Exogenous Antigens
Exogenous Antigens - Related Videos
12:48
Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
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Cited by 2 •
2017
The method described here is a new vesicle isolation protocol, which allows for the purification of the cellular compartments where exogenous antigens are processed by endoplasmic reticulum-associated degradation in cross-presentation.
05:35
Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
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Cited by 4 •
2016
Here we report protocols to detect endogenous and exogenous centromere-kinetochore proteins in human cells and quantify these protein levels at centromeres-kinetochores by indirect immunofluorescent staining through the use of fixation (paraformaldehyde, acetone, or methanol fixation).
02:40
Inactivation of Bacteriophages Using Exogenous Lipopolysaccharide to Generate Phage-Free Salmonella Cultures
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2026
Source: Fernández-Fernández, R., et. al. Bacteriophage Removal from Infected Salmonella Cultures. J. Vis. Exp. (2024)This video demonstrates the use of exogenous LPS (Lipopolysaccharide) as a receptor mimic to inactivate lytic bacteriophages in Salmonella cultures. Through sequential incubation, centrifugation, and washing, phages are eliminated, resulting in a viable, phage-free bacterial suspension for downstream applications.
10:11
Expression of Exogenous Antigens in the Mycobacterium bovis BCG Vaccine via Non-genetic Surface Decoration with the Avidin-biotin System
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2018
A novel technique for rapid antigen display on a bacterial surface is presented, which involves surface biotinylation followed by exposure to proteins of interest in fusion with monomeric avidin. Loading BCG with selected antigens successfully improves its immunogenicity, suggesting that surface decoration can replace traditional genetic approaches.
06:57
Development of an Antigen-driven Colitis Model to Study Presentation of Antigens by Antigen Presenting Cells to T Cells
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Cited by 9 •
2016
In this antigen-driven colitis model, OT-II CD4+ T cells expressing a red fluorescent protein were adoptively transferred into RAG-/- mice that express a green fluorescent protein in mononuclear phagocytes (MPs). The hosts were challenged with Escherichia coli (E.coli) expressing the ovalbumin protein (OVA) fused to a cyan fluorescent protein (CFP).
FAQs
The route of uptake determines how antigen-presenting cells acquire foreign material for intracellular processing. Endocytosis internalizes material into the cell, while phagocytosis engulfs larger foreign substances. Both routes deliver contents to acidic endosomal compartments, where digestion generates peptide fragments suitable for later presentation. This uptake-processing sequence connects extracellular exposure with activation of adaptive immune responses.
Acidic endosomal compartments provide the processing environment in which captured foreign materials are digested into peptide fragments. These fragments become the molecular information displayed to immune cells rather than remaining as intact external substances. Because processing produces the peptides presented on major histocompatibility complex class II molecules, endosomal digestion is essential for recognition by CD4+ T cells.
Dendritic cells, macrophages, and B cells can capture and process these materials. Their shared processing capacity links external foreign substances to peptide presentation, but their participation supports different stages of immune coordination. Presentation to CD4+ T cells can promote helper T-cell activation, support B-cell antibody production, and contribute to the development of immune memory.
A typical investigation follows the material from cellular capture through intracellular digestion and peptide display. Researchers can examine whether antigen-presenting cells internalize the substance, process it in acidic endosomal compartments, and present resulting fragments on major histocompatibility complex class II molecules. Connecting these stages helps relate antigen handling to CD4+ T-cell recognition and downstream immune activation.
Vaccine components can serve as external materials that antigen-presenting cells capture and process for class II presentation. Studying this pathway helps explain how vaccination can engage CD4+ helper T cells, support antibody production by B cells, and establish immune memory. These outcomes make exogenous antigen processing relevant when investigating how vaccine materials initiate coordinated adaptive immune responses.
During infection research, investigators can use this pathway to connect foreign microbial molecules with immune recognition. Proteins from bacteria or parasites may be captured, digested, and displayed to CD4+ T cells, allowing analysis of helper T-cell activation and antibody responses. The same framework helps clarify interactions between invading organisms and host antigen-presenting cells.
Allergens can enter through the same external-antigen pathway and become substrates for uptake, digestion, and class II presentation. Examining these steps helps relate allergen exposure to adaptive immune activation. More broadly, the resulting helper T-cell and B-cell responses can contribute to immune memory, making the pathway useful for interpreting both allergic responses and longer-term immune outcomes.