Changes in the soluble mucosal immune environment during genital herpes outbreaks

A non-optimal cervicovaginal microbiota in pregnancy is associated with a distinct metabolomic signature among non-Hispanic Black individuals

Biomechanical and molecular processes of premature cervical remodeling preceding spontaneous preterm birth (sPTB) likely result from interactions between the cervicovaginal microbiota and host immune responses. A non-optimal cervicovaginal microbiota confers increased risk of sPTB. The cervicovaginal space is metabolically active in pregancy; microbiota can produce, modify, and degrade metabolites within this ecosystem. We establish that cervicovaginal metabolomic output clusters by microbial community in pregnancy among Black individuals, revealing increased metabolism within the amino acid and dipeptide pathways as hallmarks of a non-optimal microbiota. Few differences were detected in metabolomic profiles when stratified by birth outcome. The study raises the possibility that metabolites could distinguish women with greater risk of sPTB among those with similar cervicovaginal microbiota, and that metabolites within the amino acid and carbohydrate pathways may play a role in this distinction.

Establishment of a Novel Porcine Model to Study the Impact of Active Stretching on a Local Carrageenan-Induced Inflammation

OBJECTIVE

Active stretching of the body is integral to complementary mind-body therapies such as yoga, as well as physical therapy, yet the biologic mechanisms underlying its therapeutic effects remain largely unknown. A previous study showed the impact of active stretching on inflammatory processes in rats. The present study tested the feasibility of using a porcine model, with a closer resemblance to human anatomy, to study the effects of active stretching in the resolution of localized inflammation.

DESIGN

A total of 12 pigs were trained to stretch before subcutaneous bilateral Carrageenan injection in the back at the L3 vertebrae, 2 cm from the midline. Animals were randomized to no-stretch or stretch, twice a day for 5 mins over 48 hrs. Animals were euthanized for tissue collection 48 hrs postinjection.

RESULTS

The procedure was well tolerated by the pigs. On average, lesion area was significantly smaller by 36% in the stretch group compared with the no-stretch group (P = 0.03).

CONCLUSION

This porcine model shows promise for studying the impact of active stretching on inflammation-resolution mechanisms. These results are relevant to understanding the stretching-related therapeutic mechanisms of mind-body therapies. Future studies with larger samples are warranted.

Model of vaccine efficacy against HSV-2 superinfection of HSV-1 seropositive mice demonstrates protection by antibodies mediating cellular cytotoxicity

A majority of the world’s population is infected with HSV-1, highlighting the need for vaccines that are effective in HSV-1-seropositive hosts. We established a superinfection model by infecting mice intranasally with a sublethal dose of HSV-1, which results in high rates of seropositive, latently infected mice susceptible to HSV-2 superinfection. Sublethal HSV-1 induced a predominantly neutralizing antibody response. Vaccination of HSV-1-seropositive mice with recombinant adjuvanted glycoprotein D (rgD-2) failed to significantly boost HSV total or neutralizing antibody responses and provided no significant increased protection against HSV-2 superinfection compared to control-vaccinated HSV-1-seropositive mice. In contrast, immunization with a single-cycle virus deleted in gD (ΔgD-2) significantly boosted total HSV-specific antibody titers and elicited new antibody-dependent cell-mediated cytotoxicity responses, providing complete protection from death following HSV-2 superinfection. This model recapitulates clinical responses to natural infection and the rgD-2 vaccine trial outcomes and suggests that ΔgD-2 may prove protective in HSV-1-seropositive hosts.

Pre-exposure prophylaxis differentially alters circulating and mucosal immune cell activation in herpes simplex virus type 2 seropositive women

OBJECTIVE

Oral tenofovir-based pre-exposure prophylaxis (PrEP) is an important tool for prevention of new HIV infections, which also reduces subclinical herpes simplex virus type 2 (HSV-2) shedding and symptomatic lesions in HIV-negative, HSV-2-seropositive individuals. However, the impact of PrEP on mucosal immunity has not been examined in detail.

