Growth of pathogenic virus in a large-scale tissue culture system

Large-scale production and concentration of human lymphoid interferon

A stable and predictable production system is described for pilot plant quantities (milligram) of human lymphoid interferon, using suspension culture of an African Burkitt's lymphoma derived cell line Namalva with induction by Newcastle disease virus, B-1 strain. Cell cultures were grown in impeller-driven 50-liter fermentors with dilution of the postinduction culture using serum-free medium. High levels of dissolved oxygen were necessary for optimum cell growth. A total of 4,207 liters of interferon culture was produced in a series of 116 fermentor runs. An average yield of 3.5 log(10) international units of interferon per ml was realized before processing. Trichloroacetic acid was used to precipitate the interferon. An average of 3.35 log(10) international units of interferon per ml was recovered in the final nonpurified product.

Adaptation and infection of mouse bone marrow (JLS-V9) cells in suspension culture for production of Rauscher leukemia virus

JLS-V9 mouse bone marrow cells were readily adapted to suspension culture, chronically infected with Rauscher leukemia virus (RLV), and subsequently grown in 7.5- and 14-liter New Brunswick fermentors. The suspension-type cell system can be modified to produce virus with clearly defined properties, such as high ribonucleic acid-dependent deoxyribonucleic acid polymerase (RDDP) activity, high particle count, and high infectious particle count. Biological and biophysical properties of suspension-produced RLV were not affected by concentration and purification employing continuous-flow and rate-zonal centrifugation procedures. The RDDP assay was standardized and showed a linear incorporation of (3)H-thymidine 5'-monophosphate ((3)H-TMP) up to 30 min. Further characterization indicated that a high percentage of (3)H-TMP incorporation was due to RDDP.

Characterization of the growth of herpes simplex virus in human lymphoid cells

Herpes simplex virus was grown in a 6-liter suspended culture of an atypical permanent human lymphoid cell line, Roswell Park Memorial Institute no. 8226. The kinetics of virus replication were determined by counting viruses by electron microscopy, plaque formation, and tissue culture infectivity. Deoxyribonucleic acid-dependent deoxyribonucleic acid polymerase activity was determined during the course of infection. Electron microscopy studies substantiated the kinetics of the virus infection in lymphoid cells.

Ultrafiltration as a method for concentrating Rift Valley fever virus grown in tissue culture

Filtration by means of a Diaflo ultrafilter was used to concentrate three 1,000-ml lots and one 3,000-ml lot of tissue culture-grown Rift Valley fever virus. Quantitation of both infectivity and total protein was achieved. Water treatment with continued ultrafiltration of the virus concentrate provided a final virus product approximately 99.25% free of low-molecular-weight materials originally present in the growth medium.