Interleukin (IL)-1, IL-6, and IL-8 predict mucosal toxicity of vaginal microbicidal contraceptives

Characterization of an air-liquid interface primary human vaginal epithelium to study Ebola virus infection and testing of antivirals

Ebola virus (EBOV) is the causative agent of the often-fatal Ebola virus disease (EVD) characterized by hemorrhagic fever in humans and non-human primates. Sexual transmission from male survivors has been at the origin of multiple outbreak flare-ups between 2015 and 2021. However, this route is still poorly understood and the resulting EVD from it is also understudied. To support epidemiological studies documenting sexual transmission to women, and as a transition from previously using monolayer vaginal epithelial cells (VK2/E6E7), we first determined the biological relevance of two similar air-liquid interface models of the human vaginal epithelium (VEC and VLC Epivaginal™) and then characterized their susceptibility to EBOV and virus-induced inflammation. Finally, we evaluated toxicity of Polyphenylene Carboxymethylene (PPCM) microbicide in VLC and reassessed its antiviral effect. As expected, the VEC, but also VLC model showed stratified layers including a lamina propria under an epithelial structure similar to the full thickness of the human vaginal epithelium. However, we could not detect the immune cells featured in the most relevant model (VLC) of the vaginal epithelium using the dendritic cell CD1a and CD11c markers. Consistent with our previous work using the VK2/E6E7 cell line, infectious virus was detected from the apical side of both primary human cell systems, but only when using a high infective dose, with titers remaining at a constant level of 103-4 pfu/ml over 7 days suggesting lasting infectious virus shedding. In addition, infection caused disruption of the epithelium of both models and virus antigen was found from the apical superficial layers down to the lamina propria suggesting full virus penetration and overall confirming the susceptibility of the human vaginal tissue for EBOV. Just like previously seen in VK2/E6E7 cells, VLC infection also caused significant increase in inflammatory markers including IL-6, IL-8, and IP-10 suggesting vaginitis which is again consistent with tissue lesions seen in non-human primates. Finally, both virus infection and virus-induced inflammatory response in VLC could be prevented by a single 5-min PPCM microbicide treatment prior infection.

The Penis, the Vagina and HIV Risk: Key Differences (Aside from the Obvious)

Globally, most Human Immunodeficiency Virus type 1 (HIV) transmission occurs through vaginal–penile sex (heterosexual transmission). The local immune environment at the site of HIV exposure is an important determinant of whether exposure during sex will lead to productive infection, and the vaginal and penile immune milieus are each critically shaped by the local microbiome. However, there are key differences in the microbial drivers of inflammation and immune quiescence at these tissue sites. In both, a high abundance of anaerobic taxa (e.g., Prevotella) is associated with an increased local density of HIV target cells and an increased risk of acquiring HIV through sex. However, the taxa that have been associated to date with increased risk in the vagina and penis are not identical. Just as importantly, the microbiota associated with comparatively less inflammation and HIV risk—i.e., the optimal microbiota—are very different at the two sites. In the vagina, Lactobacillus spp. are immunoregulatory and may protect against HIV acquisition, whereas on the penis, “skin type” flora such as Corynebacterium are associated with reduced inflammation. Compared to its vaginal counterpart, much less is known about the dynamics of the penile microbiome, the ability of clinical interventions to alter the penile microbiome, or the impact of natural/induced microbiome alterations on penile immunology and HIV risk.

Fused deposition modeling three-dimensional printing of flexible polyurethane intravaginal rings with controlled tunable release profiles for multiple active drugs

We designed and engineered novel intravaginal ring (IVR) medical devices via fused deposition modeling (FDM) three-dimensional (3D) printing for controlled delivery of hydroxychloroquine, IgG, gp120 fragment (encompassing the CD4 binding site), and coumarin 6 PLGA-PEG nanoparticles (C6NP). The hydrophilic polyurethanes were utilized to 3D-print reservoir-type IVRs containing a tunable release controlling membrane (RCM) with varying thickness and adaptable micro porous structures (by altering the printing patterns and interior fill densities) for controlled sustained drug delivery over 14 days. FDM 3D printing of IVRs were optimized and implemented using a lab-developed Cartesian 3D printer. The structures were investigated by scanning electron microscopy (SEM) imaging and in vitro release was performed using 5 mL of daily-replenished vaginal fluid simulant (pH 4.2). The release kinetics of the IVR segments were tunable with various RCM (outer diameter to inner diameter ratio ranging from 1.12 to 2.61) produced from FDM 3D printing by controlling the printing perimeter to provide daily zero-order release of HCQ ranging from 23.54 ± 3.54 to 261.09 ± 32.49 µg/mL/day. IgG, gp120 fragment, and C6NP release rates demonstrated pattern and in-fill density-dependent characteristics. The current study demonstrated the utility of FDM 3D printing to rapidly fabricate complex micro-structures for tunable and sustained delivery of a variety of compounds including HCQ, IgG, gp120 fragment, and C6NP from IVRs in a controlled manner.

Characterization of the Ovine Vaginal Microbiome and Inflammation Patterns as an Improved Testing Model of Human Vaginal Irritation

The development of therapies targeted to improve the health of women has utilized direct vaginal delivery as a more effective and less toxic method of protection from HIV and other pathogens. Vaginal applicants and delivery devices that provide sustained effects have been met with increasing acceptability, but the efficacy and toxicity outcomes have not been successfully predicted by preclinical in vitro studies and animal modeling. We have explored the utilization of sheep as a model for testing the safety of vaginal applicants and devices based on spatial and structural similarities to the human vagina. As recently noted by the FDA, an additional safety measure is an impact on the vaginal microbiome (VMB) that is known to contribute to vaginal health and influence pathogen susceptibility and drug metabolism. To advance the utility of the sheep vaginal model, we completed a thorough molecular characterization of the ovine VMB utilizing both next-generation sequencing (NGS) and PCR methods. The process also created a custom PCR array to quantify ovine VMB community profiles in an affordable, higher throughput fashion. The results from vaginal swabs (>475 samples) collected from non-pregnant crossbred Dorset and Merino ewes treated with selected vaginal applicants or collected as sham samples established 16 VMB community types (VMB CTs). To associate VMB CTs with eubiosis or dysbiosis, we also completed custom ELISAs for six cytokines identifying IL1B, IL8, TNFa, and CXCL10 as useful markers to support the characterization of ovine vaginal inflammation. The results indicated that Pasteurella, Actinobacillus, Pseudomonas, Bacteroides, Leptotrichia, and E. coli were common markers of eubiosis (low inflammatory marker expression), and that Haemophilus, Ureaplasma, and Corynebacterium were associated with dysbiosis (high cytokine levels). Utilizing the optimized workflow, we also confirmed the utility of three commonly used vaginal applicants for impact on the VMB and inflammatory state, producing a dataset that supports the recommendation for the use of sheep for testing of vaginal applicants and devices as part of preclinical pipelines.

