Data_Sheet_1.DOCX

<p>Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1’s inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1.</p

Immunochemical staining of PK15 cells transfected with rpSK-2P1.

<p>(A) or rpSK-P1 (B) or empty pSK (C) or untransfected cells were used (D). The presence of P1 antigen is indicated by blue-purple staining.</p

Electron micrographs of P1 particles, obtained from CsCl density gradients, and negatively stained with phosphotungstic acid.

<p>(A) Without addition of antiserum. Note the virus particles dispersed at random. (B) Exposure to anti-P1 antiserum generated in rabbit: antibody bridges link the P1 particles.</p

Growth curves of P1 virus in PK-15 cells.

<p>Intracellular virus (▪) and extracellular virus(⧫).</p

Clinical signs caused by P1 infection were usually visible as tan-to-purple inguinal lymph nodes.

<p>Clinical signs caused by P1 infection were usually visible as tan-to-purple inguinal lymph nodes.</p

Detection of tissue distribution of P1 by PCR in infected and control pigs.

<p>Detection of tissue distribution of P1 by PCR in infected and control pigs.</p

Detection of viremia (P1 DNA) by PCR in sera of infected and control pigs.

<p>Detection of viremia (P1 DNA) by PCR in sera of infected and control pigs.</p

Histological patterns in different tissues of the pigs.

<p>(A) Brain of a P1-inoculated pig. Note subarachnoid arterioles and capillaries telangiectasias with a large number of red blood cells. (B) Microscopic section of a pig lung. Note interstitial pneumonia characterized by greatly thickened interlobular septum and alveolar septal thickening, a small number of alveolar septum fractures, some expansion of the alveoli filled with red blood cells. (C) Myocardial cells showed atrophy of a mild degree. (D) Note swelling of the bladder muscle cells (E) Histiocytic hyperplasia of follicles in the tonsils of the inoculated pigs. (F) Haemorrhage of the inguinal lymph nodes observed in P1 plasmid DNA transfected pigs characterized as erythrocyte infiltration and haemosiderin deposition in the expanding medullary sinus. HE staining was used for all panels. Magnification. ×40.</p

Schematic diagram of the P1 molecular DNA clones constructed.

<p>Schematic diagram of the P1 molecular DNA clones constructed.</p

Cell morphology of SS2-1,Δ<i>stk</i> and CΔ<i>stk</i>.

<p>(A)Light microscope morphology of SS2 strains using Gram staining. (B)Sedimentation of bacteria cultured in THY for 12 h with gentle shaking. The arrows indicate the sedimented cells at the bottom of tubes.</p