Abstract 4280: Regulatory T cells contribute to tumor cell dissemination by extracellular matrix remodeling

Abstract

Abstract Regulatory T (Treg) cells function to enforce peripheral tolerance and are potent suppressors of tumor immunity. In breast cancer, we have shown that Treg cells promote tumor growth by favoring alternative activation of macrophages via suppression of IFN-γ. The tumor-associated extracellular matrix (ECM) is a key regulator of metastatic dissemination and is emerging as a critical regulator of tumor immunity. However, the reciprocal effects of the immune system on the ECM remain elusive. Using murine in vivo, ex vivo and bioengineering models we describe Treg cell-dependent changes in the tumor ECM that facilitate tumor cell movement and metastatic dissemination. Further, Treg cell-dependent matrisome signatures correlate with survival in human breast cancer samples. This work underscores a previously unrecognized role of Treg cells on the ECM that facilitates metastasis and is consistent with tissue Treg cell emergent function as critical regulators of tissue repair and cancer. Citation Format: Ailen Garcia-Santillan, Jessanne Y. Lichtenberg, He Shen, Mikhail G. Dozmorov, Amy L. Olex, Priscilla Y. Hwang, Paula D. Bos. Regulatory T cells contribute to tumor cell dissemination by extracellular matrix remodeling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4280.