Specific lysis of Listeria monocytogenes-infected macrophages by class II-restricted L3T4+ T cells

✍ Scribed by Stefan H. E. Kaufmann; Erika Hug; Ulla Väth; Gennaro De Libero

• Book ID: 102828252
• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 973 KB
• Volume: 17
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830170214

✦ Synopsis

Mice were infected with the intracellular bacterium, Lisferia monocytogenes, and T cell clones from spleens, lymph nodes and peritoneal exudates were established. The capacity of L3T4', Lyt2-T-cell clones to specifically lyse L. monocytogenes-infected macrophages was analyzed. As a source of target cells, bone marrow macrophages (BMMQ,) after 9 days of culture in hydrophobic teflon bags were used. These BMMQ were totally Ia-; however, significant Ia-expression could be induced by interferon-y (IFN-y). IFN-y-stimulated BMMQ,, after priming with live or killed L. monocyfogenes organisms were effectively lysed by the vast majority of L3T4' T cell clones. In the absence of either IFN-y stimulation or antigen priming, no lysis occurred. Cytolysis was demonstrable in a conventional 4-h "Cr-release assay and in an 18-h neutral red uptake assay and was antigen specific and class I1 restricted. Native T cells from L. monocytogenes-infected mice failed to lyse stimulated, L. monocytogenes-primed BMMQ and gained their cytolytic activity after antigenic restimulation in vitro. These data demonstrate that L. monocytogenes-specific L3T4' T cells could lyse MQ, presenting listerial antigens provided that Ia antigen expression had been induced. L3T4' T cell clones produced IFN-Q after restimulation with antigen plus accessory cells in vifro and IFNy secretion could be increased by costimulation with recombinant IL 2. These T cell clones conferred significant protection upon recipient mice which was more pronounced in the liver. The possible relevance of lysis by L3T4' T cells of infected MQ, to protection against and pathogenesis of intracellular bacterial infections is discussed.