Multiplex immunohistochemistry accurately defines the immune context of metastatic melanoma

Sci Rep. 2018 Jul 24;8(1):11158. doi: 10.1038/s41598-018-28944-3.


A prospective study explored the heterogeneous nature of metastatic melanoma using Multiplex immunohistochemistry (IHC) and flow cytometry (FACS). Multiplex IHC data quantitated immune subset number present intra-tumoral (IT) vs the tumor stroma, plus distance of immune subsets from the tumor margin (TM). In addition, mIHC showed a close association between the presence of IT CD8+ T cells and PDL1 expression in melanoma, which was more prevalent on macrophages than on melanoma cells. In contrast, FACS provided more detailed information regarding the T cell subset differentiation, their activation status and expression of immune checkpoint molecules. Interestingly, mIHC detected significantly higher Treg numbers than FACS and showed preferential CD4+ T cell distribution in the tumor stroma. Based on the mIHC and FACS data, we provide a model which defines metastatic melanoma immune context into four categories using the presence or absence of PDL1+ melanoma cells and/or macrophages, and their location within the tumor or on the periphery, combined with the presence or absence of IT CD8+ T cells. This model interprets melanoma immune context as a spectrum of tumor escape from immune control, and provides a snapshot upon which interpretation of checkpoint blockade inhibitor (CBI) therapy responses can be built.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Immunological / immunology
  • Antineoplastic Agents, Immunological / therapeutic use
  • B7-H1 Antigen / metabolism
  • CD8-Positive T-Lymphocytes / immunology
  • Flow Cytometry
  • Humans
  • Immunohistochemistry / methods*
  • Ipilimumab / immunology
  • Ipilimumab / therapeutic use
  • Lymphocyte Activation
  • Lymphocytes, Tumor-Infiltrating
  • Macrophages / metabolism
  • Melanoma / drug therapy
  • Melanoma / immunology*
  • Melanoma / pathology*
  • Metastasectomy
  • Middle Aged
  • Prospective Studies
  • Statistics, Nonparametric
  • T-Lymphocytes, Regulatory / immunology
  • Tumor Escape


  • Antineoplastic Agents, Immunological
  • B7-H1 Antigen
  • CD274 protein, human
  • Ipilimumab