Universiteit Leiden

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This Week’s Discoveries | 15 November 2016

15 November 2016
This Week's Discoveries
Oort Building
Niels Bohrweg 2
2333 CA Leiden
De Sitterzaal

First Lecture

The Macrophage as a 'Trojan Horse' in the Pathogenesis of Tuberculosis

Vincenzo Torraca (IBL) did his PhD in the group of Annemarie Meijer at the IBL in the context of the European Training Network FishForPharma. He will defend his thesis on November 17 and will continue as a postdoc at Imperial College London on an individual Marie Curie fellowship.

Mycobacterium tuberculosis, the agent of TB, is one of the deadliest human pathogens, infecting one third of the global population. Establishment of infection by mycobacteria relies on complex interactions with host innate immune cells, especially macrophages. Once engulfed by macrophages, mycobacteria 'usurp' the host cell machineries to facilitate dissemination and to establish an intracellular niche for survival and replication. To investigate how mycobacteria force the immune cells to support infection, we explored the chemokine pathway, best known for its capability to induce cell migration. To dissect the interplay between immune cells and the pathogen, we modelled human TB using the zebrafish-Mycobacterium marinum natural host-pathogen pair, which is attractive for the excellent optical accessibility of the zebrafish larvae and the possibility to apply genetic tools to impair the chemokine signalling. We show that depletion of either CXCR3 or CXCR4 axes are beneficial to the host. Exploitation of CXCR3 signalling leads to macrophage recruitment and to transcriptional changes in the macrophages that make them more permissive for mycobacterial intracellular persistence. Activating CXCR4 signalling triggers instead vascularisation of the nascent tuberculous granulomas, which in turn supports expansion of the infection. Therefore, inhibition of these pathways represent promising host-directed therapeutic avenues to counteract mycobacterial diseases.

Second Lecture

Language perception in birds

Michelle Spierings (IBL) is a PhD student in the group of Carel ten Cate. She will defend her thesis November 17 and continue as a postdoc in Vienna.

Language is a complex system that seems to be unique to humans. This does not mean however, that all aspects of language are only found in humans. Other animals might share particular perceptual traits with us, which could inform us about the development of our language. In this talk I will share my research on the abilities of two bird species, the zebra finch and the budgerigar, to process simple structural rules related to human language.