AIM: To develop an oral DNA vaccine against gastric cancer and evaluate its efficacy in mice.METHODS: The genes of the MG7-Ag mimotope and a universal Th epitope (Pan-DR epitope, PADRE) were included in the PCR primer...AIM: To develop an oral DNA vaccine against gastric cancer and evaluate its efficacy in mice.METHODS: The genes of the MG7-Ag mimotope and a universal Th epitope (Pan-DR epitope, PADRE) were included in the PCR primers. By PCR, the fusion gene of the two epitopes was amplified. The fusion gene was confirmed by sequencing and was then cloned into pcDNA3.1(+) plasmid. The pcDNA3.1 (+)-MG7/PADRE was used to transfect an attenuated Salrmonella typhimuriurm.C57BL/6 mice were orally immunized with 1x108 cfu Salrmonella transfectants. Salmonella harboring the empty pcDNA3.1(+) plasmid and phosphate buffer saline (PBS)were used as negative controls. At the 6th week, serum titer of MG7-Ag specific antibody was detected by ELtSA.At the 8th week cellular immunity was detected by an unprimed proliferation test of the spleenocytes by using a [3H]-thymidine incorporation assay. Ehrlich ascites carcinoma cells expressing MG7-Ag were used as a model in tumor challenge assay to evaluate the protective effect of the vaccine.RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than that in control groups (0.841 vs 0.347, P＜0.01; 0.841 vs 0.298,P＜0.01), while in vitro unprimed proliferation assay of the spleenocytes showed no statistical difference between those three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while all the mice in the control groups showed tumor formation.
CONCLUSION: Oral DNA vaccine against the MG7-Ag momitope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumor in mice, and the vaccine has partially protective effects.展开更多
AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope...AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope were designed at the 5'terminus of forward primer. Using p1.2 Ⅱ-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by 51Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538±0.043 vs 0.6531±0.018, P<0.01; 0.9538±0.043 vs 0.6915±0.012, P<0.01), while in vitro 51Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.展开更多
AIM: To determine the significance of endoscopic surveillance in the diagnosis of acute rejection after human living-donor small bowel transplantations.METHODS: Endoscopic surveillance was performed through the ileost...AIM: To determine the significance of endoscopic surveillance in the diagnosis of acute rejection after human living-donor small bowel transplantations.METHODS: Endoscopic surveillance was performed through the ileostomy after human living-donor small bowel transplantations. The intestinal mucosa was observed and biopsies were performed for pathological observations.RESULTS: Acute rejection was diagnosed in time by endoscopic surveillance. The endoscopic and pathological manifestations of acute rejection were described. CONCLUSION: Endoscopic surveillance and biopsy are reliable methods to diagnose the acute rejection after human living-donor small bowel transplantations.展开更多
AIM: To investigate the apoptosis-inducing effect of Caspases-3 expressed by constructed eukaryotic vector on gastric cancer cell line SGC7901.METHODS: PCR was employed to amplify the sequences of both small and large...AIM: To investigate the apoptosis-inducing effect of Caspases-3 expressed by constructed eukaryotic vector on gastric cancer cell line SGC7901.METHODS: PCR was employed to amplify the sequences of both small and large subunits of Caspases-3. Its products were separately cloned into the Sma I site of pBluescript KS+ to generate both plasmids pBS/SS and pBS/LS. The small subunit fragment was excised from plasmid pBS/SS with BarrH- I and then inserted into the BarnH I site of plasmid pBS/LS preceding that of the large subunit to yield plasmid pBS/Rev-Caspase-3. Rev-Caspase-3 