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Updated: Aug 14, 2026
12:48
Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
Published on: August 21, 2017
Unveiling the role of lysosomes in antigen processing and presentation
Gabriele Sergio Colangelo1,2, Kyra J Cowan3, Federico Riccardi Sirtori2
1Molecular Biotechnology Center, University of Turin, Torino, TO, Italy.
Journal of Immunology (Baltimore, Md. : 1950)
|August 12, 2026
Summary
Lysosomes process antigens for presentation by major histocompatibility complex class II (MHCII) molecules, crucial for CD4+ T helper cell activation. Dysregulation of these processes can lead to autoimmunity, highlighting the need for further research.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Lysosomes are critical for antigen processing and presentation via MHCII in antigen-presenting cells (APCs).
- Proper regulation of antigen catabolism and peptide loading by lysosomes ensures balanced immune responses.
- Dysregulation in these pathways can contribute to autoimmune diseases.
Purpose of the Study:
- To review mechanisms of antigen acquisition and lysosomal processing for MHCII presentation.
- To explore how proteolysis, redox regulation, and peptide editing influence the MHCII ligandome.
- To examine the link between lysosomal dysfunction and autoimmunity.
Main Methods:
- Review of existing literature on lysosomal function in antigen presentation.
- Analysis of endocytic trafficking and protease activity in APCs.
- Examination of evidence linking lysosomal dysfunction to autoimmune conditions.
Main Results:
- Lysosomes play a central role in generating peptides for MHCII presentation.
- Key factors influencing MHCII ligandome include proteolysis, redox state, and peptide editing.
- Evidence supports a connection between lysosomal dysfunction and the development of autoimmunity.
Conclusions:
- Understanding lysosomal mechanisms in immune cells is vital for comprehending physiological and pathological immunity.
- Targeting lysosomal pathways may offer therapeutic strategies for immune disorders.
- Further research is needed to enhance the efficacy and safety of novel biological entities targeting these pathways.
Related Concept Videos
01:31Antigen Processing Pathways
MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
MHC Class I: Presenting Endogenous...
MHC Class I: Presenting Endogenous...
01:36Delivery Pathways to the Lysosome
Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
01:22Antigen Presenting Cells
The immune system is a complex network of cells and molecules that protects the body from foreign invaders. T cells, a type of white blood cell, play a crucial role in this process. They recognize and attack foreign substances, such as pathogens, that enter the body.
T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens...
T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens...
01:22Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
01:31Lysosomes
Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules and biological polymers that are released during membrane trafficking events such as the secretory, endocytic, autophagic, and phagocytic pathways. The degradation is carried out by several hydrolytic enzymes active in an acidic environment of the lysosomal lumen. These acid hydrolases are involved in cellular processes such as cell signaling,...
01:26Antigens Involved in Adaptive Immunity
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.