Comparison of IgA Antibody Titer Induced by Human-Bovine Rotavirus Candidate Vaccine with Bovine Rotavirus and Rotarix

Rotavirus (RV) is the most common cause of acute gastroenteritis in early childhood worldwide. Gastroenteritis is a preventable disease by the vaccine, and vigorous efforts were made to produce attenuated oral rotavirus vaccines. In recent years, despite the existence of three types of live attenuated rotavirus vaccines, several countries, such as China and Vietnam, have intended to produce indigenous vaccines based on rotavirus serotypes circulating among their population. In this study, the immunogenicity of homemade human-bovine reassortant RV candidate vaccine was tested in an animal model. Rabbits were randomly distributed into eight experimental groups with three animals per group. Afterward, three rabbits in each test group designated as P1, P2, and P3 were experimentally inoculated with the 106, 107, and 108 tissue culture infectious dose 50 (TCID50) of the reassortant virus, respectively. The N1 group received the reassortant rotavirus vaccine containing 107 TCID50+zinc. The N2, N3, and N4 groups received rotavirus vaccine strain, RV4 human rotavirus, and bovine rotavirus strain, respectively, and the control group received phosphate-buffered saline. It is noteworthy that three rabbits have been included in each group. The IgA total antibody titer was measured and evaluated by non-parametric Mann-Whitney and Kruskal-Wallis tests. The antibody titer produced in the studied groups did not significantly differ. The candidate vaccine showed immunogenicity, protectivity, stability, and safety. The findings of this study indicated a critical role of IgA production, which can induce immunity against a gastroenteritis viral pathogen. Regardless of purification, candidate reassortant vaccine and cell adapted animal strains could be used as a vaccine candidate for production.

Characterization and Comparison of Mesenchymal Stem Cell-Derived Exosome Isolation Methods using Culture Supernatant

Exosomes are extracellular endosomal nanoparticles, which are formed under complex processes during the formation of multivesicular bodies. They are also achieved from conditioned media of a variety of cell types, especially mesenchymal stem cells (MSCs). Exosomes can modulate intracellular physiological actions via signaling molecules on the surface or secretion of components to the extracellular spaces. Furthermore, they are potentially used as crucial agents for cell-free therapy; however, their isolation and characterization can be challenging. In the current study, two methods of exosome isolation have been characterized and compared using a culture media of adipose-derived mesenchymal stem cells, namely ultracentrifugation and a commercial kit; moreover, the efficiency of these two methods was highlighted in this study. Two different isolation methods of exosomes from MSCs were used to compare the efficiency of exosomes. For both isolation methods, transmission electron microscopy, dynamic light scattering (DLS), and bicinchoninic acid (BCA) assay have been performed. The electron microscopy and DLS indicated the presence of exosomes. Moreover, the kit and ultracentrifugation isolates contained approximately comparable amounts of protein measured by the BCA. Overall, the two isolation methods had similar performances. Although ultracentrifugation is used as a gold standard for exosome isolation, the commercial kit has some advantages and can be applied alternatively according to its cost-effectiveness and time-saving properties.

Comparison of the Effect of Adipose Mesenchymal Stem Cells-Derived Secretome with and without Reovirus in CT26 Cells

Colorectal cancer is the fourth leading cause of cancer-related deaths that has significantly increased over the past three decades. New therapeutic approaches, such as oncolytic viruses, have become very imperative recently to destroy cancer cells. The use of mesenchymal stem cells (MSCs) secretome that is produced in response to variant conditions involves different paracrine molecules secretion that has therapeutic potential in several chronic diseases. Mesenchymal stem cells and their derivatives are employed as regenerative medicine; nevertheless, there is ambiguity in the function of these cells in the control of malignancy. This study aimed to examine the apoptotic effect of secretomes derived from MSCs affected by encompassing oncolytic reoviruses. Mesenchymal stem cells were cultured after separation from abdominal adipose tissue of BALB/c mice. After three passages, the cells were infected by reovirus at the multiplicity of infection of 1 plaque-forming unit per cell. Uninfected and infected secretomes with reovirus were collected separately. The colorectal cancer CT26 cells were confronted with uninfected secretome, infected secretions, reovirus as a positive control, and Dulbecco's Modified Eagle Medium/High Glucose as negative control separately. Finally, apoptosis and necrosis were evaluated by flow cytometry. The infected secretome with reovirus was capable to induce apoptosis more than the uninfected secretome in CT26. However, the supernatant of reovirus infected cells was more capable to induce cell death, in comparison to the infected secretome. Infected MSCs with oncolytic reovirus produced a type of condition media that enhanced apoptosis induction and could have a therapeutic effect on cancer cells. Nonetheless, tumoral cells confronted with the oncolytic reovirus showed more capability in inducing apoptosis in CT26 cells. As a result, the use of oncolytic virus and infected secretome are more effective than uninfected secretome in inducing apoptosis.

