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Updated: Aug 9, 2026
Non-invasive Imaging of Leukocyte Homing and Migration in vivo
Published on: December 6, 2010
Human leukocyte migration inhibition factor (LIF) increases polymorphonuclear cell endocytosis
M A Cortés-Castillo1, L Favila-Castillo
1Departamento de Inmunologia, Escuela Nacional de Ciencias Biológicas, México, D.F.
Insights
Leukocyte migration inhibition factor (LIF) enhances the ability of polymorphonuclear (PMN) cells to engulf yeast particles. This finding suggests LIF plays a role in modulating immune cell endocytic activity.
Area of Science:
- Immunology
- Cell Biology
Background:
- Leukocyte migration inhibition factor (LIF) is a cytokine produced by activated lymphocytes.
- The precise role of LIF in modulating immune cell function, particularly phagocytosis, requires further elucidation.
Purpose of the Study:
- To investigate the effect of purified leukocyte migration inhibition factor (LIF) on the endocytic activity of polymorphonuclear (PMN) cells.
- To determine if LIF enhances yeast uptake by PMN cells.
Main Methods:
- Preparation of supernatants from Concanavalin-A activated human lymphocytes containing LIF.
- Fractionation of supernatants using Sephadex G-100 chromatography.
- Assay of LIF activity using a yeast endocytosis model with human PMN cells.
- Inhibition studies using N-acetyl-D-glucosamine, a specific LIF blocker.
Main Results:
- A specific fraction containing high LIF activity was isolated from activated lymphocyte supernatants.
- This LIF-containing fraction significantly increased the number of endocytic PMN cells by approximately 80%.
- The observed enhancement of endocytosis was specific to LIF and blocked by N-acetyl-D-glucosamine.
Conclusions:
- Leukocyte migration inhibition factor (LIF) demonstrably enhances the endocytic capacity of polymorphonuclear (PMN) cells.
- LIF may play a crucial role in regulating phagocytic immune responses.
Abstract:
We prepared supernatants of Concanavalin-A activated human lymphocytes containing high titers of leukocyte migration inhibition factor (LIF). A pool of these supernatants was filtered thorough sephadex 6-100 as well as a pool of supernatants from parallel non activated cultures. A migration assay was carried out for each activated fraction, using as control migration the same fraction from non activated supernatants. In this way we found a fraction from activated supernatants with high LIF activity. We assayed the effect of this LIF containing fraction on a yeast endocytosis assay by polymorphonuclear (PMN) cells. We found that the LIF containing fraction increased the number of endocytic PMN in about 80%. This effect was absent from control supernatant and from other fractions from activated supernatant but without LIF activity. The LIF containing fraction did not increase the average number of endocytosed yeast per cell nor the ability to reduce NBT. The endocytosis enhancing effect was blocked by the specific LIF blocker N-acetyl-D-glucosamine. We conclude that LIF can increase the endocytic activity of PMN cells.
