Hepatitis B virus core protein can self-assemble into icosahedral symmetrical viral-like particles (VLPs) in vitro, and display exogenous sequences repeatedly and densely on the surface. VLPs also have strong immunogenicity and biological activity. When the nanoparticles enter the body, they quickly induce specific humoral and cellular immune responses to exogenous antigens. In this study, we designed an HBc-VLPs that can be coupled with antigens at specific sites, and developed a set of efficient methods to prepare HBc-VLPs. Through site-specific mutation technology, the 80th amino acid of peptide was changed from Ala to Cys, a specific cross-linking site was inserted into the main immunodominant region of HBc-VLPs, and the prokaryotic expression vector pET28a(+)-hbc was constructed. After expression and purification, high purity HBc(A80C) monomer protein was assembled into HBc-VLPs nanoparticles in Phosphate Buffer. The results of particle size analysis show that the average particle size of nanoparticles was 29.8 nm. Transmission electron microscopy (TEM) showed that HBc-VLPs formed spherical particles with a particle size of about 30 nm, and its morphology was similar to that of natural HBV particles. The influenza virus antigen M2e peptide as model antigen was connected to Cys residue of HBc-VLPs by Sulfo-SMCC, an amino sulfhydryl bifunctional cross-linking agent, and M2e-HBc-VLPs model vaccine was prepared. The integrity of HBc-VLPs structure and the correct cross-linking of M2e were verified by cell fluorescence tracing. Animal immune experiments showed that the vaccine can effectively stimulate the production of antigen-specific IgG antibody in mice, which verified the effectiveness of the vaccine carrier HBc-VLPs. This study lays a foundation for the research of HBc-VLPs as vaccine vector, and help to promote the development of HBc-VLPs vaccine and the application of HBc-VLPs in other fields.
Animals ; Hepatitis B Core Antigens ; genetics ; immunology ; Immunity, Cellular ; immunology ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Vaccines, Virus-Like Particle ; genetics ; immunology

OBJECTIVETo eliminate the side effects of aluminum adjuvant and His-tag, we constructed chimeric VLPs displaying the epitope of EV71 (SP70) without His-tagged. Then evaluating whether the VLPs could efficiently evoke not only humoral but also cellular immune responses against EV71 without adjuvant.

METHODSThe fusion protein was constructed by inserting SP70 into the MIR of truncated HBcAg sequence, expressed in E. Coli, and purified through ion exchange chromatography and density gradient centrifugation. Mice were immunized with the VLPs and sera were collected afterwards. The specific antibody titers, IgG subtypes and neutralizing efficacy were detected by ELISA, neutralization assay, and EV71 lethal challenge. IFN-γ and IL-4 secreted by splenocytes were tested by ELISPOT assay.

RESULTSHBc-SP70 proteins can self-assemble into empty VLPs. After immunization with HBc-SP70 VLPs, the detectable anti-EV71 antibodies were effective in neutralizing EV71 and protected newborn mice from EV71 lethal challenge. There was no significant difference for the immune efficacy whether the aluminum adjuvant was added or not. The specific IgG subtypes were mainly IgG1 and IgG2b and splenocytes from the mice immunized produced high levels of IFN-γ and IL-4.

CONCLUSIONThe fusion proteins without His-tagged was expressed and purified as soluble chimeric HBc-SP70 VLPs without renaturation. In the absence of adjuvant, they were efficient to elicit high levels of Th1/Th2 mixed immune response as well as assisted by aluminum adjuvant. Furthermore, the chimeric VLPs have potential to prevent HBV and EV71 infection simultaneously.

Adjuvants, Immunologic ; Animals ; Antibodies, Neutralizing ; Antibodies, Viral ; blood ; Enterovirus A, Human ; genetics ; Enterovirus Infections ; immunology ; virology ; Epitopes ; immunology ; metabolism ; Escherichia coli ; metabolism ; Female ; Immunity, Cellular ; Immunity, Humoral ; Mice ; Recombinant Fusion Proteins ; immunology

