Analysis of antibodies from HCV elite neutralizers identifies genetic determinants of broad neutralization.

The high genetic diversity of hepatitis C virus (HCV) complicates effective vaccine development. We screened a cohort of 435 HCV-infected individuals and found that 2%-5% demonstrated outstanding HCV-neutralizing activity. From four of these patients, we isolated 310 HCV antibodies, including neutralizing antibodies with exceptional breadth and potency. High neutralizing activity was enabled by the use of the VH1-69 heavy-chain gene segment, somatic mutations within CDRH1, and CDRH2 hydrophobicity. Structural and mutational analyses revealed an important role for mutations replacing the serines at positions 30 and 31, as well as the presence of neutral and hydrophobic residues at the tip of the CDRH3. Based on these characteristics, we computationally created a de novo antibody with a fully synthetic VH1-69 heavy chain that efficiently neutralized multiple HCV genotypes. Our findings provide a deep understanding of the generation of broadly HCV-neutralizing antibodies that can guide the design of effective vaccine candidates.

Identification and characterization of a hepatic IL-13-producing ILC3-like population potentially involved in liver fibrosis.

BACKGROUND AND AIMS: Human innate lymphoid cells (ILCs) are critically involved in the modulation of homeostatic and inflammatory processes in various tissues. However, only little is known about the composition of the intrahepatic ILC pool and its potential role in chronic liver disease. Here, we performed a detailed characterization of intrahepatic ILCs in both healthy and fibrotic livers. APPROACH AND RESULTS: A total of 50 livers (nonfibrotic = 22, and fibrotic = 29) were analyzed and compared with colon and tonsil tissue (each N = 14) and peripheral blood (N = 32). Human intrahepatic ILCs were characterized ex vivo and on stimulation using flow cytometry and single-cell RNA sequencing. ILC differentiation and plasticity were analyzed by both bulk and clonal expansion experiments. Finally, the effects of ILC-derived cytokines on primary human HSteCs were studied. Unexpectedly, we found that an "unconventional" ILC3-like cell represented the major IL-13-producing liver ILC subset. IL-13 + ILC3-like cells were specifically enriched in the human liver, and increased frequencies of this cell type were found in fibrotic livers. ILC3-derived IL-13 production induced upregulation of proinflammatory genes in HSteCs, indicating a potential role in the regulation of hepatic fibrogenesis. Finally, we identified KLRG1-expressing ILC precursors as the potential progenitor of hepatic IL-13 + ILC3-like cells. CONCLUSIONS: We identified a formerly undescribed subset of IL-13-producing ILC3-like cells that is enriched in the human liver and may be involved in the modulation of chronic liver disease.

HIV-Associated Microbial Translocation May Affect Cytokine Production of CD56bright NK Cells via Stimulation of Monocytes.

The mechanisms involved in HIV-associated natural killer (NK) cell impairment are still incompletely understood. We observed HIV infection to be associated with increased plasma levels of IFABP, a marker for gut epithelial barrier dysfunction, and LBP, a marker for microbial translocation. Both IFABP and LBP plasma concentrations were inversely correlated with NK cell interferon-γ production, suggesting microbial translocation to modulate NK cell functions. Accordingly, we found lipopolysaccharide to have an indirect inhibitory effect on NK cells via triggering monocytes' transforming growth factor-ß production. Taken together, our data suggest increased microbial translocation to be involved in HIV-associated NK cell dysfunction.

Autoantibodies to beta tubulin in autoimmune liver diseases - relation to pANCA and clinical relevance.

