Role of complement and Fcγ receptors in the protective activity of the long pentraxin PTX3 against Aspergillus fumigatus

Federica Moalli, Andrea Doni, Livija Deban, Teresa Zelante, Silvia Zagarella, Barbara Bottazzi, Luigina Romani, Alberto Mantovani, Cecilia Garlanda

Research output: Contribution to journalArticle


Pentraxin 3 (PTX3) is a soluble pattern recognition molecule playing a nonredundant role in resistance against Aspergillus fumigatus. The present study was designed to investigate the molecular pathways involved in the opsonic activity of PTX3. The PTX3 N-terminal domain was responsible for conidia recognition, but the full-length molecule was necessary for opsonic activity. The PTX3-dependent pathway of enhanced neutrophil phagocytic activity involved complement activation via the alternative pathway; Fcγ receptor (FcγR) IIA/CD32 recognition of PTX3-sensitized conidia and complement receptor 3 (CR3) activation; and CR3 and CD32 localization to the phagocytic cup. Gene targeted mice (ptx3, FcR common γ chain, C3, C1q) validated the in vivo relevance of the pathway. In particular, the protective activity of exogenous PTX3 against A fumigatus was abolished in FcR common γ chain-deficient mice. Thus, the opsonic and antifungal activity of PTX3 is at the crossroad between complement, complement receptor 3-, and FcγR-mediated recognition. Because short pentraxins (eg, C-reactive protein) interact with complement and FcγR, the present results may have general significance for the mode of action of these components of the humoral arm of innate immunity.

Original languageEnglish
Pages (from-to)5170-5180
Number of pages11
Issue number24
Publication statusPublished - Dec 9 2010


ASJC Scopus subject areas

  • Hematology
  • Biochemistry
  • Cell Biology
  • Immunology

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