Dampening the Flames of Inflammation - APC scientists discover a new protective role for Natural killer (NK) cells in intestinal inflammation
APC Scientists have discovered that Natural Killer (NK) cells are major regulators of inflammatory bowel disease (IBD) in an experimental model of the disease. The research is published this month in the leading Nature scientific journal “Mucosal Immunology” where it makes the front cover of the issue.
Natural Killer cells are white blood cells which act as “watchmen” or “sentries” protecting us against the development of tumours and viral infections. When a tumour or virus is identified, a vanguard of immune cells accumulates to attack the invader thereby causing inflammation. Because of this, APC scientists predicted that mice lacking Natural Killer cells would develop less inflammation in an experimental model for IBD. However, to their surprise, mice lacking Natural Killer cells developed severe acute inflammation. This was accompanied by severe signs of disease, accumulation of other immune cells called neutrophils and molecules which worsen inflammation and damage gut tissues.
“Our studies revealed that Natural Killer cells migrate to the gut as early as day 1 after onset of disease. In addition, these Natural Killer cells produce a vast amount of molecules which control the immune system. We have identified a new regulatory mechanism for Natural Killer cells in acute gut inflammation and a specific signal protein (killer cell receptor NKG2A) that can directly control neutrophil functions” said Dr Silvia Melgar, Investigator at the APC.
“This is an exciting discovery in Natural Killer cell biology. Our findings open up the possibility of new therapeutic approaches for IBD and other inflammatory diseases such as cystic fibrosis, rheumatoid arthritis and severe asthma, where neutrophil accumulation is a key feature” said Dr Lindsay Hall, first author of the study.
The study, funded by Science Foundation Ireland, was carried out by Lindsay Hall, Carola Murphy, Grainne Hurley, Aoife Quinlan, Fergus Shanahan, Ken Nally and Silvia Melgar at the Alimentary Pharmabiotic Centre. Dr Lindsay Hall is now a Lecturer in Gastrointestinal Science in the Norwich Medical School, University of East Anglia and a member of the Gut Health and Food Safety strategic research programme at the Institute for Food Research (IFR) in Norwich.
Reference: Natural killer cells protect mice from DSS-induced colitis by regulating neutrophil function via the NKG2A receptor Mucosal Immunology Issue 6(5):1016-1026 September 2013.
Read Lindsay Hall's blog
24 September 2013
