Glycan Structures in Osteosarcoma as Targets for Lectin-Based Chimeric Antigen Receptor Immunotherapy.

Osteosarcoma is a type of bone cancer that primarily affects children and young adults. The overall 5-year survival rate for localized osteosarcoma is 70-75%, but it is only 20-30% for patients with relapsed or metastatic tumors. To investigate potential glycan-targeting structures for immunotherapy, we stained primary osteosarcomas with recombinant C-type lectin CD301 (MGL, CLEC10A) and observed moderate to strong staining on 26% of the tumors. NK92 cells expressing a CD301-CAR recognized and eliminated osteosarcoma cells in vitro. Cytotoxic activity assays correlated with degranulation and cytokine release assays. Combination with an inhibitory antibody against the immune checkpoint TIGIT (T-cell immunoreceptor with lg and ITIM domains) showed promising additional effects. Overall, this study showed, for the first time, the expression of CD301 ligands in osteosarcoma tissue and demonstrated their use as potential target structures for lectin-based immunotherapy.