Innate Sensing of Chitin and Chitosan

Chitin enhances serum IgE in Aspergillus fumigatus induced allergy in mice

“…Both chitin and the partially de-acetylated version of chitin named chitosan can be phagocytised by myeloid derived cells, but the receptors responsible for this function is yet to be clearly defined (Bueter et al, 2013;Thomsen et al, 2010). Several receptors have been identified which can binds to chitin or chitin-oligosaccharides, including FIBCD1, a homotetrameric membrane protein expressed by lung and gut epithelial cells (Schlosser et al, 2009;Thomsen et al, 2010), ReGIII␥, a soluble C-type lectin (Cash et al, 2006), NKR-P1, an activating receptor on rat NK cells (Semenuk et al, 2001), and galactin-3 (Seetharaman et al, 1998).…”

“…In the past decade, the effect of chitin as a direct activator of the immune system and as an adjuvant has been analysed intranasally, orally and intraperitoneally. It is evident that chitin directs the immune responses in different directions depending on the route of administration, but the use of different sources, sizes, and potential contaminations have led to controversies in the literature (Alvarez, 2014;Bueter et al, 2013;Muzzarelli, 2010). When given orally or intranasally in mice, chitin can ameliorate Th2 induced Dermatophagoides pteronyssinus and ragweed allergic immune responses (Shibata et al, 2000;Strong et al, 2002), an effect that may be partially explained by the chitin mediated inhibition of T-cell proliferation because the direct Abbreviations: AMCase, acidic mammalian chitinase; A. fumigatus, Aspergillus fumigatus; BAL, bronchoalveolar lavage; EPO, eosinophil peroxidase assay; 1WCF, one-week culture filtrate antigen; OVA, ovalbumin.…”

AMCase is a crucial regulator of type 2 immune responses to inhaled house dust mites

“…Chitosan, a commercially available deacetylated chitin, but not chitin, has been reported to activate caspase-1 by the phagocytic pathway (19). It has also been shown that the size of chitosan was important for phagocytosis (19,20). In fact, the differential role of the size of chitin was supported by another report (21).…”

A Review of the Applications of Chitin and Its Derivatives in Agriculture to Modify Plant-Microbial Interactions and Improve Crop Yields

“…Both polysaccharides form microfibrils which differ in length and construction depending on the species and cellular location [5]. In fungi this involves cross linkages to glucan polymers to create a meshed hyphal wall [6,7]. Due to the involvement of other polymers, such as glucans, the chitin content of fungal cell walls ranges from 22%-40% [8].…”