Inhibition of avian influenza virus H9N2 infection by antiviral hexapeptides that target viral attachment to epithelial cells.

The H9N2 subtype of influenza A virus circulates frequently among poultry in Asian and North African countries causing economic loss in the poultry sector. The antigenic variations of the H9N2 virus were at the origin of its genetic evolution through the emergence of viral strains transmissible to humans and resistant to chemical antivirals, which require a strengthening of the fight means against this virus. In this study, we used a random linear hexapeptide library fused to the gene III protein of M13 filamentous bacteriophage to select new antiviral peptides that inhibit the infectivity of H9N2 virus.

Historical origins and zoonotic potential of avian influenza virus H9N2 in Tunisia revealed by Bayesian analysis and molecular characterization.

During 2009-2012, several outbreaks of avian influenza virus H9N2 were reported in Tunisian poultry. The circulating strains carried in their hemagglutinins the human-like marker 226L, which is known to be important for avian-to-human viral transmission. To investigate the origins and zoonotic potential of the Tunisian H9N2 viruses, five new isolates were identified during 2012-2016 and their whole genomes were sequenced.

The analysis of VH and VL genes repertoires of Fab library built from peripheral B cells of human rabies virus vaccinated donors.

A human combinatorial Fab antibody library was generated from immune repertoire based on peripheral B cells of ten rabies virus vaccinated donors. The analysis of random Fab fragments from the unselected library presented some bias of V gene usage towards IGHV-genes and IGLV-gen families. The screening of the Fab library on rabies virus allowed specific human Fab antibody fragments characterized for their gene encoding sequences, binding and specificities to RV.

Chemokine CCR3 ligands-binding peptides derived from a random phage-epitope library.

Eosinophils are major effectors cells implicated in a number of chronic inflammatory diseases in humans, particularly bronchial asthma and allergic rhinitis. The human chemokine receptor C-C receptor 3 (hCCR3) provides a mechanism for the recruitment of eosinophils into tissue and thus has recently become an attractive biological target for therapeutic intervention. In order to develop peptides antagonists of hCCR3-hCCL11 (human eotaxin) interactions, a random bacteriophage hexapeptide library was used to map structural features of hCCR3 by determining the epitopes of neutralizing anti-hCCR3 mAb 7B11.

hCXCR1 and hCXCR2 antagonists derived from combinatorial peptide libraries.

The human CXCL8 plays important roles in inflammation by activation of neutrophils through the hCXCR1 and hCXCR2 receptors. The role of hCXCR1 and hCXCR2 in the pathogenesis of inflammatory responses has encouraged the development of antagonists of these receptors. In this study, we used phage display peptide libraries to identify peptides antagonists that block the interactions between hCXCL8 and hCXCR1/2.

Random phage-epitope library based identification of a peptide antagonist of Mac-1 β2 integrin ligand binding.

The leukocyte β2 integrin Mac-1 (CD11b/CD18) plays a pivotal role in inflammation and host defense. To develop peptide antagonists selectively inhibiting the function of Mac-1, we used a random constrained 6-mer (cys-6aa-cys) peptide library to map the structural features of CD11b, by determining the epitope of neutralizing monoclonal antibody mAb 44a (anti-CD11b). We have used a stringent phage display strategy, which resulted in the identification of one disulfide C-RLKEKH-C constrained peptide by direct biopanning of library on decreasing amounts of purified mAb 44a.

Isolation and characterization of human neutralizing antibodies to rabies virus derived from a recombinant immune antibody library.

A human immune Fab library was constructed using RNAs from peripheral blood lymphocytes obtained from rabies virus hyperimmune volunteers on phagemid vector. The size of the constructed Fab library was 2 x 10(7) Escherichia coli transformants. After four rounds of panning on whole inactivated rabies virus (PV-11), phage clones displaying rabies virus-specific human Fab were selected.

Peptide mimotopes of rabies virus glycoprotein with immunogenic activity.

A random constrained hexapeptide phage display library (Cys-6aa-Cys) was screened with purified neutralizing human anti-rabies virus IgG antibodies (hRABVIgG) to identify peptides that correspond to or mimic natural epitopes on rabies virus glycoprotein (RABVG) and to investigate their immunogenicities in vivo. After four rounds of biopanning, 20 phage clones randomly selected for their specificity to hRABVIgG, effectively blocked the binding of the inactive rabies virus (RABV) to hRABVIgG. The phage clones were sequenced and the deduced amino acid sequences were derived (C-KRDSTW-C; C-KYLWSK-C; C-KYWLSR-C; C-KYWWSK-C; C-KYAWSR-C; C-KYSMSK-C).

Identification of biologically active peptides that inhibit binding of human CXCL8 to its receptors from a random phage-epitope library.

A random bacteriophage peptide library was used to map structural features of human (h)CXCR1 and hCXCR2 by determining the epitopes of neutralizing mAb 5A12 anti-hCXCR1 and mAb 6C6 anti-hCXCR2. After three rounds of biopanning, five mAb5 A12- and four mAb 6C6-binding peptides were identified from a 6-mer peptide library. Consensus sequences (S/T)(1)(F/A/N/D)(2)(I/M)(3)W(4)D(5)F(6) and F/L/M)(1)W(2)(D/N/L)(3)D(4)F(5)W(6) were deduced from sequences of these peptides.

Comparison of pp65 antigenemia, quantitative PCR and DNA hybrid capture for detection of cytomegalovirus in transplant recipients and AIDS patients.

The cytomegalovirus (CMV) antigenemia assay has been used frequently for rapid diagnosis of CMV infection, and antigenemia threshold values are recommended for triggering preemptive therapy. Hybrid capture of CMV's DNA and quantitative polymerase chain reaction (qPCR) are increasingly being adopted for early detection of CMV. The performance of the antigenemia assay, qPCR in plasma and hybrid capture in leukocytes were compared in 110 immunocompromised patients (38 bone-marrow transplants, 50 renal transplants and 22 AIDS patients).