Related Experiment Video
Updated: Aug 17, 2026
Isolation of Human Lymphatic Endothelial Cells by Multi-parameter Fluorescence-activated Cell Sorting
Published on: May 1, 2015
Decreased expression of L-selectin (CD62L) on lymphocytes in enzootic bovine leukaemia
R Dusinský1, M Bardotti, W Ponti
1Institute of Veterinary Microbiology and Immunology, University of Milan, Italy. dusinsky@ubgz.savba.sk
Insights
Bovine leukemia virus (BLV) infection reduces L-selectin expression on lymphocytes in cattle. This decrease in L-selectin (CD62L) on B and T lymphocytes may impair the host immune system.
Area of Science:
- Veterinary Immunology
- Molecular Biology
- Virology
Background:
- L-selectin (CD62L) is crucial for lymphocyte homing and immune surveillance.
- Bovine leukemia virus (BLV) causes persistent lymphocytosis in cattle, impacting the immune system.
- Understanding immune cell surface marker expression in BLV infection is vital for disease management.
Purpose of the Study:
- To investigate L-selectin expression on immune cells in cattle naturally infected with BLV.
- To determine if BLV infection affects L-selectin levels on granulocytes, peripheral blood mononuclear cells (PBMC), and blasts.
- To correlate L-selectin expression with lymphocyte counts in BLV-infected and healthy cattle.
Main Methods:
- Single- and two-colour immunofluorescence assays were used to detect L-selectin (CD62L) expression.
- A monoclonal antibody (IVA94) specific for bovine L-selectin was employed.
- Peripheral blood cells from healthy, BLV-infected non-lymphocytotic, and BLV-infected lymphocytotic cattle were analyzed.
Main Results:
- L-selectin was highly expressed on granulocytes (90-98%) in all cattle.
- Peripheral blood mononuclear cells (PBMC) showed lower L-selectin expression in lymphocytotic cattle, inversely correlated with lymphocyte counts.
- Both B and T lymphocytes exhibited significantly reduced L-selectin expression (approximately 50% decrease) in BLV-infected cattle compared to controls, as indicated by mean fluorescence intensity (MFI).
Conclusions:
- Bovine leukemia virus (BLV) infection leads to a significant decrease in L-selectin expression on lymphocytes.
- Reduced L-selectin expression on bovine lymphocytes may contribute to immune system deregulation during BLV infection.
- Further research is warranted to elucidate the precise mechanisms and consequences of altered L-selectin expression in BLV pathogenesis.
Abstract:
Expression of L-selectin was determined by single- and two-colour immunofluorescence on granulocytes, peripheral blood mononuclear cells (PBMC) and blasts of bovine origin by means of a monoclonal antibody IVA94 which recognizes bovine L-selectin (CD62L). Cells were separated from peripheral blood of healthy cattle and colleagues infected with bovine leukaemia virus (BLV). BLV-infected animals comprised lymphocytotic and non-lymphocytotic cows. L-selectin was expressed on 90-98% of granulocytes in all tested animals. The percentage of PBMC expressing L-selectin was lower in cattle with persistent lymphocytosis than in non-lymphocytotic or BLV-free cattle, and inversely correlated with lymphocyte counts. The ratio of B lymphocytes stained for L-selectin was significantly decreased from 60.2 +/- 1.9% in BLV-free cattle to 43.8 +/- 3.6 and 22.5 +/- 5.7% in non-lymphocytotic and lymphocytotic cattle, respectively. B-lymphocytes stained for L-selectin exhibited about 50% reduction in L-selectin expression in BLV-infected cattle compared with BLV-free cattle, as judged by the mean fluorescence intensity (MFI). The percentage of L-selectin-positive PBMC not bearing surface immunoglobulin M (predominantly T lymphocytes) was comparable in BLV-free and BLV-infected cattle. However, L-selectin expression on T lymphocytes was reduced (about 50%) in BLV-infected cattle, as judged by the MFI. We suppose that BLV infection results in a decreased L-selectin expression on lymphocytes, and accordingly, it may contribute to deregulation of the host immune system.
