Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705, USA.
This study investigated protection against Eimeria acervulina (E. acervulina) following vaccination of chickens with an Eimeria recombinant profilin in conjunction with different adjuvants, or by changing the route of administration of the adjuvants. Day-old broilers were immunized twice with profilin emulsified in Montanide IMS 1313 N VG PR adjuvant (oral, nasal, or ocular routes), Montanide ISA 71 VG adjuvant (subcutaneous route), or Freund's adjuvant (subcutaneous route) and orally challenged with virulent E. acervulina parasites. Birds orally immunized with profilin plus IMS 1313 N VG PR, or subcutaneously immunized with profilin plus ISA 71 VG, had increased body weight gains compared with animals nasally or ocularly immunized with profilin plus IMS 1313 N VG PR, or subcutaneously immunized with profilin plus Freund's adjuvant. All adjuvant formulations, except for IMS 1313 N VG PR given by the nasal or ocular routes, decreased fecal parasite excretion and/or reduced intestinal lesions, compared with non-vaccinated and infected controls. Compared with animals vaccinated with profilin plus Freund's adjuvant, chickens immunized with profilin plus IMS 1313 N VG PR or ISA 71 VG showed higher post-infection intestinal levels of profilin-reactive IgY and secretary IgA antibodies. Finally, immunization with profilin in combination with ISA 71 VG was consistently better than profilin plus IMS 1313 N VG PR or Freund's adjuvant for increasing the percentages of CD4(+), CD8(+), BU1(+), TCR1(+), and TCR2(+) intestinal lymphocytes. These results indicate that experimental immunization of chickens with the recombinant profilin subunit vaccine in conjunction with IMS 1313 or ISA 71 VG adjuvants increases protective mucosal immunity against E. acervulina infection.
Published by Elsevier B.V.