Fungal hydrophobins form a sheath preventing immune recognition of airborne conidia.

Aspergillus fumigatus is the most ubiquitous and the most threatful airborne fungal pathogen. In the atmosphere, there is thousands of conidia/m (3) originating from more than hundred fungal genera, which enter the host through the respiratory system and are eliminated by the innate immune defences. But how do A. fumigatus conidia survive long enough in the lung withstanding the host killing reactions? We demonstrated recently the role of the spore-surface rodlet layer made up of hydrophobic protein (hydrophobin) in preventing their recognition by the immune system. Upon removal of this rodlet layer by chemical, genetic or biological means, the resulting morphotypes were immunostimulatory in effect, confirming the essentiality of the role of the rodlet layer for the fungal survival in vivo.