scholarly journals Ac-HSP20 Is Associated With the Infectivity and Encystation of Acanthamoeba castellanii

2021 ◽  
Vol 11 ◽  
Author(s):  
Ningning Wang ◽  
Hongyu Sun ◽  
Di Liu ◽  
Xiaoming Jiang ◽  
Meiyu Zheng ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Early Stage ◽  
High Titer ◽  
Acanthamoeba Castellanii ◽  
Free Living ◽  
Metal Affinity ◽  
Important Target ◽  
Free Living Amoeba ◽  
Amebic Encephalitis

Acanthamoeba castellanii is a pathogenic and opportunistic free-living amoeba that causes Acanthamoeba keratitis (AK) and granulomatous amebic encephalitis (GAE) in immunocompromised individuals. The biological and pathogenic characterizations behind this opportunistic protozoan is not fully understood. This study aimed to determine the biological functions of heat shock protein (HSP)-20 of A. castellanii (Ac-HSP20) involved in the maintenance of life cycle and the infectivity of A. castellanii. Immunoscreening A. castellanii cDNA library with A. castellanii infected rabbit sera identified three positive clones, one of them was a putative heat shock protein (Ac-HSP20). The recombinant 23 kDa Ac-HSP20 protein (rAc-HSP20) was successfully expressed in Escherichia coli BL21 (DE3) and purified using metal affinity chromatography. The rabbits immunized with rAc-HSP20 produced high titer antibody (1:25,600). Immunolocalization with the antibody identified the expression of native Ac-HSP20 on the surface of both A. castellanii trophozoites and cysts. Further, Western blot with antibody identified that the expression of native Ac-HSP20 was 7.5 times higher in cysts than in trophozoites. Blocking Ac-HSP20 on the membrane of trophozoites with specific antibody or silencing Ac-hsp20 gene transcription by siRNA inhibited their transformation into cysts at the early stage but returned to normal at the late stage by stimulating the transcription of Ac-hsp20. Incubation of trophozoites with anti-Ac-HSP20 IgG increased macrophage-involved phagocytosis to the protozoa and inhibited trophozoite infectivity on the cornea of rabbits compared with that without antibody. Our study provides that Ac-HSP20 is a surface antigen involved in the encystation and infectivity of A. castellanii and thus an important target for vaccine and drug development.

scholarly journals Circulating Heat Shock Protein 70 Is a Novel Biomarker for Early Diagnosis of Lung Cancer

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Tielong Tang ◽  
Chao Yang ◽  
Ham Ebo Brown ◽  
Jing Huang
Keyword(s):  
Lung Cancer ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Cancer Patients ◽  
Heat Shock Protein 70 ◽  
Early Stage ◽  
Growth And Survival ◽  
Lung Cancer Patients ◽  
Cellular Stresses ◽  
Sensitivity Specificity

Heat shock protein 70 (HSP70) was a highly conserved protein which was significantly induced in response to cellular stresses. HSP70 played an important role in the pathogenesis of cancer which stabilized the production of large amount of oncogenic proteins and finally supported growth and survival of tumor. However, there was no report about the diagnosis of circulating HSP70 in lung cancer patients. In this study, a total of 297 participants (lung cancer: 197, healthy control: 100) were enrolled in the detection of circulating HSP70 level in plasma by ELISA assay. The results indicated that circulating HSP70 significantly decreased in lung cancer patients compared to healthy controls (P<0.0001). Receiver operating characteristic (ROC) analysis showed that HSP70 (AUC: 82.2%, SN: 74.1%, SP: 80.0%) had higher diagnosis value than clinical existing biomarkers CEA (AUC: 80.1%, SN: 76.8%, SP: 67.3%) and CA 19-9 (AUC: 63.7%, SN: 64.2%, SP: 54.0%). In the analysis of early lung cancer patients, ROC results also revealed that HSP70 (AUC: 83.8%, SN: 71.2%, SP: 84.0%) have higher sensitivity, specificity, and AUC than CEA (AUC: 73.7%, SN: 73.2%, SP: 69.1%) and CA 19-9 (AUC: 61.5%, SN: 69.4%, SP: 53.4%). In analysis of specific histological classifications, HSP70 showed more valuable in the diagnosis of SCC (AUC: 85.9%, SN: 86.1.9%, SP: 81.0%) than ADC (AUC: 81.0%, SN: 69.1%, SP: 81.0%). Combined analysis of HSP70 and existing biomarker: CEA and CA 19-9 exhibited that HSP70 combined CEA and CA 19-9 showed the highest AUC (0.945, 95% CI, 0.855–1.000). The importance of our results was that we found decreased circulating HSP70, in combination with elevated CEA and CA 19-9, could be utilized in the diagnosis of early (stage I and II) lung cancer.

