Anti-idiotypic antibodies that protect cells against the action of diphtheria toxin.
An anti-idiotypic serum prepared against the combining site (idiotype) of specific anti-diphtheria toxoid antibodies was characterized with respect to its interaction with highly diphtheria toxin-sensitive Vero cells. Although the anti-idiotypic serum protected Vero cells against the cytotoxic action of diphtheria toxin, it did not prevent the binding of 125I-labeled diphtheria toxin to the cells but did inhibit the internalization and degradation of 125I-labeled toxin. This anti-idiotypic serum immunoprecipitated a cell-surface protein from radiolabeled Vero cells with an apparent Mr of approximately 15,000. These results are consistent with the hypothesis that the anti-idiotypic serum contains antibodies that carry an internal image of an internalization site on the toxin and that a cell-surface protein involved in toxin internalization possesses a complementary site recognized by both the toxin and the anti-idiotypic antibodies.
Rolf
J M
JM
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
Gaudin
H M
HM
Tirrell
S M
SM
MacDonald
A B
AB
Eidels
L
L
D000818:Animals; D002470:Cell Survival; D004167:Diphtheria Toxin / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D066257:Heparin-binding EGF-like Growth Factor; D007106:Immune Sera / Q000494:pharmacology*; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D007163:Immunosorbent Techniques; D036341:Intercellular Signaling Peptides and Proteins; D007457:Iodine Radioisotopes; D008970:Molecular Weight; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic / Q000032:analysis / Q000276:immunology; D014709:Vero Cells
D004167:Diphtheria Toxin; D000939:Epitopes; D066257:Heparin-binding EGF-like Growth Factor; D007106:Immune Sera; D007130:Immunoglobulin Idiotypes; D036341:Intercellular Signaling Peptides and Proteins; D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D011950:Receptors, Cholinergic