Antibodies recognizing CD24 LAP epitope on human T cells enhance CD28 and IL-2 T cell proliferation

J Leukoc Biol. 2001 Feb;69(2):215-23.


Membrane expression of the CD24 molecule on activated T lymphocytes is not elucidated fully. We previously described the intracellular and cell-surface expression of the CD24 sialic acid-dependent epitope(s) on phytohemagglutinin-activated peripheral blood mononuclear cells. However, the CD24 core protein was not detected previously on human T cells. This study reinvestigated the expression and role of CD24 in T cell subsets. We analyzed binding of anti-CD24 monoclonal antibodies (mAbs) to sialic and leucine-alanine-proline (LAP) epitopes in resting and activated, normal T lymphocytes. CD24 LAP and CD24 sialic epitopes were detected on activated CD4- and CD8-positive cells. Although expression of CD24 sialic epitopes remained stably expressed in interleukin (IL)-2-dependent cultures, T cell expression of the LAP epitope was transient. Anti-LAP antibodies strongly enhanced the response of T cells to a combination of anti-CD3/CD28 mAbs and enhanced proliferative response induced by recombinant IL-2. We found similarities in the tissue distribution and function of the human CD24 LAP molecule and the murine, heat-stable antigen, which suggests that CD24 might function as a signaling molecule on human T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / metabolism
  • Adjuvants, Immunologic / pharmacology*
  • Alanine
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Monoclonal / pharmacology*
  • Antigens, CD / immunology*
  • CD24 Antigen
  • CD28 Antigens / physiology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Membrane / immunology
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Epitopes, T-Lymphocyte / immunology*
  • Epitopes, T-Lymphocyte / metabolism
  • Humans
  • Interleukin-2 / physiology*
  • Interphase / immunology
  • Leucine
  • Leukocytes, Mononuclear / immunology
  • Lymphocyte Activation / immunology*
  • Membrane Glycoproteins*
  • Oligopeptides / immunology
  • Oligopeptides / metabolism
  • Proline
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism


  • Adjuvants, Immunologic
  • Antibodies, Monoclonal
  • Antigens, CD
  • CD24 Antigen
  • CD24 protein, human
  • CD28 Antigens
  • Epitopes, T-Lymphocyte
  • Interleukin-2
  • Membrane Glycoproteins
  • Oligopeptides
  • Proline
  • Leucine
  • Alanine