Diverse Expression of NK Cell Receptor between Fetal Thymocytes and Fetal Liver Lymphocytes from the Same Individuals / 대한면역학회지

Fetal thymus may be the organ for NK cell maturation, but the in vivo evidences are few, Here, by analyzing NK cell receptor, we present that NK cells develop in fetal thymus and fetal liver and that NK cell receptor appears earlier than the expression CD16 or CD56. Moreover, the finding that the repertoire of NK cell receptor is different between fetal thymus and fetal liver lymphocytes suggests that the environmental factors may influence the NK cell receptor repertoire during NK cell maturation.

Expression of p58 in Fetal Thymocytes and Fetal Liver Lymphocytes / 대한면역학회지

Bipotent progenitors for T and natural killer (NK) lymphocytes are thought to exist among early precursor thymocytes or liver lymphocytes. The identification of such a progenitor population or mature NK cells in such organs remains undefined. Here we report the identification of a novel receptor of NK cells, p58 (HLA class I-specific inhibitory receptors), in fetal thymocytes and fetal liver lymphocytes. Our finding suggests the NK cells mature in the developmental stage during feta1 ontogeny. Flow cytometric analysis revealed p58 positive cells in thymocytes or in fetal liver lymphocytes and reverse transcription PCR also showed amplification of p58 RNA. The result of single stranded conformational polymorphism (SSCP) showed it discriminates one or two base pair differences of the p58 gene. Although the question still remains as to whether the expression of p58 is due to the NK cells or natural T cells, it is clear the p58 is expressed in fetal thymocytes or liver lymphocytes. And SSCP analysis using appropriate sets of primers used in this study, is helpful to study the diversity of p58.

Analysis of the expression of MICA on tumor cell lines of different histotypes and their sensitivity to NK cytotoxicity / 中国免疫学杂志

Objective:To investigate the expression of MHC class Ⅰ chain-related gene A(MICA) on different human tumor cells(K562,MCF-7,HR-8348,CNE-2,HeLa) and their sensitivity to NK cytotoxicity.Methods:Cytotoxicity of NK cells(isolated from 3 healthy persons) were detected by LDH releasing assay at different effect-to-target cell ratios(E∶T). The expression of MICA was measured by FACS.Results:Different level of MICA was detected on surface of tumor cell lines, anti-MICAmAb could partially inhibit the cytotoxicity of NK cells.Conclusion:NKG2D-MICA interaction can trigger the cytotoxicity of NK cells against tumor,NK cells can be a kind of effector cell for the treatment of some certain tumors.