The transcription factor CREB1 is a mechanistic driver of immunogenicity and reduced HIV-1 acquisition following ALVAC vaccination.

Development of effective human immunodeficiency virus 1 (HIV-1) vaccines requires synergy between innate and adaptive immune cells. Here we show that induction of the transcription factor CREB1 and its target genes by the recombinant canarypox vector ALVAC + Alum augments immunogenicity in non-human primates (NHPs) and predicts reduced HIV-1 acquisition in the RV144 trial. These target genes include those encoding cytokines/chemokines associated with heightened protection from simian immunodeficiency virus challenge in NHPs. Expression of CREB1 target genes probably results from direct cGAMP (STING agonist)-modulated p-CREB1 activity that drives the recruitment of CD4+ T cells and B cells to the site of antigen presentation. Importantly, unlike NHPs immunized with ALVAC + Alum, those immunized with ALVAC + MF59, the regimen in the HVTN702 trial that showed no protection from HIV infection, exhibited significantly reduced CREB1 target gene expression. Our integrated systems biology approach has validated CREB1 as a critical driver of vaccine efficacy and highlights that adjuvants that trigger CREB1 signaling may be critical for efficacious HIV-1 vaccines.

Low-dose in vivo protection and neutralization across SARS-CoV-2 variants by monoclonal antibody combinations.

Prevention of viral escape and increased coverage against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern require therapeutic monoclonal antibodies (mAbs) targeting multiple sites of vulnerability on the coronavirus spike glycoprotein. Here we identify several potent neutralizing antibodies directed against either the N-terminal domain (NTD) or the receptor-binding domain (RBD) of the spike protein. Administered in combinations, these mAbs provided low-dose protection against SARS-CoV-2 infection in the K18-human angiotensin-converting enzyme 2 mouse model, using both neutralization and Fc effector antibody functions. The RBD mAb WRAIR-2125, which targets residue F486 through a unique heavy-chain and light-chain pairing, demonstrated potent neutralizing activity against all major SARS-CoV-2 variants of concern. In combination with NTD and other RBD mAbs, WRAIR-2125 also prevented viral escape. These data demonstrate that NTD/RBD mAb combinations confer potent protection, likely leveraging complementary mechanisms of viral inactivation and clearance.

Dissecting Polyclonal Vaccine-Induced Humoral Immunity against HIV Using Systems Serology.

While antibody titers and neutralization are considered the gold standard for the selection of successful vaccines, these parameters are often inadequate predictors of protective immunity. As antibodies mediate an array of extra-neutralizing Fc functions, when neutralization fails to predict protection, investigating Fc-mediated activity may help identify immunological correlates and mechanism(s) of humoral protection. Here, we used an integrative approach termed Systems Serology to analyze relationships among humoral responses elicited in four HIV vaccine trials. Each vaccine regimen induced a unique humoral "Fc fingerprint." Moreover, analysis of case:control data from the first moderately protective HIV vaccine trial, RV144, pointed to mechanistic insights into immune complex composition that may underlie protective immunity to HIV. Thus, multi-dimensional relational comparisons of vaccine humoral fingerprints offer a unique approach for the evaluation and design of novel vaccines against pathogens for which correlates of protection remain elusive.

Accelerating HIV-1 Vaccine Efficacy Trials.

Despite major advances in HIV-1 therapeutics and prevention strategies, the development of a safe and effective prophylactic HIV-1 vaccine will likely be critical for ending the global HIV-1 epidemic. Yet only four HIV-1 vaccine concepts have been tested for clinical efficacy over the past 30 years. In this Commentary, we describe key hurdles facing the HIV-1 vaccine development field and outline strategies to accelerate efficacy evaluation of novel HIV-1 vaccine candidates.

Protective efficacy of a global HIV-1 mosaic vaccine against heterologous SHIV challenges in rhesus monkeys.

