Epitopes ; immunology ; Hepacivirus ; immunology ; Hepatitis C ; immunology ; Humans

The autoantigenic epitopes carried by the platelet glycoprotein in patients with idiopathic thrombocytopenic purpura (ITP) have been observed to localize on the specific regions of glycoprotein. There is a limited number of autoantigenic epitopes on the respective glycoproteins. The clonal B-cell and/or T cell expansion have been detected in some patients with ITP, and the autoantibodies is clonally derived. This research is of clinical importance since identification of clonally derived autoantibodies not only may help to discover the pathogenesis of ITP but also lead to less toxic and more specific therapies. In this review, the clonal limitation of autoantibody and clonal expansion of B-lymphocyte is ITP, clonal characteristics of T-lymphocyte in ITP, and significance of research on clones in ITP were discussed and summarized.
Autoantibodies ; immunology ; B-Lymphocytes ; immunology ; Epitopes ; Humans ; Purpura, Thrombocytopenic, Idiopathic ; etiology ; immunology ; T-Lymphocytes ; immunology

Epitopes, T-Lymphocyte ; immunology ; HLA Antigens ; immunology ; Hepatitis B virus ; immunology ; Humans ; T-Lymphocytes, Cytotoxic ; immunology

HLA-A * 0201, HLA-A * 1101, and HLA-A * 2401 CTL restricted epitopes of platelet membrane glycoprotein II b/III a antibody of human and mice were predicted by use of SYFPEITHI, RANKPEP, BIMAS, SVMHC, PREDEP, MHCPRED, and PROPRED predictive programs. In the results, the peptides (found in HLAPRED) that can lead to autoimmune disease and have been published were removed; and the epitopes of HLA-A * 0201 must cover the epitopes of HLA-A * 1101 and HLA-A * 2401 being combined to predTAP and TAPPred for predicting the binding affinity of peptides toward the TAP transporter and NetChop, MAPPP, PAProc for predicting cleavages; HLA-DR Th restricted epitopes of GPII b/III a antibody were predicted by SYFPEITHI, RANKPEP, MHCPRED, and HLAPRED, after removal of the peptides (found in HLAPRED) that can lead to autoimmune disease and have been published, the Th epitopes must cover the CTL mixed epitopes as being stated above. The secondary structure, hydrophobic regions, flexibility, surface probability and the B cell epitope were predicted by using various methods. Ten mixed peptides of T cell epitopes were selected from more than 1 740 peptides. They were located at the aa9-115, aa24-38, aa50-64, aa65-81, aa109-121 of anti-GP II b/III a-Human and the aal-15, aa26-40, aa46-60, aa68-82, aa93-107 of anti-GP II b/III a-Mice. B cell epitopes of anti-GP II b/III a-Human might locate at aa5-9, aa22-30, aa40-46, aa55-71, aa80-90, aa100-105, aa110-115; and the epitopes of anti-GP II b/III a-Human might locate at aa5-10, aa38-43, aa58-70, aa77-84, and aa99-105.
Animals ; Antibodies ; immunology ; Epitopes, B-Lymphocyte ; immunology ; Epitopes, T-Lymphocyte ; immunology ; Humans ; Mice ; Platelet Glycoprotein GPIIb-IIIa Complex ; immunology ; Purpura, Thrombocytopenic, Idiopathic ; immunology ; Vaccines ; immunology

This study was purposed to construct a fusion DNA vaccine containing WT1 multi-epitope and stimulating epitope of mycobacterium tuberculosis heat shock protein 70 and to detect its expression and immunogenicity. On the basis of published data, a multi-epitope gene (Multi-WT1) containing three HLA *0201-restricted CTL epitopes: one HLA*2402-restricted CTL epitope, two Th epitopes and one universal Th Pan-DR epitope (PADRE) was constructed. DNA-coding sequence was modified by Computer-Aided Design (CAD) to optimize proteasome-mediated epitope processing through the introduction of different amino acid spacer sequences. The synthetic nucleotide sequence was then inserted into an eukaryotic vector to construct the plasmid pcDNA3.1-WT1.For enhancing CTL activity, HSP70 fragment including stimulatory domain P407-426 was amplified by PCR from mycobacterial HSP70 gene and cloned into pcDNA3.1(+). Then Multi-WT1 was fused to the N-terminal of pcDNA3.1-mHSP70(407-426) to make the multi-epitope fusion gene vaccine pcDNA3.1-WT1-mHSP70(407-426). HEK-293T cells were transfected with this vaccine and the expressed product was identified by RT-PCR. Enzyme-linked immunospot assay (ELISPOT) was used to evaluate the immunological responses elicited by vaccine. The results showed that the most of WT1 epitopes could be correctly cleaved which was confirmed by software Net Chop 3.1 and PAPROCIanalysis. RT-PCR showed correct expression of target gene in HEK293T cells and ELISPOT showed specific T-cell responses. It is concluded that the eukaryotic expression vector PcDNA3.1-WT1-mHSP70(407-426) fusion gene has been successfully constructed and the immunity response is also elicited, which is a good candidate for further research of DNA vaccine.
Bacterial Proteins ; genetics ; immunology ; Epitopes ; genetics ; immunology ; Genetic Vectors ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Humans ; Immunodominant Epitopes ; Vaccines, DNA ; genetics ; immunology ; WT1 Proteins ; genetics ; immunology

