Objectives To develop a multi-stage and multi-epitope vaccine, which consists of epitopes from the early secretory and latency-associated antigens of Mycobacterium tuberculosis (MTB). Methods The B-cell, cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes of 12 proteins were predicted using an immunoinformatics. The epitopes with antigenicity, without cytotoxicity and sensitization, were further screened to construct the multi-epitope vaccine. Furthermore, the proposed vaccine underwent physicochemical properties analysis and secondary structure prediction as well as 3D structure modeling, refinement and validation. Then the refined model was docked with TLR4. Finally, an immune simulation of the vaccine was carried out. Results The proposed vaccine, which consists of 12 B-cell, 11 CTL and 12 HTL epitopes, had a flexible and stable globular conformation as well as a thermostable and hydrophilic structure. A stable interaction of the vaccine with TLR4 was confirmed by molecular docking. The efficiency of the candidate vaccine to trigger effective cellular and humoral immune responses was assessed by immune simulation. Conclusion A multi-stage multi-epitope MTB vaccine construction strategy based on immunoinformatics is proposed, which is expected to prevent both active and latent MTB infection.
Mycobacterium tuberculosis/metabolism* ; Molecular Docking Simulation ; Toll-Like Receptor 4 ; Epitopes, T-Lymphocyte/chemistry* ; Epitopes, B-Lymphocyte/chemistry* ; Vaccines, Subunit/chemistry* ; Computational Biology/methods*

OBJECTIVE: To analyze the RNA binding protein of Toxoplasma gondii (TgDDX39) using bioinformatics technology, and to evaluate the immunogenicity of TgDDX39, so as to provide insights into development of toxoplasmosis vaccines. METHODS: The amino acid sequences of TgDDX39 were retrieved from the ToxoDB database, and the physicochemical properties, transmembrane structure domain, signal peptide sites, post-translational modification sites, coils, secondary and tertiary structures, hydrophobicity, and antigenic epitopes of the TgDDX39 protein were predicted using online bioinformatics tools, incluiding ProtParam, TMHMM 2.0, SignalP 5.0, NetPhos 3.1, COILS, SOPMA, Phyre2, ProtScale, ABCpred, SYFPEITHI and DNA-STAR. RESULTS: TgDDX39 protein was predicted to be an unstable hydrophilic protein with the molecular formula of C₂₁₇₃H₃₄₅₈N₅₉₈O₆₆₁S₁₈, which contained 434 amino acids and had an estimated molecular weight of 49.1 kDa and a theoretical isoelectric point of 5.55. The protein was predicted to have an extremely low possibility of signal peptides, without transmembrane regions, and contain 27 phosphorylation sites. The β turn and random coils accounted for 39.63% of the secondary structure of the TgDDX39 protein, and a coiled helix tended to produce in one site. In addition, the TgDDX39 protein contained multiple B and T cell antigenic epitopes. CONCLUSIONS Bioinformatics analyses predict that TgDDX39 protein has high immunogenicity and contains multiple antigenic epitopes. TgDDX39 protein is a potential candidate antigen for vaccine development.
Humans ; Toxoplasma/metabolism* ; Toxoplasmosis/prevention & control* ; Vaccines ; Epitopes, T-Lymphocyte ; Computational Biology ; Protozoan Proteins/chemistry*

The abnormal glycans expressing on the surface of tumor cells are good targets to develop carbohydrate-based anti-cancer vaccines. However, one of the major problems is that carbohydrate antigens possess weak immunogenicity. This review summarizes the recent efforts to overcome this problem: glycoconjugates produced by coupling the carbohydrate antigens and proper carrier proteins improve their immunogenicity, many glycoconjugates have entered clinical trials; the vaccines become chemically well-defined when coupling the carbohydrate antigens with a T-cell peptide epitope and an immunostimulant to form fully synthetic multi-component glycoconjugate vaccines; the modification of carbohydrate antigens in combination with the technology of metabolic oligosaccharide engineering of tumor cells induces a strong immune response; and the fact that the antibodies elicited against the unnatural carbohydrate antigens can recognize the native carbohydrate antigens on tumor cells provides a new promising strategy for the development of anti-cancer vaccines.
Animals ; Antigens, Tumor-Associated, Carbohydrate ; chemistry ; immunology ; Cancer Vaccines ; chemical synthesis ; chemistry ; immunology ; therapeutic use ; Carbohydrates ; chemistry ; immunology ; Epitopes, T-Lymphocyte ; chemistry ; immunology ; Glycoconjugates ; chemistry ; immunology ; Humans ; Immune Tolerance ; Metabolic Engineering ; methods ; Neoplasms ; prevention & control ; therapy ; Oligosaccharides ; chemistry

