Anti-HIV domain antibodies and method of making and using same
Inventors
Dimitrov, Dimiter S. • Chen, Weizao
Assignees
US Department of Health and Human Services
Publication Number
US-10287340-B2
Publication Date
2019-05-14
Expiration Date
2029-01-07
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The invention provides single domain antibodies and derivatives thereof that bind antigens of interest, which are stable, soluble, and do not tend to aggregate. The invention also provides methods for constructing a dAb library and methods for screening dAb libraries to identify the dAb of the invention. The invention also provide methods of treating or preventing conditions by antigen neutralization by administering the dAbs of the invention.
Core Innovation
The invention provides single domain antibodies (dAbs) and derivatives that specifically bind HIV antigens with advantageous properties such as stability, solubility, and reduced aggregation. The invention includes methods for constructing dAb libraries using a novel VH framework, screening these libraries to identify potent domain antibodies like m36, and creating fusion proteins incorporating the domain antibodies to enhance stability and efficacy. The methods extend to therapeutic uses of these antibodies for treating or preventing HIV infections through antigen neutralization.
The problem addressed stems from known challenges in anti-HIV therapies and antibody development. Current therapies can lose effectiveness owing to rapid viral resistance. While monoclonal antibodies hold promise, no mAbs have been approved clinically against HIV-1 due to viral evasion mechanisms and epitope accessibility issues. Full-sized antibodies often cannot access sterically restricted epitopes such as the CD4-inducible (CD4i) epitopes, limiting their neutralization efficacy. Domain antibodies derived from human antibodies typically suffer poor stability, solubility, and aggregation tendencies, restricting their therapeutic application. Accordingly, there was a need for new domain antibodies overcoming these shortcomings, with a robust and diverse library source and methods to identify and produce functional anti-HIV dAbs.
The present invention overcomes these problems by identifying a novel natural human heavy chain VH framework, denoted m0, which is highly compatible with diverse CDR sequences, maintains proper folding, exhibits high soluble expression, and resists aggregation. This framework forms the basis of a large, diverse, phage-displayed dAb library from which potent broadly neutralizing anti-HIV antibodies like m36 have been isolated. The antibodies show high affinity for conserved but sterically restricted epitopes on gp120 (such as CD4i epitopes), exhibit cross-reactivity against multiple HIV clades, and display enhanced neutralizing potency compared to prior antibodies. Fusion proteins comprising these dAbs linked to agents such as serum albumin-binding peptides, CD4 fragments or Fc domains further improve stability and/or antiviral effectiveness.
Claims Coverage
The claims include multiple inventive features focusing on fusion proteins comprising the domain antibody m36 or its variants fused to specific partners, pharmaceutical compositions, and related conjugates.
Fusion protein comprising domain antibody m36 with defined framework and fusion partner
A fusion protein comprising a domain antibody that binds the CD4-induced (CD4i) epitope on Env and includes CDR1, CDR2, and CDR3 sequences of m36 (SEQ ID NO: 96), and a framework having at least 90% sequence identity with m36 (SEQ ID NO: 96) or the m0 framework (SEQ ID NO: 94), fused to a fusion partner polypeptide selected from serum albumin-binding protein or peptide, CD4 or fragment thereof, human immunoglobulin Fc domain, or CH3 domain.
Immunoconjugation of fusion protein to therapeutic or diagnostic agents
The fusion protein can be immunoconjugated to one or more cytotoxic agents, chemotherapeutic agents, natural or synthetic toxins, radioactive isotopes, or antiviral agents including antiretrovirals such as zidovudine, acyclovir, saquinavir, and others.
Fusion protein linkage and linker specificity
The fusion partner polypeptide is fused to the domain antibody via a linker, and such linker can specifically be an immunoglobulin hinge region.
Pharmaceutical composition containing fusion protein
A pharmaceutical composition comprising a therapeutically effective amount of the fusion protein and a pharmaceutically acceptable carrier, optionally further comprising a therapeutically effective amount of soluble CD4 or functional fragment thereof.
Specific sequence embodiments
Fusion protein wherein the domain antibody amino acid sequence is SEQ ID NO: 96 (m36) and fusion partner polypeptide is the human immunoglobulin Fc domain fused via an immunoglobulin hinge region.
The claims collectively cover fusion proteins composed of the domain antibody m36 or derivatives with specific fusion partners connected via suitable linkers, their immunoconjugates with therapeutic agents, and pharmaceutical compositions containing these fusion proteins, thereby protecting compositions and methods involving enhanced anti-HIV domain antibodies based on m36 and their therapeutic applications.
Stated Advantages
The domain antibodies of the invention are stable, highly soluble, and do not tend to aggregate or form polymers in solution.
The invention provides antibodies with high affinity for target epitopes and potent neutralization activity against a broad range of HIV isolates.
The novel VH framework m0 exhibits high expression levels, compatibility with diverse CDRs, and facilitates proper antibody folding.
Fusion proteins comprising the domain antibodies fused to agents such as serum albumin-binding peptides or CD4 fragments enhance stability and neutralization effectiveness.
The domain antibodies can access sterically restricted epitopes which are difficult for full-sized antibodies, improving therapeutic potential.
Documented Applications
Treatment and prevention of HIV infections by administering therapeutically effective amounts of domain antibodies or fusion proteins comprising the antibodies.
Identification of broadly neutralizing antibodies against diverse HIV-1 isolates from different clades for therapeutic use.
Use as research tools to explore conserved HIV Env structures and mechanisms of virus entry and immune evasion.
Potential use as candidate therapeutics and microbicides targeting conserved, sterically restricted epitopes on HIV-1 envelope glycoprotein.
Generation of recombinant bacteria expressing domain antibodies for mucosal delivery to treat HIV infections.
Interested in licensing this patent?