1,721,125 research outputs found
Roles of Type I and III Interferons in COVID-19
No full textCoronavirus disease 2019 (COVID-19) is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Type I and III interferon (IFN) responses act as the first line of defense against viral infection and are activated by the recognition of viruses by infected cells and innate immune cells. Dysregulation of host IFN responses has been known to be associated with severe disease progression in COVID-19 patients. However, the reported results are controversial and the roles of IFN responses in COVID-19 need to be investigated further. In the absence of a highly efficacious antiviral drug, clinical studies have evaluated recombinant type I and III IFNs, as they have been successfully used for the treatment of infections caused by two other epidemic coronaviruses, SARS-CoV-1 and Middle East respiratory syndrome (MERS)-CoV. In this review, we describe the strategies by which SARS-CoV-2 evades IFN responses and the dysregulation of host IFN responses in COVID-19 patients. In addition, we discuss the therapeutic potential of type I and III IFNs in COVID-19.
Landscapes of SARS-CoV-2-reactive CD8(+) T cells: heterogeneity of host immune responses against SARS-CoV-2
No full textClinical Implications of Chemokines in Acute and Chronic Hepatitis C Virus Infection
Full text linkHepatitis C virus (HCV), a non-cytopathic positive-stranded RNA virus, is one of the most common causes of chronic liver diseases such as chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Upon HCV infection, the majority of patients fail to clear the virus and progress to chronic hepatitis C. Chemokines are small chemotactic cytokines that direct the recruitment of immune cells and coordinate immune responses upon viral infection. Chemokine production during acute HCV infection contributes to the recruitment of immune cells with antiviral effector functions and subsequent viral clearance. In chronic HCV infection, however, continuous production of chemokines due to persistent viral replication might result in incessant recruitment of inflammatory cells to the liver, giving rise to persistence of chronic inflammation and liver injury. In this review, we will summarize the roles of chemokines in acute and chronic settings of HCV infection and the clinical relevance of chemokines in the treatment of hepatitis C.
SARS-CoV-2-Specific T Cell Responses in Patients with COVID-19 and Unexposed Individuals
No full textSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), an ongoing pandemic disease. In the current review, we describe SARS-CoV-2-specific CD4(+) and CD8(+) T-cell responses in acute and convalescent COVID-19 patients. We also discuss the relationships between COVID-19 severity and SARS-CoV-2-specific T-cell responses and summarize recent reports regarding SARS-CoV-2-reactive T cells in SARS-CoV-2-unexposed individuals. These T cells may be cross-reactive cells primed by previous infection with human common-cold coronaviruses. Finally, we outline SARS-CoV-2-specific T-cell responses in the context of vaccination. A better understanding of SARS-CoV-2-specific T-cell responses is needed to develop effective vaccines and therapeutics.
The percentage of hepatitis C virus-specific CD127+ memory T cells in the acute phase T cell response predicts the outcome of HCV infection.
No full text
Prolonged silencing of diacylglycerol acyltransferase-1 induces a dedifferentiated phenotype in human liver cells
No full textDiacylglycerol acyltransferase-1 (DGAT1), a key enzyme in triglyceride (TG) biogenesis, is highly associated with metabolic abnormalities, such as obesity and type 2 diabetes. However, the effects of DGAT1 silencing in the human liver have not been elucidated. To investigate the effects of DGAT1 silencing in human liver cells, we compared the cellular behaviours of DGAT1-deficient Huh-7.5 cell lines with those of control Huh-7.5 cells. DGAT1-deficient cells acquired dedifferentiated and stem cell-like characteristics, such as formation of aggregates in the presence of high levels of growth factors, high proliferation rates and loss of albumin secretion. In relation to aggregate formation, the expression level of various adhesion molecules was significantly altered in DGAT1-deficient cells. Microarray data analysis and immunostaining of patient tissue samples clearly showed decreased expression levels of DGAT1 and integrin beta 1 in patients who have nodular cirrhosis without fatty degeneration.
The clinical implication of HAV viral load and HAV proteins-specific IFN-gamma production in patients with acute hepatitis A
No full text- …
