What's new for 'Trypanosomatids' in PubMed

This message contains My NCBI what's new results from the National Center for Biotechnology Information (NCBI) at the U.S. National Library of Medicine (NLM).
Do not reply directly to this message.

Sender's message:

Sent on Sunday, 2011 Feb 27
Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
Click here to view complete results in PubMed. (Results may change over time.)
To unsubscribe from these e-mail updates click here.

PubMed Results

Items 1 - 10 of 14

1.	Parasitol Res. 2011 Feb 25. [Epub ahead of print] Identification and characterization of cysteine proteinases of Trypanosoma evansi. Yadav SC, Kumar R, Kumar S, Tatu U, Singh RK, Gupta AK. National Research Centre on Equines, Sirsa Road, Hisar, 125001, Haryana, India, yadavsc@rediffmail.com. Abstract Trypanosoma evansi is a causative agent of 'surra', a common haemoprotozoan disease of livestock in India causing high morbidity and mortality in disease endemic areas. The proteinases released by live and dead trypanosomes entail immunosuppression in the infected host, which immensely contribute in disease pathogenesis. Cysteine proteinases are identified in the infectious cycle of trypanosomes such as cruzain from Trypanosoma cruzi, rhodesain or brucipain from Trypanosoma brucei rhodesiense and congopain from Trypanosoma congelense. These enzymes localised in lysosome-like organelles, flagellar pocket and on cell surface, which play a critical role in the life cycle of protozoan parasites, viz. in host invasion, nutrition and alteration of the host immune response. The paper describes the identification of cysteine proteinases of T. evansi lysate, activity profile at different pH optima and inhibition pattern using a specific inhibitor, besides the polypeptide profile of an antigen. Eight proteinases of T. evansi were identified in the molecular weight (MW) ranges of 28-170 kDa using gelatin substrate-polyacrylamide gel electrophoresis (GS-PAGE), and of these proteinases, six were cysteine proteinases, as they were inhibited by L-3-carboxy-2,3-transepoxypropionyl-lecuylamido (4-guanidino)-butane (E-64), a specific inhibitor. These proteolytic enzymes were most reactive in acidic pH between 3.0 and 5.5 in the presence of dithiothreitol and completely inactive at alkaline pH 10.0. Similarly, the GS-PAGE profile of the serum samples of rats infected with T. evansi revealed strong proteolytic activity only at the 28-kDa zone at pH 5.5, while no proteolytic activity was observed in serum samples of uninfected rats. Further, the other zones of clearance, which were evident in T. evansi antigen zymogram, could not be observed in the serum samples of rats infected with T. evansi. The polypeptide pattern of the whole cell lysate antigen revealed 12-15 polypeptide bands ranging from 28 to 81 kDa along with five predominant polypeptides bands (MW of 81, 66, 62, 55 and 45 kDa), which were immunoreactive with hyperimmune serum (HIS) and serum of experimentally infected rabbits with T. evansi infection. The immunoblot recognised antibodies in experimentally infected rabbits and against HIS as well, corresponding to the zone of clearances at lower MW ranges (28-41 kDa), which may be attributed to the potential of these proteinases in the diagnosis of T. evansi infection. Since these thiol-dependent enzymes are most active in acidic pH and considering their inhibition characteristics, these data suggest that they resemble to the mammalian lysosomal cathepsin B and L.
	PMID: 21350794 [PubMed - as supplied by publisher]

2.	Vet Parasitol. 2011 Feb 3. [Epub ahead of print] Laboratory tests performed on Leishmania seroreactive dogs euthanized by the leishmaniasis control program. Silva DA, Madeira MF, Teixeira AC, de Souza CM, Figueiredo FB. Pós-graduação Stricto-sensu, Instituto de Pesquisa Clinica Evandro Chagas (IPEC), Fundação Oswaldo Cruz (FIOCRUZ), Brazil; Laboratório de Pesquisa Clínica em Dermatozoonoses em Animais Domésticos, IPEC-FIOCRUZ, Brazil. Abstract In 2008, in the west zone of Rio de Janeiro municipality-Brazil, the leishmaniasis control program identified 155 dogs with titers ≥40 by Indirect ImmunoFluorescence (IIF) on blood collected onto filter paper. The objective of this study was to describe the laboratory test findings performed in dogs euthanized by the leishmaniasis program control of Rio de Janeiro municipality. Dogs were examined, subjected to euthanasia and collection of clinical specimens. Parasite isolation was obtained in 29 animals: Leishmania chagasi was isolated in 14 dogs; Leishmania braziliensis was isolated in five dogs; Trypanosoma caninum was obtained in seven animals and one dog had mixed infection (L. braziliensis and L. chagasi). By Polymerase Chain Reaction, seventeen animals were positive in intact skin fragments. In the serological reassessment of serum samples, 28% and 22% were positive for IIF and enzyme immunoassay, respectively. Ninety-one (59%) dogs were negative for all tests performed in this study. The findings indicate that the visceral leishmaniasis control program needs to be adjusted in order to avoid non-infected dogs from being removed or permit that dogs infected with L. chagasi to remain undetected in endemic areas. Copyright © 2011 Elsevier B.V. All rights reserved.
	PMID: 21349644 [PubMed - as supplied by publisher]

3.	Vet Parasitol. 2011 Feb 2. [Epub ahead of print] Canine leishmaniasis surveillance in a northern Italy kennel. Baldelli R, Piva S, Salvatore D, Parigi M, Melloni O, Tamba M, Bellini R, Poglayen G. Dipartimento di Sanità Pubblica Veterinaria e Patologia Animale - Università di Bologna, via Tolara di sopra 50, 40064 Ozzano Emilia (BO), Italy. Abstract An epidemiological survey on canine leishmaniasis (CanL) was performed during a 3-year period (2007-2009) in a public kennel of the Bologna province. The presence of the disease was shown in the canine population for the first time in 2007 by indirect fluorescent antibody test (IFAT). The parasite circulation was confirmed also by direct diagnostic tools, as PCR, cytology and cultural method, performed on different bioptic materials. The parasite was isolated and identified as Leishmania infantum zymodeme MON 1. The serological monitoring was performed also in 2008 and 2009 on animals that previously showed negative or uncertain results. The incidence values calculated by significant seroconversions in IFAT titre ≥1/160, ranged between 4.9% and 6.6%, indicating a stable focus of leishmaniasis. The entomological survey, performed by sticky and CO(2)-baited traps in 2008, showed the presence of the vector Phlebotomus perfiliewi. This study allowed us to identify a stable focus of CanL in an area that was not considered eco-compatible with the presence of the vector and infection. Our results confirm the northward spread of CanL towards areas not previously affected by autochthonous foci. Copyright © 2011 Elsevier B.V. All rights reserved.
	PMID: 21349642 [PubMed - as supplied by publisher]

4.	Microb Pathog. 2011 Feb 21. [Epub ahead of print] In silico identification of novel protective VSG antigens expressed by Trypanosoma brucei and an effort for designing a highly immunogenic DNA vaccine using IL-12 as adjuvant. Akhoon BA, Slathia PS, Sharma P, Gupta SK, Verma V. Centre of Bioinformatics, School of Biotechnology, Shri Mata Vaishno Devi (SMVD) University, Jammu, 182320, J&K, India. Abstract African trypanosomiasis continues to be a major health problem, with more adults dying from this disease world-wide. As the sequence diversity of Trypanosoma brucei is extreme, with VSGs having 15-25% identity with most other VSGs, hence it displays a huge diversity of adaptations and host specificities. Therefore the need for an improved vaccine has become an international priority. The highly conserved and specific epitopes acting as both CD8(+) and CD4(+) T-cell epitopes (FLINKKPAL and FTALCTLAA) were predicted from large bunch of VSGs of Trypanosoma brucei. Besides, some other potential epitopes with very high affinity for MHC I and II molecules were also determined while taking consideration on the most common HLA in the general population which accounts for major ethnicities. The vaccine candidates were found to be effective even for non-african populations as predicted by population coverage analysis. Hence the migrating travelers acting as a spread means of the infection can probably also be treated successfully after injection of such a multiepitopic vaccine. Exploiting the immunoinformatics approaches, we designed a potential vaccine by using the various consensus epitopic sequences of 388 VSG proteins of Trypanosoma brucei and performed in silico cloning of multiepitopic antigenic DNA sequence in pBI-CMV1 vector. Moreover, various techniques like codon adaptation, CpG optimization, removal of self recognized epitopes, use of adjuvant and co-injection with plasmids expressing immune-stimulatory molecules were implemented to enhance the immunogenicity of the proposed in silico vaccine. Copyright © 2011 Elsevier Ltd. All rights reserved.
	PMID: 21349321 [PubMed - as supplied by publisher]

