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

PBMCs from all of the piglets and from the two sows were analysed for virus-specific and-nonspecific IFN-γ responses by ELISPOT assay at four weeks p.i. Very few IFN-γ-producing cells were found upon CSFV and PHA stimulation of PBMCs from all 7 of the surviving piglets in the Cat01-infected group and from the two surviving piglets from the PR-infected group that had not cleared the virus (Fig 4C) . In contrast, a large proportion of CSFV-specific and PHAresponsive IFN-γ-producing cells were detected in the PBMCs from the three PR-infected piglets that had seroconverted and from the two sows ( Fig 4C) . In conclusion, these data altogether showed that early postnatal infection of piglets with low virulence CSFV could result in virus persistence due to a lack of B-and T-cell responses. The lack of responsiveness of PBMCs to PHA suggested that the persistently infected piglets were immunosuppressed.