Recipient dendritic cells modified by RNA interference targeting CD80 and CD86 elicit T cell hyporesponsiveness via enhanced T cell apoptosis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Despite extensive research, the mechanism of immature dendritic cells (DCs) induced immune hyporesponsiveness remains incompletely understood.</p><p><b>METHODS</b>Recipient DCs from C3H mouse bone marrow cells were incubated with donor antigen from splenic lymphocytes of C57BL/6 mouse; these DCs were transfected with CD80/86 specific siRNA using lentiviral vectors. Flow cytometry was used to evaluate expression of CD80/86 on the antigen-pulsed recipient DCs. Immune regulatory activity was examined by mixed lymphocyte reaction, in which irradiated DCs were cultured with C3H spleen T cells. After the reaction, interleukin (IL)-2, IL-4, IL-10, and interferon (INF)-γ levels of mixed lymphocyte reaction culture supernatant were measured by enzyme-linked immunosorbent assay. The apoptotic T lymphocytes were identified by Annexin V and CD3 staining.</p><p><b>RESULTS</b>There was a significant inhibition of CD80/86 expression in DCs transfected with CD80/86 lentiviral vectors compared with the control groups (P < 0.05), indicating the specificity of RNA interference. Enzyme-linked immunosorbent assay results showed a significant reduction of INF-γ, IL-2 and IL-10 in the CD80/86 lentivirus transfected group compared to the control groups (P < 0.05). There was no significant difference in IL-4 levels between the groups (P > 0.05). We also showed that CD80/86 low DCs loaded with alloantigen (1) stimulated low T cell proliferative responses via the indirect recognition pathway and (2) enhanced apoptotic activity (P < 0.05) in co-cultured T cells.</p><p><b>CONCLUSIONS</b>Lentiviral vector transfection can effectively and specifically knock down target genes in DCs. The CD80/86 low DCs may show tolerogenic activity via induction of T-cell apoptosis, thereby modulating the activity of recipient-derived DCs. The use of this approach may potentially be clinically applicable.</p>

The clinical study on application of using a novel blockade technique for gastric cancer to decrease blood-borne metastasis of cancer cells / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of a novel blockade technique for gastric cancer on blood-borne metastasis of gastric cancer cells to portal vein.</p><p><b>METHODS</b>Twenty-three cases of gastric cancer were divided into routine operation group (8 cases intraoperatively without blockade technique) and blockade group (15 cases with blockade technique). Blood samples from portal vein pre- and intraoperatively, as well as gastroepiploic vein limited within the blockade area were obtained to detect CK19 mRNA expression by using RT-PCR technique.</p><p><b>RESULTS</b>Before the dissection of gastric lesion, the overall positive rate of CK19 mRNA expression in portal vein blood is 34.7% (9/23), including 37.5% (3/8) in routine operation group and 33.3% (5/15) in blockade group. While the course of tumor resection, those positive rates were 87.5% (7/8) in routine operation group and 6.7% (1/15) in blockade group respectively (P < 0.05). CK19 mRNA expression in the right gastroepiploic venous blood limited within the blocking area was all positive in 15 cases of blockade group.</p><p><b>CONCLUSION</b>This blockade technique can be used effectively to block the intraoperative spread of gastric cancer cells, thus prevent blood-borne metastasis due to operative manipulation.</p>