JAK/STAT signaling in insect innate immunity

Abstract

Lack of an adaptive strategy to combat infection creates opportunities for the innate immune system to guide invertebrate defense mechanisms. The innate immunity signaling cascades in invertebrates are elaborate, complex, and pathogen‐specific. Among invertebrates, the most extended repertoire of molecules that function in the regulatory signaling pathways has been observed in insects. This is highlighted by the fact that antimicrobial peptide (AMP) production against pathogens is orchestrated through diverse immune pathways, either independently or through cross‐talk mechanisms. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway coordinates immune responses from cytokines and regulates multiple homeostasis mechanisms in the host. That pathway has been implicated in the regulation of cell growth, differentiation, apoptosis, and inflammatory reactions. Many novel therapeutic interventions for tumors have been aimed at inhibitors of the JAK/STAT cascade. The regulatory pathway has much fewer components in Drosophila, and human homologs of almost all the critical pathway components and negative regulators have been identified. Loss‐of‐function mutation analysis and RNA interference‐based gene silencing modeling have produced functional characterization of the core components and negative regulators in Drosophila melanogaster, Aedes aegypti, and Anopheles gambiae, and in some hymenopteran and lepidopteran species. The genome‐wide analysis of the coleopteran species, Tribolium castaneum and Tenebrio molitor have been explored for elucidation of their JAK/STAT pathway regulatory components. Considering the promise of the JAK/STAT pathway in the mammalian model, the regulatory pathway in insects seems interesting especially for understanding pathogen surveillance mechanisms.

Reprograming of epigenetic mechanisms controlling host insect immunity and development in response to egg-laying by a parasitoid wasp

“…For example, miR-989 is normally expressed in somatic cells of the D. melanogaster ovary and its absence delays their migration and arrests oogenesis [62]. Additionally, border cell migration in D. melanogaster involves several conserved signalling pathways such as the JAK/STAT pathway [62], which coordinates cytokine-dependent immune responses and regulates homeostasis via multiple mechanisms [63]. The parasitization of D. melanogaster has been shown to suppress the secretion of JAK/STAT pathway ligands by haemocytes [63].…”

“…Additionally, border cell migration in D. melanogaster involves several conserved signalling pathways such as the JAK/STAT pathway [62], which coordinates cytokine-dependent immune responses and regulates homeostasis via multiple mechanisms [63]. The parasitization of D. melanogaster has been shown to suppress the secretion of JAK/STAT pathway ligands by haemocytes [63]. These data suggest that P. turionellae venom may suppress the expression of miRNAs to inhibit cell migration as a component of development and immunity.…”

Regulators and signalling in insect antimicrobial innate immunity: Functional molecules and cellular pathways

“…The JAK-STAT cascade is a conserved, intracellular signalling pathway playing a central role in hematopoiesis, cell movement, cell proliferation and differentiation, and regulation of cellular immune reactions (Fig. 5C) [30,316,317]. It takes place in the fat body cells and is elicited upon septic injury as well as bacterial [318,319] and fungal [320][321] infections.…”

Understanding the role of arthropod vectors in the emergence and spread of plant, animal and human diseases. A chronicle of epidemics foretold in South of France

“…), the main immune mechanisms are either cellular (phagocytosis, nodulation, encapsulation or via molecules produced by hemocytes,) or humoral and responsible for the production of proteins like prophenoloxidase or antimicrobial peptides. The main pathways are Toll, Imd, JAK/STAT, RNAi immune pathways [106][107][108]. Differential activation of these pathways depends on the arthropod's species, and whether the arthropod interacts with fungi, parasites, bacteria or viruses.…”

“…), les mécanismes immunitaires sont soit cellulaires (phagocytose, nodulation, encapsulation ou via des molécules produites par les hémocytes), soit humoraux et responsables de la production de protéines comme la prophénoloxydase ou les peptides antimicrobiens. Les principales voies immunitaires sont Toll, Imd, JAK/STAT, RNAi [106][107][108]. L'activation différentielle de ces voies dépend de l'espèce d'arthropode et de son interaction avec des champignons, des parasites, des bactéries, des phytoplasmes ou des virus.…”