Evaluation of the efficacy of a new oil-based adjuvant ISA 61 VG FMD vaccine as a potential vaccine for cattle

Foot-and-mouth disease is an important viral disease of cloven-hoofed animals. Inactivated whole particle virus vaccines are still widely used in prophylactic vaccination campaigns. The choice of adjuvant is a very important factor in enhancing immune responses and the efficacy of inactivated vaccines. Montanide ISA 61 VG is a new ready-to-use mineral oil-based adjuvant developed by SEPPIC Inc. (SEPPIC, France) with high-potential immune responses needed for clinical protection against FMD infection. In this study, we compared the efficacy of two FMD vaccines either formulated with the new oil-based adjuvant ISA 61 VG and saponin, or with aluminum hydroxide gel and saponin. Both vaccines contained the same antigen payloads of O2010/IR. Two groups of 15 naive cattle received a single vaccination with different doses (full dose, 1/3 dose and 1/9 dose) to calculate their PD50 (50% protective dose) after being challenged with the homologous virulent virus. The mean neutralizing antibody titer was determined at 0, 7, 14 and 21 days after vaccination, measured by a micro neutralization test. The new vaccine improved humoral immune responses by 19%, while inducing a higher geometric mean. The titer for neutralizing antibodies was 2.91 log10 compared to the alum-gel based adjuvant vaccine which was 2.44 log10 (P-value=0.1782). The new vaccine showed a PD50 value of 10.05 as compared to a PD50 value of 4.171, respectively. According to the results, the FMD vaccine formulated with the new oil adjuvant, ISA 61 VG, shows potential as an alternative vaccine for routine and emergency vaccinations in the FMD enzootic region.

[Antitumor effect of mIFN-λ3 in C57BL/6 mice model for papilloma tumors]

Although several years have passed since the determination of the human papilloma virus (HPV) as the causative agent for cervical cancer, a definitive treatment has not yet been found. Interferon-alpha (IFN-α) immunotherapy is one of the promising methods for tumor treatment, although numerous side effects were observed in clinical trials. Recently, a new type of interferon, lambda-interferon (IFN-λ), has been discovered with fewer side effects than IFN-α since its receptor repertoire is limited. IFN-λ has a series of activities including antiviral, anti-proliferative and anti-tumor actions. In the present study, the effects of IFN-α and IFN-λ on the TC1 papilloma tumor model in C57BL/6 mice were evaluated. TC1 cells were injected into the mice subcutaneously. Upon tumor formation, murine IFN, mIFN-α and mIFN-λ, expression plasmids were injected intratumorally in combination or alone. The survival time and tumor size as well as apoptosis in tumors and NK cytoxicity were measured after three injections. As compared with the control group, the remarkable results especially in the group which received mIFN-α and mIFN-λ together were obtained for all of the measured parameters. Although IFN-λ is a new member of the interferon family and its properties should be studied in detail, the data obtained suggests that the use of IFN-λ especially in combination with IFN-α could be considered as an effective strategy for papilloma cervical cancer immunotherapy.

HSP70 modified response against HPV based tumor

BACKGROUND AND OBJECTIVES

DNA immunization is quite inventive vaccination strategies that engage the direct introduction of plasmid DNA encoding the desired antigen into the host. DNA vaccines expand strong protective responses against tumors. The desired target E7 oncogene products represent a target of choice for the therapeutic vaccination. The efficacy of vaccination is limited and it is often necessary to enhance the immune response by using adjuvant in order to achieve the desired responses. Numerous approaches have been applied to boost the effectiveness, such as the fusion or co-administration of cytokine and co-stimulatory molecules gene. Heat-shock protein 70 a family of chaperone proteins makes possible delivery of non-covalently bound peptide to MHC I molecules and influences peptide-specific CTL responses and cure treated individuals. HSP70 have been proposed as the affective adjuvant and expected to act as an appropriate substitute of both cytokine and co-stimulatory genes.

MATERIALS AND METHODS

In the current study, the impact of HSP70 co-delivery and HPV-E7 boosting on cellular immune responses and protection has been investigated by intramuscular injection of mixed DNA constructs.

RESULTS

Our results reveal that the target DNA vaccine can influence an E7-specific CTL response, which is imperative in the lysis of infected tumor cells, compared to negative control (p < 0.05). Additionally, treatment of tumor-bearing mice with pcDNA/E7 + HSP70 plasmid generates stronger immune responses and decreased significantly tumor sizes. Immunization with HSP-based vaccine with special target immunogene can induce potent and specific anti-tumor or anti-viral immune responses.

CONCLUSIONS

Co-administration of pcDNA/E7 + HSP70 plasmid was immunologically more effective than pcDNA/E7 alone. It was concluded that all the characteristics observed during our investigation demonstrate the potent adjuvant activities of HSP70 and could be an efficient approach to persuade dramatically E7-specific immune responses as future cervical cancer vaccine.  

