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Biomedical subjects

Marlène Brandes

Publications and source records attributed to Marlène Brandes.

3 recordsLinked to original sources

Gammadelta T cells: an alternative type of professional APC.

A subtype of activated human gammadelta T cells, termed Vdelta2+ T cells, has antigen-presentation features similar in potency and efficacy to those seen in dendritic cells. Comparable treatment of alphabeta T cells does not result in 'professional' antigen presenting cells (APCs). What is so special about Vdelta2+ T cells? How do they acquire these unexpected properties? Under what physiological conditions would such a bridge between innate and adaptive immunity come into play? In addition to discussing these questions, we introduce a model that correlates the expression of lymph node homing receptors in Vdelta2+ T cells with the involvement of this alternative type of APC in anti-microbial alphabeta T cell responses.

Antigen Presentation↗

Professional antigen-presentation function by human gammadelta T Cells.

Human gammadelta T cells are considered to play a vital role in protective immunity through cytokine secretion and cytotoxic activity. We report that cells expressing the Vgamma2Vdelta2+-T cell receptor (Vdelta2+ T cells) also display principal characteristics of professional antigen-presenting cells such as dendritic cells. Thus, when activated, these cells efficiently processed and displayed antigens and provided co-stimulatory signals sufficient for strong induction of naïve alphabeta T cell proliferation and differentiation. We suggest that, upon microbial activation, Vdelta2+ T cells participate in the induction of adaptive immune responses and that these cells may be a useful tool in vaccine development and immunotherapy.

Antigen Presentation↗

Cytotoxic HIV-1 p55gag-specific CD4+ T cells produce HIV-inhibitory cytokines and chemokines.

CD4+ T-helper cells appear to be essential in sustaining immune responses in chronic viral infections, as the maintenance of CD8+ cytotoxic T-lymphocyte responses and the control of viremia were demonstrated to depend on CD4+ T cell help. In order to investigate the function of HIV-specific CD4+ T cells in chronic HIV-1-infection, 49 chronically HIV-infected patients were analyzed before and 3 and 6 months after initiation of antiviral treatment. Ten patients showed a substantial, although weak, proliferative response to HIV-1-p55gag protein for which no improvement was observed upon initiation of HAART. From one individual, HIV-1-p55gag-specific CD4-positive T-cell clones were generated that were heterogeneous in their TCR Vbeta gene usage and HLA-DRB1*13 and DRB1*03 restricted, respectively. In addition, some CD4+ TCC produced substantial amounts of IFN-gamma and MIP-1alpha/beta were perforin-positive, and showed cytotoxic activity. These diverse functional features of HIV-specific CD4+ T cells suggest that they may exert direct antiviral activity.

Anti-HIV Agents↗