scholarly journals Rapid and sensitive detection ofFeline immunodeficiency virususing an insulated isothermal PCR-based assay with a point-of-need PCR detection platform

2015 ◽  
Vol 27 (4) ◽  
pp. 510-515 ◽  
Author(s):  
Rebecca Penrose Wilkes ◽  
Stephen A. Kania ◽  
Yun-Long Tsai ◽  
Pei-Yu Alison Lee ◽  
Hsiu-Hui Chang ◽  
...  
Keyword(s):  
Nested Pcr ◽  
Opportunistic Infections ◽  
Limit Of Detection ◽  
Leukemia Virus ◽  
Infectious Agent ◽  
In Vitro Transcription ◽  
Pcr Detection ◽  
Feline Leukemia Virus ◽  
Clinical Samples

Feline immunodeficiency virus (FIV) is an important infectious agent of cats. Clinical syndromes resulting from FIV infection include immunodeficiency, opportunistic infections, and neoplasia. In our study, a 5′ long terminal repeat/ gag region–based reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) was developed to amplify all known FIV strains to facilitate point-of-need FIV diagnosis. The RT-iiPCR method was applied in a point-of-need PCR detection platform—a field-deployable device capable of generating automatically interpreted RT-iiPCR results from nucleic acids within 1 hr. Limit of detection 95% of FIV RT-iiPCR was calculated to be 95 copies standard in vitro transcription RNA per reaction. Endpoint dilution studies with serial dilutions of an ATCC FIV type strain showed that the sensitivity of lyophilized FIV RT-iiPCR reagent was comparable to that of a reference nested PCR. The established reaction did not amplify any nontargeted feline pathogens, including Felid herpesvirus 1, feline coronavirus, Feline calicivirus, Feline leukemia virus, Mycoplasma haemofelis, and Chlamydophila felis. Based on analysis of 76 clinical samples (including blood and bone marrow) with the FIV RT-iiPCR, test sensitivity was 97.78% (44/45), specificity was 100.00% (31/31), and agreement was 98.65% (75/76), determined against a reference nested-PCR assay. A kappa value of 0.97 indicated excellent correlation between these 2 methods. The lyophilized FIV RT-iiPCR reagent, deployed on a user-friendly portable device, has potential utility for rapid and easy point-of-need detection of FIV in cats.

Recombination between feline leukemia virus subgroup B or C and endogenous env elements alters the in vitro biological activities of the viruses.

1992 ◽  
Vol 66 (6) ◽  
pp. 3976 ◽  
Author(s):  
R Pandey ◽  
A K Ghosh ◽  
D V Kumar ◽  
B A Bachman ◽  
D Shibata ◽  
...  
Keyword(s):  
Biological Activities ◽  
Leukemia Virus ◽  
Feline Leukemia Virus

FLVCRb: a Mitochondrial FLVCR Isoform Important for Erythropoiesis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4243-4243
Author(s):  
Deborah Chiabrando ◽  
Sonia Mercurio ◽  
Samuele Marro ◽  
Sharmila Fagoonee ◽  
Erika Messana ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Mouse Model ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Leukemia Virus ◽  
Feline Leukemia Virus ◽  
Knock Out ◽  
Skeletal Malformations ◽  
Fetal Erythropoiesis

