Phenotypic And Functional Study Of Tonsil Immunocytes

Tonsil, lying on the entrance of both digestive and respiratory tract, is one of the secondary lymphoid organ in immune system. Tonsil was developed from the second pharyngeal pouch in human embryo. When the mesenchyme underlying the pouch epithalium become invaded with lymphoblastic B and T cells in the 12th week of gestation, the development of tonsil begins. The most characteristic structure of tonsil is reticulated lymphoepithelium. Reticulated lymphoepthelium is a kind of 搊pen?epithelium. From the mobile epitheliuxn and special M cell, antigen can be taken in. SIgA can be transported to the lumina of crypt, which was mediated by the polymeric lg receptor on epithelium cells. The lymphoepthelium is infiltrated with almost all kinds of immnunocyte---B cells, T cells, plasma cells and follicular dendritic cells, and produces many kinds of cytokines, adhesion molecules. Under the reticulated 7 2000. 5 lymphoepithelium, there are parafollicules and follicules, where B cells interact with thymus-dependent antigen. Tonsil抯 function is contacted with age. During 4 to 8 years old, tonsil had the highest immunactivity. After 20, it atrophied. Chrome inflammation can enhance this progress. Tonsil, belonging to mucosal associated lymphoid tissue, is the inductive side for respiratory tract immune. In some way, it also contributes to immunological tolerance. We still don抰 know the function of tonsil in physiological condition, though by in vitro assay, tonsil shows great irmnuno-activity. We haven抰 seen anyone after tonsillectomy, or even combined with adenotonsillectomy, developed serious infection just like after splenecotomy. In this paper, firstly, we compared the phenotype of palatine tonsil cells(PTC) with that of peripheral blood mononuclear cell(PBMC) using fluorescence staining and flow cytometry(FCM) analysis and founding that 71.2% PTC express CD2O with higher mean fluorescence intensity, MFI, compared to the 15.5% in PBMC. There were 32.8% and 57.7% CD3~ cell in PTC and PBMC and the ratios of CD4/CD8 were 6.92 and 1.11 respectively. Then we measured the natural killer cell cytotoxicity of PTC and PBMC before and after the stimulation of 11-2. The level of naturel killer cell cytotoxicity in resting PTC was very low whereas it was up to 61.5% of cytotoxicity in PTC at the effect/target ratio of 200:1 after IL-2 stimulation. On the contrary , cytotoxicity of resting PBMC was much higher. Next, CD56~NK cell were examined using immunohistocbemistry. CD56~ NK cells mainly were located in germinal center, where Ag-activated B lymphocytes differentiate, showing the intimate relationship between NK and B cells. Fourthly, two novel molecules, platelet and T cell activation antigen l(7PTA1) and 9.1C3, were found to express on PlC by immunostaining and FCM analysis. PTA1 expression can be upregulated by 11-2. By in situ hybridization, we found PTAI was localized in parafollicule and germinal center as well as endothelial cell. 8 ~4iifr~ 2000. 5 Finally, PTC were transfected with EBV to get tonsil B lymphoblastic cell line(TB-LCL) before we investigated the chemoattmctant of r...