PMC:4503824 / 14598-15790 JSONTXT

{"project":"2_test","denotations":[{"id":"25498576-18446192-43267780","span":{"begin":1186,"end":1190},"obj":"18446192"}],"text":"Phagocyte pattern recognition receptors (PRRs) are important in phagocytosis both in combination and independent of opsonic recognition. PRR bind to specific components of microbes, usually on their surface (exceptions being those receptors that bind to nucleic acid) and although often implicated in phagocytosis, are not all direct activators of pathogen internalisation. Mannose and the beta glucan are the primary pathogen recognition motifs for PRR mediated recognition and uptake of cryptococci. However, the polysaccharide capsule will interfere sterically and chemically with the recognition of these motifs. As the capsule is likely to be very small or absent in the infectious propagule, cryptococcal mannoprotein and beta glucan will be determinants in early interactions in the lung. In support of this, mannose receptor knockout mice are more susceptible to infection and show reduced CD4+ T cell proliferation in response to cryptococcal mannoprotein. Uptake of cryptococcal mannoprotein by DCs was not affected most likely through alternative sampling mechanisms such as antigen presentation from the phagosome or environmental sampling via macropinocytosis (Dan et al., 2008)."}