Abstract 3286: B-hCD94/hNKG2A mice provide a preclinical tool for evaluating therapeutic antibodies targeting human NKG2A

Abstract

Abstract The immune cell checkpoint NKG2A and its coreceptor, CD94, are expressed by many circulating NK cells and by a subset of CD8 T cells in tumors. When CD94/NKG2A recognizes the HLA-E-peptide complex, the protein tyrosine phosphatase SHP-1 is recruited to the signaling synapse, resulting in the delivery of inhibitory signals to the effector cells and inhibition of their immune activities. In preclinical mouse models, blocking antibodies against NKG2A restores the reactivity of these effector cells, resulting in better suppression of tumor growth. Thus, NKG2A targeting is currently being evaluated in the clinic to evaluate tumor cell killing. To evaluate the in vivo efficacy of anti-NKG2A in mice, we successfully generated a humanized CD94/NKG2A double knock-in mouse strain (B-hCD94/hNKG2A mice), in which the mouse CD94 and NKG2A genes are replaced by the corresponding human CD94 and NKG2A genes in situ in cis, respectively. Human CD94 and NKG2A mRNA and proteins were exclusively detectable by flow cytometry in homozygous humanized mice, confirming successful generation of the model. This model was used to demonstrate in vivo efficacy of monalizumab analog in suppressing the growth of MC38 tumor cells expressing human HLA-E (B-hHLA-E MC38). Furthermore, dual blockade of monalizumab and PD-L1 further suppressed B-hHLA-E MC38 tumor growth. Together, these data indicate that this double humanized model is an effective tool for evaluating novel anti-human NKG2A therapies, and warrants the generation of a quadruple humanized model (B-hPD-1/hPD-L1/hCD94/hNKG2A mice) to further evaluate the synergy of drugs blocking each checkpoint. Citation Format: Chengzhang Shang, Fang He, Mari Kuraguchi, Jing Zhang, Qingcong Lin. B-hCD94/hNKG2A mice provide a preclinical tool for evaluating therapeutic antibodies targeting human NKG2A [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3286.