scholarly journals Mitigation of Expression of Virulence Genes in Legionella pneumophila Internalized in the Free-Living Amoeba Willaertia magna C2c Maky

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 447 ◽  
Author(s):  
Rayane Mouh Mameri ◽  
Jacques Bodennec ◽  
Laurent Bezin ◽  
Sandrine Demanèche
Keyword(s):  
Gene Expression ◽  
Legionella Pneumophila ◽  
Virulence Genes ◽  
Natural Habitat ◽  
Acanthamoeba Castellanii ◽  
Severe Form ◽  
Aquatic Environments ◽  
Free Living ◽  
Intracellular Parasites ◽  
Free Living Amoeba

Legionella pneumophila is a human pathogen responsible for a severe form of pneumonia named Legionnaire disease. Its natural habitat is aquatic environments, being in a free state or intracellular parasites of free-living amoebae, such as Acanthamoeba castellanii. This pathogen is able to replicate within some amoebae. Willaertia magna C2c Maky, a non-pathogenic amoeba, was previously demonstrated to resist to L. pneumophila and even to be able to eliminate the L. pneumophila strains Philadelphia, Lens, and Paris. Here, we studied the induction of seven virulence genes of three L. pneumophila strains (Paris, Philadelphia, and Lens) within W. magna C2c Maky in comparison within A. castellanii and with the gene expression level of L. pneumophila strains alone used as controls. We defined a gene expression-based virulence index to compare easily and without bias the transcript levels in different conditions and demonstrated that W. magna C2c Maky did not increase the virulence of L. pneumophila strains in contrast to A. castellanii. These results confirmed the non-permissiveness of W. magna C2c Maky toward L. pneumophila strains.

Expression of metabolic enzyme genes and heat-shock protein genes during embryonic development in diapause and non-diapause egg of multivoltine silkworm Bombyx mori

Biologia ◽  
2008 ◽  
Vol 63 (5) ◽  
Author(s):  
Ragunathan Saravanakumar ◽  
Kangayam Ponnuvel ◽  
Syed Qadri
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Bombyx Mori ◽  
Early Stage ◽  
Metabolic Enzyme ◽  
Dehydrogenase Gene ◽  
Heat Shock Protein Genes ◽  
High Level ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Silkworm Bombyx Mori

AbstractThe expression of metabolic enzyme genes and heat-shock protein genes (Hsp) during early embryogenesis in diapause and non-diapause eggs of the silkworm Bombyx mori was quantified by semi-quantitative RT-PCR. The trehalase gene (Tre) was expressed in non-diapause eggs up-to nine days, while in diapause eggs was not up regulated. The glycogen phosphorylase gene (GPase) was expressed in non-diapause eggs, whereas in diapause eggs a high level was observed in early stage, but down regulated in later stage. The phosphofructokinase gene (PFK) and sorbitol dehyrogenase-2 gene (SDH-2) expression was fluctuated in non-diapause eggs, whereas in diapause eggs these were expressed only at early stage and not observed in later stage. The glucose-6-phosphate dehydrogenase gene (G6P-DH) in non-diapause eggs was highly expressed during the differentiation phase and decreased in the organogenesis phase. In contrast to this, expression in diapause eggs was of low level during differentiation phase and of high level observed in the organogenesis phase. In the tissues, PFK and SDH-2 were selectively expressed in cuticle and midgut, whereas Tre expression was high in midgut and ovary of larvae incubated at 15°C. The Hsp (20.4, 20.8, 40, 70, and 90) were expressed in both diapause and non-diapause eggs. Their expression was, however, selective in tissues with Hsp20.4 in midgut and ovary, Hsp40 in head, Hsp70 in cuticle and Hsp90 in ovary and head in high amounts at 15°C. These results suggest that the metabolic enzyme genes studied except Hsp play a major role during embryogenesis of diapause and non-diapause silkworm.

