TAPA-1, the target of an antiproliferative antibody, is associated on the cell surface with the Leu-13 antigen

J Immunol. 1990 Oct 1;145(7):2207-13.


A murine mAb, 5A6 (IgG1), has been isolated by immunization with a human B lymphoma cell line and screening for growth inhibition. The antibody immunoprecipitated a single chain protein of 26 kDa from cell lysates made with Triton X-100 but additional proteins were precipitated when cell lysates were made with the milder detergent CHAPS (3-[3-cholamidopropyl)dimethylammonio)-1-propane sulfate). We have identified one of these coprecipitated molecules as the 16-kDa Leu-13 Ag. 5A6 and anti-Leu-13 showed similar, although not identical, reactivity, growth inhibition and temperature-dependent aggregation effects among hematolymphoid cell lines. The aggregation induced by 5A6 and anti-Leu-13 was not dependent on LFA-1 (lymphocyte function-associated Ag-1). The cell-surface expression of both TAPA-1 (target of an antiproliferative antibody-1) and Leu-13 could be down-modulated by binding to their respective antibodies and they could be reciprocally comodulated. These results suggest that TAPA-1 and Leu-13 form a complex on the cell surface and play a role in growth control through a common pathway.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Antigens, CD*
  • Antigens, Differentiation / physiology*
  • Antigens, Surface / physiology*
  • Cell Aggregation
  • Cell Division
  • Endocytosis
  • Humans
  • Lymphocytes / immunology*
  • Macromolecular Substances
  • Membrane Proteins / physiology*
  • Precipitin Tests
  • Receptor Aggregation
  • Signal Transduction
  • Temperature
  • Tetraspanin 28


  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, Differentiation
  • Antigens, Surface
  • CD81 protein, human
  • Macromolecular Substances
  • Membrane Proteins
  • Tetraspanin 28
  • leu-13 antigen