A monoclonal antibody against the 66-kDa protein expressed in mouse spleen and thymus inhibits Ly-6A.2-dependent cell-cell adhesion

J Immunol. 2000 Oct 1;165(7):3763-71. doi: 10.4049/jimmunol.165.7.3763.

Abstract

The Ly-6 locus encodes several cell surface proteins of 10-12 kDa. Some members of this multigene family may function in cell signaling and/or cell adhesion processes. T lymphocytes overexpressing Ly-6A.2 (one member of the Ly-6 gene family) protein homotypically aggregate when cultured in vitro. Further analysis of this homotypic aggregation suggests that Ly-6A.2 participates in cell-cell adhesion. These observations indicated the presence of a Ly-6 ligand(s) on the surface of lymphoid cells. In this study we report generation of a hamster mAb, 9AB2, that blocks Ly-6A.2-dependent cell-cell adhesion. The 9AB2 Ab recognizes a 66-kDa glycoprotein with unique tissue expression. The 9AB2 mAb does not bind Ly-6A.2, but coimmunoprecipitates Ly-6A.2 molecule. Moreover, 9AB2 Ag-expressing thymocytes specifically bind to Chinese hamster ovary cells overexpressing Ly-6A.2 protein, and this binding is specifically blocked by 9AB2 and anti-Ly-6A.2 Abs. These results suggest that the 66-kDa protein recognized by 9AB2 mAb is the putative ligand for Ly-6A.2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Antibodies, Blocking / biosynthesis
  • Antibodies, Blocking / metabolism
  • Antibodies, Blocking / pharmacology
  • Antibodies, Monoclonal / biosynthesis
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Monoclonal / pharmacology*
  • Antigens, Ly / physiology*
  • Binding Sites, Antibody
  • CHO Cells
  • Cell Adhesion / immunology
  • Cell Aggregation / immunology
  • Cell Line
  • Cell Line, Transformed
  • Cricetinae
  • Humans
  • Immunosuppressive Agents / pharmacology*
  • Ligands
  • Membrane Proteins / antagonists & inhibitors*
  • Membrane Proteins / physiology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Transgenic
  • Molecular Weight
  • Organ Specificity / genetics
  • Organ Specificity / immunology
  • Protein Biosynthesis*
  • Proteins / immunology*
  • Proteins / isolation & purification
  • Proteins / metabolism
  • Spleen / immunology*
  • Spleen / metabolism
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Thymus Gland / cytology
  • Thymus Gland / immunology*
  • Thymus Gland / metabolism
  • Transgenes / immunology
  • Tumor Cells, Cultured

Substances

  • Antibodies, Blocking
  • Antibodies, Monoclonal
  • Antigens, Ly
  • Immunosuppressive Agents
  • Ligands
  • Ly6a protein, mouse
  • Membrane Proteins
  • Proteins