Related Experiment Videos
Renal carcinoma cell lines inhibit natural killer activity via the CD94 receptor molecule
A J Stanley1, M J Gough, R E Banks
1ICRF Cancer Medicine Research Unit, St James's University Hospital, Leeds, UK.
Abstract:
MHC class I molecules protect normal and transformed cells from lysis by natural killer (NK) cells through recognition of receptors expressed on leucocytes. Defects in NK cell activity and lymphokine activated killer (LAK) cell generation have been previously demonstrated in patients with renal cell carcinoma (RCC). However, to date, the importance of NK receptor/MHC class I interactions for immune evasion by RCC cells has not been described. In this study, human RCC cell lines (HTB46, HTB47, ACHN, CRL 1933 and HTB44) were found to be susceptible to lysis by both NK cells and interleukin-15 (IL-15)-derived LAK cells from normal donors in vitro. However, when NK cells were co-cultured with RCC cells their expression of the CD94 NK receptor molecule was significantly increased and their cytolytic activity against RCC targets was reduced. The cytolytic activity of NK cells was restored by the addition of IL-15, which further augmented the expression of CD94 on CD56+ NK cells. Disruption of NK receptor-MHC class I interactions by the addition of blocking antibodies to CD94 had no effect on the lysis of K562 or HTB47 targets by NK cells. However, the sensitivity of HTB46 cells to NK-mediated lysis was increased by blocking the CD94 receptor molecule, but only when the NK cells had not been previously co-cultured with RCC cells. This was independent of the presence of IL-15. These results show that RCC cells can inhibit NK activity via CD94 and suggest that disruption of interactions between receptor and ligand on RCC cells in vivo may augment the immune response against tumours by innate effector cells.
Insights
Renal cell carcinoma cells can evade natural killer (NK) cell attacks by increasing CD94 receptor expression. Blocking this interaction may enhance anti-tumor immunity by innate effector cells.
Area of Science:
- Immunology
- Oncology
Background:
- Natural killer (NK) cells and lymphokine-activated killer (LAK) cells are crucial for anti-tumor immunity.
- NK cells recognize MHC class I molecules on target cells to regulate lysis.
- Defects in NK and LAK cell activity are observed in renal cell carcinoma (RCC) patients.
Purpose of the Study:
- To investigate the role of NK receptor/MHC class I interactions in immune evasion by RCC cells.
- To determine how RCC cells affect NK and LAK cell activity.
- To explore potential therapeutic strategies targeting these interactions.
Main Methods:
- In vitro co-culture of human RCC cell lines with NK and interleukin-15 (IL-15)-derived LAK cells.
- Analysis of CD94 NK receptor expression on NK cells.
- Assessment of NK cell-mediated cytotoxicity against RCC targets.
- Use of blocking antibodies against CD94 to disrupt receptor-ligand interactions.
Main Results:
- RCC cells were susceptible to lysis by NK and LAK cells.
- Co-culture with RCC cells increased CD94 expression on NK cells, reducing their cytolytic activity.
- IL-15 restored NK cell activity and further increased CD94 expression.
- Blocking CD94 enhanced NK-mediated lysis of HTB46 cells when NK cells were not pre-co-cultured with RCC cells.
Conclusions:
- RCC cells can inhibit NK cell activity through CD94 receptor interactions.
- Disrupting NK receptor-MHC class I interactions on RCC cells may enhance anti-tumor immune responses.
- Targeting CD94 interactions could be a potential strategy to augment innate effector cell-mediated anti-tumor immunity in RCC.