Comprehensive baseline characterization of rhesus macaque B cell subtypes and VDJ repertoire via single-cell RNA/VDJ sequencing 2534

Abstract Description Rhesus macaques (RMs) are used widely for pre-clinical infection and vaccination studies, yet their B cell immunobiology and immunogenetics remain little characterized. In this study, single-cell RNA/VDJ-sequencing (scRNA/VDJ-seq) was conducted on peripheral blood mononuclear cell (PBMC) samples from 3 male and 3 female, 2-3 years old juvenile RM. From a total 48,888 PBMCs sequenced, 9 RM B cell clusters of distinct transcriptional states were identified, including naïve B cells (∼13% of total B cells), activated B cells (∼7%), unswitched memory B cells (∼36%, 2 subtypes), switched memory B cells (∼23%, 2 subtypes), marginal zone-like B cells (∼19%), natural killer-like B cells (∼1.6%) and antibody-secreting cells (∼0.2%). For each subset, IGH/K/L-V(D)JC gene family and subtype usage, and VDJ repertoire properties such as somatic hypermutation rate and levels, complementarity-determining region heavy chain (CDRH3) amino acid (AA) length and CDRH3 AA hydrophobicity scores were elucidated. While comparable to human B cell subsets, comprehensive analysis of baseline RM PBMC B cell subtypes, paired with their respective V(D)JC repertoire characteristics, reveals distinct properties of RM B cell subsets. Establishment of this library of data will enable a more complete analysis of humoral responses in this critical pre-clinical animal model, providing data for improved predictions of humoral responses observed in RM to anticipated results in humans. Funding Sources Supported by NIH AI153140 and AI182066 (DEG) and Jeffrey Richardson Fellowship (AKPC) Topic Categories Veterinary and Comparative Immunology (VET)