Peritoneal and Alveolar Macrophages Derived from Lymphocyte Populations During Graft-versus-Host Reaction

摘要

Graft-versus-host reaction was initiated in normal adult (C57BL × CBA-T6T6)F1 mice by the injection of C57BL spleen or glass wool-filtered lymph node cells or thoracic duct lymphocytes. Pulmonary alveolar and peritoneal macrophages were isolated for karyotypic analysis 11 days later and found to contain substantial proportions of dividing cells of donor origin.Various approaches supported the interpretation that these represented proliferating phagocytic cells. The proportion of alveolar macrophages incorporating ³H-thymidine was similar to that found amongst the very small number of contaminating lymphocytes. The same proportion of alveolar macrophages and dividing cells contained phagocytosed Berlin Blue which had been injected intra-tracheally. Peritoneal macrophages aggregated after i.p. injection of Berlin Blue and it was possible to score many donor-derived mitoses associated with previously phagocytosed particles amongst cells from this source.It is concluded that dividing phagocytic cells stemming from a precursor in donor lymphocyte populations are present throughout the macrophage system during the GVH reaction studied. The precise identity of the precursor and the significance of this transformation pathway remain obscure.