17 research outputs found
A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond
According to the World Health Organization (WHO), almost 2 billion people each year are infected worldwide with flu-like pathogens including influenza. This is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. Employee absenteeism caused by flu infection costs hundreds of millions of dollars every year. To successfully treat influenza virus infections, detection of the virus during the initial development phase of the infection is critical, when tens to hundreds of virus-associated molecules are present in the patient’s pharynx. In this study, we describe a novel universal diamond biosensor, which enables the specific detection of the virus at ultralow concentrations, even before any clinical symptoms arise. A diamond electrode is surface-functionalized with polyclonal anti-M1 antibodies, which then serve to identify the universal biomarker for the influenza virus, M1 protein. The absorption of the M1 protein onto anti-M1 sites of the electrode change its electrochemical impedance spectra. We achieved a limit of detection of 1 fg/ml in saliva buffer for the M1 biomarker, which corresponds to 5–10 viruses per sample in 5 minutes. Furthermore, the universality of the assay was confirmed by analyzing different strains of influenza A virus
A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond
According to the World Health Organization (WHO), almost 2 billion people each year are infected worldwide with flu-like pathogens including influenza. This is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. Employee absenteeism caused by flu infection costs hundreds of millions of dollars every year. To successfully treat influenza virus infections, detection of the virus during the initial development phase of the infection is critical, when tens to hundreds of virus-associated molecules are present in the patient’s pharynx. In this study, we describe a novel universal diamond biosensor, which enables the specific detection of the virus at ultralow concentrations, even before any clinical symptoms arise. A diamond electrode is surface-functionalized with polyclonal anti-M1 antibodies, which then serve to identify the universal biomarker for the influenza virus, M1 protein. The absorption of the M1 protein onto anti-M1 sites of the electrode change its electrochemical impedance spectra. We achieved a limit of detection of 1 fg/ml in saliva buffer for the M1 biomarker, which corresponds to 5–10 viruses per sample in 5 minutes. Furthermore, the universality of the assay was confirmed by analyzing different strains of influenza A virus
Presenting Influenza A M2e Antigen on Recombinant Spores of Bacillus subtilis.
Effective vaccination against influenza virus infection is a serious problem mainly due to antigenic variability of the virus. Among many of investigated antigens, the extracellular domain of the M2 protein (M2e) features high homology in all strains of influenza A viruses and antibodies against M2e and is protective in animal models; this makes it a potential candidate for generation of a universal influenza vaccine. However, due to the low immunogenicity of the M2e, formulation of a vaccine based on this antigen requires some modification to induce effective immune responses. In this work we evaluated the possible use of Bacillus subtilis spores as a carrier of the Influenza A M2e antigen in mucosal vaccination. A tandem repeat of 4 consensus sequences coding for human-avian-swine-human M2e (M2eH-A-S-H) peptide was fused to spore coat proteins and stably exposed on the spore surface, as demonstrated by the immunostaining of intact, recombinant spores. Oral immunization of mice with recombinant endospores carrying M2eH-A-S-H elicited specific antibody production without the addition of adjuvants. Bacillus subtilis endospores can serve as influenza antigen carriers. Recombinant spores constructed in this work showed low immunogenicity although were able to induce antibody production. The System of influenza antigen administration presented in this work is attractive mainly due to the omitting time-consuming and cost-intensive immunogen production and purification. Therefore modification should be made to increase the immunogenicity of the presented system
Schematic steps of building strains carrying fusion genes.
<p>Schematic steps of building strains carrying fusion genes.</p
Western blot analysis of sera from immunized mice.
<p>5 groups of 3 mice (A, B, C) were orally immunized with recombinant spores of strains <i>B</i>. <i>subtilis</i> 168; 2-BTL20(CotC-M2eH-A-S-H), BTL21(CotB-M2eH-A-S-H), BTL22(CotZ-M2eH-A-S-H) or BTL25(CgeA-M2eH-A-S-H). A 15 μg of recombinant M2eH-A-S-H-GST was separated in polyacrylamide gel and further electrotransferred on nitrocellulose which was further incubated with sera from immunized mice as a primary antibodies. Blots were developed using anti-mouse alkaline phosphatase conjugates. Figure is a merge of 20 different single-lane blot strips.</p
Densitometric analysis of protein expression.
<p>Densitometric analysis of protein expression.</p
Western blot analysis of fusion genes expression.
<p>Spore coat proteins were extracted and analyzed by western blotting with anti-influenza M2 mAb. Numbers of lanes refer to the strain used in experiment: 1-<i>B</i>. <i>subtilis</i> 168; 2-BTL20(CotC-M2eH-A-S-H, ~20 kDa); 3-BTL21(CotB-M2eH-A-S-H, ~43 kDa); 4-BTL23(CotB-LINKER-M2eH-A-S-H, ~44 kDa); 5-BTL22(CotZ-M2eH-A-S-H, ~28 kDa); 6-BTL24(CotZ-LINKER-M2eH-A-S-H, ~29 kDa); 7-BTL25(CgeA-M2eH-A-S-H, ~26 kDa); 8-BTL26(CgeA-LINKER-M2eH-A-S-H, ~27 kDa).</p
Germinantion of recombinant and parental strain induced by L-alanine and AGFK.
<p>Germination was followed by measuring the absorbance decrease at 600 nm of the spore suspension. Data are given as arithmetic mean from three independent experiments.</p