SingleB® Hybridoma Protein Expression

Fully Humanized Monoclonal Antibody Discovery Technology (Transgenic Mice)

The experimental principle for the discovery of fully humanized antibodies in transgenic mice is that antibodies are not generated with wild type mice, but with mice in which murine antibody-coding genes have been replaced by human ones. Successful production of fully humanized antibodies requires that human antibody gene fragments must be precisely integrated, efficiently rearranged and expressed in host mice and that these fragments interact with murine immune system signaling mechanisms, therefore allowing human antibody gene fragments to be selected, expressed and secretedby B cells upon antigen stimulation in mice. The basic approach is to use homologous recombination in murine embryonic stem (ES) cells to make the original murine gene deletion, and then transfer the reconstructed human antibody germline gene microsites into mice by microinjection and other techniques, and finally secrete the whole human sequence of antibody from the hybridoma of mAb.

Figure 1. Approaches for the development of therapeutic antibodies

Advantages and Disadvantages of xxx

The main advantage of getting fully human antibodies from transgenic mice is efficacy that is superior to other techniques of producing anti-normal human protein mAb, since transgenic mouse's system of recognizing antigen and producing antibodies remains intact and readily recognizes the human protein as a foreign body. Moreover, since the antibodies are produced in vivo, they undergo a normal assembly and maturation process, thus ensuring that the resulting product has high target binding affinity.

However, there are several disadvantages with transgenic mouse technology at present. First, immune tolerance remains a problem. Although immune response can be enhanced by adjuvants and tailored immunization methods, it is still difficult to obtain high-affinity antibodies to some human antigens. Second is the interference of murine antibodies. Thirdly, it is difficult to immunize against toxic antigens.

The Major Platforms of Fully Human Antibody Mice

CompanyProducthVHahVKbConstantCountry
MedarexHuMabMouse44Human(Cμ)US
AbgenixXenoMouse1717Human(Cμ-Cδ-Cγ2)US
LigandOmmiRat2212RatUS
KymabKyMouse4337MouseUS
RegeneronVelocImmune4723MouseUS
Harbour Antibodies BVH2L2Mouse1811MouseUS
TrianniTrianni Mouse4439MouseUS
ImmunocanImmuno Mouse5040MouseUS
a The number of human heavy chain variable region
b The number of human kappa chain variable region

FDA-Approved Human mAbs (Partial Listed)

With continuous optimization and upgrading in development and application, the global transgenic mouse platforms have generated dozens of antibody drugs approved by FDA so far.

No.AntibodyBrandnameCompanyApproval*TargetTechnology
1PanitumumabVectibixAmgen2006EGFRXenoMouse
2UstekinumabStelaraJohnson & Johnson2009IL-12HuMabMouse
3CanakinumabIlarisNovartis2009IL-1βHuMabMouse
4GolimumabSimponiJohnson & Johnson/Merck2009TNFαHuMabMouse
5DenosumabProlia, XgevaAmgen2010RANKLXenoMouse
6IpilimumabYervoyBristol-Myers Squibb2011CTLA-4HuMabMouse
7NivolumabOpdivoBristol-Myers Squibb2014PD-1HuMabMouse
8AlirocumabPraluentSanofi and Regeneron2015PCSK9VelocImmune Mouse
9DaratumumabDarzalexJohnson & Johnson (Genmab)2015CD38HuMabMouse
10EvolocumabRepathaAmgen2015PCSK9XenoMouse
11SecukinumabCosentyxNovartis2015IL-17αXenoMouse
12OlaratumabLartruvoEli Lilly2016PDGFRαHuMabMouse
13DupilumabDupixentSanofi and Regeneron2017IL-4RVelocImmune Mouse
14DurvalumabImfinziMedimmune/ AstraZeneca2017PD-L1XenoMouse
15SarilumabKevzaraSanofi and Regeneron2017IL-6RVelocImmune Mouse
16ErenumabAimovigNovartis and Amgen2018CGRPRXenoMouse
17CemiplimabLibtayoRegeneron2018PD-L1VelocImmune Mouse
*Year of the first US FDA approval

Hu-Mouse SingleB mAb Discovery Service

DetaiBio has partnered with Immunocan use ImmuMab Mouse. ImmuMab Mouse is the first human antibody animal platform created by MASIRT technology, achieving Mb-scale large fragment gene replacements. MASIRT allows intact human immunoglobulin variable region genes to be encompassed, with the largest genetic humanization ever achieved in mouse immunoglobulin variable loci (in situ).

With ImmuMab Mouse and SingleB Antibody Discovery Platform combined, DetaiBio is able to provide Hu-Mouse SingleB mAb Discovery service by directly screening antigen-specific memory B cells and plasma cells hu-mice. From immunization to obtaining monoclonal antibodies, the whole process can be completed in as short as 49 days, with high affinity and fully humanized antibodies delivered.

- Time-saving: from shots to hits, 49 days.
- Highly Diverse: hits from both PBC & MBC, retrieve maximal diversity.
- Fully humanized: Intact target affinity.
- Cost-effective: friendly sub-licensing agreements.

Reference

1.Fujiwara, S. (2018). Humanized mice: a brief overview on their diverse applications in biomedical research. Journal of cellular physiology, 233(4), 2889-2901.

2.Lu, R. M., Hwang, Y. C., Liu, I. J., Lee, C. C., Tsai, H. Z., Li, H. J., & Wu, H. C. (2020). Development of therapeutic antibodies for the treatment of diseases. Journal of biomedical science, 27(1), 1-30.

3.Yin, L., Wang, X. J., Chen, D. X., Liu, X. N., & Wang, X. J. (2020). Humanized mouse model: a review on preclinical applications for cancer immunotherapy. American Journal of Cancer Research, 10(12), 4568.