Natural killer (NK) cells provide a central defense against viral infection by using inhibitory and activation receptors for major histocompatibility complex class I molecules as a means of ...controlling their activity. We show that genes encoding the inhibitory NK cell receptor KIR2DL3 and its human leukocyte antigen C group 1 (HLA-C1) ligand directly influence resolution of hepatitis C virus (HCV) infection. This effect was observed in Caucasians and African Americans with expected low infectious doses of HCV but not in those with high-dose exposure, in whom the innate immune response is likely overwhelmed. The data strongly suggest that inhibitory NK cell interactions are important in determining antiviral immunity and that diminished inhibitory responses confer protection against HCV.
The British Society of Gastroenterology guidelines on the management of cholangiocarcinoma were originally published in 2002. This is the first update since then and is based on a comprehensive ...review of the recent literature, including data from randomised controlled trials, systematic reviews, meta-analyses, cohort, prospective and retrospective studies.
Background and Aims
GS‐9688 (selgantolimod) is a toll‐like receptor 8 agonist in clinical development for the treatment of chronic hepatitis B (CHB). Antiviral activity of GS‐9688 has previously been ...evaluated in vitro in HBV‐infected hepatocytes and in vivo in the woodchuck model of CHB. Here we evaluated the potential of GS‐9688 to boost responses contributing to viral control and to modulate regulatory mediators.
Approach and Results
We characterized the effect of GS‐9688 on immune cell subsets in vitro in peripheral blood mononuclear cells of healthy controls and patients with CHB. GS‐9688 activated dendritic cells and mononuclear phagocytes to produce IL‐12 and other immunomodulatory mediators, inducing a comparable cytokine profile in healthy controls and patients with CHB. GS‐9688 increased the frequency of activated natural killer (NK) cells, mucosal‐associated invariant T cells, CD4+ follicular helper T cells, and, in about 50% of patients, HBV‐specific CD8+ T cells expressing interferon‐γ. Moreover, in vitro stimulation with GS‐9688 induced NK‐cell expression of interferon‐γ and TNF‐α, and promoted hepatocyte lysis. We also assessed whether GS‐9688 inhibited immunosuppressive cell subsets that might enhance antiviral efficacy. Stimulation with GS‐9688 reduced the frequency of CD4+ regulatory T cells and monocytic myeloid‐derived suppressor cells (MDSCs). Residual MDSCs expressed higher levels of negative immune regulators, galectin‐9 and programmed death‐ligand 1. Conversely, GS‐9688 induced an expansion of immunoregulatory TNF‐related apoptosis‐inducing ligand+ NK cells and degranulation of arginase‐I+ polymorphonuclear MDSCs.
Conclusions
GS‐9688 induces cytokines in human peripheral blood mononuclear cells that are able to activate antiviral effector function by multiple immune mediators (HBV‐specific CD8+ T cells, CD4+ follicular helper T cells, NK cells, and mucosal‐associated invariant T cells). Although reducing the frequency of some immunoregulatory subsets, it enhances the immunosuppressive potential of others, highlighting potential biomarkers and immunotherapeutic targets to optimize the antiviral efficacy of GS‐9688.
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•Study patients had recurrent hepatitis C infection following liver transplantation.•The study included patients with cirrhosis (18%) and genotype 3 HCV (44%).•Twelve weeks of ...sofosbuvir/velpatasvir resulted in an SVR12 of 96%.•No liver transplant rejection episodes or deaths occurred.•Treatment did not impact immunosuppressive therapy.
Sofosbuvir, an NS5B inhibitor, combined with velpatasvir, an NS5A inhibitor (SOF/VEL), produces high sustained virologic response rates 12 weeks after treatment (SVR12) in patients with genotype 1–6 HCV infection, and has no anticipated clinically relevant drug-drug interactions with immunosuppressants. This study evaluated the safety and efficacy of SOF/VEL in adults with recurrent chronic genotype 1–4 HCV infection after liver transplant.
Patients received SOF/VEL 400/100 mg daily for 12 weeks. Patients could be treatment experienced or treatment naïve with no cirrhosis or with compensated cirrhosis. The primary endpoints were SVR12 and discontinuations due to adverse events.
A total of 79 patients were enrolled and treated in this study (37 47% had genotype 1, 3 4% genotype 2, 35 44% genotype 3, and 4 5% genotype 4 HCV). Of these, 81% were male, 82% were white, 18% had compensated cirrhosis, and 59% were treatment experienced. The most commonly used immunosuppressants were tacrolimus (71%), mycophenolic acid (24%), cyclosporine (14%), and azathioprine (11%). Median (range) time from liver transplantation was 7.5 (0.3, 23.9) years. The SVR12 rate was 96%. By genotype, SVR12 rates were 95% (genotype 1), 100% (genotype 2), 97% (genotype 3), and 100% (genotype 4). Two patients experienced virologic relapse: one with genotype 1a infection was non-cirrhotic and treatment naïve, and one with genotype 3 infection was non-cirrhotic and treatment experienced. One patient discontinued SOF/VEL due to hyperglycemia. No serious or severe adverse events were deemed SOF/VEL-related by the investigator, and no liver transplant rejection episodes or deaths occurred during the study period.
