Ca2+ Signals in CD4+ T Cells during Early Contacts with Antigen-Bearing Dendritic Cells in Lymph Node
| Autor: | Ying Yu, Ian Parker, Michael D. Cahalan, Sindy H. Wei, Kym R. Garrod, Olga Safrina |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
CD4-Positive T-Lymphocytes
Male Cell signaling Pathology medicine.medical_specialty Ovalbumin T cell Immunology Antigen presentation Epitopes T-Lymphocyte Mice Transgenic Inflammation Cell Communication Biology Epitope Mice Basal (phylogenetics) Antigen Cell Movement medicine Animals Immunology and Allergy Calcium Signaling Lymph node Cells Cultured Antigen Presentation Mice Inbred BALB C Immunodominant Epitopes Dendritic Cells Molecular biology Peptide Fragments medicine.anatomical_structure Cell Migration Inhibition Lymph Nodes Inflammation Mediators medicine.symptom |
| Zdroj: | The Journal of Immunology. 179:1586-1594 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.179.3.1586 |
| Popis: | T cell activation by APC requires cytosolic Ca2+ ([Ca2+]i) elevation. Using two-photon microscopy, we visualized Ca2+ 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 Ca2+ spikes associated with sustained slowing. Inflammation reduced velocities and Ca2+ spiking in the absence of specific Ag. During early Ag encounter, most T cells engaged Ag-presenting dendritic cells in clusters, and showed increased Ca2+ spike frequency and elevated basal [Ca2+]i. These Ca2+ signals persisted for hours, irrespective of whether T cells were in contact with visualized dendritic cells. We propose that sustained increases in basal [Ca2+]i and spiking frequency constitute a Ca2+ signaling modality that, integrated over hours, distinguishes immunogenic from basal state in the native lymphoid environment. |
| Databáze: | OpenAIRE |
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