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Copyright © 2019 Alex I. Kanno et al. This is an open access article distributed under the Creative Commons Attribution License (the “License”), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. https://creativecommons.org/licenses/by/4.0/

Abstract

Background. A recombinant BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin 9K/129G (rBCG-S1PT), previously constructed by our research group, demonstrated the ability to develop high protection in mouse models of pertussis challenge which correlated with the induction of a Th1 immune response pattern. The Th1 immune response induced by rBCG-S1PT treatment was also confirmed in the murine orthotopic bladder cancer model, in which the intravesical instillation of rBCG-S1PT resulted in an improved antitumor effect. Based on these observations, we hypothesize that the reengineering of the S1PT expression in BCG could increase the efficiency of the protective Th1 immune response in order to develop a new alternative of immunotherapy in bladder cancer treatment. Objectives. To construct rBCG strains expressing S1PT from extrachromosomal (rBCG-S1PT) and integrative vectors (rBCG-Sli), or their combination, generating the bivalent strain (rBCG-S1+S1i), and to evaluate the respective immunogenicity of rBCG strains in mice. Methods. Mycobacterial plasmids were constructed by cloning the s1pt gene under integrative and extrachromosomal vectors and used to transform BCG, individually or in combination. Antigen expression and localization were confirmed by Western blot. Mice were immunized with wild-type BCG or the rBCG strains, and cytokines quantification and flow cytometry analysis were performed in splenocytes culture stimulated with mycobacterial-specific proteins. Findings. S1PT expression was confirmed in all rBCG strains. The extrachromosomal vector directs S1PT to the cell wall-associated fraction, while the integrative vector directs its expression mainly to the intracellular fraction. Higher levels of IFN-γ were observed in the splenocytes culture from the group immunized with rBCG-S1i in comparison to BCG or rBCG-S1PT. rBCG-S1+S1i showed higher levels of CD4+ IFN-γ+ and double-positive CD4+ IFN-γ+ TNF-α+ T cells. Conclusions. rBCG-S1+S1i was able to express the two forms of S1PT and elicited higher induction of polyfunctional CD4+ T cells, indicating enhanced immunogenicity and suggesting its use as immunotherapy for bladder cancer.

Details

Title
A Bivalent Recombinant Mycobacterium bovis BCG Expressing the S1 Subunit of the Pertussis Toxin Induces a Polyfunctional CD4+ T Cell Immune Response
Author
Kanno, Alex I 1   VIAFID ORCID Logo  ; Goulart, Cibelly 1 ; Leite, Luciana C C 1   VIAFID ORCID Logo  ; Pagliarone, Ana C 1 ; Nascimento, Ivan P 1   VIAFID ORCID Logo 

 Laboratório de Biotecnologia Molecular IV, Laboratório Especial de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, SP, Brazil 
Editor
Frederick D Quinn
Publication year
2019
Publication date
2019
Publisher
John Wiley & Sons, Inc.
ISSN
23146133
e-ISSN
23146141
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2189478211
Copyright
Copyright © 2019 Alex I. Kanno et al. This is an open access article distributed under the Creative Commons Attribution License (the “License”), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. https://creativecommons.org/licenses/by/4.0/