Molecular identification and characterization of novel immune defense mechanisms for sensing bacterial signal peptides

由于耐多药细菌的稳步增加，准确表征对细菌感染的免疫反应变得越来越重要，因为更好地了解潜在的分子过程可以有助于开发针对人类和动物的新治疗策略。在项目提案中，我们的目标是研究一大类新的细菌肽对免疫防御的贡献。n端甲酰化肽片段是细菌感染免疫反应的重要触发因素。到目前为止，人们普遍认为它们的识别完全由甲酰基肽受体（FPRs）介导。Bufe实验室的新结果表明，一定有额外的、以前未知的受体参与了它们的感知。在共同努力下，Bufe和Bischoff实验室已经成功地确定了一些可能的候选者。为此，选择多肽和细菌上清液检测各种fpr相关受体。其中一些受体确实可以被甲酰基肽激活。在该提案中，该团队打算使用高通量显微镜来了解细菌信号肽通过这些额外受体引发的药理学和生理学免疫反应。为了确定不同受体的最佳激活剂，受体将受到Bufe实验室肽库中的肽和Bischoff实验室菌株收集的不同细菌上清液的挑战。然后将使用原型刺激来研究这些替代检测途径对中性粒细胞对细菌的免疫防御的生理意义。为了区分fpr依赖性和fpr非依赖性信号转导途径，我们将来自CRISPR/Cas9修饰的小鼠和人类细胞系的数据与相应原代分离细胞的反应进行了比较。

Because of the steady increase in multidrug-resistant bacteria accurate characterization of the immune response to bacterial infection is becoming increasingly important, as a better understanding of the underlying molecular processes can contribute to the development of new therapeutic treatment strategies for humans and animals. In the project proposal, we aim to investigate the contribution of a new large group of bacterial peptides to immune defense. N-terminally formylated peptide fragments are important triggers of immune responses in bacterial infections. Until now, it has been generally assumed that their recognition is mediated exclusively by formyl peptide receptors (FPRs). New results Bufe lab show that there must be additional, previously unknown receptors that contribute to their perception. In a joint effort, the Bufe and Bischoff labs already succeeded in identifying some possible candidates. To this end, various FPR-related receptors were tested with a selection of peptides and bacterial supernatants. Some of these receptors could indeed be activated by formyl peptides. In the proposal, the team intends to use the high-throughput microscope to understand the pharmacological and physiological immune responses that bacterial signaling peptides elicit through these additional receptors. To identify the best activators for the different receptors the receptors will be challenged with peptides from a peptide library in the Bufe lab and different bacterial supernatants from a strain collection in the Bischoff lab. Prototypic stimuli will then be used to investigate the physiological significance of these alternative detection pathways for the immune defense of neutrophil granulocytes against bacteria. To distinguish between FPR-dependent and FPR-independent signal transduction pathways, data from CRISPR/Cas9 modified mouse and human cell lines be compared to the responses of corresponding primary isolated cells.