There was evidence that pANCA (perinuclear antineutrophil cytoplasmic antibodies) in autoimmune liver diseases react with human beta-tubulin-5 (TBB5). Here we re-evaluate the specificity and clinical relevance of anti-TBB5 antibodies. Patients with untreated autoimmune hepatitis (AIH; n=53), AIH under immunosuppressive therapy (AIH-IS; n=125), primary sclerosing cholangitis (PSC; n=40), primary biliary cholangitis (PBC; n=250), non-autoimmune liver diseases (n=158), inflammatory bowel diseases (IBD; n=30), and healthy individuals (n=62) were tested by enzyme linked immunosorbent assay (ELISA) for IgG- and IgA-antibodies against recombinant human TBB5. pANCA were detected by immunofluorescence test. Sera were absorbed with TBB5 coupled to cyanogen bromide-activated sepharose. Prevalence and reactivity of IgG anti-TBB5 were significantly higher in patients with untreated AIH (68%; arbitrary units [AU] median:369) than in PSC (28%; AU median:84, p<0.001), other liver diseases (14%; AU median:185, p<0.0001), IBD (3%; AU median:111, p<0.0001) and healthy controls (3%; AU median:135; p<0.0001). Anti-TBB5 did not correlate with pANCA, and immunoprecipitation with TBB5 did not abolish pANCA reactivity. In untreated AIH anti-TBB5-reactivity was significantly higher than in AIH-IS. Transaminases decreased under IS preferentially in anti-TBB5 negative patients. There was no correlation between anti-TBB5-reactivity and histological stages. IgA-anti-TBB5 was mainly found in alcohol-associated liver disease (ALD; 39%). Our data do not support TBB5 as an autoantigenic target of pANCA. However, IgG-anti-TBB5 showed high specificity for (untreated) AIH. While they did not correlate with histological and laboratory parameters, their presence may indicate a poor response to IS.

People living with HIV, HCV and HIV/HCV coinfection in intensive care in a German tertiary referral center 2014-2019.

PURPOSE: The epidemiology of HIV-infected individuals on the Medical Intensive Care Units (MICU) has changed after profound progress in treatment of AIDS-defining illnesses and anti-retroviral therapy (ART). Changes of MICU utilization of Hepatitis C (HCV) patients following roll-out of direct-acting antivirals (DAA) are yet to evaluate. METHODS: We performed a retrospective study on all patients with HIV, HIV/HCV and HCV admitted to the MICU of University Hospital Bonn 2014-2019. We assessed sociodemographic data, available clinical data from HIV patients (CDC stage, CD4 + lymphocyte cell count, HIV-1-RNA, ART) and HCV patients (HCV-RNA, stage of liver cirrhosis, treatment history) and outcome. RESULTS: 237 patients (46 HIV, 22 HIV/HCV, 169 HCV; 168 male, median age 51.3 years) with 325 MICU admissions were included. Admission criteria for HIV patients were infections (39.7% AIDS-associated, 23.8% with controlled HIV-infection) and cardiopulmonary diseases (14.3%). HIV/HCV coinfected patients had infections in controlled/uncontrolled HIV-infection (46.4%), cardiopulmonary diseases and intoxication/drug abuse (17.9% each). Reasons for HCV-mono-infected patients were infections (24.4%), sequelae of liver disease (20.9%), intoxication/drug abuse (18.4%) and cardiopulmonary diseases (15%). 60 patients deceased; most important risk factor was need for mechanical ventilation. The number of HCV-patients admitted to MICU with chronic active disease and sequelae of liver disease decreased while the proportion of patients with completed DAA-treatment increased. CONCLUSION: Infections remain the most important reason for MICU admission in patients with HIV and/or HCV infection while non-AIDS related conditions increased. DAA roll-out has a beneficial effect on liver-associated morbidity in HCV patients admitted to MICU.

Circulating levels of endotrophin and cross-linked type III collagen reflect liver fibrosis in people with HIV.

BACKGROUND AND AIMS: Liver-associated complications still frequently lead to mortality in people with HIV (PWH), even though combined antiretroviral treatment (cART) has significantly improved overall survival. The quantification of circulating collagen fragments released during collagen formation and degradation correlate with the turnover of extracellular matrix (ECM) in liver disease. Here, we analysed the levels of ECM turnover markers PC3X, PRO-C5, and PRO-C6 in PWH and correlated these with hepatic fibrosis and steatosis. METHODS: This monocentre, retrospective study included 141 PWH. Liver stiffness and liver fat content were determined using transient elastography (Fibroscan) with integrated CAP function. Serum levels of formation of cross-linked type III collagen (PC3X), formation of type V collagen (PRO-C5) and formation type VI collagen (PRO-C6), also known as the hormone endotrophin, were measured with ELISA. RESULTS: Twenty-five (17.7%) of 141 PWH had clinical significant fibrosis with liver stiffness ≥ 7.1 kPa, and 62 PWH (44.0%) had steatosis with a CAP value > 238 dB/m. Study participants with fibrosis were older (p = 0.004) and had higher levels of AST (p = 0.037) and lower number of thrombocytes compared to individuals without fibrosis (p = 0.0001). PC3X and PRO-C6 were markedly elevated in PWH with fibrosis. Multivariable cox regression analysis confirmed PC3X as independently associated with hepatic fibrosis. PRO-C5 was significantly elevated in participants with presence of hepatic steatosis. CONCLUSION: Serological levels of cross-linked type III collagen formation and endotrophin were significantly associated with liver fibrosis in PWH receiving cART and thus may be suitable as a non-invasive evaluation of liver fibrosis in HIV disease.

