[The Expression and Function of NK Cells in Patients with Acute Myeloid Leukemia]
Lu Liu1, Xiao Chen1, Hui-Min Jin1
1Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing 210029, Jiangsu Province, China.
Insights
Natural killer (NK) cells in acute myeloid leukemia (AML) patients show altered expression of functional markers. The study found a decrease in NK cell numbers and impaired function in AML compared to healthy individuals.
Area of Science:
- Immunology
- Hematology
- Oncology
Background:
- Natural killer (NK) cells play a crucial role in immune surveillance against cancer.
- Acute myeloid leukemia (AML) is a hematological malignancy characterized by the abnormal proliferation of myeloid blasts.
- Understanding NK cell behavior in AML is vital for developing effective immunotherapies.
Purpose of the Study:
- To investigate the expression patterns of antigens and functional markers on NK cells in patients diagnosed with AML.
- To compare NK cell characteristics between AML patients and healthy controls.
Main Methods:
- Multi-parameter flow cytometry was employed to analyze NK cell surface markers and functional indicators.
- The study included 56 newly diagnosed AML patients and 24 healthy controls.
- Key markers assessed included activating receptors (NKG2D, NKP46, DNAM-1) and cytotoxic indicators (granzyme B, perforin).
Main Results:
- AML patients exhibited an increased proportion of CD56hi NK cells but a decreased overall number and proportion of NK cells, alongside a reduced CD56dim NK cell population compared to controls.
- Expression of NKG2D and DNAM-1 on CD56hi NK cells was lower in AML patients.
- Functional markers like NKG2D, DNAM-1, and perforin showed decreased expression on CD56dim NK cells in AML patients, suggesting impaired NK cell function.
Conclusions:
- NK cells in AML patients display an altered subset distribution, with a higher ratio of CD56hi NK cells.
- The expression of functional markers on NK cells is significantly reduced in AML patients compared to healthy individuals.
- These findings indicate compromised NK cell function in the context of AML, potentially impacting immune response against the leukemia.
Objective:
To explore the expression characteristics of antigens and functional markers of natural killer (NK) cells in patients with acute myeloid leukemia (AML).
Methods:
Multi-parameter flow cytometry was used to detect NK cell surface markers and their functional indicators in 56 newly diagnosed AML patients and 24 healthy controls, including activating receptors NKG2D, NKP46, DNAM-1, and killing indicators granzyme B, perforin.
Results:
Referring to the WHO hematopoiesis and lymph tissue tumor classification criteria, 56 cases were roughly divided into three types: AML M1, M2, and M4/M5. However, there was no differences about NK cells among the three types, so it was no longer subdivided. NK cells were divided into two groups: CD3-CD56hiCD16- (CD56hiNK) and CD3-CD56dimCD16+ (CD56dimNK). Compared with CD56dimNK cell population, except for NKP46, the positive expression levels of NKG2D and other receptors of CD56hiNK cells in AML patients decreased (P<0.001). Compared with healthy controls, the proportion of CD56hiNK cells in AML patients increased, while the number and proportion of NK cells and proportion of CD56dimNK cells significantly decreased (P<0.05). The proportion of perforin in CD56hiNK cells significantly increased (P<0.05). The expression of DNAM-1 in CD56hiNK cells, NKG2D, DNAM-1, and perforin in CD56dimNK cells decreased significantly (P<0.05). There was no statistically significant difference in expression of other functional indexes in AML patients compared with corresponding indexes of healthy controls. In addition, the proportion of CD56hiNK cells was positively correlated with the expression of CD34+ in AML (r=0.303).
Conclusion:
Compared with CD56dimNK, the ratio of CD56hiNK and the expression of functional markers in AML patients are lower. Compared with healthy controls, the number and expression ratio of NK cells in AML patients decrease and the expression of functional markers is abnormal, indicating that its function is impaired.
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