Macrophages are professional phagocytes in innate immune responses. PAMPs are known to be potent activators of innate immune signaling. Birds have both innate and adaptive immune systems. They have antiviral activity that is involved mainly in innate immune response. Filoviral infection also interferes with proper functioning of the innate immune system. MSCs have an effect on innate and specific immune cells. An immune system may contain innate and adaptive components. There is infiltration of both innate and adaptive immune cells in pancreas. Phagocytosis is one of the main mechanisms of the innate immune defense. Fruit flies have only innate immune responses. They act as messengers between the innate and the adaptive immune systems. Lactoferrin belongs to the innate immune system. Exosomes carry cargo, which can augment innate immune responses. Unlike mammals, "Drosophila" flies only have innate immunity and lack an adaptive immune response. Antibodies exert additive or synergistic effects with mechanisms of innate immunity.