Related Experiment Video
Updated: Apr 22, 2026
Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers
Published on: March 8, 2012
HIV-1 Intersection with CD4 T Cell Vesicle Exocytosis: Intercellular Communication Goes Viral
1Instituto Gulbenkian de Ciência , Oeiras , Portugal ; Faculdade de Ciências Médicas, CEDOC, Universidade Nova de Lisboa , Lisboa , Portugal.
Insights
CD4 T cell activation involves two exocytic events, including T cell receptor secretion. Human immunodeficiency virus-1 (HIV-1) exploits this process for viral budding and to induce bystander cell death, offering therapeutic targets.
Area of Science:
- Immunology
- Cell Biology
- Virology
Background:
- Extracellular vesicle secretion in immune cells is modulated by cellular activation.
- T cell activation occurs via cell-cell contact with antigen-presenting cells, forming an immunological synapse.
- CD4 T cell activation involves two distinct exocytic events following T cell receptor (TCR) recognition.
Purpose of the Study:
- To review the role of CD4 vesicle exocytosis in immune regulation.
- To examine how HIV-1 hijacks CD4 T cell exocytosis for viral replication and pathogenesis.
- To discuss potential therapeutic strategies targeting CD4 vesicle exocytosis.
Main Methods:
- Review of existing literature on CD4 T cell activation and exocytosis.
- Analysis of mechanisms by which HIV-1 interacts with the regulated secretory system of CD4 T cells.
- Discussion of the implications of these processes for immune function and disease.
Main Results:
- Cognate antigen recognition by the TCR triggers two exocytic events: signaling molecule targeting and TCR extracellular secretion.
- HIV-1 co-opts the regulated secretory pathway of CD4 T cells for viral budding.
- HIV-1-induced exocytosis contributes to bystander T cell death.
Conclusions:
- CD4 vesicle exocytosis is crucial for T cell immune regulation and synapse formation.
- HIV-1 pathogenesis is significantly linked to the manipulation of CD4 T cell exocytosis.
- Targeting CD4 vesicle exocytosis presents a potential therapeutic avenue for HIV-1 infection.
Abstract:
In cells of the immune system, the secretion of extracellular vesicles is modulated through cellular activation. In particular, T cell activation is achieved through cell-cell contacts with antigen presenting cells and the consequent formation of a specialized signaling junction called the immunological synapse. Recent works on CD4 T cells have elucidated that cognate antigen recognition by the T cell receptor (TCR) engages two distinct exocytic events. The first involves the exocytic targeting of signaling molecules at the synaptic membrane and drives the functional architecture of the immunological synapse. The second enlists the extracellular secretion of the TCR itself, once the functional architecture of the immunological synapse is accomplished. HIV-1, a human lymphotropic virus, has evolved sophisticated mechanisms to co-opt CD4 T cell physiology. Notably, it has become apparent that HIV-1 intersects the regulated secretory system of CD4 T cells in order to bud from the plasma membrane of the infected cell and to promote bystander cell death. Here, I review the relevance of CD4 vesicle exocytosis to immune regulation and to HIV-1 pathogenesis and discuss their potential therapeutic applications.
More Related Videos
08:11Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.
Published on: September 1, 2015
09:26In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function
Published on: October 15, 2013
Related Concept Videos
01:22T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
01:38Intralumenal Vesicles and Multivesicular Bodies
01:29Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
01:26Size and Structure of Viral Genomes
01:27Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
01:45Vesicular Tubular Clusters
With the help of motor proteins such...