scholarly journals Isolation of a glycoprotein responsible for the enhanced concanavalin A agglutinability of erythrocytes in Yoshida-ascites-sarcoma-bearing rats: the mechanism of paraneoplastic syndromes

1993 ◽  
Vol 292 (1) ◽  
pp. 163-170 ◽  
Author(s):  
R D Kalraiya ◽  
A Sanjay ◽  
N G Mehta
Keyword(s):  
Molecular Mass ◽  
Concanavalin A ◽  
Paraneoplastic Syndromes ◽  
Host Cells ◽  
Ascites Fluid ◽  
Con A ◽  
Tumour Bearing ◽  
Apparent Homogeneity

As a model for the development of paraneoplastic syndromes, we have studied the mechanism by which erythrocytes in the circulation of rats bearing intraperitoneal Yoshida ascites sarcoma acquire higher agglutinability with concanavalin A (Con A). The in vitro incubation of erythrocytes from normal animals with the cell-free ascites fluid or the plasma of tumour-bearing animals is able to confer an enhanced agglutinability on the cells. Fractionation of the ascites fluid has yielded three subfractions that are active in vitro. Two of these, occurring in small amounts, are a particulate fraction rich in plasma-membrane markers and a soluble fraction containing protein of molecular mass equal to or less than 50 kDa. These two are, however, unable to affect the agglutinability of erythrocytes in vivo, i.e. when injected intraperitoneally into normal rats. The third, and major, fraction consists of proteins of molecular mass equal to or greater than 680 kDa, and is able to modify the erythrocyte agglutinability in vivo. From this fraction, by using a combination of Con A affinity chromatography, gel filtration, (NH4)2SO4 fractionation and DEAE-Sephadex chromatography, an active protein has been purified to apparent homogeneity. It yields a subunit of 310 kDa in the presence of SDS and further breaks down into a polypeptide of 170 kDa when reduced with 2-mercaptoethanol. It has a pI of 5.35. The protein is rich in Glx, and appears to contain hybrid-type N-linked oligosaccharides. The protein is also present in the blood plasma of tumour-bearing, but not normal, rats. The radioiodinated protein binds to the erythrocyte surface adding about 7400 molecules/cell. The study unequivocally demonstrates that a protein from the tumour fluid can appear in the circulation, interact with host cells that are not in contact with the tumour and modify their properties.

Effects of the Japanese herbal medicine ‘Inchinko-to’ (TJ-135) on concanavalin A-induced hepatitis in mice

2000 ◽  
Vol 99 (5) ◽  
pp. 421-431 ◽  
Author(s):  
Masayoshi YAMASHIKI ◽  
Akihito MASE ◽  
Ichiro ARAI ◽  
Xian-Xi HUANG ◽  
Tsutomu NOBORI ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Concanavalin A ◽  
Serum Levels ◽  
Interferon Γ ◽  
Hepatic Necrosis ◽  
Interleukin 12 ◽  
Con A ◽  
Ifn Γ

Inchinko-to (TJ-135) is a herbal medicine consisting of three kinds of crude drugs, and in Japan it is administered mainly to patients with cholestasis. The present study evaluated the effects of TJ-135 on concanavalin A (con A)-induced hepatitis in mice in vivo and con A-induced cytokine production in vitro. When mice were pretreated with oral TJ-135 for 1 week before intravenous con A injection, the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly decreased 8 h after con A administration (-82%, -96% and -66% respectively). In histological investigations, sub-massive hepatic necrosis accompanying inflammatory cell infiltration was not observed in mice pretreated with TJ-135. Serum levels of interleukin-12 (IL-12), interferon-γ (IFN-γ) and IL-2 were significantly lower in mice pretreated with TJ-135 compared with controls, while IL-10 levels were higher in these mice. Intrasplenic IL-12 levels were significantly lower in mice pretreated with TJ-135, while intrasplenic IL-10 levels were higher in these mice. In vitro, IL-10 production by splenocytes was increased by the addition of TJ-135 to the culture medium, whereas the production of IL-12 and IFN-γ was inhibited. These results suggest that con A-induced hepatitis was ameliorated by pretreatment with TJ-135. With regard to the mechanism of these effects of TJ-135, we speculate that TJ-135 inhibits the production of inflammatory cytokine and enhances the production of anti-inflammatory cytokines. Therefore administration of TJ-135 may be useful in patients with severe acute hepatitis accompanying cholestasis or in those with autoimmune hepatitis.

scholarly journals Two distinct mechanisms regulate the in vivo generation of cytotoxic T cells.

1982 ◽  
Vol 156 (3) ◽  
pp. 918-923 ◽  
Author(s):  
M S Sy ◽  
S H Lee ◽  
M Tsurufuji ◽  
K L Rock ◽  
B Benacerraf ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Concanavalin A ◽  
Cytotoxic T Cells ◽  
Cytolytic T Lymphocytes ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Con A

Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.

Penetration of concanavalin-A-treated Chinese hamster oocytes by golden hamster spermatozoa in vitro, and chromosome analysis of hybrid 1-cell zygotes

Zygote ◽  
1996 ◽  
Vol 4 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Seiji Watanabe ◽  
Hiroyuki Tateno ◽  
Yujiroh Kamiguchi
Keyword(s):  
Concanavalin A ◽  
Golden Hamster ◽  
Chinese Hamster ◽  
Chromosome Analysis ◽  
Con A ◽  
Positive Effects ◽  
Sperm Binding ◽  
Sperm Penetration

SummaryPretreatment of zona-free Chinese hamster (CH) oocytes with three kinds of lectin – concanavalin A (Con-A), phytohaemagglutinin-P (PHA) and wheat germ agglutinin (WGA) – was attempted in order to improve penetration by golden hamster (GH) spermatozoa in vitro. Con-A had no significant effect on penetration at 2 μg/ml, adequately facilitated oocyte-sperm fusion at 4 μg/ml, and caused excessive sperm binding and resultant severe polyspermy at 10 μg/ml. Neither PHA nor WGA had positive effects on sperm penetration at any concentrations (2–10 μg/ml) examined. Using the Con-A (4 μg/ml)pretreatment, high rates of interspecific fertilisation and subsequent chromosome analysis of hybrid 1-cell zygotes were achieved. Among 258 CH oocytes used, 212 (82.2%) were fertilised and 153 (72.2% of fertilised ova) developed to the first cleavage metaphase. Eventually, 132 CH-derived chromosome complements and 153 GH-derived ones were successfully karyoanalysed. Incidences of aneuploidy and structural anomaly were 3.1% and 2.3% in CH complements, and 1.4% and 6.5% in GH complements, respectively. These incidences were not significantly different from those obtained by intraspecific in vivo fertilisation, suggesting that our interspecific in vitro fertilisation system does not cause chromosome aberrations.

scholarly journals Blocking of in vitro and in vivo susceptibility to mouse hepatitis virus.

1977 ◽  
Vol 146 (5) ◽  
pp. 1467-1472 ◽  
Author(s):  
W Y Weiser ◽  
F B Bang
Keyword(s):  
Inflammatory Response ◽  
Concanavalin A ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Spleen Cells ◽  
Con A ◽  
Virus Inoculation ◽  
Inoculation Site

By pretreatment with concanavalin A (Con A) both in vivo and in vitro genetically susceptible mice and their cultured macrophages have been converted to animals and cells which are phenotypically resistant to mouse hepatitus virus (MHV). Con A at 1.0 mg/mouse decreased the mortality from 100% to less than 40% by inducing a prominent inflammatory response, increasing the number of macrophages in the virus inoculation site, and producing a population of macrophages not uniformly susceptible to the virus. In addition, mediators derived from Con A-treated spleen cells conferred resistance to normally susceptible syngeneic macrophages to 100 TCID50 of MHV.

