The Immune Interplay between the Host and the Pathogen in Aspergillus fumigatus Lung Infection

Figure 1

Summary of Aspergillus fumigatus and host immune system interplay. The lung pulmonary epithelium is magnified, and the immune response against fungal invasion is demonstrated. First, fungal components are recognized through pathogen recognition receptors (PRRs) which led to the activation of the innate immune response, depicted by macrophages, dendritic cells, natural killer cells, and neutrophils. The role of neutrophils during fungal infection is also represented by formation of neutrophils extracellular traps (NETs). The innate immunity triggers the development of an acquired immune response in the lung draining lymph nodes, which may induce the differentiation of Th1, Th2, or Th17 cell phenotypes depending on the specific stimuli and cytokine milieu, which also accounts with the presence of cytotoxic CD8 T cells against the fungus. These effector antifungal responses may also be modulated by the action of regulatory T cells (Tregs) to avoid excessive tissue damage.