T cell-innate immune crosstalk regulates Staphylococcus aureus craniotomy infection

T细胞先天免疫串扰调节金黄色葡萄球菌开颅感染

基本信息

批准号：
10590634
负责人：
Tammy L Kielian
金额：
$ 58.08万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-11 至 2027-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10590634
关键词：
Address Aneurysm Animals Anti-Bacterial Agents Antibacterial Response Antibiotics Antibodies Antigens Attenuated Bacteria Binding Brain Burr hole procedure CD4 Positive T Lymphocytes CXCL10 gene Cell Shape Cells Cellular Metabolic Process Cephalic Chronic Clip Containment Craniotomy Data Development Epilepsy Excision Exposure to Future Gene Expression Profile Genes Genetic Transcription Goals Growth Human Hydrocephalus Immune Immune response Infection Inflammatory Interferon Type II Invaded Knockout Mice Leucocytic infiltrate Leukocytes Macrophage Magnetic Resonance Imaging Mediating Membrane Microbial Biofilms Microglia Molecular Morbidity - disease rate Myeloid-derived suppressor cells Neurologic Dysfunctions Outcome Pathway interactions Patients Pattern Phagocytes Phagocytosis Play Procedures Process Production Property Prophylactic treatment Proteins Rag1 Mouse Regulation Reporting Residual state Risk Role Sampling Seizures Shapes Specificity Staphylococcal Protein A Staphylococcus aureus Syndrome T cell response T-Cell Activation T-Cell Depletion T-Lymphocyte Tissues Virulence Virulence Factors antimicrobial antimicrobial peptide bactericide bone chronic infection cranium plastic repair effector T cell experimental study granulocyte human disease humanized mouse improved innovation leukocyte activation metabolic profile monocyte mouse model mutant neutrophil novel novel strategies pathogen prevent recruit response single-cell RNA sequencing subcutaneous transcription factor transcriptome translational study treatment strategy tumor virulence gene

项目摘要

A craniotomy is performed to access the brain for procedures that include tumor resection, localization and resection of epileptogenic foci, and aneurysm clipping, where the bone flap is replaced intraoperatively. Despite prophylaxis, infectious complications after craniotomy range from 1-3%, with approximately half caused by Staphylococcus aureus (S. aureus), which forms a biofilm on the bone flap that is recalcitrant to antibiotics. We have developed a mouse model of S. aureus craniotomy infection that shares important ultrastructural, MRI, and immune attributes with human disease, which can be exploited to identify mechanisms for infection persistence. Our preliminary results suggest that T cells maintain S. aureus in a biofilm state to minimize the shedding of planktonic bacteria into the brain. Ultimately, this helps protect the CNS parenchyma but does not clear the biofilm. This is supported by the fact that bacterial burden was unchecked in Rag1 KO mice and in WT animals following CD4+ T cell depletion, reflecting increased planktonic bacteria in the brain and galea. Furthermore, T cell loss coincided with an attenuated activation signature in microglia, macrophages, and granulocytes, with significant reductions in several IFN-ɣ-regulated genes, including CXCL10, indicative of T cell-innate immune crosstalk. We aim to understand this regulation in addition to T cell-biofilm crosstalk to devise novel strategies to promote biofilm eradication. This possibility is feasible given our innovative bacterial scRNA-seq data, where activated CD4+ T cells induced the expression of several S. aureus virulence genes, including protein A (spa) that binds the Fc portion of antibody to inhibit opsonophagocytosis. CXCL10 has been reported to induce Spa shedding from the bacterial membrane, which raises the intriguing possibility that CXCL10 induction by T cells promotes Spa release to block S. aureus phagocytosis, which is supported by our preliminary data where craniotomy infection was significantly reduced with a S. aureus spa mutant. This proposal will examine the hypothesis that CD4+ T cells regulate antimicrobial responses in the brain and galea by targeting microglia/macrophages vs. PMNs/G-MDSCs, respectively, to prevent bacterial outgrowth and limit invasion into the brain. In response, S. aureus alters its transcriptiome to augment virulence factor expression to promote biofilm persistence. This represents a host-pathogen triad that dictates infection outcome and the molecular mechanisms responsible for bacterial persistence in the brain and galea will be examined in the following Specific Aims: 1) Identify the critical CD4+ Th subset and antigen specificity in controlling S. aureus outgrowth during craniotomy infection; 2) Determine key mechanisms of T cell-innate immune crosstalk that dictate biofilm growth and CNS invasion; and 3) Identify S. aureus biofilm genes that are critical for subverting T cell effector function during craniotomy infection. An improved understanding of how T cells shape the innate immune landscape and S. aureus virulence during craniotomy infection may be leveraged to enhance antimicrobial activity and biofilm clearance to reduce patient morbidity.

进行开颅手术以进入大脑进行手术，包括肿瘤切除、定位和切除致癫痫病灶，夹闭动脉瘤，并在术中更换骨瓣。预防，开颅手术后感染性并发症的发生率为 1-3%，其中大约一半是由金黄色葡萄球菌（S. aureus），在骨瓣上形成对抗生素耐药的生物膜。开发了一种金黄色葡萄球菌开颅感染的小鼠模型，该模型具有重要的超微结构、MRI 和人类疾病的免疫属性，可用于识别感染持续的机制。我们的初步结果表明，T 细胞将金黄色葡萄球菌维持在生物膜状态，以最大限度地减少金黄色葡萄球菌的脱落。最终，这有助于保护中枢神经系统实质，但不能清除大脑中的浮游细菌。 Rag1 KO 小鼠和 WT 动物中的细菌负荷未受到控制这一事实支持了这一点。 CD4+ T 细胞耗竭后，反映了大脑和帽状腱膜中浮游细菌的增加。细胞损失与小胶质细胞、巨噬细胞和粒细胞的激活特征减弱同时发生，多个 IFN-ɣ 调节基因显着减少，包括 CXCL10（T 细胞先天免疫指标）除了 T 细胞-生物膜串扰之外，我们还旨在了解这种调节，以设计新的策略。鉴于我们创新的细菌 scRNA-seq 数据，促进生物膜根除是可行的，其中激活的 CD4+ T 细胞诱导多种金黄色葡萄球菌毒力基因的表达，包括蛋白 A (spa) 据报道，CXCL10 结合抗体的 Fc 部分来抑制调理吞噬作用，从而诱导 Spa。从细菌膜上脱落，这提出了 T 细胞诱导 CXCL10 的有趣可能性促进 Spa 释放以阻止金黄色葡萄球菌吞噬作用，我们的初步数据支持这一点金黄色葡萄球菌 spa 突变体显着减少了开颅手术感染。假设 CD4+ T 细胞通过靶向调节大脑和帽状腱膜中的抗菌反应小胶质细胞/巨噬细胞与 PMN/G-MDSC 分别，以防止细菌生长并限制侵入作为回应，金黄色葡萄球菌改变其转录组以增强毒力因子表达以促进这代表了决定感染结果和分子的宿主-病原体三联体。细菌在大脑和帽状腱膜中持续存在的机制将在下面进行研究具体目标：1) 确定控制金黄色葡萄球菌生长的关键 CD4+ Th 亚群和抗原特异性开颅手术感染期间；2) 确定决定生物膜的 T 细胞先天免疫串扰的关键机制生长和中枢神经系统侵袭；3) 识别对破坏 T 细胞效应至关重要的金黄色葡萄球菌生物膜基因进一步了解 T 细胞如何塑造先天免疫。开颅手术感染期间的景观和金黄色葡萄球菌毒力可用于增强抗菌能力活性和生物膜清除，以降低患者发病率。