The present invention relates to a method for prevention and/or reduction of aggregation of viral components.

Described are improved processes for production and purification of nucleic acid-containing compositions, such as non-naturally occurring viruses, for example, recombinant polioviruses that can be employed as oncolytic agents. Some of the described improved processes relate to improved processes for producing viral DNA template. Also described are improved processes for chromatography purification of nucleic acid-containing compositions, in which the nucleic acid is quantified in chromatography fractions using a rapid detection method of the one or more nucleic acid sequences of the nucleic acid-containing composition, such as detection by real time RT-qPCR. In addition, improved processes for production and purification of oncolytic poliovirus, such as PVS-RIPO, are described. Compositions generated using these methods are also provided.

The disclosure provides methods for poliovirus purification from crude cell culture harvests using a detergent followed by a clarification step.

Provided herein are engineered cell lines. In some embodiments, cells of an engineered cell line have altered expression of a gene and/or altered expression of an miRNA, wherein the altered expression results in increased or decreased production of a virus. The virus is a picomavirus, such as a poliovirus or Enterovirus 71. Also provided herein are methods for using the engineered cells to produce virus, and methods for treating a subject having or at risk of having a viral infection.