Soluble and membrane-bound forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B lymphocytes

J Exp Med. 1997 Mar 17;185(6):993-1004. doi: 10.1084/jem.185.6.993.

Abstract

In this study it is shown that both membrane-bound and soluble forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B cells. Activated B cells express the membrane-bound form of SLAM (mSLAM), the soluble (s) and the cytoplasmic (c) isoforms of SLAM, and the expression levels of mSLAM on B cells are rapidly upregulated after activation in vitro. Importantly, recombinant sSLAM and L cells transfected with mSLAM efficiently enhance B cell proliferation induced by anti-mu mAbs, anti-CD40 mAbs or Staphylococcus aureus Cowan I (SAC) in the presence or absence of IL-2, IL-4, IL-10, IL-12, or IL-15. sSLAM strongly enhances proliferation of both freshly isolated B cells and B cells derived from long-term in vitro cultures, indicating that SLAM acts not only during the initial phase of B cell activation but also during the expansion of preactivated B cells. In addition, sSLAM enhances production of IgM, IgG, and IgA by B cells activated by anti-CD40 mAbs. SLAM has recently been shown to be a high affinity self-ligand, and the present data suggest that signaling through homophilic SLAM-SLAM binding during B-B and B-T cell interactions enhances the expansion and differentiation of activated B cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibody Formation
  • Antigens, CD
  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology*
  • Cell Membrane / physiology
  • Cells, Cultured
  • DNA Primers
  • Glycoproteins / biosynthesis
  • Glycoproteins / pharmacology*
  • Glycoproteins / physiology*
  • Humans
  • Hypoxanthine Phosphoribosyltransferase / biosynthesis
  • Immunoglobulins / biosynthesis
  • Immunoglobulins / pharmacology*
  • Immunoglobulins / physiology*
  • Interleukins / pharmacology
  • Kinetics
  • L Cells
  • Lymphocyte Activation*
  • Mice
  • Polymerase Chain Reaction
  • Receptors, Cell Surface
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / pharmacology
  • Signal Transduction
  • Signaling Lymphocytic Activation Molecule Family Member 1
  • Spleen / immunology
  • Transfection

Substances

  • Antigens, CD
  • DNA Primers
  • Glycoproteins
  • Immunoglobulins
  • Interleukins
  • Receptors, Cell Surface
  • Recombinant Proteins
  • Signaling Lymphocytic Activation Molecule Family Member 1
  • Hypoxanthine Phosphoribosyltransferase