Does cholesterol alert our immune system to atherosclerosis?

Targeting marginal zone B cells to protect against atherosclerosis

Atherosclerosis is the build-up of fatty material inside your arteries, causing them to harden and narrow, which can eventually trigger a heart attack or stroke. B cells are a type of immune cell whose role is to produce antibodies to help the body kill foreign or rogue cells – such as bacteria. In a previous BHF-funded project, Dr Nus showed that a certain type of B cell, called marginal zone B cells (MZBs), can protect against atherosclerosis caused by a high cholesterol diet. In their study, they showed that marginal zone B cells (MZBs) protect against the atherosclerosis caused by a high fat or cholesterol diet, by controlling the activity of another set of immune cells, called helper T cells. In a recent study, they found that, when mice are fed a high fat diet, MZBs move to where the T cells are. Because they only see these results with a high fat diet, they began to suspect that our gut microbes might play a role in this protection. Dr Nus and her team now hope to find out how MZBs are switched on after a high fat diet, and what signals tell them to move towards the T cells. They will also determine whether these communication channels are influenced by the make-up of our gut flora. An understanding of these new control processes between diet, gut flora, cholesterol and the immune system will extend our understanding of atherosclerosis, and could help design more specific strategies to combat the disease.