Cloud S S, Rosenberger J K, Lillehoj H S
Delaware Agricultural Experiment Station, Department of Animal Science and Agricultural Biochemistry, University of Delaware, Newark 19716.
Vet Immunol Immunopathol. 1992 Nov;34(3-4):353-66. doi: 10.1016/0165-2427(92)90175-p.
To determine the functional impact of alterations in lymphocyte concentrations and ratios following infection with chicken anemia agent (CAA) alone or in combination with infectious bursal disease virus (IBDV) on the immune system of young chickens, in vitro lymphoproliferation assays and in vivo responses to vaccination with several common viral agents were assessed at various time intervals post-inoculation (PI). Concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) stimulation of splenic lymphocytes (SPL) collected from control birds could not be detected until 10-14 days PI. Infection with CAA was characterized by significantly higher PWM stimulation of SPL at 17 days PI and significantly lower PWM stimulation of peripheral blood lymphocytes (PBL) at 14 days PI, compared with uninfected controls. Concanavalin A and PWM stimulation of SPL was significantly increased in birds inoculated with IBDV alone. Lymphocytes harvested from birds inoculated simultaneously with CAA and IBDV had significantly lower responses. Effects on humoral and cell-mediated immunity following CAA and/or IBDV were determined by evaluating vaccination responses to Newcastle disease virus (NDV), fowl pox virus (FPV) and infectious laryngotracheitis virus (ILTV) during the acute phase of CAA infection (2 weeks PI). Vaccination of birds 2 weeks following CAA infection at 1 day of age resulted in decreased protection against NDV (85.7%) and ILTV (7.1%) challenge compared with protection rates in control birds (100% and 53.3% respectively). Infectious bursal disease virus infection was associated with decreased protection against NDV (60%) only. Concomitant infection at 1 day of age resulted in a greater reduction in NDV challenge protection (33.3%), slightly decreased FPV protection (87.5%), increased numbers of persistent FPV vaccination lesions and increased protection against ILTV challenge (71.4%). Vaccination of birds 2 weeks following CAA infection at 2 weeks of age resulted in slightly decreased NDV humoral antibody, development of persistent FPV vaccination lesions (17%) and increased immunity to ILTV challenge compared with control birds (83.3% vs. 66.7%). Chickens inoculated with IBDV alone displayed a more severe depression in NDV antibody titers and only a slight decrease in ILTV protection. Vaccination following concomitant infection at 2 weeks of age resulted in a higher percentage of FPV persistent vaccination lesions (39%) and greatly enhanced immunity to ILTV challenge (100%).
为了确定单独感染鸡贫血因子（CAA）或与传染性法氏囊病病毒（IBDV）联合感染后淋巴细胞浓度和比例的改变对雏鸡免疫系统的功能影响，在接种后（PI）的不同时间间隔评估了体外淋巴细胞增殖试验和对几种常见病毒制剂疫苗接种的体内反应。直到接种后10 - 14天才能检测到从对照鸡采集的脾淋巴细胞（SPL）对刀豆球蛋白A（Con A）、植物血凝素（PHA）和商陆有丝分裂原（PWM）的刺激。与未感染的对照相比，CAA感染的特征是在接种后17天SPL对PWM的刺激显著更高，而在接种后14天外周血淋巴细胞（PBL）对PWM的刺激显著更低。单独接种IBDV的鸡中，SPL对Con A和PWM的刺激显著增加。同时接种CAA和IBDV的鸡收获的淋巴细胞反应显著更低。通过评估在CAA感染急性期（接种后2周）对新城疫病毒（NDV）、禽痘病毒（FPV）和传染性喉气管炎病毒（ILTV）的疫苗接种反应，确定了CAA和/或IBDV对体液免疫和细胞介导免疫的影响。与对照鸡的保护率（分别为100%和53.3%）相比，1日龄雏鸡在CAA感染2周后接种疫苗，对NDV（85.7%）和ILTV（7.1%）攻击的保护作用降低。仅传染性法氏囊病病毒感染与对NDV攻击的保护作用降低（60%）有关。1日龄时同时感染导致对NDV攻击的保护作用更大幅度降低（33.3%），对FPV的保护作用略有降低（87.5%），持续的FPV疫苗接种损伤数量增加，对ILTV攻击的保护作用增加（71.4%）。2周龄雏鸡在CAA感染2周后接种疫苗，与对照鸡相比，NDV体液抗体略有降低，出现持续的FPV疫苗接种损伤（17%），对ILTV攻击的免疫力增加（83.3%对66.7%）。单独接种IBDV的鸡在NDV抗体滴度上表现出更严重的降低，对ILTV的保护作用仅略有降低。2周龄时同时感染后接种疫苗导致更高比例的FPV持续疫苗接种损伤（39%），并大大增强了对ILTV攻击的免疫力（100%）。
