Experimental Research on the Inhibitory Effect of IFN-Lambda 3 Combined with Sorafenib on the Growth of Liver Cancer Transplanted into Nude Mice

Objective: To investigate the effect of sorafenib combined with interferon-lambda 3 on the growth of liver cancer transplanted into nude mice. Methods: Female nude mice of 4-5 weeks of age that passed quarantine were selected and fed for 1-2 weeks before experimental operation. The cell suspension of human hepatoma cell line SMMC-7721 was inoculated into the right cervical axillary fossa with a syringe. The tumor-bearing mice were randomly divided into a control group and an experimental group. The control group received normal saline whereas the experimental group was further divided into three other groups: IFN-lambda 3 treatment group, sorafenib treatment group, and IFN-lambda 3 combined with sorafenib treatment group. The situation of nude mice was analyzed. At the end of the experiment, the volume of allogeneic transplanted tumor was measured, and the morphology of tumor cells, the expression of proliferating protein Ki-67, as well as the number of apoptotic cells were observed by hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and TUNEL staining. Results: The tumor cell volume of the IFN-lambda 3 treatment group, sorafenib treatment group, and IFN-lambda 3 combined with sorafenib treatment group decreased, which was statistically significant compared with the control group (p < 0.05). The increment rate of proliferating protein Ki-67 in the transplanted tumor tissue of the three drug groups was significantly lower than that of the control group (p < 0.05). IFN-lambda 3 combined with sorafenib had the greatest effect on the expression level of Ki-67 protein. Compared with the control group, the expression rate was significantly lower (p < 0.05). In terms of cell apoptosis, IFN-lambda 3 and/or sorafenib, as well as the combination of the two, showed statistically significant differences compared with the control group (p < 0.05). The rate of cell apoptosis was the highest in the IFN-lambda 3 combined with sorafenib group. Conclusion: IFN-lambda 3 combined with sorafenib can inhibit the growth and proliferation of human hepatocellular carcinoma cells in nude mice and promote the apoptosis of hepatocellular carcinoma cells, which proves that IFN-lambda 3 combined with sorafenib can treat hepatocellular carcinoma in vivo.

A mouse-adapted SARS-CoV-2 model for the evaluation of COVID-19 medical countermeasures

Coronaviruses are prone to emergence into new host species most recently evidenced by SARS-CoV-2, the causative agent of the COVID-19 pandemic. Small animal models that recapitulate SARS-CoV-2 disease are desperately needed to rapidly evaluate medical countermeasures (MCMs). SARS-CoV-2 cannot infect wildtype laboratory mice due to inefficient interactions between the viral spike (S) protein and the murine ortholog of the human receptor, ACE2. We used reverse genetics to remodel the S and mACE2 binding interface resulting in a recombinant virus (SARS-CoV-2 MA) that could utilize mACE2 for entry. SARS-CoV-2 MA replicated in both the upper and lower airways of both young adult and aged BALB/c mice. Importantly, disease was more severe in aged mice, and showed more clinically relevant phenotypes than those seen in hACE2 transgenic mice. We then demonstrated the utility of this model through vaccine challenge studies in immune competent mice with native expression of mACE2. Lastly, we show that clinical candidate interferon (IFN) lambda-1a can potently inhibit SARS-CoV-2 replication in primary human airway epithelial cells in vitro, and both prophylactic and therapeutic administration diminished replication in mice. Our mouse-adapted SARS-CoV-2 model demonstrates age-related disease pathogenesis and supports the clinical use of IFN lambda-1a treatment in human COVID-19 infections.

Porcine Intestinal Enteroids: a New Model for Studying Enteric Coronavirus Porcine Epidemic Diarrhea Virus Infection and the Host Innate Response

ABSTRACTPorcine epidemic diarrhea virus (PEDV), a member of the group of alphacoronaviruses, is the pathogen of a highly contagious gastrointestinal swine disease. The elucidation of the events associated with the intestinal epithelial response to PEDV infection has been limited by the absence of goodin vitroporcine intestinal models that recapitulate the multicellular complexity of the gastrointestinal tract. Here, we generated swine enteroids from the intestinal crypt stem cells of the duodenum, jejunum, or ileum and found that the generated enteroids are able to satisfactorily recapitulate the complicated intestinal epitheliumin vivoand are susceptible to infection by PEDV. PEDV infected multiple types of cells, including enterocytes, stem cells, and goblet cells, and exhibited segmental infection discrepancies compared with ileal enteroids and colonoids, and this finding was verifiedin vivo. Moreover, the clinical isolate PEDV-JMS propagated better in ileal enteroids than the cell-adapted isolate PEDV-CV777, and PEDV infection suppressed interferon (IFN) production early during the infection course. IFN lambda elicited a potent antiviral response and inhibited PEDV in enteroids more efficiently than IFN alpha (IFN-α). Therefore, swine enteroids provide a novelin vitromodel for exploring the pathogenesis of PEDV and for thein vitrostudy of the interplay between a host and a variety of swine enteric viruses.IMPORTANCEPEDV is a highly contagious enteric coronavirus that causes significant economic losses, and the lack of a goodin vitromodel system is a major roadblock to an in-depth understanding of PEDV pathogenesis. Here, we generated a porcine intestinal enteroid model for PEDV infection. Utilizing porcine intestinal enteroids, we demonstrated that PEDV infects multiple lineages of the intestinal epithelium and preferably infects ileal enteroids over colonoids and that enteroids prefer to respond to IFN lambda 1 over IFN-α. These events recapitulate the events that occurin vivo. This study constitutes the first use of a primary intestinal enteroid model to investigate the susceptibility of porcine enteroids to PEDV and to determine the antiviral response following infection. Our study provides important insights into the events associated with PEDV infection of the porcine intestine and provides a valuablein vitromodel for studying not only PEDV but also other swine enteric viruses.