5.	Parasitology. 2011 Feb 24:1-11. [Epub ahead of print] Bioinformatic analysis of glycogen synthase kinase 3: human versus parasite kinases. Osolodkin DI, Zakharevich NV, Palyulin VA, Danilenko VN, Zefirov NS. Department of Chemistry, Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia. Abstract SUMMARYObjective. Glycogen synthase kinase 3 (GSK-3) is a promising target for the treatment of various human diseases such as type 2 diabetes, Alzheimer's disease and inflammation. Successful inhibition of the homologues of this kinase in Plasmodium falciparum, Trypanosoma brucei and Leishmania donovani makes the kinase an attractive target for the treatment of malaria, trypanosomiasis and leishmaniasis, respectively. The aim of this work was to compare the binding sites of the GSK-3 kinases of different parasites and to analyse them as possible targets for therapeutic compounds. Methods. Both a sequence alignment and homology models of the structure of 21 different GSK-3 homologues belonging to mammals, insects, pathogenic fungi, nematodes, trematodes and protozoa have been analysed, 17 of them being studied for the first time. Results. The structure of the kinases and, in particular, their binding sites, were found to be rather conserved, possessing small insertions or deletions and conserved amino acid substitutions. Nevertheless, the kinases of most species of parasite did have some amino acid differences from the human kinase, which could be exploited for the design of selective drugs. Conclusion. Comparison of the human and parasite GSK-3 ATP binding site models has shown that the development of selective drugs affecting parasite GSK-3 is possible. Known inhibitors of human GSK-3 can also be used as starting scaffolds for the search for drugs acting against parasitic diseases.
	PMID: 21349219 [PubMed - as supplied by publisher]

6.	Immunol Rev. 2011 Mar;240(1):286-96. doi: 10.1111/j.1600-065X.2010.00983.x. Cell biology and immunology of Leishmania. Mougneau E, Bihl F, Glaichenhaus N. Institut National de la Santé et de la Recherche Médicale, University of Nice-Sophia Antipolis, Valbonne, France. Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France. Centre National de la Recherche Scientifique, UMR6097, University of Nice-Sophia Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France. Abstract Summary:  More than 20 years ago, immunologists discovered that resistance and susceptibility to experimental infection with the intracellular protozoan Leishmania major was associated with the development of T-helper 1 (Th1)- and Th2-dominated immune responses, respectively. This infectious disease model was later used to identify and assess the role of key factors, such as interleukin-12 (IL-12) and IL-4, in Th1 and Th2 maturation. While infection by Leishmania remains a popular model for immunologists who wish to assess the role of their favorite molecule in T-cell differentiation, other investigators have tried to better understand how Leishmania interact with its insect and mammalian hosts. In this review, we discuss some of these new data with an emphasis on the early events that shape the immune response to Leishmania and on the immune evasion mechanisms that allow this parasite to avoid the development of sterilizing immunity and to secure its transmission to a new host. © 2011 John Wiley & Sons A/S.
	PMID: 21349100 [PubMed - in process]

7.	Immunol Rev. 2011 Mar;240(1):72-91. doi: 10.1111/j.1600-065X.2010.00990.x. Invasion and intracellular survival by protozoan parasites. David Sibley L. Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA. Abstract Summary:  Intracellular parasitism has arisen only a few times during the long ancestry of protozoan parasites including in diverse groups such as microsporidians, kinetoplastids, and apicomplexans. Strategies used to gain entry differ widely from injection (e.g. microsporidians), active penetration of the host cell (e.g. Toxoplasma), recruitment of lysosomes to a plasma membrane wound (e.g. Trypanosoma cruzi), to host cell-mediated phagocytosis (e.g. Leishmania). The resulting range of intracellular niches is equally diverse ranging from cytosolic (e.g. T. cruzi) to residing within a non-fusigenic vacuole (e.g. Toxoplasma, Encephalitozoon) or a modified phagolysosome (e.g. Leishmania). These lifestyle choices influence access to nutrients, interaction with host cell signaling pathways, and detection by pathogen recognition systems. As such, intracellular life requires a repertoire of adaptations to assure entry-exit from the cell, as well as to thwart innate immune mechanisms and prevent clearance. Elucidating these pathways at the cellular and molecular level may identify key steps that can be targeted to reduce parasite survival or augment immunologic responses and thereby prevent disease. © 2011 John Wiley & Sons A/S.
	PMID: 21349087 [PubMed - in process]

