OBJECTIVE: The present study aimed to evaluate the immunogenicity of BA.2 variant receptor binding domain (RBD) recombinant protein formulated with CpG 1826 plus alum dual adjuvant. METHODS: The BA.2 variant RBD (residues 308-548) fusing TT-P ₂ epitope was obtained from prokaryotic expression system, purification technology and dialysis renaturation, which was designated as Sot protein. The soluble Sot protein formulated with CpG 1826 plus alum dual adjuvant was designated as Sot/CA subunit vaccine and then the BALB/c mice were intramuscularly administrated with two doses of the Sot/CA subunit vaccine at 14-day interval (day 0 and 14). On day 28, the number of effector T lymphocytes secreting IFN-γ and IL-4 in mice spleen were determined by enzyme-linked immunospot (ELISpot) assay. The serum IgG, IgG1 and IgG2a antibodies were examined by enzyme-linked immunosorbent assay (ELISA). In addition, the level of neutralizing antibodies (NAbs) induced by Sot/CA subunit vaccine was also evaluated by the microneutralization assay. RESULTS: The high-purity soluble Sot protein with antigenicity was successfully obtained by the prokaryotic expression, protein purification and dialysis renaturation. The Sot/CA subunit vaccine induced a high level of IgG antibodies and NAbs, which were of cross-neutralizing activity against SARS-CoV-2 BA.2 and XBB.1.5 variants. Meanwhile, Sot/CA subunit vaccine also induced a high level of effector T lymphocytes secreting IFN-γ (635.00 ± 17.62) and IL-4 (279.20 ± 13.10), respectively. Combined with a decreased IgG1/IgG2a ratio in the serum, which indicating Sot/CA subunit vaccine induced a Th1-type predominant immune response. CONCLUSION The Sot protein formulated with CpG 1826 plus alum dual adjuvant showed that the excellent cellular and humoral immunogenicity, which provided a scientific basis for the development of BA.2 variant subunit vaccines and references for the adjuvant application of subunit vaccines.
Animals ; COVID-19 Vaccines/immunology* ; Alum Compounds/pharmacology* ; Mice, Inbred BALB C ; Vaccines, Subunit/immunology* ; Mice ; SARS-CoV-2/immunology* ; Oligodeoxyribonucleotides/administration & dosage* ; Female ; Adjuvants, Immunologic ; COVID-19/immunology* ; Antibodies, Viral/blood* ; Immunogenicity, Vaccine ; Spike Glycoprotein, Coronavirus/immunology* ; Antibodies, Neutralizing/blood* ; Adjuvants, Vaccine ; Immunoglobulin G/blood*

In order to develop a combined live vaccine that will be used to prevent against porcine parvovirus (PPV) and Pseudorabies virus (PRV) infection, the VP2 gene of PPV was inserted into the transfer vector plasmid pG to produce the recombinant plasmid pGVP2. The plasmid pGVP2 and the genome of PRV HB98 attenuated vaccine were transfected by using lipofectamine into swine testis cells for the homologous recombination. The recombinant virus rPRV-VP2 was purified by selection of green fluorescence plaques for five cycles. 6-week-old female Kunming mice were immunized intramuscularly with attenuated PRV parent HB98 strain, commercial inactivated vaccine against PPV, recombinant virus, DMEM culture solution. The injections were repeated with an equivalent dose after 2 weeks in all of the groups, and then challenged with the virulent PRV NY strain at 7 weeks after the first immunization. The recombinant virus rPRV-VP2 was successfully generated, and the recombinant virus could effectively elicite anti-PPV and PRV antibody and significant cellular immune response as indicated by anti-PPV ELISA and HI, PRV-neutralizing assay and flow cytometry. The challenge assay indicated that recombinant virus could protect the mice against the virulent PRV challenge. These results demonstrated that the recombinant virus can be a candidate recombinant vaccine strain for the prevention of PRV and PPV.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; administration & dosage ; genetics ; immunology ; Capsid Proteins ; administration & dosage ; genetics ; immunology ; Female ; Gene Expression ; Genetic Vectors ; genetics ; metabolism ; Herpesvirus 1, Suid ; genetics ; metabolism ; Mice ; Parvovirus, Porcine ; genetics ; immunology ; Swine ; Swine Diseases ; immunology ; prevention & control ; virology ; Viral Vaccines ; administration & dosage ; genetics ; immunology

