15/43, 34.9%) than those in CIN (3/23, 13.0% of CIN I; 6/39, 15.4% of CIN II/III) and normal cervical tissues (2/43, 4.7%) (P < 0.01). Furthermore, the mRNA expression of IFN-γ in cervical tumors with methylation (0.71 ± 0.13, n = 8) was lower than that in those without methylation (1.58 ± 0.32, n = 27) (P < 0.05). Likewise, the IFN-γ expression levels in CIN II/III tissues with methylation (0.87 ± 0.16, n = 5) were significantly (P < 0.01) lower compared to those without methylation (2.12 ± 0.27, n = 32).

CONCLUSION

The hypermethylation of IFN-γ gene may be related with tumorigenesis of cervical cancer.

The regulation of inflammatory pathways and infectious disease of the cervix by seminal fluid

The connection between human papillomavirus (HPV) infection and the consequent sequelae which establishes cervical neoplastic transformation and invasive cervical cancer has redefined many aspects of cervical cancer research. However there is still much that we do not know. In particular, the impact of external factors, like seminal fluid in sexually active women, on pathways that regulate cervical inflammation and tumorigenesis, have yet to be fully understood. HPV infection is regarded as the initiating noninflammatory cause of the disease; however emerging evidence points to resident HPV infections as drivers of inflammatory pathways that play important roles in tumorigenesis as well as in the susceptibility to other infections such as human immunodeficiency virus (HIV) infection. Moreover there is emerging evidence to support a role for seminal fluid, in particular, the inflammatory bioactive lipids, and prostaglandins which are present in vast quantities in seminal fluid in regulating pathways that can exacerbate inflammation of the cervix, speed up tumorigenesis, and enhance susceptibility to HIV infection. This review will highlight some of our current knowledge of the role of seminal fluid as a potent driver of inflammatory and tumorigenic pathways in the cervix and will provide some evidence to propose a role for seminal plasma prostaglandins in HIV infection and AIDS-related cancer.

Innate and adaptive immune responses in male and female reproductive tracts in homeostasis and following HIV infection

The male and female reproductive tracts are complex microenvironments that have diverse functional demands. The immune system in the reproductive tract has the demanding task of providing a protective environment for a fetal allograft while simultaneously conferring protection against potential pathogens. As such, it has evolved a unique set of adaptations, primarily under the influence of sex hormones, which make it distinct from other mucosal sites. Here, we discuss the various components of the immune system that are present in both the male and female reproductive tracts, including innate soluble factors and cells and humoral and cell-mediated adaptive immunity under homeostatic conditions. We review the evidence showing unique phenotypic and functional characteristics of immune cells and responses in the male and female reproductive tracts that exhibit compartmentalization from systemic immunity and discuss how these features are influenced by sex hormones. We also examine the interactions among the reproductive tract, sex hormones and immune responses following HIV-1 infection. An improved understanding of the unique characteristics of the male and female reproductive tracts will provide insights into improving clinical treatments of the immunological causes of infertility and the design of prophylactic interventions for the prevention of sexually transmitted infections.

Physiologic doses of depot-medroxyprogesterone acetate do not increase acute plasma simian HIV viremia or mucosal virus shedding in pigtail macaques

OBJECTIVE

Epidemiologic studies remain inconclusive on whether the injectable contraceptive depot-medroxyprogesterone acetate (DMPA) increases mucosal HIV shedding and transmissibility. Nonhuman primate models may help to determine the effects of DMPA on acute HIV replication.

DESIGN

We defined a physiologic dose of DMPA in macaques and assessed the impact of DMPA on acute simian HIV (SHIV) replication.

METHODS

Pigtail macaques received 1-30  mg of DMPA intramuscularly followed by measurements of progesterone and medroxyprogesterone acetate (MPA). Vaginal epithelial thickness, number of cell layers and density of intraepithelial CD3 cells were measured. The effect of DMPA on SHIV viremia and genital virus shedding was investigated in six pigtail macaques infected during monthly treatment cycles with 3  mg DMPA. Six DMPA-untreated macaques were controls.