Abstract Abstract 4243 Feline Leukemia Virus subgroup C Receptor (FLVCR) was originally identified and cloned as a cell-surface protein receptor for feline leukemia virus subgroup C, causing pure red blood cell aplasia in cats. Recent studies have demonstrated that FLVCR is a heme exporter which is essential for erythropoiesis. The heme efflux via FLVCR was shown to be essential for erythroid differentiation in K562 cells as well as in CD34+ precursors cells1. Moreover, Keel and co-authors have reported that Flvcr-null mice die in utero due to the failure of fetal erythropoiesis; also post-natal mice lacking FLVCR showed severe anemia. In addition to the erythroid defect, Flvcr-null embryos display defective growth and developmental anomalies2. We have identified an alternative transcription start site giving rise to a novel FLVCR isoform (FLVCRb). Flvcr-b transcript completely lacks the first exon of the canonical isoform (FLVCRa) and code for a putative 6 transmembrane domain containing protein ubiquitously expressed. In vitro over-expression of FLVCRa and FLVCRb showed that the two proteins display different subcellular localization. As expected, FLVCRa is localized at the cell membrane while FLVCRb is in the mitochondrial compartment. The mitochondrial localization of this novel isoform is further confirmed by the identification of a N-terminal mitochondrial sorting presequence. The mitochondrion is the site in which heme biosynthesis occurs. Although all the enzymatic reactions involved in heme synthesis are well characterized, how heme is exported to the cytosol is largely unknown. Because of FLVCRa is a heme exporter at the cell membrane, we hypothesized that FLVCRb could be the mitochondrial heme exporter. According to this hypothesis, FLVCRb expression increased following the stimulation of heme biosynthesis in vitro, in correlation with the increase in hemoglobin production. The ability of FLVCRb to bind and export heme out of the mitochondria is still under investigation. To gain insights into the specific roles of the two isoforms, we have generated Flvcr mutant mice different from those previously reported2. Keel and co-author generated a mouse model in which both FLVCRa and FLVCRb have been deleted. In our mouse model, FLVCRa has been specifically deleted while FLVCRb is still expressed (FLVCRa-null mice). Flvcr-a +/− mice were grossly normal, fertile and indistinguishable from their wild-type littermates. When Flvcr-a +/− mice were intercrossed, no Flvcr-a homozygous knock-out newborns were obtained. The analysis of the embryos from timed Flvcr-a +/− intercrosses showed that the Flvcr-a homozygous knock-out genotype was lethal between E14.5 and the birth. E13.5 Flvcr-a-null embryos showed multifocal and extended hemorrhages, visible in the limbs, head and throughout the body wall, as well as subcutaneous edema. Imcomplete vasculogenesis in the Flvcr-a-null embryos was observed at E11.5, a developmental stage in which hemorrhages were not still evident. This suggests that hemorrhages arise from a defect in the development of embryonic vasculature. Moreover, FLVCRa-null embryos showed skeletal abnormalities as demonstrated by Alcian blue-alizarin red staining. Skeletal malformations were evident in the limb where digits did not form properly and in the head where Meckel's cartilage was incomplete. It is interesting to note that this kind of malformations also occurs in Diamond Blackfan Anemia (DBA) patients. Surprisingly, flow cytometric analyses of E14.5 fetal liver cells double-stained for Ter119 (erythroid-specific antigen) and CD71 (transferrin receptor) showed normal erythropoiesis in Flvcr-a-null embryos, in opposition to what occurs in the previously reported Flvcr-null mice2. Taken together, these data demonstrated that FLVCRb is sufficient to support fetal erythropoiesis when the expression of FLVCRa is loss, likely exporting heme out of the mithocondrion for hemoglobin synthesis. Moreover, the loss of FLVCRa leads to incomplete vasculogenesis, hemorrhages and skeletal malformations highlighting new roles of FLVCRa in these processes. 1. Quigley JG et al. Identification of a human heme exporter that is essential for erythropoiesis. Cell 2004 2. Keel SB et al. A heme export protein is required for red blood cell differentiation and iron homeostasis. Science 2008. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Properties of Feline Leukemia Virus II. In Vitro Labeling of the Polypeptides 1

1974 ◽  
Vol 14 (3) ◽  
pp. 700-703 ◽  
Author(s):  
Leland F. Velicer ◽  
Donald C. Graves
Keyword(s):  
Leukemia Virus ◽  
Feline Leukemia Virus

scholarly journals Retrovirus-induced feline pure red blood cell aplasia: pathogenesis and response to suramin

Blood ◽  
1991 ◽  
Vol 77 (7) ◽  
pp. 1442-1451
Author(s):  
JL Abkowitz
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Mononuclear Cells ◽  
Leukemia Virus ◽  
Transcriptase Inhibitor ◽  
Feline Leukemia Virus ◽  
Erythroid Progenitors ◽  
Marrow Cultures

Feline leukemia virus, subgroup C/Sarma (FeLV-C/Sarma) induces pure red blood cell aplasia in cats. Although erythroid (BFU-E and CFU-E) and granulocyte/macrophage (CFU-GM) progenitors are infected with this virus, only erythropoiesis is impaired. Two to 3 weeks before the onset of anemia, CFU-E become undetectable in marrow cultures while earlier erythroid progenitors (BFU-E) persist, suggesting that FeLV-C/Sarma (presumably via its envelope glycoprotein gp70) inhibits the differentiation of BFU-E to CFU-E in vivo. To correlate in vitro observations with the progression of disease, prospective studies were performed in six cats. These studies showed that at the time that the frequencies of CFU-E decreased in marrow cultures, BFU-E no longer responded to hematopoietic growth factor(s), although the responses of CFU-GM were unchanged. In further studies, anemic cats received suramin, a reverse-transcriptase inhibitor with other diverse effects. Within 4 to 14 days, erythropoiesis improved and up to 1,616 CFU-E were detected per 10(5) marrow mononuclear cells. However, progenitor cells remained infected, suggesting that suramin modulated erythroid differentiation without inhibiting progenitor infection. These observations led to the hypothesis that the gp70 of FeLV-C/Sarma impairs BFU-E differentiation by interference with ligand/receptor interactions or signal transduction pathways unique to erythroid cells. Understanding this mechanism should provide insights into the interactions controlling early erythropoiesis.