In order to observe the effect of the immune and weight of chickens after use the attenuated vaccine with low dose of chicken infectious anemia virus (CIAV). In this study, the effects of low dose of CIAV on the weight of SPF chickens and NDV antibody production were observed by simulated experiments. The results showed that 10 EID50 and 5 EID50 CIAV per plume attenuated NDV vaccines were used to cause the weight loss of SPF chickens. Compared with the use of the non contaminated vaccine group, it has significant difference. And NDV antibody levels compared with the use of the non contaminated groups also decreased after use the vaccine with two doses of CIAV contaminated. It has significant difference. A certain proportion of CIAV antibody positive was detected at the beginning of the second week after use the NDV vaccine with two doses of CIAV contaminated. The detection of a high proportion of CIAV nucleic acid was detected in the first week after the use of a contaminated vaccine. The results of the study demonstrate the effects of CIAV pollution on the production and immune function of SPF chickens, and it is suggested that increasing the detection of viral nucleic acid can help save time and improve the detection rate in the detection of exogenous virus contamination by SPF chicken test method.
Animals ; Antibodies, Viral ; immunology ; Chicken anemia virus ; genetics ; immunology ; physiology ; Chickens ; Circoviridae Infections ; immunology ; veterinary ; virology ; Poultry Diseases ; immunology ; virology ; Specific Pathogen-Free Organisms ; Vaccines, Attenuated ; administration & dosage ; genetics ; immunology

Therapeutic HIV vaccine was considered as a hopeful curative method for AIDS patients. However, there is still no suitable HIV animal model for vaccine study since the difference in the immune system between human and animals. To evaluate the therapeutic effect of combined immunization strategy with multiple vector vaccines in macaque models. Plasmid DNA, recombinant Ad5 and MVA vaccines which expressing SIV gag and env genes were constructed. Sequential and repeated immune strategy were applied to immunize mice with these three vaccines. Cellular immune responses in mice immunized with these three vaccines were measured by ELISPOT test in vitro and CTL assay in vivo. The results were analyzed and compared with different antigen combination, order of vaccines and intervals to choose a suitable immunization strategy for macaque immunization in future. It indicated that strong SIV-Gag/Env-specific cellular immune responses were induced by these three vector vaccines. It laid a foundation for evaluating the therapeutic effect of combined immunization strategy with multiple vector vaccines in SIV infected macaque models.
AIDS Vaccines ; administration & dosage ; genetics ; immunology ; Adenoviridae ; genetics ; metabolism ; Animals ; Antibodies, Viral ; immunology ; Female ; Gene Products, env ; administration & dosage ; genetics ; immunology ; Gene Products, gag ; administration & dosage ; genetics ; immunology ; Genetic Vectors ; genetics ; metabolism ; HIV Infections ; immunology ; prevention & control ; virology ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Simian Immunodeficiency Virus ; genetics ; immunology ; Vaccines, DNA ; administration & dosage ; genetics ; immunology

The cDNA fragment of JEV prME gene was cloned into the baculovirus shuttle vector (bacmid) to construct a recombinant baculovirus vector, defined as AcBac-prME. Then the recombinant baculovirus Ac-prME was obtained by transfecting Sf9 cells with AcBac-prME. Western blot analysis and immunofluorescence results indicated that both prM and E proteins were efficiently expressed in Sf9 cells. Electron microscopy suggested that prME was assembled into JEV-VLPs. To further evaluate the potential of JEV-VLPs as vaccine, the mice were immunized with JEV-VLPs and then challenged with lethal JEV. The results of mice survival and pathological changes demonstrated that the JEV-VLPs performed complete protection against JEV-P3 strain and relieved pathological changes in the mice brain significant. This study suggest that JEV-VLPs would be a potential vaccine for Japanese encephalitis virus.
Animals ; Antibodies, Viral ; immunology ; Encephalitis Virus, Japanese ; genetics ; immunology ; Encephalitis, Japanese ; immunology ; prevention & control ; virology ; Humans ; Japanese Encephalitis Vaccines ; administration & dosage ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Sf9 Cells ; Vaccination ; Vaccines, Virus-Like Particle ; administration & dosage ; genetics ; immunology ; Viral Envelope Proteins ; administration & dosage ; genetics ; immunology