Protozoan-Viral-Bacterial Co-Infections Alter Galectin Levels and Associated Immunity Mediators in the Female Genital Tract

Co-infections with sexually transmittable pathogens are common and more likely in women with disturbed vaginal bacteriome. Among those pathogens, the protozoan parasite Trichomonas vaginalis (TV) is most common after accounting for the highly persistent DNA viruses human papillomavirus (HPV) and genital herpes. The parasitic infection often concurs with the dysbiotic syndrome diagnosed as bacterial vaginosis (BV) and both are associated with risks of superimposed viral infections. Yet, the mechanisms of microbial synergisms in evading host immunity remain elusive. We present clinical and experimental evidence for a new role of galectins, glycan-sensing family of proteins, in mixed infections. We assessed participants of the HIV Epidemiology Research Study (HERS) at each of their incident TV visits (223 case visits) matched to controls who remained TV-negative throughout the study. Matching criteria included age, race, BV (by Nugent score), HIV status, hysterectomy, and contraceptive use. Non-matched variables included BV status at 6 months before the matched visit, and variables examined at baseline, within 6 months of and/or at the matched visit e.g. HSV-2, HPV, and relevant laboratory and socio-demographic parameters. Conditional logistic regression models using generalized estimating equations calculated odds ratios (OR) for incident TV occurrence with each log₁₀ unit higher cervicovaginal concentration of galectins and cytokines. Incident TV was associated with higher levels of galectin-1, galectin-9, IL-1β and chemokines (ORs 1.53 to 2.91, p <0.001). Galectin-9, IL-1β and chemokines were up and galectin-3 down in TV cases with BV or intermediate Nugent versus normal Nugent scores (p <0.001). Galectin-9, IL-1β and chemokines were up in TV-HIV and down in TV-HPV co-infections. In-vitro, TV synergized with its endosymbiont Trichomonasvirus (TVV) and BV bacteria to upregulate galectin-1, galectin-9, and inflammatory cytokines. The BV-bacterium Prevotella bivia alone and together with TV downregulated galectin-3 and synergistically upregulated galectin-1, galectin-9 and IL-1β, mirroring the clinical findings of mixed TV–BV infections. P. bivia also downregulated TVV+TV-induced anti-viral response e.g. IP-10 and RANTES, providing a mechanism for conducing viral persistence in TV-BV co-infections. Collectively, the experimental and clinical data suggest that galectin-mediated immunity may be dysregulated and exploited by viral–protozoan–bacterial synergisms exacerbating inflammatory complications from dysbiosis and sexually transmitted infections.

Comparative in vitro study on the local tolerance and efficacy of benzalkonium chloride, myristalkonium chloride and nonoxynol-9 as active principles in vaginal contraceptives

BACKGROUND

Spermicides have been identified as a potentially attractive alternative to hormonal contraceptives and/or intrauterine devices. Thus, this study aimed evaluating the efficacy and local tolerance of benzalkonium chloride (BKC) and myristalkonium chloride (MKC) contained in Pharmatex^® vaginal formulations and compare them with nonoxynol-9 (N-9), the most common active ingredient in topical vaginal contraceptives.

METHODS

Human normozoospermic samples were assessed for motility, viability, acrosome status and penetration ability after exposure to control, N-9 or different BKC and MKC doses for 0 and 10 minutes. Local tolerance on HeLa cells was evaluated by the Trypan-blue and MTT assays.

RESULTS

Exposure to BKC and MKC reduced acrosome integrity while promoting total immobilisation and complete loss of sperm viability (p < .001, n = 15). Both compounds also compromised sperm penetration ability upon exposure (p < .001, n = 15). N-9 induced the same outcomes (p < .001, n = 15); nevertheless, it was more toxic to HeLa cells than BKC and MKC (p < .05, n = 14).

CONCLUSIONS

BKC and MKC present strong in vitro spermicidal activity at lower doses than N-9 and were better tolerated after immediate exposure than N-9. Available Pharmatex^® galenic formulations were as effective as products based on N-9.

Elevation of cervical C-X-C motif chemokine ligand 10 levels is associated with HIV-1 acquisition in pregnant and postpartum women

OBJECTIVE

To evaluate the relationship between cervical cytokine/chemokine concentrations and HIV-1 acquisition in peripartum Kenyan women.

DESIGN

Nested case-control study.

METHODS

Women participating in a prospective study of peripartum HIV acquisition in Kenya (the Mama Salama Study), were tested for HIV-1 at 1-3 month intervals during pregnancy and through 9 months postpartum. Cases positive for HIV-1 RNA during follow-up (N = 14), were matched 3 : 1 with HIV-negative controls (N = 42) based on age, marital status, partner HIV-1 status, transactional sex, and timing of cervical swab collection. Concentrations of five cytokines (IL-1β, IL-6, IL-10, IFNγ, and TNFα) and four chemokines (IL-8, C-X-C motif chemokine ligand 10 (CXCL10), macrophage inflammatory protein-1 α, and macrophage inflammatory protein-1 β) were measured from cervical swabs collected at the visit prior to HIV-1 diagnosis (cases) or matched gestational/postpartum time (controls). Cytokine/chemokine concentrations were compared between cases and controls using Wilcoxon rank-sum tests. Principal component analysis was used to create a summary score for closely correlated cytokines/chemokines. Associations with HIV-1 acquisition were analyzed using conditional logistic regression. Path analysis was used to evaluate hypothesized relationships between CXCL10, vaginal washing, Nugent score, and HIV-1 acquisition.

RESULTS

Conditional logistic regression analysis demonstrated an association between increased concentrations of CXCL10 and HIV-1 acquisition (odds ratio = 1.74, 95% confidence interval 1.04, 2.93; P = 0.034). Path analysis confirmed a positive independent association between higher concentrations of CXCL10 and HIV-1 acquisition (path coefficient = 0.37, 95% confidence interval 0.15, 0.59; P < 0.001).

CONCLUSION

HIV-1 acquisition was associated with increased cervical concentrations of CXCL10 in pregnant and postpartum women.

Vaginal multipurpose prevention technologies: promising approaches for enhancing women's sexual and reproductive health

Introduction: Multipurpose prevention technologies (MPTs) have the potential to avert multiple concomitant sexual and reproductive health issues in women such as sexually transmitted infections and unintended pregnancy. MPTs incorporate one or more active pharmaceutical ingredients in a single product, which adds more convenience for users and may promote increased adherence. Various vaginal dosage forms/delivery systems have been studied for designing MPTs. However, several challenges remain that are mainly related to requirements of individual drugs or intended multiple applications.Areas covered: This review focuses on the emerging need and development of vaginal MPTs. It illustrates numerous examples that are currently in the preclinical and clinical development pipeline, highlighting the concept behind vaginal MPTs. The article also highlights the challenges associated with formulation design and development, including regulatory issues that need to be addressed.Expert opinion: Vaginal MPTs present great potential to empower women with novel, efficient, and safe products for protection against sexually transmitted infections and unintended pregnancy. However, several technological issues and regulatory gaps still need to be addressed in order to meet real-world needs.

The Pre-clinical Toolbox of Pharmacokinetics and Pharmacodynamics: in vitro and ex vivo Models

Prevention strategies against sexual transmission of human immunodeficiency virus (HIV) are essential to curb the rate of new infections. In the absence of a correlate of protection against HIV infection, pre-clinical evaluation is fundamental to facilitate and accelerate prioritization of prevention candidates and their formulations in a rapidly evolving clinical landscape. Characterization of pharmacokinetic (PK) and pharmacodynamic (PD) properties for candidate inhibitors is the main objective of pre-clinical evaluation. in vitro and ex vivo systems for pharmacological assessment allow experimental flexibility and adaptability at a relatively low cost without raising as significant ethical concerns as in vivo models. Applications and limitations of pre-clinical PK/PD models and future alternatives are reviewed in the context of HIV prevention.

Surfactant Protein D Reverses the Gene Signature of Transepithelial HIV-1 Passage and Restricts the Viral Transfer Across the Vaginal Barrier

Effective prophylactic strategy against the current epidemic of sexually transmitted HIV-1 infection requires understanding of the innate gatekeeping mechanisms at the genital mucosa. Surfactant protein D (SP-D), a member of the collectin family of proteins naturally present in the vaginal tract, is a potential HIV-1 entry inhibitor at the cellular level. Human EpiVaginal tissues compartmentalized in culture inserts were apically exposed to HIV-1 and/or a recombinant fragment of human SP-D (rfhSP-D) and viral passage was assessed in the basal chamber containing mononuclear leukocytes. To map the gene signature facilitating or resisting the transepithelial viral transfer, microarray analysis of the HIV-1 challenged EpiVaginal tissues was performed in the absence or presence of rfhSP-D. Mucosal biocompatibility of rfhSP-D was assessed ex vivo and in the standard rabbit vaginal irritation model. The passage of virus through the EpiVaginal tissues toward the underlying target cells was associated with a global epithelial gene signature including differential regulation of genes primarily involved in inflammation, tight junctions and cytoskeletal framework. RfhSP-D significantly inhibited HIV-1 transfer across the vaginal tissues and was associated with a significant reversal of virus induced epithelial gene signature. Pro-inflammatory NF-κB and mTOR transcripts were significantly downregulated, while expression of the tight junctions and cytoskeletal genes was upheld. In the absence of virus, rfhSP-D directly interacted with the EpiVaginal tissues and upregulated expression of genes related to structural stability of the cell and epithelial integrity. There was no increment in the viral acquisition by the PBMCs present in basal chambers wherein, the EpiVaginal tissues in apical chambers were treated with rfhSP-D. The effective concentrations of rfhSP-D had no effect on lactobacilli, epithelial barrier integrity and were safe on repeated applications onto the rabbit vaginal mucosa. This pre-clinical safety data, coupled with its efficacy of restricting viral passage via reversal of virus-induced gene expression of the vaginal barrier, make a strong argument for clinical trials of rfhSP-D as a topical anti-HIV microbicide.

