Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion...Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion engines.A suitable-scale chemical kinetic mechanism is very crucial for the accurate and rapid prediction of engine combustion and emissions.However,most previous researchers developed the mechanism of blend fuels through the separate simplification and merging of the reduced mechanisms of diesel and biodiesel rather than considering their cross-reaction.In this study,a new reduced chemical reaction kinetics mechanism of diesel and biodiesel was constructed through the adoption of directed relationship graph (DRG),directed relationship graph with error propagation,and full-species sensitivity analysis (FSSA).N-heptane and methyl decanoate (MD) were selected as surrogates of traditional diesel and biodiesel,respectively.In this mechanism,the interactions between the intermediate products of both fuels were considered based on the cross-reaction theory.Reaction pathways were revealed,and the key species involved in the oxidation of n-heptane and MD were identified through sensitivity analyses.The reduced mechanism of n-heptane/MD consisting of 288 species and 800 reactions was developed and sufficiently verified by published experimental data.Prediction maps of ignition delay time were established at a wide range of parameter matrices (temperature from 600 to 1 700 K,pressure from 10 bar to 80 bar,equivalence ratio from 0.5 to 1.5) and different substitution ratios to identify the occurrence regions of the crossreaction.Concentration and sensitivity analyses were then conducted to further investigate the effects of cross-reactions.The results indicate temperature as the primary factor causing cross-reactivity.In addition,the reduced mechanism with cross-reactions was more accurate than that without cross-reactions.At 700–1 000 K,the cross-reactions inhibited the consumption of n-heptane/MD,which resulted in a prolonged ignition delay time.At this point,the elementary reaction,NC_(7)H_(16)+OH<=>C_(7)H_(15)-2+H_(2)O,played a dominant role in fuel consumption.Specifically,the contribution of the MD consumption reaction to ignition decreased,and the increased generation time of OH,HO_(2),and H_(2)O_(2) was directly responsible for the increased ignition delay.展开更多
A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-contain...A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.展开更多
To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 ser...To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 serum samples from healthy controls and 104 serum specimens from autoimmune disease patients were collected.The results of ELISA showed that among 114 sera from healthy controls,4 (3.5%) were positive of SARS-CoV-IgG antibody and 114 (100%) were all negative of SARS-CoV-IgM antibody;the specificity of SARS-CoV-IgG antibody for SARS patients was 96.5%,but the specificity of both SARS-CoV-IgG and -IgM antibodies for SARS patients was 100%.In 58 cases with SLE,positive rates of SARS-CoV-IgG and -IgM antibodies were 32.8% (19/58) and 8.6% (5/58),respectively,in which 11 cases (19%) were positive of both SARS-CoV-IgG and -IgM antibodies;in 10 cases with SS,positive rate of both SARS-CoV-IgG and -IgM antibodies was 10% (1/10);in 16 cases with MCTD,positive rate of SARS-CoV-IgG was 37.5% (6/16),positive rate of both SARS-CoV-IgG and -IgM antibodies was 6.3% (1/16);in 20 cases with RA,one case was positive (5%) of SARS-CoV-IgG.However,of all samples with positive SARS-CoV-IgG and -IgM antibodies for autoimmune diseases and healthy controls,SARS-CoV RNA and antibodies were all negative by RT-PCR and IFA.All sera for negative or positive ELISA results were also negative or positive results using ELISA with Vero E6 cells lysates.These studies showed that SARS-CoV Vero E6 cell lysates for the ELISA to detect SARS-CoV antibodies could lead to the false-positive reactions or cross-reactions of SARS-CoV antibodies in non-SARS diseases and healthy controls,and the false-positive reactions or cross-reactions were related to Vero E6 cell lysates and autoantibodies in non-SARS population.Cellular & Molecular Immunology.2004;1(4): 304-307.展开更多
