title: Morphine inhibits mucosal antibody responses and TGF-beta mRNA in gut-associated lymphoid tissue following oral cholera toxin in mice.
abstract: In this study, we investigated the effect of morphine on the mucosal immune system using fragment cultures of ileal segments, Peyer's patches (PPs), and mesenteric lymph nodes. Mice were implanted s.c. with a morphine slow release pellet. Control groups received a naltrexone slow release pellet, a placebo pellet, or both a morphine and a naltrexone pellet. After 48 h, mice were orally immunized with cholera toxin (CT) and were boosted orally 1 wk later. Animals were sacrificed 1 wk after the booster immunization, and PPs, mesenteric lymph nodes, and ileal segments were cultured in 24-well plates for 12 days. Morphine resulted in a highly significant inhibition of CT-specific IgA and IgG production in fragment culture supernatants of all three tissues compared with placebo. Naltrexone blocked the reduction in Ab levels induced by morphine, indicating that the effect is opioid receptor mediated. Morphine did not significantly alter total IgA levels in any of the tissue culture supernatants. Morphine also inhibited CT-specific IgA and IgG levels in serum. By flow cytometry, morphine did not alter the lymphoid cell composition in PPs compared with placebo. The effect of morphine on TGF-beta, IL-5, and IL-6 mRNA expression in PPs and ileal segments was determined following oral immunization with CT. Morphine significantly decreased TGF-beta mRNA compared with that in the placebo group, and naltrexone blocked this effect. These results indicate that morphine inhibits Ag-specific IgA responses in gut-associated lymphoid tissue at least partially through the inhibition of TGF-beta, a putative IgA switch factor, in the gastrointestinal tract.
authors.affiliation: Department of Microbiology and Immunology, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19104, USA.
authors.forename: X
authors.initials: X
authors.lastname: Peng
authors.forename: J J
authors.initials: JJ
authors.lastname: Cebra
authors.forename: M W
authors.initials: MW
authors.lastname: Adler
authors.forename: J J
authors.initials: JJ
authors.lastname: Meissler
authors.forename: A
authors.initials: A
authors.lastname: Cowan
authors.forename: P
authors.initials: P
authors.lastname: Feng
authors.forename: T K
authors.initials: TK
authors.lastname: Eisenstein
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002772:Cholera Toxin / Q000008:administration & dosage / Q000494:pharmacology*; D004336:Drug Antagonism; D007082:Ileum / Q000187:drug effects / Q000276:immunology; D018928:Immunity, Mucosal; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology*; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology; D008643:Mesentery; D051379:Mice; D008809:Mice, Inbred C3H; D009020:Morphine / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D009020:Morphine; D002772:Cholera Toxin