Biology Reference
In-Depth Information
12
Homeostasis and Restoration of the
Immune System in HAART-Treated
HIV-Infected Patients: Implication of
Apoptosis
Marie-Lise Gougeon, Herv Lecoeur, Luzia Maria de Oliveira Pinto,
and Eric Ledru
Unit d'Oncologie Virale and CNRS URA 1930, DÂpartement SIDA et
RÂtrovirus, Institut Pasteur, Paris, France
INTRODUCTION
The primary receptor for human immunode®ciency virus ( HIV ) is the CD4
molecule, and the hallmark of HIV infection is the progressive destruction of
the CD4 T lymphocyte subset and the development of severe immune de®-
ciency. CD4 T lymphocytes represent key helper cells that contribute, through
cytokine synthesis, to the di¨erentiation of innate (including natural killer
[NK] and gd cells) and speci®c (cytotoxic CD8 T lymphocytes) antiviral cyto-
toxic cells. They also contribute, through chemokine synthesis, to the control of
lymphocyte migration to the site of infection and to inhibition of HIV entry
into CD4-expressing targets ( Levy, 1998; Malkovsky et al., 2000).
After more than 15 years of investigation, the dynamic basis for CD4 T-cell
depletion in acquired immunode®ciency syndrome (AIDS) is still a matter of
debate. It was generally accepted that CD4 T-cell destruction is the direct con-
sequence of HIV cytopathogenicity. However, the observation that a signi®cant
fraction of peripheral lymphocytes from asymptomatic HIV-infected patients
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