Cis-regulatory evolution of the recently expanded Ly49 gene family.

Comparative genomics has revealed the rapid expansion of multiple gene families involved in immunity. Members within each gene family often evolved distinct roles in immunity. However, less is known about the evolution of their epigenome and cis-regulation. Here we systematically profile the epigenome of the recently expanded murine Ly49 gene family that mainly encode either inhibitory or activating surface receptors on natural killer cells. We identify a set of cis-regulatory elements (CREs) for activating Ly49 genes. In addition, we show that in mice, inhibitory and activating Ly49 genes are regulated by two separate sets of proximal CREs, likely resulting from lineage-specific losses of CRE activity. Furthermore, we find that some Ly49 genes are cross-regulated by the CREs of other Ly49 genes, suggesting that the Ly49 family has begun to evolve a concerted cis-regulatory mechanism. Collectively, we demonstrate the different modes of cis-regulatory evolution for a rapidly expanding gene family.

Improving preparedness for introducing and scaling up long-acting HIV pre-exposure prophylaxis in Asia.

Long-acting injectable PrEP, particularly cabotegravir (CAB-LA), has the potential to enhance HIV prevention in Asia, and was the topic of a roundtable held in Singapore in June 2023. Despite proven efficacy, CAB-LA's impact in Asia is hindered by regulatory, manufacturing, and cost barriers. There is an urgent need to address these challenges to expedite CAB-LA's introduction and scale-up, including collaborative research, streamlined regulatory processes, and increased manufacturing capacity. We call for better preparedness in long-acting PrEP in research and implementation science, product licensing and accessibility, and capacity readiness for scale-up, to meet the significant demand among key populations in Asia.

Assessment of Acceptability of Pre-exposure Prophylaxis for HIV Prevention Among Men Who Sex with Men and Transgender Community in Pakistan.

OBJECTIVE: To assess the level of acceptability of oral pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) and transwomen (TW) in Pakistan. STUDY DESIGN: Cross-sectional study. Place and Duration of the Study: Online study portal from September to November 2021. METHODOLOGY: The study participants were recruited through snowball sampling. Consenting individuals who were >13 years and were identified as MSM or TW were included in the study. Data were analysed using SPSS version 25. Frequencies, percentages and correlation coefficients were computed. RESULTS: A total of 347 participants were recruited. The mean age of all participants was 29.8 ± 6.7 years. Fifty-eight (19.7%) of the participants had chemsex with amphetamine-type stimulants (ATS) at least once in preceding six months of the study, and 58 (19.7%) had a sexually transmitted infection (STI) in preceding six months whereas 10 (3.4%) participants had used drugs via injection. Two hundred and thirty-eight (72%) of the participants were aware of PrEP, 30 (11.7%) had used PrEP in the past, and 3.88% were currently using PrEP. The willingness to use PrEP, free of cost, was shown by 300 participants (86.45%) and by 180 (54.5%), if available at a low cost. CONCLUSION: There was a high prevalence of risk factors posing them at considerable risk of human immunodeficiency virus (HIV). The majority was aware of PrEP for HIV prevention. The willingness to use PrEP was high when PrEP was offered free of cost but dropped down when participants were asked to pay for PrEP. Based on this finding, PrEP should be available free of cost at the community preferred outlets. KEY WORDS: Gay, Men who have sex with men, HIV, Pre-exposure prophylaxis Pakistan, Transwomen, Chemsex, People living with HIV.

Shaping and coordinating the implementation science agenda for injectable cabotegravir for PrEP: the role of the Biomedical Prevention Implementation Collaborative (BioPIC).

