title: The "sweet" side of a long pentraxin: how glycosylation affects PTX3 functions in innate immunity and inflammation.
abstract: Innate immunity represents the first line of defense against pathogens and plays key roles in activation and orientation of the adaptive immune response. The innate immune system comprises both a cellular and a humoral arm. Components of the humoral arm include soluble pattern recognition molecules (PRMs) that recognize pathogen-associated molecular patterns and initiate the immune response in coordination with the cellular arm, therefore acting as functional ancestors of antibodies. The long pentraxin PTX3 is a prototypic soluble PRM that is produced at sites of infection and inflammation by both somatic and immune cells. Gene targeting of this evolutionarily conserved protein has revealed a non-redundant role in resistance to selected pathogens. Moreover, PTX3 exerts important functions at the crossroad between innate immunity, inflammation, and female fertility. The human PTX3 protein contains a single N-glycosylation site that is fully occupied by complex type oligosaccharides, mainly fucosylated and sialylated biantennary glycans. Glycosylation has been implicated in a number of PTX3 activities, including neutralization of influenza viruses, modulation of the complement system, and attenuation of leukocyte recruitment. Therefore, this post translational modification might act as a fine tuner of PTX3 functions in native immunity and inflammation. Here we review the studies on PTX3, with emphasis on the glycan-dependent mechanisms underlying pathogen recognition and crosstalk with other components of the innate immune system.
authors: Department of Immunology and Inflammation, Humanitas Clinical and Research Center Rozzano, Italy.
authors: Antonio
authors: A
authors: Inforzato
authors: Patrick C
authors: PC
authors: Reading
authors: Elisa
authors: E
authors: Barbati
authors: Barbara
authors: B
authors: Bottazzi
authors: Cecilia
authors: C
authors: Garlanda
authors: Alberto
authors: A
authors: Mantovani
keywords: PTX3; glycosylation; inflammation; pathogen recognition; pentraxins