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Specific lysis of Listeria monocytogenes ‐infected macrophages by class II‐restricted L3T4 + T cells
Author(s) -
Kaufmann Stefan H. E.,
Hug Erika,
Väth Ulla,
De Libero Gennaro
Publication year - 1987
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830170214
Subject(s) - biology , antigen , microbiology and biotechnology , priming (agriculture) , listeriolysin o , listeria monocytogenes , cytolysis , t cell , t lymphocyte , lysis , in vitro , immune system , immunology , listeria , cytotoxic t cell , bacteria , biochemistry , botany , germination , genetics
Abstract Mice were infected with the intracellular bacterium, Listeria 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 (BMMΦ) after 9 days of culture in hydrophobic teflon bags were used. These BMMΦ were totally Ia − ; however, significant Ia‐expression could be induced by interferon‐γ (IFN‐γ). IFN‐γ‐stimulated BMMΦ, after priming with live or killed L. monocytogenes organisms were effectively lysed by the vast majority of L3T4 + T cell clones. In the absence of either IFN‐γ stimulation or antigen priming, no lysis occurred. Cytolysis was demonstrable in a conventional 4‐h 51 Cr‐release assay and in an 18‐h neutral red uptake assay and was antigen specific and class II restricted. Native T cells from L. monocytogenes ‐infected mice failed to lyse stimulated, L. monocytogenes ‐primed BMMΦ and gained their cytolytic activity after antigenic restimulation in vitro. These data demonstrate that L. monocytogenes ‐specific L3T4 + T cells could lyse MΦ presenting listerial antigens provided that Ia antigen expression had been induced. L3T4 + T cell clones produced IFN‐γ after restimulation with antigen plus accessory cells in vitro and IFN‐γ 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 MΦ to protection against and pathogenesis of intracellular bacterial infections is discussed.