Sequence and vector shapes vaccine induced antibody effector functions in HIV vaccine trials.

Despite the advent of long-acting anti-retroviral therapy able to control and prevent infection, a preventative vaccine remains a global priority for the elimination of HIV. The moderately protective RV144 vaccine trial suggested functional IgG1 and IgG3 antibodies were a potential correlate of protection, but the RV144-inspired HVTN702 validation trial failed to demonstrate efficacy despite inducing targeted levels of IgG1/IgG3. Alterations in inserts, and antigens, adjuvant, and regimen also resulted in vaccine induced target quantitative levels of the immune correlates, but drove qualitative changes to the humoral immune response, pointing to the urgent need to define the influence of vaccine strategies on shaping antibody quality, not just quantity. Thus, defining how distinct prime/boost approaches tune long-lived functional antibodies represents an important goal in vaccine development. Here, we compared vaccine responses in Phase I and II studies in humans utilizing various combinations of DNA/vector, vector/vector and DNA/protein HIV vaccines. We found that adenoviral vector immunization, compared to pox-viral vectors, resulted in the most potent IgG1 and IgG3 responses, linked to highly functional antibody activity, including assisting NK cell related functions. Minimal differences were observed in the durability of the functional humoral immune response across vaccine regimens, except for antibody dependent phagocytic function, which persisted for longer periods in the DNA/rAd5 and rAd35/rAd5 regimen, likely driven by higher IgG1 levels. Collectively, these findings suggest adenoviral vectors drive superior antibody quality and durability that could inform future clinical vaccine studies. Trial registration: ClinicalTrials.gov NCT00801697, NCT00961883, NCT02207920, NCT00125970, NCT02852005).

Estimating the effect of timing of earned income tax credit refunds on perinatal outcomes: a quasi-experimental study of California births.

BACKGROUND: The largest poverty alleviation program in the US is the earned income tax credit (EITC), providing $60 billion to over 25 million families annually. While research has shown positive impacts of EITC receipt in pregnancy, there is little evidence on whether the timing of receipt may lead to differences in pregnancy outcomes. We used a quasi-experimental difference-in-differences design, taking advantage of EITC tax disbursement each spring to examine whether trimester of receipt was associated with perinatal outcomes. METHODS: We conducted a difference-in-differences analysis of California linked birth certificate and hospital discharge records. The sample was drawn from the linked CA birth certificate and discharge records from 2007-2012 (N = 2,740,707). To predict eligibility, we created a probabilistic algorithm in the Panel Study of Income Dynamics and applied it to the CA data. Primary outcome measures included preterm birth, small-for-gestational age (SGA), gestational diabetes, and gestational hypertension/preeclampsia. RESULTS: Eligibility for EITC receipt during the third trimester was associated with a lower risk of preterm birth compared with preconception. Eligibility for receipt in the preconception period resulted in improved gestational hypertension and SGA. CONCLUSION: This analysis offers a novel method to impute EITC eligibility using a probabilistic algorithm in a data set with richer sociodemographic information relative to the clinical and administrative data sets from which outcomes are drawn. These results could be used to determine the optimal intervention time point for future income supplementation policies. Future work should examine frequent income supplementation such as the minimum wage or basic income programs.

Using Community-Based Participatory Research to Design a Patient and Practitioner-Centered Group Prenatal Care Model.

In response to disproportionately high rates of infant mortality and preterm birth among women of color and women in poverty in Fresno County, California, community and academic partners coordinated a community-based participatory research (CBPR) project with local residents. Social isolation and stress, inaccessible prenatal care, and dissatisfaction with care experiences were identified as leading predictors of poor birth outcomes. The PRECEDE-PROCEED framework was used to lead the CBPR effort that resulted in the development of a model of group prenatal care, named Glow! Group Prenatal Care Program (Glow! Program). Group prenatal care (GPNC), which focuses on pregnancy health assessments, education, and peer support, has the potential to address the health and social priorities of women during pregnancy. As a result of the employed CBPR process and the extensive participation from stakeholders, this modified GPNC model responds to the unique needs of the at-risk community members, the agencies aiming to improve maternal-child health experiences and outcomes, and the prenatal care providers offering it to their patients. The methods from this study can be applied in the design and implementation of community-based health care interventions. Returning to community partners throughout the design, implementation, and evaluation phases underscored that health care interventions cannot be designed in silos, and require flexibility to respond to factors that promote improved maternal and infant outcomes, which affect the end goal for the intervention.

