Which cell type is primarily responsible for phagocytosis in innate immunity?

Which cell type is primarily responsible for phagocytosis in innate immunity?

• A. Neutrophils
• B. Lymphocytes
• C. Eosinophils
• D. Basophils

Answer: (A)

Phagocytosis is a frontline defense of the innate immune system, where certain white blood cells ingest and destroy microbes. Neutrophils are the cells best equipped for this role. They are the first responders to infection, rapidly exiting the bloodstream and migrating to the site of injury. Once there, they are packed with granules containing potent antimicrobial substances and enzymes. When a neutrophil engulfs a pathogen, it creates a phagosome that fuses with lysosomes to form a phagolysosome, and it generates reactive oxygen species in a respiratory burst to kill the invader. Their combination of rapid arrival, high numbers, and strong antimicrobial mechanisms makes them the primary cells responsible for phagocytosis in the early innate response. Lymphocytes are more involved in adaptive immunity, while eosinophils and basophils play roles in parasitic defense and allergic responses, not in primary phagocytosis.

Phagocytosis is a frontline defense of the innate immune system, where certain white blood cells ingest and destroy microbes. Neutrophils are the cells best equipped for this role. They are the first responders to infection, rapidly exiting the bloodstream and migrating to the site of injury. Once there, they are packed with granules containing potent antimicrobial substances and enzymes. When a neutrophil engulfs a pathogen, it creates a phagosome that fuses with lysosomes to form a phagolysosome, and it generates reactive oxygen species in a respiratory burst to kill the invader. Their combination of rapid arrival, high numbers, and strong antimicrobial mechanisms makes them the primary cells responsible for phagocytosis in the early innate response. Lymphocytes are more involved in adaptive immunity, while eosinophils and basophils play roles in parasitic defense and allergic responses, not in primary phagocytosis.