The Cap gene of antisense strand of circovirus has the most variation of the genome, and encodes a capsid protein which has the main immunogenicity. The N-terminal of capsid protein makes up of nuclear localization signal which is involved with virus location. This review summarizes the research advance of Cap gene of circovirus in the sequence characteristics, its encoding capsid protein, basic functions of the capsid protein and its interaction with MKRN1 protein, Hsp40 protein, receptor protein gClqR and complement factor C1qB protein. This paper lays a theory foundation for the further study of the capsid protein in the aspects of viral attachment, replication and transportation.
Animals ; Capsid Proteins ; genetics ; immunology ; metabolism ; Circoviridae Infections ; veterinary ; virology ; Circovirus ; genetics ; immunology ; Genetic Variation ; Genome, Viral ; genetics ; Nuclear Localization Signals ; Protein Binding ; Virus Replication

Distribution and characterization of interlukin-10 (IL-10)-secreting cells in lymphoid tissues of pigs naturally infected with porcine circovirus type 2 (PCV2) were evaluated in accordance with PCV2 antigen detection. After screening a total of 56 pigs showing the symptoms of postweaning multisystemic wasting syndrome (PMWS), 15 pigs were PCV2 positive and 5 pigs, which showed stronger positive signals over multiples tissues were further investigated. This study showed that in PCV2-infected lymphoid tissues, particularly mandibular lymph node, spleen and tonsil, IL-10 expression was mainly localized in T-cell rich areas but rarely in B cell rich areas. IL-10 was highly expressed in bystander cells but rarely in PCV2-infected cells. Elevated IL-10 expression was predominantly associated with T cells, but rarely with B cells or with macrophages. The results of this study provide evidence for the role of IL-10 in chronic PCV2 infection and its relation to PCV2 antigen in affected tissues. Constantly elevated levels of IL-10 lead to immunosuppression in persistent and chronic viral infections. The increased IL-10 expression observed in PCV2 infection in this study suggests that IL-10-mediated immunosuppression may play an important role in the pathogenesis and maintenance of naturally occurring PCV2 infection.
Animals ; Circoviridae Infections/immunology/pathology/*veterinary ; Circovirus/*immunology ; Gene Expression Regulation/*immunology ; Immunohistochemistry/veterinary ; Interleukin-10/immunology/*secretion ; Lymphoid Tissue/immunology/*pathology/secretion ; Porcine Postweaning Multisystemic Wasting Syndrome/*immunology/pathology ; Republic of Korea ; Swine ; T-Lymphocytes/immunology

In order to observe the effect of the immune and weight of chickens after use the attenuated vaccine with low dose of chicken infectious anemia virus (CIAV). In this study, the effects of low dose of CIAV on the weight of SPF chickens and NDV antibody production were observed by simulated experiments. The results showed that 10 EID50 and 5 EID50 CIAV per plume attenuated NDV vaccines were used to cause the weight loss of SPF chickens. Compared with the use of the non contaminated vaccine group, it has significant difference. And NDV antibody levels compared with the use of the non contaminated groups also decreased after use the vaccine with two doses of CIAV contaminated. It has significant difference. A certain proportion of CIAV antibody positive was detected at the beginning of the second week after use the NDV vaccine with two doses of CIAV contaminated. The detection of a high proportion of CIAV nucleic acid was detected in the first week after the use of a contaminated vaccine. The results of the study demonstrate the effects of CIAV pollution on the production and immune function of SPF chickens, and it is suggested that increasing the detection of viral nucleic acid can help save time and improve the detection rate in the detection of exogenous virus contamination by SPF chicken test method.
Animals ; Antibodies, Viral ; immunology ; Chicken anemia virus ; genetics ; immunology ; physiology ; Chickens ; Circoviridae Infections ; immunology ; veterinary ; virology ; Poultry Diseases ; immunology ; virology ; Specific Pathogen-Free Organisms ; Vaccines, Attenuated ; administration & dosage ; genetics ; immunology

A recombinant replication-defective adenovirus expressing the major epitopes of porcine circovirus-2 (PCV-2) capsid protein (rAd/Cap/518) was previously constructed and shown to induce mucosal immunity in mice following intranasal delivery. In the present study, immune responses induced by intranasal immunization with a combination of rAd/Cap/518 and cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) were evaluated in mice. The levels of PCV-2-specific IgG in serum and IgA in saliva, lung, and intestinal fluids were significantly higher in the group immunized with rAd/Cap/518 and CpG ODN than animals immunized with rAd/Cap/518 alone. The frequencies of IL-2-secreting CD4+ T cells and IFN-gamma-producing CD8+ T cells were significantly higher in the combined immunization group than mice immunized with rAd/Cap/518 alone. The frequencies of CD3+, CD3+CD4+CD8-, and CD3+CD4-CD8+ T cells in the combined immunization group were similar to that treated with CpG ODN alone, but significantly higher than mice that did not receive CpG ODN. PCV-2 load after challenge in the combined immunization group was significantly lower than that in the phosphate-buffered saline placebo group and approximately 7-fold lower in the group treated with CpG ODN alone. These results indicate that rAd/Cap/518 combined with CpG ODN can enhance systemic and local mucosal immunity in mice, and represent a promising synergetic mucosal vaccine against PCV-2.
Adenoviridae/genetics/immunology ; Administration, Intranasal ; Animals ; Capsid Proteins/*genetics/immunology ; Circoviridae Infections/*immunology ; Circovirus/*genetics/immunology ; Epitopes/genetics/immunology ; Female ; Immunity, Mucosal/immunology ; Immunoglobulin A/blood/immunology ; Immunoglobulin G/blood/immunology ; Mice ; Mice, Inbred BALB C ; Oligodeoxyribonucleotides/genetics ; Vaccines, Synthetic/genetics/immunology ; Viral Vaccines/administration & dosage/*genetics/immunology

