title: Comparing pooled peptides with intact protein for accessing cross-presentation pathways for protective CD8+ and CD4+ T cells.
abstract: To better understand the mechanisms of intracellular trafficking and presentation of exogenous peptides by antigen-presenting cells (APC), we compared the handling of overlapping 24-mer peptides from HIV Nef either mixed or covalently linked in tandem in one protein. Once internalized, peptides trafficked not only to endosomes but also to cytosol, and activated CD8(+) and CD4(+) T cells. In contrast, whole protein was found to traffic only to the endosomal compartments, and primarily activated CD4(+) T cells. Finally, with adjuvant, overlapping peptides were capable of protecting against lethal viral challenge, whereas the intact protein was less protective. These data suggest that overlapping long peptides are cross-presented through more varied intracellular routes and are more efficient in priming protective immunity than the whole protein.
authors.affiliation: MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, United Kingdom.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhang
authors.forename: Hai
authors.initials: H
authors.lastname: Hong
authors.forename: Demin
authors.initials: D
authors.lastname: Li
authors.forename: Shiwu
authors.initials: S
authors.lastname: Ma
authors.forename: Ying
authors.initials: Y
authors.lastname: Di
authors.forename: Adam
authors.initials: A
authors.lastname: Stoten
authors.forename: Neil
authors.initials: N
authors.lastname: Haig
authors.forename: Katalin
authors.initials: K
authors.lastname: Di Gleria
authors.forename: Zhanru
authors.initials: Z
authors.lastname: Yu
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Xu
authors.forename: Andrew
authors.initials: A
authors.lastname: McMichael
authors.forename: Shisong
authors.initials: S
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D045142:Cross-Priming / Q000276:immunology*; D003713:Dendritic Cells / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D010641:Phenotype; D021381:Protein Transport; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D010455:Peptides; D011994:Recombinant Proteins