Mitochondrial Dysfunction Contributes to Impaired Cytokine Production of CD56bright Natural Killer Cells From Human Immunodeficiency Virus-Infected Individuals Under Effective Antiretroviral Therapy.

Human immunodeficiency virus (HIV) infection is associated with impaired natural killer (NK) cell activity, which is only incompletely restored under antiretroviral therapy. Analyzing the bioenergetics profiles of oxygen consumption, we observed that several parameters were significantly reduced in HIV+ NK cells, indicating a mitochondrial defect. Accordingly, we found HIV+ CD56bright NK cells to display a decreased mitochondrial membrane potential and mitochondrial mass. Both parameters were positively correlated with interferon gamma (IFN-γ) production of NK cells. Finally, we demonstrated that stimulation of HIV+ NK cells with MitoTEMPO, a mitochondria-targeting antioxidant, significantly improved IFN-γ production. We identified mitochondrial dysfunction as a mechanism that contributes to impaired NK cell function.

A placebo-controlled randomised trial of budesonide for PBC following an insufficient response to UDCA.

BACKGROUND & AIMS: In patients with primary biliary cholangitis (PBC), the efficacy of budesonide, a synthetic corticosteroid displaying high first-pass metabolism, is unresolved. In a placebo-controlled, double-blind trial, we evaluated the added-value of budesonide in those with PBC and ongoing risk of progressive disease despite ursodeoxycholic acid (UDCA) treatment. METHODS: We evaluated 62 patients with PBC who had histologically confirmed hepatic inflammatory activity, according to the Ishak score, and an alkaline phosphatase (ALP) >1.5× upper limit of normal (ULN), after at least 6 months of UDCA therapy. Participants were randomly assigned 2:1 to receive budesonide (9 mg/day) or placebo once daily, for 36 months, with UDCA treatment (12-16 mg/kg body weight/day) maintained. Primary efficacy was defined as improvement of liver histology with respect to inflammation and no progression of fibrosis. Secondary outcomes included changes in biochemical markers of liver injury. RESULTS: Recruitment challenges resulted in a study that was underpowered for the primary efficacy analysis. Comparing patients with paired biopsies only (n = 43), the primary histologic endpoint was not met (p >0.05). The proportion of patients with ALP <1.67×ULN, a ≥15% decrease in ALP and normal bilirubin was higher in the budesonide group than in the placebo group at 12, 24, and 36 months (p <0.05, each). In contrast to placebo, budesonide reduced mean ALP and 35% of budesonide-treated patients achieved normalisation of ALP (placebo 9%; p = 0.023). Serious adverse events occurred in 10 patients receiving budesonide and 7 patients receiving placebo. CONCLUSION: Budesonide add-on therapy was not associated with improved liver histology in patients with PBC and insufficient response to UDCA; however, improvements in biochemical markers of disease activity were demonstrated in secondary analyses. LAY SUMMARY: Around one-third of patients with primary biliary cholangitis (PBC) needs additional medical therapy alongside ursodeoxycholic acid (UDCA) treatment. In this clinical trial, the addition of the corticosteroid budesonide did not improve liver histology; there were however relevant improvements in liver blood tests. CLINICALTRIALS. GOV NUMBER: NCT00746486.

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections.

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.8 However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Genome-Wide Association Study for Alcohol-Related Cirrhosis Identifies Risk Loci in MARC1 and HNRNPUL1.

