Authors : B.J.A. Lopez, D. Quintanar-Guerrero, R.A. Romero, G.F. Suarez, C.A. Ciprian and E.S. Mendoza
Abstract: In the present research, the capacity of the cubic phase of glyceryl monooleate was studied as a carrier and protection vehicle for Apx toxins I, II and III with the aim of obtaining an orally administered immunogen for the protection of susceptible pigs from Actinobacillus pleuropneumoniae infection. In the presence of high water concentrations and at body temperature, the monoolein, an amphiphilic lipid, produces what is called the cubic phase which is characterized by the formation of a curved double layer which extends to three dimensions, thus separating two congruent water channel systems that form a pore of approximately 5 nm in which the Apx toxins were trapped. Apx toxins I, II and III were obtained from the supernatants of cultures of A. pleuropneumoniae serotypes 1, 3, 5 and 7. The capacity of the monoolein gel to trap the apx toxins as well as the effect of their inclusion in the cubic phase were evaluated by polarized light microscopy. The gel toxin release was evaluated using in vitro dissolution tests. The monoolein gel was able to retain a 400 μg mL-1 antigen concentration without affecting the formation of the cubic phase. Approximately 60% of the protein molecules were released from the gel within 4 h. The antigenic effect of the product, orally inoculated in mice was observed in in vivo studies with changes in the T-lymphocyte and B-lymphocyte populations being identified by flow cytometry and antibodies against the antigen were sought using the ELISA test. Small changes were detected through flow cytometry in lymphocyte populations with the CD4 and CD19 markers allowing to speculate on the possible stimulation of the immune system by the antigen, which was confirmed by the appearance of antibodies in the animals’ serum, identified by the ELISA test. The results obtained are encouraging and open the possibility of developing an orally administered immunogen to protect pigs from becoming infected with A. pleuropneumoniae.
B.J.A. Lopez, D. Quintanar-Guerrero, R.A. Romero, G.F. Suarez, C.A. Ciprian and E.S. Mendoza, 2010. Preliminary Study: Evaluation of Glyceryl Monooleate Cubic Phase as a Protection and Carrier System for Actinobacillus pleuropneumoniae Toxins in Mice. Journal of Animal and Veterinary Advances, 9: 1311-1317.