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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-11-17
pubmed:abstractText
The ability of a live attenuated simian immunodeficiency virus (SIV) to protect against challenge with cloned SIVmac251/BK28 was evaluated in four cynomolgus macaques. The intravenous infection of the C8 variant of the SIVmac251/32H virus, carrying an in-frame 12 bp deletion in the nef gene, did not affect the CD4+ and CD8+ cell counts, and a persistent infection associated with an extremely low virus burden in peripheral blood mononuclear cells (PBMCs) was established. After 40 weeks, these monkeys were challenged intravenously with a 50 MID50 dose of SIVmac251/BK28 virus grown on macaque cells. Four naive monkeys were infected as controls. Monkeys were monitored for 62 weeks following challenge. Attempts to rescue virus from either PBMCs or bone marrow from the C8-vaccinated monkeys were unsuccessful, but in two cases virus was re-isolated from lymph node cells. The presence of the SIV provirus with the C8 variant genotype maintaining its original nef deletion was shown by differential PCR in PBMCs, lymph nodes and bone marrow. Furthermore, in contrast to the control monkeys, the vaccinated monkeys showed normal levels for CD4+ and CD8+ cells, minimal lymphoid hyperplasia and no clinical signs of infection. Our results confirm that vaccination with live attenuated virus can confer protection. This appears to be dependent on the ability of the C8 variant to establish a persistent but attenuated infection which is necessary for inducing an immune response, as suggested by the persistence of a strong immune B cell memory and by the over-expression of interleukin (IL)-2, interferon-gamma and IL-15 mRNAs in PBMCs of C8-vaccinated monkeys but not in those of control monkeys.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-1317
pubmed:author
pubmed:issnType
Print
pubmed:volume
78 ( Pt 10)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2529-39
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Live attenuated simian immunodeficiency virus prevents super-infection by cloned SIVmac251 in cynomolgus monkeys.
pubmed:affiliation
Laboratory of Virology, Istituto Superiore di Sanità, Rome, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't