OBJECTIVETo study the improvement of CTL effect by CTL epitopes which are modified by KDEL and recognized by CD8+ T lymphocytes to herpes simplex virus type 2.

METHODSObservations were made on the specific immune response induced by the CD8+ CTL epitopes(SSIEFARL, S1), the CD8+ CTL epitopes modified by KDEL(SSIEFARL-KDEL, S1-KDEL), the tandem four copies CD8+ CTL epitopes[(SSIEFARL)4, S4] and the tandem four copies CD8+ CTL epitopes modified by KDEL[(SSIEFARL)4-KDEL, S4-KDEL], 25 male C57BL/6 mouse were randomly divided into 5 group, 5 mice per group, respectively immunized with istonic Na chloride, S1, S1-KDEL, S4 and S4-KDEL. Lymphocyte proliferation was detected by 3H-TdR and the CTL effect induced by CTL epitopes in vivo was detected by 51Cr.

RESULTSIn the 3H-TdR test, compared with the control, the group S1 and group S1-KDEL, the cpm values of Group S4 and Group S4-KDEL were markedly higher (P < 0.05) and the cpm value of Group S4-KDEL was significantly higher than Group S4 (P < 0.05), but the cpm values of Group S1 and Group S1-KDEL were not significantly different from the control (P > 0.05), nor was that of Group S1 from Group S1-KDEL (P > 0.05). In the experiment in which the EL4 cells sensitized by S1 were attacked as target cells, the CTL activities induced in Group S4 and Group S4-KDEL were markedly higher (P < 0.05) compared with the control, Group S1 and Group S1-KDEL, and that induced in Group S4-KDEL was significantly higher than Group S4 (P < 0.05), but the CTL activity induced in Group S1 and Group S1-KDEL were not significantly different from the control (P > 0.05), nor was that induced in Group S1 from Group S1-KDEL (P > 0.05). In the experiment in which the EL4 cells were attacked as target cells, the kill rate was below 10% in every group, not significantly different from the control.

CONCLUSIONThe tandem four copies CD8+ CTL epitopes, modified by KDEL and recognized by CD8+ T lymphocytes to herpes simplex virus type 2, can improve the CTL effect.

Animals ; CD8-Positive T-Lymphocytes ; immunology ; Cell Line ; Epitopes, T-Lymphocyte ; immunology ; Herpesvirus 2, Human ; immunology ; Male ; Mice ; Mice, Inbred C57BL ; Oligopeptides ; immunology ; Protein Sorting Signals ; Random Allocation ; T-Lymphocytes, Cytotoxic ; immunology

Rhesus macaque (Macaca mulatta) is the best model to study of human immunodeficiency virus (HIV) infection and to develop acquired immunodeficiency syndrome (AIDS) vaccine. The crystal structure of its major histocompatibility antigen complex (MHC) is helpful to understand the mechanism of HIV immune evasion. In this study, we cloned the light chain (beta2m) of MHC class I allele of rhesus macaques, Mamu-A*02, and inserted it into pET21a(+) vector. We transfected the recombinant plasmid pET21a(+)-Mamu-beta2m and pET21a(+)-Mamu-alpha into BL21(DE3). Mamu-A*02 and beta2m were expressed in the form of inclusion bodies in BL21 (DE3). We co-refolded the inclusion bodies of Mamu-alpha and Mamu-beta2m with SIV nonapeptide YY9 and obtained the correct refolded protein complex. Then we purified the protein complex by the gel filtration and anion-exchange column. With hanging-drop method, we screened and optimized for the protein crystal. We managed to collect a X-ray diffraction with the resolution to 2.8 angstroms in the condition of 0.1 mol/L BIS-TRIS (pH5.5), 2.0 mol/L(NH4)2SO4. This crystal belong to perpendicular space group P2(1)2(1)2(1), with unit-cell parameters a = 128.99 angstroms, b = 129.01 angstroms, c = 129.03 angstroms. This data is available for the structure determination.
Animals ; Crystallography, X-Ray ; Epitopes ; immunology ; Escherichia coli ; genetics ; metabolism ; Histocompatibility Antigens Class I ; biosynthesis ; genetics ; Macaca mulatta ; Oligopeptides ; biosynthesis ; genetics ; Simian Immunodeficiency Virus ; immunology

OBJECTIVETo identify and characterize the epitope associated with the virus attachment protein (VAP) of hantaan virus.