Risk of early birth by body mass index in a propensity score-matched sample: A retrospective cohort study.

OBJECTIVE: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. DESIGN: Retrospective cohort analysis. SETTING: California, USA. POPULATION: Singleton live births from 2011-2017. METHODS: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. MAIN OUTCOME MEASURES: Early birth. RESULTS: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28-31 weeks (relative risk [RR] 1.2, 95% CI 1.1-1.4), 32-36 weeks (RR 1.3, 95% CI 1.2-1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1-1.1). Women with BMI ≥25.0 kg/m2 were at 1.2-1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8-0.9) and birth during the 37th or 38th week (RR 0.9). CONCLUSION: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. TWEETABLE ABSTRACT: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.

Using Collective Impact to Advance Birth Equity: A Comparison of Two Cross-Sector Efforts in California.

BACKGROUND: Preterm birth, defined as birth at gestational age before 37 weeks, is a major public health concern with marked racial disparities driven by underlying structural and social determinants of health. To achieve population-level reductions in preterm birth and to reduce racial inequities, the University of California, San Francisco's California Preterm Birth Initiative catalyzed two cross-sector coalitions in San Francisco and Fresno using the Collective Impact (CI) approach. PURPOSE: The purpose of this study is to compare two preterm birth-focused CI efforts and identify common themes and lessons learned. METHODS: Researchers conducted in-depth interviews (n = 19) and three focus groups (n = 20) with stakeholders to assess factors related to collaboration. Transcripts were coded and analyzed using modified grounded theory. Findings were compared by year of data collection (first and second cycle in each location) and geographic location (Fresno and San Francisco) and discussed with CI participants for input. RESULTS: Although both communities adopted the core tenets of CI to address preterm birth and racial inequities, each employed distinct organizational structures, strategic frameworks, and interventions. Common themes emerged around the importance of authentic community engagement, transparency in the process of prioritization and decision-making, addressing racism as a root cause of disparities in birth outcomes, and candid communication among partners. CONCLUSION: Future CI efforts, particularly those catalyzed by academic institutions, should ensure community members are active partners in program development and decision-making. CI efforts focused on combatting racial health inequities should center racism as a root cause and build capacity among coalition partners.

Coronavirus Disease 2019 Outbreak in a San Francisco Homeless Shelter.

We report the public health response to a coronavirus disease 2019 (COVID-19) outbreak in a San Francisco shelter where 67% of residents and 17% of staff tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We describe the limited utility of case investigation, person-based contact tracing and symptom screening, and the benefits of mass testing in outbreak response.

A Systematic Review of the Social Network Strategy to Optimize HIV Testing in Key Populations to End the Epidemic in the United States.

The United States (U.S.) has a plan to end the HIV epidemic by 2030. The plan's first pillar prioritizes HIV testing. Social Network Strategy (SNS) is an intervention to reach persons not routinely testing for HIV. We conducted a systematic review of SNS to understand its implementation to optimize HIV testing in the U.S. among key populations. The eligibility criteria included peer-reviewed papers based in the U.S. and focused on HIV testing. We identified and thematically analyzed 14 articles to explore factors associated with successful implementation. Key themes included: (1) social network and recruiter characteristics; (2) strategies for and effectiveness of recruiting key populations; (3) use of and types of incentives; (4) trust, confidentiality, and stigma concerns; and (5) implementation plans and real-world guidance. Cohort studies indicated that SNS detects more incident HIV cases. Partnerships with health departments are critical to confirm new diagnoses, as are developing plans that support recruiters and staff. SNS is a promising strategy to optimize HIV testing among key populations.

Structural Evidence for a [4Fe-5S] Intermediate in the Non-Redox Desulfuration of Thiouracil.

We recently discovered a [Fe-S]-containing protein with in vivo thiouracil desulfidase activity, dubbed TudS. The crystal structure of TudS refined at 1.5 Šresolution is reported; it harbors a [4Fe-4S] cluster bound by three cysteines only. Incubation of TudS crystals with 4-thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non-protein-bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe-5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site-directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information, together with modeling studies allow us to propose a mechanism for the unprecedented non-redox enzymatic desulfuration of thiouracil, in which a [4Fe-4S] cluster binds and activates the sulfur atom of the substrate.

An Aerobic Hybrid Phthalate Degradation Pathway via Phthaloyl-Coenzyme A in Denitrifying Bacteria.

