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Journal of Immunology Research
Volume 2016 (2016), Article ID 7402760, 8 pages
http://dx.doi.org/10.1155/2016/7402760
Research Article

Lactobacillus rhamnosus GG Activation of Dendritic Cells and Neutrophils Depends on the Dose and Time of Exposure

1Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
2Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594
3Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545

Received 10 March 2016; Revised 9 May 2016; Accepted 19 May 2016

Academic Editor: Lenin Pavón

Copyright © 2016 Shirong Cai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study evaluates the ability of Lactobacillus rhamnosus GG (LGG) to activate DC and neutrophils and modulate T cell activation and the impact of bacterial dose on these responses. Murine bone marrow derived DC or neutrophils were stimulated with LGG at ratios of 5 : 1, 10 : 1, and 100 : 1 (LGG : cells) and DC maturation (CD40, CD80, CD86, CD83, and MHC class II) and cytokine production (IL-10, TNF-α, and IL-12p70) were examined after 2 h and 18 h coculture and compared to the ability of BCG (the present immunotherapeutic agent for bladder cancer) to stimulate these cells. A 2 h exposure to 100 : 1 (high dose) or an 18 h exposure to 5 : 1 or 10 : 1 (low dose), LGG : cells, induced the highest production of IL-12 and upregulation of CD40, CD80, CD86, and MHC II on DC. In DCs stimulated with LGG activated neutrophils IL-12 production decreased with increasing dose. LGG induced 10-fold greater IL-12 production than BCG. T cell IFNγ and IL-2 production was significantly greater when stimulated with DC activated with low dose LGG. In conclusion, DC or DC activated with neutrophils exposed to low dose LGG induced greater Th1 polarization in T cells and this could potentially exert stronger antitumor effects. Thus the dose of LGG used for immunotherapy could determine treatment efficacy.