The virus, the human T lymphotropic virus type 1 (HTLV-1), is transmitted mainly when infected cells known as T lymphocytes, or T cells, touch uninfected T cells.
The finding helps explain how this cell-to-cell transmission happens. It suggests that an HTLV-1 protein known as p12 activates infected T cells and causes them to become sticky and adhere to other T cells.
The greater stickiness happens because the p12 viral protein causes special adherence proteins found on the surface of T cells to cluster in large groups – something that normally happens when T cells touch to communicate with one another during an immune response.
The findings also suggest that a drug that inhibits the p12 protein might also help prevent HTLV-1 transmission.
The research, published in the May issue of the Journal of Immunology, was led by scientists with The Ohio State University Comprehensive Cancer Center and the OSU College of Veterinary Medicine.
“This study indicates that the p12 protein plays an important role in programming infected cells for cell-to-cell transmission,” says principal investigator Michael D. Lairmore, professor and chair of veterinary biosciences and a member of the OSU Comprehensive Cancer Center.
“It shows that this virus takes advantage of something that T cells do normally, but, in this case, the virus is stimulating the interaction with other T cells rather than a normal immune response.”
HTLV-1 infects an estimated 15 to 25 million people worldwide. About 5 percent of those infected develop adult T cell leukemia or lymphoma (ATLL), an aggressive disease characterized by a long latent period and the proliferation of T cells. The infected cells are spread from person to person during sexual activity and by blood and breast milk.
In the body, the HTLV-1 mainly targets immune-system cells known as CD4 T lymphocytes. These immune cells coordinate immune responses in part through physical contact with other immune cells. The cells adhere to one another using a protein known as LFA-1, which is found on the cells’ surface.
In this study, Lairmore and his collaborators examined the influence of the p12 protein on LFA-1 adhesion. The researchers compared cells infected with HTLV-1 that lacked the p12 protein to cells that were infected by normal HTLV-1.
They found that the p12 protein not only activated the T cells, but caused the cells infected with normal HTLV-1 to have far greater adherence than cells infected with viruses that lacked p12 in a standardized adherence test.
In addition, they showed that the greater adherence did not occur because the infected cells made more of the LFA-1 protein, but rather because already existing LFA-1 protein molecules gathered into large clusters on the cell surface.
(LFA-1 proteins float in the cell membrane like buoys in semisolid gelatin. They can move across the surface of the cell and form clusters when directed to do so by signals from within the cell.)
“Our study is the first to show that HTLV-1 p12 not only enhances the activity of infected T cells, but that it promotes the spread of the virus from cell to cell by causing LFA-1 receptors to cluster on the cell surface,” Lairmore says.
Funding from the National Cancer Institute supported this research.
Darrell E. Ward | EurekAlert!
Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences