Lice can be nice to us

PA 111/09 Parasite infestations might have a good side. Wild mice from a Nottinghamshire forest have given experts at The University of Nottingham clues as to the importance of some parasites, such as lice, for the conditioning of a "natural" immune system. Jan Bradley, Professor of Parasitology, said: "Our understanding of mammalian immunology is largely based on rodents reared under highly unnatural pathogen and stress-free conditions. Analysing the immune response in wild populations can give crucial insights into how the immune system functions in its natural context." Many health problems in modern humans are caused by over-active immune responses. The immune system should be able to tell the difference between foreign invaders and its own body cells. But sometimes it can mistake self proteins for non self proteins 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.