Aberrantly Expressed Embryonic Protein NODAL Alters Breast Cancer Cell Susceptibility to ?? T Cell Cytotoxicity.

ABSTRACT: Gamma delta (??) T cells kill transformed cells, and increased circulating ?? T cells levels correlate with improved outcome in cancer patients; however, their function within the breast tumor microenvironment (TME) remains controversial. As tumors progress, they begin to express stem-cell associated proteins, concomitant with the emergence of therapy resistant metastatic disease. For example, invasive breast cancers often secrete the embryonic morphogen, NODAL. NODAL has been shown to promote angiogenesis, therapy resistance and metastasis in breast cancers. However, to date, little is known about how this secreted protein may interact with cells in the TME. Herein we explore how NODAL in the TME may influence ?? T cell function. We have assessed the proximity of ?? T cells to NODAL in a cohort of triple negative breast tumors. In all cases in which ?? T cells could be identified in these tumors, ?? T cells were found in close proximity to NODAL-expressing tumor cells. Migration of ?? and ?? T cells was similar toward MDA-MB-231 cells in which NODAL had been knocked down (shN) and MDA-MB-231 scrambled control cells (shC). Furthermore, V?1 ?? T cells did not migrate preferentially toward conditioned medium from these cell lines. While 24-h exposure to NODAL did not impact CD69, PD-1, or T cell antigen receptor (TCR) expression on ?? T cells, long term exposure resulted in decreased V?2 TCR expression. Maturation of ?? T cells was not significantly influenced by NODAL stimulation. While neither short- nor long-term NODAL stimulation impacted the ability of ?? T cells to kill MCF-7 breast cancer cells, the absence of NODAL resulted in greater sensitivity of targets to ?? T cell cytotoxicity, while overexpression of NODAL conferred resistance. This appeared to be at least in part due to an inverse correlation between NODAL and surface MICA/B expression on breast cancer target lines. As such, it appears that NODAL may play a role in strategies employed by breast cancer cells to evade ?? T cell targeting, and this should be considered in the development of safe and effective ?? T cell immunotherapies.

SUBMITTER: Siegers GM 

PROVIDER: S-EPMC7319087 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature