A serpin from human tumor cells with direct lymphoid immunomodulatory activity: mitogenic stimulation of human tumor-infiltrating lymphocytes.
A serum-free supernatant from an epidermal carcinoma cell line has previously been shown to contain mitogenic activity for human tumor infiltrating lymphocytes in culture [1]. From this conditioned medium we have now purified to homogeneity, as determined by SDS-PAGE analysis, a ca. 45 kDa protein which stimulates [3H]thymidine incorporation into the DNA of these human T-lymphocytes. Amino acid composition data and immunoreactivity of the purified protein as well as sequence analyses of 7 tryptic fragments obtained therefrom suggest a strong similarity with human monocyte/neutrophil elastase inhibitor, which is a member of the serine protease inhibitor (serpin) superfamily. We have previously identified and purified from the same conditioned medium a 36 kDa protein with myeloid immunomodulatory activity [2]. Taken together, these two reports support the role of tumor-derived soluble factors in tumor immunosurveillance.
Packard
B Z
BZ
OncoImmunin, Inc., College Park, MD 20742, USA.
Lee
S S
SS
Remold-O'Donnell
E
E
Komoriya
A
A
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002455:Cell Division / Q000187:drug effects; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000187:drug effects*; D008934:Mitogens / Q000302:isolation & purification* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D015166:Monitoring, Immunologic; D010446:Peptide Fragments / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D015842:Serine Proteinase Inhibitors / Q000737:chemistry; D015843:Serpins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014357:Trypsin; D014407:Tumor Cells, Cultured / Q000737:chemistry*
D000596:Amino Acids; D008934:Mitogens; D010446:Peptide Fragments; D011506:Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins; C075177:SERPINB1 protein, human; D014357:Trypsin