Trogocytosis is a gateway to characterize functional diversity in melanoma-specific CD8+ T cell clones

J Immunol. 2012 Jan 15;188(2):632-40. doi: 10.4049/jimmunol.1101429. Epub 2011 Dec 7.


Trogocytosis, the transfer of membrane patches from target to immune effector cells, is a signature of tumor-T cell interaction. In this study, we used the trogocytosis phenomenon to study functional diversity within tumor-specific T cell clones with identical TCR specificity. MART-1(26-35)-specific CD8 T cell clones, which differed in their trogocytosis capacity (low [2D11], intermediate [2G1], high [2E2]), were generated from melanoma patients. Functional evaluation of the clones showed that the percentage of trogocytosis-capable T cells closely paralleled each clone's IFN-γ and TNF-α production, lysosome degranulation, and lysis of peptide-pulsed targets and unmodified melanoma. The highly cytotoxic 2E2 clone displayed the highest TCR peptide binding affinity, whereas the low-activity 2D11 clone showed TCR binding to peptide-MHC in a CD8-dependent manner. TCR analysis revealed Vβ16 for clones 2E2 and 2G1 and Vβ14 for 2D11. When peptide-affinity differences were bypassed by nonspecific TCR stimulation, clones 2E2 and 2D11 still manifested distinctive signaling patterns. The high-activity 2E2 clone displayed prolonged phosphorylation of ribosomal protein S6, an integrator of MAPK and AKT activation, whereas the low-activity 2D11 clone generated shorter and weaker phosphorylation. Screening the two clones with identical TCR Vβ by immunoreceptor array showed higher phosphorylation of NK, T, and B cell Ag (NTB-A), a SLAM family homophilic receptor, in clone 2E2 compared with 2G1. Specific blocking of NTB-A on APCs markedly reduced cytokine production by CD8 lymphocytes, pointing to a possible contribution of NTB-A costimulation to T cell functional diversity. This finding identifies NTB-A as a potential target for improving anti-cancer immunotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / immunology*
  • Antigen-Presenting Cells / immunology*
  • Antigen-Presenting Cells / pathology
  • Cell Line, Transformed
  • Cell Line, Tumor
  • Clone Cells
  • Cytotoxicity Tests, Immunologic / methods
  • Epitopes / biosynthesis
  • Epitopes / physiology
  • Epitopes, T-Lymphocyte / immunology
  • HLA-A2 Antigen / biosynthesis
  • HLA-A2 Antigen / physiology
  • Humans
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / metabolism
  • Lymphocytes, Tumor-Infiltrating / pathology
  • Melanoma, Experimental / immunology*
  • Melanoma, Experimental / pathology*
  • Melanoma, Experimental / secondary
  • Neoplasm Proteins / biosynthesis
  • Neoplasm Proteins / physiology
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / pathology
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Cytotoxic / metabolism
  • T-Lymphocytes, Cytotoxic / pathology


  • Epitopes
  • Epitopes, T-Lymphocyte
  • HLA-A*02:01 antigen
  • HLA-A2 Antigen
  • MART-1-Melan-A(27-35) epitope
  • Neoplasm Proteins