title: SHIV infection protects against heterologous pathogenic SHIV challenge in macaques: a gold-standard for HIV-1 vaccine development?
abstract: A current debate in the HIV-1 vaccine field concerns the ability of an immunodeficiency virus to elicit a protective response. One argument is that HIV-1 superinfections are frequent in healthy individuals, because virus evades conventional immune surveillance, a serious obstacle to vaccine design. The opposing argument is that protection from superinfection is significant, reflecting a robust immune response that might be harnessed by vaccination to prevent disease. In an experiment designed to address the debate, two macaques received an I.V. inoculation with SHIV KU-1-d (a derivative of SHIV KU-1) and were rested for >10 months. Infection elicited diverse neutralizing antibody activities in both animals. Animals were then exposed to SHIV 89.6P (I.V.), a virus carrying a heterologous envelope protein relative to the vaccine strain. Infection was monitored by viral load and CD4+ T-cell measurements. All control animals were infected and most succumbed to disease. In contrast, protection from superinfection was statistically significant in test monkeys; one animal showed no evidence of superinfection at any time point and the second showed evidence of virus at only one time point over a 6-month observation period. Neither animal showed signs of disease. Perhaps this protective state may serve as a 'gold-standard' for HIV-1 vaccine development, as a similar degree of protection against immunodeficiency virus infections in humans would be much desired.
authors.affiliation: Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Sealy
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhan
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Lockey
authors.forename: Louis
authors.initials: L
authors.lastname: Martin
authors.forename: James
authors.initials: J
authors.lastname: Blanchard
authors.forename: Vicki
authors.initials: V
authors.lastname: Traina-Dorge
authors.forename: Julia L
authors.initials: JL
authors.lastname: Hurwitz
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015658:HIV Infections / Q000276:immunology*; D008251:Macaca; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000472:pathogenicity*
chemical_list: D016915:AIDS Vaccines; D057134:Antibodies, Neutralizing