Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions in Large White pigs selected for higher peripheral blood immune capacity

Abstract

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions were compared between the immunity-selected Large White line and the non-selected Large White line. The selected Large White line showed a higher level of pulmonary MPS lesions compared with the non-selected Large White line. Subsequent to vaccination, the percentage of natural killer cells and T cells (CD3(+) CD4(+) CD8(-) and CD3(+) CD4(-) CD8(+) T cells) were significantly increased in the non-selected line but remained unchanged in the immunity-selected Large White line. Secretion of Mycoplasma hyopneumoniae vaccine-specific immunoblogulin G and phagocyte activity in peripheral blood were significantly higher in the immunity-selected Large White line than in the non-selected line. Expression of interleukin (IL)-4 and IL-6 messenger RNA in hilar lymph nodes was significantly lower in the immunity-selected Large White line than in the non-selected line. However, expression of IL-10 in all immune tissues was significantly higher in the immunity-selected Large White line. These results suggest that the selection for high immunity was not effective in increasing resistance to MPS lung lesions.

Mycoplasma pneumonia of swine (MPS) resistance and immune characteristics of pig lines generated by crossing an MPS pulmonary lesion selected Landrace line and a highly immune capacity selected Large White line

“…Previous studies of the La line showed suppressed humoral immunity and enhanced natural immunity and cell-mediated immunity, resulting in a higher granular leukocyte percentage and increased interferon (INF)-γ (Katayama et al 2011;Shimazu et al 2013Shimazu et al , 2014Borjigin et al 2015a). In the Wa line, mucosal immunity is suppressed, as shown by reduced salivary IgA secretion, while humoral immunity and natural immunity are activated, resulting in IgG secretion and enhanced phagocytic activity (Borjigin et al 2015b). In this study, the LaWb and LaWa lines exhibited increased numbers of monocytes and decreased amounts of B cells and IgG secretion, providing evidence for the inheritance of immune traits from the La line.…”

“…In contrast, the Large White line selected for high immune capacity (Wa) had no strong resistance against MPS lung lesions (Borjigin et al . ). The present study confirmed the relatively low degree of MPS lung lesions in the La line, although the difference was not statistically significant.…”

“…In the Wa line, mucosal immunity is suppressed, as shown by reduced salivary IgA secretion, while humoral immunity and natural immunity are activated, resulting in IgG secretion and enhanced phagocytic activity (Borjigin et al . ). In this study, the LaWb and LaWa lines exhibited increased numbers of monocytes and decreased amounts of B cells and IgG secretion, providing evidence for the inheritance of immune traits from the La line.…”

“…Because the nonselected Large White line (Wb) exhibited a significant increase in NK cells compared with that of the Wa line (Borjigin et al . ), the two lines LaWb and LbWb were assumed to have inherited the genetic effects of the respective lines. In this study, there were differences among the four lines in not only the number of immune cells but also in the proliferative abilities of PBMCs after stimulation.…”

“…The relationship between MPS lung lesions and the immune response for the two lines described above has been reported (Borjigin et al . ,). Pig production in Japan uses the three‐way crossbreeding system by using hybrid vigor.…”