Phagocytosis, in vivo, of immune complexes by dendritic cells in the lymph of sheep.

Although the occurrence of dendritic, macrophage-like cells in the peripheral lymph of sheep, pigs, rabbits, and man is well documented, the exact nature of these cells has become controversial. Generally, such cells tend not to adhere firmly to glass or exhibit phagocytosis in in vitro systems. However, when immunized sheep were given a subcutaneous injection of specific antigen (horseradish peroxidase), most of the macrophage-like cells in the lymph from the injection site could be shown by transmission electron microscopy to have engulfed the immune complexes that had been formed in the subcuticulum.