Probiotic modulation of dendritic cell function is influenced by ageing

J You,S C Knight,P Yaqoob,E R Mann,H Dong

doi:10.1017/s0029665113002899

J You, S C Knight + Show 3 more

Open Access

https://doi.org/10.1017/s0029665113002899

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Abstract

Dendritic cells (DCs) are critical for the generation of T-cell responses. DC function may be modulated by probiotics, which confer health benefits in immunocompromised individuals, such as the elderly. This study investigated the effects of four probiotics, Bifidobacterium longum bv. infantis CCUG 52486, B. longum SP 07/3, Lactobacillus rhamnosus GG (L.GG) and L. casei Shirota (LcS), on DC function in an allogeneic mixed leucocyte reaction (MLR) model, using DCs and T-cells from young and older donors in different combinations. All four probiotics enhanced expression of CD40, CD80 and CCR7 on both young and older DCs, but enhanced cytokine production (TGF-β, TNF-α) by old DCs only. LcS induced IL-12 and IFNγ production by DC to a greater degree than other strains, while B. longum bv. infantis CCUG 52486 favoured IL-10 production. Stimulation of young T cells in an allogeneic MLR with DC was enhanced by probiotic pretreatment of old DCs, which demonstrated greater activation (CD25) than untreated controls. However, pretreatment of young or old DCs with LPS or probiotics failed to enhance the proliferation of T-cells derived from older donors. In conclusion, this study demonstrates that ageing increases the responsiveness of DCs to probiotics, but this is not sufficient to overcome the impact of immunosenescence in the MLR.

Highlights

PBMC obtained from 8 healthy young (20–30 y) and 8 healthy older (65–75 y) subjects
Stimulation of young T cells in the mixed leukocyte reaction (MLR) with Dendritic cells (DCs) was enhanced by probiotic pretreatment of old DCs, which demonstrated greater activation (CD25), gut-homing ability and TGF-b than untreated controls
Pretreatment of young or old DCs with LPS or probiotics failed to enhance the activation and proliferation of T-cells derived from older donors (Fig. 1)

Summary

Introduction

PBMC obtained from 8 healthy young (20–30 y) and 8 healthy older (65–75 y) subjects. Low density cells (LDCs), enriched source of DCs, was obtained by overnight incubation of PBMC and removal of non-adherent cells. All four probiotics enhanced expression of CD40, CD80 and CCR7 on both young and older DCs, with no differences between strains.

Results

Conclusion