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Pentraxin 3, long
Symbols PTX3 ; TNFAIP5; TSG-14
External IDs OMIM602492 MGI104641 HomoloGene7500 GeneCards: PTX3 Gene
RNA expression pattern
PBB GE PTX3 206157 at tn.png
More reference expression data
Species Human Mouse
Entrez 5806 19288
Ensembl ENSG00000163661 ENSMUSG00000027832
UniProt P26022 P48759
RefSeq (mRNA) NM_002852.3 NM_008987.3
RefSeq (protein) NP_002843.2 NP_033013.3
Location (UCSC) Chr 3:
157.15 – 157.16 Mb
Chr 3:
66.02 – 66.03 Mb
PubMed search [1] [2]

Pentraxin-related protein PTX3 also known as TNF-inducible gene 14 protein (TSG-14) is a protein that in humans is encoded by the PTX3 gene.[1][2]

Pentraxin 3 (ptx3) is a member of the pentraxin superfamily. This super family characterized by cyclic multimeric structure.[3] PTX3 is rapidly produced and released by several cell types, in particular by mononuclear phagocytes, dendritic cells (DCs), fibroblasts and endothelial cells in response to primary inflammatory signals [e.g., toll-like receptor (TLR) engagement, TNFα, IL-1β].[4] PTX3 binds with high affinity to the complement component C1q, the extracellular matrix component TNFα induced protein 6 (TNFAIP6; also called TNF-stimulated gene 6, TSG-6) and selected microorganisms, including Aspergillus fumigatus and Pseudomonas aeruginosa.[5][6][7][8][9] PTX3 activates the classical pathway of complement activation and facilitates pathogen recognition by macrophages and DCs.[4][7][5]


Human and murine PTX3, localized in the syntenic region of chromosome 3 (q24-28), are highly conserved, sharing 82% identical and 92% conserved amino acids. The human PTX3 gene is organized into three exons coding for the leader peptide (which is cleaved from the mature protein), the amino-terminal domain and the pentraxin domain of the protein.

The transcribed PTX3 protein is 381 amino acids long, has a predicted molecular weight of 40,165 Da and consists of a carboxy-terminal 203 amino acid long pentraxin domain coupled with an amino-terminal 178 amino acid long domain unrelated to other known proteins. The PTX3 carboxy-terminal domain contains a canonical pentraxin signature (HxCxS/TWxS) and two conserved cysteines (Cys-210 and Cys-271), and shares 57% conserved and 17% identical amino acids with short pentraxins. The presence of an amino-linked glycosylation site in the carboxy-terminal domain at Asn-220 accounts for the higher molecular weight observed in SDS–PAGE under reducing conditions (45 kDa as opposed to the predicted 40 kDa). Under native conditions PTX3 protomers are assembled to form multimers.[6] The crystal structure of PTX3 has not been determined yet, however according to modeling, the PTX3 pentraxin domain well-accommodates on the tertiary fold of SAP, with almost all of the β-strands and the α-helical segments conserved.[10]

PTX3 in blood[edit]

PTX3 behaves as an acute phase response protein, as the blood levels of PTX3, low in normal conditions (about 25 ng/mL in the mouse, < 2 ng/mL in humans), increase rapidly (peaking at 6–8 h after induction) and dramatically (200–800 ng/mL) during endotoxic shock, sepsis and other inflammatory and infectious conditions, correlating with the severity of the disease. Under these conditions, PTX3 is a rapid marker for primary local activation of innate immunity and inflammation.[11][12][13][14][11][15]

Pathogen versus apoptotic self recognition[edit]

Similar to other members of the pentraxin family PTX3 binds apoptotic cells, thereby inhibiting their recognition by DCs. Binding occurs late in the apoptotic process and enhances cytokine production by DCs. In addition, preincubation of apoptotic cells with PTX3 enhances C1q binding and C3 deposition on the cell surface, suggesting a role for PTX3 in the complement-mediated clearance of apoptotic cells.[16][17][18] Moreover, in the presence of dying cells, PTX3 restricts the cross presentation of antigens derived from dying cells. These results suggest that PTX3 has a dual role: protection against pathogens and control of autoimmunity.[18][19]


