Type II heat-labile toxins (LTs) from enterotoxigenic Escherichia coli (ETEC): adjuvant effect and inflammatory activity.

Author(s)

Camila Mathias dos Santos

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2014-09-23

Examining board members

Luis Carlos de Souza Ferreira; Beatriz Ernestina Cabilio Guth; Marina Baquerizo Martinez; Eliane Namie Miyaji; Irene da Silva Soares

• Advisor: Luis Carlos de Souza Ferreira

Abstract

This work has made significant advances in the understanding of the potential of type II heat-labile toxins (LT-IIs) as vaccine adjuvants by intradermal and transcutaneous route. The generated data indicate that native forms of LT-IIb and LT-IIc act as potent vaccine adjuvants when intradermally injected inducing antigen-specific immune responses, as measured by the generation of systemic serum antibody (IgG) and activation of cytotoxic CD8+ T lymphocytes. Besides the adjuvant effects, LT-IIs show reduced side effects, measured by the lesser edema formation and reduced leukocytes migration to the site of injection, in comparison to LT-I. The results also indicate that the adjuvant activity of LTs applied transcutaneously may be related to the the ganglioside GM1 binding property since the LT-IIb toxin, unable to interact with this receptor, has no adjuvant effect by this route. The presented data set opens prospects for the employment of native LT-IIs as parenteral adjuvants in vaccines for animals and humans. (AU)