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

This study bioinformatically analyzed the non-VP1 capsid proteins (VP2-VP4) of Coxasckievirus A6 (CVA6), with an attempt to predict their basic physicochemical properties, structural/functional features and linear B cell eiptopes. The online tools SubLoc, TargetP and the others from ExPASy Bioinformatics Resource Portal, and SWISS-MODEL (an online protein structure modeling server), were utilized to analyze the amino acid (AA) sequences of VP2-VP4 proteins of CVA6. Our results showed that the VP proteins of CVA6 were all of hydrophilic nature, contained phosphorylation and glycosylation sites and harbored no signal peptide sequences and acetylation sites. Except VP3, the other proteins did not have transmembrane helix structure and nuclear localization signal sequences. Random coils were the major conformation of the secondary structure of the capsid proteins. Analysis of the linear B cell epitopes by employing Bepipred showed that the average antigenic indices (AI) of individual VP proteins were all greater than 0 and the average AI of VP4 was substantially higher than that of VP2 and VP3. The VP proteins all contained a number of potential B cell epitopes and some eiptopes were located at the internal side of the viral capsid or were buried. We successfully predicted the fundamental physicochemical properties, structural/functional features and the linear B cell eiptopes and found that different VP proteins share some common features and each has its unique attributes. These findings will help us understand the pathogenicity of CVA6 and develop related vaccines and immunodiagnostic reagents.
Amino Acid Sequence ; Capsid Proteins ; genetics ; immunology ; Computational Biology ; Enterovirus ; genetics ; pathogenicity ; Epitopes, B-Lymphocyte ; genetics ; immunology ; Humans

The GapC protein of Streptococcus uberis located on the surface of bacteria is a protein with glyceraldehyde-3-phosphate dehydrogenase activity. It participates in cellular processes and exhibits a variety of biological activities. In addition, it has good antigenicity. The aim of this study was to predict the possible B-cell epitopes of the GapC protein and verify the immunogenicity of candidate epitope peptides. The gapC gene of S. uberis isolate RF5-1 was cloned into a recombinant expression plasmid pET-28a-GapC and inducibly expressed. The purified protein was used to immunize experimental rabbits to produce anti-GapC polyclonal antibodies. The three-dimensional structure and three-dimensional location of the GapC B-cell epitopes and the homology comparison of the GapC protein and its B-cell epitopes were carried out using bioinformatics softwares. The results showed that the 44-kDa GapC protein had a good immunological reactivity. Six linear and 3 conformational dominant B-cell epitopes against the GapC protein were selected and synthesized. Three dimensional analysis indicated that the selected peptides have better antigen epitope formation potential. Rabbit anti-GapC polyclonal antibodies were generated after immunized with the purified GapC protein, and the polyclonal antibodies were used to identify the epitope peptide by an indirect ELISA. The ELISA results showed that all of the 9 epitope peptides could react with anti-GapC polyclonal antibodies with varying titers. Among them, the epitope polypeptide ²⁶⁶AANDSYGYTEDPIVSSD²⁸² reacted with the polyclonal antibodies significantly stronger than with other epitope peptides. This study laid an experimental foundation for in-depth understanding of the immunological properties and utilizing effective epitopes of the GapC protein of S. uberis.
Animals ; Antigens, Bacterial/genetics* ; Bacterial Proteins/genetics* ; Epitopes, B-Lymphocyte/genetics* ; Mice ; Mice, Inbred BALB C ; Rabbits ; Streptococcus

<b>OBJECTIVEb>To 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.

<b>METHODSb>Bioinformatic 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.

<b>RESULTb>Based 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.

