Regulation of CXCR4 and CXCR5 gene expression by IL-10.

(A) The level of CXCR4 and CXCR5 expression by peritoneal B lymphocytes was evaluated by RT-PCR in freshly isolated cells (lane 1) or in cells cultured for 4 hours with a control antibody (lane 2) or an anti–IL-10R Ab (lane 3). Results are from one representative out of 2 experiments. Densitometry analysis of amplified products showed that the CXCR4/β-actin ratio (mean ± SEM) was 0.43 ± 0.09, 1.02 ± 0.07, and 1.01 ± 0.02 for lanes 1 to 3, respectively. Similar analysis for CXCR5 gene expression showed a CXCR5/β-actin ratio (mean ± SEM) of 0.78 ± 0.06, 0.91 ± 0.07, and 1.01 ± 0.03 for lanes 1 to 3, respectively. (B) The level of CXCR4 and CXCR5 expression by peritoneal B lymphocytes was evaluated by RT-PCR in freshly isolated cells (lane 4) or in cells cultured for 2 hours without (lane 5) or with IL-10 (lane 6). Results are from a single experiment. Densitometry analysis of amplified products showed that the CXCR4/β-actin ratio was 0.35, 0.88, and 0.85 for lanes 4 to 6, respectively. Similar analysis for CXCR5 gene expression showed a CXCR5/β-actin ratio of 0.44, 0.63, and 0.45 for lanes 4 to 6, respectively.