scholarly journals Comparative Study of the Anti-Human Cytomegalovirus Activities and Toxicities of a Tetrahydrofuran Phosphonate Analogue of Guanosine and Cidofovir

1999 ◽  
Vol 43 (3) ◽  
pp. 557-567 ◽  
Author(s):  
Jean Bedard ◽  
Suzanne May ◽  
Martin Lis ◽  
Leander Tryphonas ◽  
John Drach ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Guinea Pigs ◽  
Laboratory Strain ◽  
Drug Regimen ◽  
New Drugs ◽  
Murine Cytomegalovirus ◽  
Mcmv Infection ◽  
Drug Induced ◽  
Nuclear Modifications

ABSTRACT Cidofovir is the first nucleoside monophosphate analogue currently being used for the treatment of human cytomegalovirus (HCMV) retinitis in individuals with AIDS. Unfortunately, the period of therapy with the use of this compound may be limited due to the possible emergence of serious irreversible nephrotoxic effects. New drugs with improved toxicity profiles are needed. The goal of this study was to investigate the anticytomegaloviral properties and drug-induced toxicity of a novel phosphonate analogue, namely, (−)-2-(R)-dihydroxyphosphinoyl-5-(S)-(guanin-9′-yl-methyl) tetrahydrofuran (compound 1), in comparison with those of cidofovir. The inhibitory activities of both compounds on HCMV propagation in vitro were similar against the AD 169 and Towne strains, with 50% inhibitory concentrations ranging from 0.02 to 0.17 μg/ml for cidofovir and <0.05 to 0.09 μg/ml for compound 1. A clinical HCMV isolate that was resistant to ganciclovir and that had a known mutation within the UL54 DNA polymerase gene and a cidofovir-resistant laboratory strain derived from strain AD 169 remained sensitive to compound 1, whereas their susceptibilities to ganciclovir and cidofovir were reduced by 33- and 10-fold, respectively. Both compound 1 and cidofovir exhibited equal potencies in an experimentally induced murine cytomegalovirus (MCMV) infection in mice, with a prevention or prolongation of mean day to death at dosages of 1.0, 3.2, and 10.0 mg/kg of body weight/day. In cytotoxicity experiments, compound 1 was found to be generally more toxic than cidofovir in cell lines Hs68, HFF, and 3T3-L1 (which are permissive for HCMV or MCMV replication) but less toxic than cidofovir in MRC-5 cells (which are permissive for HCMV replication). Drug-induced toxic side effects were noticed for both compounds in rats and guinea pigs in a 5-day repeated-dose study. In guinea pigs, a greater weight loss was noticed with cidofovir than with compound 1 at dosages of 3.0 and 10.0 mg/kg/day. An opposite effect was detected in rats, which were treated with the compounds at relatively high dosages (up to 100 mg/kg/day). Compound 1 and cidofovir were nephrotoxic in both rats and guinea pigs, with the epithelium lining the proximal convoluted tubules in the renal cortex being the primary target site. The incidence and the severity of the lesions were found to be dose dependent. The lesions observed were characterized by cytoplasm degeneration and nuclear modifications such as karyomegaly, the presence of pseudoinclusions, apoptosis, and degenerative changes. In the guinea pig model, a greater incidence and severity of lesions were observed for cidofovir than for compound 1 (P < 0.001) with a drug regimen of 10 mg/kg/day.

scholarly journals Murine cytomegalovirus resistant to antivirals has genetic correlates with human cytomegalovirus

2005 ◽  
Vol 86 (8) ◽  
pp. 2141-2151 ◽  
Author(s):  
G. M. Scott ◽  
H.-L. Ng ◽  
C. J. Morton ◽  
M. W. Parker ◽  
W. D. Rawlinson
Keyword(s):  
Protein Kinase ◽  
Dna Polymerase ◽  
Human Cytomegalovirus ◽  
Murine Cytomegalovirus ◽  
Cross Resistance ◽  
Antiviral Resistance ◽  
Three Dimensional Model ◽  
Mcmv Infection