RESULTS

Plasma MPA concentrations directly correlated with changes in epithelial thickness (correlation = 0.84; P < 0.001) and density of intraepithelial CD3 cells (correlation = 0.41; P = 0.02). A 3 mg DMPA dose recapitulated plasma MPA concentrations and changes in vaginal epithelial thickness seen in women. DMPA-treated and untreated macaques showed similar peak plasma viremia and RNA area under the curve values over 12 weeks (P = 0.94), although treated macaques had higher odds of having virus being detected in plasma (odds ratio 6.6, P = 0.02). Rectal and vaginal virus shedding was similar between treated and untreated macaques (P  = 0.72 and P = 0.53, respectively).

CONCLUSION

In this pigtail macaque model of DMPA and vaginal SHIV infection, we found little or no effect of DMPA on plasma viremia and mucosal virus shedding during acute infection. These results do not support a role of DMPA in increasing mucosal HIV shedding.

Cervical and vaginal flora specimens are highly concordant with respect to bacterial vaginosis-associated organisms and commensal Lactobacillus species in women of reproductive age

Matched vaginal and cervical specimens from 96 subjects were analyzed by quantitative PCR for the presence and concentration of bacterial vaginosis-associated microbes and commensal Lactobacillus spp. Detection of these microbes was 92% concordant, indicating that microbial floras at these body sites are generally similar.

Pre-clinical development of a combination microbicide vaginal ring containing dapivirine and darunavir

OBJECTIVES

Combination microbicide vaginal rings may be more effective than single microbicide rings at reducing/preventing sexual transmission of HIV. Here, we report the pre-clinical development and macaque pharmacokinetics of matrix-type silicone elastomer vaginal rings containing dapivirine and darunavir.

METHODS

Macaque rings containing 25 mg dapivirine, 100 mg dapivirine, 300 mg darunavir or 100 mg dapivirine+300 mg darunavir were manufactured and characterized by differential scanning calorimetry. In vitro release was assessed into isopropanol/water and simulated vaginal fluid. Macaque vaginal fluid and blood serum concentrations for both antiretrovirals were measured during 28 day ring use. Tissue levels were measured on day 28. Ex vivo challenge studies were performed on vaginal fluid samples and IC50 values were calculated.

RESULTS

Darunavir caused a concentration-dependent reduction in the dapivirine melting temperature in both solid drug mixes and in the combination ring. In vitro release from rings was dependent on drug loading, the number of drugs present and the release medium. In macaques, serum concentrations of both microbicides were maintained between 10(1) and 10(2) pg/mL. Vaginal fluid levels ranged between 10(3) and 10(4) ng/g and between 10(4) and 10(5) ng/g for dapivirine and darunavir, respectively. Both dapivirine and darunavir showed very similar concentrations in each tissue type; the range of drug tissue concentrations followed the general rank order: vagina (1.8 × 10(3)-3.8 × 10(3) ng/g)  > cervix (9.4 × 10(1)-3.9 × 10(2) ng/g)  > uterus (0-108 ng/g)  > rectum (0-40 ng/g). Measured IC50 values were >2 ng/mL for both compounds.

CONCLUSIONS

Based on these results, and in light of recent clinical progress of the 25 mg dapivirine ring, a combination vaginal ring containing dapivirine and darunavir is a viable second-generation HIV microbicide candidate.

The injectable-only contraceptive medroxyprogesterone acetate, unlike norethisterone acetate and progesterone, regulates inflammatory genes in endocervical cells via the glucocorticoid receptor

