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Segregation of adhesion molecules during neutrophil crawling
Author(s) -
Gaborski Thomas Roger,
McGrath James,
Waugh Richard
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a648-c
Subject(s) - microbiology and biotechnology , actin , integrin , cell adhesion molecule , myosin , chemistry , biophysics , pseudopodia , adhesion , cell adhesion , cytoskeleton , cell , biology , biochemistry , organic chemistry
Fluorescence imaging reveals that the expression of adhesion molecules on the neutrophil surface is nonuniform, with L‐selectin and PSGL‐1 expressed on the tips of the membrane folds of resting neutrophils and β2 integrins found in topologically distinct domains. These adhesion molecules also show different lateral mobilities and domain dynamics on the resting cell surface. In the present study we observe changes in the lateral distribution of adhesion molecules during neutrophil activation and migration. L‐selectin and PSGL‐1 polarize and form a cap at the rear of activated neutrophils prior to shedding, while β2 integrins continue to be distributed across the cell body. The cap contains F‐actin, but polymerization of new G‐actin is restricted to the leading edge. Preliminary evidence indicates that treatment of neutrophils with blebbistatin (50 and 100 μM for 30 minutes) to inhibit myosin II contraction in the uropod inhibits cap formation, while pseudopod formation at the leading edge persists, and no change in integrin distribution occurs. Thus, the movement of L‐selectin and PSGL‐1 away from the leading edge and cell body prior to shedding involves actomyosin contraction. These results document that adhesion molecules on the surfaces of crawling neutrophils segregate laterally according to their functional roles and under the active involvement of the cytoskeleton. Supported by the NIH: F31‐EB005103 and P01‐HL18208.