Neopterin augmentation of tumor necrosis factor production

Abstract Gamma interferon (γ-IFN), lipopolysaccharide (LPS)-γ or interleukin-2 (IL-2)-induced tumor necrosis factor α (TNFα) production by both macrophages and peripheral blood mononuclear cells (PBMC), was increased in the presence of neopterin. Addition of neopterin caused an increased level of TNFα, but did not affect the kinetics of the TNFα production, which showed peak levels of cytotoxic activity 4 h after stimulatory treatment. Using anti-cytokine antibodies, we concluded that the neopterin effect was mainly γ-IFN mediated, and only slightly affected by anti IL-2 receptor antibodies. The neopterin augmented TNFα production can be attributed to an immunological role for neopterin in the enhancement of cell-mediated immune (CMI) response.