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Updated: May 3, 2026
Analysis of T-cell Receptor-Induced Calcium Influx in Primary Murine T-cells by Full Spectrum Flow Cytometry
Published on: December 16, 2022
Dendritic cell membrane CD83 enhances immune responses by boosting intracellular calcium release in T lymphocytes
Mariana Pereira Pinho1, Isabella Katz Migliori1, Elizabeth Alexandra Flatow1
1Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Brazil.
Insights
CD83 on myeloid dendritic cells (mDCs) enhances T lymphocyte proliferation by modulating calcium signaling. Blocking CD83 reduces T cell activation and proliferation, highlighting its role in immune responses.
Area of Science:
- Immunology
- Cell Biology
- Calcium Signaling
Background:
- CD83 is a marker of myeloid dendritic cells (mDCs) linked to their lymphostimulatory capacity.
- The precise mechanisms by which CD83 regulates immune responses are not fully understood.
Purpose of the Study:
- To investigate the influence of CD83 on mDCs in modulating calcium signaling within T lymphocytes.
- To elucidate the role of CD83 in T cell activation and proliferation.
Main Methods:
- Differentiated monocytes into immature dendritic cells (iDCs) and activated them with TNF-α.
- Reduced CD83 expression using siRNA (siRNACD83) or blocked surface CD83 with a monoclonal antibody (mAb).
- Analyzed calcium mobilization in T lymphocytes using Fluo-4-AM and flow cytometry/microscopy; assessed T cell proliferation via CFSE dilution.
Main Results:
- CD83 knockdown mDCs induced significantly lower calcium signal amplitude in T lymphocytes compared to control siRNA-treated mDCs.
- Blocking surface CD83 on mDCs with mAb decreased calcium signaling and the percentage of responding T cells.
- Anti-CD83 antibodies reduced T lymphocyte proliferation, and abrogated T cell signaling in the absence of extracellular calcium.
Conclusions:
- CD83 expressed on mDCs plays a crucial role in enhancing T lymphocyte calcium signaling and proliferation.
- CD83 appears to boost T cell proliferation by facilitating calcium release from intracellular stores in T lymphocytes.
- Targeting CD83 could be a strategy to modulate T cell-mediated immune responses.
Abstract:
CD83 is a marker of mDCs directly related to their lymphostimulatory ability. Some data suggest that it has a central role in the immune system regulation, but how this function is performed remains to be determined. This work aimed to analyze the influence of CD83, present in mDCs, in the modulation of calcium signaling in T lymphocytes. Mo were differentiated into iDCs and activated with TNF-α. iDCs were treated, 4 h before activation, with siRNACD83, to reduce CD83 expression. Purified allogeneic T lymphocytes were labeled with the calcium indicator Fluo-4-AM, and calcium mobilization in the presence of mDCs was analyzed. CD83 knockdown mDCs induced lower calcium signal amplitude in T lymphocytes (29.0±10.0) compared with siRNAscr-treated mDCs (45.5±5.3). In another set of experiments, surface mDC CD83 was blocked with a specific mAb, and again, decreased calcium signaling in T lymphocytes was detected by flow cytometry and microscopy (fluorescence and confocal). In the presence of antibody, the percentage of responding T cells was reduced from 58.14% to 34.29%. As expected, anti-CD83 antibodies also reduced the proliferation of T lymphocytes (as assessed by CFSE dilution). Finally, in the absence of extracellular calcium, CD83 antibodies abrogated T cell signaling induced by allogeneic mDCs, suggesting that the presence of CD83 in mDC membranes enhances T lymphocyte proliferation by boosting calcium release from intracellular stores in these cells.
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