Diabetes-prone BB rats express the RT6 alloantigen on intestinal intraepithelial lymphocytes

Eur J Immunol. 1991 Sep;21(9):2011-5. doi: 10.1002/eji.1830210907.


The RT6 alloantigen of the rat is expressed on most peripheral T cells but not on thymocytes and thus represents a marker for postthymic T lymphocyte maturation in this species. Diabetes-prone (DP) BB rats exhibit a genetically determined T cell lymphopenia associated with a deficiency of RT6+ T cells. In this study we have analyzed the expression of RT6 on lymph node (LN) cells and intestinal intraepithelial lymphocytes (IEL) in two DP BB strains (BB/OK and BB/Mol) and two control strains (non-lymphopenic BB/PhiK and LEW) by flow cytometry. In the DP BB rats the number of LN T cells was substantially reduced (less than 25% TcR2+ cells) and completely lacked RT6 expression. The IEL population was also reduced in number and in marked contrast to normal rats consisted predominantly of CD4+ cells. The majority of IEL, however clearly expressed RT6. Treatment with a phosphatidylinositol (PI)-specific phospholipase C markedly reduced the RT6 density showing that PI-mediated anchoring of RT6 in the cell membrane also applies to IEL of DP BB rats. The results demonstrate that the DP BB strains possess a functional RT6 gene and are also able to generate the PI anchor. The defect in RT6 expression is thus unlikely to be the primary cause of the T cell lymphopenia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / biosynthesis
  • CD4 Antigens / biosynthesis
  • CD5 Antigens
  • Cells, Cultured
  • Epithelium / immunology
  • Flow Cytometry
  • Immunoglobulins / biosynthesis
  • Immunophenotyping
  • Intestines / immunology*
  • Isoantigens / biosynthesis*
  • Lymph Nodes / immunology
  • Lymphopenia
  • Rats
  • Rats, Inbred BB / immunology*
  • Rats, Inbred Lew
  • Receptors, Antigen, T-Cell / biosynthesis
  • T-Lymphocytes / immunology*


  • Antigens, CD
  • CD4 Antigens
  • CD5 Antigens
  • Immunoglobulins
  • Isoantigens
  • Receptors, Antigen, T-Cell