cDNA was excised with Kpn Ⅰ+Xba I and then subcloned into plasmid pcDNA3.1(+) to construct Rev-Caspase-3 eukaryotic expression vector pcDNA/Rev-Caspase-3, which was used to transiently transfect SGC7901 cell line. Cell count, MTT assay and electron microscopy were used to confirm the antiproliferation and apoptosis-inducing effect of Rev-Caspase-3 expression on gastric cancer cells.RESULTS: Plasmid pBS/Rev-Caspase-3 and eukaryotic expression vector pcDNA/Rev-Caspase-3 were successfully constructed. SGC7901 cells were transiently transfected by either pcDNA/Rev-Caspase-3 or pcDNA3.1 (+) for 24, 48,72, and 96 h respectively. Cell growth was measured by cell count and MTT assay. In cell count assay, the cell numbers were 1.S×106, 1.55×106, 2.0×106, and 3.1×106 in the experimental group and 2.5×106, 3.1×106, 4.0×106, and 5.7×106 in the control group at 24, 48, 72 and 96 h respectively.The growth of SGC7901 cells was suppressed by RevCaspase-3 in a time-dependent manner (P＜0.05). The results of MTT assay were similar to that of cell count (P＜0.05).The characteristics of apoptosis such as chromatin condensation, crescent formation and margination were seen and more obvious with time in the given-experimental period in the experimental group, but not easily observed in the control group.CONCLUSION: The expression of Rev-Caspase-3 by the constructed eukaryotic vector can significantly induce apoptosis of gastric cancer cell line SGC7901, w展开更多
AIM: To explore the effect of Hejie decoction (HJD) (mediation decoction) on T cellular immune state of chronic hepatitis B patients.METHODS: Sixty-five patients with chronic hepatitis B were randomly divided into 2 g...AIM: To explore the effect of Hejie decoction (HJD) (mediation decoction) on T cellular immune state of chronic hepatitis B patients.METHODS: Sixty-five patients with chronic hepatitis B were randomly divided into 2 groups. Forty patients in the treatment group were treated by HJD, and 25 patients in the control group were treated by routine Western medicine. The TCRVβ7 gene expression, T lymphocyte subsets (CD3^+, CD4^+, CD8^+,CD4^+/CD8^+) levels were observed before and after treatment.RESULTS: The level of CD4^+ cells was lower whereas the level of CD8^+ cells was higher in patients than in the normal group. There was no significant difference between the levels of CD3^+ cells in patients and normal persons. After 6 months of treatment, ALT, AST, TB levels of the 2 groups were obviously decreased, and the level of CD4^+ cells was increased whereas the level of CD8^+ cells was decreased in the treatment group. However, the level of CD4^+ cells and CD8^+ cells had no significant difference in the control group. TCRVβ7 expressions were detected in 6 patients of the treatment group, whose HBV-DNA and HBeAg turned negative and ALT became normal. HBeAg in another 3 patients turned negative while HBV-DNA did not, and TCRVβ7 expressions were not detectable. TCRVβ7 expression could not be detected in the control group, HBV-DNA of the control group did not turn negative. HBeAg in 1 patient turned negative while HBV-DNA did not, and TCRVβ7 expressions were not detectable. The total effective rate was not significantly different between the 2 groups and the markedly effective rate was significantly different(P<0.01).CONCLUSION: H3D is effective for treating chronic hepatitis B, and its effect seems to relate with the improvement of the TCRVβ7 expression of chronic hepatitis B patients, thus activating T cells and eliminating HBV. T cellular immune function plays an important role in HBV infection and virus elimination.展开更多
