Growth Inhibition, Morphological Change, and Ectoenzyme Release of LLC-PK1 Cells by Phosphatidylinositol-specific Phospholipase C ofBacillus thuringiensis

Bacterial Phosphatidylinositol‐Specific Phospholipases C as Membrane‐Attacking Agents and Tools for Research on GPI‐Anchored Proteins

“…Although bacterial PI-PLCs are not hemolytic toward mammalian erythrocytes, cytotoxic or physiological actions on eucaryotic cells have been expected. Actually, PI-PLCs of B. cereus and B. thuringiensis proved to bring about growth inhibition of cultured eucaryotic cells in vitro and in vivo (Ikezawa et al, 1982(Ikezawa et al, -1983(Ikezawa et al, , 1985(Ikezawa et al, , 1989Itami et al, 1997). For instance, both PI-PLCs significantly inhibited the cell growth of Sarcoma 180 ascites tumor transplanted intraperitoneally into mice peritoneum (Ikezawa et al, 1982(Ikezawa et al, -1983.…”

“…Also, when B. thuringiensis PI-PLC was added to the culture media, the cell growth was significantly inhibited by prolonged contact with the enzyme. The cell lines tested so far were KB III and LLC-PK1, derived from mammals, and TN-368, derived from a moth, Trichoplusia ni (Ikezawa et al, 1985(Ikezawa et al, , 1989Itami et al, 1997). In these cultures, the cell growth was inhibited by 30 to 50%, after 2-4 days incubation with 1-4 units (mg order)/ml of purified PI-PLC.…”

“…In these cultures, the cell growth was inhibited by 30 to 50%, after 2-4 days incubation with 1-4 units (mg order)/ml of purified PI-PLC. By phase-contrast microscopy (Ikezawa et al, 1989;Itami et al, 1997) and transmission electronmicroscopy (Ikezawa et al, 1989), the cells of LLC-PK1 and TN-368 cultivated in the presence of PI-PLC, were examined for their morphological change. By cultivation in the presence of PI-PLC, needlelike appendages appeared in LLC-PK1 cells, and many cells were released into the medium (Itami et al, 1997).…”