Stabilized group 2 influenza hemagglutinin stem region trimers and uses thereof
Inventors
BOYINGTON, Jeffrey C. • Graham, Barney S. • Mascola, John R. • YASSINE, Hadi M. • CORBETT, Kizzmekia S. • MOIN, Syed M. • Wang, Lingshu • Kanekiyo, Masaru
Assignees
US Department of Health and Human Services
Publication Number
US-11793871-B2
Publication Date
2023-10-24
Expiration Date
2037-09-01
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Vaccines that elicit broadly protective anti-influenza antibodies. The vaccines comprise nanoparticles that display HA trimers from Group 2 influenza virus on their surface. The nanoparticles are fusion proteins comprising a monomeric subunit (e.g., ferritin) joined to stabilized stem regions of Group 2 influenza virus HA proteins. The fusion proteins self-assemble to form the HA-displaying nanoparticles. Also provided are fusion proteins, and nucleic acid molecules encoding such proteins, and assays using nanoparticles of the invention to detect anti-influenza antibodies.
Core Innovation
The invention provides vaccines comprising nanoparticles that display stabilized stem region trimers of Group 2 influenza virus hemagglutinin (HA) proteins on their surface. These nanoparticles are fusion proteins formed by joining a monomeric subunit, such as ferritin or lumazine synthase, to the stabilized stem regions of Group 2 influenza virus HAs. The fusion proteins self-assemble into nanoparticles presenting trimeric HA stem proteins in a pre-fusion conformation, eliciting broadly protective antibodies against Group 2 influenza viruses.
The core problem addressed is that current influenza vaccines primarily target the variable immunodominant head region of HA, which undergoes antigenic drift, limiting protection. In contrast, the conserved HA stem is poorly immunogenic. Existing vaccines are strain-specific, have manufacturing constraints, and elicit limited broadly neutralizing antibodies. There remains a need for efficacious vaccines capable of providing robust protection against Group 2 influenza viruses and cross-reactivity to heterologous strains, including potential pandemic variants.
To solve this, the invention describes recombinant Group 2 influenza HA proteins with the head region replaced by a short linker sequence, stabilizing the stem region by genetic modifications including extension of helix A, shortening or replacing the inter-helix region with a linker, and introduction of stabilizing mutations that form or strengthen ionic interactions or hydrophobic packing. These proteins are fused to monomeric subunits to form self-assembling nanoparticles that present native-like HA stem trimers to the immune system, thereby eliciting broadly protective immune responses against Group 2 influenza viruses.
Claims Coverage
The claims cover a nucleic acid molecule encoding a recombinant Group 2 influenza HA protein with specific structural modifications, and methods and compositions related thereto. There are eight main inventive features outlining structural modifications to the HA protein and its encoding nucleic acid, as well as related methods of vaccination and pharmaceutical compositions.
Nucleic acid encoding Group 2 influenza HA protein with head region replaced by linker and extended helix A
The nucleic acid molecule encodes a recombinant Group 2 influenza hemagglutinin protein wherein the head region is replaced with a linker sequence, and helix A in the stem region is extended by addition of helix-forming amino acid residues, improving protein stability, specifically including sequences at least 80% identical to SEQ ID NO: 113.
Replacement of inter-helix loop with linker sequence
The inter-helix loop in the stem region of the HA protein is replaced with a linker sequence to improve structural properties.
Inclusion of mutations forming or strengthening ionic interactions or salt bridges in the stem region
The stem region of the HA protein includes one or more mutations that form or strengthen ionic interactions or salt bridges, enhancing protein stability.
Inclusion of mutations increasing hydrophobic packing within the stem region
The stem region of the HA protein contains mutations that increase hydrophobic packing, further stabilizing the protein.
Extension of helix A by addition of five helix-forming amino acid residues
Helix A in the stem region is extended by five helix-forming amino acid residues to augment stability and proper conformation.
Specific extension of helix A by ALMAQ or ELMEQ sequences
Helix A is extended relative to wild-type by the addition of the specific sequences ALMAQ (SEQ ID NO: 36) or ELMEQ (SEQ ID NO: 37).
Nucleic acid molecule encoding HA protein with increased sequence identity
Encoding an HA protein comprising at least 90% or 95% sequence identity to SEQ ID NO: 113, enhancing sequence variation options while retaining function.
Method of vaccinating an individual using the nucleic acid molecule
A method of vaccination comprising administering a prophylactically or therapeutically effective amount of the nucleic acid molecule encoding the modified HA protein to an individual.
The claims collectively cover nucleic acid molecules encoding recombinant Group 2 influenza HA proteins having a shortened head region replaced by a linker, an extended helix A of specific length and sequence, stabilized inter-helix regions, and mutations enhancing ionic and hydrophobic interactions, along with methods of vaccination using these nucleic acids, vectors, host cells, and pharmaceutical compositions comprising them.
Stated Advantages
The vaccine platform enables eliciting broadly protective and heterosubtypic anti-influenza antibodies targeting the conserved HA stem region from Group 2 influenza viruses.
The stabilized stem region proteins facilitate formation of trimeric HA on nanoparticle surfaces, enhancing native-like antigenic presentation and immunogenicity.
The approach allows for improved vaccine stability, manufacturability, and the potential to overcome antigenic drift and shift seen in influenza viruses.
Documented Applications
Vaccines comprising nanoparticles displaying Group 2 influenza HA stem region trimers for prophylactic or therapeutic immunization against influenza infections in humans and other animals.
Immunogenic compositions and pharmaceutical formulations containing the recombinant proteins or nanoparticles thereof for vaccination methods.
Methods of vaccinating individuals using the disclosed recombinant proteins, nanoparticles, or nucleic acid molecules encoding such proteins.
Nucleic acid constructs encoding the recombinant proteins, vectors, and host cells for recombinant expression of the vaccine antigens.
Diagnostic assays for detecting anti-influenza antibodies in samples by utilizing nanoparticles displaying stabilized Group 2 HA stem proteins to bind influenza-specific antibodies.
Interested in licensing this patent?