DESIGN

Here we evaluate paired genital tissue and systemic immune profiles to characterize the immunological effects of PrEP in HIV-negative, HSV-2-seropositive African women sexually exposed to HIV.

METHODS

We compared local and systemic innate and T-cell characteristics in samples collected during PrEP usage and 2 months after PrEP discontinuation.

RESULTS

We found that frequencies of cervical CCR5CD4 cells, regulatory T cells, and tissue macrophages were significantly reduced during PrEP use compared with after PrEP discontinuation. In contrast, peripheral blood CD4 and CD8 T cells expressing markers of activation and trafficking were increased during PrEP usage.

CONCLUSION

Together, our data are consistent with PrEP altering immunity differentially in the female genital tract compared with circulation in HSV-2+ women. Further study including comparison with HSV-2 negative women is needed to define the overall impact and mechanisms underlying these effects. These results point to the critical need to study the human mucosal compartment to characterize immune responses to mucosal infections.

Impact of Herpes Simplex Virus Type 2 and Human Immunodeficiency Virus Dual Infection on Female Genital Tract Mucosal Immunity and the Vaginal Microbiome

BACKGROUND

Mechanisms linking herpes simplex virus type 2 (HSV-2) with human immunodeficiency virus (HIV) are not fully defined. We tested the hypothesis that HSV-2 and HIV dual infection is associated with cervicovaginal inflammation and/or vaginal dysbiosis.

METHODS

Genital tract samples were obtained weekly over a 12-week period from 30 women seropositive (+) for HIV and HSV-2 and 15 women each who were seropositive for one or seronegative (-) for both viruses. Immune mediators, antimicrobial activity, and microbial composition and diversity were compared.

RESULTS

Significant differences in the concentrations of interferon-γ (P = .002), tumor necrosis factor-α (P = .03), human beta defensin 1 (P = .001), secretory leukocyte protease inhibitor (P = .01), and lysozyme (P = .03) were observed across the 4 groups (Kruskal-Wallis). There were also significant differences in vaginal microbial alpha diversity (Simpson index) (P = .0046). Specifically, when comparing HIV-1+/HSV-2+ to HIV-1-/HSV-2- women, a decrease in Lactobacillus crispatus and increase in diverse anaerobes was observed. The number of genital HSV outbreaks was greater in HIV+ versus HIV- women (39 versus 12) (P = .04), but there were no significant differences when comparing outbreak to non-outbreak visits.

CONCLUSIONS

Increased microbial diversity and cervicovaginal inflammation in HIV and HSV-2 dually infected women may adversely impact genital health and, in the absence of antiretroviral therapy, facilitate HIV shedding.

Impact of reproductive aging on the vaginal microbiome and soluble immune mediators in women living with and at-risk for HIV infection

BACKGROUND

Reproductive aging may impact the vaginal microbiome and genital tract mucosal immune environment and contribute to genital tract health in women living with and at-risk for HIV infection.

METHODS

A cross-sectional study of 102 HIV+ (51 premenopausal, 51 postmenopausal) and 39 HIV-uninfected (HIV-) (20 premenopausal, 19 postmenopausal) women was performed in Bronx and Brooklyn, NY. Cervicovaginal lavage (CVL) was collected for quantification of innate antimicrobial activity against E. coli, HSV-2 and HIV and immune mediators by Luminex and ELISA. Microbiome studies by qPCR and 16S rRNA sequencing were performed on vaginal swabs.

RESULTS

HIV+ postmenopausal compared to premenopausal participants had lower median E. coli bactericidal activity (41% vs. 62%, p = 0.001), lower median gene copies of Lactobacillus crispatus (p = 0.005) and Lactobacillus iners (p = 0.019), lower proportions of Lactobacillus iners, higher proportions of Gardnerella and Atopobium vaginae and lower levels of human beta defensins (HBD-2, HBD-3) and secretory leukocyte protease inhibitor (SLPI), p<0.001. HSV-2 inhibitory activity was higher in HIV+ postmenopausal compared to premenopausal participants (37% vs. 17%, p = 0.001) and correlated with the proinflammatory molecules interleukin (IL) 6, IL-8, human neutrophil peptide (HNP) 1-3, lactoferrin and fibronectin. Similar trends were observed in HIV- postmenopausal compared to premenopausal participants. HIV inhibitory activity did not differ by reproductive status in the HIV+ participants but was significantly higher in HIV- postmenopausal compared to premenopausal participants and in participants with suppressed plasma viral load, and inversely correlated with gene copies of G. vaginalis and BVAB2. A significant proportion of HIV+ participants on ART exhibited HIV enhancing activity.

