Harnessing immune priming: A double-edged defence mechanism in insects

Abstract

Insects are known to dominate adverse ecological conditions due to their diverse adaptations and resilient biological traits, with their immune systems playing a crucial role in this dominance. Traditionally, insects were thought to lack adaptive immune responses due to their inability to produce antibodies and transfer immunity across generations. However, recent research using insects as model organisms has challenged this notion, revealing that prior exposure to sublethal doses of pathogens or pathogen-derived materials can protect against subsequent lethal exposures—a phenomenon known as ‘immune priming’. Evidence of bacterial, fungal and viral immune priming across different insect species highlights various types of priming, including trans-stadial (across life stages) and trans-generational (across generations) priming. Despite differing views on immune priming, its potential applications in agriculture are considerable, especially in biological control, the utilization of beneficial insects and sustainable pest management. This review explores the intricate dynamics of immune priming in insects, comparing it to vertebrate immunity and investigates its mechanisms, potential agricultural applications and future prospects.