Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Keeping the immune system on track

Specialized motor proteins help control immune activation by physically hauling clusters of signaling receptors to a central site for eventual disposal

Specialized immune cells called T cells can recognize threats and induce immune responses through T cell receptors (TCRs), but these receptors do not act alone. Multiple receptors gather together at the cell surface to cooperatively switch on T cells. “The minimum unit for triggering T lymphocyte activation is known as the TCR microcluster [TCR-MC],” explains Takashi Saito of the RIKEN Research Center for Allergy and Immunology in Yokohama. “These are the key structure for T cells to recognize antigens and become activated.”

The immune system in action
Copyright : TimVickers

At the interface between T cells and the antigen-presenting immune cells that switch them on, TCR-MCs accumulate at a structure called the central supramolecular activation cluster (cSMAC). Now, research from Saito and colleagues has revealed unexpected insights into how this accumulation occurs.

Saito and his team were the first to characterize TCR-MC function2, but they were uncertain how these clusters make their way from the periphery to the core of the cSMAC. To understand this phenomenon, they performed a series of experiments in which T cells were placed on an artificial lipid layer that mimics the membrane of an antigen-presenting cell, allowing them to microscopically visualize activation-related events at the T cell surface.

Cellular structures are reinforced by protein fibers that form a network called the cytoskeleton, and Saito and colleagues revealed that TCR-MC movement is mediated by dynein, a ‘motor protein’ that shuttles cargos along these fibers. “We knew lymphocyte activation was regulated through the cytoskeleton,” he says. “But it was most surprising that TCR complexes are physically associated with dynein and that their movement is mediated by assembling with this complex.”

Upon TCR activation, the dynein-facilitated movement drags TCR-MCs laterally along the surface of the membrane towards the cSMAC, a function previously unseen for this motor protein. Pharmacological inhibition of dynein strongly impaired migration of TCR-MCs and undermined their assembly within the cSMAC, as did the selective reduction of a key subunit of the dynein complex.

Intriguingly, the same treatments that impaired TCR-MC migration also enhanced T cell activation. Saito and colleagues therefore concluded that once these clusters reach the center of the cSMAC, they become internalized within the cell and thereby taken out of action. Saito hopes to exploit this effect by learning how the TCR-MC-dynein complex is assembled. “It would be ideal if we had a specific inhibitor of this assembly,” he says, “which could lead to stronger immune status with enhanced activation of T cells.”

The corresponding author for this highlight is based at the Laboratory for Cell Signaling, RIKEN Research Center for Allergy and Immunology

gro-pr | Research asia research news
Further information:

Further reports about: Allergy RIKEN T cells TCR TCR-MC cell surface immune cell motor protein

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>