scholarly journals Isoniazid Conjugated Magnetic Nanoparticles Loaded with Amphotericin B as a Potent Antiamoebic Agent against Acanthamoeba castellanii

Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 276
Author(s):  
Kawish Iqbal ◽  
Sumayah Abdelnasir Osman Abdalla ◽  
Ayaz Anwar ◽  
Kanwal Muhammad Iqbal ◽  
Muhammad Raza Shah ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Amphotericin B ◽  
Central Nervous System Infection ◽  
Acanthamoeba Castellanii ◽  
Acanthamoeba Keratitis ◽  
Free Living ◽  
Granulomatous Amoebic Encephalitis ◽  
Nano Drug Delivery ◽  
Free Living Amoeba ◽  
Acanthamoeba Species

The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC50 of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells.

scholarly journals Encystment Induces Down-Regulation of an Acetyltransferase-Like Gene in Acanthamoeba castellanii

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 321 ◽  
Author(s):  
Steven Rolland ◽  
Luce Mengue ◽  
Cyril Noël ◽  
Stéphanie Crapart ◽  
Anne Mercier ◽  
...  
Keyword(s):  
Bioinformatics Analysis ◽  
Acanthamoeba Castellanii ◽  
Acanthamoeba Keratitis ◽  
Free Living ◽  
Adverse Conditions ◽  
Genetic Modifications ◽  
Granulomatous Amoebic Encephalitis ◽  
Free Living Amoeba ◽  
Causative Agents

Acanthamoeba castellanii is a ubiquitous free-living amoeba. Pathogenic strains are causative agents of Acanthamoeba keratitis and granulomatous amoebic encephalitis. In response to adverse conditions, A. castellanii differentiate into cysts, which are metabolically inactive and resistant cells. This process, also named encystment, involves biochemical and genetic modifications that remain largely unknown. This study characterizes the role of the ACA1_384820 Acanthamoeba gene during encystment. This gene encodes a putative N-acetyltransferase, belonging to the Gcn5-related N-acetyltransferase (GNAT) family. We showed that expression of the ACA1_384820 gene was down-regulated as early as two hours after induction of encystment in A. castellanii. Interestingly, overexpression of the ACA1_384820 gene affects formation of cysts. Unexpectedly, the search of homologs of ACA1_384820 in the Eukaryota gene datasets failed, except for some species in the Acanthamoeba genus. Bioinformatics analysis suggested a possible lateral acquisition of this gene from prokaryotic cells. This study enabled us to describe a new Acanthamoeba gene that is down-regulated during encystment.

scholarly journals Legionella pneumophila Contains a Type II General Secretion Pathway Required for Growth in Amoebae as Well as for Secretion of the Msp Protease

1999 ◽  
Vol 67 (7) ◽  
pp. 3662-3666 ◽  
Author(s):  
Laura M. Hales ◽  
Howard A. Shuman
Keyword(s):  
Legionella Pneumophila ◽  
Acanthamoeba Castellanii ◽  
Gram Negative Bacteria ◽  
Type Ii ◽  
Free Living ◽  
Gram Negative ◽  
Secretion Pathway ◽  
Free Living Amoeba ◽  
Substitution Mutation

ABSTRACT We report the identification of a set of Legionella pneumophila genes that encode products with homology to proteins of the type II general secretion pathway of gram-negative bacteria. A strain containing a deletion-substitution mutation of two of these genes was unable to secrete the Msp protease. This strain was unable to multiply within the free-living amoeba Acanthamoeba castellanii yet was able to kill HL-60-derived macrophages. Because Msp is not required for growth in amoebae, other proteins which are important for growth in amoebae are likely secreted by this pathway.

