Novel approaches for studying cell-mediated immune responses to influenza vaccination in humans

Abstract

Abstract Vaccination is the most cost-effective public health intervention strategy in the prevention of the spread of infectious diseases. Unfortunately, each year, a substantial proportion of individuals do not respond or respond poorly to vaccination due to age, nutrition, pre-existing medical conditions, vaccine mismatch, or other unknown reasons. To investigate this further, we propose studying the mechanisms and molecular signatures associated with immunogenicity and the efficacy of influenza vaccination in different populations. The priming environment, induced by the innate immune system is crucial for initiating and fine-tuning antigen-specific adaptive immune responses. Comprehensive antibody panels have been developed to identify the new paradigms in the innate priming environment, focusing on NK, innate lymphoid cells and γδ T cells by flow cytometry in PBMC from vaccine recipients. The specific functions of these cells are then analyzed using single cell sorting and high-throughput transcriptomic and proteomics analysis. To further probe the adaptive response, we have successfully developed receptor binding site mutant HA (H1, H3, B) and HA stem (group 1 and 2) probes that are conjugated to fluorochromes to enumerate and characterize HA-specific B cells. M2e antigen probes are under development. Combining cell sorting, single cell molecular analyses, and the Illumina MiSeq system, paired heavy and light chains of B cell receptors (BCR) from isolated antigen specific B cells are sequenced to dissect antibody diversity. Through these novel approaches, we aim to identify and characterize critical host factors that can be exploited to develop as novel adjuvants and strategies for more effective influenza vaccines.