Simulation of elongated bubbles in a channel using the two-fluid model

This paper investigates the capability of the two-fluid model to predict the bubble drift velocity of elongated bubbles in channels. The two-fluid model is widely used in the oil and gas industry for dynamic multiphase pipeline simulations. The bubble drift velocity is an important quantity in predicting pipeline flushing and slug flow. In this paper, it is shown that the two-fluid model in its standard form predicts a bubble drift velocit

Low Hepatitis C Virus Prevalence among Men Who Have Sex with Men Attending Public Health Services in The Netherlands

The hepatitis C virus (HCV) prevalence is high among men who have sex with men (MSM) with HIV in the Netherlands. Large reductions in HCV incidence among MSM with HIV, however, have occurred since treatment with direct-acting antivirals. Over the years, a broader understanding of the HCV epidemic has shown that HCV infections are not solely restricted to MSM with HIV, but they also occur among HIV-negative MSM. Currently, HCV testing among HIV-negative MSM is only provided for PrEP users and is not part of routine sexually transmitted infection (STI) screening among HIV-negative MSM who are not using PrEP. In this study, we screened 1885 HIV-negative MSM who did not participate in a PrEP program, with over 1966 STI screening visits at four different public health clinic sites. Among the 1885 MSM, only one person had a new HCV infection, resulting in a 0.05% (95% confidence interval 0.0–0.3) incidence. Based on our findings, we can conclude that systematic HCV testing at STI clinics may not yield significant benefits for this particular population.</p

Simulation of Elongated Bubbles in a Channel Using the Two-Fluid Model

This paper investigates the capability of the two-fluid model to predict the bubble drift velocity of elongated bubbles in channels. The two-fluid model is widely used in the oil and gas industry for dynamic multiphase pipeline simulations. The bubble drift velocity is an important quantity in predicting pipeline flushing and slug flow. In this paper, it is shown that the two-fluid model in its standard form predicts a bubble drift velocity of (gH)^(1/2) (similar to the shallow water equations), instead of the exact value of 1/2(gH)^(1/2) as derived by Benjamin[1]. Modifying the two-fluid model with the commonly employed momentum correction parameter leads to a steady solution (in a moving reference frame), but still predicts an erroneous bubble drift velocity. To get the correct bubble drift velocity, it is necessary to include the pressure variation along the channel height due to both the hydrostatic component and the vertical momentum flux

Dendritic cell-specific deletion of β-catenin results in fewer regulatory T-cells without exacerbating autoimmune collagen-induced arthritis

Dendritic cells (DCs) are professional antigen presenting cells that have the dual ability to stimulate immunity and maintain tolerance. However, the signalling pathways mediating tolerogenic DC function in vivo remain largely unknown. The β-catenin pathway has been suggested to promote a regulatory DC phenotype. The aim of this study was to unravel the role of β-catenin signalling to control DC function in the autoimmune collagen-induced arthritis model (CIA). Deletion of β-catenin specifically in DCs was achieved by crossing conditional knockout mice with a CD11c-Cre transgen

Microenvironment-Dependent Gradient of CTL Exhaustion in the AE17sOVA Murine Mesothelioma Tumor Model

The immune system, and in particular, cytotoxic CD8+ T cells (CTLs), plays a vital part in the prevention and elimination of tumors. In many patients, however, CTL-mediated tumor killing ultimately fails in the clearance of cancer cells resulting in disease progression, in large part due to the progression of effector CTL into exhausted CTL. While there have been major breakthroughs in the development of CTL-mediated “reinvigoration”-driven immunotherapies such as checkpoint blockade therapy, there remains a need to better understand the drivers behind the development of T cell exhaustion. Our study highlights the unique differences in T cell exhaustion development in tumor-specific CTL which arises over time in a mouse model of mesothelioma. Importantly, we also show that peripheral tumor-specific T cells have a unique expression profile compared to exhausted tumor-infiltrating CTL at a late-stage of tumor progression in mice. Together, these data suggest that greater emphasis shoul

Ibrutinib directly reduces CD8+T cell exhaustion independent of BTK

Introduction: Cytotoxic CD8+ T cell (CTL) exhaustion is a dysfunctional state of T cells triggered by persistent antigen stimulation, with the characteristics of increased inhibitory receptors, impaired cytokine production and a distinct transcriptional profile. Evidence from immune checkpoint blockade therapy supports that reversing T cell exhaustion is a promising strategy in cancer treatment. Ibrutinib, is a potent inhibitor of BTK, which has been approved for the treatment of chronic lymphocytic leukemia. Previous studies have reported improved function of T cells in ibrutinib long-term treated patients but the mechanism remains unclear. We investigated whether ibrutinib directly acts on CD8+ T cells and reinvigorates exhausted CTLs. Methods: We used an established in vitro CTL exhaustion system to examine whether ibrutinib can directly ameliorate T cell exhaustion. Changes in inhibitory receptors, transcription factors, cytokine production and killing capacity of ibrutinib-treated exhausted CTLs were detected by flow cytometry. RNA-seq was performed to study transcriptional changes in these cells. Btk deficient mice were used to confirm that the effect of ibrutinib was independent of BTK expression. Results: We found that ibrutinib reduced exhaustion-related features of CTLs in an in vitro CTL exhaustion system. These changes included decreased inhibitory receptor expression, enhanced cytokine production, and downregulation of the transcription factor TOX with upregulation of TCF1. RNA-seq further confirmed that ibrutinib directly reduced the exhaustion-related transcriptional profile of these cells. Importantly, using btk deficient mice we showed the effect of ibrutinib was independent of BTK expression, and therefore mediated by one of its other targets. Discussion: Our study demonstrates that ibrutinib directly ameliorates CTL exhaustion, and provides evidence for its synergistic use with cancer immunotherapy.</p

Overcoming immune checkpoint blockade resistance in solid tumors with intermittent ITK inhibition

Cytotoxic CD8 + T cell (CTL) exhaustion is driven by chronic antigen stimulation. Reversing CTL exhaustion with immune checkpoint blockade (ICB) has provided clinical benefits in different types of cancer. We, therefore, investigated whether modulating chronic antigen stimulation and T-cell receptor (TCR) signaling with an IL2-inducible T-cell kinase (ITK) inhibitor, could confer ICB responsiveness to ICB resistant solid tumors. In vivo intermittent treatment of 3 ICB-resistant solid tumor (melanoma, mesothelioma or pancreatic cancer) with ITK inhibitor significantly improved ICB therapy. ITK inhibition directly reinvigorate exhausted CTL in vitro as it enhanced cytokine production, decreased inhibitory receptor expression, and downregulated the transcription factor TOX. Our study demonstrates that intermittent ITK inhibition can be used to directly ameliorate CTL exhaustion and enhance immunotherapies even in solid tumors that are ICB resistant.</p

Heatr9 is an infection responsive gene that affects cytokine production in alveolar epithelial cells

During infection, viruses enter susceptible host cells in order to replicate their components for production of new virions. In the process of infection, the gene expression of infected cells undergoes changes because of the production of viral components and due to the host response from detection of viral products. In the advent of RNA sequencing, the discovery of new genes and their functions in the host response generates new avenues for interventions in the host-pathogen interaction. We have identified a novel gene, Heatr9, as a virus and cytokine inducible viral responsive gene. We confirm Heatr9's expression in vitro and in vivo during virus infection and correlate it with viral burden. Heatr9 is induced by influenza virus and RSV. Heatr9 knockdown during viral infection was shown to affect chemokine expression. Our studies identify Heatr9 as a novel inflammatory and virus infection induced gene that can regulate the induction of specific cytokines