Ahmad Mobed
Abstract
Tuberculosis (TB) is believed to be one of the leading causes of death in the world; nevertheless, Bacillus Calmette-Guérin (BCG) is the solitary vaccine utilized to prevent TB. Despite the protective effect of this vaccine in children, its efficiency remains under question in adults. We conducted ...
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Tuberculosis (TB) is believed to be one of the leading causes of death in the world; nevertheless, Bacillus Calmette-Guérin (BCG) is the solitary vaccine utilized to prevent TB. Despite the protective effect of this vaccine in children, its efficiency remains under question in adults. We conducted the present study to provide an overview of DNA based vaccines against TB and highlight the vaccine delivery advances and limitations. This study also aimed to bring a review of mycobacterial antigens, including heat shock protein 65 (Hsp65), antigen 85A (Ag85A), early secretory antigenic target 6 (EAST-6), antigen 85B (Ag85B), and heat shock protein X (HspX) as the most extensively considered antigens in the development of vaccines against M. tuberculosis.
Ziba Veisi Malekshahi; Nasser Hashemi Goradel; Mehdi Shakouri Khomartash; Amir Maleksabet; Maryam kadkhodazadeh; Gholam Ali Kardar; Babak Negahdari
Abstract
Background: Human colorectal cancer cells overexpress carcinoembryonic antigen (CEA). CEA is a glycoprotein which has shown to be a promising vaccine target for immunotherapy against colorectal cancer. Objective: To design a DNA vaccine harboring CEA antigen and evaluate its effect on inducing immunity ...
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Background: Human colorectal cancer cells overexpress carcinoembryonic antigen (CEA). CEA is a glycoprotein which has shown to be a promising vaccine target for immunotherapy against colorectal cancer. Objective: To design a DNA vaccine harboring CEA antigen and evaluate its effect on inducing immunity against colorectal cancer cells in tumor bearing mice. Methods: In the first step the coding sequence of the CEA was cloned into the pcDNA3.1 vector. The mice were injected with the vaccine construct and the immune responses were monitored during the experiment period. The specific IgG anti-CEA, IFN-γ, IL-2 and IL-4 were measured by ELISA and levels of IFN-γ was detected by ELISpot assay. The lymphocyte proliferation was assessed using a 5-bromo-2-deoxyuridine (BrdU) cell proliferation assay kit. Results: Immunization of the mice with the CEA plasmid resulted in stimulation of CEA-specific T cell and antibody responses. The serum level of specific IgG antibodies against CEA was increased in immunized mice. Moreover, the injection of CEA plasmid led to the stimulation of T-helper-1 by increase in the secretion of IFN-γ, IL-2 and lymphocyte proliferation response. Conclusion: As the CEA DNA vaccine displayed encouraging antitumor effects, therefore, we suggest that it can be a potential therapeutic modality for colorectal cancer and is worthy of further investigation.
Zahra Meshkat; Amir Teimourpour; Samira Rashidian; Mohsen Arzanlou; Roghayeh Teimourpour
Volume 13, Issue 4 , December 2016, , Pages 289-295
Abstract
Background: Tuberculosis is a life threatening disease that is partially prevented by
BCG vaccine. Development of more effective vaccines is an urgent priority in TB
control. Ag85a and Tb10.4 are the members of culture filter protein (CFP) of M.
tuberculosis that have high immunogenicity. Objective: ...
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Background: Tuberculosis is a life threatening disease that is partially prevented by
BCG vaccine. Development of more effective vaccines is an urgent priority in TB
control. Ag85a and Tb10.4 are the members of culture filter protein (CFP) of M.
tuberculosis that have high immunogenicity. Objective: To analyze the
immunogenicity of Ag85a-Tb10.4 DNA vaccine by enzyme-linked immunosorbent
assay (ELISA). Methods: In this study a previously described plasmid DNA vaccine
encoding Ag85a-Tb10.4 was used to examine its capability in the stimulation of
immune responses in an animal model. Female BALB/c mice were vaccinated with 100
μg of purified recombinant vector intramuscularly 3 times at two-week intervals and the
levels of five cytokines including IFN-γ, IL-12, IL-4, IL-10 and TGF-β were measured.
Results: The levels of IFN-γ and IL-12 for the mice following immunization with
Ag85A-Tb10.4 was significantly greater than that of the BCG and control group
(p<0.05). However there was no significant difference in the levels of IL-4, IL-10 and
TGF-β between groups. Conclusion: IFN-γ and IL-12 Th1 cytokines increased
significantly in mice vaccinated with Ag85a-TB10.4 DNA vaccine in comparison to the
control and BCG groups. Our results may serve as groundwork for further research into
the prevention and treatment of tuberculosis.
