A human intestinal cell line suitable for the propagation of Type 1-6 human parechovirus with a clear cytopathic effect.

Human parechoviruses (HPeVs) are increasingly recognized pathogens that cause mild-to-life-threatening diseases in children and adults. Recently, nucleic acid detection has become the mainstream method for pathogen detection. However, virusisolation is still important for virus detection and for further virologic characterization studies as well as securing bioresources. We recently explored conventional cell lines suitable for human sapovirus isolation, and unintentionally identified a human duodenum cell line, HuTu80, that supported the efficient growth of human Parechovirus Type 3 (HPeV-3) with clear cytopathic effects (CPE). Then, we confirmed that all representative prototype HPeV Type 1-6 strains were efficiently propagated in HuTu80 with clear CPE within 4 days. Another human ileocecal cell line, HCT-8 (HRT-18) also supports HPeV propagation except HPeV-3. Titers in HuTu80 and HCT-8 reached approximately 6.83-8.83 and 6.50-8.17 log10 TCID50/50 μL, respectively, when inoculated with multiplicity of infection 0.0025. Previously reported cell lines likely support HPeV Types 1-6 with different efficiency, especially HPeV-3. In summary, HuTu80 can be used as an additional cell line for HPeV isolation and propagation with clear CPE, to produce high titer viruses, and in neutralization assays.