Treatment with SOF/VEL for 12 weeks was highly effective and well tolerated in genotype 1–4 HCV-infected liver transplant recipients with and without cirrhosis.
Sofosbuvir/velpatasvir is a combination of two drugs in one tablet that is approved for the treatment of patients with chronic hepatitis C virus (HCV) infection. When patients with chronic HCV infection receive a liver transplant, the HCV infection usually recurs, and damages the transplanted liver. This study tested the effects of 12 weeks of sofosbuvir/velpatasvir treatment in patients who had HCV recurrence after a liver transplant. Three months following the end of treatment, 96% of patients were cured of HCV infection.
Clinical trial number: NCT02781571.
Breast cancer is a heterogeneous disease, divisible into a variable number of clinical subtypes. A fundamental question is how many etiological classes underlie the clinical spectrum of breast ...cancer? An etiological subtype reflects a grouping with a common set of causes, whereas a clinical subtype represents a grouping with similar prognosis and/or prediction. Herein, we review the evidence for breast cancer etiological heterogeneity. We then evaluate the etiological evidence with mRNA profiling data. A bimodal age distribution at diagnosis with peak frequencies near ages 50 and 70 years is a fundamental characteristic of breast cancer for important tumor features, clinical characteristics, risk factor profiles, and molecular subtypes. The bimodal peak frequencies at diagnosis divide breast cancer overall into a "mixture" of two main components in varying proportions in different cancer populations. The first breast cancer tends to arise early in life with modal age-at-diagnosis near 50 years and generally behaves aggressively. The second breast cancer occurs later in life with modal age near 70 years and usually portends a more indolent clinical course. These epidemiological and molecular data are consistent with a two-component mixture model and compatible with a hierarchal view of breast cancers arising from two main cell types of origin. Notwithstanding the potential added value of more detailed categorizations for personalized breast cancer treatment, we suggest that the development of better criteria to identify the two proposed etiologic classes would advance breast cancer research and prevention.
Age-specific analyses of non-cardia gastric cancer incidence reveal divergent trends among US whites: rates are declining in individuals aged 40 years and older but rising in younger persons. To ...investigate this heterogeneity further, incidence trends were evaluated by anatomical subsite.
Gastric cancer incidence data for 1976-2007 were obtained from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program and the US Centers for Disease Control and Prevention's National Program of Cancer Registries (NPCR). Incidence rates and estimated annual percentage change were calculated by age group (25-39, 40-59 and 60-84 years), race/ethnicity and subsite.
Based on data from the nine oldest SEER registries (covering ~10% of the US population), rates for all non-cardia subsites decreased in whites and blacks, except for corpus cancer, which increased between 1976 and 2007 with estimated annual percentage changes of 1.0% (95% CI 0.1% to 1.9%) for whites and 3.5% (95% CI 1.8% to 5.2%) for blacks. In contrast, rates for all non-cardia subsites including corpus cancer declined among other races. In combined data from NPCR and SEER registries (covering 89% of the US population), corpus cancer significantly increased between 1999 and 2007 among younger and middle-aged whites; in ethnic-specific analyses, rates significantly increased among the same age groups in non-Hispanic whites and were stable among Hispanic whites. Age-specific rates for all subsites declined or were stable in this period among blacks and other races.
Long- and short-term incidence trends for gastric cancers indicate a shifting distribution by anatomical subsite. Corpus cancer may have distinctive aetiology and changing risk factor exposures, warranting further investigation.
Natural killer cells are a key component in the immune control of viral infections. Their functions are controlled by inhibitory receptors for major histocompatability complex (MHC) class I, ...including the killer cell immunoglobulin‐like receptors (KIR). KIR2DL3 in combination with its cognate human leukocyte antigen (HLA)‐C ligand has been shown to be associated with spontaneous resolution of viremia following hepatitis C virus (HCV) infection. In order to determine if this gene combination is advantageous across all potential outcomes following HCV exposure, we studied individuals with apparent resistance to HCV infection who remain seronegative and aviremic despite long‐term injection drug use and also individuals chronically infected with HCV who successfully clear HCV with treatment. Homozygosity for KIR2DL3 in combination with group 1 HLA‐C allotypes was more frequent in exposed seronegative aviremic individuals as compared to those with chronic HCV (25.0% versus 9.7%, P = 0.003, odds ratio OR = 3.1, 95% confidence interval CI = 1.3‐7.1) in a model similar to that found for those spontaneously resolving HCV. In individuals undergoing treatment for HCV, those with KIR2DL3 and group 1 HLA‐C were more likely to make a sustained virological response (SVR) (P = 0.013, OR = 2.3, 95% CI = 1.1‐4.5). KIR and HLA‐C protection in both treatment response and spontaneously resolving HCV was validated at the allelic level, in which KIR2DL3‐HLA‐Cw*03 was associated with SVR (P = 0.004, OR = 3.4, 95% CI = 1.5‐8.7) and KIR2DL3/KIR2DL3‐HLA‐Cw*03 was associated with spontaneous resolution of HCV infection (P = 0.01, OR = 2.3, 95% CI = 1.2‐4.4). Conclusion: KIR and HLA‐C genes are consistently beneficial determinants in the outcome of HCV infection. This advantage extends to the allelic level for both gene families. (HEPATOLOGY 2010.)
