Similar response of dendritic cells to bacterial and allogeneic antigens

The dendritic cells (DC) of an allograft recipients become engaged not only in an allogeneic but also antibacterial reaction. They react to the alloantigens and microorganisms which colonize the rejecting grafts. This leads to overstimulation of DCs what may non-specifically intensity the rejection process. We investigated the effects of allogeneic and bacterial antigens on splenic DCs phenotypes. In vitro stimulation of spleen DC-enriched population by E. coli, LPS and CpG DNA brought about an increase in expression of OX6 (MHC class II) from 47.4% in the control population to 65% in the E. coli stimulated group (p < 0.05) and to 85% in the LPS and CpGDNA groups (p < 0.05). Interestingly, a significant drop in the frequency of OX62+ antigen was observed after incubation with LPS. Allogeneic heart transplants brought about an increase of OX6+ (MHC class II) DCs to 100% and a decrease of EDI+ cells. Simultaneously, an increase in expression of W3/13 on DC-enriched splenic cells was observed. There was no significant change in the frequency of OX62+ expression in conclusion, both bacterial and alloantigens strongly activate splenic DCs what may add to the intensity of the rejection process.