An overview of insect innate immunity

Abstract

Due to the exposure of insects to various sources of pathogens during different stages of their life cycle and their vulnerability towards subsequent infections, moreover lack of morality issues, economical breeding and short‐term‐life cycle, insect's immunity has been considered as a high‐potential candidate to study underlying mechanisms of defense responses against all sort of invaders, as well as pandemic diseases. Currently, the world is enduring monumental pressure to meet global food production demands. One viable option would be to mass rear edible insects, such as coleopteran meal worm Tenebrio molitor, which is thought to be a substantial protein source. In addition, using antimicrobial peptides as an alternative for antibiotic source against multidrug‐resistant pathogens, makes insects a valuable option to solve this health issue. As a consequence, sufficient knowledge of insect immunity will lead us to reach advanced diagnostic and treatment technologies. To accomplish these goals, crucial importance of identification and functional characterization of the main signaling pathways, such as Toll and immune deficiency (IMD), prompted us to review the mechanisms of the signaling pathways involved in immune response in well‐known insect models.

Biosurfactants Induce Antimicrobial Peptide Production through the Activation of TmSpatzles in Tenebrio molitor

“…Toll receptors have been identified and known to recognize evolutionarily conserved bacterial components such as LPS, LP, LPT, and PGN in mammals [ 31 , 63 ]. Moreover, it has been reported that CD14 facilitates LP recognition by toll-like receptors 2 and 1 in humans [ 64 , 65 , 66 ].…”

Identification of Core Genes of Toll-like Receptor Pathway from Lymantria dispar and Induced Expression upon Immune Stimulant

“…For multicellular animals, innate immunity is an efficient first line of defense to avoid pathogen invasion and activate different signaling pathways [1]. Invertebrates, such as insects, lack an adaptive immune system and mainly depend on the innate immune system to counter the diverse pathogens that include fungi, bacteria and viruses [2].…”

Can Plant Lectins Help to Elucidate Insect Lectin-Mediated Immune Response?

“…Nonetheless, insects have evolved to be very successful organisms, occupying almost every habitat and ecological niche. This is due to a strong innate immune system consisting of a cellular and a humoral component (reviewed by [12][13][14]). The cellular defense is initiated instantly when pathogens are detected and results in the phagocytosis of smaller pathogens or encapsulation of bigger invaders [13,14].…”

“…The cellular defense is initiated instantly when pathogens are detected and results in the phagocytosis of smaller pathogens or encapsulation of bigger invaders [13,14]. The humoral defense is a relatively slow response and involves the production of a series of antimicrobial peptides (AMPs), complement proteins, lysozymes, protease inhibitors, reactive oxygen species (ROS), and enzyme cascades leading to the formation of melanin and clotting [12,14].…”