Figure 7.

Double colour flow cytometric analysis of the effect of cyclosporin A (CsA) and ionomycin on the expression of CXC chemokine receptor 4 (CXCR4) on CD4⁺ T lymphocytes. The cells were first stimulated either with or without CsA (0·1 mg/ml) or ionomycin (0·1 mg/ml), as indicated, for 30 min. The cells were then stimulated either with or without interleukin (IL)-4 (10 ng/ml) or IL-10 (10 ng/ml), as indicated, for 24 hr. The cells were subsequently stained with anti-CXCR4 monoclonal antibody as described in the Materials and methods. (/) Indicates that the percentage of CXCR4⁺ cells varied from 45 to 55%, implying no significant regulation by IL-4 or IL-10 compared with CXCR4 expression on resting CD4⁺ T lymphocytes. (−) Indicates that the percentage of CXCR4⁺ cells was <5%, implying significant down-regulation by IL-4 or IL-10 compared with CXCR4 expression on resting CD4⁺ T lymphocytes. (+) Indicates that the percentage of CXCR4⁺ cells was >90%, implying significant up-regulation by IL-4 or IL-10 compared with CXCR4 expression on resting CD4⁺ T lymphocytes. The data were taken from a single experiment, which was representative of six similar experiments performed.