ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of B7H4 on human bone marrow mesenchymal stem cells (HBMSC) mediating immune suppression.</p><p><b>METHODS</b>The expression of the negative immunoregulatory factor B7H4 on HBMSC were analyzed by RT-PCR and flow cytometry (FCM), respectively. The blocking experiment was used to detect the effects of B7H4 on HBMSC mediating suppression on PHA induced T cell activation, proliferation and cell cycle. HBMSC inhibiting T cell proliferation was examined by transwell cell culture system.</p><p><b>RESULTS</b>B7H4 was highly expressed on HBMSC. Blocking the B7H4 expression by B7H4mAb significantly attenuated the inhibitory effects of HBMSC on T cell proliferation. Compared with that of the unblocking group, T cell stimulator index (SI) of the B7H4 blocked group was significantly increased (53 +/- 5 vs 15 +/- 8, P < 0.01) and the inhibitory effects of HBMSC on T cell cycle were weakened significantly through down-regulating the cell number in G(0)/G(1) phase \[(85.6 +/- 9.9)% vs (95.8 +/- 9.9)%\] and up-regulating those in S phase\[(5.8 +/- 3.2)% vs (2.3 +/- 2.2)%, P < 0.05\]. The suppressive effects of HBMSC on T cell proliferation were significantly weakened after separating HBMSC from T cells by transwell cell culture system. Compared with the cell to cell contact group, T cell SI was significantly increased (27 +/- 17 vs 15 +/- 3, P < 0.01).</p><p><b>CONCLUSION</b>HBMSC highly express B7H4, which plays an important role in the suppressive effects of HBMSC on T cell proliferation.</p>
Subject(s)
Humans , B7-1 Antigen , Metabolism , Physiology , Bone Marrow Cells , Allergy and Immunology , Metabolism , Cell Cycle , Allergy and Immunology , Cell Proliferation , Cells, Cultured , Lymphocyte Activation , Allergy and Immunology , Mesenchymal Stem Cells , Allergy and Immunology , Metabolism , Phytohemagglutinins , Pharmacology , T-Lymphocytes , Cell Biology , Allergy and Immunology , V-Set Domain-Containing T-Cell Activation Inhibitor 1ABSTRACT
<p><b>OBJECTIVE</b>To provide materials for the study of the function of ESC42 protein specifically expressed in the human epididymis.</p><p><b>METHODS</b>The ESC42 gene was amplified from the human epididymis cDNA library by PCR and then cloned into prokaryotic expression vector pGEX-4T-1, expressed and purified by recombinant DNA techniques. The specificity of ESC42 protein was identified by Western blot and MALDI-TOF-MS. The database was searched by Ms-Fit.</p><p><b>RESULTS</b>The recombinant plasmid expressed a Mr 38 x 10(3) fusion protein in E. coli at a level of 30% of the total protein, and the purity was as high as 99%. The ESC42 protein was identified by ESC42 monoclonal antibody and its molecular weight was 11 978.12, tested by MALDI-TOF-MS. The peptide mass fingerprint analysis showed that the coverage rate of the sequence reached 48% with 100% matching. The motif scan in Prosite database reveal that ESC42 belonged to the beta-defensin family and had antibacterial activity.</p><p><b>CONCLUSION</b>Obtaining high purity of rhESC42 protein may lay a foundation for the study of its functions.</p>