AIM: To demonstrate the effect of Hewei-Decoction (Decoction for regulating the stomach) on chronic atrophic gastritis (CAG) and eradication of Helicobacter pylori. METHODS: Ninety patients with CAG entering the inves...AIM: To demonstrate the effect of Hewei-Decoction (Decoction for regulating the stomach) on chronic atrophic gastritis (CAG) and eradication of Helicobacter pylori. METHODS: Ninety patients with CAG entering the investigation were divided into six differentiation syndromes, based on their major symptoms and signs. Hewei-Decoction was taken by all the patients orally for 4 or 8 wk. The efficacy was assessed by both the composite accumulation of reduced scores of major symptoms and the eradication of H pylori.X2 test was used to compare the efficacy between H pylori-positive and negative cases, and to disclose the relationship between efficacy and eradication of H pylori. RESULTS: In patients with six different syndrome types, the efficacy of Hewei-Decoction was 91.67% (11/12), 92.86% (13/14), 97.22% (35/36), 87.50% (14/16), 75.00% (6/8), 75.00% (3/4) respectively. The rate of highly efficacious was 58.33% (7/12), 50.00% (7/14), 77.78% (28/36), 62.50% (10/16), 12.50% (1/8) and 25.00% (1/4), respectively. The total efficacy was 91.11% (82/90), and the rate of highly efficacious was 60.00% (54/90). The eradication rate of H pylori was 67.86% (38/56). The therapeutic effect of Hewei-Decoction was better in H pylori positive cases than that in H pylori-negative cases with the total effect of 96.43% vs 82.35% (P<0.05). In 56 H pylori positive cases, the therapeutic effect was better in H pylori eradicated cases than that in H pylori-existent cases with the total effect of 97.37% vs 72.22% (P<0.01). CONCLUSION: Hewei-Decoction is effective in most cases of all the syndrome types. The results indicate that eradication of H pylori is one of the important mechanisms for alleviation of symptoms and signs. Also, the decoction is efficacious in H pylori-negative cases.展开更多
AIM: Using a monoclonal antibody against gastric cancer antigen named MGbl to screen a phage-displayed random peptide library fused with coat protein plII in order to get some information on mimotopes.lV^37BODS: Throu...AIM: Using a monoclonal antibody against gastric cancer antigen named MGbl to screen a phage-displayed random peptide library fused with coat protein plII in order to get some information on mimotopes.lV^37BODS: Through affinity enrichment and EUSA screening,positive clones of phages were amplified. 10 phage clones were selected after three rounds of biopanning and the ability of specific binding of the positive phage clones to MGb1-Ab were detected by ELISA assay (DNA sequencing was performed and the amino acid sequences were deduced)By blocking test, specificity of the mimic phage epitopes was identified.RESULTS: There were approximately 200 times of enrichment about the titer of bound phages after three rounds of biopanning procedures. DNA of 10 phage clones after the third biopanning was assayed and the result showed that the positive clones had a specific binding activity to MGbl-Ab and a weak ability of binding to control mAb or to mouse IgG. DNA sequencing of 10 phage clones was performed and the amino acid sequences were deduced.According to the homology of the amino acid sequences of the displayed peptides, most of the phage clones had motifs of H(x)Q or L(x)S. And these 10 phage clones could also partly inhibit the binding of MGbl-Ab to gastric cancer cell KATO-Ⅲ. The percentage of blocking was from (21.0±1.6) %to (39.0±2.7) %.CONCLUSION: Motifs of H(x)Q and L(x)S selected and identified show a high homology in the mimic epitopes of gastric cancer associated antigen. There may be one or more clones which can act as candidates of tumor vaccines.展开更多
