Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 13, 1999
Publication Date: N/A
Interpretive Summary: Aspergillosis, caused by infection with Aspergillus fumigatus, is a common respiratory disease of poultry that results in carcass condemnation at slaughter inspection. There is no vaccine or cost-effective treatment available. Protection against several diseases can be conferred by the transfer of immune cells from a resistant to a susceptible individual; however, there are no reports evaluating the efficacy of transfer of immunity in preventing aspergillosis in birds. The results of this study showed that transfer of immune cells did not alter the susceptibility of turkeys to aspergillosis. Further, the immune cells did not respond to A. fumigatus. This is the first report of an attempt to protect birds against aspergillosis by the transfer of immune cells.
Technical Abstract: Only limited protective immunity against aspergillosis following experimental immunization of turkeys has been previously demonstrated. There are no reported studies evaluating the efficacy of transfer of immunity in preventing aspergillosis in birds. This study consists of two trials assessing the level of protection against Aspergillus fumigatus challenge afforded by transfer of splenocytes from convalescent turkeys. Three treatment groups of 12- to 14-week-old Beltsville Small White (BSW) turkeys comprising the splenocyte donors were prepared by one of the following: 1) intra-air sac (IA) challenge with Aspergillus fumigatus conidia 5 weeks prior to transfer; 2) IA challenge and then intravenous (IV) injection of killed conidia 1 week prior to transfer; or 3) sham inoculations. Splenocytes from each group were pooled, enriched for mononuclear leukocytes by density gradient centrifugation, and diluted in cell culture medium (CM). Cell viability was assessed by dye exclusion. Each splenocyte preparation was administered IV to one of three recipient groups consisting of 10 BSW turkeys each. A control group (n=10) was given cell-free CM. Recipients were challenged with viable A. fumigatus conidia 16 hours after splenocyte transfer by unilateral IA (trial 1) or IV (trial 2) inoculation. Lesion scores post-challenge revealed no differences between turkeys given splenocytes from convalescent versus naive (control) turkeys. Intra-air sac exposure produced ipsilateral lesions in air sacs and lung, whereas IV exposure produced severe miliary hepatitis. Donor cell function was confirmed by mitogen blastogenesis; however, cells were non-responsive to A. fumigatus antigens, regardless of previous exposure status.