Interaction between enteric epithelial cells and Peyer's patch lymphocytes in response to Shigella lipopolysaccharide: effect on nitric oxide and IL-6 release.
OBJECTIVE
To investigate the effect of interaction between enteric epithelial cells and lymphocytes of Peyer's patch on the release of nitric oxide (NO) and IL-6 in response to Shigella lipopolysaccharide (LPS).


METHODS
Human colonic epithelial cells (Caco-2) were mixed cocultured with lymphocytes of Peyer's patch from wild-type (C57 mice) and inducible NO synthase knockout mice, and challenged with Shigella F2a-12 LPS. Release of NO and mIL-6 was measured by Griess colorimetric assay and enzyme-linked immunosorbent assay (ELISA), respectively.


RESULTS
In the absence of LPS challenge, NO was detected in the culture medium of Caco-2 epithelial cells but not in lymphocytes of Peyer's patch, and the NO release was further up-regulated in both cocultures with lymphocytes from either the wild-type or iNOS knockout mice, with a significantly higher level observed in the coculture with iNOS knockout lymphocytes. After Shigella F2a-12 LPS challenge for 24-h, NO production was significantly increased in both Caco-2 alone and the coculture with lymphocytes of Peyer's patch from the wild-type mice but not from iNOS knockout mice. LPS was found to stimulate the release of mIL-6 from lymphocytes, which was suppressed by coculture with Caco-2 epithelial cells. The LPS-induced mIL-6 production in lymphocytes from iNOS knockout mice was significantly greater than that from the wild-type mice.


CONCLUSIONS
Lymphocytes of Peyer's patch maintain a constitutive basal level of NO production from the enteric epithelial cell Caco-2. LPS-induced mIL-6 release from lymphocytes of Peyer's patch is suppressed by the cocultured epithelial cells. While no changes are detectable in NO production in lymphocytes from both wild-type and iNOS knockout mice before and after LPS challenge, NO from lymphocytes appears to play an inhibitory role in epithelial NO release and their own mIL-6 release in response to LPS.
Chen
Jie
J
Epithelial Cell Biology Research Center, Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, China.
Ng
Chuen-Pei
CP
Rowlands
Dewi K
DK
Xu
Peng-Hui
PH
Gao
Jie-Ying
JY
Chung
Yiu-Wa
YW
Chan
Hsiao-Chang
HC
D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D004405:Dysentery, Bacillary / Q000473:pathology / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism* / Q000502:physiology; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000378:metabolism* / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000502:physiology; D010581:Peyer's Patches / Q000166:cytology / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000494:pharmacology*; D012760:Shigella
D015850:Interleukin-6; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase