Porcine epidemic diarrhea virus (PEDV) is an intestinal coronavirus that can cause porcine epidemic diarrhea, leading to diarrhea, vomiting, weight loss, and even death in piglets. Due to the diversity of PEDV strains, traditional vaccines are difficult to sustainably and effectively prevent and control PEDV. This article reviews the strategies and mechanisms of active substances in regulating intracellular signaling pathways, viral proteins, and microbial metabolites to enhance the host immune function against PEDV. It emphasizes the prevention of PEDV resistance and the potential harm of PEDV breaking through interspecies barriers to the human society, aiming to provide reliable theoretical support for the development of new antiviral drugs or vaccines.
Porcine epidemic diarrhea virus/immunology* ; Animals ; Swine ; Swine Diseases/prevention & control* ; Antiviral Agents/pharmacology* ; Coronavirus Infections/virology* ; Viral Vaccines/immunology* ; Humans ; Signal Transduction

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*

The ongoing outbreak of the coronavirus disease 2019 (COVID-19) as named by the World Health Organization has millions of confirmed cases around the world and has claimed hundreds of thousands of lives. The virus was named SARS-CoV-2 in February by International Committee on Taxonomy of Viruses. COVID-19 presents as fever, dry cough, dyspnea, headache and pneumonia. In a small subset of severe cases, the disease quickly progresses to respiratory failure and even death. Since the 21st century, there have been three major outbreaks caused by human coronaviruses, including the severe acute respiratory syndrome (SARS) that broke out in 2003, the Middle East respiratory syndrome (MERS) in 2012, and the recent pandemic of COVID-19. Since 2003, significant progress has been made in the study of SARS-CoV and MERS-CoV concerning their natural origins, pathogenesis, antiviral development and vaccine design. Since SARS-CoV-2 and SARS-CoV are closely related, previous findings on SARS-CoV are highly relevant to a better understanding as well as diagnosis, treatment, prevention and control of SARS-CoV-2. In this review, we highlight recent progresses in the field; compare the biological characteristics of SARS-CoV and SARS-CoV-2; summarize the urgently-needed diagnostic, treatment, prevention and control options; and provide future perspectives for the outcome of the outbreak and research questions to be answered, including some of the difficulties in vaccine development. Hopefully, our comments and suggestions would prove useful for the control of the SARS-CoV-2 epidemic in China and the world.
Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; immunology ; pathogenicity ; Coronavirus Infections ; diagnosis ; prevention & control ; therapy ; virology ; Humans ; Middle East Respiratory Syndrome Coronavirus ; drug effects ; immunology ; pathogenicity ; Pandemics ; prevention & control ; Pneumonia, Viral ; diagnosis ; prevention & control ; therapy ; virology ; SARS Virus ; drug effects ; immunology ; pathogenicity ; Severe Acute Respiratory Syndrome ; diagnosis ; prevention & control ; therapy ; virology ; Viral Vaccines

Thymopentin (TP5) and bursopentin (BP5) are both immunopotentiators. To explore whether the TP5-BP5 fusion peptide (TBP5) has adjuvant activity or not, we cloned the TBP5 gene and confirmed that the TBP5 gene in a recombinant prokaryotic expression plasmid was successfully expressed in Escherichia coli BL21. TBP5 significantly promoted the proliferation of thymic and splenic lymphocytes of mice. The potential adjuvant activity of the TBP5 was examined in mice by coinjecting TBP5 and H9N2 avian influenza virus (AIV) inactivated vaccine. HI antibody titers, HA antibodies and cytokines levels (IL-4 and IFN-γ) were determined. We found that TBP5 markedly elevated serum HI titers and HA antibody levels, induced the secretion of both IL-4 and IFN-γ cytokines. Furthermore, virus challenge experiments confirmed that TBP5 contributed to inhibition replication of the virus [H9N2 AIV (A/chicken/Jiangsu/NJ07/05)] from mouse lungs. Altogether, these findings suggest that TBP5 may be an effective adjuvant for avian vaccine and that this study provides a reference for further research on new vaccine adjuvants.
Adjuvants, Immunologic ; pharmacology ; Animals ; Antibodies, Viral ; blood ; Cell Proliferation ; drug effects ; Influenza A Virus, H9N2 Subtype ; drug effects ; physiology ; Influenza Vaccines ; immunology ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Lymphocytes ; drug effects ; Mice ; Oligopeptides ; immunology ; Orthomyxoviridae Infections ; drug therapy ; Recombinant Fusion Proteins ; immunology ; Spleen ; cytology ; Thymopentin ; immunology ; Thymus Gland ; cytology ; Vaccines, Inactivated ; immunology ; Virus Replication

