Pharmacokinetics of single dose doxycycline in the rectum, vagina, and urethra: implications for prevention of bacterial sexually transmitted infections

BACKGROUND

Clinical trials showed a single oral dose of doxycycline taken after sex protects against STIs among men who have sex with men (MSM) but not women. Pharmacokinetic data at vaginal, rectal and penile sites of STI exposure are lacking. We examined vaginal, rectal and urethral doxycycline concentrations in men and women to better inform STI prevention.

METHODS

Doxycycline pharmacokinetics in male and female participants 18-59 years of age were evaluated in blood and urine and on rectal and vaginal swabs collected at 1, 2, 4, 8, 24, 48, 72, 96 and 168 h after receiving a 200 mg oral doxycycline dose in a non-randomised single dose open label single centre study in Atlanta, Georgia. Rectal, vaginal, and cervical biopsies and male urethral swabs were collected 24 h after dosing (Trial registration: NCT04860505). Doxycycline was measured by liquid chromatography-mass spectrometry.

FINDINGS

Eleven male and nine female participants participated in the study. Doxycycline concentrations on rectal and vaginal swabs collected up to 96 h after dosing were approximately twice those of plasma and remained above minimum inhibitory concentrations (MICs) for at least four, three, and two days for Chlamydia trachomatis, Treponema pallidum, and tetracycline-sensitive Neisseria gonorrhoeae, respectively. Geometric mean doxycycline concentrations in male urethral secretions (1.166 μg/mL; 95% CI 0.568-2.394 μg/mL), male rectal (0.596 μg/g; 0.442-0.803 μg/g), vaginal (0.261 μg/g; 0.098-0.696 μg/g) and cervical tissue (0.410 μg/g; 0.193-0.870 μg/g) in biopsies collected 24 h after dosing exceeded MICs. Plasma and urine doxycycline levels defined adherence markers up to four and seven days postdosing, respectively. No adverse events were reported in this study.

INTERPRETATION

Doxycycline efficiently distributes to the rectum, vagina and urethra. Findings can help explain efficacy of STI prevention by doxycycline.

FUNDING

Funded by CDC intramural funds, CDC contract HCVJCG-2020-45044 (to CFK).

Randomized controlled phase IIa clinical trial of safety, pharmacokinetics and pharmacodynamics of tenofovir and tenofovir plus levonorgestrel releasing intravaginal rings used by women in Kenya

Introduction

Globally, many young women face the overlapping burden of HIV infection and unintended pregnancy. Protection against both may benefit from safe and effective multipurpose prevention technologies.

Methods

Healthy women ages 18-34 years, not pregnant, seronegative for HIV and hepatitis B surface antigen, not using hormonal contraception, and at low risk for HIV were randomized 2:2:1 to continuous use of a tenofovir/levonorgestrel (TFV/LNG), TFV, or placebo intravaginal ring (IVR). In addition to assessing genital and systemic safety, we determined TFV concentrations in plasma and cervicovaginal fluid (CVF) and LNG levels in serum using tandem liquid chromatography-mass spectrometry. We further evaluated TFV pharmacodynamics (PD) through ex vivo CVF activity against both human immunodeficiency virus (HIV)-1 and herpes simplex virus (HSV)-2, and LNG PD using cervical mucus quality markers and serum progesterone for ovulation inhibition.

Results

Among 312 women screened, 27 were randomized to use one of the following IVRs: TFV/LNG (n = 11); TFV-only (n = 11); or placebo (n = 5). Most screening failures were due to vaginal infections. The median days of IVR use was 68 [interquartile range (IQR), 36-90]. Adverse events (AEs) were distributed similarly among the three arms. There were two non-product related AEs graded >2. No visible genital lesions were observed. Steady state geometric mean amount (ssGMA) of vaginal TFV was comparable in the TFV/LNG and TFV IVR groups, 43,988 ng/swab (95% CI, 31,232, 61,954) and 30337 ng/swab (95% CI, 18,152, 50,702), respectively. Plasma TFV steady state geometric mean concentration (ssGMC) was <10 ng/ml for both TFV IVRs. In vitro, CVF anti-HIV-1 activity showed increased HIV inhibition over baseline following TFV-eluting IVR use, from a median of 7.1% to 84.4% in TFV/LNG, 15.0% to 89.5% in TFV-only, and -27.1% to -20.1% in placebo participants. Similarly, anti-HSV-2 activity in CVF increased >50 fold after use of TFV-containing IVRs. LNG serum ssGMC was 241 pg/ml (95% CI 185, 314) with rapid rise after TFV/LNG IVR insertion and decline 24-hours post-removal (586 pg/ml [95% CI 473, 726] and 87 pg/ml [95% CI 64, 119], respectively).

Conclusion

TFV/LNG and TFV-only IVRs were safe and well tolerated among Kenyan women. Pharmacokinetics and markers of protection against HIV-1, HSV-2, and unintended pregnancy suggest the potential for clinical efficacy of the multipurpose TFV/LNG IVR.

Clinical Trial Registration

NCT03762382 [https://clinicaltrials.gov/ct2/show/NCT03762382].

Pharmacology of boosted and unboosted integrase strand transfer inhibitors for two-dose event-driven HIV prevention regimens among men

BACKGROUND

Event-driven HIV prevention strategies are a priority for users who do not require daily pre-exposure prophylaxis (PrEP). Regimens containing integrase strand transfer inhibitors (INSTIs) are under evaluation as alternatives to daily PrEP. To better understand INSTI distribution and inform dosing selection we compared the pharmacology of two-dose boosted elvitegravir and unboosted bictegravir regimens in MSM.

