Compositions and methods for treating RSV-infections

Inventors

Markoutsa, EleniMohapatra, SubhraMohapatra, Shyam

Assignees

US Department of Veterans AffairsUniversity of South Florida St Petersburg

Publication Number

US-11911481-B2

Publication Date

2024-02-27

Expiration Date

2039-05-21

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Abstract

This invention provides for a RSV-targeted nanoparticle PMN (RTPMN), combining HR2D anti-fusion peptide, and plasmid encoded siRNA against RSV-NS1 and/or RSV-P gene as a safe, effective and inexpensive anti-RSV prophylaxis and/or therapy.

Core Innovation

This invention provides a novel nanoparticle composition (RTPMN) designed for the prophylaxis and treatment of respiratory syncytial virus (RSV) infections. The nanoparticles comprise three layers: an outer coat of chitosan complexed with an anti-fusion HR2D peptide to inhibit RSV entry; a lipid bilayer intermediate layer to stabilize the structure and protect the nucleic acid payload; and an inner core of chitosan complexed with a plasmid DNA vector encoding short hairpin RNAs (shRNAs) targeting RSV's non-structural 1 protein (NS1) and phosphoprotein (P) genes to inhibit viral replication.

The problem addressed arises from RSV being a major life-threatening respiratory pathogen infecting millions worldwide with no effective vaccine or comprehensive treatment. Current approaches largely focus either on inhibiting virus-cell membrane fusion or viral replication separately. There is a recognized need for new therapeutic and prophylactic compositions capable of concurrently blocking both RSV fusion and replication, effectively treating primary and secondary RSV infections.

The invention solves this by designing multifunctional, triple-layered nanoparticles. The HR2D peptide on the outer chitosan layer functions as a viral fusion inhibitor, preventing cell entry. The plasmid encoded shRNAs disrupt RSV replication by knocking down NS1, which counteracts host interferon response, and P, a critical component of viral RNA-dependent RNA polymerase. Encapsulation within a lipid bilayer stabilizes the nucleic acid and improves efficacious delivery. Experimental data demonstrate efficient transfection, low toxicity, targeted uptake by RSV-infected cells, sustained lung retention, and significant prophylactic and therapeutic reduction in viral infection in vitro and in vivo.

Claims Coverage

The patent discloses 19 main inventive features centered on a uniquely structured nanoparticle and related methods and compositions for RSV treatment.

Triple-layered nanoparticle architecture

A nanoparticle comprising three distinct layers: (a) an outer layer of chitosan combined with a heptad repeat (HR)2 peptide, (b) a middle layer comprising a lipid bilayer formed from phospholipids, and (c) an inner core comprising chitosan complexed with a vector containing nucleic acid. The lipid bilayer is positioned between the outer chitosan-HR2 layer and the inner chitosan-vector core.

Incorporation of antiviral nucleic acids

The vector in the nanoparticle comprises nucleic acids such as siRNA or shRNA specifically targeting RSV proteins critical to viral replication, including non-structural 1 protein (NS1) and phosphoprotein (P). The vector can be a dual expressing short hairpin RNA recombinant plasmid encoding shRNAs against NS1 and P.

Targeting moieties on outer layer

The outer chitosan layer can include targeting moieties, particularly antibodies like anti-ICAM antibody, to enhance nanoparticle delivery selectively to RSV-infected cells.

Specific shRNA sequences and inhibition of viral gene expression

The shRNAs encoded inhibit expression of RSV NS1 and P genes via sequences selected from disclosed nucleotide sequences, effectively disrupting viral replication mechanisms.

Ionic bonding between chitosan and HR2 peptide

The chitosan in the outer layer is ionically bonded to the HR2 peptide, stabilizing the anti-fusion functionality on the nanoparticle surface.

Optimal chitosan to shRNA ratios

The nanoparticles employ specific chitosan to shRNA ratios ranging from about 2 to about 10, with exemplified ratios of about 2, 5, or 7, optimizing nucleic acid encapsulation and delivery.

Wide range of administration routes

The nanoparticles can be formulated for intravenous, intratracheal, intramuscular, subcutaneous, intranasal, oral, inhalation, or direct injection administration, facilitating flexible therapeutic use.

Pharmaceutical compositions comprising nanoparticles

Pharmaceutical compositions include the disclosed nanoparticles combined with pharmaceutically acceptable carriers suitable for administration.

Methods of delivery and treatment of RSV infection

Methods involve administering an effective amount of the pharmaceutical compositions containing the nanoparticles to subjects in need, including humans and bovines, via various administration routes to treat or prevent RSV infection.

Combination therapy

The methods can be combined with administration of antiviral agents such as ribavirin, antibodies such as palivizumab, corticosteroids, antibiotics, or combinations thereof to enhance therapeutic effect.

Mechanism of RSV replication inhibition

Methods employ the nanoparticles to inhibit RSV replication by disrupting, impairing, or displacing the interaction between NS1 and P proteins via cellular contact.

Vaccine compositions

Pharmaceutically acceptable vaccine compositions containing the nanoparticles wherein the nucleic acid component elicits an immune response when administered.

Methods of vaccination

Administering the nanoparticles in pharmaceutical formulations to mammals, including humans, to vaccinate against viral infection, including RSV.

Upregulation of cellular interferon

The nanoparticles or compositions upregulate cellular interferon levels upon contact with cells or upon administration to subjects.

Inhibition of mature RNA-dependent RNA polymerase formation

Contacting cells or subjects with nanoparticles inhibits formation of mature RNA-dependent RNA polymerase essential for RSV replication.

The claims cover a multifunctional triple-layered nanoparticle with chitosan, HR2 peptide, and a lipid bilayer encapsulating shRNA-encoding plasmids targeting RSV proteins NS1 and P, methods of using these nanoparticles for inhibiting RSV replication and fusion, pharmaceutical compositions incorporating them, vaccination methods, and combined therapies. The inventive features comprehensively define novel compositions and methods for prophylaxis and treatment of RSV infection.

Stated Advantages

The nanoparticles show high transfection efficiency with significantly less toxicity compared to common transfection reagents.

Targeted nanoparticles with anti-ICAM antibodies demonstrate selective uptake by RSV-infected cells, improving therapeutic specificity.

The lipid bilayer stabilizes the plasmid DNA enhancing integrity and endosomal escape, resulting in improved antiviral efficacy.

Biodistribution studies demonstrate tissue accumulation and retention primarily in the lungs, ensuring relevant delivery to respiratory sites.

In vivo studies reveal significant prophylactic and therapeutic reduction in RSV infection and replication using the nanoparticles.

Documented Applications

Prophylactic and therapeutic treatment of primary and secondary RSV infections in humans and bovines via administration of the nanoparticles.

Vaccination of mammals against viral infections using the nanoparticles capable of eliciting immune responses.

Use of nanoparticles to deliver nucleic acids that interfere with RSV replication in respiratory cells.

Intranasal, intravenous, oral, inhalational, intramuscular, and subcutaneous administration of nanoparticles for RSV treatment.

Combination therapies with existing antiviral agents, antibodies, corticosteroids, or antibiotics in RSV treatment regimens.

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