| 摘要 |
Plasmid vectors are provided that carry cDNA clones coding for polypeptides exhibiting B-cell, T-cell and mast cell stimulatory activities, all of which are enhanced in the presence of other immune-reactive agents. The polypeptides also augment the activity of various CSF's, such as G-CSF and G/M-CSF, and depress proliferation of macrophages in the presence of M-CSF. The cDNA is derived from mRNA isolated from a mammalian cell source, such as T-cells typically after activation with a mitogen. The plasmid vector also contains DNA segments from the SV40 virus, permitting expression of the cDNA after transfection into a mammalian host cell, such as COS cells. Two expressed polypeptides of the present invention from different mammals are about 140 and 150 amino acids in length, including potential leader sequences. An E. coli culture containing a plasmid (pcD-2A-E3) carrying a mouse cDNA insert of the present invention was deposited with the American Type Culture Collection (A.T.C.C.) on Nov. 18, 1985, and designated accession number 53,330. Two additional E. coli cultures, each carrying plasmids with different human cDNA inserts of the present invention, were deposited with the A.T.C.C. as follows: pcD-2Fl-13 (pcD-46) was deposited on Nov. 26, 1985 and designated accession number 53,337 and pcD-125 was deposited on Mar. 7, 1986 and designated accession number 67,029.
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