Format

Send to

Choose Destination
See comment in PubMed Commons below
J Immunol. 2000 Jul 15;165(2):628-31.

Cutting edge: IL-12 is required for the maintenance of IFN-gamma production in T cells mediating chronic resistance to the intracellular pathogen, Toxoplasma gondii.

Author information

1
Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Abstract

IL-12 is required for the development of IFN-gamma-dependent resistance to intracellular pathogens but is not thought to play a major role in its maintenance. To directly assess the requirement for continuous IL-12 signaling in long-term cell-mediated immunity, recombinant cytokine was transiently administered to IL-12 p40-deficient mice during the first 2 wk of infection with the intracellular pathogen Toxoplasma gondii. As expected, these animals survived the acute phase and established chronic infections. However, 4-6 wk after IL-12 withdrawal, the mice exhibited increased brain cyst burdens and succumbed to toxoplasmic encephalitis. Reactivation was associated with a loss of T-dependent IFN-gamma production without a concomitant increase in Th2 cytokine expression. Importantly, parasite Ag-induced IFN-gamma synthesis by purified T cells from these animals could be restored by in vitro exposure to IL-12. These results argue that endogenous IL-12 is required for the long-term maintenance of IFN-gamma-dependent resistance against intracellular pathogens.

PMID:
10878333
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center