Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A1S6, Canada.
Sci Rep. 2024 Jun 15;14(1):13818. doi: 10.1038/s41598-024-64691-4.
The hematophagous common bed bug, Cimex lectularius, is not known to transmit human pathogens outside laboratory settings, having evolved various immune defense mechanisms including the expression of antimicrobial peptides (AMPs). We unveil three novel prolixicin AMPs in bed bugs, exhibiting strong homology to the prolixicin of kissing bugs, Rhodnius prolixus, and to diptericin/attacin AMPs. We demonstrate for the first time sex-specific and immune mode-specific upregulation of these prolixicins in immune organs, the midgut and rest of body, following injection and ingestion of Gr+ (Bacillus subtilis) and Gr- (Escherichia coli) bacteria. Synthetic CL-prolixicin2 significantly inhibited growth of E. coli strains and killed or impeded Trypanosoma cruzi, the Chagas disease agent. Our findings suggest that prolixicins are regulated by both IMD and Toll immune pathways, supporting cross-talk and blurred functional differentiation between major immune pathways. The efficacy of CL-prolixicin2 against T. cruzi underscores the potential of AMPs in Chagas disease management.
吸血的普通臭虫（Cimex lectularius）在实验室以外的环境中并不传播人类病原体，它进化出了各种免疫防御机制，包括抗菌肽（AMPs）的表达。我们在臭虫中揭示了三种新的 prolixicin AMPs，它们与接吻虫（Rhodnius prolixus）的 prolixicin 和双翅目昆虫素/Attacin AMPs 具有很强的同源性。我们首次证明，在注射和摄入革兰氏阳性（枯草芽孢杆菌）和革兰氏阴性（大肠杆菌）细菌后，这些 prolixicin 在免疫器官（中肠和身体其他部位）中存在性别特异性和免疫模式特异性的上调。合成的 CL-prolixicin2 显著抑制了大肠杆菌菌株的生长，并杀死或阻碍了克氏锥虫（恰加斯病的病原体）。我们的研究结果表明，prolixicin 受 IMD 和 Toll 免疫途径的调节，支持主要免疫途径之间的交叉对话和功能分化的模糊化。CL-prolixicin2 对 T. cruzi 的疗效突出了 AMP 在恰加斯病管理中的潜力。
