Receptor editing constrains development of phosphatidyl choline-specific B cells in V12-transgenic mice.

B1 B cells reactive to phosphatidyl choline (PtC) exhibit restricted immunoglobulin heavy chain (HC) and light chain (LC) combinations, exemplified by V12/Vκ4/5H. Two checkpoints are thought to focus PtC B cell maturation in V12-transgenic mice (VH12 mice): V-J rearrangements encoding a "permissive" LC capable of V12 HC pairing are selected first, followed by positive selection based on PtC binding, often requiring LC receptor editing to salvage PtC B cells and acquire PtC reactivity. However, evidence obtained from breeding VH12 mice to editing-defective dnRAG1 mice and analyzing LC sequences from PtC and PtC B cell subsets instead suggests that receptor editing functions after initial positive selection to remove PtC B cells in VH12 mice.

IL10 restrains autoreactive B cells in transgenic mice expressing inactive RAG1.

IL10 plays a dual role in supporting humoral immunity and inhibiting inflammatory conditions. B cells producing IL10 are thought to play a key regulatory role in maintaining self-tolerance and suppressing excessive inflammation during autoimmune and infectious diseases, primarily by inhibiting associated T cell responses. The extent to which B cells, through the provision of IL10, might function to sustain or inhibit autoantibody production is less clear.

Exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior.

The myxobacteria are a family of soil bacteria that form biofilms of complex architecture, aligned multilayered swarms or fruiting body structures that are simple or branched aggregates containing myxospores. Here, we examined the structural role of matrix exopolysaccharide (EPS) in the organization of these surface-dwelling bacterial cells. Using time-lapse light and fluorescence microscopy, as well as transmission electron microscopy and focused ion beam/scanning electron microscopy (FIB/SEM) electron microscopy, we found that Myxococcus xanthus cell organization in biofilms is dependent on the formation of EPS microchannels.