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Updated: Jul 16, 2026
Development and Identification of a Novel Subpopulation of Human Neutrophil-derived Giant Phagocytes In Vitro
Published on: January 25, 2017
Cryopreservable neutrophil surrogates. Stored cytoplasts from human polymorphonuclear leukocytes retain chemotactic,
S E Malawista1, G Van Blaricom, M G Breitenstein
1Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
Abstract:
Cryopreservation of polymorphonuclear leukocytes (PMN) has largely failed, probably because of their rich content of granular (lysosomal) enzymes. We have been developing granule-poor cytoplasts (anucleate fragments) from PMN which retain motile functions of the parent cell. The two types studied here were induced either by brief heating on surfaces (cytokineplasts) or by discontinuous gradient centrifugation (Ficoll) without heat or drugs (U-cytoplasts). Freshly made, these cytoplasts respond chemotactically to formyl peptide (fMet-Leu-Phe), and they take up and kill roughly half as many Staphylococcus aureus as their (larger, granular) parent PMN. Unlike their parent cells, after cryopreservation both cytoplasts remain chemotactic, and in matched experiments they take up and kill staphylococci with undiminished avidity. These findings are the first indications that PMN cytoplasts suitable for clinical use may be feasible.
Insights
Cryopreservation of polymorphonuclear leukocytes (PMN) is challenging due to enzymes. Developing granule-poor PMN cytoplasts offers a promising solution, retaining function after freezing for potential clinical applications.
Area of Science:
- Immunology
- Cell Biology
- Biotechnology
Background:
- Cryopreservation of polymorphonuclear leukocytes (PMN) is hindered by granular enzymes.
- Developing functional PMN fragments is crucial for therapeutic applications.
Purpose of the Study:
- To investigate the cryopreservation potential of granule-poor PMN cytoplasts.
- To assess the functional recovery of PMN cytoplasts post-cryopreservation.
Main Methods:
- Generation of PMN cytoplasts via heating (cytokineplasts) or Ficoll centrifugation (U-cytoplasts).
- Assessment of chemotaxis to fMet-Leu-Phe.
- Evaluation of Staphylococcus aureus uptake and killing capacity.
Main Results:
- Both cytokineplasts and U-cytoplasts retained chemotactic and phagocytic functions after cryopreservation.
- PMN cytoplasts showed undiminished bacterial uptake and killing avidity post-freezing.
- Functional recovery surpassed that of parent PMN cells.
Conclusions:
- PMN cytoplasts are a viable alternative to whole PMN for cryopreservation.
- These findings suggest the feasibility of developing clinically applicable PMN cytoplasts.
- Granule-poor PMN fragments overcome cryopreservation challenges.
