BME PhD Prospectus Defense - Ling Shi

Title: "Developing extracorporeal cross-circulation coupled with Crystal Ribcage to probe trained immunity against pneumonia"

Advisory Committee: NAME NAME NAME NAME

Abstract: Pneumonia is a serious consequence of respiratory infection and a leading global burden of disease. The prognosis is multifactorial and influenced more by variations among hosts than pathogen. Immune experience (i.e. immunity generated from prior infections) is a key factor that establishes and primes host immunity against future infections. While experience affects both systemic (blood-borne) and pulmonary (local resident) defenses against infections, discriminating the effects of experience on isolated components (e.g. systemic vs. pulmonary) remain a longstanding challenge. Moreover, there lack tools to longitudinally study the pathogenesis and resolution of pneumonia at high spatiotemporal resolution. To these ends, we propose to develop a novel extracorporeal system to cross-circulate whole blood from an awake walking “donor” mouse into an ex-vivo “recipient” lung infected with pneumonia and imaged at the cellular resolution via the Crystal Ribcage in real-time. First, I will develop the surgical means to continuously circulate blood from an awake mouse, bridged to the recipient lung through a novel extracorporeal circuit optimized for continuous whole blood transport. Second, I will establish long-term cross-circulation to probe the dynamics of pneumonia pathogenesis under the Crystal Ribcage for at least 24 hours while preserving donor welfare and recipient biology ex vivo. Third, by mismatching the immune-naïve vs. -experience status (i.e., prior exposure to pneumonia) between the donor vs. pneumonia-infected recipient systems, I will mechanistically decouple the contributions of pulmonary vs. systemic immunity to pneumonia defense. Lastly, I will serially connect a novel antiparallel dual-channel microfluidic chamber between the donor and recipient systems to longitudinally characterize the entire lung influx and efflux of immune cells throughout the progression and resolution phase of pneumonia. Together, this work is foundational for studying pneumonia pathogenesis in the long-term at high spatiotemporal resolution, and importantly enables the dissection of systemic vs. tissue-resident factors underlying trained immunity against pneumonia. In the future, this work will facilitate mechanistic mismatch studies investigating key variables, such as aging, obesity, and gender effects underlying any disease of the lung, and eventually any ex vivo organ.