MATERIALS AND METHODS

Blood, rectal and penile secretions and rectal biopsies were collected from 63 HIV-negative MSM aged 18-49 years. Specimens were collected up to 96 h after two oral doses of tenofovir alafenamide and emtricitabine with elvitegravir boosted by cobicistat or unboosted bictegravir given 24 h apart. Antiretroviral drugs were measured by LC-MS.

RESULTS

Mean bictegravir plasma concentrations remained above the 95% protein-adjusted effective concentration 96 h after dosing [273 (95% CI: 164-456) ng/mL] whereas elvitegravir plasma concentrations became undetectable 48 h after the second dose. Bictegravir and elvitegravir reached rectal tissues within 2 h after the first dose, and elvitegravir tissue concentrations [1.07 (0.38-13.51) ng/mg] were greater than bictegravir concentrations [0.27 (0.15-0.70) ng/mg]. Both INSTIs became undetectable in tissues within 96 h. Elvitegravir and bictegravir were not consistently detected in penile secretions.

CONCLUSIONS

Whereas bictegravir plasma concentrations persist at least 4 days after a two-oral-dose HIV prophylaxis regimen, elvitegravir accumulates in mucosal tissues. Differing elvitegravir and bictegravir distribution may result in variable mucosal and systemic antiviral activity and can inform dosing strategies for event-driven HIV prevention.

Short Communication: Evaluation of Antiretroviral Drug Concentrations in Minimally Invasive Specimens for Potential Development of Point-of-Care Drug Assays

Point-of-care (POC) tests for antiretroviral drugs (ARVs) could help improve individual adherence. This study sought to define the utility of urine, blood, and buccal swabs as minimally invasive specimens amenable to development of POC tests for ARVs. Urine, dried blood spots (DBS) and buccal swabs were collected from 35 HIV-negative men between 2 and 96 h after a single dose of tenofovir (TFV) alafenamide/emtricitabine (FTC)/elvitegravir (EVG)/cobicistat and darunavir (DRV). ARV concentrations were measured by high-performance liquid chromatography-mass spectrometry. High concentrations of FTC, DRV, and TFV were detectable in urine at least 24 h after dosing. FTC, DRV, and EVG remained detectable in DBS at least 24 h postdose. FTC and DRV were detectable on buccal swabs up to 2 and 24 h postdose, respectively. TFV was not detectable in DBS or buccal swabs collected between 2 and 96 h after dosing. Variable distribution of ARVs in minimally invasive specimens highlights the challenge of developing POC assays for recent ARV exposure.

Antiretroviral drug exposure in urethral and glans surface sampling of the penis

BACKGROUND

HIV exposure to penile tissues provides a risk of acquisition among men, yet studies evaluating penile antiretroviral (ARV) drug distribution have been lacking. We measured ARVs on urethral and glans surface swabs collected following a dose of tenofovir alafenamide, emtricitabine, elvitegravir, darunavir and cobicistat.

METHODS

Thirty-five HIV-negative male participants provided urethral swabs, glans swabs, rectal swabs, blood and urine up to 96 h following a single dose of tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat and darunavir. ARVs were measured by liquid chromatography-mass spectrometry with a lower limit of detection (LOD) of 1 ng/swab for swabs and 10 ng/mL for plasma and urine. Concentrations are reported as median and range.

RESULTS

Urethral swab emtricitabine and darunavir concentrations peaked at 4 h for emtricitabine (36 ng/swab; 3-307 ng/swab) and 8 h for darunavir (25 ng/swab; 2-52 ng/swab). Glans swab emtricitabine and darunavir concentrations peaked 24 h after dosing (emtricitabine 14 ng/swab, <LOD-328 ng/swab; darunavir 6 ng/swab, <LOD-149 ng/swab). Estimated peak urethral secretion emtricitabine and darunavir concentrations are between 10 and 20 μg/mL, similar to rectal secretions, 4-fold greater than in plasma, but 2-fold lower than in urine. Tenofovir and elvitegravir were detected on less than 20% of urethral or glans swabs collected within 24 h of dosing.

CONCLUSIONS

We document ARV dosing in the urethra and on the glans surface with high drug concentrations noted for emtricitabine and darunavir and lower tenofovir and elvitegravir concentrations. Data suggest a potential protective role of urethral emtricitabine or darunavir against penile HIV acquisition.

Impact of etonogestrel implant use on T-cell and cytokine profiles in the female genital tract and blood

BACKGROUND

While prior epidemiologic studies have suggested that injectable progestin-based contraceptive depot medroxyprogesterone acetate (DMPA) use may increase a woman's risk of acquiring HIV, recent data have suggested that DMPA users may be at a similar risk for HIV acquisition as users of the copper intrauterine device and levonorgestrel implant. Use of the etonogestrel Implant (Eng-Implant) is increasing but there are currently no studies evaluating its effect on HIV acquisition risk.

OBJECTIVE

Evaluate the potential effect of the Eng-Implant use on HIV acquisition risk by analyzing HIV target cells and cytokine profiles in the lower genital tract and blood of adult premenopausal HIV-negative women using the Eng-Implant.

