Neutra M R
Department of Pediatrics, Harvard Medical School, and GI Cell Biology Laboratory, Children's Hospital, Boston, MA 02115, USA.
J Infect Dis. 1999 May;179 Suppl 3:S441-3. doi: 10.1086/314800.
In the rectal mucosa, specialized M cells of the lymphoid follicle-associated epithelium conduct vesicular transport of antigens from the mucosal surface into organized mucosal lymphoid tissues, where immune responses are induced. Bacteria and viruses may exploit this mechanism to initiate mucosal or systemic infection. Viral pathogens, including reovirus, poliovirus, and possibly human immunodeficiency virus (HIV), can enter the intestinal or rectal mucosa by adhering to apical membranes of M cells, but the membrane components involved in these interactions are unknown. Glycoprotein coats on the apical surfaces of epithelial cells act as diffusion barriers that limit access of particles and microorganisms to membrane glycolipids and to certain oligosaccharide epitopes of enterocytes but allow selective adherence to M cells. The accessibility of membrane glycolipids of M cells, along with their active endocytic activity, could promote entry of HIV into the rectal mucosa.
在直肠黏膜中，淋巴滤泡相关上皮的特化M细胞将抗原从黏膜表面进行囊泡转运至有组织的黏膜淋巴组织，在此处诱导免疫反应。细菌和病毒可能利用这一机制引发黏膜或全身感染。包括呼肠孤病毒、脊髓灰质炎病毒以及可能的人类免疫缺陷病毒（HIV）在内的病毒病原体，可通过黏附于M细胞的顶端膜进入肠道或直肠黏膜，但参与这些相互作用的膜成分尚不清楚。上皮细胞顶端表面的糖蛋白外衣作为扩散屏障，限制颗粒和微生物接触膜糖脂以及肠上皮细胞的某些寡糖表位，但允许其选择性黏附于M细胞。M细胞膜糖脂的可及性及其活跃的内吞活性，可能促进HIV进入直肠黏膜。
