scholarly journals Embedding of exogenous B cell epitopes on the surface of UreB structure generates a broadly reactive antibody response against Helicobacter pylori

2021 ◽  
Author(s):  
Junfei Ma ◽  
Shuying Wang ◽  
Qianyu Ji ◽  
Jingxuan Qiu ◽  
Qing Liu
Keyword(s):  
Helicobacter Pylori ◽  
Antibody Response ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Alternative Therapy ◽  
Chimeric Protein ◽  
B Cell Epitopes ◽  
Vaccine Antigens ◽  
H Pylori ◽  
Reactive Antibody

AbstractSince Helicobacter pylori (H. pylori) resistance to antibiotic regimens is increased, vaccination is becoming an increasingly important alternative therapy to control H. pylori infection. UreB, FlaA, AlpB, SabA, and HpaA proteins of H. pylori were previously proved to be used as candidate vaccine antigens. Here, we developed an engineered antigen based on a recombinant chimeric protein containing a structural scaffold from UreB and B cell epitopes from FlaA, AlpB, SabA, and HpaA. The multi-epitope chimeric antigen, named MECU, could generate a broadly reactive antibody response including antigen-specific antibodies and neutralizing antibodies against H. pylori urease and adhesins. Moreover, therapeutic immunization with MECU could reduce H. pylori colonization in the stomach and protect the stomach in BALB/c mice. This study not only provides a promising immunotherapy to control H. pylori infection, but also offers a reference for antigen engineering against other pathogens.

Identification of B-cell epitopes in urease B subunit of Helicobacter pylori bound by neutralizing antibodies

Vaccine ◽  
2010 ◽  
Vol 28 (32) ◽  
pp. 5220-5227 ◽  
Author(s):  
Yan Qiu ◽  
Yan-Chun Wang ◽  
Hao-Xia Tao ◽  
De-Wen Zhan ◽  
Sheng-Ling Yuan ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
B Cell Epitopes ◽  
B Subunit ◽  
Urease B Subunit

scholarly journals Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons

Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 65
Author(s):  
Xin Zhang ◽  
Shuli Sang ◽  
Qing Guan ◽  
Haoxia Tao ◽  
Yanchun Wang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
B Cell ◽  
Protein A ◽  
Peptide Fragments ◽  
Nickel Ion ◽  
B Cell Epitopes ◽  
E Coli ◽  
Important Target ◽  
H Pylori

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni2+ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

scholarly journals MALT lymphoma: epidemiology, clinical diagnosis and treatment

2018 ◽  
Vol 11 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Petruta Violeta Filip ◽  
◽  
Denisa Cuciureanu ◽  
Laura Sorina Diaconu ◽  
Ana Maria Vladareanu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
B Cell ◽  
Malt Lymphoma ◽  
Cell Lymphoma ◽  
Gastric Lymphoma ◽  
Eradication Therapy ◽  
B Cell Lymphoma ◽  
Gastric Malt Lymphoma ◽  
H Pylori

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

scholarly journals Limited evidence for a relationship between HIV-1 glycan shield features in early infection and the development of neutralization breadth

2021 ◽  
Author(s):  
Yifan Li ◽  
Hongjun Bai ◽  
Eric Sanders-Buell ◽  
Vincent Dussupt ◽  
Samantha Townsley ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Early Infection ◽  
Broadly Neutralizing Antibodies ◽  
Limited Evidence ◽  
Founder Virus ◽  
Vaccine Antigens ◽  
Acute Hiv ◽  
The Relationship ◽  
Hiv 1 ◽  
Reactive Antibody

Identifying if viral features present in acute HIV-1 infection predetermine the development of neutralization breadth is critical to vaccine design. Incorporating such features in vaccine antigens could initiate cross-reactive antibody responses that could sufficiently protect vaccinees from HIV-1 infection despite the uniqueness of each founder virus. To understand the relationship between Env determinants and the development of neutralization breadth, we focused on 197 individuals enrolled in two cohorts in Thailand and East Africa (RV144 and RV217) and followed since their diagnosis in acute or early HIV-1 infection. We analyzed the distribution of variable loop lengths and glycans as well as the predicted density of the glycan shield and compared these envelope features to the neutralization breadth data obtained three years after infection (n = 121). Our study revealed limited evidence for glycan shield features that associate with the development of neutralization breadth. While the glycan shield tended to be denser in participants who subsequently developed breadth, no significant relationship was found between the size of glycan holes and the development of neutralization breadth. The parallel analysis of 3,000 independent Env sequences showed no evidence of directional evolution of glycan shield features since the beginning of the epidemic. Together, our results highlight that glycan shield features in acute and early HIV-1 infection may not play a role determinant enough to dictate the development of neutralization breadth, and instead suggest that the glycan shield’s reactive properties that are associated with immune evasion may have a greater impact. IMPORTANCE A major goal of HIV-1 vaccine research is to design vaccine candidates that elicit potent broadly neutralizing antibodies (bnAbs). Different viral features have been associated with the development of broadly neutralizing antibodies, including the glycan shield on the surface of the HIV-1 Envelope (Env). Here, we analyzed data from two cohorts of individuals who were followed from early infection to several years after infection spanning multiple HIV-1 subtypes. We compared Env glycan features in HIV-1 sequences obtained in early infection to the potency and breadth of neutralizing antibodies measured one to three years after infection. We found limited evidence of glycan shield properties that associate with the development of neutralization breadth in these cohorts. These results may have important implications for antigen design in future vaccine strategies and emphasize that HIV-1 vaccines will need to rely on a complex set of properties to elicit neutralization breadth.

scholarly journals Recombinant Protein Containing B-Cell Epitopes of Different Loxosceles Spider Toxins Generates Neutralizing Antibodies in Immunized Rabbits

2018 ◽  
Vol 9 ◽  
Author(s):  
Sabrina de Almeida Lima ◽  
Clara Guerra-Duarte ◽  
Fernanda Costal-Oliveira ◽  
Thais Melo Mendes ◽  
Luís F. M. Figueiredo ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
B Cell Epitopes ◽  
Spider Toxins

scholarly journals Serum Antibody Responses to Helicobacter pylori and the cagA Marker in Patients with Mucosa-Associated Lymphoid Tissue Lymphoma

1999 ◽  
Vol 6 (4) ◽  
pp. 633-638 ◽  
Author(s):  
Anne Taupin ◽  
Alessandra Occhialini ◽  
Agnès Ruskone-Fourmestraux ◽  
Jean-Charles Delchier ◽  
Jean-Claude Rambaud ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibody Response ◽  
Malt Lymphoma ◽  
Lymphoid Tissue ◽  
Serum Antibody ◽  
Dot Blot ◽  
Homologous Strain ◽  
H Pylori ◽  
Different Strains ◽  
Dot Blot Analysis

ABSTRACT The lymphoma of the mucosa-associated lymphoid tissue (MALT) of the stomach has been linked to Helicobacter pylori infection, but the mechanisms involved in B-cell proliferation remain elusive. In a search for putative H. pylori-specific monoclonal immunoglobulin production, an H. pylori strain was isolated from 10 patients with MALT lymphoma and used to detect the specific serum antibody response to the homologous strain by immunoblotting. Moreover, the antigenicity of the different strains was compared by using each of the 10 sera. We found that the different strains induced highly variable patterns of systemic immunoglobulin G antibody response, although several bacterial antigens, such as the 60-kDa urease B, were often recognized by the different sera. ThecagA marker was detected in the strains by PCR with specific primers and by dot blot analysis, and the CagA protein was found in the sera of 4 of the 10 patients by immunoblotting. In conclusion, MALT lymphoma patients, like other patients with H. pylori gastritis, exhibit a polymorphic systemic antibody response, despite an apparently similar antigenic profile. The CagA marker of pathogenicity is not associated with this disease.

scholarly journals The efficacy, safety, and tolerability of levofloxacin quadruple therapy for helicobacter pylori eradication: a randomized, double-blind clinical trial

2020 ◽  
Author(s):  
Fariborz Mansour-Ghanaei ◽  
Behnam Masihypour ◽  
Mohammad Fathalipour ◽  
Soheil Hassanipour ◽  
Homayoon Sokhanvar ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Helicobacter Pylori ◽  
Alternative Therapy ◽  
Double Blind ◽  
Intention To Treat ◽  
Bismuth Subcitrate ◽  
Double Blind Clinical Trial ◽  
End Of Treatment ◽  
H Pylori ◽  
To Receive

Abstract BackgroundThe incidence of microbial resistance is increasing, and new rescue regimens are needed in order to treat Helicobacter pylori (H. pylori) infection. To evaluate the efficacy, safety, and tolerability of levofloxacin based quadruple therapies in the eradication of H. pylori.MethodsIn a randomized, double-blind clinical trial, 220 patients with dyspepsia and H. pylori infection were randomly assigned to receive either bismuth subcitrate 240 mg, pantoprazole 20 mg, amoxicillin 1000 mg twice a day, and levofloxacin 500 mg daily for seven days (BPAL-7), or ten days (BPAL-10). The eradication of H. pylori was evaluated two months after the end of treatment, and adverse drug reactions (ADRs) were assessed during the intervention.ResultsAccording to intention-to-treat and per-protocol, the eradication rate was significantly lower in the BPAL-7 regimen 49.1% (95% CI: 39.3–57.8) and 47.6% (95% CI: 39.7–58.4), respectively compared to the BPAL- 10 regimen 62.7% (95% CI: 53.6–72.8) and 62.4% (95% CI: 55.1–72.8), respectively. The incidence of ADRs was not statistically significant between BPAL-7 (33.6%) and BPAL-10 (36.7%) groups.ConclusionAlthough the ADRs were negligible in both groups, these regimens could not be an ideal alternative therapy for H. pylori because of low eradication rates compared to standard regimens.Trial registration: The study reviewed and approved by the Iranian Registry of Clinical Trials (IRCT201406141155N19). This trial was retrospectively registered on July 10, 2015.

scholarly journals The Efficacy, Safety, And Tolerability of Levofloxacin Quadruple Therapy For Helicobacter Pylori Eradication: A Randomized, Double-Blind Clinical Trial

2021 ◽  
Author(s):  
Fariborz Mansour-Ghanaei ◽  
Behnam Masihypour ◽  
Mohammad Fathalipour ◽  
Soheil Hassanipour ◽  
Homayoon Sokhanvar ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Helicobacter Pylori ◽  
Alternative Therapy ◽  
Double Blind ◽  
Intention To Treat ◽  
Bismuth Subcitrate ◽  
Double Blind Clinical Trial ◽  
End Of Treatment ◽  
H Pylori ◽  
To Receive

Abstract The incidence of microbial resistance is increasing, and new rescue regimens are needed in order to treat Helicobacter pylori (H. pylori) infection. To evaluate the efficacy, safety, and tolerability of levofloxacin based quadruple therapies in the eradication of H. pylori. In a randomized, double-blind clinical trial, 220 patients with dyspepsia and H. pylori infection were randomly assigned to receive either bismuth subcitrate 240 mg, pantoprazole 20 mg, amoxicillin 1000 mg twice a day, and levofloxacin 500 mg daily for seven days (BPAL-7), or ten days (BPAL-10). The eradication of H. pylori was evaluated two months after the end of treatment, and adverse drug reactions (ADRs) were assessed during the intervention. According to intention-to-treat and per-protocol, the eradication rate was significantly lower in the BPAL-7 regimen 49.1 % (95 % CI: 39.3-57.8) and 47.6 % (95 % CI: 39.7-58.4), respectively compared to the BPAL- 10 regimen 62.7 % (95 % CI: 53.6-72.8) and 62.4 % (95 % CI: 55.1-72.8), respectively. The incidence of ADRs was not statistically significant between BPAL-7 (33.6 %) and BPAL-10 (36.7 %) groups. Although the ADRs were negligible in both groups, these regimens could not be an ideal alternative therapy for H. pylori because of low eradication rates compared to standard regimens.Trial registration: The study reviewed and approved by the Iranian Registry of Clinical Trials (IRCT201406141155N19).

