Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.16 (HIV-1 protease)
 2,107 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A stable cell line encoding the sequences of all the human immunodeficiency virus type 1 proteins, with the exception of the gp160 envelope glycoprotein, was derived from transfection of monkey COS-7 cells. This cell line, referred to as CH-1, produces active viral protease that correctly processes its natural substrates and yields capsid particles. These particles contain reverse transcriptase activity and packaged viral RNA but are noninfectious. The level of expression of viral proteins is not toxic to the cells, yet it is comparable to that observed for chronically infected lymphocytes. These constitutively synthesized viral proteins provide a consistent system for the analysis of potential inhibitors of late viral functions. The lack of gp160 increases the biosafety of this assay system, while it allows the measurement of the effects on the production and release of capsid particles. A human immunodeficiency virus type 1 protease inhibitor was used to confirm the viral polyprotein maturation pathway in this system. Particles from cells treated with this protease inhibitor contain unprocessed p55gag precursor and have the same density as the mature particles. These immature particles contain viral RNA, but reverse transcriptase activity is significantly reduced. This cell line may serve to identify compounds that are able to affect viral assembly and maturation as well as to identify the interactions between the viral and cellular proteins involved in these essential processes.
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PMID:Constitutive production of nonenveloped human immunodeficiency virus type 1 particles by a mammalian cell line and effects of a protease inhibitor on particle maturation. 784 May 83

The central role of endoconvertases and HIV-1 protease (HIV-1 PR) in the processing of HIV proproteins makes the design of specific inhibitors important in anti-HIV gene therapy. Accordingly, we tested native alpha(1) antitrypsin (alpha(1)AT) delivered by a recombinant simian virus-40-based vector, SV(AT), as an inhibitor of HIV-1 proprotein maturation. Cell lines and primary human lymphocytes were transduced with SV(AT) without selection and detectable toxicity. Expression of alpha(1)AT was confirmed by Northern blotting, immunoprecipitation and immunostaining. SV(AT)-transduced cells showed no evidence of HIV-1-related cytopathic effects when challenged with high doses of HIV-1(NL4-3). As measured by HIV-1 p24 assay, SV(AT)-transduced cells were protected from HIV-1(NL4-3) at challenge dose of 40 000 TCID(50) (MOI = 0.04). In addition, peripheral blood lymphocytes treated with SV(AT) were protected from HIV doses challenge up to 40 000 TCID(50) (MOI = 0.04). By Western blot analyses, the delivered alpha(1)AT inhibited cellular processing of gp160 to gp120 and decreased HIV-1 virion gp120. SV(AT) inhibited processing of p55(Gag) as well. Furthermore, high levels of uncleaved p55(Gag) protein were detected in HIV virus particles recovered from SV(AT)-transduced cells lines and primary lymphocytes. Thus, delivering alpha(1)AT using SV(AT) to human lymphocytes strongly inhibits replication of HIV-1, most likely by inhibiting the activities both of the cellular serine proteases involved in processing gp160 and of the aspartyl protease, HIV-1 PR, which cleaves p55(Gag). alpha(1)AT delivered by SV(AT) may represent a novel and effective strategy for gene therapy to interfere with HIV replication, by blocking a stage in the virus replicative cycle that has until now been inaccessible to gene therapeutic intervention.
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PMID:HIV-1 proprotein processing as a target for gene therapy. 1262 51