Abstract
The role of CD8+ T cells in adaptive immunity is well documented and involves numerous effector mechanisms including direct cytolysis of targets and secretion of cytokines. The role of CD8+ T cells in innate immunity has not been previously appreciated. Using J774 macrophages infected in vitro with the intracellular bacterium, Listeria monocytogenes (LM), we show that CD8+ T cells isolated from naïve C57BL/6 (B6) mice respond rapidly by secreting IFN-γ. CD8+ T cells secreting IFN-γ can also be found in naïve B6 mice 16 h after infection with LM. This rapid IFN-γ response is TCR-independent and mediated through the actions of IL-12 and IL-18. Cell surface staining and cell sorting experiments indicate that these novel CD8+ T cells express memory markers. In vitro CFSE-labeling experiments show that IFN-γ-secreting CD8+ T cells proliferate rapidly after 2 days in culture and after 4 days constitute the majority of the CD8+ T cell population. Together, these data suggest an important role for IFN-γ-secreting CD8+ T cells in the innate response to bacterial pathogens.
Original language | English |
---|---|
Pages (from-to) | 2807-2816 |
Number of pages | 10 |
Journal | European Journal of Immunology |
Volume | 32 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2002 |
Keywords
- Cell surface molecule
- Cellular activation
- Cytokine
- T lymphocyte