Diya Ramchandani
BME MS Thesis Defense Presentation
Date: 2025-12-03
Time: 1:30pm
Location / Meeting Link: IBB Suddath Seminar Room 1128 

Committee Members:
Dr. Ankur Singh; Dr. Aniruddh Sarkar; Dr. Marian A Ackun-Farmmer


Title: Engineering ex vivo human immune organoids to elucidate innate immune (particularly macrophages) modulation of germinal center dynamics.

Abstract:
Immunology research has traditionally been based on animal models. However, key differences between humans and non-human models limit their translational relevance. Notably, these species differ in immune subsets and lymph node microenvironments. Very recently, ex vivo human immune organoid models have enabled the study of human adaptive immune responses. In this study, we extend the ex vivo human immune organoid to investigate how the innate immune arm (particularly macrophages) regulates a key process, namely the germinal center reaction, that defines the adaptive immune responses. We engineered an autologous human macrophage-immune organoid coculture system to mimic the structure and function of secondary lymphoid tissues. We observed that the presence of macrophages suppressed the B cell population and activation of B cells. Macrophages reduced both germinal center (GC) and antibody-secreting cell (ASC) populations. This suggests a potential regulatory role of macrophages in defining adaptive immune reactions by controlling inflammatory responses, which we are further investigating.