Characterization of candidate anti-allergic probiotic strains in a model of th2-skewed human peripheral blood mononuclear cells.
BACKGROUND
Pre-clinical and clinical studies have evaluated the efficacy of probiotics in allergy. However, predictive in vitro systems for rational strain selection are still missing.


METHODS
We developed a novel in vitro screening system for the characterization of probiotics with anti-allergic potential. In this model, human peripheral blood mononuclear cells (PBMC) from healthy donors (n = 68) were skewed towards a Th2 cytokine phenotype by culture with IL-4 and anti-CD40, to resemble cells from allergic donors. Th2-skewed cells were then co-cultured with probiotics; a total of 35 strains were tested. Levels of IFN-γ, IL-10, IL-5 and 7 additional cytokines in culture supernatants were determined by ELISA or multiplex assay. Gene expression was assessed by real-time PCR. For validation, splenocytes from ovalbumin-primed mice and PBMC from grass-allergic donors were restimulated with respective antigen and co-cultured with probiotics, and cytokine profiles were correlated.


RESULTS
Culture with IL-4 and anti-CD40 antibody induced secretion of IL-5 from PBMC, indicative of induction of a Th2 phenotype. Cytokine profiles induced by probiotics were strain specific even though species- and genus-specific clustering was observed for many strains by principal component analysis. This was paralleled by mRNA levels of the corresponding genes such as increased Tbet and reduced GATA-3 gene expression. Cytokine profiles induced by probiotics in PBMC stimulated with IL-4 and anti-CD40 correlated with those obtained from allergen-stimulated murine splenocytes or human PBMC from grass-allergic donors.


CONCLUSIONS
Cytokine profiling of probiotic strains with IL-4-/anti-CD40-stimulated PBMC allowed to determine the effect of probiotics on Th2-skewed cells and thus to classify probiotic strains with anti-allergic potential.
Allergy Group, Department of Nutrition and Health, Nestlé Research Center, Lausanne, Switzerland. sebastien.holvoet@rdls.nestle.com
Sébastien
S
Holvoet
Adrian W
AW
Zuercher
Françoise
F
Julien-Javaux
Marie
M
Perrot
Annick
A
Mercenier
D000293:Adolescent; D000328:Adult; D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000517:prevention & control; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D025341:Principal Component Analysis; D019936:Probiotics; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018418:Th2 Cells / Q000276:immunology*; D055815:Young Adult
D016207:Cytokines; D012333:RNA, Messenger