The degradation of the xenobiotic phthalic acid esters by microorganisms is initiated by the hydrolysis to the respective alcohols and ortho-phthalate (hereafter, phthalate). In aerobic bacteria and fungi, oxygenases are involved in the conversion of phthalate to protocatechuate, the substrate for ring-cleaving dioxygenases. In contrast, anaerobic bacteria activate phthalate to the extremely unstable phthaloyl-coenzyme A (CoA), which is decarboxylated by oxygen-sensitive UbiD-like phthaloyl-CoA decarboxylase (PCD) to the central benzoyl-CoA intermediate. Here, we demonstrate that the facultatively anaerobic, denitrifying Thauera chlorobenzoica 3CB-1 and Aromatoleum evansii KB740 strains use phthalate as a growth substrate under aerobic and denitrifying conditions. In vitro assays with extracts from cells grown aerobically with phthalate demonstrated the succinyl-CoA-dependent activation of phthalate followed by decarboxylation to benzoyl-CoA. In T. chlorobenzoica 3CB-1, we identified PCD as a highly abundant enzyme in both aerobically and anaerobically grown cells, whereas genes for phthalate dioxygenases are missing in the genome. PCD was highly enriched from aerobically grown T. chlorobenzoica cells and was identified as an identical enzyme produced under denitrifying conditions. These results indicate that the initial steps of aerobic phthalate degradation in denitrifying bacteria are accomplished by the anaerobic enzyme inventory, whereas the benzoyl-CoA oxygenase-dependent pathway is used for further conversion to central intermediates. Such a hybrid pathway requires intracellular oxygen homeostasis at concentrations low enough to prevent PCD inactivation but sufficiently high to supply benzoyl-CoA oxygenase with its cosubstrate.IMPORTANCE Phthalic acid esters (PAEs) are industrially produced on a million-ton scale per year and are predominantly used as plasticizers. They are classified as environmentally relevant xenobiotics with a number of adverse health effects, including endocrine-disrupting activity. Biodegradation by microorganisms is considered the most effective process to eliminate PAEs from the environment. It is usually initiated by the hydrolysis of PAEs to alcohols and o-phthalic acid. Degradation of o-phthalic acid fundamentally differs in aerobic and anaerobic microorganisms; aerobic phthalate degradation heavily depends on dioxygenase-dependent reactions, whereas anaerobic degradation employs the oxygen-sensitive key enzyme phthaloyl-CoA decarboxylase. We demonstrate that aerobic phthalate degradation in facultatively anaerobic bacteria proceeds via a previously unknown hybrid degradation pathway involving oxygen-sensitive and oxygen-dependent key enzymes. Such a strategy is essential for facultatively anaerobic bacteria that frequently switch between oxic and anoxic environments.

Development and Validation of the Personalized Sexual Health Promotion (SexPro) HIV Risk Prediction Model for Men Who Have Sex with Men in the United States.

Accurate HIV risk assessment among men who have sex with men (MSM) is important to help providers assess risk, and target HIV prevention interventions. We sought to develop an evidence-based HIV risk assessment tool for US MSM that is inclusive of Black MSM. Data from four large longitudinal cohorts of MSM were used to develop (EXPLORE), and validate (VAX004, HPTN061, and HVTN505). These data included visits in which participants self-reported HIV risk behavior and underwent HIV testing. We developed a pooled logistic model for incident HIV infection based on self-reported risk behaviors during the 6 months before each study visit. A total of 4069 MSM were used for the development cohort, and 8047 MSM in the three validation cohorts through 2013. The final model includes age (< 35, ≥ 35); Black race and Latino ethnicity; numbers of HIV-negative anal sex partners; number of insertive or receptive anal intercourse episodes; having 1 HIV-negative partner only; self-reported substance use; and bacterial sexually transmitted infection diagnosis. The model showed good discrimination in internal validation (C-statistic = 79.5). The external validation cohorts also showed good discrimination, with C-statistics of 73.1, 71.0, 71.9 in VAX004, HPTN061, and HVTN505 respectively, and acceptable calibration. We developed and validated an HIV risk assessment tool for MSM, which showed good predictive ability, including among the largest cohort of HIV-uninfected Black MSM in the US. This tool is available online (mysexpro.org) and can be used by providers to support targeting of HIV prevention interventions such as pre-exposure prophylaxis for MSM.

A catalytically versatile benzoyl-CoA reductase, key enzyme in the degradation of methyl- and halobenzoates in denitrifying bacteria.

