Immune response of broiler chickens immunized orally with the recombinant proteins flagellin and the subunit B of cholera toxin associated with Lactobacillus spp.

Abstract

This study investigated the immune response of broiler chickens with oral treatment of a Lactobacillus spp. pool (PL) associated with microencapsulated recombinant proteins flagellin (FliC) and the subunit B of cholera toxin (CTB). Immune responses were evaluated by measuring IgA from intestinal fluid, serum IgY, and immunostaining of CD8(+) T lymphocytes present in the cecum. The evaluations were performed on d 0, 7, 14, 21, and 28 posttreatment. A significant increase (P < 0.05) was observed in IgA levels in all immunized groups, especially 3 wk after immunization. Treatments 2 (recombinant CTB) and 3 (recombinant FliC+CTB) showed the highest concentrations. Similarly, serum concentrations IgY (μg/mL) increased along the experiment, and the means for treatments 2 and 3 showed significant differences (P < 0.05) compared with controls, reaching concentrations of 533 and 540 μg/mL, respectively. The number of CD8(+) T lymphocytes in all treatments greatly differed (P < 0.05) compared with the negative control at 21 d posttreatment. However, only treatment 2 (recombinant CTB), 4 (PL), and 5 (recombinant FliC+ recombinant CTB + PL) remained significantly (P < 0.05) different from the control at 28 d posttreatment. Thus, it is concluded that the microencapsulated recombinant proteins administered orally to broiler chickens are capable of stimulating humoral and cellular immune response, and the combinations of these antigens with Lactobacillus spp. can influence the population of CD8(+) T cells residing in the cecum.

Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

“…Fortunately, it was found that by coupling the antigen to CTB, a much stronger response is achieved via the oral administration route [ 47 ]. We should also point out that the adjuvant potential of CTB has also been shown in large animal models, indicating that the adjuvant potential is scalable to higher species [ 48 , 49 , 50 ]. The utility of CTB becomes apparent when looking at the various disease states in which it has been used as an adjuvant: bacterial and viral infections, allergy, and diabetes have been targeted [ 51 , 52 , 53 ].…”

A plant-made cholera toxin B subunit enhances mucosal wound healing and protects against ulcerative colitis and colon cancer.

“…We should also point out that the adjuvant potential of CTB has also been shown in large animal models, indicating that the adjuvant potential is scalable to higher species (48)(49)(50).…”