title: Vaccine-induced virus-neutralizing antibodies and cytotoxic T cells do not protect macaques from experimental infection with simian immunodeficiency virus SIVmac32H (J5).
abstract: To gain further insight into the ability of subunit vaccines to protect monkeys from experimental infection with simian immunodeficiency virus (SIV), two groups of cynomolgus macaques were immunized with either recombinant SIVmac32H-derived envelope glycoproteins (Env) incorporated into immune-stimulating complexes (iscoms) (group A) or with these SIV Env iscoms in combination with p27gag iscoms and three Nef lipopeptides (group B). Four monkeys immunized with recombinant feline immunodeficiency virus Env iscoms served as controls (group C). Animals were immunized intramuscularly at weeks 0, 4, 10, and 16. Two weeks after the last immunization, monkeys were challenged intravenously with 50 monkey 50% infectious doses of virus derived from the J5 molecular clone of SIVmac32H propagated in monkey peripheral blood mononuclear cells. High titers of SIV-neutralizing antibodies were induced in the monkeys of groups A and B. In addition, p27gag-specific antibodies were detected in the monkeys of group B. Vaccine-induced cytotoxic-T-lymphocyte precursors against Env, Gag, and Nef were detected on the day of challenge in the monkeys of group B. Env-specific cytotoxic-T-lymphocyte precursors were detected in one monkey from group A. In spite of the observed antibody and T-cell responses, none of the monkeys was protected from experimental infection. In addition, longitudinal determination of cell-associated virus loads at weeks 2, 4, 6, 9, and 12 postchallenge revealed no significant differences between vaccinated and control monkeys. These findings illustrate the need to clarify the roles of the different arms of the immune system in conferring protection against primate lentivirus infections.
authors.affiliation: Institute of Virology, Erasmus University Rotterdam, The Netherlands.
authors.forename: E G
authors.initials: EG
authors.lastname: Hulskotte
authors.forename: A M
authors.initials: AM
authors.lastname: Geretti
authors.forename: K H
authors.initials: KH
authors.lastname: Siebelink
authors.forename: G
authors.initials: G
authors.lastname: van Amerongen
authors.forename: M P
authors.initials: MP
authors.lastname: Cranage
authors.forename: E W
authors.initials: EW
authors.lastname: Rud
authors.forename: S G
authors.initials: SG
authors.lastname: Norley
authors.forename: P
authors.initials: P
authors.lastname: de Vries
authors.forename: A D
authors.initials: AD
authors.lastname: Osterhaus
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D015686:Gene Products, env / Q000276:immunology*; D015683:Gene Products, gag / Q000276:immunology*; D016882:ISCOMs / Q000276:immunology*; D007115:Immunization Schedule; D008252:Macaca fascicularis; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000302:isolation & purification / Q000502:physiology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors; D014614:Vaccines, Synthetic / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D015686:Gene Products, env; D015683:Gene Products, gag; D016882:ISCOMs; D010455:Peptides; D014614:Vaccines, Synthetic; D014765:Viral Vaccines