Class I benzoyl-CoA (BzCoA) reductases (BCRs) are key enzymes in the anaerobic degradation of aromatic compounds. They catalyze the ATP-dependent reduction of the central BzCoA intermediate and analogues of it to conjugated cyclic 1,5-dienoyl-CoAs probably by a radical-based, Birch-like reduction mechanism. Discovered in 1995, the enzyme from the denitrifying bacterium Thauera aromatica (BCRTar) has so far remained the only isolated and biochemically accessible BCR, mainly because BCRs are extremely labile, and their heterologous production has largely failed so far. Here, we describe a platform for the heterologous expression of the four structural genes encoding a designated 3-methylbenzoyl-CoA reductase from the related denitrifying species Thauera chlorobenzoica (MBRTcl) in Escherichia coli This reductase represents the prototype of a distinct subclass of ATP-dependent BCRs that were proposed to be involved in the degradation of methyl-substituted BzCoA analogues. The recombinant MBRTcl had an αßγδ-subunit architecture, contained three low-potential [4Fe-4S] clusters, and was highly oxygen-labile. It catalyzed the ATP-dependent reductive dearomatization of BzCoA with 2.3-2.8 ATPs hydrolyzed per two electrons transferred and preferentially dearomatized methyl- and chloro-substituted analogues in meta- and para-positions. NMR analyses revealed that 3-methylbenzoyl-CoA is regioselectively reduced to 3-methyl-1,5-dienoyl-CoA. The unprecedented reductive dechlorination of 4-chloro-BzCoA to BzCoA probably via HCl elimination from a reduced intermediate allowed for the previously unreported growth of T. chlorobenzoica on 4-chlorobenzoate. The heterologous expression platform established in this work enables the production, isolation, and characterization of bacterial and archaeal BCR and BCR-like radical enzymes, for many of which the function has remained unknown.

Randomized Controlled Trial of a Mobile Health Intervention to Promote Retention and Adherence to Preexposure Prophylaxis Among Young People at Risk for Human Immunodeficiency Virus: The EPIC Study.

BACKGROUND: Young men who have sex with men are among the most vulnerable to human immunodeficiency virus (HIV) infection. Although preexposure prophylaxis (PrEP) has demonstrated effectiveness, adherence and retention have been low among youth. METHODS: We conducted a randomized controlled trial to evaluate the impact of a youth-tailored, bidirectional text-messaging intervention (PrEPmate) on study retention and PrEP adherence. Young individuals at risk for HIV initiating PrEP within Chicago's safety-net system were randomized 2:1 to receive PrEPmate or standard of care (SoC) for 36 weeks. The primary retention outcome was study-visit completion, and the primary adherence outcome was tenofovir diphosphate (TFV-DP) concentrations ≥700 fmol/punch (consistent with ≥4 doses/week) assessed at 4, 12, 24, and 36 weeks. The impact of PrEPmate on retention and adherence was evaluated using generalized estimating equation logistic models with robust standard errors. RESULTS: From April 2015 to March 2016, 121 participants enrolled (mean age 24; 27% black, 36% Latino). Participants who received PrEPmate were more likely to attend study visits (86% PrEPmate vs. 71% SoC, odds ratio [OR] = 2.62, 95% confidence interval [CI] 1.24-5.54) and have TFV-DP levels consistent with ≥4 doses/week (72% PrEPmate vs. 57% SoC, OR = 2.05, 95% CI 1.06-3.94). PrEPmate efficacy did not differ significantly by age, race/ethnicity, education, or insurance. Overall, 88% reported PrEPmate to be very/somewhat helpful, and 92% would recommend PrEPmate to others. CONCLUSIONS: An interactive text-messaging intervention had high acceptability and significantly increased study-visit retention and PrEP adherence among young individuals at risk for HIV acquisition. CLINICAL TRIALS REGISTRATION: NCT02371525.

An Online Geographic Data Visualization Tool to Relate Preterm Births to Environmental Factors.

Preterm birth (<37 weeks gestation) continues to be a significant cause of disease and death in the United States. Its complex causes are associated with several genetic, biological, environmental, and sociodemographic factors. Organizing and visualizing various data that may be related to preterm birth is an essential step for pattern exploration and hypothesis generation and presents an opportunity to increase public and stakeholder involvement. In this article, we describe a collaborative effort to create an online geographic data visualization tool using open software to explore preterm birth in Fresno County, where rates are the highest in California. The tool incorporates information on births, environmental exposures, sociodemographic characteristics, the built environment, and access to care. We describe data sets used to build the tool, the data-hosting platform, and the process used to engage stakeholders in its creation. We highlight an important example of how collaboration can increase the utility of geographic data visualization to improve public health and address health equity in birth outcomes.

