April 27, 2009

Study: Parasites might provide benefits

British researchers say they've discovered parasite infestations might have a good side, acting as a conditioning agent for a natural immune system.

Our understanding of mammalian immunology is largely based on rodents reared under highly unnatural pathogen and stress-free conditions, said University of Nottingham Professor Jan Bradley, who led the study. Analyzing the immune response in wild populations can give crucial insights into how the immune system functions in its natural context.

Bradley said many health problems in modern humans are caused by over-active immune responses that sometimes mistake self proteins for non-self proteins, thereby triggering an attack on its own body and causing an autoimmune disease such as arthritis, asthma, diabetes or multiple sclerosis. Or the body can mistake a harmless substance as a threat,causing an allergic response.

Much like laboratory mice, people in developed countries are currently exposed to a very different profile of infections to that encountered by their ancestors, said Bradley. It is possible that the immune dysfunctions we see today are the result of immune systems molded by evolution for a set of challenges completely different to those encountered in modern times.

The study appears in the journal BMC Biology.