Porcine Reproductive and Respiratory Syndrome virus (PRRSV) is a worldwide pathogen and it is isolated in 1990 at Lelystad Laboratories (Holland). This virus has a tropism for swine respiratory and reproductive apparatus; the symptoms are described in piglets (cough, fever, anorexia), finishing pigs (cough, fever, lympho nodes iperplasia) and in sows (abortions, infertility). PRRS is a disease with a high impact on the economic losses in swine industry. Nowadays there is not an efficacy vaccine able to protect animals from the disease and the main problem is the poor knowledges about host-virus interaction. The aim of this study was to evaluate the time-course of the immune response to a field Porcine Respiratory and Reproductive Syndrome virus isolate in PRRS-naïve, untreated pigs, as well as in three groups of age and breed-matched pigs injected with a live attenuated PRRS vaccine, its adjuvant and an inactivated PRRS vaccine, respectively. Humoral response was measured by IgG evaluation (ELISA test) and it took place earlier in pigs injected with the live attenuated vaccine, which also developed a much stronger serum-neutralizing antibody response to the vaccine strain. On the other hand no clear protection was evidenced in terms of viremia against field isolate, which showed 11,1% nucleotide divergence in ORF7 from the vaccine strain. Cellular-mediated immunity was evaluated by in vitro test and the interferon (IFN)-g response to PRRSV was almost absent on PVD 60 in all groups under study, the same was evidenced for interleukin (IL)-10 responses to PRRSV. Results indicate that distinct patterns of immune response to a field PRRSV strain can be recognized in PRRS-vaccinated and naïve pigs, which probably underlies fundamental differences in the development and differentiation of PRRSV-specific immune effector cells.

INFEZIONE DI CAMPO DA VIRUS DELLA PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME (PRRSV): VALUTAZIONE DELLA RISPOSTA IMMUNITARIA IN SUINI NAIVE E SOTTOPOSTI A VACCINAZIONE / S. Dotti ; Tutor: Luigi Bonizzi ; Coordinatore del dottorato: Fulvio Gandolfi. Universita' degli Studi di Milano, 2010 Dec 14. 23. ciclo, Anno Accademico 2010. [10.13130/dotti-silvia_phd2010-12-14].

INFEZIONE DI CAMPO DA VIRUS DELLA PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME (PRRSV): VALUTAZIONE DELLA RISPOSTA IMMUNITARIA IN SUINI NAIVE E SOTTOPOSTI A VACCINAZIONE

S. Dotti
2010

Abstract

Porcine Reproductive and Respiratory Syndrome virus (PRRSV) is a worldwide pathogen and it is isolated in 1990 at Lelystad Laboratories (Holland). This virus has a tropism for swine respiratory and reproductive apparatus; the symptoms are described in piglets (cough, fever, anorexia), finishing pigs (cough, fever, lympho nodes iperplasia) and in sows (abortions, infertility). PRRS is a disease with a high impact on the economic losses in swine industry. Nowadays there is not an efficacy vaccine able to protect animals from the disease and the main problem is the poor knowledges about host-virus interaction. The aim of this study was to evaluate the time-course of the immune response to a field Porcine Respiratory and Reproductive Syndrome virus isolate in PRRS-naïve, untreated pigs, as well as in three groups of age and breed-matched pigs injected with a live attenuated PRRS vaccine, its adjuvant and an inactivated PRRS vaccine, respectively. Humoral response was measured by IgG evaluation (ELISA test) and it took place earlier in pigs injected with the live attenuated vaccine, which also developed a much stronger serum-neutralizing antibody response to the vaccine strain. On the other hand no clear protection was evidenced in terms of viremia against field isolate, which showed 11,1% nucleotide divergence in ORF7 from the vaccine strain. Cellular-mediated immunity was evaluated by in vitro test and the interferon (IFN)-g response to PRRSV was almost absent on PVD 60 in all groups under study, the same was evidenced for interleukin (IL)-10 responses to PRRSV. Results indicate that distinct patterns of immune response to a field PRRSV strain can be recognized in PRRS-vaccinated and naïve pigs, which probably underlies fundamental differences in the development and differentiation of PRRSV-specific immune effector cells.
14-dic-2010
Settore VET/05 - Malattie Infettive degli Animali Domestici
PRRSV ; pig ; immuno response
BONIZZI, LUIGI
GANDOLFI, FULVIO
Doctoral Thesis
INFEZIONE DI CAMPO DA VIRUS DELLA PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME (PRRSV): VALUTAZIONE DELLA RISPOSTA IMMUNITARIA IN SUINI NAIVE E SOTTOPOSTI A VACCINAZIONE / S. Dotti ; Tutor: Luigi Bonizzi ; Coordinatore del dottorato: Fulvio Gandolfi. Universita' degli Studi di Milano, 2010 Dec 14. 23. ciclo, Anno Accademico 2010. [10.13130/dotti-silvia_phd2010-12-14].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/150113
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