METHODSThe monoclonal antibody 3G1 was used as the ligand to biospan from a phage-displayed 12-amino acid peptide library, then the positive phage clones were chosen and sequenced. The amino acid sequences of them were compared with that of hantaan virus G2 in homology. The characteristics of positive phage were studied by IFA and ELISA. A decapeptide combining to cell membrane was observed under laser scanning confocal microscope (LSCM).

RESULTSThe conservative motif PX(1-2) HX(0-2) H displaying on positive clones shared homologous amino acid sequence with G2 96YPWHTAKCHY105.

CONCLUSIONG2 96YPWHTAKCHY105 might play some roles in virus binding to host cell, and might be a possible key epitope of hantaan virus VAP.

Animals ; CHO Cells ; Cell Membrane ; metabolism ; Cercopithecus aethiops ; Cricetinae ; Cricetulus ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; immunology ; metabolism ; Hantaan virus ; immunology ; Microscopy, Confocal ; Oligopeptides ; immunology ; metabolism ; Peptide Library ; Vero Cells ; Viral Proteins ; immunology ; metabolism

OBJECTIVETo establish systemic lupus erythematosus (SLE) -like murine model by immunizing BALB/C mice with Sm mimotope.

METHODSSm mimotope was identified by screening a 12-mer random peptide library with monoclonal anti-Smith antibody. Sm mimotope was initially defined with sandwich ELISA, DNA sequencing, and deduced amino acid sequence; and BALB/C mice were subcutaneously injected with mixture phages clones. Sera Sm antibody, anti-double stranded DNA (dsDNA) antibody, and antinuclear antibody (ANA) of mice were detected using direct immunofluorescence; kidney histological changes were examined by HE staining.

RESULTSFive randomly selected peptides were sequenced and the amino acid sequences IR, SQ, and PP were detected in a higher frequency. High-titer IgG autoantibodies of dsDNA, Sm, and ANA in the sera of experiment group were detected by ELISA 28 days after having been immunized by Sm mimotope. Proteinuria was detected 33 days later; immune complex and nephritis were observed in kidney specimens.

CONCLUSIONSLE-like murine model can be successfully induced by Sm phage mimotope.

Animals ; Antibodies, Antinuclear ; blood ; Autoantibodies ; blood ; Disease Models, Animal ; Epitopes ; immunology ; Immunoglobulin G ; blood ; Lupus Erythematosus, Systemic ; immunology ; Mice ; Mice, Inbred BALB C ; Molecular Mimicry ; Oligopeptides ; immunology ; Peptide Library

To investigate the interaction between tumor necrosis factor alpha (TNF alpha) mimotopes and TNF alpha-binding peptides screened from random phage display peptide library with TNF alpha mimotopes displayed on phage clone as the target, the computational docking program AutoDock (with confirmation calculations using Discover) was used to predict and analyze the binding modes of LLT-18 (TNF alpha binding peptide, sequence EHMALTYPFRPP) with TNF alpha, after which LCS-7 (TNF alpha mimic phage clone, displayed positive sequence c-RRPAQSG-c) was docked to LLT-18 manually. The binding between LLT-18 and TNF alpha or LCS-7 was stabilized predominantly through electrostatic interaction and H-bond formation. The Arg residues in TNF alpha or LCS-7 were important for their interaction with LLT-18. For LLT-18, the key amino acid residues were Glu1, His2, Met3 and Tyr7. These results suggest the feasibility of screening ligand to single epitope with specific phage clone as the target, and of predicting the interaction between small peptides by computer-aided molecular modeling.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; immunology ; Biotinylation ; Computer Simulation ; Drug Evaluation, Preclinical ; methods ; Epitopes ; immunology ; Humans ; Ligands ; Models, Molecular ; Oligopeptides ; chemistry ; metabolism ; Peptide Library ; Protein Conformation ; Solubility ; Tumor Necrosis Factor-alpha ; chemistry ; immunology ; metabolism

