ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objectives:The biologic phenotype of HIV-1 primary isolates obtained from ˜50% of patients who progress to AIDS switches from non-syncytium-inducing (NSI) to syncytium-inducing (SI). We evaluated possible associations between virus coreceptor usage, sensitivity to inhibition by &bgr;-chemokines, and disease progression of patients who continue to yield NSI isolates after developing AIDS.Study Design/Methods:Sequential virus isolates were analyzed for biologic phenotype using the MT-2 cell assay, for sensitivity to &bgr;-chemokines using RANTES inhibition, and for coreceptor usage using U87.CD4 and GHOST.CD4 cells expressing different chemokine/orphan receptors or donor peripheral blood mononuclear cells (PBMC) defective in CCR5 expression. In addition, the env V3 region was sequenced and the length of the V2 region determined.Results:All NSI isolates, regardless of patient status at time of isolation, were dependent on CCR5 expression for cell entry. Furthermore, there was no indication of broadened coreceptor usage of NSI isolates obtained from persons with latestage AIDS. A majority of NSI isolates remained RANTES sensitive; however, virus variants with reduced sensitivity were observed. The V2 lengths and the V3 sequences exhibited no or minor changes at analysis of sequential NSI isolates.Conclusions:Our data suggest that NSI isolates obtained from AIDS patients remain CCR5 dependent (ie, R5) and, in many cases, also remain sensitive to RANTES inhibition. However, virus variants with decreased sensitivity to RANTES inhibition may evolve during disease progression, not only as a result of a switch from NSI to SI but also in patients who develop AIDS while continuing to maintain R5 isolates.GenBank Accession Numbers:AF199032-AF199043.Journal of Human Virology 1999;2:325-338 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objectives:To investigate the subtype classification of the circulating virus strains among human immunodeficiency virus type 1 (HIV-1)-infected children in Greece.Study Design/Methods:Since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic in Greece in 1982, 23 children have been reported to be vertically infected with HIV-1. Blood samples were available for 19 of these children, and the C2-C4envregion was successfully amplified by nested polymerase chain reaction (PCR) for 16 subjects. HIV-1 subtype was established by the heteroduplex mobility assay (HMA) in 16 subjects and confirmed by DNA sequencing and phylogenetic analysis in 8 subjects.Results:Most subjects (9; 56%) fell into subtype B. However, a substantial proportion (44%) were classified as subtypes A (3; 19%), C (1; 6%), D (1; 6%), and I (2; 12%). According to epidemiologic information, 5 of 7 children infected with non-B HIV-1 subtypes were born to Greek parents.Conclusion:These findings clearly suggest that non-B strains have been introduced into Greece, providing evidence that HIV epidemic in this country will probably change profile over time. In addition, subtype I was identified in 2 HIV-1-infected children, both of whom were born to Greek parents.Journal of Human Virology 1999;2:339-343 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Background:Potent combination antiretroviral therapy can reduce HIV plasma viral load (VL) to levels below the detection limit for as long as 2 years or more. A VL <500 HIV RNA copies/mL was until recently considered a reasonable therapeutic goal. However, lower levels seem necessary if VL rebounds and development of drug resistance are to be avoided.Patients and Methods:The clinical and virologic outcome at 1 year were prospectively examined in a group of 100 patients who began a triple combination antiretroviral therapy regimen consisting of stavudine (d4T), lamivudine (3TC), and indinavir (IDV). A modified ultrasensitive VL test with a detection limit of 40 copies/mL and a point mutation nested polymerase chain reaction (PCR) assay for detecting the codon 184 mutation conferring 3TC resistance were used for testing samples collected longitudinally from these individuals.Results:Overall, VL values <40 copies/mL were reached in 45% and 32% of patients at nadir and at 12 months, respectively. More than half (24 of 45 persons) who achieved a level <40 copies/mL at nadir remained with undetectable VL at 1 year, whereas this occurred in only one fourth (7 of 28 persons) of those having levels of 40 to 500 copies/mL (P< .05). However, rebounds in VL to >500 copies/mL at 1 year were seen at similar rates (26.6% and 25%, respectively) in persons achieving either complete (<40 copies/mL) or partial (40-500 copies/mL) VL suppression at nadir. In contrast, the codon 184 mutation emerged more frequently at 1 year in patients whose VL remained between 40 and 500 copies/mL at nadir than in those who reached a level <40 copies/mL (30.7% versus 0%;P< .05).Conclusion:Plasma VL at nadir after beginning highly active antiretroviral therapy (HAART) predicts the 1-year outcome. The achievement of levels of viremia <40 copies/mL are desirable during antiretroviral therapy if prolonged benefit is to be obtained. Because more than two thirds of persons with residual viremia do not show drug resistance, intensification strategies should be investigated for those patients with a good virologic response but without complete suppression during the first 6 months on HAART.Journal of Human Virology 1999;2:344-349 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objectives:This paper describes a unique JC virus (JCV) variant recovered from the Highlands of Papua New Guinea that contains an inframe 21-bp deletion in the agnoprotein gene. We characterize the mutation and suggest possible roles for the deletion in JCV evolution.Study Design/Methods:JCV DNA was extracted from urine and polymerase chain reaction (PCR) amplified using whole genome primers. PCR products were cloned, and multiple clones were sequenced. The JCV agnogene was PCR amplified to verify the presence of the agnogene deletion.Results:This mutation creates a 21-bp deletion near the 3′ end, which alters the predicted secondary structure of the messenger RNA and changes local codon usage at the 3′ end of the agnogene. Protein secondary structure predictions suggest the deleted portion of the agnoprotein may be a flexible surface feature.Conclusions:We describe the first stable coding region deletion in JCV that presumably signifies a single evolutionary event that led to the split from other Highlands viral groups and occurred well after the human expansions that led to the peopling of the Southwest Pacific.Journal of Human Virology 1999;2:350-358 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:Human adeno-associated virus (AAV) is ubiquitous and known to establish latency by chromosomal integration. We have constructed a wild-type plus AAV vector, ins96-0.9Neo, containing the neomycin resistance gene open reading frame (Neo ORF) of 960 bases in length at map unit 96 of the virus. Ins96-0.9Neo was constructed in an unconventional manner in that the Neo ORF lacked a dedicated heterologous promoter. In this study, this wild-type plus AAV vector was to used to test AAV's packaging capacity and ability for chromosome 19 AAVS1 integration. However, when it was discovered that ins96-0.9Neo also transduced cells to G418 resistance, we also investigated the mechanism of Neo ORF expression in this vector.Study Design/Methods:We investigated the ability of ins96-0.9Neo to produce virus at high titers and to retain the Neo sequences by Southern blot analysis. The ability of ins96-0.9Neo virus to transduce theNeogene into cells was analyzed by colony formation under G418 selection, and the ability of ins96-0.9Neo to latently infect cells, including the AAVS1 region of chromosome 19, was investigated by a series of polymerase chain reaction (PCR) amplifications. Finally, the RNA expression of theNeogene at map unit 96 was investigated by reverse transcriptase primer extension (RTPE) analyses with two different primers and by S1 nuclease protection.Results:High titers of the ins96-0.9Neo virus could be generated (109infectious units [IU]/mL without concentration), theNeogene was retained in the encapsidated viral genome, infection by this virus resulted in G418 resistance, and significant integration was taking place within the AAVS1 sequences of human chromosome 19 on transduction. Analysis of mRNA by RTPE using both primers and by the S1 nuclease protection assay mapped the 5′ end of the Neo transcripts to ˜700 bases upstream of the Neo ATG at map unit 81 (nt 3793-3813), thus identifying a new AAV promoter.Conclusions:These data demonstrate that ins96-0.9Neo will be useful for studying wild-type AAV integration and suggest that such wild-type plus recombinant AAV vectors may be useful for human gene therapy. The advantages of using such wild-type plus AAV vectors over defective AAV vectors include the ease in production of recombinant virus and the ability for site-specific integration into chromosome 19. This study also uncovered a previously unknown AAV promoter, p81. This finding suggests that the as yet uncharacterized ORF (nt 3922-4388) located just downstream of this promoter is likely an expressed gene. Furthermore, these data support our earlier findings that the AAV virion can package >900 bases more than can the wild-type.Journal of Human Virology 1999;2:359-368 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objectives:The pathogenesis of coxsackievirus B3 (CVB3)-induced myocarditis was investigated in adult Han:NMRI mice. The outbred model, in comparison with inbred models, represents better the natural variable susceptibility of the human population.Study Design/Methods:We analyzed the replicating virus titer, the antibody response in the acute and chronic phase of disease, the histology of myocardial injury, and the persistence of viral RNA.Results:NMRI mice infected with 5000 plaque-forming units (PFU) of the CVB3 variant “P”D, a lytic variant to human fibroblast lines, showed a peak of virus replication at day 14 and developed a severe acute myocarditis. The chronic myocarditis was characterized by progressive fibrosis, small foci of infiltrates, persistent viral RNA in the heart, and detectable anti-CVB3 IgG production and neutralizing antibody response up to day 98 postinfection.Conclusions:CVB3 “P”D is able to induce chronic myocarditis in NMRI mice. This model provides a method for examining and proving the mechanisms of myocardial pathogenesis and of developing therapeutic strategies.Journal of Human Virology 1999;2:369-379 © Lippincott Williams & Wilkins, Inc.

ISSN:1090-9508    

出版商:OVID    

年代:1999

数据来源: OVID