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NEWS
June 2023 ESRFnews
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Parasite s defences revealed Small-angle X-ray scattering (SAXS) at the ESRF s BM29 beamline has helped researchers from the Czech Republic to confirm the structures of a complex involving the human parasite Trypanosoma brucei gambiense, which causes sleeping sickness. The structures could help scientists understand how the parasite escapes immune response at early stages of infection.
While most pathogens find ways to avoid the immune system by seeking cells or less accessible tissues, African
trypanosomes hide in plain sight, proliferating within the human blood stream. Their trick is to deploy a range of countermeasures to avoid clearance from the cardio-vascular system, many mechanisms of which have been identified and described in detail. According to Sebastian Zoll and colleagues at the Czech Academy of Sciences in Prague, however, an understanding of other innate immune defence mechanisms, particularly during the early stage of infection, is incomplete.
Zoll s group employed an integrative approach, including cryo-EM (at the Central European Institute of Technology in Brno, in the Czech Republic) and SAXS at BM29, to determine structures of the surface receptor of T. b. gambiense in complex with C3, the central hub of the human complement system, in different conformations. The researchers found that the interaction between C3 and the invariant surface glycoprotein 65 from the parasite is inhibitory and highly specific, in a such a way as to provide a tailored and efficient immune defence (Nat. Commun. 14 2403).
Nature Portfolio highlights EBS design
Communications Physics, a journal in the Nature Portfolio, has published a paper on the ESRF s Extremely Brilliant Source (EBS) that discusses the upgrade s design as an inspiration for a new generation of high-energy synchrotrons around the world. Authored by more than 40 ESRF engineers and scientists, the reference article reports in detail the key aspects of the EBS which was invented by Pantaleo Raimondi, and developed by Raimondi and the ESRF Beam Dynamics Group from the conception of the novel
hybrid multi-bend achromat (HMBA) storage ring to its successful commissioning and operation. It highlights the innovative aspects of the HMBA design compared to previous designs, reports on the significant improvements in key beam parameters and demonstrates how, nearly three years after the start of operation, the ESRF EBS extends the reach of synchrotron X-ray science with the first exciting scientific results confirming the HMBA concept for facility upgrades and new constructions (Commun. Phys. 6 82).
Endometriosis linked to toxic metals
Researchers from the Institute for Maternal and Child Health IRCCS Burlo Garofolo in Trieste, Italy, have found a link between iron presence in endometriosis and the accumulation of environmental metals. The study suggests that exposure to toxic chemicals in the environment plays a role in the disease.
Around 1 in 10 women of reproductive age live with endometriosis, an inflammatory disease caused when tissue similar to the uterus lining grows outside the womb. As iron deposits are known to be common in endometrial lesions, Lorella Pascolo and colleagues from the IRCCS came to the ESRF to compare iron nanoaggregates in samples of endometrial lesions and healthy endometrium. They used X-ray fluorescence (XRF) at the ID21 beamline to track the presence and distribution of iron and environmental pollutants, and ID16B to fine-tune the findings and reveal additional heavy metals at the nanoscale. They also used X-ray spectroscopy to reveal the chemical state of the iron. The ESRF beamlines are exceptional instruments to get a clear picture of the role of iron and how it transforms into endometrial lesions, says Pascolo.
The XRF showed that, when endometriosis affects the ovaries, excess iron is not only close to endometrial cysts, but also spreads into other areas of the ovarian tissue. In the areas where the iron concentration is higher, there are also traces of lead, aluminium, titanium, bromine, chromium, silicon and rubidium. Some of these metals are metalloestrogens , which mimic the effects of the hormone oestrogen. The presence of these toxic elements where the iron is more prevalent suggests that they may influence at least the progression of the pathology, says Pascolo.
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Sleeping sickness is caused by a parasite carried by the Tsetse fly.
Like the original ESRF source did in the 1990s, the EBS today is blazing a new path for synchrotron science.