BACKGROUND AND AIMS: Little is known about genetic factors that affect development of alcohol-related cirrhosis. We performed a genome-wide association study (GWAS) of samples from the United Kingdom Biobank (UKB) to identify polymorphisms associated with risk of alcohol-related liver disease. METHODS: We performed a GWAS of 35,839 participants in the UKB with high intake of alcohol against markers of hepatic fibrosis (FIB-4, APRI, and Forns index scores) and hepatocellular injury (levels of aminotransferases). Loci identified in the discovery analysis were tested for their association with alcohol-related cirrhosis in 3 separate European cohorts (phase 1 validation cohort; n=2545). Variants associated with alcohol-related cirrhosis in the validation at a false discovery rate of less than 20% were then directly genotyped in 2 additional European validation cohorts (phase 2 validation, n=2068). RESULTS: In the GWAS of the discovery cohort, we identified 50 independent risk loci with genome-wide significance (P < 5 × 10-8). Nine of these loci were significantly associated with alcohol-related cirrhosis in the phase 1 validation cohort; 6 of these 9 loci were significantly associated with alcohol-related cirrhosis in phase 2 validation cohort, at a false discovery rate below 5%. The loci included variants in the mitochondrial amidoxime reducing component 1 gene (MARC1) and the heterogeneous nuclear ribonucleoprotein U like 1 gene (HNRNPUL1). After we adjusted for age, sex, body mass index, and type-2 diabetes in the phase 2 validation cohort, the minor A allele of MARC1:rs2642438 was associated with reduced risk of alcohol-related cirrhosis (adjusted odds ratio, 0.76; P=.0027); conversely, the minor C allele of HNRNPUL1:rs15052 was associated with an increased risk of alcohol-related cirrhosis (adjusted odds ratio, 1.30; P=.020). CONCLUSIONS: In a GWAS of samples from the UKB, we identified and validated (in 5 European cohorts) single-nucleotide polymorphisms that affect risk of alcohol-related cirrhosis in opposite directions: the minor A allele in MARC1:rs2642438 decreases risk, whereas the minor C allele in HNRNPUL1:rs15052 increases risk.

Genetic Variation in HSD17B13 Reduces the Risk of Developing Cirrhosis and Hepatocellular Carcinoma in Alcohol Misusers.

BACKGROUND AND AIMS: Carriage of rs738409:G in patatin-like phospholipase domain containing 3 (PNPLA3) is associated with an increased risk for developing alcohol-related cirrhosis and hepatocellular carcinoma (HCC). Recently, rs72613567:TA in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) was shown to be associated with a reduced risk for developing alcohol-related liver disease and to attenuate the risk associated with carriage of PNPLA3 rs738409:G. This study explores the risk associations between these two genetic variants and the development of alcohol-related cirrhosis and HCC. APPROACH AND RESULTS: Variants in HSD17B13 and PNPLA3 were genotyped in 6,171 participants, including 1,031 with alcohol-related cirrhosis and HCC, 1,653 with alcohol-related cirrhosis without HCC, 2,588 alcohol misusers with no liver disease, and 899 healthy controls. Genetic associations with the risks for developing alcohol-related cirrhosis and HCC were determined using logistic regression analysis. Carriage of HSD17B13 rs72613567:TA was associated with a lower risk for developing both cirrhosis (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.72-0.88; P = 8.13 × 10-6 ) and HCC (OR, 0.77; 95% CI, 0.68-0.89; P = 2.27 × 10-4 ), whereas carriage of PNPLA3 rs738409:G was associated with an increased risk for developing cirrhosis (OR, 1.70; 95% CI, 1.54-1.88; P = 1.52 × 10-26 ) and HCC (OR, 1.77; 95% CI, 1.58-1.98; P = 2.31 × 10-23 ). These associations remained significant after adjusting for age, sex, body mass index, type 2 diabetes, and country. Carriage of HSD17B13 rs72613567:TA attenuated the risk for developing cirrhosis associated with PNPLA3 rs738409:G in both men and women, but the protective effect against the subsequent development of HCC was only observed in men (ORallelic , 0.75; 95% CI, 0.64-0.87; P = 1.72 × 10-4 ). CONCLUSIONS: Carriage of variants in PNPLA3 and HSD17B13 differentially affect the risk for developing advanced alcohol-related liver disease. A genotypic/phenotypic risk score might facilitate earlier diagnosis of HCC in this population.

A genetic variant in toll-like receptor 5 is linked to chemokine levels and hepatocellular carcinoma in steatohepatitis.

BACKGROUND & AIMS: Bacterial translocation drives liver disease progression. We investigated whether functional genetic variants in toll-like receptor 5 (TLR5), the receptor for bacterial flagellin, affect the risk for hepatocellular carcinoma (HCC). METHODS: Healthy controls (n = 212), patients with alcohol abuse without liver disease (n = 382), and patients from a discovery cohort of alcohol-associated cirrhosis (n = 372 including 79 HCC cases), a validation cohort of alcohol-associated cirrhosis (n = 355 including 132 HCC cases), and a cohort of cirrhosis due to nonalcoholic steatohepatitis (NASH) (n = 145 including 62 HCC cases) were genotyped for the TLR5 rs5744174 and rs5744168 polymorphisms. Chemokine levels were measured by ELISA in patients' sera and supernatants of flagellin-stimulated healthy monocytes. RESULTS: Frequency of the TLR5 rs5744174 TT genotype was similar in healthy controls (33%), controls with alcohol abuse (34%), and patients with alcohol-associated cirrhosis in the discovery (28%), validation (33%), and NASH cohort (31%). The TT genotype was enriched in patients with versus without HCC in the discovery, validation, and NASH cohort (41% vs 25%; 39% vs 29%; 40% vs 24%; p < .05 each). This genotype remained a risk factor for HCC (OR = 1.9; p = .01) after multivariate correction for age, gender, diabetes, and carriage of the PNPLA3 148M variant. Interleukin-8 induction in monocytes from healthy controls and serum levels of interleukin-8 and CXCL1 from cirrhotic patients with the TT genotype were significantly increased versus C allele carriers. CONCLUSION: The TLR5 rs5744174 polymorphism, affecting immune response to flagellin, is linked to occurrence of HCC in cirrhosis caused by steatohepatitis.

The Development and Outcome of Acute-on-Chronic Liver Failure After Surgical Interventions.

Acute-on-chronic liver failure (ACLF) is a syndrome with high short-term mortality. Precipitating events, including hemorrhage and infections, contribute to ACLF development, but the role of surgery remains unknown. We investigated the development of ACLF in patients with cirrhosis undergoing surgery. In total, 369 patients with cirrhosis were included in the study. The clinical and laboratory data were collected prior to and on days 1-2, 3-8, and 9-28, and at 3 and 12 months after surgery. Surgery type was classified as limited or extensive, as well as liver and nonliver surgery. A total of 39 patients had baseline ACLF. Surgery was performed during acute decompensation in 35% of the rest of the 330 patients, and 81 (24.5%) developed ACLF within 28 days after surgery. Surrogate markers of systemic inflammation were similar in patients who developed ACLF or not. Age, sex, serum sodium, baseline bacterial infection, and abdominal nonliver surgery were independent predictors for the development of ACLF after surgery. Patients who developed ACLF within 28 days after surgery had a higher mortality at 3, 6, and 12 months. Survival did not differ between patients with ACLF at surgery and those developing ACLF after surgery. Development of ACLF within 28 days after surgery and elevated alkaline phosphatase and international normalized ratio were independent predictors of 90-day mortality. Independent predictors of 1-year all-cause mortality were alkaline phosphatase, Model for End-Stage Liver Disease score, and preoperative hepatic encephalopathy, whereas nonliver surgery was associated with improved survival. ACLF frequently develops in patients with cirrhosis undergoing surgery, especially in those with active bacterial infection, lower serum sodium, and kidney or coagulation dysfunction. Prognoses of ACLF both at and after surgery are similarly poor. Patients with cirrhosis should be carefully managed perioperatively.

The burden of hepatitis E among patients with haematological malignancies: A retrospective European cohort study.

BACKGROUND & AIMS: The burden of hepatitis E virus (HEV) infection among patients with haematological malignancy has only been scarcely reported. Therefore, we aimed to describe this burden in patients with haematological malignancies, including those receiving allogeneic haematopoietic stem cell transplantation. METHODS: We conducted a retrospective, multicentre cohort study across 11 European centres and collected clinical characteristics of 50 patients with haematological malignancy and RNA-positive, clinically overt hepatitis E between April 2014 and March 2017. The primary endpoint was HEV-associated mortality; the secondary endpoint was HEV-associated liver-related morbidity. RESULTS: The most frequent underlying haematological malignancies were aggressive non-Hodgkin lymphoma (NHL) (34%), indolent NHL (iNHL) (24%), and acute leukaemia (36%). Twenty-one (42%) patients had received allogeneic haematopoietic stem cell transplantation (alloHSCT). Death with ongoing hepatitis E occurred in 8 (16%) patients, including 1 patient with iNHL and 1 patient >100 days after alloHSCT in complete remission, and was associated with male sex (p = 0.040), cirrhosis (p = 0.006) and alloHSCT (p = 0.056). Blood-borne transmission of hepatitis E was demonstrated in 5 (10%) patients, and associated with liver-related mortality in 2 patients. Hepatitis E progressed to chronic hepatitis in 17 (34%) patients overall, and in 10 (47.6%) and 6 (50%) alloHSCT and iNHL patients, respectively. Hepatitis E was associated with acute or acute-on-chronic liver failure in 4 (8%) patients with 75% mortality. Ribavirin was administered to 24 (48%) patients, with an HEV clearance rate of 79.2%. Ribavirin treatment was associated with lower mortality (p = 0.037) and by trend with lower rates of chronicity (p = 0.407) when initiated <24 and <12 weeks after diagnosis of hepatitis E, respectively. Immunosuppressive treatment reductions were associated with mortality in 2 patients (28.6%). CONCLUSION: Hepatitis E is associated with mortality and liver-related morbidity in patients with haematological malignancy. Blood-borne transmission contributes to the burden. Ribavirin should be initiated early, whereas reduction of immunosuppressive treatment requires caution. LAY SUMMARY: Little is known about the burden of hepatitis E among patients with haematological malignancy. We conducted a retrospective European cohort study among 50 patients with haematological malignancy, including haematopoietic stem cell transplant recipients, with clinically significant HEV infection and found that hepatitis E is associated with hepatic and extrahepatic mortality, including among patients with indolent disease or among stem cell transplant recipients in complete remission. Hepatitis E virus infection evolved to chronic hepatitis in 5 (45.5%) patients exposed to a rituximab-containing regimen and 10 (47.6%) stem cell transplant recipients. Reducing immunosuppressive therapy because of hepatitis E was associated with mortality, while early ribavirin treatment was safe and effective.

