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Sent on Thursday, 2012 January 05Search: kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | PLoS Negl Trop Dis. 2011 Dec;5(12):e1461. Epub 2011 Dec 27.Genetic Engineering of Trypanosoma (Dutonella) vivax and In Vitro Differentiation under Axenic Conditions.D'Archivio S, Medina M, Cosson A, Chamond N, Rotureau B, Minoprio P, Goyard S.SourceLaboratoire des Processus Infectieux à Trypanosoma, Department of Infection and Epidemiology, Paris, France. AbstractTrypanosoma vivax is one of the most common parasites responsible for animal trypanosomosis, and although this disease is widespread in Africa and Latin America, very few studies have been conducted on the parasite's biology. This is in part due to the fact that no reproducible experimental methods had been developed to maintain the different evolutive forms of this trypanosome under laboratory conditions. Appropriate protocols were developed in the 1990s for the axenic maintenance of three major animal Trypanosoma species: T. b. brucei, T. congolense and T. vivax. These pioneer studies rapidly led to the successful genetic manipulation of T. b. brucei and T. congolense. Advances were made in the understanding of these parasites' biology and virulence, and new drug targets were identified. By contrast, challenging in vitro conditions have been developed for T. vivax in the past, and this per se has contributed to defer both its genetic manipulation and subsequent gene function studies. Here we report on the optimization of non-infective T. vivax epimastigote axenic cultures and on the process of parasite in vitro differentiation into metacyclic infective forms. We have also constructed the first T. vivax specific expression vector that drives constitutive expression of the luciferase reporter gene. This vector was then used to establish and optimize epimastigote transfection. We then developed highly reproducible conditions that can be used to obtain and select stably transfected mutants that continue metacyclogenesis and are infectious in immunocompetent rodents. |
| 2. | PLoS Negl Trop Dis. 2011 Dec;5(12):e1406. Epub 2011 Dec 27.Single Dose Novel Salmonella Vaccine Enhances Resistance against Visceralizing L. major and L. donovani Infection in Susceptible BALB/c Mice.Schroeder J, Brown N, Kaye P, Aebischer T.SourceInstitute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom. AbstractVisceral leishmaniasis is a major neglected tropical disease, with an estimated 500,000 new cases and more than 50,000 deaths attributable to this disease every year. Drug therapy is available but costly and resistance against several drug classes has evolved. Despite all efforts, no commercial, let alone affordable, vaccine is available to date. Thus, the development of cost effective, needle-independent vaccines is a high priority. Here, we have continued efforts to develop live vaccine carriers based on recombinant Salmonella. We used an in silico approach to select novel Leishmania parasite antigens from proteomic data sets, with selection criteria based on protein abundance, conservation across Leishmania species and low homology to host species. Five chosen antigens were differentially expressed on the surface or in the cytosol of Salmonella typhimurium SL3261. A two-step procedure was developed to select optimal Salmonella vaccine strains for each antigen, based on bacterial fitness and antigen expression levels. We show that vaccine strains of Salmonella expressing the novel Leishmania antigens LinJ08.1190 and LinJ23.0410 significantly reduced visceralisation of L. major and enhanced systemic resistance against L. donovani in susceptible BALB/c mice. The results show that Salmonella are valid vaccine carriers for inducing resistance against visceral leishmaniasis but that their use may not be suitable for all antigens. |
| 3. | Parasitol Res. 2012 Jan 4. [Epub ahead of print]Ultrastructural analysis of mil tefosine-induced surface membrane damage in adult Schistosoma mansoni BH strain worms.Bertão HG, da Silva RA, Padilha RJ, de Azevedo Albuquerque MC, Rádis-Baptista G.SourceRede Nordeste de Biotecnologia (RENORBIO), Universidade Federal de Pernambuco e Universidade Federal Rural de Pernambuco, Recife, PE, Brazil. AbstractSchistosomiasis is an infectious parasitic disease caused by helminths from the genus Schistosoma; it affects over 200 million people globally and is endemic in 70 countries. In Brazil, 6 million individuals are infected with Schistosoma mansoni. Furthermore, as the prevalence of S. mansoni infections is increasing, approximately 26 million citizens in 19 Brazilian states are at risk for infection. Schistosomiasis disease control involves predominately the administration of a single drug, praziquantel. Although praziquantel exhibits chemotherapeutic efficacy and safety, its massive use in endemic