ABSTRACT

One of the essential problems of athymic life must be the defensive and regulatory systems which are roughly termed phagocytic and include both monocytes-macrophages and granulocytes of the neutrophil, possibly also of the eosinophil series from the metamyelocyte stage on. The enhanced phagocytic uptake in nude fetuses was found to be associated with a higher expression of some Fc receptors, due to a higher stimulation of nude mononuclear phagocyte system cells. Although antimicrobial defense becomes the principal role of phagocytic cells in postnatal life, their secretory and regulatory functions in tissue growth, decay, and repair must be retained. Hence, the permanent or chronic activation of nude mouse macrophages is convincingly documented by the phagocytic uptake and to a lesser extent on cidal properties of the cells due to either oxidative or nonoxidative killing mechanisms.