Functional and immunogenic characterization of diverse HCV glycoprotein E2 variants.

BACKGROUND & AIMS: Induction of cross-reactive antibodies targeting conserved epitopes of the envelope proteins E1E2 is a key requirement for an hepatitis C virus vaccine. Conserved epitopes like the viral CD81-binding site are targeted by rare broadly neutralizing antibodies. However, these viral segments are occluded by variable regions and glycans. We aimed to identify antigens exposing conserved epitopes and to characterize their immunogenicity. METHODS: We created hepatitis C virus variants with mutated glycosylation sites and/or hypervariable region 1 (HVR1). Exposure of the CD81 binding site and conserved epitopes was quantified by soluble CD81 and antibody interaction and neutralization assays. E2 or E1-E2 heterodimers with mutations causing epitope exposure were used to immunize mice. Vaccine-induced antibodies were examined and compared with patient-derived antibodies. RESULTS: Mutant viruses bound soluble CD81 and antibodies targeting the CD81 binding site with enhanced efficacy. Mice immunized with E2 or E1E2 heterodimers incorporating these modifications mounted strong, cross-binding, and non-interfering antibodies. E2-induced antibodies neutralized the autologous virus but they were not cross-neutralizing. CONCLUSIONS: Viruses lacking the HVR1 and selected glycosylation sites expose the CD81 binding site and cross-neutralization antibody epitopes. Recombinant E2 proteins carrying these modifications induce strong cross-binding but not cross-neutralizing antibodies. LAY SUMMARY: Conserved viral epitopes can be made considerably more accessible for binding of potently neutralizing antibodies by deletion of hypervariable region 1 and selected glycosylation sites. Recombinant E2 proteins carrying these mutations are unable to elicit cross-neutralizing antibodies suggesting that exposure of conserved epitopes is not sufficient to focus antibody responses on production of cross-neutralizing antibodies.

Patterns of Resistance-Associated Substitutions in Patients With Chronic HCV Infection Following Treatment With Direct-Acting Antivirals.

BACKGROUND & AIMS: Little is known about substitutions that mediate resistance of hepatitis C virus (HCV) to direct-acting antivirals (DAAs), due to the small number of patients with treatment failure in approval studies. It is important to identify resistance patterns to select effective salvage treatments. METHODS: We performed a comprehensive analysis for resistance-associated substitutions (RASs) in HCV genes (nonstructural protein [NS]3, NS5A, NS5B) targeted by DAAs. We compared NS3, NS5A, and NS5B sequences from 626 patients in Europe with DAA failure with sequences from 2322 DAA-naïve patients, infected with HCV genotypes 1 to 4. We considered RASs to be relevant if they were associated with DAA failure in patients or conferred a greater than twofold change in susceptibility compared with a reference strain in in vitro replicon assays. Data were collected on pretreatment status, DAA regimen, the treatment initiation date and duration, and virologic response. Patients who received at least 4 weeks of antiviral treatment were included in the analysis. RESULTS: RASs in NS3 associated with simeprevir or paritaprevir failure include R155K and D168E/V. In addition, several RASs were specifically associated with failure of simeprevir (Q80K/R in patients with genotype 1a or 4) or paritaprevir (Y56H in combination with D168V in patients with genotype 1b). Y93H in NS5A was the RAS most frequently associated with failure of daclatasvir, ledipasvir, or ombitasvir in patients with genotype 1b infection, and L31M was associated with failure of daclatasvir or ledipasvir, but not ombitasvir. RASs in NS5A were heterogeneous among patients with HCV genotype 1a or genotype 4 infections. In patients with HCV genotype 3, Y93H was associated with resistance to daclatasvir, but no RASs were associated with ledipasvir failure, pointing to a limited efficacy of ledipasvir in patients with genotype 3. Among patients failed by sofosbuvir-containing regimens, L159F was enriched in patients with genotype 1b (together with C316N) or genotype 3 infection, whereas the RAS S282T was rarely observed. CONCLUSIONS: We compared RASs in NS3, NS5A, and NS5B among patients failed by DAA therapy. Theses varied with the HCV genotype and subtype, and the different drug classes. These findings might be used to select salvage therapies.

Role of regulatory T cells and checkpoint inhibition in hepatocellular carcinoma.

Immune checkpoint inhibition suggests promising progress for the treatment of advanced hepatocellular carcinoma (HCC). However, the underlying cellular mechanisms remain unclear because liver cancer cells apparently do not upregulate inhibitory checkpoint molecules. Here, we analysed whether regulatory T cells (Tregs) can alternatively trigger checkpoint inhibition pathways in HCC. Using flow cytometry we analysed expression of checkpoint molecules (PD-1, PD-L1, CTLA-4, GITR, Tim-3) on peripheral CD4+CD25+Foxp3+ Tregs and their secretion of inhibitory mediators (IL-10, IL-35, TGF-beta, galectin-9) in 116 individuals (50 patients with HCC, 41 non-tumour bearing liver disease controls, 25 healthy controls). Functional activity of Tregs on T effector cells (IFN-gamma production, cytotoxicity) was characterized in vitro using a lectin-dependent cellular cytotoxicity (LDCC) assay against checkpoint inhibitor-negative P815 target cells. Unlike liver patients without malignancy and healthy controls, the frequency of checkpoint inhibitor-positive Tregs inversely correlated to age of patients with HCC (PD-L1, p = 0.0080; CTLA-4, p = 0.0029) and corresponded to enhanced numbers of Tregs producing IL-10 and IL-35 (p < 0.05 each). Tregs inhibited IFN-gamma secretion and cytotoxicity of CD8+ T cells when added to LDCC against P815 cells. Treg-induced inhibition of IFN-gamma secretion could be partially blocked by neutralizing PD-1 and PD-L1 antibodies specifically in HCC patients. In HCC peripheral Tregs upregulate checkpoint inhibitors and contribute to systemic immune dysfunction and antitumoural activity by several inhibitory pathways, presumably facilitating tumour development at young age. Blocking PD-L1/PD-1 interactions in vitro selectively interfered with inhibitory Treg -T effector cell interactions in the patients with HCC and resulted in improved antitumoural activity also against checkpoint inhibitor-negative tumour cells.

Compartment-specific distribution of human intestinal innate lymphoid cells is altered in HIV patients under effective therapy.

Innate lymphocyte cells (ILCs), a novel family of innate immune cells are considered to function as key orchestrators of immune defences at mucosal surfaces and to be crucial for maintaining an intact intestinal barrier. Accordingly, first data suggest depletion of ILCs to be involved in human immunodeficiency virus (HIV)-associated damage of the intestinal mucosa and subsequent microbial translocation. However, although ILCs are preferentially localized at mucosal surfaces, only little is known regarding distribution and function of ILCs in the human gastrointestinal tract. Here, we show that in HIV(-) individuals composition and functional capacity of intestinal ILCs is compartment-specific with group 1 ILCs representing the major fraction in the upper gastrointestinal (GI) tract, whereas ILC3 are the predominant population in ileum and colon, respectively. In addition, we present first data indicating that local cytokine concentrations, especially that of IL-7, might modulate composition of gut ILCs. Distribution of intestinal ILCs was significantly altered in HIV patients, who displayed decreased frequency of total ILCs in ileum and colon owing to reduced numbers of both CD127(+)ILC1 and ILC3. Of note, frequency of colonic ILC3 was inversely correlated with serum levels of I-FABP and sCD14, surrogate markers for loss of gut barrier integrity and microbial translocation, respectively. Both expression of the IL-7 receptor CD127 on ILCs as well as mucosal IL-7 mRNA levels were decreased in HIV(+) patients, especially in those parts of the GI tract with reduced ILC frequencies, suggesting that impaired IL-7 responses of ILCs might contribute to incomplete reconstitution of ILCs under effective anti-retroviral therapy. This is the first report comparing distribution and function of ILCs along the intestinal mucosa of the entire human gastrointestinal tract in HIV(+) and HIV(-) individuals.

