title: Proteoliposomal formulations of an HIV-1 gp41-based miniprotein elicit a lipid-dependent immunodominant response overlapping the 2F5 binding motif.
abstract: The HIV-1 gp41 Membrane Proximal External Region (MPER) is recognized by broadly neutralizing antibodies and represents a promising vaccine target. However, MPER immunogenicity and antibody activity are influenced by membrane lipids. To evaluate lipid modulation of MPER immunogenicity, we generated a 1-Palmitoyl-2-oleoylphosphatidylcholine (POPC)-based proteoliposome collection containing combinations of phosphatidylserine (PS), GM3 ganglioside, cholesterol (CHOL), sphingomyelin (SM) and the TLR4 agonist monophosphoryl lipid A (MPLA). A recombinant gp41-derived miniprotein (gp41-MinTT) exposing the MPER and a tetanus toxoid (TT) peptide that favors MHC-II presentation, was successfully incorporated into lipid mixtures (>85%). Immunization of mice with soluble gp41-MinTT exclusively induced responses against the TT peptide, while POPC proteoliposomes generated potent anti-gp41 IgG responses using lower protein doses. The combined addition of PS and GM3 or CHOL/SM to POPC liposomes greatly increased gp41 immunogenicity, which was further enhanced by the addition of MPLA. Responses generated by all proteoliposomes targeted the N-terminal moiety of MPER overlapping the 2F5 neutralizing epitope. Our data show that lipids impact both, the epitope targeted and the magnitude of the response to membrane-dependent antigens, helping to improve MPER-based lipid carriers. Moreover, the identification of immunodominant epitopes allows for the redesign of immunogens targeting MPER neutralizing determinants.
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Molinos-Albert
authors.affiliation: Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Universidad del País Vasco (UPV/EHU), 48940, Bilbao, Spain.
authors.forename: Eneritz
authors.initials: E
authors.lastname: Bilbao
authors.affiliation: Department of Biosciences, U Science Tech (UST), Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Agulló
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Marfil
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Elisabet
authors.initials: E
authors.lastname: García
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Rodríguez de la Concepción
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Izquierdo-Useros
authors.affiliation: Unitat de Tuberculosi Experimental, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vilaplana
authors.affiliation: Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Universidad del País Vasco (UPV/EHU), 48940, Bilbao, Spain.
authors.forename: Jon A
authors.initials: JA
authors.lastname: Nieto-Garai
authors.affiliation: Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Universidad del País Vasco (UPV/EHU), 48940, Bilbao, Spain.|Ikerbasque Basque Foundation for Science, 48011 Bilbao, Spain.
authors.forename: F-Xabier
authors.initials: FX
authors.lastname: Contreras
authors.affiliation: Department of Biosciences, U Science Tech (UST), Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.|Molecular Graphics Suite, Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, Chile.
authors.forename: Martin
authors.initials: M
authors.lastname: Floor
authors.affiliation: Unitat de Tuberculosi Experimental, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Pere J
authors.initials: PJ
authors.lastname: Cardona
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.|Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.|Chair on AIDS and related diseases, Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Martinez-Picado
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.|Chair on AIDS and related diseases, Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.|Fundació Lluita contra la Sida, Hospital Germans Trias i Pujol, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Clotet
authors.affiliation: Department of Biosciences, U Science Tech (UST), Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Villà-Freixa
authors.affiliation: Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Universidad del País Vasco (UPV/EHU), 48940, Bilbao, Spain.
authors.forename: Maier
authors.initials: M
authors.lastname: Lorizate
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Carrillo
authors.affiliation: AIDS Research Institute IrsiCaixa-HIVACAT, Institut de Recerca en Ciències de la Salut Germans Trias i Pujol (IGTP), Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Barcelona, Catalonia, Spain.|Chair on AIDS and related diseases, Universitat de Vic - Universitat Central de Catalunya (UVic-UCC), 08500 Vic, Barcelona, Spain.
authors.forename: Julià
authors.initials: J
authors.lastname: Blanco
mesh_terms: D000818:Animals; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D005260:Female; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000276:immunology*; D000071497:Immunogenicity, Vaccine; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D013745:Tetanus Toxoid / Q000737:chemistry / Q000276:immunology
chemical_list: D000939:Epitopes; D015700:HIV Envelope Protein gp41; D008563:Membrane Lipids; D010455:Peptides; D013745:Tetanus Toxoid