Xenogeneic red blood cell degradation in a regional lymph node and dissemination of antigens by circulating lymphocytes.

The degradation of intramuscularly injected autogenic and xenogenic red blood cells are studied with electron microscopy and immunoferritin technique. Autogenic red blood cells are phagocytosed and completely degradated by macrophages within the draining lymph node in a relatively short time. Phagocytosis and initial degradation of xenogeneic red blood cells by macrophages in the draining lymph node are similar; however, portions of the degradation products persist in macrophages as characteristic myelinic-like figures. After 4 days, identical figures appear in large numbers in the adjacent lymphocytes within membrane-bound vacuoles. With the conjugated ferritin antibody technique, these myelinic-like figures are shown to contain antigens of the xenogeneic red blood cells. Subsequently, lymphocytes containing the inclusions are found in the peripheral blood, the marginal zone of the spleen, other lymph nodes, and the bone marrow. As in the draining lymph node the number of plasma cells increases in these organs in areas adjacent to lymphocytes with the inclusions. In a parallel study, uncoated polystyrene spheres injected intramuscularly accumulate and remain localized in macrophages of the draining lymph node. When coated with xenogeneic hemoglobin and membranes, these spheres appear in lymphocytes of the draining lymph node and subsequently in lymphocytes of the blood and spleen.