title: MHC class I-restricted exogenous presentation of a synthetic 102-mer malaria vaccine polypeptide.
abstract: The circumsporozoite (CS) is the most abundant surface protein of the Plasmodium sporozoite, and is also present early in the liver stage of the infection. Following successful protective experiments in mice and monkeys, the synthetic 102-mer malaria vaccine polypeptide representing the C-terminal region of the CS of Plasmodium falciparum was tested in a clinical trial with healthy human volunteers. This vaccine induced strong CD8(+), CD4(+) T lymphocyte and antibody responses specific for the immunizing peptide. CD8(+) T lymphocyte responses elicited in HLA-A*0201 volunteers recognized two well-defined cytotoxic T lymphocyte epitopes within the CS. Here, we show that both monocyte-derived dendritic cells (Mo-DC) and Epstein-Barr virus-transformed B-lymphoblastoid cells (LCL) can present a cytotoxic T lymphocyte epitope contained within the 102-mer synthetic peptide. Paraformaldehyde and low temperature inhibited presentation, indicating that cellular processing was required. Using specific inhibitors, we show that, in both cell types, processing requires the proteasome and the MHC class I pathway, while the endosomal compartment appears to be critical only for the presentation by Mo-DC. Antigen uptake is associated with actin polymerization in both cell types. These in vitro results demonstrate the likely pathway of antigen presentation achieved via vaccination with this synthetic peptide.
authors.affiliation: Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Australia.
authors.forename: Sandro
authors.initials: S
authors.lastname: Prato
authors.forename: Tammy
authors.initials: T
authors.lastname: Maxwell
authors.forename: Alberto
authors.initials: A
authors.lastname: Pinzón-Charry
authors.forename: Christopher William
authors.initials: CW
authors.lastname: Schmidt
authors.forename: Giampietro
authors.initials: G
authors.lastname: Corradin
authors.forename: José Alejandro
authors.initials: JA
authors.lastname: López
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000821:virology; D003713:Dendritic Cells / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005434:Flow Cytometry; D004854:Herpesvirus 4, Human; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D017780:Malaria Vaccines / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology; D014614:Vaccines, Synthetic
chemical_list: D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D017780:Malaria Vaccines; D010455:Peptides; D015800:Protozoan Proteins; D014614:Vaccines, Synthetic; C041595:circumsporozoite protein, Protozoan