Investigation Of The Phenotypes And Immunological Function Of Infiltrating Dendritic Cells In Human Tumor Microenvirment And Their Clinic Significance

Dendritic cells(DCs)are important professional antigen- presenting cells(APC),which express a lot of molecules associated with antigen-presenting. CD1a is the specific marker expressed on human DCs.MHC class II . C costimulatory molecules D80(B7-1)and CD86(B7-2) and adhesion molecules CD54(ICAM-1) are highly expressed on mature DCs.DCs play an important role in regulating both cellular immunology and humoral immunology.There are many long projections on mature DCscmbrane.Although the investigation in dendritic cells has attracted researcher's more attention than before and some progress have been made 8 in recent years,but few studies on DCs in human tumor microenviromcnt especially on tumor infiltrating dendritic cells(TIDCs)?function have been reported. It is important to investigate DCs in tumor immunology because DCs contact with tumor cells directly in tumor microenvirmcnt .The aim of our study was to investigate the TIDCs umber phenotypes .~. immune function ~ clinic significance and the role in tumor escaping from immune recognition in human tumor microenviromcnt. For the first time, Tumor infiltrating cells were investigated by digesting with enzyme .~ cells separating and anti-S-100 protein antibody immunohistochemical staining in 5 gastric cancer patients and 9 colorectal cancer patients .The results indicated that TIDCs were differently distributed in different tumor stages and the number of T[DCs was small.Most of TIDCs was round ,with projections on their mcmbrane.The immunohistochemical staining showed that the number of TIDCs was 12.3 ?3.8/HPF(high-power field,HPF),which could be divided into two parts by its morphology:Onc was round and small obviously stained in the cytoplasm and cell nucleus with no projection on their membrane.Thc other was bigger ,slightly stained in cytoplasm with some projections on their membrane. Therefore we reasoned that changes in TIDCsorphology could affect their ability to swallow or capture antigen .Further more,the grades of TIDCs infiltration were reversely correlated with tumor 9 invasion tumor histologic differentiation and lymph node metastasis and had a paralled relationship with patients? prognosis.Our results suggested that S-100(+)TIDCs had an important clinic significance and was an important prognostic parameter in cases of carcinoma and that TIDCs were closely linked to cancer s arising and progressing. For the first time phenotypes of separated infiltrating cells were examined by FACS and the reason of abnormal phenotypes was analysised .The results showed that there were a few cells which expressed CD1a and CD86 in separated infiltrating cells in 10 of 14 cases and these cells accounted for about 4.62% ?2.39% of separated infiltrating lymphocytes.There was no expression of MHC class II molecules on the surface of these DCs except for four cases and the expression level of adhension molecules CD54(ICAM-1) costimulatory molecules CD8O(B7-1) and CD83 was very low or even negative ,but the expression level of costimulatory molecules CD86(B7-2) was comparatively high.MHC class II molecules played an important role in antigen presentation.Exogenous antigens were processed through MHC class II pathway into peptides, which were presented to the surface of DCs after loading of MHC class...