Intratumoral Activation of 41BB Costimulatory Signals Enhances CD8 T Cell Expansion and Modulates Tumor-Infiltrating Myeloid Cells.

In this study, we describe that the intratumoral administration of 41BB agonistic Abs led to increases in CD8 T cell infiltration followed by tumor regression in murine models. We found that granulocytes and monocytes rapidly replaced macrophages and dendritic cells in tumors following administration of anti-41BB Abs. Overall, myeloid cells from anti-41BB-treated tumors had an improved capacity to stimulate T cells in comparison with control-treated tumors. In human coculture systems, we demonstrated that the agonism of the 41BB-41BBL axis enhanced costimulatory signals and effector functions among APC and autologous TILs. Overall, these findings suggest that the effect of 41BB agonistic Abs are supported by additional costimulatory signals from tumor-associated myeloid cells,v leading to enhanced TIL expansion and function. PMID: 33020146 [PubMed - as supplied by publisher]
Source: Journal of Immunology - Category: Allergy & Immunology Authors: Tags: J Immunol Source Type: research