CXCR3/CXCR3 ligand biological axis impairs RENCA tumor growth by a mechanism of immunoangiostasis

J Immunol. 2006 Feb 1;176(3):1456-64. doi: 10.4049/jimmunol.176.3.1456.

Abstract

Metastatic renal cell carcinoma (RCC) responds poorly to chemo- or radiation therapy but appears to respond to systemic immunotherapy (i.e., IL-2 and/or IFN-alpha), albeit with only 5-10% durable response. The CXCR3/CXCR3 ligand biological axis plays an important role in mediating type 1 cytokine-dependent cell-mediated immunity, which could be beneficial for attenuating RCC if optimized. We found that systemic IL-2 induced the expression of CXCR3 on circulating mononuclear cells but impaired the CXCR3 ligand chemotactic gradient from plasma to tumor by increasing circulating CXCR3 ligand levels in a murine model of RCC. Moreover, the antitumor effect of systemic IL-2 was CXCR3-dependent, as IL-2 failed to inhibit tumor growth and angiogenesis in CXCR3-/- mice. We hypothesized that the immunotherapeutic effect of the CXCR3/CXCR3 ligand biological axis could be optimized by first priming with systemic IL-2 to induce CXCR3 expression on circulating mononuclear cells followed by enhancing the intratumor CXCR3 ligand levels to establish optimal CXCR3-dependent chemotactic gradient. We found that combined systemic IL-2 with an intratumor CXCR3 ligand (CXCL9) lead to significantly greater reduction in tumor growth and angiogenesis, increased tumor necrosis, and increased intratumor infiltration of CXCR3+ mononuclear cells, as compared with either IL-2 or CXCL9 alone. The enhanced antitumor effect of the combined strategy was associated with a more optimized CXCR3-dependent chemotactic gradient and increased tumor-specific immune response. These data suggest that the combined strategy of systemic IL-2 with intratumor CXCR3 ligand is more efficacious than either strategy alone for reducing tumor-associated angiogenesis and augmenting tumor-associated immunity, the concept of immunoangiostasis.

MeSH terms

  • Adjuvants, Immunologic / metabolism*
  • Adjuvants, Immunologic / physiology
  • Adjuvants, Immunologic / therapeutic use
  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Carcinoma, Renal Cell / blood supply
  • Carcinoma, Renal Cell / immunology*
  • Carcinoma, Renal Cell / pathology
  • Carcinoma, Renal Cell / prevention & control
  • Cell Movement / immunology
  • Chemokine CXCL10
  • Chemokine CXCL11
  • Chemokine CXCL9
  • Chemokines, CXC / metabolism*
  • Chemokines, CXC / therapeutic use
  • Growth Inhibitors / metabolism
  • Growth Inhibitors / physiology
  • Growth Inhibitors / therapeutic use*
  • Interleukin-2 / therapeutic use
  • Kidney Neoplasms / immunology*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Kidney Neoplasms / prevention & control
  • Leukocytes, Mononuclear / immunology
  • Ligands
  • Mice
  • Mice, Inbred BALB C
  • Neovascularization, Pathologic / immunology*
  • Neovascularization, Pathologic / pathology
  • Neovascularization, Pathologic / prevention & control*
  • Receptors, CXCR3
  • Receptors, Chemokine / metabolism
  • Receptors, Chemokine / physiology*

Substances

  • Adjuvants, Immunologic
  • Chemokine CXCL10
  • Chemokine CXCL11
  • Chemokine CXCL9
  • Chemokines, CXC
  • Cxcl11 protein, mouse
  • Cxcl9 protein, mouse
  • Cxcr3 protein, mouse
  • Growth Inhibitors
  • Interleukin-2
  • Ligands
  • Receptors, CXCR3
  • Receptors, Chemokine