Baranzini Nicolò, Pulze Laura, Reguzzoni Marcella, Roncoroni Rossella, Orlandi Viviana Teresa, Tettamanti Gianluca, Acquati Francesco, Grimaldi Annalisa
Department of Biotechnology and Life Science, University of Insubria, 21100 Varese, Italy.
Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy.
Int J Mol Sci. 2020 Dec 19;21(24):9722. doi: 10.3390/ijms21249722.
Recent studies performed on the invertebrate model (medicinal leech) suggest that the T2 ribonucleic enzyme RNASET2 modulates the leech's innate immune response, promoting microbial agglutination and supporting phagocytic cells recruitment in challenged tissues. Indeed, following injection of both lipoteichoic acid (LTA) and in the leech body wall, RNASET2 is expressed by leech type I granulocytes and induces bacterial aggregation to aid macrophage phagocytosis. Here, we investigate the RNASET2 antimicrobial role, in particular assessing the effects on the Gram-negative bacteria . For this purpose, starting from the three-dimensional molecule reconstruction and in silico analyses, the antibacterial activity was evaluated both in vitro and in vivo. The changes induced in treated bacteria, such as agglutination and alteration in wall integrity, were observed by means of light, transmission and scanning electron microscopy. Moreover, immunogold, AMPs (antimicrobial peptides) and lipopolysaccharide (LPS) binding assays were carried out to evaluate RNASET2 interaction with the microbial envelopes and the ensuing ability to affect microbial viability. Finally, in vivo experiments confirmed that RNASET2 promotes a more rapid phagocytosis of bacterial aggregates by macrophages, representing a novel molecule for counteracting pathogen infections and developing alternative solutions to improve human health.
最近对无脊椎动物模型（药用蚂蟥）进行的研究表明，T2核糖核酸酶RNASET2调节蚂蟥的先天免疫反应，促进微生物凝集，并支持在受攻击组织中募集吞噬细胞。事实上，在蚂蟥体壁注射脂磷壁酸（LTA）后，RNASET2由蚂蟥I型粒细胞表达，并诱导细菌聚集以帮助巨噬细胞吞噬。在这里，我们研究RNASET2的抗菌作用，特别是评估其对革兰氏阴性菌的影响。为此，从三维分子重建和计算机分析开始，在体外和体内评估了抗菌活性。通过光学显微镜、透射电子显微镜和扫描电子显微镜观察处理过的细菌中诱导的变化，如凝集和细胞壁完整性改变。此外，还进行了免疫金、抗菌肽（AMPs）和脂多糖（LPS）结合试验，以评估RNASET2与微生物包膜的相互作用以及随后影响微生物活力的能力。最后，体内实验证实RNASET2促进巨噬细胞对细菌聚集体的更快吞噬，代表了一种对抗病原体感染和开发改善人类健康替代解决方案的新分子。
