Baumgarth Lab

Defining How the Immune System is Regulated, How it Functions, and Why it May Fail in Response to Certain Infections

The immune system is a complex organ system consisting of solid tissues and numerous distinct cell populations with unique functions that have developed to control and protect the normal functions of a complex multicellular host. The immune system responds to infections and eliminates invading pathogens. It also contributes to tissue repair and tissue regeneration and performs general “housekeeping” functions, such as the removal of dead and dying cells. 

The Baumgarth Lab investigates the basic immunological mechanisms that regulate and control responses by B lymphocytes, especially immediate early responses, and the induction and function of antibody-mediated immunity to pathogens. 

We aim to identify and understand the various factors that drive protective B cell responses to influenza virus infection and determine how these responses might be derailed by bacterial spirochetes called Borrelia burgdorferi—the causative agent of Lyme disease. These bacteria establish persistent infections in mice and other small rodents. Understanding how they are suppressing effective immunity may help with future therapies that bolster the immune responses of infected hosts. 

We are particularly interested in understanding how signals of the innate immune system—such as cytokines and innate pathogen recognition receptors on B cells—affect the effectiveness of their responses, and how the absence of such signals during vaccinations may limit vaccine-induced immunity. We are also interested in understanding the development, roles, and functions of a small, innate-like B cell subset (termed B-1 cells) and the natural IgM that this subset is producing.

The lab is using various mouse models to study the regulatory processes controlling successful and unsuccessful immune responses. This includes the use of reporter mice and mice engineered to lack certain components of the immune system so we can dissect their importance during antiviral or antibacterial immune responses. 

Much of the work relies on in vivo and ex vivo analysis tools such as multiparameter flow cytometry for both functional and phenotypic studies, histology, immunohistochemistry and immunofluorescent imaging, as well as ELISA, ELISPOT, bulk and single-cell RNA sequencing, spatial transcriptomics, and other state-of-the-art cellular and molecular immunological assays and “omics” approaches. Cell culture studies are used to further dissect in vivo observations.

Research Interests

• Host-pathogen interactions
• B cell responses and functions
• Extrafollicular B cell responses
• Immune subversion by Borrelia burgdorferi
• Tickborne Diseases
• Tissue-specific immunity in the respiratory tract
• B-1 cell development, function, and regulation
• Natural IgM and the FcuR