Epithelial cell recognition of C. albicans. Epithelial cells recognise C. albicans via a two-step process [40]. Initial recognition of yeast by surface PRRs results in prolonged activation of NF-kB and an early transient activation of MAPK signalling leading to activation of c-Jun through the ERK1/2 and JNK pathways. When the burden of hyphae passes a threshold, recognition of these hyphae triggers a second, prolonged activation of MAPK signalling. This results in activation of MKP1 through the ERK1/2 pathway and c-Fos via p38 signalling. NF-κB and c-Fos then play essential roles in the transcription of cytokines secreted by the epithelial cells, whilst MKP1 acts as a negative regulator to control the activation of JNK and p38 signalling.
