THE RED-CELL CHEMOKINE RECEPTOR IS DISTINCT FROM THE FY6 EPITOPE

Background: Previous studies established an association between the re d cell chemokine receptor and Fy6 of the Duffy glycoprotein. The relat ionship between Duffy system antigens and interleukin 8 binding by red cells was examined. Study Design and Methods: Interleukin 8 adsorptio n was measured by using red cells from owl, squirrel, and rhesus monke ys, and human red cells before and after saturation with anti-Fy(a) (a nti-Fy1), anti-Fy(b) (anti-Fy2), or anti-Fy6. The effect of cell satur ation with interleukin 8 on Duffy system antigen expression and the ef fect of enzyme treatment on interleukin 8 adsorption were also examine d. Results: Fy:1,-2,6 or Fy:-1,2,6 (owl monkey, squirrel monkey, human ) red cells adsorbed interleukin 8 over a wide range of concentrations (125-1000 pg/mL). Human Fy:-1,-2,-6 red cells bound minimal interleuk in 8. Human red cells saturated with corresponding antibodies displaye d decreased interleukin 8 binding. Saturation of human cells with inte rleukin 8 failed to interfere with Duffy system antigen expression. Rh esus monkey cells lacking Fy1, Fy2, and Fy6 were able to adsorb interl eukin 8 in a manner similar to Fy:1,-2,6 or Fy:-1,2,6 primate cells, F icin treatment eliminated both Duffy system antigen expression and int erleukin 8 adsorption from red cells. Conclusion: The Duffy glycoprote in binds interleukin 8. Although previous studies suggested that inter leukin 8 bound either directly to or close to the Fy6 epitope, the abi lity of Fy:-1,-2,-6 rhesus monkey cells to adsorb interleukin 8 sugges ts that the interleukin 8 receptor is distinct from Fy6, Fy1, and Fy2.