The human airway epithelium is the initial site of SARS-CoV-2 infection. We used flow cytometry and single cell RNA-sequencing to understand how the heterogeneity of this diverse cell population contributes to elements of viral tropism and pathogenesis, antiviral immunity, and treatment response to remdesivir. We found that, while a variety of epithelial cell types are susceptible to infection, ciliated cells are the predominant cell target of SARS-CoV-2. The host protease TMPRSS2 was required for infection of these cells. Importantly, remdesivir treatment effectively inhibited viral replication across cell types, and blunted hyperinflammatory responses. Induction of interferon responses within infected cells was rare and there was significant heterogeneity in the antiviral gene signatures, varying with the burden of infection in each cell. We also found that heavily infected secretory cells expressed abundant IL-6, a potential mediator of COVID-19 pathogenesis.

Hepatocellular carcinoma (HCC) is the primary form of liver cancer and a leading cause of cancer-related death worldwide. Early detection remains the most effective strategy in HCC management. However, the spectrum of underlying liver diseases preceding HCC, its genetic complexity, and the lack of symptomatology in early stages challenge early detection. Regardless of underlying etiology, unresolved chronic inflammation is a common denominator in HCC. Hence, many inflammatory molecules, including cytokines, have been investigated as potential biomarkers to predict different stages of HCC. Soluble cytokines carry cell-signaling functions and are easy to detect in the bloodstream. However, its biomarkers’ role remains limited due to the dysregulation of immune parameters related to the primary liver process and their ability to differentiate carcinogenesis from the underlying disease. In this review, we discuss and provide insight on cytokines with clinical relevance for HCC differentiating those implicated in tumor formation, early detection, advanced disease, and response to therapy.

Inactive carrier phases in chronic hepatitis B virus (HBV) infection present minimal liver disease and HBV replication activity suggesting partial immune reconstitution, although the mechanisms responsible remain elusive. Moreover, hepatitis B surface antigen (HBsAg) production—hypothesized to modulate the immune response—is unaltered. In the current study, we assessed the intrahepatic transcriptome in inactive carriers of HBV versus healthy liver donors, including in the context of diverse HBsAg levels (serum and liver), to better understand the phenomenon of immune control. We found a deregulated liver transcriptome in inactive carriers compared with healthy controls, despite normal liver function. Moreover, diverse HBsAg levels have minimal impact on the liver transcriptome in inactive carriers, although gene correlation analysis revealed that leukocyte activation, recruitment, and innate responses genes were correlated with liver HBsAg levels. These findings provide more insight into the mechanisms underlying anti-HBV strategies currently under development, aimed at interfering with HBsAg production or inducing a state of immune control.