<b>CONCLUSIONb>All 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

Objective: To study the polymorphism in P66 and its human B-cell epitopes of Methods: Polymerase chain reaction (PCR) and sequencing were used to obtain the P66 sequences of 59 Chinese Results: Results showed that genetic and amino acid diversity presented in the 66 kD protein of all 59 Chinese strains, especially in Conclusion In P66 of 59 Chinese strains, polymorphisms were widely distributed. More importantly, the P66 amino acid sequences of
Bacterial Proteins/genetics* ; Borrelia burgdorferi/genetics* ; China ; Cluster Analysis ; Epitopes, B-Lymphocyte/genetics* ; Genetic Markers ; Genotype ; Humans ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Porins/genetics*

The possibility of using a subunit or fragment of human chorionic gonadotropin (hCG) as an immunogen for birth control has been actively explored for many years. This protein homone is produced by the fertilized egg and is required for implantation of the blastocyst into the maternal uterus and the maitenance of pregnancy. In previous studies, several bio-synthesized hCG chimeric peptides (CP) that contain three linear B-cell epitopes (beta5, beta9 and beta8) of beta-hCG subunit together with various foreign 'promiscuous' T-cell epitopes were constructed and expressed as potential new hCG vaccine immunogens. In order to detect antibodies to each of the individual B-cell epitopes present in the animal antiserum raised against the hCG CPs, we decided to construct three recombinant proteins, each contains a single target B-cell epitope (betaE) of beta-hCG. Two sets of DNA fragments were chemically synthesized encoding the beta5, beta9 and beta8 epitopes (betaE) 45 approximately 52, 113 approximately 116 or 133 approximately 144 of beta-hCG subunit and were inserted into the downstream of streptavidin (Stv) gene in pTSA18 separately, with or without an extra TAA codon at the 3'-terminals of the genes. SDS-PAGE analysis revealed that only Stv-betaE (-beta5, -beta9 or -beta8) fusion genes set with the TAA codon can be expressed in E. coli BL21 (DE3) pLysS strain at high level after 1mM IPTG induction for 4 hours. Additionally, these fusion proteins can all be recognized by specific polyclonal antiserum (RS-4157) generated upon immunization with the loop peptide 38 approximately 57 of beta-hCG, monoclonal antibody (mAb) FB12 to beta9 epitope and mAb OT3A that specially recognizes reporter sequence 133 approximately 139 of beta8 epitope 137 approximately 144. Each of the proteins can be purified to 95% relative homogeneity using an improved method of preparative gel polyacrylamide gel electrophoresis. The yields were 5 mg per 1 L culture. The three target Stv-betaE fusion proteins will be useful in determining the immunogenicity of designed hCG CPs and hCG vaccines, including hCG DNA vaccines.
Chorionic Gonadotropin, beta Subunit, Human ; genetics ; immunology ; Epitopes, B-Lymphocyte ; genetics ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification ; Streptavidin ; genetics ; Vaccines, Synthetic ; immunology

Plasmodium falciparum can invade all stages of red blood cells, while Plasmodium vivax can invade only reticulocytes. Although many P. vivax proteins have been discovered, their functions are largely unknown. Among them, P. vivax reticulocyte binding proteins (PvRBP1 and PvRBP2) recognize and bind to reticulocytes. Both proteins possess a C-terminal hydrophobic transmembrane domain, which drives adhesion to reticulocytes. PvRBP1 and PvRBP2 are large (> 326 kDa), which hinders identification of the functional domains. In this study, the complete genome information of the P. vivax RBP family was thoroughly analyzed using a prediction server with bioinformatics data to predict B-cell epitope domains. Eleven pvrbp family genes that included 2 pseudogenes and 9 full or partial length genes were selected and used to express recombinant proteins in a wheat germ cell-free system. The expressed proteins were used to evaluate the humoral immune response with vivax malaria patients and healthy individual serum samples by protein microarray. The recombinant fragments of 9 PvRBP proteins were successfully expressed; the soluble proteins ranged in molecular weight from 16 to 34 kDa. Evaluation of the humoral immune response to each recombinant PvRBP protein indicated a high antigenicity, with 38-88% sensitivity and 100% specificity. Of them, N-terminal parts of PvRBP2c (PVX_090325-1) and PvRBP2 like partial A (PVX_090330-1) elicited high antigenicity. In addition, the PvRBP2-like homologue B (PVX_116930) fragment was newly identified as high antigenicity and may be exploited as a potential antigenic candidate among the PvRBP family. The functional activity of the PvRBP family on merozoite invasion remains unknown.
Epitopes, B-Lymphocyte/*chemistry/genetics/*immunology ; Female ; Humans ; Immunodominant Epitopes/chemistry/genetics/*immunology ; Malaria, Vivax/immunology/*parasitology ; Middle Aged ; Plasmodium vivax/chemistry/genetics/*immunology ; Protein Structure, Tertiary ; Protozoan Proteins/chemistry/genetics/*immunology ; Reticulocytes/*parasitology

<b>OBJECTIVEb>To search for and verify some common B cell epitopes in the core proteins of woodchuck hepatitis virus and human hepatitis B virus.

<b>METHODSb>Monoclonal antibodies against both core proteins of woodchuck hepatitis virus (WHV) and human hepatitis B virus (HBV) were prepared by inoculating Balb/c mice with denatured recombination WHV and HBV core proteins. ELISA and immunoblotting assays for WHcAg and HBcAg were carried out by using these antibodies. Immunohistochemistry was carried out with liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients. The epitopes were mapped with the mouse mAbs (6D1 and 1H4) by using a panel of 24 16mer overlapping peptides covering the entire WHcAg. The amino acid sequences of WHcAg and HBcAg were compared.

<b>RESULTSb>Cross-reactions were observed between mAbs (6D1 and 1H4) and WHcAg and between Mabs and HBcAg/HBcAg in ELISA and immunoblotting assay. Liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients could be stained specifically by mAbs. The epitopes were mapped at aa1-8 (6D1) and aa125-140 (1H4) of the core proteins of both WHV and HBV by using ELISA assay. WHcAg and HBcAg share similar amino acids sequences at aa1-8 and aa125-140 respectively.

<b>CONCLUSIONb>The core proteins of woodchuck hepatitis virus and human hepatitis B virus share common linear B cell epitopes which span aa1-8 and aa125-140 respectively.

Animals ; Antibodies, Monoclonal ; biosynthesis ; B-Lymphocytes ; immunology ; Cell Line, Tumor ; Cross Reactions ; Epitopes, B-Lymphocyte ; immunology ; Hepatitis B Core Antigens ; immunology ; Hepatitis B Virus, Woodchuck ; genetics ; immunology ; Hepatitis B virus ; genetics ; immunology ; Humans ; Marmota ; Mice ; Viral Core Proteins ; immunology

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

Dengue virus (DENV) envelope [E] protein is the major surface protein of the virions that indued neutralizing antibodies. The domain III of envelope protein (EDIII) is an immunogenic region that holds potential for the development of vaccines; however, the epitopes of DENV EDIII, especially neutralizing B-cell linear epitopes, have not been comprehensively mapped. We mapped neutralizing B-cell linear epitopes on DENV-1 EDIII using 27 monoclonal antibodies against DENV-1 EDIII proteins from mice immunized with the DENV-1 EDIII. Epitope recognition analysis was performed using two set of sequential overlapping peptides (16m and 12m) that spanned the entire EDIII protein from DENV-1, respectively. This strategy identified a DENV-1 type- specific and a group-specific neutralizing epitope, which were highly conserved among isolates of DENV-1 and the four DENV serotypes and located at two regions from DENV-1 E, namely amino acid residues 309-320 and 381-392(aa 309-320 and 381-392), respectively. aa310 -319(310KEVAETQHGT319)was similar among the four DENV serotypes and contact residues on aa 309 -320 from E protein were defined and found that substitution of residues E309 , V312, A313 and V320 in DENV-2, -3, -4 isolates were antigenically silent. We also identified a DENV-1 type-specific strain-restricted neutralizing epitope, which was located at the region from DENV-1 E, namely amino acid residues 329-348 . These novel type- and group-specific B-cell epitopes of DENV EDIII may aid help us elucidate the dengue pathogenesis and accelerate vaccine design.
Amino Acid Sequence ; Animals ; Antibodies, Neutralizing ; immunology ; Dengue ; virology ; Dengue Virus ; chemistry ; genetics ; immunology ; Epitope Mapping ; Epitopes, B-Lymphocyte ; chemistry ; genetics ; immunology ; Humans ; Mice ; Molecular Sequence Data ; Viral Envelope Proteins ; chemistry ; genetics ; immunology