A cyclophosphamide-sensitive cell compartment is essential for homologous protection conferred by licensed vaccines for the control of avian pathogenic Escherichia coli in chickens

作者：Sadeyen Jean Remy; Kaiser Pete; Stevens Mark P; Dziva Francis^*

来源：Vaccine, 2015, 33(31): 3624-3627.

DOI：10.1016/j.vaccine.2015.06.034

• APEC
• Vaccination
• Bursectomy
• Cyclophosphamide
• Chicken
• Antibody

Avian pathogenic Escherichia colt (APEC) exert substantial economic costs on poultry producers worldwide. Vaccination is an attractive method of control, but the immunological basis of protection is poorly understood. Here, we examine the effect of intramuscular injection of cyclophosphamide or saline on homologous protection induced by licensed inactivated or live-attenuated APEC 078 vaccines in chickens. In saline-treated birds, both vaccines induced significant APEC-specific IgY and protection against homologous challenge, as evidenced by enumeration of tissue-associated bacteria and analysis of pathology. In cyclophosphamide-treated birds, B cells were severely depleted whereas percentages of circulating CD4- and CD8-positive T cells were normal as detected by flow cytometry. Further, such birds did not produce APEC-specific IgY and were as susceptible to challenge as age-matched unvaccinated controls. The data indicate that homologous protection conferred by licensed APEC vaccines strictly requires a cyclophosphamide-sensitive cell population that includes B cells.

• 出版日期2015-7-17