Middle East respiratory syndrome coronavirus (MERS-CoV) was identified as a novel human coronavirus and posed great threat to public health world wide,which calls for the development of effective and safe vaccine urgently. In the study, peptide epitopes tagrgeting spike antigen were predicted based on bioinformatics methods. Nine polypeptides with high scores were synthesized and linked to keyhole limpet hemocyanin (KLH). Female BALB/C mice were immunized with individual polypeptide-KLH, and the total IgG was detected by ELISA as well as the cellular mediated immunity (CMI) was analyzed using ELIs-pot assay. The results showed that an individual peptide of YVDVGPDSVKSACIEVDIQQTFFDKTWPRPIDVSKADGI could induce the highest level of total IgG as well as CMI (high frequency of IFN-γ secretion) against MERS-CoV antigen in mice. Our study identified a promising peptide vaccine candidate against MERS-CoV and provided an experimental support for bioinformatics-based design of peptide vaccine.
Animals ; Antibodies, Viral ; immunology ; Computational Biology ; Coronavirus Infections ; immunology ; prevention & control ; virology ; Female ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Middle East Respiratory Syndrome Coronavirus ; genetics ; immunology ; Peptides ; administration & dosage ; genetics ; immunology ; Spike Glycoprotein, Coronavirus ; administration & dosage ; genetics ; immunology ; Viral Vaccines ; administration & dosage ; genetics ; immunology

To develop a safe and broad-spectrum effective hepatitis C virus (HCV) T cell vaccine,we constructed the recombinant adenovirus-based vaccine that carried the hepatitis C virus truncated NS3 and core fusion proteins. The expression of the fusion antigen was confirmed by in vitro immunofluorescence and western blotting assays. Our results indicated that this vaccine not only stimulated antigen-specific antibody responses,but also activated strong NS3-specific T cell immune responses. NS3-specific IFN-γ+ and TNF-α+ CD4+ T cell subsets were also detected by a intracellular cytokine secretion assay. In a surrogate challenge assay based on a recombinant heterologous HCV (JFH1,2a) vaccinia virus,the recombinant adenovirus-based vaccine was capable of eliciting effective levels of cross-protection. These findings have im- portant implications for the study of HCV immune protection and the future development of a novel vaccine.
Adenoviridae ; genetics ; metabolism ; Animals ; CD4-Positive T-Lymphocytes ; immunology ; Cross Protection ; Female ; Genetic Vectors ; biosynthesis ; genetics ; Hepacivirus ; genetics ; immunology ; Hepatitis C ; immunology ; prevention & control ; virology ; Humans ; Interferon-gamma ; immunology ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; administration & dosage ; genetics ; immunology ; Viral Core Proteins ; administration & dosage ; genetics ; immunology ; Viral Hepatitis Vaccines ; administration & dosage ; genetics ; immunology ; Viral Nonstructural Proteins ; administration & dosage ; genetics ; immunology

Routine and emergency vaccination of small ruminants against foot-and-mouth disease (FMD) is mandatory in many endemic countries, yet data on the field effectiveness of the vaccines used is scarce. We conducted an investigation of a serotype O FMD outbreak that took place in a sheep and goat pen, and estimated the effectiveness of various routine vaccination statuses. We also evaluated the protection provided by colostrum administration and emergency vaccination. Animals which were routinely vaccinated twice were not clinically affected while disease incidence was observed among animals routinely vaccinated only once (p = 0.004 according to a two-sided Fisher's exact test). In groups vaccinated only once, there was a significant association between the average time that elapsed since last vaccination and the disease incidence (n = 5; Spearman correlation coefficient: r(s) = 1.0, p < 0.01). In addition, non-vaccinated lambs fed colostrum from dams vaccinated more than 2 months before parturition had a mortality rate of 33%. Administration of emergency vaccination 2 days after the occurrence of the index case was the probable reason for the rapid blocking of the FMD spread within 6 days from its onset in the pen.
Animals ; Colostrum ; Disease Outbreaks/veterinary ; Foot-and-Mouth Disease/*prevention & control ; Goat Diseases/*prevention & control ; Goats ; Immunization Schedule ; Sheep ; Sheep Diseases/*prevention & control ; Viral Vaccines/administration & dosage/*immunology