Giant Mitochondria in Hepatocytes Following Concanavalin A Administration

1975 ◽  
Vol 33 ◽  
pp. 310-311
Author(s):  
Waykin Nopanitaya ◽  
Marvin L. Tyan
Keyword(s):  
Single Dose ◽  
Intravenous Injection ◽  
Concanavalin A ◽  
Ultrastructural Changes ◽  
Con A ◽  
Giant Mitochondria ◽  
Cell Plasma ◽  
Cervical Dislocation

Concanavalin A (Con A), a protein obtained from the jack bean, has been used intensively in vitro in a topographical study of the structure of cell plasma membrane. In vivo toxicity following a single dose of intravenous injection of Con A has been recently noted in the mouse during an investigation of the immunosuppressive properties of this known phytohaemagglutinin. In that preliminary report, histopathological changes in various organs including the liver were described by light microscopy. Ultrastructural changes in hepatocytes caused by Con A have not been described. Presented here are observations on the ultrastructural alterations in hepatocytes and their mitochondria following a single dose of intravenous injection of this toxic lectin.Concanavalin A in a balanced salt solution (800 μg Con A in 0.2 ml) was individually given intravenously to adult male B6D2F1 mice. Groups of mice were sacrificed by cervical dislocation 1, 2, 7, 14, and 28 days after the injection of Con A.

ACIS, A Novel KepTide™, Binds to ACE-2 Receptor and Inhibits the Infection of SARS-CoV2 Virus in vitro in Primate Kidney Cells: Therapeutic Implications for COVID-19 (Preprint)

2020 ◽  
Author(s):  
Avik Sotira Scientific
Keyword(s):  
Social Life ◽  
Plaque Assay ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
Crystallographic Structure ◽  
Therapeutic Implications ◽  
Biochemical Assays ◽  
Targeted Medicine

UNSTRUCTURED Coronavirus disease 2019 (COVID-19) is a severe acute respiratory syndrome (SARS) caused by a virus known as SARS-Coronavirus 2 (SARS-CoV2). Without a targeted-medicine, this disease has been causing a massive humanitarian crisis not only in terms of mortality, but also imposing a lasting damage to social life and economic progress of humankind. Therefore, an immediate therapeutic strategy needs to be intervened to mitigate this global crisis. Here, we report a novel KepTide™ (Knock-End Peptide) therapy that nullifies SARS-CoV2 infection. SARS-CoV2 employs its surface glycoprotein “spike” (S-glycoprotein) to interact with angiotensin converting enzyme-2 (ACE-2) receptor for its infection in host cells. Based on our in-silico-based homology modeling study validated with a recent X-ray crystallographic structure (PDB ID:6M0J), we have identified that a conserved motif of S-glycoprotein that intimately engages multiple hydrogen-bond (H-bond) interactions with ACE-2 enzyme. Accordingly, we designed a peptide, termed as ACIS (ACE-2 Inhibitory motif of Spike), that displayed significant affinity towards ACE-2 enzyme as confirmed by biochemical assays such as BLItz and fluorescence polarization assays. Interestingly, more than one biochemical modifications were adopted in ACIS in order to enhance the inhibitory action of ACIS and hence called as KEpTide™. Consequently, a monolayer invasion assay, plaque assay and dual immunofluorescence analysis further revealed that KEpTide™ efficiently mitigated the infection of SARS-CoV2 in vitro in VERO E6 cells. Finally, evaluating the relative abundance of ACIS in lungs and the potential side-effects in vivo in mice, our current study discovers a novel KepTide™ therapy that is safe, stable, and robust to attenuate the infection of SARS-CoV2 virus if administered intranasally. INTERNATIONAL REGISTERED REPORT RR2-https://doi.org/10.1101/2020.10.13.337584

scholarly journals Effective decellularisation of human saphenous veins for biocompatible arterial tissue engineering applications: Bench optimisation and feasibility in vivo testing

2021 ◽  
Vol 12 ◽  
pp. 204173142098752
Author(s):  
Nadiah S Sulaiman ◽  
Andrew R Bond ◽  
Vito D Bruno ◽  
John Joseph ◽  
Jason L Johnson ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Vascular Tissue ◽  
Sodium Dodecyl ◽  
Host Cells ◽  
Replacement Model ◽  
In Vivo Testing ◽  
Vascular Scaffolds

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

scholarly journals Lipoproteins Are Responsible for the Pro-Inflammatory Property of Staphylococcus aureus Extracellular Vesicles

2021 ◽  
Vol 22 (13) ◽  
pp. 7099
Author(s):  
Pradeep Kumar Kopparapu ◽  
Meghshree Deshmukh ◽  
Zhicheng Hu ◽  
Majd Mohammad ◽  
Marco Maugeri ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Inflammatory Responses ◽  
Surface Proteins ◽  
Host Cells ◽  
Immune Stimulation ◽  
Domains Of Life ◽  
Major Surface ◽  
Staphylococcal Aureus