The global diversity of HIV-1 represents a critical challenge facing HIV-1 vaccine development. HIV-1 mosaic antigens are bioinformatically optimized immunogens designed for improved coverage of HIV-1 diversity. However, the protective efficacy of such global HIV-1 vaccine antigens has not previously been evaluated. Here, we demonstrate the capacity of bivalent HIV-1 mosaic antigens to protect rhesus monkeys against acquisition of infection following heterologous challenges with the difficult-to-neutralize simian-human immunodeficiency virus SHIV-SF162P3. Adenovirus/poxvirus and adenovirus/adenovirus vector-based vaccines expressing HIV-1 mosaic Env, Gag, and Pol afforded a significant reduction in the per-exposure acquisition risk following repetitive, intrarectal SHIV-SF162P3 challenges. Protection against acquisition of infection correlated with vaccine-elicited binding, neutralizing, and functional nonneutralizing antibodies, suggesting that the coordinated activity of multiple antibody functions may contribute to protection against difficult-to-neutralize viruses. These data demonstrate the protective efficacy of HIV-1 mosaic antigens and suggest a potential strategy for the development of a global HIV-1 vaccine. PAPERCLIP:

Prospects for a Zika Virus Vaccine.

A recent unprecedented outbreak of Zika virus (ZIKV) in the Americas has been associated with microcephaly and other congenital malformations in infants as well as Guillain-Barre syndrome in adults. The development of a safe and effective ZIKV vaccine is therefore an urgent global health priority. Promising data from preclinical vaccine studies in mice and monkeys suggest that an effective vaccine will likely be possible, but important scientific challenges remain. Here we review the current state of ZIKV vaccine development. We discuss different vaccination strategies and we highlight challenges facing clinical evaluation of ZIKV vaccine candidates.

Prediction of differential Gag versus Env responses to a mosaic HIV-1 vaccine regimen by HLA class I alleles.

HLA class I variation has the strongest effect genome-wide on outcome after HIV infection, and as such, an understanding of the impact of HLA polymorphism on response to HIV vaccination may inform vaccine design. We sought HLA associations with HIV-directed immunogenicity in the phase 1/2a APPROACH vaccine trial, which tested vaccine regimens containing mosaic inserts in Ad26 and MVA vectors, with or without a trimeric gp140 protein. While there were no HLA allelic associations with the overall cellular immune response to the vaccine assessed by ELISpot (Gag, Pol, and Env combined), significant associations with differential response to Gag compared to Env antigens were observed. Notably, HLA class I alleles known to associate with disease susceptibility in HIV natural history cohorts are associated with stronger Env-directed responses, whereas protective alleles are associated with stronger Gag-directed responses. Mean viral loads determined for each HLA allele in untreated individuals correlated negatively with the strength of the Gag response minus the Env response in Black vaccinees based on both ELISpot and CD8+ T cell ICS responses. As the association of T cell responses to conserved Gag epitopes with lower viral load in untreated individuals is well established, our data raise the possibility that the Ad26.Mos.HIV vaccine may induce more effective cellular responses in those with HLA alleles that confer improved virologic control in untreated HIV infection.IMPORTANCENo vaccine tested to date has shown sufficient efficacy against HIV infection. A vaccine that induces robust responses in one individual may fail to do so in another individual due to variation in HLA class I genes, loci central to the immune response. Extensive data have shown the strong effect of HLA variation on outcome after HIV infection, but very little is known about the effect of such variation on HIV vaccine success. Here, we identify a link between the effect of HLA variation on HIV disease outcome and immune responses to an HIV vaccine. HLA variants associated with better HIV control after infection also induce stronger responses against the HIV Gag protein relative to the Env protein after vaccination. Given the virologic control conferred by responses to Gag in natural history of HIV infection, these data suggest that HLA alleles conferring protection after HIV infection may also support a more effective cellular response to HIV vaccination.

Viral vector delivered immunogen focuses HIV-1 antibody specificity and increases durability of the circulating antibody recall response.

