The prophylactic efficacies of several multivalent replication-incompetent adenovirus serotype 5 (Ad5) vaccines were examined in rhesus macaques using an intrarectal high-dose simian immunodeficiency virus SIVmac239 challenge model. Cohorts of Mamu-A*01(+)/B*17(-) Indian rhesus macaques were immunized with one of several combinations of Ad5 vectors expressing Gag, Pol, Nef, and Env gp140; for c...

With HIV persisting lifelong in infected persons, therapeutic vaccination is a novel alternative concept to control virus replication. Even though CD8 and CD4 cell responses to such immunizations have been demonstrated, their effects on virus replication are still unclear. In view of this fact, we studied the impact of a therapeutic vaccination with HIV nef delivered by a recombinant modified v...

High-level expression of foreign proteins in chloroplasts of transplastomic plants provides excellent opportunities for the development of oral vaccines against a range of debilitating or fatal diseases. The HIV-1 capsid protein p24 and a fusion of p24 with the negative regulatory protein Nef (p24-Nef) accumulate to ∼4% and ∼40% of the total soluble protein of leaves of transplastomic tobacco (...

the green fluorescent protein (gfp) was originally isolated from the jellyfish aequorea victoria that fluoresces green when exposed to blue light. gfp protein is composed of 238 amino acids with the molecular mass of 26.9 kd. the gfp gene is frequently used in cellular and molecular biology as a reporter gene. to date, many bacterial, yeast , fungal, plants, fly and mammalian cells, including h...

there are two different co-expression systems including bicistronic; dual-vector or two-promoter to express two different genes simultaneously and also to study protein-protein interactions. bicistronic system has disadvantages e.g. compared with two-promoter system. in this paper, a simple method based on spliced overlap extension by polymerase chain reaction (soe-pcr) technique was demonstrat...

Human immunodeficiency virus-1 (HIV-1) infection leads to changes in cellular gene expression, which in turn tend to modulate viral gene expression and replication. Cellular heat shock proteins (HSPs) are induced upon heat shock, UV irradiation and microbial or viral infections. We have reported earlier Nef-dependent induction of HSP40 leading to increased HIV-1 gene expression; however, the me...

BACKGROUND Rhesus macaques (RMs) inoculated with live-attenuated Rev-Independent Nef¯ simian immunodeficiency virus (Rev-Ind Nef¯SIV) as adults or neonates controlled viremia to undetectable levels and showed no signs of immunodeficiency over 6-8 years of follow-up. We tested the capacity of this live-attenuated virus to protect RMs against pathogenic, heterologous SIVsmE660 challenges. METHO...

The accessory Nef protein is expressed by all primate lentiviruses--HIV-1,HIV-2 and simian immune deficiency virus (SIV). Its expression in the early stages of the viral life cycle ensures two basic attributes of HIV infection. These are T-cell activation and the establishment of a persistent state of infection. Nef has a positive effect on viral infection and replication by promoting the survi...

To avoid immune recognition by cytotoxic T lymphocytes (CTLs), human immunodeficiency virus (HIV)-1 Nef disrupts the transport of major histocompatibility complex class I molecules (MHC-I) to the cell surface in HIV-infected T cells. However, the mechanism by which Nef does this is unknown. We report that Nef disrupts MHC-I trafficking by rerouting newly synthesized MHC-I from the trans-Golgi n...