Phenotypic and functional characterisation of myofibroblasts, macrophages,and lymphocytes migrating out of the human gastric lamina propria following the loss of epithelial cells

Background-The basement membrane of human colonic mucosa contains numerous discrete pores. We have recently shown that following loss of the surface e pithelium, many cells migrate out of the colonic lamina propria via basemen t membrane pores. Aims-To characterise cells migrating out via basement membrane pores of the human gastric lamina propria, following loss of the surface epithelium. Methods-Fresh human gastric mucosal samples were completely denuded of epit helial cells and placed in culture. Tissue samples were studied by electron microscopy (EM) and cells by EM, FAGS analysis, immunohistochemistry, and reverse transcription polymerase chain reaction (RT-PCR). Results-EM showed numerous discrete pores (0.65-8.29 mu m in diameter) in t he subepithelial basement membrane. During culture of mucosal samples denud ed of epithelial cells, lymphocytes, macrophages, and myofibroblasts migrat ed out of the lamina propria via the basement membrane pores. The lymphocyt es were predominantly CD45RO+ and CD69+ T cells. Macrophages were shown to express cyclooxygenase (COX) 1 and 2 enzymes. Myofibroblasts were establish ed in culture and, despite prolonged culture and passage, retained their ph enotype. They expressed mRNA and protein for COX 1 and 2 enzymes and their release of prostaglandin E-2 was inhibited by selective COX 1 and 2 inhibit ors. Conclusions-Lamina propria cells migrating out of cultured denuded gastric mucosal samples have been characterised phenotypically and functionally. Su ch cells would be suitable for studies of their interactions with epithelia l cells and also with Helicobacter pylori and its products.