Objective To explore the effect of blocking BTLA-HVEM (herpesvirus entry mediator-B and T lymphocyte attenuator) pathway on dendritic cell function and the related immunological mechanisms. Methods Murine BTLA extracellular domain eukaryotic expression vector psBTLA was constructed by gene recombination and transfected CHO by Lipofection method. Mouse bone marrow cells were induced to differentiate into DCs by GM-CSF plus IL-4. Expression of BTLA and HVEM on DCs was detected after HSPT0-TC-1 peptide complex stimulation by FACS. Expression of BT-1 and secretion of IL-12 were detected after HSP70-TC-1 peptide complex plus psBTLA transfected CHO culture supernatant stimulation on DCs. Pretreated DCs co-cultured with the same genetic background mouse splenocytes and lymphocytes proliferation and cytokine secretion were detected. Effect of psBTLA gene transfer in vivo on BT-1 expression of DCs and tumor growth on tumor-bearing mice was detected. Results Extracellular domain of murine BTLA was successfully constructed, psBTLA stable transfection CHO cells were obtained and expression of BTLA extracellular domain(sBTLA) was detected the in its culture supernatant. BTLA and HVEM expression of DCs were increased after stimulation by the antigen peptide complex. When DCs were treated with antigen peptide complex plus culture supernatant containing sBTLA, B7-1 expression and IL-12 secretion were increased. Co-cultured with splenocytes, lymphocytes proliferation and cytokine secretion, such as IL-2 and IFN-γ,, were also increased. Gene transfection with psBTLA in vivo promoted B7-1 expression on DCs and inhibited cervical cancer cells growth. Conclusion Blockade of BTLA-HVEM inhibitory pathway with sBTLA can further improve DCs function, activation of lymphocytes and promote antitumor immune response.

Objective To propose a new multi-joint series venipuncture system, explore the mechanics and kinematics-based related control problems involved in needle insertion and needle picking during the puncture process, and verify feasibility of this system. Methods A puncture manipulator was built, and needle displacement control algorithm was proposed by combing with the puncture mechanics model. The the forward kinematics was calculated by using DH method, so as to obtain the tip coordinates. Then the inverse kinematics was calculated by using the geometric method. The forward and inverse processes were closely connected. The position error of the end coordinates before and after needle picking was compared by using the method of kinematics positive solution-inverse solution-re-positive solution. Finally, experimental verification and simulation were conducted by combining with the physical object. Results Through simulation and experiments, accuracy of the theoretical model was verified. The needle insertion algorithm could be used to achieve success with only one needle insertion, which provided theoretical basis for the control of robot arm. The position error before and after needle picking could be controlled within 1 mm from the end trajectory. The end needle tip of robot arm was almost kept fixed during the needle picking process. Therefore, this needle picking scheme was feasible and could basically verify that the needle picking action of robot arm met the accuracy and safety requirements. Conclusions The venipuncture manipulator truly simulates the needle insertion and needle picking action during the puncture process, and can safely and accurately realize the needle insertion and needle picking action with needle tip as the fixed point, indicating that it has certain clinical value.