A novel immunochromatographic system for easy-to-use detection of group 1 avian influenza viruses with acquired human-type receptor binding specificity

Abstract

A switch of viral hemagglutinin receptor binding specificity from bird-type α2,3- to human-type α2,6-linked sialic acid is necessary for an avian influenza virus to become a pandemic virus. In this study, an easy-to-use strip test to detect receptor binding specificity of influenza virus was developed. A biotinylated anti-hemagglutinin antibody that bound a broad range of group 1 influenza A viruses and latex-conjugated α2,3 (blue) and α2,6 (red) sialylglycopolymers were used in an immunochromatographic strip test, with avidin and lectin immobilized on a nitrocellulose membrane at test and control lines, respectively. Accumulation of a sialylglycopolymer-virus-antibody complex at the test line was visualized by eye. The strip test could be completed in 30min and did not require special equipment or skills, thereby avoiding some disadvantages of current methods for analyzing receptor binding specificity of influenza virus. The strip test could detect the receptor binding specificity of a wide range of influenza viruses, as well as small increases in the binding affinity of variant H5N1 viruses to α2,6 sialylglycans at viral titers >128 hemagglutination units. The strip test results were in agreement with those of ELISA virus binding assays, with correlations >0.95. In conclusion, the immunochromatographic strip test developed in this study should be useful for monitoring potential changes in the receptor binding specificity of group 1 influenza A viruses in the field.

Multiple polymerase gene mutations for human adaptation occurring in Asian H5N1 influenza virus clinical isolates

“…To investigate the effect(s) of the mutations on viral polymerase activity, we carried out minigenome assays of polymerases with these mutations in the genetic background of A/Vietnam/HN31432/2008 (VN/HN). VN/HN is a representative H5N1 clade 2.3.4 strain 27 with no known human adaptation mutations (e.g., PB2-E627K and PB2-D701N) in its HA and polymerase genes. VN/HN was used as the genetic background in this study because most of the identified mutations (13/24) were in clade 2.3.4, clade 2.3.4.1 or clade 2.3.4.3 viruses (Table S1 ).…”

A fluorescent immunochromatographic strip test using Quantum Dots for fumonisins detection

“…Fumonisin B1, zearalenone, aflatoxin B1, deoxynivalenol (Oekanal standard solutions), polyethylene glycol (PEG, average mw 10 kDa), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), cadmium oxide (CdO, 99,99%), selenium powder (Se, 99,99%), sulfur powder (S, 99%), zinc acetate (Zn(OAc) 2 , 99,99%), oleic acid (90%), 1-octadecene (90%), oleylamine (70%), octadecylamine (90%), and trioctylphosphine, poly(maleic anhydride-alt-1-octadecene) (PMAO, M ~ 30 000-50 000) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Tween 20, Triton X-100 and other chemicals were purchased from Merck-VWR (Milan, Italy).…”

Label-free sensitive detection of influenza virus using PZT discs with a synthetic sialylglycopolymer receptor layer

“…It was previously shown that oligosaccharide sequences do not affect the overall receptor stability [18,19]. Using sialic saccharides instead of antibodies to detect antigenic drift of influenza virus is promising [20]. Several groups have recently developed sensors based on sialic saccharides [21,22].…”