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Relations between Fc receptor function and locomotion in human lymphocytes
Clinical and Experimental Immunology
|December 1, 1979
Summary
Chemotactic factors and immunoglobulin G (IgG) binding to lymphocytes do not compete for the same receptor. Instead, they may trigger a calcium influx, temporarily desensitizing cells to further stimulation.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Lymphocytes utilize surface receptors for chemotactic factors and the Fc portion of immunoglobulin G (IgG).
- Chemotactic factors guide cell movement, while Fc-IgG interactions are crucial for immune responses.
Purpose of the Study:
- To investigate the relationship between lymphocyte surface binding sites for chemotactic factors and Fc-IgG.
- To determine if these entities compete for the same cell surface receptors.
Main Methods:
- Utilized human blood lymphocytes and lymphoblast cultures.
- Performed Fc-rosette inhibition assays and filter migration assays.
- Conducted binding studies on cultured lymphoblasts.
Main Results:
- Chemotactic factors inhibited Fc-rosette formation, and IgG inhibited responses to chemoattractants.
- Inhibition by aggregated IgG required divalent cations and was blocked by calcium ionophore A23187.
- Binding studies indicated no competition for shared receptors.
Conclusions:
- Reciprocal inhibition between chemotactic factors and Fc-IgG is not due to receptor competition.
- A calcium-gated entry mechanism may explain the observed inhibition and subsequent unresponsiveness.