Viral selection pressure and CD4+T cell epitope in HLA-DRB1 * 11:01 of HCV infected patients / 中国输血杂志

【Objective】 HLA-DRB1 * 11:01, as a class HLA-Ⅱ gene, was reported to be associated with spontaneous clearance of HCV in Han and Li population. Our study was to investigate the effects of viral selection pressure and CD4+T cell epitope on the natural outcome of HCV infection in HLA-DRB1 * 11:01 positive infected patients. 【Methods】 The positive selection sites and population growth of E1E2 and NS3 genes of common HCV 6a in HLA-DRB1 * 11:01 positive and negative groups in Guangdong were respectively analyzed. The peptide library covering the conserved regions of common HCV genotypes was used to stimulate HCV spontaneous clearance group and chronic infection group using ELISPOT method. Reactive peptides were obtained according to the number of spot-forming cells per well and the frequency of occurrence in different groups. 【Results】 The positive selection sites (PSSs) of E1E2 and NS3 of common HCV 6a in HLA-DRB1 * 11:01 negative group were greater than those in HLA-DRB1 * 11:01 positive group. Furthermore, the number of PPSs in CD4+T cell peptide in HLA-DRB1 * 11:01 negative group were also greater than those in HLA-DRB1 * 11:01 positive group; Both groups of HCV 6a had a population growth in Guangdong, and the expansion trend of HLA-DRB1 * 11:01 negative group was significantly higher than that of HLA-DRB1 * 11 :01 positive group. Compared to HCV chronic infection group, the response rate of HCV spontaneous clearance group to five peptides (C-52 E2691-707, C-119 NS31545-1560, C-134 NS4A1669-1684, C-154 NS4B1912-1927, C-159 NS4B1929-1944) was higher. However, the HCV chronic infection group showed a higher response rate to two of the peptides(C-111 NS31497-1512, C-130 NS31650-1665). When HLA-DRB1 * 11:01 typing was considered, there was no significant difference in HCV-specific immune response generated by PBMCs between HLA-DRB1 * 11:01 positive and HLA-DRB1 * 11:01 negative groups. 【Conclusion】 This study revealed the relationship between viral selection pressure of HLA-DRB1 * 11:01 HCV infected persons and CD4+T cell antigen epitopes. At the same time, CD4+ T cell antigen epitopes of HCV pan-genotype were obtained, providing basic data for the development of T cell vaccine suitable for HCV pan-genotype.

Preliminary immunological evaluation of Mycobacterium tuberculosis multicomponent protein vaccine candidates EPDPA015f and EPDPA015m / 中华微生物学和免疫学杂志

Objective:To preliminarily evaluate the immunogenicity and efficacy of two novel tuberculosis vaccine candidates (a fusion multicomponent protein EPDPA015f and a mixed multicomponent protein EPDPA015m) and to provide a new antigen combination for the development of tuberculosis vaccines.Methods:Recombinant plasmids for the expression of EPDPA015f and EPDPA015m proteins were constructed. Six-week-old BALB/c mice were immunized with EPDPA015f or EPDPA015m in combination with aluminium adjuvant (50 μg/mouse) for three times with an interval of 10 d. The mice were sacrificed 10 d after the last immunization to collect blood and spleen samples. Serum antibody titers and cytokine levels were measured by ELISA, Luminex technique and enzyme-linked immunospot assay (ELISPOT). Mycobacterial growth inhibition assay (MGIA) was used to detect the ability of mouse splenocytes to inhibit the growth of Mtb in vitro. One-way analysis of variance and t-test were used for statistical analysis. Results:Both EPDPA015f and EPDPA015m could induce the production of various cytokines and IgG antibodies at a high level. The levels of cytokines related to Th1 (IL-2, TNF-α, IFN-γ), Th2 (IL-4, IL-6, IL-10) and Th17 (IL-17) as well as other proinflammatory cytokines (GM-CSF, IL-12) were higher in the EPDPA015f group than in the adjuvant group ( P<0.05). The titer of IgG antibody induced by EPDPA015f was as high as 1∶4×10 6. The results of MGIA showed that the numbers of Mtb (lgCFU) in the PBS, adjuvant, EPDPA015f and EPDPA015m groups were 3.46±0.11, 3.51±0.06, 2.98±0.09 and 3.19±0.08, respectively. The number of colonies in the EPDPA015f group was the least as compared with that in the other three groups ( P<0.001, P<0.001, P<0.01). Conclusions:The vaccine candidate EPDPA015f could elicit more comprehensive and high-level cellular and humoral immune responses, and exhibited superior in vitro inhibitory activity against the growth of Mtb. EPDPA015f had the potential to be used as a preventive vaccine or a booster vaccine

