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CpG ODN activity in swine: From ex vivo to in vivo activity
Abstracts / Veterinary Immunology and Immunopathology 128 (2009) 211–347
Colostrum from sows vaccinated with an inactivated PCV2 vaccine contains antigen specific leukocytes A. Goubier 1 , F. Piras 2 , M. Gnudi 3 , L. Chapat 1 , H. El Garch 1 , F. Joisel 3 , C. Charreyre 4 , S. Richard 1 , L. Forest 1 , C. Andreoni 1 , V. Juillard 1 1
Merial S.A.S., Discovery Research, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 2 Sanofi pasteur, Research, 1541 Avenue Marcel Merieux, 69280, Marcy l’Etoile, France 3 Merial S.A.S., Technical Support, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 4 Merial S.A.S., R&D, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France Keywords: Colostrum; PCV2; Cellular immune response; Inactivated vaccine; Pig
Species: Swine In species having an epitheliochorial placenta, like swine, it has been largely demonstrated that colostrum from vaccinated mothers contains antigen-specific maternal immunoglobulins which have an important role in the passive protection of newborn animals. However, it has been demonstrated that colostrum also contains T and B lymphocytes. Little is known about the functionality of these colostral leukocytes and their importance in protection of newborns against infection. The aim of this study was to evaluate if sow vaccination would lead to the presence not only of specific immunoglobulin but also of specific immune cells in colostrum. Two groups of specific pathogen free sows were included in this study. The first group was vaccinated with an inactivated PCV2 vaccine, whereas the other group did not receive the vaccine. As expected, PCV2-specific IgG1 and IgG2 antibodies were detected in colostrum of vaccinated sows by ELISA. Interestingly, the IgG1/IgG2 ratio differed between blood and colostrum immunoglobulins with a lower ratio in the colostrum than in the blood. Phenotypic analysis of colostral leukocytes demonstrated an increase in CD8+ T cells and a diminution of CD4+ T cells in vaccinated sows’ colostrum as compared to non-vaccinated sows. These colostral leukocytes were assessed by flow cytometry for intra-cellular cytokines and by IFN ␥ ELIspots assay for their ability to produce IFN ␥ and TNF ␣ upon antigenic restimulation. These functional experiments clearly showed that colostrum from vaccinated sows contained IFN ␥- and TNF ␣-producing PCV2-specific CD4+ and CD8+ T cells, whereas no IFN ␥ or TNF ␣ production could be detected in the colostrum of non-vaccinated sows. Our data, together with previous reports demonstrating that leukocytes isolated from colostrum can pass through the intestinal barrier of newborn piglets, strongly suggest that maternal antigenspecific leukocytes may be transferred to the piglets via the colostrum and constitute another line of active defense against infections in neonate piglets. doi:10.1016/j.vetimm.2008.10.117
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CpG ODN activity in swine: From ex vivo to in vivo activity A. Goubier 1 , F. Piras 2 , H. El Garch, S. Richard 1 , L. Forest 1 , C. Andreoni 1 , J.C. Audonnet 1 , R. Nordgren 3 , V. Juillard 1,∗ 1
Merial S.A.S., Discovery Research, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 2 Sanofi Pasteur, Research, 1541 avenue Marcel Mérieux, 69280, Marcy l’Etoile, France 3 Merial Limited, 3239 Satellite Blvd., Duluth, GA, USA Keywords: CpG; Swine; TLR9; IFN␥; Immunomodulation; Epitope spreading Species: Swine CpG ODNs signal through TLR9 and trigger a cascade of events that lead to activation of innate and adaptive immune responses. The post-TLR9 signalling pathways and the biological activities resulting from the activation depend on the class of CpG ODN used. Interestingly, it has been shown that synthetic CpG ODNs may enhance the quality of the immune response to vaccination, an effect that could be reinforced by using appropriate formulation agents. This study aimed at selecting an effective combination of CpG ODN and formulation agents which could be used to enhance the porcine immune response to vaccination. Different CpG ODN sequences were analyzed for their capacity to activate porcine PBMCs ex vivo, especially their induction of IFN-␣ secretion and promotion of B cell proliferation. Two sequences showing promising features were retained and assessed in vivo in combination with two different oil-in-water emulsions. Various systemic parameters were followed up at different times after injection, and the results were analyzed as a combination of linear parameters in a discriminatory analysis. The results of that analysis allowed us to discriminate both sequences and to select one of the emulsions for its ability to increase the biological activity of the CpG ODNs tested. The more potent sequence, in combination with the oil emulsion showing best effects, was further assessed as adjuvant of a recombinant protein in pigs. We showed that CpG ODN enhanced IFN-␥+ antigen-specific T cell responses. Interestingly, analysis of cellular immune responses after re-stimulation with an overlapping peptide library clearly showed that CpG ODN increased the number of T cell epitopes recognized by antigen specific-T cells. This CpG-mediated T cell epitope spreading emphasizes that CpG ODN not only improve the magnitude of the cellular immune response but also impact on the quality of this response. Collectively, our data suggest that CpG ODN could be employed as an effective immuno-adjuvant to optimize immune responses induced by vaccination in pigs. doi:10.1016/j.vetimm.2008.10.118
