(4ff) Engineering Chemical Tools for Autoimmune Modulation and Investigation

Complex immunological problems such as autoimmune diseases and evasive infections often require elegant, multidisciplinary solutions to diagnosis, study and treat. My multidisciplinary background and experience in engineering, chemistry, biology and immunology affords me a unique opportunity to apply chemical tools towards these immunological problems.

PhD Research, University of Notre Dame, Advisor: Dr. Basar Bilgicer

My training, both in chemistry and immunology, has been exceptionally productive. As a graduate student, I developed chemical tools to treat and diagnose type 1 hypersensitivity reactions (allergies) to both food and drugs. By modifying liposomes with allergy epitopes, I created a diagnostic system for both peanut and penicillin allergies. This technique was also modified to become the first reliable diagnostic test for chemotherapeutic drug allergies. Using the knowledge gleaned from the allergy diagnostic project, I developed a targeted inhibitor for the allergen specific antibodies responsible for allergies for both penicillin and peanut allergies. While the work was primarily translational, my peanut inhibitor work revealed that only a small number of peanut allergy epitopes are crucial for strong allergic reactions.

Postdoctoral Research, University of Chicago, Pritzker School of Molecular Engineering, Advisor: Dr. Aaron Esser-Kahn

My most recent work is focused on innate immune cells in two distinct areas. The most prominent is using toll-like-receptor (TLR) agonist conjugated microparticles (MPs) to identify and characterize a unique highly TLR agonist responsive DC subtype. A subset of DCs, which we call First Responder cells or FRs (<5% of all DCs) phagocytoses an unusually high number of MPs and has increased immune activation. I isolated these cells, identified their phenotype as a subset of cDC2 cells, identified several unique surface markers for FRs and demonstrated that they facilitate adaptive immune responses via paracrine signaling. Currently, I am developing FR targeted vaccine formulations for difficult to vaccinate diseases, such as HIV and TB. The other distinct area of innate immune research is using the TLR conjugated microparticles to perform quantitative measurements of TLR activation thresholds. By measuring the number of TLR agonists conjugated to the MP surface and the number of MPs phagocytosed by an innate immune cell, I can calculate a number of TLR agonists required to trigger cellular activation, as measured by TNFα secretion. Taken as a whole, my research experience has spanned a number of immunological topics, deploying chemical and biochemical tools to measure and modulate immune interaction.

Research Awards: NIH Ruth L. Kirschstein National Research Service Award Individual Postdoctoral Fellowship (Parent F32) 2019, CBE GSO Symposium Outstanding Session Speaker, (Chemical and Biomolecular Engineering Department), 2016, Outstanding Presentation Award, (Chemistry Biology Biochemistry Interface Program) 2016, Three Minute Thesis Competition Finalist, (University of Notre Dame Graduate School) 2016.

Future Research Interests:

My future research plans will have similar themes but focus mainly upon leveraging chemical tools for autoimmune therapies. One major problem for autoimmune diseases is that they widely vary in their pathogenesis and symptoms; however, they do share an underlying cause, namely the inappropriate activation of immunity via self-antigen presentation leading to auto-reactive adaptive (T and B cell) responses. My proposal seeks to modulate the initial self-antigen presentation by activated antigen-presenting cells (APC) toward a more tolerogenic phenotype as a treatment for autoimmunity. In normal development of immunity, APCs are activated via molecular pattern recognition receptors (PPR) and present a local antigen to adaptive immune cells. In this case, any self-antigens are accompanied with various inhibitory signals leading to self-antigen specific T regulatory cells (Treg) that actively suppress autoreactive responses to the self-antigen. I plan to treat autoimmunity by mimicking this natural response and use a combination of chemical signals to alter the APC phenotype to generate Treg responses that abrogate autoimmune T and B cells in a process I call “molecular immune tuning” or MIT.

