Cross-talk between immunity and behavior: insights from entomopathogenic fungi and their insect hosts

Abstract

Insects are one of the most successful animals in nature, and entomopathogenic fungi play a significant role in the natural epizootic control of insect populations in many ecosystems. The interaction between insects and entomopathogenic fungi has continuously co-evolved over hundreds of millions of years. Many components of the insect innate immune responses against fungal infection are conserved across phyla. Additionally, behavioral responses, which include avoidance, grooming, and/or modulation of body temperature, have been recognized as important mechanisms for opposing fungal pathogens. In an effort to investigate possible crosstalk and mediating mechanisms between these fundamental biological processes, recent studies have integrated and/or explored immune and behavioral responses. Current information indicates that during discrete stages of fungal infection, several insect behavioral and immune responses are altered simultaneously, suggesting important connections between the two systems. This review synthesizes recent advances in our understanding of the physiological and molecular aspects influencing crosstalk between behavioral and innate immune antifungal reactions, including chemical perception and olfactory pathways.

Ecotoxicity of Cadmium along the Soil-Cotton Plant-Cotton Bollworm System: Biotransfer, Trophic Accumulation, Plant Growth, Induction of Insect Detoxification Enzymes, and Immunocompetence

“…Insects’ immune response consists of cellular and humoral immunity. The cellular immunity includes mainly phagocytosis, aggregation, and encapsulation, and during this process, hemolymph aggregates and encapsulates foreign objects, leading to the death of invading pathogens by asphyxiation . The humoral immunity includes mainly the coagulation and melanization process, during which the prophenoloxidase cascade produces toxic quinone intermediates that may toxify pathogens .…”

“…The cellular immunity includes mainly phagocytosis, aggregation, and encapsulation, and during this process, hemolymph aggregates and encapsulates foreign objects, leading to the death of invading pathogens by asphyxiation. 49 The humoral immunity includes mainly the coagulation and melanization process, during which the prophenoloxidase cascade produces toxic quinone intermediates that may toxify pathogens. 49 We found enhanced PO activity in the 10 and 20 mg kg −1 Cd treatment groups and an attenuated encapsulation rate in the cotton bollworm larvae as well as decreased PO activity in response to high Cd concentrations compared to the control.…”

“…49 The humoral immunity includes mainly the coagulation and melanization process, during which the prophenoloxidase cascade produces toxic quinone intermediates that may toxify pathogens. 49 We found enhanced PO activity in the 10 and 20 mg kg −1 Cd treatment groups and an attenuated encapsulation rate in the cotton bollworm larvae as well as decreased PO activity in response to high Cd concentrations compared to the control. Coincidently, Dubovskiy et al observed similar results for encapsulation rate and PO activities in Galleria mellonella exposed to dietary nickel.…”