Figure 4.

Peripheral blood mononuclear cell proliferation in medium previously conditioned by culture with villous explants

Peripheral blood mononuclear cells were cultured for 72 h either in non-conditioned medium or in medium previously conditioned by culture of villous explants with 1000 units ml⁻¹ interferon-γ (IFN-γ) and/or 2 mm 1-methyl-tryptophan (1-Methyl-Trp) or 2 mm 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). [³H]Thymidine incorporation was then determined as described in Methods. Culture was performed by adding 100 μl of peripheral blood mononuclear cells suspended in tryptophan-free medium to 100 μl of non-conditioned or conditioned medium, and therefore tryptophan concentration in peripheral blood mononuclear cell culture was half of that in each medium. Data represent the mean ±s.d. of three separate experiments with quadruplicate assay, expressed as a percentage of control (i.e. values cultured in non-conditioned medium with or without 1-methyl-tryptophan or 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid).