Protective effects of bicistronic DNA vaccines of herpes simplex virus type 2 glycoprotein D and adjuvant CCL28 on mice / 中华微生物学和免疫学杂志

Objective:To study the protective effects of bicistronic DNA vaccines carrying herpes simplex virus type 2 glycoprotein D (HSV-2 gD) and adjuvant CCL28 sequences that were connected by internal ribosome entry site (IRES) sequence in mouse model.Methods:The recombinant DNA vaccines, pgD-IRES-CCL28 and pCCL28-IRES-gD, encoding HSV-2 gD and adjuvant CCL28 were constructed with IRES sequence. After verified by sequencing, they were intramuscularly injected twice into BALB/c mice. Serum samples and vaginal lavage fluids were collected regularly. Splenocytes, mesenteric lymph node cells and rectal mucosa tissues were separated and collected. The titers of antigen-specific antibodies in immunized mice were analyzed with end-point ELISA. In vitro neutralization assay was used to measure neutralizing antibody titers in serum and vaginal lavage fluid after vaccination and virus challenge. CCL28-responsive immune cells in splenocytes, mesenteric lymph node cells and rectal tissues were detected by chemotaxis experiment and immunohistochemical staining. The protective effects of the bicistronic DNA vaccines were evaluated by fluorescent quantitative PCR, weighing and disease severity assessment. Humoral and cellular immune responses induced by the bicistronic DNA vaccines and their efficacy in immunoprotection were analyzed by comparing with pgD+ pCCL28 group. Results:IgG titers in serum samples and IgA antibody titers in vaginal lavage fluids of mice immunized with pCCL28-IRES-gD were similar to those in pgD+ pCCL28 group. The neutralizing ability of antibodies, the number of rectal mucosal IgA+ plasma cells and CCL28-responsive immune cells in mucosal tissues were increased in pCCL28-IRES-gD group. Serum neutralizing antibodies were not produced immediately in the mice challenged with HSV-2, but no weight loss, disease symptoms or death was observed. However, pgD+ pcDNA3.1 and pgD-IRES-CCL28 were ineffective against HSV-2 infection in mice.Conclusions:The recombinant bicistronic DNA vaccine of pCCL28-IRES-gD could induce stronger mucosal immune response in mice and provide better protective effects.

Protective effects of fusion recombinant DNA vaccine of herpes simplex virus type 2 glycoprotein D and adjuvant CCL19 on mice / 中华微生物学和免疫学杂志

Objective:To compare the immune responses to simply mixed and fused recombinant DNA vaccines of herpes simplex virus type 2 glycoprotein D (HSV-2 gD) and molecular adjuvant CCL19 in mice and to evaluate the protective effects.Methods:Gene recombination technology was used to construct recombinant DNA vaccines expressing HSV-2 gD and CCL19 alone or fused together. After verification by sequencing, Western blot and ELISA, BALB/c mice were immunized twice by intramuscular injection. Serum samples and vaginal lavage fluids were collected regularly after immunization. Splenocytes, mesenteric lymph node cells and rectal tissues were collected after immunization. Differences in humoral and cellular immune responses to the two forms of vaccines and their protective effects in mice were analyzed using end-point ELISA, in vitro neutralization assay, immunohistochemical staining, chemotaxis assay, vaginal virus challenge, fluorescence quantitative PCR, weighing and disease severity assessment. Results:The fused recombinant pgD-IZ-CCL19 plasmid could express gD protein and CCL19 protein in vitro, but the level of expressed CCL19 protein by pCCL19-IZ-gD plasmid was less than that by pgD-IZ-CCL19. The mice immunized with pgD-IZ-CCL19 showed higher levels of IgG in sera and IgA in vaginal lavage fluids ( P<0.01) and stronger neutralization ability than the mice vaccinated with pgD+ pCCL19. Compared with other groups, more lymphocytes were recruited in the rectal mucosa, the spleen and mesenteric lymph nodes of mice immunized with pgD-IZ-CCL19. Weight loss or disease symptoms were not observed in the pgD-IZ-CCL19 group after virus challenge. In addition, the positive rate of HSV-2 in vaginal mucosa and the mortality rate in the pgD-IZ-CCL19 group were the lowest. However, pCCL19-IZ-gD turned out ineffective in preventing HSV-2 infection. Conclusions:The fused recombinant DNA vaccine pgD-IZ-CCL19 could induce stronger immune responses in mice and provide better protective effects, which was superior to the simply mixed DNA vaccine.

