The study describes the cloning and characterization of a human interleukin-8 (IL-8) receptor. The receptor, encoded by a cDNA clone from HL-60 neutrophils, was found to be a low-affinity IL-8 receptor that did not bind to N-formyl peptide receptors. The receptor was expressed in Xenopus oocytes, which responded to IL-8 with calcium mobilization. The receptor had 77% amino acid identity with another human neutrophil receptor and 69% identity with a rabbit N-formyl peptide receptor (F3R). The IL-8 receptor contained seven transmembrane domains and a predicted site for N-linked glycosylation. The receptor's NH2-terminal segment was rich in acidic residues, which may form the binding site for IL-8. The study also found that the IL-8 receptor was not expressed in T lymphocytes or Jurkat cells but was detected in monocyte cell lines. The genomic analysis of the receptor showed one copy per haploid genome, suggesting the presence of a low-affinity receptor. A high-affinity IL-8 receptor was later identified, which had 77% amino acid identity with the low-affinity receptor and was more closely related to F3R. The study concludes that human neutrophils express at least two distinct IL-8 receptors, one low-affinity and one high-affinity.The study describes the cloning and characterization of a human interleukin-8 (IL-8) receptor. The receptor, encoded by a cDNA clone from HL-60 neutrophils, was found to be a low-affinity IL-8 receptor that did not bind to N-formyl peptide receptors. The receptor was expressed in Xenopus oocytes, which responded to IL-8 with calcium mobilization. The receptor had 77% amino acid identity with another human neutrophil receptor and 69% identity with a rabbit N-formyl peptide receptor (F3R). The IL-8 receptor contained seven transmembrane domains and a predicted site for N-linked glycosylation. The receptor's NH2-terminal segment was rich in acidic residues, which may form the binding site for IL-8. The study also found that the IL-8 receptor was not expressed in T lymphocytes or Jurkat cells but was detected in monocyte cell lines. The genomic analysis of the receptor showed one copy per haploid genome, suggesting the presence of a low-affinity receptor. A high-affinity IL-8 receptor was later identified, which had 77% amino acid identity with the low-affinity receptor and was more closely related to F3R. The study concludes that human neutrophils express at least two distinct IL-8 receptors, one low-affinity and one high-affinity.