Priming of T-cell responses in mice by porins of Salmonella typhimurium.
An imbalance in signals delivered to T cells via T-cell receptor and accessory molecules can lead to anergy, apoptosis, or both. In the present study we have demonstrated that Salmonella typhimurium infection in mice leads to a progressive loss of CD4+ T helper (Th) cell population, abnormal T-cell death by apoptosis and loss of accessory molecules (B7 and intracellular adhesion molecule-1) on macrophages. Quantification of interleukin-2 (IL-2), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) secretion revealed a Th2-type of response in lymphocytes isolated from spleen. However, preimmunization of mice with porins resulted in an increased CD4+ Th cell population and accessory molecules on the surface of macrophages. Quantification of cytokines revealed a Th1-type of response. We conclude that preimmunization of mice with porins provides a microenvironment in which a well-balanced accessory molecule and cytokine network is established, which results in the prevention of cell death by apoptosis.
Division of Cardiology, V.A. Medical Center, Minneapolis, MN, USA.
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D000818:Animals; D017209:Apoptosis; D018122:B7-1 Antigen / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D007108:Immune Tolerance; D007114:Immunization; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D018272:Porins / Q000276:immunology / Q000494:pharmacology*; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000517:prevention & control; D012485:Salmonella typhi / Q000378:metabolism*
D018122:B7-1 Antigen; D007378:Interleukins; D018272:Porins; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma