Ca2+ signals in CD4+ T cells during early contacts with antigen-bearing dendritic cells in lymph node |
| |
Authors: | Wei Sindy H Safrina Olga Yu Ying Garrod Kym R Cahalan Michael D Parker Ian |
| |
Institution: | Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA. |
| |
Abstract: | T cell activation by APC requires cytosolic Ca(2+) (Ca(2+)](i)) elevation. Using two-photon microscopy, we visualized Ca(2+) signaling and motility of murine CD4(+) T cells within lymph node (LN) explants under control, inflammatory, and immunizing conditions. Without Ag under basal noninflammatory conditions, T cells showed infrequent Ca(2+) spikes associated with sustained slowing. Inflammation reduced velocities and Ca(2+) spiking in the absence of specific Ag. During early Ag encounter, most T cells engaged Ag-presenting dendritic cells in clusters, and showed increased Ca(2+) spike frequency and elevated basal Ca(2+)](i). These Ca(2+) signals persisted for hours, irrespective of whether T cells were in contact with visualized dendritic cells. We propose that sustained increases in basal Ca(2+)](i) and spiking frequency constitute a Ca(2+) signaling modality that, integrated over hours, distinguishes immunogenic from basal state in the native lymphoid environment. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|