Vaccine-boosted CAR T crosstalk with host immunity to reject tumors with antigen heterogeneity

Cell. 2023 Jul 20;186(15):3148-3165.e20. doi: 10.1016/j.cell.2023.06.002. Epub 2023 Jul 5.

Abstract

Chimeric antigen receptor (CAR) T cell therapy effectively treats human cancer, but the loss of the antigen recognized by the CAR poses a major obstacle. We found that in vivo vaccine boosting of CAR T cells triggers the engagement of the endogenous immune system to circumvent antigen-negative tumor escape. Vaccine-boosted CAR T promoted dendritic cell (DC) recruitment to tumors, increased tumor antigen uptake by DCs, and elicited the priming of endogenous anti-tumor T cells. This process was accompanied by shifts in CAR T metabolism toward oxidative phosphorylation (OXPHOS) and was critically dependent on CAR-T-derived IFN-γ. Antigen spreading (AS) induced by vaccine-boosted CAR T enabled a proportion of complete responses even when the initial tumor was 50% CAR antigen negative, and heterogeneous tumor control was further enhanced by the genetic amplification of CAR T IFN-γ expression. Thus, CAR-T-cell-derived IFN-γ plays a critical role in promoting AS, and vaccine boosting provides a clinically translatable strategy to drive such responses against solid tumors.

Keywords: CAR T; IFN-γ; antigen loss; antigen spreading; antigenic heterogeneity; cancer; chimeric antigen receptor T cell; immunotherapy; solid tumor; tumor heterogeneity; vaccine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Cancer Vaccines*
  • Humans
  • Immunotherapy, Adoptive
  • Neoplasms* / therapy
  • Receptors, Antigen, T-Cell / metabolism
  • Receptors, Chimeric Antigen*
  • T-Lymphocytes

Substances

  • Receptors, Chimeric Antigen
  • Cancer Vaccines
  • Receptors, Antigen, T-Cell