Human dendritic cells (DC) generated from CD34+ hematopoietic progenitors cultured in the presence of granulocyte macrophage colony stimulating factor (GM-CSF) and tumor necrosis factor (TNF)-alpha are related to Langerhans cells (DLC) and have been shown to induce a strong proliferation of allogeneic CD4+ T cells. The present study shows that recombinant human IL-10 (h-IL-10) inhibits the primary and secondary proliferative responses of both CD4+ and CD8+ T cells induced by allogeneic CD1a+ DLC. The alloreaction induced by DLC generated after 5-18 days of culture of CD34+ HPC was equally inhibited by h-IL-10, thus indicating that DLC were sensitive to h-IL-10 at all stages of differentiation. This is further indicated by the h-IL-10-induced inhibition of the T cell alloreaction mediated by interdigitating DC freshly isolated from tonsils. h-IL-10 specifically acted on DLC as it did not affect the proliferation induced by Epstein-Barr virus lymphoblastoid cell lines (EBV-LCL) nor that induced by immobilized anti-CD3. The inhibitory effect of h-IL-10 was not due to the production of suppressive factors by the DLC, as the addition of DLC and IL-10 did not inhibit EBV-LCL-induced T cell proliferation. Rather, the inhibition of cytokine production (IL-2, GM-CSF, TNF, IFN-gamma) observed after 24 h of co-culture may explain the inhibition of T cell DNA synthesis detected 3 days later. The h-IL-10-induced inhibition of human DC mediated alloreaction advocates considering the use of h-IL-10 in the prevention of transplant rejection and graft versus host disease, phenomena initiated by DC.

No abstract

No abstract

Volume 108 | Number 8 Corrigendum Figure 3Immunophenotype of isolated thymic DC subsets analyzed by flow cytometry. Thymic DCs were sorted into Lin -(PE-Cy5) HLA-DR int (FITC) and Lin -HLA-DR hi subsets. Anti-CD13-PE-Cy5 labeling of HLA-DR int cells clearly resolved two distinct populations. CD13 + HLA-DR int , CD13 -HLA-DR int , and CD13 + HLA-DR hi DCs were analyzed using PE-conjugated mAb's for the expression of a number of lymphoid, myeloid, costimulatory, and adhesion markers. Data shown are representative of three experiments. Ag, antigen.

No abstract