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Updated: Jul 6, 2026
08:58
Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques
Published on: July 5, 2018
Overlapping but nonidentical binding sites on CD2 for CD58 and a second ligand CD59
W C Hahn1, E Menu, A L Bothwell
1Division of Pediatric Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA.
Science (New York, N.Y.)
|June 26, 1992
Summary
The T cell glycoprotein CD2 interacts with CD59, a complement-inhibitory protein, as a second ligand besides CD58. This interaction is crucial for T cell activation and adhesion, revealing new insights into immune cell function.
Area of Science:
- Immunology
- Cell Biology
- Molecular Interactions
Background:
- The T cell glycoprotein CD2 plays a critical role in T cell function.
- CD2's known ligand, CD58, mediates T cell activation and adhesion.
- The precise molecular mechanisms governing CD2-mediated T cell responses require further elucidation.
Purpose of the Study:
- To identify novel physiological ligands for the T cell glycoprotein CD2.
- To investigate the role of CD59 as a potential ligand for CD2.
- To characterize the binding interactions between CD2, CD58, and CD59 and their impact on T cell activation.
Main Methods:
- Utilized murine T cell hybridomas expressing human CD2.
- Employed antibodies targeting CD59 to assess its effect on CD2-dependent T cell activation.
- Performed in vitro binding assays with purified CD58 and CD59 using CD2+ cells.
- Applied complementary approaches to analyze the binding sites of CD58 and CD59 on CD2.
Main Results:
- Identified CD59, a complement-inhibitory glycoprotein, as a second physiological ligand for CD2.
- Demonstrated that antibodies to CD59 inhibit CD2-dependent T cell activation.
- Confirmed that CD2+ cells bind to both immobilized CD58 and CD59 in vitro.
- Revealed that the binding sites for CD58 and CD59 on CD2 are overlapping but distinct.
Conclusions:
- CD59 functions as a novel ligand for CD2, in addition to CD58.
- Direct interactions between CD2 and both CD58 and CD59 contribute significantly to T cell activation.
- These findings suggest a complex regulatory mechanism involving CD2-ligand interactions in T cell adhesion and function.
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