Related Experiment Video
Updated: Jun 24, 2026
05:56
Imaging Initial Ca2+ Microdomains in Primary T Cells
Published on: October 4, 2024
Adenosine primes resting stage dendritic cells before their activation
Tracy L Flach1, Winston Pang, Elaine M T Chau
1Immunology Research Group & Department of Microbiology and Infectious Diseases, 4A18 HRIC, 3330 Hospital Dr. NW, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
Biochemical and Biophysical Research Communications
|April 3, 2009
Summary
Dendritic cells (DCs) overcome adenosine-mediated immune suppression by desensitizing their adenosine receptors. This allows DCs to activate fully during infection or tissue stress, bypassing inhibitory signals.
Area of Science:
- Immunology
- Cellular Signaling
Background:
- Adenosine signaling typically suppresses immune cell activation.
- Dendritic cells (DCs) are crucial for initiating immune responses.
- How DCs overcome adenosine-induced suppression remains unclear.
Purpose of the Study:
- To investigate the mechanism by which DCs bypass adenosine-mediated immune suppression.
- To understand how DCs achieve full activation in adenosine-rich environments.
Main Methods:
- In vivo and in vitro studies on resting-stage DCs.
- Analysis of adenosine receptor function and cAMP signaling pathways.
Main Results:
- Adenosine receptors on resting DCs become functionally desensitized after ligand binding.
- This desensitization persists for several hours, rendering DCs insensitive to adenosine.
- cAMP signaling mediates this desensitization process.
Conclusions:
- DCs possess a regulatory mechanism to overcome adenosine-mediated inhibition.
- Desensitization of adenosine receptors allows DCs to activate effectively during immune challenges.
- This finding elucidates a key process for robust immune responses in suppressive conditions.
Related Concept Videos
01:24B Cell Activation and Differentiation
The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
01:28Action Potential: Phases of Stimulation
The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
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...
01:21G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
01:22T Cell Activation and Clonal Selection
T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Naive T cells that have not yet encountered an antigen express two primary CD...
01:09GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...