Sequence analysis of the foot and mouth disease virus type O/IRN/2007 VP1 gene from Iranian isolate

The foot and mouth disease virus (FMDV) causes a vesicular and contagious disease of cloven-hoofed animals. In this study, the virus was isolated from vesicles of the infected cattle using cell culture and serotyped by ELISA test. The extracted RNA from the infected cells was reverse transcribed and amplified using VP1 gene-specific primer pairs by means of one-step RT-PCR. The purified VP1 gene was sub-cloned into the uniqe KpnI and BamHI cloning sites of the pcDNA3.1+ vector. The DH5α strain of E. coli was transformed by the vector. The sequences of sub-cloned FMDV type O/IRN/2007 VP1 were aligned with FMDV type O/UKG/2001 VP1 using MegAlign software. Nucleotide sequence comparisons were made using the BLAST software available from the NCBI website. The amino acid sequences of three sub-cloned FMDV type O/IRN/2007 VP1 were also aligned with three other similar sequences using MegAlign software. Nineteen of the most similar VP1 nucleotide sequences (by BLASTN program), FMDV O/IRN/2007 VP1 sequence, twenty isolates of FMDV-O VP1 in Iran and eight topotypes of FMDV type O were aligned by Mega5 to create a FMDV-O VP1-based sequence similarity tree. The nucleotide sequence comparison indicated that FMDV O/ IRN/2007 VP1 had the greatest nucleotide sequence similarity to the VP1 gene of FMDV O1/Manisa/Turkey/69 (99%), FMDV O1/Manisa/Netherlands (98%) and FMDV O1/Manisa/iso87/Turkey (98%). It was also observed that the highest identity between FMDV O/IRN/2007 VP1 sequence and other nucleotide sequences of FMDV type O VP1 genes isolated in Iran during 1997-2004 was about 91%.

Production of human papilloma virus type 16 e6 oncoprotein as a recombinant protein in eukaryotic cells

BACKGROUND

Cervical cancer is one of the most important and widespread cancer which affects women. There are several causes of cervical cancer; among them HPV types 16 and 18 are the most prominent ones which are recurrent and persistent infections. These genotypes are currently about 70% of cervical cancer causes in developing countries. Due to the importance of these viruses in cervical cancer, we pioneered the production of Human Papilloma Virus type16 E6 oncoprotein as a recombinant protein in order to develop a vaccine. Two HPV oncoproteins, E6 and E7, are consistently expressed in HPV-associated cancer cells and are responsible for malignant transformation. These oncogenic proteins represent ideal target antigens for developing vaccine and immunotherapeutic strategies against HPV-associated neoplasm.

METHODS

In the present study, the cloned E6-oncoprotein of HPV16 in pTZ57R/T-E6 vector was used to produce professional expression vector. The target gene was subcloned in a eukaryotic expression vector. The pcDNA3-E6 vector was propagated in E.coli strain DH5α and transfected into CHO cells 72 hours post-transfection.

RESULTS

The transfected cells were harvested; mRNA detection and the interest protein production were confirmed by western blot analysis using specific anti E6 monoclonal antibody.

CONCLUSION

HPV16-E6 target protein recognized by specific antibody could be an appropriate form of protein, which can be used for further studies. Due to potential effect of this protein, its DNA construction can be used for DNA vaccine in future studies.

Prevalence of HI antibody titer against rubella virus to determine the effect of mass vaccination in Tehran

BACKGROUND

Rubella is an infectious viral disease, has a worldwide distribution and is normally a mild childhood disease. Infection during early pregnancy may cause fetal death or congenital rubella syndrome. The highest risk of CRS is found in countries with high susceptibility rates among women of childbearing age. In many developed and some developing countries, large-scale rubella vaccination during the past decade has drastically reduced or practically eliminated rubella and CRS. Mass vaccination campaigns and Expanded Program of Immunization (EPI) have increased vaccine coverage in the world with a substantial impact on the reduction of rubella infections, such as CRS.

OBJECTIVE

The present study was preformed to evaluate the immune status against rubella before and after the mass campaign vaccination on 22 December 2003.

STUDY DESIGN

A total of 320 samples were collected from the healthy subjects before and after the vaccination and 80 paired sera were collected and tested for the presence of rubella antibody using HI test.

RESULTS AND CONCLUSIONS

Based on the results, 98.1% of the population has gained anti-rubella antibody, compared with 92.2% before the vaccination. The data revealed that 98.75% of the paired subjects had rubella antibody after mass vaccination which is statistically significant.

Immunogenicity and protective effect of a DNA construct encoding certain neutralizing epitopes of herpes simplex virus type-1 glycoprotein B

Much attention is presently focused on the vaccination with certain epitopes of an antigen. To further study the ability of neutralizing epitopes mapped in the first 1515 nucleotides of glycoprotein B of herpes simplex virus type-1 (gB-1) to induce neutralizing antibodies, a DNA immunization approach was employed. Vaccination of mice with a plasmid expressing the neutralizing epitopes induced humoral immune responses, although the antibody titre was significantly lower than that of antibodies induced by the full-length gB-1 gene. Furthermore, the plasmid DNA could not protect the mice against HSV-1 lethal challenge, but could significantly prolong the survival time compared to mock-vaccinated group.