Table 4 Overview of the defining features of innate and adaptive immunity [1].
| Â | Innate immune system | Adaptive immune system |
|---|---|---|
Cells | Hematopoietic cells: • macrophages • dendritic cells • mast cells • neutrophils • basophils • eosinophils • NK cells • T cells • non-hematopoietic cells • epithelial cells (skin, airways, gastrointestinal tract) | Hematopoietic cells: • T cells • B cells |
Molecules | cytokines • complement • proteins and glycoprotein | antibodies (Ig) • cytokines |
Response time | immediate | delayed by hours to days |
Immunologic memory | none: responses are the same with each exposure | responsiveness enhanced by repeated antigen exposure |