CONCLUSIONS

HIV+ postmenopausal compared to premenopausal participants have less CVL E. coli bactericidal activity, reflecting a reduction in Lactobacilli and a greater proportion of Gardnerella and A. vaginae, and more HSV-2 inhibitory activity, reflecting increased mucosal inflammation. The effect of menopause on mucosal immunity was greater in HIV+ participants, suggesting a synergistic impact. Promotion of a lactobacillus dominant vaginal microbiome and reduced mucosal inflammation may improve vaginal health and reduce risk for shedding of HIV and potential for HIV transmission in HIV+ menopausal women.

Etiology of Genital Ulcer Disease in Male Patients Attending a Sexually Transmitted Diseases Clinic: First Assessment in Cuba

BACKGROUND

Sexually transmitted diseases (STDs) and in particular genital ulcer disease (GUD) have a major impact on morbidity and mortality in developing countries. The World Health Organization recommends the use of syndromic guidelines for the treatment of sexually transmitted infections (STIs) in resource-constrained countries. Surveillance of autochthonous etiologies provides epidemiological information contributing to the prevention and treatment of STIs. We investigated the etiology and factors associated with GUD among male patients attending a STD clinic in Havana, Cuba.

METHODS

Swabs from genital ulcers of 113 male patients, collected from May 2012 to June 2015, were analyzed using PCR for herpes simplex virus types 1 and 2, Treponema pallidum, Haemophilus ducreyi, and Chlamydia trachomatis. We also investigated the clinical and epidemiological characteristics associated with the presence of these pathogens in GUD.

RESULTS

At least one of the pathogens was detected in 70% of patients. The occurrence of the pathogens was herpes simplex virus type 2 (HSV-2) (51.3%), T. pallidum (29.2%), and C. trachomatis (1.8%). Co-infections occurred as follows: T. pallidum-HSV-2 (10.6%), C. trachomatis-HSV-2 (0.9%) and C. trachomatis-T. pallidum (0.9%). Herpes simplex virus type 1 and H. ducreyi were not detected. Ages 15 to 40 years, HIV-positive serostatus, and no condom use were significant risk factors for the presence of HSV-2 in genital ulcers.

CONCLUSIONS

Our preliminary results highlight the predominance of HSV-2 and T. pallidum as the leading GUD etiologies in the study population and identified risk factors associated with HSV-2. This information should help to inform guidelines for better management of GUD in Havana, Cuba.

Association of vaginal dysbiosis and biofilm with contraceptive vaginal ring biomass in African women

We investigated the presence, density and bacterial composition of contraceptive vaginal ring biomass and its association with the vaginal microbiome. Of 415 rings worn by 120 Rwandese women for three weeks, the biomass density was assessed with crystal violet and the bacterial composition of biomass eluates was assessed with quantitative polymerase chain reaction (qPCR). The biomass was visualised after fluorescence in situ hybridisation (FISH) and with scanning electron microscopy (SEM). The vaginal microbiome was assessed with Nugent scoring and vaginal biofilm was visualised after FISH. All vaginal rings were covered with biomass (mean optical density (OD) of 3.36; standard deviation (SD) 0.64). Lactobacilli were present on 93% of the rings, Gardnerella vaginalis on 57%, and Atopobium vaginae on 37%. The ring biomass density was associated with the concentration of A. vaginae (OD +0.03; 95% confidence interval (CI) 0.01–0.05 for one log increase; p = 0.002) and of G. vaginalis (OD +0.03; (95% CI 0.01–0.05; p = 0.013). The density also correlated with Nugent score: rings worn by women with a BV Nugent score (mean OD +0.26), and intermediate score (mean OD +0.09) had a denser biomass compared to rings worn by participants with a normal score (p = 0.002). Furthermore, presence of vaginal biofilm containing G. vaginalis (p = 0.001) and A. vaginae (p = 0.005) correlated with a denser ring biomass (mean OD +0.24 and +0.22 respectively). With SEM we observed either a loose network of elongated bacteria or a dense biofilm. We found a correlation between vaginal dysbiosis and the density and composition of the ring biomass, and further research is needed to determine if these relationships are causal. As multipurpose vaginal rings to prevent pregnancy, HIV, and other sexually transmitted diseases are being developed, the potential impact of ring biomass on the vaginal microbiota and the release of active pharmaceutical ingredients should be researched in depth.