This study aims to investigate the characteristics of genomic variation of pandemic A/H1N1/2009 influenza virus isolated in Fujian Province, China. Complete genome sequence analysis was performed on 14 strains of pandemic A/H1N1/2009 influenza virus isolated from Fujian during 2009-2012. All virus strains were typical low-pathogenic influenza viruses, with resistance to amantadine and sensitivity to neuraminidase inhibitors. Eight genome fragments of all strains were closely related to those of A/California/07/2009 (H1N1) vaccine strain, with > or = 98.2% homology. Compared with the vaccine strain, the influenza strains from Fujian had relatively large variation, and variation was identified at 11 amino acid sites of the HA gene of A/Fujiangulou/SWL1155/2012 strain, including 4 sites (H138R, L161I, S185T, and S203T) involved inthree antigen determinants (Ca, Sa, and Sb). In conclusion, the influenza vaccine has a satisfactory protective effect on Fujian population, but the influenza strains from Fujian in 2012 has antigenic drift compared with the vaccine strain, more attention should therefore be paid to the surveillance of mutations of pandemic A/H1N1/2009 influenza virus.
Antiviral Agents ; pharmacology ; China ; epidemiology ; Drug Resistance, Viral ; genetics ; Genome, Viral ; genetics ; Genomics ; Humans ; Influenza A Virus, H1N1 Subtype ; drug effects ; genetics ; immunology ; physiology ; Influenza, Human ; epidemiology ; prevention & control ; Pandemics ; prevention & control ; Viral Vaccines ; immunology

Currently, killed-virus and modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccines are used to control porcine reproductive and respiratory syndrome. However, both types of vaccines have inherent drawbacks; accordingly, the development of novel PRRSV vaccines is urgently needed. Previous studies have suggested that yeast possesses adjuvant activities, and it has been used as an expression vehicle to elicit immune responses to foreign antigens. In this report, recombinant Kluyveromyces lactis expressing GP5 of HP-PRRSV (Yeast-GP5) was generated and immune responses to this construct were analyzed in mice. Intestinal mucosal PRRSV-specific sIgA antibody and higher levels of IFN-gamma in spleen CD4+ and CD8+ T cells were induced by oral administration of Yeast-GP5. Additionally, Yeast-GP5 administered subcutaneously evoked vigorous cell-mediated immunity, and PRRSV-specific lymphocyte proliferation and IFN-gamma secretion were detected in the splenocytes of mice. These results suggest that Yeast-GP5 has the potential for use as a vaccine for PRRSV in the future.
Administration, Oral ; Animals ; Antibodies, Viral/*immunology ; B-Lymphocytes/immunology/virology ; Enzyme-Linked Immunosorbent Assay ; *Immunity, Cellular ; *Immunity, Mucosal ; Injections, Subcutaneous ; Kluyveromyces/genetics ; Mice ; Mice, Inbred BALB C ; Porcine respiratory and reproductive syndrome virus/*immunology ; Recombinant Proteins/genetics/immunology ; T-Lymphocytes/immunology/virology ; Viral Envelope Proteins/*genetics/*immunology ; Viral Vaccines/administration & dosage/*pharmacology

OBJECTIVETo investigate the epidemiological features, genetic drift in the epitopes of hemagglutinin (HA) of the novel influenza A (H1N1) virus and oseltamivir-resistant variants characterized by H275Y and N295S mutations in children in Shanghai since the outbreak.

