Research on the innate immunsystem

Innate immunology

The research on innate immunology focuses on the immune system's immediate, general and rapid response to infection.

Innate immune reactions are very important for the ability of the immune system to combat infections rapidly and efficiently. In addition innate immune reactions have been shown to be pivotal for the development of long-term, specific immunity as seen after an infection or, ideally, after vaccination. In other words, thorough knowledge of innate immune mechanisms, the factors controlling them and the interplay between these and a pathogenic microorganism is central for the development of new vaccines and vaccine adjuvants and for the discovery of diagnostic biomarkers for infections and other diseases involving tissue changes. This is due to the fact that it has been discovered that a wide range of innate immune reactions also take place during other forms of disease, unrelated to infections but always including challenged tissue, especially when the challenge continues ofr a long time, as observed with auto-immune diseases, cancer, aging and obesity.

Biomarkers
Biomarkers of the innate immune system make it possible to detect infection very early in the course of the disease, which allows one to make treatment decisions and to identify animal with an infectious disease efore overt disease is seen. Typical biomarkers are cytokines and acute phase proteins, both in the blood and both of which are heavily influenced by innate immune reactions.

Therefore, a significant part of the research on innate immunology focuses on how different types of infections affect cytokines and acute phase proteins, with the aim of developing new and better methods to detect these blood biomarkers of disease. In addition, there is activity on investigating possibilities for implementing such biomarkers at the herd level for surveillance for current disease status (ongoing disease) in herds, based on blood samples from a random sample of a herd. Examples of diseases with special focus are pleuropneumonia and influenza in pigs and mastitis in dairy cattle.

Based on the knowledge of biomarkers of swine in particular, and of methods for their quantification at gene as well as at protein levels a broad range of projects use the pig as a model animal, and cell culture models, including a project focusing on microRNA biomarkers for embryo survival and quality  in vitro fertilization.

Development of vaccines
Based on the study of the innate immune system, one can design new types of immune stimulating drugs for use in vaccines. These drugs should have the ability to stimulate the innate immune system in order to help the vaccinated animal to obtain efficient and durable immunity. Immune stimulating drugs are developed through experiments with chemically synthesized copies of cell surface molecules from bacteria (pathogen-associated molecular patterns, PAMPs) as well as other, chemically well-defined compounds.

Obesity and inflammation
Using the pig as a model animal, we do research on the host responses triggered by obesity-induced inflammation. In human subjects obesity can cause a number of serious medical conditions such as cardiovascular diseases and diabetes, partly caused by a chronic low-grade inflammation in the body. The objective is to identify correlations between the different innate immune factors triggered by inflammation and their long term effects on the organs of the body which will increase the understanding of the disease mechanisms operating in he development of obesity-induced disease. In this work, human-relevant animal models such as pigs are very important.

Prevention with immunoglobulin
We also work on using natural antibodies (immunoglobulins) to strengthen the immune system in livestock. We put special emphasis on preventing diarrhea in piglets, which is currently a major problem in modern pig production systems with implications for the production economy, antibiotics consumption, and animal welfare. Furthermore, we are working on feeding immunoglobulin to chickens, to protect consumers against Campylobacter bacteria. Most recently, a project on cultured fish has been initiated. The research employs an efficient and economically viable method for purification of immunoglobulin from the large amounts of blood plasma, which today is a waste product in slaughterhouses.

 


Professor

Peter Mikael Helweg Heegaard
Professor
DTU Vet
+45 35 88 62 41