Replication of porcine circovirus: induction by glucosamine and cell cycle dependence

Abstract

Multiplication of porcine circovirus (PCV) was found to be inducible by treatment of infected cell cultures with 300 mM glucosamine. One day after glucosamine treatment and after growth in fresh medium, an increase in the number of cells containing virus antigen of up to 50 times as compared to mock-treated cultures was observed. Analysis of this phenomenon revealed that replication of PCV DNA was induced. Only aminohexoses but not hexoses and acetylated aminohexoses were efficacious. The course of PCV replication in synchronized cell cultures infected at different periods of the cell cycle showed that PCV DNA synthesis depends on cellular enzymes expressed during S phase growth of cells. However, whereas in cell cultures treated with glucosamine after infection in G0 or during G1, the start of PCV replication was observed during the first S phase after growth stimulation, the latent period in mock-treated cultures lasted until the second S phase. Also in cell cultures transfected with PCV DNA in G0 or during G1 using DEAE-dextran as mediator, PCV replication started during the first S phase after growth release of the cells. From these findings the conclusion is drawn that glucosamine and DEAE-dextran initiate PCV replication by enabling the PCV genome to get entry to the cell nucleus that normally can be achieved only by inclusion in the daughter nuclei at the end of mitosis.

Coinfection by Porcine Circoviruses and Porcine Parvovirus in Pigs with Naturally Acquired Postweaning Multisystemic Wasting Syndrome

“…6,13,24 Although it has been documented in vitro that the replication of at least the original isolates of PCV are dependent on the S, or synthesis phase, of the cell cycle, currently little is known about the requirements for PCV growth in vivo. 23 Replication of both PPV and PCV depends on cellular enzymes expressed during S phase of the cell cycle, 24 suggesting that PPV and PCV may target the same cells in vivo. They may interact in some way to synergistically enhance replication, or the same physiologic factors may enhance replication of both viruses.…”

“…Both PPV and PCV are small, single-stranded DNA viruses that have a small coding capacity and are, therefore, highly dependent on host cell functions. 17,24 The predilection of autonomous parvoviruses from a variety of species for rapidly dividing cells is well recognized and well documented both in vivo and in vitro. 6,13,24 Although it has been documented in vitro that the replication of at least the original isolates of PCV are dependent on the S, or synthesis phase, of the cell cycle, currently little is known about the requirements for PCV growth in vivo.…”

“…17,24 The predilection of autonomous parvoviruses from a variety of species for rapidly dividing cells is well recognized and well documented both in vivo and in vitro. 6,13,24 Although it has been documented in vitro that the replication of at least the original isolates of PCV are dependent on the S, or synthesis phase, of the cell cycle, currently little is known about the requirements for PCV growth in vivo. 23 Replication of both PPV and PCV depends on cellular enzymes expressed during S phase of the cell cycle, 24 suggesting that PPV and PCV may target the same cells in vivo.…”

Isolation and characterization of porcine circovirus type 2 from pigs showing signs of post‐weaning multisystemic wasting syndrome in the Netherlands

“…The mixtures were incubated in F25 tissue culture flasks at 37°C for 5 hours (5% CO2). The resulting semi-confluent monolayers were treated with 300 mM D-glucosamine-HCL (Serva, Heidelberg, Germany) (18) and incubated at 37°C for 30 min (5% CO2). The semi-confluent cell monolayer was washed twice with EMEM to remove the D-glucosamine-HCI.…”

A double-antibody sandwich ELISA based on the porcine circovirus type 2 (PCV2) propagated in cell culture for antibody detection

“…Lysates of uninfected ST cells were prepared in the same way and used as ST antigen (ST Ag). PK-15 cell lysate persistently infected with PCV1 treated with D-glucosamine (Tischer et al 1987) was used as PCV1 antigen (PCV1 Ag).…”