Respuesta inmunoprotectora inducida por la glicoproteina D recombinante en el modelo de infección respiratoria de ratones BALB/c por alfaherpesvirus equino 1 / Immunoprotective response induced by recombinant glycoprotein D in the BALB/c respiratory mouse model " of Equid alphaherpesvirus 1 infection

Equid alphaherpesvirus 1 (EHV-1) infection causes abortion, respiratory disease, perinatal deaths and neurological disorders in horses. The natural infection and available vaccines provide only partial and short-lived protection against reinfections. In the present study, we analyzed the ability of purified baculovirus-expressed glycoprotein D (gD) administered by different routes to induce protective immunity in BALB/c mice after challenge with the EHV-1 AR8 strain. Clinical signs varied among the different groups of mice immunized by parenteral routes, and, although gD induced a specific serum IgG response, it did not prevent the virus from reaching the lungs. Intranasally immunized mice showed no clinical signs, and virus isolation from lungs, histological lesions and antigen detection by immunohistochemistry were negative. In addition, by this route, gD did not stimulate the production of serum IgG and IgA. However, a specific IgA response in the respiratory tract was confirmed in intranasally immunized mice. Thus, we conclude that the mucosal immune response could reduce the initial viral attachment and prevent the virus from reaching the lungs. Our findings provide additional data to further study new immunization strategies in the natural host.

La infección con alfaherpesvirus equino 1 (EHV-1) causa abortos, enfermedad respiratoria, muertes perinatales y desórdenes neurológicos en equinos. La infección natural y las vacunas disponibles solo proporcionan protección parcial y de corta duración contra las reinfecciones. En el presente estudio se analizó la inducción de inmunidad protectiva de la glicoproteina D (gD) expresada en baculovirus y purificada al ser administrada por diferentes rutas en ratones BALB/c desafiados con la cepa AR8 de EHV-1. Los signos clínicos fueron variables entre los grupos de ratones inmunizados por rutas parenterales y, aunque la gD indujo respuesta especifica de IgG en suero, no logró prevenir la llegada del virus al pulmón. En los ratones inmunizados intranasalmente no se observaron signos clinicos ni lesiones histopatológi-cas, y el aislamiento viral y la detección de antigenos por inmunohistoquímica en pulmón fueron negativos. Además, por esta ruta la gD no estimuló la producción de IgG y de IgA en suero. Sin embargo se confirmó la respuesta de IgA especifica en el tracto respiratorio de ratones inmunizados intranasalmente. Esta respuesta inmune mucosal podría haber reducido la unión inicial del virus a la célula huésped y, de este modo, prevenir la llegada del virus al pulmón. Nuestros hallazgos proporcionan un aporte para continuar estudiando nuevas estrategias de inmunización en el huésped natural.

Expression and immunization assessment of HSV-2 glycoprotein D in baculovirus expression vector system / 吉林大学学报(医学版)

