title: Chitinases and immunity: Ancestral molecules with new functions.
abstract: Chitinases belonging to 18 glycosyl hydrolase family is an ancient gene family that is widely expressed from prokaryotes to eukaryotes. In humans, despite the absence of endogenous chitin, a number of Chitinases and Chitinase-like Proteins (C/CLPs) have been identified. Chitinases with enzymatic activity have a chitin binding domain containing six cysteine residues responsible for their binding to chitin. In contrast, CLPs do not contain such typical chitin-binding domains, but still can bind to chitin with high affinity. Molecular phylogenetic analyses suggest that active Chitinases result from an early gene duplication event. Further duplication events, followed by mutations leading to loss of chitinase activity, allowed evolution of the chi-lectins. For the majority of the mammalian chitinases the last decades have witnessed the appearance of a substantial number of studies describing their expression differentially regulated during more specific immunologic activities. It is becoming increasingly clear that their function is not exclusive to catalyse the hydrolysis of chitin producing pathogens, but include crucial role in bacterial infections and inflammatory diseases. Here we provide an overview of all family members to shed light on the mechanisms and molecular interactions of Chitinases and CLPs in relation to immune response regulation, in order to delineate their future utilization as diagnostic and prognostic markers for numerous diseases.
authors.affiliation: Department of Biomedical and Biotechnology Sciences, University of Catania, Italy.
authors.forename: Michelino
authors.initials: M
authors.lastname: Di Rosa
authors.affiliation: Department of Biomedical and Biotechnology Sciences, University of Catania, Italy.
authors.forename: Gisella
authors.initials: G
authors.lastname: Distefano
authors.affiliation: Department of Immunobiology and Environment Microbiology Medical University of Gdańsk, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Zorena
authors.affiliation: Department of Biomedical and Biotechnology Sciences, University of Catania, Italy. Electronic address: lucmal@unict.it.
authors.forename: Lucia
authors.initials: L
authors.lastname: Malaguarnera
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002352:Carrier Proteins / Q000378:metabolism; D002688:Chitinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004198:Disease Susceptibility; D006596:Hexosaminidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D007107:Immune System / Q000166:cytology / Q000502:physiology; D007109:Immunity; D007527:Isoenzymes; D011485:Protein Binding
chemical_list: D002352:Carrier Proteins; D007527:Isoenzymes; D006596:Hexosaminidases; C086400:chitotriosidase; D002688:Chitinases
keywords: Chitinase 3 like 1; Chitinase 3 like 2; Chitotriosidase; Immune response; Stabilin-interacting chitinase-like proteins