This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematic...This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematically reviewing available literature using multiple databases,including Web of Science,PubMed,Google Scholar and medRxiv.Among a total of 16 presented cases from clinical settings,cross-reaction to COVID-19 serological tests was observed in two(12.5%)dengue-positive patients,while 14 patients(87.5%)confirmed positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)showed a cross-reaction with dengue serological tests,leading to misdiagnosis and mismanagement by attending clinicians.Of 1789 SARS-CoV-2-positive sera,cross-reaction to dengue serological tests was observed in 180 sera(10%),which is higher than the cross-reaction observed for SARS-CoV-2 in archived pre-COVID-19 sera positive for a dengue infection(75 of 811,9.2%,P=0.674).Clinicians in tropical regions are therefore advised to interpret serological tests with caution and use a more pragmatic approach to triage these infections.展开更多
Objective:To characterize the group-29 allergens from Dermatophagoides(D.)pteronyssinus and investigate their ability to cross-react with other group-29 allergens from D.pteronyssinus as well as those from D.farinae a...Objective:To characterize the group-29 allergens from Dermatophagoides(D.)pteronyssinus and investigate their ability to cross-react with other group-29 allergens from D.pteronyssinus as well as those from D.farinae and Tyrophagus putrescentiae.Methods:Der p 29,Der f 29,and Tyr p 29 cDNA sequences were amplified from total RNA isolated from D.pteronyssinus,D.farinae and Tyrophagus putrescentiae,respectively.Then they were cloned into the pET28a vector,expressed in Rosetta2(DE3)plysS,and purified using anion exchange chromatography.The IgE-binding rates of rDer p 29 were assessed by IgE Western blotting.The four epitopes of rDer p 29 were predicted,synthesized,and detected by IgE-ELISA.The cross-reactivity among the recombinant proteins rDer p 29,rDer f 29,and rTyr p 29 was investigated using dot blot and IgE-ELISA inhibition experiments.The allergens’physiochemical properties,amino acid sequences,and tertiary structures were also compared.Results:Der p 29 was successfully expressed in Rosetta2(DE3)plysS as a single,393-bp open reading frame.Western blotting showed that the purified rDer p 29 protein exhibited an IgE-binding rate of 100%when tested on patient sera.The following four Der p 29 epitopes were predicted and synthesized:37-45(EP1),57-69(EP2),75-80(EP3),and 104-117(EP4).IgE-ELISA tests on 20 D.pteronyssinus-positive sera yielded IgE-binding rates of 85%(rDer p 29),80%(EP1),55%(EP2),40%(EP3),and 55%(EP4),respectively.The dot blot experiments further confirmed cross-reactivity among the three group-29 proteins.When used as an inhibitor,rDer p 29 demonstrated an average cross-reactive inhibition rate of 49.7%against rDer f 29 and 54.4%against rTyr p 29.When rTyr p 29 was used as an inhibitor,it showed an average cross-reactive inhibition rate of 56.3%against rDer f 29.Conclusions:A recombinant protein,rDer p 29 with strong allergenicity was produced.Moreover,it was found that rDer p 29 cross-reacted with rDer f 29 and rTyr p 29,due to their highly homologous sequences and structures.These findings highlight the importance of considering inter-species epitope cross-reactivity when diagnosing and treating allergic diseases.展开更多
As an important shellfish group,the oyster can induce severe allergic reactions.We aimed to identify and characterize the major allergen in Crassostrea gigas,and elucidate the molecular basis of its allergenicity and ...As an important shellfish group,the oyster can induce severe allergic reactions.We aimed to identify and characterize the major allergen in Crassostrea gigas,and elucidate the molecular basis of its allergenicity and cross-reactivity.The native and recombinant C.gigas-arginine kinase(AK)displayed significant immunoglobulin(Ig)G-and Ig E-binding activity.The Ig E-binding activity of C.gigas-AK could be reduced by thermal treatment and strong acidic and alkaline conditions.Besides,cross-reactivity of AK was demonstrated between shellfish species.Among seven epitope peptides identified here,P2 is responsible for the specificity of C.gigas-AK,while P3 is responsible for cross-reactions between mollusks and crustaceans.Furthermore,Glu98 and His31 in the light chain,Arg101,and Lys57 in the heavy chain are identified as key Ig E residues in recognizing epitopes.These findings provide new insights into the prevention and treatment of shellfish allergy and the development of hypoallergenic shellfish products.展开更多
In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitizati...In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.展开更多
Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare w...Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare were used to immunize BALB/c mice.The antigens were evaluated using cellular and humoral immunoassays.The common genes between M.intracellular and M.tuberculosis were identified using genome-wide comparative analysis,and cross-reactive proteins were screened using immunoproteome microarrays.Results Immunization with M.intracellulare proteins induced significantly higher levels of the cytokines interferon-γ(IFN-γ),interleukin-2(IL-2),interleukin-12(IL-12),interleukin-6(IL-6)and immunoglobulins IgG,IgG1,IgM,and IgG2a in mouse serum.Bone marrow-derived macrophages isolated from mice immunized with M.intracellulare antigens displayed significantly lower bacillary loads than those isolated from mice immunized with adjuvants.Whole-genome sequence analysis revealed 396 common genes between M.intracellulare and M.tuberculosis.Microchip hybridization with M.tuberculosis proteins revealed the presence of 478 proteins in the serum of mice immunized with M.intracellulare protein extracts.Sixty common antigens were found using both microchip and genomic comparative analyses.Conclusion This is the advanced study to investigate the immunogenicity of M.intracellulare proteins and the cross-reactive proteins between M.intracellulare and M.tuberculosis.The results revealed the presence of a number of cross-reactive proteins between M.intracellulare and M.tuberculosis.Therefore,this study provides a new way of identifying immunogenic proteins for use in tuberculosis vaccines against both M.intracellulare and M.tuberculosis in future.展开更多
AIM:To evaluate the presence and cross-reactive anti-bodies against hypervariable region 1(HVR1) in hepatitis C virus(HCV) infected patients and its relationship with the progression of the disease.METHODS:Sixteen rep...AIM:To evaluate the presence and cross-reactive anti-bodies against hypervariable region 1(HVR1) in hepatitis C virus(HCV) infected patients and its relationship with the progression of the disease.METHODS:Sixteen representative HVR1 proteins selected from a unique set of 1600 natural sequences were used to semiquantitate the cross-reactivity of HVR1 antibodies in the sera of HCV patients.Fifty-five chronic HCV patients including 23 with asymptomatic mild hepatitis,18 with chronic hepatitis and 16 with liver cirrhosis patients were studied.RESULTS:The degree of the cross-reactivity of anti-HVR1 antibodies in 23 patients with mild asymptomatic hepatitis was 3.09 ± 2.68,which was signif icantly lower than in those with chronic hepatitis(5.44 ± 3.93,P < 0.05) and liver cirrhosis(7.44 ± 3.90,P < 0.01).No correlation was observed between the broadness of the cross-reactivity anti-HVR1 antibodies and patient's age,infection time,serum alanine aminotransferase activity,or serum HCV-RNA concentration.It was the breath of cross-reactivity rather than the presence of anti-HVR1 antibody in HCV sera that was associated with the progression of liver disease.CONCLUSION:The broadly cross-reactive HVR1 antibodies generated in natural HCV patients can not neutralize the virus,which results in persistent infection in patients with chronic hepatitis.展开更多
An ester activation method was employed to couple enrofloxacin(ENFX) to the carrier proteins BSA and OVA. The conjugates ENFX-BSA and ENFX-OVA were identified with an UV spectrophotometer and amino acid automation a...An ester activation method was employed to couple enrofloxacin(ENFX) to the carrier proteins BSA and OVA. The conjugates ENFX-BSA and ENFX-OVA were identified with an UV spectrophotometer and amino acid automation analysis instrument, and resulted in conjugates with 48 ENFX molecules per carrier molecule(BSA). Splenocytes from mice immunized with ENFX-BSA were fused with SP2/0 myeloma cells and hybridomas secreting antibodies against enrofloxacin were selected and cloned. Two stable monoclonal antibodies, 2C5, 5D5 of the subclass IgG2a, were isolated. Using antibody 5D5, an indirect competitive inhibition enzyme-linked immunosorbent assay (Ci-ELISA) was developed for the quantitative detection of enrofloxacin and its metabolites. The IC50 of the standard curve was 21.67 ng mL-1 and the limit of detection for enrofloxacin was 0.13 ng mL-1. This method was sensitive and had a linear range from 0.13 to 10 000 ng mL-1 (r= -0.9782). Monoclonal antibody 5D5 exhibited high relative affinity to enrofloxacin, and the cross-reactivities with ciprofloxacin, marbofloxacin, sarafloxacin and danorfloxacin were 110.8, 27.40, 71.05 and 37.41%, respectively. Three non-fluoroquinolones of cefadroxil, chloramphenicol, sulfadimethoxine were tested and there was no cross-reaction between them.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 52171298)the National Foreign Experts Program (G2023180006L)+1 种基金the Natural Science Foundation of Heilongjiang Province of China (Grant No. ZD2019E003)the Fundamental Research Funds for the Central Universities (Grant No. 3072022TS0303)。
