Comparison of cytokine profiles in peripheral blood mononuclear cells between piglets born from Porcine circovirus 2 vaccinated and non-vaccinated sows

Abstract

This study was aimed to evaluate the effect of Porcine circovirus 2 (PCV2) sow vaccination on cell-mediated immune responses in sows and their progeny. At 7 weeks before farrowing, fifteen PCV2 PCR negative pregnant sows with medium-low antibody values were selected and randomly distributed in two groups according to the antibody levels. Seven sows were vaccinated with a commercial PCV2 vaccine and eight were injected with phosphate-buffered saline at 6 and 3 weeks before farrowing. Blood samples were taken from sows and their piglets (n = 90) during the study duration. PCV2 DNA and antibodies were tested in sera, and cytokine (IFN-α, IFN-γ, IL-12p40, TNF-α, IL-1β, IL-8, IL-4, IL-6 and IL-10) levels were assessed in supernatant from cultured peripheral blood mononuclear cells. All sows and piglets were negative by PCV2 PCR throughout the study. Significantly higher PCV2 antibody levels were detected in vaccinated sows after vaccination and in their offspring after colostrum ingestion compared to the non-vaccinated counterparts. Vaccinated sows did not show significant differences in cytokine secretion levels at farrowing compared to unvaccinated dams. In contrast, piglets from vaccinated sows had significantly higher levels of cytokines linked to Th1 memory cells (IFN-γ and TNF-α) in comparison to the ones from non-vaccinated dams. In conclusion, PCV2 sow vaccination, apart from triggering a humoral immunity response in sows and their progeny, might be associated to an increased transfer of cell-mediated immunity from the dam to the piglet.

Revisiting Porcine Circovirus Disease Diagnostic Criteria in the Current Porcine Circovirus 2 Epidemiological Context

“…A proportion of these animals may eventually become replacement stock, therefore generating a pool of seronegative breeding stock, potentially susceptible to the viral infection. This situation fits well with the significant variability in serological values of gilts and sows that can be found in herds that vaccinate piglets only [ 56 ]. Hence, with time, continuous piglet vaccination likely generates immunologically diverse “subpopulations” of gilts/sows at the herd level.…”

“…Considering that PCV-2 is present in almost all pig farms worldwide, the possibility of those “naïve” sows getting an infection is highly plausible. Although the overall rate of sow infection is usually low [ 56 ], it is expected that such a rate would be higher in animals devoid of immunity, as it has been demonstrated by the descriptions of PCV-2-RD basically in start-up herds [ 11 , 57 ]. Following this rationale, having susceptible gilts and sows in the farm would parallel with evidence of intrauterine infections in a proportion of breeding stock individuals.…”

Impact of maternally derived immunity on immune responses elicited by piglet early vaccination against the most common pathogens involved in porcine respiratory disease complex

“…Colostrum and milk also contain large numbers of cells that may vary depending on the mammary gland’s developmental stage and the sow’s physiologic and immunologic status [ 28 ]. Many of them are leukocytes, such as neutrophils, other granulocytes, and mostly antigen-experienced lymphoid cells [ 29 – 32 ] that participate in the cell-mediated immune (CMI) response. In addition, there are also other components that are thought to play an immunomodulatory role, such as the antibacterial protein lactoferrin, lysozyme and cytokines [ 33 , 34 ].…”

Sow Vaccination with a Protein Fragment against Virulent Glaesserella (Haemophilus) parasuis Modulates Immunity Traits in Their Offspring

“…Sow vaccination increases the level of colostrum antibodies and, subsequently, the period when maternal antibodies are maintained at a detectable level in their offspring [10,11]. For this reason, together with the short window available for piglet vaccination and their immature immune system, maternal immunization can be an option to prevent diseases early in life [12][13][14][15].…”