Which cell is primarily responsible for the body's defense against parasite invasion?

Eosinophils play a crucial role in the body's defense against parasitic infections. They are a type of white blood cell that becomes particularly active during allergic reactions and infections caused by multicellular parasites, such as helminths (worms). These cells contain granules filled with toxic proteins and enzymes that can be released to damage or destroy the parasites.

The mechanism often involves eosinophils binding to the surface of the parasites and releasing these substances, leading to the destruction of the parasites or limiting their growth. This is important because many parasites develop in such a way that they can evade or resist the actions of other immune cells, making the specific functions of eosinophils vital for effective defense against these invaders.

While T lymphocytes, neutrophils, and B lymphocytes have roles in the immune response—such as recognizing infected cells, phagocytizing pathogens, and producing antibodies, respectively—they are not specifically geared towards combating parasitic infections as prominently as eosinophils are.