Intestinal polymeric immunoglobulin receptor is affected by type and route of nutrition.
BACKGROUND
Secretory immunoglobulin A (SIgA) prevents adherence of pathogens at mucosal surfaces to prevent invasive infection. Polymeric immunoglobulin receptor (pIgR) is located on the basolateral surface of epithelial cells and binds dimeric immunoglobulin A (IgA) produced by plasma cells in the lamina propria. This IgA-pIgR complex is transported apically, where IgA is exocytosed as SIgA to the mucosal surface. Our prior work shows that mice fed intragastric (IG, an elemental diet model) and IV parenteral nutrition (PN) solution have reduced intestinal T and B cells, SIgA, and interleukin-4 (IL-4) compared with mice fed chow or a complex enteral diet (CED). Prior work also demonstrates a reduction in IgA transport to mucosal surfaces in IV PN-fed mice. Because IL-4 up-regulates pIgR production, this work studies the effects of these diets on intestinal pIgR.


METHODS
Male Institute of Cancer Research (ICR) mice were randomized to chow (n = 11) with IV catheter, CED (n = 10) or IG PN (n = 11) via gastrostomy and IV PN (n = 12) for 5 days. CED and PN were isocaloric and isonitrogenous. Small intestine was harvested for pIgR and IL-4 assays after mucosal washing for IgA. IgA and IL-4 levels were analyzed by enzyme-linked immunosorbent assay and pIgR by Western blot.


RESULTS
Small intestinal pIgR expression, IgA levels, and IL-4 levels decreased significantly in IV PN and IG PN groups.


CONCLUSIONS
Lack of enteral stimulation affects multiple mechanisms responsible for decreased intestinal SIgA levels, including reduced T and B cells in the lamina propria, reduced Th-2 IgA-stimulating cytokines, and impaired expression of the IgA transport protein, pIgR.
Sano
Yoshifumi
Y
Department od Surgery, University of Wisconsin-Madison School of Medicine and Public Health, USA.
Gomez
F Enrique
FE
Kang
Woodae
W
Lan
Jinggang
J
Maeshima
Yoshinori
Y
Hermsen
Joshua L
JL
Ueno
Chikara
C
Kudsk
Kenneth A
KA
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D004750:Enteral Nutrition; D004797:Enzyme-Linked Immunosorbent Assay; D005774:Gastrostomy; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis* / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010288:Parenteral Nutrition / Q000009:adverse effects; D011897:Random Allocation; D019056:Receptors, Polymeric Immunoglobulin / Q000378:metabolism*
D007071:Immunoglobulin A, Secretory; D019056:Receptors, Polymeric Immunoglobulin; D015847:Interleukin-4