Efficient oral vaccination by bioengineering virus-like particles with protozoan surface proteins

Intestinal and free-living protozoa, such as Giardia lamblia , express a dense coat of variant-specific surface proteins (VSPs) on trophozoites that protects the parasite inside the host’s intestine. Here we show that VSPs not only are resistant to proteolytic digestion and extreme pH and temperatures but also stimulate host innate immune responses in a TLR-4 dependent manner. We show that these properties can be exploited to both protect and...