Abstract
The present study was performed to determine the protective role of dietary selenium (Se) yeast supplementation in porcine circovirus type 2 (PCV2) infected mice. Forty-eight Kun Ming female mice were randomly assigned to Se yeast group (0.3%Se +basal diet, n = 24) and control group (basal diet, n = 24). After 3 days of adaptive feeding and 15 days treatment with the experimental feed, mice were challenged by intraperitioneal injection of PCV2 at the dosage of 2000 TCID50 (50% tissue culture infection dose, TCID50). Serum total superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and interleukin-1 beta (IL-1β) levels were measured at 5, 10, 15, 20 days post infection (dpi). The PCV2 virus load in the liver, spleen and lung, and the microscopic lesions in the liver, spleen and lung also were determined on 5, 10, 15, and 20 dpi. Dietary Se yeast supplementation decreased (Pμ0.05) the serum levels of TNF-α, but had no significant effect on the activity of SOD and the levels of MDA, CRP and IL-1β between experimental and control groups. Dietary Se yeast supplementation had little effect on the PCV2 virus load in the liver, spleen and lung. However, mice in the selenium yeast group showed a significant decrease in microscopic lesion scores in the lung and spleen compared with those in the control group (Pμ0.05). These data indicate Se yeast attenuated the PCV2 infection through altering the systemic inflammation and maintaining the normal organ morphology.
Highlights
Porcine circovirus type 2 (PCV2) is highly pathogenic and is associated with a wasting disorder recognized as post-weaning multi-systemic wasting syndrome (PMWS) [1,2], porcine dermatitis and nephropathy syndrome (PDNS) [3], reproductive disorders [4], enteritis [5], proliferative and necrotizing pneumonia (PNP) [6] and porcine respiratory disease complex (PRDC) [7]
PCV2 infection resulted in interstitial pneumonia and alveolar wall thickening in the lung, lymphohistiocytic inflammation in the liver, and lymphoid depletion and histiocytic inflammation in the spleen, which been observed in PCV2 infected pigs [24,26,27]
The serum level of TNF-α in the selenium yeast group was significantly lower than the control group (Table 2) at 5 (P = 0.004), 10 (P = 0.019), 15 (P = 0.045), and 20 (P = 0.013) dpi respectively
Summary
Porcine circovirus type 2 (PCV2) is highly pathogenic and is associated with a wasting disorder recognized as post-weaning multi-systemic wasting syndrome (PMWS) [1,2], porcine dermatitis and nephropathy syndrome (PDNS) [3], reproductive disorders [4], enteritis [5], proliferative and necrotizing pneumonia (PNP) [6] and porcine respiratory disease complex (PRDC) [7]. Nutritional regulation with immunoregulators to enhance the immune response might be useful as a prophylactic measure against PCV2 infection [13,14]. Selenium (Se) is an essential trace element in human nutrition It is a functional component of the antioxidant defense system and is needed for the maintenance of the immune functions. It has been reported that dietary Se supplementation can enhance the immune function [15,16], inhibit the activation of HIV-1 in cell culture through oxidative stress [17], and suppress the TNF-α-induced HIV replication in culture [18]. In the present study, we evaluated the effects of dietary selenium yeast supplementation on the immunological responses against PCV2 in mice infected with PCV2. PCV2 infection resulted in interstitial pneumonia and alveolar wall thickening in the lung, lymphohistiocytic inflammation in the liver, and lymphoid depletion and histiocytic inflammation in the spleen, which been observed in PCV2 infected pigs [24,26,27]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