AIM:To testify the immunogenicity of a conservative B-cell linear epitope of Helicobacter pylori ( H pylori) flagellin A. METHODS: Different programs were used to analyze the secondary structure, molecular hydropathy,...AIM:To testify the immunogenicity of a conservative B-cell linear epitope of Helicobacter pylori ( H pylori) flagellin A. METHODS: Different programs were used to analyze the secondary structure, molecular hydropathy, and surface accessibility of Hpyloriflagellin A. Linear B-cell epitopes were estimated based on the structural and physiochemical information. Analysis of residue divergence was proposed to screen a conservative linear epitope. The 29-peptide (Pep29mer) synthesized by chemical method, including the predicted conservative B-cell epitope and a known K^2d compatible T-cell epitope, was used to immunize mice, and then H pylori-specific antibodies were detected by ELISA. RESULTS: Based on the analyses of divergent amino acid residues, structural and physiochemical characteristics, it was strongly suggested that the short fragment NDSDGR was the core of a conservative linear epitope in flagellin A. Animals immunized by Pep29mer acquired efficient immune response. In detail, serum Hpylori-specific IgA and IgGl increased significantly in immunized group, while IgG2a only had an insignificant change. Hpylori-specific IgA in gastrointestinal flushing fluid also increased significantly. CONCLUSION: The conservative short fragment NDSDGR is the core of a linear B-cell epitope of flagellin A.展开更多
基金the National Natural Science Foundation of China, No.39870742
文摘AIM: To develop an oral DNA vaccine against gastric cancer and evaluate its efficacy in mice.METHODS: The genes of the MG7-Ag mimotope and a universal Th epitope (Pan-DR epitope, PADRE) were included in the PCR primers. By PCR, the fusion gene of the two epitopes was amplified. The fusion gene was confirmed by sequencing and was then cloned into pcDNA3.1(+) plasmid. The pcDNA3.1 (+)-MG7/PADRE was used to transfect an attenuated Salrmonella typhimuriurm.C57BL/6 mice were orally immunized with 1x108 cfu Salrmonella transfectants. Salmonella harboring the empty pcDNA3.1(+) plasmid and phosphate buffer saline (PBS)were used as negative controls. At the 6th week, serum titer of MG7-Ag specific antibody was detected by ELtSA.At the 8th week cellular immunity was detected by an unprimed proliferation test of the spleenocytes by using a [3H]-thymidine incorporation assay. Ehrlich ascites carcinoma cells expressing MG7-Ag were used as a model in tumor challenge assay to evaluate the protective effect of the vaccine.RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than that in control groups (0.841 vs 0.347, P＜0.01; 0.841 vs 0.298,P＜0.01), while in vitro unprimed proliferation assay of the spleenocytes showed no statistical difference between those three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while all the mice in the control groups showed tumor formation.
CONCLUSION: Oral DNA vaccine against the MG7-Ag momitope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumor in mice, and the vaccine has partially protective effects.
基金Supported by the National Natural Science Foundation of China, No. 39870742
文摘AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope were designed at the 5'terminus of forward primer. Using p1.2 Ⅱ-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by 51Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538±0.043 vs 0.6531±0.018, P<0.01; 0.9538±0.043 vs 0.6915±0.012, P<0.01), while in vitro 51Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.
文摘AIM: To determine the significance of endoscopic surveillance in the diagnosis of acute rejection after human living-donor small bowel transplantations.METHODS: Endoscopic surveillance was performed through the ileostomy after human living-donor small bowel transplantations. The intestinal mucosa was observed and biopsies were performed for pathological observations.RESULTS: Acute rejection was diagnosed in time by endoscopic surveillance. The endoscopic and pathological manifestations of acute rejection were described. CONCLUSION: Endoscopic surveillance and biopsy are reliable methods to diagnose the acute rejection after human living-donor small bowel transplantations.
文摘AIM: To investigate the apoptosis-inducing effect of Caspases-3 expressed by constructed eukaryotic vector on gastric cancer cell line SGC7901.METHODS: PCR was employed to amplify the sequences of both small and large subunits of Caspases-3. Its products were separately cloned into the Sma I site of pBluescript KS+ to generate both plasmids pBS/SS and pBS/LS. The small subunit fragment was excised from plasmid pBS/SS with BarrH- I and then inserted into the BarnH I site of plasmid pBS/LS preceding that of the large subunit to yield plasmid pBS/Rev-Caspase-3. Rev-Caspase-3 cDNA was excised with Kpn Ⅰ+Xba I and then subcloned into plasmid pcDNA3.1(+) to construct Rev-Caspase-3 eukaryotic expression vector pcDNA/Rev-Caspase-3, which was used to transiently transfect SGC7901 cell line. Cell count, MTT assay and electron microscopy were used to confirm the antiproliferation and apoptosis-inducing effect of Rev-Caspase-3 expression on gastric cancer cells.RESULTS: Plasmid pBS/Rev-Caspase-3 and eukaryotic expression vector pcDNA/Rev-Caspase-3 were successfully constructed. SGC7901 cells were transiently transfected by either pcDNA/Rev-Caspase-3 or pcDNA3.1 (+) for 24, 48,72, and 96 h respectively. Cell growth was measured by cell count and MTT assay. In cell count assay, the cell numbers were 1.S×106, 1.55×106, 2.0×106, and 3.1×106 in the experimental group and 2.5×106, 3.1×106, 4.0×106, and 5.7×106 in the control group at 24, 48, 72 and 96 h respectively.The growth of SGC7901 cells was suppressed by RevCaspase-3 in a time-dependent manner (P＜0.05). The results of MTT assay were similar to that of cell count (P＜0.05).The characteristics of apoptosis such as chromatin condensation, crescent formation and margination were seen and more obvious with time in the given-experimental period in the experimental group, but not easily observed in the control group.CONCLUSION: The expression of Rev-Caspase-3 by the constructed eukaryotic vector can significantly induce apoptosis of gastric cancer cell line SGC7901, w
基金Supported by Guangdong Administrative Bureau of TCM and Chinese Drugs,No.98374 and No.100108
文摘AIM: To explore the effect of Hejie decoction (HJD) (mediation decoction) on T cellular immune state of chronic hepatitis B patients.METHODS: Sixty-five patients with chronic hepatitis B were randomly divided into 2 groups. Forty patients in the treatment group were treated by HJD, and 25 patients in the control group were treated by routine Western medicine. The TCRVβ7 gene expression, T lymphocyte subsets (CD3^+, CD4^+, CD8^+,CD4^+/CD8^+) levels were observed before and after treatment.RESULTS: The level of CD4^+ cells was lower whereas the level of CD8^+ cells was higher in patients than in the normal group. There was no significant difference between the levels of CD3^+ cells in patients and normal persons. After 6 months of treatment, ALT, AST, TB levels of the 2 groups were obviously decreased, and the level of CD4^+ cells was increased whereas the level of CD8^+ cells was decreased in the treatment group. However, the level of CD4^+ cells and CD8^+ cells had no significant difference in the control group. TCRVβ7 expressions were detected in 6 patients of the treatment group, whose HBV-DNA and HBeAg turned negative and ALT became normal. HBeAg in another 3 patients turned negative while HBV-DNA did not, and TCRVβ7 expressions were not detectable. TCRVβ7 expression could not be detected in the control group, HBV-DNA of the control group did not turn negative. HBeAg in 1 patient turned negative while HBV-DNA did not, and TCRVβ7 expressions were not detectable. The total effective rate was not significantly different between the 2 groups and the markedly effective rate was significantly different(P<0.01).CONCLUSION: H3D is effective for treating chronic hepatitis B, and its effect seems to relate with the improvement of the TCRVβ7 expression of chronic hepatitis B patients, thus activating T cells and eliminating HBV. T cellular immune function plays an important role in HBV infection and virus elimination.
