Candida Infection Biology – fungal armoury, battlefields ... - FINSysB

Poster number: 20
Investigation of combinatorial stress responses in C.
albicans
Anna Theresa Tillmann 1 , Elahe Radmaneshfar 2 , Tao You 2 , Despoina
Kaloriti 1 , Mette Jacobsen 1 , Zhikang Yin 1 , Marco Thiel 2 , Celso Grebogi 2 ,
Neil A.R. Gow 1 , Mike Gustin 3 , Alistair J.P.Brown 1
1 School of Medical Sciences, University of Aberdeen, UK; 2 Institute of Complex Systems
and Mathematical Biology, University of Aberdeen, UK; 3 Department of Cell Biochemistry
and Cell Biology, Rice University, USA.
Candida albicans is a major human fungal pathogen that causes mucosal and
systemic infections. Immune cells combat Candida infections with reactive nitrogen
and reactive oxygen species. Meanwhile Candida has evolved strategies to
minimise the damage caused by these environmental stresses, and the success of
this pathogen depends partly on its robust adaptation to these stresses. We
examined three infection-associated stresses: nitrosative, oxidative and osmotic
stress. First we examined responses to each individual stress. Then we analysed
responses to stress combinations because C. albicans cells are exposed to such
combinatorial stresses in vivo. The Hog1 SAPK, the cell wall integrity and the Cta4-
Yhb1 pathways contribute to these combinatorial stress responses. The
involvement of these pathways was confirmed by sensitivity testing of null mutants
to NO, H 2 O 2 and NaCl, and by testing the activation of the corresponding MAP
kinases by Western blotting. Furthermore transcription factor localisation and the
expression of downstream target genes provided further evidence for this activation.
The relative contributions of these nitrosative, oxidative and/or osmotic stress
resistance pathways during C. albicans infections are discussed.
150