Functional differences between monocyte chemotactic protein-1 receptor A and monocyte chemotactic protein-1 receptor B expressed in a Jurkat T cell
| Autor: | Gregory J. LaRosa, Sheila M. Crean, Debra Kellner, Sheila K. Sanders, Peter A. Boxer, Stephen W. Hunt |
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| Rok vydání: | 2000 |
| Předmět: |
CCR2
animal structures Receptors CCR2 viruses T cell T-Lymphocytes Immunology Biology Pertussis toxin Transfection Jurkat cells Iodine Radioisotopes Jurkat Cells medicine Immunology and Allergy Humans Calcium Signaling Virulence Factors Bordetella Receptor Chemokine CCL2 Monocyte fungi Chemotaxis Molecular biology Cell biology Chemotaxis Leukocyte medicine.anatomical_structure Pertussis Toxin Guanosine 5'-O-(3-Thiotriphosphate) Calcium Receptors Chemokine Protein Binding |
| Zdroj: | Journal of immunology (Baltimore, Md. : 1950). 165(9) |
| ISSN: | 0022-1767 |
| Popis: | The monocyte chemotactic protein-1 (MCP-1) receptor (MCP-1R) is expressed on monocytes, a subpopulation of memory T lymphocytes, and basophils. Two alternatively spliced forms of MCP-1R, CCR2A and CCR2B, exist and differ only in their carboxyl-terminal tails. To determine whether CCR2A and CCR2B receptors function similarly, Jurkat T cells were stably transfected with plasmids encoding the human CCR2A or CCR2B gene. Nanomolar concentrations of MCP-1 induced chemotaxis in the CCR2B transfectants that express high, intermediate, and low levels of MCP-1R. Peak chemotactic activity was shifted to the right as receptor number decreased. Five-fold more MCP-1 was required to initiate chemotaxis of the CCR2A low transfectant, but the peak of chemotaxis was similar for the CCR2A and CCR2B transfectants expressing similar numbers of receptors. MCP-1-induced chemotaxis was sensitive to pertussis toxin, implying that both CCR2A and CCR2B are Giα protein coupled. MCP-1 induced a transient Ca2+ flux in the CCR2B transfectant that was partially sensitive to pertussis toxin. In contrast, MCP-1 did not induce Ca2+ flux in the CCR2A transfectant. Since MCP-1 can stimulate chemotaxis of the CCR2A transfectant without inducing Ca2+ mobilization, Ca2+ flux may not be required for MCP-1-induced chemotaxis in the Jurkat transfectants. These results indicate that functional differences exist between the CCR2A and CCR2B transfectants that can be attributed solely to differences in the carboxyl-terminal tail. |
| Databáze: | OpenAIRE |
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