Momotani E, Whipple D L, Thiermann A B, Cheville N F
US Department of Agriculture, National Animal Disease Center, Ames, IA.
Vet Pathol. 1988 Mar;25(2):131-7. doi: 10.1177/030098588802500205.
Ligated ileal loops of calves were inoculated with live and heat-killed Mycobacterium paratuberculosis and were examined by light and electron microscopy. At 5 hours after inoculation, acid-fast bacilli were in subepithelial macrophages, but not in M cells covering domes. At 20 hours, more than 50 acid-fast bacilli per cross section were in subepithelial macrophages in domes. Both living and heat-killed bacilli passed into domes. Addition of anti-M. paratuberculosis bovine serum to the inoculum enhanced entry of bacteria into domes. By electron microscopy, intact bacilli with electron-transparent zones (peribacillary spaces) were in the supranuclear cytoplasm of M cells at 20 hours. M cells also contained vacuoles, including electron-dense material interpreted as degraded bacilli. Subepithelial and intraepithelial macrophages contained bacilli and degraded bacterial material in phagosomes. These results suggest that calf ileal M cells take up bacilli, and that subepithelial and intraepithelial macrophages secondarily accept bacilli or bacterial debris which are expelled from M cells.
用活的和热灭活的副结核分枝杆菌接种小牛的结扎回肠袢，并通过光学显微镜和电子显微镜进行检查。接种后5小时，抗酸杆菌存在于上皮下巨噬细胞中，但不存在于覆盖穹窿的M细胞中。20小时时，穹窿处上皮下巨噬细胞每横截面积超过50个抗酸杆菌。活的和热灭活的杆菌都进入了穹窿。在接种物中添加抗副结核分枝杆菌牛血清可增强细菌进入穹窿的能力。通过电子显微镜观察，20小时时，带有电子透明区（杆菌周围间隙）的完整杆菌位于M细胞核上细胞质中。M细胞还含有空泡，包括被解释为降解杆菌的电子致密物质。上皮下和上皮内巨噬细胞在吞噬体中含有杆菌和降解的细菌物质。这些结果表明，小牛回肠M细胞摄取杆菌，上皮下和上皮内巨噬细胞继而接受从M细胞排出的杆菌或细菌碎片。
