title: Heat shock fusion proteins as vehicles for antigen delivery into the major histocompatibility complex class I presentation pathway.
abstract: Mice immunized with heat shock proteins (hsps) isolated from mouse tumor cells (donor cells) produce CD8 cytotoxic T lymphocytes (CTL) that recognize donor cell peptides in association with the major histocompatibility complex (MHC) class I proteins of the responding mouse. The CTL are induced apparently because peptides noncovalently associated with the isolated hsp molecules can enter the MHC class I antigen processing pathway of professional antigen-presenting cells. Using a recombinant heat shock fusion protein with a large fragment of ovalbumin covalently linked to mycobacterial hsp70, we show here that when the soluble fusion protein was injected without adjuvant into H-2b mice, CTL were produced that recognized an ovalbumin-derived peptide, SIINFEKL, in association with Kb. The peptide is known to arise from natural processing of ovalbumin in H-2b mouse cells, and CTL from the ovalbumin-hsp70-immunized mice and a highly effective CTL clone (4G3) raised against ovalbumin-expressing EL4 tumor cells (EG7-OVA) were equally effective in terms of the concentration of SIINFEKL required for half-maximal lysis in a CTL assay. The mice were also protected against lethal challenge with ovalbumin-expressing melanoma tumor cells. Because large protein fragments or whole proteins serving as fusion partners can be cleaved into short peptides in the MHC class I processing pathway, hsp fusion proteins of the type described here are promising candidates for vaccines aimed at eliciting CD8 CTL in populations of MHC-disparate individuals.
authors.affiliation: Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
authors.forename: K
authors.initials: K
authors.lastname: Suzue
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.forename: H N
authors.initials: HN
authors.lastname: Eisen
authors.forename: R A
authors.initials: RA
authors.lastname: Young
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D008546:Melanoma, Experimental / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D011993:Recombinant Fusion Proteins; D010047:Ovalbumin