Understanding Cerebral Malaria using 3D Blood-Brain Barrier models

Projektinformationen

Mal3D-BBB

ID Finanzhilfevereinbarung: 948088

DOI

10.3030/948088

EK-Unterschriftsdatum 29 Oktober 2020

Startdatum 1 Mai 2021

Enddatum 30 April 2027

Finanziert unter

• EXCELLENT SCIENCE - European Research Council (ERC)

Gesamtkosten

€ 1 492 900,00

EU-Beitrag

€ 1 492 900,00

Koordiniert durch

EUROPEAN MOLECULAR BIOLOGY LABORATORY
Germany

Periodic Reporting for period 3 - Mal3D-BBB (Understanding Cerebral Malaria using 3D Blood-Brain Barrier models)

Berichtszeitraum: 2024-05-01 bis 2025-10-31

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

The blood-brain barrier (BBB) acts as a protective layer between blood vessels and the brain. This barrier is selective for nutrients, and prevents the entry of harmful pathogens and molecules to the brain. When damaged, it can lead to the leakage of toxins and infectious agents, causing severe and fatal consequences. Additionally, the impermeability of the BBB hinders the entry of drugs and treatments into the brain during brain damage. Opening or closing this barrier at will poses one of the most significant challenges in the pharmaceutical field. Establishing a 3D-BBB model in the lab is crucial, as it could provide insights into its function and contribute to the development of treatments that improve outcomes for brain diseases.

Malaria is one of the important infectious diseases affecting the brain. Cerebral malaria, a severe consequence of malaria infections, contributes to the majority of malaria-related deaths worldwide. In regions with high malaria transmission, it predominantly affects children under 10 years old, and in areas with low transmission, such as South and South East Asia or South America, it can also impact adults. Despite more than 100 years of knowledge about cerebral malaria, we still don't fully understand the causes of this complication. Improved treatments for this disease have the potential to prevent hundreds of thousands of deaths annually.

The primary goal of Mal3D-BBB is to develop 3D-BBB models to gain a better understanding of cerebral malaria. By introducing malaria parasites and human immune cells, we aim to identify the causative agent of this complication and pinpoint the disrupted molecular pathways in affected patients. We will validate whether the mechanisms discovered in the lab are also present in samples from cerebral malaria patients. This knowledge will contribute to the development of treatments that, when combined with antimalarials, can prevent patient deaths and reduce the likelihood of long-term neurological consequences.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

Our research focuses on developing and studying a 3D-BBB model. This model is made of a collagen gel and it contains a complex network of blood vessels, each as thin as a human hair. The BBB consists of three main cell types: endothelial cells lining the blood vessels, pericytes providing support and wrapping the blood vessels, and astrocytes connecting the blood vessels with other brain cell types. We've made different versions of this model. The first one involves human endothelial cells covered by pericytes. The second model adds astrocytes to the mix. These models show improved barrier permeability, but they do not reach BBB barrier levels yet. To get there, we are working on models where endothelial cells come from adult pluripotent stem cells. Our preliminary findings show that these models maintain brain endothelial identity and have physiological barrier values.

We are using these models to figure out how the human malaria parasite Plasmodium falciparum might affect the BBB. We are evaluating whether intact infected red blood cells or parasite products released during each cycle can harm the 3D brain microvessels we have created. We're using advance confocal fluorescent and electron microscopy, along with single-cell RNA sequencing, to understand which cells are affected and what molecular mechanisms are at play. We have seen that most of the disruption happens in endothelial cells, the first layer of the barrier. But interestingly, malaria products manage to cross the BBB and affect other brain cells.

We are also exploring whether our immune system could be causing some of this damage. The first response from immune cells, known as the innate immune response, is quite powerful. While it can effectively combat pathogens, it might also accidentally damage nearby tissue. We are adding various human immune cell types like platelets, neutrophils, and leukocytes to our model. Our early findings suggest that, in some cases, the innate immune system might cause damage equal to or even greater than the human malaria parasite P. falciparum.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

We are pioneering innovative methods to grow brain blood vessels in the lab and understand the BBB in health and disease. Leveraging our expertise in studying infections and building tissues, we are developing advanced models to address fundamental questions about how brain blood vessels respond to pathogens. Our goal is to develop a lab-based model that not only mimics brain blood vessel barrier function, but also includes other factors important for tissue response to infection and inflammation. While our current models are being used to study malaria, the approach can be adapted to understand and model other brain diseases or used in the pre-clinical testing of drugs that target the brain or its blood vessels.

Secondly, we're about to reveal groundbreaking discoveries of the processes that cause cerebral malaria. We are first focused in disease mechanisms driven by the malaria parasite P. falciparum. These processes cannot be studied in mouse models, as the pathogenic mechanism of P. falciparum is different from rodent malaria parasites. We are leveraging complex lab-based models to delve into the intricate molecular processes that lead to the disruption of the brain barrier during cerebral malaria. While many research groups focus on the first layer of the barrier -endothelial cells- we take a holistic approach, examining the entire BBB as a whole, and including other brain cell types such as astrocytes

Lastly, recent studies on the brains of children who succumbed to cerebral malaria have highlighted the role of the immune system in disease. Traditionally, the role of the immune response in cerebral malaria has been studied in animal models, but our unique system offers a more physiological way to understand how the combination of parasites and the immune system influence blood vessel function.