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schistosome

Parasite-derived molecule could accelerate recovery from UTI

schistosome

Eggs from S. haematobium may produce the molecule IPSE to reduce the immune response against them, which happens to dampen UTI-induced bladder inflammation.

IPSE, a urogenital parasite-derived immunomodulatory molecule, can suppress bladder pathogenesis and anti-microbial peptide gene expression in bacterial urinary tract infection (UTI) according to a new study led by Michael Hsieh, Ph.D., director of Transitional Urology at Children’s National Hospital.

Half of all girls and women, and about 5% of boys and men, will have at least one urinary tract infection (UTI) in their lifetimes.

“Although antibiotics are very helpful for these infections, there are concerns that overuse of antibiotics may contribute to antibiotic-resistant infections,” Dr. Hsieh said. “There are also concerns that antibiotic therapy for UTI does not uniformly resolve infection-induced or inflammation-associated symptoms quickly.”

Parasitic infections are often associated with bacterial co-infections for unclear reasons. This may be true for urogenital schistosomiasis (caused by Schistosoma haematobium infection) and bacterial urinary tract co-infection (UTI), the study noted. Dr. Hsieh and other leading experts previously reported that this co-infection is facilitated by S. haematobium eggs triggering interleukin-4 (IL-4) production and sought to dissect the underlying mechanisms.

“Despite S. haematobium’s ability to make hosts more susceptible to UTI, we have identified IPSE, a bladder parasite protein, as a potential anti-inflammatory agent to accelerate recovery from UTI,” Dr. Hsieh explained. “S. haematobium eggs may produce IPSE to reduce the immune response against them, which happens to dampen UTI-induced bladder inflammation. It may be possible to develop IPSE as novel therapeutic to accelerate recovery from UTI.”

The study’s data showed that IPSE may play a major role in S. haematobium-associated urinary tract co-infection, although in an unexpected way. The study’s findings also indicated that IPSE either works in concert with other IL-4 -inducing factors to increase susceptibility of S. haematobium-infected hosts to bacterial co-infection or does not contribute to enchaining vulnerability to this co-infection.

You can find the full study published in Parasites and Vectors. Learn more about the Children’s National Department of Urology.

Schistosoma

Parasitic eggs trigger upregulation in genes associated with inflammation

Schistosoma

Of the 200 million people around the globe infected with Schistosomiasis, about 100 million of them were sickened by the parasite Schistosoma haematobium.

Of the 200 million people around the globe infected with Schistosomiasis, about 100 million of them were sickened by the parasite Schistosoma haematobium. As the body reacts to millions of eggs laid by the blood flukes, people can develop fever, cough and abdominal pain, according to the Centers for Disease Control and Prevention. Schistosomiasis triggered by S. haematobium can also include hematuria, bladder calcification and bladder cancer.

Despite the prevalence of this disease, there are few experimental models specifically designed to study it, and some tried-and-true preclinical models don’t display the full array of symptoms seen in humans. It’s also unclear how S. haematobium eggs deposited in the host bladder modulate local tissue gene expression.

To better understand the interplay between the parasite and its human host, a team led by Children’s National Hospital injected 6,000 S. haematobium eggs into the bladder wall of seven-week-old experimental models.

After four days, they isolated RNA for analysis, comparing differences in gene expression in various treatment groups, including those that had received the egg injection and experimental models whose bladders were not exposed to surgical intervention.

Using the Database for Annotation, Visualization and Integrated Discovery (DAVID) – a tool that helps researchers understand the biological meaning of a long list of genes – the team identified commonalities with other pathways, including malaria, rheumatoid arthritis and the p53 signaling pathway, the team recently presented during the American Society of Tropical Medicine and Hygiene 2019 annual meeting. Some 325 genes were differentially expressed, including 34 genes in common with previous microarray data.

“Of particular importance, we found upregulation in genes associated with inflammation and fibrosis. We also now know that the body may send it strongest response on the first day it encounters a bolus of eggs,” says Michael Hsieh, M.D., Ph.D., director of transitional urology at Children’s National, and the research project’s senior author. “Next, we need to repeat these experiments and further narrow the list of candidate genes to key genes associated with immunomodulation and bladder cancer.”

