title: Expression of a single-chain HLA class I molecule in a human cell line: presentation of exogenous peptide and processed antigen to cytotoxic T lymphocytes.
abstract: We have synthesized a recombinant gene encoding a single-chain HLA-A2/beta 2-microglobulin (beta 2m) molecule by linking beta 2m through its carboxyl terminus via a short peptide spacer to HLA-A2 (A*0201). This gene has been expressed in the beta 2m-deficient colorectal tumor cell line DLD-1. Transfection of this cell with the single-chain construct was associated with conformationally correct cell surface expression of a class I molecule of appropriate molecular mass. The single-chain HLA class I molecule presented either exogenously added peptide or (after interferon-gamma treatment) endogenously processed antigen to an influenza A matrix-specific, HLA-A2-restricted cytotoxic T-lymphocyte line. The need for interferon gamma for the processing and presentation of endogenous antigen suggests that DLD-1 has an antigen-processing defect that can be up-regulated, a feature that may be found in other carcinomas. Our data indicate that single-chain HLA class I constructs can form functional class I molecules capable of presenting endogenously processed antigens. Such molecules should be of use for functional studies, as well as providing potential anticancer immunotherapeutic agents or vaccines.
authors.affiliation: Imperial Cancer Research Fund, Cancer Immunology Laboratory, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Toshitani
authors.forename: V
authors.initials: V
authors.lastname: Braud
authors.forename: M J
authors.initials: MJ
authors.lastname: Browning
authors.forename: N
authors.initials: N
authors.lastname: Murray
authors.forename: A J
authors.initials: AJ
authors.lastname: McMichael
authors.forename: W F
authors.initials: WF
authors.lastname: Bodmer
mesh_terms: D000595:Amino Acid Sequence; D000938:Antigen-Presenting Cells / Q000502:physiology*; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000737:chemistry; D015789:HLA-A2 Antigen / Q000737:chemistry*; D006801:Humans; D008211:Lymphocyte Cooperation; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology; D011993:Recombinant Fusion Proteins; D015398:Signal Transduction; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection; D001613:beta 2-Microglobulin / Q000737:chemistry*
chemical_list: D017931:DNA Primers; D015789:HLA-A2 Antigen; D009842:Oligopeptides; D011993:Recombinant Fusion Proteins; D001613:beta 2-Microglobulin