Antimicrobial peptides in marine invertebrate health and disease

Abstract

One contribution of 13 to a theme issue 'Evolutionary ecology of arthropod antimicrobial peptides'. Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as 'marine invertebrates'. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context. This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.

Perspectives on the evolutionary ecology of arthropod antimicrobial peptides

“…Even in such a well-studied organism such as Drosophila a new group of AMPs, the bomanins, was only discovered last year [16]. While the discovery of new AMPs is considered economically and medically important as a potential source for new antimicrobials (see also [9] and [17]), using AMPs as drugs is also controversial because of the risks of cross-resistance to host AMPs (see below; [18]). Questions such as why such a diversity of AMPs exists, or how and why it is maintained are of fundamental interest for understanding their biology.…”

“…Yet AMPs do not act only as immune effectors; therefore, AMPs are presumably under concurrent, pleiotropic selection for being able to fulfil their different roles. In vertebrates [11] and to a lesser extent in crustaceans [17], AMPs are also immune-modulators and have anti-inflammatory properties or contribute to wound healing. Thus, while research on AMPs has mostly focused on their antimicrobial properties in the context of pathogens (a fact that might partly be ascribed to the history of their discovery [4]), in many multicellular organisms, AMPs have other functions.…”

“…In this volume, this was especially discussed for aquaculture [17], and has also been considered for the mass rearing of insects [124]. Antimicrobial compounds can leak into the environment and enter the human food chain and here AMPs have the advantage of reduced stability of AMPs in the environment [17].…”

Antimicrobial effectors in the nematode Caenorhabditis elegans : an outgroup to the Arthropoda

“…This may suggest that they contribute to defence and/ or digestion in a form clearly distinct from the other microbeinducible effectors. These abf genes may thus also have a less prominent role as inducible immune effectors than the homologous defensin-like genes in arthropods (see [3,85,86] in this issue).…”

“…Such comparisons have previously revealed important differences in the general organization of nematode and insect immune systems (see below). They complement broader evolutionary comparisons, for example between insects and more distantly related animal lineages such as molluscs or cnidarians [3]. In the current review, we focus on the model nematode Caenorhabditis elegans, which has become a central model organism for studying the genetics of invertebrate immunity.…”