International Immunology, Vol. 13, No. 10, 1223-1231,
October 2001
© 2001 Japanese Society for Immunology
Inhibition of mucosal and systemic Th2-type immune responses by intranasal peptides containing a dominant T cell epitope of the allergen Der p 1
University of Western Australia Centre for Child Health Research and Department of Microbiology, TVW Telethon Institute for Child Health Research, PO Box 855, West Perth, WA 6872, Australia
1 Department of Microbiology, Fujita Health University, School of Medicine Toyoake, Aichi, Japan
Correspondence to: Correspondence to: W. R. Thomas
Although the intranasal administration of peptides containing T cell epitopes has been shown to be a potent method of inhibiting responses to the allergen Der p 1, the experiments to date have concentrated on their ability to regulate immune responses to the injection of antigen in a Th1-type adjuvant. Their ability to regulate responses to a Th2-type immunization and to sensitization via the respiratory mucosa has not been examined. Here it is shown that peptide used in doses required to block delayed-type hypersensitivity can also readily inhibit IgE responses to Der p 1 injected in alum. To examine responses induced in the respiratory mucosa, mice pretreated with intranasal peptide were sensitized with an intranasal dose of Der p 1 in conjunction with a mutated enterotoxin adjuvant. Intranasal peptide even in very high doses did not reduce IgE titers, but the ability of cells from the draining lymph nodes to release IL-4 and IL-13 but not IL-2, IL-5, IL-10 or IFN-
was reduced. These are the first reports on the effect of intranasal peptides containing T cell epitopes on IgE in Th2 immunization and on responses to respiratory immunization. Thus the effect of the peptide-induced mucosal tolerance differs depending on the type of immunization used for sensitization, but the potential to inhibit Th2 responses and responses to respiratory sensitization as well as Th1 responses has been demonstrated.
Keywords: inhibition, Der p 1, IgE, peptides, intranasal