In vitro Th1 cytokine-independent Th2 suppressive effects of bifidobacteria.
A comparison between 17 strains of lactic acid bacteria and 15 strains of bifidobacteria indicated that bifidobacteria induced significantly lower levels of interleukin-12 (IL-12) in murine splenic cells. The present study aims to evaluate the effect and mechanism of Bifidobacterium longum BB536, a probiotic strain, in suppressing antigen-induced Th2 immune response in vitro. BB536 suppressed immunoglobulin (Ig) E and IL-4 production by ovalbumin-sensitized splenic cells, but induction of Th1-inducing cytokine production, such as IL-12 and gamma interferon (IFN-gamma) tended to be lower compared with lactic acid bacteria. Neutralization with antibodies to IL-12, IFN-gamma, IL-10 and transforming growth factor beta indicated negative involvement of Th1-inducing cytokines and regulatory cytokines in the suppression of Th2 immune response by BB536, especially when treated at higher doses of BB536 (>10 microg cells/ml). Furthermore, BB536 induced the maturation of immature bone marrow-derived dendritic cells (BM-DCs), and suppressed antigen-induced IL-4 production mediated by BM-DCs. These results suggested that BB536 suppressed Th2 immune responses, partially independent of Th1-inducing cytokines and independent of regulatory cytokines, mediated by antigen-presenting cells such as dendritic cells.
Iwabuchi
Noriyuki
N
Food Science and Technology Institute, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa, Japan. n-iwabuchi@morinagamilk.co.jp
Takahashi
Noritoshi
N
Xiao
Jin-zhong
JZ
Miyaji
Kazuhiro
K
Iwatsuki
Keiji
K
D000818:Animals; D001644:Bifidobacterium / Q000276:immunology / Q000502:physiology*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D007073:Immunoglobulin E / Q000096:biosynthesis; D007165:Immunosuppression Therapy; D007777:Lactobacillaceae / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013291:Streptococcus / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism
D016207:Cytokines; D007073:Immunoglobulin E