Modulation of human enteric epithelial barrier and ion transport function by Peyer's patch lymphocytes.
OBJECTIVE
To investigate the role of Peyer's patch lymphocytes in the regulation of enteric epithelial barrier and ion transport function in homeostasis and host defense.


METHODS
Mouse Peyer's patch lymphocytes were co-cultured with human intestinal epithelial cell line Caco-2 either in the mixed or separated (isolated but permeable compartments) culture configuration. Barrier and transport functions of the Caco-2 epithelial monolayers were measured with short-circuit current (Isc) technique. Release of cytokines was measured by enzyme-linked immunosorbent assay (ELISA) and cytokine mRNA expression was analyzed by semi-quantitative RT-PCR. Barrier and iontransport functions of both culture conditions following exposure to Shigella lipopolysaccharide (LPS) were also examined.


RESULTS
The transepithelial resistance (TER) of the epithelial monolayers co-cultured with Peyer's patch lymphocytes was maintained whereas that of the Caco-2 monolayers alone significantly decreased after eight days in culture. The forskolin-induced anion secretion, in either absence or presence of LPS, was significantly suppressed in the both co-cultures as compared with the Caco-2 cells alone. Furthermore, only the mixed co-culture condition induced the expression and release of mIL-6 from Peyer's patch lymphocytes, which could be further enhanced by LPS. However, both co-culture conditions suppressed expression and release of epithelial hIL-8 under the unstimulated conditions, while the treatment with LPS stimulated their hIL-8 expression and release.


CONCLUSIONS
Peyer's patch lymphocytes may modulate intestinal epithelial barrier and ion transport function in homeostasis and host defense via cell-cell contact and cytokine signaling.
Chen
Jie
J
Department of Physiology, Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
Tsang
Lai-Ling
LL
Ho
Lok-Sze
LS
Rowlands
Dewi-K
DK
Gao
Jie-Ying
JY
Ng
Chuen-Pei
CP
Chung
Yiu-Wa
YW
Chan
Hsiao-Chang
HC
D000818:Animals; D000838:Anions / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D018938:Caco-2 Cells; D002450:Cell Communication / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D005260:Female; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D007477:Ions / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008214:Lymphocytes / Q000166:cytology* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*
D000838:Anions; D007477:Ions; D008070:Lipopolysaccharides