Cell penetrable human scFv specific to middle domain of matrix protein-1 protects mice from lethal influenza.

A new anti-influenza remedy that can tolerate the virus antigenic variation is needed. Influenza virus matrix protein-1 (M1) is highly conserved and pivotal for the virus replication cycle: virus uncoating, assembly and budding. An agent that blocks the M1 functions should be an effective anti-influenza agent. In this study, human scFv that bound to recombinant M1 middle domain (MD) and native M1 of A/H5N1 was produced. Phage mimotope search and computerized molecular docking revealed that the scFv bound to the MD conformational epitope formed by juxtaposed helices 7 and 9 of the M1. The scFv was linked molecularly to a cell penetrable peptide, penetratin (PEN). The PEN-scFv (transbody), when used to treat the cells pre-infected with the heterologous clade/subclade A/H5N1 reduced the viral mRNA intracellularly and in the cell culture fluids. The transbody mitigated symptom severity and lung histopathology of the H5N1 infected mice and caused reduction of virus antigen in the tissues as well as extricated the animals from the lethal challenge in a dose dependent manner. The transbody specific to the M1 MD, either alone or in combination with the cognate human scFvs specific to other influenza virus proteins, should be an effective, safe and mutation tolerable anti-influenza agent.

Developing an indirect ELISA based on recombinant hexon protein for serological detection of inclusion body hepatitis in chickens.

Fowl adenovirus (FAdv) serotype 2 causes inclusion body hepatitis (IBH) disease which adversely affects the broiler industry in Thailand. We developed an indirect ELISA based on the recombinant hexon protein produced by E. coli. The recombinant hexon protein was tested with sera, in both infected and noninfected chickens. The recombinant hexon protein was standardized with an antigen concentration of 3.75 µg/ml and test sera. The intra- and inter-assays were repeatable. The cutoff value from TG-ROC curve analysis was 0.106. The specificity and sensitivity were 80 and 80%, respectively. The correlation coefficient (r) of absorbance values from this ELISA compared with the serum neutralization test was 0.76. This ELISA might be helpful for IBH diagnosis and surveillance.

Avian and human influenza A virus receptors in trachea and lung of animals.

BACKGROUND: Influenza A viruses are capable of crossing the specific barrier between human beings and animals resulting in interspecies transmission. The important factor of potential infectivity of influenza A viruses is the suitability of the receptor binding site of the host and viruses. The affinities of avian and human influenza virus to bind with the receptors and the distributions of receptors in animals are different. OBJECTIVE: This study aims to investigate the anatomical distribution of avian and human influenza virus receptors using the double staining lectin histochemistry method. METHODS: Double staining of lectin histochemistry was performed to identify both SA alpha2,3 Gal and SA alpha2,6 Gal receptors in trachea and lung tissue of dogs, cats, tigers, ferret, pigs, ducks and chickens. RESULTS: We have demonstrated that avian and human influenza virus receptors were abundantly present in trachea, bronchus and bronchiole, but in alveoli of dogs, cats and tigers showed SA alpha2,6 Gal only. Furthermore, endothelial cells in lung tissues showed presence of SA alpha2,3 Gal. CONCLUSION: The positive sites of both receptors in respiratory tract, especially in the trachea, suggest that all mammalian species studied can be infected with avian influenza virus. These findings suggested that dogs and cats in close contact with humans should be of greater concern as an intermediate host for avian influenza A in which there is the potential for viral adaptation and reassortment.