Study On The Role Of Intestinal Dendritic Cells In Multiple Organs Dysfunction Syndrome

Objective To observe the morphological form,quantity and distribution of interstitial dendritic cells in intestine,and detect intestinal DC function-associated molecules and the surface chemokine receptor 7 in the course of MODS changes in laws.To investigate the significance of the intestinal DC in the immune disorder,excessive inflammatory and organs injury mechanism,providing new theory basis for the studies on immunological pathogenic mechanism and clinical treatment of MODS.Methods The model of MODS was replicated by zymosan injecting into the peritoneal cavity of the C57BL/6 mice,then the mice were randomly divided into groups of normal,3-6 hours,12-48 hours,5-7 days,10-12 days post trauma. Pathological changes of intestine and interstitial dendritic ceils in them were observed by light microscope and transmission electron microscope in each gr6up.Immunohistochemistry was used to observe the mice intestine DC CD11_c,MHC-â…¡molecule and CCR7 expression. Using flow cytometry methods to detect CD4+ and CD8+ T lymphocyte subgroup and MHC-â…¡expression by DC/APC in peripheral blood.Results Low number interstitial dendritic ceils distributed in intestine of normal mice with a premature form expressing low level of makers MHC-â…¡molecule.In the early stage(3-6 hours)of injury,interstitial dendritic cells had a proliferation still expressing low level of makers MHC-â…¡molecule.CCR7 in intestine increased. The level of MHC-â…¡by the mononuclear cells and CD4/8 ratio declined in peripheral blood.In the acute injury stage(12-48 hours),the pathological and functional changes of organ were more obvious.Interstitial dendritic cells had a continuous proliferation with high expression of MHC-â…¡molecule.CCR7 in intestine increased obviously.The expression of MHC-â…¡by the mononuclear cells and CD4/8 ratio declined markedly in peripheral blood.In the remission stage(5-7d),interstitial dendritic cells still kept on proliferating,but functional molecule decreased to the extent of normal groups.CCR7 began to decline.In MODS stage(10-12d),the pathological and functional changes of organ were the most severe.Interstitial dendritic cells further proliferated obviously,and the expression of MHC-â…¡molecule declined to very low level.The expression of MHC-â…¡by the mononuclear ceils and CD4/8 ratio declined remarkably in peripheral blood,the level of CCR7 still kept decreasing.Conclusions 1.Changes of the number and activity of intestinal dendritic cells have close relationship with the functional and structural injury of organs in MODS,and they probably influenced and participated in the course of immunological dysfunction of MODS.2.CCR7 were probably an important factor which influences immunological function of interstitial dendritic cells in intestinal.The level of CCR7 could become one index evaluating the transfer activity of interstitial dendritic ceils and immune response ability of body.