POLYMERASE CHAIN-REACTION CLONING AND EXPRESSION OF THE RAT GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR

We used reverse transcription-polymerase chain reaction (RT-PCR) to cl one a rat complementary DNA that encoded the PVC rat granulocyte-macro phage colony-stimulating factor (GM-CSF). PCR products were cloned int o a eukaryotic expression vector and transfected into the mouse myelom a cell line Sp2/0-Ag14. Cell culture supernatants of two of these tran sfectants supported proliferation of the growth factor-dependent cell line, DA-3, and promoted myeloid colony formation in rat and mouse bon e marrow cell (BMC) cultures. The GM-CSF activity in these supernatant s was neutralized by a polyclonal antibody to mouse GM-CSF, The clonin g and expression of rat GM-CSF provides a valuable reagent for the stu dy of the biology and clinical applications of the GM-CSFs.