Adjuvant action of Escherichia coli enterotoxin for delayed-type hypersensitivity to Oka vaccine virus on pernasal co-administration in mice

The usefulness of a mutant of Escherichia coli enterotoxin for the induction of cellular immunity to varicella-zoster virus as a mucosal adjuvant is assessed in mice. When a commercially available live varicella vaccine (the Oka strain) and toxin were once administered simultaneously via the nasal route, delayed-type hypersensitivity to Oka vaccine virus was significantly induced and detected by footpad test in mice. Moreover, when spleen cells from mice immunized with the vaccine and toxin were re-stimulated with live vaccine in vitro, they showed more thymidine uptake and produced more IL-2 than those from mice immunized with the vaccine alone. These results suggest that mutant enterotoxin has adjuvant action to induce a specific delayed-type hypersensitivity to Oka vaccine virus on nasal co-administration with live vaccine virus. (C) 2000 Elsevier Science Ltd. All rights reserved.