Institute for Fish and Wildlife Health

Epigenetics & Evolution

Trout immune priming

The effect of a pathogen encounter with its host is far from predictable. An agent may induce devastating disease in one setting and not even cause a rash in another setting. For accurate epidemiological models, disease management, and long-term predictions, knowledge about factors underlying disease susceptibility, resistance, and severity is essential. This proposal uses an ecologically and economically relevant model of parasitic disease in salmonids to characterize such factors.

What is the impact of early life conditions and parental experiences on disease resistance in salmonid fish? What are the underlying molecular mechanisms? Own epidemiological and genetic data suggest that early life experiences, and potentially even parental experiences, play an essential role in the immune reaction of the salmonid flagship species brown trout Salmo trutta to the myxozoan parasite Tetracapsuloides bryosalmonae. These observations align with data from insects and birds on cross-generational immunity (also called "immune priming").

We use the brown trout - Tetracapsuloides bryosalmonae model to study the impact of rearing environment on disease severity, from the molecular to the macroscopic level, across two generations. We will

  1. generate a thorough cellular-molecular co-characterization of brown trout immunity using FACS and single cell RNA sequencing (scRNA seq)
  2. describe the cellular immune reaction of brown trout to Tetracapsuloides bryosalmonae using infection experiments, qPCR, histology, FACS and scRNA seq
  3. quantify rearing environment impacts in three trout populations from wild and hatchery environments
  4. explore imprinting mechanisms by following infected and non-infected trout to the next generation.

The results will improve our understanding of the immune responses in this important salmonid species with respect to cellular/molecular immunity and host-parasite interactions. From this we can hypthesize how rearing/environment (and genetics) may predict an individual’s response towards infection later in life.

We also expect to obtain key insights into immune priming in vertebrates. This is highly relevant for current debates regarding multigenerational impacts of environmental parameters on human individuals as well as populations. Among vertebrates, fish are particularly useful to disentangle effects mediated by non-genetic inheritance, brood care, intrauterine development and nursing. Given the overall conservation of vertebrate molecular biology, our model will hopefully provide data fruitful for continued studies with relevance for human health. Trans-generational imprinting is a topic of current debate and investigation where our improved understanding of this phenomenon would greatly benefit overall managament of human health, disease management in aquaculture and stock breeding, as well as wild life management.

This project is supported by a project grant from SNSF awarded to I. Adrian-Kalchhauser.

Project team: Heike Schmidt-Posthaus, Helena Saura Martinez, James Ord, Dragan Stajic, Irene Adrian-Kalchhauser

Collaborators: Stephanie Talker (IVI, Uni Bern), Monica Hongroe Solbakken (Oslo University)