scholarly journals Resistance to ChronicToxoplasma gondiiInfection Induced by a DNA Vaccine Expressing GRA16

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Ling-Ying Hu ◽  
Nian-Zhang Zhang ◽  
Fu-Kai Zhang ◽  
Meng Wang ◽  
Qi Gao ◽  
...  
Keyword(s):  
Dna Vaccine ◽  
Cellular Response ◽  
Protective Efficacy ◽  
Dense Granule ◽  
Human Beings ◽  
Igg Antibody ◽  
Lethal Challenge ◽  
Specific Igg ◽  
Brain Cysts ◽  
Further Development

Toxoplasma gondiican infect all warm-blooded animals including human beings.T. gondiidense granule protein 16 (TgGRA16) as a crucial virulence factor could modulate the host gene expression. Here, a DNA vaccine expressing TgGRA16 was constructed to explore the protective efficacy againstT. gondiiinfection in Kunming mice. The immune responses induced by pVAX-GRA16 were also evaluated. Mice immunized with pVAX-GRA16 could elicit higher levels of specific IgG antibody and strong cellular response compared to those in controls. The DNA vaccination significantly increased the levels of cytokines (IFN-γ, IL-2, IL-4, and IL-10) and the percentages of CD4+ and CD8+ T cells in mice. After lethal challenge, mice immunized with pVAX-GRA16 (8.4±0.78days) did not show a significant longer survival time than that in controls (7.1±0.30days) (p>0.05). However, in chronic toxoplasmosis model (administration of 10 brain cysts of PRU strain orally), numbers of tissue cysts in mice immunized with pVAX-GRA16 were significantly reduced compared to those in controls (p<0.05) and the rate of reduction could reach 43.89%. The results indicated that the TgGRA16 would be a promising vaccine candidate for further development of effective epitope-based vaccines against chronicT. gondiiinfection in mice.

scholarly journals RHΔgra17Δnpt1 Strain of Toxoplasma gondii Elicits Protective Immunity Against Acute, Chronic and Congenital Toxoplasmosis in Mice

2020 ◽  
Vol 8 (3) ◽  
pp. 352 ◽  
Author(s):  
Qin-Li Liang ◽  
Li-Xiu Sun ◽  
Hany M. Elsheikha ◽  
Xue-Zhen Cao ◽  
Lan-Bi Nie ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Cellular Response ◽  
Protective Efficacy ◽  
Interleukin 2 ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Dense Granule ◽  
Lethal Challenge ◽  
Double Deletion ◽  
Brain Cysts

In the present study, a dense granule protein 17 (gra17) and novel putative transporter (npt1) double deletion mutant of Toxoplasma gondii RH strain was engineered. The protective efficacy of vaccination using RHΔgra17Δnpt1 tachyzoites against acute, chronic, and congenital toxoplasmosis was studied in a mouse model. Immunization using RHΔgra17Δnpt1 induced a strong humoral and cellular response, as indicated by the increased levels of anti-T. gondii specific IgG, interleukin 2 (IL-2), IL-10, IL-12, and interferon-gamma (IFN-γ). Vaccinated mice were protected against a lethal challenge dose (103 tachyzoites) of wild-type homologous (RH) strain and heterologous (PYS and TgC7) strains, as well as against 100 tissue cysts or oocysts of Pru strain. Vaccination also conferred protection against chronic infection with 10 tissue cysts or oocysts of Pru strain, where the numbers of brain cysts in the vaccinated mice were significantly reduced compared to those detected in the control (unvaccinated + infected) mice. In addition, vaccination protected against congenital infection with 10 T. gondii Pru oocysts (administered orally on day 5 of gestation) as shown by the increased litter size, survival rate and the bodyweight of pups born to vaccinated dams compared to those born to unvaccinated + infected dams. The brain cyst burden of vaccinated dams was significantly lower than that of unvaccinated dams infected with oocysts. Our data show that T. gondii RHΔgra17Δnpt1 mutant strain can protect mice against acute, chronic, and congenital toxoplasmosis by balancing inflammatory response with immunogenicity.

