by Donna Huber
Vaccines can be an efficient and cost-effective method of preventing and treating pathogen-induced illnesses. As new pathogens appear and old pathogens re-emerge, improved vaccines are needed. For one emerging global disease, Chagas Disease, effective vaccine development has long been elusive. Now, Rick Tarleton, Regents’ Professor in the department of cellular biology, and former graduate student Sam Kurup have received a patent for a vaccine method that improves efficacy. Even more promising, it can be used to develop vaccines for a variety of pathogens.
Chagas Disease, caused by the parasite Trypanosoma cruzi and spread by blood-feeding insects commonly known as “kissing bugs”, is endemic to the Americas, including the U.S. The infection can result in irreparable damage to the heart and digestive system, and in Central and South America, it kills more than 50,000 people each year.
Tarleton and Kurup found that vaccines consisting of parasites that have been genetically modified to produce stronger pathogen-associated molecular patterns, or PAMPs, increase the immune response of the host. PAMPs are molecules associated with the pathogen that are recognized by the immune system. T. cruzi does not naturally produce strong PAMPs.
In mice vaccinated with transgenic T. cruzi expressing potent bacterial PAMPs, they saw a superior immune response and a more rapid and persistently stronger acquired immune response. Furthermore, in chronically infected mice, they also saw a boost in immune response and a reduction in parasite load. This is good news as presently available treatments are not completely effective and often have severe side effects.
The inability of classical adjuvants to induce innate immunity and to generate a long-lasting T-cell response in T. cruzi infection has been a hurdle in the development of T-cell-based vaccines. Using PAMPs-modified attenuated vaccines may be an ingredient for preventing and treating this and other pathogenic illnesses.