PROJECT SUMMARY
Defining how FoxP3+ regulatory T cells (Tregs) limit amnestic responses to common allergens has the
potential to provide new and effective therapies for asthma and other atopic diseases. Recent work has
demonstrated that T helper type 2 (Th2) tissue-resident memory T cells (Trm) persist around the airways
following allergic sensitization where they become rapidly activated and drive the asthma phenotype upon
allergen re-exposure. The immunoregulatory mechanisms that limit the proinflammatory functions of Th2-Trm
at mucosal sites are less clear. The objective of this proposal is to define the factors influencing allergen-
specific resident (r) Treg maintenance in the lungs and their suppression of Th2-Trm following re-exposure to
inhaled allergen. Our central hypothesis is that allergen-specific rTregs are positioned in a unique niche in the
lung that enables potent suppression of allergic inflammation. Mechanistically, we hypothesize that rTregs co-
localize with Th2-Trm based upon the CXCR6 and CCR8 chemokine systems. This proposal will explore these
questions using novel experimental systems to define the function of rTregs in a mouse model of allergic
asthma, including polyclonal adoptive transfer of house dust mite (HDM)-specific cells, parabiosis, single cell
RNA sequencing analysis of HDM-specific T cells, and CRISPR-Cas9 gene editing. With Aim 1, we will build
upon preliminary data to define the role of allergen-specific rTregs in suppressing lung Th2-Trm. We will
characterize the localization, persistence, suppressive potency, and transcriptional profile of the Tregs that
persist in the lung following allergen clearance. In Aim 2, we will determine the role of the CXCR6 and CCR8
chemokine systems in rTreg positioning and function. To identify additional factors important for the rTreg
tissue residency program and provide additional training in genome editing and systems biology, we will
perform an in vivo CRISPR-Cas9 screen on HDM-specific TCR transgenic cells isolated from the HDM
memory lung. Dr. Nelson will perform the work in this K08 proposal, sponsored by Boston Children’s Hospital,
at the Center for Immunology and Inflammatory diseases (CIID) at Massachusetts General Hospital (MGH)
under the mentorship of Dr. Andrew Luster. Dr. Nelson has developed a career development plan consisting of
coursework in advanced microscopy, bioinformatics, and translational research, along with mentored hands-on
training in cutting-edge research methods to explore his research aims. The goal of this K08 award is to
provide Dr. Nelson with the necessary skills and knowledge to become an independent, NIH-funded
investigator with expertise in human disease models of atopic diseases and immunoregulation in non-lymphoid
tissues.