Thymopentin (TP5) and bursopentin (BP5) are both immunopotentiators. To explore whether the TP5-BP5 fusion peptide (TBP5) has adjuvant activity or not, we cloned the TBP5 gene and confirmed that the TBP5 gene in a recombinant prokaryotic expression plasmid was successfully expressed in Escherichia coli BL21. TBP5 significantly promoted the proliferation of thymic and splenic lymphocytes of mice. The potential adjuvant activity of the TBP5 was examined in mice by coinjecting TBP5 and H9N2 avian influenza virus (AIV) inactivated vaccine. HI antibody titers, HA antibodies and cytokines levels (IL-4 and IFN-γ) were determined. We found that TBP5 markedly elevated serum HI titers and HA antibody levels, induced the secretion of both IL-4 and IFN-γ cytokines. Furthermore, virus challenge experiments confirmed that TBP5 contributed to inhibition replication of the virus [H9N2 AIV (A/chicken/Jiangsu/NJ07/05)] from mouse lungs. Altogether, these findings suggest that TBP5 may be an effective adjuvant for avian vaccine and that this study provides a reference for further research on new vaccine adjuvants.
Adjuvants, Immunologic ; pharmacology ; Animals ; Antibodies, Viral ; blood ; Cell Proliferation ; drug effects ; Influenza A Virus, H9N2 Subtype ; drug effects ; physiology ; Influenza Vaccines ; immunology ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Lymphocytes ; drug effects ; Mice ; Oligopeptides ; immunology ; Orthomyxoviridae Infections ; drug therapy ; Recombinant Fusion Proteins ; immunology ; Spleen ; cytology ; Thymopentin ; immunology ; Thymus Gland ; cytology ; Vaccines, Inactivated ; immunology ; Virus Replication

The purpose of this study was to construct a HA-1-DC nucleic acid vaccine and to induce anti-leukemia effect after hematopoietic stem cell transplantation (HSCT). The dendritic cells (DCs) were generated from HSCT donors in vitro, and its immunologic activity was studied by using flow cytometry and mix lymphocyte reaction. HA-1 gene was electroporated into the cultured DCs to construct a DC nucleic acid vaccine. After transfecting for 48 hours, the expression of HA-1 protein was detected by Western blot. The DCs were cultured with isogenic lymphocytes to induce specific cytotoxic T lymphocytes (CTLs). The cytotoxicity of the CTLs was detected by LDH assay. The results showed that the DCs derived from peripheral blood monocytes (PBMCs) expressed the DC phenotype, and were effective in stimulating proliferation of the allogenic lymphocytes. After electroporating for 48 hours, HA-1 protein was detected by Western blot. The cytotoxity of inducing CTLs was higher than that in the control group. It is concluded that the minor histocompatibility antigen HA-1 can be considered as a target of immunotherapy against leukemia after HSCT.
Cancer Vaccines ; biosynthesis ; genetics ; immunology ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; Electroporation ; Graft vs Host Disease ; prevention & control ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Leukemia ; immunology ; therapy ; Minor Histocompatibility Antigens ; genetics ; immunology ; Oligopeptides ; genetics ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Vaccines, DNA ; biosynthesis ; genetics ; immunology

OBJECTIVETo clone IgHV genes from childhood B-ALL cells and identify CTL epitopes deduced from IgHV gene.

METHODSSeven IgHV gene families were respectively amplified by PCR and directly sequenced for 37 childhood B-ALL cases. Bioinformatics were applied for analyzing characteristics of sequences available and predicting HLA-A*0201 molecule-binding nonapeptides derived from IgHV. The predicted nonapeptide QLVQSGAEV was synthesized and its binding affinity to T2 cells determined. CD8+ T cells from a healthy HLA-A*0201+ donor peripheral blood were stimulated repeatedly with QLVQSGAEV-loaded antigen presenting cells.

RESULTSIgHV gene rearrangements were identified in 37 B-ALL. Forty IgHV gene sequences available preferentially utilized V(H)4-59 and V(H)4-34 gene segments. Increased frequency (15.4%) of D7-27 in B-ALL IgHV was found compared to that reported for adult PBLs (P = 0.02); 20.0% DJ(H) junctions in B-ALL lacked non-encoding nucleotides, a frequency higher than that reported for adult PBLs (P = 0.02). 17.5% B-ALL IgHV contained < 2% replacement mutations. Forty B-ALL IgHV sequences acquired 12 high HLA-A*0201-binding nonapeptides, 10 (83.0%) peptides were located in frame region (FR)1 and 3. The synthesized peptide QLVQSGAEV up-regulated HLA-A*0201 expression 1.63 fold on the surface of T2 cells. The frequency of QLVQSGAEV-specific CD8+ T cells in a healthy HLA-A*0201+ donor peripheral blood increased from 1.6% and 82.6% after two-round and 3-round stimulations, respectively.

CONCLUSIONIgHV genes in childhood B-ALL are of germline characteristics. Their heavy chain framework regions contain HLA-A*0201-binding nonapeptides. These peptides are capable of inducing specific CD8+ T cells to activate and proliferate.

Adolescent ; Burkitt Lymphoma ; genetics ; immunology ; CD8-Positive T-Lymphocytes ; cytology ; immunology ; Cell Proliferation ; Child ; Child, Preschool ; Epitopes, T-Lymphocyte ; immunology ; Gene Rearrangement ; HLA-A Antigens ; immunology ; metabolism ; HLA-A2 Antigen ; Humans ; Immunoglobulin Heavy Chains ; genetics ; immunology ; Immunoglobulin Variable Region ; genetics ; immunology ; Infant ; Oligopeptides ; immunology

BACKGROUNDImmunoglobulin heavy chain variable region (IgHV) is a well-characterized tumor antigen for B-cell malignancies. It can function as a target for T cell-mediated immune response. Clinical trials of IgHV protein vaccines against lymphoma have demonstrated induction of tumor-specific cytotoxic T lymphocyte (CTL) responses. However, complementary determining regions-based individual vaccines have disadvantages for wide clinical application. Although a recent study demonstrated that immunogenic peptides are derived from framework regions (FR) shared among patients with B-cell lymphoma, how to choose the appropriate peptides for each patient is still unsolved. The aim of this study was to investigate whether immunoglobulin heavy chain FR-derived peptides shared in each IgHV family are potential CTL epitopes presented by B-cell acute lymphoblastic leukemia (B-ALL). Such CTL epitopes might be beneficial to shifting vaccination strategies against B-ALL from individual specificity to family specificity.

METHODSSeven IgHV gene families were amplified respectively by PCR and sequenced directly from 71 childhood B-ALL cases. Bioinformatics was applied in analyzing characteristics of sequences available and predicting HLA-A*0201-restricted CTL epitopes for each IgHV family. An antigen-specific T cell expansion system was used to generate peptide-specific CTLs. The cytotoxicity of CTLs against B-ALL cells was assessed in the lactate dehydrogenase release assay.

RESULTSComplete IgHV rearrangements were identified in all of the 71 B-ALL cases. All of 40 sequences available showed > or = 98% homology with the nearest germline IgHV genes, indicating IgHV genes in B-ALL of germline nature. Twelve nonapeptides of high HLA-A*0201-binding scores were obtained from 26 productive IgHV protein sequences. Ten (83%) of the peptides were located in FR1 and FR3 shared among the corresponding IgHV family. CTLs specific for the peptide QLVQSGAEV located in FR1 (3 - 11) shared among the IgHV1 family could be successfully generated from peripheral blood mononuclear cells of two HLA-A*0201 + healthy donors in vitro and were capable of killing HLA-matched B-ALL cell clones belonging to the IgHV1 family.

CONCLUSIONAnti-B-ALL CTLs against immunoglobulin heavy chain FR-derived peptides have family-specific cytotoxicity.

Amino Acid Sequence ; Burkitt Lymphoma ; genetics ; immunology ; Epitopes, T-Lymphocyte ; genetics ; immunology ; Genes, Immunoglobulin Heavy Chain ; genetics ; Humans ; Immunoglobulin Heavy Chains ; chemistry ; genetics ; immunology ; Immunoglobulin Variable Region ; chemistry ; genetics ; immunology ; Molecular Sequence Data ; Oligopeptides ; immunology ; Polymerase Chain Reaction ; Protein Binding ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo develop a novel protein carrier which can not only regulate the immune system but also deliver DNA into the tumor cell as an effective non-viral gene delivery system.

METHODSBy using gene engineering techniques, we constructed a fusion protein containing the -COOH end of human hepatitis B virus core antigen (HBcAg), small home-to-cancer peptide ligand RGD and Glutathione S-transferase (GST), which was expressed in E. coli and purified by size exclusion chromatography and affinity chromatography. We labeled it with FITC to observe whether it could bind prostate cancer PC-3 cell lines, and meanwhile used it as a non-viral gene delivery carrier with the plasmid pEGFP-N1 that could express GFP in PC-3 cells. Furthermore, we observed the regulatory function of this fusion protein to the mouse immune system.

RESULTSThe results of SDS-PAGE showed that the new protein carrier was obtained, which It could enter PC-3 cells with DNA in vitro and induce the mouse immune system to produce IgG1 and IgG2alpha simultaneously.

CONCLUSIONThe new protein carrier can be used as a target protein, especially in positive cells and the immune system. It promises to be a good novel carrier for the gene therapy of cancer.

Animals ; DNA ; genetics ; immunology ; Female ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; immunology ; Glutathione Reductase ; genetics ; Hepatitis B Core Antigens ; genetics ; Mice ; Mice, Inbred BALB C ; Oligopeptides ; Plasmids ; Recombinant Proteins