Specific Humoral Immune Response Induced by Propionibacterium acnes Can Prevent Actinobacillus pleuropneumoniae Infection in Mice

Abstract

bPorcine contagious pleuropneumonia, caused by Actinobacillus pleuropneumoniae, has a major impact on economics, ecology, and animal welfare in the pig-rearing industry. Propionibacterium acnes, a facultative anaerobic Gram-positive corynebacterium, exists widely in normal healthy adult animals. We have shown previously that P. acnes can prevent A. pleuropneumoniae infections in mice and pigs. To elucidate the mechanism of this effect and to identify novel A. pleuropneumoniae vaccines, the role of anti-P. acnes antibodies in preventing infection was analyzed by indirect immunofluorescence and opsonophagocytosis assays in vitro. The role of the specific humoral immune response induced by P. acnes was confirmed in a B cell depletion mouse model. The survival rates of mice challenged with A. pleuropneumoniae exhibited a highly significant positive rank correlation with the levels of anti-P. acnes antibodies. The specific antibodies induced by P. acnes had the ability to combine with A. pleuropneumoniae and increase opsonization of A. pleuropneumoniae for phagocytosis. Furthermore, analysis in the murine B cell depletion model confirmed that the humoral immune response induced by P. acnes played an important role in resistance to A. pleuropneumoniae infection. In this study, we further elucidated the reasons that P. acnes can prevent A. pleuropneumoniae infection, which provides useful evidence for the development of heterologous vaccines for the control of porcine contagious pleuropneumonia.

Humoral immunity is the primary means of heterologous Propionibacterium acnes vaccination against Actinobacillus pleuropneumoniae infection in pig

“…These results indicated that IL-4 production induced by P. acnes vaccination enhanced the humoral immune responses and induced the production of specific antibody. In our previous antibody transfer experiments, afer mice treated by swine anti-P.acnes serum were challenged with A. pleuropneumoniae serotype 1 (CCVC 259) and 5 (CCVC 264), the survival rates of both group were even 100% (n=5 for each group) (Yang, Lei et al 2009). From above, we concluded that induction of the specific humoral immune response by P. acnes played an important role in the immnoprotection against A.plruropneumonia infection.…”

“…And one subunit is difficult to be selected for vaccine or epitope, witch to provide multiple serotype immunity protection (Ramjeet, Deslandes et al 2008). In our previous study, vaccination of P. acnes could protect mice against A.pleuropneumoniae serotype 1 and 5 infection (Yang, Lei et al 2009).…”

“…This was confirmed by the further experiments that a significant immunoprotection against A.pleuropneumoniae was observed after the vaccination in mice (serotype 1, CCVC 295 and serotype 5, CCVC 263) and pigs (A.pleuropneumoniae serotype 1, CCVC 259) with P.acnes. Furthermore, we treated mice with the swine anti-P.acnes serum and then challenged them with A.pleuropneumoniae serotype 1 and 5, all the mice (n=10) continued to live for 7 days after challenge (Yang, Lei et al 2009).…”

Galactose-1-phosphate uridyltransferase (GalT), an in vivo-induced antigen of Actinobacillus pleuropneumoniae serovar 5b strain L20, provided immunoprotection against serovar 1 strain MS71

“…The use of vaccines has proven to be a better choice in efforts to control PCP outbreaks. Apart from use of traditional inactivated vaccine, many studies have focused on new vaccines to control PCP [45][46][47][48][49][50][51][52]. GALT was demonstrated as an efficient antigen against APP, and could be taken as a potential vaccine candidate [36].…”

Recombinant tandem epitope vaccination provides cross protection against Actinobacillus pleuropneumoniae challenge in mice

“…The antibody level in the mouse serum in each group was detected by indirect ELISA according to the reference (Yang et al 2014). When the ratio of the OD value of the positive control serum and the negative control serum was ≥2.1, the test results were recorded at 450 nm.…”