The efficacy of novel arylimidamides against Trypanosoma cruzi in vitro

Parasitology ◽  
2011 ◽  
Vol 138 (14) ◽  
pp. 1863-1869 ◽  
Author(s):  
CRISTIANE FRANÇA DA SILVA ◽  
ANISSA DALIRY ◽  
PATRÍCIA BERNARDINO DA SILVA ◽  
SENOL AKAY ◽  
MOLOY BANERJEE ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mammalian Cells ◽  
Primary Cultures ◽  
Alternative Therapy ◽  
Cardiac Cells ◽  
Intracellular Parasites ◽  
Blood Banks ◽  
Potential Use

SUMMARYThe present study aimed to determine the in vitro biological efficacy and selectivity of 7 novel AIAs upon bloodstream trypomastigotes and intracellular amastigotes of Trypanosoma cruzi. The biological activity of these aromatic compounds was assayed for 48 and 24 h against intracellular parasites and bloodstream forms of T. cruzi (Y strain), respectively. Additional assays were also performed to determine their potential use in blood banks by treating the bloodstream parasites with the compounds diluted in mouse blood for 24 h at 4°C. Toxicity against mammalian cells was evaluated using primary cultures of cardiac cells incubated for 24 and 48 h with the AIAs and then cellular death rates were determined by MTT colorimetric assays. Our data demonstrated the outstanding trypanocidal effect of AIAs against T. cruzi, especially DB1853, DB1862, DB1867 and DB1868, giving IC50 values ranging between 16 and 70 nanomolar against both parasite forms. All AIAs presented superior efficacy to benznidazole and some, such as DB1868, also demonstrated promising activity as a candidate agent for blood prophylaxis. The excellent anti-trypanosomal efficacy of these novel AIAs against T. cruzi stimulates further in vivo studies and justifies the screening of new analogues with the goal of establishing a useful alternative therapy for Chagas disease.

scholarly journals Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Neuronal Cell ◽  
Host Cells ◽  
Neurotrophin Receptor ◽  
Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

Activity profile of two 5-nitroindazole derivatives over the moderately drug-resistant Trypanosoma cruzi Y strain (DTU TcII): in vitro and in vivo studies

Parasitology ◽  
2020 ◽  
Vol 147 (11) ◽  
pp. 1216-1228
Author(s):  
Cristina Fonseca-Berzal ◽  
Cristiane França da Silva ◽  
Denise da Gama Jaen Batista ◽  
Gabriel Melo de Oliveira ◽  
José Cumella ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Positive Impact ◽  
Cardiac Cells ◽  
In Vivo Studies ◽  
Drug Resistant ◽  
Activity Profile ◽  
Reference Drug ◽  
Novel Drugs

AbstractIn previous studies, we have identified several families of 5-nitroindazole derivatives as promising antichagasic prototypes. Among them, 1-(2-aminoethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one, (hydrochloride) and 1-(2-acetoxyethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one (compounds 16 and 24, respectively) have recently shown outstanding activity in vitro over the drug-sensitive Trypanosoma cruzi CL strain (DTU TcVI). Here, we explored the activity of these derivatives against the moderately drug-resistant Y strain (DTU TcII), in vitro and in vivo. The outcomes confirmed their activity over replicative forms, showing IC50 values of 0.49 (16) and 5.75 μm (24) towards epimastigotes, 0.41 (16) and 1.17 μm (24) against intracellular amastigotes. These results, supported by the lack of toxicity on cardiac cells, led to better selectivities than benznidazole (BZ). Otherwise, they were not as active as BZ in vitro against the non-replicative form of the parasite, i.e. bloodstream trypomastigotes. In vivo, acute toxicity assays revealed the absence of toxic events when administered to mice. Moreover, different therapeutic schemes pointed to their capability for decreasing the parasitaemia of T. cruzi Y acute infected mice, reaching up to 60% of reduction at the peak day as monotherapy (16), 79.24 and 91.11% when 16 and 24 were co-administered with BZ. These combined therapies had also a positive impact over the mortality, yielding survivals of 83.33 and 66.67%, respectively, while untreated animals reached a cumulative mortality of 100%. These findings confirm the 5-nitroindazole scaffold as a putative prototype for developing novel drugs potentially applicable to the treatment of Chagas disease and introduce their suitability to act in combination with the reference drug.

scholarly journals Liposomes Composed by Membrane Lipid Extracts from Macrophage Cell Line as a Delivery of the Trypanocidal N,N’-Squaramide 17 towards Trypanosoma cruzi

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5505
Author(s):  
Christian Rafael Quijia ◽  
Cínthia Caetano Bonatto ◽  
Luciano Paulino Silva ◽  
Milene Aparecida Andrade ◽  
Clenia Santos Azevedo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mammalian Cells ◽  
Entrapment Efficiency ◽  
Membrane Lipid ◽  
Raw 264.7 Cells ◽  
Hydrodynamic Diameter ◽  
Raw 264.7 ◽  
Low Cytotoxicity

Chagas is a neglected tropical disease caused by Trypanosoma cruzi, and affects about 25 million people worldwide. N, N’-Squaramide 17 (S) is a trypanocidal compound with relevant in vivo effectiveness. Here, we produced, characterized, and evaluated cytotoxic and trypanocidal effects of macrophage-mimetic liposomes from lipids extracted of RAW 264.7 cells to release S. As results, the average hydrodynamic diameter and Zeta potential of mimetic lipid membranes containing S (MLS) was 196.5 ± 11 nm and −61.43 ± 2.3 mV, respectively. Drug entrapment efficiency was 73.35% ± 2.05%. After a 72 h treatment, MLS was observed to be active against epimastigotes in vitro (IC50 = 15.85 ± 4.82 μM) and intracellular amastigotes (IC50 = 24.92 ± 4.80 μM). Also, it induced low cytotoxicity with CC50 of 1199.50 ± 1.22 μM towards VERO cells and of 1973.97 ± 5.98 μM in RAW 264.7. MLS also induced fissures in parasite membrane with a diameter of approximately 200 nm in epimastigotes. MLS showed low cytotoxicity in mammalian cells and high trypanocidal activity revealing this nanostructure a promising candidate for the development of Chagas disease treatment.

scholarly journals Effect of the Tc13Tul antigen from Trypanosoma cruzi on splenocytes from naïve mice

Parasitology ◽  
2020 ◽  
Vol 147 (10) ◽  
pp. 1114-1123
Author(s):  
Laura Mónica Tasso ◽  
Andrea Cecilia Bruballa ◽  
Patricia Andrea Garavaglia ◽  
Mónica Inés Esteva ◽  
María Cecilia Albareda ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Cell Activation ◽  
Primary Cultures ◽  
Group Iv ◽  
B Cell Activation ◽  
Host Immune Responses ◽  
Viable Cells ◽  
Specific Igg

AbstractTrypanosoma cruzi, the etiological agent of Chagas disease, releases factors, including antigens from the trans-sialidase (TS) superfamily, which modulate the host immune responses. Tc13 antigens belong to group IV of TSs and are characterized by C-terminal EPKSA repeats. Here, we studied the effect of the Tc13 antigen from the Tulahuén strain, Tc13Tul, on primary cultures of splenocytes from naïve BALB/c mice. Recombinant Tc13Tul increased the percentage of viable cells and induced B (CD19+) lymphocyte proliferation. Tc13Tul stimulation also induced secretion of non-specific IgM and interferon-γ (IFN-γ). The same effects were induced by Tc13Tul on splenocytes from naïve C3H/HeJ mice. In vivo administration of Tc13Tul to naïve BALB/c mice increased non-specific IgG in sera. In addition, in vitro cultured splenocytes from Tc13Tul-inoculated mice secreted a higher basal level of non-specific IgM than controls and the in vitro Tc13Tul stimulation of these cells showed an enhanced effect on IgM and IFN-γ secretion. Our results indicate that Tc13Tul may participate in the early immunity in T. cruzi infection by favouring immune system evasion through B-cell activation and non-specific Ig secretion. In contrast, as IFN-γ is an important factor involved in T. cruzi resistance, this may be considered a Tc13Tul effect in favour of the host.

scholarly journals Trypanosoma cruzi: in vitro induction of macrophage microbicidal activity.