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.
Animals ; Epitopes, B-Lymphocyte/immunology ; Epitopes, T-Lymphocyte/immunology ; Evolution, Molecular ; Korea ; *Open Reading Frames ; Phylogeny ; Pilot Projects ; Porcine Reproductive and Respiratory Syndrome/blood/genetics/immunology/*virology ; Porcine respiratory and reproductive syndrome virus/*genetics/immunology ; RNA, Viral/chemistry/genetics ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Swine ; Viral Vaccines/immunology/standards ; Viremia/genetics/immunology/virology

BACKGROUND AND OBJECTIVEAs a prospective vaccine carrier, nanoparticles can protect antigens from degradation and enhance immune response. This study prepared nanovaccines with MAGE-3-derived CD4+-CD8+T cell epitope peptides, and investigated its character and antitumor effects on transplanted gastric cancer in mice.

METHODSWe adopted the self-assembly method to prepare peptide/chitosan conjugated with deoxycholic acid (chitosan-deoxycholic acid) nanoparticles. We observed the appearance of the chitosan-deoxycholic acidnanoparticles through a transmission electron microscope (TEM) and analyzed the peptide content and its release pattern by fluorescence spectrophotometry. We observed tumor-suppression efficacy in vivo through animal experiments.

RESULTSWe successfully prepared nanoparticles with MAGE-3 peptide antigen, and its encapsulation efficiency and loading level were about 37% and 17.0%, respectively. These nanoparticles presented a delayed release pattern in phosphate buffered saline (PBS) at pH 7.4, and the full release time was about 48 h. In 2 mg/mL lysozyme, the nanoparticles showed a sudden release, and the full release time was about 24 h. ELISPOT and cytotoxic experiments showed that the MAGE-3 peptide loaded nanoparticles could stimulate immune response in vivo and could generate MAGE-3-targeted cytotoxic T lymphocytes (CTLs), and kill MAGE-3-specific tumor cells. Tumor suppression experiments showed that the regression ratio of the peptide-loaded nanoparticles group was 37.81%.

CONCLUSIONSMAGE-3 peptide/chitosan-deoxycholic acidvaccine-loaded nanoparticles can stimulate antitumor immune response in vivo and can regress the growth of mouse forestomach carcinoma cell line MFC.

Animals ; Antigens, Neoplasm ; chemistry ; immunology ; Cancer Vaccines ; administration & dosage ; Cell Line, Tumor ; Chitosan ; chemistry ; Dendritic Cells ; immunology ; Deoxycholic Acid ; chemistry ; Drug Carriers ; chemistry ; Epitopes, T-Lymphocyte ; immunology ; Male ; Mice ; Nanoparticles ; Neoplasm Proteins ; chemistry ; immunology ; Neoplasm Transplantation ; Stomach Neoplasms ; pathology ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Burden

BACKGROUNDImmunoglobulin heavy chain variable region (IgHV) is a well-characterized tumor antigen for B-cell malignancies. It can function as a target for T cell-mediated immune response. Clinical trials of IgHV protein vaccines against lymphoma have demonstrated induction of tumor-specific cytotoxic T lymphocyte (CTL) responses. However, complementary determining regions-based individual vaccines have disadvantages for wide clinical application. Although a recent study demonstrated that immunogenic peptides are derived from framework regions (FR) shared among patients with B-cell lymphoma, how to choose the appropriate peptides for each patient is still unsolved. The aim of this study was to investigate whether immunoglobulin heavy chain FR-derived peptides shared in each IgHV family are potential CTL epitopes presented by B-cell acute lymphoblastic leukemia (B-ALL). Such CTL epitopes might be beneficial to shifting vaccination strategies against B-ALL from individual specificity to family specificity.

METHODSSeven IgHV gene families were amplified respectively by PCR and sequenced directly from 71 childhood B-ALL cases. Bioinformatics was applied in analyzing characteristics of sequences available and predicting HLA-A*0201-restricted CTL epitopes for each IgHV family. An antigen-specific T cell expansion system was used to generate peptide-specific CTLs. The cytotoxicity of CTLs against B-ALL cells was assessed in the lactate dehydrogenase release assay.

RESULTSComplete IgHV rearrangements were identified in all of the 71 B-ALL cases. All of 40 sequences available showed > or = 98% homology with the nearest germline IgHV genes, indicating IgHV genes in B-ALL of germline nature. Twelve nonapeptides of high HLA-A*0201-binding scores were obtained from 26 productive IgHV protein sequences. Ten (83%) of the peptides were located in FR1 and FR3 shared among the corresponding IgHV family. CTLs specific for the peptide QLVQSGAEV located in FR1 (3 - 11) shared among the IgHV1 family could be successfully generated from peripheral blood mononuclear cells of two HLA-A*0201 + healthy donors in vitro and were capable of killing HLA-matched B-ALL cell clones belonging to the IgHV1 family.

