Monocyte-derived CD1a+ dendritic cells generated in two different culture systems: immunophenotypic and functional comparison.

Previous studies demonstrated that CD1a+ dendritic cells (DCs) could not be prepared ex vivo without using fetal calf serum (FCS). Recently, we developed a method of using heparin to induce differentiation of human monocytes into CD1a+ DCs without using FCS. In order to determine the potential clinical applicability of heparin-induced CD1a+ DCs, we conducted this study to compare both types of CD1a+ DCs, immunophenotypically and functionally. Our results showed that the expression of CD1a on heparin-DCs was lower than that on FCS-DCs. Both types of DCs expressed similar levels of CD11c, HLA-DR, CD40, CD83, CD80 and CD86 before and after lipopolysaccharide stimulation. Immature heparin-DCs and FCS-DCs had similar phagocytic activities. Heparin-DCs consistently secreted higher interleukin-10 (IL-10) and lesser IL-12 than FCS-DCs after activation. Mature heparin-DCs were slightly more active than mature FCS-DCs in stimulating the proliferation of allogeneic CD4+ T cells. Both types of mature CD1a+ DCs primed the naïve CD4+ T cells to produce large amount of interferon-gamma (IFN-gamma). However, naïve CD4+ T cells stimulated with FCS-DCs produced more IFN-gamma, while the naïve CD4+ T cells stimulated with heparin-DCs produced more IL-5. The results indicate that both types of CD1a+ DCs do not have identical function in the priming of CD4+ T cells and have minor difference in immunophenotypes.