Impaired cell motility in chronic myeloid leukemic granulocytes related to altered cytoskeletal pattern

Area of Science:

• Cell Biology
• Hematology
• Immunology

Background:

• Polymorphonuclear leucocytes (PMNL) are crucial for bacterial infection response, involving cytoskeletal changes affecting adhesion and locomotion.
• Microfilaments, composed of actin, drive these cellular movements through polymerization.
• PMNL from chronic myeloid leukemia (CML) patients show impaired locomotion, but the underlying mechanisms are not fully understood.

Purpose of the Study:

• To investigate the spatial distribution and reorganization of microfilaments and microtubules in CML patient PMNL in response to n-formyl-methionyl-leucyl-phenylalanine (fMLP).
• To elucidate the mechanisms behind defective motility and reduced chemotaxis in CML PMNL.

Main Methods:

• Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine cytoskeletal structures.
• Comparison of PMNL morphology and cytoskeletal organization between normal subjects and CML patients, both unstimulated and stimulated with fMLP.

Main Results:

• SEM revealed smoother surfaces with reduced ruffling and less polarized morphology in CML PMNL.
• Both normal and CML PMNL showed fewer and shorter microtubules and evenly distributed microfilaments when unstimulated.
• fMLP stimulation led to altered cytoskeletal configurations in CML PMNL compared to normal PMNL.

Conclusions:

• Defective PMNL locomotion in CML is attributed to reduced surface activity stemming from altered cytoskeletal configuration.
• Impaired functional appendages and overall cytoskeletal changes contribute to reduced cell motility and chemotaxis in CML patients.