Most clinical autoimmune therapies rely upon broad immunosuppressive drugs that impair multiple immune signaling cascades in both innate and adaptive immune cells, thereby reducing symptoms associated with overactive self-immunity but also reducing overall immune effectiveness. Rather than broad immune suppression, I plan to combine activating and inhibitory signals for a particular PPR called toll-like-receptors (TLR) present on APCs to generate a more “active” (by leading to the development of antigen specific Tregs) and specific (by targeting APCs) immune suppression rather than non-specific inhibitory signals alone. Furthermore, I plan to improve the tolerizing potential of this therapy by specifically targeting APCs that are more inclined to facilitate T regulatory responses. This proposal will seek to develop a disease specific MIT that targets APCs as a proof of principle in three specific aims:

While prior literature shows that inhibitory and activating TLR signaling combination can induce a tolerogenic phenotype in DCs, our first goal is to verify this hypothesis and optimize the drug combinations. By screening a large library (>15,000 combinations using the UChicago Screening facility, work currently underway) of TLR agonists with TLR inhibitors at varying concentrations using model cell lines and eventually primary mouse APC lines, I will identify an appropriate combination of TLR inhibitors and agonists that limit inflammatory signaling (e.g., IL-6, TNFα, etc.) and promote tolerance signaling (IL-10, TGF-β, etc.). A small number of candidates will be screened in vivo for Tregs responses to a model antigen.

The next step will be to develop an appropriate nanocarrier that can selectively target APCs primarily responsible for tolerance responses. I hypothesize that targeting FRs would improve the overall effectiveness of MIT, as cDC2 cells are primarily responsible for generating the tolerogenic cytokines and FRs are known to coordinate larger immune responses via paracrine signaling. This formulation will consist of four components: (1) the activating/inhibiting TLR combination, (2) a FR targeting domain, (3) an antigen of interest and (4) an appropriate nanocarrier to deliver the other three components. Nanocarriers are ideal for targeting immune cells, given that APCs uptake particles in the nano-regime and offer more versatility to deliver antigen and targeting elements. I would validate several nanocarriers, TLR inhibitor/agonist combinations and FR targeting moieties through in vitro and in vivo screening using model antigens. The final aspect of this project will be testing the formulation on animal models of autoimmunity.

In addition to the translational outcomes of this project, I anticipate that the MIT project will also yield more understanding into the mechanism of inhibitory/activation balance in innate immune cells and DCs in particular. This project can incorporate other PRR and their downstream targets. Furthermore, my future research plans will also branch out into different areas of immunology. Two in particular are of interest: Quantitative immunology and autoinflammatory disease diagnostics.

I plan to use my knowledge of chemistry and material sciences to design nanoparticles with precise numbers of immune related molecules in order to determine quantitative relationships of immune phenomena, particularly tolerance interactions. For example, I plan to conjugate PD-L1 proteins on particulate surfaces to determine the precise number of PD-L1/PD-1 interactions required to generate Treg responses. I also plan to explore cellular ratios of tolDCs/ inflammatory DCs which induce T reg responses using precise in vitro cell culture assays.

Finally, I plan to use my materials and chemistry knowledge to advance the understanding and diagnostic capabilities in autoinflammatory disease (AD). ADs are a group of inflammatory diseases were innate immune cells trigger debilitating inflammation in responses to auto-antigens. Unlike autoimmune diseases, no adaptive (T or B cells) responses are involved, rather just release of inflammatory cytokines, such as IL-6 and TNF. There is a severe lack of precision diagnostics for these diseases and I plan to use my knowledge of chemistry to design microfluidic systems to measure the inflammatory cytokine output of circulating innate immune cells to develop the first non-genetic diagnostic for ADs.

It is my hope that I can use my experience in both chemistry and immunology to successfully increase our fundamental understanding of immunology and develop translational vaccines and autoimmune therapies that have real impact of patients.

Teaching Interests:

Both as a graduate student and postdoctoral researcher, I have had many opportunities to gain experience in a classroom setting. As a graduate student, I was a teaching assistant for Transport Phenomena and Intro Bioengineering classes where I held office hours, graded the student’s work, and performed a few guest lectures. I was also involved in as a mentor to an undergraduate fermentation-based energy project at Notre Dame. Later in my career, I had an opportunity 2-3 times per year to give a lecture for my advisor’s advanced bioengineering course, which I deeply enjoyed. I have also had the opportunity several times to do this for my postdoctoral advisor. These experiences have given me a great appreciation for teaching and a willingness to teach any core chemical engineering class (particularly Transport Phenomena) and bioengineering or immune-engineering based courses.