HLA-F surface expression on B cell and monocyte cell lines is partially independent from tapasin and completely independent from TAP

J Immunol. 2003 Nov 15;171(10):5264-71. doi: 10.4049/jimmunol.171.10.5264.

Abstract

In this study we examined HLA-F expression in normal cells and cell lines, with a particular focus on identifying cells that express surface protein. While HLA-F protein was expressed in a number of diverse tissues and cell lines, including bladder, skin, and liver cell lines, no surface expression could be detected in the majority of them. However, surface expression was observed on EBV-transformed lymphoblastoid cell lines and on some monocyte cell lines. Expression on B lymphoblastoid cell lines was observed, while no surface expression on normal B cells or on any peripheral blood lymphocytes could be detected. Surface expression correlated with the presence of a limited amount of endoglycosidase H (Endo H)-resistant HLA-F. However, clearly not all surface-expressed HLA-F was fully glycosylated. We further examined the requirement of HLA-F surface expression for functional TAP and tapasin molecules and identified a clear departure from the dependence shown by other class I molecules on TAP. In contrast, of the two surface glycosylation forms expressed, an Endo H-sensitive form was tapasin independent, while an Endo H-resistant form was clearly tapasin dependent. Finally, we tested whether HLA-F could be stabilized for surface expression without peptide by using the classical cold treatment for surface stabilization of empty class I. Of several cell lines tested, only MHC deletion mutant 721.221 demonstrated a typical class I phenotype, indicating that control of surface stabilization may have a genetic basis resident in the MHC.

Publication types

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

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters / physiology*
  • Animals
  • Antibodies, Monoclonal / analysis
  • Antiporters / physiology*
  • B-Lymphocyte Subsets / enzymology
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism*
  • Cell Line, Transformed
  • Cell Line, Tumor
  • Cell Membrane / immunology
  • Cell Membrane / metabolism
  • Cell Transformation, Viral / immunology
  • Cells, Cultured
  • Glycosylation
  • HLA Antigens / biosynthesis*
  • HLA Antigens / genetics
  • HLA Antigens / immunology
  • HLA Antigens / metabolism
  • Histocompatibility Antigens Class I / biosynthesis*
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / immunology
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Immunoglobulins / physiology*
  • Membrane Transport Proteins
  • Mice
  • Mice, Transgenic
  • Monocytes / immunology*
  • Monocytes / metabolism*
  • Recombinant Proteins / analysis
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • U937 Cells

Substances

  • ATP Binding Cassette Transporter, Subfamily B, Member 2
  • ATP-Binding Cassette Transporters
  • Antibodies, Monoclonal
  • Antiporters
  • HLA Antigens
  • HLA-F antigens
  • Histocompatibility Antigens Class I
  • Immunoglobulins
  • Membrane Transport Proteins
  • Recombinant Proteins
  • TAP1 protein, human
  • Tap1 protein, mouse
  • tapasin