9LME

Checkpoint regulator protein in complex with a nanobody

Summary for 9LME

• Entry DOI: 10.2210/pdb9lme/pdb
• Descriptor: CD276 antigen, MAGNESIUM ION, CALCIUM ION, ... (13 entities in total)
• Functional Keywords: nanobody, complex, checkpoint regulator, immune system
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 4
• Total formula weight: 86075.49

Authors

Chen, W.M.,Sahili, A.,Yew, W.N.,Lescar, J. (deposition date: 2025-01-18, release date: 2026-01-21, Last modification date: 2026-08-05)

Primary citation

Chen, W.M.,Kishore, S.,Ramanujam, V.S.,Yew, W.N.,Fradale, L.,Bouyx, C.,Koh, A.,Maricar, S.,Perez, J.,El Sahili, A.,Czarny, B.,Roussel, A.,Lescar, J.
B7-H3/CD276-specific nanobody T3CL11 enables tumor imaging in murine osteosarcoma and colorectal cancer models.
Cell Rep, 45:117758-117758, 2026

PubMed Abstract: Members of the B7 receptor family regulate immune responses and tumor progression. B7-H3 (CD276) is highly expressed in many solid tumors, where it suppresses immune surveillance and is associated with poor clinical prognosis, making it an attractive diagnostic and therapeutic target. Here, we generated T3CL11, a nanobody specific for the human B7-H3 ectodomain, and report a crystal structure at 2.4-Å resolution of its complex with a single IgV-IgC module of B7-H3. T3CL11 binds the membrane-distal IgV domain on the face opposite the two N-glycosylation sites, with recognition mediated primarily by CDR2 and CDR3. In murine osteosarcoma and colorectal cancer models, T3CL11 enabled tumor imaging and co-localized with the clinically evaluated anti-B7-H3 antibody DS-7300a, confirming specific tumor-surface binding in vivo. These findings establish T3CL11 as a promising candidate for the development of B7-H3-targeted diagnostic imaging and future theranostic applications.

PubMed: 42525538
DOI: 10.1016/j.celrep.2026.117758

Experimental method

X-RAY DIFFRACTION (2.404 Å)