120 results found
Abdool Karim Q, Archary D, Barré-Sinoussi F, et al., 2022, Women for science & science for women: gaps, challenges and opportunities towards optimizing HIV-1 prevention, Frontiers in Immunology, ISSN: 1664-3224
Herrera C, Olejniczak N, Noël-Romas L, et al., 2022, Pre-clinical Evaluation of Antiproteases as Potential Candidates for HIV-1 Pre-exposure Prophylaxis, Frontiers in Reproductive Health
Berry N, Stein M, Ferguson D, et al., 2022, Mucosal responses to Zika Virus infection in cynomolgus macaques, Pathogens, Vol: 11, Pages: 1-18, ISSN: 2076-0817
Zika virus (ZIKV) cases continue to be reported, and no vaccine or specific antiviral agent has been approved for the prevention or treatment of infection. Though ZIKV is primarily transmitted by mosquitos, cases of sexual transmission and prolonged viral RNA presence in semen have been reported. In this observational study, we report the mucosal responses to sub-cutaneous and mucosal ZIKV exposure in cynomolgus macaques during acute and late chronic infection. Subcutaneous challenge induced a decrease in the growth factor VEGF in colorectal and cervicovaginal tissues 100 days post-challenge, in contrast to the observed increase in these tissues following vaginal infection. This different pattern was not observed in the uterus, where VEGF was upregulated independently of the challenge route. Vaginal challenge induced a pro-inflammatory profile in all mucosal tissues during late chronic infection. Similar responses were already observed during acute infection in a vaginal tissue explant model of ex vivo challenge. Non-productive and productive infection 100 days post-in vivo vaginal challenge induced distinct proteomic profiles which were characterized by further VEGF increase and IL-10 decrease in non-infected animals. Ex vivo challenge of mucosal explants revealed tissue-specific modulation of cytokine levels during the acute phase of infection. Mucosal cytokine profiles could represent biosignatures of persistent ZIKV infection.
Petkov S, Herrera C, Else L, et al., 2022, Mobilization of systemic CCL4 following HIV pre-exposure prophylaxis in young men in Africa, Frontiers in Immunology, Vol: 13, Pages: 1-12, ISSN: 1664-3224
HIV-1 pre-exposure prophylaxis (PrEP) relies on inhibition of HIV-1 replication steps. To understand how PrEP modulates the immunological environment, we derived the plasma proteomic profile of men receiving emtricitabine-tenofovir (FTC-TDF) or emtricitabine-tenofovir alafenamide (FTC-TAF) during the CHAPS trial in South Africa and Uganda (NCT03986970). The CHAPS trial randomized 144 participants to one control and 8 PrEP arms, differing by drug type, number of PrEP doses and timing from final PrEP dose to sampling. Blood was collected pre- and post-PrEP. The inflammatory profile of plasma samples was analyzed using Olink (N=92 proteins) and Luminex (N=33) and associated with plasma drug concentrations using mass spectrometry. The proteins whose levels changed most significantly from pre- to post-PrEP were CCL4, CCL3 and TNF-α; CCL4 was the key discriminator between pre- and post-PrEP samples. CCL4 and CCL3 levels were significantly increased in post-PrEP samples compared to control specimens. CCL4 was significantly correlated with FTC drug levels in plasma. Production of inflammatory chemokines CCL4 and CCL3 in response to short-term PrEP indicates the mobilization of ligands which potentially block virus attachment to CCR5 HIV-1 co-receptor. The significant correlation between CCL4 and FTC levels suggests that CCL4 increase is modulated as an inflammatory response to PrEP.