The Effects of Hormones and Vaginal Microflora on the Glycome of the Female Genital Tract: Cervical-Vaginal Fluid

In this study, we characterized the glycome of cervical-vaginal fluid, collected with a Catamenial cup. We quantified: glycosidase levels; sialic acid and high mannose specific lectin binding; mucins, MUC1, MUC4, MUC5AC, MUC7; and albumin in the samples collected. These data were analyzed in the context of hormonal status (day of menstrual cycle, hormonal contraception use) and role, if any, of the type of the vaginal microflora present. When the Nugent score was used to stratify the subjects by microflora as normal, intermediate, or bacterial vaginosis, several important differences were observed. The activities of four of six glycosidases in the samples from women with bacterial vaginosis were significantly increased when compared to normal or intermediate women: sialidase, P = <0.001; α-galactosidase, P = 0.006; β-galactosidase, P = 0.005; α-glucosidase, P = 0.056. Sialic acid binding sites as measured by two lectins, Maackia amurensis and Sambucus nigra binding, were significantly lower in women with BV compared to women with normal and intermediate scores (P = <0.0001 and 0.008 respectively). High mannose binding sites, a measure of innate immunity were also significantly lower in women with BV (P = <0.001). Additionally, we observed significant increases in MUC1, MUC4, MUC5AC, and MUC7 concentrations in women with BV (P = <0.001, 0.001, <0.001, 0.02 respectively). Among normal women we found that the membrane bound mucin MUC4 and the secreted MUC5AC were decreased in postmenopausal women (P = 0.02 and 0.07 respectively), while MUC7 (secreted) was decreased in women using levonorgestrel-containing IUDs (P = 0.02). The number of sialic acid binding sites was lower in the postmenopausal group (P = 0.04), but the number of high mannose binding sites, measured with Griffithsin, was not significantly different among the 6 hormonal groups. The glycosidase levels in the cervical-vaginal mucus were rather low in the groups, with exception of α-glucosidase activity that was much lower in the postmenopausal group (P<0.001). These studies present compelling evidence that the vaginal ecosystem responds to the presence of different vaginal microorganisms. These effects were so influential that it required us to remove subjects with BV for data interpretation of the impact of hormones. We also suggest that certain changes occurring in vaginal/cervical proteins are due to bacteria or their products. Therefore, the quantitation of vaginal mucins and lectin binding offers a new method to monitor bacteria-host interactions in the female reproductive tract. The data suggest that some of the changes in these components are the result of host processing, such as the increases in mucin content, while the microflora is responsible for the increases in glycosidases and the decreases in lectin binding. The methods should be considered a valid marker for insult to the female genital tract.

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.

Association of High-Risk Human Papillomavirus with Genital Tract Mucosal Immune Factors in HIV-Infected Women

PROBLEM

High-risk human papillomavirus (HR-HPV) is prevalent in HIV-infected women and may be associated with mucosal changes that promote HIV replication.

METHOD OF STUDY

Innate immune molecules, antimicrobial activity, HIV RNA, and HPV DNA genotypes were measured in a cross-sectional study of 128 HIV-infected women categorized into HPV-16 (n = 8), other HR-HPV (n = 41), and non-HR-HPV controls (n = 79).

