Bacillus pumilus ribonuclease rescues mice infected by double-stranded RNA-containing reovirus serotype 1

Fibrin-Rhamnogalacturonan I Composite Gel for Therapeutic Enzyme Delivery to Intestinal Tumors

Therapy of colorectal cancer with protein drugs, including targeted therapy using monoclonal antibodies, requires the preservation of the drug's structure and activity in the gastrointestinal tract or bloodstream. Here, we confirmed experimentally the fundamental possibility of creating composite protein-polysaccharide hydrogels based on non-degrading rhamnogalacturonan I (RG) and fibrin as a delivery vehicle for antitumor RNase binase. The method is based on enzymatic polymerization of fibrin in the presence of RG with the inclusion of liposomes, containing an encapsulated enzyme drug, into the gel network. The proposed method for fabricating a gel matrix does not require the use of cytotoxic chemical cross-linking agents and divalent cations, and contains completely biocompatible and biodegradable components. The process proceeds under physiological conditions, excluding the effect of high temperatures, organic solvents and ultrasound on protein components. Immobilization of therapeutic enzyme binase in the carrier matrix by encapsulating it in liposomes made from uncharged lipid made it possible to achieve its prolonged release with preservation of activity for a long time. The release time of binase from the composite carrier can be regulated by variation of the fibrin and RG concentration.

Alginate-Based Hydrogel as Delivery System for Therapeutic Bacterial RNase

To deliver therapeutic proteins into a living body, it is important to maintain their target activity in the gastrointestinal tract after oral administration. Secreted ribonuclease from Bacillus pumilus (binase) has antitumor and antiviral activity, which makes it a promising therapeutic agent. This globular protein of small molecular weight (12.2 kDa) is considered as a potential agent that induces apoptosis of tumor cells expressing certain oncogenes, including colorectal and duodenum cancer. The most important problem of its usage is the preservation of its structure and target activity, which could be lost during oral administration. Here, we developed alginate microspheres reinforced with divalent cations and analyzed the enzyme release from them. Using methods of scanning electron microscopy, measurements of fluorescence, enzyme catalytic activity, and determination of viability of the duodenum adenocarcinoma tumor cell line, we characterized obtained microspheres and chose calcium as a biogenic ion-strengthening microsphere structure. Among such modified additivities as beta-casein, gelatin, and carbon nanotubes introduced into microspheres, only gelatin showed a pronounced increase in their stability and provided data on the prolonged action of enzyme release from microspheres into tumor cell culture medium during 48 h in an amount of about 70% of the loaded quantity.

Anti-Influenza Activity of the Ribonuclease Binase: Cellular Targets Detected by Quantitative Proteomics

Unpredictable influenza pandemics, annual epidemics, and sporadic poultry-to-human avian influenza virus infections with high morbidity and mortality rates dictate a need to develop new antiviral approaches. Targeting cellular pathways and processes is a promising antiviral strategy shown to be effective regardless of viral subtypes or viral evolution of drug-resistant variants. Proteomics-based searches provide a tool to reveal the druggable stages of the virus life cycle and to understand the putative antiviral mode of action of the drug(s). Ribonucleases (RNases) of different origins not only demonstrate antiviral effects that are mediated by the direct RNase action on viral and cellular RNAs but can also exert their impact by signal transduction modulation. To our knowledge, studies of the RNase-affected cell proteome have not yet been performed. To reveal cellular targets and explain the mechanisms underlying the antiviral effect employed by the small extra-cellular ribonuclease of Bacillus pumilus (binase) both in vitro and in vivo, qualitative shotgun and quantitative targeted proteomic analyses of the influenza A virus (IAV) H1N1pdm09-infected A549 cells upon binase treatment were performed. We compared proteomes of mock-treated, binase-treated, virus-infected, and virus-infected binase-treated cells to determine the proteins affected by IAV and/or binase. In general, IAV demonstrated a downregulating strategy towards cellular proteins, while binase had an upregulating effect. With the help of bioinformatics approaches, coregulated cellular protein sets were defined and assigned to their biological function; a possible interconnection with the progression of viral infection was conferred. Most of the proteins downregulated by IAV (e.g., AKR1B1, AKR1C1, CCL5, PFN1, RAN, S100A4, etc.) belong to the processes of cellular metabolism, response to stimulus, biological regulation, and cellular localization. Upregulated proteins upon the binase treatment (e.g., AKR1B10, CAP1, HNRNPA2B1, PFN1, PPIA, YWHAB, etc.) are united by the processes of biological regulation, cellular localization, and immune and metabolic processes. The antiviral activity of binase against IAV was expressed by the inversion of virus-induced proteomic changes, resulting in the inhibition of virus-associated processes, including nuclear ribonucleoprotein export (NCL, NPM1, Nup205, and Bax proteins involved) and cytoskeleton remodeling (RDX, PFN1, and TUBB) induced by IAV at the middle stage of single-cycle infection in A549 cells. Modulation of the immune response could be involved as well. Overall, it seems possible that binase exerts its antiviral effects in multiple ways.