Herrera C, Cottrell ML, Prybylski J, et al., 2022, The ex vivo pharmacology of HIV-1 antiretrovirals differs between macaques and humans, iScience, Vol: 25, ISSN: 2589-0042
Non-human primates (NHP) are widely used for the pre-clinical assessment of antiretrovirals (ARVs) for HIV treatment and prevention. However, the utility of these models is questionable given the differences in ARV pharmacology between humans and macaques. Here, we report a model based on ex vivo ARV exposure and the challenge of mucosal tissue explants to define pharmacological differences between NHPs and humans. For colorectal and cervicovaginal explants in both species, high concentrations of tenofovir (TFV) and maraviroc were predictive of anti-viral efficacy. However, their combinations resulted in increased inhibitory potency in NHP when compared to human explants. In NHPs, higher TFV concentrations were measured in colorectal versus cervicovaginal explants (p = 0.042). In humans, this relationship was inverted with lower levels in colorectal tissue (p = 0.027). TFV-resistance caused greater loss of viral fitness for HIV-1 than SIV. This, tissue explants provide an important bridge to refine and appropriately interpret NHP studies.
Laura E, Pillay A-DAP, Seiphetlo TB, et al., 2022, Pre-clinical evaluation of tenofovir and tenofovir alafenamide for HIV-1 pre-exposure prophylaxis in foreskin tissue, Pharmaceutics, Vol: 14, Pages: 1-13, ISSN: 1999-4923
Background: HIV-1 pre-exposure prophylaxis (PrEP) has focused predominantly on the protective efficacy in receptive sex, with limited research on dosing requirements for insertive sex.We pre-clinically assessed the ex vivo pharmacokinetic/pharmacodynamic (PK/PD) profile oftenofovir (TFV) and tenofovir alafenamide (TAF) in foreskin tissue. Methods: Inner and outer fore-skin explants were exposed to serial dilutions of TFV or TAF prior to addition of HIV-1BaL at a high(HVT) or a low viral titer (LVT). Infection was assessed by measurement of p24 in foreskin culturesupernatants. TFV, TAF and TFV-diphosphate (TFV-DP) concentrations were measured in tissue,culture supernatants, dosing and washing solutions. Results: Dose-response curves were obtainedfor both drugs with greater potency observed against LVT. Inhibitory equivalency mimicking oraldosing was defined between 1 mg/mL of TFV and 15 µg/mL of TAF against HVT challenge. Concentrations of TFV-DP in foreskin explants were approximately 6-fold higher after ex vivo dosingwith TAF than with TFV. Statistically significant negative linear correlations were observed between explant levels of TFV or TFV-DP and p24 concentrations following HVT. Conclusions: Pre-clinical evaluation of TAF in foreskin explants revealed greater potency than TFV against penileHIV transmission. Clinical evaluation is underway to support this finding.
Reuschl A-K, Mesner D, Shivkumar M, et al., 2022, HIV-1 Vpr drives a tissue residency-like phenotype during selective infection of resting memory T cells, CELL REPORTS, Vol: 39, ISSN: 2211-1247
Herrera C, Veazey R, Lemke MM, et al., 2022, Ex vivo evaluation of mucosal responses to vaccination with ALVAC and AIDSVAX of non-human primates, Vaccines, Vol: 10, ISSN: 2076-393X
Non-human primates (NHPs) remain the most relevant challenge model for the evaluation of HIV vaccine candidates; however, discrepancies with clinical trial results have emphasized the need to further refine the NHP model. Furthermore, classical evaluation of vaccine candidates is based on endpoints measured systemically. We assessed the mucosal responses elicited upon vaccination with ALVAC and AIDSVAX using ex vivo Rhesus macaque mucosal tissue explant models. Following booster immunization with ALVAC/AIDSVAX, anti-gp120 HIV-1CM244-specific IgG and IgA were detected in culture supernatant cervicovaginal and colorectal tissue explants, as well as systemically. Despite protection from ex vivo viral challenge, no neutralization was observed with tissue explant culture supernatants. Priming with ALVAC induced distinct cytokine profiles in cervical and rectal tissue. However, ALVAC/AIDSVAX boosts resulted in similar modulations in both mucosal tissues with a statistically significant decrease in cytokines linked to inflammatory responses and lymphocyte differentiation. With ALVAC/AIDSVAX boosts, significant correlations were observed between cytokine levels and specific IgA in cervical explants and specific IgG and IgA in rectal tissue. The cytokine secretome revealed differences between vaccination with ALVAC and ALVAC/AIDSVAX not previously observed in mucosal tissues and distinct from the systemic response, which could represent a biosignature of the vaccine combination.
