A Silicon Rhodamine-fused Glibenclamide to Label and Detect Malaria-infected Red Blood Cells.

The malaria parasite Plasmodium falciparum affects the lives of millions of people worldwide every year. The detection of replicating parasites within human red blood cells is of paramount importance, requiring appropriate diagnostic tools. Herein, we design and apply a silicon rhodamine-fused glibenclamide (SiR-glib).

Novel secretory organelles of parasite origin - at the center of host-parasite interaction.

Reorganization of cell organelle-deprived host red blood cells by the apicomplexan malaria parasite Plasmodium falciparum enables their cytoadherence to endothelial cells that line the microvasculature. This increases the time red blood cells infected with mature developmental stages remain within selected organs such as the brain to avoid the spleen passage, which can lead to severe complications and cumulate in patient death. The Maurer's clefts are a novel secretory organelle of parasite origin established by the parasite in the cytoplasm of the host red blood cell in order to facilitate the establishment of cytoadherence by conducting the trafficking of immunovariant adhesins to the host cell surface.

Microscopic Evidence of Malaria Infection in Visceral Tissue from Medici Family, Italy.

Microscopy of mummified visceral tissue from a Medici family member in Italy identified a potential blood vessel containing erythrocytes. Giemsa staining, atomic force microscopy, and immunohistochemistry confirmed Plasmodium falciparum inside those erythrocytes. Our results indicate an ancient Mediterranean presence of P.

Cerebral Malaria and Neuronal Implications of Plasmodium Falciparum Infection: From Mechanisms to Advanced Models.

Reorganization of host red blood cells by the malaria parasite Plasmodium falciparum enables their sequestration via attachment to the microvasculature. This artificially increases the dwelling time of the infected red blood cells within inner organs such as the brain, which can lead to cerebral malaria. Cerebral malaria is the deadliest complication patients infected with P.

Visualization of Infected Red Blood Cell Surface Antigens by Fluorescence Microscopy.

Immunofluorescence labeling enables the detection and characterization of various parasite proteins presented on the surface of the infected red blood cell. Several approaches for immunofluorescence detection of red blood cell surface-presented proteins of Plasmodium spp. have been successfully established and published over the years.

KAHRP dynamically relocalizes to remodeled actin junctions and associates with knob spirals in Plasmodium falciparum-infected erythrocytes.

The knob-associated histidine-rich protein (KAHRP) plays a pivotal role in the pathophysiology of Plasmodium falciparum malaria by forming membrane protrusions in infected erythrocytes, which anchor parasite-encoded adhesins to the membrane skeleton. The resulting sequestration of parasitized erythrocytes in the microvasculature leads to severe disease. Despite KAHRP being an important virulence factor, its physical location within the membrane skeleton is still debated, as is its function in knob formation.

Mitochondrial Fission Governed by Drp1 Regulates Exogenous Fatty Acid Usage and Storage in Hela Cells.

In the presence of high abundance of exogenous fatty acids, cells either store fatty acids in lipid droplets or oxidize them in mitochondria. In this study, we aimed to explore a novel and direct role of mitochondrial fission in lipid homeostasis in HeLa cells. We observed the association between mitochondrial morphology and lipid droplet accumulation in response to high exogenous fatty acids.

Chemical Biology Tools To Investigate Malaria Parasites.

Parasitic diseases like malaria tropica have been shaping human evolution and history since the beginning of mankind. After infection, the response of the human host ranges from asymptomatic to severe and may culminate in death. Therefore, proper examination of the parasite's biology is pivotal to deciphering unique molecular, biochemical and cell biological processes, which in turn ensure the identification of treatment strategies, such as potent drug targets and vaccine candidates.

Palmitoylated Proteins in Plasmodium falciparum-Infected Erythrocytes: Investigation with Click Chemistry and Metabolic Labeling.

The examination of the complex cell biology of the human malaria parasite Plasmodium falciparum usually relies on the time-consuming generation of transgenic parasites. Here, metabolic labeling and click chemistry are employed as a fast transfection-independent method for the microscopic examination of protein S-palmitoylation, an important post-translational modification during the asexual intraerythrocytic replication of P. falciparum.

Diagnosis of Malaria Parasites Plasmodium spp. in Endemic Areas: Current Strategies for an Ancient Disease.

