Abstract
A nontoxic mutant (LTK7) of the Escherichia coli heat-labile enterotoxin (LT) lacking ADP-ribosylating activity but retaining holotoxin formation was constructed. By using site-directed mutagenesis, the arginine at position 7 of the A subunit was replaced with lysine. This molecule, which was nontoxic in several assays, was able to bind to eukaryotic cells and acted as a mucosal adjuvant for co-administered proteins; BALB/c mice immunized intranasally with LTK7 and ovalbumin developed high levels of serum and local antibodies to ovalbumin and toxin. In addition, mice immunized intranasally with fragment C of tetanus toxin and LTK7 were protected against lethal challenge with tetanus toxin. Thus nontoxic mutants of heat-labile toxin can act as effective intranasal mucosal adjuvants.
Original language | English |
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Pages (from-to) | 1644-1648 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 92 |
Issue number | 5 |
DOIs | |
Publication status | Published - 28 Feb 1995 |
Externally published | Yes |
Keywords
- Heat-labile enterotoxin
- Nontoxic mutant
- Tetanus