Mora-Peris B, Keegan MR, Penchala SD, et al., 2021, Cerebral function parameters in people with HIV switching integrase inhibitors: a randomized controlled trial, HIV RESEARCH & CLINICAL PRACTICE, Vol: 22, Pages: 151-159, ISSN: 2578-7489
Herrera C, Harman S, Aldon Y, et al., 2021, The entry inhibitor DS003 (BMS-599793): a BMS-806 analogue, provides superior activity as a pre-exposure prophylaxis candidate, AIDS, Vol: 35, Pages: 1907-1917, ISSN: 0269-9370
Rowan AG, May P, Badhan A, et al., 2021, Optimized protocol for a quantitative SARS-CoV-2 duplex RT-qPCR assay with internal human sample sufficiency control., Journal of Virological Methods, Vol: 294, Pages: 1-7, ISSN: 0166-0934
There is growing evidence that measurement of SARS-CoV-2 viral copy number can inform clinical and public health management of SARS-CoV-2 carriers and COVID-19 patients. Here we show that quantification of SARS-CoV-2 is feasible in a clinical setting, using a duplex RT-qPCR assay which targets both the E gene (Charité assay) and a human RNA transcript, RNase P (CDC assay) as an internal sample sufficiency control. Samples in which RNase P is not amplified indicate that sample degradation has occurred, PCR inhibitors are present, RNA extraction has failed or swabbing technique was insufficient. This important internal control reveals that 2.4% of nasopharyngeal swabs (15/618 samples) are inadequate for SARS-CoV-2 testing which, if not identified, could result in false negative results. We show that our assay is linear across at least 7 logs and is highly reproducible, enabling the conversion of Cq values to viral copy numbers using a standard curve. Furthermore, the SARS-CoV-2 copy number was independent of the RNase P copy number indicating that the per-swab viral copy number is not dependent on sampling- further allowing comparisons between samples. The ability to quantify SARS-CoV-2 viral copy number will provide an important opportunity for viral burden-guided public health and clinical decision making.
Gomara MJ, Pons R, Herrera C, et al., 2021, Peptide Amphiphilic-Based Supramolecular Structures with Anti-HIV-1 Activity, BIOCONJUGATE CHEMISTRY, Vol: 32, Pages: 1999-2013, ISSN: 1043-1802
Herrera C, Lwanga J, Lee M, et al., 2021, Pharmacokinetic/pharmacodynamic investigation of raltegravir with or without lamivudine in the context of HIV-1 pre-exposure prophylaxis (PrEP), Journal of Antimicrobial Chemotherapy, Vol: 76, Pages: 2129-2136, ISSN: 0305-7453
Background:To characterize their potential use in pre-exposure prophylaxis (PrEP) we compared the pharmacokinetics of raltegravir and lamivudine in genital tissue against ex vivo tissue infection with HIV-1.Methods:Open-label trial of 36 HIV-negative females and males randomized to 7 days raltegravir 400 mg twice daily and 7 days raltegravir 400 mg+lamivudine 150 mg twice daily (after washout), or vice versa. Blood, saliva, rectal fluid, rectal tissue, vaginal fluid and vaginal tissue were sampled at baseline and on and off PrEP during a total of 12 days, for pharmacokinetics and antiviral activity via ex vivo HIV-1BaL challenge. Ex vivo infectivity was compared with baseline. The trial has been registered in https://clinicaltrials.gov/ with the identifier NCT03205566.Results:Steady state for both drugs was reached by day 4. Dosing with raltegravir alone provided modest ex vivo HIV protection with higher drug levels in rectal tissue and vaginal tissue than in plasma on and off PrEP. Off PrEP, plasma and vaginal concentrations declined rapidly, while persisting in the rectum. On PrEP, the highest lamivudine concentrations were in the rectum, followed by vaginal tissue then plasma. Lamivudine washout was rapid in plasma, while persisting in the rectum and vagina. Raltegravir/lamivudine increased ex vivo protection on and off PrEP compared with raltegravir alone, reaching maximum protection at day 2 in rectal tissue and at day 8 in vaginal tissue.Conclusions:Raltegravir 400 mg+lamivudine 150 mg showed high levels of ex vivo HIV protection, associated with high drug concentrations persisting after discontinuation in vaginal and rectal compartments, supporting further investigation of these agents for PrEP.