RESULTS

Compared to controls, HR-HPV groups had higher plasma viral loads (P = 0.004), lower CD4 cells (P = 0.02), more genital tract HIV RNA (P = 0.03), greater number of different HPV types (P < 0.001), higher cervicovaginal lavage (CVL) IL-1α (P = 0.03) and human beta-defensin 2 (HBD2) (P = 0.049), and less anti-HIVB al activity (P = 0.03). HPV-16 remained significantly associated with higher HBD2 (P = 0.03), higher IL-1α (P = 0.009), and lower anti-HIVB aL activity (P = 0.03) compared to controls after adjusting for plasma viral load and CD4 T cell count.

CONCLUSION

HR-HPV is associated with mucosal changes in HIV-infected women that could adversely impact genital tract health.

Herpes Simplex Virus Cervicitis Mimicking Preterm Premature Rupture of Membranes

BACKGROUND

The diagnosis of preterm premature rupture of membranes (PROM) is based on pooling, ferning, and Nitrazine tests; definitive diagnosis is made with a blue dye test.

CASE

A 21-year-old woman, gravida 1 para 0, at 25 5/7 weeks of gestation was admitted for preterm PROM with positive findings of pooling, Nitrazine, and ferning. Her cervix was bluish with white plaques. Amniotic fluid volume was normal. On hospital day 8, her discharge ceased; examination was negative for pooling, Nitrazine, and ferning. A blue dye tampon test was negative. A Pap test result from her hospitalization returned consistent with herpes infection.

CONCLUSION

The diagnosis of preterm PROM should be constantly reevaluated in the setting of a normal amniotic fluid volume.

Impact of bacterial vaginosis, as assessed by nugent criteria and hormonal status on glycosidases and lectin binding in cervicovaginal lavage samples

The objective of this study was to evaluate the impact of hormonal status and bacterial vaginosis (BV) on the glycosidases present and glycosylation changes as assessed by lectin binding to cervicovaginal lavage constituents. Frozen cervicovaginal lavage samples from a completed study examining the impact of reproductive hormones on the physicochemical properties of vaginal fluid were utilized for the present study. In the parent study, 165 women were characterized as having BV, intermediate or normal microflora using the Nugent criteria. The presence of glycosidases in the samples was determined using quantitative 4-methyl-umbelliferone based assays, and glycosylation was assessed using enzyme linked lectin assays (ELLA). Women with BV had elevated sialidase, α-galactosidase, β-galactosidase and α-glucosidase activities compared to intermediate or normal women (P<0.001, 0.003, 0.006 and 0.042 respectively). The amount of sialic acid (Sambucus nigra, P = 0.003) and high mannose (griffithsin, P<0.001) were reduced, as evaluated by lectin binding, in women with BV. When the data were stratified according to hormonal status, α-glucosidase and griffithsin binding were decreased among postmenopausal women (P<0.02) when compared to premenopausal groups. These data suggest that both hormonal status and BV impact the glycosidases and lectin binding sites present in vaginal fluid. The sialidases present at increased levels in women with BV likely reduce the number of sialic acid binding sites. Other enzymes likely reduce griffithsin binding. The alterations in the glycosidase content, high mannose and sialic acid binding sites in the cervicovaginal fluid associated with bacterial vaginosis may impact susceptibility to viruses, such as HIV, that utilize glycans as a portal of entry.

Cross-Sectional Analysis of Selected Genital Tract Immunological Markers and Molecular Vaginal Microbiota in Sub-Saharan African Women, with Relevance to HIV Risk and Prevention

