Summary: Home : BioWorld International : May 18, 2011 : Article
Parasite Study Challenges Old Thinking on Inflammation
By Sharon Kingman
BioWorld International Correspondent
LONDON The discovery of a new type of inflammation is challenging the received wisdom about how white blood cells
react when they respond to infection and could eventually lead to novel therapeutic strategies for treatment of wounds
and scars, allergic reactions, autoimmune diseases and cancer.
Until now, the accepted view of how the immune system springs into action when it encounters a pathogen or an injury
has been that monocytes in the blood invade the affected tissues and mature into macrophages. Once in the tissues, they
respond to signals that direct them to become either M1 cells, which fight and kill microbes, or M2 cells, which can fight
parasites such as worms and which are also involved in wound repair.
What a team of researchers from the University of Edinburgh in Scotland has now shown is that, in some circumstances,
macrophages already in the tissues can divide rapidly in response to the stimulus, without involving cells that enter the
tissue from the bloodstream. In addition, the team, which was funded by the UK Medical Research Council, was able to
demonstrate that the cytokine interleukin-4 (IL-4), which directs cells into the M2 pathway, is responsible for driving this
Judith Allen, professor of immunobiology at the University of Edinburgh, told BioWorld International: "This finding will
completely change the way that people think about inflammation. In the past, scientists have believed that inflammation
results when white blood cells enter tissue from the blood, and that these macrophages are terminally differentiated that
they can't divide."