Transcriptional analysis of in vivo Plasmodium yoelii liver stage gene expression

2005 ◽  
Vol 142 (2) ◽  
pp. 177-183 ◽  
Author(s):  
John B. Sacci ◽  
Jose M.C. Ribeiro ◽  
Fengying Huang ◽  
Uzma Alam ◽  
Joshua A. Russell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plasmodium Yoelii ◽  
Transcriptional Analysis ◽  
Liver Stage

scholarly journals Transcriptome of Proteus mirabilis in the Murine Urinary Tract: Virulence and Nitrogen Assimilation Gene Expression

2011 ◽  
Vol 79 (7) ◽  
pp. 2619-2631 ◽  
Author(s):  
Melanie M. Pearson ◽  
Alejandra Yep ◽  
Sara N. Smith ◽  
Harry L. T. Mobley
Keyword(s):  
Gene Expression ◽  
Urinary Tract ◽  
Glutamate Dehydrogenase ◽  
Proteus Mirabilis ◽  
Transcriptional Analysis ◽  
Broth Culture ◽  
Pathogenic Potential ◽  
Content Type ◽  
Tract Infections

ABSTRACTThe enteric bacteriumProteus mirabilisis a common cause of complicated urinary tract infections. In this study, microarrays were used to analyzeP. mirabilisgene expressionin vivofrom experimentally infected mice. Urine was collected at 1, 3, and 7 days postinfection, and RNA was isolated from bacteria in the urine for transcriptional analysis. Across nine microarrays, 471 genes were upregulated and 82 were downregulatedin vivocompared toin vitrobroth culture. Genes upregulatedin vivoencoded mannose-resistantProteus-like (MR/P) fimbriae, urease, iron uptake systems, amino acid and peptide transporters, pyruvate metabolism enzymes, and a portion of the tricarboxylic acid (TCA) cycle enzymes. Flagella were downregulated. Ammonia assimilation geneglnA(glutamine synthetase) was repressedin vivo, whilegdhA(glutamate dehydrogenase) was upregulatedin vivo. Contrary to our expectations, ammonia availability due to urease activity inP. mirabilisdid not drive this gene expression. AgdhAmutant was growth deficient in minimal medium with citrate as the sole carbon source, and loss ofgdhAresulted in a significant fitness defect in the mouse model of urinary tract infection. UnlikeEscherichia coli, which repressesgdhAand upregulatesglnAin vivoand cannot utilize citrate, the data suggest thatP. mirabilisuses glutamate dehydrogenase to monitor carbon-nitrogen balance, and this ability contributes to the pathogenic potential ofP. mirabilisin the urinary tract.

scholarly journals Chemically Attenuated Blood-Stage Plasmodium yoelii Parasites Induce Long-Lived and Strain-Transcending Protection

2016 ◽  
Vol 84 (8) ◽  
pp. 2274-2288 ◽  
Author(s):  
Amber I. Raja ◽  
Yeping Cai ◽  
Jennifer M. Reiman ◽  
Penny Groves ◽  
Sumana Chakravarty ◽  
...  
Keyword(s):  
T Cells ◽  
Strong Support ◽  
Plasmodium Yoelii ◽  
Blood Stage ◽  
Liver Stage ◽  
Content Type ◽  
Successful Vaccine ◽  
Blood Stage Infection ◽  
Induced Immunity

The development of a vaccine is essential for the elimination of malaria. However, despite many years of effort, a successful vaccine has not been achieved. Most subunit vaccine candidates tested in clinical trials have provided limited efficacy, and thus attenuated whole-parasite vaccines are now receiving close scrutiny. Here, we test chemically attenuatedPlasmodium yoelii17X and demonstrate significant protection following homologous and heterologous blood-stage challenge. Protection against blood-stage infection persisted for at least 9 months. Activation of both CD4+and CD8+T cells was shown after vaccination; however,in vivostudies demonstrated a pivotal role for both CD4+T cells and B cells since the absence of either cell type led to loss of vaccine-induced protection. In spite of significant activation of circulating CD8+T cells, liver-stage immunity was not evident. Neither did vaccine-induced CD8+T cells contribute to blood-stage protection; rather, these cells contributed to pathogenesis, since all vaccinated mice depleted of both CD4+and CD8+T cells survived a challenge infection. This study provides critical insight into whole-parasite vaccine-induced immunity and strong support for testing whole-parasite vaccines in humans.

