ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Lipopolysaccharide (LPS) can activate human and murine T cells in vivo and in vitro. Here we analysed the effects of LPS on T cells with defined specificities in T-cell receptor (TCR)-transgenic systems. LPS rapidly induced high amounts of interferon (IFN)-γ in a subpopulation of purified T cells from DO11.10 (OVA323–339/H2-Ad) and OT-1 (OVA257–264/H2-Kb) mice when coincubated with antigen-pulsed peritoneal exudate cells (PECs). LPS induced IFN-γ in T cell cultures even when the number of antigenic major histocompatibility complex (MHC) class-I complexes was too small to stimulate the T cells. LPS, thus, overruled the unresponsiveness of the otherwise ‘antigen-ignorant’ T cells. The release of IFN-γ strictly correlates with the PECs' ability to produce interleukin (IL)-12. In contrast to the induction of IFN-γ, antigen-specific IL-2 secretion and proliferation of T cells were rather decreased in the presence of LPS. Only very few IFN-γ-secreting natural killer (NK) cells and natural killer T (NKT) cells in the given experimental system could be detected using intracellular fluorescence-activated cell sorter (FACS) staining. Taken together, our results indicate that LPS has the potential to activate quiescent T cells and to specifically induce IFN-γ in CD4 and CD8 T cells. This may have direct consequences for the activation of autoreactive T cells following bacterial infections.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-3083.2002.01061.x
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