Project description:Proteomic characterization of complexity and dynamics of detergent resistant membranes of sexual and asexual stages of the rodent malaria parasite Plasmodium berghei
Project description:The purpose of this research is to identify and evaluate the global gene expression of the rodent malaria parasites Plasmodium yoelii, Plasmodium berghei and Plasmodium chabaudi blood-stage parasites and specifically compare the blood stage gene expression profiles of samples derived from previous studies on Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi
Project description:During the malaria infection, Plasmodium parasites invade the host’s red blood cells where they can differentiate into two different life forms. The majority will replicate asexually and infect new erythrocytes. A small percentage, however, will transform into gametocytes – a specialized sexual stage able to survive and develop when taken up by Anopheles mosquito. As the gametocytes ensure the parasite’s transmission to a new host, their generation is an attractive target for new antimalarial interventions. The molecular mechanisms controlling gametocytogenesis, however, remain largely unknown due to the technical challenges: the early gametocytes are morphologically indistinguishable from asexual parasites and present in very low numbers during the infection. Recently, AP2-G - a transcription factor from an apicomplexa-specific apiAP2 family – was described as indispensable for gametocyte commitment in both human malaria parasite Plasmodium falciparum and rodent malaria model Plasmodium berghei. Therefore, we have decided to test whether the overexpression of this factor alone could increase gametocyte production and enable the investigation of uncharacterised, earliest stages of gametocyte development. To this end, we have engineered PBGAMi - a Plasmodium berghei line, in which all parasites were ap2-g deficient by default but able to overexpress it when induced with rapamycin. While the control parasites (PBGAMi R-), as expected, differentiated into asexual forms (schizonts) only, almost all rapamycin-treated parasites (PBGAMi R+) transformed into gametocytes. We used the generated line to perform RNA-seq analysis of the R- and R+ populations at different time points of their development and identify the changes arising between them, mapping the sequence of events leading to the formation of gametocytes.
Project description:During the malaria infection, Plasmodium parasites invade the host’s red blood cells where they can differentiate into two different life forms. The majority will replicate asexually and infect new erythrocytes. A small percentage, however, will transform into gametocytes – a specialized sexual stage able to survive and develop when taken up by Anopheles mosquito. As the gametocytes ensure the parasite’s transmission to a new host, their generation is an attractive target for new antimalarial interventions. The molecular mechanisms controlling gametocytogenesis, however, remain largely unknown due to the technical challenges: the early gametocytes are morphologically indistinguishable from asexual parasites and present in very low numbers during the infection. Recently, AP2-G - a transcription factor from an apicomplexa-specific apiAP2 family – was described as indispensable for gametocyte commitment in both human malaria parasite Plasmodium falciparum and rodent malaria model Plasmodium berghei. Therefore, we have decided to test whether the overexpression of this factor alone could increase gametocyte production and enable the investigation of uncharacterised, earliest stages of gametocyte development. To this end, we have engineered PBGAMi - a Plasmodium berghei line, in which all parasites were ap2-g deficient by default but able to overexpress it when induced with rapamycin. While the control parasites (PBGAMi R-), as expected, differentiated into asexual forms (schizonts) only, almost all rapamycin-treated parasites (PBGAMi R+) transformed into gametocytes. We used the generated line to perform RNA-seq analysis of the R- and R+ populations at different time points of their development and identify the changes arising between them, mapping the sequence of events leading to the formation of gametocytes. At the same time we have generated purified transcriptomes of male and female gametocytes for the reference
Project description:To study the liver stage of the rodent malaria parasite Plasmodium berghei, we molecularly characterized thousands of infected and uninfected hepatocytes in different time points and inferred their spatial coordinates. Thus enabling us to characterize the host’s and parasite’s temporal expression programs in a zonally-controlled manner.
Project description:The transmission of the malaria parasite between mosquitoes and mammals requires translational repression to ensure that only the proper proteins are expressed and correct folded at the right time, it will need for the next developmental stage.Due to their essential role for malaria transmission, gametocytes represent prime targets for transmission-blocking strategies intended to prevent spread of the deadly disease. In this study, we generate HspJ62 gene knockout line (ΔHspJ62) that is gametocyte non-producing lines. Transcriptional profiling of wild type Plasmodium berghei and genetic KO Hspj62 genes at single time points during erythrocytic parasite development.
Project description:The liver stage of the etiological agent of malaria, Plasmodium, is obligatory for successful infection of its various mammalian hosts. Differentiation of the rod-shaped sporozoites of Plasmodium into spherical exoerythrocytic forms (EEFs) via bulbous expansion is essential for parasite development in the liver. However, little is known about the host factors regulating the morphological transformation of Plasmodium sporozoites in this organ. Here, we show that sporozoite differentiation into EEFs in the liver involves protein kinase Cζ-mediated NF-κB activation, which robustly induces the expression of C-X-C chemokine receptor type 4 (CXCR4) in hepatocytes and subsequently elevates intracellular Ca2+ levels, thereby triggering sporozoite transformation into EEFs. Blocking CXCR4 expression by genetic or pharmacological intervention profoundly inhibited the liver stage development of the P. berghei rodent malaria parasite and the human P. falciparum parasite also. Collectively, our experiments show that CXCR4 is a key host factor for Plasmodium development in the liver, and CXCR4 warrants further investigation for malaria prophylaxis.