Effect of aminergic signaling on the humoral innate immunity response of Drosophila

Giulia Cattabriga; Giorgia Giordani; Giuseppe Gargiulo; Valeria Cavaliere

doi:10.3389/fphys.2023.1249205

Effect of aminergic signaling on the humoral innate immunity response of Drosophila

Front Physiol. 2023 Aug 24:14:1249205. doi: 10.3389/fphys.2023.1249205. eCollection 2023.

Authors

Giulia Cattabriga^#¹, Giorgia Giordani^#¹, Giuseppe Gargiulo¹, Valeria Cavaliere^{1

2}

Affiliations

¹ Dipartimento di Farmacia e Biotecnologie, Alma Mater Studiorum Università di Bologna, Bologna, Italy.
² Interuniversity Center for Studies on Bioinspired Agro-Environmental Technology (BAT Center), University of Napoli "Federico II", Naples, Italy.

^# Contributed equally.

Abstract

Biogenic amines are crucial signaling molecules that modulate various physiological life functions both in vertebrates and invertebrates. In humans, these neurotransmitters influence the innate and adaptive immunity systems. In this work, we analyzed whether the aminergic neurotransmission of dopamine, serotonin, and octopamine could have an impact on the humoral innate immune response of Drosophila melanogaster. This is a powerful model system widely used to uncover the insect innate immunity mechanisms which are also conserved in mammals. We found that the neurotransmission of all these amines positively modulates the Toll-responsive antimicrobial peptide (AMP) drosomycin (drs) gene in adult flies infected with the Micrococcus luteus bacterium. Indeed, we showed that either blocking the neurotransmission in their specific aminergic neurons by expressing shibire^ts (Shi^ts) or silencing the vesicular monoamine transporter gene (dVMAT) by RNAi caused a significantly reduced expression of the Toll-responsive drs gene. However, upon M. luteus infection, the block of aminergic transmission did not alter the expression of AMP attacin genes responding to the immune deficiency (Imd) and Toll pathways. Overall, our results not only reveal a neuroimmune function for biogenic amines in humoral immunity but also further highlight the complexity of the network controlling AMP gene regulation.

Keywords: aminergic signaling downregulation; dopamine; drosomycin; neurogenetic manipulation; neuroimmunity; octopamine; serotonin.

Grants and funding

The authors acknowledge funding from the Italian Ministry of University, PRIN 2017—UNICO (2017954WNT). GGi and GC were supported by a fellowship funded by the Italian Ministry of University, PRIN 2017—UNICO (2017954WNT).