Recombinant Mycobacterium smegmatis expressing Hsp65-hIL-2 fusion protein and its influence on lymphocyte function in mice

Objective:To coastruct a strain of recombinant Mycobacterium smegmatis expressing the heat shock protein 65(Hsp65) and human interleukin 2(IL-2) fusion protein(rMS-Hsp65/IL-2) and to explore the effect of this construct on lymphocyte function in mice.Methods:The fusion gene encoding Hsp65-hIL-2 was cloned into shuttle vector pSMT3.The recombinant plasmid pSMT3- Hsp65-hIL-2 was transferred to Mycobacterium smegmatis by electroporation.Positive clones were selected by hygromycin and identified by PCR.The expression of fusion protein Hsp65- hIL-2 was verified using indirect immunofluorescence staining.Mice were immunized for two times by subcutaneously injection with 1×10~6 CFU rMS-Hsp65/IL-2 at a three-week interval.Two weeks after the second immunization,mice were sacrificed and the serum samples were collected for determination of anli-Hsp65 specific IgG.Splenic lymphocytes were isolated and treated with the rMS-Hsp65/IL-2 to determine lymphocytic proliferation activity by MTT assay.IFN-γand IL-2 in the medium of the treated cells were also determined by ELISA.Results:Successful construction of rMS-Hsp65/IL-2 was verified by PCR and immunofluorescence staining.Compared to the splenic lymphocytes isolated from mice immunized with Bacille Calmette-Guerin or mice immunized with Mycobacterium smegmatis alone,the splenic lymphocytes isolated from mice immunized with rMS-Hsp65/IL-2 showed a marked increase in the proliferation of lymphocytes, together with an increased production of important cytokines such as IFN- 7 and IL-2. Conclusions:rMS-Hsp65/IL-2 markedly enhances lymphocyte function.Therefore,the fusion protein generated by rMS-Hsp65/lL-2 may be of potential value in generating an effective vaccine against tuberculosis.

Ionic Radius Dependent Kinetic Behavior for the Self-Assemblyand Chiral Amplification of Lanthanide Tetrahedral Cages

Comprehensive Summary Understanding the kinetic process during the self-assembly and chiral amplification of metal-organic polyhedra(MOPs)is critical for the rational preparation of chiral MOPs.Herein,we report the ionic radius dependent kinetic processes for the self-assembly and chiral amplification of Ln4L4-type(Ln,Lanthanides;L,ligand)lanthanide tetrahedral cages.The chiral Eu4(LR)4 tetrahedral cage is structurally characterized by nuclear magnetic resonance(NMR),electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS),and single crystal X-ray diffraction.Kinetic study on the stereo-controlled self-assembly of circularly polarized luminescence(CPL)-active Ln4(LR)4(Ln=LaIII,PrIII and EuIII)tetrahedra manifests that the larger ionic radius of Ln leads to faster assembly rates.Mixed-ligand cage assembly experiments with chiral LR/S,achiral Lac and Ln(1:3:4 molar ratio)reveal that the self-assembly and chiral amplification occur synchronously for the LaIII and PrIII cages,while two distinct steps,i.e.,first self-assembly and then chiral amplification,are observed for the EuIII cage.Such distinct kinetic behavior is attributed to different ligands exchange rates among the mixed-ligand Ln4L4 cages.This work provides fundamental guidance for fabrication and property-optimization of chiral lanthanide-based molecular materials.

Aristolochic Acid-Induced Genotoxicity and Toxicogenomic Changes in Rodents

Aristolochic acid(AA)is a group of structurally related nitrophenanthrene carboxylic acids found in many plants that are widely used by many cultures as traditional herbal medicines.AA is a causative agent for Chinese herbs nephropathy,a term replaced later by AA nephropathy.Evidence indicates that AA is nephrotoxic,genotoxic,and carcinogenic in humans;and it also induces tumors in the forestomach,kidney,renal pelvis,urinary bladder,and lung of rats and mice.Therefore,plants containing AA have been classified as carcinogenic to humans(Group 1)bytheInternational AgencyforResearchonCancer.In our laboratories,we have conducted a series of genotoxicity and toxicogenomic studies in the rats exposed to AA of 0.1–10 mg/kg for 12 weeks.Our results demonstrated that AA treatments induced DNA adducts and mutations in the kidney,liver,and spleen of rats,as well as significant alteration of gene expression in both its target and nontarget tissues.AA treatments altered mutagenesis-or carcinogenesis-related microRNA expression in rat kidney and resulted in significant changes in protein expression profiling.We also applied benchmark dose(BMD)modeling to the 3-month AA-induced genotoxicity data.The obtained BMDL10(the lower 95%confidence interval of the BMD10 that is a 10%increase over the background level)for AA-induced mutations in the kidney of rats was about 7μg/kg body weight per day.This review constitutes an overview of our investigations on AA-induced genotoxicity and toxicogenomic changes including gene expression,microRNA expression,and proteomics;and presents updated information focused on AA-induced genotoxicity in rodents.

Coordination-Assembled Lanthanide-Organic Ln3L3 Sandwiches or Ln4L4 Tetrahedron: Structural Transformation and Luminescence Modulation

Photo-functional supramolecular lanthanides assemblies have shown great potential in the materials and biomedical fields.Two new tri(tridentate) ligands (L3 and L4) highlighting small variation of the connection position to the central tridentate linkers have been designed,which leads to the emergent formation of either Ln3L3-type sandwich structures or Ln4L4-type tetrahedral cages.Moreover,nonlinear enhancement of lanthanide luminescence based on the modulation of inter-ligand charge-transfer states has been revealed on the mix-ligand Ln3L3 sandwiches.Our results provide important guidance for structure-design and photoluminescence optimization of supramolecular lanthanide-organic assemblies.