What question did this study set out to answer?

To determine how chemoattractants, immunocomplexes, and transforming growth factor beta regulate the surface expression of L-selectin and CD11b/CD18 in neutrophils, along with their underlying signal-transduction pathways.

May 1, 1994Biochemical JournalOpen Access

Immunocomplexes stimulate different signalling events to chemoattractants in the neutrophil and regulate L-selectin and beta 2-integrin expression differently.

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Authors

YMYair MoladTel Aviv University KHKathleen HainesConnecticut Children's Medical Center DAD. C. AndersonUniversity of Colorado Denver

Discussion

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Implication

Laboratory study demonstrates divergent regulation of L-selectin and CD11b/CD18 in neutrophils by immunocomplexes versus chemoattractants, indicating distinct downstream signalling mechanisms.

Key Points

To determine how chemoattractants, immunocomplexes, and transforming growth factor beta regulate the surface expression of L-selectin and CD11b/CD18 in neutrophils, along with their underlying signal-transduction pathways.
Treated isolated neutrophils with G-protein-coupled chemoattractants (C5a, IL-8, FMLP, substance P), BSA-anti-BSA immunocomplexes targeting Fc gamma receptors, or TGF-beta 1 across multiple concentrations (n=5).
Measured surface levels of L-selectin shedding and beta 2-integrin CD11b/CD18 expression via quantitative assays.
Assessed intracellular mechanisms by inhibiting actin microfilaments with cytochalasin B (5 µg/ml) and tyrosine kinases with tyrphostin-25 (25 µM), alongside measuring diacylglycerol synthesis and calcium flux.
Fc gamma receptor occupancy by immunocomplexes induced CD11b/CD18 upregulation at concentrations that did not alter L-selectin expression (EC50 9 µg/ml vs. 350 µg/ml, P < 0.00001, n=5).
Recombinant C5a, recombinant IL-8, and FMLP concurrently increased CD11b/CD18 expression (170–260% of basal, P < 0.001, n=5) and reduced L-selectin (56–75% reduction, P < 0.001, n=5) at similar potencies (EC50 of 2, 5, and 3 nM, respectively).
Cytochalasin B amplified diacylglycerol generation in response to FMLP but not immunocomplexes, while substance P and TGF-beta 1 showed no regulatory effect on either adhesion molecule.

Cite This Study

Molad et al. (1994) studied this question.

synapsesocial.com/papers/6a7055e9febe604dd70920b5 https://doi.org/10.1042/bj2990881

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May 1, 1994Biochemical JournalOpen Access

Immunocomplexes stimulate different signalling events to chemoattractants in the neutrophil and regulate L-selectin and beta 2-integrin expression differently.

View Full Paper

Ask AI

Bookmark

Authors

YMYair MoladTel Aviv University KHKathleen HainesConnecticut Children's Medical Center DAD. C. AndersonUniversity of Colorado Denver

Discussion

Member takes

Implication

Laboratory study demonstrates divergent regulation of L-selectin and CD11b/CD18 in neutrophils by immunocomplexes versus chemoattractants, indicating distinct downstream signalling mechanisms.

Key Points

To determine how chemoattractants, immunocomplexes, and transforming growth factor beta regulate the surface expression of L-selectin and CD11b/CD18 in neutrophils, along with their underlying signal-transduction pathways.
Treated isolated neutrophils with G-protein-coupled chemoattractants (C5a, IL-8, FMLP, substance P), BSA-anti-BSA immunocomplexes targeting Fc gamma receptors, or TGF-beta 1 across multiple concentrations (n=5).
Measured surface levels of L-selectin shedding and beta 2-integrin CD11b/CD18 expression via quantitative assays.
Assessed intracellular mechanisms by inhibiting actin microfilaments with cytochalasin B (5 µg/ml) and tyrosine kinases with tyrphostin-25 (25 µM), alongside measuring diacylglycerol synthesis and calcium flux.
Fc gamma receptor occupancy by immunocomplexes induced CD11b/CD18 upregulation at concentrations that did not alter L-selectin expression (EC50 9 µg/ml vs. 350 µg/ml, P < 0.00001, n=5).
Recombinant C5a, recombinant IL-8, and FMLP concurrently increased CD11b/CD18 expression (170–260% of basal, P < 0.001, n=5) and reduced L-selectin (56–75% reduction, P < 0.001, n=5) at similar potencies (EC50 of 2, 5, and 3 nM, respectively).
Cytochalasin B amplified diacylglycerol generation in response to FMLP but not immunocomplexes, while substance P and TGF-beta 1 showed no regulatory effect on either adhesion molecule.

Cite This Study

Molad et al. (1994) studied this question.

synapsesocial.com/papers/6a7055e9febe604dd70920b5 https://doi.org/10.1042/bj2990881

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