| abstract |
PURPOSE:To obtain the titled factor, by cloning cDNA coding human necrotic factor with a cloned DNA coding a rabbit cancer necrotic factor as a probe, integrating the resultant cloned cDNA in a plasmid, transforming a microorganism with the plasmid, and using the transformant microorganism. CONSTITUTION:A human macrophage is collected from an air cell, blood or abdominal cavity, etc. and cultivated in an inducer, e.g. endotoxin, to separate a fraction containing a human cancer nectrotic factor mRNA from the above-mentioned cell. A single-stranded cDNA is prepared from the above-mentioned mRNA with a reverse transcriptase, and converted into a double-stranded cDNA, which is inserted into a vector. The resultant vector is then transformed to a host to prepare a cDNA library. A cDNA coding a human cancer necrotic factor is cloned from the above-mentioned cDNA library with a DNA coding a rabbit cancer necrotic factor as a probe, and a microorganism transformed by a plasmid having the integrated cloned DNA is used to give the aimed factor, e.g. a polypeptide having amino acid sequence expressed by the formula. |