Autophagy-targeted DNA vaccine against Japanese encephalitis virus promotes dendritic cell function in BALB/c mice / 中华微生物学和免疫学杂志

Objective:To investigate the effects of autophagy-targeted DNA vaccine against Japanese encephalitis virus (JEV) on the immune-related functions of dendritic cells (DCs) in BALB/c mice.Methods:Healthy female BALB/c mice were randomly divided into 5 groups and injected with pcDNA3.1(+ ) empty vector (negative control), pJME plasmid, recombinant pJME-LC3 plasmid muscle, sterile PBS (blank control group) and live attenuated JEV vaccine (positive control group), respectively. The mice were immunized three times with an interval of two weeks. Splenic DCs were isolated two weeks after the last immunization. Immunofluorescence assay was used to observe the expression of the recombinant plasmid in dendritic cells. Expression of major histocompatibility complex Ⅱ (MHC Ⅱ) on DCs and the uptake of FITC-Dextran by DCs were observed by flow cytometry. CCK8 assay was used to detect the effects of DCs on the proliferation of spleen mononuclear cells from allogeneic mice.Results:The expression of plasmid-encoded protein in the DCs of the pJME-LC3 group was significantly higher than that of the pJME, pJME-LC3+ 3-MA and pcDNA3.1(+ ) empty vector groups. The uptake of FITC-Dextran by DCs was significantly enhanced in the pJME-LC3 group than in the other groups ( P<0.05), and the expression of MHC Ⅱ moleculars on DCs was increased in the pJME-LC3 group as well ( P<0.05). The splenic DCs from the mice in the pJME-LC3 group had a stronger effect on the proliferation of spleen mononuclear cells from allogeneic mice that those from other groups ( P<0.05). Conclusions:The recombinant plasmid pJME-LC3 could promote the ability of mouse splenic DCs to present antigen and to stimulate lymphocyte proliferation after immunization, suggesting that the autophagy-targeted recombinant DNA vaccine against JEV could enhance immune responses by affecting the function of DCs in BALB/c mice.

Progress in autophagy-regulated immune cell differentiation / 中华微生物学和免疫学杂志

As a conservative lysosomal degradation pathway, autophagy possess various functions that have been well studied in the immune system. Regulatory effects of autophagy on the differentiation of immune cells have been gradually revealed. In order to investigate the specific mechanisms, it is very necessary to summarize the role of autophagy in the proliferation, development and differentiation of immune cells. Effects of autophagy on the functions and differentiation of immune cells have been summarized by introducing the selective degradation function of autophagy in some articles. This review focused on some classical immune cells and elucidated the important regulatory effects of autophagy and the nutrient signaling metabolic pathways involved in autophagy on immune cell differentiation.

Construction and Expression of Recombinant Plasmid Encoding prME Protein Derived from Japanese Encephalitis Virus and Granulocyte-macrophage Colony-stimulating Factor of BALB/c Murine / 中国医科大学学报

Objective Construction and expression of recombinant plasmid fusing encoding prME protein derived from Japanese encephalitis virus （JEV） and GM-CSF of BALB/c mouse. Methods GM-CSF gene was ampli/ied by nested-RT-PCR from BALB/c spleen cells. JEV prME protein gene was eluted by the digestion with restrict/on endonucleases BamH I/EcoR I from pJME piasmid. Genetic fusion of prME protein and GM-CSF are subcloned info pcDNA3.1 （＋） eukaryotic vector, and named as pJME/GM-CSF.The recombinant was confirmed by restriction enzymes digestion and DNA sequencing, and then transfected into China hamster ovary （CHO） cells by Lipofectamine2000. pJME/ GM-CSF expression in CHO cells was examined by Western blot. Results We observed 2001 bp and 2472 bp DNA fragments when pJME/GM-CSF was digested with BamHI/EcoRI and BamHI/NotI respectively as expected. The estimated molecular weight of the fusion protein was 85kD. Conclusion The recombinant pJME/GM-CSF was constructed and transfected into CHO cells successfully with pJME/GMCSF stably expressed.

