IFI207, a young and fast-evolving antiviral factor, stabilizes STING.

Mammalian ALR proteins bind nucleic acids and initiate production of type I interferons or inflammasome assembly, thereby contributing to host innate immunity. ALR s are encoded at a single genetic locus. In mice, the Alr locus is highly polymorphic at the sequence and copy number level. We suggest that one rapidly evolving member of the Alr family, Ifi207 , was introduced to the Mus genome by a recent recombination event. Ifi207 has a large, distinctive repeat region that differs in sequence and length in different Mus strains. We show that IFI207 plays a key role in the STING-mediated response to cGAMP, DNA, and MLV, and that IFI207 controls MLV infection in vivo. Uniquely, IFI207 acts by stabilizing STING protein via its repeat region. Our studies suggest that under the pressure of host-pathogen coevolution, in a dynamic locus such as the Alr , recombination between gene family members creates new genes with novel and essential functions that play diverse roles in biological processes.

Assessing the productivity of PAs and NPs.

ABSTRACT: The improvement of healthcare efficiency and productivity is of international interest. Following an expansion phase of physician associate/assistant (PA) and NPs employment, the Department of Veterans Affairs (VA) assessed how and where they were being used. Using data from 134 VA medical centers, annual productivity was examined across 30 medical and surgical specialties spanning primary care, mental health, and surgery. PA productivity differences averaged 82 relative value units per full-time employee per year more than NPs, a difference of 4%. In general, PAs were found in higher productivity ranges than NP counterparts. PAs and NPs have statistically similar productivity levels in primary care and mental health. In specialty medicine and surgery, PAs average higher annual productivity than NPs. This analysis provides some utility for managers regarding workforce composition, given the relative productivity of two types of clinicians.

Characteristics and productivity of the chiropractic workforce of the Veterans Health Administration.

BACKGROUND: Increasingly, integrated healthcare systems such as the United States Veterans Health Administration (VHA) are employing chiropractors. However, little is known about chiropractor employee clinical productivity which may be important for resource planning and monitoring care delivery. With its history of delivering chiropractic care and its enterprise-level assessment metrics, the VHA is an ideal setting to study a chiropractic workforce. We aim to assess characteristics of chiropractors employed by the VHA and explore associations between these characteristics and clinical productivity. METHODS: This was a cross-sectional and serial analyses of VHA administrative data. Characteristics of the chiropractor workforce were evaluated from fiscal year (FY) 2016 to FY2019. Productivity was calculated using the VHA productivity measure, the quotient of an individual's total work relative value units (wRVUs) per FY divided by the direct clinical full-time equivalent (FTE) worked. A multivariable regression model was used to analyze the association between productivity and characteristics of the chiropractor and VHA facility. RESULTS: From FY2016 to FY2019, the number of chiropractor employees increased from 102 to 167. In FY2019, the typical chiropractor employee was male, white, and 45.9 years old with 5.2 years of VHA experience. In FY2019, the VHA chiropractor workforce was 25.1% female, 79% white, and 20.4% Veteran. The productivity measure of a chiropractor was 3040 in FY2019. A higher facility complexity measure, presence of 3 chiropractor employees at a facility, and older age of the providers were the only characteristics studied that had a significant impact on productivity after adjusting for other covariates. CONCLUSION: Provider characteristics and productivity metrics of the VHA chiropractor employee workforce are presented. The productivity measure provides an initial benchmarking that may be relevant to future modeling of chiropractor personnel in VHA and other healthcare systems.

Insights into Sensing of Murine Retroviruses.

Retroviruses are major causes of disease in animals and human. Better understanding of the initial host immune response to these viruses could provide insight into how to limit infection. Mouse retroviruses that are endemic in their hosts provide an important genetic tool to dissect the different arms of the innate immune system that recognize retroviruses as foreign. Here, we review what is known about the major branches of the innate immune system that respond to mouse retrovirus infection, Toll-like receptors and nucleic acid sensors, and discuss the importance of these responses in activating adaptive immunity and controlling infection.

AIM2-Like Receptors Positively and Negatively Regulate the Interferon Response Induced by Cytosolic DNA.

Cytosolic DNAs derived from retrotransposons serve as pathogen-associated molecular patterns for pattern recognition receptors (PRRs) that stimulate the induction of interferons (IFNs) and other cytokines, leading to autoimmune disease. Cyclic GMP-AMP synthase is one PRR that senses retrotransposon DNA, activating type I IFN responses through the stimulator of IFN genes (STING). Absent in melanoma 2 (AIM2)-like receptors (ALRs) have also been implicated in these pathways. Here we show that the mouse ALR IFI205 senses cytosolic retrotransposon DNA independently of cyclic GMP-AMP production. AIM2 antagonizes IFI205-mediated IFN induction activity by sequestering it from STING. We also found that the complement of genes located in the ALR locus in C57BL/6 and AIM2 knockout mice are different and unique, which has implications for interpretation of the sensing of pathogens in different mouse strains. Our data suggest that members of the ALR family are critical to the host IFN response to endogenous DNA.IMPORTANCE Autoimmune diseases like Aicardi-Goutières syndrome and lupus erythematosus arise when cells of the immune system become activated and attack host cells and tissues. We found that DNA generated by endogenous retroviruses and retroelements in inbred mice and mouse cells is recognized by several host proteins found in macrophages that are members of the ALR family and that these proteins both suppress and activate the pathways leading to the generation of cytokines and IFNs. We also show that there is great genetic diversity between different inbred mouse strains in the ALR genes, which might contribute to differential susceptibility to autoimmunity. Understanding how immune cells become activated is important to the control of disease.

PA and NP productivity in the Veterans Health Administration.

This study assessed the 2014 clinical productivity of 5,959 physician assistants (PAs) and nurse practitioners (NPs) in the US Department of Veterans Affairs' Veterans Health Administration (VHA). Total work relative value units divided by the direct clinical full-time equivalent measured annual productivity, and correlated factors were examined using weighted analysis of variance. PAs and NPs in adult primary care roles were more productive than those in other specialties. Both providers were more productive in rural than in nonrural settings and less productive in teaching than nonteaching hospitals. Men were slightly more productive than women but age and years of VHA employment were not correlates of productivity. PAs were more productive when their scope of practice allowed significant autonomy; NP productivity was unaffected by supervisory requirements. PAs and NPs are an important component of the VHA provider workforce, and their productivity correlates with a number of factors. More organizational research is necessary to better understand the contributing roles PAs and NPs provide in a rapidly evolving, vertically integrated, national health delivery system.

Synthetic α-Hydroxytropolones Inhibit Replication of Wild-Type and Acyclovir-Resistant Herpes Simplex Viruses.

Herpes simplex virus 1 (HSV-1) and HSV-2 remain major human pathogens despite the development of anti-HSV therapeutics as some of the first antiviral drugs. Current therapies are incompletely effective and frequently drive the evolution of drug-resistant mutants. We recently determined that certain natural troponoid compounds such as ß-thujaplicinol readily suppress HSV-1 and HSV-2 replication. Here, we screened 26 synthetic α-hydroxytropolones with the goals of determining a preliminary structure-activity relationship for the α-hydroxytropolone pharmacophore and providing a starting point for future optimization studies. Twenty-five compounds inhibited HSV-1 and HSV-2 replication at 50 µM, and 10 compounds inhibited HSV-1 and HSV-2 at 5 µM, with similar inhibition patterns and potencies against both viruses being observed. The two most powerful inhibitors shared a common biphenyl side chain, were capable of inhibiting HSV-1 and HSV-2 with a 50% effective concentration (EC50) of 81 to 210 nM, and also strongly inhibited acyclovir-resistant mutants. Moderate to low cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50] of 50 to >100 µM). Therapeutic indexes ranged from >170 to >1,200. These data indicate that troponoids and specifically α-hydroxytropolones are a promising lead scaffold for development as anti-HSV drugs provided that toxicity can be further minimized. Troponoid drugs are envisioned to be employed alone or in combination with existing nucleos(t)ide analogs to suppress HSV replication far enough to prevent viral shedding and to limit the development of or treat nucleos(t)ide analog-resistant mutants.

Hydroxylated tropolones inhibit hepatitis B virus replication by blocking viral ribonuclease H activity.

Hepatitis B virus (HBV) remains a major human pathogen despite the development of both antiviral drugs and a vaccine, in part because the current therapies do not suppress HBV replication far enough to eradicate the virus. Here, we screened 51 troponoid compounds for their ability to suppress HBV RNaseH activity and HBV replication based on the activities of α-hydroxytropolones against HIV RNaseH, with the goal of determining whether the tropolone pharmacophore may be a promising scaffold for anti-HBV drug development. Thirteen compounds inhibited HBV RNaseH, with the best 50% inhibitory concentration (IC50) being 2.3 µM. Similar inhibition patterns were observed against HBV genotype D and C RNaseHs, implying limited genotype specificity. Six of 10 compounds tested against HBV replication in culture suppressed replication via blocking of viral RNaseH activity, with the best 50% effective concentration (EC50) being 0.34 µM. Eighteen compounds inhibited recombinant human RNaseH1, and moderate cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50]=25 to 79 µM). Therapeutic indexes ranged from 3.8 to 94. Efficient inhibition required an intact α-hydroxytropolone moiety plus one or more short appendages on the tropolone ring, but a wide variety of constituents were permissible. These data indicate that troponoids and specifically α-hydroxytropolones are promising lead candidates for development as anti-HBV drugs, providing that toxicity can be minimized. Potential anti-RNaseH drugs are envisioned to be employed in combination with the existing nucleos(t)ide analogs to suppress HBV replication far enough to block genomic maintenance, with the goal of eradicating infection.

Hepatitis B virus replication is blocked by a 2-hydroxyisoquinoline-1,3(2H,4H)-dione (HID) inhibitor of the viral ribonuclease H activity.

Nucleos(t)ide analog drugs profoundly suppress Hepatitis B virus (HBV) replication but rarely cure the infection, so therapy is usually life-long. The nucleos(t)ide analogs inhibit the viral DNA polymerase and often push HBV to the brink of extinction, so it may be possible to eradicate HBV by suppressing HBV replication further. The HBV ribonuclease H (RNaseH) is a logical new drug target because it is the second of only two viral enzymes essential for viral replication. We recently developed a low throughput screening pipeline for inhibitors of the HBV RNaseH and viral replication. Here, we screened a series of twenty-three nitrogen-based polyoxygenated heterocycles including sixteen 2-hydroxyisoquinoline-1,3(2H,4H)-dione derivatives for anti-HBV RNaseH activity. Nine compounds inhibited the HBV RNaseH, but activity was marginal for eight of them. Compound #1 [2-hydroxyisoquinoline-1,3(2H,4H)-dione, HID] was the best hit with an IC50 of 28.1µM and an EC50 of 4.2µM. It preferentially suppressed accumulation of the viral plus-polarity DNA strand in replication inhibition assays, indicating that replication was blocked due to suppression of HBV RNaseH activity. It had a CC50 of 75µM, yielding a therapeutic index of ∼18. The EC50 value was 7-fold lower than the IC50, possibly due to cellular retention or metabolism of the compound, or higher affinity for the full-length enzyme than the recombinant form used for screening. These data indicate that the 2-hydroxyisoquinoline-1,3(2H,4H)-diones will have different structure-activity relationships for the HBV and HIV RNaseHs. Therefore, HID compounds may provide a foundation for development of more effective RNaseH inhibitors of HBV replication.