8.	J Parasitol. 2011 Feb;97(1):88-93. Epub 2010 Sep 3. Effect of Trypanosoma brucei brucei on Erythropoiesis in Infected Rats. Nishimura K, Nakaya H, Nakagawa H, Matsuo S, Ohnishi Y, Yamasaki S. Laboratory of Bioenvironmental Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan nisimura@vet.osakafu-u.ac.jp. Abstract Abstract Anemia generated from African trypanosome infection is considered an important symptom in humans and in domestic animals. In order to recover from anemia, the process of erythropoiesis is essential. Erythropoiesis is affected by erythropoietin (EPO), an erythropoietic hormone, supplying iron and inflammatory and proinflammatory cytokines. However, the role of these factors in erythropoiesis during African trypanosome infection remains unclear. In the present study, we analyze how erythropoiesis is altered in anemic Trypanosoma brucei brucei (interleukin-tat 1.4 strain [ILS])-infected rats. We report that the packed cell volume (PCV) of blood from ILS-infected rats was significantly lower 4 days after infection, whereas the number of reticulocytes, as an index of erythropoiesis, did not increase. The level of EPO mRNA in ILS-infected rats did not increase from the third day to the sixth day after infection, the same time that the PCV decreased. Kidney cells of uninfected rats cultured with ILS trypanosome strain for 8 hr in vitro decreased EPO mRNA levels. Treatment of both ILS and cobalt chloride mimicked hypoxia, which restrained the EPO-production-promoting effect of the cobalt. Messenger RNA levels of β-globin and transferrin receptor, as markers of erythropoiesis in the bone marrow, also decreased in ILS-infected rats. Levels of hepcidin mRNA, which controls the supply of iron to the marrow in liver, were increased in ILS-infected rats; however, the concentration of serum iron did not change. Furthermore, mRNA levels of interleukin-12, interferon-γ, tumor necrosis factor-α, and macrophage migration inhibitory factor in the spleen, factors that have the potential to restrain erythropoiesis in bone marrow, were elevated in the ILS-infected rats. These results suggest that ILS infection in rats affect erythropoiesis, which responds by decreasing EPO production and restraining its function in the bone marrow.
	PMID: 21348612 [PubMed - in process]

9.	J Parasitol. 2011 Feb;97(1):48-54. Epub 2010 Aug 27. Differential Effects of Trypanosoma brucei gambiense and Trypanosoma brucei brucei on Rat Macrophages. Nishimura K, Nakaya H, Nakagawa H, Matsuo S, Ohnishi Y, Yamasaki S. Laboratory of Bioenvironmental Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan nisimura@vet.osakafu-u.ac.jp. Abstract Abstract Mammalian immune responses to Trypanosoma brucei infection are important to control of the disease. In rats infected with T. brucei gambiense (Wellcome strain; WS) or T. brucei brucei (interleukin-tat 1.4 strain [ILS]), a marked increase in the number of macrophages in the spleen can be observed. However, the functional repercussions related to this expansion are not known. To help uncover the functional significance of macrophages in the context of trypanosome infection, we determined the mRNA levels of genes associated with an increase in macrophage number or macrophage function in WS- and ILS-infected rats and in cultured cells. Specifically, we assayed mRNA levels for macrophage colony stimulating factor (M-CSF), granulocyte macrophage colony stimulating factor (GM-CSF), and macrophage migration inhibitory factor (MIF). Upregulation of GM-CSF and MIF mRNA levels was robust in comparison with changes in M-CSF levels in ILS-infected rats. By contrast, upregulation of M-CSF was more robust in WS-infected rats. The phagocytic activity in macrophages harvested from ILS-infected rat spleens, but not WS-infected spleens, was higher than that in macrophages from uninfected rats. These results suggest that macrophages of WS-infected rats change to an immunosuppressive type. However, when WS or ILS is cocultured with spleen macrophages or HS-P cells, a cell line of rat macrophage origin, M-CSF is upregulated relative to GM-CSF and MIF in both cell types. Anemia occurs in ILS-, but not WS-infected, rats. Treatment of spleen macrophages or HS-P cells cocultured with ILS with cobalt chloride, which mimics the effects of anemia-induced hypoxia, led to downregulation of M-CSF mRNA levels, upregulation of GM-CSF and MIF, and an increase in phagocytic activity. However, the effect of cobalt chloride on spleen macrophages and HS-P cells cocultured with WS was restricted. These results suggest that anemia-induced hypoxia in ILS-infected rats stimulates the immune system and activates macrophages.
	PMID: 21348606 [PubMed - in process]

10.	Nat Med. 2011 Jan;17(1):14-7. Putting sleeping sickness to bed. Willyard C.
	PMID: 21217663 [PubMed - indexed for MEDLINE]
	Related citations