Effects of mannoprotein E1 in liquid diet on inflammatory response and TLR5 expression in the gut of rats infected by Salmonella typhimurium.
BACKGROUND
Mannoproteins are yeast cell wall componend, and rich in mannose. The use of foods rich in mannose as carbohydrate, could have a bioprotective effect against entrobacteria intestinal infection. Nothing is known about mannoproteins' activity in inflammatory bowel processes induced by entrobacteria.This study investigates the effects of mannoprotein administration via a liquid diet on inflammatory response and TLR5 expression during intestinal tissue injury in a rat model of infection with Salmonella typhimurium.


METHODS
Adult Wistar male rats were divided into three groups: control, and mannoprotein E1 at 10 or 15%. Animals were fed with a liquid diet supplemented or not with mannoprotein E1. Groups were infected by intragastrical administration of S. typhimurium. 24 h post-inoculation samples of spleen, ileum and liver were collected for microbiological studies. Gut samples were processed to determine levels of proinflammatory cytokines (mRNA) and TLR5 (mRNA and protein) by quantitative PCR and Western-blot, and the number of proliferative and apoptotic cells determined by immunohistochemistry.


RESULTS
Ininfected levels of proinflammatory cytokines and TLR5 were higher in untreated controls than in the animals receiving mannoprotein. Proliferation was similar in both groups, whereas apoptosis was higher in controls. Curiosly, the mannoprotein effect was dose dependent.


CONCLUSIONS
Mannoprotein administration in a liquid diet seems to protect intestinal tissue against S. typhimurium infection. This protection seems to expressed as a lower pro-inflammatory response and TLR5 downregulation in gut epithelium, as well as by an inhibition of apoptosis. Nevertheless, the molecular mechanism by which mannoprotein is able to regulate these responses remain unclear. These results could open up new avenues in the use of mannoproteins as prebiotics in the therapeutic strategy for treatment of inflammatory gut processes induced by microbia.
Experimental Surgery Department, La Paz Hospital, Paseo de la Castellana 261, 28046 Madrid, Spain.
Sinforiano J
SJ
Posadas
Victor
V
Caz
Isabel
I
Caballero
Emilio
E
Cendejas
Immaculada
I
Quilez
Carlota
C
Largo
Marcos
M
Elvira
Enrique
E
De Miguel
D000284:Administration, Oral; D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism / Q000517:prevention & control; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000382:microbiology* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D012480:Salmonella Infections / Q000378:metabolism / Q000473:pathology; D012486:Salmonella typhimurium; D051198:Toll-Like Receptor 5 / Q000378:metabolism*
D016207:Cytokines; D008562:Membrane Glycoproteins; D051198:Toll-Like Receptor 5; C025363:mannoproteins