Modulation of the chemotactic responsiveness of guinea pig neutrophils to hrIL-8 and fMLP

• Published in: Journal of leukocyte biology 1994-12, Vol.56 (6), p.776-783
• Main Authors: Dai, Yalei, Holgate, Stephen T., Church, Martin K., Shute, Janis K.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; cell migration; Chemotactic Factors - pharmacology; Chemotaxis, Leukocyte - drug effects; Cyclic AMP - biosynthesis; Cyclic AMP - metabolism; Cyclic AMP - physiology; Guinea Pigs; Interleukin-8 - pharmacology; Kinetics; Male; Molecular Sequence Data; N-Formylmethionine Leucyl-Phenylalanine - pharmacology; Neutrophils - cytology; Neutrophils - drug effects; Protein Kinase C - antagonists & inhibitors; Protein Kinase C - metabolism; Receptors, Formyl Peptide; Receptors, Immunologic - metabolism; Receptors, Interleukin - metabolism; Receptors, Peptide - metabolism; Recombinant Proteins - pharmacology; signal transduction
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.56.6.776

Neutrophils elicited in the peritoneal cavity of guinea pigs were purified on Percoll gradients and their chemotactic response to hrIL‐8 and fMLP measured in vitro. hrIL‐8 and fMLP were effective chemoattractants with optimal concentrations of 6 10‐9 and 1 10‐7 M, respectively. Scatchard analysis revealed approximately 205,000 IL‐8 receptors/cell and 34,000 fMLP receptors/cell with K d values of 4.1 10‐9 and 3.3 10‐8 M, respectively. At suboptimal concentrations of chemoattractants the response was inhibited by dibutyryl cyclic AMP, histamine, and adenosine in the presence of a phosphodiesterase inhibitor. IL‐8 and fMLP induced an increase in cellular cyclic AMP and the response to optimal concentrations of chemoattractants was inhibited by Calphostin C and Ro 31‐8220, inhibitors of protein kinase C (PKC). Our results indicate that the chemoattractants activate the same PKC‐dependent pathway that is down‐regulated by cyclic AMP‐dependent mechanisms. J. Leukoc. Biol. 56: 776–783; 1994.