The study of antigenic epitopes from Toxoplasma gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology, but it also plays a significant role in the development of new diagnostic reagents and vaccines. In the present study, T. gondii GRA6 epitopes were identified using bioinformatics tools and a synthetic peptide technique. The potential B cell epitopes of GRA6 predicted by bioinformatics tools concentrated upon 3 regions of GRA6, 1-20 aa, 44-103 aa, and 172-221 aa. Ten shorter peptides from the 3 regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the 10 peptides (amino acids 44-63, 172-191, and 192-211) tested were recognized by all sera and determined to be immunodominant B-cell epitopes of GRA6. The results indicated that we precisely and accurately located the T. gondii GRA6 epitopes using pig sera collected at different time points after infection. The identified epitopes may be very useful for further studies of epitope-based vaccines and diagnostic reagents.
Allergy and Immunology ; Antibodies ; Computational Biology ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Epitopes, B-Lymphocyte* ; Indicators and Reagents ; Peptides ; Toxoplasma* ; Vaccines

OBJECTIVETo explore whether the antibody subtypes against the extracellular 1-2 (EC1-2) epitopes of pemphigus vulgaris antigen (PVA) are related to the pathogenesis of PVA.

METHODSEC1-2 fusion protein, emulsified with complete Freund's adjuvant (CFA) or aluminum hydroxide hydrate [Al ( OH)3], was used to immunize C57BL/6 mouse. After immunization, the cytokine types, specific antibody titers, and antibody subtypes were detected. Also, a neonatal mice model was used to evaluate the pathogenesis of different antibodies.

RESULTSTh1 type cytokine interferon gamma (IFNgamma) was elevated in CFA group, while Th 2 type cytokine interleukin-4 (IL-4) was increased in Al (OH)3 group. The antibody subtypes were different in both groups. After the two groups were transferred with antisera separately, the neonatal mice developed erosion on the skin from Al(OH)3 group, with acantholysis histopathologically and bright immuno-fluorescence deposition, which was not seen in CFA group.

CONCLUSIONDifferent antibody subtypes may contribute to the pathogenesis of disease.

Animals ; Antibody Specificity ; Autoantibodies ; immunology ; Desmoglein 3 ; immunology ; Epitopes ; immunology ; Mice ; Mice, Inbred C57BL ; Pemphigus ; immunology ; pathology

Multiple epitopes from one or more viruses can be lined up and co-expressed in one vector to generate multi-epitopes DNA vaccines. In the study, four recombinant plasmids were constructed based on HA and NP gene of avian influenza virus (AIV) (H5N1): (1) pIRES/HA, carrying the complete HA gene; (2) pIRES/tHA, carrying a truncated HA gene fragment of major neutralizing antigenic epitopes; (3) pIRES/tHA-NPep, in which three CTL epitopes of NP gene of AIV were fused to the truncated HA from the C-terminal; and (4) pIRES/tHA-NPep-IFN-gamma, which was constructed by replacing neo gene in pIRES/ tHA-NPep with IFN-y of chicken. Fifty five SPF chickens were randomly divided into five groups and immunized with the above four constructs and control plasmid. Each chicken was intramuscally immunized with 200 microg plasmid DNA three times in a two-week interval. Two weeks after the third immunization, chickens were injected with H5N1 subtype avian influenza virus. Before the virus loading no detectable antibodies to HA were found in the chicken serum; but high levels of HI antibodies were detected in the serum of the survived chickens. The percentages of CD4+ and CD8+ T lymphocyte in peripheral blood of immunized chickens increased steadily after the vaccination. After virus loading all chickens in the control group died within three to eight days, and the survival rates of the four DNA vaccine groups were as follows: pIRES/HA, 54.5%; pIRES/tHA, 30%, pIRES/ tHA-NPep, 36.3%, pIRES/tHA-NPep-IFN-gamma, 50%. These results indicated that multi-epitopes DNA immunization can induce immune response and protect chickens from homologous virus loading.
Animals ; Chickens ; Epitopes ; immunology ; Influenza A Virus, H5N1 Subtype ; immunology ; pathogenicity ; Influenza in Birds ; immunology ; prevention & control ; virology ; Vaccines, DNA ; immunology

Monoclonal antibody (mAb) is an important biological macromolecule and widely used in immune detection, in vitro diagnostics, and drug discovery. However, the inherent properties of mAb restrict its further development, such as high molecular weight and complex structure. Therefore, there is an urgent need to develop alternatives for mAb. Various types of miniaturized antibodies have been developed, among which the variable domain of immunoglobulin new antigen receptor (VNAR) is very attractive. The shark single-domain antibody, also known as shark VNAR, is an antigen-binding domain obtained by genetic engineering technology based on the immunoglobulin new antigen receptor (IgNAR) that naturally exists in selachimorpha. It has a molecular weight of 12 kDa, which is the smallest antigen-binding domain found in the known vertebrates at present. Compared with mAb, the shark VNAR exhibits various superiorities, such as low molecular weight, high affinity, tolerance to the harsh environment, good water solubility, strong tissue penetration, and recognition of the hidden epitopes. It has attracted wide attention in the fields of immunochemical reagents and drug discovery. In this review, various aspects of shark VNAR are elaborated, including the structural and functional characteristics, generating and humanization techniques, affinity maturation strategies, application fields, advantages and disadvantages, and prospects.
Animals ; Antibodies, Monoclonal ; immunology ; Antibodies, Monoclonal, Humanized ; immunology ; Antigens ; Epitopes ; metabolism ; Protein Domains ; immunology ; Receptors, Antigen ; chemistry ; immunology ; Sharks

Computational Biology ; Epitopes, T-Lymphocyte ; Humans ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza Vaccines ; immunology