Journal of Leukocyte Biology 47:64-69 (1990) © 1990 Wiley-Liss, Inc. Characterization of the Interaction Between Recombinant Human Interferon-y and Its Receptor on

The interaction of human recombinant interferon-y (rIFN--y) with human polymorphonu-clear cells (PMN) was investigated. Bolton-Hunter radioiodinated rIFN-y bound to PMN in a specific and saturable manner. Eleven hundred binding sites were observed with a Ka of 0.56 x 1010 M1. Binding to PMN was rapid with a K1 of 9 x 10 M1 sec-1 at 4#{176}C.At 37#{176}C binding was complete within 6 mm. About 50 % of bound Iigand was internalized within 30 mm at 37#{176}C.The receptor demonstrated moderate lability at 37#{176}Cin culture. After 1 h at 37#{176}C,PMN lost 80 % of their 1251-rIFN-’y binding sites. This loss was reversed in part by the presence of interleukin-1 in the culture, but not tumor necrosis factor. These studies provide a framework for further investigation into the signalling process of rIFN-’y on PMN. Key words: phagocytes, lymphokmnes, monokine