scholarly journals ASCVac-1, a Multi-Peptide Chimeric Vaccine, Protects Mice Against Ascaris suum Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Clara Gazzinelli-Guimarães ◽  
Denise Silva Nogueira ◽  
Chiara Cássia Oliveira Amorim ◽  
Fabrício Marcus Silva Oliveira ◽  
Anderson Coqueiro-Dos-Santos ◽  
...  
Keyword(s):  
B Cell ◽  
Expression System ◽  
Immune Serum ◽  
Preclinical Trial ◽  
B Cell Epitopes ◽  
Specific Igg ◽  
Lower Morbidity ◽  
Chimeric Vaccine ◽  
Soluble Recombinant Protein ◽  
Promising Vaccine Candidate

Control of human ascariasis, the most prevalent neglected tropical disease globally affecting 450 million people, mostly relies on mass drug administration of anthelmintics. However, chemotherapy alone is not efficient due to the high re-infection rate for people who live in the endemic area. The development of a vaccine that reduces the intensity of infection and maintains lower morbidity should be the primary target for infection control. Previously, our group demonstrated that immunization with crude Ascaris antigens in mice induced an IgG-mediated protective response with significant worm reduction. Here, we aimed to develop a multipeptide chimera vaccine based on conserved B-cell epitopes predicted from 17 common helminth proteomes using a bioinformatics algorithm. More than 480 B-cell epitopes were identified that are conserved in all 17 helminths. The Ascaris-specific epitopes were selected based on their reactivity to the pooled sera of mice immunized with Ascaris crude antigens or infected three times with A. suum infective eggs. The top 35 peptides with the strongest reactivity to Ascaris immune serum were selected to construct a chimeric antigen connected in sequence based on conformation. This chimera, called ASCVac-1, was produced as a soluble recombinant protein in an Escherichia coli expression system and, formulated with MPLA, was used to immunize mice. Mice immunized with ASCVac-1/MPLA showed around 50% reduced larvae production in the lungs after being challenged with A. suum infective eggs, along with significantly reduced inflammation and lung tissue/function damage. The reduced parasite count and pathology in infected lungs were associated with strong Th2 immune responses characterized by the high titers of antigen-specific IgG and its subclasses (IgG1, IgG2a, and IgG3) in the sera and significantly increased IL-4, IL-5, IL-13 levels in lung tissues. The reduced IL-33 titers and stimulated eosinophils were also observed in lung tissues and may also contribute to the ASCVac-1-induced protection. Taken together, the preclinical trial with ASCVac-1 chimera in a mouse model demonstrated its significant vaccine efficacy associated with strong IgG-based Th2 responses, without IgE induction, thus reducing the risk of an allergic response. All results suggest that the multiepitope-based ASCVac-1 chimera is a promising vaccine candidate against Ascaris sp. infections.

scholarly journals In Vivo Expression and Immunological Studies of the 42-Kilodalton Carboxyl-Terminal Processing Fragment of Plasmodium falciparum Merozoite Surface Protein 1 in the Baculovirus-Silkworm System

2002 ◽  
Vol 70 (6) ◽  
pp. 2772-2779 ◽  
Author(s):  
Alan L. Y. Pang ◽  
Caryn N. Hashimoto ◽  
Leslie Q. Tam ◽  
Z. Q. Meng ◽  
George S. N. Hui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
B Cell ◽  
Expression System ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Attractive Alternative ◽  
B Cell Epitopes ◽  
Merozoite Surface Protein 1 ◽  
Carboxyl Terminal

ABSTRACT The 42-kDa carboxyl-terminal processing fragment of Plasmodium falciparum merozoite surface protein 1 (MSP-142) is an anti-erythrocytic stage malaria vaccine candidate. In this study, MSP-142 was expressed by using the Bombyx mori nuclear polyhedrosis virus-silkworm expression system, and the antigenicity and immmunogenicity of the recombinant protein, Bmp42, were evaluated. The average yield of Bmp42, as determined by a sandwich enzyme-linked immunosorbent assay (ELISA), was 379 μg/ml of infected silkworm hemolymph, which was >100-fold higher than the level attainable in cell culture medium. N-terminal amino acid sequencing revealed that Bmp42 was correctly processed in silkworm cells. Data from immunoblotting, as well as from the inhibition ELISA, suggested that the conformational B-cell epitopes of MSP-142 were recreated in Bmp42. Immunization of rabbits with Bmp42 in complete Freund's adjuvant generated high-titer antibody responses against the immunogen. Specificity analyses of the anti-Bmp42 antibodies using several recombinant MSP-119 proteins expressing variant and conserved B-cell epitopes suggested that the anti-Bmp42 antibodies recognized primarily conserved epitopes on MSP-119. Furthermore, the anti-Bmp42 antibodies were highly effective in inhibiting the in vitro growth of parasites carrying homologous or heterologous MSP-142. Our results demonstrated that the baculovirus-silkworm expression system could be employed to express biologically and immunologically active recombinant MSP-142 at elevated levels; thus, it is an attractive alternative for producing a protective MSP-142 vaccine for human use.

scholarly journals Linear B-Cell Epitopes in Human Norovirus GII.4 Capsid Protein Elicit Blockade Antibodies

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 52
Author(s):  
Hassan Moeini ◽  
Suliman Qadir Afridi ◽  
Sainitin Donakonda ◽  
Percy A. Knolle ◽  
Ulrike Protzer ◽  
...  
Keyword(s):  
B Cell ◽  
Capsid Protein ◽  
Immune Escape ◽  
Solvent Accessibility ◽  
Effective Vaccine ◽  
Blood Group Antigens ◽  
Human Norovirus ◽  
B Cell Epitopes ◽  
Blocking Rate ◽  
Linear B

Human norovirus (HuNoV) is the leading cause of nonbacterial gastroenteritis worldwide with the GII.4 genotype accounting for over 80% of infections. The major capsid protein of GII.4 variants is evolving rapidly, resulting in new epidemic variants with altered antigenic potentials that must be considered for the development of an effective vaccine. In this study, we identify and characterize linear blockade B-cell epitopes in HuNoV GII.4. Five unique linear B-cell epitopes, namely P2A, P2B, P2C, P2D, and P2E, were predicted on the surface-exposed regions of the capsid protein. Evolving of the surface-exposed epitopes over time was found to correlate with the emergence of new GII.4 outbreak variants. Molecular dynamic simulation (MD) analysis and molecular docking revealed that amino acid substitutions in the putative epitopes P2B, P2C, and P2D could be associated with immune escape and the appearance of new GII.4 variants by affecting solvent accessibility and flexibility of the antigenic sites and histo-blood group antigens (HBAG) binding. Testing the synthetic peptides in wild-type mice, epitopes P2B (336–355), P2C (367–384), and P2D (390–400) were recognized as GII.4-specific linear blockade epitopes with the blocking rate of 68, 55 and 28%, respectively. Blocking rate was found to increase to 80% using the pooled serum of epitopes P2B and P2C. These data provide a strategy for expanding the broad blockade potential of vaccines for prevention of NoV infection.

scholarly journals Comparison of Monoclonal Gammopathies Linked to Poliovirus or Coxsackievirus vs. Other Infectious Pathogens

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 438
Author(s):  
Jean Harb ◽  
Nicolas Mennesson ◽  
Cassandra Lepetit ◽  
Maeva Fourny ◽  
Margaux Louvois ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
B Cell ◽  
Monoclonal Gammopathy ◽  
Coat Proteins ◽  
Chronic Stimulation ◽  
B Cell Epitopes ◽  
Monoclonal Immunoglobulins ◽  
Self Antigen ◽  
Coxsackievirus B1 ◽  
Undetermined Significance

