Temporal analysis of T and B cell receptors in vaccine recipients reveals individualized clonotype changes without common CDR3 signatures 3778

Abstract Description Production of antigen specific B and Tcell receptors, created by random rearrangement of the heavy (IgH) and light chain (IgL, k and l) gene segments of B-cells and the a, b and g, d gene segments of T-cells, is a hallmark of adaptive immunity. The CDR3 region of each is the major antigen binding portion and reflects the most diverse region of the adaptive immune response. The production of antigen specific B and T cells is critical to the immune response, immunologic memory, and vaccination strategy. We have investigated the temporal immune response to COVID-19 vaccination in a cohort of 10 patients. Samples were collected at the time of the first COVID-19 vaccine (baseline) and at 7, 14 and 21 days post-first vaccination as well as days 3 and 7 after a second COVID vaccination. iRepertoire 7-chain multiplex PCR was utilized to rapidly sequence immune system receptors within this patient cohort. Between days 7 and 10 following vaccination, a small subset of B and T cell receptors in each individual showed significant increases in expression level or underwent affinity maturation and isotope switching, indicating the development of antigen-specific clones. However, no common clonotypes (unique CDR3 sequences) were observed across different individuals in these emerging clones. We are applying network theory analysis to investigate multi-dimensional variables to develop more insightful analytics from this study. Topic Categories Immune Mechanisms of Human Disease (HUM)