Comparing antibody responses in chickens against Plasmodium falciparum lactate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase with Freund’s and Pheroid® adjuvants

Abstract

Pheroid® technology was assessed as an alternative to Freund's adjuvant to raise antibodies in experimental animals. Chickens were immunized with two recombinantly expressed Plasmodium falciparum proteins, lactate dehydrogenase (PfLDH) and glyceraldehyde-3-phosphate dehydrogenase (PfGAPDH), alone or in combination with Freund's adjuvant or Pheroid®. Chicken egg yolk antibodies (IgY) were isolated and compared for specificity, sensitivity and yield. Freund's adjuvant and Pheroid® stimulated prolonged antibody responses in chickens against both antigens. Affinity purified antibodies had specificity for the recombinant and the native proteins on Western blots. Antibodies generated in the presence of Freund's adjuvant had high sensitivity for both antigens. Pheroid® generated antibodies that detected the lowest concentration of recombinant PfLDH. Freund's adjuvant and Pheroid® both improved chicken IgY yields, with Pheroid® showing a 2-fold increase relative to controls. Pheroid® was well-tolerated in chickens and has potential for development as a safe adjuvant for testing alternative stimulatory factors to improve adjuvant formulations