Mouse CD20 Antibody (clone 18B12)

Recombinant murinized CD20 antibody for in vivo use

Anti-mCD20-mIgG2a InvivoFit™ is a mouse anti-mouse monoclonal antibody (mAb) featuring the variable region of the previously described anti-mCD20 18B12 clone [1]. Using recombinant technology, the original 18B12 murine IgG1 constant region has been replaced with a murine IgG2a format which mediates potent cytotoxic functions [2].

CD20 is a cell surface protein mainly expressed by resting and activated B lymphocytes, but not plasma cells [3]. CD20 is also expressed by most malignant B cells, which makes it an ideal target for antibody-based immunotherapies against lymphoid malignancies [3-6].

The anti-mCD20 18B12 mAb is commonly used for in vivo depletion of the CD20+ B cell population to study the role of B cells in various immune responses, including auto-immune or tumoral contexts [1, 7].
Anti-mCD20-mIgG2a is provided in an InvivoFit™ grade, a high-quality standard specifically adapted to in vivo

Key features of Anti-mCD20-mIgG2a InvivoFit™:

• Derives from the 18B12 clone, mouse IgG1, κ
• Features the mIgG2a isotype (constant region)
• Filter-sterilized (0.2 µm), endotoxin level < 1 EU/mg
• Suitable for parental delivery in mice (azide-free)
• Low aggregation < 5%
• Produced in animal-free facilities and defined media

Anti-mCD20-mIgG2a InvivoFit™ is produced in Chinese hamster ovary (CHO) cells and purified by affinity chromatography with protein A. The specific binding of this mAb to cell surface mCD20 and its in vivo depleting function have been confirmed (see Figures).

References:

1. Ahuja A. et al., 2007. Depletion of B cells in murine lupus: efficacy and resistance. J. Immunol. 179(5):3351-3361.
2. Nimmerjahn F. & Ravetch J.V., 2005. Divergent immunoglobulin g subclass activity through selective Fc receptor binding. Science. 310(5753):1510-2.
3. Uchida J. et al., 2004. Mouse CD20 expression and function  Int Immunol. 16(1):119-29.
4. Cvetković R.S. & Perry C.M., 2006. Rituximab. Drugs. 66:791-820.
5. Freeman C. L. & Sehn L. H., 2018. A tale of two antibodies: obinutuzumab versus rituximab. Br. J. Haematol. 182(1):29-45.
6. Soe Z. N. & Allsup D., 2017. The use of ofatumumab in the treatment of B-cell malignancies. Future Oncol. 13(29):2611-2628. 
7. Maglioco A. et al., 2017. B cells inhibit the antitumor immunity against an established murine fibrosarcoma. Oncology letters. 13(5):3225-3232.