(Taken from Abstract) Infection of macaques with simian immunodeficiency virus (SIV) provides incisive opportunities to analyze the in vivo function of viral genes for induction of simian AIDS (SAIDS). Such studies in juvenile and adult macaques revealed that viral accessory genes, including nef, are important for pathogenesis. Accordingly, SIV clones with deletions in nef, as well as replication-competent SIV vectors expressing cytokines in place of nef, were tested as live-attenuated viral vaccines in juveniles and adults. We have found that juvenile, as well as newborn macaques, can develop SAIDS after inoculation with an SIV clone with a large deletion in nef, or with SIV-interleukin-2 vectors. Viruses recovered from several of these animals with disease produced either (i) a novel truncated form of Nef protein, designated tNef, or (ii) no detectable form of Nef protein (Sawai et al. 1999-Appendix) These findings indicate strong selection pressure to restore pathogenic potential in live attenuated primate lentivirus vaccines containing large deletions in viral accessory genes. Accordingly, the hypothesis for this project is that SIV pathogenesis can be mediated by truncated forms of Nef and/or changes in other viral genes that compensate for the loss of Nef function(s). This project proposes a genetic study of SIV Nef, both in vitro (tissue culture systems) and in vivo (experimental infection of macaques).
Specific Aim 1 characterizes Nef mutants in two newly identified domains required for interaction with the Nef-associated kinase in vitro.
Specific Aim 2 determines whether the Nef domains described in Aim 1 are important for pathogenesis by analysis of SIV nef mutants in vivo in macaques.
Specific Aim 3 explores viral phenotypes in pathogenic viruses recovered from macaques infected with SIV clones containing large deletions in the nef genes.
Specific Aim 4 searches for viral gene(s), which compensate for loss of Nef function, by testing novel recombinant viruses for pathogenic potential in macaques. The proposed in vitro and in vivo studies will define the regions of multifunctional SIV Nef that are critical for pathogenesis. Furthermore, it may be possible to identify viral gene changes that compensate for loss of one or more functions ascribed to this viral protein. Accordingly, the proposed studies will provide critical insight into molecular changes in the viral genome that are necessary for pathogenic conversion of live-attenuated viral vaccines.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI046145-04
Application #
6651955
Study Section
Special Emphasis Panel (ZRG1-AARR-2 (01))
Program Officer
Young, Janet M
Project Start
2000-09-01
Project End
2005-06-30
Budget Start
2003-07-01
Budget End
2005-06-30
Support Year
4
Fiscal Year
2003
Total Cost
$310,935
Indirect Cost
Name
University of California Davis
Department
Pathology
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
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Sodhi, Akrit; Montaner, Silvia; Patel, Vyomesh et al. (2004) Akt plays a central role in sarcomagenesis induced by Kaposi's sarcoma herpesvirus-encoded G protein-coupled receptor. Proc Natl Acad Sci U S A 101:4821-6
Gemeniano, Malou C; Sawai, Earl T; Sparger, Ellen E (2004) Feline immunodeficiency virus Orf-A localizes to the nucleus and induces cell cycle arrest. Virology 325:167-74
Montaner, Silvia; Sodhi, Akrit; Servitja, Joan-Marc et al. (2004) The small GTPase Rac1 links the Kaposi sarcoma-associated herpesvirus vGPCR to cytokine secretion and paracrine neoplasia. Blood 104:2903-11
Montaner, Silvia; Sodhi, Akrit; Molinolo, Alfredo et al. (2003) Endothelial infection with KSHV genes in vivo reveals that vGPCR initiates Kaposi's sarcomagenesis and can promote the tumorigenic potential of viral latent genes. Cancer Cell 3:23-36
Gemeniano, Malou C; Sawai, Earl T; Leutenegger, Christian M et al. (2003) Feline immunodeficiency virus ORF-Ais required for virus particle formation and virus infectivity. J Virol 77:8819-30