Lactobacillus casei Zhang modulate cytokine and toll-like receptor expression and beneficially regulate poly I:C-induced immune responses in RAW264.7 macrophages.
Lactobacilli are frequently used as probiotics due to their beneficial effects on health. Lactobacillus casei Zhang (LcZ), which has favorable probiotic properties, was first isolated from koumiss. In this study, the immunomodulating effects of LcZ on cytokine and toll-like receptor expression in RAW264.7 macrophages was assessed and it was found that live LcZ promotes production of nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and interferon (IFN)-β. Transcription of inducible nitric oxide synthase (iNOS) was also enhanced by viable LcZ. The immunostimulating effects of live LcZ are significantly attenuated in heat-killed LcZ. Live LcZ promotes TLR2 mRNA transcription, whereas heat-killed LcZ enhances transcription of TLR2, TLR3, TLR4 and TLR9. Furthermore, live LcZ significantly suppresses polyinosinic:polycytidylic acid (poly I:C)-stimulated NO, iNOS and TNF-α expression while enhancing expression of IFN-β. It was also found that poly I:C-induced interferon regulatory factor 3 (IRF-3) reporter gene activity was significantly up-regulated by live LcZ. These results suggest that LcZ keeps the innate immune system alert by increasing transcription of Toll-like receptors and enhancing production of pro-inflammatory mediators and type I IFN in macrophages. The synergistic effect of live LcZ with poly I:C on IFN-β expression is associated with increased activity of IRF-3. LcZ has the potential to be used as an adjuvant against viral infections.
College of Life Science, Inner Mongolia Agricultural University, Hohhot 010018, China.
Yuzhen
Y
Wang
Jiming
J
Xie
Na
N
Wang
Yunxu
Y
Li
Xiaolin
X
Sun
Yong
Y
Zhang
Heping
H
Zhang
D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism*; D020869:Gene Expression Profiling; D007780:Lacticaseibacillus casei / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D011070:Poly I-C / Q000276:immunology*; D051193:Toll-Like Receptors / Q000096:biosynthesis*
D016207:Cytokines; D051193:Toll-Like Receptors; D009569:Nitric Oxide; D011070:Poly I-C