Screening and identification of H-2 d-restricted T cell epitopes in fusion and attachment glycoproteins of Nipah virus by ELISPOT / 中华微生物学和免疫学杂志

Objective:To screen and identify H-2 d-restricted T cell epitopes in fusion (F) and attachment (G) glycoproteins of Nipah virus (NiV) in mice. Methods:The complete peptides (single peptide contains 15 amino acids, and 10 amino acids were repeated in the front and back peptides) derived from F and G antigens were mixed into peptide libraries. BALB/c mice were immunized with DNA vaccines expressing NiV F and G proteins alone and in combination. The full sequence peptide libraries of F and G antigens were mixed into peptide pools by matrix design, and spleen cells of immunized mice were collected and analyzed by IFN-γ ELISPOT assay to detect the dominant H-2 d-restricted epitope peptides. Results:Twelve dominant H-2 d-restricted peptides were screened from the F protein-specific peptide library and the 56th peptide produced the strongest reaction. Four dominant peptides were screened from the G protein-specific peptide library and the 72nd peptide produced the strongest reaction. Conclusions:In this study, 12 F antigen-specific and 4 G antigen-specific H-2 d restricted dominant T cell epitopes of NiV were screened and identified by IFN-γ ELISPOT, which could provide reference for immunological analysis of NiV and vaccine research.

Preliminary identification of CD4 T cell epitopes in genotype 1 and 6 of hepatitis C virus / 中国输血杂志

【Objective】 To study the CD4 T cell epitopes in Core and NS3 protein of genotype 1(GT1) and 6(GT6) of hepatitis C virus(HCV). 【Methods】 A total of 298 overlapping peptides(16-mer) spanning Core and NS3 protein of GT1 and GT6 HCV were synthesized. Peripheral blood mononuclear cells(PBMCs) from 17 HCV+ and 7 healthy blood donors were stimulated by peptide pools, followed by evaluating T cell response by IFN-γ ELISPOT, by which 21 peptides with positive results were found. These peptides were further applied to individually stimulate 20 HCV+ and 18 healthy PBMCs. The differences of responsive frequencies to the 21 positive peptides between the two study groups were compared. 【Results】 Pooled and individual peptide stimulation tests showed that HCV+ PBMCs were responsive to the stimulation of 5 peptides(GT1 NS31273-1288 and NS31315-1330; GT6 NS31033-1048, NS31087-1102 and NS31351-1366), with a responsive frequency ranging 18.9%-27.0%. In contrast, healthy PBMCs were not or low responsive(0%-4.0%) to these five peptides. The responsive frequencies were statistically different between the two groups(P<0.05). No reported epitopes in IEDB were found identical with these 5 peptides via sequence alignment. 【Conclusion】 Our study identified novel CD4 T cell epitopes in NS3 protein of GT1 and GT6 HCV, which has potential application value for the research and development of HCV vaccine.

Design and antitumor effect of nitrated T helper cell epitope vaccine CD47-NitraTh / 中国药科大学学报

@#Using the genetic code extension technology, the immunogenic amino acid, p-nitrophenylalanine, was introduced into the universal T cell epitope and then fused with the fragment of the extracellular region of the immune checkpoint molecular CD47(19-140)to construct a vaccine targeting CD47. The CD47-NitraTh vaccine elicited high titer antibody in BALB/c mice, significantly inhibited CT26 colon cancer cells growth, and increased the ratio of spleen CD4+ T cells and CD8+ T cells. Meanwhile, it promoted the polarization of naï ve T cells to Th1 cells. Notably, CD47-NitraTh not only increased the proportion of tumour-infiltrating lymphocytes but also reduced the proportion of Treg cells in tumour tissues, which means that CD47-NitraTh vaccine can remodel the tumour immunosuppressive microenvironment. The results of this study suggested that CD47-NitraTh can be used as an effective tumour vaccine candidate.

