Effect of alpha-1 antitrypsin Portland variant (α1-PDX) on HIV-1 replication

Abstract

The present work investigated the potential role of alpha-1 antitrypsin Portland variant (alpha 1-PDX), a bioengineered serine proteinase inhibitor (serpin), in the interference with the viral replication of HIV-1, induction of syncytia and maturation of envelope glycoprotein gp160 to gp120 and gp41. A Jurkat lymphoid cell line transfected with a plasmid containing the alpha 1-PDX cDNA (J-PDX) and expressing the protein in a stable manner was infected with HIV-1(Lai). Controls were Jurkat cells transfected with the same vector pcDNA3 without the cDNA insert (J-pcDNA3). The results showed that viral replication of HIV-1 was significantly inhibited with a delay in replication kinetics in J-PDX cells as compared with J-pcDNA3 cells. In addition, a comparison of the infectious capacity of viruses produced in the presence and absence of alpha 1-PDX revealed that this capacity differed. It was found that alpha 1-PDX exerts its effect by interfering with the formation of syncytia between J-PDX cells infected with gp160 recombinant vaccinia virus, or after infection by HIV-1 and co-culture with uninfected Molt-4 cells. In contrast, when the same experiments were performed with J-pcDNA3 cells, a large number of syncytia was obtained. Analysis of viral proteins by Western blotting and densitometry showed that the inhibition of the cytopathic effect of HIV-1 and viral replication was correlated with the capacity of alpha 1-PDX to interfere with the maturation of gp160 to gp120 and gp41.

Effects of l- and d-REKR amino acid-containing peptides on HIV and SIV envelope glycoprotein precursor maturation and HIV and SIV replication

“…In the presence of peptides dec14 or dec14cmk, there is a significant inhibition of the maturation of Env (HIV-1 BRU gp160 and SIV mac#&" gp140), as shown by the increase in the gp160\gp120 and gp140\gp32 ratios in infected cells. These results agree with work showing that the inhibition of Env maturation produced non-functional glycoproteins in terms of their capacity to induce membrane fusions [15,18]. In addition, the maturation of the Env affects the efficacy of its incorporation into the envelope during the budding of viral particles on the membranes of infected cells [40].…”

“…This mutant is called α1-anti-trypsin Portland variant protein, and it shows a remarkable potency to inhibit overexpressed gp160 processing and its fusogenic properties [1,17]. We have recently demonstrated [16,18] the ability of the α1-antitrypsin Portland variant protein to block the replication, syncytium induction and maturation of Env precursors of both HIV-1 BRU and HIV-2 ROD .…”

“…HIV-1 Tat-mediated activation of β-galactosidase activity in the infected cells was detected as described previously [18,32]. In this assay, infected cells are coloured blue after addition of the enzyme substrate.…”

“…), collected in the presence or absence of 5-35 µM of the D-peptides. The supernatants were discarded and Tat-mediated activation of β-galactosidase activity was revealed by the addition of the enzyme substrate as described previously [18]. Infected cells that were coloured blue were then counted.…”

HIV-1 proprotein processing as a target for gene therapy

“…Recently, a 1 PDX has been reported to interfere with HIV-1 replication, after stable transfection in the CD4-positive Jurkat cells. 35 Inhibition of the cytopathic effect of HIV-1 and of virus replication appeared to correlate with the capacity of the engineered serpin to interfere with the maturation of gp160 to gp120 and gp41. Recently, a 1 AT has been reported as a candidate circulating HIV-1 inhibitor in vivo.…”