The gut microbiota can play a role in pancreatitis and, likely, in the development of type 1 diabetes (T1D). Anti-microbial peptides and secretory proteins are important mediators of the innate immune response against bacteria but their expression in the human pancreas is not fully known. In this study, immunohistochemistry was used to analyze the expression of seven anti-microbial peptides (Defensin α1, α4, β1-4 and Cathelicidin) and two secretory proteins with known antimicrobial properties (REG3A and GP2) in pancreatic and duodenal biopsies from 10 non-diabetic organ donors and one organ donor that died at onset of T1D. Immunohistochemical data was compared with previously published whole-transcriptome data sets. Seven (Defensin α1, β2, β3, α4, GP2, Cathelicidin, and REG3A) host defense molecules showed positive staining patterns in most non-diabetic organ donors, whereas two (Defensin β1 and β4) were negative in all non-diabetic donors. Two molecules (Defensin α1 and GP2) were restricted to the exocrine pancreas whereas two (Defensin β3, α4) were only expressed in islet tissue. Cathelicidin, β2, and REG3A were expressed in both islets and exocrine tissue. The donor that died at onset of T1D had generally less positivity for the host defense molecules, but, notably, this pancreas was the only one where defensin β1 was found. Neither donor age, immune-cell infiltration, nor duodenal expression correlated to the pancreatic expression of host defense molecules. In conclusion, these findings could have important implications for the inflammatory processes in diabetes and pancreatitis as we find several host defense molecules expressed by the pancreatic tissue.

肠道菌群可以在胰腺炎中起作用，并且很可能在1型糖尿病（T1D）的发生中起作用。抗微生物肽和分泌蛋白是针对细菌的先天免疫应答的重要介体，但它们在人胰腺中的表达尚不完全清楚。在这项研究中，使用免疫组织化学分析了10种非胰腺癌和十二指肠活检组织中的7种抗菌肽（防御素α1，α4，β1-4和Cathelicidin）和2种具有已知抗菌特性的分泌蛋白（REG3A和GP2）的表达。 -糖尿病器官供体和一名在T1D发作时死亡的器官供体。将免疫组织化学数据与先前发表的全转录组数据集进行了比较。七种（防御素α1，β2，β3，α4，GP2，Cathelicidin，（REG3A）和REG3A）宿主防御分子在大多数非糖尿病器官供体中显示阳性染色模式，而在所有非糖尿病器官供体中两个（防御素β1和β4）均为阴性。两个分子（防御素α1和GP2）被限制在外分泌胰腺中，而两个分子（防御素β3，α4）仅在胰岛组织中表达。Cathelicidin，β2和REG3A在胰岛和外分泌组织中均表达。在T1D发作时死亡的供体通常对宿主防御分子的阳性率较低，但值得注意的是，该胰腺是唯一发现防御素β1的胰腺。供体年龄，免疫细胞浸润或十二指肠表达均与宿主防御分子的胰腺表达无关。结论，