CONCLUSIONAnti-B-ALL CTLs against immunoglobulin heavy chain FR-derived peptides have family-specific cytotoxicity.

Amino Acid Sequence ; Burkitt Lymphoma ; genetics ; immunology ; Epitopes, T-Lymphocyte ; genetics ; immunology ; Genes, Immunoglobulin Heavy Chain ; genetics ; Humans ; Immunoglobulin Heavy Chains ; chemistry ; genetics ; immunology ; Immunoglobulin Variable Region ; chemistry ; genetics ; immunology ; Molecular Sequence Data ; Oligopeptides ; immunology ; Polymerase Chain Reaction ; Protein Binding ; T-Lymphocytes, Cytotoxic ; immunology

The purpose is to screen and identify the specific H-2d restricted T-cell epitopes. These epitopes are used to investigate the cellular immune response of BALB/c (H-2d) mice immunized with a HIV-1 vaccine which expresses six antigens of gp160, gag, pol, rev, tat and nef of HIV subtype B'/C. A replicating DNA vaccine and a non-replicating recombinant vaccinia virus vector, both expressing the six antigens mentioned above, were used to immune BALB/c (H-2d) mice in a prime-boost regiment. The six peptide libraries of HIV B'/C corresponding respectively to the six complete antigens were pooled according to a designed matrix format and used to test for IFN-gamma production from splenocytes of immunized mice by an enzyme-linked immunospot (IFN-gamma ELISPOT) assay. The ELISPOT data indicated that two of seven Gag-specific T-cell epitope peptides were identified to be the novel epitopes. One of three Pol-specific T-cell epitope is unreported. One novel epitope was confirmed in two gp160-specific T-cell epitope peptides. One Nef-specific T-cell epitope was identified. Three Tat-specific T-cell epitope peptides were continuous sequences in Tat peptide library and all contained either complete or partial sequence reported. Rev-specific T-cell epitope was not be found. The specific T-cell epitopes (H-2d restricted) were identified by IFN-7 ELISPOT assay, which could be used to detect the cellular immune response of BALB/c mice immunized with the HIV-1 vaccine expressing six antigens of gp160, gag, pol, rev, tat and nef of HIV subtype B'/C.
Amino Acid Sequence ; Animals ; Enzyme-Linked Immunospot Assay ; methods ; Epitopes, T-Lymphocyte ; chemistry ; genetics ; immunology ; Female ; H-2 Antigens ; chemistry ; genetics ; immunology ; HIV Antigens ; chemistry ; genetics ; immunology ; HIV Infections ; immunology ; virology ; HIV-1 ; classification ; genetics ; immunology ; Histocompatibility Antigen H-2D ; Humans ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Peptide Mapping ; methods

Immunocastration is a considerable alternative to a surgical castration method especially in male animal species for alleviating unwanted male behaviors and characteristics. Induction of high titer of antibody specific for gonadotropin-releasing hormone (GnRH) correlates with the regression of testes. Fusion proteins composed of canine GnRH and T helper (Th) cell epitope p35 originated from canine distemper virus (CDV) F protein and goat rotavirus VP6 protein were produced in E. coli. When these fusion proteins were injected to male dogs which were previously immunized with CDV vaccine, the fusion protein of GnRH-CDV Th cell epitope p35 induced much higher antibody than that of GnRH-rotavirus VP6 protein or GnRH alone. The degeneration of spermatogenesis was also verified in the male dogs immunized with the fusion protein of GnRH-CDV Th cell epitope p35. These results indicate that canine GnRH conjugated to CDV Th cell epitope p35 acted as a strong immunogen and the antibody to GnRH specifically neutralized GnRH in the testes. This study also implies a potential application of GnRH-based vaccines for immunocastration of male pets.
Amino Acid Sequence ; Animals ; Antibodies/blood ; Base Sequence ; Contraception, Immunologic/methods/*veterinary ; Distemper Virus, Canine/*immunology ; Dogs/immunology/*physiology ; Epitopes, T-Lymphocyte/*immunology ; Fertility/immunology ; Gonadotropin-Releasing Hormone/chemistry/*immunology ; Male ; Molecular Sequence Data ; Organ Size ; Recombinant Proteins/immunology ; Spermatogenesis/immunology ; T-Lymphocytes, Helper-Inducer/immunology ; Testis/immunology ; Vaccines, Contraceptive/immunology