Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Biological Chemistry

Vaccines Using Toxin-Absorbing Nanosponges

Researchers leverage the cell-membrane affinity of a bacterium-secreted toxin to make a live vaccine based on coated nanoparticles

by
December 9, 2013 | A version of this story appeared in Volume 91, Issue 49

[+]Enlarge
Credit: Adapted from Nat. Nanotechnol.
This schematic depicts a nanoparticle vaccine with α-hemolysin a pore-forming toxin of methicillin-resistant Staphylococcus aureus, embedded in a red blood cell membrane coating.
This schematic shows a nanoparticle vaccine with a toxin embedded into a red blood cell-derived membrane.
Credit: Adapted from Nat. Nanotechnol.
This schematic depicts a nanoparticle vaccine with α-hemolysin a pore-forming toxin of methicillin-resistant Staphylococcus aureus, embedded in a red blood cell membrane coating.

As vaccines against infectious diseases, nanoparticles with coatings that soak up unaltered bacterial protein toxins like a sponge could be more effective than heat-deactivated toxins, according to a report by Liangfang Zhang and coworkers at the University of California, San Diego (Nat. Nanotechnol. 2013, DOI: 10.1038/nnano.2013.254). Some bacterial toxins operate by embedding themselves in cell membranes, creating pores that leak cellular contents. Heating the toxins denatures them, thereby reducing their toxicity, but it also potentially reduces a vaccine’s effectiveness in stimulating the immune system to produce antibodies. Zhang’s team leveraged one bacterial toxin’s affinity for cell membranes to make a vaccine containing the unaltered toxin. The researchers coated plastic nanoparticles with red blood cell membranes embedded with α-hemolysin, a red-blood-cell-puncturing protein secreted by methicillin-resistant Staphylococcus aureus. Mice receiving the coated nanoparticles made more anti­bodies than mice receiving heat-treated α-hemolysin alone. Also, more mice receiving the nanoparticles survived direct injection of α-hemolysin. The nanoparticle membranes showed no sign of releasing the pore-forming toxins, which would be a problem in vaccines that use an unaltered toxin. The researchers say they could adapt the nanoparticles for toxins made by other bacteria.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.