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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Antibodies, Monoclonal, Arthritis, Rheumatoid, Cell Movement, Cell Transformation, Viral, Cells, Cultured, Chemotactic Factors, Chemotaxis, Flow Cytometry, Homozygote, Humans, Neutralization Tests, Receptors, CCR5, Synovial Fluid, T-Lymphocytes.
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Is the chemoattraction of lymphocytes by rheumatoid arthritis - synovial fluid dependent on the chemokine receptor CCR5? Context: The objective was to study the potential role of the chemokine receptor CCR5 in the chemoattraction of lymphocytes by rheumatoid arthritis synovial fluid (RA-SF). The expression of the CCR5 receptor was studied by flow cytometry. Chemotaxis of peripheral blood lymphocytes in response to RA-SF was analyzed on transmigration chambers. Chemotaxis of immortalized lymphocytes from individuals homozygous for the Delta32 deletion of the CCR5 gene (CCR5-/-) was analyzed. The effect of a neutralizing anti-CCR5 antibody on the migration of CCR5+/+ cells was also studied. We confirmed an increase in the proportion of CCR5-expressing lymphocytes in RA-SF and a preferential migration of CCR5+ lymphocytes toward RA-SF in vitro. CCR5-/- lymphocytes showed decreased chemotactic responses to the chemokine MIP-1beta but not to RA-SF. The chemotactic responses of CCR5+/+ lymphocytes to RA-SF were not modified by anti-CCR5 neutralizing antibody.
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We confirm a preferential accumulation of CCR5-expressing lymphocytes into RA-SF. However, the chemotactic responses of lymphocytes to RA-SF were not dependent on a functional CCR5 receptor, suggesting that CCR5 is a marker of a lymphocyte subset rather than a specific mediator of chemotactic responses to chemokines in RA-SF. Final Decision: no