Enteroviruses, with their diverse clinical manifestations ranging from mild or asymptomatic infections to severe diseases such as poliomyelitis and viral myocarditis, present a public health threat. However, they can also be used as oncolytic agents. This review shows the intricate relationship between enteroviruses and host cell factors. Enteroviruses utilize specific receptors and coreceptors for cell entry that are critical for infection and subsequent viral replication. These receptors, many of which are glycoproteins, facilitate virus binding, capsid destabilization, and internalization into cells, and their expression defines virus tropism towards various types of cells. Since enteroviruses can exploit different receptors, they have high oncolytic potential for personalized cancer therapy, as exemplified by the antitumor activity of certain enterovirus strains including the bioselected non-pathogenic Echovirus type 7/Rigvir, approved for melanoma treatment. Dissecting the roles of individual receptors in the entry of enteroviruses can provide valuable insights into their potential in cancer therapy. This review discusses the application of gene-targeting techniques such as CRISPR/Cas9 technology to investigate the impact of the loss of a particular receptor on the attachment of the virus and its subsequent internalization. It also summarizes the data on their expression in various types of cancer. By understanding how enteroviruses interact with specific cellular receptors, researchers can develop more effective regimens of treatment, offering hope for more targeted and efficient therapeutic strategies.

Non-pathogenic natural and recombinant strains of human Enteroviruses are the subject of ongoing study with some strains having been approved for use as anticancer agents. The efficacy of oncolytic virotherapy depends upon identifying the receptor utilized by a specific strain for cell entry, and the presence of this receptor on the surface of cancer cells. Accordingly, a rapid and straightforward approach to determining the enteroviral receptors is necessary for developing an effective patient-specific, virus-based cancer therapy. To this end, we created a panel of seven lines with double knockouts on the background of the HEK293T cell line, which lacks the IFNAR1 gene. In these lines, the main viral receptor genes, including PVR, CXADR, CD55, ITGA2, SCARB2, ICAM1, and FCGRT, were knocked out using the CRISPR/Cas9 system. The panel of lines was validated on twelve different Enteroviruses types, providing a basis for studying the molecular mechanisms of enterovirus entry into cells, and for developing new therapeutic strains.

Background/Objectives: Glioblastoma remains the most lethal primary brain tumor in adults, and progress in oncolytic virotherapy is limited by the lack of immunocompetent models permissive to human-tropic viruses. Methods: Here, murine CT-2A and GL261 glioma and B16 melanoma cell lines were engineered to express human Coxsackievirus and Adenovirus Receptor (CXADR) fused to tagBFP, generating “humanized” tumors that preserve parental growth characteristics while acquiring high susceptibility to group B Coxsackieviruses (CVBs) and adenovirus serotype 5. Results: CXADR expression in CT-2A, GL261, and B16 cells markedly enhanced binding, internalization, and replication of CVBs in vitro, with the strongest effect observed for LEV14 (attenuated CVB5), which reached up to 10⁵-fold higher viral titers in humanized cells compared with parental cells. Unchanged sensitivity to vesicular stomatitis virus indicated receptor-specific effects. Humanized CT-2A-CXADR-BFP and GL261-CXADR-BFP cells initiated aggressive subcutaneous and intracranial tumors in syngeneic C57BL/6 mice without signs of immune rejection, and histology and MRI confirmed invasive high-grade glioma phenotypes. In intracranial CT-2A-CXADR-BFP tumors, repeated intratumoral LEV14 administration induced extensive tumor necrosis and prolonged survival despite the rapid development of neutralizing antibodies. Systemic intravenous LEV14 dosing produced strong oncolytic activity against subcutaneous CT-2A-CXADR-BFP tumors, as demonstrated by pronounced tumor growth inhibition, long-lasting regression in a subset of animals with gliomas, and improved overall survival. Conclusions: Collectively, these data establish CXADR-humanized models as versatile, immunocompetent platforms for evaluation of CXADR-dependent oncolytic enteroviruses.

Non-pathogenic natural and recombinant strains of human Enteroviruses are the subject of ongoing study, with some strains having been approved for use as anticancer agents. The efficacy of on-colytic virotherapy is dependent upon the identification of the receptor utilized by a specific strain for cell entry and the presence of this receptor on the surface of cancer cells. Accordingly, a rapid and straightforward approach for determining the enteroviral receptors is necessary for the de-velopment of effective patient-specific virus-based cancer therapy. To this end, we created a panel of seven lines with double knockouts on the background of the HEK293T cell line, which lacks the IFNAR1 gene. In these lines, the main viral receptor genes, including PVR, CXADR, CD55, ITGA2, SCARB2, ICAM1, and FCGRT, were knocked out using the CRISPR/Cas9 system. A panel of lines was validated on a set of 12 Enteroviruses, providing a basis for studying the molecular mechanisms of enterovirus entry into cells and developing new therapeutic strains.