Concurrent replication of a papovavirus and a C-type virus in the CCL 33 porcine cell line

A papovavirus, CCL 33 PV, isolated from a porcine cell line, CCL 33 (GT), was characterized. Based on a comparison of four isoenzyme systems, CCL 33 (GT) and CCL 33 (ATCC), obtained directly from the American Type Culture Collection, appeared to be the same. In addition to the previously characterized C-type virus of CCL 33 cultures, CCL 33 (GT) produced CCL 33 PV in high quantity, but CCL 33 (ATCC) produces a papovalike virus, presumably the same as CCL 33 PV, in barely detectable amounts. Serological results showed that CCL 33 PV is apparently identical to a papovavirus (SPV) isolated by Newman and Smith after inoculation of CCL 33 with concentrated porcine trypsin. These studies extend the characterization of this papovavirus, demonstrating that CCL 33 PV is weakly hemagglutinating after neuraminidase treatment, has a high affinity for a component of fetal bovine serum and is highly infectious in appropriate porcine cell systems rather than very defective as reported previously. Moreover, it was concluded from the data that CCL 33 PV is probably indigenous to the CCL 33 porcine cell line.