The generation of T cells with maximal anti-tumor activities will significantly impact the field of T-cell-based adoptive immunotherapy. In this report, we found that OKT3/IL-2-stimulated T cells were phenotypically more heterogeneous, with enhanced anti-tumor activity in vitro and when locally administered in a solid tumor mouse model. To further improve the OKT3/IL-2-based T cell manufacturing procedure, we developed a novel T cell stimulation and expansion method in which peripheral blood mononuclear cells were electroporated with mRNA encoding a chimeric membrane protein consisting of a single-chain variable fragment against CD3 and the intracellular domains of CD28 and 4-1BB (OKT3-28BB). The expanded T cells were phenotypically and functionally similar to T cells expanded by OKT3/IL-2. Moreover, co-electroporation of CD86 and 4-1BBL could further change the phenotype and enhance the in vivo anti-tumor activity. Although T cells expanded by the co-electroporation of OKT3-28BB with CD86 and 4-1BBL showed an increased central memory phenotype, the T cells still maintained tumor lytic activities as potent as those of OKT3/IL-2 or OKT3-28BB-stimulated T cells. In different tumor mouse models, T cells expanded by OKT3-28BB RNA electroporation showed anti-tumor activities superior to those of OKT3/IL-2 T cells. Hence, T cells with both a less differentiated phenotype and potent tumor killing ability can be generated by RNA electroporation, and this T cell manufacturing procedure can be further optimized by simply co-delivering other splices of RNA, thus providing a simple and cost-effective method for generating high-quality T cells for adoptive immunotherapy.
Animals ; CD28 Antigens ; genetics ; immunology ; Electroporation ; Humans ; Immunity, Cellular ; Interleukin-2 ; immunology ; K562 Cells ; Mice ; Muromonab-CD3 ; immunology ; Neoplasms, Experimental ; genetics ; immunology ; pathology ; RNA, Messenger ; genetics ; immunology ; T-Lymphocytes ; immunology ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; genetics ; immunology

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells contribute to the body's immune defenses. Current chimeric antigen receptor (CAR)-modified T cell immunotherapy shows strong promise for treating various cancers and infectious diseases. Although CAR-modified NK cell immunotherapy is rapidly gaining attention, its clinical applications are mainly focused on preclinical investigations using the NK92 cell line. Despite recent advances in CAR-modified T cell immunotherapy, cost and severe toxicity have hindered its widespread use. To alleviate these disadvantages of CAR-modified T cell immunotherapy, additional cytotoxic cell-mediated immunotherapies are urgently needed. The unique biology of NK cells allows them to serve as a safe, effective, alternative immunotherapeutic strategy to CAR-modified T cells in the clinic. While the fundamental mechanisms underlying the cytotoxicity and side effects of CAR-modified T and NK cell immunotherapies remain poorly understood, the formation of the immunological synapse (IS) between CAR-modified T or NK cells and their susceptible target cells is known to be essential. The role of the IS in CAR T and NK cell immunotherapies will allow scientists to harness the power of CAR-modified T and NK cells to treat cancer and infectious diseases. In this review, we highlight the potential applications of CAR-modified NK cells to treat cancer and human immunodeficiency virus (HIV), and discuss the challenges and possible future directions of CAR-modified NK cell immunotherapy, as well as the importance of understanding the molecular mechanisms of CAR-modified T cell- or NK cell-mediated cytotoxicity and side effects, with a focus on the CAR-modified NK cell IS.
Animals ; HIV Infections ; immunology ; therapy ; HIV-1 ; immunology ; Humans ; Immunity, Cellular ; Immunological Synapses ; Immunotherapy ; Killer Cells, Natural ; transplantation ; Neoplasms ; immunology ; therapy ; Receptors, Antigen, T-Cell ; genetics ; immunology ; Recombinant Fusion Proteins ; genetics ; immunology ; T-Lymphocytes ; immunology ; transplantation