Adjuvant effect of granulocyte-macrophage colony-stimulating factor coding gene on cellular immunity of Japanese encephalitis virus DNA vaccine / 中华传染病杂志

Objective To study the adjuvant effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) coding gene on cellular immunity induced by Japanese encephalitis (JE) virus DNA vaccine. Methods GM-CSF coding gene was amplified by nested-reverse transcriptase-polymerase chain reaction (RT-PCR) technique from BALB/c murine spleen cells. Recombinant plasmids pJME/GM-CSF and pGM-CSF were constructed by JE virus (JEV) prM-E protein with GM-CSF coding gene or GM-CSF coding gene only, respectively. The plasmids were transfected into China hamster ovary (CHO) cells by Lipofectamine 2000. The coding protein expressions and distributions were detected by immunofluorescence. The BALB/c mice were vaccinated with indicated immunogens with or without GM-CSF gene. The changes of T lymphocyte subsets in the spleen and levels of intracellular cytokines, such as interferon (IFN)-γ and interleukin (IL)-4 of splenic cells from mice immunized with different immunogens were evaluated by flow cytometry. The cytotoxicity T lymphocyte (CTL) activity was assessed by lactate dehydrogenase (LDH). The data were compared by one-factor analysis of variance and least significant difference. Results The constructed recombinant pGM-CSF and pJME/GM-CSF were confirmed by restrict enzyme digestion and DNA sequencing. The expressions of the above proteins were mainly in the cytoplasm and minor on cell membrane. The percentage of CD4+ T lymphocytes in pJME/GM-CSF vaccinated group was (33.90±0.79)%, which was significantly higher than that of in other groups (t values were 9. 818, 6. 804, 6.594, 10.061, 9.380, and 17.675, all P<0.05). The percentages of CD4+T lymphocytes in pJME +pGM-CSF (0) and pJME+pGM-CSF (-3) vaccinated groups were (29.83±0.61)% and (29.70±0.51)%, respectively, which were both higher than that in pJME+pGM-CSF (+3) vaccinated group of (27.69+0.50)% (t=3.466, t=3.255, both P<0.05). The percentages of CD8+ T cells in pJME/GM-CSF and pJME+pGM-CSF vaccinated groups were both higher than that in empty vector (pcDNA 3.1+) group and JE inactivated vaccine vaccinated group (t values were 3.811, 2.627, 10.537, and 3.811, all P<0.05). The CTL activity in pJME/GM-CSF vaccinated group was (51.48±0.10)%, which was higher than those in other groups (t values were 22.868, 13.823, 5.377, 32.287, 34.632, and 53.795, all P<0.05). The IFN-γ/IL-4 ratios in pJME/GM-CSF, pJME+pGM-CSF (0) and pJME + pGM-CSF (-3) vaccinated groups were (19.13±1.36), (12.32±0.82) and (7.05±0.43), respectively, which were higher than those in other groups (P<0.05). Conclusion GM-CSF coding gene could enhance the cellular immune response induced by Japanese encephalitis DNA vaccine.

DNA immunity by recombinant encoding prME protein derived from Japanese encephalitis virus and immunogiobulin G Fc of BALB/c mice / 中华微生物学和免疫学杂志

Objective To study the effect of lgG Fc gene on JEV DNA vaccine immunity. Methods Gene encoding IgG Fc was amplified by nested-RT-PCR technique from BALB/c murine spleen cells. JEV prME protein gene was obtained with restriction endonuclease BamH Ⅰ/EcoR Ⅰ from the eukaryotic recombinant named after pJME, which was constructed by us before. Recombinant, named after pJME/IgG Fc, with above two genes encoding JEV prME protein and BALB/c murine IgG Fc was constructed, and was tested by restriction enzymes analysis and DNA sequencing, then was transfected into China hamster ovary (CHO) cells by Lipo-fectAMINE 2000. Distribution and expression of the fusion proteins encoded by JEV prME protein and BALB/c murine IgG Fc genes in transfected CHO cells were detected by immunofluorescence and Western blot. The BALB/c micc were vaccinated with pJME/IgG Fc via intramuscular injection. Then the cytotoxic T lymphocyt (CTL) activity were assessed by lactic dehydrogenase (LDH) and the neutralizing antibody titer were assessed by 80% plaque reduction neutralization test. Results Molecular weights (2001 bp, 2730 bp) of the two in- serts released from pJME/IgG Fc with two group of restriction analysis associated with BamH 1/EcoR I and BamH Ⅰ/Not Ⅰ were correlated to the expected theoretic results respectively. It was estimated that molecular weight (Mr) of the fusion protein was 101 x 103. The expression of the above fusion protein was mainly distribu- ted in endochylema of transfected CHO cells,and not much in membrane of transfected CHO cells. CHO cells transfected with pJME/IgG Fc could express the fusion protein at the 32th cell passage. After immunization, the CTL activity and the neutralizing antibody titer in the pJMF/IgG Fc vaccinated group increased significantly compared with other vaccinated groups(P <0.05). Conclusion The recombinant pJME/IgG Fc was construc- ted and transfected into CHO cells successfully, and CHO cellular lines expressed fusion protein encoded by JEV prME protein and BALB/c murine lgG Fc genes stably were obtained. IgG Fc gene could reinforce the cellular immunity and humoral immunity of JEV DNA vaccine.