Pentraxins in invertebrates and vertebrates: From structure, function and evolution to clinical applications

Area of Science:

• Immunology
• Biochemistry

Background:

• Lectins are crucial for innate and adaptive immunity, acting as defense chemicals against pathogens and regulating immune responses.
• Pentraxins, a class of animal lectins, are vital for pathogen defense and inflammation control, binding diverse ligands and activating immune pathways.
• Pentraxins are classified into short (CRP, SAP) and long (PTX3) types, with differing distributions and functions across species.

Purpose of the Study:

• To review the ligands, functions, and complement activation pathways of C-reactive protein (CRP), serum amyloid P (SAP), and pentraxin 3 (PTX3).
• To analyze the distinct characteristics and evolutionary relationships of these pentraxins in various animals, including humans.
• To summarize the clinical applications of CRP, SAP, and PTX3 in human medicine and identify areas for future research.

Main Methods:

• Literature review of scientific articles on pentraxins.
• Comparative analysis of pentraxin characteristics, ligands, and functions across species.
• Examination of evolutionary trees and clinical studies related to CRP, SAP, and PTX3.

Main Results:

• CRP and SAP are found in both vertebrates and invertebrates, while PTX3 appears restricted to vertebrates.
• Pentraxins bind a wide range of ligands and activate complement and Fcγ receptor pathways for pathogen clearance.
• Significant differences exist in the specific roles and evolutionary trajectories of short and long pentraxins.

Conclusions:

• Pentraxins (CRP, SAP, PTX3) are versatile immune proteins with critical roles in host defense and inflammation.
• Understanding their diverse functions and evolutionary history provides insights into immune system development.
• Further research is needed to fully elucidate their complex mechanisms and optimize clinical applications.