ELSEVIER zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA PII: zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA SO264-410X(97)00129-1 Vaccine, Vol. 15, No. 17118, 1908~1916, 1997 0 1997 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0264-410X/97 $l7+0.00 Immunization of cattle with a BHVl vector vaccine or a DNA vaccine both coding for the G protein of BRSV Remco S. Schrijver*$, Johannes P.M. Langedijk*, Giinther M. Keilj-, Wiechert G.J. Middel”, Mieke Maris-Veldhuis*, Jan T. Van Oirschot” and Frans A.M. Rijsewijk” zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA A gE-negative bovine herpesvirus 1 (BHVl) vector vaccine carrying a gene coding for the G protein of bovine respiratory syncytial virus (BRSV) (BHVIIBRW G) induced the same high degree of protection in calves against BRSV infection and BHVl infection as a multivalent commercial vaccine. A DNA plasmid vaccine, carrying the same gene as the BHVlfBRSVG vaccine, significantly reduced BRSV shedding after BRSV infection compared with that in control calves, but less well than the BHVlfBRSVG vaccine. Flow cytomettic analysis showed a significant relative increase of y/6’ T cells in peripheral blood after BRSV challenge-infection of the calves of the control group but not in the vaccinated groups. These results indicate that the G protein of BRSV can induce significant protection against BRSV infection in cattle, and that the BHVlIBRSVG vaccine protects effectively against a subsequent BRSV and BHVl infection. 0 1997 Elsevier Science Ltd. Keywords: Bovine respiratory syncytial virus; bovine herpesvirus 1; BHVl vector vaccine; DNA vaccination Live and inactivated vaccines against bovine herpes- virus 1 (BHVI) and bovine respiratory syncytial virus (BRSV) infections have been available for some time. However, the high prevalence of BHVl-infected cattle has stimulated the development of marker vaccines, which may reduce the number of newly infected cattle in an infected population similarly to the use of marker vaccines against pseudorabies virus in pigs”. Because respiratory disease in cattle is caused by an interplay of various micro-organisms’4.3” and because it causes severe economic losses, there is a need for multivalent vaccines. Furthermore, maternal antibodies prevent successful vaccination at an ear-$ age when young calves are most severely affected- . Therefore, in this study two new candidate vaccines were evaluated. One candidate vaccine was based on a BHVl vector, in which the gE gene was replaced by a gene encoding the G protein of BRSV. The other candidate vaccine was a DNA plasmid carrying the same gene. In BHVl vector the gE was replaced by the BRSV G gene, because the gE-negative mutant (without the inserted G gene) is a safe and efficacious vaccine’4. A gene *Institute zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA fo r A nim a l zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Science and Health (ID-DLO), Depart- ment of Mammalian Virology, P.O. Box 65, NL 6200 AB, Lelystad, Netherlands. tFederal Research Centre for Virus Diseases of Animals, Friedrich Loeffler Institutes, D-l 7498, lnsel Riems, Germany. *To whom correspondence should be addressed. Tel: +31 320 238238; fax: +31 320 238050. (Received 28 February 1997; revised version received 2 April 1997; accepted 23 April 1997) 1908 Vaccine 1997 Volume 15 Number 17118 encoding the putative attachment protein G of BRSV” was used, because this protein may induce a protective immune response in calves”2. A plasmid encoding the G protein of BRSV was included as vaccine in this study. In addition to clinical and serological parameters in the BRSV model”, we investigated the relative distribution of T-cell subsets in vaccinated and control cattle after BRSV challenge-infection. Cellular immunity is important in recovery from BRSV infec- tion in calves”, but little is known about the role of different T-cell subsets in immunized calves. zyxwvutsrqponm MATERIALS AND METHODS Viruses and cells Recombinant BHVl was propagated in Madin- Darby bovine kidney (MDBK) cells. For BHVl titra- tions, embryonic bovine tracheal (EBTr) cells were used. For BRSV titrations, bovine foetal diploid lung (BFDL) cells were used. MDBK cells were grown in Earle’s lactalbumin medium (Flow Laboratories, Herts, UK) with 5% foetal bovine serum (FBS) and antibiotics (125 IU penicillin (Gist-brocades, Delft, The Netherlands), 125 Pg streptomycin (Biochemie), 37.5 IU nystatin (Sigma, St Louis, MO), and 37.5 /lg kanamycin (Sigma) per millilitre). BFDL and EBTr cells were grown in Earle’s minimal essential medium with 10% FBS and antibiotics. Cells and viruses were found free of bovine virus diarrhoea virus (BVDV), and mycoplasmas.