Victora, G. D. | bioRxiv Science

bioRxiv2017

One-step generation of monoclonal B cell receptor mice capable of class switch recombination and somatic hypermutation

We developed a method for rapid generation of B cell receptor (BCR) monoclonal mice expressing pre-rearranged Igh and Igk chains monoallelically from the Igh locus by CRISPR/Cas9 injection into fertilized oocytes. B cells from these mice undergo somatic hypermutation (SHM), class switch recombination (CSR), and affinity-based selection in germinal centers. This method combines the practicality of BCR transgenes with the ability to study Ig SHM, CSR and affinity maturation.

immunology↗

bioRxiv2017

Intestinal epithelial and intraepithelial T cell crosstalk mediates a dynamic response to infection

Intestinal intraepithelial lymphocytes (IELs) are located at the critical interface between the intestinal lumen, which is chronically exposed to food and microbes, and the core of the body. Using high-resolution microscopy techniques and intersectional genetic tools, we investigated the nature of IEL responses to luminal microbes. We observed that TCR{gamma}{delta} IELs exhibit distinct location and movement patterns in the epithelial compartment that were microbiota-dependent and quickly altered upon enteric infections. These infection-induced changes included increased inter-epithelial cell (EC) scanning, anti-microbial gene expression and glycolysis. Direct modulation of glycolysis was sufficient to change {gamma}{delta} IEL behavior and susceptibility to early pathogen invasion. Both {gamma}{delta} IEL behavioral and metabolic changes were dependent on EC pathogen sensing. Our results uncover a coordinated EC-IEL response to enteric infections that modulates lymphocyte energy utilization and dynamics and supports maintenance of the intestinal epithelial barrier.

immunology↗