Identification of a New Stromal Cell Type Involved in the Regulation of Inflamed B Cell Follicles

Cyrille Mionnet (1) , Isabelle Mondor (1) , Audrey Jorquera (1) , Marie Loosveld (1) , Julien Maurizio (1) , Marie-Laure Arcangeli (2) , Nancy Ruddle (3) , Jonathan Nowak (1) , Michel Aurrand-Lions (2) , Hervé Luche (1) , Marc Bajenoff (1)

1 CIML - Centre d'Immunologie de Marseille - Luminy
2 CRCM - Centre de Recherche en Cancérologie de Marseille
3 YSM - Yale School of Medicine [New Haven, Connecticut]

Lymph node (LN) stromal cells provide survival signals and adhesive substrata to lymphocytes. During an immune response, B cell follicles enlarge, questioning how LN stromal cells manage these cellular demands. Herein, we used a murine fate mapping system to describe a new stromal cell type that resides in the T cell zone of resting LNs. We demonstrated that upon inflammation, B cell follicles progressively trespassed into the adjacent T cell zone and surrounded and converted these stromal cells into CXCL13 secreting cells that in return delineated the new boundaries of the growing follicle. Acute B cell ablation in inflamed LNs abolished CXCL13 secretion in these cells, while LT-β deficiency in B cells drastically affected this conversion. Altogether, we reveal the existence of a dormant stromal cell subset that can be functionally awakened by B cells to delineate the transient boundaries of their expanding territories upon inflammation.

Domaines: Biologie cellulaire

Cyrille Mionnet, Isabelle Mondor, Audrey Jorquera, Marie Loosveld, Julien Maurizio, et al.. Identification of a New Stromal Cell Type Involved in the Regulation of Inflamed B Cell Follicles. PLoS Biology, 2013, 11 (10), pp.e1001672. ⟨10.1371/journal.pbio.1001672⟩. ⟨inserm-02131392⟩