Enteral feeding of a chemically defined diet preserves pulmonary immunity but not intestinal immunity: the role of lymphotoxin beta receptor.
BACKGROUND
Compared with chow or a complex enteral diet (CED), IV administration of a parenteral nutrition solution (IV-PN) impairs intestinal and respiratory mucosal immunity, resulting in cellular and immunoglobulin A (IgA) defects in the intestine and impaired respiratory antiviral and antibacterial defenses. PN given intragastrically (IG-PN) impairs intestinal immunity similar to IV-PN but preserves antiviral defences and partially preserves antibacterial defenses. Lymphotoxin beta receptor (LTbetaR) is a molecule essential for development and organization of lymphoid tissue. It controls many molecules important in mucosal immune integrity. This study examines effects of route (IV or enteral) and type (PN, CED, or chow) on murine intestine and lung LTbetaR expression.


METHODS
Forty-three mice randomly received IV-PN (n = 12), IG-PN (n = 11), IV saline + chow (chow; n = 11), or a CED (n = 9). After 5 days of feeding, intestinal and lung samples were obtained and processed for levels of LTbetaR by Western blot.


RESULTS
IV-PN significantly reduced intestinal and lung LTbetaR compared with CED and chow. IG-PN reduced LTbetaR levels only in the intestine but preserved lung levels.


CONCLUSIONS
Route and type of nutrition differentially influence molecular events in the intestinal and respiratory mucosal immune systems. Enteral feeding with any diet (complex or chemically defined) maintains lung LTbetaR expression, whereas intestinal LTbetaR levels are maintained only with CEDs (chow and CED). We hypothesize that LTbetaR is responsible for the observed preservation of respiratory tract immunity with administration of a noncomplex, chemically defined enteral diet, whereas intestinal immunity is compromised with this diet.
Kudsk
Kenneth A
KA
Veterans Administration Surgical Services, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA. kudsk@surgery.wisc.edu
Gomez
F Enrique
FE
Kang
Woodae
W
Ueno
Chikara
C
D000818:Animals; D015153:Blotting, Western; D004333:Drug Administration Routes; D004750:Enteral Nutrition; D005786:Gene Expression Regulation; D018928:Immunity, Mucosal / Q000187:drug effects* / Q000502:physiology; D007070:Immunoglobulin A / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis; D007262:Infusions, Intravenous; D007413:Intestinal Mucosa / Q000378:metabolism*; D007421:Intestine, Small / Q000276:immunology; D008168:Lung / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D053259:Lymphotoxin beta Receptor / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010288:Parenteral Nutrition; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D011897:Random Allocation
D007070:Immunoglobulin A; D007136:Immunoglobulins; D053259:Lymphotoxin beta Receptor