title: Serpins, immunity and autoimmunity: old molecules, new functions.
abstract: Serine protease inhibitors (serpins) are evolutionary old, structurally conserved molecules which encompass nearly all branches of life. More than 1,000 serpins were characterized to date which are subdivided into 16 subgroups (A-P) according to their common ancestry; among them, 37 are found in humans. Serpins were termed after their capability to inhibit serine proteases, but mounting evidence suggests that they may achieve a greater deal of functions, ranging from embryological growth to synaptic plasticity, development of both myeloid and lymphoid immune cells, and modulation of apoptosis. Serpins are mainly extracellular molecules, although some of them (namely, ov-serpins or clade B serpins) mostly act inside the cells, being either ubiquitously or tissue-specifically expressed. Among newly characterized serpin functions, regulation of cellular proliferation through apoptosis modulation and proteasome disturbance seems to play a major role. Accordingly, several serpins were found to be hyperexpressed in tumor cells. Indeed, apoptosis dysregulation is likely to be a cornerstone in both tumorigenesis and autoimmunity, since uncontrolled cellular viability results in tumor proliferation, while inefficient disposal of apoptotic debris may favor the rescue of autoreactive immune cells. Such a process was widely documented in systemic lupus erythematosus (SLE). Interestingly, alterations in the expression of some serpins, e.g., the ov-serpin SERPINB3, are being unraveled in patients affected with SLE and other autoimmune disorders, suggesting that a failure in serpin function might affect immune homeostasis and self-tolerance, thereby contributing to autoimmunity. Here, we provide an overview of serpin origin, function, and dysfunction, focusing on human serpins and ov-serpins, with a hub on SERPINB3.
authors: Division of Rheumatology, Department of Medicine, University of Padua, Via Giustiniani 2, 35128, Padua, Italy.
authors: Mariele
authors: M
authors: Gatto
authors: Luca
authors: L
authors: Iaccarino
authors: Anna
authors: A
authors: Ghirardello
authors: Nicola
authors: N
authors: Bassi
authors: Patrizia
authors: P
authors: Pontisso
authors: Leonardo
authors: L
authors: Punzi
authors: Yehuda
authors: Y
authors: Shoenfeld
authors: Andrea
authors: A
authors: Doria
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis; D015551:Autoimmunity; D048708:Cell Growth Processes; D047109:Fetal Development; D005786:Gene Expression Regulation / Q000276:immunology; D006706:Homeostasis; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology*; D017634:Self Tolerance; D015842:Serine Proteinase Inhibitors / Q000276:immunology*; D015843:Serpins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D009435:Synaptic Transmission
chemical_list: D000951:Antigens, Neoplasm; D015842:Serine Proteinase Inhibitors; D015843:Serpins; C051072:squamous cell carcinoma-related antigen