The modestly efficacious HIV-1 vaccine regimen (RV144) conferred 31% vaccine efficacy at 3 years following the four-shot immunization series, coupled with rapid waning of putative immune correlates of decreased infection risk. New strategies to increase magnitude and durability of protective immunity are critically needed. The RV305 HIV-1 clinical trial evaluated the immunological impact of a follow-up boost of HIV-1-uninfected RV144 recipients after 6-8 years with RV144 immunogens (ALVAC-HIV alone, AIDSVAX B/E gp120 alone, or ALVAC-HIV + AIDSVAX B/E gp120). Previous reports demonstrated that this regimen elicited higher binding, antibody Fc function, and cellular responses than the primary RV144 regimen. However, the impact of the canarypox viral vector in driving antibody specificity, breadth, durability and function is unknown. We performed a follow-up analysis of humoral responses elicited in RV305 to determine the impact of the different booster immunogens on HIV-1 epitope specificity, antibody subclass, isotype, and Fc effector functions. Importantly, we observed that the ALVAC vaccine component directly contributed to improved breadth, function, and durability of vaccine-elicited antibody responses. Extended boosts in RV305 increased circulating antibody concentration and coverage of heterologous HIV-1 strains by V1V2-specific antibodies above estimated protective levels observed in RV144. Antibody Fc effector functions, specifically antibody-dependent cellular cytotoxicity and phagocytosis, were boosted to higher levels than was achieved in RV144. V1V2 Env IgG3, a correlate of lower HIV-1 risk, was not increased; plasma Env IgA (specifically IgA1), a correlate of increased HIV-1 risk, was elevated. The quality of the circulating polyclonal antibody response changed with each booster immunization. Remarkably, the ALVAC-HIV booster immunogen induced antibody responses post-second boost, indicating that the viral vector immunogen can be utilized to selectively enhance immune correlates of decreased HIV-1 risk. These results reveal a complex dynamic of HIV-1 immunity post-vaccination that may require careful balancing to achieve protective immunity in the vaccinated population. Trial registration: RV305 clinical trial (ClinicalTrials.gov number, NCT01435135). ClinicalTrials.gov Identifier: NCT00223080.

Circulating HIV-Specific Interleukin-21(+)CD4(+) T Cells Represent Peripheral Tfh Cells with Antigen-Dependent Helper Functions.

A central effort in HIV vaccine development is to generate protective broadly neutralizing antibodies, a process dependent on T follicular helper (Tfh) cells. The feasibility of using peripheral blood counterparts of lymph node Tfh cells to assess the immune response and the influence of viral and vaccine antigens on their helper functions remain obscure. We assessed circulating HIV-specific IL-21(+)CD4(+) T cells and showed transcriptional and phenotypic similarities to lymphoid Tfh cells, and hence representing peripheral Tfh (pTfh) cells. pTfh cells were functionally active and B cell helper quality differed depending on antigen specificity. Furthermore, we found higher frequency of pTfh cells in peripheral blood mononuclear cell specimens from the ALVAC+AIDSVAX (RV144) HIV vaccine trial associated with protective antibody responses compared to the non-protective DNA+Ad5 vaccine trial. Together, we identify IL-21(+)CD4(+) T cells as pTfh cells, implicating them as key populations in the generation of vaccine-evoked antibody responses.

Evolution of Antibody Responses in HIV-1 CRF01_AE Acute Infection: Founder Envelope V1V2 Impacts the Timing and Magnitude of Autologous Neutralizing Antibodies.

