B cell dysregulation in immune mediated diseases

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Abstract/Contents

Abstract
Alterations in B cell homeostasis drive pathogenesis of various immune mediated diseases. Breaks in peripheral tolerance allow autoreactive B cells to differentiate in to pathogenic auto-antibody secreting cells. B cells themselves may directly drive pathogenesis through antigen-presentation capabilities and secretion of pro-fibrotic factors. Lastly, the inability of B cells to mount effective responses against pathogens may trigger subsequent inflammatory or autoimmune reactions. In this work, we dissect various ways in which B cells contribute to pathogenesis of inflammatory disease by evaluating their role in three different immune mediated diseases. In chapter 2 we identify a potential regulatory role for B cells in the context of Systemic Lupus Erythematosus (SLE), an autoimmune disease characterized by the pathogenic secretion of anti-nuclear antibodies. We found that CD52 is a B cell regulatory glycoprotein elevated on the surface of B cells in patients and acts to suppress B cell hyperactivity both through its surface expression and through the secretion of a soluble form that can bind receptor Siglec-10. In chapter 3 we describe a population of B cells that is significantly expanded in IgG4-RD, a fibroinflammatory condition characterized by infiltration of IgG4+ plasma cells into tumefactive lesions and the development of storiform fibrosis. The expanded population of B cells was CD21— and CXCR5+, expressing high levels of pathogenic B cell marker CD11c. Moreover, the frequency of this expanded population correlated with clinical parameters such as IgG4 titers. We observed a tremendous elevation of CXCL13, the ligand for CXCR5, strongly implicating the CXCR5-CXCL13 axis in recruiting B cells to affected tissue, making it a viable therapeutic target. Lastly, in chapter 4 we performed high-dimensional sequencing on B cells from sarcoidosis patients, a disease characterized by spontaneous granuloma formation. Although B cells have not been directly implicated in the inflammation, we observed a less diverse and less mutated B cell receptor repertoire; together, our findings point to the initiation of sarcoidosis after ineffective antibody mediated clearance of pathogen from affected organs. In total, this work sheds novel insights on the role of B cells— from the initial stages of activation and germinal center recruitment, to the development of a diverse antibody repertoire— in the context of poorly understood immune mediated conditions and contributes important knowledge for the advancement of better treatments for affected patients.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2021; ©2021
Publication date 2021; 2021
Issuance monographic
Language English

Creators/Contributors

Author Bhamidipati, Kartik
Degree supervisor Robinson, William (William Hewitt)
Thesis advisor Robinson, William (William Hewitt)
Thesis advisor Maltzman, Jonathan
Thesis advisor Mellins, Elizabeth
Degree committee member Maltzman, Jonathan
Degree committee member Mellins, Elizabeth
Associated with Stanford University, Program in Immunology

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Kartik Bhamidipati.
Note Submitted to the Program in Immunology.
Thesis Thesis Ph.D. Stanford University 2021.
Location https://purl.stanford.edu/ms911hv5230

Access conditions

Copyright
© 2021 by Kartik Bhamidipati
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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