Human Anti-Glycan Reactivity is Driven by the Selection of B cells Utilizing Private Antibody Gene Rearrangements that are Affinity Maturated in Germinal Centers.

The human antibody repertoire is broadly reactive with carbohydrate antigens represented in the universe of all living things, including both the host/self- as well as the commensal microflora-derived glycomes. Here we have used BCR receptor cloning and expression together with single-cell transcriptomics to analyze the B cell repertoire to the ubiquitous N-acetyl-D-glucosamine (GlcNAc) epitope in human cohorts and dissect the immune phylogeny of this predominant class of antibodies. We find that circulating anti-GlcNAc B cells exhibiting canonical BMem phenotypes emerge rapidly after birth and couple this observation with evidence for germinal center-dependent affinity maturation of carbohydrate-specific B cell receptors during early childhood.

A Neuron-Optimized CRISPR/dCas9 Activation System for Robust and Specific Gene Regulation.

CRISPR-based technology has provided new avenues to interrogate gene function, but difficulties in transgene expression in post-mitotic neurons has delayed incorporation of these tools in the central nervous system (CNS). Here, we demonstrate a highly efficient, neuron-optimized dual lentiviral CRISPR-based transcriptional activation (CRISPRa) system capable of robust, modular, and tunable gene induction and multiplexed gene regulation across several primary rodent neuron culture systems. CRISPRa targeting unique promoters in the complex multi-transcript gene brain-derived neurotrophic factor () revealed both transcript- and genome-level selectivity of this approach, in addition to highlighting downstream transcriptional and physiological consequences of regulation.