Herrera C, McRaven MD, Laing KG, et al., 2021, Early colorectal responses to HIV-1 and modulation by antiretroviral drugs, Vaccines, Vol: 9, Pages: 1-15, ISSN: 2076-393X
Innate responses during acute HIV infection correlate with disease progression and pathogenesis. However, limited information is available about the events occurring during the first hours of infection in the mucosal sites of transmission. With an ex vivo HIV-1 challenge model of human colorectal tissue we assessed the mucosal responses induced by R5- and X4-tropic HIV-1 isolates in the first 24 h of exposure. Microscopy studies demonstrated virus penetration of up to 39 μm into the lamina propia within 6 h of inoculation. A rapid, 6 h post-challenge, increase in the level of secretion of inflammatory cytokines, chemokines, interferon- γ (IFN-γ), and granulocyte-macrophage colony-stimulating factor (GM-CSF) was observed following exposure to R5- or X4-tropic isolates. This profile persisted at the later time point measured of 24 h. However, exposure to the X4-tropic isolate tested induced greater changes at the proteomic and transcriptomic levels than the R5-tropic. The X4-isolate induced greater levels of CCR5 ligands (RANTES, MIP-1α and MIP-1β) secretion than R5-HIV-1. Potential drugs candidates for colorectal microbicides, including entry, fusion or reverse transcriptase inhibitors demonstrated differential capacity to modulate these responses. Our findings indicate that in colorectal tissue, inflammatory responses and a Th1 cytokine profile are induced in the first 24 h following viral exposure.
Herrera C, Gallagher A, Ferguson D, et al., 2021, Mucosal responses to HIV-1 co-infection with an emerging pathogen, Zika virus, Publisher: JOHN WILEY & SONS LTD
Herrera C, Else L, Penchala SD, et al., 2021, Pharmacokinetic and pharmacodynamic study of tenofovir and tenofovir alafenamide for PrEP in foreskin tissue, Publisher: JOHN WILEY & SONS LTD
Pillay TD, Kondratiuk A, Davies M, et al., 2021, THE INDUCTION OF EARLY, DYNAMIC AIRWAY MUCOSAL AND SYSTEMIC IMMUNE RESPONSES FOLLOWING RECENT SARS-COV-2 HOUSEHOLD EXPOSURE, Publisher: BMJ PUBLISHING GROUP, Pages: A225-A226, ISSN: 0040-6376
LiWang P, Crakes K, Herrera C, et al., 2021, Silk fibroin as a mucosal delivery vehicle for Griffithsin and antiviral compounds: effective protection of macaques and high acceptance among user groups, Publisher: JOHN WILEY & SONS LTD
Gibani MM, Toumazou C, Sohbati M, et al., 2020, Assessing a novel, lab-free, point-of-care test for SARS-CoV-2 (CovidNudge): a diagnostic accuracy study., The Lancet Microbe, Vol: 1, Pages: e300-e307, ISSN: 2666-5247
Background: Access to rapid diagnosis is key to the control and management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Laboratory RT-PCR testing is the current standard of care but usually requires a centralised laboratory and significant infrastructure. We describe our diagnostic accuracy assessment of a novel, rapid point-of-care real time RT-PCR CovidNudge test, which requires no laboratory handling or sample pre-processing. Methods: Between April and May, 2020, we obtained two nasopharyngeal swab samples from individuals in three hospitals in London and Oxford (UK). Samples were collected from three groups: self-referred health-care workers with suspected COVID-19; patients attending emergency departments with suspected COVID-19; and hospital inpatient admissions with or without suspected COVID-19. For the CovidNudge test, nasopharyngeal swabs were inserted directly into a cartridge which contains all reagents and components required for RT-PCR reactions, including multiple technical replicates of seven SARS-CoV-2 gene targets (rdrp1, rdrp2, e-gene, n-gene, n1, n2 and n3) and human ribonuclease P (RNaseP) as sample adequacy control. Swab samples were tested in parallel using the CovidNudge platform, and with standard laboratory RT-PCR using swabs in viral transport medium for processing in a central laboratory. The primary analysis was to compare the sensitivity and specificity of the point-of-care CovidNudge test with laboratory-based testing. Findings: We obtained 386 paired samples: 280 (73%) from self-referred health-care workers, 15 (4%) from patients in the emergency department, and 91 (23%) hospital inpatient admissions. Of the 386 paired samples, 67 tested positive on the CovidNudge point-of-care platform and 71 with standard laboratory RT-PCR. The overall sensitivity of the point-of-care test compared with laboratory-based testing was 94% (95% CI 86-98) with an overall specificity of 100% (99-100). The sensitivity of the test varied
