Postnatal Persistent Infection with Classical Swine Fever Virus and Its Immunological Implications

Muñoz-González, Sara; Ruggli, Nicolas; Rosell, Rosa; Pérez, Lester Josué; Frías-Leuporeau, Maria Teresa; Fraile, Lorenzo; Montoya, Maria; Cordoba, Lorena; Domingo, Mariano; Ehrensperger, Felix; Summerfield, Artur; Ganges, Llilianne

After having shown that the adaptive immune response of the persistently infected piglets was clearly impaired, we wondered whether their innate immune responses were also affected. Thus, serum IFN-α levels in the persistent and immunocompetent piglets and the sows were analysed by ELISA at 7, 14, 21 and 42 dpi. Considerable but variable levels of serum IFN-α were found in all of the animals mainly at day 7 p.i. and in some of the PR virus persistently infected piglets at 14 and 21 d.p.i. (Fig 5) . The mean IFN-α content was significantly higher in the piglets infected with the PR strain than in the piglets infected with the Cat01 strain (P = 0.0046), although viraemia was lower. Interestingly, the three immunocompetent piglets responded with IFN-α similar to that of the persistently infected animals. Interestingly, the two sows exhibited different IFN-α patterns than the piglets, with the Cat01-infected sow having a higher concentration of IFN-α in the serum than the sow infected with the PR strain (Fig 5) . These results showed that the IFN-α response was not affected in the persistently infected piglets, as opposed to the adaptive humoral and cellular immune responses.