An ecoimmunological approach to study evolutionary and ancient links between coagulation, complement and Innate...

Area of Science:

• Ecoimmunology
• Evolutionary biology
• Innate immunity

Background:

• Coagulation, complement, and innate immunity are interconnected systems with ancient evolutionary origins.
• Tissue Factor Pathway Inhibitor (TFPI)-1 is a key regulator of the coagulation cascade.

Purpose of the Study:

• To investigate the evolutionary conservation and antibacterial activity of TFPI-1-derived peptides across vertebrate species.
• To determine the role of plasma components, specifically the complement system, in mediating the antibacterial effects of these peptides.

Main Methods:

• An ecoimmunological approach was used, analyzing TFPI-1-derived peptides from fish, reptiles, birds, and mammals.
• Peptides were tested for their ability to enhance the killing of human bacterial pathogens in plasma from different vertebrate classes.
• Interactions with human coagulation and complement pathways were assessed.

Main Results:

• TFPI-1-derived peptides exhibited species-specific antibacterial activity, with significant conservation and diversification observed during evolution.
• Bactericidal activity was noted in mammalian plasma (excluding rodents) but not in plasma from birds, reptiles, or fish.
• Peptides interfered with the human intrinsic pathway of coagulation, but this effect was not conserved across species.

Conclusions:

• The antibacterial efficacy of TFPI-1-derived peptides is species-specific and evolutionarily influenced.
• The classical pathway of the complement system plays a critical role in mediating the bactericidal activity of these peptides in mammalian plasma.
• While TFPI-1 peptides interact with coagulation, this mechanism is not evolutionarily conserved for antibacterial functions.