Novel hyperimmune egg yolk IgY antibodies developed against protective antigens of Eimeria and Clostridium perfringens protect against necrotic enteritis

Authors: GOO, DOYUN - US Department Of Agriculture (USDA); GADDE, U - Us Food & Drug Administration (FDA); KIM, WOO-KYUN - University Of Georgia; Gay, Cyril; PORTIA, E.W. - Arkion Life Sciences; JONES, S.W. - Arkion Life Sciences; WALKER, S - Arkion Life Sciences; Lillehoj, Hyun

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2023
Publication Date: 10/1/2024
Citation: Goo, D., Gadde, U., Kim, W., Gay, C.G., Portia, E., Jones, S., Walker, S., Lillehoj, H.S. 2024. Novel hyperimmune egg yolk IgY antibodies developed against protective antigens of Eimeria and Clostridium perfringens protect against necrotic enteritis. Poultry Science. 102. Article e102841. https://doi.org/10.1016/j.psj.2023.102841.
DOI: https://doi.org/10.1016/j.psj.2023.102841

Interpretive Summary: Necrotic enteritis (NE) is a devastating enteric disease caused by pathogenic Clostridium perfringens type A/G anaerobic bacteria. NE impacts global poultry industry by compromising performance, and health of the chickens. In the absence of effective vaccines against NE, ARS scientists collaborated with scientists in the private industry to develop a novel orally deliverable chicken IgY antibody mixture that reduces gut lesions mediated by NE. To develop NE-specific IgY antibodies that are specific against NE-causing pathogens, broiler hen chickens were hyperimmunized multiple times with 4 immunodominant protein antigens from pathogens causing NE, and the egg yolks from hens were used to isolate antibody-enriched protein fractions to develop novel immunotherapeutics. To prove the disease-mitigating effects of novel immunoglobulins against NE, yolk fraction containing high levels of antibodies against NE antigens were pooled (IgY fraction) and fed to newly hatched chickens. Results showed that oral feeding of newly hatched chickens with hyperimmune IgY antibodies protect chickens against NE infection and mitigated negative effects of NE promoting growth performance of commercial broiler chickens. In young chickens which received hyperimmune IgY antibodies, gut lesion was reduced with better performance in a dose-dependent manner. This is the first study reporting IgY-based protective strategy against NE.

Technical Abstract: Necroticenteritis (NE) is a wide spread infectious disease caused by Clostridium perfringens that inflicts major economic losses on the global poultry industry. Due to regulations on antibiotic use in poultry production, there is an urgent need for alternative strategies to mitigate the negative effects of NE. This paper presents a passive immunization technology that utilizes hyper immune egg yolk immunoglobulin Y (IgY) specific to the major immunodominant antigens of C. perfringens. Egg yolk IgYs were generated by immunizing hens with 4 different recombinant C. perfringens antigens, and their protective effects against NE were evaluated in commercial broilers. Six different spray-dried egg powders were produced using recombinant C. perfringens antigens: a-toxin, NEB-like toxin (NetB;EB), elongation factor-Tu (ET), pyruvate:ferredoxin oxido-reductase, amixture of 4 antigens (EM-1), and a non-mmunized control (EC).The challenged groups were either provided with different egg powders at a 1% level or no egg powders (EN). The NE challenge model based on Eimeria maxima and C. perfringens dual infection was used. In Experiments 1 and 2, the EB and ET group sex hibited increased body weight gain (BWG; P<0.01), decreased NE lesion scores (P<0.001), and reduced serum NetB levels (P<0.01) compared to the EN and EC groups. IgY against NetB significantly reduced Leghorn male hepato cellular cytotoxicity in an in vitro test (P<0.01). In Experiment 3, the protective effect of the IgYs mixture (EM-2) against C. perfringens antigens (NetB and EFTu) and Eimeria antigens(elonationfactor-1-alpha: EF1a and Eimeriaprofilin: 3-1E) was tested. The EM-2 group showed similar body weight ,BWG, and feed intake from d7 to 22 compared to the NCgroup (P<0.05). On d20, the EM-2 group showed comparable intestinal permeability, NE lesion scores, and jejunal NetB and collagen adhesion protein levels to the NC group (P<0.05). In conclusion, dietary mixture containing antibodies to NetB and EFTu provides protection against experimental NE in chickens through passiveimmunization.