COMPARATIVE SEQUENCE-ANALYSIS OF CYTOKINE GENES FROM HUMAN AND NONHUMAN-PRIMATES

Two major issues severely limit the studies of human recombinant cytok ines/growth factors in nonhuman primates. First, assays and reagents s pecific for the detection and quantitation of human cytokines do not a ll function when utilized to detect/quantitate the nonhuman primate cy tokines. Second, although most of the human cytokines appear to induce similar, if not identical, biologic function when used with cells fro m nonhuman primates in vitro or in vivo, they invariably induce Ab res ponses in vivo, precluding their repeated and/or continued use in vivo . Our laboratory has thus initiated studies to clone, sequence, and pr epare recombinant cytokines from nonhuman primates and to define assay s and reagents for their detection and quantitation at the nucleic aci d and protein level. The data that were derived from such studies show that the nonhuman primate cytokines IL-1 alpha, IL-1 beta, IL-2, IL-4 , IL-5, IL-6, IL-8, IL-10, IL-12 alpha, IL-12 beta, IL-15, IFN-alpha, IFN-gamma, and TNF-alpha share 93 to 99% homology at the nucleic acid and protein level with the human equivalents. The most prominent diffe rences between human and nonhuman primate cytokine sequences were note d for IL-1 alpha/beta, IL-2, IL-8, IFN-alpha, IFN-gamma, and IL-12 bet a. The aligned sequences of cytokines for human and several nonhuman p rimate species are provided herein, and a phylogenetic analysis of the published sequences of select cytokines from other species, along wit h those of the nonhuman primates, are described. In addition, comparat ive analysis of the relative bioactivity of our immunoaffinity-purifie d recombinant rhesus macaque IL-4, IL-15, and IFN-gamma with commercia lly available human recombinant cytokines is described herein. x