Mass Tag-Assisted Identification of Naturally Processed HLA Class II-Presented Meningococcal Peptides Recognized by CD4+ T Lymphocytes

• Published in: The Journal of immunology (1950) Vol. 174; no. 9; pp. 5636 - 5643
• Main Authors: Meiring, Hugo D, Kuipers, Betsy, van Gaans-van den Brink, Jacqueline A. M, Poelen, Martien C. M, Timmermans, Hans, Baart, Gino, Brugghe, Humphrey, van Schie, Joost, Boog, Claire J. P, de Jong, Ad P. J. M, van Els, Cecile A. C. M
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.05.2005
• Subjects: Amino Acid Sequence; Amino Acid Substitution - genetics; Antigen Presentation - immunology; Bacterial Outer Membrane Proteins - immunology; Bacterial Outer Membrane Proteins - isolation & purification; Bacterial Outer Membrane Proteins - metabolism; CD4-Positive T-Lymphocytes - immunology; CD4-Positive T-Lymphocytes - metabolism; CD4-Positive T-Lymphocytes - microbiology; Cells, Cultured; Dendritic Cells - immunology; Dendritic Cells - metabolism; Epitopes, T-Lymphocyte - genetics; Epitopes, T-Lymphocyte - immunology; Epitopes, T-Lymphocyte - metabolism; HLA-DR1 Antigen - biosynthesis; HLA-DR1 Antigen - genetics; HLA-DR1 Antigen - immunology; HLA-DR1 Antigen - metabolism; Homozygote; Humans; Immunodominant Epitopes - genetics; Immunodominant Epitopes - immunology; Immunodominant Epitopes - metabolism; Meningococcal Vaccines - genetics; Meningococcal Vaccines - immunology; Meningococcal Vaccines - metabolism; Molecular Sequence Data; Neisseria meningitidis - immunology; Neisseria meningitidis - isolation & purification; Neisseria meningitidis - metabolism; Nitrogen - metabolism; Nitrogen Isotopes - metabolism; Peptide Fragments - genetics; Peptide Fragments - immunology; Peptide Fragments - metabolism; Porins - genetics; Porins - immunology; Porins - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.174.9.5636

The meningococcal class I outer membrane protein porin A plays an important role in the development of T cell-dependent protective immunity against meningococcal serogroup B infection and is therefore a major component of candidate meningococcal vaccines. T cell epitopes from porin A are poorly characterized because of weak in vitro memory T cell responses against purified Ag and strain variation. We applied a novel strategy to identify relevant naturally processed and MHC class II-presented porin A epitopes, based on stable isotope labeling of Ag. Human immature HLA-DR1-positive dendritic cells were used for optimal uptake and MHC class II processing of (14)N- and (15)N-labeled isoforms of the neisserial porin A serosubtype P1.5-2,10 in bacterial outer membrane vesicles. HLA-DR1 bound peptides, obtained after 48 h of Ag processing, contained typical spectral doublets in mass spectrometry that could easily be assigned to four porin A regions, expressed at diverging densities ( approximately 30-4000 copies/per cell). Epitopes from two of these regions are recognized by HLA-DR1-restricted CD4(+) T cell lines and are conserved among different serosubtypes of meningococcal porin A. This mass tag-assisted approach provides a useful methodology for rapid identification of MHC class II presented bacterial CD4(+) T cell epitopes relevant for vaccine development.