[Phagocytosis and intracellular proliferation of Nocardia asteroides (strain Weipheld) in cell structures in vitro. 2. Peritoneal macrophages of guinea-pigs (author's transl)]

Abstract

The study deals with the phagocytosis of Nocardia asteroides (strain Weipheld) and the subsequent intracellular proliferation in peritoneal macrophage cells. Normal, two-stage-immunized and long-term cortison-treated guinea-pig (28 mg cortison / kg weight / day during 30 days) macrophages were used. Further, 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 studied. Among the cells obtained from the peritoneal washing liquid macrophages were most frequently subject to phagocytosis, leukocytes to a lesser degree. The normal macrophages phagocytized in 14.56% (Fig. 1), macrophages of two-stage-immunized guinea-pigs in 18.21% (Fig. 2) and macrophages from cortison treated guinea-pigs in 12.48% of cases. Intracellular observation showed phagocytized germs after 3 min. of exposure. The course of the intracellular proliferation of Nocardia can be seen in Fig. 3. The phagocytosis index increases slowly in all three groups of macrophages; least so in the immunized macrophages (1.30-after 8 hours). The highest values were obtained in the macrophages of cortison treated guinea-pigs (2.02-after 8 hours). Within 8 hours of exposure the filaments of Nocardia grew through the cell membrane of phagocytizing cells (Figs. 4 A, 4 B). Fig. 5 shows the course of the cytopathogenic effect of Nocardia upon the cells. After 1 hr. the number of dead cells increased from 0.30% to 1.9-3.8%; after 4 hrs. it reached 8.15-9.80%; after 8 hrs. 10.1-14.80%. The highest values were observed in cells from cortison treated guinea-pigs (14.80%). After addition of normal serum (time of phagocytosis 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 with in 8 hours; the differences were statistically not significant (Fig. 6). A significant increase of proliferation was observed in peritoneal macrophages with antimacrophage serum (2.07 in 8 hours). Neither normal nor immune guine-pig serum influenced the cytopathogenic effect of Nocardia on the cells of peritoneal washing liquid (Fig. 7). The antimacrophage serum had a rapid and expressive effect upon the macrophages (78.23% of cells died after 2 hours, 100% after 3 hours of exposure).