Distinct roles of the meningeal layers in CNS autoimmunity.

The meninges, comprising the leptomeninges (pia and arachnoid layers) and the pachymeninx (dura layer), participate in central nervous system (CNS) autoimmunity, but their relative contributions remain unclear. Here we report on findings in animal models of CNS autoimmunity and in patients with multiple sclerosis, where, in acute and chronic disease, the leptomeninges were highly inflamed and showed structural changes, while the dura mater was only marginally affected. Although dural vessels were leakier than leptomeningeal vessels, effector T cells adhered more weakly to the dural endothelium. Furthermore, local antigen-presenting cells presented myelin and neuronal autoantigens less efficiently, and the activation of autoreactive T cells was lower in dural than leptomeningeal layers, preventing local inflammatory processes. Direct antigen application was required to evoke a local inflammatory response in the dura. Together, our data demonstrate an uneven involvement of the meningeal layers in CNS autoimmunity, in which effector T cell trafficking and activation are functionally confined to the leptomeninges, while the dura remains largely excluded from CNS autoimmune processes.

Improvement and use of CRISPR/Cas9 to engineer a sperm-marking strain for the invasive fruit pest Drosophila suzukii.

BACKGROUND: The invasive fruit pest Drosophila suzukii was reported for the first time in Europe and the USA in 2008 and has spread since then. The adoption of type II clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) as a tool for genome manipulation provides new ways to develop novel biotechnologically-based pest control approaches. Stage or tissue-specifically expressed genes are of particular importance in the field of insect biotechnology. The enhancer/promoter of the spermatogenesis-specific beta-2-tubulin (ß2t) gene was used to drive the expression of fluorescent proteins or effector molecules in testes of agricultural pests and disease vectors for sexing, monitoring, and reproductive biology studies. Here, we demonstrate an improvement to CRISPR/Cas-based genome editing in D. suzukii and establish a sperm-marking system. RESULTS: To improve genome editing, we isolated and tested the D. suzukii endogenous promoters of the small nuclear RNA gene U6 to drive the expression of a guide RNA and the Ds heat shock protein 70 promoter to express Cas9. For comparison, we used recombinant Cas9 protein and in vitro transcribed gRNA as a preformed ribonucleoprotein. We demonstrate the homology-dependent repair (HDR)-based genome editing efficiency by applying a previously established transgenic line that expresses DsRed ubiquitously as a target platform. In addition, we isolated the Ds_ß2t gene and used its promoter to drive the expression of a red fluorescence protein in the sperm. A transgenic sperm-marking strain was then established by the improved HDR-based genome editing. CONCLUSION: The deployment of the endogenous promoters of the D. suzukii U6 and hsp70 genes to drive the expression of gRNA and Cas9, respectively, enabled the effective application of helper plasmid co-injections instead of preformed ribonucleoproteins used in previous reports for HDR-based genome editing. The sperm-marking system should help to monitor the success of pest control campaigns in the context of the Sterile Insect Technique and provides a tool for basic research in reproductive biology of this invasive pest. Furthermore, the promoter of the ß2t gene can be used in developing novel transgenic pest control approaches and the CRISPR/Cas9 system as an additional tool for the modification of previously established transgenes.