• Parasites, Hosts and Diseases
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• v.57 no.5
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• pp.543-547
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• 2019

Toxoplasma gondii can infect humans worldwide, causing serious diseases in pregnant women and immunocompromised individuals. T. gondii rhoptry protein 13 (ROP13) is known as one of the key proteins involved in host cell invasion. In this study, we generated virus-like particles (VLPs) vaccine expressing T. gondii rhoptry ROP13 and investigated VLPs vaccine efficacy in mice. Mice immunized with ROP13 VLPs vaccine elicited significantly higher levels of T. gondii-specific IgG, IgG1, IgG2a, and IgA antibody responses following boost immunization and challenge infection, whereas antibody inductions were insignificant upon prime immunization. Differing immunization routes resulted in differing antibody induction, as intranasal immunization (IN) induced greater antibody responses than intramuscular immunization (IM) after boost and challenge infection. IN immunization induced significantly higher levels of IgG and IgA antibody responses from feces, antibody-secreting cells (ASCs), $CD4^+$ T, $CD8^+$ T cells and germinal center B cell responses in the spleen compared to IM immunization. Compared to IM immunization, IN immunization resulted in significantly reduced cyst counts in the brain as well as lesser body weight loss, which contributed to better protection. All of the mice immunized through either route survived, whereas all na?ve control mice perished. These results indicate that the ROP13 VLPs vaccine could be a potential vaccine candidate against T. gondii infection.

• Korean Journal of Veterinary Research
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• v.53 no.4
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• pp.245-251
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• 2013

Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been suspected to have immunosuppressive effects on pigs. To investigate the correlation between these virus infection and the lesions of lymph nodes including sub-mandibular and inguinal lymph node, 44 pigs (PCV2 single, n = 14; PRRSV single, n = 10; PCV2/PRRSV, n = 14; negative control, n = 6) were examined by histopathology and immunohistochemistry. Histopathologically, granulomatous lymphadenitis characterized by lymphoid depletion with histiocytic cells infiltration was observed in PCV-2 single and PCV-2/PRRSV group. Immunohistochemically, there were significant reduction of B and T lymphocytes in lymph nodes of these groups, while the number of macrophages was increased. In only PRRSV infected group, germinal center hypertrophy and lymphoid necrosis were observed. Immunohistochemically, the number of CD3+ T lymphocytes was slightly increased. Severe lymphocytic depletion in PCV-2 infection-related lymph nodes might be associated with producing immunocompromised state in pig. Comparing with PCV-2 infected group, PRRSV produced minor effects on the changes in immune cell population in the lymph nodes of pigs. PRRSV may increase susceptibility of the disease in pigs by disruption of the first defense lines in target organs, such as the alveolar macrophages in lungs.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.53-60
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• 1987

This experiment was performed on mice to investigate the effects of an immunopotentiator, picibanil(PC), on the immune responses such as phagocytic activity of reticuloen-dothelial(RE) system, E rosette formation rate of splenic lmphocytes and morphological changes of lymph node tissue. Groups of mice were treated with a single(1KE/kg BW) or sequential(0.1, 0.25 and 0.5KE/kg BW for successive 3 days) intravenous injections of PC. PC treated and untreated control mice were sensitized with 50% sheep erythrocyte suspension(0.2ml/mouse) at 1, 3, 5, 7 and 10 days after PC treatment. Functional and morphological examinations were carried out 5 days after sensitization. The following results were obtained: The phagocytic activity of RE system and the weight of liver and spleen were increased significantly at 3rd, 5th and 7th day. The peripheral polymorphonuclear leukocyte and percent of lymphocyte and monocyte were slightly increased. The rates of E rosette formation of splenic lymphotytes, sequential PC treated groups were more increased at 3rd and 5th day in sequential PC treated groups than in single treated groups. Thereafter it returned gradually to the control level by the time of 10th day. Microscopically primary lymph follicles with indistinct germinal center (GC) were partially disrupted and the parafollicular areas were consisted of the pyroninophilic cells in control group. In PC treated group, the parafollicular areas were markedly proliferated and developments of secondary lymph follicles with enlarged and prominent GC were more pronounced in the sequential injected groups compared to single injected groups. These results indicate that PC affected not only parafollicular area of the T-cell area, but also GC of the B-cell area. It suggests that PC may potentiate both cell mediated immunity and humoral immunity.