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Human promyelocytic cell line: a convenient tool for studying the molecular basis of WBC filtration
L Barbe1, B Boval, M P Wautier
1Laboratory of Vascular and Cellular Biology, Hôpital Lariboisière, University of Paris, France.
Background:
Blood filtration is a technique widely used to reduce the levels of WBCs in blood components. Several studies have been conducted to define the factors that are involved in WBC reduction, but the various mechanisms are not clearly delineated. This study explored the role of WBC adhesion molecules in WBC reduction during filtration.
Study Design And Methods:
A minifilter has been developed that has properties similar to those of the standard filter (Sepacell, Asahi Medical) but that allows a smaller volume of blood to be used (15 mL). WBC reduction was achieved to a similar extent in the standard filter and the minifilter (4.15 log and 4.18 log, respectively). Samples of human promyelocytic cell line (HL60) were filtered before and after differentiation induced by vitamin D3 (D3-HL60). Flow cytometry was used to characterize the D3-HL60 filtrates and to count the WBCs after filtration.
Results:
HL60 was retained in the filter to the same extent as all other WBCs. A higher level of integrin receptors (CD11b/CD18; CD11c/CD18) was expressed by D3-HL60 than by HL60. When the blood was incubated with anti-CD11b, anti-CD11c, or anti-CD18, fewer D3-HL60 cells were trapped by the filter, while only anti-CD11b alters HL60 retention in the filter.
Conclusion:
The receptors CD11b/CD18 and CD11c/CD18 appear to bind to the filter fibers and to be one of the mechanisms responsible for WBC retention.
Insights
This study reveals that white blood cell (WBC) adhesion molecules, specifically integrin receptors CD11b/CD18 and CD11c/CD18, play a key role in reducing WBC levels during blood filtration. Blocking these receptors decreases WBC retention in filters.
Area of Science:
- Biomedical Engineering
- Hematology
- Cell Biology
Background:
- Blood filtration is crucial for reducing white blood cells (WBCs) in blood products.
- Mechanisms underlying WBC reduction during filtration are not fully understood.
- This research investigates the role of WBC adhesion molecules in filtration efficiency.
Purpose of the Study:
- To explore the involvement of white blood cell (WBC) adhesion molecules in WBC reduction during blood filtration.
- To elucidate the specific mechanisms by which WBCs are retained in filters.
Main Methods:
- A minifilter with properties similar to standard filters was used with a smaller blood volume (15 mL).
- Human promyelocytic cell line (HL60) and differentiated D3-HL60 cells were filtered.
- Flow cytometry analyzed cell retention and characterized filtrates before and after differentiation.
Main Results:
- WBC reduction was comparable between standard and minifilters (4.15 and 4.18 log reduction).
- Differentiated D3-HL60 cells expressed higher levels of integrin receptors (CD11b/CD18, CD11c/CD18) than undifferentiated HL60 cells.
- Blocking CD11b/CD18 or CD11c/CD18 reduced D3-HL60 cell retention in the filter.
Conclusions:
- Integrin receptors CD11b/CD18 and CD11c/CD18 are implicated in WBC retention within blood filters.
- These adhesion molecules appear to bind to filter fibers, contributing to WBC reduction mechanisms.