Tag Archives: vaccine

How To Make Cells Immune To HIV

Some viruses, no matter how hard we try, remain resistant to vaccines. Now, researchers are using a different method, gene editing, as a way to make cells immune to mankind’s most difficult viruses. Led by Dr. Justin Taylor, a team at the Fred Hutchinson Cancer Research Center has targeted four infections for which there’s no protective vaccine: HIV, influenza, the Epstein-Barr virus (EBV) and respiratory syncytial virus (RSV).

The researchers used CRISPR/Cas9 technology to modify B cells, a class of white blood cells that produce antibodies to protect us from diseases. By coding the cells with genes that create specific antibodies, the team was able to make them immune without the use of a vaccine.

The researchers tested the method in both human cells in a test tube and in living mice. On average, about 30 percent of the cells produced the desired antibody. Taylor said that the mice remained protected for 83 days following the procedure, an important benchmark given that patients who receive stem cell transplants can have weakened immune systems for three to six months. To be clear, Taylor doesn’t have anything against traditional vaccination. “Vaccines are great,” he said. “I wish we had more of them.”

Instead, Taylor thinks the gene editing method could work one day for diseases where we don’t have a vaccine. It may help patients who are immuno-compromised, meaning their bodies can no longer fight infections, as well as older patients whose bodies aren’t as receptive to vaccines. Gene-edited immunity might also be used to protect people faster than can be done with traditional vaccines, which could be useful during unexpected outbreaks.

Taylor’s team included Fred Hutch researchers and co-authors Howell Moffett, Carson Harms, Kristin Fitzpatrick, Marti Tooley and Jim Boonyaratanakornkit. The results will be published in the journal Science Immunology.

Source: https://www.fredhutch.org/
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Micromotors Deliver Oral Vaccines

Researchers are working on new generations of oral vaccines for infectious diseases. But to be effective, oral vaccines must survive digestion and reach immune cells within the intestinal wall. As a step in this direction, UC San Diego nanoengineering researchers have developed oral vaccines powered by micromotors that target the mucus layer of the intestine.

The work appears in the ACS journal Nano Letters. It’s a collaboration between the labs of nanoengineering professors Joseph Wang and Liangfang Zhang at the UC San Diego Jacobs School of Engineering.

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The lack of needles is one reason oral vaccines are attractive. Another reason: oral vaccines can generate a broad immune response by stimulating immune cells within the mucus layer of the intestine to produce a special class of antibody called immunoglobulin A (IgA). The NanoLetters paper documents the team’s efforts to use magnesium particles as tiny motors to deliver an oral vaccine against the bacterial pathogen Staphylococcus aureus. When coated over most of their surfaces with titanium dioxide, magnesium microparticles use water as fuel to generate hydrogen bubbles that power their propulsion.

To develop the oral vaccine, the researchers coated magnesium micromotors with red blood cell membranes that displayed the Staphylococcal α-toxin, along with a layer of chitosan to help them stick to the intestinal mucus. Then, they added an enteric coating that protects drugs from the acidic conditions of the stomach.

The micromotors safely passed through the stomach to the intestine, at which point the enteric coating dissolved, activating the motors. Imaging of mice that had been given the vaccine showed that the micromotors accumulated in the intestinal wall much better than non-motorized particles. The micromotors also stimulated the production of about ten times more IgA antibodies against the Staphylococcal α-toxin than the static particles.

Source: http://jacobsschool.ucsd.edu/