Microfold (M) cells are a kind of intestinal epithelial cell in the follicle-associated epithelium (FAE) of Peyer’s patches. They can transport antigens and microorganisms to lymphoid tissues. Bovine spongiform encep...Microfold (M) cells are a kind of intestinal epithelial cell in the follicle-associated epithelium (FAE) of Peyer’s patches. They can transport antigens and microorganisms to lymphoid tissues. Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disorder in cattle. It is linked to variant Creutzfeldt-Jakob disease in humans. Although it is thought that M cells transport the BSE agent, the exact mechanism by which it crosses the intestinal barrier is not clear. We have bovine intestinal epithelial cell line (BIE cells), which can differentiate into the M cell type in vitro after stimulation, and which is able to transport the BSE agent. We show here that M cells are able to incorporate large numbers of PrP coated magnetic particles into intracellular vesicles, which we collected. The results of 2-DE show a specific protein associated with the PrP-coated particles, compared with non-coated particles. This protein was identified as aldolase A, a glycolytic pathway enzyme, using LC-MS/MS analysis. Aldolase A was synthesized and secreted by BIE cells, and increased during M cell differentiation. In the villi of the bovine intestine, aldolase A was detected on the surface of the epithelium and in the mucus droplet of goblet cells. In the FAE of bovine jejunal and ileal Peyer’s patches, aldolase A was localized on the surface and the apical part of the M cells. The binding of rbPrP to aldolase A was clearly detected and inhibited by pre-treatment of anti-aldolase A antibody. Aldolase A was co-stained with incorporated PrPSc in M-BIE cells. These results suggest that bovine M cells and goblet cells synthesize aldolase A, and that aldolase A may have the ability to bind PrP and associate with PrP in cellular vesicles. Therefore, aldolase A-positive M cells may play a key role in the invasion of BSE into the body.展开更多
We isolated cDNA encoding porcine MyD88 （poMyD88） from Peyer＇s patches （Pps） of GALT. The complete open reading frame （ORF） of poMyD88 contains 879 bp encoding a deduced 293 aa residues. The amino acid sequence...We isolated cDNA encoding porcine MyD88 （poMyD88） from Peyer＇s patches （Pps） of GALT. The complete open reading frame （ORF） of poMyD88 contains 879 bp encoding a deduced 293 aa residues. The amino acid sequence of poMyD88 was characterized by N-terminal death, intermediate and C-terminal Toll/IL-1 receptor （TIR） domains. The putative poMyD88 protein shares a higher level of homology with its human （87.2% amino acid identity） than with its mouse （77.4% amino acid identity） counterpart. Overexpression of poMyD88 participated in the further enhanced activation of NF-w.B in human embryonic kidney （HEK） 293 cells expressing porcine TLR2 and porcine TLR4/MD-2, but not porcine RP105/MD-1 after stimulation with the corresponding ligands. The expression levels of MyD88 were highest in the spleen and mesenteric lymph nodes （MLNs）, and lower in digestive tissues of newborn swine. In adult swine, the expression levels in the digestive tissues were lower than those in MLNs and the spleen. These results suggest that an MyD88-dependent signaling pathway is present in newborn as well as in adult swine and that it is involved in the innate immune system of these animals.展开更多
文摘Microfold (M) cells are a kind of intestinal epithelial cell in the follicle-associated epithelium (FAE) of Peyer’s patches. They can transport antigens and microorganisms to lymphoid tissues. Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disorder in cattle. It is linked to variant Creutzfeldt-Jakob disease in humans. Although it is thought that M cells transport the BSE agent, the exact mechanism by which it crosses the intestinal barrier is not clear. We have bovine intestinal epithelial cell line (BIE cells), which can differentiate into the M cell type in vitro after stimulation, and which is able to transport the BSE agent. We show here that M cells are able to incorporate large numbers of PrP coated magnetic particles into intracellular vesicles, which we collected. The results of 2-DE show a specific protein associated with the PrP-coated particles, compared with non-coated particles. This protein was identified as aldolase A, a glycolytic pathway enzyme, using LC-MS/MS analysis. Aldolase A was synthesized and secreted by BIE cells, and increased during M cell differentiation. In the villi of the bovine intestine, aldolase A was detected on the surface of the epithelium and in the mucus droplet of goblet cells. In the FAE of bovine jejunal and ileal Peyer’s patches, aldolase A was localized on the surface and the apical part of the M cells. The binding of rbPrP to aldolase A was clearly detected and inhibited by pre-treatment of anti-aldolase A antibody. Aldolase A was co-stained with incorporated PrPSc in M-BIE cells. These results suggest that bovine M cells and goblet cells synthesize aldolase A, and that aldolase A may have the ability to bind PrP and associate with PrP in cellular vesicles. Therefore, aldolase A-positive M cells may play a key role in the invasion of BSE into the body.
文摘We isolated cDNA encoding porcine MyD88 （poMyD88） from Peyer＇s patches （Pps） of GALT. The complete open reading frame （ORF） of poMyD88 contains 879 bp encoding a deduced 293 aa residues. The amino acid sequence of poMyD88 was characterized by N-terminal death, intermediate and C-terminal Toll/IL-1 receptor （TIR） domains. The putative poMyD88 protein shares a higher level of homology with its human （87.2% amino acid identity） than with its mouse （77.4% amino acid identity） counterpart. Overexpression of poMyD88 participated in the further enhanced activation of NF-w.B in human embryonic kidney （HEK） 293 cells expressing porcine TLR2 and porcine TLR4/MD-2, but not porcine RP105/MD-1 after stimulation with the corresponding ligands. The expression levels of MyD88 were highest in the spleen and mesenteric lymph nodes （MLNs）, and lower in digestive tissues of newborn swine. In adult swine, the expression levels in the digestive tissues were lower than those in MLNs and the spleen. These results suggest that an MyD88-dependent signaling pathway is present in newborn as well as in adult swine and that it is involved in the innate immune system of these animals.
