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Objective: To simplify the PNA-FISH (Peptide nucleic acid-fluorescence in situ hybridization) test, molecular beacon based PNA probe combined with fluorescence scanning detection technology was applied to replace the original microscope observation to detect Listeria monocytogenes, Methods: The 5′ end and 3′ end of the L. monocytogenes specific PNA probes were labeled with the fluorescent group and the quenching group respectively, to form a molecular beacon based PNA probe., Results: When PNA probe used for fluorescence scanning and N1 treatment as the control, the false positive rate was 11.4%, and the false negative rate was 0; when N2 treatment as the control, the false positive rate decreased to 4.3%, but the false negative rate rose to 18.6%. When beacon based PNA probe used for fluorescence scanning, taken N1 treatment as blank control, the false positive rate was 8.6%, and the false negative rate was 1.4%; taken N2 treatment as blank control, the false positive rate was 5.7%, and the false negative rate was 1.4%. Compared with PNA probe, molecular beacon based PNA probe can effectively reduce false positives and false negatives. The success rates of hybridization of the two PNA probes were 83.3% and 95.2% respectively; and the rates of the two beacon based PNA probes were 91.7% and 90.5% respectively, which indicated that labeling the both ends of the PNA probe dose not decrease the hybridization rate with the target bacteria., Conclusions: The combination of liquid phase PNA-FISH and fluorescence scanning method, can significantly improve the detection efficiency.

The aim of this study was to build a gene chip system with surface plasmon resonance (SPR) technique, for which Gamma-peptide nucleic acid (Gamma-PNA) functioned as a probe, in order to improve sensitivity and its specificity. With the use of self-assembled monolayer (SAM) technology, surface chemistry of two-dimensional structure was used. Gamma-PNA was designed according to the bioinformatics, and was plated on the SPR chip modified by SAM. Subsequently, relevant parameters of the experiment were ensured and optimized. The results showed that the performances of Gamma-PNA probe was little affected by the ion concentration of buffer, and it had a strong light signal in a stable state. As the ion concentration was 0, there were still good hybrid reactions; pH value had less influence upon Gamma-PNA probe, and acid environment of buffer could be better. Gamma-PNA probe combined with sensor technologies achieved made the probe with dispensable labels and real-time detection. It also improved the efficiency of the hybridization and the stability, providing the foundation for clinical application.

Objective: To identify the effect of PNA CXCR3 on acute rejection of islet allograft., Methods: The mice islet transplant models were used. The mice were divided into three groups including saline group, PNA CXCR3 group and mismatch PNA group. In vitro the proliferation capability of T cell was assessed by proliferative responses. RT-PCR and western blot were used to detect the expression of mRNA and protein. Flow cytometry was applied to determine the expression level of CXCR3 in spleen CD3(+) T cells., Results: Compared with saline [(6.72 +/- 1.48) d] and PNA mismatch-treated recipients [(6.54 +/- 0.86) d], PNA CXCR3-treated recipients demonstrated statistically significant prolongation [(9.70 +/- 1.57) d] in functional allograft survival. The CXCR3 mRNA expression level of PNA CXCR3 group (1.06 +/- 0.07) was significantly down-regulated compared with saline (1.98 +/- 0.22) and PNA mismatch (1.87 +/- 0.10) group at the 7th day after transplant. The date showed that CXCR3 protein and lymphocytes proliferation capability was significantly down-regulated in PNA CXCR3 group compared with saline and PNA mismatch group (P<0.01)., Conclusions: The present study indicates that PNA CXCR3 can inhibit T cell activating and prolonging the survival time of islet allograft and has a substantial therapeutic effect on inhibiting acute allograft rejection.

Peptide Nucleic Acids(PNA) are DNA analogues in which the naturally occurring nucleobases are attached via methylene carbonyl linkages to an achiral pseudopeptide backbone of N-(2-aminoethyl) glycine units. PNA can bind to both DNA and RNA targets in a sequence-specific manner. PNA provides a powerful tool to study the mechanism for gene replication and transcription as well as an innovative strategy to regulate target gene expression. Advances as a probe in molecular biotechnology have greatly improved the sensitivity and the efficiency in genetic investigations and diagnosis. Peptide Nucleic Acid (PNA) which recognizes and binds to a complementary nucleic acid sequence presents unique physicochemical properties and has been incorporated into an expanding set of biological investigations. Accordingly, PNA is becoming the explorer of gene mystery.

Objectives: To construct a novel virus-like particulate peptide-nucleic acid vaccine (VPNV) of human telomerase reverse transcriptase (hTERT), and to study its anti-liver cancer immunity., Methods: A cationic antigenic peptide was synthesized and purified, and then human granulocyte macrophage colony stimulating factor (hGM-CSF) and TERT gene were cloned into the eukaryotic expression vector pTCAE. The peptide was combined with the nucleic acid vaccine to make a VPNV, which was transfected into eukaryotic cell COS-7. The immunogenicity of hGM-CSF and hTERT were detected using ELISA and Western blot. The efficacy of VPNV for inducing antigen specific CTL response was determined using the lactate dehydrogenase release method., Results: VPNV was verified capable to trigger specific CTL responses and has shown a specific cytolytic activity to liver cancer cell HepG2., Conclusion: A VPNV which can stimulate antigen specific CTL response was successfully constructed. This paves the way for our further investigation of anti-liver cancer immunity in mice.