Study On Effects Of Severe Injury On Cellular Immunity And Dendritic Cells

Trauma is one of the reasons to threaten the human life and health seriously. Statistics from Ministry of Public Health of our country show in recent years that trauma and poison have already been the fifth leading cause of death in our country. In the developed country, trauma is the third leading cause of death, and the main reason that cause the death of people under the age of 40, too. Severe trauma often results in microbial infection, sepsis, systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS), which make the treatment and cure of trauma very difficult, and lead to significant morbidity and mortality in intensive care units (ICU). And these phenomena have important relations to the changes of the immune system after trauma. Many studies found that trauma have complicated effects on the immune system. On one hand the inflammation factor such as IL-6, etc obviously rises, which often cause the excessive inflammation. On the other hand the antigen presenting ability drops, which decreases the responses of T and B cells. So the immune function is obviously suppressed, which often results in infection. Thus these two respects have caused the high death rate of the severe trauma. Only correcting the imbalanced immune system in time, and recovering the normal innate and adaptive immune responses can improve the survival rate of serious trauma.The dendritic cell (DC), well known as the most powerful or"professional"antigen-presenting cell (APC), plays a key role in initiating and modulating innate and adaptive immune responses. The extraordinary and unique capacity of DC to regulate the activity and survival of B and T cells is so attractive that DC has become the focus of more and more recent researches. There are two populations of DCs: immature DCs for antigen-capturing and mature DCs for immune-stimulating [6]. Immature DCs are located in blood and tissues where they construct primary defensive network to sample and capture antigens. Once DCs have captured antigens they migrate to lymphoid organs where they become mature and present these antigens to immune cells, then stimulate naive T cells to proliferate and differentiate into effector T cells. During this process, they exhibit diverse phenotypes. If something wrong with the process, the function of whole immune system will be disturbed. Therefore it is important to understand the effects of trauma on DCs.But these days about the impact of trauma on immune system, most studies pay...