Assessing and screening for T-cell epitopes from Mycobacterium tuberculosis RD2 proteins for the diagnosis of active tuberculosis

ABSTRACT The Region of D eletion 2 (RD2) of Mycobacterium tuberculosis encodes reserved antigens that contribute to bacterial virulence. Among these antigens, Rv1983, Rv1986, Rv1987, and Rv1989c have been shown to be immunodominant in infected cattle; however, their diagnostic utility has not been evaluated in humans.In this study, we screened 87 overlapping synthetic peptides encoded by five RD2 proteins for diagnosing tuberculosis epitopes in 50 active tuberculosis (TB) cases, 31 non-tuberculosis patients and 36 healthy individuals. A pool of promising epitopes was then assessed for their diagnostic value in 233 suspected TB patients using a whole blood IFN-γ release assay.Only 10 peptides were recognized by more than 10% of active tuberculosis patients. The IFN-γ release responses to Rv1986-P9, P15, P16, Rv1988-P4, P11, and Rv1987-P11 were significantly higher in the active TB group than in the control groups (p < 0.05). The whole blood IFN-γ release assay based on these epitopes yielded a sensitivity of 51% and a specificity of 85% in diagnosing active tuberculosis, and the corresponding results using the T-SPOT.TB assay were 76% and 75%, respectively.In conclusion, these results suggest that the six epitopes from the RD2 of M. tuberculosis have potential diagnostic value in TB.

Homology modeling and epitope prediction of Der f 33

Dermatophagoides farinae (Der f), one of the main species of house dust mites, produces more than 30 allergens. A recently identified allergen belonging to the alpha-tubulin protein family, Der f 33, has not been characterized in detail. In this study, we used bioinformatics tools to construct the secondary and tertiary structures and predict the B and T cell epitopes of Der f 33. First, protein attribution, protein patterns, and physicochemical properties were predicted. Then, a reasonable tertiary structure was constructed by homology modeling. In addition, six B cell epitopes (amino acid positions 34-45, 63-67, 103-108, 224-230, 308-316, and 365-377) and four T cell epitopes (positions 178-186, 241-249, 335-343, and 402-410) were predicted. These results established a theoretical basis for further studies and eventual epitope-based vaccine design against Der f 33.

A specific immune therapeutic effect of Der p2 T cell epitope vaccine on asthma mice / 中国血吸虫病防治杂志

Objective To investigate the specific immune therapeutic effect of the T cell fusion peptide vaccine from group II allergens from Dermatophagoides pteronyssinus(Der p2). Methods Thirty mice were randomly divided into three groups, namely a negative control group(a PBS group),positive control group(an asthma group)and protein Der p2 T cell fusion epit?ope for specific immunotherapy(SIT)group(a Der p2 T group). The extract of house dust mites(HDM)was used to establish the asthmatic models in BALB/c mice,and the PBS group was always used with PBS buffer. Thirty minutes before spray inhala?tion from 25 to 27 days,the mice of the Der p2 T group were respectively injected subcutaneously with the therapeutic proteins for SIT,then the serum and bronchoalveolar lavage fluid(BALF)were collected. ELISA was used to assay the levels of IFN?γ, IL?4,and IL?13 in BALF,as well as serum levels of specific IgE and IgG2a. The lung tissue sections were stained with haematox?ylin and eosin(H&E)for pathological examinations. Results The ELISA detection revealed that the number of eosinophil in BALF of the asthmatic mice was(5.57 ± 0.64)× 105/ml,which was significantly higher than that in the PBS group[(0.50 ± 0.30)× 105/ml,P < 0.01],the number of eosinophil in the Der p2 T immunotherapy group decreased significantly[(3.45 ± 0.36)×105/ml,P<0.01]. The content of IFN?γin the PBS group,asthma group and Der p2 T group were(267.00 ± 21.98), (155.80 ± 20.53)pg/ml and(234.40 ± 24.46)pg/ml respectively. Compared with the asthma group,the mice with Der p2 T vac?cine specific immune treatment produced a high level of IFN?γ(P<0.01). The content of IL?4 in the PBS group,asthma group and Der p2 T group were(23.40 ± 5.96),(53.28 ± 8.26)pg/ml and(30.00 ± 5.50)pg/ml respectively. Compared with the asth?ma group,the content of IL?4 in the mice of the Der p2 T treatment group was significantly lower(P<0.01). Compared with the asthma group[(308.10 ± 28.32)pg/ml],the content of IL?13 in BALF of the mice in the Der p2 T treatment group was signifi?cantly decreased,which was[(174.50 ± 25.99)pg/ml,P<0.01]. The content of IL?13 in the PBS group was(95.99 ± 31.14) pg/ml. The lung tissue sections showed that the lung inflammation in the p2 T Der group was significantly less than that in the asthma group,and the inflammatory cell infiltration was significantly decreased,and airway epithelial construction remodeled. Conclusion The Der p2 T cell fusion epitope,which is as vaccines for specific immunotherapy with asthma models,can allevi?ate effectively allergic inflammation of airway and lung in the mice,and it may be used as a candidate vaccine for asthma.

