PD-L1 blockade immunotherapy rewires cancer-induced emergency myelopoiesis.

Introduction: Immune checkpoint blockade (ICB) immunotherapy has revolutionized cancer treatment, demonstrating exceptional clinical responses in a wide range of cancers. Despite the success, a significant proportion of patients still fail to respond, highlighting the existence of unappreciated mechanisms of immunotherapy resistance. Delineating such mechanisms is paramount to minimize immunotherapy failures and optimize the clinical benefit.

Regulatory T Cells in Autoimmunity and Cancer: A Duplicitous Lifestyle.

Regulatory T (Treg) cells, possess a strategic role in the maintenance of immune homeostasis, and their function has been closely linked to development of diverse pathologies including autoimmunity and cancer. Comprehensive studies in various disease contexts revealed an increased plasticity as a characteristic of Treg cells. Although Treg cell plasticity comes in various flavors, the major categories enclose the loss of Foxp3 expression, which is the master regulator of Treg cell lineage, giving rise to "ex-Treg" cells and the "fragile" Treg cells in which expression is retained but accompanied by the engagement of an inflammatory program and attenuation of the suppressive activity.

Measuring Suppressive Activity and Autophagy in Myeloid-Derived Suppressor Cells.

Myeloid-derived suppressor cells (MDSC) are potent suppressor cells that accumulate in tumor microenvironment and inhibit anti-tumor responses. Assessment of cell-autonomous MDSC responses allows the precise characterization of MDSCs in various disease settings and elucidates the underlying mechanisms of MDSC-mediated immune suppression. Here we describe a protocol for the isolation of tumor infiltrating or splenic MDSC, as well as their subpopulations, from melanoma-inoculated mice using Fluorescent Activated Cell Sorting (FACS).