Figure 1.

Normal immune responses to mucosal C. albicans and genetic defects associated with chronic mucocutaneous candidiasis. Various defects in the normal immune pathway from C. albicans sensing at the pattern recognition receptor (especially C-type lectin receptors (CLRs)) to IL-17 action on target cells can result in susceptibility to chronic mucocutaneous candidiasis. Known deficiencies associated with chronic mucocutaneous candidiasis include Dectin^-1, CARD9 (caspase recruitment domain-containing protein 9), IL-12/23 (p40 deficiency), IL-12/23 receptor (IL12Rβ1 deficiency), STAT3 (signal transducer and activator of transcription 3), IL-17A, IL-17F and IL-17RA. Gain-of-function mutations in STAT1 can also inhibit the normal Th17/IL-17 pathway. AIRE mutations resulting in anti-cytokine antibodies disrupt the pathway through direct interference with IL-17 (including IL-17A and IL-17F, which can form homodimers and heterodimers).