Activation-Induced Cytidine Deaminase Expression in CD4+ T Cells is Associated with a Unique IL-10-Producing Subset that Increases with Age

Activation-induced cytidine deaminase (AID), produced by the Aicda gene, is essential for the immunoglobulin gene (Ig) alterations that form immune memory. Using a Cre-mediated genetic system, we unexpectedly found CD4+ T cells that had expressed Aicda (exAID cells) as well as B cells. ExAID cells increased with age, reaching up to 25% of the CD4+ and B220+ cell populations. ExAID B cells remained IgM+, suggesting that class-switched memory B cells do not accumulate in the spleen. In T cells, AID was expressed in a subset that produced IFN-γ and IL-10 but little IL-4 or IL-17, and showed no evidence of genetic mutation. Interestingly, the endogenous Aicda expression in T cells was enhanced in the absence of B cells, indicating that the process is independent from the germinal center reaction. These results suggest that in addition to its roles in B cells, AID may have previously unappreciated roles in T-cell function or tumorigenesis

Efficient Genome Editing in Rice Protoplasts Using CRISPR/CAS9 Construct

International audienceGenome editing technologies, mainly CRISPR/CAS9, are revolutionizing plant biology and breeding. Since the demonstration of its effectiveness in eukaryotic cells, a very large number of derived technologies has emerged. Demonstrating and comparing the effectiveness of all these new technologies in entire plants is a long, tedious, and labor-intensive process that generally involves the production of transgenic plants and their analysis. Protoplasts, plant cells free of their walls, offer a simple, high-throughput system to test the efficiency of these editing technologies in a few weeks' time span. We have developed a routine protocol using protoplasts to test editing technologies in rice. Our protocol allows to test more than 30 constructs in protoplasts prepared from leaf tissues of 100, 9-11-day-old seedlings. CRISPR/CAS9 construct effectiveness can be clearly established within less than a week. We provide here a full protocol, from designing sgRNA to mutation analysis