Nash S, Dietrich J, Ssemata AS, et al., 2020, Combined HIV Adolescent Prevention Study (CHAPS): comparison of HIV pre-exposure prophylaxis regimens for adolescents in sub-Saharan Africa-study protocol for a mixed-methods study including a randomised controlled trial., Trials, Vol: 21, ISSN: 1745-6215
BACKGROUND: HIV remains a major public health issue, especially in Eastern and Southern Africa. Pre-exposure prophylaxis is highly effective when adhered to, but its effectiveness is limited by cost, user acceptability and uptake. The cost of a non-inferiority phase III trial is likely to be prohibitive, and thus, it is essential to select the best possible drug, dose and schedule in advance. The aim of this study, the Combined HIV Adolescent PrEP and Prevention Study (CHAPS), is to investigate the drug, dose and schedule of pre-exposure prophylaxis (PrEP) required for the protection against HIV and the acceptability of PrEP amongst young people in sub-Saharan Africa, and hence to inform the choice of intervention for future phase III PrEP studies and to improve strategies for PrEP implementation. METHODS: We propose a mixed-methods study amongst young people aged 13-24 years. The first component consists of qualitative research to identify the barriers and motivators towards the uptake of PrEP amongst young people in South Africa, Uganda and Zimbabwe. The second component is a randomised clinical trial (ClinicalTrials.gov NCT03986970, June 2019) using a novel ex vivo HIV challenge method to investigate the optimal PrEP treatment (FTC-TDF vs FTC-TAF), dose and schedule. We will recruit 144 amongst HIV-negative uncircumcised men aged 13-24 years from voluntary male medical circumcision clinics in two sites (South Africa and Uganda) and randomise them into one of nine arms. One group will receive no PrEP prior to surgery; the other arms will receive either FTC-TDF or FTC-TAF, over 1 or 2 days, and with the final dose given either 6 or 20 h prior to surgery. We will conduct an ex vivo HIV challenge on their resected foreskin tissue. DISCUSSION: This study will provide both qualitative and quantitative results to help decide the optimum drug, dose and schedule for a future phase III trial of PrEP. The study will also provide crucial information
Crakes KR, Herrera C, Morgan JL, et al., 2020, Efficacy of silk fibroin biomaterial vehicle for in vivo mucosal delivery of Griffithsin and protection against HIV and SHIV infection ex vivo, Journal of the International AIDS Society, Vol: 23, ISSN: 1758-2652
INTRODUCTION: The majority of new HIV infections occur through mucosal transmission. The availability of readily applicable and accessible platforms for anti-retroviral (ARV) delivery is critical for the prevention of HIV acquisition through sexual transmission in both women and men. There is a compelling need for developing new topical delivery systems that have advantages over the pills, gels and rings, which currently fail to guarantee protection against mucosal viral transmission in vulnerable populations due to lack of user compliance. The silk fibroin (SF) platform offers another option that may be better suited to individual circumstances and preferences to increase efficacy through user compliance. The objective of this study was to test safety and efficacy of SF for anti-HIV drug delivery to mucosal sites and for viral prevention. METHODS: We formulated a potent HIV inhibitor Griffithsin (Grft) in a mucoadhesive silk fibroin (SF) drug delivery platform and