The cytotoxicity of Pseudomonas exotoxin A, inactivated by modification of the cell-binding domain I, is restored when conjugated to an erythroid cell-specific targeting agent.
To be capable of selective killing of tumor cells, the non-selective Pseudomonas aeruginosa exotoxin A must have its cell-binding domain inactivated or removed and then be chemically linked to, or genetically fused with, a specific targeting agent. In the present study, epsilon-NH2 groups of lysine residues of the cell-binding domain of exotoxin A were extensively propionylated with N-succinimidyl-3-propionate (NSP). The NSP-treated exotoxin retained its cytocidal ADP-ribosyltransferase activity, but it could no longer bind to, and inhibit the proliferation of, Friend murine erythroleukemia cells. Cytotoxicity (i.e., the ability to inhibit proliferation) for the Friend erythroid cells was restored completely to the NSP-inactivated exotoxin by conjugating it to ADIF, an autocrine factor secreted by chicken erythroleukemia cells which selectively inhibits the differentiation of erythroid cells such as Friend erythroleukemia cells without inhibiting their proliferation.
Bourdenet
S
S
Laboratoire de Biochimie Microbienne (CNRS UA 1176), Universite Claude Bernard, Lyon, France.
Doyonnas
R
R
Vacheron
M J
MJ
Guinand
M
M
Fasciotto
B
B
Ristic
A
A
Michel
G
G
Cozzone
A J
AJ
Durkin
J P
JP
Whitfield
J F
JF
D036002:ADP Ribose Transferases; D000818:Animals; D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D001665:Binding Sites / Q000187:drug effects; D001685:Biological Factors / Q000378:metabolism / Q000494:pharmacology*; D002454:Cell Differentiation; D002455:Cell Division; D015672:Erythroid Precursor Cells / Q000378:metabolism* / Q000473:pathology; D005098:Exotoxins / Q000378:metabolism / Q000494:pharmacology*; D000922:Immunotoxins / Q000494:pharmacology*; D004915:Leukemia, Erythroblastic, Acute / Q000473:pathology; D051379:Mice; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011422:Propionates / Q000494:pharmacology; D013388:Succinimides / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000473:pathology; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
D036002:ADP Ribose Transferases; D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D001685:Biological Factors; D005098:Exotoxins; D000922:Immunotoxins; D011065:Poly(ADP-ribose) Polymerases; D011422:Propionates; D013388:Succinimides; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C018151:N-succinimidyl 3-(2-pyridyldithio)propionate; C021749:N-succinimidyl propionate