title: The neuropeptide bombesin improves IgA-mediated mucosal immunity with preservation of gut interleukin-4 in total parenteral nutrition-fed mice.
abstract: BACKGROUND
  The Th2 cytokines, interleukin-4 (IL-4) and interleukin-10 (IL-10), stimulate IgA production. Total parenteral nutrition (TPN) reduces IL-4 and IL-10 messenger RNA in gut lamina propria lymphocytes, total IL-4 and IL-10 in gut homogenates, and IgA-mediated mucosal immunity. Bombesin (BBS) can maintain mucosal immunity in TPN-fed mice, but the effects of BBS on gut IL-4 and IL-10 levels and their mRNA expression in the lamina propria are unknown.
  
  
  METHODS
  In experiment 1, mice that were fed chow, TPN, or TPN + BBS (15 microg/kg intravenously-three times a day) for 5 days were killed, and respiratory tract IgA and intestinal IgA, IL-4, and IL-10 levels were measured. In experiment 2, IL-4 and IL-10 mRNA were measured in isolated lamina propria lymphocytes from chow-, TPN-, and TPN+BBS-fed mice by reverse transcriptase-polymerase chain reaction. Intestines were harvested 1 hour after injection of 100 7 microg of lipopolysaccharide intraperitoneally. Samples were standardized to beta-actin.
  
  
  RESULTS
  TPN-fed mice had significantly lower respiratory tract IgA levels than chow- or TPN + BBS-fed mice. TPN+BBS did not increase intestinal IL-10 or IL-10 lamina propria mRNA levels but maintained intestinal IL-4 levels and lamina propria IL-4 mRNA expression equal to those of chow-fed mice.
  
  
  CONCLUSIONS
  BBS reverses the effects of TPN on intestinal and respiratory tract IgA levels and most effects on gut cytokines. Lamina propria cytokine mRNA levels reflect total gut cytokine concentration.
authors.affiliation: Department of Surgery, The University of Tennessee Health Science Center, Memphis, Tenn., USA.
authors.forename: Ben L
authors.initials: BL
authors.lastname: Zarzaur
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fukatsu
authors.forename: Cheryl D
authors.initials: CD
authors.lastname: Johnson
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Kudsk
mesh_terms: D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D018928:Immunity, Mucosal; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D016753:Interleukin-10 / Q000235:genetics; D015847:Interleukin-4 / Q000032:analysis* / Q000235:genetics; D007413:Intestinal Mucosa / Q000276:immunology*; D008297:Male; D051379:Mice; D010289:Parenteral Nutrition, Total; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D007071:Immunoglobulin A, Secretory; D012333:RNA, Messenger; D016753:Interleukin-10; D015847:Interleukin-4; D001839:Bombesin