Randomized, placebo controlled phase I trial of safety, pharmacokinetics, pharmacodynamics and acceptability of tenofovir and tenofovir plus levonorgestrel vaginal rings in women

To prevent the global health burdens of human immunodeficiency virus [HIV] and unintended/mistimed pregnancies, we developed an intravaginal ring [IVR] that delivers tenofovir [TFV] at ~10mg/day alone or with levonorgestrel [LNG] at ~20μg/day for 90 days. We present safety, pharmacokinetics, pharmacodynamics, acceptability and drug release data in healthy women. CONRAD A13-128 was a randomized, placebo controlled phase I study. We screened 86 women; 51 were randomized to TFV, TFV/LNG or placebo IVR [2:2:1] and 50 completed all visits, using the IVR for approximately 15 days. We assessed safety by adverse events, colposcopy, vaginal microbiota, epithelial integrity, mucosal histology and immune cell numbers and phenotype, cervicovaginal [CV] cytokines and antimicrobial proteins and changes in systemic laboratory measurements, and LNG and TFV pharmacokinetics in multiple compartments. TFV pharmacodynamic activity was measured by evaluating CV fluid [CVF] and tissue for antiviral activity using in vitro models. LNG pharmacodynamic assessments were timed based on peak urinary luteinizing hormone levels. All IVRs were safe with no significant colposcopic, mucosal, immune and microbiota changes and were acceptable. Among TFV containing IVR users, median and mean CV aspirate TFV concentrations remained above 100,000 ng/mL 4 hours post IVR insertion and mean TFV-diphosphate [DP] concentrations in vaginal tissue remained above 1,000 fmol/mg even 3 days post IVR removal. CVF of women using TFV-containing IVRs completely inhibited [94-100%] HIV infection in vitro. TFV/LNG IVR users had mean serum LNG concentrations exceeding 300 pg/mL within 1 hour, remaining high throughout IVR use. All LNG IVR users had a cervical mucus Insler score <10 and the majority [95%] were anovulatory or had abnormal cervical mucus sperm penetration. Estimated in vivo TFV and LNG release rates were within expected ranges. All IVRs were safe with the active ones delivering sustained high concentrations of TFV locally. LNG caused changes in cervical mucus, sperm penetration, and ovulation compatible with contraceptive efficacy. The TFV and TFV/LNG rings are ready for expanded 90 day clinical testing. Trial registration ClinicalTrials.gov #NCT02235662.

Implant delivering hydroxychloroquine attenuates vaginal T lymphocyte activation and inflammation

Evidence suggests that women who are naturally resistant to HIV infection exhibit low baseline immune activation at the female genital tract (FGT). This "immune quiescent" state is associated with lower expression of T-cell activation markers, reduced levels of gene transcription and pro-inflammatory cytokine or chemokine production involved in HIV infection while maintaining an intact immune response against pathogens. Therefore, if this unique immune quiescent state can be pharmacologically induced locally, it will provide an excellent women-oriented strategy against HIV infection To our knowledge, this is the first research article evaluating in vivo, an innovative trackable implant that can provide controlled delivery of hydroxychloroquine (HCQ) to successfully attenuate vaginal T lymphocyte activation and inflammation in a rabbit model as a potential strategy to induce an "immune quiescent" state within the FGT for the prevention of HIV infection. This biocompatible implant can deliver HCQ above therapeutic concentrations in a controlled manner, reduce submucosal immune cell recruitment, improve mucosal epithelium integrity, decrease protein and gene expression of T-cell activation markers, and attenuate the induction of key pro-inflammatory mediators. Our results suggest that microbicides designed to maintain a low level of immune activation at the FGT may offer a promising new strategy for reducing HIV infection.

Development of podophyllotoxin‑loaded nanostructured lipid carriers for the treatment of condyloma acuminatum

Condyloma acuminatum (CA) is a common sexually transmitted disease caused by human papillomavirus (HPV). Podophyllotoxin (POD), a cytotoxic compound, is able to effectively treat HPV; however, the severe irritation side effects of POD restrict its use as a treatment for CA. The aim of the present study was to construct novel POD‑loaded nanostructured nanolipid carriers (POD‑NLCs) and evaluate their physicochemical characteristics and cytotoxicity. POD‑NLCs (0.5%) were prepared using emulsion‑evaporation and low temperature‑solidification methods with optimized conditions and preparations. Subsequently, the POD‑NLCs were physicochemically characterized and their in vitro and in vivo release efficiencies and in vitro cytotoxicity were studied. The prepared POD‑NLCs had an average particle size, ζ potential, polydispersity index and encapsulation efficacy of 178.5±20 nm, ‑27±0.5 mV, 0.18±0.01 and 82.9±2%, respectively. In vitro and in vivo release studies demonstrated that POD‑NLCs are able to provide sustained drug delivery for 72 h in vitro and 10 h in the mucosa. Compared with a tincture formulation of POD (POD‑T), POD‑NLC induced less inflammatory cytokine production in the cervical mucous and led to a decreased histopathological score. In addition, a cytotoxicity assay demonstrated that inhibition of the POD‑NLCs was 98.4% at 24 h and remained >98% up to 72 h. Furthermore, more cells were arrested in the G2/M phase of the cell cycle following POD‑NLC treatment compared with the POD‑T treatment. The present study provides evidence that POD‑NLC is a promising delivery system for the treatment of CA.

Sustained Simultaneous Delivery of Metronidazole and Doxycycline From Polycaprolactone Matrices Designed for Intravaginal Treatment of Pelvic Inflammatory Disease

Poly(ɛ-caprolactone) (PCL) intravaginal matrices were produced for local delivery of a combination of antibacterials, by rapidly cooling a mixture of drug powders dispersed in PCL solution. Matrices loaded with different combinations of metronidazole (10%, 15%, and 20% w/w) and doxycycline (10% w/w) were evaluated in vitro for release behavior and antibacterial activity. Rapid "burst release" of 8%-15% of the doxycycline content and 31%-37% of the metronidazole content occurred within 24 h when matrices were immersed in simulated vaginal fluid at 37°C. The remaining drug was extracted gradually over 14 days to a maximum of 65%-73% for doxycycline and 62%-71% for metronidazole. High levels of antibacterial activity up to 89%-91% against Gardnerella vaginalis and 84%-92% against Neisseria gonorrhoeae were recorded in vitro for release media collected on day 14, compared to "nonformulated" metronidazole and doxycycline solutions. Based on the in vitro data, the minimum levels of doxycycline and metronidazole released from PCL matrices in the form of intravaginal rings into vaginal fluid in vivo were predicted to exceed the minimum inhibitory concentrations for N. gonorrhea (reported range 0.5-4.0 μg/mL) and G. vaginalis (reported range 2-12.8 μg/mL) respectively, which are 2 of the major causative agents for pelvic inflammatory disease.

Evaluation of immunological markers of ovine vaginal irritation: Implications for preclinical assessment of non-vaccine HIV preventive agents

The presence of genital inflammatory responses and a compromised vaginal epithelial barrier have been linked to an increased risk of HIV acquisition. It is important to assure that application of candidate microbicides designed to limit HIV transmission will not cause these adverse events. We previously developed high resolution in vivo imaging methodologies in sheep to assess epithelial integrity following vaginal application of a model microbicide, however characterization of genital inflammation in sheep has not been previously possible. In this study, we significantly advanced the sheep model by developing approaches to detect and quantify inflammatory responses resulting from application of a nonoxynol-9-containing gel known to elicit vaginal irritation. Vaginal application of this model microbicide resulted in foci of disrupted epithelium detectable by confocal endomicroscopy. Leukocytes also infiltrated the treated mucosa and the number and composition of leukocytes obtained by cervicovaginal lavage (CVL) were determined by differential staining and flow cytometry. By 18h post-treatment, a population comprised predominantly of granulocytes and monocytes infiltrated the vagina and persisted through 44h post-treatment. The concentration of proinflammatory cytokines and chemokines in CVL was determined by quantitative ELISA. Concentrations of IL-8 and IL-1β were consistently significantly increased after microbicide application suggesting these cytokines are useful biomarkers for epithelial injury in the sheep model. Together, the results of these immunological assessments mirror those obtained in previous animal models and human trials with the same compound and greatly extend the utility of the sheep vaginal model in assessing the vaginal barrier and immune microenvironment.

Stabilization and Sustained Release of HIV Inhibitors by Encapsulation in Silk Fibroin Disks

Topical microbicides have the potential to provide effective protection against sexual transmission of HIV. Challenges in developing microbicides include their application in resource-poor settings with high temperatures and a lack of refrigeration, and low user adherence to a rigorous daily regimen. Several protein-based HIV inhibitors show great promise as microbicides, being highly specific and not expected to lead to resistance that would affect the efficacy of current antiretroviral treatments. We show that four potent protein HIV inhibitors, 5P12-RANTES, 5P12-RANTES-L-C37, Grft, and Grft-L-C37 can be formulated into silk fibroin (SF) disks and remain functional for 14 months at 25, 37, and 50 °C. These HIV inhibitor-encapsulated SF disks show excellent inhibition properties in PBMC and in human colorectal and cervical tissue explants, and do not induce inflammatory cytokine secretion. Further, the SF provides a mechanically robust matrix with versatile material formats for this type of application. Finally, a formulation was developed to allow sustained release of functional Grft for 4 weeks at levels sufficient to inhibit HIV transmission. This work establishes the suitability of HIV inhibitor-encapsulated SF disks as topical HIV microbicides that can be further developed to allow easy insertion for extended protection.

Human vaginal epithelial cells augment autophagy marker genes in response to Candida albicans infection

PROBLEM

Autophagy plays an important role in clearance of intracellular pathogens. However, no information is available on its involvement in vaginal infections such as vulvo-vaginal candidiasis (VVC). VVC is intimately associated with the immune status of the human vaginal epithelial cells (VECs). The objective of our study is to decipher if autophagy process is involved during Candida albicans infection of VECs.

METHODS OF STUDY

In this study, C. albicans infection system was established using human VEC line (VK2/E6E7). Infection-induced change in the expression of autophagy markers like LC3 and LAMP-1 were analyzed by RT-PCR, q-PCR, Western blot, immunofluorescence and transmission electron microscopy (TEM) studies were carried out to ascertain the localization of autophagosomes. Multiplex ELISA was carried out to determine the cytokine profiles.

RESULTS

Analysis of LC3 and LAMP-1 expression at mRNA and protein levels at different time points revealed up-regulation of these markers 6 hours post C. albicans infection. LC3 and LAMP-1 puncti were observed in infected VECs after 12 hours. TEM studies showed C. albicans entrapped in autophagosomes. Cytokines-TNF-α and IL-1β were up-regulated in culture supernatants of VECs at 12 hours post-infection.

CONCLUSION

The results suggest that C. albicans invasion led to the activation of autophagy as a host defense mechanism of VECs.

Isolation and Flow Cytometric Analysis of Human Endocervical Gamma Delta T Cells

The female reproductive tract (FRT) mucosal immune system serves as the first line of defense. Better knowledge of the genital mucosa is therefore essential for understanding pathogenicity of different pathogens including HIV. Gamma delta (GD) T cells are the prototype of 'unconventional' T cells and represent a relatively small subset of T cells defined by their expression of heterodimeric T-cell receptors (TCRs) composed of gamma and delta chains. This sets them apart from the classical and much better known CD4⁺ helper T cells and CD8⁺ cytotoxic T cells that are defined by alpha-beta TCRs. GD T cells often show tissue-specific localization and are enriched in epithelium. GD T cells orchestrate immune responses in inflammation, tumor surveillance, infectious disease, and autoimmunity. Here, we present a method to reproducibly isolate and analyze human endocervical intraepithelial GD T lymphocytes. We have used endocervical cytobrush samples from women participating in the Women's Interagency HIV Infection Study (WIHS). Knowledge about GD T cells interactions during conditions in which there is an insult to the vaginal mucosal could be applied to any clinical study in which mucosal vulnerability is addressed, including the development of vaginal microbicides.In addition, knowledge about mucosal GD T cell responses has potential for application of GD T cell-based immune therapy in treating infectious diseases.

Reversibly pH-responsive polyurethane membranes for on-demand intravaginal drug delivery

To provide better protection for women against sexually transmitted infections, on-demand intravaginal drug delivery was attempted by synthesizing reversibly pH-sensitive polyether-polyurethane copolymers using poly(ethylene glycol) (PEG) and 1,4-bis(2-hydroxyethyl)piperazine (HEP). Chemical structure and thermo-characteristics of the synthesized polyurethanes were confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), ¹H-nuclear magnetic resonance (¹H-NMR), and melting point testing. Membranes were cast by solvent evaporation method using the prepared pH-sensitive polyurethanes. The impact of varying pH on membrane swelling and surface morphology was evaluated via swelling ratio change and scanning electron microscopy (SEM). The prepared pH-responsive membranes showed two times higher swelling ratio at pH 4 than pH 7 and pH-triggered switchable surface morphology change. The anionic anti-inflammatory drug diclofenac sodium (NaDF) was used as a model compound for release studies. The prepared pH-responsive polyurethane membranes allowed continuous NaDF release for 24h and around 20% release of total NaDF within 3h at pH 7 but little-to-no drug release at pH 4.5. NaDF permeation across the prepared membranes demonstrated a reversible pH-responsiveness. The pH-responsive polyurethane membranes did not show any noticeable negative impact on vaginal epithelial cell viability or induction of pro-inflammatory cytokine production compared to controls. Overall, the non-cytotoxic HEP-based pH-responsive polyurethane demonstrated its potential to be used in membrane-based implants such as intravaginal rings to achieve on-demand "on-and-off" intravaginal drug delivery.

STATEMENT OF SIGNIFICANCE

A reversible and sharp switch between "off" and "on" drug release is achieved for the first time through new pH-sensitive polyurethane membranes, which can serve as window membranes in reservoir-type intravaginal rings for on-demand drug delivery to prevent sexually transmitted infections (STIs). Close to zero drug release occurs at the normal vaginal pH (4.5) for minimal side effects. Drug release is only triggered by elevation of pH to 7 during heterosexual intercourse. The reversibly sharp and fast "on-and-off" switch arises from the creative incorporation of a pH-sensitive monomer in the soft segment of polyurethane. This polyurethane biomaterial holds great potential to better protect women who are generally at higher risk and are more vulnerable to STIs.

In Vivo Rectal Mucosal Barrier Function Imaging in a Large-Animal Model by Using Confocal Endomicroscopy: Implications for Injury Assessment and Use in HIV Prevention Studies

Injury occurring on the surface of the rectal mucosal lining that causes defects in barrier function may result in increased risk for transmission of infection by HIV and other pathogens. Such injury could occur from microbicidal or other topical agents, mechanical trauma during consensual or nonconsensual intercourse, or inflammatory conditions. Tools for evaluation of rectal mucosal barrier function for assessing the mucosa under these conditions are lacking, particularly those that can provide in vivo structural and functional barrier integrity assessment and are adaptable to longitudinal imaging. We investigated confocal endomicroscopy (CE) as a means for in vivo imaging of the rectal epithelial barrier in the ovine model following spatially confined injury to the surface at a controlled site using a topical application of the microbicide test agent benzalkonium chloride. Topical and intravenous (i.v.) fluorescent probes were used with CE to provide subcellular resolution imaging of the mucosal surface and assessment of barrier function loss. A 3-point CE grading system based on cellular structure integrity and leakage of dye through the mucosa showed significant differences in score between untreated (1.19 ± 0.53) and treated (2.55 ± 0.75) tissue (P < 0.0001). Histological grading confirmed findings of barrier compromise. The results indicate that CE is an effective means for detecting epithelial injury and barrier loss following localized trauma in a large-animal model. CE is promising for real-time rectal mucosal evaluation after injury or trauma or topical application of emerging biomedical prevention strategies designed to combat HIV.

Topical injury evaluation of the murine colorectal mucosa using confocal endomicrosopy: a valuable method for assessing mucosal injuries associated with risk of pathogen transmission

BACKGROUND

Concern regarding the effect of epithelial damage to the colorectal surface and possible impact on sexually transmitted infection transmission prompts the need for methods to evaluate the mucosal microscopic surface in preclinical studies examining such injury. This includes determining the effect of topical HIV prevention products on mucosal barrier integrity. In vivo imaging with high-resolution endomicroscopy could reveal defects in the mucosal barrier resulting from injury/surface trauma.

METHODS

Confocal endomicroscopy was investigated to assess the ability to image surface injury resulting from topical application of a chemical used in lubricants and microbial products. Mice treated with a 50 μL rectal dose of 0.2% benzalkonium chloride solution, 1% benzalkonium chloride or phosphate-buffered saline control for 20 min were imaged in vivo using confocal endomicroscopy for assessment of epithelial disruption. Following imaging, mice were sacrificed and rectal tissue evaluated by histology. Confocal images were graded based on degree of disruption to crypt and epithelial microstructure. Histology was graded based on percent of epithelial disruption observed in stained sections. Confocal image features were confirmed by high-resolution two-photon microscopy.

RESULTS

Based on quantitative grading of in vivo confocal endomicroscopy images, disruption at the microscopic scale was observed following treatment with benzalkonium chloride, with increased injury occurring with higher dose. Epithelial disruption at the lumen surface, evident between crypts and alteration in crypt structure on the luminal side were observed in confocal endomicroscopy and confirmed by histology.

CONCLUSIONS

High-resolution imaging by confocal endomicroscopy can be used as a noninvasive tool for rapid visual assessment of rectal epithelial integrity following surface injury, potentially providing valuable indication of epithelial injury or trauma.

A Study of the Potential of the Pig as a Model for the Vaginal Irritancy of Benzalkonium Chloride in Comparison to the Nonirritant Microbicide PHI-443 and the Spermicide Vanadocene Dithiocarbamate

A porcine model was established to test the mucosal toxicity potential of a thiophene thiourea (PHI-443)-based anti-HIV microbicide and a vanadocene-based spermicide, vanadocene dithiocarbamate (VDDTC) in comparison to benzalkonium chloride (BZK). Nine domestic pigs (Duroc) in nonestrus stage received a single intravaginal application of 2% BZK, 2% PHI-443, or 0.1% VDDTC-containing gel. At various times after gel application, cell differentials and levels of inflammatory cytokines (IL-1 β, IL-4, IL-6, IL-8, IL-10, IL-18, IFN- γ, and TNF- α) in cervicovaginal lavage (CVL) fluid were monitored by flow cytometry and ELISA, respectively. Eight pigs were exposed intravaginally to a gel with and without BZK or VDDTC for 4 consecutive days and vaginal tissues were scored histologically for inflammation using a new scoring system. Only CVL fluid from pigs exposed to BZK showed a significant increase of IL-1 β, IL-8, and also IL-18 production when compared to the controls, PHI-443 or VDDTC-treated groups. Maximum levels of BZK-induced IL-1 β (100-fold), IL-8 (2,500-fold), IL-18 (80-fold), and IFN- γ(10-fold) were found at 24 hours. In the in vivo porcine vaginal irritation model, increased levels of vaginal IL-1 β, IL-8, and IL-18 were associated with histological changes consistent with vaginal inflammation. These results demonstrate that key cervicovaginal inflammatory cytokines are useful in vivo biomarkers for predicting the mucosal toxicity potential of vaginal products in the physiologically relevant and sensitive porcine model.

An update on multipurpose prevention technologies for the prevention of HIV transmission and pregnancy

INTRODUCTION

Multipurpose Prevention Technologies (MPTs) are designed to address two or more indications from a single product. The overall goal is to prevent unintended pregnancy and transmission of one or more STIs including HIV-1.

AREAS COVERED

The topics covered herein are advances in over the past three years. Advances include development of novel intravaginal rings capable of releasing microbicides to prevent transmission of HIV-1 and unintended pregnancy. These rings include the potential to prevent transmission of more than one STI and unintended pregnancy. There are also gels that can potentially accomplish the same thing. Finally, combination of a drug and barrier device are also covered.

EXPERT OPINION

There has been considerable advance in this field over the past three years. There is one ring currently in a Phase I clinical trial and others are soon to follow. Some of these drug delivery systems are by necessity rather complicated and hence could be prohibitively expensive in the developing world. Conducting multiple clinical trials to support regulatory approval of two or more indications represents a significant barrier. It remains unclear that women will be more motivated to use MPT products than has been observed in recent microbicide-only clinical trials. Despite these challenges, the need for MPTs remain acute hopefully ensuring they will continue to be developed over the coming years.

Trichomonas vaginalis Lipophosphoglycan Exploits Binding to Galectin-1 and -3 to Modulate Epithelial Immunity

Trichomoniasis is the most common non-viral sexually transmitted infection caused by the vaginotropic extracellular protozoan parasite Trichomonas vaginalis. The infection is recurrent, with no lasting immunity, often asymptomatic, and linked to pregnancy complications and risk of viral infection. The molecular mechanisms of immune evasion by the parasite are poorly understood. We demonstrate that galectin-1 and -3 are expressed by the human cervical and vaginal epithelial cells and act as pathogen-recognition receptors for the ceramide phosphoinositol glycan core (CPI-GC) of the dominant surface protozoan lipophosphoglycan (LPG). We used an in vitro model with siRNA galectin knockdown epithelial clones, recombinant galectins, clinical Trichomonas isolates, and mutant protozoan derivatives to dissect the function of galectin-1 and -3 in the context of Trichomonas infection. Galectin-1 suppressed chemokines that facilitate recruitment of phagocytes, which can eliminate extracellular protozoa (IL-8) or bridge innate to adaptive immunity (MIP-3α and RANTES (regulated on activation normal T cell expressed and secreted)). Silencing galectin-1 increased and adding exogenous galectin-1 suppressed chemokine responses to Trichomonas or CPI-GC/LPG. In contrast, silencing galectin-3 reduced IL-8 response to LPG. Live Trichomonas depleted the extracellular levels of galectin-3. Clinical isolates and mutant Trichomonas CPI-GC that had reduced affinity to galectin-3 but maintained affinity to galectin-1 suppressed chemokine expression. Thus via CPI-GC binding, Trichomonas is capable of regulating galectin bioavailability and function to the benefit of its parasitic survival. These findings suggest novel approaches to control trichomoniasis and warrant further studies of galectin-binding diversity among clinical isolates as a possible source for symptom disparity in parasitic infections.

