White blood cells, which are produced in the bone marrow, usually help to prevent bacteria and injury, but sometimes they may turn against the body, according to a new study. In this instance, inflammation can impact the brain and arteries, and other immune systems may develop new therapies for conditions that arise when the balance of white blood cell production goes awry.
According to Matthias Nahrendorf, a senior author and researcher at the MGH Research Institute and Harvard Medical School, the nervous system plays a role in controlling blood cell production by chemical messengers or neurotransmitters. This is particularly important in people who are exposed to stress, where stress hormonespart of the fight-or-flight response control the sympathetic nervous system may increase bone marrow activity and cardiovascular inflammation in response to the neurotransmitter noradrenaline. These are, for instance
The study found that acetylcholine, which is known as the precursor to inflammation and heart disease, reduced white blood cells, contrary to noradrenaline, which increases them. The source of the neurotransmitter acetylcholine was also unanswered.
The investigator found no evidence in the bone marrow of the typical nerve fibers that are known to release acetylcholine. Instead, B cells, which are themselves a type of white blood cell (most commonly known for making antibodies), supplied the acetylcholine in the bone marrow. Thus, B cells counter inflammationeven in the heart and the arteriesvia dampening white blood cell production in the bone marrow. Surprisingly, they employ a neurotransmitter to
Researchers might assist with developing strategies to prevent inflammation in cardiovascular conditions such as atherosclerosis. According to Nahrendorf, this may lead to development of new therapies that combat myocardial infarction, stroke, and heart failure.