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Polarization of chemokine receptors to the leading edge during lymphocyte chemotaxis.

Nieto M, Frade JM, Sancho D, Mellado M, Martinez-A C, Sánchez-Madrid F - J. Exp. Med. (1997)

Bottom Line: In this study, we demonstrate that the CC chemokine receptors CCR2 and CCR5, but not cytokine receptors such as interleukin (IL)-2Ralpha, IL-2Rbeta, tumor necrosis factor receptor 1, or transforming growth factor betaR, are redistributed to a pole in T cells that are migrating in response to chemokines.Immunofluorescence and confocal microscopy studies show that the chemokine receptors concentrate at the leading edge of the cell on the flattened cell-substratum contact area, induced specifically by the signals that trigger cell polarization.The redistribution of chemokine receptors is blocked by pertussis toxin and is dependent on cell adhesion through integrin receptors, which mediate cell migration.

View Article: PubMed Central - PubMed

Affiliation: Servicio de Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid, E-28006, Madrid, Spain.

ABSTRACT
Leukocyte migration in response to cell attractant gradients or chemotaxis is a key phenomenon both in cell movement and in the inflammatory response. Chemokines are quite likely to be the key molecules directing migration of leukocytes that involve cell polarization with generation of specialized cell compartments. The precise mechanism of leukocyte chemoattraction is not known, however. In this study, we demonstrate that the CC chemokine receptors CCR2 and CCR5, but not cytokine receptors such as interleukin (IL)-2Ralpha, IL-2Rbeta, tumor necrosis factor receptor 1, or transforming growth factor betaR, are redistributed to a pole in T cells that are migrating in response to chemokines. Immunofluorescence and confocal microscopy studies show that the chemokine receptors concentrate at the leading edge of the cell on the flattened cell-substratum contact area, induced specifically by the signals that trigger cell polarization. The redistribution of chemokine receptors is blocked by pertussis toxin and is dependent on cell adhesion through integrin receptors, which mediate cell migration. Chemokine receptor expression on the leading edge of migrating polarized lymphocytes appears to act as a sensor mechanism for the directed migration of leukocytes through a chemoattractant gradient.

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(a) The CCR2 receptor  patches on the cell-sustratum contact  areas at the leading edge of the migrating T cell. Confocal microscopy  was performed as described in Materials and Methods. Three representative optical cell sections are shown,  out of the eight obtained. Serial sections are from the upper level (left,  2.464 μm), which shows staining of  ICAM-3 (red fluorescence) at the uropod, to the sustratum level (right,  3.92 μm), where CCR-2 (green fluorescence) is found at the leading edge. (b) Polarized distribution of the CCR2 receptor and ICAM-3 on migrating T cells. Cells adhered to FN-80–coated  coverslips were double stained with anti-ICAM-3 HP2/19 (yellow fluorescence) and anti-CCR2 mAb MCP-1R03 (green fluorescence). Original magnification:  ×1,200. Bar, 10 μm. The inset shows another T lymphoblast from the same sample at equal magnification.
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Figure 4: (a) The CCR2 receptor patches on the cell-sustratum contact areas at the leading edge of the migrating T cell. Confocal microscopy was performed as described in Materials and Methods. Three representative optical cell sections are shown, out of the eight obtained. Serial sections are from the upper level (left, 2.464 μm), which shows staining of ICAM-3 (red fluorescence) at the uropod, to the sustratum level (right, 3.92 μm), where CCR-2 (green fluorescence) is found at the leading edge. (b) Polarized distribution of the CCR2 receptor and ICAM-3 on migrating T cells. Cells adhered to FN-80–coated coverslips were double stained with anti-ICAM-3 HP2/19 (yellow fluorescence) and anti-CCR2 mAb MCP-1R03 (green fluorescence). Original magnification: ×1,200. Bar, 10 μm. The inset shows another T lymphoblast from the same sample at equal magnification.

Mentions: During migration, lymphocytes are polarized such that the leading edge of the cell develops cytoplasmic extensions (lamellipodia), whereas the posterior part of the cell forms an appendage (the uropod) (16, 17). Two-color fluorescence microscopy analyses allow us to conclude that the CCR2 and the CCR5 receptors are located at the advance front of migrating lymphocytes (Fig. 4, and data not shown). This is confirmed by confocal microscopy studies showing its presence on the flattened cell-substratum contact area at the leading edge. On the opposite pole of the cell, ICAM-3 was found to decorate the uropod that protrudes from the contact area of migrating T lymphocytes with endothelial or extracellular matrix substrates (Fig. 4, a and b; references 11, 12).


Polarization of chemokine receptors to the leading edge during lymphocyte chemotaxis.

Nieto M, Frade JM, Sancho D, Mellado M, Martinez-A C, Sánchez-Madrid F - J. Exp. Med. (1997)

(a) The CCR2 receptor  patches on the cell-sustratum contact  areas at the leading edge of the migrating T cell. Confocal microscopy  was performed as described in Materials and Methods. Three representative optical cell sections are shown,  out of the eight obtained. Serial sections are from the upper level (left,  2.464 μm), which shows staining of  ICAM-3 (red fluorescence) at the uropod, to the sustratum level (right,  3.92 μm), where CCR-2 (green fluorescence) is found at the leading edge. (b) Polarized distribution of the CCR2 receptor and ICAM-3 on migrating T cells. Cells adhered to FN-80–coated  coverslips were double stained with anti-ICAM-3 HP2/19 (yellow fluorescence) and anti-CCR2 mAb MCP-1R03 (green fluorescence). Original magnification:  ×1,200. Bar, 10 μm. The inset shows another T lymphoblast from the same sample at equal magnification.
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Related In: Results  -  Collection

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Figure 4: (a) The CCR2 receptor patches on the cell-sustratum contact areas at the leading edge of the migrating T cell. Confocal microscopy was performed as described in Materials and Methods. Three representative optical cell sections are shown, out of the eight obtained. Serial sections are from the upper level (left, 2.464 μm), which shows staining of ICAM-3 (red fluorescence) at the uropod, to the sustratum level (right, 3.92 μm), where CCR-2 (green fluorescence) is found at the leading edge. (b) Polarized distribution of the CCR2 receptor and ICAM-3 on migrating T cells. Cells adhered to FN-80–coated coverslips were double stained with anti-ICAM-3 HP2/19 (yellow fluorescence) and anti-CCR2 mAb MCP-1R03 (green fluorescence). Original magnification: ×1,200. Bar, 10 μm. The inset shows another T lymphoblast from the same sample at equal magnification.
Mentions: During migration, lymphocytes are polarized such that the leading edge of the cell develops cytoplasmic extensions (lamellipodia), whereas the posterior part of the cell forms an appendage (the uropod) (16, 17). Two-color fluorescence microscopy analyses allow us to conclude that the CCR2 and the CCR5 receptors are located at the advance front of migrating lymphocytes (Fig. 4, and data not shown). This is confirmed by confocal microscopy studies showing its presence on the flattened cell-substratum contact area at the leading edge. On the opposite pole of the cell, ICAM-3 was found to decorate the uropod that protrudes from the contact area of migrating T lymphocytes with endothelial or extracellular matrix substrates (Fig. 4, a and b; references 11, 12).

Bottom Line: In this study, we demonstrate that the CC chemokine receptors CCR2 and CCR5, but not cytokine receptors such as interleukin (IL)-2Ralpha, IL-2Rbeta, tumor necrosis factor receptor 1, or transforming growth factor betaR, are redistributed to a pole in T cells that are migrating in response to chemokines.Immunofluorescence and confocal microscopy studies show that the chemokine receptors concentrate at the leading edge of the cell on the flattened cell-substratum contact area, induced specifically by the signals that trigger cell polarization.The redistribution of chemokine receptors is blocked by pertussis toxin and is dependent on cell adhesion through integrin receptors, which mediate cell migration.

View Article: PubMed Central - PubMed

Affiliation: Servicio de Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid, E-28006, Madrid, Spain.

ABSTRACT
Leukocyte migration in response to cell attractant gradients or chemotaxis is a key phenomenon both in cell movement and in the inflammatory response. Chemokines are quite likely to be the key molecules directing migration of leukocytes that involve cell polarization with generation of specialized cell compartments. The precise mechanism of leukocyte chemoattraction is not known, however. In this study, we demonstrate that the CC chemokine receptors CCR2 and CCR5, but not cytokine receptors such as interleukin (IL)-2Ralpha, IL-2Rbeta, tumor necrosis factor receptor 1, or transforming growth factor betaR, are redistributed to a pole in T cells that are migrating in response to chemokines. Immunofluorescence and confocal microscopy studies show that the chemokine receptors concentrate at the leading edge of the cell on the flattened cell-substratum contact area, induced specifically by the signals that trigger cell polarization. The redistribution of chemokine receptors is blocked by pertussis toxin and is dependent on cell adhesion through integrin receptors, which mediate cell migration. Chemokine receptor expression on the leading edge of migrating polarized lymphocytes appears to act as a sensor mechanism for the directed migration of leukocytes through a chemoattractant gradient.

Show MeSH
Related in: MedlinePlus