Biology subjects

Baloul, S.

Publications and source records attributed to Baloul, S..

2 recordsLinked to original sources

bioRxiv2021

Regulation of neuronal progenitor delamination by dynein-driven post-Golgi apical transport

Radial glial (RG) cells are the neural stem cells of the developing neocortex. Apical RG (aRG) cells can delaminate to generate basal RG (bRG) cells, a cell type associated with human brain expansion. Here, we report that this delamination is regulated by the post-Golgi secretory pathway. Using in situ subcellular live imaging, we show that post-Golgi transport of RAB6+ vesicles occurs toward the minus ends of microtubules and depends on dynein. We demonstrate that the apical determinant Crumbs3 (CRB3) is also transported by dynein. Double knockout of RAB6A/A and RAB6B impairs apical localization of CRB3, and induces a retraction of aRG cell apical process, leading to delamination and ectopic division. These defects are phenocopied by knock-out of the dynein activator LIS1. Overall, our results identify a RAB6-dynein-LIS1 complex for Golgi to apical surface transport in aRG cells, and highlights the role of this pathway in the maintenance of neuroepithelial integrity.

cell biology↗

bioRxiv2020

Maturation and persistence of the anti-SARS-CoV-2 memory B cell response.

Memory B cells play a fundamental role in host defenses against viruses, but to date, their role have been relatively unsettled in the context of SARS-CoV-2. We report here a longitudinal single-cell and repertoire profiling of the B cell response up to 6 months in mild and severe COVID-19 patients. Distinct SARS-CoV-2 Spike-specific activated B cell clones fueled an early antibody-secreting cell burst as well as a durable synchronous germinal center response. While highly mutated memory B cells, including preexisting cross-reactive seasonal Betacoronavirus-specific clones, were recruited early in the response, neutralizing SARS-CoV-2 RBD-specific clones accumulated with time and largely contributed to the late remarkably stable memory B-cell pool. Highlighting germinal center maturation, these cells displayed clear accumulation of somatic mutations in their variable region genes over time. Overall, these findings demonstrate that an antigen-driven activation persisted and matured up to 6 months after SARS-CoV-2 infection and may provide long-term protection.

immunology↗