Azam Torabi; Mojtaba Tahmoorespur; Fatemeh Vahedi; Nader Mosavari; Mohammadreza Nassiri
Volume 10, Issue 4 , December 2013, , Pages 205-215
Abstract
Background: Tuberculosis is a disease with high morbidity, caused mainly by Mycobaterium tuberculosis (M.tb.). DNA vaccines show a promising future due to their unique advantages over conventional methods. The early-secreted antigen target (ESAT)-6 and culture filtrate protein (CFP)-10 of M.tb. antigens ...
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Background: Tuberculosis is a disease with high morbidity, caused mainly by Mycobaterium tuberculosis (M.tb.). DNA vaccines show a promising future due to their unique advantages over conventional methods. The early-secreted antigen target (ESAT)-6 and culture filtrate protein (CFP)-10 of M.tb. antigens have been identified as vaccine candidates against Mycobacteria and used as subunit vaccines, DNA or protein, in different studies. Objective: To investigate the potential of pcDNA3.1+ plasmid containing CFP-10 and ESAT-6 genes in induction of local immune responses after intramuscular injection in BALB/c mice. Methods: pcDNA 3.1+ CFP-10 and pcDNA3.1+ ESAT-6 plasmids were prepared and defined groups of mice were injected intramuscularly with the plasmids both separately and in combination. The RNA was extracted from muscles after one month and cDNA was made using RT-PCR. The expressions of IL-4, IL-10 and IFN-γ genes cytokines were evaluated using comparative real time PCR. Results: Expression of IL-4 and IL-10 increased in the injection site of the mice groups which received plasmids encoding ESAT-6 and CFP-10 individually or together. More than 10-fold increase in IFN-γ expression was found in samples taken from mice groups inoculated by plasmids encoding ESAT-6 and CFP-10 individually or together. Conclusion: pcDNA 3.1+ESAT-6 and pcDNA3.1+CFP-10 plasmids can increase the expression of IFN-γ in mice after immunization.
Rohollah Dorostkar; Taravat Bamdad; Masoud Parsania; Hassan Pouriayevali
Volume 9, Issue 4 , December 2012, , Pages 215-225
Abstract
Background: Improving vaccine potency in the induction of a strong cell-mediated cytotoxicity can enhance the efficacy of vaccines. Necrotic cells and the supernatant of necrotic tumor cells are attractive adjuvants, on account of their ability to recruit antigen-presenting cells to the site of antigen ...
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Background: Improving vaccine potency in the induction of a strong cell-mediated cytotoxicity can enhance the efficacy of vaccines. Necrotic cells and the supernatant of necrotic tumor cells are attractive adjuvants, on account of their ability to recruit antigen-presenting cells to the site of antigen synthesis as well as its ability to stimulate the maturation of dendritic cells. Objective: To evaluate the utility of supernatant of necrotic tumor cells as a DNA vaccine adjuvant in a murine model. Method: The supernatant of EL4 necrotic cells was co-administered with a DNA vaccine expressing the glycoprotein B of Herpes simplex virus-1 as an antigen model under the control of Cytomegalovirus promoter. C57BL/6 mice were vaccinated three times at two weeks intervals with glycoprotein B DNA vaccine and supernatant of necrotic EL4 cells. Five days after the last immunization, cell cytotoxicity, IFN-γ and IL-4 were evaluated. Results: The obtained data showed that the production of IFN-γ from the splenocytes after antigenic stimulation in the presence of the supernatant of necrotic EL4 cells was significantly higher than the other groups (p<0.002). The flow cytometry results showed a significant increase in the apoptosis/necrosis of EL4 cells in the mice immunized with DNA vaccine and supernatant of necrotic EL4 cells comparing to the other groups (p<0.001). Conclusion: The supernatant of necrotic cells contains adjuvant properties that can be considered as a candidate for tumor vaccination.
Fatemeh Roodbari; Farzaneh Sabahi; Mohamad Nabi Sarbolouki; Farzaneh Barkhordari; Ahmad Adeli; Amel Jamedar; Fereidoun Mahboudi
Volume 9, Issue 2 , June 2012, , Pages 86-97
Abstract
Background: Development of an effective vaccine is highly needed in order to restrict the AIDS pandemic. DNA vaccines initiate both arms of immunity without the potential of causing disease. HIV-1 p24 and gp41 (gag and env) proteins play important roles in viral pathogenesis and are effective candidates ...