Immunogenicity and efficacy of recombinant 78 kDa antigen of Leishmania donovani formulated in various adjuvants against murine visceral leishmaniasis

Objective: To analyze the protective efficacy of recombinant 78 kDa antigen of Leishmania donovani in combination with two adjuvants, that is, cationic liposomes or MPL-A against visceral leishmaniasis in BALB/c mice. Methods: The genomic DNA of promastigotes was isolated and 583 bp of T cell epitopes of gene encoding 78 kDa was amplified using specific primers. The amplified gene was cloned into pET28c, transformed into Escherichia coli BL21 (DE3) and got expressed after IPTG induction. The recombinant protein was then purified using Ni-NTA and named r78. Three groups of mice were immunized with 10 μg of r78 plus MPL-A, r78 encapsulated in positively charged liposomes and control animals immunized with PBS. Two booster doses were given with the respective vaccine at an interval of 2 weeks each. Mice were challenged with 1 × 107 Leishmania promastigotes and sacrificed on different post infection/challenge days. Results: Immunization with r78 along with MPL-A and liposome-encapsulated r78 brought a significant reduction in parasite load. In comparison to the infected controls, the parasite load declined by 96.2% in mice immunized with r78 plus MPL-A and 97.23% in animals immunized with liposome-encapsulated r78. The immunized animals also exhibited profound DTH response. The serum antibody responses increased from 15 to 90 days post infection/challenge. Immunized animals showed greater IgG2a levels and lesser IgG1 levels in comparison to the infected controls. The splenocytes from immunized mice were cultured, stimulated with r78 and analyzed for cytokine profile. The levels of IL-2 and IFN-γ were greater in immunized animals as compared to control mice. Conclusions: The study proves that r78 in combination with suitable adjuvants is a potential vaccine candidate and may be instrumental in control of visceral leishmaniasis.

Immunogenicity and efficacy of recombinant 78 kDa antigen of Leishmania donovani formulated in various adjuvants against murine visceral leishmaniasis

OBJECTIVE@#To analyze the protective efficacy of recombinant 78 kDa antigen of Leishmania donovani in combination with two adjuvants, that is, cationic liposomes or MPL-A against visceral leishmaniasis in BALB/c mice.@*METHODS@#The genomic DNA of promastigotes was isolated and 583 bp of T cell epitopes of gene encoding 78 kDa was amplified using specific primers. The amplified gene was cloned into pET28c, transformed into Escherichia coli BL21 (DE3) and got expressed after IPTG induction. The recombinant protein was then purified using Ni-NTA and named r78. Three groups of mice were immunized with 10 μg of r78 plus MPL-A, r78 encapsulated in positively charged liposomes and control animals immunized with PBS. Two booster doses were given with the respective vaccine at an interval of 2 weeks each. Mice were challenged with 1 × 10(7)Leishmania promastigotes and sacrificed on different post infection/challenge days.@*RESULTS@#Immunization with r78 along with MPL-A and liposome-encapsulated r78 brought a significant reduction in parasite load. In comparison to the infected controls, the parasite load declined by 96.2% in mice immunized with r78 plus MPL-A and 97.23% in animals immunized with liposome-encapsulated r78. The immunized animals also exhibited profound DTH response. The serum antibody responses increased from 15 to 90 days post infection/challenge. Immunized animals showed greater IgG2a levels and lesser IgG1 levels in comparison to the infected controls. The splenocytes from immunized mice were cultured, stimulated with r78 and analyzed for cytokine profile. The levels of IL-2 and IFN-γ were greater in immunized animals as compared to control mice.@*CONCLUSIONS@#The study proves that r78 in combination with suitable adjuvants is a potential vaccine candidate and may be instrumental in control of visceral leishmaniasis.