INTRODUCTION: Data from two randomized controlled trials (RCTs) showed that injectable cabotegravir (CAB) for pre-exposure prophylaxis (PrEP) was efficacious in reducing HIV acquisition. The US Food and Drug Administration approved CAB for PrEP in December 2021; Australia in August 2022; Zimbabwe in October 2022; South Africa in November 2022; Malawi in March 2023; and regulatory approvals are being sought in additional countries. The World Health Organization (WHO) recommended CAB be offered to people at substantial risk of HIV in July 2022. However, implementation experience beyond RCTs is limited. As countries consider CAB implementation, questions remain regarding delivery and involvement of populations excluded from the trials. A coordinated approach is needed to ensure these are addressed and CAB can be introduced in low- and middle-income countries in timely, acceptable and effective ways. DISCUSSION: Beginning in 2018, the Biomedical Prevention Implementation Collaborative (BioPIC) convened over 100 global health experts to develop a comprehensive introduction strategy for CAB. Using this roadmap, country landscaping for CAB introduction and lessons from oral PrEP implementation, AVAC and WHO co-convened 50 researchers, donors, implementers and civil society in September 2021 to: (1) identify questions and evidence gaps related to CAB across contexts and partners; (2) define the implementation science agenda; and (3) agree on mechanism(s) for future coordination. As a result, CAB-related questions were identified, including: defining optimal and feasible HIV testing strategies that expand access; delivery models; integration with a range of services, including family planning and antenatal care; and embedding CAB in demand generation for HIV prevention choices. Through convenings and mapping of implementation research, BioPIC identified gaps in populations, geographies and delivery approaches. CONCLUSIONS: The introduction strategy refined by BioPIC lays the groundwork for future HIV prevention products. Ongoing policy and implementation dialogue is critical to accelerate the design of CAB implementation studies that adequately address priority knowledge gaps. Additional long-acting HIV prevention products may be available over the next 5 years, increasing choice, but potentially making delivery and stakeholder engagement more complex. Ongoing coordination with WHO will accelerate the adoption of evidence-based policies and wide-scale implementation, and lessons from BioPIC can inform introduction processes for long-acting HIV prevention products.

Systematic review of the values and preferences regarding the use of injectable pre-exposure prophylaxis to prevent HIV acquisition.

INTRODUCTION: Pre-exposure prophylaxis (PrEP) is an important HIV prevention option. Two randomized trials have provided efficacy evidence for long-acting injectable cabotegravir (CAB-LA) as PrEP. In considering CAB-LA as an additional PrEP modality for people at substantial risk of HIV, it is important to understand community response to injectable PrEP. We conducted a systematic review of values, preferences and perceptions of acceptability for injectable PrEP to inform global guidance. METHODS: We searched nine databases and conference websites for peer-reviewed and grey literature (January 2010-September 2021). There were no restrictions on location. A two-stage review process assessed references against eligibility criteria. Data from included studies were organized by constructs from the Theoretical Framework of Acceptability. RESULTS: We included 62 unique references. Most studies were observational, cross-sectional and qualitative. Over half of the studies were conducted in North America. Men who have sex with men were the most researched group. Most studies (57/62) examined injectable PrEP, including hypothetical injectables (55/57) or placebo products (2/57). Six studies examined CAB-LA specifically. There was overall interest in and often a preference for injectable PrEP, though there was variation within and across groups and regions. Many stakeholders indicated that injectable PrEP could help address adherence challenges associated with daily or on-demand dosing for oral PrEP and may be a better lifestyle fit for individuals seeking privacy, discretion and infrequent dosing. End-users reported concerns, including fear of needles, injection site pain and body location, logistical challenges and waning or incomplete protection. DISCUSSION: Despite an overall preference for injectable PrEP, heterogeneity across groups and regions highlights the importance of enabling end-users to choose a PrEP modality that supports effective use. Like other products, preference for injectable PrEP may change over time and end-users may switch between prevention options. There will be a greater understanding of enacted preference as more end-users are offered anti-retroviral (ARV)-containing injectables. Future research should focus on equitable implementation, including real-time decision-making and how trained healthcare providers can support choice. CONCLUSIONS: Given overall acceptability, injectable PrEP should be included as part of a menu of prevention options, allowing end-users to select the modality that suits their preferences, needs and lifestyle.

Improving access to oral pre-exposure prophylaxis for HIV among international migrant populations.

Pre-exposure prophylaxis (PrEP) is recommended for people susceptible to HIV acquisition, and the scale-up of PrEP programmes has contributed to new HIV case reductions at a population level. However, international migrants continue to be disproportionately affected by HIV. Understanding barriers and facilitators to PrEP implementation among international migrants can optimise PrEP use among this population and ultimately reduce HIV incidence worldwide. We reviewed the evidence regarding factors influencing PrEP implementation among international migrants; 19 studies were included. The barriers and facilitators at the individual level were related to knowledge and risk perception of HIV. Cost, provider discriminations, and health system navigation influenced PrEP use at the service level. Positive or negative perception towards LGBT+ identities, HIV, and PrEP users affected PrEP use at the societal level. Most existing PrEP campaigns do not target international migrants; therefore, culturally tailored approaches for people from different backgrounds are warranted. Potentially migration-related and HIV-related discriminatory policies must be reviewed to increase access to HIV prevention services to end HIV transmission at a population level.

The Future of Pre-Exposure Prophylaxis (PrEP) for HIV Prevention: A Global Qualitative Consultation on Provider Perspectives on New Products and Differentiated Service Delivery.

