MMP-9 inhibition promotes anti-tumor immunity through disruption of biochemical and physical barriers to T-cell trafficking to tumors

Abstract

Matrix metalloproteinase-9 (MMP-9), whose expression is frequently dysregulated in cancer, promotes tumor growth, invasion, and metastasis by multiple mechanisms, including extracellular matrix remodeling and growth-factor and cytokine activation. We developed a monoclonal antibody against murine MMP-9, which we found decreased growth of established primary tumors in an orthotopic model of HER2-driven breast cancer (HC11-NeuT) in immunocompetent mice. RNA sequencing (RNAseq) profiling of NeuT tumors and additional mouse model tumors revealed that anti-MMP-9 treatment resulted in upregulation of immune signature pathways associated with cytotoxic T-cell response. As there is a need to boost the low response rates observed with anti-PDL1 antibody treatment in the clinical setting, we assessed the potential of anti-MMP-9 to improve T-cell response to immune checkpoint inhibitor anti-PDL1 in NeuT tumors. Anti-MMP-9 and anti-PDL1 cotreatment reduced T-cell receptor (TCR) clonality and increased TCR diversity, as detected by TCR sequencing of NeuT tumors. Flow cytometry analyses of tumors showed that the combination treatment increased the frequency of CD3+ T cells, including memory/effector CD4 and CD8 T cells, but not regulatory T cells, among tumor-infiltrating leukocytes. Moreover, in vitro enzymatic assays corroborated that MMP-9 cleaves key T-cell chemoattractant CXC receptor 3 ligands (CXC ligand [CXCL] 9, CXCL10, and CXCL11) and renders them inactive in T-cell migration assays. Consistent with our in vitro experiments, analysis of NeuT tumor protein lysates showed that anti-MMP-9 treatment increases expression of CXCL10 and other T cell–stimulating factors, such as interleukin (IL)-12p70 and IL-18. We show that inhibition of MMP-9, a key component of the tumor-promoting and immune-suppressive myeloid inflammatory milieu, increases T-helper cell 1 type cytokines, trafficking of effector/memory T cells into tumors, and intratumoral T-cell diversity.

Role of the Neutrophil in the Pathogenesis of Advanced Cancer and Impaired Responsiveness to Therapy

“…Although unproven in the clinical setting, other potential MDSC-targeted adjunctive strategies include: (i) mAb targeting of MMP-9 [143], which promotes activation of TGFβ1 in the TME [98]; (ii) small molecule inhibitors of MDSC-derived arginase-1 (CB-1158) [144] and IDO (indoximod) [145], which may preserve arginine and tryptophan, respectively, in the TME; (iii) attenuation of activation of adenylyl cyclase in TILs using antagonists of adenosine A2 A receptors (CPI-444 and AZD4635) and ATP ectonucleotidases [146], as well as inhibitors of cyclooxygenases; and iv) pharmacological targeting of PAD4, a key enzyme in NET formation. Additionally, recent data suggest that TRAIL-R2 (an agonistic antibody of the TNF-Related Apoptosis-Inducing Ligand Receptor 2) induces death of PMN-MDSCs in vitro and also potentiates the effect of the CTLA-4-targeted immune checkpoint blockade in animal models of experimental tumorigenesis [147].…”

The Impact of Matrix Metalloproteinase-9 on the Sequential Steps of the Metastatic Process

“…However, for a metastasis to settle successfully, local antitumor immune responses must be neutralized. Noticeably, MMP-9 counters the anticancer activity of tumor-infiltrating cytotoxic T lymphocytes or natural killer cells [ 130 , 131 , 132 ].…”

MMP25 Regulates Immune Infiltration Level and Survival Outcome in Head and Neck Cancer Patients

“…This partly explained the role of MMP25 in the activation of the CD4 + T memory cell by CIBERSORT analysis. Juric et al revealed that MMP9 inhibition was able to promote T cell response by disruption of biochemical and physical barriers (26). The MMP23 expression of primary melanoma also demonstrated a trend toward an increased proportion of immunosuppressive Foxp3+ regulatory T cells.…”