PHAGOCYTOSIS AND INTRACELLULAR PROLIFERATION OF NOCARDIA ASTEROIDES (STRAIN WEIPHELD) IN CELL STRUCTURES INVITRO .2. PERITONEAL MACROPHAGES OF GUINEA-PIGS

Abstract

Phagocytosis of N. asteroides (strain Weipheld) and the subsequent intracellular proliferation in peritoneal macrophage cells were studied. Normal, 2-stage immunized and long-term cortisone-treated guinea pig (28 mg cortisone/kg weight/day during 30 days) macrophages were used. The cytotoxic effect of Nocardia upon the cells in the peritoneal washing liquid in vitro and the influence of the normal, immune and antimacrophage serum upon the phagocytosis and the intracellular proliferation were also studied. Among the cells obtained from the peritoneal wash liquid, macrophages were most frequently phagocytic. The normal macrophages phagocytized in 14.56%, macrophages of 2-stage immunized guinea pigs in 18.2 and macrophages from cortisone treated guinea pigs in 12.48% of cases. Intracellular observation showed phagocytized bacteria after 3 min of exposure. The phagocytosis index increases slowly in all 3 groups of macrophages; least so in the immunized macrophages (1.30 after 8 h). The highest values were obtained in the macrophages of cortisone treated guinea pigs (2.02 after 8 h). Within 8 h of exposure, the filaments of Nocardia grew through the cell membrane of phagocytizing cells. After addition of normal serum (at 60 min) normal peritoneal macrophages phagocytized in 13.30% of cases; immune serum stimulated phagocytosis (16.21%); antimacrophage serum significantly reduced phagocytosis (4.10%). The phagocytosis index in peritoneal macrophages with normal and immune serum increased, reaching values of 1.20-1.58 within 8 h; the differences were statistically not significant. A significant increase of proliferation was observed in peritoneal macrophages with antimacrophage serum (2.07 in 8 h). Neither normal nor immune guinea pig serum influenced the cytopathogenic effect of Nocardia on the peritoneal wash cells. The antimacrophage serum had an intense, rapid effect upon the macrophages (78.23% of cells died after 2 h, 100% after 3 h exposure).