Antibody Humanization Service

The humanized antibodies are a type of antibodies derived from non-human species, whose protein sequences have been modified to improve their similarity with human natural antibody variants. Currently, antibody humanization is acknowledged to play a fundamental role in the remarkable progress of antibodies as therapeutic agents.

Fig.1 Humanized antibody. (Jones, 1986)

Recombinant antibody technology is rapidly becoming available and displaying considerable success in clinical practices. However, the immunogenicity of murine monoclonal antibodies is observed to be restrictive in cancer immunotherapy. To reduce the chance of immunogenicity, humanized antibodies are created to address immunogenic response and thus they are considered to be a promising alternative reagent in the clinic. In Creative Biolabs, we possess a variety of methods and toolkits used in the antibody humanization process and provide customized antibody humanization services.

Antibody Humanization Services at Creative Biolabs

➢ Process

Creative Biolabs has launched the GHA® Platform to develop humanized antibodies as well as Hi-Affi™ Platform to develop human monoclonal antibodies from non-human primates. The steps for designing humanized antibodies are as follows.

Fig.2 A humanized process in Creative Biolabs.

➢ Our Capability

i. Universal antibody humanization service or one-stop, customized antibody service for special needs.
ii. 30 days guaranteed services for the whole project, once clients’ VH and VK sequences received.
iii. High-quality service. We deliver humanized candidates and ensure their epitope specificity and binding affinity.
iv. If clients are satisfied with humanized antibody variants, we can provide the stable cell line further optimized for high yield expression and validated for scale-up.

➢ Humanization Toolkits

Fig.3 Diverse antibody forms. (Carter, 2001)

• CDR grafting - Antibody variables are termed complementarity-determining regions (CDRs) determining where antibodies bind to a specific antigen, are combined with human constants. In CDR grafting, antigen affinity and antibody specificity are maintained by utilizing residues related to antigen binding and it is common to select an appropriate human acceptor framework.
• SDR grafting - Humanized antibodies from CDR grafting may still elicit an anti-idiotypic (anti-id) immune response in organisms. To minimize anti-V region responses, the antibody can be humanized only by grafting the specificity determining residues (SDRs) upon the human frameworks.
• Phage display - It is a process using bacteriophages to display antibodies which are fused to the phage coat protein. Through repeated cycles of antigen-guided selection, bacteriophages are genetically designed to generate a human phage display library, then screened for binding affinity to a particular antigen.
• Transgenic animals - Model animals (e.g. mouse) are genetically engineered by introducing human antibody light/heavy chain gene sequences, as well as targeted modification of endogenous animal antibody genes to suppress their expressions. The result is transgenic animals can produce complete human antibody repertoires.
• Resurfacing - This approach is based on the identification of accessible, protruding residues in the non-human antibody which need to change human sequences without affecting the conformation of CDR loops to create humanized antibodies with reduced immunogenicity.
• Superhumanization - The superhumanization is based on structural homologies between human and mouse CDRs in which a framework homology is uncorrelated. By this method, the best superhumanized form of antibody shows a better affinity (6-fold loss) than that with the CDR grafted variant (70-fold loss).
• HSC optimization - The immunologically relevant metric of antibody humanness named human string content (HSC) is a new strategy for antibody humanization. Through maximizing HSC quantity, the humanization of target sequence is to create multiple diverse humanized variants, whose variable domains are less immunogenic, more binding affinities.

Features & Advantages

✔ Rich Experience: Creative Biolabs has extensive experience in antibody engineering for diagnostics and therapeutics and there are more than 15 murine humanization projects have been accomplished successfully.
✔ Strategy Diversity: We have multiple toolkits for humanized antibodies, including CDR back mutation library screening, human framework selection, etc.
✔ Species Diversity: Our humanization services to antibodies can be allowed to any species, such as non-human primate (NHP), rabbit, llama, dog, chicken, etc.
✔ Guaranteed Quality: The optimized antibody with minimal immunogenicity, almost equivalent to a mature human antibody, is guaranteed to remain parental affinity and specificity. The affinity maturation can improve the affinity by at least 10 folds.
✔ Free of Rights: Clients would get the full ownership of humanized antibodies from our customized platform.
✔ Full Suit of Characterization Assays: Binding assays by ELISA (Enzyme-linked immuno sorbent assay), thermostability, aggregation rate, KD determination against soluble antigens, IC50 (Half maximal inhibitory concentration), SPR (Surface plasmon resonance), endotoxin detection, etc.

With the flourish of antibody drugs, the demand for humanized antibodies is rapidly growing. Due to strict ethical and moral principles, it is totally impossible to immunize humans directly with interested antigens. Here, Creative Biolabs sets up two reliable platforms for humanized antibodies with high-affinity, low immunogenicity and has extensive experience in providing multiple diverse antibody humanization services for both laboratory and therapeutic purposes. If there is any question, please contact us for more information.

References

1. Jones, P. T.; et al. (1986) Replacing the complementarity-determining regions in a human antibody with those from a mouse. Nature, 321(6069), 522-525.
2. Carter, P. Improving the efficacy of antibody-based cancer therapies. Nat Rev Cancer. 2001, 1(2): 118-129.