IMMUNE

A British immunologist explores “the incredible arsenal that lives within us and how it kills off a plethora of diseases, from the common cold to the plague.”

Currently a health policy researcher at Harvard, Carver begins with our “innate” immune system, the cells and chemicals that roam the bloodstream or are found on cell surfaces or in secretions like tears or saliva. They’re also in the stomach making hydrochloric acid, which spells death for invading bacteria, and even populate ear wax, which exists to eliminate bacteria and remove debris. In the bloodstream, neutrophils and macrophages are on patrol to seek and destroy the enemy. They are aided by whole families of circulating proteins that are able to destroy invaders as well as a population of chemical messengers that orchestrate events, including the triggering of inflammation. There are also inherited proteins that serve as bar codes to tell immune cells to ignore them because they are not foreign. Without that identification or a good match, a transplanted organ will be rejected and necessitate immunosuppressant drugs. Carver ably explains it all, including why a fetus is not rejected during pregnancy or why a transplant sometimes attacks its host. The author then moves on to the “adaptive” immune system, comprised of T cells that learn, remember, and can kill specific pathogens or cancer cells, and the B cells, which generate disease-specific antibodies. Catastrophe occurs when the immune system goes into overdrive, which can lead to allergies, autoimmune disease, or even death. Carver agrees that allergies may be on the rise given the hygiene hypothesis—i.e., our overly sanitized lives. She also decries the growth of antibiotic resistance. In the final chapter, she points to some new approaches to killing bacteria, including the use of bacteriophages, viruses that infect bacteria, to do the dirty work.

Not easy going for general readers given the depth, breadth, and detail Carver brings to a complex subject, but credit her for the wits—and wittiness—she uses to enlighten us.