Figure 1.

Effects of interleukin-10 (IL-10) on the phenotype and T-cell stimulatory capacity of in vitro-generated murine myeloid bone marrow (BM)-derived dendritic cells (DC). DC were generated from BALB/c BM cells by culture in the presence of granulocyte–macrophage colony-stimulating factor (GM-CSF), with or without IL-10. Neutralizing anti-IL-10 immunoglobulin (Ig) was added simultaneously with IL-10 when indicated, as a specificity control. (a) The expression of major histocompatibility complex (MHC) class II, CD40, CD80 and CD86 was analysed by three-colour flow cytometry on day 9 of culture. Expression of costimulatory molecules by gated CD11c⁺ cells is shown in histograms: GM-CSF alone (solid line), GM-CSF + IL-10 (bold solid line) and GM-CSF + IL-10 + anti-IL-10 Ig (dotted line). (b) Kinetics of acquisition of CD80 by DC. Cells were analysed by flow cytometry, for the expression of CD80, at different time-points (days 3, 6, 8 and 9) after initiation of the culture. (c) IL-10 inhibits the T-cell stimulatory capacity of DC. Graded numbers of day-9 DC were cultured with purified allogeneic (C57Bl/6) CD4⁺ T cells. The proliferation was determined after 4 days by measuring the incorporation of [³H]thymidine. Representative examples of five experiments are shown.