zones, the possibility of the emergence of drug-resistant Schistosoma parasites, and the lack of another efficacious antischistosomal drug demand the discovery of new schistosomicidal compounds. First developed as anti-tumor drug, miltefosine is an alkylphospholipid derivative that exhibits bioactivity against Leishmania and Trypanosoma parasites, free-living protozoa, bacteria, and fungi. With its anti-parasite activity, miltefosine was the first orally administered drug against visceral and cutaneous leishmaniasis approved. Previously, by means of the MTT cytotoxic assay and a DNA fragmentation test, we verified that, at doses of 100 and 200 μM (40 and 80 μg/mL), miltefosine exhibited in vitro schistosomicidal activity against adult S. mansoni worms. Here, we present ultrastructural evidence of rapid, severe miltefosine-induced surface membrane damage in S. mansoni following drug treatment. The number of dead parasites was concentration- and time-dependent following miltefosine treatment. At a miltefosine concentration of 200 μM (∼80 μg/mL), in vitro parasite killing was initiated as early as 3 h post-incubation, and it was maximal after 24 h of treatment. The parasite death was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. According to our present results, miltefosine is very effective at inducing membrane destruction of S. mansoni with a short onset of pharmacological action. |
| 4. | BMC Biol. 2012 Jan 3;10(1):1. [Epub ahead of print]Detailed interrogation of trypanosome cell biology via differential organelle staining and automated image analysis.Wheeler RJ, Gull K, Gluenz E.AbstractABSTRACT: BACKGROUND:Many trypanosomatid protozoa are important human or animal pathogens. The well-defined morphology and precisely choreographed division of trypanosomatid cells makes morphological analysis a powerful tool for analysing the effect of mutations, chemical insults and changes between lifecycle stages. High throughput image analysis of micrographs has the potential to accelerate collection of quantitative morphological data. Trypanosomatid cells have two large DNA-containing organelles, the kinetoplast (mitochondrial DNA) and nucleus, which provide useful markers for morphometric analysis; however they need to be accurately identified and often lie in close proximity. This presents a technical challenge. Accurate identification and quantitation of the DNA content of these organelles is a central requirement of any automated analysis method. RESULTS:We have developed a technique based on double staining of the DNA with a minor groove binding (DAPI) and a base pair intercalating (propidium iodide or SYBR green) fluorescent stain and colour deconvolution. This allows the identification of kinetoplast and nuclear DNA in the micrograph based on whether the organelle has DNA with a more A-T or G-C rich composition. Following unambiguous identification of the kinetoplasts and nuclei the resulting images are amenable to quantitative automated analysis of kinetoplast and nucleus number and DNA content. On this foundation we have developed a demonstrative analysis tool capable of measuring kinetoplast and nucleus DNA content, size and position and cell body shape, length and width automatically. CONCLUSIONS:Our approach to DNA staining and automated quantitative analysis of trypanosomatid morphology accelerated analysis of trypanosomatid protozoa. We have validated this approach using Leishmania mexicana, Crithidia fasciculata and wild-type and mutant Trypanosoma brucei. Automated analysis of T. brucei morphology was of comparable quality to manual analysis while being faster and less susceptible to experimentalist bias. The complete data set from each cell and all analysis parameters used can be recorded ensuring repeatability and allowing complete data archiving and reanalysis. |
| 5. | Curr Pharm Biotechnol. 2012 Jan 2. [Epub ahead of print]Cellular and Subcellular Imaging in Live Mice Using Fluorescent Proteins.Hoffman RM.SourceAntiCancer Inc., 7917 Ostrow Street, San Diego, CA 92111. all@anticancer.com. AbstractFluorescent proteins have revolutionized in vivo biology. Due to their intrinsic brightness, multiple colors, and ease of generic manipulation, fluorescent proteins are the genetic reporters of choice for in vivo imaging. The present report reviews applications of fluorescent protein for imaging cancer progression, gene expression, angiogenesis, stem cells, bacterial infection, Leishmania, and asthma at the cellular level in live mice. With fluorescent protein-expressing cells and a highly sensitive small animal imaging system, cellular and subcellular dynamics can now be observed in live mice in real time. Fluorescent proteins thus enable both micro as well as macro imaging technology and thereby provide the basis for the new field of in vivo cell biology. |
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