T cells use two directionally distinct pathways for cytokine secretion
T cell use two directionally distinct pathways for cytokine secretion
Nature immunology Vol 7, 247-255 (2006)
Speaker: 顏嘉良 Place: Room 601
Commentator: 林以行老師 Date: 2006/4/26 13:00-14:00
Abstract:
A critical event in the initiation of adaptive immune response is the activation of T lymphocytes. Activated T lymphocytes can secrete many cytokines through immunological synapse (IS), where is the place that T cell receptors (TCRs) interact with major histocompatibility complex (MHC)-peptide complexes. This will promote the specific communication between T cells and target cells, and also can prevent cytokines from diffusing and effecting bystander cells. It is known that CD4+ T helper (TH) cells can secrete some cytokines to the antigen-presenting cells (APCs) through IS. However, how CD4+ TH cells secrete factors which have more generalized effects, such as promoting inflammation or establishing chemokine gradients is still unknown. The authors used immunocytochemistry, live-cell imaging and a surface-mediated secretion assay to show that there are two cytokine secretion pathways in TH cells. Some cytokines, including interleukin 2 and interferon-γ, were secreted into the synapse, but others, including tumor necrosis factor and the chemokine CCL3, were released multidirectionally. The authors also found that these two secretion pathway were associated with different trafficking proteins, indicating that they are molecularly distinct processes. These finding suggested that TH cells may use both synaptic and multidirectional secretion pathway to secrete different cytokines depending on their functions. TH cell cytokine response is not only dependent on what cytokines are synthesized but also on how they are secreted.
Reference:
1. Johannes B. Huppa and Mark M. Davis, T-cell-antigen recognition and the immunological synapse. Nature Reviews Immunology. Vol 3, 973-982 (2003)
2. Morgan Huse, et al. T cells use two directionally distinct pathways for cytokine secretion. Nature Immunology. Vol 7, 247-255 (2006)