Bovine immunodeficiency virus and bovine leukemia virus and their mixed infection in Iranian Holstein cattle.
BACKGROUND
Bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) have worldwide distributions, but their prevalences in Iran are unknown. We investigated the presence of infections in Iranian Holstein cattle and determined changes in hematological values for infected animals.


METHODS
Nested PCR was used on blood samples from 143 animals Holstein cattle to detect proviral BIV and BLV gag sequences. Flow cytometric analysis was performed using monoclonal antibodies (mAbs) against CD4, CD8, and CD21 bovine T lymphocyte subsets.


RESULTS
Proviral BIV and BLV gag sequences were detected in 20.3% and 17% of the animals, respectively. BIV-BLV confection was also detected in 4.2% of the study population but this was not statistically significant. Flow cytometric analysis showed that both BIV-infected cows and non-infected ones had CD4/CD8 ratios of 2.45 and 1.43, respectively, and this difference was significant. BLV infected and non-infected animals had no significant differences in their CD4/CD8 ratio. In comparison to non-infected cattle, those with both BIV and BLV had a significant decrease in their CD4/CD8 ratios (1.5 % vs. 2.3; P = 0.01).


CONCLUSIONS
This is the first report of BIV and BLV infections in Iran. We found no evidence that infection with one agent predisposed an animal to infection with the other. BIV infection may have a role in decreasing T CD8 counts, but this may depend on the genetics of the cattle and virus strains involved.
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. nikbakht@ut.ac.ir
Gholamreza Nikbakht
GN
Brujeni
Taghi Taghi
TT
Poorbazargani
Susan
S
Nadin-Davis
Mohammad
M
Tolooie
Neda
N
Barjesteh
D000818:Animals; D001769:Blood / Q000821:virology; D016516:CD4-CD8 Ratio; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D015897:Comorbidity; D016583:Enzootic Bovine Leukosis / Q000453:epidemiology* / Q000821:virology; D005434:Flow Cytometry; D016087:Immunodeficiency Virus, Bovine / Q000302:isolation & purification*; D007492:Iran / Q000453:epidemiology; D016180:Lentivirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D001909:Leukemia Virus, Bovine / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D016176:T-Lymphocyte Subsets / Q000276:immunology