Interferon status and white blood cells during infection with African swine fever virus in vivo.

African swine fever virus (ASFV) is the causative agent of African swine fever that is the significant disease of domestic pigs, with high rates of mortality. ASFV is double-stranded DNA virus whose genes encode some proteins that are implicated in the suppression of host immune response. In this study, we have modeled in vivo infection of ASFV for determination of interferon (IFN) status in infected pigs. We measured the level of IFN-α, -ß and -γ by enzyme-linked immunosorbent assay and showed that the level of IFN-α sharply decreased during infection. Unlike IFN-α, the level of IFN-ß and -γ increased from the 2nd and 4th days post-infection, respectively. Also, we analyzed the population dynamics of peripheral white blood cells of infected pigs due to their important role in host immune system. We showed that the atypical lymphocytes appeared after short time of infection and this result is in accordance with our previous study done in vitro. At the last day of infection about 50% of the total white blood cells were destroyed, and the remaining cells were represented mainly by small-sized lymphocytes, reactive lymphocytes and lymphoblasts.

Phenotypic and cytologic studies of lymphoid cells and monocytes in primary culture of porcine bone marrow during infection of African swine fever virus.

We have modeled in vitro infection of African swine fever virus (ASFV) in primary unstimulated cells of the porcine bone marrow and have studied the phenotypical changes in the population of porcine lymphoid cells by cytophotometry. Monocytes and large-sized lymphocytes completely vanished in 72 h of infection which is result of high sensitivity of those cells to ASFV. We describe DNA synthesis in monocytes at 24 h post infection. Cytophotometry of the uninfected cells revealed the few number of atypical lymphocytes and lymphoblasts after 72 h of cultivation; whereas in viral infected cultures, atypical cells appeared in large quantity (about 14%) with 24 h. Most of atypical lymphocytes and lymphoblasts had altered nucleus, and only a small number of atypical cells had additional nucleus. The cytophotometry of main and additional nuclei showed that DNA content didn't exceed diploid standard which indicates that the additional nuclei were consequence of fragmentation of nuclei in lymphocytes.