Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease, and the lack of effective therapy results in inevitable death within a few years of onset. Failure of GluA2 RNA editing resulting from downregulation of the RNA-editing enzyme adenosine deaminase acting on RNA 2 (ADAR2) occurs in the majority of ALS cases and causes the death of motor neurons via a Ca2+-permeable AMPA receptor-mediated mechanism. Here, we explored the possibility of gene therapy for ALS by upregulating ADAR2 in mouse motor neurons using an adeno-associated virus serotype 9 (AAV9) vector that provides gene delivery to a wide array of central neurons after peripheral administration. A single intravenous injection of AAV9-ADAR2 in conditional ADAR2 knockout mice (AR2), which comprise a mechanistic mouse model of sporadic ALS, caused expression of exogenous ADAR2 in the central neurons and effectively prevented progressive motor dysfunction. Notably, AAV9-ADAR2 rescued the motor neurons of AR2 mice from death by normalizing TDP-43 expression. This AAV9-mediated ADAR2 gene delivery may therefore enable the development of a gene therapy for ALS.

Claudin-18 isoform 2 (CLDN18.2) is a member of the human claudin family of tetraspan membrane proteins that are crucial structural and functional components of tight junctions. Unlike other family members, CLDN18.2 expression is strictly limited to differentiated epithelial cells of gastric mucosa. Interestingly CLDN18.2 was ectopically expressed at a significant level in multiple tumor types including gastric, esophageal, pancreatic and lung cancers, which makes it as an attractive anti-cancer target. TST001 is a novel humanized IgG1 monoclonal antibody, which specifically binds to cells expressing human CLDN18.2 with high affinity but not to the closely related Claudin 18.1. TST001 can compete with IMAB362, the clinical stage anti-CLDN18.2 mAb, for its binding to CLDN18.2 yet engages distinct epitope for binding. By reducing fucosylation during cell culture process, TST001 has further enhanced binding affinity to FcγRIIIa, which translates into more potent ADCC activity. Indeed, TST001 showed sub-nanomolar ADCC activity against gastric cancer cells expressing medium to low CLDN18.2 in the presence of human PBMC and NK cells, which is significantly more potent than IMAB362. TST001 also showed more potent CDC and ADCP activities against CLDN18.2 expressing cells than IMAB362. In both Sprague Dawley Rat and Cynomolgus Monkey, the systemic exposure of TST001 increased proportionally in a dose-dependent manner. In gastric cancer cell line and patient derived xenograft tumor models, TST001 showed more potent anti-tumor activity as compared with IMAB362. Furthermore, the combination of TST001 with chemo agents resulted in synergistic anti-tumor effect in these tumor models. In addition, we have also generated and characterized an antibody that is suitable for IHC based detection and is selective to CLDN18.2 over CLDN18.1. Altogether, these preclinical findings warrant further clinical evaluation of TST001 in patients with CLDN18.2 positive tumors. Citation Format: Fei Teng, Yi Gu, Hui Chai, Huanhuan Guo, Hongjun Li, Xiwen Wu, Xinlai Yao, Fei Xu, Lei Shi, Zhenzhi Yan, Xiaoli Zi, Zheng Dai, Timethy Liao, Lisa Zheng, Francis Fan, Zhen Li, Jerry Yang, Xueming Qian. The preclinical characterization of TST001, a novel humanized anti-claudin18.2 mAb with enhanced binding affinity and anti-tumor activity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5183.

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Two non-normalized cDNA libraries of uteri from Danish Landrace and Chinese Erhualian pigs were constructed, and 13,756 expressed sequence tags (ESTs) were randomly sequenced. The ESTs were clustered by Phrap software, and 6,139 distinct tentative consensus sequences were produced, including 2,730 contigs and 3,409 singlets. Using Blast tools, these 6,139 candidate genes were compared to the nr and nt databases; 5,210 of them were assigned putative functions, whereas 929 potentially represent new genes. Highly expressed genes appear to be associated with basic energy metabolism, transferase activity, localization, cellular physiological process, protein binding, and nucleic acid binding. Antileukoproteinase was the most highly expressed gene, corresponding to endometrial differentiation and conceptus or fetal development.