What are Macrophages?
These white blood cells, found in virtually all tissues of the human body, are crucial to immune system functioning. Macrophages emerge from bone marrow. Some macrophages attack antigens (foreign substances) throughout the body, while others are perform specialized functions, like lymphoid, adipose tissue, or lung tissue macrophages.
Macrophages gain their name from the Greek for “eating cells” because they feed on foreign cells. The macrophages will then release enzymes alerting the rest of the body to an invader, a process known as phagocytosis. The released enzymes will neutralize the invaders so they cannot replicate in the body.
Macrophages also serve in healing wounds by recognizing and responding to the cytokine interleukin-4 that is released when body tissues are injured.
The Bad: Rogue Macrophages
When macrophages become overactive, they can lead to chronic inflammation, a symptom of autoimmune diseases like multiple sclerosis, psoriasis and psoriatic arthritis, and rheumatoid arthritis. In addition, asthma and allergies occur when macrophages and other cells of the immune system attack harmless substances that they deem to be threats to the body.
Most of us know that obesity is a risk factor for Type 2 Diabetes. However, we do not know why that is. Macrophages may play a role. In obese individuals, the fat cell macrophages that normally help the body maintain insulin sensitivity begin to lead the cells to become resistant to insulin.
Studies show that macrophages could also be involved in the spread of HIV. The cells are among the first in the body to become infected with the virus, and they help to spread the virus to tissues like the brain.
The Good: Daily Immune Functioning
While rogue macrophages are associated with numerous illnesses, the ordinary everyday functioning of macrophages is crucial for immune functioning. Macrophages do more good than harm, as they guard the body from infection and aid in the quick healing of wounds. Macrophages destroy bacteria, viruses, fungi, parasites, and tumors. When you recover from a cold or the flu, you have macrophages to thank.
Scientists can use their understanding of the roles and functions of macrophages to develop innovative treatments. States Dr. David Mosser, Professor of Cell Biology and Molecular Biology at the University of Maryland, “It might be possible to manipulate macrophages to make better vaccines, prevent immunosuppression, or develop novel therapeutics that promote anti-inflammatory immune responses.” In addition, knowledge of macrophages’ role in the spread of HIV may lead to new HIV treatments.