scholarly journals Studies in feline long-term marrow culture: hematopoiesis on normal and feline leukemia virus infected stromal cells

Blood ◽  
1992 ◽  
Vol 80 (3) ◽  
pp. 651-662
Author(s):  
ML Linenberger ◽  
JL Abkowitz
Keyword(s):  
Stromal Cells ◽  
Mononuclear Cells ◽  
Clonal Selection ◽  
Leukemia Virus ◽  
Feline Leukemia Virus ◽  
Erythroid Progenitors ◽  
Gag Protein ◽  
Cell Engraftment

To study the effects of feline leukemia virus (FeLV) on the hematopoietic microenvironment, a two-step feline long-term marrow culture (LTMC) system was developed and characterized. The adherent, stromal layer of these cultures is composed of fibroblastoid cells (50% to 80%), macrophages (10% to 30%), fat cells (10% to 20%), and large, polygonal cells that express muscle actin (1% to 2%). When fresh, enriched marrow mononuclear cells (MMNC) were added to 3-week-old irradiated stromal cultures, nonadherent erythroid progenitors (BFU-E) and granulocyte/macrophage progenitors (CFU-GM) could be detected for up to 5 and 12 weeks, respectively. LTMC stromal layers established from marrow cells from cats viremic with either a nonpathogenic strain of FeLV (FeLV-A/61E) or the anemogenic strain FeLV-C/Sarma were morphologically equivalent to uninfected LTMC stromal layers, although more than 80% of the stromal cells expressed FeLV gag protein. When FeLV-infected stromal cultures were recharged with uninfected MMNC, altered patterns of hematopoiesis were observed, compared with recharged, uninfected stromal cultures. In cultures with infected stroma, fewer nonadherent cells (NAC), nonadherent BFU-E, and nonadherent CFU-GM were detected during the first 4 to 5 weeks after recharge. In contrast, greater numbers of NAC and nonadherent CFU-GM were found from weeks 5 to 12 after recharge. When FeLV-infected stromal cultures were recharged with MMNC from a cat heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase (G-6- PD), the percentage of nonadherent CFU-GM expressing the domestic type G-6-PD isoenzyme remained stable over time (mean % domestic [%d], 53% +/- 3%), and was equivalent to that of nonadherent CFU-GM maintained in uninfected cultures (mean %d, 56% +/- 3%), indicating that clonal drift or clonal selection was not responsible for the enhanced maintenance of CFU-GM. Furthermore, as only 10% to 20% of recharged hematopoietic cells became infected with FeLV in vitro, it is unlikely that the altered pattern was due to progenitor infection. We hypothesize that the increase in NAC and nonadherent CFU-GM in FeLV-infected cultures resulted from enhanced growth factor production by stromal cells. The two-step LTMC system may facilitate the characterization of stromal- derived factors that affect progenitor cell engraftment and proliferation.

scholarly journals Cell lines produce factors that induce fetal hemoglobin in human BFUe- derived colonies

Blood ◽  
1992 ◽  
Vol 80 (10) ◽  
pp. 2650-2655
Author(s):  
P Constantoulakis ◽  
M Walmsley ◽  
R Patient ◽  
T Papayannopoulou ◽  
T Enver ◽  
...  
Keyword(s):  
Cell Lines ◽  
Leukemia Virus ◽  
Fetal Hemoglobin ◽  
Feline Leukemia Virus ◽  
In Vitro Translation ◽  
Expression Cloning ◽  
Bladder Cell ◽  
Relative Production ◽  
Established Cell

Established cell lines were screened for secretion of activities than can stimulate fetal hemoglobin (HbF) production in adult burst-forming unit-erythroid (BFUe) cultures. Conditioned media from four cell lines, a human teratocarcinoma, an osteosarcoma, a bladder cell carcinoma, and feline leukemia virus (FeLV) A-infected feline fibroblasts (FEF-A cells), consistently increased the relative production of fetal globin in BFUe-derived colonies. In vitro translation of RNA from these cells in Xenopus oocytes yielded products that increased the gamma to gamma+beta ratio in adult erythroid colonies. These results demonstrate that a variety of cell lines produce factors that stimulate the production of HbF in vitro. The genes of such factors could be isolated by expression cloning of cDNA from cell lines using the Xenopus oocyte system.

