Vet. Res. 38 (2007) 261-279
DOI: 10.1051/vetres:200657

Molecular biology of avian infectious laryngotracheitis virus

Walter Fuchs^a, Jutta Veits^a, Dorothee Helferich^a, Harald Granzow^b, Jens P. Teifke^b and Thomas C. Mettenleiter<sup>a

a</sup>  Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Boddenblick 5A, 17493 Greifswald - Insel Riems, Germany
^b  Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Boddenblick 5A, 17493 Greifswald - Insel Riems, Germany

(Received 6 April 2006; accepted 19 October 2006; published online 13 February 2007)

Abstract - Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes an economically important chicken disease, which results in delayed growth, reduced egg production, and also frequently in death of the animals. After acute infection of the upper respiratory tract, the virus can establish latency in the central nervous system, and subsequent reactivations can lead to infection of naive chickens. For prevention of ILT, conventionally attenuated live vaccines are available. However, these vaccine strains are genetically not characterized, and reversions to a virulent phenotype occur. Although molecular analyses of ILTV are hampered by the lack of an optimal cell culture system, the complete nucleotide sequence of the ILTV genome has recently been elucidated, and several ILTV recombinants lacking nonessential, but virulence determining genes have been constructed. Animal trials indicated that genetically engineered stable gene deletion mutants are safe alternatives to the current vaccine strains. Furthermore, since live ILTV vaccines are suitable for fast and inexpensive mass administration, they are promising as vectors for immunogenic proteins of other chicken pathogens. Thus, immunization with ILTV recombinants expressing avian influenza virus hemagglutinin was shown to protect chickens against ILT and fowl plague. Using monospecific antisera and monoclonal antibodies several virion proteins of ILTV have been identified and characterized. Since they include immunogenic envelope glycoproteins, these results can contribute to the improvement of virus diagnostics, and to the development of marker vaccines.

Key words: infectious laryngotracheitis virus / DNA sequence / monoclonal antibodies / recombinant live-virus vaccines / viral vectors

Corresponding author: walter.fuchs@fli.bund.de

© INRA, EDP Sciences 2007