1978 ◽  
Vol 148 (1) ◽  
pp. 288-300 ◽  
Author(s):  
N Nogueira ◽  
Z A Cohn
Keyword(s):  
Trypanosoma Cruzi ◽  
Spleen Cell ◽  
Peritoneal Macrophages ◽  
Complete Disappearance ◽  
Microbicidal Activity ◽  
Trypanocidal Activity ◽  
Intracellular Parasites ◽  
Normal Spleen

Normal, resident and inflammatory mouse peritoneal macrophages can be induced to display microbicidal activity against trypomastigotes of Trypanosoma cruzi by exposure to products from antigen-pulsed, sensitized spleen cell populations. Optimal macrophage microbicidal activity was achieved by constant exposure and daily renewal of the spleen cell factors. Macrophages obtained after an intraperitoneal injection of mild inflammatory agents were rapidly induced, displaying trypanocidal activity 24 h after exposure to the active spleen cell factor(s), and by 48 h, parasites were no longer observed. Resident peritoneal macrophages required 24 h longer for activation. Removal of the factor(s) before achieving complete disappearance of intracellular parasites led to resumed growth of the surviving organisms. The spleen cell factor(s) is effective when added either before or after exposure of the macrophages to trypomastigotes, and does not itself alter parasite viability. Dilution of the factor(s) up to 1:16 still results in significant trypanocidal activity. In vivo activated cells, obtained after a specific secondary challenge of animals infected with T. cruzi or Bacille Calmette-Guérin, lose their trypanocidal activity under in vitro conditions. This loss of activity can be prevented or restored by the addition of the active spleen cell factor(s). Induction of trypanocidal activity is also obtained with products from Concanavalin A- or lipopolysaccharide-stimulated normal spleen cells.

scholarly journals Coadministration of an Interleukin-12 Gene and a Trypanosoma cruzi Gene Improves Vaccine Efficacy

2002 ◽  
Vol 70 (9) ◽  
pp. 4833-4840 ◽  
Author(s):  
Masaharu Katae ◽  
Yasushi Miyahira ◽  
Kazuyoshi Takeda ◽  
Hironori Matsuda ◽  
Hideo Yagita ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Cruzi ◽  
Vaccine Efficacy ◽  
Protective Immunity ◽  
Interleukin 12 ◽  
Mouse Strains ◽  
Dna Encoding ◽  
Intracellular Parasites

ABSTRACT We tested the immunogenicity of two Trypanosoma cruzi antigens injected into mice in the form of DNA vaccine. Immunization with DNA encoding dihydroorotate dehydrogenase did not confer protective immunity in all mouse strains tested. Immunization with DNA encoding trans-sialidase surface antigen (TSSA) protected C57BL/6 (H-2b ) mice but not BALB/c (H-2d ) or C3H/Hej (H-2k ) mice against lethal T. cruzi infection. In vivo depletion of CD4+ or CD8+ T cells abolished the protective immunity elicited by TSSA gene in C57BL/6 mice. Enzyme-linked immunospot assay with splenocytes from T. cruzi-infected mice or TSSA gene-vaccinated mice identified an H-2Kb -restricted antigenic peptide, ANYNFTLV. The CD8+-T-cell line specific for this peptide could recognize T. cruzi-infected cells in vitro and could protect naive mice from lethal infection when adoptively transferred. Coadministration of the interleukin-12 (IL-12) gene with the TSSA gene facilitated the induction of ANYNFTLV-specific CD8+ T cells and improved the vaccine efficacy against lethal T. cruzi infection. These results reinforced the utility of immunomodulatory adjuvants such as IL-12 gene for eliciting protective immunity against intracellular parasites by DNA vaccination.

scholarly journals Heterologous expression of methylxanthine synthesis enzymes in mammalian cells and their use as reporter proteins

2020 ◽  
Author(s):  
Brandon T. Cisneros ◽  
Neal K. Devaraj
Keyword(s):  
Coffea Arabica ◽  
Mammalian Cells ◽  
Human Cells ◽  
Intercellular Signaling ◽  
Non Invasive ◽  
Paullinia Cupana ◽  
Plant Enzymes ◽  
Potential Use

