High attenuation and immunogenicity of a simian immunodeficiency virus expressing a proteolysis-resistant inhibitor of NF-kappaB.
NF-kappaB/IkappaB proteins play a major role in the transcriptional regulation of human immunodeficiency virus, type-1 (HIV-1). In the case of simian immunodeficiency virus (SIV) the cellular factors required for the viral transcriptional activation and replication in vivo remain undefined. Here, we demonstrate that the p50/p65 NF-kappaB transcription factors enhanced the Tat-mediated transcriptional activation of SIVmac239. In addition, IkappaB-alpha S32/36A, a proteolysis-resistant inhibitor of NF-kappaB, strongly inhibited the Tat-mediated transactivation of SIVmac239. Based on this evidence, we have generated a self-regulatory virus by endowing the genome of SIV-mac239 with IkappaB-alpha S32/36A; the resulting virus, SIVIkappaB-alpha S32/36A, was nef-deleted and expressed the NF-kappaB inhibitor. We show that SIVIkappaB-alpha S32/36A was highly and stably attenuated both in cell cultures and in vivo in rhesus macaque as compared with a nef-deleted control virus. Moreover, the high attenuation was associated with a robust immune response as measured by SIV-specific antibody production, tetramer, and intracellular IFN-gamma staining of SIV gag-specific T cells. These results underscore the crucial role of NF-kappaB/IkappaB proteins in the regulation of SIV replication both in cell cultures and in monkeys. Thus, inhibitors of NF-kappaB could efficiently counteract the SIV/HIV replication in vivo and may assist in developing novel approaches for AIDS vaccine and therapy.
Department of Clinical and Experimental Medicine, Medical School, University of Catanzaro, 88100 Catanzaro, Italy. quinto@dbbm.unina.it
Ileana
I
Quinto
Antimina
A
Puca
Jack
J
Greenhouse
Peter
P
Silvera
Jake
J
Yalley-Ogunro
Mark G
MG
Lewis
Camillo
C
Palmieri
Francesca
F
Trimboli
Russ
R
Byrum
Joseph
J
Adelsberger
David
D
Venzon
Xueni
X
Chen
Giuseppe
G
Scala
D016915:AIDS Vaccines; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D008253:Macaca mulatta; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000502:physiology; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000472:pathogenicity*; D020079:Terminal Repeat Sequences; D014613:Vaccines, Attenuated; D014779:Virus Replication
D016915:AIDS Vaccines; D000914:Antibodies, Viral; D016328:NF-kappa B; D014613:Vaccines, Attenuated