Dendritic cells from burn and septic injured rats modulate CD4+ CD25+ T cells from sham control rats (111.13)

Abstract

Abstract Dendritic cells (DCs) play a vital role in presenting antigen to CD4+ CD25+ (Reg) T cells. We hypothesize that burn plus sepsis injury adversely affects antigen presenting cells, in particular the DCs, such that these DC are unable to adequately prime Reg T cell; the inadequate stimulation of Reg T cell by DCs may contribute to burn-induced impairment in T cell IL-2 production and proliferation. In this study, we examined the effect of presence of anti-CD3, anti-CD28, and/or IL-2 in the T cell cultures with or without the added APC/DCs. The results show when sham rat Reg T cells were cocultured with DCs or APCs from burn septic rats, IL-2 production and proliferation was decreased, compared to that in sham T cells cocultured with sham DCs or APCs. When exogenous IL-2 was added to sham Reg T cell and burn and sepsis rat APC cocultures, there was an enhancement in Reg T cell proliferation to the level found in cocultures of sham rat T cells with sham rat APCs. Sham rat T cell proliferation was enhanced in the presence of anti-CD3 but not to the level in cocultures with burn plus sepsis rat APCs. Similarly, addition of anti-CD28 produced but a small increase (~20%) in proliferation of sham rat Reg T cell cocultured with rat APCs, compared to the effect of anti-CD28 in cocultures of sham rat T cell with sham rat APCs. These studies indicate a role of burn-derived APC and DCs in modulating a Reg T cell response in burn and sepsis injury.