METHODS

We prospectively obtained paired cervicovaginal lavage (CVL) and blood samples at 4 study visits over 16 weeks from women between ages 18-45, with normal menses (22-35 day intervals), HIV uninfected with no recent hormonal contraceptive or copper intrauterine device (IUD) use, no clinical signs of a sexually transmitted infection at enrollment and who were medically eligible to initiate Eng-Implant. Participants attended pre-Eng-Implant study visits (week -2, week 0) with the Eng-Implant inserted at the end of the week 0 study visit and returned for study visits at weeks 12 and 14. Genital tract leukocytes (enriched from CVL) and peripheral blood mononuclear cells (PBMC) from the study visits were evaluated for markers of activation (CD38, HLA-DR), retention (CD103) and trafficking (CCR7) on HIV target cells (CCR5+CD4+ T cells) using multicolor flow cytometry. Cytokines and chemokines in the CVL supernatant and blood plasma were measured in a Luminex assay. We estimated and compared study endpoints among the samples collected before and after contraception initiation with repeated-measures analyses using linear mixed models.

RESULTS

Fifteen of 18 women who received an Eng-Implant completed all 4 study visits. The percentage of CD4+ T cells in CVL was not increased after implant placement but the percentage of CD4+ T cells expressing the HIV co-receptor CCR5 did increase after implant placement (p = 0.02). In addition, the percentage of central memory CD4+ T-cells (CCR7+) in CVL increased after implant placement (p = 0.004). The percentage of CVL CD4+, CCR5+ HIV target cells expressing activation markers after implant placement was either reduced (HLA-DR+, p = 0.01) or unchanged (CD38+, p = 0.45). Most CVL cytokine and chemokine concentrations were not significantly different after implant placement except for a higher level of the soluble lymphocyte activation marker (sCD40L; p = 0.04) and lower levels of IL12p70 (p = 0.02) and G-CSF (p<0.001). In systemic blood, none of the changes noted in CVL after implant placement occurred except for decreases in the percentage CD4 T-cells expressing HLA-DR+ T cells (p = 0.006) and G-CSF (p = 0.02).

CONCLUSIONS

Eng-Implant use was associated with a moderate increase in the availability of HIV target cells in the genital tract, however the percentage of these cells that were activated did not increase and there were minimal shifts in the overall immune environment. Given the mixed nature of these findings, it is unclear if these implant-induced changes alter HIV risk.

Cornelia de Lange syndrome, related disorders, and the Cohesin complex: Abstracts from the 8th biennial scientific and educational symposium 2018

Cornelia de Lange Syndrome (CdLS), due to mutations in genes of the cohesin protein complex, is described as a disorder of transcriptional regulation. Phenotypes in this expanding field include short stature, microcephaly, intellectual disability, variable facial features and organ involvement, resulting in overlapping presentations, including established syndromes and newly described conditions. Individuals with all forms of CdLS have multifaceted complications, including neurodevelopmental, feeding, craniofacial, and communication. Coping mechanisms and management of challenging behaviors in CdLS, disruption of normal behaviors, and how behavior molds the life of the individual within the family is now better understood. Some psychotropic medications are known to be effective for behavior. Other medications, for example, Indomethacin, are being investigated for effects on gene expression, fetal brain tissue, brain morphology and function in Drosophila, mice, and human fibroblasts containing CdLS-related mutations. Developmental studies have clarified the origin of cardiac defects and role of placenta in CdLS. Chromosome architecture and cohesin complex structure are elucidated, leading to a better understanding of regulatory aspects and controls. As examples, when mutations are present, the formation of loop domains by cohesin, facilitating enhancer-promotor interactions, can be eliminated, and embryologically, the nuclear structure of zygotes is disrupted. Several important genes are now known to interact with cohesin, including Brca2. The following abstracts are from the 8th Cornelia de Lange Syndrome Scientific and Educational Symposium, held in June 2018, Minneapolis, MN, before the CdLS Foundation National Meeting, AMA CME credits provided by GBMC, Baltimore, MD. All studies have been approved by an ethics committee.

Non-adherence among women enrolled in a contraceptive vaginal ring use study in Kisumu, Kenya, 2014-2015

Background

Given future potential use of vaginal rings to prevent HIV infection, we examined the association of contraceptive vaginal ring (CVR) non-adherence with user dissatisfaction, tolerability, demographic, and behavioral factors.

Methods

In an open-label single-group study, sexually active women aged 18-34 years using oral or injectable hormonal contraception, conveniently sampled from general population, were assigned to 6-month use of a commercial CVR currently not licensed for use in Kenya. Non-adherence in any CVR cycle completed was assessed from: (1) self-report (not used for at least 1 day), and (2) pharmacy record (failure to timely receive a new CVR or return a used one). Additionally, non-adherence was assessed in a subset of participants by residual progestin and estrogen levels measured in returned CVRs.

Results

Of 202 participants who underwent CVR insertion by a study clinician, 142 completed all 6 visits, 172 responded to questions about ring use, and 43 provided used CVRs from months 1, 3, and 6 for residual hormone analysis. Non-adherence was 14.0% (24/172) by self-report and 54.5% (110/202) by pharmacy record. Non-adherence by pharmacy record was significantly reduced among women with a salary-based income (prevalence ratio (PR) 0.71, 95% confidence interval (CI) (0.55-0.91)] compared to women with income not salary-based or no income. Participants dissatisfied with CVR on ≥4 aspects (ambiguity of instructions, inconvenience of use, sensation, sexual discomfort, etc.) were more likely to report non-adherence (PR 2.69, 95% CI=(1.31-5.52)] compared to those dissatisfied with ≤3 aspects. Non-adherence by residual hormone levels was identified in 46.5% (20/43) participants. Over time, this subset of participants showed increasing non-adherence (P=0.004). We found lack of agreement among the various measures of non-adherence.

