title: Characterization of human cytomegalovirus peptide-specific CD8(+) T-cell repertoire diversity following in vitro restimulation by antigen-pulsed dendritic cells.
abstract: Under conditions of impaired T-cell immunity, human cytomegalovirus (HCMV) can reactivate from lifelong latency, resulting in potentially fatal disease. A crucial role for CD8(+) T cells has been demonstrated in control of viral replication, and high levels of HCMV-specific cytotoxic T-lymphocytes are seen in immunocompetent HCMV-seropositive individuals despite very low viral loads. Elucidation of the minimum portion of the anti-HCMV T-cell repertoire that is required to suppress viral replication requires further study of clonal composition. The ability of dendritic cells to take up and process exogenous viral antigen by constitutive macropinocytosis was used to study HCMV-specific T-cell memory in the absence of viral replication. The specificity and clonal composition of the CD8(+) T-cell responses were evaluated using HLA tetrameric complexes and T-cell receptor beta chain (TCRBV) spectratypic analyses. There was a skewed reactivity toward the matrix protein pp65, with up to 40-fold expansion of CD8(+) T cells directed toward a single peptide-MHC combination. Individual expansions detected on TCRBV spectratype analysis were HCMV-specific and composed of single or highly restricted numbers of clones. There was preferential TCRBV gene usage (BV6.1/6.2, BV8, and BV13 in HLA-A*0201(+) individuals) but lack of conservation of CDR3 length and junctional motifs between donors. While there was a spectrum of TCR repertoire diversity directed toward individual MHC-peptide combinations between donors, a relatively small number of clones appeared to predominate the response in each case. These data provide further insight into the range of anti-HCMV responses and will aid the design and monitoring of adoptive immunotherapy protocols.
authors.affiliation: Department of Haematology, University College London, United Kingdom.
authors.forename: Karl
authors.initials: K
authors.lastname: Peggs
authors.forename: Stephanie
authors.initials: S
authors.lastname: Verfuerth
authors.forename: Arnold
authors.initials: A
authors.lastname: Pizzey
authors.forename: Jenni
authors.initials: J
authors.lastname: Ainsworth
authors.forename: Paul
authors.initials: P
authors.lastname: Moss
authors.forename: Stephen
authors.initials: S
authors.lastname: Mackinnon
mesh_terms: D000595:Amino Acid Sequence; D000916:Antibody Diversity; D000956:Antigens, Viral / Q000276:immunology*; D001483:Base Sequence; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003001:Cloning, Molecular; D018920:Coculture Techniques; D022801:Complementarity Determining Regions / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D003587:Cytomegalovirus / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D015234:HLA-A Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015789:HLA-A2 Antigen; D006801:Humans; D007156:Immunologic Memory; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010641:Phenotype; D010750:Phosphoproteins / Q000276:immunology; D010873:Pinocytosis; D016133:Polymerase Chain Reaction; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D011994:Recombinant Proteins / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D022801:Complementarity Determining Regions; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D046911:Macromolecular Substances; D010750:Phosphoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011994:Recombinant Proteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa