Autor(es): Carmona, J. A. ; Cruz, Andrea ; Teixeira, Lucia de Fatima Moreira ; Sousa, Carole Lara Veiga de ; Sousa, Jeremy Nicolas Carvalho ; Osório, Nuno S. ; Saraiva, Ana Laura ; Svenson, Stefan ; Kalleniu, Gunilla ; Pedrosa, Jorge ; Rodrigues, Fernando José dos Santos ; Castro, António G. ; Saraiva, Margarida
Data: 2013
Identificador Persistente: https://hdl.handle.net/1822/25623
Origem: RepositóriUM - Universidade do Minho
Tuberculosis associates with a wide spectrum of disease outcomes. The Beijing (Bj) lineage of Mycobacterium tuberculosis (Mtb) is suggested to be more virulent than other Mtb lineages and prone to elicit non-protective immune responses. However, highly heterogeneous immune responses were reported upon infection of innate immune cells with Bj strains or stimulation with their glycolipids. Using both in vitro and in vivo mouse models of infection, we here report that the molecular mechanism for this heterogeneity may be related to distinct TLR activations. Among this Mtb lineage, we found strains that preferentially activate TLR2, and others that also activate TLR4. Recognition of Mtb strains by TLR4 resulted in a distinct cytokine profile in vitro and in vivo, with specific production of type I IFN. We also uncover a novel protective role for TLR4 activation in vivo. Thus, our findings contribute to the knowledge of the molecular basis underlying how host innate immune cells handle different Mtb strains, in particular the intricate host-pathogen interaction with strains of the Mtb Bj lineage.