Enhanced immunogenicity of a synthetic DNA vaccine expressing consensus SARS-CoV-2 Spike protein using needle-free immunization

2021 ◽  
Author(s):  
Sawsan S Alamri ◽  
Khalid A Alluhaybi ◽  
Rowa Y Alhabbab ◽  
Abdullah Algaissi ◽  
Sarah Almahboub ◽  
...  
Keyword(s):  
Immune Response ◽  
Dna Vaccine ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Igg Antibodies ◽  
Free System ◽  
Mammalian Expression ◽  
Specific Igg ◽  
Needle Injection ◽  
Specific Igg Antibodies

AbstractThe ongoing global pandemic of Coronavirus Disease 2019 (COVID-19) calls for an urgent development of effective and safe prophylactic and therapeutic measures. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) glycoprotein is a major immunogenic and protective protein, and plays a crucial role in viral pathogenesis. In this study, we successfully constructed a synthetic codon-optimized DNA-based vaccine as a countermeasure against SARS-CoV-2; denoted as VIU-1005. The design was based on the synthesis of codon-optimized coding sequence for optimal mammalian expression of a consensus full-length S glycoprotein. The successful construction of the vaccine was confirmed by restriction digestion and sequencing, and the protein expression of the S protein was confirmed by western blot and immunofluorescence staining in mammalian cells. The immunogenicity of the vaccine was tested in two mouse models (BALB/c and C57BL/6J). Th1-skewed systemic S-specific IgG antibodies and neutralizing antibodies (nAbs) were significantly induced in both models four weeks post three injections with 100 μg of the VIU-1005 vaccine via intramuscular needle injection but not intradermal or subcutaneous routes. Importantly, such immunization induced long-lasting IgG response in mice that lasted for at least 6 months. Interestingly, using a needle-free system, we showed an enhanced immunogenicity of VIU-1005 in which lower doses such as 25-50 μg or less number of doses were able to elicit significantly high levels of Th1-biased systemic S-specific IgG antibodies and nAbs via intramuscular immunization compared to needle immunization. Compared to the intradermal needle injection which failed to induce any significant immune response, intradermal needle-free immunization elicited robust Th1-biased humoral response similar to that observed with intramuscular immunization. Furthermore, immunization with VIU-1005 induced potent S-specific cellular response as demonstrated by the significantly high levels of IFN-γ, TNF and IL-2 cytokines production in memory CD8+ and CD4+ T cells in BALB/c mice. Together, our results demonstrate that the synthetic VIU-1005 candidate DNA vaccine is highly immunogenic and capable of inducing long-lasting and Th1-skewed immune response in mice. Furthermore, we show that the use of needle-free system could enhance the immunogenicity and minimize doses needed to induce protective immunity in mice, supporting further preclinical and clinical testing of this candidate vaccine.

scholarly journals Protective Immunity Induced byToxoplasma gondiiRhoptry Protein 16 against Toxoplasmosis in Mice

2010 ◽  
Vol 18 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Zi-Guo Yuan ◽  
Xiu-Xiang Zhang ◽  
Xian-Hui He ◽  
Eskild Petersen ◽  
Dong-Hui Zhou ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cellular Response ◽  
Interleukin 2 ◽  
Cell Interaction ◽  
Eukaryotic Expression ◽  
Human Beings ◽  
Survival Times ◽  
Lymphoproliferative Response ◽  
Lethal Challenge ◽  
High Level

ABSTRACTToxoplasma gondiican infect a large variety of domestic and wild animals and human beings, sometimes causing severe pathology. Rhoptries are involved inT. gondiiinvasion and host cell interaction and have been implicated as important virulence factors. In this study, we constructed a DNA vaccine expressing rhoptry protein 16 (ROP16) ofT. gondiiand evaluated the immune responses it induced in Kunming mice. The gene sequence encoding ROP16 was inserted into the eukaryotic expression vector pVAX I. We immunized Kunming mice intramuscularly. After immunization, we evaluated the immune response using a lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged lethally. The results showed that mice immunized with pVAX-ROP16 developed a high level of specific antibody responses againstT. gondiiROP16 expressed inEscherichia coli, a strong lymphoproliferative response, and significant levels of gamma interferon (IFN-γ), interleukin-2 (IL-2), IL-4, and IL-10 production compared with results for other mice immunized with either empty plasmid or phosphate-buffered saline, respectively. The results showed that pVAX-ROP16 induces significant humoral and cellular Th1 immune responses. After lethal challenge, the mice immunized with pVAX-ROP16 showed a significantly (P< 0.05) prolonged survival time (21.6 ± 9.9 days) compared with control mice, which died within 7 days of challenge. Our data demonstrate, for the first time, that ROP16 triggers a strong humoral and cellular response againstT. gondiiand that ROP16 is a promising vaccine candidate against toxoplasmosis, worth further development.

