![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=1735815091&Signature=EHmK6vXKZK8frYODZGOe1Se8J~eOTDTH-NWiYwJLvnAQycmWX9cMgsd3x2MnVxImgdZIn4PipPvsEjRvJNjfbf94iA2iCMlt5hmUbhtjp1KxRBAXxoyXJ8ahttp8nlCpYtG7daNp4pJlHQdVYkfaKUSWYr3khez547SkPD~2aZ7pQHgDUbmN2JFXzvg36aPBnNvf2tkHrag~1Xqde1cMziEk1wi6yGFXXvD3UGSOzmU5OSXKhAr2Q4JDNXXVq-~viTlXydHYHFpH11qyEwCrfkG~CvSadNT4~kmOWRQ-p~AJOD6Z25Vt0ROgSQWLnoHXM6mE8SK07AQ97SUa42kLGw__&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.