文摘Biodiesel is a clean and renewable energy,and it is an effective measure to optimize engine combustion fueled with biodiesel to meet the increasingly strict toxic and CO_(2) emission regulations of internal combustion engines.A suitable-scale chemical kinetic mechanism is very crucial for the accurate and rapid prediction of engine combustion and emissions.However,most previous researchers developed the mechanism of blend fuels through the separate simplification and merging of the reduced mechanisms of diesel and biodiesel rather than considering their cross-reaction.In this study,a new reduced chemical reaction kinetics mechanism of diesel and biodiesel was constructed through the adoption of directed relationship graph (DRG),directed relationship graph with error propagation,and full-species sensitivity analysis (FSSA).N-heptane and methyl decanoate (MD) were selected as surrogates of traditional diesel and biodiesel,respectively.In this mechanism,the interactions between the intermediate products of both fuels were considered based on the cross-reaction theory.Reaction pathways were revealed,and the key species involved in the oxidation of n-heptane and MD were identified through sensitivity analyses.The reduced mechanism of n-heptane/MD consisting of 288 species and 800 reactions was developed and sufficiently verified by published experimental data.Prediction maps of ignition delay time were established at a wide range of parameter matrices (temperature from 600 to 1 700 K,pressure from 10 bar to 80 bar,equivalence ratio from 0.5 to 1.5) and different substitution ratios to identify the occurrence regions of the crossreaction.Concentration and sensitivity analyses were then conducted to further investigate the effects of cross-reactions.The results indicate temperature as the primary factor causing cross-reactivity.In addition,the reduced mechanism with cross-reactions was more accurate than that without cross-reactions.At 700–1 000 K,the cross-reactions inhibited the consumption of n-heptane/MD,which resulted in a prolonged ignition delay time.At this point,the elementary reaction,NC_(7)H_(16)+OH<=>C_(7)H_(15)-2+H_(2)O,played a dominant role in fuel consumption.Specifically,the contribution of the MD consumption reaction to ignition decreased,and the increased generation time of OH,HO_(2),and H_(2)O_(2) was directly responsible for the increased ignition delay.
文摘A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.
文摘To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 serum samples from healthy controls and 104 serum specimens from autoimmune disease patients were collected.The results of ELISA showed that among 114 sera from healthy controls,4 (3.5%) were positive of SARS-CoV-IgG antibody and 114 (100%) were all negative of SARS-CoV-IgM antibody;the specificity of SARS-CoV-IgG antibody for SARS patients was 96.5%,but the specificity of both SARS-CoV-IgG and -IgM antibodies for SARS patients was 100%.In 58 cases with SLE,positive rates of SARS-CoV-IgG and -IgM antibodies were 32.8% (19/58) and 8.6% (5/58),respectively,in which 11 cases (19%) were positive of both SARS-CoV-IgG and -IgM antibodies;in 10 cases with SS,positive rate of both SARS-CoV-IgG and -IgM antibodies was 10% (1/10);in 16 cases with MCTD,positive rate of SARS-CoV-IgG was 37.5% (6/16),positive rate of both SARS-CoV-IgG and -IgM antibodies was 6.3% (1/16);in 20 cases with RA,one case was positive (5%) of SARS-CoV-IgG.However,of all samples with positive SARS-CoV-IgG and -IgM antibodies for autoimmune diseases and healthy controls,SARS-CoV RNA and antibodies were all negative by RT-PCR and IFA.All sera for negative or positive ELISA results were also negative or positive results using ELISA with Vero E6 cells lysates.These studies showed that SARS-CoV Vero E6 cell lysates for the ELISA to detect SARS-CoV antibodies could lead to the false-positive reactions or cross-reactions of SARS-CoV antibodies in non-SARS diseases and healthy controls,and the false-positive reactions or cross-reactions were related to Vero E6 cell lysates and autoantibodies in non-SARS population.Cellular & Molecular Immunology.2004;1(4): 304-307.
