Functional amyloids in insect immune response.
The innate immune system of insects consists of humoural and cellular responses that provide protection against invading pathogens and parasites. Defence reactions against these latter include encapsulation by immune cells and targeted melanin deposition, which is usually restricted to the surface of the foreign invader, to prevent systemic damage. Here we show that a protein produced by haemocytes of Heliothis virescens (Lepidoptera, Noctuidae) larvae, belonging to XendoU family, generates amyloid fibrils, which accumulate in large cisternae of the rough endoplasmic reticulum and are released upon immune challenge, to form a layer coating non-self objects entering the haemocoel. This amyloid layer acts as a molecular scaffold that promotes localised melanin synthesis and the adhesion of immune cells around the non-self intruder during encapsulation response. Our results demonstrate a new functional role for these protein aggregates that are commonly associated with severe human diseases. We predict that insects will offer new powerful experimental systems for studying inducible amyloidogenesis, which will likely provide fresh perspectives for its prevention.
Difesa e Biotecnologie Agro-Forestali, Dipartimento di Biologia, Università della Basilicata, Via dell'Ateneo Lucano 10, 85100 Potenza, Italy.
Patrizia
P
Falabella
Lea
L
Riviello
Mariarosa
M
Pascale
Ilaria Di
ID
Lelio
Gianluca
G
Tettamanti
Annalisa
A
Grimaldi
Carla
C
Iannone
Maria
M
Monti
Piero
P
Pucci
Antonio Mario
AM
Tamburro
Magda
M
Deeguileor
Silvia
S
Gigliotti
Francesco
F
Pennacchio
D000595:Amino Acid Sequence; D000682:Amyloid / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D006434:Hemocytes / Q000502:physiology; D007113:Immunity, Innate; D019476:Insect Proteins / Q000235:genetics / Q000276:immunology*; D007814:Larva / Q000276:immunology; D008543:Melanins / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics / Q000276:immunology*
D000682:Amyloid; D019476:Insect Proteins; D008543:Melanins