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Background: Development of an effective vaccine is highly needed in order to restrict the AIDS pandemic. DNA vaccines initiate both arms of immunity without the potential of causing disease. HIV-1 p24 and gp41 (gag and env) proteins play important roles in viral pathogenesis and are effective candidates for immune induction and vaccine design. Objective: In this study, new DNA vaccine candidates constructed from HIV-1 fused p24- gp41 or gp41 alone were evaluated in Balb/c mice for induction of cellular and humoral immune responses. Methods: Recombinant plasmids, pcDNA3.1/Hygro expression vector containing immunogenic sequences of fused p24-gp41 or gp41alone were produced. Dendrosome used as a system for carrying vectors in laboratory animals, and an IL-12 containing vector (pCAGGS-IL-12) was co-immunized with the p24-gp41 vector as a genetic adjuvant. Induction of effective immune responses against the designed vectors as DNA vaccine candidates in Balb/c mice was evaluated. Levels of total antibodies, IgG isotypes (IgG2a and IgG1); IFN-γ and IL-4 were measured by ELISA. MTT assay was used to evaluate lymphoproliferation. Results: The results confirmed that the immunogenic epitopes of both p24 and gp41 genes are highly effective inducers of immune responses, and administration of fused p24-gp41 alone or along with IL-12 resulted in further enhancement of immune responses. Group 4 that received fused fragments (p24-gp41) along with an IL-12 expressing vector demonstrated a significantly higher Stimulation Index (SI) and IFN- production (p<0.0001) with a significant increase in IgG2a/IgG1 ratio, indicating the stimulation of CMI towards Th1. Although gp41 containing vector (group 6) also showed significant increases in both proliferation and IFN- production, the responses were persistently lower than that of p24-gp41 containing vectors. Total antibody production was highest in group 6 as expected. Conclusion: Dendrosome proved to be an efficient carrier of recombinant plasmids constructed in this study. Further studies are necessary to evaluate these constructs as HIV vaccine candidates.
Zahra Meshkat; Hoorieh Soleimanjahi; Hessam Mirshahabi; Mojtaba Meshkat; Maryam Kheiandish; Zuhair Mohammad Hassan
Volume 8, Issue 2 , June 2011, , Pages 65-75
Abstract
Background: Vaccines capable of controlling tumor virus based infections are found difficult to develop due to the consistence latent infection in the host. DNA vaccines are attractive tools for the development of HPV vaccines and inducing antigen-specific immunity owing to the stability, simplicity ...
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Background: Vaccines capable of controlling tumor virus based infections are found difficult to develop due to the consistence latent infection in the host. DNA vaccines are attractive tools for the development of HPV vaccines and inducing antigen-specific immunity owing to the stability, simplicity of delivery, safety and cost effectiveness. However, there is a need to increase their potency by procedures such as using HSP70 gene as an adjuvant. Objective: To evaluate a DNA vaccine containing HPV16 truncated E7 C-terminal cytotoxic T-lymphocyte epitopes linked to HSP70 gene (HSP70-tE7) in an animal model. Methods: Mice were immunized with the plasmid DNA after pre-treatment with cardiotoxin. The splenocytes of immunized mice were then tested for CTL activity by detecting the apoptosis and necrosis in target cells, cytokine production by ELISA, CD4 and CD8 frequencies by flow cytometry, and lymphocyte stimulation by MTT assay. Results: The recombinant expression vector was able to elicit immune responses close to that of full length E7 complete gene. Although the use of a small part of a target antigen can induce immune responses equivalent to the full length antigen, it fails to elicit statistically significant stronger immune responses when fused with HSP70 compared to the complete E7 gene alone. Conclusion: The potent immunogenicity of HPV16 E7 was preserved in the HSP70-tE7 vaccine and may represent a target of choice for the therapeutic vaccination strategies. However, to improve the immunogenicity polytope DNA vaccines which elicit multiple effector and memory CTL responses should be considered in future studies of DNAbased cancer vaccines.
Fatemeh Vahedi; Mahmoud Reza Jaafari; Mahmoud Mahmoudi
Volume 7, Issue 4 , December 2010, , Pages 210-216
Abstract
Background: DNA vaccines are third generation vaccines which have made promises to combat infectious diseases. Cationic liposomes are used as effective delivery systems for DNA vaccines to generate stronger immunity. Objective: Encapsulation of pcDNA3.1+PA plasmid, encoding protective antigen (PA) of ...
