Related Experiment Videos
A lymphokine-activated killer (LAK)-resistant cell line, and low expression of adhesion molecules LFA-3 and VCAM-1 on
1Blood Transfusion Service, School of Medicine, Tokyo Medical and Dental University, Japan.
Abstract:
Tumor cell lines are generally killed by lymphokine-activated killer (LAK) cells. In this study, however, we report a LAK-resistant cell line, OKM-2T. The OKM-2T is an adult T-cell leukemia (ATL) cell line, and was compared to other ATL cell lines and non-ATL cell lines. The LAK cells were generated from healthy volunteers. Cell surface markers were determined by a flow cytometry test. The ATL and non-ATL cell lines were killed by the LAK cells, markedly or moderately. However, the OKM-2T was scarcely killed. The adhesion tendency of the OKM-2T to the LAK cells was preserved at the same level as that of the other cell lines, whereas the OKM-2T showed low levels of adhesion molecules CD58 (LFA-3), CD86, and CD106 (VCAM-1). We determined blocking tests using specific antibodies. Anti-CD58 blocked the LAK lysis. Anti-CD54 and anti-CD106 enhanced the blocking effect of the anti-CD58; anti-CD86 did not show such an effect. These results suggest that the low expression of CD58 in the OKM-2T may have an intimate relationship with LAK resistance, and that the low expression of CD106 may also be responsible for it, in part.
Insights
A new adult T-cell leukemia (ATL) cell line, OKM-2T, demonstrates resistance to lymphokine-activated killer (LAK) cells. This resistance is linked to reduced expression of CD58 and CD106 adhesion molecules.
Area of Science:
- Immunology
- Cell Biology
- Oncology
Background:
- Lymphokine-activated killer (LAK) cells are crucial for tumor cell apoptosis.
- Adult T-cell leukemia (ATL) is an aggressive malignancy with limited treatment options.
Purpose of the Study:
- To investigate the mechanism of LAK cell resistance in a novel ATL cell line, OKM-2T.
- To identify specific cell surface markers associated with LAK resistance in ATL.
Main Methods:
- Generation of LAK cells from healthy volunteers.
- Flow cytometry analysis of cell surface markers on ATL and non-ATL cell lines.
- Blocking assays using specific antibodies against adhesion molecules (CD58, CD86, CD106, CD54).
Main Results:
- The OKM-2T cell line exhibited significant resistance to LAK cell-mediated lysis compared to other ATL and non-ATL lines.
- OKM-2T cells showed reduced expression of CD58 (LFA-3), CD86, and CD106 (VCAM-1).
- Blocking of CD58 inhibited LAK lysis, an effect enhanced by anti-CD106 and anti-CD54 antibodies.
Conclusions:
- Low CD58 expression is strongly associated with LAK resistance in the OKM-2T cell line.
- Reduced CD106 expression contributes, in part, to the observed LAK resistance.
- These findings provide insights into therapeutic resistance mechanisms in ATL and potential targets for immunotherapy.