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

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

OBJECTIVETo identify HLA-A0201 restricted cytotoxic T lymphocyte (CTL) epitopes derived from the hepatitis B virus e (HBe) antigen, for future use in a specific immunotherapy based on the identified epitope(s).

METHODSHBe gene sequences from the hepatitis B virus serotypes with the highest frequencies in China were analyzed by bioinformatic web-based interfaces for quantitative motif prediction, extended motif prediction, and peptide super-motif prediction. Four candidate peptides were identified: HBe1, HBe2, HBe3, and HBe4. The affinities of each were tested in vitro with T2 cells, which lack the transporter-associated with antigen transport (TAP) protein but express low levels of the MHC class I surface molecule, and measured by the T2 binding assay and DC50 assay. Flow cytometry was used to detect the fluorescence index of control and experimental groups.

RESULTSThe peptides HBe1 (LLWFHISCL), HBe2 (YLVSFGVWI), HBe3 (CLTFGRETV), and HBe4 (DLLDTASAL) were identified and tested as candidate targets. HBe2 and HBe3 showed higher HLA-A0201 affinity. HBe1, HBe2, and HBe3 showed better binding stability.

CONCLUSIONTwo peptides based on HBe antigen, YLVSFGVWI and CLTFGRETV, possess both sufficient binding affinity and stability and may represent useful HLA-A0201-restricted CTL epitopes. Further study is needed to determine the immunogenic properties of these two peptides in vivo.

Amino Acid Sequence ; Epitopes, T-Lymphocyte ; Hepatitis B e Antigens ; Hepatitis B virus ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation.
Animals ; Antigen Presentation ; Antigen-Presenting Cells/immunology/metabolism ; CD8-Positive T-Lymphocytes/*immunology ; Epitopes, T-Lymphocyte/*immunology ; Female ; Graft Rejection/*immunology ; Interferon-gamma ; Lymphocyte Activation/immunology ; Lymphocyte Count ; Mice ; Minor Histocompatibility Antigens/*immunology/metabolism ; *Skin Transplantation ; Transplantation, Homologous

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

Animals ; Epitopes, T-Lymphocyte ; immunology ; Equine Infectious Anemia ; immunology ; virology ; Horses ; Infectious Anemia Virus, Equine ; immunology ; physiology ; T-Lymphocytes, Cytotoxic ; immunology ; physiology

OBJECTIVETo identify immune epitopes existed in the framework region (FR) of the IgHV protein of B-cell malignance, and explore the use of these FR-derived peptides to induce the family specific immune response in vitro, in order to explore the possibility of a new IgHV gene family-specific immunotherapy for B-cell malignance.

METHODSBioinformatics was used for predicting T cell epitopes in IgHV protein. Peptides of interest were synthesized in vitro. T2 cell binding assay was performed to determine the binding ability of the peptides to HLA-A*0201 molecules. Peptide/HLA tetramer staining was used to detect the number of peptide-specific cytotoxic T lymphocytes (CTLs). Cytotoxicity assay was used to determine killing activity.

RESULTSTwelve peptides that were common to seven IgHV gene subfamilies were identified, and 10 (83%) of them were located in the FR of IgHV protein. The synthesized peptides up-regulated HLA*0201 molecules fluorescence intensity on cell surfaces of T2. By using an antigen-specific T-cell expansion system in vitro, the peripheral blood mononuclear cells (PBMNC) from a healthy HLA-A0201 donor were stimulated weekly by autologous PBMNC loaded with the peptide as antigen presenting cells (APC), and the peptide-specific CTLs were demonstrated to be generated successfully in the healthy donors. The frequency of CD8 and peptide/HLA tetramer double positive cells in the gated lymphocyte population was 0.38% before stimulation and increased to 49.38 % after four times stimulation. Cytotoxicity assay indicated that these CTLs were capable of killing the HLA-A*0201, IgHV1 (+) lymphoma cells. Furthermore, the generated CTL could not kill the target cell loaded with the IgHV3 peptide, indicating that the cytotoxicity is family-specific.

CONCLUSIONPeptides derived from the IgHV protein FR can successfully induce the generation of peptide-specific CTLs in vitro. These CTLs are capable of killing the lymphoma cell belonged to the same subfamily in a peptide-specific and MHC-restricted way. These findings could potentially form the basis of broadening application of immunoglobulin-directed immunotherapy in B-cell malignancies.

Cells, Cultured ; Epitopes, B-Lymphocyte ; immunology ; Humans ; Immunoglobulin Heavy Chains ; immunology ; Immunoglobulin Variable Region ; immunology ; Lymphoma, B-Cell ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

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

OBJECTIVETo investigate the immunotherapy efficacy of both helper T lymphocytes (Th) and cytotoxic T lymphocytes (CTL) epitopes augmented dendritic cells (DCs) tumor vaccine on gastric cancer.

METHODSNaïve spleen T cells were stimulated by mixed peptides (a mixture of Th epitope MAGE-3 (22-36)) primed DCs per week in vitro. After 4 cycles of restimulation, peptide specific T cells were harvested and subgroups of which were determined with flow cytometry. Cytokines secreting profiles by CD4+ T cells and cytotoxicities of CD8+ T cells on tumor cells were assessed. The protective immunity by referred DCs tumor vaccines was also monitored.

RESULTSBoth Th and CTL epitopes primed DCs could elicit both CD4+ T cells and CD8+ T cells in vitro,of which CD4+ T cells released high amount of Th1 type cytokines (IFN-gamma, IL-2) on recognizing specific antigen, as well as CD8+ T cells exhibited efficient tumor-killing capacity. The effects induced by DCs pulsed with single epitope (Th or CTL epitope) in vivo were less effective than those induced by DCs pulsed with mixture epitopes.

CONCLUSIONSBoth Th and CTL epitopes augmented DCs tumor vaccine can induce CD4+ Th1 and CD8+ CTL mediated immune responses to eradicate gastric cancer cells.

Animals ; Cancer Vaccines ; immunology ; therapeutic use ; Cell Line ; Cell Line, Tumor ; Dendritic Cells ; immunology ; Epitopes, T-Lymphocyte ; immunology ; Immunotherapy ; Melanoma, Experimental ; Mice ; Peptides ; immunology ; Stomach Neoplasms ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology