The α1β1 Integrin and TNF Receptor II Protect Airway CD8+ Effector T Cells from Apoptosis during Influenza Infection

• Published in: The Journal of immunology (1950) 2007-10, Vol.179 (8), p.5054-5063
• Main Authors: Richter, Martin V., Topham, David J.
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.179.8.5054

Primary viral infections of the lung induce potent effector CD8 T cell responses. To function in the influenza-infected airways, CD8 T cells must be able to resist cell death. The majority of the CD8 T cells in the airways and lung parenchyma expressed CD49a, the α-chain of the type IV collagen receptor VLA-1, and these cells were highly activated, producing both IFN-γ and TNF-α. In the airways, where type IV collagen is abundant, but not the spleen, the CD49a+ CD8 cells had reduced proportions of annexin V and caspase 8, and >80% expressed the TNF-α receptor II, while Fas, TNFR-I, and CD27 expression were similar to CD49a− cells. Furthermore, the CD49a+, but not CD49a−, CD8 T cells from the airways were resistant to active induction of apoptosis in the presence of type IV collagen and TNF-α in vitro. We propose that TNFR-II and the VLA-1 synergize to protect effector CD8 T cells in the infected airways from apoptosis during the acute infection.