Functionally active CD8alphabeta+ TCRgammadelta intestinal intraepithelial lymphocytes in athymic nu/nu mice

Int Immunol. 2004 Jan;16(1):111-7. doi: 10.1093/intimm/dxh008.

Abstract

Murine intestinal intraepithelial lymphocytes (IEL) encompass a high proportion of TCRgammadelta cells. A vast majority of these TCRgammadelta IEL express CD8alpha, but not CD8beta (CD8alphaalpha homodimer), and are considered to develop in intestinal epithelial layers independently of a functional thymus. Here we show that TCRgammadelta cells expressing both CD8alpha and CD8beta (CD8alphabeta heterodimer) appear in athymic nu/nu mice, although their appearance is random. The IEL comprising CD8alphabeta(+) TCRgammadelta cells expressed pronounced cytolytic and IFN-gamma-producing activities after TCRgammadelta ligation, which were markedly stronger than activities of IEL lacking CD8alphabeta(+) TCRgammadelta cells. Purified CD8alphabeta(+) TCRgammadelta cells expressed strong cytolytic activities and produced large quantities of IFN-gamma after TCR engagement. CD8alphabeta(+) TCRgammadelta cells were also identified among IEL from euthymic C57BL/6 mice, although their abundance varied among individual animals. However, cytolytic and IFN-gamma-producing activities in euthymic C57BL/6 mice were markedly lower than those in athymic nu/nu mice. Our findings suggest that CD8alphabeta(+) TCRgammadelta cells can develop in the intestine independently of a functional thymus/thymic epithelial cells and that they perform biological functions in situ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD8 Antigens / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytotoxicity, Immunologic
  • Epithelium / immunology*
  • Flow Cytometry
  • Immunoassay
  • Interferon-gamma / metabolism
  • Intestines / immunology*
  • Mice
  • Mice, Nude
  • Receptors, Antigen, T-Cell, gamma-delta / immunology*
  • T-Lymphocyte Subsets / immunology*

Substances

  • CD8 Antigens
  • CD8alphabeta antigen
  • Receptors, Antigen, T-Cell, gamma-delta
  • Interferon-gamma