Understanding the dynamics of early immune responses to HIV-1 infection, including the evolution of initial neutralizing and antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies, will inform HIV vaccine design. In this study, we assess the development of autologous neutralizing antibodies (ANAbs) against founder envelopes (Envs) from 18 participants with HIV-1 CRF01_AE acute infection. The timing of ANAb development directly associated with the magnitude of the longitudinal ANAb response. Participants that developed ANAbs within 6 months of infection had significantly higher ANAb responses at 1 year (50% inhibitory concentration [IC50] geometric mean titer [GMT] = 2,010 versus 184; P = 0.001) and 2 years (GMT = 3,479 versus 340; P = 0.015), compared to participants that developed ANAb responses after 6 months. Participants with later development of ANAb tended to develop an earlier, potent heterologous tier 1 (92TH023) neutralizing antibody (NAb) response (P = 0.049). CRF01_AE founder Env V1V2 loop lengths correlated indirectly with the timing (P = 0.002, r = -0.675) and directly with magnitude (P = 0.005, r = 0.635) of ANAb responses; Envs with longer V1V2 loop lengths elicited earlier and more potent ANAb responses. While ANAb responses did not associate with viral load, the viral load set point correlated directly with neutralization of the heterologous 92TH023 strain (P = 0.007, r = 0.638). In contrast, a striking inverse correlation was observed between viral load set point and peak ADCC against heterologous 92TH023 Env strain (P = 0.0005, r = -0.738). These data indicate that specific antibody functions can be differentially related to viral load set point and may affect HIV-1 pathogenesis. Exploiting Env properties, such as V1V2 length, could facilitate development of subtype-specific vaccines that elicit more effective immune responses and improved protection. IMPORTANCE Development of an effective HIV-1 vaccine will be facilitated by better understanding the dynamics between the founder virus and the early humoral responses. Variations between subtypes may influence the evolution of immune responses and should be considered as we strive to understand these dynamics. In this study, autologous founder envelope neutralization and heterologous functional humoral responses were evaluated after acute infection by HIV-1 CRF01_AE, a subtype that has not been thoroughly characterized. The evolution of these humoral responses was assessed in relation to envelope characteristics, magnitude of elicited immune responses, and viral load. Understanding immune parameters in natural infection will improve our understanding of protective responses and aid in the development of immunogens that elicit protective functional antibodies. Advancing our knowledge of correlates of positive clinical outcomes should lead to the design of more efficacious vaccines.

Targeting the Spike Receptor Binding Domain Class V Cryptic Epitope by an Antibody with Pan-Sarbecovirus Activity.

Novel therapeutic monoclonal antibodies (MAbs) must accommodate comprehensive breadth of activity against diverse sarbecoviruses and high neutralization potency to overcome emerging variants. Here, we report the crystal structure of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD) in complex with MAb WRAIR-2063, a moderate-potency neutralizing antibody with exceptional sarbecovirus breadth, that targets the highly conserved cryptic class V epitope. This epitope overlaps substantially with the spike protein N-terminal domain (NTD) -interacting region and is exposed only when the spike is in the open conformation, with one or more RBDs accessible. WRAIR-2063 binds the RBD of SARS-CoV-2 WA-1, all variants of concern (VoCs), and clade 1 to 4 sarbecoviruses with high affinity, demonstrating the conservation of this epitope and potential resiliency against variation. We compare structural features of additional class V antibodies with their reported neutralization capacity to further explore the utility of the class V epitope as a pan-sarbecovirus vaccine and therapeutic target. IMPORTANCE Characterization of MAbs against SARS-CoV-2, elicited through vaccination or natural infection, has provided vital immunotherapeutic options for curbing the COVID-19 pandemic and has supplied critical insights into SARS-CoV-2 escape, transmissibility, and mechanisms of viral inactivation. Neutralizing MAbs that target the RBD but do not block ACE2 binding are of particular interest because the epitopes are well conserved within sarbecoviruses and MAbs targeting this area demonstrate cross-reactivity. The class V RBD-targeted MAbs localize to an invariant site of vulnerability, provide a range of neutralization potency, and exhibit considerable breadth against divergent sarbecoviruses, with implications for vaccine and therapeutic development.

HIV-1 infections with multiple founders associate with the development of neutralization breadth.