Enantioselective Enzymatic Naphthoyl Ring Reduction.

Birch reductions of aromatic hydrocarbons by means of single-electron-transfer steps depend on alkali metals, ammonia, and cryogenic reaction conditions. In contrast, 2-naphthoyl-coenzyme A (2-NCoA) and 5,6-dihydro-2-NCoA (5,6-DHNCoA) reductases catalyze two two-electron reductions of the naphthoyl-ring system to tetrahydronaphthoyl-CoA at ambient temperature. Using a number of substrate analogues, we provide evidence for a Meisenheimer complex-analogous intermediate during 2-NCoA reduction, whereas the subsequent reduction of 5,6-dihydro-2-NCoA is suggested to proceed via an unprecedented cationic transition state. Using vibrational circular dichroism (VCD) spectroscopy, we demonstrate that both enzymatic reductions are highly stereoselective in D2 O, providing an enantioselective pathway to products inaccessible by Birch reduction. Moreover, we demonstrate the power of VCD spectroscopy to determine the absolute configuration of isotopically engendered alicyclic stereocenters.

Population-Level Immune-Mediated Adaptation in HIV-1 Polymerase during the North American Epidemic.

UNLABELLED: Human leukocyte antigen (HLA) class I-associated polymorphisms in HIV-1 that persist upon transmission to HLA-mismatched hosts may spread in the population as the epidemic progresses. Transmission of HIV-1 sequences containing such adaptations may undermine cellular immune responses to the incoming virus in future hosts. Building upon previous work, we investigated the extent of HLA-associated polymorphism accumulation in HIV-1 polymerase (Pol) through comparative analysis of linked HIV-1/HLA class I genotypes sampled during historic (1979 to 1989; n = 338) and modern (2001 to 2011; n = 278) eras from across North America (Vancouver, BC, Canada; Boston, MA; New York, NY; and San Francisco, CA). Phylogenies inferred from historic and modern HIV-1 Pol sequences were star-like in shape, with an inferred most recent common ancestor (epidemic founder virus) sequence nearly identical to the modern North American subtype B consensus sequence. Nevertheless, modern HIV-1 Pol sequences exhibited roughly 2-fold-higher patristic (tip-to-tip) genetic distances than historic sequences, with HLA pressures likely driving ongoing diversification. Moreover, the frequencies of published HLA-associated polymorphisms in individuals lacking the selecting HLA class I allele was on average ∼2.5-fold higher in the modern than in the historic era, supporting their spread in circulation, though some remained stable in frequency during this time. Notably, polymorphisms restricted by protective HLA alleles appear to be spreading to a greater relative extent than others, though these increases are generally of modest absolute magnitude. However, despite evidence of polymorphism spread, North American hosts generally remain at relatively low risk of acquiring an HIV-1 polymerase sequence substantially preadapted to their HLA profiles, even in the present era. IMPORTANCE: HLA class I-restricted cytotoxic T-lymphocyte (CTL) escape mutations in HIV-1 that persist upon transmission may accumulate in circulation over time, potentially undermining host antiviral immunity to the transmitted viral strain. We studied >600 experimentally collected HIV-1 polymerase sequences linked to host HLA information dating back to 1979, along with phylogenetically reconstructed HIV-1 sequences dating back to the virus' introduction into North America. Overall, our results support the gradual spread of many-though not all-HIV-1 polymerase immune escape mutations in circulation over time. This is consistent with recent observations from other global regions, though the extent of polymorphism accumulation in North America appears to be lower than in populations with high seroprevalence, older epidemics, and/or limited HLA diversity. Importantly, the risk of acquiring an HIV-1 polymerase sequence at transmission that is substantially preadapted to one's HLA profile remains relatively low in North America, even in the present era.

Pseudocyclic Arylbenziodoxaboroles: Efficient Benzyne Precursors Triggered by Water at Room Temperature.

New organohypervalent iodine compounds, arylbenziodoxaborole triflates, were prepared from 1-acetoxybenziodoxaboroles and arenes by treatment with trifluoromethanesulfonic acid under mild conditions. Single crystal X-ray crystallography of these compounds revealed a pseudocyclic structure with a short intramolecular interaction of 2.698 to 2.717 Šbetween oxygen and iodine in the benziodoxaborole ring. These new pseudocyclic aryliodonium salts readily generate aryne intermediates upon treatment with water at room temperature. The generated aryne intermediates react with various substrates to give the corresponding aryne adducts in moderate to good yields. Furthermore, the new benzyne precursors can also work as arylating reagents towards aromatic rings. The aryne intermediates generated from arylbenziodoxaborole triflates selectively react with tert-butyl phenol forming products of ortho arylation in moderate yields.