  1. ^ Breviario F, d'Aniello EM, Golay J, Peri G, Bottazzi B, Bairoch A et al. (Dec 1992). "Interleukin-1-inducible genes in endothelial cells. Cloning of a new gene related to C-reactive protein and serum amyloid P component". J Biol Chem 267 (31): 22190–7. PMID 1429570. 
  2. ^ "Entrez Gene: PTX3 Pentraxin-related gene, rapidly induced by IL-1 beta". 
  3. ^ Emsley J, White HE, O'Hara BP, Oliva G, Srinivasan N, Tickle IJ et al. (January 1994). "Structure of pentameric human serum amyloid P component". Nature 367 (6461): 338–45. doi:10.1038/367338a0. PMID 8114934. 
  4. ^ a b Garlanda C, Bottazzi B, Bastone A, Mantovani A (2005). "Pentraxins at the crossroads between innate immunity, inflammation, matrix deposition, and female fertility". Annu. Rev. Immunol. 23: 337–66. doi:10.1146/annurev.immunol.23.021704.115756. PMID 15771574. 
  5. ^ a b Diniz SN, Nomizo R, Cisalpino PS, Teixeira MM, Brown GD, Mantovani A et al. (April 2004). "PTX3 function as an opsonin for the dectin-1-dependent internalization of zymosan by macrophages". J. Leukoc. Biol. 75 (4): 649–56. doi:10.1189/jlb.0803371. PMID 14726497. 
  6. ^ a b Bottazzi B, Vouret-Craviari V, Bastone A, De Gioia L, Matteucci C, Peri G et al. (December 1997). "Multimer formation and ligand recognition by the long pentraxin PTX3. Similarities and differences with the short pentraxins C-reactive protein and serum amyloid P component". J. Biol. Chem. 272 (52): 32817–23. doi:10.1074/jbc.272.52.32817. PMID 9407058. 
  7. ^ a b Garlanda C, Hirsch E, Bozza S, Salustri A, De Acetis M, Nota R et al. (November 2002). "Non-redundant role of the long pentraxin PTX3 in anti-fungal innate immune response". Nature 420 (6912): 182–6. doi:10.1038/nature01195. PMID 12432394. 
  8. ^ Nauta AJ, Bottazzi B, Mantovani A, Salvatori G, Kishore U, Schwaeble WJ et al. (February 2003). "Biochemical and functional characterization of the interaction between pentraxin 3 and C1q". Eur. J. Immunol. 33 (2): 465–73. doi:10.1002/immu.200310022. PMID 12645945. 
  9. ^ Salustri A, Garlanda C, Hirsch E, De Acetis M, Maccagno A, Bottazzi B et al. (April 2004). "PTX3 plays a key role in the organization of the cumulus oophorus extracellular matrix and in in vivo fertilization". Development 131 (7): 1577–86. doi:10.1242/dev.01056. PMID 14998931. 
  10. ^ Introna M, Alles VV, Castellano M, Picardi G, De Gioia L, Bottazzai B et al. (March 1996). "Cloning of mouse ptx3, a new member of the pentraxin gene family expressed at extrahepatic sites". Blood 87 (5): 1862–72. PMID 8634434. 
  11. ^ a b Muller B, Peri G, Doni A, Torri V, Landmann R, Bottazzi B et al. (July 2001). "Circulating levels of the long pentraxin PTX3 correlate with severity of infection in critically ill patients". Crit. Care Med. 29 (7): 1404–7. doi:10.1097/00003246-200107000-00017. PMID 11445697. 
  12. ^ Fazzini F, Peri G, Doni A, Dell'Antonio G, Dal Cin E, Bozzolo E et al. (December 2001). "PTX3 in small-vessel vasculitides: an independent indicator of disease activity produced at sites of inflammation". Arthritis Rheum. 44 (12): 2841–50. doi:10.1002/1529-0131(200112)44:12<2841::AID-ART472>3.0.CO;2-6. PMID 11762945. 
  13. ^ Mairuhu AT, Peri G, Setiati TE, Hack CE, Koraka P, Soemantri A et al. (August 2005). "Elevated plasma levels of the long pentraxin, pentraxin 3, in severe dengue virus infections". J. Med. Virol. 76 (4): 547–52. doi:10.1002/jmv.20397. PMID 15977234. 
  14. ^ Azzurri A, Sow OY, Amedei A, Bah B, Diallo S, Peri G et al. (January 2005). "IFN-gamma-inducible protein 10 and pentraxin 3 plasma levels are tools for monitoring inflammation and disease activity in Mycobacterium tuberculosis infection". Microbes Infect. 7 (1): 1–8. doi:10.1016/j.micinf.2004.09.004. PMID 15716076. 
  15. ^ Latini R, Maggioni AP, Peri G, Gonzini L, Lucci D, Mocarelli P et al. (October 2004). "Prognostic significance of the long pentraxin PTX3 in acute myocardial infarction". Circulation 110 (16): 2349–54. doi:10.1161/01.CIR.0000145167.30987.2E. PMID 15477419. 
  16. ^ Gershov D, Kim S, Brot N, Elkon KB (November 2000). "C-Reactive Protein Binds to Apoptotic Cells, Protects the Cells from Assembly of the Terminal Complement Components, and Sustains an Antiinflammatory Innate Immune Response: Implications for Systemic Autoimmunity". J. Exp. Med. 192 (9): 1353–64. doi:10.1084/jem.192.9.1353. PMC 2193350. PMID 11067883. 
  17. ^ Familian A, Zwart B, Huisman HG, Rensink I, Roem D, Hordijk PL et al. (July 2001). "Chromatin-independent binding of serum amyloid P component to apoptotic cells". J. Immunol. 167 (2): 647–54. doi:10.4049/jimmunol.167.2.647. PMID 11441067. 
  18. ^ a b Rovere P, Peri G, Fazzini F, Bottazzi B, Doni A, Bondanza A et al. (December 2000). "The long pentraxin PTX3 binds to apoptotic cells and regulates their clearance by antigen-presenting dendritic cells". Blood 96 (13): 4300–6. PMID 11110705. 
  19. ^ Baruah P, Propato A, Dumitriu IE, Rovere-Querini P, Russo V, Fontana R et al. (January 2006). "The pattern recognition receptor PTX3 is recruited at the synapse between dying and dendritic cells, and edits the cross-presentation of self, viral, and tumor antigens". Blood 107 (1): 151–8. doi:10.1182/blood-2005-03-1112. PMID 16166594. 

Further reading[edit]