Eimeria maxima: efficacy of recombinant Mycobacterium bovis BCG expressing apical membrane antigen1 against homologous infection.
Coccidiosis is one of the most important protozoan diseases and inflicts severe economic losses on the poultry industry. The aim of this study was to evaluate the capacity of Bacillus Calmette-Guerin (BCG) to deliver apical membrane antigen1 (AMA1) of Eimeria maxima to stimulate specific cellular and humoral immune responses in chickens. Day-old birds were immunized twice with rBCG/pMV261-AMA1, rBCG/pMV361-AMA1, or BCG via oral, intranasal, and subcutaneous routes and then orally challenged with homologous E. maxima sporulated oocysts. Gain of body weight, fecal oocyst output, lesion scores, serum antibody responses, numbers of splenocyte CD4(+) and CD8(+) T cells, and gut cytokine transcript levels were assessed as measures of protective immunity. Challenge experiments demonstrated that rBCG vaccination via intranasal or subcutaneous routes could increase weight gain, decrease intestinal lesions, and reduce fecal oocyst shedding, and the subcutaneous and intranasal routes were superior to the oral route based on the immune effects. Furthermore, intranasal rBCG immunization could also lead to a significant increase in serum antibody, the percentage of CD4+ and CD8+ T lymphocyte cells, and the levels of IL-1β, IFN-γ, IL-15, and IL-10 mRNAs compared with the control group. These results suggested that intranasal rBCG immunization could induce a strong humoral and cellular response directed against homologous E. maxima infection. This study provides data for the use of rBCG to develop a prophylactic vaccine against coccidiosis.
College of Animal Medicine, Jilin University, Changchun, 130062, China.
Wen-Chao
WC
Li
Xu-ke
XK
Zhang
Ling
L
Du
Le
L
Pan
Peng-Tao
PT
Gong
Jian-Hua
JH
Li
Ju
J
Yang
He
H
Li
Xi-Chen
XC
Zhang
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D001835:Body Weight; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002645:Chickens; D003048:Coccidiosis / Q000276:immunology / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D016207:Cytokines / Q000096:biosynthesis; D004337:Drug Carriers; D004539:Eimeria / Q000235:genetics / Q000276:immunology*; D005243:Feces / Q000469:parasitology; D020869:Gene Expression Profiling; D005822:Genetic Vectors; D009163:Mycobacterium bovis / Q000235:genetics*; D059208:Parasite Load; D011201:Poultry Diseases / Q000276:immunology / Q000469:parasitology / Q000473:pathology / Q000517:prevention & control*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D012720:Severity of Illness Index; D014611:Vaccination / Q000379:methods
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D004337:Drug Carriers; D016052:Protozoan Vaccines