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mice is that antibodies are not generated with wild type mice, but with mice in which murine antibody-coding genes have been replaced by human ones.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

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.

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.