AIDS 2006 - T Cell Immunity to HIV in Acute/Chronic Infection

T Cell Immunity to HIV in Acute/Chronic Infection

WEAA04

Type:

Oral abstract session

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Venue:

Session Room 6

Interpretation:

None

Time:

16:15 - 17:45

Code:

WEAA04

Co-Chairs:

Andrzej Horban, Poland
Aikichi Iwamoto, Japan
Mariza Morgado, Brazil

Presentations in this session:
16:15
WEAA0401
Abstract
Powerpoint (234 KB) Long-term nonprogressor’s journey into progressive disease: association with escape from cellular immune control
Presented by Kimdar Kemal, United States
K. Kemal¹, T. Beattie², T. Dong², B. Weiser¹, C. Kuiken³, J. Sutton², D. Lang³, H. Yang², P. Yang², R. Collman⁴, S. Philpott¹, S. Rowland-Jones², H. Burger¹
¹Wadsworth Center, New York State Department of Health, Albany, United States, ²University of Oxford, Weatherall Institute of Molecular Medicine, Oxford, United Kingdom, ³Los Alamos National Laboratory, Los Alamos, United States, ⁴University of Pennsylvania, School of Medicine, Philadelphia, United States

16:30
WEAA0403
Abstract
Powerpoint (612 KB) Surveillance of IL-2 inducing CD4+ T cell epitopes in acute HIV-1 infection for the emergence of escape mutants
Presented by R. Brad Jones, Canada
R.B. Jones¹, F.Y. Yue¹, C.M. Kovacs², R. Mohamed¹, K.S. MacDonald¹, M.A. Ostrowski¹
¹University of Toronto, Department of Immunology, Toronto, Canada, ²Canadian Immunodeficiency Research Collaborative, Toronto, Canada

16:45
WEAA0404
Abstract T cell responses to human endogenous Retroviruses in primary HIV infection: a novel vaccine strategy?
Presented by Keith Garrison, United States
K. Garrison¹, R.B. Jones², D.A. Meiklejohn¹, A. Agrawal¹, N. Anwar², G. Spotts³, F.M. Hecht³, S. Rakoff-Nahoum⁴, J. Lenz⁵, M.A. Ostrowski², D.F. Nixon¹
¹Gladstone Institute, University of California San Francisco, Gladstone Institute of Virology and Immunology, San Francisco, United States, ²University of Toronto, Department of Immunology, Toronto, Canada, ³University of California San Francisco, Positive Health Program, San Francisco, United States, ⁴Yale University, New Haven, United States, ⁵Albert Einstein College of Medicine, New York, United States

17:00
WEAA0405
Abstract
Powerpoint (2.68 MB) HIV-specific IFN- and IL-2 secreting responses and their association to HLA alleles
Presented by Yoav Peretz, Canada
Y. Peretz¹, L.M. Ndongala¹, R. Boulassel², J.-P. Routy², R.-P. Sékaly³, C.L. Tremblay³, C.M. Tsoukas⁴, N.F. Bernard¹
¹McGill University Health Center, Experimental Medicine, Montreal, Canada, ²Royal Victoria Hospital, Immunodeficiency service, Montreal, Canada, ³Centre Hospitalier de l'Université de Montréal, Montreal, Canada, ⁴McGill University Health Center, Immune Deficiency Treatment Centre, Montreal, Canada

17:15
WEAA0406
Abstract
Powerpoint (1.07 MB) Comparative viral fitness assessment of congenic mutations within an immunodominant CD8+ T cell epitope of HIV
Presented by Natasha Christie, Canada
N. Christie¹, D.O. Willer², M. Lobritz³, A. Cochrane⁴, M.A. Luscher², E.J. Arts³, K.S. MacDonald⁵
¹University of Toronto, Immunology, Toronto, Canada, ²University of Toronto, Medicine, Toronto, Canada, ³Case Western Reserve University, Molecular Biology and Microbiology, Cleveland, United States, ⁴University of Toronto, Molecular Genetics, Toronto, Canada, ⁵Mt. Sinai Hospital, Microbiology, Toronto, Canada

Audio files:

English audio file (mp3 format, 19.6 MB)

Rapporteur report

Science Track A: Biology and Pathogenesis of HIV report by Dr. Nicole Bernard

Much of the session dealt with characterizing HIV-specific immune responses that may play a role in controlling viral replication by studying various model systems

Dr K Kemai

WEAA0401

A case was presented of a long term non progressor infected for 18 years who began to progress. In order to identify immune charactistics that may acccount for change in disease course, immune responses screening was performed for CD4 and CD8 responses and the disappearance of some of these responses was documented as were sequence changes in the virus corresponding to times soon before the change in rate of progression.

R.B. Jones

WEAA0402

Optimal CD4 epitopes restricted to HLA DR alleles were identified that elicited IL-2 secretion in a subject in PI. These responses disappeared by 12 months of infection. In 1 epitope an sequence change occured although none were seen in the other 2 CD4 epitopes.

K Garrison

WEAA0403

Human genomic DNA encodes endogenous retroviruses (HERV) that share sequence similarity with HIV at regions having binding motifs for HLA alleles and previously shown to be recognized by HIV infected subjects. It is possible that populations of T cells specific for HIV or HERV exist that can cross recognize each other. This phenomenon may be exploitable in novel vaccine strategies.

Y Peretz

WEAA0404

A comprehensive dual color ELISPOT assay was used to screen long term non progressors and progressors for HIV-specific cells able to secrete IFN-gamma alone, IL-2 alone and both IFN-gamma and IL-2 simultaneously. The breadth and magnitude of dual cytokine responses were greater in LTNP versus progressors and correlated positively with CD4 and negatively with viral load.

N Christie

WEAA0405

If the HLA-A2 restricted SLYNTVATL epitope is so "immunodominant" why is it so well conserved in A2 positive HIV infected subjects? Three mutations need to accumulate in a step-wise fashion in order to reduce the recognition of this epitope by cells specific for SLYNTVATL. Presence of these 3 mutations does not affect viral replication capacity and presumably fitness.

In the work presented on HERV HIV interactions, implication that retrovirus cross recognition could be exploited for vaccine strategies raised cautions that immune responses induced to HERV may have deleterious adverse reactions such as inducing tolerance or autoimmunity. IL-2/IFN-gamma HIV specific cells in long term non progressors were found to be mostly CD8+ but CD4+ cells with this functional profile were also seen.

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