Effect of immunotherapy of recombinant chimeric epitopes of major aller-gen group 1 from Dermatophagoides farina on asthma of mice / 中国血吸虫病防治杂志

Objective To investigate the effect of immunotherapy of recombinant chimeric epitopes of major allergen group 1 from Dermatophagoides farina on asthma of mice. Methods Forty mice were randomly divided into 4 groups:a negative con?trol group,an asthma group,an immunotherapy group of Der f 1,and an immunotherapy group of Der f 1A. On the 1st,7th and 14th day,the mice in the asthma group,immunotherapy group of Der f 1,and immunotherapy group of Der f 1A were injected intraperitoneally with the extract of D. farina 3 times to sensitize;and on the 21st day,the atomized inhalation was carried out for 7 days. In the control group,phosphate buffer solution(PBS)was applied for sensitization and inhalation. In the immunother?apy groups,Der f 1 and Der f 1A were applied to carry out the specific immunotherapy respectively for 30 min before the inhala?tion. Then,the leukocytes in the bronchoalveolar lavage fluid(BALF)were numbered and the pathological sections of lung tis?sues were observed;IL?5 and IFN?γin BALF and spleen cell culture supernatants(SCCS)as well as the specific IgE,IgG2a in the sera were detected. Results Compared with the asthma group,the lung inflammation of mice in the immunotherapy groups was lightened,and the total numbers of leukocytes in BALF were significantly reduced;IL?5 was significantly reduced and IFN?γwas significantly increased in BALF and SCCS of mice in the immunotherapy groups;and the specific IgE was significantly re?duced and IgG2a was significantly increased in the sera of mice in the immunotherapy groups(all P<0.01). Conclusion The recombinant chimeric epitopes of major allergen group 1 from D. farina could effectively relieve the symptom of asthma in mice, so as to provide the evidence for specific immunotherapy.

Conservation of T cell epitopes between seasonal inlfuenza viruses and the novel inlfuenza A H7N9 virus / 中国病毒学·英文版

A novel avian influenza A (H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian inlfuenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 inlfuenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal inlfuenza and avian inlfuenza H7N9 was comparable to that with the highly pathogenic avian inlfuenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses (compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our ifndings predict signiifcant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.

Prediction and identification of T-cell epitopes in major group 3 allergen de-rived from Dermatophagoides farina / 中国血吸虫病防治杂志

Objective To predict and identify T cell epitopes of major group 3 allergen derived from Dermatophagoides fari-na(Der f 3). Methods The T cell epitopes of Der f 3 were analyzed through the sequence analysis by using the bioinformatics online tools. The five predicted peptides of T-cell epitopes were artificially synthesized. The spleen lymphocytes were co-cultured with the five T cell epitopes by using the modified MTT method and the levels of IL-2,IFN-γ,IL-4 and IL-5 in the supernatant of the cultures were detected by ELISA. Results Five T cell epitopes of Der f 3 were predicted and three of which could pro-mote the proliferation of the mouse spleen lymphocytes. The secretions of IL-2 and IFN-γwere significantly induced and the se-cretions of IL-4 and IL-5 were significantly decreased by three of five prediction epitopes of Der f 3:37GDCPYQISLQSSSHFC-GG54,98IYQHENYDSMTIDNDVALIKLKTPMT123 and 164SELQRVDIDVVSREQCDQLYS184. Conclusion Three T cell epitopes of Der f 3 have been initially identified,which lays the foundation of the diagnosis and treatment of asthma.

Construction and expression of a chimeric gene with T-/B-cell epitopes of major allergen group 1 from Dermatophagoides farina / 中国血吸虫病防治杂志

Objective To construct and express a chimeric gene with T-/B-cell epitopes of the major allergen group 1 from Dermatophagoides farina(Der f 1). Methods Two chimeric genes,Der f 1A and Der f 1B,were synthesized as B1-T1-B2-T2-B3-T3-B4-T4-B5-T5-B6 and B1-B2-B3-B4-B5-B6-T1-T2-T3-T4-T5 pattens. Two recombinant vectors,pET-28a(+)-Der f 1A and pET-28a(+)-Der f 1B,were constructed for prokaryotic expression. These chimeric genes were induced by 1 mmol/L IPTG (final concentration),digested with restriction enzymes and sequenced. The chimeric proteins were analyzed by SDS-PAGE and Western blotting. Results After digestion by restriction enzymes and sequencing,the recombinant vectors were constructed successfully. The specific bands for chimeric proteins were visible by SDS-PAGE and Western blotting,suggesting that these proteins were purified successfully. Further analyses were performed for IgE-binding properties of Der f 1A and Der f 1B to sera from patients sensitized to house dust mite. Compared with the parental allergens Der f 1,Der f 1A and Der f 1B had reduced IgE-binding capacity(both P0.05). Conclusion Two chimeric proteins are expressed successfully,which contain T-/B-cell epitopes of Der f 1 and provide a basis for specific immunotherapy.