Data on immune mediators in the genital tract and the factors that modulate them in sub-Saharan women are limited. Cervicovaginal lavage (CVL) samples from 430 sexually active women from Kenya, South Africa, and Rwanda were analyzed for 12 soluble immune mediators using Bio-Plex and Meso Scale Discovery multiplex platforms, as well as single enzyme-linked immunosorbent assays. Ten bacterial species were quantified in vaginal swab samples. Bacterial vaginosis (BV) was defined by Nugent scoring. CVL samples from HIV-infected women showed a clear-cut proinflammatory profile. Pregnant women, adolescents, and women engaging in traditional vaginal practices differed in specific soluble markers compared to reference groups of adult HIV-negative women. Cervical mucus, cervical ectopy, abnormal vaginal discharge, and having multiple sex partners were each associated with an increase in inflammatory mediators. The levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12(p70), and IL-8 were elevated, whereas the IL-1RA/IL-1(α+β) ratio decreased in women with BV. The level of gamma interferon-induced protein 10 was lower in BV-positive than in BV-negative women, suggesting its suppression as a potential immune evasion mechanism by BV-associated bacteria. Lactobacillus crispatus and Lactobacillus vaginalis were associated with decreased proinflammatory cytokines and each BV-associated species with increased proinflammatory cytokines. Remarkably, the in vitro anti-HIV activity of CVL samples from BV-positive women was stronger than that of BV-negative women. In conclusion, we found significant associations of factors, including vaginal microbiota, which can influence immune mediators in the vaginal environment in sexually active women. These factors need to be considered when establishing normative levels or pathogenic cutoffs of biomarkers of inflammation and associated risks in African women.

Persistence of mucosal T-cell responses to herpes simplex virus type 2 in the female genital tract

Relatively little is known about the human T-cell response to herpes simplex virus type 2 (HSV-2) in the female genital tract, a major site of heterosexual HSV-2 acquisition, transmission, and reactivation. In order to understand the role of local mucosal immunity in HSV-2 infection, T-cell lines were expanded from serial cervical cytobrush samples from 30 HSV-2-infected women and examined for reactivity to HSV-2. Approximately 3% of the CD3+ T cells isolated from the cervix were HSV-2 specific and of these, a median of 91.3% were CD4+, whereas a median of 3.9% were CD8+. HSV-2-specific CD4+ T cells expanded from the cervix were not only more frequent than CD8+ T cells but also exhibited greater breadth in terms of antigenic reactivity. T cells directed at the same HSV-2 protein were often detected in serial cervical cytobrush samples and in blood. Thus, broad and persistent mucosal T-cell responses to HSV-2 were detected in the female genital tract of HSV-2+ women suggesting that these cells are resident at the site of HSV-2 infection. Understanding the role of these T cells at this biologically relevant site will be central to the elucidation of adaptive immune mechanisms involved in controlling HSV-2 disease.

HSV-2-driven increase in the expression of α4β7 correlates with increased susceptibility to vaginal SHIV(SF162P3) infection

The availability of highly susceptible HIV target cells that can rapidly reach the mucosal lymphoid tissues may increase the chances of an otherwise rare transmission event to occur. Expression of α4β7 is required for trafficking of immune cells to gut inductive sites where HIV can expand and it is expressed at high level on cells particularly susceptible to HIV infection. We hypothesized that HSV-2 modulates the expression of α4β7 and other homing receptors in the vaginal tissue and that this correlates with the increased risk of HIV acquisition in HSV-2 positive individuals. To test this hypothesis we used an in vivo rhesus macaque (RM) model of HSV-2 vaginal infection and a new ex vivo model of macaque vaginal explants. In vivo we found that HSV-2 latently infected RMs appeared to be more susceptible to vaginal SHIVSF162P3 infection, had higher frequency of α4β7high CD4+ T cells in the vaginal tissue and higher expression of α4β7 and CD11c on vaginal DCs. Similarly, ex vivo HSV-2 infection increased the susceptibility of the vaginal tissue to SHIVSF162P3. HSV-2 infection increased the frequencies of α4β7high CD4+ T cells and this directly correlated with HSV-2 replication. A higher amount of inflammatory cytokines in vaginal fluids of the HSV-2 infected animals was similar to those found in the supernatants of the infected explants. Remarkably, the HSV-2-driven increase in the frequency of α4β7high CD4+ T cells directly correlated with SHIV replication in the HSV-2 infected tissues. Our results suggest that the HSV-2-driven increase in availability of CD4+ T cells and DCs that express high levels of α4β7 is associated with the increase in susceptibility to SHIV due to HSV-2. This may persists in absence of HSV-2 shedding. Hence, higher availability of α4β7 positive HIV target cells in the vaginal tissue may constitute a risk factor for HIV transmission.

