Dataset of immune responses induced in swine by an inactivated Porcine Circovirus 2b vaccine.

A whole virus, inactivated, Porcine Circovirus 2b (PCV2b) vaccine was submitted to a quantal assay of potency, as explained in detail in our companion paper [1]. To this purpose, twenty, 45-day old piglets, checked for maternally-derived antibody (MDA), were allocated to four groups of 5 animals each; these were vaccinated with 800/266/88/0 nanograms, respectively, of an inactivated PCV2b strain, consisting of two distinct virion populations. Twenty-six days later, all the pigs were challenged intranasally with the homologous PCV2b strain. In the presence of a clear dose-dependent protection in terms of viremia, no such effect was observed in terms of weight gain after challenge. The 800 and 266-ng payloads were associated with neutralizing antibody titers above the MDA levels in oral fluids. Higher levels of viremia in control and 88-ng groups [1] coincided with a higher Natural Killer activity of tracheobronchial lymph node cells from PCV2-infected pigs. The PCV2 ORF2-specific ELISPOT assay for IFN-g- secreting cells showed very few (2-4) ORF2-specific cells/105 peripheral blood mononuclear cells beyond the basal levels under our experimental conditions (non-significant differences among groups). Also, no significant differences were observed in the degree of lymphoid tissue hyperplasia among the different groups.

Protective immunity in swine induced by Porcine Circovirus 2b inactivated vaccines with different antigen payload.

Porcine Circovirus 2 (PCV2) vaccines are poorly standardized in terms of antigen payload and correlates of protection. Therefore, twenty, 45-day old piglets were divided into four groups of 5 animals each and vaccinated with 800 / 266 / 88 / 0 nanograms, respectively, of an inactivated PCV2b strain formulated in the same oil adjuvant. Twenty-six days later, all the pigs were challenged intranasally with the homologous PCV2b strain. No clinical signs were observed in the pigs under study. Viremia was observed after challenge in all the control pigs, as well as in 3 pigs of the 266 and 88-ng groups (one and two, respectively). No pigs of the 800-ng group developed viremia. On the basis of post challenge viremia, the PCV2b vaccine under study had a titer of 11 Protective Doses (PD) 50 %, and 1 PD50 amounted to 74 ng of PCV2b Ag. Neutralizing and ELISA Ab titers showed no obvious correlation with protection in the single animals, even though the 800-ng group developed a significantly higher mean Ab response. All the pigs with a PCV2-specific, IFN-gamma response at 3 weeks after vaccination in whole blood samples were protected against viremia. In lymphoid tissues (mainly tonsils and ileum) the presence of sparse reactive histiocytes and multinucleated giant cells was the only PCV2-associated feature and, by immunohistochemistry, only 3 out of 20 subjects showed a low viral load.

Long-term stability, functional competence, and safety of microencapsulated specific pathogen-free neonatal porcine Sertoli cells: a potential product for cell transplant therapy.

BACKGROUND: Porcine Sertoli cells (pSCs) have been employed for cell therapy in pre-clinical studies for several chronic/immune diseases as they deliver molecules associated with trophic and anti-inflammatory effects. To be employed for human xenografts, pSCs products need to comply with safety and stability. To fulfill such requirements, we employed a microencapsulation technology to increase pre-transplant storage stability of specific pathogen-free pSCs (SPF-pSCs) and evaluated the in vivo long-term viability and safety of grafts. METHODS: Specific pathogen free neonatal pigs underwent testis excision under sterility. pSCs were isolated, characterized by immunofluorescence (IF) and cytofluorimetric analysis (CA) and examined in terms of viability and function [namely, production of anti-müllerian hormone (AMH), inhibin B, and transforming growth factor beta-1 (TFGß-1)]. After microencapsulation in barium alginate microcapsules (Ba-MC), long-term SPF-pSCs (Ba-MCpSCs) viability and barium concentrations were evaluated at 1, 24 throughout 40 h to establish pre-transplant storage conditions. RESULTS: The purity of isolated pSCs was about 95% with negligible contaminating cells. Cultured pSCs monolayers, both prior to and after microencapsulation, maintained high function and full viability up to 24 h of storage. At 40 h post-encapsulation, pSCs viability decreased to 80%. Barium concentration in Ba-MCpSCs lagged below the normal maximum daily allowance and was stable for 4 months in mice with no evident side effects. CONCLUSIONS: Such results suggest that this protocol for the isolation and microencapsulation of pSCs is compatible with long-haul transportation and that Ba-MCpSCs could be potentially employable for xenotransplantation.