tested the application in a non-human primate model in vivo and a pre-clinical human cervical and colorectal tissue explant model. Both vaginal and rectal compartments were assessed in rhesus macaques (Mucaca mulatta) that received SF (n = 4), no SF (n = 7) and SF-Grft (n = 11). In this study, we evaluated the composition of local microbiota, inflammatory cytokine production, histopathological changes in the vaginal and rectal compartments and mucosal protection after ex vivo SHIV challenge. RESULTS: Effective Grft release and retention in mucosal tissues from the SF-Grft platform resulted in protection against HIV in human cervical and colorectal tissue as well as against SHIV challenge in both rhesus macaque vaginal and rectal tissues. Mucoadhesion of SF-Grft inserts did not cause any inflammatory responses or changes in local microbiota. CONCLUSIONS: We demonstrated that in vivo delivery of SF-Grft in rhesus macaques fully protects against SHIV challenge ex vivo after two
Gomara MJ, Perez Y, Gomez-Gutierrez P, et al., 2020, Importance of structure-based studies for the design of a novel HIV-1 inhibitor peptide, Scientific Reports, Vol: 10, Pages: 1-14, ISSN: 2045-2322
Based on the structure of an HIV-1 entry inhibitor peptide two stapled- and a retro-enantio peptides have been designed to provide novel prevention interventions against HIV transmission. The three peptides show greater inhibitory potencies in cellular and mucosal tissue pre-clinical models than the parent sequence and the retro-enantio shows a strengthened proteolytic stability. Since HIV-1 fusion inhibitor peptides need to be embedded in the membrane to properly interact with their viral target, the structural features were determined by NMR spectroscopy in micelles and solved by using restrained molecular dynamics calculations. Both parent and retro-enantio peptides demonstrate a topology compatible with a shared helix–turn–helix conformation and assemble similarly in the membrane maintaining the active conformation needed for its interaction with the viral target site. This study represents a straightforward approach to design new targeted peptides as HIV-1 fusion inhibitors and lead us to define a retro-enantio peptide as a good candidate for pre-exposure prophylaxis against HIV-1.
Aanensen DM, Abudahab K, Adams A, et al., 2020, An integrated national scale SARS-CoV-2 genomic surveillance network, The Lancet Microbe, Vol: 1, Pages: E99-E100, ISSN: 2666-5247
Thornhill J, Pace M, Genevieve M, et al., 2019, CD32 expressing doublets in HIV infected gut-associated lymphoid are associated with a T follicular helper cell phenotype, Mucosal Immunology, Vol: 12, Pages: 1212-1219, ISSN: 1933-0219
Gut-associated lymphoid tissue (GALT) is a key location for the HIV reservoir. The observation that B-cell–T-cell doublets are enriched for CD32a (a low-affinity IgG receptor) in peripheral blood raises interesting questions, especially as these cells have been associated with HIV DNA in some studies. We sought to determine if similar doublets were present in GALT, the significance of these doublets, and their implications for the HIV reservoir. Given the importance of GALT as a reservoir for HIV, we looked for expression of CD32 on gut CD4 T cells and for evidence of doublets, and any relationship with HIV DNA in HIV + individuals initiated on antiretroviral therapy (ART) during primary HIV infection (PHI). Tonsil tissue was also available for one individual. As previously shown for blood, CD32high CD4 cells were mainly doublets of CD4 T cells and B cells, with T-cell expression of ICOS in tonsil and gut tissue. CD4 T cells associated with CD32 (compared with ‘CD32−' CD4 cells) had higher expression of follicular markers CXCR5, PD-1, ICOS, and Bcl-6 consistent with a T follicular helper (TFH) phenotype. There was a significant correlation between rectal HIV DNA levels and CD32 expression on TFH cells. Together, these data suggest that CD32high doublets are primarily composed of TFH cells, a subset known to be preferentially infected by HIV.
