ABSTRACT
Objective To investigate the immunological activity change of regulatory T cells (Treg) and discuss its significance in the outcomes of patients with multiple organ dysfunction syndrome (MODS) and severe burn. Methods A total of 106 patients with total burn surface area (TBSA) larger than 30% were included in the study and randomly divided into three groups according to the burn area: Group Ⅰ (TBSA of 30%-49%, n = 41), Group Ⅱ (TBSA of 50% -69%, n = 34) and Group Ⅲ (TBSA of 70%-99%, n = 31). According to the development of MODS, patients were divided into MODS group (n =21) and non-MODS group (n =85). The patients with MODS were further divided into non-survival group (n = 16) and survival group (n = 5) based on their outcomes. Healthy volunteers were served as normal control (n = 25). Peripheral blood samples were collected at days 1,3,7, 14 and 21 postburn. The immunomagnetic separation technique was applied to separate and purify CD4+ CD25+Tregs in peripheral blood, and phenotypes (CTLA-4) were analyzed by flow cytometry and the contents of interleukin-10 released in the supernatants were determined by ELISA. Results Expression of CTLA-4 and level of IL-10 were significantly increased in burn patients compared with normal control group, with statistical differences. The expression of CTLA-4 and level of IL-10 were significantly increased in patients with severe burns at all time points. The expression of CTLA-4 and level of IL-10 in MODS group were much higher than those in non-MODS group at days 3-21 postburn (P ＜ 0.01). Among the MODS patients, the expression of CTLA-4 and level of IL-10 in the survival group were obviously lower than those in the non-survival group at days 3-21 postburn (P ＜ 0.05 or P ＜ 0.01). Conclusions After severe burn injury, expressions of the markers on CD4 + CD25 + Treg surface and secretion of cytokines produced by CD4 + CD25 + Tregs show significant difference in patients with different born areas, MODS development and survival state. CD4 + CD25 + Treg may play an important role in the pathogenesis of immunoregulation, MODS and mortality of burn patients through secretion of inhibitory cytokines.
ABSTRACT
Objective To evaluate the suppressive effect of CDS+ CD28-regulatory T cells(Treg)in vivo from spontaneous tolerance models on the acute rejection responses in rat liver transplantation.Methods Spontaneous tolerance models of inbred rat liver transplantation were established.CDS+ CD28-Treg isolated from recipients of spontaneous tolerance models were adoptively transferred into the recipients with acute rejection responses one day before the operation.The survival time and histological changes were observed in the adoptive-transferred models.Results CDS+ CD28-Treg from spontaneous tolerance models(LEW→DA)prolonged the survival time of the recipients in acute rejection models(LEW→BN)(from 14.0±2.2 days to 24.0 ± 3.0 days,P=0.0049),and the severity of rejection was alleviated in liver pathology.Conclusion CDS+ CD28-Treg from spontaneous tolerance models can suppress the acute rejection responses in rat liver transplantation,with antigen-specific properties.