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Updated: Sep 28, 2026
Assessing the Cellular Immune Response of the Fruit Fly, Drosophila melanogaster, Using an In Vivo Phagocytosis Assay
Published on: April 10, 2019
The Drosophila immune defense against gram-negative infection requires the death protein dFADD
Silvia Naitza1, Carine Rossé, Christine Kappler
1Institut de Biologie Moleculaire et Cellulaire, UPR 9022 du CNRS, 15 Rue René Descartes, 67084 Cedex, Strasbourg, France. s.naitza@ibmc.u-strasbg.fr
Abstract:
Drosophila responds to Gram-negative infections by mounting an immune response that depends on components of the IMD pathway. We recently showed that imd encodes a protein with a death domain with high similarity to that of mammalian RIP. Using a two-hybrid screen in yeast, we have isolated the death protein dFADD as a molecule that associates with IMD. Our data show that loss of dFADD function renders flies highly susceptible to Gram-negative infections without affecting resistance to Gram-positive bacteria. By genetic analysis we show that dFADD acts downstream of IMD in the pathway that controls inducibility of the antibacterial peptide genes.
Insights
Drosophila melanogaster immune response to Gram-negative bacteria involves the IMD pathway. The death domain protein dFADD acts downstream of IMD, crucial for antibacterial peptide gene induction.
Area of Science:
- * Molecular immunology
- * Insect immunity
- * Signal transduction pathways
Background:
- * Drosophila melanogaster mounts an immune response against Gram-negative bacterial infections.
- * This response relies on the immune deficiency (IMD) pathway.
- * The IMD pathway involves a protein kinase cascade and downstream transcriptional regulation.
Purpose of the Study:
- * To identify novel components of the Drosophila IMD pathway.
- * To elucidate the function of the death domain protein dFADD in innate immunity.
- * To determine the precise role of dFADD within the IMD signaling cascade.
Main Methods:
- * Yeast two-hybrid screening to identify interacting proteins with IMD.
- * Genetic analysis of dFADD loss-of-function mutants in Drosophila.
- * Assessment of fly survival rates following Gram-negative and Gram-positive bacterial infections.
Main Results:
- * dFADD was identified as a binding partner of IMD through yeast two-hybrid screening.
- * Loss of dFADD function significantly increases susceptibility to Gram-negative infections.
- * dFADD is essential for the induction of antibacterial peptide genes downstream of IMD.
Conclusions:
- * dFADD is a critical component of the Drosophila IMD pathway.
- * dFADD functions downstream of IMD to regulate innate immune responses.
- * The IMD-dFADD interaction is vital for effective defense against Gram-negative pathogens.
