This file contains a detailed experimental description for the Supplementary Figure legends. Briefly, Supplementary Figure 1 describes the effects of the anti-Jagged therapy in the distribution of CD31+ cells in tumors. Supplementary Figure 2 summarizes the sorting strategy by flow cytometry to identify cancer cells and myeloid cells. Supplementary Figure 3 defines the effects of the anti-Gr-1 therapy on MDSCs and MDSC-LC in tumors. Supplementary Figure 4 illustrates the effect of anti-Jagged on immunogenic antigen-presenting cells. Supplementary Figure 5 shows that anti-Jagged increases the function of antigen-specific T-cells. Supplementary Figure 6 defines the effects of the tumor-derived factors on the expression of Jagged molecules on MDSCs.
ARTICLE ABSTRACT
Myeloid-derived suppressor cells (MDSC) are a major obstacle to promising forms of cancer immunotherapy, but tools to broadly limit their immunoregulatory effects remain lacking. In this study, we assessed the therapeutic effect of the humanized anti–Jagged1/2-blocking antibody CTX014 on MDSC-mediated T-cell suppression in tumor-bearing mice. CTX014 decreased tumor growth, affected the accumulation and tolerogenic activity of MDSCs in tumors, and inhibited the expression of immunosuppressive factors arginase I and iNOS. Consequently, anti-Jagged therapy overcame tumor-induced T-cell tolerance, increased the infiltration of reactive CD8+ T cells into tumors, and enhanced the efficacy of T-cell–based immunotherapy. Depletion of MDSC-like cells restored tumor growth in mice treated with anti-Jagged, whereas coinjection of MDSC-like cells from anti–Jagged-treated mice with cancer cells delayed tumor growth. Jagged1/2 was induced in MDSCs by tumor-derived factors via NFkB-p65 signaling, and conditional deletion of NFkB-p65 blocked MDSC function. Collectively, our results offer a preclinical proof of concept for the use of anti-Jagged1/2 to reprogram MDSC-mediated T-cell suppression in tumors, with implications to broadly improve the efficacy of cancer therapy. Cancer Res; 77(20); 5628–38. ©2017 AACR.
