Chandrasekar, K. | Search bioRxiv

bioRxiv2024

Immunogenicity and protection efficacy of self-amplifying and circular mRNA vaccines for SARS-CoV-2

Recent advances in vaccine technology have positioned messenger RNA (mRNA) vaccines as safe and reliable options for human use. Conventionally, mRNA vaccines were designed using linear or self-amplifying mRNA (SAM), the latter considered to be superior. However, limited success was achieved with SAM vaccines during the COVID-19 pandemic. Further, studies on Circular mRNA (Circ-RNA) vaccines against the SARS-CoV-2, Ebola and monkey pox proved their efficacy. Circ-RNAs are highly stable, neither they induce inflammatory response nor require any extracellular protein for their function. Here, we compared the efficacy of SAM- and Circ-RNA vaccines using the SARS-CoV-2-RBD (receptor binding domain) as the antigen. Both SAM-RBD and Circ-RBD induced a comparable anti-RBD IgG titer and virus-neutralizing antibody titer. However, the latter induced a significantly higher memory T-cell response. Immunization with SAM- and Circ-RBD showed no mortality and improved lung pathophysiology against acute SARS-CoV-2 infection in mice. The Circ-RBD vaccine is stable for 4 weeks at 40C. A bivalent vaccine containing Circ-RBD of both delta and omicron SARS-CoV-2 variants potently neutralized these viruses. These findings demonstrate Circ-RNA-RBD as an excellent vaccine candidate against COVID-19 and also provide a platform for developing bivalent Circ-RNA vaccine candidates against SARS-CoV-2 or other viruses with rapidly emerging variants.

microbiology↗

bioRxiv2024

Network controllability analysis reveals the antiviral potential of Etravirine against Hepatitis E Virus infection

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis in lower- and middle-income countries. HEV infection may lead to acute liver failure, chronic liver disease and high mortality in pregnant women. Antiviral therapy is not a standard treatment for HEV patients. Computational biology tools promise to revolutionize the antiviral drug discovery. Here, we analyzed the transcriptome data of HEV infected primary human hepatocyte (PHH)-cells through connectivity map database and applied control theory on functional network to identify antiviral targets against HEV. The above analyses predicted PKC{beta}, PKB/AKT and CK1{varepsilon} as potential antiviral targets against HEV. The antiviral function of PKB/AKT and CK1{varepsilon} was experimentally validated by using respective biochemical inhibitors in g3 (genotype 3)-HEV replicon and Huh7 cell-based model of g3 and g1-HEV infection. Further, knockdown of CK1{varepsilon} showed a similar effect. These data confirmed that CK1{varepsilon} is an antiviral target for HEV. At present, there are no FDA approved drugs targeting CK1{varepsilon}. Etravirine is an FDA approved non-nucleoside reverse transcriptase inhibitor drug, used for the treatment of Human immunodeficiency virus type 1 (HIV-1) infected patients. An in silico study predicted Etravirine to be a potent inhibitor of CK1{varepsilon}. Our experiments revealed potent antiviral activity of Etravirine against HEV, which was mediated via its ability to inhibit the activity of CK1{varepsilon}. Taken together, the current study demonstrates that PKB/AKT and CK1{varepsilon} are bonafide antiviral targets for HEV and paves the way for repurposing Etravirine for the treatment of HEV infected patients. ImportanceAntiviral treatment is not the standard care for acute viral hepatitis E patients. Unbiased identification of antiviral targets or large-scale screening of antiviral compounds against the hepatitis E virus (HEV) has not been reported. Here, computational biology approach was followed to unbiasedly identify antiviral targets of HEV. Transcriptome data of HEV infected primary human hepatocyte (PHH) cells were analyzed to identify modulators of the network and generate directional networks. Network controllability analysis identified PKC{beta}, PKB/AKT and CK1{varepsilon} as potential antiviral targets against HEV. Antiviral function of PKB/AKT and CK1{varepsilon} was confirmed using cell-based models of genotype 1 (g1)- and g3-HEV infection. Further experiments demonstrated the antiviral activity of Etravirine against HEV, mediated via its ability to inhibit the CK1{varepsilon} activity. Etravirine is an FDA approved non-nucleoside reverse transcriptase inhibitor, used for the treatment of Human immunodeficiency virus type-1 (HIV-1)-infected patients. This study reveals the potential of repurposing Etravirine for treatment of HEV patients and illustrate the importance of computational biology in antiviral drug discovery.

microbiology↗