Fast and effective detection of the causative agent of malaria in humans, protozoan Plasmodium parasites, is of crucial importance for increasing the effectiveness of treatment and to control a devastating disease that affects millions of people living in endemic areas. The microscopic examination of Giemsa-stained blood films still remains the gold-standard in Plasmodium detection today. However, there is a high demand for alternative diagnostic methods that are simple, fast, highly sensitive, ideally do not rely on blood-drawing and can potentially be conducted by the patients themselves.

Evidence for vesicle-mediated antigen export by the human pathogen .

The apicomplexan parasite is the primary agent of human babesiosis, a malaria-like illness and potentially fatal tick-borne disease. Unlike its close relatives, the agents of human malaria, develops within human and mouse red blood cells in the absence of a parasitophorous vacuole, and its secreted antigens lack trafficking motifs found in malarial secreted antigens. Here, we show that after invasion of erythrocytes, undergoes a major morphogenic change during which it produces an interlacement of vesicles (IOV); the IOV system extends from the plasma membrane of the parasite into the cytoplasm of the host erythrocyte.

Establishment of a continuous culture of in human erythrocytes reveals unusually high tolerance to recommended therapies.

Human babesiosis is an emerging tick-borne disease caused by apicomplexan parasites of the genus Clinical cases caused by have been associated with high parasite burden, severe pathology, and death. In both mice and hamsters, the parasite causes uncontrolled fulminant infections, which ultimately lead to death. Resolving these infections requires knowledge of biology, virulence, and susceptibility to anti-infectives, but little is known and further research is hindered by a lack of relevant model systems.

Role of phospholipid synthesis in the development and differentiation of malaria parasites in the blood.

The life cycle of malaria parasites in both their mammalian host and mosquito vector consists of multiple developmental stages that ensure proper replication and progeny survival. The transition between these stages is fueled by nutrients scavenged from the host and fed into specialized metabolic pathways of the parasite. One such pathway is used by , which causes the most severe form of human malaria, to synthesize its major phospholipids, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine.

A novel physiological role for ARF1 in the formation of bidirectional tubules from the Golgi.

Capitalizing on CRISPR/Cas9 gene-editing techniques and super-resolution nanoscopy, we explore the role of the small GTPase ARF1 in mediating transport steps at the Golgi. Besides its well-established role in generating COPI vesicles, we find that ARF1 is also involved in the formation of long (∼3 µm), thin (∼110 nm diameter) tubular carriers. The anterograde and retrograde tubular carriers are both largely free of the classical Golgi coat proteins coatomer (COPI) and clathrin.

Hemoglobin S and C affect protein export in Plasmodium falciparum-infected erythrocytes.

Malaria is a potentially deadly disease. However, not every infected person develops severe symptoms. Some people are protected by naturally occurring mechanisms that frequently involve inheritable modifications in their hemoglobin.

Haemoglobin S and C affect the motion of Maurer's clefts in Plasmodium falciparum-infected erythrocytes.

The haemoglobinopathies S and C protect carriers from severe Plasmodium falciparum malaria. We have recently shown that haemoglobin S and C interfere with host-actin remodelling in parasitized erythrocytes and the generation of an actin network that seems to be required for vesicular protein trafficking from the Maurer's clefts (a parasite-derived intermediary protein secretory organelle) to the erythrocyte surface. Here we show that the actin network exerts skeletal functions by anchoring the Maurer's clefts within the erythrocyte cytoplasm.

Hemoglobins S and C interfere with actin remodeling in Plasmodium falciparum-infected erythrocytes.

The hemoglobins S and C protect carriers from severe Plasmodium falciparum malaria. Here, we found that these hemoglobinopathies affected the trafficking system that directs parasite-encoded proteins to the surface of infected erythrocytes. Cryoelectron tomography revealed that the parasite generated a host-derived actin cytoskeleton within the cytoplasm of wild-type red blood cells that connected the Maurer's clefts with the host cell membrane and to which transport vesicles were attached.

3-D analysis of the Plasmodium falciparum Maurer's clefts using different electron tomographic approaches.

The human malaria parasite Plasmodium falciparum exports a large number of proteins into its host erythrocyte to install functions necessary for parasite survival. Important structural components of the export machinery are membrane profiles of parasite origin, termed Maurer's clefts. These profiles span much of the distance between the parasite and the host cell periphery and are believed to deliver P.