These paradoxical findings likely arise from the usage of
chitin preparations differing in origin (commercially available
chitin is usually extracted from crab/shrimp shells), purity and
particle size. Whereas large chitin fragments are immunologically
inert, chitin particles of 40–70 μm induce tumour
necrosis factor (TNF) through dectin-1 and TLR2, while
chitin particles below 40 μm induce TNF and IL-10 through
dectin-1, the mannose receptor and TLR2 in macrophages