CLONING AND SEQUENCE-ANALYSIS OF THE IMMEDIATE PROMOTER REGION AND CDNA OF PORCINE GRANULOCYTE-COLONY-STIMULATING FACTOR

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that stimu lates the proliferation and differentiation of hematopoietic progenito r cells committed to the neutrophil/granulocyte lineage. Recombinant G -CSF (rG-CSF) is routinely used in the prevention of chemotherapy-indu ced neutropenia and in the setting of bone marrow transplantation. Chr onic idiopathic and congenital neutropenic disorders also show improve ment after rG-CSF injections. Applications of either rG-CSF or G-CSF g ene transfected cells into mice give rise to leukocytosis, which can b e measured easily. This makes G-CSF a versatile tool for studying syst emic effects of therapeutic proteins delivered by genetically modified cells in vivo. Although the biological activity of G-CSF is not speci es-specific, studies on long-term expression would require the use of species-identical proteins in order to avoid host immune reactions aga inst the foreign gene product. Because of the physiological and immuno logical similarity of pigs and human, the pig has become an important large-animal model for biomedical research. We have therefore cloned p orcine G-CSF cDNA from RNA isolated from pig PBLs. Pig G-CSF is a 195- amino-acid polypeptide that shares a high degree of homology to human (78%), murine (71%) as well as rat (68%) G-CSF. In contrast to human a nd murine, but not to rat G-CSF, a different ATG translation start cod on is used, resulting in a shorter, but still functional signal sequen ce. (C) 1997 Elsevier Science B.V.