Precultured and fresh human T-cells suppress the mitogen response of autologous lymphocytes

Increased interferon-gamma (IFN-gamma), IL-10 and decreased IL-4 mRNA expression in peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE)

Cytokines are important regulators of lymphocyte function in SLE. However, the profile of Th1 and Th2 cytokines produced by circulating lymphocytes in human SLE has not been clearly elucidated. The aim of the present study was to characterize the gene expressions of the Th1-type cytokine IFN-gamma, and the Th2-type cytokines IL-10 and IL-4 in PBMC of 15 patients with SLE and 10 healthy individuals by a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Our results showed that expression of IFN-gamma (P = 0.0004) and IL-10 (P = 0.002) transcripts were significantly increased in PBMC of patients with SLE compared with healthy controls. By contrast, expression of IL-4 transcripts in PBMC of patients with SLE was significantly decreased compared with the healthy controls (P = 0.0008). Primary sources of IL-10 were B cells and monocytes, with variable contribution of T cells as detected in various fractions of PBMC of patients with SLE (P = 0.049). These findings support the hypothesis that the enhanced production of IFN-gamma by mononuclear cells may trigger inflammatory responses, together with the enhanced production of IL-10 resulting in autoantibody production by B cells in human SLE.

Altered spontaneous and histamine-induced in vitro suppressor-cell function in dogs with atopic dermatitis

Spontaneous, histamine-induced and Concanavalin A (Con A)-induced suppression of Con A mitogenesis of autologous responder cells was studied in normal dogs and in dogs with atopic dermatitis. Histamine-induced suppression was significantly decreased in the atopic dogs, as was the Con A-induced suppression, at supraoptimal concentration of Con A, to a lesser extent. Total numbers of histamine type 1 or type 2 receptors were not different for cells from atopic or normal dogs. The spontaneous suppression was significantly greater for the atopic dogs and this was not accounted for by the effect of non-specific dermatitis, increased macrophage-induced suppression or increased induction by mitogenic factors in the culture medium. Some possible mechanisms for these results are discussed, and the similarities to suppressor cell function in humans with atopic disease are noted.

Ketoconazole in vitro inhibits mitogen-induced blastogenesis, antibody-dependent cellular cytotoxicity, natural killer activity and random migration of human leukocytes

Ketoconazole at concentrations of 1-10 micrograms/ml dose dependently inhibits mitogen-induced blastogenesis, antibody-dependent and spontaneous cytotoxic (natural killer) activity of human lymphocytes and random migration of human leukocytes. Lectin-dependent cytotoxic activity is not affected by the drug.