The ATG16L1 gene variant rs2241880 (p.T300A) is associated with susceptibility to HCC in patients with cirrhosis.

BACKGROUND AND AIMS: Protein and organelle turnover by autophagy is a key component to maintain cellular homeostasis. Loss of the autophagy protein ATG16L1 is associated with reduced bacterial killing and aberrant interleukin-1ß production, perpetuating inflammation and carcinogenesis. Here we hypothesized that the functional p.T300A gene variant in ATG16L1 is associated with an increased risk for hepatocellular carcinoma (HCC) in cirrhosis. METHODS: A case-control study was performed using a prospective derivation cohort (107 patients with HCC and 101 controls) and an independent validation cohort (124 patients with HCC and 108 controls) of patients with cirrhosis of any aetiology. ATG16L1 p.T300A (rs2241880) and PNPLA3 p.I148M (rs738409) variants were determined by real-time PCR. RESULTS: The G allele of the ATG16L1 p.T300A variant was more frequent in patients with HCC compared to controls without HCC in the derivation cohort (0.62 vs. 0.51, P = .022) and in the validation cohort (0.59 vs. 0.50, P = .045). In combined analysis, the odds ratios (OR) were 1.76 (95% CI: 1.07-2.88) for G allele positivity and 2.43 (95% CI: 1.37-4.31) for p.T300A G allele homozygosity. This association was independent from the presence of a PNPLA3 variant, which was also associated with HCC (OR 2.10; 95% CI: 1.20-3.66), and it remained significant after adjustment for male sex, age and aetiology in multivariate analysis. CONCLUSION: The common germ-line ATG16L1 gene variant is a risk factor for HCC in patients with cirrhosis. Personalized strategies employing the genetic risk conferred by ATG16L1 and PNPLA3 may be used for risk-based surveillance in cirrhosis.

Genetic variants in PNPLA3 and TM6SF2 predispose to the development of hepatocellular carcinoma in individuals with alcohol-related cirrhosis.

OBJECTIVES: Variants in patatin-like phospholipase domain-containing 3 (PNPLA3; rs738409), transmembrane 6 superfamily member 2 (TM6SF2; rs58542926), and membrane bound O-acyltransferase domain containing 7 (MBOAT7; rs641738) are risk factors for the development of alcohol-related cirrhosis. Within this population, PNPLA3 rs738409 is also an established risk factor for the development of hepatocellular carcinoma (HCC). The aim of this study was to explore possible risk associations of TM6SF2 rs58542926 and MBOAT7 rs641738 with HCC. METHODS: Risk variants in PNPLA3, TM6SF2, and MBOAT7 were genotyped in 751 cases with alcohol-related cirrhosis and HCC and in 1165 controls with alcohol-related cirrhosis without HCC. Association with the risk of developing HCC was analyzed using multivariate logistic regression. RESULTS: The development of HCC was independently associated with PNPLA3 rs738409 (ORadjusted 1.84 [95% CI 1.55-2.18], p = 1.85 × 10-12) and TM6SF2 rs58542926 (ORadjusted 1.66 [1.30-2.13], p = 5.13 × 10-05), using an additive model, and controlling the sex, age, body mass index, and type 2 diabetes mellitus; the risk associated with carriage of MBOAT7 rs641738 (ORadjusted 1.04 [0.88-1.24], p = 0.61) was not significant. The population-attributable fractions were 43.5% for PNPLA3 rs738409, 11.5% for TM6SF2 rs58542926, and 49.9% for the carriage of both the variants combined. CONCLUSIONS: Carriage of TM6SF2 rs58542926 is an additional risk factor for the development of HCC in people with alcohol-related cirrhosis. Carriage of both PNPLA3 rs738409 and TM6SF2 rs58542926 accounts for half of the attributable risk for HCC in this population. Genotyping will allow for more precise HCC risk-stratification of patients with alcohol-related cirrhosis, and genotype-guided screening algorithms would optimize patient care.