Analytical and computational modeling of early penetration of non-enveloped icosahedral viruses into cells

BACKGROUND: As obligate intracellular parasites, all viruses penetrate target cells to initiate replication and infection. OBJECTIVE: This study introduces two approaches for evaluating the contact loads applied to a cell during early penetration of non-enveloped icosahedral viruses. METHODS: The first approach is analytical modeling which is based on Hertz's theory for the contact of two elastic bodies; here we model the virus capsid as a triangle and the cell as an order-of-magnitude larger sphere. The second approach is finite element modeling, where we simulate three types of viruses: adeno-, papilloma- and polio- viruses, each interacting with a cell section. RESULTS: We find that the peak contact pressures and forces generated at the initial virus-cell contact depend on the virus geometry - that is both size and shape. With respect to shape, we show that the icosahedral virus shape induces greater peak pressures compared to a spherical virus shape. With respect to size, it is shown that the larger the virus is the greater are the contact loads in the attacked cell. CONCLUSION: Utilization of our modeling can be substantially useful not only for basic science studies, but also in other, more applied fields, such as in the field of gene therapy, or in 'phage' virus studies.