(POSTER PRESENTATION): BLV-CoCoMo-qPCR: Estimation of Bovine Leukemia Virus (BLV) harbored by lymphocyte subpopulation in BLV-infected cattle at the subclinical stage of enzootic bovine leucosis

AIDA YOKO; SHIN-NOSUKETAKESHIMA; PANEI CARLOS JAVIER; OMORI TAKASHI; NUNOYA TETSUO; DAVIS WILLIAM C.; ISHIZAKI HIROSHI; MATOBA KAZUHIRO

RETROVIROLOGY

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2014 p. 143 - 143

1742-4690

Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis (EBL), which is the most common neo- plastic disease of cattle. The present study reports the distribution of BLV provirus in peripheral blood mono-nuclear cell subpopulations isolated from BLV-infected cows at the subclinical stage of EBL as examined by cell sorting and a new quantitative real-time PCR method, BLV-CoCoMo-qPCR, to measure the proviral load of both known and novel BLV variants in BLV-infected ani- mals. Phenotypic characterization of five BLV-infected but clinically normal cattle with a proviral load of > 100 copies per 1 x 105 cells identified a high percentage of CD5+ IgM+ cells (but not CD5- IgM+ B cells, CD4+ T cells, or CD8+T cells). These lymphocyte subpopula- tions were purified from three cattle by cell sorting or using magnetic beads, and the BLV proviral load was estimated using BLV-CoCoMo-qPCR. The CD5+ IgM+ B cell population in all animals harbored a higher BLV proviral load than the other cell populations. The copy number of proviruses infecting CD5- IgM+ B cells, CD4+ cells, and CD8+ T cells (per 1 ml of blood) was 1/34 to 1/4, 1/22 to 1/3, and 1/31 to 1/3, respectively, compared with that in CD5+ IgM+ B cells. Moreover, the BLV provirus remained integrated into the genomic DNA of CD5+ IgM+ B cells, CD5- IgM+ B cells, CD4+ T cells, and CD8+ T cells, even in BLV-infected cattle with a proviral load of