Low affinity binding of an LFA-3/IgG1 fusion protein to CD2+ T cells is independent of cell activation
| Autor: | Werner Meier, Adrian Whitty, Paula S. Hochman, Kalvin Yim, Gerard R. Majeau |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
T cell
Recombinant Fusion Proteins CD2 Antigens chemical and pharmacologic phenomena Mice Transgenic Plasma protein binding Receptors Fc Ligands Lymphocyte Activation Epitope Jurkat Cells Mice T-Lymphocyte Subsets Protein A/G medicine Animals Humans Avidity Cell adhesion biology Chemistry General Medicine CD58 Antigens Flow Cytometry Fusion protein Molecular biology Kinetics Macaca fascicularis medicine.anatomical_structure Immunoglobulin G Biophysics biology.protein Cell activation Papio Protein Binding |
| Zdroj: | Cell adhesion and communication. 7(3) |
| ISSN: | 1061-5385 |
| Popis: | Quantitative analysis of binding of the bivalent recombinant soluble fusion protein, LFA-3/IgG1, shows that the fusion protein binds to human CD2+ PBLs primarily through low affinity (KD approximately 140 microM) but also through high avidity (90 nM) interactions. The concentration dependence for LFA-3/IgG1 PBL binding took the form of two overlapping bell-shaped curves separated by a clear and reproducible minimum. This was accounted for in part by minor heterogeneity in the LFA-3/IgG1 preparations, and potentially by the ability of the ligand to bind to both CD2 and Fc receptors (FcR), best evidenced by the distinct binding properties of the fusion protein to NK and T cells. The low affinity LFA-3/ IgG1 binding to T cells is consistent with binding to CD2 only, and is in agreement with the low affinity reported for interactions between soluble forms of LFA-3 and CD2 by surface plasmon resonance technology. Moreover, as the low affinity determinations are similar for CD2 on resting and activated T cells, although the CD2 molecule has been reported to be altered to reveal new epitopes upon T cell activation, the binding data argue against multiple cell activation-dependent affinity states of CD2 for LFA-3 binding. This is distinct from that observed with other adhesion partners, and suggests that the different adhesion pathways utilize distinct mechanisms to mediate cell adhesion. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|