MM cell lines express MIP-1α and MIP-1α receptor CCR5.

(A) MM1.S, XG-1, ARH77, pat MM, IM9, and H929 cells secrete MIP-1α. Supernatants were collected after 48 hours in culture and analyzed for MIP-1α by ELISA. (B) Equal amounts of RNA were reverse transcribed to generate cDNA that was used for PCR analysis of MIP-1α mRNA expression in cell lines that were negative in MIP-1α ELISA. MM1.S served as a positive control. (C) CCR5 expression was studied by flow cytometry. MM1.S cell line and pat MM cells were stained with an FITC-labeled anti-CCR5 mab (filled histogram) or an FITC-conjugated IgG2b-isotype control mab (open histogram).