Chronic stimulation by infectious pathogens or self-antigen glucosylsphingosine (GlcSph) can lead to monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). Novel assays such as the multiplex infectious antigen microarray (MIAA) and GlcSph assays, permit identification of targets for >60% purified monoclonal immunoglobulins (Igs). Searching for additional targets, we selected 28 purified monoclonal Igs whose antigen was not represented on the MIAA and GlcSph assays; their specificity of recognition was then analyzed using microarrays consisting of 3760 B-cell epitopes from 196 pathogens. The peptide sequences PALTAVETG and PALTAAETG of the VP1 coat proteins of human poliovirus 1/3 and coxsackievirus B1/B3, respectively, were specifically recognized by 6/28 monoclonal Igs. Re-analysis of patient cohorts showed that purified monoclonal Igs from 10/155 MGUS/SM (6.5%) and 3/147 MM (2.0%) bound to the PALTAVETG or PALTAAETG epitopes. Altogether, PALTAV/AETG-initiated MGUS are not rare and few seem to evolve toward myeloma.

scholarly journals Mining of linear B cell epitopes of SARS-CoV-2 ORF8 protein from COVID-19 patients

2021 ◽  
pp. 1-19
Author(s):  
Xiaohui Wang ◽  
Joy-Yan Lam ◽  
Linlei Chen ◽  
Shannon Wing-Ngor Au ◽  
Kelvin K. W. To ◽  
...  
Keyword(s):  
B Cell ◽  
B Cell Epitopes ◽  
Linear B

In silico prediction of T‐cell and B‐cell epitopes of human papillomavirus type 16 L1 protein

2021 ◽  
Author(s):  
Shahab Mahmoudvand ◽  
Somayeh Shokri ◽  
Manoochehr Makvandi ◽  
Reza Taherkhani ◽  
Mohammad Rashno ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
T Cell ◽  
B Cell ◽  
In Silico ◽  
In Silico Prediction ◽  
B Cell Epitopes ◽  
Human Papillomavirus Type 16 ◽  
L1 Protein

scholarly journals Evolution of immune responses to SARS-CoV-2 in mild-moderate COVID-19

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adam K. Wheatley ◽  
Jennifer A. Juno ◽  
Jing J. Wang ◽  
Kevin J. Selva ◽  
Arnold Reynaldi ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Vaccine Development ◽  
Natural Infection ◽  
Population Level ◽  
Cell Dynamics ◽  
Follicular Helper ◽  
Cell Immunity ◽  
Specific Igg ◽  
Over Time

AbstractThe durability of infection-induced SARS-CoV-2 immunity has major implications for reinfection and vaccine development. Here, we show a comprehensive profile of antibody, B cell and T cell dynamics over time in a cohort of patients who have recovered from mild-moderate COVID-19. Binding and neutralising antibody responses, together with individual serum clonotypes, decay over the first 4 months post-infection. A similar decline in Spike-specific CD4+ and circulating T follicular helper frequencies occurs. By contrast, S-specific IgG+ memory B cells consistently accumulate over time, eventually comprising a substantial fraction of circulating the memory B cell pool. Modelling of the concomitant immune kinetics predicts maintenance of serological neutralising activity above a titre of 1:40 in 50% of convalescent participants to 74 days, although there is probably additive protection from B cell and T cell immunity. This study indicates that SARS-CoV-2 immunity after infection might be transiently protective at a population level. Therefore, SARS-CoV-2 vaccines might require greater immunogenicity and durability than natural infection to drive long-term protection.

scholarly journals Design of a new Multi-Epitope vaccine against Brucella based on T and B cell epitopes using bioinformatics methods

2021 ◽  
pp. 1-41
Author(s):  
Zhiqiang Chen ◽  
Yuejie Zhu ◽  
Tong Sha ◽  
Zhiwei Li ◽  
Yujiao Li ◽  
...  
Keyword(s):  
B Cell ◽  
Epitope Vaccine ◽  
B Cell Epitopes
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