Inhibition of Chlamydia pneumoniae growth in HEp-2 cells pretreated with gamma interferon and tumor necrosis factor alpha

J. T. Summersgill, N. N. Sahney, C. A. Gaydos, T. C. Quinn, J. A. Ramirez

Research output: Contribution to journalArticle


An in vitro culture system was used to study the effects of increasing concentrations of human cytokines on the intracellular replication of Chlamydia pneumoniae. HEp-2 cell monolayers, pretreated for 24 h with 200 U of human recombinant gamma interferon (IFN-γ) per ml restricted the intracellular replication of C- pneumoniae. Tumor necrosis factor alpha (TNF- α; 25 ng/ml) exhibited a synergistic effect with IFN-γ by reducing the concentration of IFN-γ necessary to restrict intracellular growth to 100 U/ml. The addition of 200 μg of tryptophan per ml significantly reversed the inhibitory effects of IFN-γ and TNF-α, suggesting involvement of the indoleamine-2,3-dioxygenase pathway in the restriction process.

Original languageEnglish (US)
Pages (from-to)2801-2803
Number of pages3
JournalInfection and immunity
Issue number7
StatePublished - Jul 7 1995


ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Infectious Diseases

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