Increased levels of inflammatory cytokines in the female reproductive tract are associated with altered expression of proteases, mucosal barrier proteins, and an influx of HIV-susceptible target cells

Elevated inflammatory cytokines (EMCs) at mucosal surfaces have been associated with HIV susceptibility, but the underlying mechanisms remain unclear. We characterized the soluble mucosal proteome associated with elevated cytokine expression in the female reproductive tract. A scoring system was devised based on the elevation (upper quartile) of at least three of seven inflammatory cytokines in cervicovaginal lavage. Using this score, HIV-uninfected Kenyan women were classified as either having EMC (n=28) or not (n=68). Of 455 proteins quantified in proteomic analyses, 53 were associated with EMC (5% false discovery rate threshold). EMCs were associated with proteases, cell motility, and actin cytoskeletal pathways, whereas protease inhibitor, epidermal cell differentiation, and cornified envelope pathways were decreased. Multivariate analysis identified an optimal signature of 16 proteins that distinguished the EMC group with 88% accuracy. Three proteins in this signature were neutrophil-associated proteases that correlated with many cytokines, especially GM-CSF (granulocyte-macrophage colony-stimulating factor), IL-1β (interleukin-1β), MIP-3α (macrophage inflammatory protein-3α), IL-17, and IL-8. Gene set enrichment analyses implicated activated immune cells; we verified experimentally that EMC women had an increased frequency of endocervical CD4(+) T cells. These data reveal strong linkages between mucosal cytokines, barrier function, proteases, and immune cell movement, and propose these as potential mechanisms that increase risk of HIV acquisition.

The Contribution of Cervicovaginal Infections to the Immunomodulatory Effects of Hormonal Contraception

Particular types of hormonal contraceptives (HCs) and genital tract infections have been independently associated with risk of HIV-1 acquisition. We examined whether immunity in women using injectable depot medroxyprogesterone acetate (DMPA), combined oral contraceptives (COC), or no HCs differs by the presence of cervicovaginal infections. Immune mediators were quantified in cervical swabs from 832 HIV-uninfected reproductive-age Ugandans and Zimbabweans. Bacterial infections and HIV were diagnosed by PCR, genital herpes serostatus by enzyme-linked immunosorbent assay (ELISA), altered microflora by Nugent score, and Trichomonas vaginalis and Candida albicans infection by wet mount. Generalized linear models utilizing Box-Cox-Power transformation examined associations between levels of mediators, infection status, and HCs. In no-HC users, T. vaginalis was associated with broadest spectrum of aberrant immunity (higher interleukin 1β [IL-1β], IL-8, macrophage inflammatory protein 3α [MIP-3α], β-defensin 2 [BD2], and IL-1 receptor antigen [IL-1RA]). In women with a normal Nugent score and no genital infection, compared to the no-HC group, COC users showed higher levels of IL-1β, IL-6, IL-8, and IL-1RA, while DMPA users showed higher levels of RANTES and lower levels of BD2, both associated with HIV seroconversion. These effects of COC were blunted in the presence of gonorrhea, chlamydia, trichomoniasis, candidiasis, and an abnormal Nugent score; however, RANTES was increased among COC users with herpes, chlamydia, and abnormal Nugent scores. The effect of DMPA was exacerbated by lower levels of IL-1RA in gonorrhea, chlamydia, or herpes, SLPI in gonorrhea, and IL-1β, MIP-3α, and IL-1RA/IL1β ratio in trichomoniasis. Thus, the effects of HC on cervical immunity depend on the genital tract microenvironment, and a weakened mucosal barrier against HIV may be a combined resultant of genital tract infections and HC use.

IMPORTANCE

In this article, we show that in young reproductive-age women most vulnerable to HIV, hormonal contraceptives are associated with altered cervical immunity in a manner dependent on the presence of genital tract infections. Through altered immunity, hormones may predispose women to bacterial and viral pathogens; conversely, a preexisting specific infection or disturbed vaginal microbiota may suppress the immune activation by levonorgestrel or exacerbate the suppressed immunity by DMPA, thus increasing HIV risk by their cumulative action. Clinical studies assessing the effects of contraception on HIV susceptibility and mucosal immunity may generate disparate results in populations that differ by microbiota background or prevalence of undiagnosed genital tract infections. A high prevalence of asymptomatic infections among HC users that remain undiagnosed and untreated raises even more concerns in light of their combined effects on biomarkers of HIV risk. The molecular mechanisms of the vaginal microbiome's simultaneous interactions with hormones and HIV remain to be elucidated.

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.

Precise engineering of dapivirine-loaded nanoparticles for the development of anti-HIV vaginal microbicides

Polymeric nanoparticles (NPs) have the potential to provide effective and safe delivery of antiretroviral drugs in the context of prophylactic anti-HIV vaginal microbicides. Dapivirine-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) NPs were produced by an emulsion-solvent evaporation method, optimized for colloidal properties using a 3-factor, 3-level Box-Behnken experimental design, and characterized for drug loading, production yield, morphology, thermal behavior, drug release, in vitro cellular uptake, cytotoxicity and pro-inflammatory potential. Also, drug permeability/membrane retention in well-established HEC-1-A and CaSki cell monolayer models as mediated by NPs was assessed in the absence or presence of mucin. Box-Behnken design allowed optimizing monodisperse 170nm drug-loaded NPs. Drug release experiments showed an initial burst effect up to 4h, followed by sustained 24h release at pH 4.2 and 7.4. NPs were readily taken up by different genital and macrophage cell lines as assessed by fluorescence microscopy. Drug-loaded NPs presented lower or at least similar cytotoxicity as compared to the free drug, with up to around one-log increase in half-maximal cytotoxic concentration values. In all cases, no relevant changes in cell pro-inflammatory cytokine/chemokine production were observed. Dapivirine transport across cell monolayers was significantly decreased when mucin was present at the donor side with either NPs or the free drug, thus evidencing the influence of this natural glycoprotein in membrane permeability. Moreover, drug retention in cell monolayers was significantly higher for NPs in comparison with the free drug. Overall, obtained dapivirine-loaded PLGA NPs possess interesting technological and biological features that may contribute to their use as novel safe and effective vaginal microbicides.

Vaginal cytokines do not correlate with postmenopausal vulvovaginal symptoms

OBJECTIVES

Exploratory pilot study to determine the correlation between postmenopausal vulvovaginal symptoms and vaginal cytokine levels.

METHODS

Postmenopausal women (n = 34) not using menopausal hormone therapy and presenting with or without symptoms of vulvovaginal irritation were screened. Each participant underwent a vaginal examination and screening for vaginitis. A cervicovaginal lavage (CVL) with sterile saline and a peripheral blood sample were obtained. Main outcome measures were assessed by Luminex® X-map method on the Bio-Plex® platform. Main outcome measures were cervicovaginal and serum interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, TNF-α, GM-CSF, MIP-1-alpha and RANTES level. Cervicovaginal cytokines were adjusted to total protein concentration [pg/mcg protein].

RESULTS

Twenty-six postmenopausal women were enrolled (symptomatic: n = 15; asymptomatic: n = 11). There were no significant differences between groups: age, age at menopause, vaginal pH and all CVL and serum cytokines (IL-4, IL-5, IL-10, IL-12, IL-13, TNF-α, GM-CSF, MIP-1-alpha and RANTES). GM-CSF was the most abundant vaginal cytokine (symptomatic: 146.5 ± 165.6 pg/mcg protein; asymptomatic: 146.0 ± 173.5 pg/mcg protein; p = 0.99).

CONCLUSIONS

Postmenopausal vulvovaginal symptoms did not correlate with vaginal inflammatory marker. There was no difference in serum or CVL cytokines between symptomatic and asymptomatic postmenopasual women. Vaginal symptoms after menopause are not related to the vaginal cytokine changes associated with loss of estrogen.

