Project description:The black soldier fly (Hermetia illucens) is important in antimicrobial peptides (AMP) research due to its exposure to diverse microbial environments. However, the impact of different fungal exposures on AMP abundance in H. illucens has not been thoroughly explored. Our study focused on basal conditions and interactions with three fungi: the non-pathogenic Candida tropicalis (isolated from larval gut), Saccharomyces cerevisiae, and the pathogenic Beauveria bassiana. Using RNA-seq and LC-MS/MS, we found that under standard conditions, the majority of AMPs belonged to the Lysozyme, Cecropin, and Defensin classes, with Defensins exhibiting the highest quantification levels. Exposure to any of the fungi upregulated AMP gene expression, indicating immune activation. Notably, exposure to C. tropicalis and B. bassiana led to notable downregulation of AMPs in H. illucens larvae compared to S. cerevisiae, suggesting these fungi may suppress or modulate the host immune response to aid their survival and colonization. The immune response of H. illucens larvae revealed that S. cerevisiae and B. bassiana trigger similar AMP pathways, whereas C. tropicalis elicits a distinct response with upregulation of Defensins and Cecropins. Lysozymes, known for their antibacterial and antifungal activity, were upregulated in response to S. cerevisiae and B. bassiana, but downregulated with C. tropicalis, potentially facilitating fungal survival in the larvae’s gut. This suggests that C. tropicalis adapts to reduce immune pressure, while B. bassiana may suppress AMPs to persist. Understanding these mechanisms opens possibilities for leveraging AMPs in combating C. tropicalis, which is implicated in human diseases.
Project description:Nutritional immunology: Diversification and diet-dependent expression of antimicrobial peptides in the Black soldier fly Hermetia illucens
Project description:The larvae of black soldier fly (BSF), Hermetia illucens L., are of economic importance due to their potential as livestock feed. However, the knowledge on their immune response to infection and wounding remains limited. In this study, we uncover the transcriptomic response of BSF larvae to wounding as well as infection with Gram-negative pathogen, Pseudomonas protegens Pf-5 at multiple timepoints. We observed that initially the BSF larvae generated a common immune response to both wounding and infection. However, the immune response is only upregulated in infected larvae over time, while the gene expression in response to wounding reduced over time. Genes encoding for signalling molecules such as PGRP-SA, Relish as well as genes encoding antimicrobial peptides like cecropin, defensin and attacin contributed primarily to BSF larvae's immune responses to both wounding as well as infection.