文摘This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematically reviewing available literature using multiple databases,including Web of Science,PubMed,Google Scholar and medRxiv.Among a total of 16 presented cases from clinical settings,cross-reaction to COVID-19 serological tests was observed in two(12.5%)dengue-positive patients,while 14 patients(87.5%)confirmed positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)showed a cross-reaction with dengue serological tests,leading to misdiagnosis and mismanagement by attending clinicians.Of 1789 SARS-CoV-2-positive sera,cross-reaction to dengue serological tests was observed in 180 sera(10%),which is higher than the cross-reaction observed for SARS-CoV-2 in archived pre-COVID-19 sera positive for a dengue infection(75 of 811,9.2%,P=0.674).Clinicians in tropical regions are therefore advised to interpret serological tests with caution and use a more pragmatic approach to triage these infections.
基金supported by Jiangsu Maternal and child health research project(no.F202068)the Taihu Lake talent plan(Top-Level,no.2020THRC-GD-7)The Project of Wuxi Health Commission(no.201949).
文摘Objective:To characterize the group-29 allergens from Dermatophagoides(D.)pteronyssinus and investigate their ability to cross-react with other group-29 allergens from D.pteronyssinus as well as those from D.farinae and Tyrophagus putrescentiae.Methods:Der p 29,Der f 29,and Tyr p 29 cDNA sequences were amplified from total RNA isolated from D.pteronyssinus,D.farinae and Tyrophagus putrescentiae,respectively.Then they were cloned into the pET28a vector,expressed in Rosetta2(DE3)plysS,and purified using anion exchange chromatography.The IgE-binding rates of rDer p 29 were assessed by IgE Western blotting.The four epitopes of rDer p 29 were predicted,synthesized,and detected by IgE-ELISA.The cross-reactivity among the recombinant proteins rDer p 29,rDer f 29,and rTyr p 29 was investigated using dot blot and IgE-ELISA inhibition experiments.The allergens’physiochemical properties,amino acid sequences,and tertiary structures were also compared.Results:Der p 29 was successfully expressed in Rosetta2(DE3)plysS as a single,393-bp open reading frame.Western blotting showed that the purified rDer p 29 protein exhibited an IgE-binding rate of 100%when tested on patient sera.The following four Der p 29 epitopes were predicted and synthesized:37-45(EP1),57-69(EP2),75-80(EP3),and 104-117(EP4).IgE-ELISA tests on 20 D.pteronyssinus-positive sera yielded IgE-binding rates of 85%(rDer p 29),80%(EP1),55%(EP2),40%(EP3),and 55%(EP4),respectively.The dot blot experiments further confirmed cross-reactivity among the three group-29 proteins.When used as an inhibitor,rDer p 29 demonstrated an average cross-reactive inhibition rate of 49.7%against rDer f 29 and 54.4%against rTyr p 29.When rTyr p 29 was used as an inhibitor,it showed an average cross-reactive inhibition rate of 56.3%against rDer f 29.Conclusions:A recombinant protein,rDer p 29 with strong allergenicity was produced.Moreover,it was found that rDer p 29 cross-reacted with rDer f 29 and rTyr p 29,due to their highly homologous sequences and structures.These findings highlight the importance of considering inter-species epitope cross-reactivity when diagnosing and treating allergic diseases.
基金financially supported by the State key research and development plan(2019YFC1605000)the National Natural Science Foundation of China(31871735)。
文摘As an important shellfish group,the oyster can induce severe allergic reactions.We aimed to identify and characterize the major allergen in Crassostrea gigas,and elucidate the molecular basis of its allergenicity and cross-reactivity.The native and recombinant C.gigas-arginine kinase(AK)displayed significant immunoglobulin(Ig)G-and Ig E-binding activity.The Ig E-binding activity of C.gigas-AK could be reduced by thermal treatment and strong acidic and alkaline conditions.Besides,cross-reactivity of AK was demonstrated between shellfish species.Among seven epitope peptides identified here,P2 is responsible for the specificity of C.gigas-AK,while P3 is responsible for cross-reactions between mollusks and crustaceans.Furthermore,Glu98 and His31 in the light chain,Arg101,and Lys57 in the heavy chain are identified as key Ig E residues in recognizing epitopes.These findings provide new insights into the prevention and treatment of shellfish allergy and the development of hypoallergenic shellfish products.
文摘In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.
