Role of Bone Marrow-Derived Cells in Presenting MHC Class I-Restricted Tumor Antigens

TLDR

Tumors express tumor‑specific antigens that can be presented to CD8+ T cells via MHC class I, yet models predict the tumor cells themselves should perform this presentation. In mice, tumor antigens were not presented by tumor cells but were exclusively transferred to and presented by host bone marrow‑derived antigen‑presenting cells, suggesting HLA matching may be less critical for tumor vaccines.

Abstract

Many tumors express tumor-specific antigens capable of being presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules. Antigen presentation models predict that the tumor cell itself should present these antigens to T cells. However, when conditions for the priming of tumor-specific responses were examined in mice, no detectable presentation of MHC class I-restricted tumor antigens by the tumor itself was found. Rather, tumor antigens were exclusively presented by host bone marrow-derived cells. Thus, MHC class I-restricted antigens are efficiently transferred in vivo to bone marrow-derived antigen-presenting cells, which suggests that human leukocyte antigen matching may be less critical in the application of tumor vaccines than previously thought.