scholarly journals DNA Vaccine of SARS-Cov S Gene Induces Antibody Response in Mice

2004 ◽  
Vol 36 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Ping Zhao ◽  
Jin-Shan Ke ◽  
Zhao-Lin Qin ◽  
Hao Ren ◽  
Lan-Juan Zhao ◽  
...  
Keyword(s):  
Antibody Response ◽  
Dna Vaccine ◽  
Protein A ◽  
Mouse Serum ◽  
Igg Antibody ◽  
S Protein ◽  
E Coli ◽  
S Gene ◽  
Specific Igg ◽  
Convalescence Phase

Abstract The spike (S) protein, a main surface antigen of SARS-coronavirus (SARS-CoV), is one of the most important antigen candidates for vaccine design. In the present study, three fragments of the truncated S protein were expressed in E. coli, and analyzed with pooled sera of convalescence phase of SARS patients. The full length S gene DNA vaccine was constructed and used to immunize BALB/c mice. The mouse serum IgG antibody against SARS-CoV was measured by ELISA with E. coli expressed truncated S protein or SARS-CoV lysate as diagnostic antigen. The results showed that all the three fragments of S protein expressed by E. coli was able to react with sera of SARS patients and the S gene DNA candidate vaccine could induce the production of specific IgG antibody against SARS-CoV efficiently in mice with seroconversion ratio of 75% after 3 times of immunization. These findings lay some foundations for further understanding the immunology of SARS-CoV and developing SARS vaccines.

scholarly journals Complete protection for mice conferred by a DNA vaccine based on Japanese encephalitis virus P3 strain that is used to prepare the inactivated vaccine in China

2020 ◽  
Author(s):  
Ran Wang ◽  
Xiaozheng Yu ◽  
Yan Wang ◽  
Xiaoyan Zheng
Keyword(s):  
Japanese Encephalitis Virus ◽  
Dna Vaccine ◽  
Japanese Encephalitis ◽  
Protective Efficacy ◽  
Neutralizing Antibody ◽  
Encephalitis Virus ◽  
Inactivated Vaccine ◽  
Complete Protection ◽  
Igg Antibody ◽  
Humoral Immune

Abstract Background The incidence of Japanese encephalitis (JE) has been dramatically reduced in China after the coverage of the vaccine. It is believed that the live-attenuated Japanese encephalitis virus (JEV) vaccine SA14-14-2 has contributed a lot. Another vaccine that seems to have faded out of the public is an inactivated vaccine based on the JEV P3 strain, which is still considered to have certain modifiability, such as being transformed into a DNA vaccine to improve its immunogenicity. Methods In this study, the protective efficacy induced by a Japanese encephalitis DNA vaccine candidate pV-JP3ME encoding pre-membrane (prM) and envelope (E) proteins of P3 strain in BALB/c mice. The prM/E genes of the JEV P3 strain were subcloned into vector pVAX1 (pV) to construct pV-JP3ME. Results The plasmid DNA was immunized BALB/c mice, high titers of IgG antibody and neutralizing antibody (nAb) against JEV were detected. The key cytokines in splenocytes upon stimulation with JEV antigens were secreted. Finally, complete protective efficacy was generated after challenge with the JEV P3 strain in mice. Conclusions The DNA vaccine pV-JP3ME based on JEV P3 strain in this study can induce specific humoral immune and cytokine responses in mice, and provide complete protection for mice against JEV.

scholarly journals Immune effects against influenza A virus and a novel DNA vaccine with co-expression of haemagglutinin- and neuraminidase-encoding genes

2009 ◽  
Vol 58 (7) ◽  
pp. 845-854 ◽  
Author(s):  
Weidong Zhang ◽  
Wanyi Li ◽  
Yan Li ◽  
Hong Li ◽  
Baoning Wang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Dna Vaccine ◽  
Influenza A ◽  
Protective Efficacy ◽  
Survival Rates ◽  
Serum Antibody ◽  
Lethal Challenge ◽  
Vector Systems