Chicken anemia virus (CAV) is an important viral pathogen that causes anemia and severe immunodeficiency syndrome in chickens worldwide. In this study, a potential diagnostic monoclonal antibody against the CAV VP1 protein was developed which can precisely recognize the CAV antigen for diagnostic and virus recovery purposes. The VP1 gene of CAV encoding the N-terminus-deleted VP1 protein, VP1Nd129, was cloned into an Escherichia (E.) coli expression vector. After isopropyl-beta-D-thiogalactopyronoside induction, VP1Nd129 protein was shown to be successfully expressed in the E. coli. By performing an enzyme-linked immunoabsorbent assay using two coating antigens, purified VP1Nd129 and CAV-infected liver tissue lysate, E3 monoclonal antibody (mAb) was found to have higher reactivity against VP1 protein than the other positive clones according to the result of limiting dilution method from 64 clones. Using immunohistochemistry, the presence of the VP1-specific mAb, E3, was confirmed using CAV-infected liver and thymus tissues as positive-infected samples. Additionally, CAV particle purification was also performed using an immunoaffinity column containing E3 mAb. The monoclonal E3 mAb developed in this study will not only be very useful for detecting CAV infection and performing histopathology studies of infected chickens, but may also be used to purify CAV particles in the future.
Animals ; Antibodies, Monoclonal/biosynthesis/genetics/*immunology ; Antigens, Viral/analysis ; Capsid Proteins/genetics/*immunology ; Chicken anemia virus/genetics/*immunology ; *Chickens ; Circoviridae Infections/blood/immunology/*veterinary/virology ; Escherichia coli/genetics ; Immunohistochemistry/veterinary ; Liver/virology ; Mice ; Mice, Inbred BALB C ; Microscopy, Fluorescence/veterinary ; Poultry Diseases/blood/immunology/*virology ; Specific Pathogen-Free Organisms ; Thymus Gland/virology

Porcine circovirus 2 (PCV2) has been implicated as the etiological agent of postweaning multisystemic wasting syndrome (PMWS). Co-infection of PCV2 and porcine reproductive and respiratory syndrome virus (PRRSV) can result in severe economic losses to the swine industry. In this study, we constructed the recombinant adenovirus rAd-Cap-GP5 expressing Cap of PCV2 and GP5 of PRRSV. And the expression of Cap and GP5 protein in the HEK-293 cells inoculated with rAd-Cap-GP5 were confirmed by immunoperoxidase monolayer assay (IPMA), indirect immunofluorescence assay (IFA) and Western blotting, respectively. The immunogenicity of recombinant adenoviruses rAd-Cap-GP5 was examined in mice by vaccination with the recombinant adenovirus. The results showed that the mice could produce anti-PCV2 and PRRSV antibodies detected by indirect ELISA and virus neutralization assay. It indicated that rAd-Cap-GP5 could provide humoral immunity responses in mice. The recombinant adenovirus rAd-Cap-GP5 might be an attractive candidate vaccine for preventing the disease associated with PCV2 and PRRSV infection.
Adenoviridae ; genetics ; metabolism ; Animals ; Capsid Proteins ; biosynthesis ; genetics ; immunology ; Cell Line ; Circoviridae Infections ; prevention & control ; virology ; Circovirus ; genetics ; metabolism ; Immunization ; Mice ; Porcine Reproductive and Respiratory Syndrome ; prevention & control ; virology ; Porcine respiratory and reproductive syndrome virus ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Transfection ; Viral Envelope Proteins ; biosynthesis ; genetics ; immunology

Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are very two important pathogens that have coursed huge economic losses in swine production in worldwide. In this study,a vector pCMV-TJM containing the full-length cDNA clone of PRRSV attenuated strain TJM-F92 was firstly constructed by PCR method. Then a gene sequence containing Afl II/Mlu I e restriction enzyme sites and a transcription regulatory sequence for ORF6 (TRS6) was inserted be- tween ORF7 and 3'UTR, yielding a expression vector pCMV-TJM-TRS. Subsequently, a plasmid pCMV-TJM-Cap was constructed by cloning of PCV2 ORF2 gene into the unique sites Afl II /Mlu I of pCMV- TJM-TRS plasmid DNA. Then three recombinant PRRSV, rTJM, rTJM/TRS and rTJM/Cap, were rescued by transfection of pCMV-TJM, pCMV-TJM-TRS and pCMV-TJM-Cap into Marc-145 cells, respectively,and confirmed by the genome sequence, restriction enzyme digestion, Western Blot and IFA. They all had the molecular markers which was different from the parent virus. The growth characteristics of the rescued viruses were similar to that of parent virus. rTJM/Cap could also express efficiently PCV2 Cap protein in Marc-145 cells. At passage 8, it still had PCV2 ORF2 gene which examined by RT-PCR. It indicated that the full-length cDNA clone of PRRSV attenuated strain TJM-F92 and recombinant PRRSV rTJM/Cap expressing PCV2 Cap protein were successfully constructed. It made an important foundation for studying on the pathogenic mechanisms of PRRSV and PRRSV-PCV2 vaccine in the future.
Animals ; Capsid Proteins ; genetics ; immunology ; Cell Line ; Circoviridae Infections ; veterinary ; virology ; Circovirus ; classification ; genetics ; metabolism ; Gene Expression ; Open Reading Frames ; Porcine Reproductive and Respiratory Syndrome ; virology ; Porcine respiratory and reproductive syndrome virus ; genetics ; metabolism ; Recombination, Genetic ; Swine ; Swine Diseases ; virology ; Viral Vaccines ; genetics ; immunology