Reilly D S, Tomassini N, Bevins C L, Zasloff M
Division of Human Genetics and Molecular Biology, Children's Hospital of Philadelphia, Pennsylvania.
J Histochem Cytochem. 1994 Jun;42(6):697-704. doi: 10.1177/42.6.8189032.
Antimicrobial peptides are a widespread component of host defense. We characterized the tissue distribution and cellular localization of expression of the magainin family of antimicrobial peptide genes in Xenopus laevis. Two genes from this family, magainin and PGLa, are expressed at high levels in the skin and throughout the gastrointestinal tract. Magainin and PGLa mRNAs are synthesized in the granular multinucleated cell (GMC) of the gastric mucosa, a cell shown previously to contain magainin and PGLa peptides by immunohistochemical methods. In addition, we have localized magainin and PGLa mRNAs to distinct cells of Xenopus small intestine. Further characterization of this large, granule-filled cell by electron microscopy demonstrates features in common with the Paneth cell of mammalian small intestine, previously identified as a site of expression of antimicrobial peptide genes of the defensin family in mouse and human. Our identification of granule-laden, eosinophilic intestinal cells in Xenopus as a site of magainin and PGLa antimicrobial peptide gene expression suggests that these cells are functional analogues of mammalian Paneth cells and further supports a conserved role of antimicrobial peptides in host defense of the vertebrate small intestine.
抗菌肽是宿主防御系统中广泛存在的组成部分。我们对非洲爪蟾抗菌肽基因马盖宁家族的组织分布和表达的细胞定位进行了表征。该家族的两个基因，即马盖宁和PGLa，在皮肤和整个胃肠道中高水平表达。马盖宁和PGLa mRNA在胃黏膜的颗粒多核细胞（GMC）中合成，先前通过免疫组织化学方法已证明该细胞含有马盖宁和PGLa肽。此外，我们已将马盖宁和PGLa mRNA定位到非洲爪蟾小肠的不同细胞中。通过电子显微镜对这种大的、充满颗粒的细胞进行进一步表征，显示出与哺乳动物小肠潘氏细胞的共同特征，潘氏细胞先前被确定为小鼠和人类中防御素家族抗菌肽基因的表达位点。我们将非洲爪蟾中充满颗粒的嗜酸性肠细胞鉴定为马盖宁和PGLa抗菌肽基因的表达位点，这表明这些细胞是哺乳动物潘氏细胞的功能类似物，并进一步支持了抗菌肽在脊椎动物小肠宿主防御中的保守作用。
