A tissue communication network coordinating innate immune response during muscle stress

Area of Science:

• Immunology
• Developmental Biology
• Genetics

Background:

• Complex tissue communication networks are crucial for maintaining organismal homeostasis throughout life.
• Immune responses are activated in response to various physiological stresses, including muscle damage.

Purpose of the Study:

• To define the network of immune responses activated by muscle stresses in Drosophila melanogaster.
• To investigate the role of JAK-STAT and Toll signaling in response to muscle detachment and altered muscle physiology.

Main Methods:

• Utilized Drosophila melanogaster as a genetic model system.
• Induced muscle stresses including hypercontraction, detachment, and oxidative stress.
• Analyzed JAK-STAT and Toll signaling pathway activation, hemocyte recruitment, and antimicrobial peptide expression.

Main Results:

• Muscle detachment induced the strongest JAK-STAT activation compared to other muscle stresses.
• Loss of the fondue (fon) gene resulted in hemocyte recruitment and melanin accumulation at muscle attachment sites.
• fon mutants exhibited pathogen-independent Toll signaling and increased Drosomycin expression.
• Genetic interactions showed that Toll pathway components enhance muscle detachment.
• Demonstrated reciprocal activation between JAK-STAT and Toll signaling in larval tissues.

Conclusions:

• Muscle detachment activates integrated innate immune responses involving JAK-STAT and Toll signaling.
• A model for tissue communication integrating local and systemic immune responses to altered muscle physiology is proposed.
• These findings highlight the intricate interplay between muscle physiology and immune system regulation.