Unknown

Dataset Information

0

The immune suppressive microenvironment affects efficacy of radio-immunotherapy in brain metastasis


ABSTRACT: The tumor microenvironment in brain metastases is characterized by high myeloid cell content associated with immune-suppressive and cancer-permissive functions. Moreover, brain metastases induce the recruitment of lymphocytes. Despite their presence, T cell-directed therapies fail to elicit effective anti-tumor immune responses. Here we seek to evaluate the applicability of radio-immunotherapy to modulate tumor immunity and overcome inhibitory effects that diminish anti-cancer activity. Radiotherapy-induced immune modulation resulted in an increase in cytotoxic T cell numbers and prevented the induction of lymphocyte-mediated immune suppression. Radio-immunotherapy led to significantly improved tumor control with prolonged median survival in experimental breast-to-brain metastasis. However, long-term efficacy was not observed. Recurrent brain metastases showed accumulation of blood-borne PD-L1+ myeloid cells after radio-immunotherapy indicating the establishment of an immune-suppressive environment to counteract re-activated T cell responses. This finding was further supported by transcriptional analyses indicating a crucial role for monocyte-derived macrophages in mediating immune-suppression and regulating T cell function. Therefore, selective targeting of immune suppressive functions of myeloid cells is expected to be critical for improved therapeutic efficacy of radio-immunotherapy in brain metastases.

SUBMITTER: Dr. Lisa Sevenich 

PROVIDER: S-SCDT-EMM-2020-13412 | biostudies-other |

REPOSITORIES: biostudies-other

Similar Datasets

| S-EPMC8103101 | biostudies-literature
2021-02-12 | GSE164049 | GEO
| PRJNA688709 | ENA
| S-EPMC8507988 | biostudies-literature
| S-EPMC5514373 | biostudies-literature
| S-EPMC10313918 | biostudies-literature
| S-EPMC7185871 | biostudies-literature
| S-EPMC8986255 | biostudies-literature
| S-EPMC9772302 | biostudies-literature
| S-EPMC9299092 | biostudies-literature