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Entry of diphtheria toxin linked to concanavalin A into primate and murine cells
Author(s) -
Guillemot Jean Claude,
Sundan Anders,
Olsnes Sjur,
Sandvig Kirsten
Publication year - 1985
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041220205
Subject(s) - vero cell , diphtheria toxin , conjugate , concanavalin a , toxin , immunotoxin , biology , microbiology and biotechnology , chemistry , biochemistry , cytotoxicity , in vitro , mathematical analysis , mathematics
Diphtheria toxin linked by a disulfide bridge to concanavalin A was highly toxic to HeLa S 3 and Vero cells, as well as to murine L cells. The cells could be protected with α‐methyl mannoside, indicating that the conjugate binds mainly through its concanavalin A moiety. Treatment of Vero cells with phospholipase C, TPA (12‐O‐tetradecanoylphorbol‐13‐acetate), and vanadate, which strongly reduce the ability of the cells to bind free diphtheria toxin, had little protective effect against the conjugate, whereas SITS (L‐acetamido‐4′‐isothiocyano‐stilbene‐2,2′disulfonic acid), which inhibits diphtheria toxin binding, as well as the subsequent entry, protected Vero cells, but not L cells. Both types of cells are protected against the conjugate by NH 4 Cl and monensin, indicating that an acidified compartment is necessary for entry into the cytosol. Exposure of cells, bound with surface conjugate, to low pH induced entry of the toxin into Vero cells, but not into L Cells. Phospholipase C, TPA, and vanadate did not protect L cells against the conjugate. It is concluded that toxin in the conjugate enters L cells by a route which involves low pH, but which is not identical to that in Vero cells.