"This finding will have important implications in vaccine science and autoimmune disease therapy development," said Michael Gunn, M.D., an immunologist and cardiologist at Duke and senior author of the study published in Nature Immunology.
Type 1 helper (TH1) T cell immune responses are critical for the control of viruses and certain bacteria. Immunologists have generally believed that TH1 responses are induced by rare immune cells, called dendritic cells. When activated by infection or vaccination, the dendritic cells were thought to move from peripheral tissues into lymph nodes to stimulate T cell responses.
The Duke researchers found, however, that the dendritic cells that stimulate TH1 responses didn't come from peripheral tissues, but rather arose from monocytes, a common cell type in the blood, that moved directly into lymph nodes after infection.
"The result speaks to the most basic principles of immune response to pathogens," Gunn said. "It may also explain the poor results we have seen in attempts to develop effective dendritic-cell vaccines."
Gunn previously had identified a particular protein, known as a chemokine, that stimulates the migration of activated dendritic cells from peripheral tissues to lymph nodes. The Duke researchers generated a TH1 response in laboratory mice that lacked this chemokine with influenza viruses.
"We really thought the mice would not be able to generate much of an immune response at all," Gunn said, because they wouldn't be able to mobilize dendritic cells. "The mice, however, had increased TH1 responses. We knew we had to find what was really causing the response."
One scientist who knew about these findings told Gunn the Duke group would "never figure this out" because their findings were so unconventional.
To solve the mystery, the Duke team studied several different types of mice, which were missing other chemokines or chemokine receptors. They found that mice without the Ccr2 chemokine receptor that controls the migration of inflammatory monocytes had much lower accumulation of monocyte-derived dendritic cells and TH1 responses.
The scientists concluded that there is a blood-derived lymph node dendritic cell type that has a key role in developing acute T-cell responses. "For so long, dendritic cells from tissues were the obvious answer," Gunn said. "We found out that that's not always the case."
The team now plans to look at the blood-derived dendritic cells under different conditions to see if they may have other activities. "We observed the activity of these cells after TH1-inducing stimuli, like influenza," Gunn said. "Next we'd like to study other types of immune stimuli to see how the cells respond."
Understanding how dendritic cells stimulate different types of immune response would open the door to enhancing or inhibiting these responses, a major goal of immunologists trying to prevent infections or control autoimmune disease, Gunn said.
Mary Jane Gore | EurekAlert!
Further reports about: > Ccr2 chemokine receptor > Influenza > Nature Immunology > TH1 > autoimmune disease > autoimmune disease therapy development > dendritic cells > dendritic-cell vaccines > immune cell > immune response > immune system response > influenza virus > lymph node > monocytes > peripheral tissues > vaccine science
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy