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Published on: January 15, 2011
CD81 expressed on human thymocytes mediates integrin activation and interleukin 2-dependent proliferation
1Department of Biology and Molecular Biology Institute, San Diego State University, California 92182-4614, USA.
The Journal of Experimental Medicine
|November 1, 1996
Summary
CD81, or target of antiproliferative antigen (TAPA)-1, associates with T cell coreceptors in human thymocytes. This interaction promotes cell adhesion and costimulates T cell activation, suggesting a regulatory role in thymocyte development.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- T cell receptor (TCR) and coreceptor signaling regulate lymphocyte adhesion and function.
- CD81 (target of antiproliferative antigen [TAPA]-1) is a cell surface protein with known roles in cell proliferation and adhesion.
Purpose of the Study:
- To investigate the expression and function of CD81 in human thymocytes.
- To determine the association of CD81 with T cell coreceptors (CD4 and CD8).
- To elucidate the role of CD81 in regulating thymocyte adhesion and activation.
Main Methods:
- Immunohistochemistry to detect CD81 expression on human thymocytes.
- Co-immunoprecipitation to assess the physical association of CD81 with CD4 and CD8 coreceptors.
- Flow cytometry to measure integrin-mediated cell-cell adhesion (LFA-1) and T cell proliferation following CD81 ligation.
Main Results:
- CD81 is expressed on human thymocytes and physically associates with CD4 and CD8 coreceptors.
- Antibody-mediated ligation of CD81 rapidly induces integrin-mediated cell-cell adhesion via LFA-1.
- Cross-linking CD81 acts as a costimulatory signal with TCR/CD3, leading to interleukin-2-dependent thymocyte proliferation.
Conclusions:
- CD81 plays a significant role in regulating human thymocyte adhesion and activation.
- A CD81-mediated signaling pathway contributes to the control of cell adhesion and immune cell activation during thymocyte development.
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