The present invention provides purified and isolated polynucleotide sequences encoding a novel macrophage-derived C—C chemokine designated "Macrophage Derived Chemokine" (MDC), and polypeptide fragments and analogs thereof. Also provided are materials and methods for the recombinant or synthetic production of the chemokine, fragments, and analogs; and purified and isolated chemokine protein, and polypeptide fragments and analogs thereof. Also provided are antibodies reactive with the chemokine and methods of making and using all of the foregoing. Also provided are assays for identifying modulators of MDC chemokine activity.