In vivo imaging with two-photon microscopy to assess the tumor-selective binding of an anti-CD137 switch antibody.

ABSTRACT: STA551, a novel anti-CD137 switch antibody, binds to CD137 in an extracellular ATP concentration-dependent manner. Although STA551 is assumed to show higher target binding in tumor tissues than in normal tissues, quantitative detection of the target binding of the switch antibody in vivo is technically challenging. In this study, we investigated the target binding of STA551 in vivo using intravital imaging with two-photon microscopy. Tumor-bearing human CD137 knock-in mice were intravenously administered fluorescently labeled antibodies. Flow cytometry analysis of antibody-binding cells and intravital imaging using two-photon microscopy were conducted. Higher CD137 expression in tumor than in spleen tissues was detected by flow cytometry analysis, and T cells and NK cells were the major CD

SUBMITTER: Kaneko C 

PROVIDER: S-EPMC8941111 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature