Lymph Node Stromal Network-Guided Lymph Drainage Regulates Neutrophil Response to S. aureus Infection

Xue, Jingna

Lymph Node Stromal Network-Guided Lymph Drainage Regulates Neutrophil Response to S. aureus Infection

dc.contributor.advisor	Liao, Shan
dc.contributor.author	Xue, Jingna
dc.contributor.committeemember	Kubes, Paul
dc.contributor.committeemember	Peters, Nathan
dc.contributor.committeemember	Lahl Christoforo, Katharina
dc.contributor.committeemember	Gommerman, Jennifer
dc.date	2024-11
dc.date.accessioned	2024-09-16T17:04:59Z
dc.date.available	2024-09-16T17:04:59Z
dc.date.issued	2024-09-12
dc.description.abstract	The lymph transports various molecules (i.e., tissue waste, antigens, immunoregulators, cells) to the lymph nodes (LNs). A unique LN conduit network made by fibroblastic reticular cells (FRC-conduit network) guides the drainage of lymph-derived molecules inside the LNs from entry to exit, as well as to high endothelial venules (HEVs) efficiently. Thereby, lymph drainage ensures timely immune protection. Within 4 hour-post-Staphylococcus aureus skin infection (4hpi), neutrophils infiltrate the LN through HEVs and prevent systemic S. aureus dissemination. The mechanism of this efficient recruitment and the connection between skin and LN was not fully understood. Here, I found that the timely neutrophil migration from HEV relies on lymph drainage using a lymphatic occlusion model. Further studies showed that the essential regulatory factors drained with lymph that regulate neutrophil recruitment in the LN are infection-induced chemokines (i.e., CXCL1 and CXCL2) rather than bacteria. Infection often occurs with complicated pre-existing conditions, potentially due to the pre-altered host immune environment. Using Oxazolone (OX)-induced skin inflammation, I observed an interrupted FRC-conduit network and reduced lymph reaching HEV in the LN. When infection occurs during OX-induced inflammation, I found altered neutrophil distribution, which diminished interaction with bacteria and a decreased CXCL1/2 level in the LN. A prolonged bacterial clearance was also observed in OX-inflamed LN, and a trend of systemic bacterial spreading was found in OX-induced inflammation. Next, I investigated the mechanism by which the FRC-conduit network is altered and explored whether targeting the FRC-conduit network can improve neutrophil response. Using single-cell RNA sequencing (scRNAseq) and immunofluorescence staining, I characterized the alteration of FRC subsets and plotted the changes to the LN niches. Notably, I identified a new FRC subset, Cxcl13inter RCs, generated in the OX-inflamed LNs, which only produce low levels of conduit components and thus cause a conduit loss. The induction of this new subset is from proliferative adjacent FRCs depending on B cell-derived lymphotoxins. Depletion of B cells eliminates the induction of Cxcl13inter RCs and preserves the conduit network and lymph drainage to HEVs. Upon subsequent S. aureus infection, the neutrophil response was also rescued, which is associated with better restrained systemic bacteria dissemination. Overall, this thesis demonstrates that lymph drainage guided by the FRC-conduit network in the LNs is critical to ensure optimal neutrophil migration and timely innate immune protection in S. aureus infection.
dc.identifier.citation	Xue, J. (2024). Lymph node stromal network-guided lymph drainage regulates neutrophil response to S. aureus infection (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/119727
dc.language.iso	en
dc.publisher.faculty	Cumming School of Medicine
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Lymphatic system
dc.subject	lymph drainage
dc.subject	Infection
dc.subject	Fibroblast reticular cells
dc.subject	Conduit network
dc.subject	Neutrophils
dc.subject.classification	Education--Health
dc.subject.classification	Bioinformatics
dc.subject.classification	Immunology
dc.subject.classification	Microbiology
dc.title	Lymph Node Stromal Network-Guided Lymph Drainage Regulates Neutrophil Response to S. aureus Infection
dc.type	doctoral thesis
thesis.degree.discipline	Medicine – Microbiology & Infectious Diseases
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.