Epitopes, T-Lymphocyte ; HLA-A2 Antigen ; immunology ; Hepatitis B Core Antigens ; genetics ; Hepatitis B virus ; genetics ; immunology ; Humans ; Mutation

OBJECTIVETo predict and screen the efficient antigenic epitopes in genus-specific envelope protein LipL41 of Leptospira interrogans and to determine the immunoreactive diversity of LipL41s from different genotypes.

METHODSBioinformatic methods were applied to predict the T/B combined epitope candidates in LipL41/1 and LipL41/2 molecules. The nucleotide fragments encoding epitopes were amplified by PCR. Phage display system with SDS-PAGE was performed to obtain the recombinant PIIIs containing different T/B combined epitopes. Western Blot assays were performed to determine the immunoreactivity of recombinant PIIIs to various antisera including antiserum against rLipL41/1, rLipL41/2 and whole cell of L.interrogans strain Lai, and serum from patients with leptospirosis.

RESULTBased on the predicting data, eight common or differential combined epitopes in LipL41s were selected. The nucleotide fragments encoding the epitopes were obtained by PCR. All the T/B combined epitope fragments were correctly inserted into the N end of phage PIII protein and then successfully expressed. All the antisera were able to recognize each of the epitopes but the hybridization signal intensity was different. Among these epitopes, the common T/B combined epitopes LipL41/1-30 and LipL41/1-233 showed a stronger and stable hybridization signals.

CONCLUSIONAll 8 selected T/B combined epitopes in the study are the efficient antigenic epitopes. The common T/B epitopes LipL41/1-30 and LipL41/1-233 can be first used in development of leptospiral MAP vaccine. The cross immunoreaction is between the differential T/B epitopes LipL41s-89,LipL41s-299 and the different antisera.

Amino Acid Sequence ; Antigens, Bacterial ; genetics ; immunology ; Bacterial Vaccines ; genetics ; immunology ; Cloning, Molecular ; Epitopes, B-Lymphocyte ; genetics ; immunology ; Epitopes, T-Lymphocyte ; genetics ; immunology ; Genotype ; Molecular Sequence Data ; Peptide Library

Untreated human immunodeficiency virus (HIV) infections usually lead to death from AIDS, although the rate of the disease progression varies widely among individuals. The cytotoxic T lymphocyte (CTL) response, which is restricted by highly polymorphic MHC class I alleles, plays a central role in controlling HIV replication. It is now recognized that the antiviral efficacy of CTLs at the single cell level is dependent on their antigen specificity and is important in determining the quality of host response to viruses so that the individual will remain asymptomatic. However, because of the extreme mutational plasticity of HIV, HIV-specific CTL responses are continuously and dynamically changing. In order to rationally design an effective vaccine, the questions as to what constitutes an effective antiviral CTL response and what characterizes a potent antigenic peptide to induce such responses are becoming highlighted as needing to be answered.
Animals ; Antigens, Viral ; immunology ; metabolism ; Epitopes, T-Lymphocyte ; Evolution, Molecular ; Genetic Variation ; HIV Infections ; immunology ; virology ; HIV-1 ; genetics ; pathogenicity ; physiology ; Host-Pathogen Interactions ; Humans ; Immunodominant Epitopes ; T-Lymphocytes, Cytotoxic ; immunology ; metabolism ; virology ; Virus Replication

Amino Acid Sequence ; Epitopes, T-Lymphocyte ; immunology ; Forecasting ; HLA Antigens ; immunology ; Hepacivirus ; genetics ; immunology ; Hepatitis C ; immunology ; virology ; Hepatitis C Antigens ; immunology ; Humans ; T-Lymphocytes, Cytotoxic ; immunology ; virology ; Viral Hepatitis Vaccines ; immunology

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

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

T cell anergy has been successfully induced under different conditions in cloned CD4(+) T cells, but induction of T cell anergy in vivo has been difficult and controversial. Due to the low frequency of naturally occurring T cell population with specificity to a defined antigen, it is very difficult to study anergy of naïve T cells without prior in vivo priming which complicates the interpretation of experimental data. To solve this problem, we adopted the HNT-TCR transgenic mice which have homogeneous antigen specific CD4(+) T cell population. In this study, we generated an influenza virus hemagglutinin (HA) peptide-specific CD4(+) T cell clone from the HNT-TCR transgenic mice and induced anergy using APCs which were treated with the crosslinker, ECDI (1-ethyl-3-3(3-dimethylaminopropyl) carbodiimide). The proliferative response of the cloned or freshly purified naïve CD4(+) transgenic T cells after treatment with ECDI-treated APCs and the HA peptide antigen was monitored as the index of anergy induction. The results showed that anergy was successfully induced in the cloned HNT-TCR transgenic CD4(+) T cells. It was determined that the induced anergy was antigen- and MHC-specific. By contrast, anergy was not observed in freshly purified naïve CD4(+) transgenic T cells under the same conditions. The results suggest that naïve CD4(+) T cells may have different anergy inducing requirements, or that cloned CD4(+) T cells may have certain priming or in vitro cloning artifact which makes them more susceptible to anergy induction. We propose that induction of T cell anergy may depend on the T cell growth, activation and differentiation state or cloning conditions. The results from the present study may have important implications for the study of the mechanism(s) underlying T cell anergy induction in vivo and for applications of immune tolerance based therapy.
Animals ; Antigen-Presenting Cells ; immunology ; metabolism ; Antigens, CD ; genetics ; immunology ; metabolism ; CD4 Antigens ; immunology ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; Clonal Anergy ; genetics ; immunology ; Clone Cells ; immunology ; Epitopes, T-Lymphocyte ; biosynthesis ; Immune Tolerance ; genetics ; Major Histocompatibility Complex ; immunology ; Mice ; Mice, Transgenic ; Receptors, Antigen, T-Cell ; physiology

UNLABELLEDThe gene encoding classical swine fever virus (CSFV) T cell epitope E290 peptide was synthesized by PCR, cloned into the expression vector pPG-VP2 and named pPG-VP2-E290. The recombinant plasmid was electrotransformed into Lactobacillus casei 393 generating pPG-VP2-E290/L. casei 393. Specific anti-CSFV E290 peptide immunoglobulin G (IgG) antibody was detected by indirect ELISA in the serum of BALB/c mice and rabbits immunized with recombinant strain by oral administration. The CTL of E290 was analyzed with lymphocytes taken from the immunized mice, and the immunized rabbits were attacked with CSFV to validate the protective function of E290 antibody induced.

RESULTThe recombinant expression system constructed with L. casei 393 in this study show a good immunization property and could elicit the mice and rabbits to produce high anti-E290 antibody levels. Furthermore, E290 peptide antibody could elicit specific CTL response, and restrain attack of CSFV to rabbits.

Administration, Oral ; Animals ; Classical Swine Fever ; prevention & control ; Classical swine fever virus ; genetics ; immunology ; Epitopes, T-Lymphocyte ; biosynthesis ; genetics ; immunology ; Female ; Immunization ; methods ; Lactobacillus casei ; genetics ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Protein Engineering ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; Swine ; T-Lymphocytes, Cytotoxic ; immunology ; Vaccines, Synthetic ; immunology ; Viral Envelope Proteins ; biosynthesis ; genetics ; immunology ; Viral Vaccines ; immunology

OBJECTIVETo identify autoepitopes of E2 subunit of pyruvate dehydrogenase complex (PDC-E2) specific CD8+ CTL in primary biliary cirrhosis (PBC) patients.

METHODSAn online database SYFPEITHI was applied to predict HLA-A*0201 restricted epitopes which located in PDC-E2 30-50 aa and 150-190 aa where B-cell epitopes clustered with CD4+ T-cell epitopes. T2 cell line reconstitution and stabilization assay, induction of specific CTL lines from peripheral blood mononuclear cells (PBMCs) of patients with PBC and cytotoxicity of peptides-induced CTL were performed to screen the epitopes from those candidates.

RESULTSFive potential epitopes were predicted by database. Of the 5 candidates, two peptides 159-167 aa and 165-174 aa, with highly binding activity to HLA-A*0201 molecules, could stimulate PBMCs from most HLA-A*0201 positive PBC patients to proliferate and peptide-induced CTL lines showed specific cytotoxicity.

CONCLUSIONPeptides of KLSEGDLLA (159-167 aa) and LLAEIETDKA (165-174 aa) in the inner lipoyl domain of PDC-E2 are HLA-A*0201 restricted CD8+ CTL immunodominant epitopes in PBC.

Antibody-Producing Cells ; cytology ; Autoantigens ; immunology ; Autoimmunity ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; metabolism ; Cell Line ; Dihydrolipoyllysine-Residue Acetyltransferase ; Epitope Mapping ; Epitopes, T-Lymphocyte ; immunology ; HLA-A Antigens ; immunology ; HLA-A2 Antigen ; Humans ; Liver Cirrhosis, Biliary ; enzymology ; genetics ; immunology ; Phenotype ; Protein Binding ; Pyruvate Dehydrogenase Complex ; genetics ; immunology ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo study whether dendritic cells (DCs) derived from the peripheral blood in chronic hepatitis B patients can induce specific T cell immune response.

METHODS(1)The subjects were divided into 3 groups: chronic hepatitis B group (CHB), acute hepatitis B group (AHB), and normal donor group (ND). The peripheral blood mononuclear cells (PBMCs) isolated from those subjects were stimulated with HBcAg 18 to 27 CTL epitope peptide, and intracellular cytokine staining (ICCS) was used for detecting IFN-gamma, IL-2 and TNF-alpha produced by CD8+ T cell. (2) DCs generated from PBMCs were pulsed with HBcAg 18 to 27 CTL epitope peptide, then were cocultured with autologous lymphocytes for 10 days to induce antigen-specific T cell, which was assessed by ICCS and cytotoxic assay.

RESULTS(1) The memory effect of the PBMCs from AHB group to HBcAg 18 to 27 CTL epitope peptide was stronger than that from CHB or ND group (t=2.508-3.305, P<0.05). (2)After lymphocytes were cocultured with DC treated with HBcAg 18 to 27 CTL epitope peptide, antigen-specific T cell effect was induced. And the killing rates were (57.0+/-23.0)%, (49.5+/-20.2)%, (21.8+/-12.9)% at the effector/target of 30:1, 10:1, 3:1, which were higher than that in control group.

CONCLUSIONSThe memory T cells against HBV antigen lacks in CHB patients. DCs from CHB patients pulsed with HBcAg 18 to 27 epitope peptide can induce HBV antigen-specific T cell, which can kill specific target cells and produce cytokines involved in virus clearance.

Adult ; CD8-Positive T-Lymphocytes ; immunology ; Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; virology ; Epitopes, T-Lymphocyte ; immunology ; Female ; Hepatitis B Core Antigens ; immunology ; Hepatitis B virus ; genetics ; immunology ; Hepatitis B, Chronic ; immunology ; Humans ; Leukocytes, Mononuclear ; immunology ; Male ; Middle Aged ; T-Lymphocytes, Cytotoxic ; immunology