Ueda Wataru, Tohno Masanori, Shimazu Tomoyuki, Fujie Hitomi, Aso Hisashi, Kawai Yasushi, Numasaki Muneo, Saito Tadao, Kitazawa Haruki
Food Immunology Group, Graduate School of Agricultural Science, Tohoku University, Aobaku, Sendai 981-8555, Japan.
Vet Immunol Immunopathol. 2011 Sep 15;143(1-2):148-54. doi: 10.1016/j.vetimm.2011.05.026. Epub 2011 May 27.
Peptidoglycan recognition proteins (PGRPs) are innate immune molecules that are present in most invertebrates and vertebrates. Mammals have four PGRPs, PGLYRP1-4. In the present study, we cloned the cDNAs encoding porcine PGLYRP3 and 4 from the esophagus of adult swine. The length of the complete open reading frames of porcine PGLYRP3 and 4 are identical and contain 1125bp encoding 374 amino acid residues. The amino acid sequences of these two proteins were more similar to their human orthologs (78.9% [PGLYRP3] and 73.9% [PGLYRP4]) than to their mouse orthologs (71.3% [PGLYRP3] and 67.9% [PGLYRP4]). Expression analysis revealed that both PGLYRP3 and 4 were more strongly expressed in digestive tract, especially the esophagus, than in immune organs such as spleen or mesenteric lymph nodes in both newborn and adult swine. To analyze the subcellular distribution of porcine PGLYRP1-4, we constructed transfectant cell lines. Western blot and flow cytometric analyses revealed that porcine PGLYRP3 and 4 are not only secreted, but also expressed on the cell surface, unlike PGLYRP1 and 2. These results should help contribute to the understanding of PGLYRP3- and 4-mediated immune responses via their recognition of intestinal microorganisms in newborn and adult swine.
肽聚糖识别蛋白（PGRPs）是大多数无脊椎动物和脊椎动物体内存在的天然免疫分子。哺乳动物有四种PGRPs，即PGLYRP1 - 4。在本研究中，我们从成年猪的食管中克隆了编码猪PGLYRP3和4的cDNA。猪PGLYRP3和4的完整开放阅读框长度相同，均为1125bp，编码374个氨基酸残基。这两种蛋白质的氨基酸序列与其人类同源物（PGLYRP3为78.9%，PGLYRP4为73.9%）的相似性高于与其小鼠同源物（PGLYRP3为71.3%，PGLYRP4为67.9%）。表达分析显示，在新生和成年猪中，PGLYRP3和4在消化道，尤其是食管中的表达比在脾脏或肠系膜淋巴结等免疫器官中更强。为了分析猪PGLYRP1 - 4的亚细胞分布，我们构建了转染细胞系。蛋白质免疫印迹和流式细胞术分析表明，与PGLYRP1和2不同，猪PGLYRP3和4不仅分泌，而且在细胞表面表达。这些结果有助于理解新生和成年猪中PGLYRP3和4通过识别肠道微生物介导的免疫反应。