Antiviral activity of genital tract secretions after oral or topical tenofovir pre-exposure prophylaxis for HIV-1

BACKGROUND

Surrogate markers of HIV-1 pre-exposure prophylaxis and microbicide efficacy are needed. One potential surrogate is the antiviral activity in cervicovaginal lavage (CVL) after exposure to candidate products. We measured CVL antiviral activity in women using oral or vaginal tenofovir-based pre-exposure prophylaxis and correlated activity with drug and immune mediator levels.

METHODS

Inhibitory activity against HIV-1 and herpes simplex virus (HSV)-2 and concentrations of interleukin (IL)-1β, IL-6, IL-8, interferon-γ, induced protein 10 (IP-10), macrophage inflammatory protein (MIP)-1α, MIP-3a, lactoferrin, secretory leukocyte protease inhibitor, and defensins were measured in CVL obtained from 60 women at baseline and after 6 weeks of a randomized sequence of oral and topical tenofovir. CVL tenofovir concentrations were measured by mass spectrometry.

RESULTS

The number of women with CVL anti-HIV activity ≥ 90% increased significantly from 5.0% at baseline to 89.1% after daily use of 1% tenofovir gel (relative risk = 17.85, P < 0.001), but there was no increase after daily oral tenofovir. The CVL anti-HIV activity correlated with drug levels (Spearman correlation coefficient 0.64 after tenofovir gel; P < 0.001) but not with the concentrations of mucosal immune mediators. No increase in CVL anti-HSV activity was observed after either drug regimen, an observation consistent with the higher concentrations of tenofovir needed to inhibit HSV-2 infection. The CVL anti-HSV activity correlated with lactoferrin, defensins, IP-10, IL-8, and detectable levels of MIP-1α but not with drug levels.

CONCLUSIONS

CVL may provide a surrogate for local but not systemic drug efficacy and a tool to better understand mucosal factors that modulate antiviral activity in genital tract secretions.

Lactobacillus crispatus dominant vaginal microbiome is associated with inhibitory activity of female genital tract secretions against Escherichia coli

Objective

Female genital tract secretions inhibit E. coli ex vivo and the activity may prevent colonization and provide a biomarker of a healthy microbiome. We hypothesized that high E. coli inhibitory activity would be associated with a Lactobacillus crispatus and/or jensenii dominant microbiome and differ from that of women with low inhibitory activity.

Study Design

Vaginal swab cell pellets from 20 samples previously obtained in a cross-sectional study of near-term pregnant and non-pregnant healthy women were selected based on having high (>90% inhibition) or low (<20% inhibition) anti-E. coli activity. The V6 region of the 16S ribosomal RNA gene was amplified and sequenced using the Illumina HiSeq 2000 platform. Filtered culture supernatants from Lactobacillus crispatus, Lactobacillus iners, and Gardnerella vaginalis were also assayed for E. coli inhibitory activity.

Results

Sixteen samples (10 with high and 6 with low activity) yielded evaluable microbiome data. There was no difference in the predominant microbiome species in pregnant compared to non-pregnant women (n = 8 each). However, there were significant differences between women with high compared to low E. coli inhibitory activity. High activity was associated with a predominance of L. crispatus (p<0.007) and culture supernatants from L. crispatus exhibited greater E. coli inhibitory activity compared to supernatants obtained from L. iners or G. vaginalis. Notably, the E. coli inhibitory activity varied among different strains of L. crispatus.

Conclusion

Microbiome communities with abundant L. crispatus likely contribute to the E. coli inhibitory activity of vaginal secretions and efforts to promote this environment may prevent E. coli colonization and related sequelae including preterm birth.