Eliciting broadly neutralizing antibodies (bnAbs) is a cornerstone of HIV-1 vaccine strategies. Comparing HIV-1 envelope (env) sequences from the first weeks of infection to the breadth of antibody responses observed several years after infection can help define viral features critical to vaccine design. We investigated the relationship between HIV-1 env genetics and the development of neutralization breadth in 70 individuals enrolled in a prospective acute HIV-1 cohort. Half of the individuals who developed bnAbs were infected with multiple HIV-1 founder variants, whereas all individuals with limited neutralization breadth had been infected with single HIV-1 founders. Accordingly, at HIV-1 diagnosis, env diversity was significantly higher in participants who later developed bnAbs compared to those with limited breadth (p = 0.012). This association between founder multiplicity and the subsequent development of neutralization breadth was also observed in 56 placebo recipients in the RV144 vaccine efficacy trial. In addition, we found no evidence that neutralization breath was heritable when analyzing env sequences from the 126 participants. These results demonstrate that the presence of slightly different HIV-1 variants in acute infection could promote the induction of bnAbs, suggesting a novel vaccine strategy, whereby an initial immunization with a cocktail of minimally distant antigens would be able to initiate bnAb development towards breadth.

Differences in neutralizing antibody sensitivities and envelope characteristics indicate distinct antigenic properties of Nigerian HIV-1 subtype G and CRF02_AG.

The magnitude of the HIV-1 epidemic in Nigeria is second only to the subtype C epidemic in South Africa, yet the subtypes prevalent in Nigeria require further characterization. A panel of 50 subtype G and 18 CRF02_AG Nigerian HIV-1 pseudoviruses (PSV) was developed and envelope coreceptor usage, neutralization sensitivity and cross-clade reactivity were characterized. These PSV were neutralized by some antibodies targeting major neutralizing determinants, but potentially important differences were observed in specific sensitivities (eg. to sCD4, MPER and V2/V3 monoclonal antibodies), as well as in properties such as variable loop lengths, number of potential N-linked glycans and charge, demonstrating distinct antigenic characteristics of CRF02_AG and subtype G. There was preferential neutralization of the matched CRF/subtype when PSV from subtype G or CRF02_AG were tested using pooled plasma. These novel Nigerian PSV will be useful to study HIV-1 CRF- or subtype-specific humoral immune responses for subtype G and CRF02_AG.

Percutaneous intervention of a giant native coronary artery aneurysm using self-expanding stents.

In the absence of standardized management guidelines, coronary artery aneurysms (CAAs) present therapeutic challenges. Percutaneous coronary intervention (PCI) is rarely explored, especially in giant aneurysms with persistent angina, where surgery might be presumed as a preferred option. We describe the technical aspects and feasibility of PCI using Gore Viabahn expanded polytetrafluoroethylene (ePTFE)-covered nitinol self-expanding stents in a 66-year-old woman with a complex medical history and an enlarging, symptomatic right coronary artery aneurysm. The case was complicated by endoleak after the first stent, but intravascular ultrasound guidance enabled the precise deployment of additional stents, resulting in the successful exclusion of the aneurysm. This case demonstrates steps to successful CAA PCI with Gore Viabahn ePTFE-covered nitinol self-expanding stents and emphasizes that in unsuitable surgical candidates, PCI might be a potential alternative for symptomatic CAAs.

A novel approach to saline/contrast delivery in excimer laser coronary atherectomy (ELCA) to enhance efficacy: MAXCon ELCA technique.

The advent of excimer laser coronary atherectomy (ELCA) nearly four decades ago heralded a novel way to treat complex lesions, both coronary and peripheral, which were previously untraversable and thus untreatable. These complex lesions include heavily calcified lesions, ostial lesions, bifurcation lesions, chronic total occlusions, in-stent restenosis (including stent underexpansion), and degenerative saphenous vein grafts. We discuss the technology of ELCA, its indications, applications, and complications, and suggest the "MAXCon ELCA" technique for better outcomes without increased risk. Lastly, we present a case of MAXCon ELCA effectively treating a complex lesion.

Percutaneous endovascular management of Angio-Seal related vascular occlusion.

BACKGROUND: The use of vascular closure devices (VCDs) to achieve quick and safe hemostasis after femoral arterial access is widely accepted. Major complications include bleeding and occlusion of the femoral artery due to device failure, which often necessitates vascular intervention. This manuscript details our peripheral percutaneous endovascular interventional (PEI) approach for the management of femoral artery occlusion resulting from Angio-Seal (Terumo, Somerset, New Jersey, USA) VCD deployment. METHODS: Consecutive patients who developed occlusive complications after Angio-Seal deployment underwent PEI to overcome specific complications. Patients' clinical and procedural characteristics, along with their short- and long-term follow-up data, were analyzed. RESULTS: The study cohort included 40 patients who experienced Angio-Seal occlusive complications between July 2013 and September 2023. The mean age of the patients was 74 ± 10 years and 55% were female. All the patients were treated with PEI, with an overall procedural success rate of 100%. The primary approach for PEI was directional atherectomy, which was used in 35 cases (88%), followed by balloon, while a cutting balloon was used in 5 patients (13%). Stenting served as the definitive therapy in only 7 patients (18%). No procedural complications or conversions to surgery were observed. During a median follow-up of 244 (IQR = 100-707) days, none of the patients required re-intervention related to Angio-Seal occlusion and salvage intervention. CONCLUSION: In the management of Angi-Seal VCD-related femoral artery occlusion, the adjunctive use of directional atherectomy followed by balloon angioplasty was effective and safe, allowing re-establishment of flow with excellent long-term outcomes.

Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet.

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.

Intravascular Lithotripsy for Treatment of Severely Calcified Common Femoral Artery Disease: Results From the Disrupt PAD III Observational Study.

BACKGROUND: Surgical endarterectomy is currently considered the front-line therapy for the treatment of calcified lesions in the common femoral artery (CFA). Endovascular interventions have evolved, and their use is increasing in frequency. Intravascular lithotripsy (IVL) has shown promising safety and effectiveness in calcified CFA lesions in a small pilot study, but "real-world" evidence from a larger cohort is lacking. METHODS: The Disrupt PAD III Observational Study (NCT02923193) was a prospective, multicenter registry designed to assess the acute safety and effectiveness of IVL treatment for calcified peripheral arterial disease. Any concomitant treatment with other calcium-modifying technologies as well as definitive treatment strategies was at the discretion of the operators. Patients with CFA lesions were evaluated for acute angiographic safety and effectiveness outcomes following IVL treatment as determined by an independent angiographic core lab. RESULTS: Common femoral artery treatment was indicated in 177 patients (n=163 could be analyzed based on core-laboratory data) enrolled at 23 sites. Characteristics for 164 treated lesions included moderate-severe calcification 95.1%, diameter stenosis 74.8±17.7%, and lesion length 53.6±53.1 mm. Concomitant calcium-modifying therapy was used in 32.3% of lesions. Final therapy included drug-coated balloons in 68.9% and stenting in 16.5% of lesions. Post-IVL and final residual stenoses were 29.2±16.5%and 23.6±11.5%, respectively. No vascular complications (flow-limiting dissections, perforations, embolization, slow or no reflow, or abrupt closure) were present at the end of the procedure by core-laboratory assessment, with 1 (0.8%) flow-limiting dissection initially occurring immediately following IVL treatment. CONCLUSION: This study represents the largest real-world experience of IVL treatment in heavily calcified CFA lesions. Intravascular lithotripsy treatment showed significant stenosis reduction and favorable periprocedural safety in this challenging patient population. CLINICAL IMPACT: In this study we show that calcified common femoral artery disease can be safely and effectively treated with shockwave balloon angioplasty with high procedural success and low complication rates and in clinical practice can now be offered as an alternative to surgical treatment in those patients reluctant to or high risk for vascular surgery. This opens another option for clinicians to treat calcified common femoral artery disease without the risk of dissection, perforation or distal embolization that are associated with atherectomy. This study shows that shockwave lithoplasty offers an innovative plaque modification technology to tackle calcified disease in the common femoral artery.

