NATURAL KILLER CELL STIMULATING FACTOR

摘要

PROBLEM TO BE SOLVED: To obtain a new DNA molecule encoding NK cell stimulating factor protein capable of inducing γ-interferon production in vitro in human peripheral blood lymphocytes, and useful for e.g. producing substances stimulating the function of NK cells and other immune system cells. SOLUTION: This new DNA molecule is such one as to encode natural killer cell stimulating factor(NKSF) protein (or subunits thereof) capable of inducing γ-interferon production in vitro in human peripheral blood lymphocytes(PBL) and including 1st subunit which has an apparent molecular weight of about 70-80 kD under SDS PAGE non-reducing conditions, an apparent molecular weight of about 40 kD under SDS PAGE reducing conditions, and an N- terminated amino acid sequence of formula I and the like, and 2nd subunit which has an apparent molecular weight of about 30-35 kD under SDS PAGE reducing conditions and an N-terminated amino acid sequence of formula II (X is any amino acid). This DNA molecule is useful for e.g. producing cytokine which stimulates the function of immune system cells.