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

This study aimed to investigate the immune adjuvant effect and mechanism induced by chitosan nanoparticles carrying pJME/GM-CSF. In this study, plasmid DNA (pJME/GM-CSF) was encapsulated in chitosan to prepare chitosan-pJME/GM-CSF nanoparticles using a complex coacervation process. Immunohistochemistry was used to detect the type of infiltrating cells at the site of intramuscular injection. The phenotype and functional changes of splenic DCs were measured by flow cytometry after different immunogens were injected intramuscularly. The killing activity of CTLs was assessed using the lactate dehydrogenase (LDH) release assay. The preparation of chitosan-pJME/GM-CSF nanoparticles matched the expected theoretical results. Our results also found that, after pJME/GM-CSF injection, the incoming cells were a mixture of macrophages, neutrophils, and immature DCs. Meanwhile, pJME/GM-CSF increased the expression of MHC class II molecules on splenic DCs, and enhanced their Ag capture and presentation functions. Cell-mediated immunity was induced by the vaccine. Furthermore, chitosan-pJME/GM-CSF nanoparticles outperformed the administration of standard pJME/GM-CSF in terms of DC recruitment, antigen processing and presentation, and vaccine enhancement. These findings reveal that chitosan could be used as delivery vector for DNA vaccine intramuscular immunizations, and enhance pJME/GM-CSF-induced cellular immune responses.
Adjuvants, Immunologic ; administration & dosage ; Animals ; Chitosan ; administration & dosage ; immunology ; Dendritic Cells ; immunology ; virology ; Encephalitis Virus, Japanese ; genetics ; immunology ; Encephalitis, Japanese ; immunology ; prevention & control ; virology ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; administration & dosage ; genetics ; immunology ; Humans ; Immunity, Cellular ; Japanese Encephalitis Vaccines ; administration & dosage ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Nanoparticles ; administration & dosage ; Spleen ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; virology ; Vaccines, DNA ; administration & dosage ; genetics ; immunology

To enhance the immunogenicity of DNA and adenoviral vector vaccines expressing HIV-1 subtype B gp160, human interleukin 15 (hIL15) DNA adjuvant (pVR-hIL15) was constructed. BALB/c mice received DNA prime/protein boost immunization with pVR-HIVgp160/Ad5-HIVgp160 alone or combined with pVR-hIL15. Cellular and humoral immune responses were evaluated by IFN-gamma enzyme-linked immunosorbent spot assay and enzyme-linked immunosorbent assay, respectively. Compared with those immunized with vaccines alone, the mice immunized with vaccines combined with pVR-hIL15 had significantly increased specific cellular response and antibody titer (P < 0.05). It suggests that the IL15 DNA adjuvant can enhance the immune responses induced by prime-boost regimen using DNA and adenoviral vector encoding HIV-1 subtype B gp160.
Adenoviridae ; genetics ; Adjuvants, Immunologic ; Animals ; Antibodies, Viral ; immunology ; Antibody Specificity ; Female ; Genetic Vectors ; genetics ; HIV Envelope Protein gp120 ; immunology ; HIV Envelope Protein gp160 ; genetics ; immunology ; HIV Envelope Protein gp41 ; immunology ; Humans ; Immunity, Cellular ; Immunity, Humoral ; Interleukin-15 ; genetics ; Mice ; Mice, Inbred BALB C ; Vaccines, DNA ; genetics ; immunology

OBJECTIVETo explore the effect of compound qizhu granule (CQG) on cellular immunity of chronic hepatitis B (CHB) patients.

METHODSTotally 103 CHB patients treated with lamivudin (LAM) for 6 months, who had partial virological response (HBeAg positive) were randomly assigned to two groups, 50 in the treatment group and 53 in the control group. All patients took LAM 100 mg (once a day) plus ADV 10 mg (once a day). Patients in the treatment group additionally took CQG, one dose per day. After one-year treatment hepatitis B virus (HBV) DNA negative rates, HBeAg seroconversion, levels of HBV specific cytotoxic T lymphocyte (CTL), non-specific CTL and natural killing (NK) cells were compared between the two groups.

RESULTSAfter 1-year treatment, HBV DNA negative rate of the treatment group was 88: 0% in 44 cases, slightly higher than that of the control group (41 cases, 77.4%), but with no statistical difference (P >0.05). HBeAg seroconversion of the treatment group was 32.0% in 16 cases, higher than that of the control group (8 cases, 15.1%), with statistical difference (P <0.05). Levels of HBV specific CTL (0.79%±0. 07%), non-specific CTL (19.4%±1.8%) and NK cells (14. 1%± 1.5%) of the treatment group were higher than those of the control group (0.58% ± 0.08%, 17.5% ± 1.7%, and 11.1%±1.5%, respectively; allP <0.01).

CONCLUSIONTreating CHB patients with partial virological response by ADV plus CQG could improve specific and non-specific cellular immunity, thereby elevating HBeAg seroconversion rate.

