CD4⁺ T cells facilitate the RT-induced abscopal effect by promoting antigen cross-presentation to CD8⁺ T cells at unirradiated tumor sites.

ABSTRACT:

Background

The local effect of radiotherapy (RT) is enhanced by CD8⁺ T-cell responses elicited through dendritic cell (DC)-mediated cross-presentation of tumor antigens, facilitated by RT-induced damage-associated molecular patterns. The abscopal effect-regression of non-irradiated tumors-has been observed clinically, particularly in combination with immune checkpoint blockade, although it remains uncommon. To better understand how to enhance this effect, we investigated two RT/α-programmed death 1 (PD-1)-based triple combinations incorporating either α-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) or CD122-targeted interleukin (IL)-2 complexes (IL-2c).

Methods

We tested these regimens in B16 melanoma and C51 colon carcinoma models in mice with one irradiat

SUBMITTER: Rao X 

PROVIDER: S-EPMC12911821 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature