Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex.
Human HLA B27-restricted cytotoxic T lymphocytes (CTL) specific for the influenza A epitope NP383-391 use similar TCR alpha and beta chains, with two closely related J alpha segments used by six of nine CTL clones from three unrelated donors (Bowness et al., Eur J. Immunol. 1993. 23: 1417-1421). The...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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1998
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| _version_ | 1797097546188849152 |
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| author | Bowness, P Allen, R Barclay, D Jones, E Mcmichael, A |
| author_facet | Bowness, P Allen, R Barclay, D Jones, E Mcmichael, A |
| author_sort | Bowness, P |
| collection | OXFORD |
| description | Human HLA B27-restricted cytotoxic T lymphocytes (CTL) specific for the influenza A epitope NP383-391 use similar TCR alpha and beta chains, with two closely related J alpha segments used by six of nine CTL clones from three unrelated donors (Bowness et al., Eur J. Immunol. 1993. 23: 1417-1421). The role of TCR complementarity-determining region (CDR)3alpha residues 93 and 100-102 was examined by site-directed mutagenesis, following expression of the TCR alpha and beta extracellular domains from one clone as a TCR zeta fusion heterodimer in rat basophil leukemia (RBL) cells. For the first time we have measured direct binding of tetrameric HLA B*2705/NP383-391 complexes to transfected TCR. Independently peptide-pulsed antigen-presenting cells (APC) were used to induce TCR-mediated degranulation of RBL transfectants. Our results show a key role for the conserved TCRalpha CDR3 J alpha-encoded residue Y102 in recognition of HLA B27/NP383-391. Thus the Y102D mutation abolished both tetramer binding and degranulation in the presence of peptide-pulsed APC. Even the Y102F mutation, differing only by a single hydroxyl group from the native TCR, abolished detectable degranulation. Further mutations F93A and S100R also abolished recognition. Interestingly, the N101A mutation recognized HLA B27/NP in functional assays despite having significantly reduced tetramer binding, a finding consistent with "kinetic editing" models of T cell activation. Modeling of the GRb TCR CDR3alpha loop suggests that residue Y102 contacts the HLA B*2705 alpha1 helix. It is thus possible that selection of germ-line TCRAJ-encoded residues at position 102 may be MHC driven. |
| first_indexed | 2024-03-07T04:57:05Z |
| format | Journal article |
| id | oxford-uuid:d6f980cc-a79c-4d48-a895-a2b513e4ce19 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:57:05Z |
| publishDate | 1998 |
| record_format | dspace |
| spelling | oxford-uuid:d6f980cc-a79c-4d48-a895-a2b513e4ce192022-03-27T08:37:36ZImportance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d6f980cc-a79c-4d48-a895-a2b513e4ce19EnglishSymplectic Elements at Oxford1998Bowness, PAllen, RBarclay, DJones, EMcmichael, AHuman HLA B27-restricted cytotoxic T lymphocytes (CTL) specific for the influenza A epitope NP383-391 use similar TCR alpha and beta chains, with two closely related J alpha segments used by six of nine CTL clones from three unrelated donors (Bowness et al., Eur J. Immunol. 1993. 23: 1417-1421). The role of TCR complementarity-determining region (CDR)3alpha residues 93 and 100-102 was examined by site-directed mutagenesis, following expression of the TCR alpha and beta extracellular domains from one clone as a TCR zeta fusion heterodimer in rat basophil leukemia (RBL) cells. For the first time we have measured direct binding of tetrameric HLA B*2705/NP383-391 complexes to transfected TCR. Independently peptide-pulsed antigen-presenting cells (APC) were used to induce TCR-mediated degranulation of RBL transfectants. Our results show a key role for the conserved TCRalpha CDR3 J alpha-encoded residue Y102 in recognition of HLA B27/NP383-391. Thus the Y102D mutation abolished both tetramer binding and degranulation in the presence of peptide-pulsed APC. Even the Y102F mutation, differing only by a single hydroxyl group from the native TCR, abolished detectable degranulation. Further mutations F93A and S100R also abolished recognition. Interestingly, the N101A mutation recognized HLA B27/NP in functional assays despite having significantly reduced tetramer binding, a finding consistent with "kinetic editing" models of T cell activation. Modeling of the GRb TCR CDR3alpha loop suggests that residue Y102 contacts the HLA B*2705 alpha1 helix. It is thus possible that selection of germ-line TCRAJ-encoded residues at position 102 may be MHC driven. |
| spellingShingle | Bowness, P Allen, R Barclay, D Jones, E Mcmichael, A Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title | Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title_full | Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title_fullStr | Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title_full_unstemmed | Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title_short | Importance of a conserved TCR J alpha-encoded tyrosine for T cell recognition of an HLA B27/peptide complex. |
| title_sort | importance of a conserved tcr j alpha encoded tyrosine for t cell recognition of an hla b27 peptide complex |
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