| Background With stealthy onset and no typical symptoms, epithelial ovarian cancer lacks sensitive and specific method of its early diagnosis, whose five-year survival rate rests only around 30%, while fatality rate ranks first among the female malignant genital diseases. Ovarian cancer has the biological characteristics of its extensive spreading in the abdominal cavity and the massive ascites formation. The tumor remains confined in the abdominal cavity even in its advanced stage. The tumor immunological microenvironment is a new concept put forward recently in further studies of the interaction between the tumor cells and the local immunocytes of the tumor. It has been found that even in the tumor' s early stage, tumor local immune suppression has already come forth despite the fact that the systemic immune function shows no apparent change.The T-cell mediated immune response plays the most important role in the growth control of immunogenic tumor cells. The antigen-pulsed T cells are able to kill and liquefy the specific tumor cells with corresponding antigens under the restriction of MHC. In order to induce and activate the T cell mediated immune reaction against tumor, the tumor antigens need to be processed into tumor antigen polypeptides inside the cells, which are then expressed in combination with MHC I molecules onto the surface of tumor cellsand get identified by CDS' CTL, or fall at first off the surface to be incepted by antigen presenting cells (APC), and then are processed into polypeptides to be finally presented to CD4 Th cells by MHC II molecules on the cell surface . As to the change of T lymphocyte subsets in the peripheral blood, it has been found in some studies that the decline of CD4+/CD8+ ratio or becomes reversed with the advance of tumor. Nevertheless, examining the host' s reaction by examining the patient' s peripheral blood immunocyte distribution proves incomplete, because many malignant tumors, especially those in their early stage, lead to local immune suppression but no systemic damage. Tumor-infiltrating lymphocytes (TIL) play a central role in tumour immunnology, which hold the most forward position in the patient' s fighting against tumor, and whose characteristics such as composition and function reflect to some extent the efficieney, intensity and general level of the reaction against tumor. Therefore, examining TIL in the tumor' s local immunological environment is of great significance. Dendritic cells (DC)are specifically antigen-presenting cells, Cytokines like IL~2, GM-CSF in the tumor microenvironment are able to induce DC to infiltrate into the tumor tissue, spread around the tumor region, where they capture and process antigens and then migrate to the regional lymph nodes. During the migration, the phenotypes and functions undergo the change of up-regulating such co-stimulating and adhesion molecules as MHC-II , CD80, CD86, CD40 on the surface of DC, which then turn into mature DC to activate the local immune reaction.It has been found several special DC markers after S-100 was demonstrated as a marker for DC. Though S-100 is always thought as the DC marker for diagnosis from clinic tissue slides, it was not clear whether all of the DC in different phase could express S-100, and it was also unclear what special molecules did mature DC or activated DC express. CD83 was thought as thespecial markers for mature DC in these years, because only the activated DC could express CD83, and the resting DC could not express CD83. It was also found that CD83 DC could express many ligands, which participate the activated procession of T cells, such as CD86, CD80, and CD40. So CD83 may be as a special marker for mature and functional DC.TIL distribution in the tumor tissue has received attention in recent years. It has been found in some research that most CDS positive cells in the tissue of prostatic tumor concentrate around the cancer nest and in its peripheral tissue, while the positive cells within the nest are comparatively few. Some research foun... |
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