AbstractThis work demonstrates the reconstitution of active methylxanthine synthesis enzymes in human cells and their potential use as inducible reporter enzymes. A variety of plant enzymes involved in caffeine synthesis have been characterized in vitro and several of these methylxanthine synthesis enzymes have been heterologously-expressed in yeast or bacteria. In this work, enzymes from Coffea arabica, Camellia sinensis, and Paullinia cupana have been heterologously-expressed in human cells. We demonstrate that the enzymes tested exhibit similar patterns of activity with a set of xanthine substrates in human cells when compared to previous reports of in vitro activity. We demonstrate that the activity of these enzymes can be used as a reporter for juxtacrine signaling using synNotch-induced expression in the presence of an appropriate substrate. When used in combination with synthetic caffeine receptors, this work has potential for use as an in vivo reporter (e.g. enabling non-invasive monitoring of cell-cell interactions after a cellular transplant) or in synthetic intercellular signaling a methylxanthine, such as caffeine, acting as a synthetic paracrine hormone.

scholarly journals In Vitro and In Vivo Activities of Trybizine Hydrochloride against Various Pathogenic Trypanosome Species

1998 ◽  
Vol 42 (11) ◽  
pp. 2858-2862 ◽  
Author(s):  
Ronald Kaminsky ◽  
Reto Brun
Keyword(s):  
Mammalian Cells ◽  
Leishmania Donovani ◽  
Central Nervous System Involvement ◽  
Multidrug Resistant ◽  
Trypanosoma Evansi ◽  
Rodent Model ◽  
Resistant Organism ◽  
Intracellular Parasites

ABSTRACT Trybizine hydrochloride [O,O′-bis(4,6-diamino-1,2-dihydro-2,2-tetramethylene-s-triazine-1-yl)-1,6-hexanediol dihydrochloride] was active in vitro against the sleeping sickness-causing agents Trypanosoma brucei subsp.rhodesiense and T. brucei subsp.gambiense; against a multidrug-resistant organism, T. brucei subsp. brucei; and against animal-pathogenic organisms Trypanosoma evansi, Trypanosoma equiperdum, and Trypanosoma congolense; but not against the intracellular parasites Trypanosoma cruzi andLeishmania donovani. Cytotoxic effects against mammalian cells were observed at approximately 106-fold higher concentrations than those necessary to inhibit T. bruceisubsp. rhodesiense. Trybizine hydrochloride was able to eliminate T. brucei subsp. rhodesiense andT. brucei subsp. gambiense in an acute rodent model with four intraperitoneal doses of 0.25 mg kg of body weight−1 or four doses of 1 mg kg−1, respectively, or with four oral doses of 20 mg kg−1. The compound expressed activity against suramin-resistant T. evansi strains in mice. However, these concentrations were not sufficient to cure mice infected with multidrug-resistant T. brucei subsp. brucei. A late-stage rodent model with central nervous system involvement could not be cured, indicating that trybizine may not pass the blood-brain barrier in sufficient quantities.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

Cytological changes induced by platinum-thymine in sarcoma-180 cells: Electron microscopy study

1990 ◽  
Vol 48 (3) ◽  
pp. 290-291
Author(s):  
Gustav Ofosu
Keyword(s):  
Mammalian Cells ◽  
Antitumor Agent ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Limiting Factor ◽  
Sarcoma 180 ◽  
Electron Microscopic ◽  
Cytological Changes

Platinum-thymine has been found to be a potent antitumor agent, which is quite soluble in water, and lack nephrotoxicity as the dose-limiting factor. The drug has been shown to interact with DNA and inhibits DNA, RNA and protein synthesis in mammalian cells in vitro. This investigation was undertaken to elucidate the cytotoxic effects of piatinum-thymine on sarcoma-180 cells in vitro ultrastructurally, Sarcoma-180 tumor bearing mice were treated with intraperitoneal injection of platinum-thymine 40mg/kg. A concentration of 60μg/ml dose of platinum-thymine was used in in vitro experiments. Treatments were at varying time intervals of 3, 7 and 21 days for in vivo experiments, and 30, 60 and 120 min., 6, 12, and 24th in vitro. Controls were not treated with platinum-thymine.Electron microscopic analyses of the treated cells in vivo and in vitro showed drastic cytotoxic effect.

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