Assemblin Homolog of Herpes Simplex Virus Type 1 Retains Proteolytic Activity When Expressed as a Recombinant Two-Chain Enzyme

AbstractThe herpes simplex virus type 1 (HSV) maturational proteinase is synthesized as a precursor that undergoes two autoproteolytic cleavages; one at its (M)aturational site, which eliminates its carboxyl “tail,” and a second at its (R)elease site, which separates the amino proteolytic half of the precursor from its nonproteolytic carboxyl half. In cytomegalovirus (CMV) the proteolytic half of the precursor, called assemblin, undergoes a third cleavage at an (I)nternal site that converts it from a single-chain to a two-chain enzyme that retains activity. The HSV assemblin homolog has no I site and therefore does not form a counterpart two-chain enzyme. In the work reported here we have cloned and expressed HSV sequences that encode mimics of the Anand Acsubunits of two-chain CMV assemblin. We show that when these HSV sequences are coexpressed in eukaryotic cells, the resulting subunits associate spontaneously to form an active two-chain enzyme. We also show that the two-chain HSV enzyme, like the natural one-chain form, retains its marked preference for HSV over CMV substrates, and that intertypic recombinant two-chain assemblin (e.g., HSV An/CMV Ac) does not form because the cross-species subunits do not interact. We conclude from these results that (i) there are not intrinsic structural differences in the HSV assemblin homolog that preclude its functioning as a CMV-like two-chain enzyme, (ii) the substrate selectivity shown by the single-chain HSV enzyme was not noticeably relaxed in the HSV two-chain mimic, and (iii) the interactive domains, through which the Anand Acportions of the single-chain enzymes associate, differ between HSV and CMV

Improving causality in microbiome research:can human genetic epidemiology help?

Evidence supports associations between human gut microbiome variation and multiple health outcomes and diseases. Despite compelling results from in vivo and in vitro models, few findings have been translated into an understanding of modifiable causal relationships. Furthermore, epidemiological studies have been unconvincing in their ability to offer causal evidence due to their observational nature, where confounding by lifestyle and behavioural factors, reverse causation and bias are important limitations. Whilst randomized controlled trials have made steps towards understanding the causal role played by the gut microbiome in disease, they are expensive and time-consuming. This evidence that has not been translated between model systems impedes opportunities for harnessing the gut microbiome for improving population health. Therefore, there is a need for alternative approaches to interrogate causality in the context of gut microbiome research. The integration of human genetics within population health sciences have proved successful in facilitating improved causal inference (e.g., with Mendelian randomization [MR] studies) and characterising inherited disease susceptibility. MR is an established method that employs human genetic variation as natural “proxies” for clinically relevant (and ideally modifiable) traits to improve causality in observational associations between those traits and health outcomes. Here, we focus and discuss the utility of MR within the context of human gut microbiome research, review studies that have used this method and consider the strengths, limitations and challenges facing this research. Specifically, we highlight the requirements for careful examination and interpretation of derived causal estimates and host (i.e., human) genetic effects themselves, triangulation across multiple study designs and inter-disciplinary collaborations. Meeting these requirements will help support or challenge causality of the role played by the gut microbiome on human health to develop new, targeted therapies to alleviate disease symptoms to ultimately improve lives and promote good health

Improving causality in microbiome research: Can human genetic epidemiology help?

Evidence supports associations between human gut microbiome variation and multiple health outcomes and diseases. Despite compelling results from in vivo and in vitro models, few findings have been translated into an understanding of modifiable causal relationships. Furthermore, epidemiological studies have been unconvincing in their ability to offer causal evidence due to their observational nature, where confounding by lifestyle and behavioural factors, reverse causation and bias are important limitations. Whilst randomized controlled trials have made steps towards understanding the causal role played by the gut microbiome in disease, they are expensive and time-consuming. This evidence that has not been translated between model systems impedes opportunities for harnessing the gut microbiome for improving population health. Therefore, there is a need for alternative approaches to interrogate causality in the context of gut microbiome research. The integration of human genetics within population health sciences have proved successful in facilitating improved causal inference (e.g., with Mendelian randomization [MR] studies) and characterising inherited disease susceptibility. MR is an established method that employs human genetic variation as natural “proxies” for clinically relevant (and ideally modifiable) traits to improve causality in observational associations between those traits and health outcomes. Here, we focus and discuss the utility of MR within the context of human gut microbiome research, review studies that have used this method and consider the strengths, limitations and challenges facing this research. Specifically, we highlight the requirements for careful examination and interpretation of derived causal estimates and host (i.e., human) genetic effects themselves, triangulation across multiple study designs and inter-disciplinary collaborations. Meeting these requirements will help support or challenge causality of the role played by the gut microbiome on human health to develop new, targeted therapies to alleviate disease symptoms to ultimately improve lives and promote good health

Walking Through Black History Digital Humanities Project

The focus of the project was to illustrate African American history including four periods: Antebellum, Reconstruction, Jim Crow and Civil Rights. We focused on choosing sites that could illustrate that history most effectively, noting that the Reconstruction era is often the most challenging of the four periods in that it is short-lived with little material culture left

Three Cases of COVID-19 Pneumonia That Responded to Icosapent Ethyl Supportive Treatment

BACKGROUND Icosapent ethyl, a form of eicosapentaenoic acid with anti-inflammatory activity, has been approved as an adjunctive treatment with statins in patients with hypertriglyceridemia. Icosapent ethyl is currently undergoing clinical trials to determine its anti-inflammatory effects in patients with coronavirus disease 2019 (COVID-19). This report describes 3 intensive care unit (ICU) patients with moderate to severe COVID-19 pneumonia treated with icosapent ethyl as part of their supportive care who had favorable outcomes. CASE REPORT Case 1 was a 75-year-old man with a past medical history of hyperlipidemia, hypertension, type 2 diabetes mellitus, obesity, and benign prostatic hyperplasia. Case 2 was a 23-year old man with a past medical history of type 2 diabetes mellitus and obesity. Case 3 was a 24-year old man with a history of autism. All cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were confirmed from a nasopharyngeal swab using the Becton Dickinson nasopharyngeal reverse-transcription polymerase chain reaction. All patients in these cases were treated with a course of 2 g of icosapent ethyl twice a day by nasogastric tube. CONCLUSIONS This report of 3 cases describes the use of icosapent ethyl as a component of supportive treatments in ICU patients with moderate to severe COVID-19 pneumonia. However, as of yet there are no evidence-based treatments for SARS-CoV-2 infection from controlled clinical trials. The outcomes of ongoing clinical trials are awaited to determine whether icosapent ethyl has anti-inflammatory effects in patients with SARS-CoV-2 infection and which patients might benefit from the use of this adjunctive treatment

Calibration Uncertainty for Advanced LIGO's First and Second Observing Runs

Calibration of the Advanced LIGO detectors is the quantification of the detectors' response to gravitational waves. Gravitational waves incident on the detectors cause phase shifts in the interferometer laser light which are read out as intensity fluctuations at the detector output. Understanding this detector response to gravitational waves is crucial to producing accurate and precise gravitational wave strain data. Estimates of binary black hole and neutron star parameters and tests of general relativity require well-calibrated data, as miscalibrations will lead to biased results. We describe the method of producing calibration uncertainty estimates for both LIGO detectors in the first and second observing runs.Comment: 15 pages, 21 figures, LIGO DCC P160013