No abstract

The VP35 protein of Ebola virus is a viral antagonist of interferon. It acts to block virus or double-stranded RNA-mediated activation of interferon regulatory factor 3, a transcription factor that facilitates the expression of interferon and interferon-stimulated genes. In this report, we show that the VP35 protein is also able to inhibit the antiviral response induced by alpha interferon. This depends on the VP35 function that interferes with the pathway regulated by double-stranded RNA-dependent protein kinase PKR. When expressed in a heterologous system, the VP35 protein enhanced viral polypeptide synthesis and growth in Vero cells pretreated with alpha/beta interferon, displaying an interferon-resistant phenotype. In correlation, phosphorylation of PKR and eIF-2␣ was suppressed in cells expressing the VP35 protein. This activity of the VP35 protein was required for efficient viral replication in PKR ؉/؉ but not PKR ؊/؊ mouse embryo fibroblasts. Furthermore, VP35 appears to be a RNA binding protein. Notably, a deletion of amino acids 1 to 200, but not R312A substitution in the RNA binding motif, abolished the ability of the VP35 protein to confer viral resistance to interferon. However, the R312A substitution rendered the VP35 protein unable to inhibit the induction of the beta interferon promoter mediated by virus infection. Together, these results show that the VP35 protein targets multiple pathways of the interferon system.

The majority of people infected with SARS-CoV-2 fully recovered within a few weeks. However, a considerable number of patients of different ages still suffer from long-lasting problems similar to the multi-organ damage in its acute phase of infection, or experience symptoms continuously for a longer term after the recovery. The severity of the primary infection seems not to be associated with the possibility and severity of long-term symptoms. Various unresolved symptoms have been reported in COVID-19 survivors months after hospital discharge. Long COVID-19 Syndrome refers to survivors 4 months after initial symptoms onset. It is important to understand the systemic effects of Long COVID-19 Syndrome, its presentations, and the need for rehabilitations to restore functional recovery in survivors. Government, healthcare workers, and survivor groups should collaborate to establish a self-sustaining system to facilitate follow-up and rehabilitations, with prioritization of resources to more severely Long COVID-19 Syndrome survivors. This review looks into the systemic effects of Long COVID-19 Syndrome in various aspects: respiratory, cardiovascular, hematological, renal, gastrointestinal, neurological, and metabolic effects of Long COVID-19 Syndromes. Recommendations for follow-up and rehabilitations details have been explored to cope with the tremendous Long COVID-19 Syndrome patients.