Mesenchymal contribution to recruitment, infiltration, and positioning of leukocytes in human melanoma tissues

J Invest Dermatol. 2013 Sep;133(9):2255-64. doi: 10.1038/jid.2013.88. Epub 2013 Feb 27.

Abstract

To understand factors that regulate leukocyte entry and positioning within human melanoma tissues, we performed a multiparametric quantitative analysis of two separated regions: the intratumoral area and the peritumoral stroma. Using two mesenchymal markers, fibroblast activation protein (FAP) and CD90, we identified three subsets of mesenchymal cells (MCs): (i) intratumoral FAP(+)CD90(low/-) MC, (ii) peritumoral FAP(+)CD90(+) MC, and (iii) FAP(-)CD90(+) perivascular MC. We characterized CD90(+) MCs, which showed a stable CCL2-secretory phenotype when long-term expanded ex vivo, and heavily surrounded peritumoral Duffy antigen receptor for chemokine(+) (DARC) postcapillary venules, supporting a role for these vessels in peritumoral inflammatory leukocyte recruitment. Conversely, the intratumoral area was variably invaded by FAP(+)CD90(low/-) MCs that colocalized with a distinct extracellular matrix (ECM) network. A positive correlation was observed between intratumoral stromal cell/ECM networks and leukocyte infiltration among tumor cells (TCs), as well as in a stroma-dependent xenograft tumor model. Adoptively transferred T lymphocytes preferentially infiltrated tumors composed of TC+MC, compared with TCs only. Altogether, our results suggest that a variety of MCs contribute to regulate different steps of leukocyte tumor infiltration, that is, CD90(+) cells surrounding peritumoral vessels secrete CCL2 to recruit CCR2(+) leukocytes at the tumor periphery, whereas intratumoral FAP(+) cells organize a stromal scaffold that contact guide further invasion among densely packed tumor cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biopsy
  • Cell Communication / immunology
  • Cell Movement / immunology
  • Chemokine CCL2 / immunology
  • Humans
  • Leukocytes / immunology
  • Leukocytes / pathology*
  • Melanoma / blood supply
  • Melanoma / immunology
  • Melanoma / secondary*
  • Mesoderm / immunology
  • Mesoderm / pathology
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Invasiveness
  • Neoplasm Transplantation
  • Receptors, CCR2 / immunology
  • Skin Neoplasms / blood supply
  • Skin Neoplasms / immunology
  • Skin Neoplasms / pathology*
  • Stromal Cells / immunology
  • Stromal Cells / pathology
  • Tumor Microenvironment / immunology*

Substances

  • CCL2 protein, human
  • CCR2 protein, human
  • Chemokine CCL2
  • Receptors, CCR2