scholarly journals Cross-Reactive SARS-CoV-2 Neutralizing Antibodies From Deep Mining of Early Patient Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Georgia Bullen ◽  
Jacob D. Galson ◽  
Gareth Hall ◽  
Pedro Villar ◽  
Lien Moreels ◽  
...  
Keyword(s):  
Antibody Response ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Deep Mining ◽  
Recent Emergence ◽  
Repertoire Sequencing ◽  
Patient Responses

Passive immunization using monoclonal antibodies will play a vital role in the fight against COVID-19. The recent emergence of viral variants with reduced sensitivity to some current antibodies and vaccines highlights the importance of broad cross-reactivity. This study describes deep-mining of the antibody repertoires of hospitalized COVID-19 patients using phage display technology and B cell receptor (BCR) repertoire sequencing to isolate neutralizing antibodies and gain insights into the early antibody response. This comprehensive discovery approach has yielded a panel of potent neutralizing antibodies which bind distinct viral epitopes including epitopes conserved in SARS-CoV-1. Structural determination of a non-ACE2 receptor blocking antibody reveals a previously undescribed binding epitope, which is unlikely to be affected by the mutations in any of the recently reported major viral variants including B.1.1.7 (from the UK), B.1.351 (from South Africa) and B.1.1.28 (from Brazil). Finally, by combining sequences of the RBD binding and neutralizing antibodies with the B cell receptor repertoire sequencing, we also describe a highly convergent early antibody response. Similar IgM-derived sequences occur within this study group and also within patient responses described by multiple independent studies published previously.

scholarly journals Peptide-Based Subunit Vaccine Design of T- and B-Cells Multi-Epitopes against Zika Virus Using Immunoinformatics Approaches

2019 ◽  
Vol 7 (8) ◽  
pp. 226 ◽  
Author(s):  
Vivitri Dewi Prasasty ◽  
Karel Grazzolie ◽  
Rosmalena Rosmalena ◽  
Fatmawaty Yazid ◽  
Fransiskus Xaverius Ivan ◽  
...  
Keyword(s):  
B Cell ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Pacific Islands ◽  
Virus Disease ◽  
Peptide Vaccine ◽  
Human Leukocyte ◽  
T Cell Epitopes ◽  
B Cell Epitopes ◽  
The Pacific

The Zika virus disease, also known as Zika fever is an arboviral disease that became epidemic in the Pacific Islands and had spread to 18 territories of the Americas in 2016. Zika virus disease has been linked to several health problems such as microcephaly and the Guillain–Barré syndrome, but to date, there has been no vaccine available for Zika. Problems related to the development of a vaccine include the vaccination target, which covers pregnant women and children, and the antibody dependent enhancement (ADE), which can be caused by non-neutralizing antibodies. The peptide vaccine was chosen as a focus of this study as a safer platform to develop the Zika vaccine. In this study, a collection of Zika proteomes was used to find the best candidates for T- and B-cell epitopes using the immunoinformatics approach. The most promising T-cell epitopes were mapped using the selected human leukocyte antigen (HLA) alleles, and further molecular docking and dynamics studies showed a good peptide-HLA interaction for the best major histocompatibility complex-II (MHC-II) epitope. The most promising B-cell epitopes include four linear peptides predicted to be cross-reactive with T-cells, and conformational epitopes from two proteins accessible by antibodies in their native biological assembly. It is believed that the use of immunoinformatics methods is a promising strategy against the Zika viral infection in designing an efficacious multiepitope vaccine.

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