A purified protein from Salmonella typhimurium inhibits high-affinity interleukin-2 receptor expression on CTLL-2 cells.
Previously, we have demonstrated that the immunosuppression induced by the purified substance Salmonella typhimurium-derived inhibitor of T-cell proliferation (STI) involves T-cell non-responsiveness to interleukin-2 (IL-2). In the present study, it was found that STI inhibited the growth of CTLL-2 cells, which are an IL-2-dependent cytotoxic T-cell line. Analysis of IL-2 receptor (IL-2R) function showed that STI inhibited high-affinity receptor expression and internalization by CTLL-2 cells. Furthermore, FACS analysis demonstrated that STI inhibited both beta chain and gamma chain expression of IL-2R on the cells. These results suggest that the suppression of T-cell proliferation induced by STI results from a defect in IL-2R function.
Arai
T
T
Department of Microbiology, Meiji College of Pharmacy, Tokyo, Japan.
Matsui
K
K
D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology* / Q000302:isolation & purification; D002455:Cell Division; D002460:Cell Line; D015536:Down-Regulation; D007376:Interleukin-2 / Q000378:metabolism; D051379:Mice; D015375:Receptors, Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D012486:Salmonella typhimurium / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D001426:Bacterial Proteins; D007376:Interleukin-2; D015375:Receptors, Interleukin-2