Staphylococcal aureus (S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria–bacteria and bacteria–host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.

scholarly journals Lankesterella (Apicomplexa, Lankesterellidae) Blood Parasites of Passeriform Birds: Prevalence, Molecular and Morphological Characterization, with Notes on Sporozoite Persistence In Vivo and Development In Vitro

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1451
Author(s):  
Carolina Romeiro Fernandes Chagas ◽  
Josef Harl ◽  
Vytautas Preikša ◽  
Dovilė Bukauskaitė ◽  
Mikas Ilgūnas ◽  
...  
Keyword(s):  
Morphological Characterization ◽  
Life Cycles ◽  
Diagnostic Methods ◽  
Host Cells ◽  
Blood Parasites ◽  
Serinus Canaria ◽  
Long Time ◽  
Development In Vitro

Recent studies confirmed that some Hepatozoon-like blood parasites (Apicomplexa) of birds are closely related to the amphibian parasite Lankesterella minima. Little is known about the biology of these pathogens in birds, including their distribution, life cycles, specificity, vectors, and molecular characterization. Using blood samples of 641 birds from 16 species, we (i) determined the prevalence and molecular diversity of Lankesterella parasites in naturally infected birds; (ii) investigated the development of Lankesterella kabeeni in laboratory-reared mosquitoes, Culex pipiens forma molestus and Aedes aegypti; and (iii) tested experimentally the susceptibility of domestic canaries, Serinus canaria, to this parasite. This study combined molecular and morphological diagnostic methods and determined 11% prevalence of Lankesterella parasites in Acrocephalidae birds; 16 Lankesterella lineages with a certain degree of host specificity and two new species (Lankesterella vacuolata n. sp. and Lankesterella macrovacuolata n. sp.) were found and characterized. Lankesterella kabeeni (formerly Hepatozoon kabeeni) was re-described. Serinus canaria were resistant after various experimental exposures. Lankesterella sporozoites rapidly escaped from host cells in vitro. Sporozoites persisted for a long time in infected mosquitoes (up to 42 days post exposure). Our study demonstrated a high diversity of Lankesterella parasites in birds, and showed that several avian Hepatozoon-like parasites, in fact, belong to Lankesterella genus.

Cellular and immunological basis of the host-parasite relationship during infection withNeospora caninum

Parasitology ◽  
2006 ◽  
Vol 133 (3) ◽  
pp. 261-278 ◽  
Author(s):  
A. HEMPHILL ◽  
N. VONLAUFEN ◽  
A. NAGULESWARAN
Keyword(s):  
Host Cell ◽  
Cell Biology ◽  
Neospora Caninum ◽  
Host Cells ◽  
Term Survival ◽  
Prevention Of Infection ◽  
Parasite Relationship ◽  
Potential Applications

Neospora caninumis an apicomplexan parasite that is closely related toToxoplasma gondii, the causative agent of toxoplasmosis in humans and domestic animals. However, in contrast toT. gondii, N. caninumrepresents a major cause of abortion in cattle, pointing towards distinct differences in the biology of these two species. There are 3 distinct key features that represent potential targets for prevention of infection or intervention against disease caused byN. caninum. Firstly, tachyzoites are capable of infecting a large variety of host cellsin vitroandin vivo. Secondly, the parasite exploits its ability to respond to alterations in living conditions by converting into another stage (tachyzoite-to-bradyzoite orvice versa). Thirdly, by analogy withT. gondii, this parasite has evolved mechanisms that modulate its host cells according to its own requirements, and these must, especially in the case of the bradyzoite stage, involve mechanisms that ensure long-term survival of not only the parasite but also of the host cell. In order to elucidate the molecular and cellular bases of these important features ofN. caninum, cell culture-based approaches and laboratory animal models are being exploited. In this review, we will summarize the current achievements related to host cell and parasite cell biology, and will discuss potential applications for prevention of infection and/or disease by reviewing corresponding work performed in murine laboratory infection models and in cattle.

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