Open AccessCharacterization and Purification of an Immunosuppressive Factor Produced by a Small Cell Lung Cancer Cell Line
Author(s) -
Ikeda Toshiyuki,
Masuno Tomiya,
Ogura Takeshi,
Watanabe Masatoshi,
Shirasaka Takuma,
Kara Hideki,
Tanio Yoshiro,
Kawase Ichiro,
Kishimoto Susumu
Publication year - 1991
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1991.tb01850.x
Subject(s) - concanavalin a , cell culture , lymphokine , trypsin , biology , microbiology and biotechnology , sodium dodecyl sulfate , gel electrophoresis , biochemistry , immune system , immunology , enzyme , in vitro , genetics
The present study was undertaken to determine whether small cell lung cancer (SCLC) cell lines produce immunosuppressive factors and, if they do, to characterize the factors. The supernatants of SCLG cell lines, H69 and N857, inhibited not only the blastogenic response of human peripheral blood lymphocytes (PBL) to phytohemagglutinin or concanavalin A, but also the cytotoxic activity of lymphokine‐activated killer cells. Neither was inhibited by supernatants from non‐SCLC cell lines PC9, QG56, and A549. The immunosuppressive activity of H69 supernatant was stable upon heating to 56°C for 60 min, but labile when heated to 70°C for 10 min. The activity was abolished after dialysis at pH 2.0 or pH 11.0, but not at pH 4.5 or pH 9.0. Digestion with trypsin or proteinase eliminated the immunosuppressive activity, whereas treatment with neuraminidase, mixed glycosidase, DNase or RNase had no effect, suggesting that the immunosuppressive activity in H69 supernatant is due to a protein factor. This H69‐derived immunosuppressive factor was isolated by ion exchange chromatography using a gradient of 0.04 to 0.08 M NaCl solution. Gel filtration and sodium dodecyl sulfate‐polyacrylamide gel electrophoresis showed the factor to have molecular weights of 98 kD and 102 kD, respectively. These results suggest that SCLC cells produce a potent immunosuppressive factor which may account for the immune deficiency in SCLC patients.