Identification of three novel B cell epitopes in ORF2 protein of the emerging goose astrovirus and their application

Avian hepatitis E virus (avian HEV) was recently discovered in chickens from the USA that had hepatitis–splenomegaly (HS) syndrome. The complete genomic sequence of avian HEV shares about 50 % nucleotide sequence identity with those of human and swine HEVs. The open reading frame 2 (ORF2) protein of avian HEV has been shown to cross-react with human and swine HEV ORF2 proteins, but the B-cell epitopes in the avian HEV ORF2 protein have not been identified. Nine synthetic peptides from the predicted four antigenic domains of the avian HEV ORF2 protein were synthesized and corresponding rabbit anti-peptide antisera were generated. Using recombinant ORF2 proteins, convalescent pig and chicken antisera, peptides and anti-peptide rabbit sera, at least one epitope at the C terminus of domain II (possibly between aa 477–492) that is unique to avian HEV, one epitope in domain I (aa 389–410) that is common to avian, human and swine HEVs, and one or more epitopes in domain IV (aa 583–600) that are shared between avian and human HEVs were identified. Despite the sequence difference in ORF2 proteins between avian and mammalian HEVs and similar ORF2 sequence between human and swine HEV ORF2 proteins, rabbit antiserum against peptide 6 (aa 389–399) recognized only human HEV ORF2 protein, suggesting complexity of the ORF2 antigenicity. The identification of these B-cell epitopes in avian HEV ORF2 protein may be useful for vaccine design and may lead to future development of immunoassays for differential diagnosis of avian, swine and human HEV infections.

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Faculty Opinions recommendation of Characterization of the B cell epitopes associated with a truncated form of Pseudomonas exotoxin (PE38) used to make immunotoxins for the treatment of cancer patients.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1113121.569111 ◽

2008 ◽

Author(s):

Arthur Frankel

Keyword(s):

B Cell ◽

Cancer Patients ◽

Truncated Form ◽

Pseudomonas Exotoxin ◽

B Cell Epitopes

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

Vaccines ◽

10.3390/vaccines9010052 ◽

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.

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

Cells ◽

10.3390/cells10020438 ◽

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.

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