Clinical studies suggest that the injectable contraceptive medroxyprogesterone acetate (MPA) increases susceptibility to infections such as HIV-1, unlike the injectable contraceptive norethisterone enanthate (NET-EN). We investigated the differential effects, molecular mechanism of action and steroid receptor involvement in gene expression by MPA as compared to NET and progesterone (P4) in the End1/E6E7 cell line model for the endocervical epithelium, a key point of entry for pathogens in the female genital mucosa. MPA, unlike NET-acetate (NET-A) and P4, increases mRNA expression of the anti-inflammatory GILZ and IκBα genes. Similarly, MPA unlike NET-A, decreases mRNA expression of the pro-inflammatory IL-6, IL-8 and RANTES genes, and IL-6 and IL-8 protein levels. The predominant steroid receptor expressed in the End1/E6E7 and primary endocervical epithelial cells is the glucocorticoid receptor (GR), and GR knockdown experiments show that the anti-inflammatory effects of MPA are mediated by the GR. Chromatin-immunoprecipitation results suggest that MPA, unlike NET-A and P4, represses pro-inflammatory cytokine gene expression in cervical epithelial cells via a mechanism involving recruitment of the GR to cytokine gene promoters, like the GR agonist dexamethasone. This is at least in part consistent with direct effects on transcription, without a requirement for new protein synthesis. Dose response analysis shows that MPA has a potency of ∼24 nM for transactivation of the anti-inflammatory GILZ gene and ∼4–20 nM for repression of the pro-inflammatory genes, suggesting that these effects are likely to be relevant at injectable contraceptive doses of MPA. These findings suggest that in the context of the genital mucosa, these GR-mediated glucocorticoid-like effects of MPA in cervical epithelial cells are likely to play a critical role in discriminating between the effects on inflammation caused by different progestins and P4 and hence susceptibility to genital infections, given the predominant expression of the GR in primary endocervical epithelial cells.

Role of semen in altering the balance between inflammation and tolerance in the female genital tract: does it contribute to HIV risk?

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.

Induction of Potent and Long-Lived Antibody and Cellular Immune Responses in the Genitorectal Mucosa Could be the Critical Determinant of HIV Vaccine Efficacy

The field of HIV prevention has indeed progressed in leaps and bounds, but with major limitations of the current prevention and treatment options, the world remains desperate for an HIV vaccine. Sadly, this continues to be elusive, because more than 30 years since its discovery there is no licensed HIV vaccine. Research aiming to define immunological biomarkers to accurately predict vaccine efficacy have focused mainly on systemic immune responses, and as such, studies defining correlates of protection in the genitorectal mucosa, the primary target site for HIV entry and seeding are sparse. Clearly, difficulties in sampling and analysis of mucosal specimens, as well as their limited size have been a major deterrent in characterizing the type (mucosal antibodies, cytokines, chemokines, or CTL), threshold (magnitude, depth, and breadth) and viral inhibitory capacity of HIV-1-specific immune responses in the genitorectal mucosa, where they are needed to immediately block HIV acquisition and arrest subsequent virus dissemination. Nevertheless, a few studies document the existence of HIV-specific immune responses in the genitorectal mucosa of HIV-infected aviremic and viremic controllers, as well as in highly exposed persistently seronegative (HEPS) individuals with natural resistance to HIV-1. Some of these responses strongly correlate with protection from HIV acquisition and/or disease progression, thus providing significant clues of the ideal components of an efficacious HIV vaccine. In this study, we provide an overview of the key features of protective immune responses found in HEPS, elite and viremic controllers, and discuss how these can be achieved through mucosal immunization. Inevitably, HIV vaccine development research will have to consider strategies that elicit potent antibody and cellular immune responses within the genitorectal mucosa or induction of systemic immune cells with an inherent potential to home and persist at mucosal sites of HIV entry.

HIV-1 vaginal transmission: cell-free or cell-associated virus?

The vast majority of new HIV infections in male-to-female transmission occurs through semen, where HIV-1 is present in two different forms: as free and as cell-associated virus. In the female lower genital tract, semen mixes with female genital secretions that contain various factors, some of which facilitate or inhibit HIV-1 transmission. Next, HIV-1 crosses the genital epithelia, reaches the regional lymph nodes, and disseminates through the female host. Cervico-vaginal mucosa contains multiple barriers, resulting in a low probability of vaginal transmission. However, in some cases, HIV-1 is able to break these barriers. Although the exact mechanisms of how these barriers function remain unclear, their levels of efficiency against cell-free and cell-associated HIV-1 are different, and both cell-free and cell-associated virions seem to use different strategies to overcome these barriers. Understanding the basic mechanisms of HIV-1 vaginal transmission is required for the development of new antiviral strategies to contain HIV-1 epidemics.