NK cells contribute to hepatic CD8+ T cell failure in hepatitis B virus-carrier mice after alcohol consumption

Detection technology and clinical applications of serum viral products of hepatitis B virus infection

Viral hepatitis, caused by its etiology, hepatitis virus, is a public health problem globally. Among all infections caused by hepatitis-associated viruses, hepatitis B virus (HBV) infection remains the most serious medical concern. HBV infection particularly affects people in East Asia and Africa, the Mediterranean region, and Eastern Europe, with a prevalence rate of > 2%. Currently, approximately 1 billion people worldwide are infected with HBV, and nearly 30% of them experience chronic infection. Chronic HBV infection can lead to chronic hepatitis B (CHB), liver cirrhosis, and hepatocellular carcinoma (HCC), resulting in the related death of approximately 1 million people annually. Although preventative vaccines and antiviral therapies are currently available, there is no cure for this infection. Clinical testing is not only the gateway for diagnosis of HBV infection, but also crucial for judging the timing of medication, evaluating the effect of antiviral therapy, and predicting the risk of relapse after drug withdrawal in the whole follow-up management of hepatitis B infected persons. With advances in detection technology, it is now possible to measure various viral components in the blood to assess the clinical status of HBV infection. Serum viral products of HBV infection, such as HBV DNA, HBV RNA, hepatitis B surface antigen, hepatitis B e-antigen, and hepatitis B core-related antigen, are non-invasive indicators that are critical for the rapid diagnosis and management of related diseases. Improving the sensitivity of monitoring of these products is essential, and the development of corresponding detection technologies is pivotal in achieving this goal. This review aims to offer valuable insights into CHB infection and references for its effective treatment. We provide a comprehensive and systematic overview of classical and novel methods for detecting HBV serum viral products and discusses their clinical applications, along with the latest research progress in this field.

Impact of alcohol consumption on coronavirus disease 2019 severity: A systematic review and meta-analysis

Fear and misinformation lead to widespread myths in the coronavirus disease 2019 (COVID-19) pandemic, such as "consuming high-strength alcohol kills the virus in the inhaled air." However, whether alcohol consumption can affect COVID-19 has not been clarified yet. This study aims to investigate the impact of alcohol consumption on COVID-19 severity. PubMed, Embase, Cochrane Library, Central, CINAHL, ClinicalTrials.gov, and WHO-International Clinical Trials Registry Platform were searched until November 25, 2022. Forty studies (1,697,683 COVID-19 individuals) were analyzed. Brown (patients numbers: 1317, risk ratios [RR] = 1.58, 95% [confidence interval] CI = 1.31 to 1.90, I2  = 0.0%, p < 0.001), American (patients numbers: 3721, RR = 1.51, 95% CI = 1.30 to 1.75, I2  = 0.0%, p < 0.001), and European (patients numbers: 261,437, RR = 2.04, 95% CI = 1.96 to 2.13, I2  = 0.0%, p < 0.001) drinkers were at high risk of severe COVID-19, intensive care unit (ICU) admission, and invasive mechanical ventilation (IMV), respectively. Consistently, individuals with a drinking history were at high risk of severe COVID-19 (patients numbers: 5399, RR = 1.23, 95% CI = 1.02 to 1.48, I2  = 38.4%, p = 0.03) and ICU admission (patients numbers: 6995, RR = 1.32, 95% CI = 1.08 to 1.60, I2  = 46.6%, p = 0.01). In addition, current drinkers had an increased risk of symptomatic COVID-19. However, excessive drinkers were at high risk of COVID-19 hospitalization. Alcohol consumption intensifies COVID-19 severity and deteriorates its clinical outcomes. Here, we strongly propose that people do not drink alcohol during the COVID-19 pandemic.

Interplay Between Liver Type 1 Innate Lymphoid Cells and NK Cells Drives the Development of Alcoholic Steatohepatitis

BACKGROUND & AIMS

Liver contains high frequency of group 1 innate lymphoid cells (ILC), which are composed of comparable number of type 1 ILC (ILC1) and natural killer (NK) cells in steady state. Little is known about whether and how the interaction between ILC1 and NK cells affects the development of alcoholic liver disease.

METHODS

A mouse model of chronic alcohol abuse plus single-binge (Gao-Binge model) was established. The levels of alanine aminotransferase/aspartate aminotransferase, hepatic lipid, and inflammatory cytokines or neutrophils were measured to evaluate the degree of liver injury, steatosis, and inflammation. Flow cytometric analysis, cell depletion, or adoptive transfer were used to interrogate the interaction between ILC1 and NK cells.

RESULTS

Upon chronic alcohol consumption, NK cells, but not ILC1, underwent apoptosis, resulting in ILC1 dominance among group 1 ILC. Interleukin (IL) 17A expression was up-regulated, and increased IL17A was mainly derived from liver ILC1 after chronic alcohol feeding. Either depletion of ILC1 or neutralization of IL17A could significantly attenuate liver steatosis, inflammation, and injury in alcohol-fed mice. In contrast, normalization of the ILC1/NK cells ratio through NK cells transfer or expanding NK cells had a significant hepatoprotection against alcohol-induced steatohepatitis. Furthermore, NK cell-derived interferon gamma exerted a protective function via inhibiting IL17A production by liver ILC1 during alcoholic steatohepatitis.

CONCLUSIONS

This is the first study showing that the interplay between liver ILC1 and NK cells occurs and drives the development of alcoholic steatohepatitis. Our findings support further exploration of liver ILC1 or NK cells as a therapeutic target for the treatment of alcohol-associated liver disease.

Serum HBV pregenomic RNA exhibited opposite associations with NKdim and NKbright cell immunity in treatment-naïve chronic hepatitis B patients

Hepatitis B virus (HBV) pregenomic RNA (pgRNA) is a new biomarker that reflects HBV replication, but its relationship with natural killer (NK) cell immunity in chronic hepatitis B (CHB) is unknown. We assessed serum HBV pgRNA levels in 323 CHB patients by reverse transcription-polymerase chain reaction, assessed cytokine production and activation and inhibitory markers of NK cells by flow cytometry, and measured serum cytokines by enzyme-linked immunosorbent assays (ELISAs). Among the different CHB phases, the serum HBV pgRNA level was highest in the immune-tolerant (IT) and immune-active (IA) phases. Regarding NK and NKdim cells, HBV pgRNA was negatively associated with frequencies, but positively associated with NKp44 and NKp46 expression (activation markers). Regarding NKbright cells, serum HBV pgRNA was positively associated with frequency and programmed cell death protein 1 (PD1) expression (inhibitory marker), but negatively associated with NKp44 and NKp46. Serum HBV pgRNA was not associated with NKp30 (activation marker) on NK cells or subsets. Lastly, serum HBV pgRNA was positively correlated with the levels of serum IL-7 and IL-12P40 (NK cell-promoting cytokines) and negatively correlated with serum prostaglandin E2 (PGE2) level (which negatively regulates NK cells). In conclusion, we found varied relationships between serum HBV pgRNA and NK cells and subsets, indicating that HBV pgRNA may play a complicated role in NK cell-related immunity, providing new information on HBV and host immunity.