METHODBetween June 2009 and May 2012, a prospective surveillance study was carried out in Shanghainese children who attended the outpatient clinic of Children's Hospital of Fudan University for influenza-like illness. One-step real-time fluorescence quantitative RT-PCR was performed to detect seasonal influenza A and influenza B virus and the novel influenza A (H1N1) virus in the respiratory samples. Genetic drift from the vaccine strain in HA epitopes of the novel influenza H1N1 virus and the molecular markers associated with oseltamivir resistance in neuraminidase (NA) were analyzed.

RESULTOut of 3475 enrolled cases, the novel influenza A (H1N1) virus was confirmed virologically in 222 (6.4%) otherwise healthy children with 133 (59.9%) being boys and 89 (40.1%) girls. The median ages of children with the novel influenza A (H1N1) virus infection during the first wave from August 2009 to February 2010 and the second wave from December 2010 to February 2011 were 53.5 months and 32.0 months, respectively (Z = -4.601, P = 0.000); 119 (46.9%) had the close contact with persons suffering from fever or respiratory infection, of whom, 68 (57.1%) contacts were family members and 47 (39.5%) contacts were classmates. During the outbreak in 2009-2010 season, 66 (40.9%) were exposed to primary index cases, school students were the major exposure subjects, accounting for 50.0%. The nucleotide sequences of HA1 gene were highly homologous between the vaccine strain A/California/07/2009 and Shanghai circulating novel influenza A (H1N1) strains and only S83P mutation in epitope E of HA was detected inclusively in the circulating strains. The H275Y and N295S amino acid mutations associated with oseltamivir resistance were not found in the circulating novel influenza (H1N1) strains.

CONCLUSIONTwo major waves of the novel influenza A (H1N1) outbreaks occurred in Shanghainese children during 2009-2011. Institutional children were the major affected individuals during the 2009 pandemic wave. Households and schools were the main sites of transmission among children during influenza pandemic. Influenza vaccination should be enhanced in children and their close family contacts. The novel influenza A (H1N1) virus in Shanghai has not undergone significant genetic changes. Oseltamivir is effective for the treatment of the novel influenza A (H1N1) virus.

Adolescent ; Amino Acid Sequence ; Antiviral Agents ; pharmacology ; Child ; Child, Preschool ; China ; epidemiology ; Drug Resistance, Viral ; Female ; Hemagglutinins, Viral ; genetics ; Humans ; Infant ; Influenza A Virus, H1N1 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; drug therapy ; epidemiology ; pathology ; virology ; Male ; Molecular Epidemiology ; Molecular Sequence Data ; Neuraminidase ; genetics ; Oseltamivir ; pharmacology ; Pandemics ; Viral Vaccines ; genetics ; immunology

OBJECTIVETo investigate the high expression of HPV16L2N120E7E6 fusion protein by prokaryotic expression system, and evaluate its immunogenicity and antitumor efficacy in vaccinated mice.

METHODSThe HPV16L2N120E7E6 fusion gene, its codons were optimized to increase the expression of the protein, was constructed by overlap extension PCR and inserted into prokaryotic expression vector pET9a. Then the fusion protein was expressed by inducing with IPTG in E. coli strain BL21 (DE3) harboring with plasmid pETL2N120E7E6, and further detected by SDS-PAGE and Western-blot. Finally, the humoral and cellular immune responses were measured by ELISA and ELISPOT, respectively, in vaccinated mice with the purified HPV16L2N120E7E6 fusion protein, and the antitumor efficacy was assessed in mice using the TC-1 tumor challenge model.

