Overexpression of proinflammatory TLR-2-signalling lipoproteins in hypervirulent mycobacterial variants Anne-Laure Roux, 1† Aurélie Ray, 2,3† Alexandre Pawlik, 1,4 Halima Medjahed, 5 Gilles Etienne, 2,3 Martin Rottman, 1 Emilie Catherinot, 1 Jean-Yves Coppée, 6 Karima Chaoui, 2,3 Bernard Monsarrat, 2,3 Antoine Toubert, 7 Mamadou Daffé, 2,3 Germain Puzo, 2,3 Jean-Louis Gaillard, 1 Roland Brosch, 4 Nicolas Dulphy, 7 Jérôme Nigou 2,3‡ and Jean-Louis Herrmann 1 * ‡ 1 EA 3647 Physiopathologie et diagnostic des infections microbiennes, Université Versailles St Quentin, and Laboratoire de Microbiologie, Hôpital Raymond Poincaré, AP-HP, Garches, France. 2 CNRS – IPBS (Institut de Pharmacologie et de Biologie Structurale), Département Mécanismes Moléculaires des Infections Mycobactériennes 3 Université de Toulouse, UPS, 205 route de Narbonne, F-31077 Toulouse, France. 4 Institut Pasteur, Pathogénomique Mycobactérienne Intégrée, Paris, France. 5 Université Paris Descartes, Faculté de Médecine Paris Descartes, and Inserm, U1002, Unité de Pathogénie des Infections Systémiques, Paris Cedex 15, F-75730, France. 6 Institut Pasteur, Génopole, Plate-forme Transcriptome PF2, Paris, France. 7 Inserm UMR940, Université Paris-Diderot, and Service d’Immunologie et d’Histocompatibilité, Hôpital Saint Louis, AP-HP, Paris, France. Summary Changes in the cell envelope composition of myco- bacteria cause major changes in cytokine profiles of infected antigen presenting cells. We describe here the modulation of inflammatory responses by Mycobacterium abscessus, an emerging pathogen in cystic fibrosis. M. abscessus is able to switch from a smooth (S) to a rough (R) morphotype by the loss of a surface glycopeptidolipid. R variants are associated with severe clinical forms and a ‘hyper-proinflammatory’ response in ex vivo and in vivo models. Using partitioning of cell surface components we found that a complex fraction, more abundant in R variants than in S variants, made a major contribution to the TLR-2-dependent hyper-proinflammatory response induced by R variants. Lipoproteins were the main TLR-2 ago- nists in this fraction, consistent with the larger amounts of 16 lipoproteins in cell surface extracts from R variants; 15 out of 16 being more strongly induced in R variant than in S variant. Genetic interruption of glycopeptidolipid pathway in wild- type S variant resulted in R phenotype with similar induction of lipoprotein genes. In conclusion, R morphotype in M. abscessus is associated with increased synthesis/exposure at the cell surface of lipoproteins, these changes profoundly modifying the innate immune response through TLR-2- dependent mechanisms. Introduction Mycobacteria form a group of more than one hundred species, highly diverse in terms of their pathogenicity and distribution in the environment. One of the key character- istics of these bacteria is their unique cell envelope (Daffé and Draper, 1998). Many reports have highlighted the potential effects of mycobacterial cell wall components on the innate and adaptive immune responses of the host. Even small changes in a single major inflammatory mol- ecule of the mycobacterial cell wall may have dramatic consequences (Cooper, 2009). For example, clinical iso- lates of Mycobacterium tuberculosis, the causal agent of human tuberculosis, vary widely in their capacity to stimulate the secretion of proinflammatory and/or anti- inflammatory cytokines in macrophages (Mf). These dif- ferences are thought to be associated, in part, with the production of a surface phenol glycolipid, suggesting a direct link between mycobacterial surface variation, cytok- ine profiles and pathogenicity (Reed et al., 2004; Tsenova et al., 2005). We show here that the situation is similar for certain cell wall components of Mycobacterium abscessus. Received 23 September, 2010; revised 30 November, 2010; accepted 6 December, 2010. *For correspondence. E-mail jean-louis. herrmann@rpc.aphp.fr; Tel. (+33) 1 47 10 79 50; Fax (+33) 1 47 10 79 49. † Both authors contributed equally to this work. ‡ Equal contribution as senior authors. Cellular Microbiology (2011) 13(5), 692–704 doi:10.1111/j.1462-5822.2010.01565.x First published online 5 January 2011 © 2011 Blackwell Publishing Ltd cellular microbiology