Mouse PD-L1 Antibodies (clones 10F.9G2 and RG7446)

Recombinant anti-PD-L1 antibodies for in vivo use

InvivoGen offers two murinized monoclonal antibodies (mAb) targeting PD-L1 (programmed cell death ligand 1), and therefore blocking the interaction with its receptor PD-1:

• Anti-PD-L1-mIgG1e3 (10F.9G2) InvivoFit™ features the variable region of the rat-derived clone 10F.9G2, targeting mouse PD-L1 [1].
   
• Anti-PD-L1-mIgG1e3 (RG7446) InvivoFit™ features the variable region of atezolizumab, recognizing human and mouse PD-L1 [2].

The original anti-mPD-L1-rIgG2b (clone 10F.9G2) is the most commonly used PD-L1-targeting mAb in mouse in vivo studies. Atezolizumab (anti-PD-L1-hIgG1, a lso known as MPDL3280A) is a fully humanized therapeutic mAb, approved by the FDA for the treatment of various types of cancer [3]. Interestingly, it binds both human and mouse PD-L1. Upon repeated injections into mice, these mAbs can lead to immunogenicity and risks of fatal hypersensitivity reaction, since they are humanized and rat-derived, respectively [4].

To overcome these issues, InvivoGen replaced the humanized (Atezo) and rat-derived (10F.9G2) constant regions with a murine constant region, making the mAbs ~65% of murine origin. Both mAbs now harbor an engineered murine IgG1 constant region (mIgG1e3). Within that region, a point mutation was introduced changing the aspartic (D) acid at position 265 to an alanine (A) (D265A). This leads to a complete loss of unwanted Fc-associated effector functions [5]. These alterations increase antibody performance and overcome immunogenic events, especially in vivo [6].

Both antibodies are produced in Chinese hamster ovary (CHO) cells and purified by affinity chromatography with protein A. Its binding is validated by flow cytometry and ELISA. InvivoGen's anti-PD-L1 mAbs are provided in an InvivoFit™ grade, a high-quality standard specifically adapted to in vivo studies.

Key features of Anti-PD-L1-mIgG1e3 InvivoFit™ antibodies

• Derived from well-referenced clones: 10F.9G2 or Atezolizumab (aka MPDL3280A)
• Feature mouse IgG1e3 isotype (constant region)
• mIgG1e3 (IgG1 with a D265A point mutation) is effectorless
• Filter-sterilized (0.2 µm), endotoxin level: 1 EU/mg
• Suitable for parenteral delivery in mice (azide-free)
• Low aggregation < 5%
• Produced in animal-free facilities and defined media

Programmed cell death ligand 1 (PD-L1; also called B7-H1 or CD274) binds to programmed cell death protein 1 (PD-1) on T cells and contributes to T cell exhaustion during chronic infections. Moreover, the engagement of PD-1 on T cells and PD-L1 on malignant cells is associated with the immune escape of tumors. Clinical trials have highlighted the anti-tumor efficacy of blockades targeting the PD-1/PD-L1 pathway [7].

References:

1. Eppihimer MJ, et al. 2002. Expression and regulation of the PD-L1 immunoinhibitory molecule on microvascular endothelial cells. Microcirculation.9(2):133-45.
2. Lesniak W.G. et al., 2016. PD-L1 Detection in Tumors Using [(64)Cu]Atezolizumab with PET. Bioconjug Chem. 27(9):2103-10.
3. Emens LA, et al., 2019. Long-term Clinical Outcomes and Biomarker Analyses of Atezolizumab Therapy for Patients With Metastatic Triple-Negative Breast Cancer: A Phase 1 Study. JAMA Oncol. 5(1):74-82.
4. Mall C. et al., 2016. Repeated PD-1/PD-L1 monoclonal antibody administration induces fatal xenogenic hypersensitivity reactions in a murine model of breast cancer. Onco Immunol. 5(2):e1075114.
5. Baudino L. et al., 2008. Crucial role of aspartic acid at position 265 in the CH2 domain for murine IgG2a and IgG2b Fc-associated effector functions. J. Immunol. 181(9):6664-9.
6. Brüggemann M. et al., 1989. The immunogenicity of chimeric antibodies. J. Exp. Med. 170:2153-2157.
7. McDermott D. & Atkins M. 2013. PD-1 as a potential target in cancer therapy. Cancer Med. 2(5): 662–673.