Inhibition of Human Coronaviruses by Combinations of Host-Targeted and Direct-Acting Antivirals.

Antiviral compounds targeting cellular metabolism are part of the therapeutic arsenal to control the spread of virus infection, either as sole treatment or in combination with direct-acting antivirals (DAA) or vaccines. Here, we describe the effect of two of them, lauryl gallate (LG) and valproic acid (VPA) both exhibiting a wide antiviral spectrum, against infection by coronaviruses such as HCoV-229E, HCoV-OC43, and SARS-CoV-2. A consistent 2 to 4-log-decrease in virus yields was observed in the presence of each antiviral, with an average IC value of 1.

Inhibition of Porcine Viruses by Different Cell-Targeted Antiviral Drugs.

Antiviral compounds targeting cellular metabolism instead of virus components have become an interesting issue for preventing and controlling the spread of virus infection, either as sole treatment or as a complement of vaccination. Some of these compounds are involved in the control of lipid metabolism and/or membrane rearrangements. Here, we describe the effect of three of these cell-targeting antivirals: lauryl gallate (LG), valproic acid (VPA), and cerulenin (CRL) in the multiplication of viruses causing important porcine diseases.

The African swine fever virus lectin EP153R modulates the surface membrane expression of MHC class I antigens.

We have modeled a 3D structure for the C-type lectin domain of the African swine fever virus protein EP153R, based on the structure of CD69, CD94 and Ly49A cell receptors, and this model predicts that a dimer of EP153R may establish an asymmetric interaction with one MHC-I molecule. A functional consequence of this interaction could be the modulation of MHC-I expression. By using both transfection and virus infection experiments, we demonstrate here that EP153R inhibits MHC-I membrane expression, most probably by impairing the exocytosis process, without affecting the synthesis or glycosylation of MHC antigens.

The use of COS-1 cells for studies of field and laboratory African swine fever virus samples.

Different naturally occurring, cell adapted or genetically manipulated stocks of African swine fever virus were able to infect directly cultures of COS-1 cells, producing extensive cytopathic effects and amounts from 10(6) to 10(7) of infective progeny virus per ml. The induction of late virus-specific proteins, demonstrated by RT-PCR and immunoblotting, and the development of lysis plaques by all the virus samples tested so far, allowed the optimization of both titration and diagnostic assays, as well as the proposal of a method for selection of virus clones during the generation of virus mutants with specific gene deletions.

Antiviral activity of lauryl gallate against animal viruses.

Background: Antiviral compounds are needed in the control of many animal and human diseases.

Methods: We analysed the effect of the antitumoural drug lauryl gallate on the infectivity of the African swine fever virus among other DNA (herpes simplex and vaccinia) and RNA (influenza, porcine transmissible gastroenteritis and Sindbis) viruses, paying attention to its effect on the viability of the corresponding host cells.

Results: Viral production was strongly inhibited in different cell lines at non-toxic concentrations of the drug (1-10 microM), reducing the titres 3->5 log units depending on the multiplicity of infection.