Conclusions

Economic empowerment interventions, especially those emphasizing partner-independent income options, and expanded education on CVR features may alleviate non-adherence. Addressing CVR dissatisfaction preemptively may also help mitigate non-adherence.

Short Communication: Reduced Nevirapine Concentrations Among HIV-Positive Women Receiving Mefloquine for Intermittent Preventive Treatment for Malaria Control During Pregnancy

Clinical trials demonstrated intermittent preventive treatment in pregnancy with mefloquine (MQ) reduced malaria rates among pregnant women, yet an unexpected higher risk of mother-to-child transmission (MTCT) of HIV among HIV-positive women receiving MQ has also been observed. To determine if interactions between antiretroviral drugs (ARVs) and MQ could contribute to the increased MTCT observed in women receiving MQ, we performed a retrospective cross-sectional analysis of ARV plasma concentrations in peripheral blood (maternal plasma) and cord blood (cord plasma) collected at delivery from 186 mothers participating in a randomized clinical trial of MQ (n = 102) compared with placebo (n = 84) in Kenya. Plasma zidovudine (AZT), lamivudine (3TC), and nevirapine (NVP) concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry. Although only 4% (7/186) reported not using these ARVs, AZT, 3TC, and NVP were all below the limit of detection in 44% of maternal plasma and 42% of cord plasma samples, and proportions were similar between the two study arms. Median concentrations of AZT and 3TC were not significantly lower in the MQ arm compared with the placebo arm for maternal plasma and cord plasma (p > .05). However, median NVP concentrations were significantly lower in the MQ study arm compared with the placebo study arm in both maternal plasma (1,597 ng/mL vs. 2,353 ng/mL, Mann-Whitney Rank Sum, p = .023) and cord plasma (2,038 ng/mL vs. 2,434 ng/mL, p = .048). Reduced NVP concentrations in maternal and cord plasma of women receiving MQ suggest MQ may affect NVP metabolism for both mother and infant. These results highlight the need to evaluate potential drug-drug interactions between candidate antimalarials and ARVs for use in pregnant women.

Repeated rectal application of a hyperosmolar lubricant is associated with microbiota shifts but does not affect PrEP drug concentrations: results from a randomized trial in men who have sex with men

INTRODUCTION

Oral pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) is highly effective in preventing HIV infection among men who have sex with men (MSM). The effects of consistent personal lubricant use in the rectum on tissue PrEP drug concentrations and the rectal microbiota are unknown. We investigated rectal PrEP drug concentrations and the microbiota in MSM before and after repeated rectal application of a hyperosmolar lubricant.

METHODS

We randomized 60 HIV-negative MSM to apply 4 mL of hyperosmolar rectal lubricant daily (n = 20), take daily oral TDF/FTC (n = 19), or both (n = 21) for seven days. Blood, rectal biopsies and rectal secretions were collected via rigid sigmoidoscopy before and on day 8 after product use. Tenofovir (TFV) and FTC as well as their intracellular metabolites tenofovir-diphosphate (TFV-DP), FTC-triphosphate (FTC-TP) were measured by HPLC-mass spectrometry. Rectal mucosal microbiota was sequenced with 16S rRNA sequencing using Illumina MiSeq.

RESULTS

Seven days of lubricant application was not associated with differences in PrEP drug concentrations in rectal tissue or secretions. Lubricant use was associated with a decrease in the relative abundance of the Bacteroides genus (p = 0.01) and a non-significant increase in the Prevotella genus (p = 0.09) in the rectum. PrEP drug concentrations in rectal tissue and secretions were not associated with microbiota composition or diversity either before or after lubricant use.

CONCLUSIONS

Repeated rectal application of a hyperosmolar lubricant does not affect mucosal PrEP drug concentrations but is associated with changes in the rectal microbiome.

The Female Genital Tract Microbiome Is Associated With Vaginal Antiretroviral Drug Concentrations in Human Immunodeficiency Virus-Infected Women on Antiretroviral Therapy

Background

The female genital tract (FGT) microbiome may affect vaginal pH and other factors that influence drug movement into the vagina. We examined the relationship between the microbiome and antiretroviral concentrations in the FGT.

Methods

Over one menstrual cycle, 20 human immunodeficiency virus (HIV)-infected women virologically suppressed on tenofovir (TFV) disoproxil fumarate/emtricitabine and ritonavir-boosted atazanavir (ATV) underwent serial paired cervicovaginal and plasma sampling for antiretroviral concentrations using high-performance liquid chromatography-tandem mass spectrometry. Analysis of 16S ribosomal RNA gene sequencing of cervicovaginal lavage clustered each participant visit into a unique microbiome community type (mCT).

Results

Participants were predominantly African American (95%), with a median age of 38 years. Cervicovaginal lavage sequencing (n = 109) resulted in a low-diversity mCT dominated by Lactobacillus (n = 40), and intermediate-diversity (n = 28) and high-diversity (n = 41) mCTs with abundance of anaerobic taxa. In multivariable models, geometric mean FGT:plasma ratios varied significantly by mCT for all 3 drugs. For both ATV and TFV, FGT:plasma was significantly lower in participant visits with high- and low-diversity mCT groups (all P < .02). For emtricitabine, FGT:plasma was significantly lower in participant visits with low- vs intermediate-diversity mCT groups (P = .002).

