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Study · In vitro (cells) · 2009

6 results

The cathelicidin LL-37 activates human mast cells and is degraded by mast cell tryptase: counter-regulation by CXCL4.

Schiemann F, Brandt E, Gross R, Lindner B, Mittelstädt J, Sommerhoff CP, Schulmistrat J, Petersen F

Journal of immunology (Baltimore, Md. : 1950)22 Jul 2009Cited by 36 (Europe PMC)

PMID19625657 (opens in a new tab)DOI10.4049/jimmunol.0803587 (opens in a new tab)PepBankPUB-19625657
Publisher pagePubMedAsk about this study
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study6

2 results from studies that gave the peptide. No result from this study comes from people.

  1. 01LabIn vitro (cells)Activity measurement

    In purified human lung mast cells, physiological concentrations of LL‑37 induced degranulation.

    In plain wordsIn cells, normal body levels of LL‑37 made human lung mast cells release their granules.

    Peptide
    LL-37
    Outcome
    IncreaseMast cell degranulation
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Immune response · Immune and inflammation
    Studied dose
    physiological concentrationsAs given in this study (human).

    Source sentences

    Summary
    In this study, we show for the first time to our knowledge that physiological concentrations of LL-37 induce degranulation in purified human lung MC.
  2. 02LabIn vitro (cells)Mechanism

    In human lung mast cells, LL‑37 was rapidly cleaved to a limited degree by released beta-tryptase.

    In plain wordsIn cells, a protein released by mast cells quickly cut LL‑37 into pieces.

    Peptide
    LL-37
    Outcome
    Not applicableCleavage of LL-37 by mast cell beta-tryptase
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Receptor activity and mechanism · Immune and inflammation
    Studied dose
    Dose not stated

    Source sentences

    Summary
    Intriguingly, as a consequence LL-37 rapidly undergoes limited cleavage by a released protease. The enzyme was identified as beta-tryptase by inhibitor studies and by comparison to the recombinant protease.

Studies that did not test the peptide alone4

In this study, LL-37 was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking LL-37.

  1. 03LabNot a test of LL-37 aloneIn vitro (cells)Activity measurement

    The LL‑37 fragments produced by tryptase cleavage did not keep the mast cell degranulation activity of intact LL‑37.

    In plain wordsIn lab tests, the pieces of LL‑37 left after cutting no longer made mast cells release granules.

    Peptide
    LL-37
    Outcome
    DecreaseMast cell degranulation by LL-37 fragments
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Immune response · Immune and inflammation

    Source sentences

    Summary
    Examining the resulting LL-37 fragments for their functional activity, we found that none of the typical capacities of intact LL-37, i.e., MC degranulation, bactericidal activity, and neutralization of LPS, were retained.

    In this study, LL-37 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking LL-37.

  2. 04LabNot a test of LL-37 aloneIn vitro (cells)Activity measurement

    The LL‑37 fragments produced by tryptase cleavage did not keep the bactericidal activity of intact LL‑37.

    In plain wordsIn lab tests, the pieces of LL‑37 left after cutting no longer killed bacteria.

    Peptide
    LL-37
    Outcome
    DecreaseBactericidal activity of LL-37 fragments
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Infection and antimicrobial activity · Infection

    Source sentences

    Summary
    Examining the resulting LL-37 fragments for their functional activity, we found that none of the typical capacities of intact LL-37, i.e., MC degranulation, bactericidal activity, and neutralization of LPS, were retained.

    In this study, LL-37 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking LL-37.

  3. 05LabNot a test of LL-37 aloneIn vitro (cells)Activity measurement

    The LL‑37 fragments produced by tryptase cleavage did not keep the LPS-neutralizing activity of intact LL‑37.

    In plain wordsIn lab tests, the pieces of LL‑37 left after cutting no longer neutralised LPS.

    Peptide
    LL-37
    Outcome
    DecreaseLPS neutralization by LL-37 fragments
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Inflammation markers · Immune and inflammation

    Source sentences

    Summary
    Examining the resulting LL-37 fragments for their functional activity, we found that none of the typical capacities of intact LL-37, i.e., MC degranulation, bactericidal activity, and neutralization of LPS, were retained.

    In this study, LL-37 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking LL-37.

  4. 06LabNot a test of LL-37 aloneIn vitro (cells)Mechanism

    In lab tests, the chemokine CXCL4 reduced the cleavage of LL‑37 by beta-tryptase.

    In plain wordsIn lab tests, CXCL4 protected LL‑37 from being cut by beta-tryptase.

    Peptide
    LL-37
    Outcome
    DecreaseProtection of LL-37 from beta-tryptase cleavage by CXCL4
    Study

    humann: not reported in source

    purified human lung mast cells
    Outcome group
    Receptor activity and mechanism · Immune and inflammation

    Source sentences

    Summary
    Conversely, we found that another inflammatory protein, the platelet-derived chemokine CXCL4, protects LL-37 from cleavage by beta-tryptase.

    In this study, LL-37 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking LL-37.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 3Current

    11 Oct 2026, 00:50 UTC

    Study results updated

  2. Version 2

    9 Oct 2026, 03:03 UTC

    Study data updated · source update from Europe PMC

  3. Version 1

    9 Oct 2026, 02:58 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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