Relationship between Poor Immunogenicity of HLA-A2-Restricted Peptide Epitopes and Paucity of Naive CD8+ T-Cell Precursors in HLA-A2-Transgenic Mice

We examined the immunogenicity of H-2 class I-restricted and HLA-A2-restricted epitopes through peptide immunization of HLA-A2-transgenic mice that also express mouse H-2 class I molecules. All four of the tested epitopes restricted by H-2 class I robustly elicited T-cell responses, but four of seven epitopes restricted by HLA-A2 did not induce T-cell responses, showing that HLA-A2-restricted peptide epitopes tend to be poorly immunogenic in HLA-A2-transgenic mice. This finding was confirmed in HLA-A2-transgenic mice infected with a recombinant vaccinia virus expressing hepatitis C virus proteins. We examined the precursor frequency of epitope-specific naive CD8+ T cells in HLA-A2-transgenic and conventional C57BL/6 mice and found that the poor immunogenicity of HLA-A2-restricted peptide epitopes is related to the paucity of naive CD8+ T-cell precursors in HLA-A2-transgenic mice. These results provide direction for the improvement of mouse models to study epitope repertoires and the immunodominance of human T-cell responses.

Phage display and immunological identification of efficient T- and B-combined antigenic epitopes in Helicobacter pylori adhesin A / 中华微生物学和免疫学杂志

Objective To analyze and determine the efficient T- and B-combined (T/B) antigenic epitopes in Helicobacter pylori adhesin A. Methods Recombinant HpaA (rHpaA) was expressed for immunizing rabbit to generate antiserum. T- and B-cell epitopes in HpaA molecule were predicted by using bioinformatic technique. The segments to encode T/B combined epitope peptides were amplified by PCR and the phage display systems of T/B combined epitopes were subsequently constructed. PEG/NaCl precipitation method was applied to extract the recombinant phage PⅢ (rPⅢ) that displayed T/B combined epitopes. By using either commercial IgG against whole-cell of Helicobacter pylori or rHpaA antiserum as the primary antibody, the T/B combined epitopes displayed in rP Ⅲ s were screened and identified by Western blot and ELISA. MTT was applied to determine the proliferation of rHpaA-immunized mouse splenocytes after stimulation of the different recombinant rPⅢ proteins. Results In the HpaA molecule there were five T/B combined epitopes: HpaA10, HpaA37, HpaA79, HpaA116 and HpaA143. All the T/B combined epitopes were successfully displayed on the surface of PⅢ protein of phage M13. The results of Western blot, ELISA and MTT confirmed that HpaA116 was the predominant antigenic epitope, both HpaA37 and HpaA79 were the efficient antigenic epitopes. However, HpaA10 and HpaA143 were identified as ineffective antigenic epitopes. Conclusion The phage display systems of T/B combined epitope peptides of H. pylori adhesin A have been successfully generated in this study. HpaA37 and HpaA79, especially HpaA116 are the efficient T/B combined antigenic epitopes in HpaA of H. pylori.

Approaches for Antigen Epitope Study and the Development of Antigen Epitopes of Foot-and-mouth Disease Virus / 微生物学通报

This paper reviews the common approaches for B cell epitopes and T cell epitopes study in recent years, and its application in foot-and-mouth disease virus (FMDV)’s antigen epitope study. The development of antigen epitopes of FMDV are also summarized.