Conclusions

Certain FGT mCTs are associated with decreased FGT antiretroviral concentrations. These findings are relevant for optimizing antiretrovirals used for biomedical HIV prevention in women.

Cornelia de Lange syndrome and molecular implications of the cohesin complex: Abstracts from the 7th biennial scientific and educational symposium 2016

Cornelia de Lange Syndrome (CdLS) is due to mutations in the genes for the structural and regulatory proteins that make up the cohesin complex, and is considered a cohesinopathy disorder or, more recently, a transcriptomopathy. New phenotypes have been recognized in this expanding field. There are multiple clinical issues facing individuals with all forms of CdLS, particularly in the neurodevelopmental system, but also gastrointestinal, cardiac, and musculoskeletal. Aspects of developmental and cell biology have found common endpoints in the biology of the cohesin complex, with improved understanding of the mechanisms, easier diagnostic tests, and the possibility of potential therapeutics, all major clinical implications for the individual with CdLS. The following abstracts are the presentations from the 7th Cornelia de Lange Syndrome Scientific and Educational Symposium, June 22-23, 2016, in Orlando, FL, in conjunction with the Cornelia de Lange Syndrome Foundation National Meeting. In addition to the scientific and clinical discussions, there were talks related to practical aspects of behavior including autism, transitions, communication, access to medical care, and databases. At the end of the symposium, a panel was held, which included several parents, affected individuals and genetic counselors, and discussed the greatest challenges in life and how this information can assist in guiding future research. The Research Committee of the CdLS Foundation organizes this meeting, reviews, and accepts abstracts, and subsequently disseminates the information to the families through members of the Clinical Advisory Board and publications. AMA CME credits were provided by Greater Baltimore Medical Center, Baltimore, MD.

Trauma, stress, and HIV-associated immune cell levels in women

Lifetime trauma, stress exposure, and current perceived stress are believed to lower immune responsiveness to infections but their effect on immune cell targets of HIV infection and pathogenesis are not known. We examined lifetime trauma and current perceived stress for associations with HIV target cells in genital mucosa and PBMC from 50 STI negative women of reproductive age. Validated scores for the number of traumatic exposures on the lifetime trauma and victimization history (LTVH) instrument, the 51-item Chronic Stress Scale (CSS) and the 10-item current perceived stress scale (PSS) were compiled. Paired cervicovaginal lavage (CVL) and blood samples were analyzed for T cell expression of CCR5 and activation markers (CD38, HLA-DR). Spearman correlations were used to evaluate associations between T cell subsets and LTVH, CSS, and PSS scores. LTVH number correlated with PBMC CD4/CD8 ratios and CCR5+ expression on CCR7+ CD4 T cells, but were inversely correlated with effector memory T cell frequency; CSS score was correlated CCR5+ expression on CCR7+ CD4 T cells. PSS scores were not correlated with T cell phenotypes. Genital tract T cell subsets were highly variable and not correlated with LTVH, CSS, or PSS scores. These findings suggest that increased lifetime trauma and chronic stress exposure is associated with shifts in circulating T cell populations that influence HIV susceptibility and its long-term pathogenesis. A better understanding of how lifetime trauma/stress exposure may affect immunologic mediators of HIV susceptibility, biomedical prevention efficacy, and HIV disease progression is warranted.

Residual hormone levels in used contraceptive rings as a measurement of adherence to vaginal ring use

OBJECTIVE

This study sought to measure residual contraceptive hormone levels in vaginal rings as an adherence marker for monitoring product use in clinical trials.

STUDY DESIGN

Residual etonogestrel and ethinyl estradiol levels from used NuvaRings® of 26 self-reported adherent women enrolled in a clinical trial of vaginal ring acceptability were compared to those from 16 women who used NuvaRing® as their contraceptive choice.

RESULTS

Twenty-one (81%) clinical trial rings had contraceptive hormone levels within the range of those used as a contraceptive choice. Five returned rings had unused or discordant levels of residual contraceptive hormones.

CONCLUSION

Residual vaginal ring drug levels could help assess adherence in clinical trials.

Progesterone Levels Associate with a Novel Population of CCR5+CD38+ CD4 T Cells Resident in the Genital Mucosa with Lymphoid Trafficking Potential

The female genital tract (FGT) provides a means of entry to pathogens, including HIV, yet immune cell populations at this barrier between host and environment are not well defined. We initiated a study of healthy women to characterize resident T cell populations in the lower FGT from lavage and patient-matched peripheral blood to investigate potential mechanisms of HIV sexual transmission. Surprisingly, we observed FGT CD4 T cell populations were primarily CCR7(hi), consistent with a central memory or recirculating memory T cell phenotype. In addition, roughly half of these CCR7(hi) CD4 T cells expressed CD69, consistent with resident memory T cells, whereas the remaining CCR7(hi) CD4 T cells lacked CD69 expression, consistent with recirculating memory CD4 T cells that traffic between peripheral tissues and lymphoid sites. HIV susceptibility markers CCR5 and CD38 were increased on FGT CCR7(hi) CD4 T cells compared with blood, yet migration to the lymphoid homing chemokines CCL19 and CCL21 was maintained. Infection with GFP-HIV showed that FGT CCR7(hi) memory CD4 T cells are susceptible HIV targets, and productive infection of CCR7(hi) memory T cells did not alter chemotaxis to CCL19 and CCL21. Variations of resident CCR7(hi) FGT CD4 T cell populations were detected during the luteal phase of the menstrual cycle, and longitudinal analysis showed the frequency of this population positively correlated to progesterone levels. These data provide evidence women may acquire HIV through local infection of migratory CCR7(hi) CD4 T cells, and progesterone levels predict opportunities for HIV to access these novel target cells.

Clinical, developmental and molecular update on Cornelia de Lange syndrome and the cohesin complex: abstracts from the 2014 Scientific and Educational Symposium

Cornelia de Lange Syndrome (CdLS) is the most common example of disorders of the cohesin complex, or cohesinopathies. There are a myriad of clinical issues facing individuals with CdLS, particularly in the neurodevelopmental system, which also have implications for the parents and caretakers, involved professionals, therapists, and schools. Basic research in developmental and cell biology on cohesin is showing significant progress, with improved understanding of the mechanisms and the possibility of potential therapeutics. The following abstracts are presentations from the 6th Cornelia de Lange Syndrome Scientific and Educational Symposium, which took place on June 25-26, 2014, in conjunction with the Cornelia de Lange Syndrome Foundation National Meeting in Costa Mesa, CA. The Research Committee of the CdLS Foundation organizes the meeting, reviews and accepts abstracts, and subsequently disseminates the information to the families through members of the Clinical Advisory Board. In addition to the scientific and clinical discussions, there were educationally focused talks related to practical aspects of behavior and development. AMA CME credits were provided by Greater Baltimore Medical Center, Baltimore, MD.

Recent advances in research of HIV infection: implications of viral and host genetics on treatment and prevention

The genetic diversity among human immunodeficiency virus (HIV) subtypes as well as the variability of viral sequences found in HIV-infected individuals presents a number of difficult obstacles for the development of universally effective HIV treatment and prevention methods. Here, we present a brief summary of recent developments in the analysis of viral genetics and human genomics to provide insight into future methods for HIV treatment and prevention. Recent studies have mined viral sequences found in newly infected individuals to identify common features of all transmitted viruses that could provide potential targets for HIV vaccine development. Analysis of human immunogenetics has identified specific alleles associated with reduced virus loads in HIV-infected individuals providing valuable information that may influence individual responses to treatment and prevention methods. Increased sensitivity of antiretroviral drug resistance testing has improved the detection of hidden drug resistant virus but also highlighted the potential for drug resistant viruses to reduce the effectiveness of clinical treatment regimens. The rapidly expanding amount of data generated by studies of viral genetics and human immunogenetics will provide valuable information to guide the design of new strategies to improve clinical treatment and enhance HIV vaccine development.

Female genital tract shedding of CXCR4-tropic HIV Type 1 is associated with a majority population of CXCR4-tropic HIV Type 1 in blood and declining CD4(+) cell counts

This study compared HIV-1 genotypes shed over time (≤3.5 years) in the vaginal secretions (VS) and blood plasma (BP) of 15 chronically infected women. Analysis of predicted coreceptor tropism (CCR5=R5, CXCR4=X4) for quasispecies shedding revealed three patterns: (1) viral quasispecies shed in both VS and BP were restricted to R5-tropism at all time points, (2) quasispecies shed in VS were restricted to R5-tropism at all time points but X4 quasispecies were identified in the BP at one or more time points, and (3) quasispecies shed in matched VS and BP both contained X4-tropic viruses. Overall, the frequency of X4 quasispecies circulation in VS was 2-fold less than in BP and detection of X4 virus in VS was more likely to occur when X4 quasispecies comprised more than 50% of BP viruses (p=0.01) and when declines in blood CD4(+) lymphocyte levels were the greatest (p=0.038). Additionally, the mean number of predicted N-glycosylation sites between matched VS and BP samples was strongly correlated (r=0.86, p<0.0001) with glycosylation densities in the following order (VS R5=BP R5 > BP X4 > VS X4). The X4 glycosylation densities may result from compartmentalization pressures in the female genital tract or the delayed appearance of these viruses in VS. Our results suggest that the presence of X4 virus in VS is associated with a threshold population of X4 quasispecies in BP, which are increasing during the HIV-induced failure of the human immune system.

HIV-1 RNA rectal shedding is reduced in men with low plasma HIV-1 RNA viral loads and is not enhanced by sexually transmitted bacterial infections of the rectum

BACKGROUND

Among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) taking combination antiretroviral therapy (cART), the impact of rectal sexually transmitted infections (STIs) on rectal HIV-1 shedding is unknown.

METHODS

Human immunodeficiency virus type 1 (HIV-1) RNA was quantified from rectal swabs collected for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) screening of HIV-1-infected MSM. Correlations of STIs with rectal viral load were explored using multinomial regression modeling. HIV-1 coreceptor tropism was predicted from sequencing in a subset of men.

RESULTS

Thirty-one (39%) of 80 men (59 prescribed combination antiretroviral therapy [cART]) had HIV detected in 38 (42%) of 91 rectal swabs. Rectal HIV detection was associated with plasma virus loads above 3.15 log₁₀ copies/mL (95% confidence limit [CL] 2.73, 3.55) and paired rectal viral loads and plasma viral loads were correlated (Kendall's tau [τ] 0.68, Spearman rho [P] = .77). Rectal STIs and abnormal anal cytology were not associated with rectal viral load. HIV coreceptor distribution was very similar between the plasma and rectum in 3 of 4 men.

