Association between BoLA and subclinical bovine leukemia virus infection in a herd of Holstein-Friesian cows.
The role of the bovine major histocompatibility system (BoLA) in subclinical bovine leukemia virus (BLV) infection was investigated in a herd of Holstein-Friesian cows (n = 240). The BoLA W8.1 allele was negatively associated with the presence of antibodies to the major BLV envelope glycoprotein, BLV-gp51 (corrected P less than 0.001, relative risk = 0.31). These results suggest that a BoLA-linked gene(s) may influence the early spread of BLV infection. Since B cells are the primary target of BLV infection, we then determined the relationship between BoLA-A locus phenotypes and B-cell numbers in peripheral blood of seropositive and seronegative cows. There were no significant differences between BoLA-A alleles for any hematological parameter in seronegative cows. Seropositive cows with the W12.1 allele had significantly greater absolute numbers of lymphocytes per microliter and B cells per microliter than did seropositive cows with other BoLA-A phenotypes (P less than 0.01, respectively). The average effect associated with the W12.1 allele in BLV-infected cows was an increase of 2010 B cells per microliter of whole blood relative to BLV-infected cows with other BoLA-A phenotypes. These results demonstrate that susceptibility to the polyclonal expansion of BLV-infected B lymphocytes is associated with the W12.1 allele in Holstein-Friesian cattle. Compared with results of a previous study in a herd of Shorthorn cattle, it appears that resistance and susceptibility to subclinical progression of BLV infection are associated with different BoLA-A locus alleles in different cattle breeds.
Lewin
H A
HA
Department of Animal Sciences, University of Illinois, Urbana 61801.
Wu
M C
MC
Stewart
J A
JA
Nolan
T J
TJ
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D000956:Antigens, Viral / Q000276:immunology; D001402:B-Lymphocytes / Q000473:pathology; D002417:Cattle / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D004198:Disease Susceptibility; D006649:Histocompatibility Antigens / Q000032:analysis* / Q000235:genetics; D001909:Leukemia Virus, Bovine / Q000276:immunology / Q000302:isolation & purification*; D007942:Leukemia, Experimental / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D008285:Major Histocompatibility Complex; D010641:Phenotype; D012190:Retroviridae / Q000302:isolation & purification*; D014759:Viral Envelope Proteins / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D006649:Histocompatibility Antigens; D014759:Viral Envelope Proteins