Growth characteristics and antibody detection of human parechovirus types 1-6 in the intestinal HuTu80 cell line

Abstract

Human parechoviruses (PeVs) are common pathogens associated with a wide clinical spectrum ranging from mild respiratory and gastrointestinal symptoms to severe, life-threatening neurological infections, particularly in infants. While nucleic acid detection methods such as PCR are considered the diagnostic gold standard due to their high sensitivity and specificity, their cost limits diverse use in resource-limited settings. Viral culture remains a more accessible alternative; however, its application is limited by the absence of a universal cell line capable of supporting the replication of multiple PeV-A genotypes. This study aimed to evaluate the permissiveness of the HuTu80 cell line for the replication of PeV-A genotypes and to identify suitable antibodies for viral detection. The in vitro growth characteristics of PeV-A1 to PeV-A6 strains in HuTu80 cells were assessed using cytopathic effect (CPE) analysis, immunofluorescence assay (IFA), real-time RT-qPCR, and ELISA. The most suitable antibody was subsequently used to compare viral replication in HuTu80, HT-29, and Vero E6 cell lines. The results demonstrated that all six PeV-A genotypes replicated efficiently in HuTu80 cells, with time- and strain-dependent cytopathic effects observed within 24 hours post-infection. Both the monoclonal antibody P5C4 and several polyclonal antibodies (K8873, K8851, K306, and K316) successfully detected all six genotypes; however, P5C4 was selected for further analyses due to its specific recognition of the PeV-A1 VP0 protein. Comparative analyses showed that HuTu80 and HT-29 cells were permissive to PeV-A infection and compatible with immunofluorescence-based detection of viral antigens, whereas Vero E6 cells were not suitable for this application. Overall, these findings demonstrate that HuTu80 cells represent a useful additional cell line for the cultivation, isolation, and antibody-based visualization of PeV-A, and that specific antibodies, particularly P5C4, provide effective tools for detecting parechoviruses. Together, these may help improve laboratory strategies for molecular analysis of parechoviruses and their detection.