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Chemotactic factor-induced effects upon deformability of human polymorphonuclear leukocytes
Abstract:
We have compared the effects of the synthetic chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe), on the deformability and chemotaxis of human polymorphonuclear leukocytes (PMNs). By utilizing the technique of cell elastimetry (deformability), which measures the negative pressure required to aspirate cells into a micropipet, we have shown a correlation between f-Met-Leu-Phe concentrations and PMN deformability which parallels the effects of that chemoattractant on filter chemotaxis. At concentrations as low as 10(-11) M, a change in the deformability characteristics of a population of neutrophils was demonstrated. The increase in deformability became most marked at peptide concentrations in the range of 1-5 x 10(-9) M, corresponding to the optimal concentration range in the filter chemotaxis assay. Concentrations of 10(-8) M and greater were associated with a significant increase in the negative pressure required to aspirate the cells into a micropipet. Alterations in PMN deformability, therefore, occur as a natural consequence of stimulation of a human PMN with a chemotactic factor and may be a prerequisite to efficient movement.
Insights
The synthetic peptide N-formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe) alters human neutrophil (PMN) deformability. This change in cell elastimetry correlates with PMN chemotaxis, suggesting it
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Human polymorphonuclear leukocytes (PMNs) are crucial immune cells.
- Chemotactic factors guide PMN migration to sites of inflammation.
- Understanding PMN mechanics is key to immune response.
Purpose of the Study:
- To investigate the impact of N-formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe) on human PMN deformability.
- To correlate changes in PMN deformability with chemotaxis.
- To elucidate the biophysical basis of PMN migration.
Main Methods:
- Cell elastimetry was used to measure PMN deformability by assessing the negative pressure for micropipet aspiration.
- Filter chemotaxis assays were employed to evaluate PMN migration.
- f-Met-Leu-Phe was used at varying concentrations (10(-11) M to 10(-8) M and greater).
Main Results:
- f-Met-Leu-Phe significantly altered PMN deformability, even at concentrations as low as 10(-11) M.
- Optimal deformability changes occurred at 1-5 x 10(-9) M, mirroring optimal chemotaxis.
- Higher f-Met-Leu-Phe concentrations (≥10(-8) M) increased the negative pressure for cell aspiration, indicating reduced deformability.
Conclusions:
- PMN deformability is modulated by chemotactic factors like f-Met-Leu-Phe.
- Alterations in PMN deformability are a direct consequence of chemotactic stimulation.
- Changes in cell mechanics may be essential for effective PMN movement and immune surveillance.