Chlamydiae Modulate Gamma Interferon, Interleukin-1β, and Tumor Necrosis Factor Alpha Receptor Expression in HeLa Cells

ABSTRACT Chlamydia psittaci was found to modulate receptor expression for the cytokine receptors that are involved in the synergistic induction of indoleamine dioxygenase in epithelial cells. Increases in receptor expression were seen even with inactivated Chlamydia, suggesting that chlamydial antigens and not products of infection are important for up-regulating cytokine receptor expression.