Molecular mechanism of Aspergillus fumigatus adherence to host constituents

Abstract

Inhaled conidia of Aspergillus fumigatus rapidly adhere to pulmonary epithelial cells and other host constituents. Identifying molecular mechanisms underlying A. fumigatus adherence has therefore been the focus of a number of studies aimed at identifying novel therapeutic targets. Early studies of A. fumigatus adherence to host constituents focused on fungal proteins, including RodA and AspF2. None of these proteins however has been found to play a role in virulence in experimental animal models. Recent advances have suggested an important role for fungal carbohydrate components of the cell wall and extracellular matrix in adherence, including sialic acid and mannose residues, and the newly described polysaccharide galactosaminogalactan. Despite these advances, the host cell receptors that are bound by these ligands remain unknown.

Figure 1

Model of known and suspected molecules involved in A. fumigatus adherence to host cells and host cell constituents. For the sake of clarity, only single molecules of each type of adhesin and or receptor are represented. Basal laminin molecules include collagen, fibronectin and laminin.