The high variability of influenza virus causes difficulties in the control and prevention of influenza, thus seeking a promising approach for dealing with these problems is a hot topic. Haemagglutinin (HA) and neuraminidase (NA) are major surface antigens of the influenza virus, and provide effective protection against lethal challenges with this virus. We constructed a DNA vaccine (pHA-IRES2-NA) that co-expressed both HA and NA, and compared its protective efficacy and immunogenic ability with that of singly expressed HA or NA, or a mixture of the two singly expressed proteins. Our findings showed that both HA and NA proteins expressed by pHA-IRES2-NA could be detected in vivo and in vitro. The protection of DNA vaccines was evaluated by serum antibody titres, residual lung virus titres and survival rates of the mice. In the murine model, immunization of pHA-IRES2-NA generated significant anti-HA and anti-NA antibody, increased the percentage of CD8+ cells and gamma interferon-producing CD8+ cells and the ratio of Th1/Th2 (T helper) cells, which was comparable to the effects of immunization with HA or NA DNA alone or with a mixture of HA and NA DNA. All the mice inoculated by pHA-IRES2-NA resisted the lethal challenge by homologous influenza virus and survived with low lung virus titre. In addition, previous studies reported that co-expression allowed higher-frequency transduction compared to co-transduction of separated vector systems encoding different genes. The novel HA and NA co-expression DNA vaccine is a successful alternative to using a mixture of purified HA and NA proteins or HA and NA DNA.

Immunogenicity and protective efficacy of ApxIA and ApxIIA DNA vaccine against Actinobacillus pleuropneumoniae lethal challenge in murine model

Vaccine ◽  
2009 ◽  
Vol 27 (34) ◽  
pp. 4565-4570 ◽  
Author(s):  
Chung-Hao Chiang ◽  
Wei-Fang Huang ◽  
Li-Pu Huang ◽  
Shuen-Fuh Lin ◽  
Wen-Jen Yang
Keyword(s):  
Dna Vaccine ◽  
Murine Model ◽  
Protective Efficacy ◽  
Actinobacillus Pleuropneumoniae ◽  
Lethal Challenge

scholarly journals Protective Efficacy of a Toxoplasma gondii Rhoptry Protein 13 Plasmid DNA Vaccine in Mice

2012 ◽  
Vol 19 (12) ◽  
pp. 1916-1920 ◽  
Author(s):  
Pei-Yuan Wang ◽  
Zi-Guo Yuan ◽  
Eskild Petersen ◽  
Jie Li ◽  
Xiu-Xiang Zhang ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Vaccine ◽  
Cellular Response ◽  
Protective Efficacy ◽  
Eukaryotic Expression ◽  
Economic Losses ◽  
Type I ◽  
Content Type ◽  
Strain Type ◽  
Rhoptry Protein

ABSTRACTToxoplasma gondiiis an obligate intracellular parasite infecting humans and other warm-blooded animals, resulting in serious public health problems and economic losses worldwide. Rhoptries are involved inT. gondiiinvasion and host cell interaction and have been implicated as important virulence factors. In the present study, a DNA vaccine expressing rhoptry protein 13 (ROP13) ofT. gondiiinserted into eukaryotic expression vector pVAX I was constructed, and the immune protection it induced in Kunming mice was evaluated. Kunming mice were immunized intramuscularly with pVAX-ROP13 and/or with interleukin-18 (IL-18). Then, we evaluated the immune response using a lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged with the virulentT. gondiiRH strain (type I) and the cyst-forming PRU strain (type II). The results showed that pVAX-ROP13 alone or with pVAX/IL-18 induced a high level of specific anti-T. gondiiantibodies and specific lymphocyte proliferative responses. Coinjection of pVAX/IL-18 significantly increased the production of gamma interferon (IFN-γ), IL-2, IL-4, and IL-10. Further, challenge experiments showed that coimmunization of pVAX-ROP13 with pVAX/IL-18 significantly (P< 0.05) increased survival time (32.3 ± 2.7 days) compared with pVAX-ROP13 alone (24.9 ± 2.3 days). Immunized mice challenged withT. gondiicysts (strain PRU) had a significant reduction in the number of brain cysts, suggesting that ROP13 could trigger a strong humoral and cellular response againstT. gondiicyst infection and that it is a potential vaccine candidate against toxoplasmosis, which provided the foundation for further development of effective vaccines againstT. gondii.

