Defective monocyte to macrophage maturation in human immunodeficiency virus infection

To look for possible defects in cells of the monocyte/macrophage system, blood monocytes from patients infected with human immunodeficiency virus (HIV) were cultured on hydrophobic Teflon for 7 days and their ability to differentiate into mature macrophages in the presence of serum was followed. The following parameters were studied as indicative of successful terminal maturation: (1) the expression of maturation-associated antigens (transferrin receptor, surface transferrin, the BA-2 antigen, MAX antigens), (2) the disappearance of the MOP15 antigen, and (3) a more than 20-fold increase in intracellular ferritin concentration. It was found that the patients' blood monocytes did not differentiate in vitro but rather remained immature precursor cells. If the same holds true in vivo, the results could indicate that the pathophysiology of the acquired immunodeficiency syndrome (AIDS) may be, to a large extent, linked with the functional consequences of this impaired monocyte-to-macrophage maturation.