Lars Niklasson

Doktorand, zoofysiologi

Tel: 031-786 36 28 | lars.niklasson@bioenv.gu.se

Forskningsintressen

I’m currently working on my PhD project in the Fish Endocrinology Laboratory (abbr. FEL) focusing on fish intestinal immune function and its responses to stress and stress related hormones as well as pathogens. I’m a member of the EU project Lifecycle, including 14 collaborators in 9 European countries. I’m also a member of the GRIP platform, the research platform on integrated physiology at Gothenburg University.

The endocrine and immune systems are integrated in many ways, with hormones affecting the immune system and immune factors like cytokines affecting the endocrine system. Stress responses are found in all vertebrates and can be caused by different factors ranging from temperature fluctuations and oxygen levels to pathogens and, in aquaculture, feed ingredients. These factors may all alter the immune response for better or for worse.

An increased interest in comparative immunology as well as the importance to understand fish diseases and, in aquaculture, the response mechanisms in fish to antibiotics and vaccines have lead to an increased attention to the immune system of fish. Recent advances in genome sequencing, the emergence of new molecular techniques available and the steady increase in species specific molecular tools available have made it possible to, more in detail, study the molecular mechanisms behind the immune response also in different fish species.

My project is focused on the regulation of the fish immune system at the intestinal mucosal level. The function of the fish intestinal epithelia is to absorb nutrients and ions and it therefore needs to maintain a selective permeability. At the same time, it is constantly exposed to the environment through feeding and drinking. This leads to a constant exposure to more or less hostile substances and microorganisms leading to a constant pressure on defensive mechanisms. Under the influence of a pathogen or a stressor the intestinal barrier may be compromised which can lead to increased risk of disease. The molecular mechanisms behind this regulation are not well studied and needs to be addressed. I am therefore looking at the mediators, the cytokines, which control the immune response, trying to figure out how they are connected and how they are integrated into the endocrine system as well as with the physical barrier properties of the intestinal mucosal system.

The results will hopefully increase the understanding of primary barriers and thus the first line of defense in fish and how they are regulated. This is of great importance e.g. when creating fish feed and vaccines but also when working with conservation issues.