Determination of ability of a thymidine kinase-negative deletion mutant of bovine herpesvirus-1 to cause abortion in cattle.
The Cooper isolate of bovine herpesvirus-1, which causes abortion in cattle, was used to construct a thymidine kinase-negative (TK-) deletion mutant virus. Twelve heifers were inoculated IV at 25 to 29 weeks of pregnancy with either TK- or thymidine kinase-positive (TK+) Cooper virus. All heifers developed fevers of 1 to 2 C during the first week after inoculation. Temperatures of TK+ inoculates were slightly higher and remained above normal a few days longer than in TK- inoculates. Viremia was detected in 5 of 6 TK+ inoculates and in all 6 TK- inoculates. More virus isolations were made from nasal and vaginal swab specimens of TK+ inoculates than from swab specimens of TK- inoculates. All heifers developed virus neutralizing antibody within 14 days after inoculation and antibody titers were similar between the 2 groups. None of the TK- inoculated heifers aborted and their calves did not have neutralizing antibody at birth. Abortion occurred in 5 of 6 heifers given TK+ virus. All aborted fetuses were infected with bovine herpesvirus-1, as demonstrated by virus isolation or detection of viral antigen in fetal tissues. These results indicate that inactivation of the TK gene reduces abortifacient activity of bovine herpesvirus-1.
Miller
J M
JM
Virology Cattle Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA 50010.
Whetstone
C A
CA
Bello
L J
LJ
Lawrence
W C
WC
D000034:Abortion, Veterinary / Q000382:microbiology*; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000956:Antigens, Viral / Q000032:analysis; D001345:Autoradiography; D001831:Body Temperature; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D005260:Female; D007242:Herpesvirus 1, Bovine / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D007150:Immunohistochemistry; D016296:Mutagenesis; D009297:Nasal Mucosa / Q000382:microbiology; D009500:Neutralization Tests; D016366:Open Reading Frames; D010920:Placenta / Q000382:microbiology; D010957:Plasmids; D011247:Pregnancy; D015183:Restriction Mapping; D013937:Thymidine Kinase / Q000235:genetics*; D014621:Vagina / Q000382:microbiology; D014766:Viremia / Q000662:veterinary
D000914:Antibodies, Viral; D000956:Antigens, Viral; D013937:Thymidine Kinase