Drugs, Chinese Herbal ; therapeutic use ; Hepatitis B e Antigens ; immunology ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; drug therapy ; immunology ; Humans ; Immunity, Cellular ; immunology ; T-Lymphocytes, Cytotoxic ; drug effects

The purpose of this study was to investigate the effects of porcine interleukin (IL)-2 and IL-4 genes on enhancing the immunogenicity of a porcine reproductive and respiratory syndrome virus ORF5 DNA vaccine in piglets. Eukaryotic expression plasmids pcDNA-ORF5, pcDNA-IL-2, and pcDNA-IL-4 were constructed and then expressed in Marc-145 cells. The effects of these genes were detected using an indirect immunofluorescent assay and reverse transcription polymerase chain reaction (RT-PCR). Characteristic fluorescence was observed at different times after pcDNA-ORF5 was expressed in the Marc-145 cells, and PCR products corresponding to ORF5, IL-2, and IL-4 genes were detected at 48 h. Based on these data, healthy piglets were injected intramuscularly with different combinations of the purified plasmids: pcDNA-ORF5 alone, pcDNA-ORF5 + pcDNA-IL-2, pcDNA-ORF5 + pcDNA-IL-4, and pcDNA-ORF5 + pcDNAIL-4 + pcDNA-IL-2. The ensuing humoral immune responses, percentages of CD4+ and CD8+ T lymphocytes, proliferation indices, and interferon-gamma expression were analyzed. Results revealed that the piglets co-immunized with pcDNA-ORF5 + pcDNA-IL-4 + pcDNA-IL-2 plasmids developed significantly higher antibody titers and neutralizing antibody levels, had significantly increased levels of specific T lymphocyte proliferation, elevated percentages of CD4+ and CD8+ T lymphocytes, and significantly higher IFN-gamma production than the other inoculated pigs (p < 0.05).
Animals ; Cell Line ; Escherichia coli/genetics ; Haplorhini ; Immunity, Cellular ; Interleukin-2/genetics/*metabolism ; Interleukin-4/genetics/*metabolism ; Neutralization Tests/veterinary ; Plasmids ; Porcine Reproductive and Respiratory Syndrome/*prevention & control ; Porcine respiratory and reproductive syndrome virus/*immunology ; Recombinant Proteins/genetics/metabolism ; Swine ; Vaccines, DNA/immunology ; Viral Envelope Proteins/*genetics/metabolism ; Viral Vaccines/*immunology

OBJECTIVETo construct a Mycobacterium tuberculosis DNA vaccine pVAX1/ESAT-6 plasmid and investigate its immunoreactivity.

METHODSThe ESAT-6 gene fragment amplified from Mycobacterium tuberculosis genome was inserted into pVAX1 vector to construct the recombinant plasmid pVAX1/ESAT-6, which was identified by restriction enzyme digestion and sequencing. The recombinant plasmid was transformed into Hela cells using Sofast® Transfection reagent, and the cellular expressions of ESAT-6 mRNA and protein were analyzed by RT-PCR and immunofluorescence assay, respectively. The recombinant plasmid pVAX1/ESAT-6 was also transfected into mouse by electronic pulse method, and the mouse serum IFN-γ level and anti-ESAT-6 IgG antibody level were detected by ELISA, mouse lymphocyte proliferation assessed with flow cytometry, and IFN-γ-secreting lymphocytes counted using ELISPOT.

RESULTSDouble restriction-enzyme digestion and sequencing showed that the inserted fragment in the recombinant plasmid pVAX1/ESAT-6 was identical to ESAT-6 gene with an inframe insertion. RT-PCR yielded the target band as expected on agarose gel, and immunofluorescence assay of the transfected cells showed specific green fluorescence signals. The mice transfected with the recombinant plasmid showed significantly elevated serum level of anti-ESAT-6 IgG antibody and increased serum IFN-γ level, spleen cell proliferation, and number of IFN-γ-secreting lymphocytes.

CONCLUSIONThe Mycobacterium tuberculosis DNA vaccine pVAX1/ESAT-6 plasmid we constructed can induce high levels of cellular and humoral immunoreactivity in mice.

Animals ; Antibodies, Bacterial ; blood ; Antibody Formation ; Antigens, Bacterial ; immunology ; Bacterial Proteins ; immunology ; Female ; Genetic Vectors ; HeLa Cells ; Humans ; Immunity, Cellular ; Immunity, Humoral ; Immunoglobulin G ; blood ; Interferon-gamma ; blood ; Mice ; Mice, Inbred BALB C ; Mycobacterium tuberculosis ; immunology ; Plasmids ; immunology ; Tuberculosis Vaccines ; genetics ; immunology ; Vaccines, DNA ; genetics ; immunology