Biochemical functions and structure of Caenorhabditis elegans ZK177.8 protein: Aicardi-Goutières syndrome SAMHD1 dNTPase ortholog.

Mutations in sterile alpha motif domain and histidine-aspartate domain-containing protein 1 (SAMHD1) are found in a neurodevelopmental disorder, Aicardi-Goutières syndrome, and cancers, and SAMHD1, which is a deoxynucleoside triphosphate (dNTP) triphosphorylase, was identified as a myeloid-specific HIV-1 restriction factor. Here, we characterized the enzymology and structure of an SAMHD1 ortholog of Caenorhabditis elegans, ZK177.8, which also reportedly induces developmental defects upon gene knockdown. We found ZK177.8 protein is a dNTPase allosterically regulated by dGTP. The active site of ZK177.8 recognizes both 2' OH and triphosphate moieties of dNTPs but not base moiety. The dGTP activator induces the formation of the enzymatically active ZK177.8 tetramers, and ZK177.8 protein lowers cellular dNTP levels in a human monocytic cell line. Finally, ZK177.8 tetramers display very similar X-ray crystal structure with human and mouse SAMHD1s except that its lack of the canonical sterile alpha motif domain. This striking conservation in structure, function, and allosteric regulatory mechanism for the hydrolysis of the DNA building blocks supports their host developmental roles.

Training obstetrician gynaecologists in HIV PrEP (pre-exposure prophylaxis): a 2-year experience.

OBJECTIVE: We aimed to evaluate the efficacy of PrEP (pre-exposure prophylaxis) training sessions for OBGYN (obstetrician gynaecologist) providers given underutilisation of PrEP among women despite a high HIV burden. METHODS: Three separate training sessions were held for providers in the OBGYN department at an academic medical centre in New York City from 2019 to 2021. The 1-hour training sessions were conducted by HIV specialists as in-person lectures or online live lectures. Participants were surveyed after the training on metrics of PrEP awareness, knowledge and comfort with management. Two-sample t-tests were used to compare difference in proportions of binomial variables and difference in means of Likert-scored answers pretraining and post-training events. RESULTS: 63 respondents completed the surveys. There were low rates (13%) of past PrEP prescription among the respondents, while awareness of PrEP as an HIV prevention strategy was high before (95%) and after (98%) the training. After the training, there was an increase in understanding the epidemiology of HIV transmission (40% to 97%, p<0.00), familiarity with the PrEP clinical trials (18% to 97%, p<0.00), comfort in determining PrEP candidacy (mean score 2.3 to 4.1, p<0.00) and comfort prescribing PrEP (mean score 2.0 to 3.6, p<0.00). After the trainings, the majority of participants reported feeling 'comfortable' or 'very comfortable' in determining candidacy for PrEP and prescribing PrEP with follow-up. CONCLUSION: Implementation of PrEP training courses for OBGYN providers increased knowledge and comfort in identifying and managing patients who may benefit from PrEP services. Increasing training among OBGYN providers serving women at risk for HIV infection is an effective tool to narrow gaps in PrEP access.

Syntaxin 11 Contributes to the Interferon-Inducible Restriction of Coxiella burnetii Intracellular Infection.