Differentiated service delivery and new products, such as long-acting injectable cabotegravir (CAB-LA) and the dapivirine vaginal ring (DVR), could increase uptake and use of pre-exposure prophylaxis (PrEP) for HIV prevention. We explored PrEP provider perspectives on differentiated PrEP service delivery and new PrEP products to inform World Health Organization (WHO) guidelines and programme implementation. 150 PrEP providers who participated in a WHO survey were randomly selected and 67 were invited for interviews based on geographic representation, provider cadre, gender, experience with community-based PrEP service delivery, and familiarity with new PrEP products. Semi-structured interviews were conducted virtually. Key themes were inductively extracted relating to differentiated service delivery and benefits and concerns regarding new PrEP products. 30 PrEP providers from 24 countries were interviewed. Across regions, providers were supportive of differentiated service delivery to respond to clients' needs and preferences, maintain services during COVID-19, and ensure access for priority populations that may face access challenges. Providers welcomed prospects of offering CAB-LA to their clients but had concerns about HIV testing, costs, and the need for clinic-based services, including staff who can administer injections. Providers felt the DVR was potentially important for some cisgender women, especially young clients and female sex workers, and raised fewer concerns compared to injectable PrEP. Providers' views are critical for the development of guidelines and implementing programmes that will best serve PrEP users. Understanding areas where provider capacities and biases may create barriers can define opportunities for training and support to ensure that providers can deliver effective programmes.

Discovering the Solid-State Secrets of Lorlatinib by NMR Crystallography: To Hydrogen Bond or not to Hydrogen Bond.

Lorlatinib is an active pharmaceutical ingredient (API) used in the treatment of lung cancer. Here, an NMR crystallography analysis is presented whereby the single-crystal X-ray diffraction structure (CSD: 2205098) determination is complemented by multinuclear (1H, 13C, 14/15N, 19F) magic-angle spinning (MAS) solid-state NMR and gauge-including projector augmented wave (GIPAW) calculation of NMR chemical shifts. Lorlatinib crystallises in the P21 space group, with two distinct molecules in the asymmetric unit cell, Z' = 2. Three of the four NH2 hydrogen atoms form intermolecular hydrogen bonds, N30-H…N15 between the two distinct molecules and N30-H…O2 between two equivalent molecules. This is reflected in one of the NH21H chemical shifts being significantly lower, 4.0 ppm compared to 7.0 ppm. Two-dimensional 1H-13C, 14N-1H and 1H (double-quantum, DQ)-1H (single-quantum, SQ) MAS NMR spectra are presented. The 1H resonances are assigned and specific HH proximities corresponding to the observed DQ peaks are identified. The resolution enhancement at a 1H Larmor frequency of 1 GHz as compared to 500 or 600 MHz is demonstrated.

Integrated transcriptomics contrasts fatty acid metabolism with hypoxia response in ß-cell subpopulations associated with glycemic control.

BACKGROUND: Understanding how heterogeneous ß-cell function impacts diabetes is imperative for therapy development. Standard single-cell RNA sequencing analysis illuminates some factors driving heterogeneity, but new strategies are required to enhance information capture. RESULTS: We integrate pancreatic islet single-cell and bulk RNA sequencing data to identify ß-cell subpopulations based on gene expression and characterize genetic networks associated with ß-cell function in obese SM/J mice. We identify ß-cell subpopulations associated with basal insulin secretion, hypoxia response, cell polarity, and stress response. Network analysis associates fatty acid metabolism and basal insulin secretion with hyperglycemic-obesity, while expression of Pdyn and hypoxia response is associated with normoglycemic-obesity. CONCLUSIONS: By integrating single-cell and bulk islet transcriptomes, our study explores ß-cell heterogeneity and identifies novel subpopulations and genetic pathways associated with ß-cell function in obesity.

Widespread contribution of transposable elements to the rewiring of mammalian 3D genomes.

Transposable elements (TEs) are major contributors of genetic material in mammalian genomes. These often include binding sites for architectural proteins, including the multifarious master protein, CTCF, which shapes the 3D genome by creating loops, domains, compartment borders, and RNA-DNA interactions. These play a role in the compact packaging of DNA and have the potential to facilitate regulatory function. In this study, we explore the widespread contribution of TEs to mammalian 3D genomes by quantifying the extent to which they give rise to loops and domain border differences across various cell types and species using several 3D genome mapping technologies. We show that specific families and subfamilies of TEs have contributed to lineage-specific 3D chromatin structures across mammalian species. In many cases, these loops may facilitate sustained interaction between distant cis-regulatory elements and target genes, and domains may segregate chromatin state to impact gene expression in a lineage-specific manner. An experimental validation of our analytical findings using CRISPR-Cas9 to delete a candidate TE resulted in disruption of species-specific 3D chromatin structure. Taken together, we comprehensively quantify and selectively validate our finding that TEs contribute to shaping 3D genome organization and may, in some cases, impact gene regulation during the course of mammalian evolution.

