Intracellular survival of Lichtheimia spp.

Main risk factors are immunocompromised conditions such as neutropenic patients, diabetes mellitus complication, ketoacidosis or Farmer’s lung disease, a hypersensitivity pneumonitis in immuncompetent patients. The main route of the infection is via the respiratory tract where alveolar macrophages (AM) act as the immune system’s first line of defense. To date, little is known about the interaction of Lichtheimia species with the human immune system. Various methods were used to study the details of this encounter. First, the phagocytic efficiency of murine alveolar macrophages (MH-S) is measured in co-incubations of MH-S and fungal spores for the determination of the phagocytic index (PI). The spores are prepared in various conditions such as resting, pre-swollen, and opsonized to mimic in vivo situation. Quantification of complement activator products and factor H via Fluoresence-Activated Cell Sorting (FACS) is performed. The morphological examination of surfaces on two strains will be carried out via Scanning and Transmission Electron Microscopy (SEM and TEM) to determine structural differences on the spore surfaces. We are currently investigating various factors (e.g. iron starvation, phagolysosome acidification) that could possibly contribute to the lack of germination within the macrophages. This proejct is carried out in collaboration with the departments Infection Biology, Microbial Pathogenicity Mechanisms and Molecular and Applied Microbiology as well as the research group Applied Systems Biology and the associated group Infections in Hematology/Oncology.

Intracellular survival of Lichtheimia spp.
Intracellular survival of Lichtheimia spp.