34 DIFFERENTIALLY EXPRESSED PROTEINS OF EARLY-STAGE PLACENTA DERIVED FROM CLONED CAT EMBRYOS USING PROTEOMICS ANALYSIS

2012 ◽  
Vol 24 (1) ◽  
pp. 129
Author(s):  
J. I. Bang ◽  
D. W. Bae ◽  
Y. S. Kwon ◽  
G. K. Deb ◽  
B. H. Choi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Early Pregnancy ◽  
Protein Disulfide Isomerase ◽  
Triosephosphate Isomerase ◽  
Early Stage ◽  
Differentially Expressed ◽  
Differentially Expressed Proteins ◽  
Disulfide Isomerase ◽  
Protein Disulfide

We have previously demonstrated that differentially expressed proteins affect abnormal development and function of cloned term placenta. This is associated with cloned fetus morbidity and mortality. We also frequently observed loss of the cloned fetus and failed development during early pregnancy periods. To confirm the pattern of important gene expression in cloned placenta during pre- and post-implantation, we investigated expression pattern of proteins in early stage (21 days) domestic cat placentas of cloned embryo transfer (CEP; n = 2) and artificial insemination (CP; n = 4) derived pregnancy. The differentially expressed proteins were investigated by 2-DE and MALDI-TOF/MS. Twenty-three proteins were up- and down-regulated at least 1.5-fold in the CEP (P < 0.05) compared with the CP. Differentially expressed proteins were analysed using PDQest program and statistically analysed by 1-way ANOVA using the SPSS software. In CEP, 13 proteins were up-regulated, such as 78-kDa glucose-regulated protein (GRP78), annexin A2 (ANXA2), protein DJ-1 (DJ1), adenylate kinase isoenzyme 1 (AK1), protein disulfide-isomerase A3 (PDIA3), heat shock protein β-1 (HSPB1), actin, cytoplasmic 1 (ACTB), serum albumin (ALB), protein disulfide-isomerase A6 (PDIA6), G protein-regulated inducer of neurite outgrowth 1 (GRIN1) and triosephosphate isomerase (TIM). In contrast, 10 proteins were down-regulated, such as vinculin (VCL), triosephosphate isomerase (TIM), heterogeneous nuclear ribonucleoprotein H (hnRNPH), tropomyosin α-4 (TPM4), 60-kDa heat shock protein, mitochondrial (Hsp60), serum albumin (ALB), calumenin (CALU), keratin type 1 (CK1) and prohibitin (PHB). To validate the identified proteins in the CEP compared with the CP, we investigate a peptide sequences using MALDI-TOF/TOF tandem mass spectrometry. The sequence information obtained a high ions score from NCBI and Swiss-Prot databases. In conclusion, we did identify abnormal expression of proteins that might be associated with impaired development of CEP, which may endanger the cloned fetus during early pregnancy. This work was partly supported by the BK21 program and the KOSEF (10525010001-05N2501-00110) and the Next-generation BioGreen21 program (No. PJ007990012011).

Synthesis of diphosphoinositide by a supernatant fraction from Acanthamoeba castellanii

1976 ◽  
Vol 54 (9) ◽  
pp. 772-777 ◽  
Author(s):  
J. Thomas Buckley
Keyword(s):  
Acanthamoeba Castellanii ◽  
Supernatant Fraction ◽  
Two Dimensional ◽  
Free Living ◽  
Low Concentrations ◽  
Free Living Amoeba

Homogenates of the free-living amoeba Acanthamoeba castellanii incorporate phosphate from [γ-32P]ATP into a lipid which co-chromatographs with diphosphoinositide on one- and two-dimensional chromatography. Incorporation into lipids similar in mobility to triphosphoinositide is not detected. The product co-chromatographs with diphosphoinositide whether exogenous phosphatidylinositol or total amoeba lipid is the substrate. The inositide kinase is almost entirely located in the supernatant fraction after centrifugation at 100 000 g. Incorporation of phosphate from [γ-32P]ATP is linear for at least 15 min in the presence of 0.5 mM phosphatidylinositol. The enzyme requires Mg2+ or Mn2+ as well as ATP and it is not affected by low concentrations of Ca2+. The apparent Km for phosphatidylinositol is 2 mM. Both ADP and cAMP inhibit the reaction.

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