scholarly journals Elucidating Spatially-Resolved Changes in Host Signaling During Plasmodium Liver-Stage Infection

2022 ◽  
Vol 11 ◽  
Author(s):  
Elizabeth K. K. Glennon ◽  
Tinotenda Tongogara ◽  
Veronica I. Primavera ◽  
Sophia M. Reeder ◽  
Ling Wei ◽  
...  
Keyword(s):  
Blood Stream ◽  
Plasmodium Yoelii ◽  
Liver Stage ◽  
Infected Hepatocyte ◽  
Spatially Resolved ◽  
Spatial Profiling ◽  
Host Signaling ◽  
Infected Cells ◽  
Spatial Locations

Upon transmission to the human host, Plasmodium sporozoites exit the skin, are taken up by the blood stream, and then travel to the liver where they infect and significantly modify a single hepatocyte. Low infection rates within the liver have made proteomic studies of infected hepatocytes challenging, particularly in vivo, and existing studies have been largely unable to consider how protein and phosphoprotein differences are altered at different spatial locations within the heterogeneous liver. Using digital spatial profiling, we characterized changes in host signaling during Plasmodium yoelii infection in vivo without disrupting the liver tissue. Moreover, we measured alterations in protein expression around infected hepatocytes and identified a subset of CD163+ Kupffer cells that migrate towards infected cells during infection. These data offer the first insight into the heterogeneous microenvironment that surrounds the infected hepatocyte and provide insights into how the parasite may alter its milieu to influence its survival and modulate immunity.

scholarly journals Model forIn VivoAssessment of Humoral Protection against Malaria Sporozoite Challenge by Passive Transfer of Monoclonal Antibodies and Immune Serum

2013 ◽  
Vol 82 (2) ◽  
pp. 808-817 ◽  
Author(s):  
Brandon K. Sack ◽  
Jessica L. Miller ◽  
Ashley M. Vaughan ◽  
Alyse Douglass ◽  
Alexis Kaushansky ◽  
...  
Keyword(s):  
Natural Infection ◽  
Passive Transfer ◽  
Plasmodium Yoelii ◽  
Immune Serum ◽  
Liver Stage ◽  
Content Type ◽  
Mosquito Bite ◽  
Infection Inhibition ◽  
Liver Infection

ABSTRACTEvidence from clinical trials of malaria vaccine candidates suggests that both cell-mediated and humoral immunity to pre-erythrocytic parasite stages can provide protection against infection. Novel pre-erythrocytic antibody (Ab) targets could be key to improving vaccine formulations, which are currently based on targeting antigens such as the circumsporozoite protein (CSP). However, methods to assess the effects of sporozoite-specific Abs on pre-erythrocytic infectionin vivoremain underdeveloped. Here, we combined passive transfer of monoclonal Abs (MAbs) or immune serum with a luciferase-expressingPlasmodium yoeliisporozoite challenge to assess Ab-mediated inhibition of liver infection in mice. Passive transfer of aP. yoeliiCSP MAb showed inhibition of liver infection when mice were challenged with sporozoites either intravenously or by infectious mosquito bite. However, inhibition was most potent for the mosquito bite challenge, leading to a more significant reduction of liver-stage burden and even a lack of progression to blood-stage parasitemia. This suggests that Abs provide effective protection against a natural infection. Inhibition of liver infection was also achieved by passive transfer of immune serum from whole-parasite-immunized mice. Furthermore, we demonstrated that passive transfer of a MAb againstP. falciparumCSP inhibited liver-stage infection in a humanized mouse/P. falciparumchallenge model. Together, these models constitute unique and sensitivein vivomethods to assess serum-transferable protection againstPlasmodiumsporozoite challenge.

scholarly journals Human Antibodies against Plasmodium falciparumLiver-Stage Antigen 3 Cross-React with Plasmodium yoelii Preerythrocytic-Stage Epitopes and Inhibit Sporozoite Invasion In Vitro and In Vivo

