Immunoanalysis of IgG and IgM molecules on the surface of BLV infected cattle lymphocytes

Abstract

The BLV-infected animals were divided into lymphocytotic (9 animals: BLV+PL+) and non lymphocytotic (11 animals: BLV+PL -). BLV-free animals formed a control group (7 animals: BLV-PL-). Flow cytometry immunofluorescence (FACS) and scanning electron microscopy (SEM) were used to evaluate the expression of IgG and IgM molecules on the surface of the lymphocytes of cattle infected with the bovine leukaemia virus (BLV). The percentage of IgM-bearing cells was significantly higher in the BLV+PL+ (75% and 74%) than in BLV+PL (43% and 50%) and BLV-PL (39% and 44%) groups by FACS and SEM respectively. The percentage of IgG-bearing cells was higher in BLV+PL+ (6%) and BLV+PL (8%) compared to BLV-PL (0.7%) determined by FACS and significantly higher in BLV+PL+ (62%) in relation to BLV+PL (17%) and BLV-PL (8%) groups ascertained by SEM. A significantly higher intensity of IgM expression was observed in the BLV+PL+ group by SEM and FACS; a higher intensity of IgG expression in BLV+PL+ group was detected only by SEM. The results suggest that FACS and SEM are complementary. The finding of significant differences in the expression of IgG molecules in BLV+ groups compared with BLV - animals confirms the sensitivity of the SEM method.