Autophagy is a conserved eukaryotic mechanism that mediates the removal of long-lived cytoplasmic macromolecules and damaged organelles via a lysosomal degradative pathway. Recently, a multitude of studies have reported that viral infections may have complex interconnections with the autophagic process. The findings reported here demonstrate that hepatitis B virus (HBV) can enhance the autophagic process in hepatoma cells without promoting protein degradation by the lysosome. Mutation analysis showed that HBV small surface protein (SHBs) was required for HBV to induce autophagy. The overexpression of SHBs was sufficient to induce autophagy. Furthermore, SHBs could trigger unfolded protein responses (UPR), and the blockage of UPR signaling pathways abrogated the SHB-induced lipidation of LC3-I. Meanwhile, the role of the autophagosome in HBV replication was examined. The inhibition of autophagosome formation by the autophagy inhibitor 3-methyladenine (3-MA) or small interfering RNA duplexes targeting the genes critical for autophagosome formation (Beclin1 and ATG5 genes) markedly inhibited HBV production, and the induction of autophagy by rapamycin or starvation greatly contributed to HBV production. Furthermore, evidence was provided to suggest that the autophagy machinery was required for HBV envelopment but not for the efficiency of HBV release. Finally, SHBs partially colocalized and interacted with autophagy protein LC3. Taken together, these results suggest that the host's autophagy machinery is activated during HBV infection to enhance HBV replication.Hepatitis B virus (HBV) is a noncytopathic, enveloped DNA virus that belongs to the family Hepadnaviridae (57, 70). It is one of the most successful human pathogens, with an estimated 2 billion people infected worldwide, of whom 400 million have chronic HBV infection (54). Chronic HBV infection is correlated with a strongly increased risk for the development of liver cirrhosis and hepatocellular carcinoma (HCC) (49, 54).Effective preventive vaccines against HBV have been available for nearly three decades; however, their effectiveness in preventing blood-borne transmission from an infected mother to her newborn is about 90% (77), and therapeutic vaccines for the treatment of established hepatitis B infection are not available (65, 67). Currently, two types of antiviral therapies are approved: pegylated alpha interferon and nucleoside/nucleotide analogues (60). However, these antivirals cannot completely eradicate the virus, and their efficacy in preventing liver cirrhosis and HCC is limited (21, 64). Thus, the details of the host-virus relationship during HBV infection urgently need to be further clarified to facilitate the development of efficient therapeutic strategies for the control of HBV infection.Autophagy, an evolutionarily conserved intracellular process, involves the formation of a double membrane structure, called the autophagosome, which engulfs long-lived cytoplasmic macromolecules and damaged organelles and delivers them to lysosomes for degrada...

Highlights d The nuclear matrix protein SAFA is required for antiviral immunity in cells and mice d SAFA directly senses viral RNA in the nucleus d SAFA facilitates antiviral immunity through interacting with chromatin remodelers d Oligomerized SAFA mediates IFNB1 transcription by activating its distal enhancers

Objectives To delineate the evolution of CT findings in patients with mild COVID-19 pneumonia. Methods CT images and medical records of 88 patients with confirmed mild COVID-19 pneumonia, a baseline CT, and at least one follow-up CT were retrospectively reviewed. CT features including lobar distribution and presence of ground glass opacities (GGO), consolidation, and linear opacities were analyzed on per-patient basis during each of five time intervals spanning the 3 weeks after disease onset. Total severity scores were calculated. Results Of patients, 85.2% had travel history to Wuhan or known contact with infected individuals. The most common symptoms were fever (84.1%) and cough (56.8%). The baseline CT was obtained on average 5 days from symptom onset. Four patients (4.5%) had negative initial CT. Significant differences were found among the time intervals in the proportion of pulmonary lesions that are (1) pure GGO, (2) mixed attenuation, (3) mixed attenuation with linear opacities, (4) consolidation with linear opacities, and (5) pure consolidation. The majority of patients had involvement of ≥ 3 lobes. Bilateral involvement was more prevalent than unilateral involvement. The proportions of patients observed to have pure GGO or GGO and consolidation decreased over time while the proportion of patients with GGO and linear opacities increased. Total severity score showed an increasing trend in the first 2 weeks. Conclusions While bilateral GGO are predominant features, CT findings changed during different time intervals in the 3 weeks after symptom onset in patients with COVID-19. Key Points • Four of 88 (4.5%) patients with COVID-19 had negative initial CT.• Majority of COVID-19 patients had abnormal CT findings in ≥ 3 lobes.• A proportion of patients with pure ground glass opacities decreased over the 3 weeks after symptom onset.

Objective: To identify the initial chest computed tomography (CT) findings and clinical characteristics associated with the course of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: Baseline CT scans and clinical and laboratory data of 72 patients admitted with COVID-19 pneumonia (39 men, 46.2 ± 15.9 years) were retrospectively analyzed. Baseline CT findings including lobar distribution, presence of ground glass opacities, consolidation, linear opacities, and lung severity score were evaluated. The outcome event was recovery with hospital discharge. The time from symptom onset to discharge or the end of follow-up (for those remained hospitalized) was recorded. Data were censored in events such as death or discharge without recovery. Multivariable Cox proportional hazard regression was used to explore the association between initial CT, clinical or laboratory findings, and discharge with recovery, whereby hazard ratio (HR) values < 1 indicated a lower rate of discharge at four weeks and longer time until discharge. Results: Thirty-two patients recovered and were discharged during the study period with a median length of admission of 16 days (range, 9 to 25 days), while the rest remained hospitalized at the end of this study (median, 17.5 days; range, 4 to 27 days). None died during the study period. After controlling for age, onset time, lesion characteristics, number of lung lobes affected, and bilateral involvement, the lung severity score on baseline CT (> 4 vs. ≤ 4 [reference]: adjusted HR = 0.41 [95% confidence interval, CI = 0.18-0.92], p = 0.031) and initial lymphocyte count (reduced vs. normal or elevated [reference]: adjusted HR = 0.14 [95% CI = 0.03-0.60], p = 0.008) were two significant independent factors that influenced recovery and discharge. Conclusion: Lung severity score > 4 and reduced lymphocyte count at initial evaluation were independently associated with a significantly lower rate of recovery and discharge and extended hospitalization in patients admitted for COVID-19 pneumonia.