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Background: DNA vaccines are third generation vaccines which have made promises to combat infectious diseases. Cationic liposomes are used as effective delivery systems for DNA vaccines to generate stronger immunity. Objective: Encapsulation of pcDNA3.1+PA plasmid, encoding protective antigen (PA) of Bacillus anthracis (B. anthracis) into cationic liposomes, and evaluation of its effect on specific humoral specific immunity against PA were aimed. Methods: The liposomes containing pcDNA3.1+PA plasmids were prepared with phosphatidylcholine (PC), dioleoyl phosphatidylethanolamine (DOPE) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) using dehydration-rehydration method. BALB/c mice were immunized by intramuscular (IM) injection to investigate the immunogenicity of the formulations. The resulting specific antibodies against PA, total IgG, IgG1, IgG2a and IgG2b isotypes, were evaluated by enzyme linked immunosorbent assay (ELISA) method. Conclusion: A higher concentration of specific IgG against PA was found in sera of a group immunized with the encapsulated plasmid compared with the naked plasmid alone. This difference was significant for IgG1 isotype.
Zahra Meshkat; Hoorieh Soleimajjahi; Mahmoud Mahmoudi; Zuhair Mohammad Hassan; Hessam Mirshahabi; Mojtaba Meshkat; Maryam Kheirandish
Abstract
Background: Cervical cancer is the most prevalent tumor in developing countries and the second most frequent cancer among female population worldwide. Specific human papillomaviruses and, most notably, HPV types 16 and 18 are recognized as being caus-ally associated with cervical carcinomas. The early ...
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Background: Cervical cancer is the most prevalent tumor in developing countries and the second most frequent cancer among female population worldwide. Specific human papillomaviruses and, most notably, HPV types 16 and 18 are recognized as being caus-ally associated with cervical carcinomas. The early HPV type 16 genes, E6 and E7, di-rectly participate in the in vitro transformation of primary human keratinocytes and rep-resent an excellent target for immune therapy of HPV related disease. Objective: The aim of this study was the evaluation of the efficacy of a DNA vaccine containing human papillomaviruse type 16 E7 gene (Iranian isolate) in induction of CTL responses in an animal model. Methods: In this study, the expression vector containing HPV type 16 E7 gene was constructed and chosen as a model antigen in the development of a thera-peutic DNA vaccine in an animal model. CTL responses, cytokine assay, lymphocyte stimulation test, CD4 and CD8 staining and flowcytometry were done for evaluating of the immune responses. Results: Our findings indicate that the target DNA vaccine can induce an E7-specific CTL response, which is important in the lysis of infected tumor cells, compared to negative control (p<0.005) after in vivo immunization in the mouse system. Conclusion: The developed vaccine may be promising as an anti-cancer vac-cine.
Fatemeh Vahedi; Naser Taiebi Meibody; Mahdi KianiZadeh; Mahmoud Mahmoudi
Volume 2, Issue 3 , September 2005, , Pages 134-140
Abstract
Background: DNA immunization with plasmid DNA encoding bacterial, viral, parasitic and tumor antigens has been reported to trigger protective immunity. Objective: To evaluate the use of a DNA immunization strategy for protection against anthrax, a plasmid was constructed. Methods: The partialsequence ...
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Background: DNA immunization with plasmid DNA encoding bacterial, viral, parasitic and tumor antigens has been reported to trigger protective immunity. Objective: To evaluate the use of a DNA immunization strategy for protection against anthrax, a plasmid was constructed. Methods: The partialsequence of protective antigen of Bacillus anthracis, amino acids 175-764, as a potent immunogenic target was selected. The DNA encoding this segment was utilized in the construction of pcDNA3.1+PA plasmid. After intramuscular injection of rats with pcDNA3.1+PA plasmid, the expression of PA was assessed by RT-PCR and immunohistochemistry at RNA and protein levels, respectively. We also evaluated the presence of anti-PA antibodies in sera of immunized mice with pcDNA3.1+PA construct using immunoblotting. Results: The integrity of pcDNA3.1+PA construct was confirmed with restriction analysis and sequencing. The expression of PA was detected at RNA and protein levels. The presence of anti-PA antibodies in immunized mice with pcDNA3.1+PA construct was also confirmed. Conclusion: Our results indicate that pcDNA3.1+PA eukaryotic expressing vector could express PA antigen, induce antibody response and may be used as a candidate for DNA vaccine against anthrax.