CONCLUSIONS

Plasma and rectal viral load were correlated, and rectal STIs did not increase the likelihood of detecting HIV in the rectal secretions in MSM, including those with low or undetectable plasma viral load. Suppressing plasma viral load is likely to reduce risk of HIV transmission to insertive partners.

Escape from autologous neutralizing antibodies in acute/early subtype C HIV-1 infection requires multiple pathways

One aim for an HIV vaccine is to elicit neutralizing antibodies (Nab) that can limit replication of genetically diverse viruses and prevent establishment of a new infection. Thus, identifying the strengths and weaknesses of Nab during the early stages of natural infection could prove useful in achieving this goal. Here we demonstrate that viral escape readily occurred despite the development of high titer autologous Nab in two subjects with acute/early subtype C infection. To provide a detailed portrayal of the escape pathways, Nab resistant variants identified at multiple time points were used to create a series of envelope (Env) glycoprotein chimeras and mutants within the background of a corresponding newly transmitted Env. In one subject, Nab escape was driven predominantly by changes in the region of gp120 that extends from the beginning of the V3 domain to the end of the V5 domain (V3V5). However, Nab escape pathways in this subject oscillated and at times required cooperation between V1V2 and the gp41 ectodomain. In the second subject, escape was driven by changes in V1V2. This V1V2-dependent escape pathway was retained over time, and its utility was reflected in the virus's ability to escape from two distinct monoclonal antibodies (Mabs) derived from this same patient via introduction of a single potential N-linked glycosylation site in V2. Spatial representation of the sequence changes in gp120 suggested that selective pressure acted upon the same regions of Env in these two subjects, even though the Env domains that drove escape were different. Together the findings argue that a single mutational pathway is not sufficient to confer escape in early subtype C HIV-1 infection, and support a model in which multiple strategies, including potential glycan shifts, direct alteration of an epitope sequence, and cooperative Env domain conformational masking, are used to evade neutralization.

Inflammatory genital infections mitigate a severe genetic bottleneck in heterosexual transmission of subtype A and C HIV-1

The HIV-1 epidemic in sub-Saharan Africa is driven largely by heterosexual transmission of non-subtype B viruses, of which subtypes C and A are predominant. Previous studies of subtype B and subtype C transmission pairs have suggested that a single variant from the chronically infected partner can establish infection in their newly infected partner. However, in subtype A infected individuals from a sex worker cohort and subtype B individuals from STD clinics, infection was frequently established by multiple variants. This study examined over 1750 single-genome amplified viral sequences derived from epidemiologically linked subtype C and subtype A transmission pairs very early after infection. In 90% (18/20) of the pairs, HIV-1 infection is initiated by a single viral variant that is derived from the quasispecies of the transmitting partner. In addition, the virus initiating infection in individuals who were infected by someone other than their spouse was characterized to determine if genital infections mitigated the severe genetic bottleneck observed in a majority of epidemiologically linked heterosexual HIV-1 transmission events. In nearly 50% (3/7) of individuals infected by someone other than their spouse, multiple genetic variants from a single individual established infection. A statistically significant association was observed between infection by multiple genetic variants and an inflammatory genital infection in the newly infected individual. Thus, in the vast majority of HIV-1 transmission events in cohabiting heterosexual couples, a single genetic variant establishes infection. Nevertheless, this severe genetic bottleneck can be mitigated by the presence of inflammatory genital infections in the at risk partner, suggesting that this restriction on genetic diversity is imposed in large part by the mucosal barrier.

Previous studies of HIV transmission have yielded conflicting results regarding the genetic heterogeneity of the virus establishing infection in the newly infected individual. In this study of populations from Zambia and Rwanda that are infected by two distinct viral genetic subtypes, we compared viral sequences that encode the entry-mediating envelope glycoproteins from newly infected individuals (recipients) and their spouses (donors) very early after infection, as well as newly infected individuals infected by someone other than their spouse. In spite of the genetically diverse virus population in the donor, approximately 90% of newly infected individuals were infected by a single viral variant, while the rest were infected by multiple viral variants. The homogeneity of the virus population in the newly infected recipient, as well as the presence, in some cases, of identical virus variants in the donor, allowed us to precisely identify the transmitted variant. We were able to examine the clinical history of each newly infected individual and observed that all individuals infected by multiple variants also showed evidence of inflammatory genital infections. Our results suggest that the genital mucosa provides a natural barrier to infection by multiple genetic variants of HIV-1, but that this barrier can be lowered by inflammatory genital infections.

siRNA depletion of 7SK snRNA induces apoptosis but does not affect expression of the HIV-1 LTR or P-TEFb-dependent cellular genes

P-TEFb is a general transcriptional elongation factor composed of Cdk9 and either cyclin T1, T2, or K. A substantial portion of P-TEFb is associated with the 7SK small nuclear RNA (7SK) and the HEXIM1 or HEXIM2 proteins; this complex has reduced kinase activity in vitro relative to free P-TEFb. Here we report that 7SK and HEXIM1 levels are induced in activated lymphocytes concomitantly with increased P-TEFb activity and global transcription. We used siRNA-mediated depletion to probe the function of 7SK in HeLa cells. Depletion of 7SK caused a large reduction in the association of HEXIM1 with Cdk9 and cyclin T1, and greatly reduced the amount of the cyclin T1 present in the 7SK/HEXIM1/P-TEFb complex. Similar to previous studies, siRNA-mediated depletion of 7SK resulted in increased expression of several reporter plasmids tested, including a plasmid lacking promoter elements. However, in contrast to previous studies, which did not examine the effects of 7SK depletion on endogenous gene expression, depletion of 7SK did not appear to affect the expression of the corresponding endogenous genes. Moreover, 7SK depletion had no effect on expression from the integrated HIV-1 provirus or the c-myc and MCL-1 genes, three transcription units known to be highly dependent upon P-TEFb. Importantly, depletion of 7SK was found to cause apoptosis by 72 h post-transfection in HeLa cells. These results suggest that 7SK may provide an essential cellular function whose relation to P-TEFb function is unclear.

