Various checkpoint molecules, and tumor-infiltrating lymphocytes in common pediatric solid tumors: Possibilities for novel immunotherapy

AbstractLong-term survival rates for pediatric patients with cancer have significantly improved, but novel approaches are desired for those with refractory/relapsed solid tumors. Recently, programed cell death-1/ programed cell death-ligand-1 blockade has emerged as an effective option for many intractable cancers. However, not all patients show objective response to such therapy. On the other hand, several other checkpoint pathways, including Herpes virus entry mediator (HVEM)/B- and T-lymphocyte attenuator ( BTLA), galectin-9 (GAL9)/T-cell immunoglobulin and mucin domain-3 (TIM3), and major histocompatibility complexclass II (MHC-II)/lymphocyte activation gene-3 ( LAG3), also regulate immune responses in the tumor microenvironmentand may be alternative targets for novel immune therapies. In this study, we examined 65 common pediatric solid tumors and characterized the expression of Herpes virus entry mediator, GAL9, and MHC-II on tumor cells and their corresponding receptors B- and T-lymphocyte attenuato...