Hepatitis B Virus Surface Antigen: A Multifaceted Protein / 대한간학회지

Despite the small size of its genome (3.2 kb) and having only four genes that are encoded within it, the hepatitis B virus (HBV) is one of the most successful viral pathogens in human history. It is estimated that there are about 350-400 million people worldwide who are chronically infected with HBV, and even with the extensive efforts that are being done with preventive vaccination, this malady still remains a clear and present danger to the public health. How is it possible that this small double-stranded DNA virus can escape and outfox the surveillance of the complex human immune system? One explanation is that HBV gene products play multiple roles in infections and throughout the viral life cycle so that the virus can effectively survive under various hostile circumstances. Indeed, the HBV DNA polymerase, for example, exerts several functions such as reverse transcription and RNA degradation, and the HBV X protein not only acts as a transcriptional activator, but it also interferes with the host cells' DNA repair mechanism as well as inducing apoptosis and controlling signal transduction. The HBV surface protein, which is encoded in the env gene, is another intriguing example of such multifunctionality. Thus, our present article overviews and summarizes the multifaceted role of this membrane protein as shown in 1) its role as a structural protein of the virus envelope; 2) its function as the viral ligand for interacting with the viral receptors on host cells; 3) its characteristics as an energy-independent transporter molecule that can mediate the nuclear accumulation of itself and other tagged molecules; 4) its role as a viral transactivator protein that can cause hepatocellular carcinoma; 5) its hypothetical function in viral apoptotic mimicry that results in host anti-inflammatory responses; and last 6) its immunostimulatory property by providing for strong and well-defined B- and T-cell epitopes. Understanding these various functions and the versatility of this single protein will help us decipher and understand the viral- and immuno-pathogenesis of HBV itself.

Cancer therapeutic vaccines targeting hTERT-derived T-cell epitope peptide: Advances in researches / 医学研究生学报

Human telomerase reverse transcriptase(hTERT),a catalytic subunit of telomerase,is highly expressed in a vast majority of cancer cells,but not in most normal adult cells,which makes it a broadly applicable molecular target for cancer immunotherapy.T cell epitope-based vaccines make use of T-cell epitopes from tumor antigens,and have its own unique advantages in cancer immunotherapy.The T-cell epitope peptide vaccine derived from hTERT can efficiently evoke specific cytotoxic T lymphocytes(CTL) responses,and has exhibited its anti-tumor effect in vivo in mice.Now it has already been put into experiment on human beings and displayed a good application prospect.

The Importance of Helper T-cell Epitope in Vaccine Development / 热带医学杂志

The major challenge in vaccine development a gainst various disease-causing organisms is to use defined antigen to stimulate appropriate immune responses that lead to resistance. The use of peptide-based vaccine is gaining greater attention asits flexibility in the incorporation of multiple defined and different epitopes into a single construct for eliciting d esirable arms of the immune system. It is generally safer than the use of live a ttenuated vaccine while it is relative ease of manufacture than subunit vaccine. However, development of peptide-based vaccine faces significant challenges. This approach has limited ability to elicit immune responses in a genetically dive rse outbred population due to the Major Histocompatibility Complexes (MHC) polym orphism. For the same reason, peptide immunizations often elicit inadequate cyto toxic T lymphocyte (CTL) and antibody (Ab) responses due to the lack of appropri ate helper Tlymphocyte (HTL) activity. Another possible disadvantage of using linear peptide construct is that, for eliciting appropriate antibody responses, s urface immunoglobulin (Ig) receptor clustering is needed in order to activate th e resting B cells. Problems caused by MHC polymorphism may be circumvented by the use of promiscuous T-cell epitopes. Promiscuous T-cell epitopes from the mea sles virus F protein (amino acid [aa] 288 to 302) and a murine defined T-helper cell epitope (V1E8, aa 191-209) that bind to multiple MHC molecules have bee n identified and have been used in highly immunogenic constructs to overcome hap lotype-restricted immune responses. Synthetic non-natural Pan DR Epitope (PADR E) which have degenerate binding capacity to several common HLA-DR can enhance immunogenicity of short-peptide immunogen, both in terms of absolute titers and quality of antibody responses. Besides, a number of so called "promiscuous" T -cell epitopes from Influenza virus hemagglutinin (HA), Plasmodium falciparum pre-erythrocytic stage antigens and mycobacterial proteins have been reporte d to be universally immunogenic. For promiscuous binding to several isotypic and allotypic forms of MHC class Ⅱ molecules, these peptides should display overla pping MHC-binding motifs or should use anchors that are conserved among ligands and should lack allele-specific anchor residues that would prevent binding wit h the other class Ⅱ molecules. Understanding the biophysical basis for both the promiscuity and the specificity of peptide recognition by MHC Ⅱ molecules will provide a molecular rationale for strategies to overcome genetic restriction in the context of vaccine design.