基金supported by National Science and Technology Major Project of China[2018ZX10731301-002]。
文摘Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare were used to immunize BALB/c mice.The antigens were evaluated using cellular and humoral immunoassays.The common genes between M.intracellular and M.tuberculosis were identified using genome-wide comparative analysis,and cross-reactive proteins were screened using immunoproteome microarrays.Results Immunization with M.intracellulare proteins induced significantly higher levels of the cytokines interferon-γ(IFN-γ),interleukin-2(IL-2),interleukin-12(IL-12),interleukin-6(IL-6)and immunoglobulins IgG,IgG1,IgM,and IgG2a in mouse serum.Bone marrow-derived macrophages isolated from mice immunized with M.intracellulare antigens displayed significantly lower bacillary loads than those isolated from mice immunized with adjuvants.Whole-genome sequence analysis revealed 396 common genes between M.intracellulare and M.tuberculosis.Microchip hybridization with M.tuberculosis proteins revealed the presence of 478 proteins in the serum of mice immunized with M.intracellulare protein extracts.Sixty common antigens were found using both microchip and genomic comparative analyses.Conclusion This is the advanced study to investigate the immunogenicity of M.intracellulare proteins and the cross-reactive proteins between M.intracellulare and M.tuberculosis.The results revealed the presence of a number of cross-reactive proteins between M.intracellulare and M.tuberculosis.Therefore,this study provides a new way of identifying immunogenic proteins for use in tuberculosis vaccines against both M.intracellulare and M.tuberculosis in future.
基金Supported by The National Natural Science Foundation of China, No 30500476The National High-Tech Science Foundation of China, No 2008AA02Z434+1 种基金National S and T Major Projects for Infectious Disease Control, No 2008ZX10002-013 and 2009ZX09103-621Beijing Natural Science Foundation, No 7082048
文摘AIM:To evaluate the presence and cross-reactive anti-bodies against hypervariable region 1(HVR1) in hepatitis C virus(HCV) infected patients and its relationship with the progression of the disease.METHODS:Sixteen representative HVR1 proteins selected from a unique set of 1600 natural sequences were used to semiquantitate the cross-reactivity of HVR1 antibodies in the sera of HCV patients.Fifty-five chronic HCV patients including 23 with asymptomatic mild hepatitis,18 with chronic hepatitis and 16 with liver cirrhosis patients were studied.RESULTS:The degree of the cross-reactivity of anti-HVR1 antibodies in 23 patients with mild asymptomatic hepatitis was 3.09 ± 2.68,which was signif icantly lower than in those with chronic hepatitis(5.44 ± 3.93,P < 0.05) and liver cirrhosis(7.44 ± 3.90,P < 0.01).No correlation was observed between the broadness of the cross-reactivity anti-HVR1 antibodies and patient's age,infection time,serum alanine aminotransferase activity,or serum HCV-RNA concentration.It was the breath of cross-reactivity rather than the presence of anti-HVR1 antibody in HCV sera that was associated with the progression of liver disease.CONCLUSION:The broadly cross-reactive HVR1 antibodies generated in natural HCV patients can not neutralize the virus,which results in persistent infection in patients with chronic hepatitis.
基金supported by the Natural Science Foundation of Guangdong Province,China(994162).
文摘An ester activation method was employed to couple enrofloxacin(ENFX) to the carrier proteins BSA and OVA. The conjugates ENFX-BSA and ENFX-OVA were identified with an UV spectrophotometer and amino acid automation analysis instrument, and resulted in conjugates with 48 ENFX molecules per carrier molecule(BSA). Splenocytes from mice immunized with ENFX-BSA were fused with SP2/0 myeloma cells and hybridomas secreting antibodies against enrofloxacin were selected and cloned. Two stable monoclonal antibodies, 2C5, 5D5 of the subclass IgG2a, were isolated. Using antibody 5D5, an indirect competitive inhibition enzyme-linked immunosorbent assay (Ci-ELISA) was developed for the quantitative detection of enrofloxacin and its metabolites. The IC50 of the standard curve was 21.67 ng mL-1 and the limit of detection for enrofloxacin was 0.13 ng mL-1. This method was sensitive and had a linear range from 0.13 to 10 000 ng mL-1 (r= -0.9782). Monoclonal antibody 5D5 exhibited high relative affinity to enrofloxacin, and the cross-reactivities with ciprofloxacin, marbofloxacin, sarafloxacin and danorfloxacin were 110.8, 27.40, 71.05 and 37.41%, respectively. Three non-fluoroquinolones of cefadroxil, chloramphenicol, sulfadimethoxine were tested and there was no cross-reaction between them.
