» Articles » PMID: 31199313

Stimulation of Nucleotide Oligomerization Domain and Toll-Like Receptors 2 to Enhance the Effect of Bacillus Calmette Guerin Immunization for Prevention of Mycobacterium Tuberculosis Infection: Protocol for a Series of Preclinical Randomized...

Overview
Journal JMIR Res Protoc
Publisher JMIR Publications
Specialty General Medicine
Date 2019 Jun 15
PMID 31199313
Citations 1
Authors
Affiliations
Soon will be listed here.
Abstract

Background: Bacillus calmette guerin (BCG) immunization has been associated with a reduction in Mycobacterium tuberculosis (MTB) infection. BCG immunization has been shown to enhance innate immunity. This effect of BCG can be explained by an enhancing effect on innate immunity.

Objective: This study aimed to test the following hypotheses: (1) BCG immunization can prevent infection with MTB, (2) prevention of infection occurs via stimulation of NOD2 (nucleotide oligomerization domain) and toll-like receptors 2 (TLR2), and (3) the effect of BCG immunization on prevention of infection with MTB can be enhanced by giving stimulators of NOD2 and TLR2.

Methods: To detect the influence of immunization on infection rates, the ultralow dose (ULD) infection model is used. The infection rate of mice vaccinated with BCG and exposed after 6 weeks to ULD of MTB and unvaccinated mice are compared via cultures of lung homogenates and interferon (IFN) gamma release assay. If a reduced infection rate by BCG immunization is confirmed, the experiment is repeated by giving BCG combined simultaneously or in time sequence with the enhancers of innate immunity murabutide or beta-glycan. The influence of murabutide or beta-glycan alone on infection rates is investigated. To quantify the contribution of innate immunity levels of tumor necrosis factor, IFN gamma expression, histone H3 K4me3 trimethylation, and concentrations of monocytes with features of activation of innate immunity as defined by the Ly6Chigh as well as CD11b positive phenotype in immunized versus unimmunized infected and uninfected mice in the various immunization protocols is compared. The experiments will be repeated with prior application of the inhibitors of epigenetic programming of innate immunity histone methyltransferase inhibitor 5'-deoxy-5'-methylthio-adenosine and histone acetyl transferase inhibitor epigallocatechin-3-gallate. The influence of BCG on innate immunity is further corroborated by a prospective observational study in human infants.

Results: Investigations of derivatives of muramyl dipeptide (MDP) to enhance early immunity in the C57BL/6 mouse strain (mice aged 7 weeks) by another group used 300 micrograms per mouse of oil-associated 6-0-mycoloyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (mycol-MDP) 50/50 mixed with Freund's incomplete adjuvant. Comparison of colony-forming unit (CFU) count in the lungs 3 weeks after aerosol challenge with Mycobacterium bovis of groups (n=5) between groups receiving mycol-MDP in oil emulsion (see above) versus controls (n=5) showed a significantly lower CFU count of 94.5 x106 (SD 22.0) in cases versus controls with 204.0 X 106 (SD 77.6). It is important to note that after elimination of T-cells in this model, a reduction of CFU in lungs of mice treated with mycol-MDP persisted albeit without statistical significance, which was possibly related to the small number of animals used.

Conclusions: Demonstration of a reduction of MTB infection by enhancement of innate immunity could show a new approach to improving vaccine efficacy against this pathogen.

International Registered Report Identifier (irrid): PRR1-10.2196/13045.

Citing Articles

NOD2/RIG-I Activating Adjuvant Enhances the Efficacy of BCG Vaccine Against Tuberculosis in Mice.

Khan A, Singh V, Mishra A, Soudani E, Bakhru P, Singh C Front Immunol. 2020; 11:592333.

PMID: 33365029 PMC: 7751440. DOI: 10.3389/fimmu.2020.592333.

References
1.
Liu X, Xu Y, Hardy L, Khammanivong V, Zhao W, Fernando G . IL-10 mediates suppression of the CD8 T cell IFN-gamma response to a novel viral epitope in a primed host. J Immunol. 2003; 171(9):4765-72. DOI: 10.4049/jimmunol.171.9.4765. View

2.
Filaci G, Fravega M, Negrini S, Procopio F, Fenoglio D, Rizzi M . Nonantigen specific CD8+ T suppressor lymphocytes originate from CD8+CD28- T cells and inhibit both T-cell proliferation and CTL function. Hum Immunol. 2004; 65(2):142-56. DOI: 10.1016/j.humimm.2003.12.001. View

3.
Gutierrez M, Master S, Singh S, Taylor G, Colombo M, Deretic V . Autophagy is a defense mechanism inhibiting BCG and Mycobacterium tuberculosis survival in infected macrophages. Cell. 2004; 119(6):753-66. DOI: 10.1016/j.cell.2004.11.038. View

4.
Uehori J, Fukase K, Akazawa T, Uematsu S, Akira S, Funami K . Dendritic cell maturation induced by muramyl dipeptide (MDP) derivatives: monoacylated MDP confers TLR2/TLR4 activation. J Immunol. 2005; 174(11):7096-103. DOI: 10.4049/jimmunol.174.11.7096. View

5.
Ferwerda G, Girardin S, Kullberg B, Le Bourhis L, de Jong D, Langenberg D . NOD2 and toll-like receptors are nonredundant recognition systems of Mycobacterium tuberculosis. PLoS Pathog. 2005; 1(3):279-85. PMC: 1291354. DOI: 10.1371/journal.ppat.0010034. View