PROJECT SUMMARY “Immunotherapeutic targeting of MIF-dependent chaperone activity” Metabolic reprogramming that favors mitochondrial respiration plays an important role in controlling differential gene expression patterns in myeloid lineage cells. Our recent findings have identified a novel protein chaperone-dependent pathway that indirectly controls mitochondrial homeostasis and metabolic programming that are needed to drive maximal intratumoral myeloid cell immune suppressive phenotypes. Our hypothesis predicts that small molecule inhibition of this chaperone activity, carried out by the multifunctional cytokine MIF, induces spontaneous Cu/Zn superoxide dismutase (SOD1) misfolding and aberrant mitochondrial binding leading to metabolic reprogramming and subsequent phenotypic reversion of intratumoral myeloid cell immune suppressive phenotypes into immune stimulatory phenotypes. Studies proposed in this application will: 1) Delineate the mechanisms of action of 4-IPP-based MIF chaperone inhibitors in the context of MIF/SOD1- dependent TAM/MDSC polarization; 2) Determine the relative contribution of hypoxia as a physiologic ER stressor that exacerbates myeloid wt SOD1 misfolding in the context of MIF and 4-IPP, and 3) Evaluate the therapeutic potential of lead MIF chaperone antagonists as individual and combinatorial modalities against established metastatic melanoma.