Genotypic and functional impact of HIV-1 adaptation to its host population during the North American epidemic.

HLA-restricted immune escape mutations that persist following HIV transmission could gradually spread through the viral population, thereby compromising host antiviral immunity as the epidemic progresses. To assess the extent and phenotypic impact of this phenomenon in an immunogenetically diverse population, we genotypically and functionally compared linked HLA and HIV (Gag/Nef) sequences from 358 historic (1979-1989) and 382 modern (2000-2011) specimens from four key cities in the North American epidemic (New York, Boston, San Francisco, Vancouver). Inferred HIV phylogenies were star-like, with approximately two-fold greater mean pairwise distances in modern versus historic sequences. The reconstructed epidemic ancestral (founder) HIV sequence was essentially identical to the North American subtype B consensus. Consistent with gradual diversification of a "consensus-like" founder virus, the median "background" frequencies of individual HLA-associated polymorphisms in HIV (in individuals lacking the restricting HLA[s]) were ∼ 2-fold higher in modern versus historic HIV sequences, though these remained notably low overall (e.g. in Gag, medians were 3.7% in the 2000s versus 2.0% in the 1980s). HIV polymorphisms exhibiting the greatest relative spread were those restricted by protective HLAs. Despite these increases, when HIV sequences were analyzed as a whole, their total average burden of polymorphisms that were "pre-adapted" to the average host HLA profile was only ∼ 2% greater in modern versus historic eras. Furthermore, HLA-associated polymorphisms identified in historic HIV sequences were consistent with those detectable today, with none identified that could explain the few HIV codons where the inferred epidemic ancestor differed from the modern consensus. Results are therefore consistent with slow HIV adaptation to HLA, but at a rate unlikely to yield imminent negative implications for cellular immunity, at least in North America. Intriguingly, temporal changes in protein activity of patient-derived Nef (though not Gag) sequences were observed, suggesting functional implications of population-level HIV evolution on certain viral proteins.

Growing the Pipeline of Diverse HIV Investigators: The Impact of Mentored Research Experiences to Engage Underrepresented Minority Students.

Structured, mentored research programs for high school and undergraduate students from underrepresented minority (URM) backgrounds are needed to increase the diversity of our nation's biomedical research workforce. In particular, a robust pipeline of investigators from the communities disproportionately affected by the HIV epidemic is needed not only for fairness and equity but for insights and innovations to address persistent racial and ethnic disparities in new infections. We created the Summer HIV/AIDS Research Program (SHARP) at the San Francisco Department of Public Health for URM undergraduates as a 12-week program of hands-on research experience, one-on-one mentoring by a senior HIV investigator, didactic seminars for content and research methods, and networking opportunities. The first four cohorts (2012-2015) of SHARP gained research skills, built confidence in their abilities and self-identified as scientists. In addition, the majority of program alumni is employed in research positions and has been admitted to or is pursuing graduate degree programs in fields related to HIV prevention. While we await empirical studies of specific mentoring strategies at early educational stages, programs that engage faculty who are sensitive to the unique challenges facing diverse students and who draw lessons from established mentoring frameworks can help build an inclusive generation of HIV researchers.

The influence of the Internet on immunology education.

The potential of the Internet as a medium through which to teach basic and applied immunology lies in the ability to illustrate complex concepts in new ways for audiences that are diverse and often geographically dispersed. This article explores two collaborative Internet-based learning projects (also known as e-learning projects) that are under development: Immunology Online, which will present an Internet-based curriculum in basic and clinical immunology to Swiss undergraduate and graduate students across five campuses; and the OCTAVE project, which will offer online training to an international cadre of new investigators, the members of which are carrying out clinical trials of vaccines against HIV infection.

Saccharin-based µ-oxo imidoiodane: a readily available and highly reactive reagent for electrophilic amination.

Three new saccharin-based hypervalent iodine compounds were prepared by the reaction of saccharine with (diacetoxyiodo)arenes or acetoxybenziodoxole. Structures of these new imidoiodanes were established by X-ray crystallography. The saccharin-based µ-oxo-bridged imidoiodane readily reacts with silyl enol ethers under mild conditions to give the corresponding α-aminated carbonyl compounds in moderate yields.