Human Mtb-specific T-cell responses in blood and tissue
Event details
| Date | 13.12.2011 |
| Hour | 11:00 |
| Speaker | Dr. Alexandre Harari |
| Location | |
| Category | Conferences - Seminars |
T lymphocytes are thought to play an important role in the control of TB since Mtb reactivates when there is a decrease in immune surveillance. The Mtb-specific T-cell response is a typical Th1 response and the main function of these CD4 T cells is to produce cytokines such as IFN-γ or TNF-α that contribute to the recruitment of monocytes and granulocytes and activate the anti-microbial activity of macrophages. In some studies, Th17 cells were shown to be involved in the early formation of protective immunity in the lung whereas other investigations indicated that Th17 cells were not associated to protection. Another open question is centered on the role of Mtb-specific CD8 T-cells. Indeed, work performed in mouse models of TB suggested a role of these cells in the control of Mtb infection. Specifically, secretion of perforin and granulysin by Mtb-specific CD8 T cells was required to protect mice from Mtb infection. Other studies performed in humans reached the same conclusions. However, the mechanisms underlying CD8 T-cell priming and recruitment remain to be clarified (e.g. what are the cell subsets allowing Mtb-derived epitope presentation on MHC class I molecules). Finally, most research in humans was performed in cells isolated from the blood and little is known regarding the magnitude or the quality of Mtb-specific T-cells at the sites of infection (e.g. in the lung for pulmonary TB, which represents the most common type of TB disease). Recently a comprehensive investigation of Mtb-specific CD4 and CD8 T- cells using polychromatic flow cytometry in patients with latent Mtb infection or active TB disease was performed at the Service of Immunology and Allergy from CHUV. In addition, both Th1 and Th17 T-cell subsets were analyzed in peripheral blood as well as in blonchoalveolar lavages. Data from these investigations will be presented during the seminar.
Practical information
- General public
- Free
Contact
- Dr Claudia Sala