V3 sequence analysis and biological characterization of HTV‐1 isolates from asymptomatic and early symptomatic Tanzanian individuals

Holm‐Hansen, Carol; Stern, Beate; Rustad, Siren; Shao, John F.; Åsjö, Birgitta

doi:10.1034/j.1600-0463.2000.d01-104.x

Cited by 8 publications

(3 citation statements)

References 40 publications

(31 reference statements)

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“…In 2005, serotypes C (43%), A (40%), D (15%), B (1%) and E (1%) were circulating in northern Tanzania. The distribution of serotypes in 2005 is in accordance with reports of HIV-1 genetic subtypes from other parts of the country (13,14,(16)(17)(18)24). Thus, since 2000/01 we have witnessed the predominance of HIV-1 serotype C, the decline of serotype D, and a stable prevalence of serotype A (Table 4).…”

Section: Discussionsupporting

confidence: 85%

“…However, V3 serotyping using an antigen limiting dilution has been reported to increase the antibody avidity and specificity of PEIA (8,11). In Tanzania, HIV-1 subtypes A, C, D, CRF10 and URF have been described (12)(13)(14)(15)(16)(17)(18)(19)(20). However, the changing pattern of circulating HIV-1 subtypes over time and distribution of subtypes throughout the different regions of Tanzania has not been adequately investigated.…”

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confidence: 99%

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Evolution of human immunodeficiency virus type 1 serotypes in northern Tanzania: a retrospective study

Nyombi

Nkya

Barongo

et al. 2008

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The HIV-1 epidemic in Tanzania is characterized by the circulation of heterogeneous virus subtypes. A retrospective study was conducted to determine the changing pattern of circulating HIV-1 subtypes in northern Tanzania. A peptide-binding enzyme immunoassay (PEIA) was employed to analyse 305 HIV-1 positive serum and plasma samples collected between 1985 and 2005. Samples were serotyped using synthetic peptides representing HIV-1 genotypes A-E derived from consensus gp120 V3 sequences. Plasma samples collected in 2005 were V3 genotyped for comparison with PEIA results. In 1985, serotypes A and D were co-circulating while serotype C was first detected in 1990. In 2001 and 2005, serotype C was the most prevalent, serotype A was stable, and serotype D was declining. PEIA is relatively rapid and simple to perform compared to molecular approaches, and is a valuable epidemiological tool in regions with limited resources. HIV-1 classification into serotypes based on antigenic V3 diversity may be a useful screening tool for the identification of HIV-1 variants with regard to diagnosis, treatment, disease progression and candidate vaccine development.

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Section: Discussionsupporting

confidence: 85%

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confidence: 99%

Evolution of human immunodeficiency virus type 1 serotypes in northern Tanzania: a retrospective study

Nyombi

Nkya

Barongo

et al. 2008

APMIS

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“…HIV-1 isolates representing subtypes A, C, and D from Tanzania have also been characterized in our laboratory. 15 In contrast to the HIV-1 subtype F viruses from Romania, V3 loop sequences derived from Tanzanian subtype A and D X4 viruses presented positively charged amino acids at positions 306, 320, and/ or 324 (Table 3). No HIV-1 subtype C viruses that use the CXCR4 coreceptor were identified in our laboratory.…”

Section: Holm-hansen Et Al 868mentioning

confidence: 98%

Short Communication: Determinants for the Syncytium-Inducing Phenotype of HIV-1 Subtype F Isolates Are Located in the V3 Region

Goudsmit

Jong

Holm‐Hansen

et al. 2000

AIDS Research and Human Retroviruses

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The HIV-1 syncytium-inducing phenotype is determined by virus replication and the presence of cytopathic effects in MT-2 cells. There is a strong correlation between the syncytium-inducing/MT-2-tropic phenotype and positively charged amino acids at positions 306 and 320 in the V3 loop for HIV-1 subtypes A, B, D, and E. In contrast, a lack of correlation between signature amino acids and syncytium formation in MT-2 cells for subtype F viruses from Romania has been reported. Virus phenotype and V3 loop amino acid sequences from Romanian HIV-1 subtype F isolates were further investigated in the present study. While the determinants of MT-2 tropism are clearly harbored in the V3 loop of subtype F isolates from Romania, the induction of syncytium formation occurs in the presence or absence of positively charged amino acids at positions 306, 320, and/or 324. However, the net positive charge of V3 loop sequences derived from syncytium-inducing viruses was higher than that of the nonsyncytium-inducing isolate.

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Structural Basis for Coreceptor Selectivity by The HIV Type 1 V3 Loop

Cardozo

Kimura

Philpott

et al. 2007

AIDS Research and Human Retroviruses

147

162

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The third variable region (V3) of the HIV-1 surface glycoprotein, gp120, plays a central role in the interaction of the virus envelope with the cell surface chemokine receptors, triggering membrane fusion and virus entry into human lymphocytes and macrophages. The CXCR4 and CCR5 chemokine receptors are used by "X4-tropic" and "R5-tropic" viruses, respectively. Recently, the crown of the V3 loop was shown to bear a close structural homology to the beta2-beta3 loop in the CXC and CC chemokines, the natural ligands of CXCR4 and CCR5, respectively. This homology can serve as the foundation for 3D molecular modeling of the V3 loops from primary isolates whose coreceptor usage was experimentally defined. The modeling revealed a charged "patch" on the surface of V3 that correlates with coreceptor usage. This V3 surface patch is positively charged in X4-tropic viruses and negatively charged or neutral in R5-tropic viruses, and is formed by two amino acids, at position 11 and at position 24 or 25; amino acids 11 and 24 or 11 and 25 contact each other in 3D space. Residues at positions 11 and 25 were known previously to influence coreceptor usage, and the charge of the residues at these two positions is often used to predict viral tropism. However, we found that the predictive value of using the charge of residues 11, 24, and 25 to identify X4 or R5 tropism was improved over using only the charge of residues 11 and 25. Thus, the data suggest a new " 11/24/25 rule" : a positively charged amino acid at position 11, 24, or 25 defines X4; otherwise R5. This rule gave an overall predictive value of 94% for 217 viruses whose tropism had been determined experimentally as either X4 or R5. The results have additional implications for the design of HIV therapeutics, vaccines, and strategies for monitoring disease progression.

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V3 sequence analysis and biological characterization of HTV‐1 isolates from asymptomatic and early symptomatic Tanzanian individuals

Cited by 8 publications

References 40 publications

Evolution of human immunodeficiency virus type 1 serotypes in northern Tanzania: a retrospective study

Evolution of human immunodeficiency virus type 1 serotypes in northern Tanzania: a retrospective study

Short Communication: Determinants for the Syncytium-Inducing Phenotype of HIV-1 Subtype F Isolates Are Located in the V3 Region

Structural Basis for Coreceptor Selectivity by The HIV Type 1 V3 Loop

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