Local immunity in Newcastle disease: some recent experiments
Aitken, I.D.; Parry, S.H.; Powell, J.R.; Survashe, B.D.
Developments in Biological Standardization 33: 302-308
1976
ISSN/ISBN: 0301-5149 PMID: 182586 Document Number: 98636
After primary exposure by the ocular route to lentogenic Newcastle disease virus (NDV) the lacrimal fluid, saliva and tracheal washes of three-week-old SPF chicks acquired specific virus-neutralizing activity which considerably exceeded transudation of circulating antibody. All three secretions contain IgA which, at least in saliva, accounted for 85% of its activity, the remainder being due to IgG. Antibody in secretions limited, but did not prevent, reinfection of the trachea when birds were challenged two weeks later. In contrast to an elevation of circulating antibody titre, challenge induced only a repeated primary response in secreted antibody. Ocular infection induced marked lymphoid and plasma cell activity in the Harderian gland which is a major source of specific antibody in lacrimal and possibly other fluids. Functional ablation of the gland can be effected by occlusion of its draining duct, providing a means for evaluation of its immunological significance.