2001 ◽  
Vol 69 (6) ◽  
pp. 3845-3852 ◽  
Author(s):  
Karima Brahimi ◽  
Edgar Badell ◽  
Jean-Pierre Sauzet ◽  
Lbachir BenMohamed ◽  
Pierre Daubersies ◽  
...  
Keyword(s):  
Peripheral Blood Lymphocytes ◽  
Plasmodium Yoelii ◽  
T Cell Epitopes ◽  
Liver Stage ◽  
Human Antibodies ◽  
In Vitro Invasion ◽  
Synthetic Polypeptides ◽  
Mouse Hepatocytes

ABSTRACT The Plasmodium falciparum liver-stage antigen 3 (LSA3), a recently identified preerythrocytic antigen, induces protection against malaria in chimpanzees. Using antibodies from individuals with hyperimmunity to malaria affinity purified on recombinant or synthetic polypeptides of LSA3, we identified four non-cross-reactive B-cell epitopes in Plasmodium yoelii preerythrocytic stages. On sporozoites the P. yoelii protein detected has a molecular mass similar to that of LSA3. T-cell epitopes cross-reacting withP. yoelii were also demonstrated using peripheral blood lymphocytes from LSA3-immunized chimpanzees. In contrast, no cross-reactive epitopes were found in Plasmodium berghei. LSA3-specific human antibodies exerted up to 100% inhibition of in vitro invasion of P. yoelii sporozoites into mouse hepatocytes. This strong in vitro activity was reproduced in vivo by passive transfer of LSA3 antibodies. These results indicate that the homologous epitopes may be biologically functional and suggest that P. yoelii could be used as a model to assess the antisporozoite activity of anti-LSA3 antibodies.

scholarly journals Blast cells surviving acute myeloid leukemia induction therapy are in cycle with a signature of FOXM1 activity

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mark S. Williams ◽  
Naseer J. Basma ◽  
Fabio M. R. Amaral ◽  
Daniel H. Wiseman ◽  
Tim C. P. Somervaille
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Induction Chemotherapy ◽  
Myeloid Leukemia ◽  
Clonal Selection ◽  
Transcriptional Analysis ◽  
Cd34 Cells ◽  
Acute Myeloid

Abstract Background Disease relapse remains common following treatment of acute myeloid leukemia (AML) and is due to chemoresistance of leukemia cells with disease repopulating potential. To date, attempts to define the characteristics of in vivo resistant blasts have focused on comparisons between leukemic cells at presentation and relapse. However, further treatment responses are often seen following relapse, suggesting that most blasts remain chemosensitive. We sought to characterise in vivo chemoresistant blasts by studying the transcriptional and genetic features of blasts from before and shortly after induction chemotherapy using paired samples from six patients with primary refractory AML. Methods Leukemic blasts were isolated by fluorescence-activated cell sorting. Fluorescence in situ hybridization (FISH), targeted genetic sequencing and detailed immunophenotypic analysis were used to confirm that sorted cells were leukemic. Sorted blasts were subjected to RNA sequencing. Lentiviral vectors expressing short hairpin RNAs were used to assess the effect of FOXM1 knockdown on colony forming capacity, proliferative capacity and apoptosis in cell lines, primary AML cells and CD34+ cells from healthy donors. Results Molecular genetic analysis revealed early clonal selection occurring after induction chemotherapy. Immunophenotypic characterisation found leukemia-associated immunophenotypes in all cases that persisted following treatment. Despite the genetic heterogeneity of the leukemias studied, transcriptional analysis found concerted changes in gene expression in resistant blasts. Remarkably, the gene expression signature suggested that post-chemotherapy blasts were more proliferative than those at presentation. Resistant blasts also appeared less differentiated and expressed leukemia stem cell (LSC) maintenance genes. However, the proportion of immunophenotypically defined LSCs appeared to decrease following treatment, with implications for the targeting of these cells on the basis of cell surface antigen expression. The refractory gene signature was highly enriched with targets of the transcription factor FOXM1. shRNA knockdown experiments demonstrated that the viability of primary AML cells, but not normal CD34+ cells, depended on FOXM1 expression. Conclusions We found that chemorefractory blasts from leukemias with varied genetic backgrounds expressed a common transcriptional program. In contrast to the notion that LSC quiescence confers resistance to chemotherapy we find that refractory blasts are both actively proliferating and enriched with LSC maintenance genes. Using primary patient material from a relevant clinical context we also provide further support for the role of FOXM1 in chemotherapy resistance, proliferation and stem cell function in AML.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

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