Discovery of phagocytes

The history of phagocytosis is intimately associated with the rise of immunology and growth in understanding of host resistance to infection.

Elie Metchnikoff (1845 - 1916) was a Russian biologist, was one of the vital figures in modern medicine. He first observed cells apparently eating and destroying bacteria.

He called these cells phagocytes – Greek for ‘cell that eat’. He described the two principal types of phagocyte, the macrophage and the granulocyte.

He noted that the microphages were very motile, had lobulated nuclei and that they were eventually ingested by the less mobile macrophages.

Metchnikoff was the first to state clearly that the body actively defends itself against invading microbial agents.

While Metchnikoff was not the first to observe bacteria inside white blood cells, he was the first to see link between the intracellular digestion of microbes and the body’s defense mechanisms.

His view that the phagocyte was the organism’s sole defender was, however, challenged when Emil Behring and Shibasaburo Kitasato in 1890 reported that reported substances were present also in the cell free fraction of the blood.
Discovery of phagocytes