In addition to Dr. Hsieh, presentation co-authors include Lead Author Kenji Ishida, Children’s National; Evaristus Mbanefo and Nirad Banskota, National Institutes of Health; James Cody, Vigene Biosciences; Loc Le, Texas Tech University; and Neil Young, University of Melbourne.

Financial support for research described in this post was provided by the National Institutes of Health under award No. R01-DK113504.

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Schistosoma haematobium egg

For hemorrhagic cystitis, harnessing the power of a parasite

Schistosoma haematobium egg

“Urogenital Schistosoma infestation, which is caused by S. haematobium, also causes hemorrhagic cystitis, likely by triggering inflammation when the parasite’s eggs are deposited in the bladder wall or as eggs pass from the bladder into the urinary stream. S. haematobium eggs secrete proteins, including IPSE, that ensure human hosts are not so sickened that they succumb to hemorrhagic cystitis,” says Michael H. Hsieh, M.D., Ph.D.

Every year, hundreds of thousands of U.S. patients – and even more throughout the world – are prescribed cyclophosphamide or ifosfamide. These two chemotherapy drugs can be life-saving for a wide range of pediatric cancers, including leukemias and cancers of the eyes and nerves. However, these therapies come with a serious side effect: Both cause hemorrhagic cystitis in up to 40 percent of patients. This debilitating condition is characterized by severe inflammation in the bladder that can cause tremendous pain, life-threatening bleeding, and frequent and urgent urination.

Infection with a parasitic worm called Schistosoma haematobium also causes hemorrhagic cystitis, but this organism has a fail-safe: To keep its host alive, the parasite secretes a protein that suppresses inflammation and the associated pain and bleeding.

In a new study, a Children’s-led research team harnessed this protein to serve as a new therapy for chemotherapy-induced hemorrhagic cystitis.

“Urogenital Schistosoma infestation, which is caused by S. haematobium, also causes hemorrhagic cystitis, likely by triggering inflammation when the parasite’s eggs are deposited in the bladder wall or as eggs pass from the bladder into the urinary stream. S. haematobium eggs secrete proteins, including IPSE, that ensure human hosts are not so sickened that they succumb to hemorrhagic cystitis,” says Michael H. Hsieh, M.D., Ph.D., senior author of the study published April 3, 2018, by The FASEB Journal. “This work in an experimental model is the first published report of exploiting an uropathogen-derived host modulatory molecule in a clinically relevant model of bladder disease, and it points to the potential utility of this as an alternate treatment approach.”

S. mansoni IPSE binds to Immunoglobulin E (IgE), an antibody produced by the immune system that is expressed on the surface of basophils, a type of immune cell; and mast cells, another immune cell that mediates inflammation; and sequesters chemokines, signaling proteins that alert white cells to infection sites. The team produced an ortholog of the uropathogen-derived protein. A single IV dose proved superior to multiple doses of 2-Mercaptoethane sulfonate sodium (MESNA), the current standard of care, in suppressing chemotherapy-induced bladder hemorrhaging in an experimental model. It was equally potent as MESNA in dampening chemotherapy-induced pain, the research team finds.

“The current array of medicines we use to treat hemorrhagic cystitis all have shortcomings, so there is a definite need for novel therapeutic options,” says Dr. Hsieh, a Children’s National Health System urologist. “And other ongoing research projects have the potential to further expand patients’ treatment options by leveraging other urogenital parasite-derived, immune-modulating molecules to treat inflammatory bowel diseases and autoimmune disorders.”

Future research will aim to describe the precise molecular mechanisms of action, as well as to generate other orthologs that boost efficacy while reducing side effects.

In addition to Dr. Hsieh, Children’s study co-authors include Lead Author, Evaristus C. Mbanefo; Loc Le and Luke F. Pennington; Justin I. Odegaard and Theodore S. Jardetzky, Stanford University; Abdulaziz Alouffi, King Abdulaziz City for Science and Technology; and Franco H. Falcone, University of Nottingham.

Financial support for this research was provided by National Institutes of Health under award number RO1-DK113504.