Demonstration of substances of innate immunity in the esophageal epithelium of domesticated mammals: Part II--Defence mechanisms, including species comparison.
The second part of our study deals with a comparative evaluation and discussion of the immunohistochemical results that were obtained. The cryoscanning electron microscopy (cryoSEM) observations confirmed a monolayer colonization of the esophageal surface with bacteria and fungi (yeasts); the latter in particular was prominent in the ruminant species studied. We demonstrated the existence of several innate immune parameters, including pathogen recognition receptors (PRRs), such as Toll-like receptor 2, which was primarily expressed in the stratum basale; however, the presence β-glucan receptors remained inconclusive. Furthermore, the group of cationic antimicrobial peptides (CAPs) was shown, comprising β-defensins 2 and 3 and cathelicidin. The less keratinized esophageal epithelium of the carnivorous cat was protected by high amounts of CAPs; whereas the more strongly keratinized epithelium of the herbivorous and omnivorous species with its characteristic layer structure exhibited clearly weaker reactions. Moreover, lysozyme could distinctly be demonstrated in the cells of the esophageal epithelium. It can be concluded that a first line of defence mechanisms of the innate immune system contributes to maintaining a microbial homeostasis on the surface of the esophageal epithelium of domesticated mammals. The results are discussed in comparison to findings from studies on the human esophagus.
Nina Hornickel
Isabelle
I
Institute for Anatomy, University of Veterinary Medicine Hannover Foundation, Bischofsholer Damm 15, Hannover, Germany.
Kacza
Johannes
J
Schnapper
Anke
A
Beyerbach
Martin
M
Schoennagel
Britta
B
Seeger
Johannes
J
Meyer
Wilfried
W
D000818:Animals; D000829:Animals, Domestic / Q000033:anatomy & histology / Q000276:immunology*; D023181:Antimicrobial Cationic Peptides / Q000032:analysis*; D002415:Cats; D002417:Cattle; D004285:Dogs; D004848:Epithelium / Q000276:immunology*; D004947:Esophagus / Q000166:cytology / Q000276:immunology*; D005260:Female; D006041:Goats; D006736:Horses; D006801:Humans; D007113:Immunity, Innate; D007150:Immunohistochemistry; D008297:Male; D010316:Particle Size; D051381:Rats; D013048:Specimen Handling; D013499:Surface Properties; D013552:Swine; D016610:Tissue Embedding; D016707:Tissue Fixation; D023083:beta-Defensins / Q000032:analysis*; D054804:Cathelicidins
D023181:Antimicrobial Cationic Peptides; D023083:beta-Defensins; D054804:Cathelicidins