AEGiS-14IAC: Non infected dendritic cells can cross-present HIV antigens from apoptotic infected CD4+ T lymphocytes.

14th International AIDS Conference


Barcelona, Spain - July 7-12, 2002

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Non infected dendritic cells can cross-present HIV antigens from apoptotic infected CD4+ T lymphocytes.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. LbPeA9006)

Maranon C, Cohen W, Hosmalin A
Institut Cochin U567 INSERM, UMR8104 CNRS, Paris, France

BACKGROUND: CD8+ lymphocyte response is fundamental in protection against HIV infection, in association with CD4+ lymphocyte and antibody responses. Dendritic cells (DC) are required for the activation of naïve T lymphocytes, and thus they have a central role in the induction of protective immune responses during HIV infection. However, they are not frequently infected themselves. They have developed specific "cross-presentation" pathways that allow them to present exogenous antigens that are not directly produced in their cytosol, and this pathway is especially effective in the case of antigens expressed in apoptotic cells. To our knowledge, it has never been shown for HIV antigen presentation.

METHODS: HIV-infected human lymphoblastoid CD4+ T cells were UV-irradiated to induce apoptosis and incubated with monocyte-derived DC. Viral antigen presentation was detected through IFN-γ ELISPOT secretion functional assays using CD8 T cell lines specific for different Class-I MHC-restricted HIV epitopes.

RESULTS: HIV gag, nef and reverse transcriptase epitopes were presented specifically to CD8 T cell lines derived from infected patients. The presentation was Class-I MHC dependent, occured in the presence of AZT and required physical contact between DC and apoptotic bodies, excluding soluble antigens or DC infection as a source of antigens for presentation.

CONCLUSIONS: This presentation pathway could be particularly relevant in HIV infection, which induces death and apoptosis of huge numbers of infected CD4+ lymphocytes. The potential importance of this antigen presentation mechanism in the generation of an effective immune response during HIV infection will be discussed.

Keywords: AEGIS, HIV Antigens, Dendritic Cells, Antigen Presentation, CD8-Positive T-Lymphocytes, CD4-Positive T-Lymphocytes, T-Lymphocytes, HIV Infections, Antigens, CD4, Apoptosis, Antigens, Viral, Epitopes, Human, immunologyKWDaegis,hivantigens,dendriticcells,antigenpresentation,cd8-positivet-lymphocytes,cd4-positivet-lymphocytes,t-lymphocytes,hivinfections,antigens,cd4,apoptosis,antigens,viral,epitopes,human,immunology

020707
LbPeA9006

Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.