Vaccination is one of the most successful applications of immunology and for a long time has depended on parenteral administration protocols. However, recent studies have pointed to the promise of mucosal vaccination because of its ease, economy and efficiency in inducing an immune response not only systemically, but also in the mucosal compartment where many pathogenic infections are initiated. However, successful mucosal vaccination requires the help of an adjuvant for the efficient delivery of vaccine material into the mucosa and the breaking of the tolerogenic environment, especially in oral mucosal immunization. Given that M cells are the main gateway to take up luminal antigens and initiate antigen-specific immune responses, understanding the role and characteristics of M cells is crucial for the development of successful mucosal vaccines. Especially, particular interest has been focused on the regulation of the tolerogenic mucosal microenvironment and the introduction of the luminal antigen into the lymphoid organ by exploiting the molecules of M cells. Here, we review the characteristics of M cells and the immune regulatory factors in mucosa that can be exploited for mucosal vaccine delivery and mucosal immune regulation.
Administration, Oral ; Animals ; Antigens, Bacterial/*immunology ; Antigens, Viral/*immunology ; Bacterial Vaccines/administration & dosage/*immunology ; Humans ; Immunity, Mucosal ; Intestinal Mucosa/cytology/*immunology ; Peyer's Patches/cytology/*immunology ; Viral Vaccines/administration & dosage/*immunology

To optimize the immunization strategy against HIV-1, a DNA vaccine was combined with a recombinant vaccinia virus (rTV) vaccine and a protein vaccine. Immune responses against HIV-1 were detected in 30 female guinea pigs divided into six groups. Three groups of guinea pigs were primed with HIV-1 DNA vaccine three times, boosted with rTV at week 14, and then boosted with gp140 protein at intervals of 4, 8 or 12 weeks. Simultaneously, the other three groups of animals were primed with rTV vaccine once, and then boosted with gp140 after 4, 8 or 12 weeks. The HIV-1 specific binding antibody and neutralizing antibody, in addition to the relative affinity of these antibodies, were detected at different time points after the final administration of vaccine in each group. The DNA-rTV-gp140 immune regimen induced higher titers and affinity levels of HIV-1 gp120/gp140 antibodies and stronger V1V2-gp70 antibodies than the rTV-gp140 regimen. In the guinea pigs that underwent the DNA-rTV-gp140 regimen, the highest V1V2-gp70 antibody was induced in the 12-week-interval group. However, the avidity of antibodies was improved in the 4-week-interval group. Using the rTV-gp140 immunization strategy, guinea pigs boosted at 8 or 12 weeks after rTV priming elicited stronger humoral responses than those boosted at 4 weeks after priming. In conclusion, this study shows that the immunization strategy of HIV-1 DNA vaccine priming, followed by rTV and protein vaccine boosting, could strengthen the humoral response against HIV-1. Longer intervals were better to induce V1V2-gp70-specific antibodies, while shorter intervals were more beneficial to enhance the avidity of antibodies.
AIDS Vaccines ; administration & dosage ; genetics ; immunology ; Animals ; DNA, Viral ; administration & dosage ; genetics ; immunology ; Female ; Guinea Pigs ; HIV Infections ; immunology ; prevention & control ; virology ; HIV-1 ; genetics ; immunology ; Humans ; Immunization ; methods ; Vaccines, DNA ; administration & dosage ; genetics ; immunology ; Vaccinia virus ; genetics ; immunology ; env Gene Products, Human Immunodeficiency Virus ; administration & dosage ; genetics ; immunology