T Lymphocytes infiltrating various tumour types express the MHC class II ligand lymphocyte activation gene-3 (LAG-3): role of LAG-3/MHC class II interactions in cell-cell contacts

Eur J Cancer. 2001 Sep;37(13):1709-18. doi: 10.1016/s0959-8049(01)00184-8.


The product of the Lymphocyte Activation Gene-3 (LAG-3, CD223) is a high affinity MHC class II ligand expressed by activated CD4(+) and CD8(+) T cells, which can associate with the T cell receptor (TCR) and downregulate TCR signalling in vitro. We have also reported that a soluble mLAG-3Ig fusion protein works as a vaccine adjuvant in vivo in mice, enhancing Th1 and CD8 T cell responses. Here, we report that LAG-3 expression was found, using fluorescent activated cell sorting (FACS) analysis, on 11-48% of human tumour-infiltrating lymphocytes (TILs) isolated from eight freshly dissociated renal cell carcinomas (RCCs), and was restricted mostly to CD8(+) cells. Immunohistochemical analysis confirmed LAG-3 expression by TILs in 9/11 RCCs, as well as in tumours of different origins, such as melanomas (3/5) and lymphomas (7/7). Since not only antigen presenting cells (APCs), but also TILs themselves strongly express major histocompatibility complex (MHC) class II, we firstly investigated whether LAG-3/MHC class II T-T cell contacts might influence tumour cell recognition. However, cytotoxicity inhibition was not observed in two RCC-specific CD8(+) T cell clones in the presence of the LAG-3-specific MAb, and there was also no observed difference in the recognition of LAG-3-transfected or wild-type RCC by these cytotoxic T lymphocytes (CTLs). In contrast, MHC class II engagement by LAG-3Ig was found to enhance the capacity of immature dendritic cells to stimulate naive T cell proliferation and IL-12-dependent IFN-gamma production by T cells in vitro. These results therefore provide support for a role for TIL-expressed LAG-3 in the engagement of class II molecules on APCs, thereby contributing to APC activation and Th1/Tc1 commitment, without downregulating cytotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD*
  • CD3 Complex / metabolism
  • CD4-Positive T-Lymphocytes / immunology
  • Carcinoma, Renal Cell / immunology
  • Cell Communication / immunology
  • Dendritic Cells / immunology
  • Flow Cytometry
  • Genes, MHC Class II / immunology*
  • Humans
  • Immunohistochemistry
  • Kidney Neoplasms / immunology
  • Lymphocyte Activation / immunology
  • Lymphocyte Activation Gene 3 Protein
  • Membrane Proteins / metabolism*
  • Neoplasms / immunology*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes, Cytotoxic / immunology
  • Tumor Cells, Cultured


  • Antigens, CD
  • CD3 Complex
  • Membrane Proteins
  • Lymphocyte Activation Gene 3 Protein
  • Lag3 protein, human
  • soluble LAG-3 protein, human