Interaction between Peripheral Blood Monocytes (PBM) and Lymphocytes (PBLs) of Healthy Porcine Circovirus TypeⅡ (PCV2)-Carrier Pigs Following Monophasic or Biphasic Stimulation
| Autor: | Chia-Lin Lai, 賴佳琳 |
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| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Porcine circovirus type Ⅱ (PCV2) infection has been demonstrated to be an essential factor in the induction of the newly emerged disease, postweaning multisystemic wasting syndrome (PMWS), in pigs. PCV2 antibodies have been found in pigs worldwidely, usually with high seroprevalence. Although monocyte/macrophage lineage cells are considered as the major target cells, the role of lymphocytes on the disease development is still uncertain. Immune activation and co-factors such as bacteria or viruses have been suggested to be important factors in the induction of PMWS. Our previous studies have demonstrated that the PCV2 nucleic acid and antigens could be detected intranuclearly in bacterial lipopolysaccharide (LPS)-treated PCV2-inoculated swine alveolar macrophages (AMs) and in concanavalin A (Con A)-stimulated swine peripheral blood lymphocytes (PBLs). The objective of the present study was to further evaluate whether there is an enhancement effect on the PCV2-positive rate in either monocytes or lymphocytes of peripheral blood following monophasic or biphasic stimulation with LPS and/or Con A in healthy PCV2-carrier pigs. After stimulation with LPS and/or Con A, both PCV2 antigen- and nucleic acid-containing rates of the peripheral blood mononuclear cells (PBMCs) of healthy PCV2-carrier pigs measured by immunofluorescent assay (IFA), surface marker IFA, in situ hybridization-polymerase chain reaction (ISH-PCR), and real time PCR increased with time. The levels of the PCV2 antigen-containing rate in Con A-treated group and the group treated simultaneously with LPS and Con A ( (LPS + Con A)-treated groups) were significantly greater than those of the NT and LPS-treated groups. Significant difference was also seen among the LPS-, Con A, and (LPS + Con A)-treated groups. The viral titer of the (LPS + Con A)-treated group increased at 3 days post-incubation (DPI) as did antigen- and nucleic acid-containing rates. Two third of the PCV2-positive cells belonged to SWC3－ population; this implies that lymphocytes may also play an important role on PCV2 replication. The results indicate that interaction between PBMs and PBLs may exist and simultaneous activation of PBMs and PBLs may result in increased PCV2 load in both cells. The results further support that immune activation may increase the morbidity of PMWS in PCV2-infected pigs via the increase in viral load. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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