Pre-exposure prophylaxis (PrEP) for HIV prevention among people who inject drugs: a global mapping of service delivery.

BACKGROUND: The World Health Organization (WHO) recommends oral pre-exposure prophylaxis (PrEP) for all people at substantial risk of HIV as part of combination prevention. The extent to which this recommendation has been implemented globally for people who inject drugs is unclear. This study mapped global service delivery of PrEP for people who inject drugs. METHODS: Between October and December 2021, a desk review was conducted to obtain information on PrEP services for people who inject drugs from drug user-led networks and HIV, harm reduction, and human rights stakeholders. Websites of organizations involved in HIV prevention or services for people who inject drugs were searched. Models of service delivery were described in terms of service location, provider, and package. RESULTS: PrEP services were identified in 27 countries (15 high-income). PrEP delivery models varied within and across countries. In most services, PrEP services were implemented in healthcare clinics without direct links to other harm reduction services. In three countries, PrEP services were also provided at methadone clinics. In 14 countries, PrEP services were provided through community-based models (outside of clinic settings) that commonly involved peer-led outreach activities and integration with harm reduction services. CONCLUSIONS: This study indicates limited PrEP availability for people who inject drugs. There is potential to expand PrEP services for people who inject drugs within harm reduction programs, notably through community-based and peer-led services. PrEP should never be offered instead of evidence-based harm reduction programs for people who inject drugs; however, it could be offered as an additional HIV prevention choice as part of a comprehensive harm reduction program.

Safety and efficacy of long-acting injectable cabotegravir as preexposure prophylaxis to prevent HIV acquisition.

OBJECTIVE: HIV remains a significant burden, despite expanding HIV prevention tools. Long-acting injectable cabotegravir (CAB-LA) is a new preexposure prophylaxis (PrEP) product. We reviewed existing evidence to determine the efficacy and safety of CAB-LA as PrEP to inform global guidelines. DESIGN: Systematic review and meta-analysis. METHODS: We systematically reviewed electronic databases and conference abstracts for citations on CAB-LA from January 2010 to September 2021. Outcomes included HIV infection, adverse events, drug resistance, pregnancy-related adverse events, and sexual behavior. We calculated pooled effect estimates using random-effects meta-analysis and summarized other results narratively. RESULTS: We identified 12 articles/abstracts representing four multisite randomized controlled trials. Study populations included cisgender men, cisgender women, and transgender women. The pooled relative risk of HIV acquisition comparing CAB-LA to oral PrEP within efficacy studies was 0.21 (95% confidence interval: 0.07-0.61), resulting in a 79% reduction in HIV risk. Rates of adverse events were similar across study groups. Of 19 HIV infections among those randomized to CAB-LA with results available, seven had integrase strand transfer inhibitor (INSTI) resistance. Data on pregnancy-related adverse events were sparse. No studies reported on sexual behavior. CONCLUSIONS: CAB-LA is highly efficacious for HIV prevention with few safety concerns. CAB-LA may lead to an increased risk of INSTI resistance among those who have acute HIV infection at initiation or become infected while taking CAB-LA. However, results are limited to controlled studies; more research is needed on real-world implementation. Additional data are needed on the safety of CAB-LA during pregnancy (for mothers and infants) and among populations not included in the trials.

Preferences for pre-exposure prophylaxis for HIV: A systematic review of discrete choice experiments.

Background: We aimed to systematically review the health preference literature using discrete choice experiments (DCEs), an attribute-based stated preference method, to investigate patient preferences for HIV pre-exposure prophylaxis (PrEP). Methods: A search in PubMed, Scopus, CINAHL, and Embase was conducted on July 1, 2021, and updated on November 3, 2021. We used two concepts to create our search strategy: (1) discrete choice experiments/conjoint analysis/best-worst scaling, and (2) HIV PrEP.The study is registered in PROSPERO (CRD42021267026). Findings: In total, 1060 studies were identified, and 18 were included in the analysis. Various attributes were examined, including dosing regimen, type of PrEP products, side effects, other side benefits, cost, effectiveness, dispensing venue, and additional support services. Dosing frequency, cost, the effectiveness of PrEP, dispensing venue, and side effects were the most common attributes examined in DCEs. Despite significant heterogeneity in preferences across subpopulations, overall, the most important attributes were cost (28%, 5/18), effectiveness (28%, 5/18) followed by dosing frequency (17%, 3/18). Interpretation: Notably, in studies where all of these three attributes were examined, some individuals would trade effectiveness for cost or vice versa. Ensuring PrEP is low cost or free, widely disseminating information of its effectiveness and advancements in reducing dosing frequency could accelerate the uptake of PrEP for those who would benefit from PrEP the most. Funding: None.

