[Identifying and targeting multiple myeloma-specific antigens resulting from post-translational protein modifications by CAR-T cell therapies].

CAR-T cell therapy is a twenty-first-century immunotherapy breakthrough. Another breakthrough in immunotherapy is checkpoint antibody therapy, which can treat multiple cancers with a single antibody, whereas CAR-T cell therapy requires an appropriate target for each cancer type. Other than B-cell malignancies, no good target antigen for cancers has been discovered. We have been working on the development of CAR-T cells that target differences in post-translational changes such as conformation or glycosylation, between cancer and normal cells rather than differences in protein expression levels. CAR-T cells specific for activated integrins, which are consistently overexpressed in multiple myeloma, are one of the achievements. We recently discovered an antibody with myeloma specificity despite binding to a ubiquitously expressed protein, CD98hc, and hypothesized that this specificity may be owing to altered N-glycosylation of CD98hc.