Impact of genetically regulated T cell proliferation on acquired resistance to Listeria monocytogenes.
Two lines of mice genetically selected for high and low in vitro responses to PHA were used to evaluate the impact of T cell polyclonal expansion on acquired resistance to Listeria monocytogenes. The selective breeding induced two major consequences in low responder mice: (1) a reduction of the number of L3T4+ cells and (2) a restriction of T cell expansion upon PHA stimulation, predominantly affecting the Lyt-2+ subset, and associated with an abridgment of IL-2 production. In vivo PHA stimulation induced anti-Listeria protection in high responder mice, but was much less effective in low responder mice. Flow cytometer analysis revealed that T cell proliferation was also reduced in low responder mice during the course of Listeria infection, implying both L3T4+ and Lyt-2+ subsets. This defect did not apparently influence the kinetics of bacterial elimination in host tissues, which was similar in both lines during primary Listeria infection. In contrast, the expression of delayed-type hypersensitivity to Listeria antigens and the level of immunologic memory were significantly reduced in low responder mice. In vivo selective T cell depletion by anti-L3T4 or anti-Lyt-2 mAb allowed us to demonstrate the predominant role of Lyt-2+ cells in protection and that of L3T4+ cells in the expression of delayed-type hypersensitivity.
Faculté de Médecine Necker-Enfants Malades, Laboratoire de Microbiologie, Paris, France.
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P
Berche
C
C
Decreusefond
I
I
Theodorou
C
C
Stiffel
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D000950:Antigens, Ly / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D006968:Hypersensitivity, Delayed / Q000235:genetics / Q000276:immunology; D007113:Immunity, Innate; D007275:Injections, Intravenous; D007700:Kinetics; D008088:Listeriosis / Q000235:genetics* / Q000276:immunology / Q000517:prevention & control; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D010835:Phytohemagglutinins / Q000008:administration & dosage; D013154:Spleen; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D010835:Phytohemagglutinins