A quantitative multiplex nuclease protection assay reveals immunotoxicity gene expression profiles in the rabbit model for vaginal drug safety evaluation

Any vaginal product that alters the mucosal environment and impairs the immune barrier increases the risk of sexually transmitted infections, especially HIV infection, which thrives on mucosal damage and inflammation. The FDA-recommended rabbit vaginal irritation (RVI) model serves as a first line selection tool for vaginal products; however, for decades it has been limited to histopathology scoring, insufficient to select safe anti-HIV microbicides. In this study we incorporate to the RVI model a novel quantitative nuclease protection assay (qNPA) to quantify mRNA levels of 25 genes representing leukocyte differentiation markers, toll-like receptors (TLR), cytokines, chemokines, epithelial repair, microbicidal and vascular markers, by designing two multiplex arrays. Tissue sections were obtained from 36 rabbits (6 per treatment arm) after 14 daily applications of a placebo gel, saline, 4% nonoxynol-9 (N-9), and three combinations of the anti-HIV microbicides tenofovir (TFV) and UC781 in escalating concentrations (highest: 10% TFV+2.5%UC781). Results showed that increased expression levels of toll-like receptor (TLR)-4, interleukin (IL)-1β, CXCL8, epithelial membrane protein (EMP)-1 (P<0.05), and decreased levels of TLR2 (P<0.05), TLR3 and bactericidal permeability increasing protein (BPI) (P<0.001) were associated with cervicovaginal mucosal alteration (histopathology). Seven markers showed a significant linear trend predicting epithelial damage (up with CD4, IL-1β, CXCL8, CCL2, CCL21, EMP1 and down with BPI). Despite the low tissue damage RVI scores, the high-dose microbicide combination gel caused activation of HIV host cells (SLC and CD4) while N-9 caused proinflammatory gene upregulation (IL-8 and TLR4) suggesting a potential for increasing risk of HIV via different mechanisms depending on the chemical nature of the test product.

Cleavage/alteration of interleukin-8 by matrix metalloproteinase-9 in the female lower genital tract

Objective

Interleukin-8 (IL-8, CXCL8) plays important roles in immune responses at mucosal sites including in the lower genital tract. Since several types of bacteria produce proteases that cleave IL-8 and many types of bacteria can be present in lower genital tract microbiota, we assessed genital fluids for IL-8 cleavage/alteration.

Study Design

Genital fluids collected by lavage from 200 women (23 HIV-seronegative and 177 HIV-seropositive) were tested for IL-8 cleavage/alteration by ELISA.

Results

IL-8 cleaving/altering activity was observed in fluids from both HIV-positive (28%) and HIV-negative women (35%). There was no clear relationship between the activity and the types of bacteria present in the lower genital tract as determined by high-throughput sequencing of the 16S rRNA gene. Protease inhibitors specific for matrix metalloproteinases (MMPs) reduced the activity and a multiplex assay that detects both inactive and active MMPs showed the presence of multiple MMPs, including MMP-1, -3, -7, -8, -9, -10 and -12 in genital secretions from many of the women. The IL-8-cleaving/altering activity significantly correlated with active MMP-9 as well as with cleavage of a substrate that is acted on by several active MMPs.

Conclusions

These studies show that multiple MMPs are present in the genital tract of women and strongly suggest that MMP-9 in genital secretions can cleave IL-8 at this mucosal site. These studies suggest that MMP-mediated cleavage of IL-8 can modulate inflammatory responses in the lower genital tract.

In situ stabilized AgNPs and (Cu-Cur)CD dispersed gel, a topical contraceptive antiretroviral (ARV) microbicide

Nano silver and (copper-curcumin)β-cyclodextrin based pre-exposure contraceptive-antiretroviral topical prophylaxis.

Nanotech-derived topical microbicides for HIV prevention: the road to clinical development

More than three decades since its discovery, HIV infection remains one of the most aggressive epidemics worldwide, with more than 35 million people infected. In sub-Saharan Africa, heterosexual transmissions represent nearly 80% of new infections, with 50% of these occurring in women. In an effort to stop the dramatic spread of the HIV epidemic, new preventive treatments, such as microbicides, have been developed. Nanotechnology has revolutionized this field by designing and engineering novel highly effective nano-sized materials as microbicide candidates. This review illustrates the most recent advances in nanotech-derived HIV prevention strategies, as well as the main steps required to translate promising in vitro results into clinical trials.

New candidate biomarkers in the female genital tract to evaluate microbicide toxicity

Vaginal microbicides hold great promise for the prevention of viral diseases like HIV, but the failure of several microbicide candidates in clinical trials has raised important questions regarding the parameters to be evaluated to determine in vivo efficacy in humans. Clinical trials of the candidate microbicides nonoxynol-9 (N9) and cellulose sulfate revealed an increase in HIV infection, vaginal inflammation, and recruitment of HIV susceptible lymphocytes, highlighting the need to identify biomarkers that can accurately predict microbicide toxicity early in preclinical development and in human trials. We used quantitative proteomics and RT-PCR approaches in mice and rabbits to identify protein changes in vaginal fluid and tissue in response to treatment with N9 or benzalkonium chloride (BZK). We compared changes generated with N9 and BZK treatment to the changes generated in response to tenofovir gel, a candidate microbicide that holds promise as a safe and effective microbicide. Both compounds down regulated mucin 5 subtype B, and peptidoglycan recognition protein 1 in vaginal tissue; however, mucosal brush samples also showed upregulation of plasma proteins fibrinogen, plasminogen, apolipoprotein A-1, and apolipoprotein C-1, which may be a response to the erosive nature of N9 and BZK. Additional proteins down-regulated in vaginal tissue by N9 or BZK treatment include CD166 antigen, olfactomedin-4, and anterior gradient protein 2 homolog. We also observed increases in the expression of C-C chemokines CCL3, CCL5, and CCL7 in response to treatment. There was concordance in expression level changes for several of these proteins using both the mouse and rabbit models. Using a human vaginal epithelial cell line, the expression of mucin 5 subtype B and olfactomedin-4 were down-regulated in response to N9, suggesting these markers could apply to humans. These data identifies new proteins that after further validation could become part of a panel of biomarkers to effectively evaluate microbicide toxicity.

[Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates]

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Development of polyether urethane intravaginal rings for the sustained delivery of hydroxychloroquine

Hydroxychloroquine (HCQ) has been shown to demonstrate anti-inflammatory properties and direct anti-HIV activity. In this study, we describe for the first time the fabrication and in vitro evaluation of two types of intravaginal ring (IVR) devices (a surfaced-modified matrix IVR and a reservoir segmental IVR) for achieving sustained delivery (>14 days) of HCQ as a strategy for preventing male-to-female transmission of HIV. Both IVRs were fabricated by hot-melt injection molding. Surface-modified matrix IVRs with polyvinylpyrrolidone or poly(vinyl alcohol) coatings exhibited significantly reduced burst release on the first day (6.45% and 15.72% reduction, respectively). Reservoir IVR segments designed to release lower amounts of HCQ displayed near-zero-order release kinetics with an average release rate of 28.38 μg/mL per day for IVRs loaded with aqueous HCQ and 32.23 μg/mL per day for IVRs loaded with HCQ mixed with a rate-controlling excipient. Stability studies demonstrated that HCQ was stable in coated or noncoated IVRs for 30 days. The IVR segments had no significant effect on cell viability, pro-inflammatory cytokine production, or colony formation of vaginal and ectocervical epithelial cells. Both IVR systems may be suitable for the prevention of HIV transmission and other sexually transmitted infections.

Immune quiescence: a model of protection against HIV infection

Aberrant immune activation is a strong correlate of HIV disease progression, but little is known about how immune activation alters susceptibility to HIV infection. Susceptibility to HIV infection varies between individuals, but the immunological determinants of HIV transmission are not well understood. Here, we present evidence from studies of HIV transmission in the context of clinical trials and HIV-exposed seronegative (HESN) cohorts that implicates elevated immune activation as a risk factor for acquiring HIV. We propose a model of protection from infection based on a phenotype of low baseline immune activation referred to as immune quiescence. Immune quiescence is evidenced by reduced expression of T cell activation markers, low levels of generalized gene transcription and low levels of proinflammatory cytokine and chemokine production in the periphery and genital mucosa of HESN. Since HIV preferentially replicates in activated CD4+ T cells, immune quiescence may protect against infection by limiting HIV target cell availability. Although the determinants of immune quiescence are unclear, several potential factors have been identified that may be involved in driving this phenotype. HESN were shown to have elevated proportions of regulatory T cells (Tregs), which are known to suppress T cell activation. Likewise, proteins involved in controlling inflammation in the genital tract have been found to be elevated in HESN. Furthermore, expression of interferon regulatory factor 1 (IRF-1) is reduced in HESN as a consequence of genetic polymorphisms and differential epigenetic regulation. Since IRF-1 is an important regulator of immune responses, it may play a role in maintaining immune quiescence. Based on this model, we propose a novel avenue for HIV prevention targeted based on reducing host mucosal immune activation.

