Lumen Interstitial space 10% Direct Intact protein Ann N Y Acad sci. 2000 915: 171-83 pathw Phagocytosis 200 ng/(h-cm" Role of m cells in intestinal barrier function Kucharzik T1, Lugering N, Rautenberg K, of proteins Enterocyte Lugering A, Schmidt MA, Stoll R, Domschke W. 3200 ng o% Degradative Processed protein 3000 ng/(h-cm?) Small intestine Follicle-associated 口 pathway villus E Direct Intact proten Enterocyte Peyer's patch Phagocytosis pathway of proteins 200 ng/h-cm Crypt 400ng Degradative O- Processed protein Enteroendocrine pathway 438 200 ng/(h-cm" TLRITR2 M cell Underlying lymphocytes 完整蛋白质的吸收 Absorption of whole proteins. Both enterocytes and specialized M cells can take up intact proteins. The more abundant enterocytes can endocytose far more total protein than can the m cells. However the lysosomal proteases in the enterocytes degrade 90% of this endocytosed protein the less abundant m cells take up relatively little intact protein, but approximately half of this emerges intact at the basolateral membrane. There, immunocompetent cells process the target antigens and then transfer them to lymphocytes, thus initiating an immune response完整蛋白质的吸收 Absorption of whole proteins. Both enterocytes and specialized M cells can take up intact proteins. The more abundant enterocytes can endocytose far more total protein than can the M cells. However, the lysosomal proteases in the enterocytes degrade ∼90% of this endocytosed protein. The less abundant M cells take up relatively little intact protein, but approximately half of this emerges intact at the basolateral membrane. There, immunocompetent cells process the target antigens and then transfer them to lymphocytes, thus initiating an immune response Ann N Y Acad Sci. 2000;915:171-83. Role of M cells in intestinal barrier function. Kucharzik T1, Lügering N, Rautenberg K, Lügering A, Schmidt MA, Stoll R, Domschke W