The goals of our study were to compare the immune response to different killed and modified live vaccines against PRRS virus and to monitor the antibody production and the cell mediated immunity both at the systemic and local level. In the experiment, we immunized four groups of piglets with two commercial inactivated (A1-Progressis, A2-Suivac) and two modified live vaccines (B3-Amervac, B4-Porcilis). Twenty-one days after the final vaccination, all piglets, including the control non-immunized group (C5), were i.n., infected with the Lelystad strain of PRRS virus. The serum antibody response (IgM and IgG) was the strongest in group A1 followed by two MLV (B3 and B4) groups. Locally, we demonstrated the highest level of IgG antibodies in bronchoalveolar lavages (BALF), and saliva in group A1, whereas low IgA antibody responses in BALF and feces were detected in all groups. We have found virus neutralization antibody at DPV 21 (days post vaccination) and higher levels in all groups including the control at DPI 21 (days post infection). Positive antigen specific cell-mediated response in lymphocyte transformation test (LTT) was observed in groups B3 and B4 at DPV 7 and in group B4 at DPV 21 and in all intervals after infection. The IFN-γ producing lymphocytes after antigen stimulation were found in CD4-CD8+ and CD4+CD8+ subsets of all immunized groups 7 days after infection. After infection, there were obvious differences in virus excretion. The virus was detected in all groups of piglets in serum, saliva, and occasionally in feces at DPI 3. Significantly lower virus load was found in groups A1 and B3 at DPI 21. Negative samples appeared at DPI 21 in B3 group in saliva. It can be concluded that antibodies after immunization and infection, and the virus after infection can be detected in all the compartments monitored. Immunization with inactivated vaccine A1-Progressis induces high levels of antibodies produced both systemically and locally. Immunization with MLV-vaccines (Amervac and Porcilis) produces sufficient antibody levels and also cell-mediated immunity. After infection virus secretion gradually decreases in group B3, indicating tendency to induce sterile immunity.

• Keywords
• antibody, cell-mediated immunity, inactive vaccine, modified-live vaccine, porcine reproductive and respiratory syndrome, virus,
• MeSH
• Lymphocyte Activation * MeSH
• Vaccines, Inactivated immunology   MeSH
• Swine MeSH
• Antibodies, Viral biosynthesis   MeSH
• Vaccination * MeSH
• Viral Load MeSH
• Viral Vaccines immunology   MeSH
• Porcine respiratory and reproductive syndrome virus immunology   MeSH
• Vaccines, Live, Unattenuated immunology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Vaccines, Inactivated MeSH
• Antibodies, Viral MeSH
• Viral Vaccines MeSH
• Vaccines, Live, Unattenuated MeSH

Mononuclear phagocytes (MP) are cells of nonspecific immunity, playing an essential role in defense against bacterial pathogens. Although various MP subpopulations have been described in the pig, relations among these populations in vivo are unknown to date. The present study was aimed at describing porcine MP subpopulations infiltrating inflamed tissue of pigs under in vivo conditions. Actinobacillus pleuropneumoniae (APP) infection was used to induce an inflammatory response. CD172alpha, CD14, CD163, MHCII and CD203alpha cell surface molecules were used to identify MP by flow cytometry. Changes in MP subpopulations in the peripheral blood (PB) and bone marrow (BM) compartments along with the analysis of MP appearing in the inflamed lungs were assessed to elucidate the possible origin and maturation stages of the infiltrating MP. The MP population migrating to the inflamed lungs was phenotype CD14+ CD163+ CD203alpha+/- MHCII+/-. Concomitantly, after APP infection there was an increase in the PB MP CD14+ CD163+ CD203alpha- MHC II- population, suggesting that these cells give rise to inflammatory monocytes/macrophages. The CD203alpha and MHCII molecules appear on these cells after leaving the PB. In healthy animals, the BM MP precursors were represented by CD14- CD163- cells maturing directly into CD14+ CD163- that were then released into the PB. After infection, an altered maturation pathway of MP precursors appeared, represented by CD14- CD163- CD203alpha- MHCII- MP directly switching into CD14+ CD163+ CD203alpha- MHCII- MP. In conclusion, two different MP maturation pathways were suggested in pigs. The use of these pathways differs under inflammatory and noninflammatory conditions.

• MeSH
• Actinobacillus pleuropneumoniae * MeSH
• Bone Marrow Cells physiology   MeSH
• Antigens, CD genetics   metabolism   MeSH
• Phagocytes cytology   physiology   MeSH
• Genes, MHC Class II genetics   physiology   MeSH
• Actinobacillus Infections blood   microbiology   pathology   veterinary   MeSH
• Swine Diseases microbiology   pathology   MeSH
• Lung cytology   MeSH
• Swine MeSH
• Gene Expression Regulation MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens, CD MeSH