Parasite-induced genetically driven autoimmune chagas disease

Mar 29, 2011

Researchers have shown that the Trypanosoma cruzi agent of Chagas Disease (CD) invades host embryo cells and spreads its mitochondrial DNA (kDNA) minicircles into the host's genome. Dr. Antonio Teixeira and associates at the University of Brasília, Brazil, inoculated virulent typanosomes in fertile chicken eggs and documented the heritability and fixation of the kDNA mutations in the chicks and their progeny. The results, published in the open-access journal PLoS Neglected Tropical Diseases on March 29th, show that kDNA-mutated chickens undergo genotype alterations, developing an inflammatory heart condition similar to Chagas disease in humans.

Chagas is one of the most lethal endemic infectious diseases in the Western Hemisphere, and although initially restricted to South America, it is now present in many parts of the world. This insect-born infection can also be transmitted from mother to child and via blood transfusion, and while acute infections are usually acquired in infancy or childhood, chronic Chagas disease kills many of those infected after they reach 40 years of age. The disease attacks the and is the most frequent cause of heart failure in endemic regions. While the treatment of Chagas disease with anti-trypanosomal nitroderivatives curtails the parasitic infection, it does not abrogate the destructive heart lesions which can lead to death.

An earlier study by Santos-Buch and Teixeira (1974) showed that immune lymphocytes from chagasic rabbits destroy embryo heart cells in vitro, and that this accelerated rejection of target cells occurred within 10 hours. Control, non-immune lymphocytes adhered to target heart cells 72 hours after incubation. Now, Dr Teixeira's research team describes the origin of the autoimmune rejection of the target in Chagas disease: "This chicken model was necessary to eliminate any residual active infection, because the birds are resistant to T. cruzi infection upon hatching. The kDNA-mutated chickens develop clinical signs of the heart disease and failure - their hearts are grossly enlarged and microscopic exams reveal that immune lymphocytes adhere to the target cells and lyses."

As Dr. Teixeira explains, this is "the first time that an autoimmune disease has been experimentally reproduced in an animal model, showing specific parasite induced kDNA modifications in coding regions of the host's ".

Explore further: Sierra Leone faces criticism over Ebola shutdown

More information: Teixeira ARL, Gomes C, Nitz N, Sousa AO, Alves RM, et al. (2011) Trypanosoma cruzi in the Chicken Model: Chagas-Like Heart Disease in the Absence of Parasitism. PLoS Negl Trop Dis 5(3): e1000. doi:10.1371/journal.pntd.0001000

add to favorites email to friend print save as pdf

Related Stories

Major breakthrough in the diagnosis of parasitic diseases

Apr 27, 2010

Montreal, April 27, 2010 - Chagas disease is one of the most deadly parasitic diseases in the world. It affects more than 10 million people, primarily in the Americas. In South America alone it kills 50 000 people each year. ...

Dogs may help collar Chagas disease

Jul 12, 2010

Chagas disease, for example, is caused by a parasite that roams with only limited control among the rural poor in Latin America. The main vector for the parasite Trypanosoma cruzi is the triatomine insect, or "kissing bug," ...

Parasite evades death by promoting host cell survival

Dec 08, 2009

Researchers have discovered how the parasite Trypanosoma cruzi, which causes Chagas' disease, prolongs its survival in infected cells. A protein on the parasite activates the enzyme Akt, which blocks cell ...

Recommended for you

Sierra Leone faces criticism over Ebola shutdown

1 hour ago

Sierra Leone began the second day of a 72-hour nationwide shutdown aimed at containing the spread of the deadly Ebola virus on Saturday amid criticism that the action was a poorly planned publicity stunt.

Presence of peers ups health workers' hand hygiene

16 hours ago

(HealthDay)—The presence of other health care workers improves hand hygiene adherence, according to a study published in the October issue of Infection Control and Hospital Epidemiology.

Sierra Leone streets deserted as shutdown begins

Sep 19, 2014

Sierra Leone's normally chaotic capital resembled a ghost town on Friday as residents were confined to their homes for the start of a three-day lockdown aimed at halting the deadly Ebola epidemic.

Sierra Leone launches controversial Ebola shutdown

Sep 19, 2014

Sierra Leone on Friday launched a controversial three-day shutdown to contain the deadly spread of the Ebola virus, as the UN Security Council declared the deadly outbreak a threat to world peace.

User comments : 0