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.