BioE MS Defense Presentation - Divya Bhatka

Advisor: Aniruddh Sarkar, Ph.D.(Biomedical Engineering, Georgia Institute of Technology & Emory University) 

Committee: 

Ankur Singh, Ph.D. (Mechanical & Biomedical Engineering, Georgia Institute of Technology & Emory University) 

Sudhir Pai Kasturi, Ph.D. (Experimental Pathology and Laboratory Medicine, Emory University) 

Antibody-omics for Biomarker Discovery in Vaccinology and Infectious Diseases 

Antibodies play a critical role in the immune response by neutralizing toxins, thereby modulating vaccine response and disease outcome. Their protective effector functions are primarily regulated by the antigen-binding domain (Fab) and the crystallizable domain (Fc). While traditional methods of antibody profiling have successfully applied top-down approaches for mainly Fab analysis indicative of overall isotype titer, the Fc interactions between adaptive and innate immunity remain overlooked. As a result, a poorly defined antibody profile of heterogenous individuals can lead to incomplete conclusions regarding disease state or vaccine efficacy. Thus, the long-term objective of this research was to fully characterize the antibody profile using both top-down and bottom-up approaches in a rapid, cost-effective, and efficient manner for translational applications in biomarker discovery, point-of-care diagnostics, vaccine development, and therapeutics. The first specific aim focused on measuring Fc N-linked glycosylation, which is a common post-translational modification well known for its influence on pro- and anti-inflammatory antibody functionality. Currently, gold-standard methods of glycosylation analysis, such as mass spectrometry, are often sample and time-intensive, which can present a critical bottleneck in biomarker discovery. Here, I systematically validated the use of cost-effective sugar-binding lectins with glycoengineered antibodies for rapid (~2.5hr) high-throughput screening of antigen-specific antibody glycosylation. Ultimately, our established multiplexed antibody-omics platform was expanded for deep biophysical characterization on a broad set of antigen-specific antibodies including isotype, subclass, FcR-binding, and glycosylation analysis. The second specific aim was to apply our robust antibody-omics platform to characterize vaccine and adjuvant efficacy. While the role of adjuvants in improving the immunogenicity of vaccines has long been recognized and developed, maintaining and assessing vaccine efficacy over extended periods continues to be a critical challenge. Here, I evaluated the immunogenicity of two adjuvanted vaccine cohorts: HIV-1 and Onchocerciasis. Univariate statistical analysis indicated an IgG1 and IgG4 polarization in both vaccine studies across adjuvant groups, amongst other unique vaccine/adjuvant antibody correlates of protection. A similar experimental approach, with the addition of complement analysis, was performed in the third specific aim to assess and predict the risk of antibody-mediated rejection (ABMR) from sera of kidney transplant patients. While the chance of experiencing rejection is increased by the presence of donor specific antibodies (DSAs) against human leukocyte antigens (HLAs) on the graft, not all transplant recipients experience rejection. Thus, multivariate LASSO-SVM analysis was performed between ABMR+DSA+ and ABMR-DSA+ patients to elucidate the antibody signatures that led to rejection versus non-rejection. Ultimately, this work provides a foundation for rapid, multiplexed humoral profiling with the potential to screen antibody biomarkers across a range of disease and vaccine efficacy studies.

https://gatech.zoom.us/j/99510868434 

Meeting ID: 995 1086 8434