There is a limited understanding of host defense mechanisms targeting intracellular pathogens that proliferate in a lysosome. Coxiella burnetii is a model bacterial pathogen capable of replicating in the hydrolytic and acidic environment of the lysosome. It has been shown that gamma interferon (IFNγ)-stimulated host cells restrict C. burnetii replication by a mechanism that involves host IDO1 depletion of tryptophan. Host cells deficient in IDO1 activity, however, retain the ability to restrict C. burnetii replication when stimulated with IFNγ, which suggests additional mechanisms of host defense. This study identified syntaxin 11 (STX11) as a host protein that contributes to IFNγ-mediated suppression of C. burnetii replication. STX11 is a SNARE protein; SNARE proteins are proteins that mediate fusion of host vesicles with specific subcellular organelles. Depletion of STX11 using either small interfering RNA (siRNA)- or CRISPR-based approaches enhanced C. burnetii replication intracellularly. Stable expression of STX11 reduced C. burnetii replication in epithelial cells and macrophages, which indicates that this STX11-dependent cell-autonomous response is operational in multiple cell types and can function independently of other IFNγ-induced factors. Fluorescently tagged STX11 localized to the Coxiella-containing vacuole (CCV), and STX11 restriction was found to involve an interaction with STX8. Thus, STX11 regulates a vesicle fusion pathway that limits replication of this intracellular pathogen in a lysosome-derived organelle. IMPORTANCE Cell intrinsic defense mechanisms are used by eukaryotic cells to restrict the replication and dissemination of pathogens. This study identified a human protein called syntaxin 11 (STX11) as a host restriction factor that inhibits the intracellular replication of Coxiella burnetii. Syntaxins regulate the delivery of cargo inside vesicles by promoting specific membrane fusion events between donor and acceptor vesicles. Data presented here demonstrate that STX11 regulates an immunological defense pathway that controls replication of pathogens in lysosome-derived organelles, which provides new insight into the function of this SNARE protein.

Developing Community Co-designed Scenario-Based Training for Police Mental Health Crisis Response: a Relational Policing Approach to De-escalation.

Using the current empirical landscape of police responses to people in mental health crisis as a backdrop, this methods paper makes an argument for the central role of collaborative co-design and production by diverse community experts and stakeholders to build transformative specialized training for frontline officers. Subject matter experts (SMEs) from across key domains participated in focus groups and curriculum creation, with outputs being the co-development of a conceptual approach and an innovative experiential learning training program. Part 1 unpacks the team's conceptual development of a relational policing approach. This humanized method is shaped by procedural justice, trauma-informed, person-centred, and cultural safety frameworks. Part 2 details the co-production of a novel problem-based training method for a police service in Southern Ontario, Canada. The program centres on the acquisition of core competencies related to relational policing, de-escalation, and mental health crisis response. The training was designed to bring learners through a spectrum of authentic crisis scenarios: from observer-participant scenarios informed by Forum Theatre methods and targeted SME feedback to a range of high-fidelity assessment simulations that test officers' abilities to effectively communicate, de-escalate, and make decisions under stress. This program offers repeated opportunities for officers to practice alternative crisis management strategies in scenarios that might otherwise result in the use of force.

An innovative multiphased strategy to recruit underserved adults into a randomized trial of a community-based diabetes risk reduction program.

PURPOSE: To conduct and evaluate a two-phased community-based approach to recruit lower socioeconomic status, minority, or Spanish-speaking adults at risk of developing diabetes to a randomized trial of a lifestyle intervention program delivered by a public health department. DESIGN: Within geographic areas comprising our target population, 4 community organizations provided local space for conducting the study and program. Phase I-outreach in venues surrounding these organizations-included diabetes education, a short diabetes risk appraisal (DRA), and diabetes risk screening based on a fasting fingerstick glucose test. Phase II-trial recruitment-began concurrently for those found to be at risk of developing diabetes in Phase I by explaining the study, lifestyle program, and research process. Those interested and eligible enrolled in the 1-year study. RESULTS: Over 2 years, approximately 5,110 individuals received diabetes education, 1,917 completed a DRA, and 1,164 were screened of which 641 (55%) had an elevated fingerstick result of ≥ 106 mg/dl. Of the study sampling frame-persons over age 25 at risk of developing diabetes (N = 544)-238 (43%) enrolled in the trial; of those who were study eligible (n = 427), 56% enrolled. In the final sample, mean age was 56 years (SD = 17), 78% were ethnic minorities, 32% were Spanish-speaking, and 15% had a high school education or less. IMPLICATIONS: Providing diabetes health education and screening prior to study recruitment may help overcome barriers to research participation in underserved communities, thus helping address difficulties recruiting minority and older populations into research, particularly research pertaining to chronic disease risk factors.