title: The actin-based motor protein myosin II regulates MHC class II trafficking and BCR-driven antigen presentation.
abstract: Antigen (Ag) capture and presentation onto major histocompatibility complex (MHC) class II molecules by B lymphocytes is mediated by their surface Ag receptor (B cell receptor [BCR]). Therefore, the transport of vesicles that carry MHC class II and BCR-Ag complexes must be coordinated for them to converge for processing. In this study, we identify the actin-associated motor protein myosin II as being essential for this process. Myosin II is activated upon BCR engagement and associates with MHC class II-invariant chain complexes. Myosin II inhibition or depletion compromises the convergence and concentration of MHC class II and BCR-Ag complexes into lysosomes devoted to Ag processing. Accordingly, the formation of MHC class II-peptides and subsequent CD4 T cell activation are impaired in cells lacking myosin II activity. Therefore, myosin II emerges as a key motor protein in BCR-driven Ag processing and presentation.
authors: Institut National de la Santé et de la Recherche Medicale Unité 653, Unité Mixte de Recherche 144 Institut Curie, 75005 Paris, France.
authors: Fulvia
authors: F
authors: Vascotto
authors: Danielle
authors: D
authors: Lankar
authors: Gabrielle
authors: G
authors: Faure-André
authors: Pablo
authors: P
authors: Vargas
authors: Jheimmy
authors: J
authors: Diaz
authors: Delphine
authors: D
authors: Le Roux
authors: Maria-Isabel
authors: MI
authors: Yuseff
authors: Jean-Baptiste
authors: JB
authors: Sibarita
authors: Marianne
authors: M
authors: Boes
authors: Graça
authors: G
authors: Raposo
authors: Evelyne
authors: E
authors: Mougneau
authors: Nicolas
authors: N
authors: Glaichenhaus
authors: Christian
authors: C
authors: Bonnerot
authors: Bénédicte
authors: B
authors: Manoury
authors: Ana-Maria
authors: AM
authors: Lennon-Duménil
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D008247:Lysosomes / Q000276:immunology / Q000378:metabolism; D046911:Macromolecular Substances / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D024462:Myosin Type II / Q000276:immunology / Q000378:metabolism*; D021381:Protein Transport / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology / Q000378:metabolism*; D022161:Transport Vesicles / Q000276:immunology / Q000378:metabolism*
chemical_list: D000199:Actins; D000949:Histocompatibility Antigens Class II; D046911:Macromolecular Substances; D011947:Receptors, Antigen, B-Cell; D024462:Myosin Type II