The Inducing Roles of the New Isolated Bursal Hexapeptide and Pentapeptide on the Immune Response of AIV Vaccine in Mice

2019 ◽  
Vol 26 (7) ◽  
pp. 542-549 ◽  
Author(s):  
Shan Shan Hao ◽  
Man Man Zong ◽  
Ze Zhang ◽  
Jia Xi Cai ◽  
Yang Zheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Amino Acid ◽  
T Cell ◽  
Antigen Presentation ◽  
Amino Acid Sequences ◽  
Cell Subpopulation ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Specific Igg

Background: Bursa of Fabricius is the acknowledged central humoral immune organ. The bursal-derived peptides play the important roles on the immature B cell development and antibody production. Objective: Here we explored the functions of the new isolated bursal hexapeptide and pentapeptide on the humoral, cellular immune response and antigen presentation to Avian Influenza Virus (AIV) vaccine in mice immunization. Methods: The bursa extract samples were purified following RP HPLC method, and were analyzed with MS/MS to identify the amino acid sequences. Mice were twice subcutaneously injected with AIV inactivated vaccine plus with two new isolated bursal peptides at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from the immunized mice to measure AIV-specific IgG antibody levels and HI antibody titers. Also, on 7th day after the second immunization, lymphocytes were isolated from the immunized mice to detect T cell subtype and lymphocyte viabilities, and the expressions of co-stimulatory molecule on dendritic cells in the immunized mice. Results: Two new bursal hexapeptide and pentapeptide with amino acid sequences KGNRVY and MPPTH were isolated, respectively. Our investigation proved the strong regulatory roles of bursal hexapeptide on AIV-specific IgG levels and HI antibody titers, and lymphocyte viabilities, and the significant increased T cells subpopulation and expressions of MHCII molecule on dendritic cells in the immunized mice. Moreover, our findings verified the significantly enhanced AIV-specific IgG antibody and HI titers, and the strong increased T cell subpopulation and expressions of CD40 molecule on dendritic cells in the mice immunized with AIV vaccine and bursal pentapeptide. Conclusion: We isolated and identified two new hexapeptide and pentapeptide from bursa, and proved that these two bursal peptides effectively induced the AIV-specific antibody, T cell and antigen presentation immune responses, which provided an experimental basis for the further clinical application of the bursal derived active peptide on the vaccine improvement.

scholarly journals Protective efficacy of a SARS-CoV-2 DNA vaccine in wild-type and immunosuppressed Syrian hamsters

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Rebecca L. Brocato ◽  
Steven A. Kwilas ◽  
Robert K. Kim ◽  
Xiankun Zeng ◽  
Lucia M. Principe ◽  
...  
Keyword(s):  
Dna Vaccine ◽  
Neutralizing Antibodies ◽  
Protective Efficacy ◽  
Phase 1 ◽  
Severe Disease ◽  
Disease Model ◽  
Wild Type ◽  
Jet Injection ◽  
Syrian Hamsters ◽  
Dna Targeting

AbstractA worldwide effort to counter the COVID-19 pandemic has resulted in hundreds of candidate vaccines moving through various stages of research and development, including several vaccines in phase 1, 2 and 3 clinical trials. A relatively small number of these vaccines have been evaluated in SARS-CoV-2 disease models, and fewer in a severe disease model. Here, a SARS-CoV-2 DNA targeting the spike protein and delivered by jet injection, nCoV-S(JET), elicited neutralizing antibodies in hamsters and was protective in both wild-type and transiently immunosuppressed hamster models. This study highlights the DNA vaccine, nCoV-S(JET), we developed has a great potential to move to next stage of preclinical studies, and it also demonstrates that the transiently-immunosuppressed Syrian hamsters, which recapitulate severe and prolonged COVID-19 disease, can be used for preclinical evaluation of the protective efficacy of spike-based COVID-19 vaccines.

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