Ribonuclease fromBacillusActs as an Antiviral Agent against Negative- and Positive-Sense Single Stranded Human Respiratory RNA Viruses

Abstract

Bacillus pumilus ribonuclease (binase) was shown to be a promising antiviral agent in animal models and cell cultures. However, the mode of its antiviral action remains unknown. To assess the binase effect on intracellular viral RNA we have selected single stranded negative- and positive-sense RNA viruses, influenza virus, and rhinovirus, respectively, which annually cause respiratory illnesses and are characterized by high contagious nature, mutation rate, and antigen variability. We have shown that binase exerts an antiviral effect on both viruses at the same concentration, which does not alter the spectrum of A549 cellular proteins and expression of housekeeping genes. The titers of influenza A (H1N1pdm) virus and human rhinovirus serotype 1A were reduced by 40% and 65%, respectively. A preincubation of influenza virus with binase before infection significantly reduced viral titer after single-cycle replication of the virus. Using influenza A virus mini genome system we showed that binase reduced GFP reporter signaling indicating a binase action on the expression of viral mRNA. Binase reduced the level of H1N1pdm viral NP mRNA accumulation in A549 cells by 20%. Since the viral mRNA is a possible target for binase this agent could be potentially applied in the antiviral therapy against both negative- and positive-sense RNA viruses.

Bacterial ribonuclease binase exerts an intra-cellular anti-viral mode of action targeting viral RNAs in influenza a virus-infected MDCK-II cells

“…Nevertheless, mechanisms underlying the anti-viral effects of binase remain unclear. We had previously shown that pre-treatment of IAV with binase before infection of A549 and MDCK-II cells resulted in an anti-viral effect that was dependent on the amount of binase [ 13 , 21 , 22 ]. Furthermore, we reported that binase degrades vRNA, which is not protected by the virion/RNP complex and that binase added to cells (HEK293, A549) reduces of a GFP reporter gene expression by a transient IAV mini-genome system [ 21 , 22 ].…”

“…We had previously shown that pre-treatment of IAV with binase before infection of A549 and MDCK-II cells resulted in an anti-viral effect that was dependent on the amount of binase [ 13 , 21 , 22 ]. Furthermore, we reported that binase degrades vRNA, which is not protected by the virion/RNP complex and that binase added to cells (HEK293, A549) reduces of a GFP reporter gene expression by a transient IAV mini-genome system [ 21 , 22 ]. Moreover, we showed that binase is able to penetrate into A549 cells [ 23 ] and that treatment of IAV-infected A549 cells led to titer reduction and reduced the viral NP mRNA amount 12 h post-infection (h p.i.)…”

Secretome of Intestinal Bacilli: A Natural Guard against Pathologies

“…Secretion of low-molecular-weight guanyl-preferring ribonucleases (RNases) is a distinct feature of some Bacillus species ( Ulyanova et al, 2016 ). A well-studied representative of these RNases, binase from B. pumilus , has manifested antitumor ( Ulyanova et al, 2011 ; Cabrera-Fuentes et al, 2013 ; Mitkevich et al, 2013 ) and antiviral activities ( Shah Mahmud and Ilinskaya, 2013 ; Ilinskaya and Shah Mahmud, 2014 ; Shah Mahmud et al, 2016 , 2017 ; Müller et al, 2017 ). KRAS which has mutations in about 40% of patients with colorectal cancer ( Prior et al, 2012 ) was shown to be a direct target for antitumor binase ( Ilinskaya et al, 2016 ).…”

Endophytic Bacillus bacteria with RNase activity in the resistance of potato plants to viruses

“…Low concentrations of RNases stimulate plant growth and resistance to a broad spectrum of stress factors, high levels of them show antiviral properties by destroying viral RNA. Microbial RNases are potential therapeutic agents which are suggested for the treatment of human viral diseases (Mahmud et al, 2017). In this regard, the identification of the biological properties of endophytic Bacillus spp.…”