Memory CD8 T lymphocytes express inhibitory MHC-specific Ly49 receptors

Eur J Immunol. 2000 Jan;30(1):236-44. doi: 10.1002/1521-4141(200001)30:1<236::AID-IMMU236>3.0.CO;2-X.


Natural killer (NK) cells survey potential targets using an array of receptors specific for major histocompatibility complex class I molecules. In mice, members of the Ly49 receptor gene family are expressed on overlapping subsets of NK cells and on CD1-restricted NK1 T cells. Here we characterize a population of memory cytotoxic (CD8(+)) T lymphocytes which also express inhibitory Ly49 family members. This cell population increases steadily with age; by 11 months, over one third of memory CD8(+) T cells express Ly49 molecules. These cells appear to express a normal TCR repertoire, and share several traits with previously activated T cells. Analysis of mutant mouse strains reveals that normal development of these cells depends upon the presence of the transporter associated with antigen presentation (TAP), classical class I molecules, and class II molecules. As a functional consequence of Ly49 expression, we demonstrate that T cell receptor-mediated activation of CD8(+) T cells is inhibited by Ly49 interactions with cognate class I molecules. We hypothesize that conventional memory CD8(+) T cells initiate Ly49 expression as a means of dampening an immune response and / or inhibiting T cell autoreactivity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Animals
  • Antigens, Ly*
  • CD8-Positive T-Lymphocytes / chemistry*
  • CD8-Positive T-Lymphocytes / immunology
  • Histocompatibility Antigens Class I / physiology*
  • Immunologic Memory*
  • Lectins, C-Type
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Receptors, Antigen, T-Cell, alpha-beta / analysis
  • Receptors, Immunologic / analysis*
  • Receptors, NK Cell Lectin-Like


  • Antigens, Ly
  • Histocompatibility Antigens Class I
  • Lectins, C-Type
  • Receptors, Antigen, T-Cell, alpha-beta
  • Receptors, Immunologic
  • Receptors, NK Cell Lectin-Like