Purpose: Our broadly specific, high affinity IgG anti-norovirus reagents will prove essential in the development of reliable and accurate immunoassays for norovirus diagnostics or detection.
Methods: For rapid and accurate diagnostics, the most useful antibodies would possess a high affinity for any human norovirus particle in its native state while not displaying crossreactivity to other closely related viruses. To this end, eight peptide antigens mimicking conserved GI and GII linear epitopes in the VP1 norovirus capsid protein were chosen based on their estimated accessibility to antibodies when displayed on the surface of intact icosahedral norovirus particles. Balb/c mouse polyclonal sera made in response to the peptides were tested for reactivity on GI.1, GI.2, GII.1, GII.2, GII.3, GII.4, GII.5, GII.6, GII.7 virus-like particles (VLP). Four out of the eight peptides generated serum antibodies with desirable reactivity patterns.
Results: Hyperimmune mice were sacrificed for hybridoma fusions, generating high affinity IgG anti-norovirus mAbs possessing the same reactivity patterns observed in serum assays. Extrapolating from the initial analysis of the reactivity patterns seen on the VLPs tested, we infer that certain key immunodominant epitopes within peptide antigens KLp5 and KLp6 generate antibodies which, when combined, appear capable of detecting potentially 100% of all GI norovirus strains. Similarly, key immunodominant epitopes within peptide antigens KLp7 and KLp8 generate antibodies with the potential to detect 80% of all GII noroviruses strains.
Significance: Such antibodies will be a welcome and useful reagent for the development of many different types of norovirus diagnostic immunoassays including dipstick, ELISA, IMS, and IMS-PCR.