title: Preclinical development of an adjuvant-free peptide vaccine with activity against CMV pp65 in HLA transgenic mice.
abstract: Epitope vaccines have shown promise for inducing cellular immune responses in animal models of infectious disease. In cases where cellular immunity was augmented, peptide vaccines composed of covalently linked minimal cytotoxic T-lymphocyte (CTL) and T-helper (T(H)) epitopes generally showed the most efficacy. To address a clinical vaccine strategy for cytomegalovirus (CMV) in the context of HCT (hematopoietic cell transplantation), we observed that linking the synthetically derived pan-DR epitope peptide (PADRE) or one of several tetanus T(H) epitopes to the immunodominant human leukocyte antigen (HLA) A*0201-restricted CTL epitope from CMV-pp65 to create a fusion peptide caused robust cytotoxic cellular immune responses in HLA A*0201/K(b) transgenic mice. Significantly, the fusion peptides are immunogenic when administered in saline solution by either subcutaneous or intranasal routes. CpG-containing single-stranded DNA (ss-oligodeoxynucleotide [ODN]) added to the fusion peptides dramatically up-regulated immune recognition by either route. Notably, target cells that either expressed full-length pp65 protein from vaccinia viruses or were sensitized with the CTL epitope encoded in the vaccine were recognized by splenic effectors from immunized animals. Visualization of murine peptide-specific CTL by flow cytometry was accomplished using an HLA A*0201 tetramer complexed with the pp65(495-503) CTL epitope. T(H)-CTL epitope fusion peptides in combination with CpG ss-ODN represent a new strategy for parenteral or mucosal delivery of vaccines in a safe and effective manner that has applicability for control or prophylaxis of infectious disease, especially in situations such as vaccination of donors or recipients of HCT, where highly inflammatory adjuvants are not desired.
authors.affiliation: Laboratory of Vaccine Research, Division of Virology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
authors.forename: Corinna
authors.initials: C
authors.lastname: La Rosa
authors.forename: Zhongde
authors.initials: Z
authors.lastname: Wang
authors.forename: John C
authors.initials: JC
authors.lastname: Brewer
authors.forename: Simon F
authors.initials: SF
authors.lastname: Lacey
authors.forename: Maria C
authors.initials: MC
authors.lastname: Villacres
authors.forename: Rahul
authors.initials: R
authors.lastname: Sharan
authors.forename: Radhika
authors.initials: R
authors.lastname: Krishnan
authors.forename: Matthew
authors.initials: M
authors.lastname: Crooks
authors.forename: Susan
authors.initials: S
authors.lastname: Markel
authors.forename: Rebecca
authors.initials: R
authors.lastname: Maas
authors.forename: Don J
authors.initials: DJ
authors.lastname: Diamond
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology* / Q000378:metabolism; D003587:Cytomegalovirus / Q000276:immunology; D022482:Cytomegalovirus Vaccines / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D004337:Drug Carriers / Q000008:administration & dosage / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D000939:Epitopes / Q000008:administration & dosage / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology; D006801:Humans; D007114:Immunization; D017780:Malaria Vaccines / Q000138:chemical synthesis / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D010455:Peptides / Q000008:administration & dosage / Q000138:chemical synthesis / Q000276:immunology*; D010750:Phosphoproteins / Q000138:chemical synthesis / Q000276:immunology*; D013742:Tetanus / Q000276:immunology; D014763:Viral Matrix Proteins / Q000138:chemical synthesis / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D022482:Cytomegalovirus Vaccines; D004337:Drug Carriers; D000939:Epitopes; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; D015789:HLA-A2 Antigen; D017780:Malaria Vaccines; D009838:Oligodeoxyribonucleotides; C401223:PADRE 45; D010455:Peptides; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa