Tobamovirus-based virus-like particles and vaccines

Inventors

Dutta, Sheetij • Batchelor, Adrian • Khan, Farhat • Langowski, Mark

Assignees

Government Of United States Represen AS • United States Department of the Army

Abstract

The disclosure generally provides recombinant proteins comprising Tobamovirus capsid proteins and an immunogenic epitope of an antigen of interest. The recombinant protein can be used to assemble an array comprising a plurality of associated recombinant proteins that can enhance the immunogenicity of the epitope and induce and/or enhance an immune response to the antigen. The disclosure also provides compositions, such as vaccines, that include the recombinant protein as well as methods for inducing and/or enhancing an immune response in a mammal.

Core Innovation

The invention relates to recombinant proteins comprising Tobamovirus capsid proteins and an immunogenic epitope of an antigen of interest, capable of assembling into an array that enhances immunogenicity and induces or enhances an immune response in a mammal. The Tobamovirus capsid proteins can be native or modified sequences, including proteins from Tobacco mosaic virus (TMV) and zucchini green mottled mosaic virus (ZMV). The immunogenic epitope may derive from various antigens that induce immune responses against diseases, microbes, cancer cells, or allergens, including epitopes from Plasmodium species.

The problem addressed is the ongoing need for improved vaccines and vaccine technologies that enhance safety and immunogenicity against antigens. Existing vaccines display limitations such as epitope flexibility, density, and size constraints affecting immunogenicity. Many virus-like particle systems have restricted capacity for peptide insertion due to steric hindrance. Additionally, soluble antigens smaller than 10 nm are generally weakly immunogenic and require complex adjuvants. There is also a need to reduce reactogenicity and the use of expensive immune modulators in adjuvants. The invention solves these issues by using Tobamovirus capsid-based recombinant proteins that assemble into particles displaying epitopes optimally to improve immune responses without requiring complex adjuvants.

The disclosure illustrates that placing the immunogenic epitope on an exposed loop variant of the Tobamovirus capsid protein, particularly TMV, enhances immune responses by modulating epitope density, valency, and flexibility. The circular permutant of TMV allows a flexible external loop for epitope display, overcoming limitations of spherical VLPs. The recombinant proteins can self-assemble into disk-like particles displaying the epitope on the external surface, which are highly immunogenic and can confer superior protection compared to soluble protein vaccines. Methods for producing, purifying, and administering these recombinant proteins and their use as vaccines are also described.

Claims Coverage

The patent contains multiple independent claims covering recombinant proteins, compositions, vaccines, purification methods, methods of enhancing immunogenicity, and methods for inducing immune responses. The main inventive features relate to the structure of the recombinant protein, its components, assembly into arrays, and immunological applications.

The claims cover recombinant Tobamovirus capsid proteins modified to incorporate an immunogenic epitope at defined locations, forming assembled arrays that display the epitope externally to improve immunogenicity. Claims extend to compositions, vaccines with or without adjuvants, methods of purification, methods of enhancing immunogenicity through assembly, and methods of inducing immune responses in mammals. Specific epitopes such as the (NPNA)n repeat of P. falciparum CSP and modifications to capsid sequences are recited as inventive elements.

Stated Advantages

Documented Applications