IAS 2007 - HIV Diversity, Tropism and Compartmentalization

HIV Diversity, Tropism and Compartmentalization

MOAA2

Type:

Oral abstract session

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Venue:

Bayside Auditorium A

Time:

14:30 - 16:00, Monday, 23.07.2007

Code:

MOAA2

Co-Chairs:

Eric Arts, United States
Mina John, Australia

Presentations in this session:
14:30
MOAA201
Abstract
Powerpoint (1.02 MB) HIV-1 genetic diversity: a comparison of viral evolution in blood and the vaginal tract right from seroconversion and during disease progression
Presented by Immaculate Nankya, United States
Nankya I.¹, Demers K.², Kyeyune F.², Bulime S.², Nanyonjo H.², Salata R.³, Arts E.³
¹Case Western Reserve University, Microbiology and Molecualr Biology, Cleveland, United States, ²Joint Clinical Research Center, Virology, Kampala, Uganda, ³Division of Infectious Diseases, School of Medicine, Case Western Reserve University, Cleveland, United States

14:45
MOAA202
Abstract Evidence for critical differences in HIV-1 env gp120 N-linked glycosylation patterns in plasma and diverse blood leukocyte compartments in vivo
Presented by Yung Shwen Ho, Australia
Ho Y.S.¹, Abecasis A.B.², Potter S.J.¹, Charleston M.³, Vandamme A.M.², Saksena N.K.¹
¹Westmead Millennium Institute, Center for Virus Research, Sydney, Australia, ²Rega Institute for Medical Research, Clinical and Epidemiological Virology, Leuven, Belgium, ³University of Sydney, School of Information Technologies and SUBIT, Sydney, Australia

15:00
MOAA203
Abstract
Powerpoint (1.38 MB) Long-range recombination gradient in intersubtype HIV-1 recombination
Presented by Mario P. S. Chin, United States
Chin M.P.S.¹, Lee S.-K.¹, Chen J.¹, Nikolaitchik O.A.¹, Powell D.², Fivash Jr. M.J.², Hu W.-S.¹
¹HIV Drug Resistance Program, National Cancer Institute, Frederick, United States, ²Data Management Services, National Cancer Institute, Frederick, United States

15:15
MOAA204
Abstract Analysis of the transcriptional activity of HIV-1 long terminal repeats from central nervous system-derived isolates of patients with HIV-1 associated dementia
Presented by Daniel John Cowley, Australia
Cowley D.J.¹, Gray L.¹, Chiavaroli L.¹, Gorry P.R.¹, Wesselingh S.¹, Churchill M.¹
¹The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia

15:30
MOAA205
Abstract Macrophage infiltration is not enough for the development of dementia in HIV patients: evidence for middle part of the brain involvement in HIV-D
Presented by Julie Zhou, Australia
Zhou J.¹, Ng T.², Brew B.³, Saksena N.¹
¹Westmead Millennium Institute, Retroviral Gentics, Westmead, Sydney, Australia, ²ICPMR, Anatomical pathology, Westmead, Sydney, Australia, ³St. Vincents Hospital, Neurology, Darlinghurst, Australia

15:45
MOAA2LB
Abstract Ability to detect and to manipulate HIV-1 evolution via recombination – a new tool to suppress the generation of multiple drug resistant and immune escape HIV-1
Presented by Johnson Mak, Australia
Smyth R.¹, Schlub T.², Tachedjian G.¹, Davenport M.², Mak J.³
¹The Burnet Institute, Melbourne, Australia, ²University of NSW, Sydney, Australia, ³The Burnet Institute, Port Melbourne, Australia

Audio files:

audio file - high quality (mp3 format, 39.5 MB)
audio file - low quality (mp3 format, 19.8 MB)

Rapporteur report

Track A: HIV Basic Science report by Eric Arts
This session commenced with a presentation by Nankya et al. describing modulation of HIV-1 genetic diversity in subtype A, C, and D infected women. All women, regardless of subtype were infected with virus of low genetic diversity, which subsequently increased during disease. The increase in genetic diversity in both nucleotide substitutions and in genetic length was observed in the V3 and more so, in the V1/V2 domains of env. A question from the audience raised the possibility that the patients with the shorter V1/V2 domains may actually progress faster to disease.

Continuing with the theme of genetic diversity in env, Yung Shwen Ho presented on the evolution of the "glycan shield" of env by comparing glycosylation sites in env within various compartments (plasma, CD4 T, CD8 T, and monocytes). There did appear to be increased glycosylation sites in the plasma virus compared to the cell-derived virus but the significance of this observation is still not clearly understood. Using Bayesian networks, they were able to find distinct linkages of glycosylation sites that might co-evolve to preserve function or to increase resistance to neutralizing Abs.

In this session we had two presentations on HIV-1 recombination using in vitro models to better understand intersubtype exchanges of genetic information (Mario Chin) or develop tools block recombination (Johnson Mak). Dr. Chin employed the viral vectors that repaired GFP with recombination and showed that recombination breakpoints between subtype B and C gag/pol regions was not selective but was highly dependent on complementarity between the DIS. Dr. Mak introduced synonymous mutations to map recombination sites and again found that mutations in the DIS will reduce the mutation frequency.

Two talks in this session analyzed aspects of HIV-related dementia. Daniel John Cowley showed that the CNS-derived LTRs as compared to those from blood in the same patients had alterations in various promoter/enhancer elements. These mutations in the CNS LTR diminished both basal and Tat-mediated transcription in astrocytes.

In a talk by Julie Zhou, it appears that dementia was not linked to infiltration of macrophages considering similar levels of CD8 cells and HIV-1 p24 was distributed in different regions of the brain.

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