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Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
Published on: August 21, 2017
Cathepsin G: roles in antigen presentation and beyond.
Timo Burster1, Henriette Macmillan, Tieying Hou
1Division of Endocrinology and Diabetes, Department of Internal Medicine I, Ulm University, Ulm, Germany. tburster@stanford.edu
Molecular Immunology
|November 14, 2009
Summary
Cathepsin G (CatG), a neutrophil enzyme, plays a key role in antigen presentation by processing antigens into peptides within antigen-presenting cells. Its presence in various immune cells highlights its importance in immune responses.
Area of Science:
- Immunology
- Cell Biology
- Proteomics
Background:
- Antigen processing requires multiple cathepsins in endosomes.
- Cysteine and aspartyl cathepsins are known to digest antigenic proteins.
- The role of serine protease, cathepsin G (CatG), in antigen processing is a recent discovery.
Purpose of the Study:
- To review historical and recent data on CatG expression, distribution, function, and disease involvement.
- To focus on CatG's role in antigen presentation and immune-related events.
Main Methods:
- Literature review of existing studies on CatG.
- Analysis of CatG expression and distribution in various antigen-presenting cells.
- Discussion of functional assays implicating CatG in antigen processing.
Main Results:
- CatG is found in endocytic compartments of human monocytes, B cells, myeloid dendritic cells (mDC1, mDC2), plasmacytoid DCs (pDC), and murine microglia.
- CatG is not expressed in B cell lines or monocyte-derived DCs.
- Purified CatG can be internalized into endocytic compartments of CatG non-expressing cells.
- Functional assays demonstrate CatG's critical role in processing antigens and autoantigens.
Conclusions:
- CatG is an important enzyme in antigen processing and presentation.
- CatG's presence in diverse antigen-presenting cells suggests a broad role in immune responses.
- Further research into CatG's involvement in disease is warranted.
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