海角社区

Degrees

BSc (海角社区)
MSc equivalent (Diplom) (Ruprecht-Karls-University Heidelberg, Germany)
PhD equivalent (Dr. rer. nat.) (German Cancer Research Centre, Heidelberg, Germany)
Habilitation, venia legendi (Heidelberg University School of Medicine, Germany)

Short Bio

Petra Rohrbach obtained her PhD from the University of Heidelberg at the German Cancer Research Centre (Germany) in 2000, after completing her BSc at 海角社区. She continued her studies as a postdoctoral researcher at the Centre for Infectious Diseases, Heidelberg University School of Medicine (Germany), where she obtained her habilitation early 2008. In the Fall of 2008, she joined 海角社区 as an Assistant Professor at the Institute of Parasitology and was granted tenure and Associate Professor in 2014. She currently serves as Research Ambassador for the German Academic Exchange Service (DAAD) and is a Visiting Professor at the University of Erlangen-Nuremberg, Germany.

Awards and Recognitions

CFI-LOF Leaders Opportunity Fund Award (2010)
Visiting Professor, Friedrich-Alexander University of Erlangen-Nuremberg, Germany

Active Affiliations

President, Canadian Society for Extracellular Vesicles (CanSEV) [
Associate Member, Department of Microbiology and Immunology, 海角社区
Member, 海角社区 Interdisciplinary Initiative in Infection and Immunity: M[i]⁴ [
Research Ambassador for the German Academic Exchange Service (DAAD)
Chair, Heidelberg Alumni Association in Montreal

Research Interests

Malaria remains a critical global health challenge, causing millions of clinical episodes and hundreds of thousands of deaths annually. The human malaria parasite Plasmodium falciparum is a single-celled microorganism with a complex life cycle that includes stages in both human hepatocytes and red blood cells (RBCs). A significant portion of its lifecycle occurs within RBCs, which are primarily composed of hemoglobin and lack nuclei and organelles. The parasite's invasion and subsequent modification of RBCs are essential for its survival and pathogenicity.

During its development within RBCs, the parasite relies on a specialized acidic organelle called the digestive vacuole (DV). This organelle is critical for hemoglobin degradation, providing amino acids for growth, and managing other essential functions such as detoxification, ion homeostasis, and nutrient transport. Key transporters located on the DV membrane, including the multidrug resistance transporter PfMDR1 and the chloroquine resistance transporter PfCRT, play vital roles in these processes and are central to drug resistance mechanisms. Despite their significance, the molecular functions of these transporters remain poorly understood. Our research seeks to unravel the underlying biology of the DV and elucidate the mechanisms of drug resistance using cutting-edge imaging techniques tailored to P. falciparum.

In addition, we investigate extracellular vesicles (EVs) released by P. falciparum during its blood-stage development. EVs are small, membrane-bound particles secreted by cells that play a critical role in intercellular communication and may influence malaria pathogenesis. Our research focuses on developing precise methods for isolating EVs from blood-stage parasites, analyzing their cargo, and understanding their functional roles in parasite development and host-parasite interactions.

Current Research

Our laboratory combines molecular biology, cell biology, omics, and advanced imaging to investigate the biology of P. falciparum, with a particular focus on the blood stages of the parasite鈥檚 lifecycle. The following are our key areas of research:

Extracellular Vesicles
EVs released during P. falciparum blood stages are emerging as critical mediators in malaria pathogenesis and parasite biology. Our laboratory has developed refined techniques to isolate EVs from infected RBCs, ensuring the purity and reproducibility of the samples. Through advanced proteomic analyses, we have characterized the protein profiles of EVs across various blood-stage parasites, revealing stage-specific differences in their molecular cargo. These findings suggest that EVs may serve as delivery vehicles for proteins, RNA, and metabolites that influence host-parasite interactions and contribute to disease progression.

A major focus of our research is to explore the role of EVs in triggering gametocytogenesis, the developmental process by which sexual-stage parasites are formed. Gametocytes are essential for the transmission of malaria to mosquitoes, and understanding the molecular signals involved in this process is crucial for disrupting the transmission cycle. We are investigating whether specific proteins or signaling molecules carried by EVs act as triggers for this transformation, potentially linking EV-mediated communication to parasite survival and adaptation.

Additionally, we are exploring how EVs interact with the host immune system and contribute to immune evasion or modulation. By identifying the molecular content of EVs and their effects on host cells, we aim to uncover new therapeutic targets and biomarkers for malaria diagnosis and treatment.

Drug Resistance
Drug resistance poses a significant challenge to malaria treatment and eradication efforts, with chloroquine resistance (P. falciparum) being one of the most critical barriers. Our research focuses on understanding the cellular, molecular, and pharmacological mechanisms underlying this resistance. We investigate the differential responses of chloroquine-sensitive (CQS) and chloroquine-resistant (CQR) parasites to equipotent concentrations of chloroquine, using live cell imaging to analyze parasite killing kinetics and cellular outcomes in real time.

Central to chloroquine resistance are two key transporters on the digestive vacuole (DV) membrane: PfMDR1 and PfCRT. These transporters play critical roles in nutrient uptake, ion homeostasis, and drug efflux, directly influencing resistance phenotypes. To unravel their functions, we employ reverse Fluo-4 imaging assays to quantify PfMDR1 transport kinetics and assess the impact of specific mutations. This enables us to determine how genetic alterations affect drug transport and resistance, providing insights into parasite adaptations.

Beyond these studies, we integrate multidisciplinary approaches鈥攇enomics, proteomics, metabolomics, and advanced imaging鈥攖o gain a holistic understanding of resistance mechanisms. These techniques allow us to identify key genes, proteins, and metabolic pathways involved in drug resistance and to explore how parasites evade drug action and adapt to selective pressures.

By elucidating the molecular and biochemical underpinnings of drug resistance, we aim to inform the development of next-generation antimalarial compounds and optimize treatment regimens. This research is essential for slowing the spread of resistance, improving therapeutic efficacy, and ultimately reducing the global burden of malaria.

Courses

Publications

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