Colostrum from sows vaccinated with an inactivated PCV2 vaccine contains antigen specific leukocytes A. Goubier 1 , F. Piras 2 , M. Gnudi 3 , L. Chapat 1 , H. El Garch 1 , F. Joisel 3 , C. Charreyre 4 , S. Richard 1 , L. Forest 1 , C. Andreoni 1 , V. Juillard 1 1
Merial S.A.S., Discovery Research, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 2 Sanofi pasteur, Research, 1541 Avenue Marcel Merieux, 69280, Marcy l’Etoile, France 3 Merial S.A.S., Technical Support, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 4 Merial S.A.S., R&D, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France Keywords: Colostrum; PCV2; Cellular immune response; Inactivated vaccine; Pig
Species: Swine In species having an epitheliochorial placenta, like swine, it has been largely demonstrated that colostrum from vaccinated mothers contains antigen-specific maternal immunoglobulins which have an important role in the passive protection of newborn animals. However, it has been demonstrated that colostrum also contains T and B lymphocytes. Little is known about the functionality of these colostral leukocytes and their importance in protection of newborns against infection. The aim of this study was to evaluate if sow vaccination would lead to the presence not only of specific immunoglobulin but also of specific immune cells in colostrum. Two groups of specific pathogen free sows were included in this study. The first group was vaccinated with an inactivated PCV2 vaccine, whereas the other group did not receive the vaccine. As expected, PCV2-specific IgG1 and IgG2 antibodies were detected in colostrum of vaccinated sows by ELISA. Interestingly, the IgG1/IgG2 ratio differed between blood and colostrum immunoglobulins with a lower ratio in the colostrum than in the blood. Phenotypic analysis of colostral leukocytes demonstrated an increase in CD8+ T cells and a diminution of CD4+ T cells in vaccinated sows’ colostrum as compared to non-vaccinated sows. These colostral leukocytes were assessed by flow cytometry for intra-cellular cytokines and by IFN ␥ ELIspots assay for their ability to produce IFN ␥ and TNF ␣ upon antigenic restimulation. These functional experiments clearly showed that colostrum from vaccinated sows contained IFN ␥- and TNF ␣-producing PCV2-specific CD4+ and CD8+ T cells, whereas no IFN ␥ or TNF ␣ production could be detected in the colostrum of non-vaccinated sows. Our data, together with previous reports demonstrating that leukocytes isolated from colostrum can pass through the intestinal barrier of newborn piglets, strongly suggest that maternal antigenspecific leukocytes may be transferred to the piglets via the colostrum and constitute another line of active defense against infections in neonate piglets. doi:10.1016/j.vetimm.2008.10.117
265
CpG ODN activity in swine: From ex vivo to in vivo activity A. Goubier 1 , F. Piras 2 , H. El Garch, S. Richard 1 , L. Forest 1 , C. Andreoni 1 , J.C. Audonnet 1 , R. Nordgren 3 , V. Juillard 1,∗ 1
Merial S.A.S., Discovery Research, 254 rue Marcel Mérieux, 69342 Cedex 07 Lyon, France 2 Sanofi Pasteur, Research, 1541 avenue Marcel Mérieux, 69280, Marcy l’Etoile, France 3 Merial Limited, 3239 Satellite Blvd., Duluth, GA, USA Keywords: CpG; Swine; TLR9; IFN␥; Immunomodulation; Epitope spreading Species: Swine CpG ODNs signal through TLR9 and trigger a cascade of events that lead to activation of innate and adaptive immune responses. The post-TLR9 signalling pathways and the biological activities resulting from the activation depend on the class of CpG ODN used. Interestingly, it has been shown that synthetic CpG ODNs may enhance the quality of the immune response to vaccination, an effect that could be reinforced by using appropriate formulation agents. This study aimed at selecting an effective combination of CpG ODN and formulation agents which could be used to enhance the porcine immune response to vaccination. Different CpG ODN sequences were analyzed for their capacity to activate porcine PBMCs ex vivo, especially their induction of IFN-␣ secretion and promotion of B cell proliferation. Two sequences showing promising features were retained and assessed in vivo in combination with two different oil-in-water emulsions. Various systemic parameters were followed up at different times after injection, and the results were analyzed as a combination of linear parameters in a discriminatory analysis. The results of that analysis allowed us to discriminate both sequences and to select one of the emulsions for its ability to increase the biological activity of the CpG ODNs tested. The more potent sequence, in combination with the oil emulsion showing best effects, was further assessed as adjuvant of a recombinant protein in pigs. We showed that CpG ODN enhanced IFN-␥+ antigen-specific T cell responses. Interestingly, analysis of cellular immune responses after re-stimulation with an overlapping peptide library clearly showed that CpG ODN increased the number of T cell epitopes recognized by antigen specific-T cells. This CpG-mediated T cell epitope spreading emphasizes that CpG ODN not only improve the magnitude of the cellular immune response but also impact on the quality of this response. Collectively, our data suggest that CpG ODN could be employed as an effective immuno-adjuvant to optimize immune responses induced by vaccination in pigs. doi:10.1016/j.vetimm.2008.10.118