Cyclin T1 but not cyclin T2a is induced by a post-transcriptional mechanism in PAMP-activated monocyte-derived macrophages

Positive transcription elongation factor b (P-TEFb) is an RNA polymerase II elongation factor which exists as multiple complexes in human cells. These complexes contain cyclin-dependent kinase 9 as the catalytic subunit and different cyclin subunits-cyclin T1, T2a, T2b, or K. Cyclin T1 is targeted by the human immunodeficiency virus (HIV) Tat protein to activate transcription of the HIV provirus. Expression of this P-TEFb subunit is highly regulated in monocyte-derived macrophages (MDMs). Cyclin T1 is induced early during differentiation and is shut off later by proteasome-mediated proteolysis. Cyclin T1 can be reinduced by pathogen-associated molecular patterns (PAMPs) or HIV infection. In this study, we analyzed regulation of P-TEFb in MDMs by examining 7SK small nuclear RNA and the HEXIM1 protein; these factors associate with P-TEFb and are thought to regulate its function. 7SK and HEXIM1 were induced early during differentiation, and this correlates with increased overall transcription. 7SK expression remained high, but HEXIM1 was shut off later during differentiation by proteasome-mediated proteolysis. Significantly, the cyclin T2a subunit of P-TEFb was not shut off during differentiation, and it was not induced by activation. Induction of cyclin T1 by PAMPs was found to be a slow process and did not involve an increase in cyclin T1 mRNA levels. Treatment of MDMs with PAMPs or a proteasome inhibitor induced cyclin T1 to a level equivalent to treatment with both agents together, suggesting that PAMPs and proteasome inhibitors act at a similar rate-limiting step. It is therefore likely that cyclin T1 induction by PAMPs is the result of a reduction in proteasome-mediated proteolysis.

Identification of LKLF-regulated genes in quiescent CD4 T lymphocytes

The transcription factor LKLF (lung Krüppel-like factor) is expressed at high levels in quiescent CD4+ and CD8+ T lymphocytes and provides an important role in establishment and maintenance of the quiescent state. To identify LKLF-regulated genes, we performed microarray analysis using an established Jurkat T cell line containing a tetracycline-inducible LKLF. LKLF induction in this Jurkat T cell line generates a quiescent phenotype that resembles memory CD4+ T lymphocytes. We found that LKLF induction in Jurkat cells resulted in up-regulation (>1.5-fold) of about 100 mRNAs, while it repressed (>1.5-fold) a similar number of mRNAs. A striking feature of the LKLF-stimulated mRNAs was that a significant number of them encode cell surface proteins or proteins implicated in initiating and propagating cellular signaling cascades. The data suggests that LKLF may establish a phenotype that primes quiescent cells for responses to specific extracellular stimuli. The mRNAs encoding CDw52, IL-10R alpha and paxillin were among the most highly induced transcripts in Jurkat T cells, and we observed that the encoded proteins are down-regulated following activation of quiescent CD4+ T cells isolated from healthy blood donors. We also examined whether LKLF-induced quiescence in Jurkat cells could silence transcription of integrated HIV-1 proviruses. We found however that LKLF-induced quiescence is not sufficient to repress expression of HIV-1 proviruses in Jurkat T cells, suggesting that the HIV-1 provirus is resistant to LKLF-regulated quiescence.

Increased association of 7SK snRNA with Tat cofactor P-TEFb following activation of peripheral blood lymphocytes

OBJECTIVE

This study was undertaken to determine whether 7SK small nuclear RNA (snRNA), which has been proposed to function as an inhibitor of Tat cofactor P-TEFb, plays a role in transcriptional latency in T cells.

DESIGN AND METHODS

The association of 7SK snRNA with P-TEFb was investigated in resting and activated peripheral blood lymphocytes (PBLs). Primary PBLs were isolated by standard methods and activated with phytohemagglutinin (PHA). Levels of 7SK snRNA were determined by Northern blotting and levels of the P-TEFb subunits cyclin-dependent kinase 9 and cyclin T1 were analyzed by immunoblotting.

RESULTS

The association of 7SK snRNA with P-TEFb complexes was specific. Following activation of PBLs, the levels of 7SK snRNA increased in a manner similar to U1 and U6 snRNA, sn RNAs involved in positive aspects of cellular gene expression. Unexpectedly, the association of 7SK snRNA with P-TEFb increased dramatically following lymphocyte activation.

CONCLUSION

Increased association of 7SK snRNA with P-TEFb in activated lymphocytes correlates with increased global transcription. This suggests that 7SK snRNA is unlikely to promote transcriptional latency in lymphocytes through an association with P-TEFb; it also suggests that the proposal that the association of 7SK snRNA with P-TEFb acts to inhibit transcriptional elongation needs to be re-evaluated.