The TRAIL pathway can mediate apoptosis of hepatic stellate cells to promote the resolution of liver fibrosis. However, TRAIL has the capacity to bind to regulatory receptors in addition to ...death-inducing receptors; their differential roles in liver fibrosis have not been investigated. Here we have dissected the contribution of regulatory TRAIL receptors to apoptosis resistance in primary human hepatic stellate cells (hHSC). hHSC isolated from healthy margins of liver resections from different donors expressed variable levels of TRAIL-R2/3/4 (but negligible TRAIL-R1) ex vivo and after activation. The apoptotic potential of TRAIL-R2 on hHSC was confirmed by lentiviral-mediated knockdown. A functional inhibitory role for TRAIL-R3/4 was revealed by shRNA knockdown and mAb blockade, showing that these regulatory receptors limit apoptosis of hHSC in response to both oligomerised TRAIL and NK cells. A close inverse ex vivo correlation between hHSC TRAIL-R4 expression and susceptibility to apoptosis underscored its central regulatory role. Our data provide the first demonstration of non-redundant functional roles for the regulatory TRAIL receptors (TRAIL-R3/4) in a physiological setting. The potential for these inhibitory TRAIL receptors to protect hHSC from apoptosis opens new avenues for prognostic and therapeutic approaches to the management of liver fibrosis.
Gadd45a-null mice generated by gene targeting exhibited several of the phenotypes characteristic of p53-deficient mice, including genomic instability, increased radiation carcinogenesis and a low ...frequency of exencephaly. Genomic instability was exemplified by aneuploidy, chromosome aberrations, gene amplification and centrosome amplification, and was accompanied by abnormalities in mitosis, cytokinesis and growth control. Unequal segregation of chromosomes due to multiple spindle poles during mitosis occurred in several Gadd45a -/- cell lineages and may contribute to the aneuploidy. Our results indicate that Gadd45a is one component of the p53 pathway that contributes to the maintenance of genomic stability.
► Myofibroblastic, activated hepatic stellate cells (HSC) play a pivotal role in the development of liver fibrosis. ► We used short interfering RNA (siRNA) to investigate the effects of autocrine ...TIMP-1 and -2 on HSC proliferation. ► Specific silencing of TIMP-1, but not TIMP-2, significantly reduces HSC proliferation and is associated with reduced Akt phosphorylation. ► TIMP-1 is localised in part to the HSC nucleus. ► TIMP-1 might promote liver fibrosis by means other than its previously described anti-apoptotic effect on HSC.
Myofibroblastic, activated hepatic stellate cells (HSC) play a pivotal role in the development of liver fibrosis through the secretion of fibrillar collagens and the tissue inhibitors of metalloproteinase (TIMP)-1 and -2. TIMPs are believed to promote hepatic fibrosis by inhibiting both matrix degradation and apoptosis of HSC. In other cell types, there is evidence that TIMP-1 has effects on proliferation, however the role of TIMPs in the regulation of HSC proliferation remains unexplored. Therefore, we have used short interfering RNA (siRNA) to investigate the effects of autocrine TIMP-1 and -2 on HSC proliferation. TIMP-1 and -2 siRNA were highly effective, producing peak target protein knockdown compared to negative control siRNA of 92% and 63%, respectively. Specific silencing of TIMP-1, using siRNA, significantly reduced HSC proliferation. TIMP-1 was localised in part to the HSC nucleus and TIMP-1 siRNA resulted in loss of both cytoplasmic and nuclear TIMP-1. Attenuated proliferation was associated with reduced Akt phosphorylation and was partially rescued by addition of recombinant TIMP-1. We have revealed a novel autocrine mitogenic effect of TIMP-1 on HSC, which may involve Akt-dependent and specific nuclear mechanisms of action. We suggest that TIMP-1 might promote liver fibrosis by means other than its previously described anti-apoptotic effect on HSC. Moreover, these findings, together with our previous reports and the emerging data from
in vivo studies of TIMP inhibition, provide strong evidence that TIMP-1 is mechanistically central to liver fibrosis and an important potential therapeutic target.
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