Dlk1 Up Regulated Might Be an Important Event in Human MDS.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4842-4842
Author(s):  
Q.F. Xiao ◽  
Zi X. Chen ◽  
Dan D. Liu ◽  
Jian N. Cen ◽  
Jun He ◽  
...  
Keyword(s):  
Experimental System ◽  
K562 Cells ◽  
In Vitro Transcription ◽  
Clinical Samples ◽  
Mrna Levels ◽  
Amplification Protocol ◽  
Cd34 Cells ◽  
Normal Controls

Abstract The diagnosis of myelodysplastic syndrome (MDS) is made largely on the dysplastic morphology of BM cells from aspiration or biopsies. Prognosis scored by IPSS is depending on the percentage of marrow myeloblasts and the clonal cytogenetic abnormalities. To expand the understanding of genetic defects in hematopoietic cells of MDS in hope of finding novel genes correlated to pathogenesis and provide possible diagnostic marker for MDS, we have applied microarray to analyze the clinical samples from MDS patients. Total RNAs of CD34+ cells from 8 patients ( 2 RAEBt,2 RAEB,2 RA,1 RAS,1 CAA ) and one healthy people were extracted followed by a double in vitro transcription to circumvent the limited number of CD34+ cells. Following a modified Affymetrix target amplification protocol. Biotinylated cRNA was synthesized from 50 ng total RNA by double-round amplification and hybridized to an Human Genome U133 Plus 2.0 Array (Affymetrix). From the expression profile of 18404 different genes, we revealed that DNTT,MLL3,IL1R2,MAPK1,IGLL1 were down regulated while EGR-1, Rap1GAP or MAF were up regulated compared with normal controls. Most notably, Dlk1 was up regulated in MDS, while down regulated in AML and normal. By real-time RT-PCR we confirmed that in BMNCs the median levels of Dlk1 transcript in patients with RA and RAS were 2.55 (range, 0.00–23.7), RAEB and RAEBt were 8.24(range, 2.01–18.44), AML were 1.88 (range, 0.12–5.13), and other patients were 0.37(range, 0.00–1.79), respectively. The abundance of Dlk1 mRNA in MNCs from most MDS patients was markedly greater than that in the MNCs from others (P <0.05 ). Dlk1 expression in RAEB and RAEBt is markedly higher than AML (P <0.05 ) Forced expression of Dlk1 in transfected K562 cells resulted in faster growth than control cells, affected apoptosis induced by As2O3. and reduced the G2 arrested cells induced by TPA. By using the same experimental system we found that forced expression of Dlk1 can increase the mRNA levels of HES1 and p21WAF1 transcript variant 1. To elucidate the mechanisms we analyzed the levels of phosphorylated-p38 and p38 in Dlk1 transfected K562 cells treated with TPA. Dlk1 inhibited p38 phosphorylation while expression of p38 kept no change. These results support further investigation on the role of Dlk1 in abnormal hematopoiesis in MDSheterogeneous cell component. Diagnosis is currently depending on the dysplastic morphology of.

scholarly journals Application of in situ PCR for the Detection of Bovine Leukaemia Virus (BLV) Infection in Dendritic Cell cultures

2014 ◽  
Vol 58 (3) ◽  
pp. 347-352 ◽  
Author(s):  
Ewelina Iwan ◽  
Maria Szczotka ◽  
Jacek Kuźmak
Keyword(s):  
Cell Cultures ◽  
Nested Pcr ◽  
Leukemia Virus ◽  
Positive Control ◽  
Adherent Cell ◽  
Bovine Leukaemia Virus ◽  
Leukaemia Virus ◽  
Pcr Method

Abstract The aim of the study was to develop an in situ PCR (IS-PCR) method for detection of bovine leukemia virus (BLV) in cell cultures. Samples from five BLV positive and five BLV negative cows were collected and dendritic cells (DCs) from blood, bone marrow, spleen, and lymph node were cultured. Cultures prepared from healthy animals were infected with BLV. After two weeks, the cells were tested by nested PCR and IS-PCR for the presence of proviral DNA. As a positive control adherent cell line permanently infected with BLV was used. BLV was successfully detected by IS-PCR in DCs from naturally infected cattle and DCs infected in vitro. In control, non-infected DCs, the results of the reaction were negative. The results of provirus detection by IS-PCR were similar with these performed with nested PCR. Additionally, IS-PCR provides many advantages, like specific localisation of infection and smaller number of cells needed as template for PCR.

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