Objective:To express the glycoprotein D of herpes simplex virus type 2 (gD2) in the insect cells,and to determine its immunogenicity.Methods:HSV-2 genome was used as the template for amplification of gD2 extracellular domain fragment gene by PCR.The PCR product was inserted into the vector Bacmind,and the constructed recombinant plasmid gD2-Bacmind was transfected into the sf9 cells to package the recombinant baculovirus.The Sf9 cells were infected by recombinant baculovirus seed derived from the forth passage(P4),the titer of P4 recombinant baculovirus was detected by a plaque assay and the expression of recombinant protein gD2 was determined by Western blotting method.The supernatant of infected cells was collected and purified by Ni-NTA affinity chromatography to obtain the target protein gD2,the purified gD2 protein was used to immunize the BALB/c mice in 0, 2, 4 weeks (gD2 group),and PBS was used as negative control(PBS group);the titers of gD2 specific IgG in serum were detected by ELISA assay.Results: The PCR analysis and sequencing results proved that gD2-Bacmind was constructed correctly.The titer of recombinant baculovirus was 2.0×109 pfu·mL-1,the purified gD2 was about 37 000 with expectation,the percentage of gD2 in total protein was 90%.The average value of Log10 of titer of gD2 specific IgG in serum detected by ELISA assay in gD2 group at the sixth week was 4.34,and there was significant difference compared with PBS group(P<0.01).Conclusion: The gD2 expressed by insect-baculovirus expression vector system has the immunogenicity and can be selected as candidate protein for HSV-2 vaccine.

Molecular characterization of Brazilian equid herpesvirus type 1 strains based on neuropathogenicity markers

Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.

High Efficiency Expression of the Gene From Herpes Simplex Virus Type 1(HSV-1)Glycoprotein D / 中国生物工程杂志

Objective:To obtain the high expression of Herpes Simplex Virus Type 1(HSV-1)Glycoprotein D gene. Methods:The Herpes Simplex Virus Type 1(HSV-1)Glycoprotein D(gD1) gene fragment containing dominant antigen epitopes confirmed by computer analysis was cloned by PCR technical and inserted into plasmid vector pTrxA. Then the recombinant plasmid was transformed into Rosetta. The expressed product was analyze by SDS-PAGE. Results:930 bp gene fragment was amplified by PCR as anticipated. Nucleotide sequencing showed a 100 % homology with that of the published sequence in GenBank. The molecular weight of the expressed protein was about 48kDa, Western blotting indicated that the antigenicity of the protein was good. Conclusion:The plasmid pTrxA-gd1 was constructed and a high efficiency expression of the gd1 gene from Herpes Simplex Virus Type 1(HSV-1)strain was made. The expressed product shows a good antigenicity.

Construction of a DNA vaccine encoding herpes simplex virus type 1 glycoprotein D / 新乡医学院学报

Objective To construct a recombinant plasmid DNA containing herpes simplex virus type 1(HSV-1) glycoprotein D (gD) gene.Methods The HSV-1 gD gene was obtained by polymerase chain reaction (PCR) and inserted into TA cloning vector pGEM-T, then cloned into the eukaryotic expression vector pcDNA3.1 to generate pLy-D. The recombinant plasmid pLy-D, which was confirmed by partial sequencing and restriction endonuclease analysis, was transfected into Cos-7 cells and used to inoculate ICR mice via muscular injection. Immunohistochemistry and enzyme-linked immunoabsorbent assay (ELISA) were employed to test the gD expression in transfected cells and the specific anti-HSV-1 antibody in the serum of immunized mice, respectively.Results The gD eukaryotic expression plasmid pLy-D was constructed. Using the immunohistochemistry technique, the gD expression in pLy-D-transfected cells was detected. The ELISA demonstrated that specific anti-HSV-1 antibody could be induced in immunized mice after three times injection.Conclusions We constructed HSV-1 gD eukaryotic expression plasmid pLy-D which could express gD protein in transfected cells and could induce humoral immune response in mice. This observation will be helpful in designing HSV prophylactic vaccine.

Clinical Feature and Glycoprotein D Gene Sequence Analysis of a Wild Strain of HSV-2 Isolated from One Relapsed Patient with Genital Herpes / 中华皮肤科杂志

Objective To study the relation between the clinical feature and glycoprotein D gene sequence analysis of a wild strain of HSV 2 isolated from one relapsed patient with genital herpes. Methods The partial glycoprotein D gene sequence of the above mentioned strain was amplified and cloned with PCR. Results The comparison of the amino acid sequence of gD gene between the wild strain and HSV 2G strain published showed that there was a mutation at site80 and site159. Conclusion In order to develop effective vaccine which is suitable for China, it is necessary to investigate the differences of the gene structure and function of gD among HSV isolated from China and other countries.