In vivo evaluation of safety and toxicity of a Lactobacillus jensenii producing modified cyanovirin-N in a rhesus macaque vaginal challenge model

Sexual transmission of human immunodeficiency virus type 1 (HIV-1) across the cervicovaginal mucosa in women is influenced by many factors including the microbiota and the presence of underlying inflammation. It is important that potential HIV preventative agents do not alter the mucosal environment in a way that enhances HIV acquisition. We examined the impact of a "live" microbicide on the vaginal mucosal environment in a rhesus macaque repeated vaginal simian-HIV (SHIVSF162P3) challenge model. The microbicide contained a human vaginal Lactobacillus jensenii expressing the HIV-1 entry inhibitor, modified Cyanovirin-N (mCV-N), and henceforth called LB-mCV-N. Macaques were colonized vaginally each week with LB-mCV-N and sampled six days after colonization for culturable bacteria, pH and cervical-vaginal cytokines during the duration of the six-week study. We show that macaques that retained the engineered LB-mCV-N strain in their vaginal microbiota, during SHIV challenge, had lower pH, when colonization levels were higher, and had no evidence of inflammatory cytokines. Indeed, Interleukin-13, a mediator of inflammation, was detected less often in LB-mCV-N colonized macaques than in controls and we found higher levels of Interleukin 1 receptor antagonist (IL-1RA) in LB-mCV-N colonized macaques during the SHIV challenge period. We noted an inverse correlation between levels of mucosal IL-1RA and peak plasma viral load, thus higher IL-1RA correlated with lower viral load in LB-mCV-N treated macaques. These data support the use of LB-mCV-N as a safe "live" microbicide and suggest that lactobacilli themselves may positively impact the mucosal environment.

TGF-β induces Wnt10b in osteoclasts from female mice to enhance coupling to osteoblasts

In young adults, bone lost through osteoclast-mediated resorption is precisely replaced in both location and amount. Understanding how these two processes are coupled is crucial to advancing treatments for osteoporosis, a disease that progresses when the processes become uncoupled. We documented that osteoclasts secrete the mammalian integration 1 gene that is the homolog of Drosophila Wngless (Wnt) 10b, bone morphogenetic protein 6 (BMP6), and the chemokine sphingosin 1 phosphate (S1P) to promote mesenchymal cell mineralization in vitro. During bone resorption, TGF-β1 is released from the bone extracellular matrix and activated by osteoclasts. Thus, TGF-β1 levels are elevated during the resorption phase of bone turnover. We therefore investigated the influences of TGF-β1 on osteoclast-mediated support of mineralization. TGF-β1 increased osteoclast production of Wnt10b, but not BMP6 or S1P. Blocking Wnt10b activity with the Wnt signaling inhibitor Dickkoph-related protein 1 suppressed the ability of TGF-β-treated osteoclast-conditioned media to promote osteoblast mineralization. Examination of TGF-β signaling in osteoclasts revealed that induction of Wnt10b expression was dependent on Smad2/3 activation and independent from TGF-β1 stimulation of protein kinase B (AKT) or MAPK kinase. TGF-β1-treated osteoclast-conditioned media from cells with blocked Smad signaling exhibited a reduced ability to support mineralization, demonstrating the importance of Smad signaling in this response. Parallel cultures with suppressed TGF-β activation of AKT or MAPK kinase signaling retained their ability to elevate mineralization. These results demonstrate that TGF-β1 stimulates Wnt10b production in osteoclasts, which may enhance restoration of the bone lost during the resorptive phase of bone turnover.

Recruitment of HIV-1 target cells at topical mucosal sites: a sensitive and early marker for determining the safety of microbicide candidates

To explore early biomarkers for establishing more sensitive safety evaluation assays in preclinical settings that determine the potential risks during the application of microbicide candidates, three representative microbicide candidates (cellulose sulphate, nonoxynol-9 and tenofovir), whose safety profiles have been well established in clinical trials, were included to gauge the sensitivities of different assays. Both mouse models and cell lines were employed to determine the sensitivities. The recruitment of immune cells at topical mucosal sites and the upregulation of HIV receptor/coreceptors in vitro were identified as highly sensitive biomarkers of the impact of microbicide candidates. Our data suggest that different evaluations/assays have their inherent sensitivities, and at least one assay from each sensitivity level should be included in the safety evaluation algorithm.

Anti-HIV-1 activity, protease inhibition and safety profile of extracts prepared from Rhus parviflora

Background

In the present study, extracts prepared from the leaves of Rhus parviflora Roxb. (Anacardiaceae) were evaluated for their anti-HIV activity, which have been traditionally used for the treatment of neurological disorders such as anxiety, insomnia and epilepsy.

Methods

Aqueous and 50% ethanolic extracts prepared from leaves of the plant were tested for their cytotoxicity and anti-HIV property using reporter gene based assays as well as human peripheral blood lymphocytes (PBLs). Further these extracts were evaluated for their ability to inhibit HIV-1 reverse transcriptase (RT) and protease activity. Safety profile of the extracts was determined on viability of Lactobacillus sp., secretion of pro-inflammatory cytokines by vaginal keratinocytes and transepithelial resistance.

Results

Both aqueous (IC₅₀ = 15 μg/ml) and 50% ethanolic (IC₅₀ = 26 μg/ml) extracts prepared from leaves of R. parviflora showed anti-HIV activity in TZM-bl cells wherein the virus was treated with the extracts prior to infection. Further, both the extracts also inhibited virus load in HIV infected CEM-GFP cells and human PBLs. The anti-HIV activity is mediated through inhibition of HIV-1 protease activity. Both the extracts did not disturb the integrity of monolayer formed by intestinal epithelial Caco-2 cells. The extracts when tested up to 100 μg/ml did not significantly reduce the viability of L. plantarum, L. fermentum, L. rhamnosus and L. casei. The extracts (100 μg/ml) did not reveal any cytotoxic effect on vaginal keratinocytes (Vk2/E6E7). Levels of pro-inflammatory cytokines secreted by Vk2/E6E7 cells treated with both the plant extracts were within the non-inflammatory range.

Conclusions

The studies reported herein showed in vitro anti-HIV activity and preliminary safety profile of the extracts prepared from the leaves of R. parviflora.

Effects of feminine hygiene products on the vaginal mucosal biome

Background

Over-the-counter (OTC) feminine hygiene products come with little warning about possible side effects. This study evaluates in-vitro their effects on Lactobacillus crispatus, which is dominant in the normal vaginal microbiota and helps maintain a healthy mucosal barrier essential for normal reproductive function and prevention of sexually transmitted infections and gynecologic cancer.

Methods

A feminine moisturizer (Vagisil), personal lubricant, and douche were purchased OTC. A topical spermicide (nonoxynol-9) known to alter the vaginal immune barrier was used as a control. L. crispatus was incubated with each product for 2 and 24h and then seeded on agar for colony forming units (CFU). Human vaginal epithelial cells were exposed to products in the presence or absence of L. crispatus for 24h, followed by epithelium-associated CFU enumeration. Interleukin-8 was immunoassayed and ANOVA was used for statistical evaluation.

Results

Nonoxynol-9 and Vagisil suppressed Lactobacillus growth at 2h and killed all bacteria at 24h. The lubricant decreased bacterial growth insignificantly at 2h but killed all at 24h. The douche did not have a significant effect. At full strength, all products suppressed epithelial viability and all, except the douche, suppressed epithelial-associated CFU. When applied at non-toxic dose in the absence of bacteria, the douche and moisturizer induced an increase of IL-8, suggesting a potential to initiate inflammatory reaction. In the presence of L. crispatus, the proinflammatory effects of the douche and moisturizer were countered, and IL-8 production was inhibited in the presence of the other products.

Conclusion

Some OTC vaginal products may be harmful to L. crispatus and alter the vaginal immune environment. Illustrated through these results, L. crispatus is essential in the preservation of the function of vaginal epithelial cells in the presence of some feminine hygiene products. More research should be invested toward these products before they are placed on the market.