Is there a role for antioxidant carotenoids in limiting self-harming immune response in invertebrates?

Area of Science:

• * Invertebrate immunology
• * Dietary influences on immune function
• * Antioxidant roles in biological systems

Background:

• * Innate immunity utilizes cytotoxic molecules that can harm host tissues.
• * Dietary antioxidants, such as carotenoids, mitigate self-harm in vertebrate immune responses by scavenging radicals.
• * The function of antioxidants in invertebrate immunity remains largely unexplored.

Purpose of the Study:

• * To investigate the potential role of dietary antioxidants in invertebrate immunity.
• * To examine the relationship between carotenoid concentration and innate immune defense in crustaceans.
• * To test the hypothesis that carotenoids reduce the self-harming costs of immunity.

Main Methods:

• * Analysis of carotenoid concentration in the haemolymph of Gammarus pulex populations.
• * Assessment of the prophenoloxidase system's maintenance and utilization.
• * Correlation analysis between haemolymph carotenoid levels and immune system parameters.

Main Results:

• * A significant positive correlation was observed between circulating carotenoid concentration and the prophenoloxidase system in Gammarus pulex.
• * This relationship held true both within and among natural populations of the studied crustacean.
• * Findings suggest carotenoids are linked to the maintenance and function of innate immunity.

Conclusions:

• * Carotenoids play a role in invertebrate innate immunity, potentially by reducing self-inflicted damage.
• * The prophenoloxidase system's reliance on carotenoids highlights the importance of dietary antioxidants for immune defense in crustaceans.
• * This study provides evidence for the conserved function of carotenoids in mitigating immune-associated costs across diverse animal taxa.