Research gaps in defining the biological link between HIV risk and hormonal contraception

Epidemiologic data suggest an association between depot medroxyprogesterone acetate (DMPA), a progesterone-based hormonal contraceptive, and increased risk of HIV acquisition and transmission. DMPA is highly effective and is among the most commonly used form of hormonal contraception in areas of high HIV prevalence. Thus, defining the biological mechanisms that contribute to the potential negative synergy between DMPA and HIV is key and may facilitate the identification of alternative contraceptive strategies. Proposed mechanisms include thinning or disruption of the cervicovaginal epithelial barrier, induction of mucosal inflammation, interference with innate and adaptive soluble and cellular immune responses, and/or alterations in the vaginal microbiome. DMPA may also indirectly increase the risk of HIV by promoting genital herpes or other sexually transmitted infections. However, there is a paucity of rigorous in vitro, animal model and clinical data to support these potential mechanisms highlighting the need for future research.

Plasma and mucosal HIV viral loads are associated with genital tract inflammation in HIV-infected women

BACKGROUND

Systemic and mucosal inflammation may play a role in HIV control. A cross-sectional comparison was conducted among women in the Women's Interagency HIV Study to explore the hypothesis that compared with HIV-uninfected participants, women with HIV, and, in particular, those with high plasma viral load (PVL) have increased levels of mucosal and systemic inflammatory mediators and impaired mucosal endogenous antimicrobial activity.

METHODS

Nineteen HIV-uninfected, 40 HIV-infected on antiretroviral therapy (ART) with PVL ≤ 2600 copies/mL (low viral load) (HIV-LVL), and 19 HIV-infected on or off ART with PVL >10,000 (high viral load) (HIV-HVL) were evaluated. Immune mediators and viral RNA were quantified in plasma and cervicovaginal lavage (CVL). The CVL antimicrobial activity was also determined.

RESULTS

Compared to HIV-uninfected participants, HIV-HVL women had higher levels of mucosal but not systemic proinflammatory cytokines and chemokines, higher Nugent scores, and lower Escherichia coli bactericidal activity. In contrast, there were no significant differences between HIV-LVL and HIV-uninfected controls. After adjusting for PVL, HIV genital tract shedding was significantly associated with higher CVL concentrations of IL-6, IL-1β, MIP-1α, and CCL5 (RANTES) and higher plasma concentrations of MIP-1α. High PVL was associated with higher CVL levels of IL-1β and RANTES, as well as with higher Nugent scores, lower E. coli bactericidal activity, smoking, and lower CD4 counts; smoking and CD4 count retained statistical significance in a multivariate model.

CONCLUSIONS

Further study is needed to determine if the relationship between mucosal inflammation and PVL is causal and to determine if reducing mucosal inflammation is beneficial.

Griffithsin protects mice from genital herpes by preventing cell-to-cell spread

Griffithsin, which binds N-linked glycans on gp120 to prevent HIV entry, has the most potent HIV-1 inhibitory activity described for any antiviral lectin and is being developed for topical preexposure prophylaxis. The current studies were designed to further assess its potential by exploring its activity against herpes simplex virus 2 (HSV-2), a cofactor for HIV acquisition, in vitro and in a murine model. Safety was evaluated by examining its impact on epithelial barrier integrity in polarized cultures and testing whether repeated intravaginal dosing potentiates the susceptibility of mice to genital herpes. Griffithsin displayed modest inhibitory activity against HSV-2 if present during viral entry but completely blocked plaque formation if present postentry, reduced plaque size, and prevented cell-to-cell spread. These in vitro findings translated to significant protection against genital herpes in mice treated with 0.1% griffithsin gel. Griffithsin, but not placebo gel, prevented viral spread (visualized with a luciferase-expressing virus), significantly reduced disease scores, and resulted in greater survival (P < 0.05, log rank test). Protection persisted when HSV-2 was introduced in seminal plasma. Although griffithsin triggered a small decline in transepithelial electrical resistance in polarized cultures, this did not translate to any significant increase in the ability of HIV to migrate from the apical to the basolateral chamber nor to an increase in susceptibility to HSV-2 in mice treated with griffithsin gel for 7 days. These findings demonstrate that griffithsin inhibits HSV-2 by a unique mechanism of blocking cell-to-cell spread and support its further development for HIV and HSV-2 prevention.