Ficolin-1 (FCN1)

Ficolin-1 is a soluble and cell-associated pattern recognition receptor belonging to the collectin family, characterized by a collagen-like domain and a C-terminal fibrinogen-like domain. It is primarily expressed in myeloid cells (monocytes, neutrophils) and type II alveolar epithelial cells, and released upon cellular activation. Ficolin-1 binds to acetylated and sialylated compounds on pathogens, facilitating their neutralization, opsonization, and complement system activation via the lectin pathway. It also binds IgG1 and interacts with CD43 at cell membranes. Ficolin-1 has emerging relevance as a therapeutic target and biomarker in vasculitis, Kawasaki disease, and rheumatoid arthritis due to its upregulation in these conditions and positive response to targeted therapies in preclinical models.

Other names

FCN1Ficolin-1M-ficolinFicolin-AFicolin-alphaCollagen/fibrinogen domain-containing protein 1Ficolin (collagen/fibrinogen domain-containing) 1FCNM

Inhibition of complement activation (by blocking FCN1 binding or function); Suppression of inflammatory cell activation; Promotion of cell removal via ADCC (antibody-dependent cell-mediated cytotoxicity) or CDC (complement-dependent cytotoxicity)