RESULTSThe codon-optimized HPV16L2N120E7E6 fusion gene was highly expressed in E. coli strain BL21 (DE3) harboring with plasmid pETL2N120E7E6, and the amount of fusion protein was nearly 48.6% of the total bacterial protein. The purified fusion protein could induce high titer of specific antibody against L2, E7 and E6 in vaccinated mice. When accompanied with the adjuvant CpG, the fusion protein was able to elicit strong and moderate cellular immune responses in vaccinated mice against peptide HPV16E7(49-57) and peptide pools of HPV16E6, respectively. Furthermore, the tumor therapeutic experiment showed that HPV16L2N120E7E6 + CpG could prevent the tumor formation in 80.0% (8/10) vaccinated mice.

CONCLUSIONSThe data of this study suggest that HPV16L2N120E7E6 fusion protein could be a promising candidate vaccine for treatment of chronic HPV16 infection and post-operative adjuvant therapy for cervical cancer.

Adjuvants, Immunologic ; pharmacology ; Animals ; Cancer Vaccines ; immunology ; therapeutic use ; Capsid Proteins ; genetics ; immunology ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Codon ; Escherichia coli ; immunology ; metabolism ; Female ; Humans ; Immunization ; methods ; Immunotherapy ; methods ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Oligodeoxyribonucleotides ; immunology ; Oncogene Proteins, Viral ; genetics ; immunology ; metabolism ; Papillomavirus E7 Proteins ; genetics ; immunology ; metabolism ; Papillomavirus Vaccines ; immunology ; therapeutic use ; Plasmids ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism ; Repressor Proteins ; genetics ; immunology ; metabolism

We investigated the enhanced immune response of a recombinant T cell immunogen as an effective cellular immune adjuvant. The T cell immunogen named TI contained several T cell epitopes from the VP1, VP4, 3A and 3D proteins of foot-and-mouth disease virus (FMDV) and two pan-T helper (T(H)) cell sites to broaden the immunogenicity of the protein. Meanwhile, another fusion protein named OA-VP1 was expressed in bacteria, which contained two VP1 proteins of O and Asia1 type FMDV. Mice were vaccinated with commercially inactivated vaccine or OA-VP1 protein with or without the TI immunogen. The results show that mice inoculated with inactivated vaccine or OA-VP1 protein supplemented with TI immunogen produced significantly higher level of neutralizing antibodies (P < 0.01 or P < 0.05) than the mice only inoculated with inactivated vaccine or OA-VP1 protein by microneutralization assay. An obvious increase in T cell number by flow cytometric analysis and significantly higher concentration of IFN-gamma secreted in culture media of spleen lymphocytes were observed in groups supplemented with TI immunogen (P < 0.01). TI immunogen was an effective stimulator for humoral and cellular immunity and could help improve the immunogenicity of inactivated vaccine or protein subunit vaccine.
Adjuvants, Immunologic ; pharmacology ; Animals ; Capsid Proteins ; genetics ; immunology ; Epitopes, T-Lymphocyte ; genetics ; immunology ; Foot-and-Mouth Disease ; immunology ; prevention & control ; virology ; Foot-and-Mouth Disease Virus ; immunology ; Immunization ; Mice ; Viral Vaccines ; genetics ; immunology ; pharmacology

In 1990, it was reported that the naked DNA encoding an antigen (so-called DNA vaccine) transduced directly into the muscle is able to induce immune responses just like antigen inoculation. Since then, a number of DNA vaccines against different diseases have been developed and shown to induce different levels of specific humoral and/or cell-mediated immunity. Efforts have been made to develop effective DNA vaccines against classical swine fever (CSF). This review covered the following aspects in the development and application of CSF DNA vaccines: construction and evaluation, application of adjuvants, combination with other vaccines and the existing problems and solutions.
Adjuvants, Immunologic ; pharmacology ; Animals ; Classical Swine Fever ; prevention & control ; Swine ; Vaccines, DNA ; biosynthesis ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Vaccines ; biosynthesis ; immunology