![Fig. 5. Desensitization of CXCR4 by W peptide pretreatment and the effect of staurosporine. / Hos/CD4/CXCR4/FPRL1 cells were preincubated in the absence (A) or presence (B) of staurosporine (1.4 ng/mL) at 37°C for 1 hour, followed by treatment with W peptide (1 μM) at 37°C for an additional 1 hour. Ca++ flux in response to SDF-1α (100 ng/mL) was measured. Hos/CD4/CXCR4/FPRL1 cells were preincubated with (C) or without (D) staurosporine (1.4 ng/mL) at 37°C for 1 hour, and SDF-1α–induced Ca++ flux was then measured. (E) Hos/CD4/CXCR4/FPRL1 cells were preincubated at 37°C with medium, W peptide (1 μM, 1 hour; W pep), staurosporine (1.4 ng/mL, 1 hour) followed by W peptide (1 μM, 1 hour; Stauro+Wpep), or staurosporine alone (1.4 ng/mL, 1 hour; Stauro alone). After washing, cell migration in response to SDF-1α (50 ng/mL) was measured. The asterisk indicates a significantly reduced cell migration after W peptide treatment, compared with cells treated with medium only. ▪ indicates medium; ■, W pep; ░, stauro + W pep; ▨, stauro alone. (F) [32P] orthophosphate-labeled Hos/CD4/CXCR4/FPRL1 cells were treated at 37°C with SDF-1α (1 μg/mL, 1 minute) or W peptide (1 μM, 60 minutes). The cell lysates were immunoprecipitated (IP) by using an anti-CXCR4 polyclonal antibody to detect increased phosphorylation of CXCR4.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/97/10/10.1182_blood.v97.10.2941/6/h81011073005.jpeg?Expires=1724963782&Signature=2cprucdWxqI5Cg4ctIpM6d5cpJ-V89q1dbczbOmfNZVz~uL11EAuhb8s7fwzBd3ylFG3M6lZysHyuqa~CIPxPblpAIKtICUITjRZ4455yynb~bR-01pQiHtFqpPlXBENX9mMkB3v3JhTh6z8kBUIMgK3lRXC5IG1oihTToV5s4xjHSXulFlda4Yy4c2vuM0U-KZ47~-s4wzLYwsHRI3nka~EcTl7j4qlUoetuoVZr3ZngmXVuLZhVepmh0pV4L4b2xm5p1WQU0DDc6E6adXqlyBX7J6Bp8XRPNkpBVuq~ksWZeyioGZo07bSXvyN~KFFwBFMjYje1FRAByawz23B6g__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Desensitization of CXCR4 by W peptide pretreatment and the effect of staurosporine.
Hos/CD4/CXCR4/FPRL1 cells were preincubated in the absence (A) or presence (B) of staurosporine (1.4 ng/mL) at 37°C for 1 hour, followed by treatment with W peptide (1 μM) at 37°C for an additional 1 hour. Ca++ flux in response to SDF-1α (100 ng/mL) was measured. Hos/CD4/CXCR4/FPRL1 cells were preincubated with (C) or without (D) staurosporine (1.4 ng/mL) at 37°C for 1 hour, and SDF-1α–induced Ca++ flux was then measured. (E) Hos/CD4/CXCR4/FPRL1 cells were preincubated at 37°C with medium, W peptide (1 μM, 1 hour; W pep), staurosporine (1.4 ng/mL, 1 hour) followed by W peptide (1 μM, 1 hour; Stauro+Wpep), or staurosporine alone (1.4 ng/mL, 1 hour; Stauro alone). After washing, cell migration in response to SDF-1α (50 ng/mL) was measured. The asterisk indicates a significantly reduced cell migration after W peptide treatment, compared with cells treated with medium only. ▪ indicates medium; ■, W pep; ░, stauro + W pep; ▨, stauro alone. (F) [32P] orthophosphate-labeled Hos/CD4/CXCR4/FPRL1 cells were treated at 37°C with SDF-1α (1 μg/mL, 1 minute) or W peptide (1 μM, 60 minutes). The cell lysates were immunoprecipitated (IP) by using an anti-CXCR4 polyclonal antibody to detect increased phosphorylation of CXCR4.