HIV incidence and its associated factors among young adults with multiple sexual partners in Maputo, Mozambique: a vaccine preparedness study.

INTRODUCTION: Sub-Saharan Africa has a high burden of HIV, particularly among female sex workers (FSW) and men who have sex with men (MSM). Future clinical trials to evaluate vaccines and other interventions to prevent HIV will need to enroll populations with high HIV incidence. We conducted an observational study of HIV incidence among men and women with multiple sexual partners-including MSM and FSW-in Maputo, Mozambique, in order to prepare the country to conduct future efficacy trials of candidate HIV vaccines and other HIV prevention products. METHODS: We conducted a prospective observational HIV incidence study in Maputo, Mozambique, that enrolled adults aged 18-35 years, without HIV, who had two or more sexual partners in the preceding three months. Recruitment strategies prioritized participation of MSM and FSW. Participants were followed for 24 months with HIV-1 testing every 3 months and staff-administered behavioral questionnaires every 6 months. Cox proportional hazard modeling was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for factors potentially associated with HIV acquisition. RESULTS: From January 2014 to October 2017, 505 adults without HIV were enrolled with median age of 21 years (interquartile range:19-24); 41% were female and 82% were single. There were 19 HIV seroconversions (10 female and 9 male) during 943 person-years (PY) of observation (overall HIV incidence 2.02/100PY; 95%CI 1.21-3.15). The highest HIV incidence was observed among sex workers (2.08/100PY; 95%CI 0.25-7.52) and MSM (19.18/100PY; 95%CI 3.96-56.06). Increased hazard of incident HIV was observed among participants who were MSM (HR = 27.95, 95%CI 4.39-117.94), p = 0.0004), reported three or more sexual partners at enrollment (HR = 7.39, 95%CI 1.64-33.25, p = 0.009), and indicated ever having a sexual partner living with HIV (HR = 9.64, 95%CI 2.23-41.71, p = 0.002). CONCLUSION: Our findings may inform inclusion criteria for upcoming clinical trials of HIV prevention interventions, including vaccine candidates, which may prioritize enrollment of MSM, people with more than three sexual partners, and people with sexual partners who are living with HIV. These same populations are in need of further intervention to reduce HIV incidence.

Preferential and persistent impact of acute HIV-1 infection on CD4+ iNKT cells in colonic mucosa.

Acute HIV-1 infection (AHI) results in the widespread depletion of CD4+ T cells in peripheral blood and gut mucosal tissue. However, the impact on the predominantly CD4+ immunoregulatory invariant natural killer T (iNKT) cells during AHI remains unknown. Here, iNKT cells from peripheral blood and colonic mucosa were investigated during treated and untreated AHI. iNKT cells in blood were activated and rapidly depleted in untreated AHI. At the time of peak HIV-1 viral load, these cells showed the elevated expression of cell death-associated transcripts compared to preinfection. Residual peripheral iNKT cells suffered a diminished responsiveness to in vitro stimulation early into chronic infection. Additionally, HIV-1 DNA, as well as spliced and unspliced viral RNA, were detected in iNKT cells isolated from blood, indicating the active infection of these cells in vivo. The loss of iNKT cells occurred from Fiebig stage III in the colonic mucosa, and these cells were not restored to normal levels after initiation of ART during AHI. CD4+ iNKT cells were depleted faster and more profoundly than conventional CD4+ T cells, and the preferential infection of CD4+ iNKT cells over conventional CD4+ T cells was confirmed by in vitro infection experiments. In vitro data also provided evidence of latent infection in iNKT cells. Strikingly, preinfection levels of peripheral blood CD4+ iNKT cells correlated directly with the peak HIV-1 load. These findings support a model in which iNKT cells are early targets for HIV-1 infection, driving their rapid loss from circulation and colonic mucosa.