Binary isobaric phase diagrams of stearyl alcohol-poloxamer 407 formulations in the molten and solid state.

Multiparticulate formulations allow for the design of specialized pharmaceutical dosage forms that cater to the needs of a wide range of patient demographics, such as pediatric and geriatric populations, by affording control over the release rate and facilitating the formulation of fixed-dose combination drugs. Melt spray-congealing (MSC) is a method for preparing multiparticulate dosage forms from a suspension or solid solution of active pharamaceutical ingredients (API) and a molten carrier matrix. Stearyl alcohol and poloxamer 407 mixtures are widely used as carrier matrices in MSC microsphere formulations. In this report, the phase equilibria of stearyl alcohol-poloxamer 407 mixtures were investigated by generating binary phase diagrams of composition, i.e. weight/weight percent of poloxamer 407 in stearyl alcohol, and temperature in the molten form and the solid state. The phase equilibria of the molten state were characterized by 1H NMR measurements. The miscibility curves of stearyl alcohol-poloxamer 407 molten mixtures revealed that stearyl alcohol and poloxamer 407 are not miscible in all proportions and that miscibility substantially increases with temperature. The phase equilibria of the solid state were characterized by DSC and PXRD experiments. The phase diagrams of the solid state indicate that stearyl alcohol and poloxamer 407 crystallize and melt separately and, thus, do not form a eutectic or a single phase. The phases equilibria of the bulk mixtures were compared to the phases observed in placebo MSC microspheres and it was determined that the microspheres consist of a mixture of thermodynamically stable and metastable stearyl alcohol crystals immediately after manufacture.

Cost-effectiveness and impact of pre-exposure prophylaxis to prevent HIV among men who have sex with men in Asia: A modelling study.

INTRODUCTION: More than 70% of new HIV infections in Asia occurred in eight countries in 2020: Cambodia, China, India, Indonesia, Myanmar, Nepal, Thailand, and Vietnam-with a rising incidence among men who have sex with men (MSM). The World Health Organization (WHO) recommends pre-exposure prophylaxis (PrEP) for those at risk of acquiring HIV, yet wide-scale implementation of PrEP, on a daily or event-driven basis, has been limited in Asia. METHODS: The Optima HIV model was applied to examine the impact of scaling-up PrEP over five-years to cover an additional 15% of MSM compared with baseline coverage, a target deemed feasible by regional experts. Based on behavioral survey data, we assume that covering 15% of higher-risk MSM will cover 30% of all sexual acts in this group. Scenarios to compare the impact of generic-brand daily dosing of PrEP with generic event-driven dosing (15 days a month) were modelled from the start of 2022 to the end of 2026. Cost-effectiveness of generic versus branded PrEP was also assessed for China, the only country with an active patent for branded, higher cost PrEP. The impact on new HIV infections among the entire population and cost per HIV-related disability-adjusted life year (DALY) averted were estimated from the beginning of 2022 to the end of 2031 and from 2022 to 2051. RESULTS: If PrEP were scaled-up to cover an additional 15% of MSM engaging in higher-risk behavior from the beginning of 2022 to the end of 2026 in the eight Asian countries considered, an additional 100,000 (66,000-130,000) HIV infections (17%) and 300,000 (198,000-390,000) HIV-related DALYs (3%) could be averted over the 2022 to 2031 period. The estimated cost per HIV-related DALY averted from 2022 to 2031 ranged from US$600 for event-driven generic PrEP in Indonesia to US$34,400 for daily branded PrEP in Thailand. Over a longer timeframe from 2022 to 2051, the cost per HIV-related DALY averted could be reduced to US$100-US$12,700. CONCLUSION: PrEP is a critical tool to further reduce HIV incidence in highly concentrated epidemics. Implementing PrEP in Asia may be cost-effective in settings with increasing HIV prevalence among MSM and if PrEP drug costs can be reduced, PrEP could be more cost-effective over longer timeframes.