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Expression of complement regulatory proteins on human natural killer cell subsets
Lin Wang1, Deborah Halliday, Peter M Johnson
1Division of Immunology, School of Infection and Host Defence, University of Liverpool, Liverpool, UK.
Immunology Letters
|August 28, 2007
Summary
Complement regulatory proteins CD46, CD55, and CD59 protect cells. Human natural killer (NK) cells show varied expression of these proteins, with some subsets downregulating them upon activation, unlike other leukocytes.
Area of Science:
- Immunology
- Cell Biology
Background:
- Cell surface complement regulatory (CReg) proteins CD46, CD55, and CD59 protect human leukocytes from complement-mediated damage.
- Natural killer (NK) cells are crucial immune cells with diverse functions and phenotypic subsets.
Purpose of the Study:
- To investigate the heterogeneity in CReg protein expression on human NK cell subsets.
- To determine how NK cell activation affects CReg protein levels.
Main Methods:
- Flow cytometry was used to assess CReg protein expression (CD46, CD55, CD59) on resting and activated NK cell subsets.
- NK cell subsets were identified using CD56 and CD158 markers.
- NK cells were stimulated with phytohemagglutinin (PHA), interleukin-2 (IL-2), or interleukin-15 (IL-15).
Main Results:
- NK cells expressed lower CReg protein levels than T cells.
- CD56(bright) NK cells had higher CD55 levels than CD56dim cells.
- Specific CD158+ NK cell subsets showed reduced CD46 and CD59 expression.
- IL-2 stimulation decreased CD46 and CD59 on NK cells, contrasting with other leukocytes.
- IL-15 stimulation increased all three CReg proteins on NK cells.
Conclusions:
- NK cell subsets exhibit distinct CReg protein expression patterns.
- Activation with IL-2 leads to CReg protein downregulation on NK cells, suggesting alternative protective mechanisms.
- IL-15 promotes CReg protein expression on NK cells.
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