NK Cells, Macrophages, and Innate Immunity

The Innate Immune System

Differences Between Innate and Specific Immunity

Specific Immunity

Innate Immunity

Depends on antigen-specific, clonally expressed antigen receptors expressed by lymphocytes.

Early in infection. Begins essentially immediately after infection, because we already have the immune components before exposure.

Specific immunity developed in the evolution of vertebrates. Invertebrates rely on innate immunity.

There is no memory involved.

Innate immunity is still important to vertebrates. Specific immunity cannot replace it, partly because specific is too slow.

Disruptions in innate immunity can result in serious immune problems.


Not specific in an immunological sense, but are specific in a biochemical sense.

Contributions to Innate Immunity

Example of Innate Immunity