Probiotic Leuconostoc mesenteroides ssp. cremoris and Streptococcus thermophilus induce IL-12 and IFN-gamma production.
OBJECTIVE
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-alpha, IL-12, IFN-gamma and IL-10 were determined by ELISA and Northern blotting, respectively.


RESULTS
All tested bacteria induced TNF-alpha production. The best inducers of Th1 type cytokines IL-12 and IFN-gamma 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.


CONCLUSIONS
The probiotic S. thermophilus and Leuconostoc strains are more potent inducers of Th1 type cytokines IL-12 and IFN-gamma than the probiotic Lactobacillus strains. Bacterial combinations did not result in enhanced cytokine production.
Kekkonen
Riina-A
RA
University of Helsinki, Institute of Biomedicine, Pharmacology, Helsinki 00014, Finland. riina.kekkonen@valio.fi
Kajasto
Elina
E
Miettinen
Minja
M
Veckman
Ville
V
Korpela
Riitta
R
Julkunen
Ilkka
I
D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D018664:Interleukin-12 / Q000096:biosynthesis*; D007700:Kinetics; D007934:Leuconostoc / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008954:Models, Biological; D019936:Probiotics / Q000378:metabolism*; D048249:Streptococcus thermophilus / Q000378:metabolism*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D007371:Interferon-gamma