文摘AIM: To demonstrate the effect of Hewei-Decoction (Decoction for regulating the stomach) on chronic atrophic gastritis (CAG) and eradication of Helicobacter pylori. METHODS: Ninety patients with CAG entering the investigation were divided into six differentiation syndromes, based on their major symptoms and signs. Hewei-Decoction was taken by all the patients orally for 4 or 8 wk. The efficacy was assessed by both the composite accumulation of reduced scores of major symptoms and the eradication of H pylori.X2 test was used to compare the efficacy between H pylori-positive and negative cases, and to disclose the relationship between efficacy and eradication of H pylori. RESULTS: In patients with six different syndrome types, the efficacy of Hewei-Decoction was 91.67% (11/12), 92.86% (13/14), 97.22% (35/36), 87.50% (14/16), 75.00% (6/8), 75.00% (3/4) respectively. The rate of highly efficacious was 58.33% (7/12), 50.00% (7/14), 77.78% (28/36), 62.50% (10/16), 12.50% (1/8) and 25.00% (1/4), respectively. The total efficacy was 91.11% (82/90), and the rate of highly efficacious was 60.00% (54/90). The eradication rate of H pylori was 67.86% (38/56). The therapeutic effect of Hewei-Decoction was better in H pylori positive cases than that in H pylori-negative cases with the total effect of 96.43% vs 82.35% (P<0.05). In 56 H pylori positive cases, the therapeutic effect was better in H pylori eradicated cases than that in H pylori-existent cases with the total effect of 97.37% vs 72.22% (P<0.01). CONCLUSION: Hewei-Decoction is effective in most cases of all the syndrome types. The results indicate that eradication of H pylori is one of the important mechanisms for alleviation of symptoms and signs. Also, the decoction is efficacious in H pylori-negative cases.
基金the National High Technology Research and Development Program(863 Program)of China,No.2001AA215421
文摘AIM: Using a monoclonal antibody against gastric cancer antigen named MGbl to screen a phage-displayed random peptide library fused with coat protein plII in order to get some information on mimotopes.lV^37BODS: Through affinity enrichment and EUSA screening,positive clones of phages were amplified. 10 phage clones were selected after three rounds of biopanning and the ability of specific binding of the positive phage clones to MGb1-Ab were detected by ELISA assay (DNA sequencing was performed and the amino acid sequences were deduced)By blocking test, specificity of the mimic phage epitopes was identified.RESULTS: There were approximately 200 times of enrichment about the titer of bound phages after three rounds of biopanning procedures. DNA of 10 phage clones after the third biopanning was assayed and the result showed that the positive clones had a specific binding activity to MGbl-Ab and a weak ability of binding to control mAb or to mouse IgG. DNA sequencing of 10 phage clones was performed and the amino acid sequences were deduced.According to the homology of the amino acid sequences of the displayed peptides, most of the phage clones had motifs of H(x)Q or L(x)S. And these 10 phage clones could also partly inhibit the binding of MGbl-Ab to gastric cancer cell KATO-Ⅲ. The percentage of blocking was from (21.0±1.6) %to (39.0±2.7) %.CONCLUSION: Motifs of H(x)Q and L(x)S selected and identified show a high homology in the mimic epitopes of gastric cancer associated antigen. There may be one or more clones which can act as candidates of tumor vaccines.
文摘AIM:To testify the immunogenicity of a conservative B-cell linear epitope of Helicobacter pylori ( H pylori) flagellin A. METHODS: Different programs were used to analyze the secondary structure, molecular hydropathy, and surface accessibility of Hpyloriflagellin A. Linear B-cell epitopes were estimated based on the structural and physiochemical information. Analysis of residue divergence was proposed to screen a conservative linear epitope. The 29-peptide (Pep29mer) synthesized by chemical method, including the predicted conservative B-cell epitope and a known K^2d compatible T-cell epitope, was used to immunize mice, and then H pylori-specific antibodies were detected by ELISA. RESULTS: Based on the analyses of divergent amino acid residues, structural and physiochemical characteristics, it was strongly suggested that the short fragment NDSDGR was the core of a conservative linear epitope in flagellin A. Animals immunized by Pep29mer acquired efficient immune response. In detail, serum Hpylori-specific IgA and IgGl increased significantly in immunized group, while IgG2a only had an insignificant change. Hpylori-specific IgA in gastrointestinal flushing fluid also increased significantly. CONCLUSION: The conservative short fragment NDSDGR is the core of a linear B-cell epitope of flagellin A.
