PMID- 3498987
OWN - NLM
STAT- MEDLINE
DCOM- 19871120
LR  - 20190618
IS  - 0036-8075 (Print)
IS  - 0036-8075 (Linking)
VI  - 238
IP  - 4826
DP  - 1987 Oct 23
TI  - Mutations in diphtheria toxin separate binding from entry and amplify immunotoxin 
      selectivity.
PG  - 536-9
AB  - Monoclonal antibodies linked to toxic proteins (immunotoxins) can selectively 
      kill some tumor cells in vitro and in vivo. However, reagents that combine the 
      full potency of the native toxins with the high degree of cell type selectivity 
      of monoclonal antibodies have not previously been designed. Two heretofore 
      inseparable activities on one polypeptide chain of diphtheria toxin and ricin 
      account for the failure to construct optimal reagents. The B chains (i) 
      facilitate entry of the A chain to the cytosol, which allows immunotoxins to 
      efficiently kill target cells, and (ii) bind to receptors present on most cells, 
      which imparts to immunotoxins a large degree of non-target cell toxicity. This 
      report identifies point mutations in the B polypeptide chain of diphtheria toxin 
      that block binding but allow cytosol entry. Three mutants of diphtheria toxin 
      have 1/1,000 to 1/10,000 the toxicity and 1/100 to 1/8,000 the binding activity 
      of diphtheria toxin. Linking of either of two of the inactivated mutant toxins 
      (CRM103, Phe508; CRM107, Phe390, Phe525) to a monoclonal antibody specific for 
      human T cells reconstitutes full target-cell toxicity--indistinguishable from 
      that of the native toxin linked to the same antibody--without restoring 
      non-target cell toxicity. This separation of the entry function from the binding 
      function generates a uniquely potent and cell type-specific immunotoxin that 
      retains full diphtheria toxin toxicity, yet is four to five orders of magnitude 
      less toxic than the native toxin is to nontarget cells.
FAU - Greenfield, L
AU  - Greenfield L
AD  - Department of Microbial Genetics, Cetus Corporation, Emeryville, CA 94608.
FAU - Johnson, V G
AU  - Johnson VG
FAU - Youle, R J
AU  - Youle RJ
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - Science
JT  - Science (New York, N.Y.)
JID - 0404511
RN  - 0 (Antibodies, Monoclonal)
RN  - 0 (Antigens, Differentiation, T-Lymphocyte)
RN  - 0 (Antigens, Surface)
RN  - 0 (Diphtheria Toxin)
RN  - 0 (HBEGF protein, human)
RN  - 0 (Heparin-binding EGF-like Growth Factor)
RN  - 0 (Immunotoxins)
RN  - 0 (Intercellular Signaling Peptides and Proteins)
RN  - 0 (Receptors, Cell Surface)
RN  - 0 (Receptors, Cholinergic)
RN  - 9009-86-3 (Ricin)
SB  - IM
MH  - Animals
MH  - Antibodies, Monoclonal
MH  - Antigens, Differentiation, T-Lymphocyte/immunology
MH  - Antigens, Surface/immunology
MH  - Cell Line
MH  - Cell Survival/drug effects
MH  - Chemical Phenomena
MH  - Chemistry
MH  - Diphtheria Toxin/genetics/*metabolism/pharmacology
MH  - Heparin-binding EGF-like Growth Factor
MH  - Immunotoxins/*pharmacology
MH  - Intercellular Signaling Peptides and Proteins
MH  - *Mutation
MH  - *Receptors, Cell Surface
MH  - Receptors, Cholinergic/metabolism
MH  - Ricin/metabolism
MH  - Structure-Activity Relationship
MH  - T-Lymphocytes/immunology
MH  - Vero Cells
EDAT- 1987/10/23 00:00
MHDA- 1987/10/23 00:01
CRDT- 1987/10/23 00:00
PHST- 1987/10/23 00:00 [pubmed]
PHST- 1987/10/23 00:01 [medline]
PHST- 1987/10/23 00:00 [entrez]
AID - 10.1126/science.3498987 [doi]
PST - ppublish
SO  - Science. 1987 Oct 23;238(4826):536-9. doi: 10.1126/science.3498987.