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!
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy