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*

The levels of Streptococcus (S.) mutans infections in saliva were evaluated and a comparison for specific antibody levels among children with different levels of S. mutans infection was made. The promising epitopic regions of antigen AgI/II (PAc) and glucosyltransferase (GTF) for potential vaccine targets related to S. mutans adherence were screened. A total of 94 children aged 3-4 years were randomly selected, including 53 caries-negative and 41 caries-positive children. The values of S. mutans and those of salivary total secretory immunoglobulin A (sIgA), anti-PAc and anti-Glucan binding domain (anti-GLU) were compared to determine the correlation among them. It was found the level of s-IgA against specific antigens did not increase with increasing severity of S. mutans infection, and the complete amino acid sequence of PAc and GTFB was analyzed using the DNAStar Protean system for developing specific anti-caries vaccines related to S. mutans adherence. A significantly positive correlation between the amount of S. mutans and children decayed, missing, and filled teeth index was observed. No significant difference was detected in specific sIgA against PAc or GLU between any two groups. No significant correlation was found between such specific sIgA and caries index. A total of 16 peptides from PAc as well as 13 peptides from GTFB were chosen for further investigation. S. mutans colonization contributed to early children caries as an important etiological factor. The level of sIgA against specific antigens did not increase with increasing severity of S. mutans infection in children. The epitopes of PAc and GTF have been screened to develop the peptide-based or protein-based anti-caries vaccines.
Antibodies, Bacterial ; biosynthesis ; Antigens, Bacterial ; chemistry ; immunology ; Bacterial Proteins ; chemistry ; immunology ; Case-Control Studies ; Child, Preschool ; Dental Caries ; immunology ; pathology ; prevention & control ; Epitopes ; chemistry ; immunology ; Female ; Glucosyltransferases ; chemistry ; immunology ; Humans ; Immunoglobulin A, Secretory ; biosynthesis ; Male ; Peptides ; chemistry ; immunology ; Saliva ; chemistry ; microbiology ; Severity of Illness Index ; Streptococcal Vaccines ; biosynthesis ; chemistry ; immunology ; Streptococcus mutans ; chemistry ; immunology ; pathogenicity ; Vaccines, Subunit ; Virulence Factors ; chemistry ; immunology

OBJECTIVETo construct the expression vectors of GPC-3 CTL epitope.

METHODSThe HBsAg gene with three different EYILSLEEL (EYI) sites was named EYI1, and another with one EYI replacing CTL epitope FLG or SIL of pcHBsAg were named EYI2 and EYI3, respectively. All the three DNAs were amplified by SEOing PCR from pcHBsAg plasmid and linked into pBSSK+ vector to construct Pbssk/EYI1, pBSSK/EYI2, and pBSSK/EYI3. The three plasmid were identified by PCR, double digestion and sequencing, and the fragments with EYI1-3 were obtained by double digestion and then inserted into pcDNA3.1+ vector.

RESULTS AND CONCLUSIONPCR, enzyme digestion and sequence analysis confirmed successful construction of the eukaryotic expression vectors pcDNA-EYI1/HBsAg, pcDNA-EYI2/HBsAg, pcDNA-EYI3/HBsAg, which facilitate further studies of the GPC3-HBsAg multiple peptides vaccine for HBV infection.

Amino Acid Sequence ; Epitopes ; chemistry ; genetics ; immunology ; Genetic Vectors ; genetics ; Glypicans ; genetics ; immunology ; metabolism ; Hepatitis B Surface Antigens ; genetics ; immunology ; Plasmids ; genetics ; metabolism ; Polymerase Chain Reaction ; T-Lymphocytes, Cytotoxic ; immunology ; Vaccines, Subunit ; chemistry ; genetics ; immunology