Basic Research
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Feb 28, 2008; 14(8): 1192-1203
Published online Feb 28, 2008. doi: 10.3748/wjg.14.1192
Probiotic Leuconostoc mesenteroides ssp. cremoris and Streptococcus thermophilus induce IL-12 and IFN-γ production
Riina A Kekkonen, Elina Kajasto, Minja Miettinen, Ville Veckman, Riitta Korpela, Ilkka Julkunen
Riina A Kekkonen, Riitta Korpela, University of Helsinki, Institute of Biomedicine, Pharmacology, PO Box 63, Helsinki 00014, Finland
Riina A Kekkonen, Riitta Korpela, Valio Ltd, Research Centre, Meijeritie 4, 00370 Helsinki, Finland
Riina A Kekkonen, Elina Kajasto, Minja Miettinen, Ville Veckman, Ilkka Julkunen, National Public Health Institute, Department of Viral Diseases and Immunology, Mannerheimintie 166, Helsinki 00300, Finland
Riitta Korpela, Foundation for Nutrition Research, PO Box 30, Valio 00039, Finland
Author contributions: Kekkonen R, Kajasto E, Miettinen M, Korpela R and Julkunen I designed research; Kekkonen R, Kajasto E, Miettinen M and Veckman V performed the experiments; Kekkonen R and Kajasto E analysed data; Kekkonen R, Miettinen M, Korpela R and Julkunen I wrote the paper.
Correspondence to: Riina Kekkonen, Valio Research Centre, Meijeritie 4, Helsinki 00370, Finland. riina.kekkonen@valio.fi
Telephone: +358-50-3842571
Fax: +358-10-3813019
Received: September 21, 2007
Revised: December 11, 2007
Published online: February 28, 2008
Abstract

AIM: To investigate the capacity of potentially probiotic strains from six bacterial genera to induce cytokine production alone or in combinations in order to identify potential enhancing or synergistic effects in order to select probiotic bacteria for in vivo purposes.

METHODS: Cytokine production in human peripheral blood mononuclear cells (PBMC) in response to stimulation with eleven different potentially probiotic bacterial strains from Streptococcus, Lactobacillus, Bifidobacterium, Lactococcus, Leuconostoc and Propionibacterium genera was analysed. Production and mRNA expression of TNF-α, IL-12, IFN-γ and IL-10 were determined by ELISA and Northern blotting, respectively.

RESULTS: All tested bacteria induced TNF-α production. The best inducers of Th1 type cytokines IL-12 and IFN-γ were Streptococcus and Leuconostoc strains. All Bifidobacterium and Propionibacterium strains induced higher IL-10 production than other studied bacteria. Stimulation of PBMC with any bacterial combinations did not result in enhanced cytokine production suggesting that different bacteria whether gram-positive or gram-negative compete with each other during host cell interactions.

CONCLUSION: The probiotic S. thermophilus and Leuconostoc strains are more potent inducers of Th1 type cytokines IL-12 and IFN-γ than the probiotic Lactobacillus strains. Bacterial combinations did not result in enhanced cytokine production.

Keywords: Probiotics; Streptococcus; Lactobacillus; Bifidobacterium; Lactococcus; Leuconostoc; Propionibacterium; Immune response; Cytokines; Mononuclear cells