摘要:

Objectives:We examined the effect and time of addition of &bgr;-chemokines on human immunodeficiency virus type 1 (HIV-1) replication, binding, and uncoating in human macrophages and measured CCR5 receptor expression during virus binding and uncoating.Methods:Macrophages were treated with &bgr;-chemokines before infection, at infection, or postinfection, and virus replication was determined by p24 antigen level. Binding and uncoating of35[S]-methionine-labeled HIV-1 was measured. CCR5 expression was determined by flow cytometry.Results:The &bgr;-chemokines potently inhibited virus replication. The strongest inhibition occurred when cultures were pretreated and maintained with &bgr;-chemokines. &bgr;-Chemokines also caused strong inhibition of viral uncoating and a considerable decrease in CCR5 expression during uncoating.Conclusions:CCR5 receptors appear to be internalized and recycled to the cell surfaces during HIV entry. The downregulation of CCR5 expression by &bgr;-chemokines during virus uncoating probably accounts for the reduction in virus uncoating (entry) and hence in virus replication.Journal of Human Virology 1999;2:123-132 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:Inheritance of a mutant allele of theSDF1gene delays the onset of human immunodeficiency virus type 1 (HIV-1) disease. Because the mutation lies in the 3′ untranslated region of the gene, it was suggested that this mutation may upregulate transcription of the gene, resulting in more abundant SDF1, which in turn inhibits T-tropic HIV-1 and delays disease onset. This implies that this segment ofSDF1gene contains a negative regulatory element. We directly tested this hypothesis in vitro.Study Design/Methods:We cloned the wild-type and the mutantSDF1gene in an HIV-2 gene transfer vector as well as in a baculovirus expression vector. We expressed the cloned genes in human and insect cells in culture and analyzed the abundance of SDF1 RNA by hybridization and protein using antiviral assays.Results:The abundance of SDF1 RNA synthesized by the mutant clone with the mutation in the 3′ untranslated region was no different from that synthesized by the wild-type clone in cultured cells. This was the case for both the HIV-2 long terminal repeat (LTR)-directed expression in human cells and baculovirus promoter-directed expression in insect cells. Both clones apparently synthesized SDF1 with equivalent biologic activity. Similar results were obtained for a mutant with the deletion of a GC-rich segment in the 5′ untranslated region.Conclusions:Mutation of the 3′ untranslated exon did not affect SDF1 RNA synthesis in vitro. It also did not appear to affect translation of SDF1 RNA. A similar mutational analysis of the 5′ noncoding exon suggested that this region also did not regulate SDF1 expression.Journal of Human Virology 1999;2:133-138 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objectives:Widespread dendritic injury may be one mechanism involved in the neurologic impairment that occurs in HIV-1 infection. The objectives of this study were to quantitate the extent of dendritic injury in a primate model of central nervous system (CNS) infection, investigate the role of nitric oxide (NO) as a mediator of neuropathologic changes, and evaluate the relation of these changes to cognitive and motor function.Study Design/Methods:Cognitive and motor function was assessed in rhesus macaque monkeys infected with simian immunodeficiency virus (SIV). In situ hybridization, immunohistochemistry, and quantitative image analysis were employed to assess the relations among productive infection, NO synthase (iNOS), and dendritic injury.Results:Productive infection of cells of the macrophage lineage in CNS is associated with inflammation, increased expression of iNOS, and dendritic injury. The tests of cognitive and motor function employed were abnormal in both animals that had evidence of productive infection and those that did not.Conclusions:Increased NO accompanying productive infection and encephalitis may be one cause of neuronal injury in lentivirus infections of the CNS. Extension of tests of cognitive and motor function to late-stage AIDS in rhesus monkeys is needed to assess the potential role of NO-induced dendritic damage in lentiviral encephalopathy/AIDS dementia complex.Journal of Human Virology 1999;2:139-145

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:A novel 2-amino acid insertion between codons 69 and 70 of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) which confers multiple drug resistance has recently been reported. Independently, we have identified similar insertion mutations in Japanese hemophiliacs and attempted to analyze their emergence in conjunction with therapy regimens and their contribution to drug resistance using recombinant technology.Methods:The plasma and peripheral blood mononuclear cells (PBMCs) of 348 HIV-1-infected hemophiliacs were screened for HIV-1 RT mutations relevant to nucleoside analogue inhibitors and isolating viruses. Contribution of each insertion to drug resistance was studied by introducing the mutations into a T-cell line-tropic NL4-3 infectious clone and testing the drug susceptibilities of the recovered virus.Results:Insertion of the 2-amino acid residue was found in 4 of the 348 cases and was strongly associated with prolonged chemotherapy with zidovudine (AZT) and didanosine (ddI). The virus isolated from 1 of the 4 cases possessed the same insertion. Characterization of these virus and the recombinant NL4-3 with the insertion strongly suggested that the insertion caused resistance not only to AZT and ddI but also to lamivudine (3TC) and zalcitabine (ddC).Conclusion:A 2-amino acid insertion between codons 69 and 70 of RT was detected in 4 of 348 (1.1%) Japanese hemophiliacs and was found to be associated with multiple drug resistance to nucleoside analogue RT inhibitors.Journal of Human Virology 1999;2:146-153 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To investigate the transactivating activity of Vpr proteins from human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and simian immunodeficiency viruses (SIVs) on various primate lentivirus long terminal repeats (LTRs), and to determine whether the Vpx proteins shared by HIV-2 and SIV are able to transactivate any HIV or SIV promoter.Study Design/Methods:Thevprandvpxgenes of the HIVs and SIVs encode virion-associated proteins, which are implicated in viral replication and pathogenesis. HIV-1 Vpr is involved in the transport of the preintegration complex (PIC) to the nucleus, transactivates the viral LTR, and induces cell cycle arrest. HIV-2 and SIV Vpx proteins share amino acid sequence similarities with Vpr and are involved in PIC translocation into the nucleus but are unable to induce cell cycle arrest. We cloned and expressed thevprandvpxgenes from several primate lentiviruses and tested their transactivating ability on HIV-1, HIV-2, SIVmac and SIVagm LTRs cloned upstream of the CAT reporter gene.Results:All Vpr tested had a transactivating effect on several viral LTRs; however, none of the Vpx proteins showed a detectable transactivating effect.Conclusions:These results indicate that the transactivating properties of Vpr proteins were conserved throughout evolution in primate lentiviruses, which suggests that they have an important role in virus replication.Journal of Human Virology 1999;2:167-174 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID