The role of mucosal antibody in immunity to infectious laryngotracheitis virus in chickens

CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No. 1, P.O., Parkville, Victoria 3052, Australia The role of mucosal antibody in recovery from a primary infection and resistance to reinfection with infectious laryngotracheitis (ILT) herpesvirus was studied in bursectomized chickens, which were unable to synthesize specific antibodies. Viral antigen in the infected trachea was assessed by indirect immunofluorescence on tissue sections and by ELISA. The ability of bursectomized chickens to resolve primary infections as effectively as intact chickens and of vaccinated-bursectomized chickens to prevent the replication of challenge virus without the participation of mucosal antibody, is evidence for the importance of local cell-mediated rather than humoral immune mechanisms in the outcome of infection with ILT virus. Received 27 April 1990; accepted 3 July 1990.