Interleukin 10 prevents cytokine-induced disruption of T84 monolayer barrier integrity and limits chloride secretion.
OBJECTIVE
The proinflammatory cytokine interferon gamma (IFN-gamma) disrupts epithelial barrier integrity and attenuates secretagogue-induced chloride secretion. This study tested the efficacy of the anti-inflammatory cytokine interleukin 10 (IL-10) in maintaining epithelial barrier and chloride secretory function in the presence of IFN-gamma.


METHODS
T84 epithelial cell monolayers were treated with IL-10, IFN-gamma, or IFN-gamma plus IL-10. Monolayer barrier integrity was assessed by measurements of electrical conductance, unidirectional mannitol and inulin fluxes, and tight junctional charge selectivity in Ussing chambers. Short-circuit current (Isc) was measured in response to carbachol and forskolin stimulation.


RESULTS
IL-10 attenuated the IFN-gamma-induced increase in electrical conductance and totally prevented the IFN-gamma-induced increase in mannitol and inulin fluxes. IL-10 did not prevent the IFN-gamma-induced abolishment of tight junctional charge selectivity but did attenuate the total increase in sodium and chloride permeability. IFN-gamma and IL-10 both separately reduced peak forskolin and carbachol-stimulated Isc. IL-10 pretreatment further enhanced the IFN-gamma-induced reduction in secretagogue-induced Isc.


CONCLUSIONS
In T84 epithelial monolayers, IL-10 maintains the size, but not the charge, selectivity of the epithelial tight junction in the presence of IFN-gamma. In addition, both IL-10 and IFN-gamma limit carbachol and forskolin-induced increase in Isc.
Madsen
K L
KL
Division of Gastroenterology, University of Alberta, Edmonton, Canada.
Lewis
S A
SA
Tavernini
M M
MM
Hibbard
J
J
Fedorak
R N
RN
D002217:Carbachol / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D004847:Epithelial Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D016753:Interleukin-10 / Q000494:pharmacology* / Q000502:physiology; D007444:Inulin / Q000493:pharmacokinetics; D017136:Ion Transport / Q000187:drug effects / Q000502:physiology; D008353:Mannitol / Q000493:pharmacokinetics; D019108:Tight Junctions / Q000187:drug effects* / Q000502:physiology
D002712:Chlorides; D016753:Interleukin-10; D005576:Colforsin; D008353:Mannitol; D007371:Interferon-gamma; D002217:Carbachol; D007444:Inulin