Shacklett BL, Blanco J, Hightow-Weidman L, et al., 2019, HIV Research for Prevention 2018: From research to impact: Conference summary and highlights, AIDS Research and Human Retroviruses, Vol: 35, Pages: 598-607, ISSN: 0889-2229
The HIV Research for Prevention (HIVR4P) conference is dedicated to advancing HIV prevention research, responding to a growing consensus that effective and durable prevention will require a combination of approaches as well as unprecedented collaboration among scientists, practitioners, and community workers from different fields and geographic areas. The conference theme in 2018, “From Research to Impact,” acknowledged an increasing focus on translation of promising research findings into practical, accessible, and affordable HIV prevention options for those who need them worldwide. HIVR4P 2018 was held in Madrid, Spain, on 21–25 October, with >1,400 participants from 52 countries around the globe, representing all aspects of HIV prevention research and implementation. The program included 137 oral and 610 poster presentations. This article presents a brief summary of highlights from the conference. More detailed information, complete abstracts as well as webcasts and daily Rapporteur summaries may be found on the conference website.
Herrera C, 2019, The pre-clinical toolbox of pharmacokinetics and pharmacodynamics: in vitro and ex vivo models, Frontiers in Pharmacology, Vol: 10, ISSN: 1663-9812
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.
Yavuz B, Morgan JL, Herrera C, et al., 2019, Sustained release silk fibroin discs: Antibody and protein delivery for HIV prevention, Journal of Controlled Release, Vol: 301, Pages: 1-12, ISSN: 0168-3659
With almost 2 million new HIV infections worldwide each year, the prevention of HIV infection is critical for stopping the pandemic. The only approved form of pre-exposure prophylaxis is a costly daily pill, and it is recognized that several options will be needed to provide protection to the various affected communities around the world. In particular, many at-risk people would benefit from a prevention method that is simple to use and does not require medical intervention or a strict daily regimen. We show that silk fibroin protein can be formulated into insertable discs that encapsulate either an antibody (IgG) or the potent HIV inhibitor 5P12-RANTES. Several formulations were studied, including silk layering, water vapor annealing and methanol treatment to stabilize the protein cargo and impact the release kinetics over weeks. In the case of IgG, high concentrations were released over a short time using methanol treatment, with more sustained results with the use of water vapor annealing and layering during device fabrication. For 5P12-RANTES, sustained release was obtained for 31 days using water vapor annealing. Further, we show that the released inhibitor 5P12-RANTES was functional both in vitro and in ex vivo colorectal tissue. This work shows that silk fibroin discs can be developed into formidable tools to prevent HIV infection.
Thornhill J, Pace M, Martin G, et al., 2019, CD32 expression identifies B cell-T cell doublets in gut-associated lymphoid tissue that are enriched for T follicular helper cells but not for HIV DNA, Publisher: WILEY, Pages: 24-25, ISSN: 1464-2662
Thornhill J, Herrera C, Hoare J, et al., 2019, The impact of vorinostat and therapeutic vaccine on gut HIV DNA: the RIVER gut study, Publisher: WILEY, Pages: 7-7, ISSN: 1464-2662
Fox J, Herrera C, Lwanga J, et al., 2019, The role of raltegravir alone or combined with lamivudine as PrEP: a phase 2 randomised controlled clinical trial, Publisher: WILEY, Pages: 5-6, ISSN: 1464-2662
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