Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Radioimmunotherapy: Promising treatment for HIV infection and viral cancers

17.02.2009
Novel therapy presented in featured lecture at AAAS Annual Meeting

Scientists at Albert Einstein College of Medicine of Yeshiva University have piggybacked antibodies onto radioactive payloads to deliver doses of radiation that selectively target and destroy microbial and HIV-infected cells.

The experimental treatment — called radioimmunotherapy, or RIT — holds promise for treating various infectious diseases, including HIV and cancers caused by viruses. The research was presented today at the annual meeting of the American Association for the Advancement of Science (AAAS), the world's largest general scientific society and the publishers of the journal Science.

The talk, part of the AAAS Topical Lecture Series, was delivered by Ekaterina Dadachova, Ph.D., a leading RIT researcher at Einstein. Dr. Dadachova is the Olnick Faculty Scholar in Cancer Research, as well as an associate professor of nuclear medicine and of microbiology & immunology at the College of Medicine.

RIT, which is currently used in cancer treatment, capitalizes on the fact that each type of antibody is programmed to seek out just one type of antigen in the body. Thus, by attaching radioactive material to a particular antibody, radiation can be targeted at specific cells that express the corresponding antigen, minimizing collateral damage to other tissues. This level of specificity is not possible with existing forms of radiation therapy.

RIT was originally developed as a therapy for cancer treatment and has been the most successful so far in treatment of non-Hodgkin lymphoma, a cancer that originates in cells of the immune system. Over the last few years, in collaboration with Dr. Arturo Casadevall, Chair and Forchheimer Professor of Microbiology & Immunology at Einstein, Dr. Dadachova has adapted the technique for fighting fungal, bacterial, and viral infections. Drs. Dadachova and Casadevall performed these studies in conjunction with scientists at Einstein and NYU, and at the European Commission Joint Research Centre; the latter of which supplied some of the important radionuclides for arming the antibodies.

Since viruses are quite different from cancer cells, devising radioimmunotherapy for HIV posed significant challenges. Viruses are tiny bits of DNA or RNA wrapped in a thin protein coat. Simple, tough, and resilient, viruses easily shrug off radiation directed at them and can readily repair any damage that might occur. Complicating matters, HIV can hide in immune cells keeping the virus beyond the reach of antibodies.

"Our approach is not to target the virus particles themselves, but rather lymphocytes that harbor the virus," says Dr. Dadachova. "Fortunately, lymphocytes are among the most radiosensitive cells in the body."

The RIT devised by Einstein researchers consists of an antibody for glycoprotein 41 (gp41) and a radioactive isotope called Bismuth-213, bound together with a special molecule known as a ligand. The gp41 antibody was selected because its corresponding gp41 antigen is reliably expressed on the surface of cells infected with HIV. In addition, unlike other HIV-related glycoproteins, gp41 antigen usually is not shed into the bloodstream, which would lead many of radioactive-labeled antibodies to miss their target. Bismuth-213 was chosen because of several characteristics, including a half-life, or decay rate, of 46 minutes. Such a short half-life rate allows just enough time for the treatment to be administered and for the radioactive antibodies to do their job. After four hours, Bismuth-213 radioactivity falls to negligible levels.

Drs. Dadachova and Casadevall and their colleagues have demonstrated that the treatment can effectively eliminate HIV-infected human cells in both laboratory and animal studies, the latter involving two different models of mice with HIV. The team is now conducting pre-clinical testing of the therapy's efficacy and safety in preparation for a Phase I clinical trial in HIV-infected patients.

RIT also has potential as a therapy for cancers that are preceded by viral infections, such as cervical cancer (certain forms of which are associated with human papilloma virus) and hepatocellular carcinoma (associated with hepatitis B virus). Such cancers account for almost a quarter of all cancers. "Many virus-associated cancer cells continue to express viral antigens," Dr. Dadachova explains. "As these antigens are not found anywhere else in the body, RIT of viral cancers promises exquisite specificity of treatment and very low toxicity to the patient."

Michael Heller | EurekAlert!
Further information:
http://www.aecom.yu.edu

More articles from Health and Medicine:

nachricht Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin

nachricht Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Turmoil in sluggish electrons’ existence

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...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

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...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>