0000000000289632
AUTHOR
Helmut Hahn
Interleukin 2 Induction in Lyt 1 + 23 − T Cells from Listeria monocytogenes -Immune Mice
Peritoneal exudate T lymphocytes from mice experimentally infected with the intracellular bacterium Listeria monocytogenes secreted high interleukin 2 activities after interaction with syngeneic normal macrophage presenting listerial antigen in vitro. L. monocytogenes -immune cells secreting IL 2 were radioresistant and bore the phenotype Thy 1 + Lyt 1 + 23 − .
Bakterien: Definition und Aufbau
Bakterien sind einzellige Mikroorganismen mit einem fur Prokaryonten typischen Zellaufbau (◘ Tab. 22.1). So fehlt Bakterien im Vergleich zu eukaryonten (oder eukaryoten) Zellen die Kernmembran. Weiterhin sind bei Bakterien Nukleolus, endoplasmatisches Retikulum, Golgi-Apparat, Lysosomen, Chloroplasten, Mitochondrien und Mikrotubuli nicht vorhanden. Andererseits besitzen Bakterien eine komplexe Zellhulle, die den Eukaryonten fehlt. Die Grose der meisten Bakterien liegt - bezogen auf den kleineren Durchmesser - zwischen 0,2 und 2 μm.
Effects of Dextran Sulfate 500 on Cell-Mediated Resistance to Infection with Listeria monocytogenes in Mice.
Injection of dextran sulfate 500 caused loss of antibacterial resistance. Mice became more susceptible to an infection with Listeria monocytogenes and were unable to develop antilisterial immunity after both active and passive immunization with passively administered spleen cells from Listeria -immune donors. Indirect evidence suggests that the phagocytic component of cell-mediated resistance to bacterial infection is the site of attack of dextran sulfate.
Morphological Changes Induced by Dextran Sulfate 500 in Mononuclear Phagocytes of Listeria-Infected Mice
Morphological changes involving mononuclear phagocytes in Listeria -infected mice after treatment with dextran sulfate 500 were investigated. Mononuclear phagocytes in livers and spleens, both circulating monocytes and fixed macrophages, showed uptake of electron-dense material. Mononuclear phagocyte changes were most pronounced within granulomatous lesions, where many phagocytes showed large membrane-bound inclusions and extensive cellular damage. It is concluded that dextran sulfate 500 selectively damages mononuclear phagocytes and that, in listerial infection, dextran sulfate 500 renders mononuclear phagocytes unable to express cellular resistance.
Pathogenität und Virulenz
Die Fahigkeit einer Spezies von Mikroorganismen, in einem Makroorganismus Krankheit zu erzeugen, heist Pathogenitat. Der Ausdruck Virulenz (lat. Giftigkeit) beschreibt den Auspragungsgrad der krankheitserzeugenden Eigenschaften bei einem gegebenen Stamm einer pathogenen Spezies.