Human cytomegalovirus (HCMV) resistance to antivirals is a significant clinical problem. Murine cytomegalovirus (MCMV) infection of mice is a well-described animal model for in vivo studies of CMV pathogenesis, although the mechanisms of MCMV antiviral susceptibility need elucidation. Mutants resistant to nucleoside analogues aciclovir, adefovir, cidofovir, ganciclovir, penciclovir and valaciclovir, and the pyrophosphate analogue foscarnet were generated by in vitro passage of MCMV (Smith) in increasing concentrations of antiviral. All MCMV antiviral resistant mutants contained DNA polymerase mutations identical or similar to HCMV DNA polymerase mutations known to confer antiviral resistance. Mapping of the mutations onto an MCMV DNA polymerase three-dimensional model generated using the Thermococcus gorgonarius Tgo polymerase crystal structure showed that the DNA polymerase mutations potentially confer resistance through changes in regions surrounding a catalytic aspartate triad. The ganciclovir-, penciclovir- and valaciclovir-resistant isolates also contained mutations within MCMV M97 identical or similar to recognized GCV-resistant mutations of HCMV UL97 protein kinase, and demonstrated cross-resistance to antivirals of the same class. This strongly suggests that MCMV M97 has a similar role to HCMV UL97 in the phosphorylation of nucleoside analogue antivirals. All MCMV mutants demonstrated replication-impaired phenotypes, with the lowest titre and plaque size observed for isolates containing mutations in both DNA polymerase and M97. These findings indicate DNA polymerase and protein kinase regions of potential importance for antiviral susceptibility and replication. The similarities between MCMV and HCMV mutations that arise under antiviral selective pressure increase the utility of MCMV as a model for in vivo studies of CMV antiviral resistance.

scholarly journals Impact of new cyclooxygenase 2 inhibitors on human cytomegalovirus replication in vitro

2021 ◽  
pp. 135965352110640
Author(s):  
D Andouard ◽  
R Gueye ◽  
S Hantz ◽  
C Fagnère ◽  
B Liagre ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Laboratory Strain ◽  
Cyclooxygenase 2 ◽  
Immunocompromised Patients ◽  
Toxic Compound ◽  
Cox 2 ◽  
Cyclooxygenase 2 Inhibitors ◽  
Strain Ad169

Background Human cytomegalovirus (HCMV) is involved in complications on immunocompromised patients. Current therapeutics are associated with several drawbacks, such as nephrotoxicity. Purpose: As HCMV infection affects inflammation pathways, especially prostaglandin E2 (PGE2) production via cyclooxygenase 2 enzyme (COX-2), we designed 2'-hydroxychalcone compounds to inhibit human cytomegalovirus. Study design We first selected the most efficient new synthetic chalcones for their effect against COX-2-catalyzed PGE2. Study sample Among the selected compounds, we assessed the antiviral efficacy against different HCMV strains, such as the laboratory strain AD169 and clinical strains (naïve or multi-resistant to conventional drugs) and toxicity on human cells. Results The most efficient and less toxic compound (chalcone 7) was tested against HCMV in combination with other antiviral molecules: artesunate (ART), baicalein (BAI), maribavir (MBV), ganciclovir (GCV), and quercetin (QUER) using Compusyn software. Association of chalcone 7 with MBV and BAI is synergistic, antagonistic with QUER, and additive with GCV and ART. Conclusion These results provide a promising search path for potential bitherapies against HCMV.

scholarly journals Pyrazinamide triggers degradation of its target aspartate decarboxylase

2019 ◽  
Author(s):  
Pooja Gopal ◽  
Jickky Sarathy ◽  
Michelle Yee ◽  
Priya Ragunathan ◽  
Joon Shin ◽  
...  
Keyword(s):  
Protein Function ◽  
Enzyme Inhibitor ◽  
Drug Regimen ◽  
Growth Media ◽  
Antibacterial Drug ◽  
Missense Mutations ◽  
Binding Studies ◽  
Drug Induced

AbstractThe introduction of pyrazinamide (PZA) in the tuberculosis drug regimen shortened treatment from 12 to 6 months 1. PZA is a prodrug that is activated by a Mycobacterium tuberculosis (Mtb) amidase to release its bioactive component pyrazinoic acid (POA) 2. Aspartate decarboxylase PanD, a proenzyme activated by autocatalytic cleavage (Supplementary Fig. 1A, 3) and required for Coenzyme A (CoA) biosynthesis, emerged as a target of POA 4-7. In vitro and in vivo screening to isolate spontaneous POA-resistant Mtb mutants identified missense mutations in either panD or the unfoldase clpC1, encoding a component of the caseinolytic protease ClpC1-ClpP 4,6-9. Overexpression and binding studies of PanD or ClpC1 pointed to PanD as the direct target of POA whereas clpC1 mutations appeared to indirectly cause resistance 4,5,7,9,10. Indeed, supplementing growth media with CoA precursors downstream of the PanD catalyzed step conferred POA resistance 4,7,11. Metabolomic analyses and biophysical studies using recombinant proteins confirmed targeting of PanD by POA 5. However, the exact molecular mechanism of PanD inhibition by POA remained unknown. While most drugs act by inhibiting protein function upon target binding, we show here that POA is not a bona fide enzyme inhibitor. Rather, POA binding to PanD triggers degradation of the protein by ClpC1-ClpP. Thus, the old tuberculosis drug PZA promotes degradation of its target. While novel for an antibacterial, drug-induced target degradation has recently emerged as a strategy in drug discovery across disease indications. Our findings provide the basis for the rational discovery of next generation PZA.

A Novel Peptide Aldehyde with Activity against Human Cytomegalovirus in Two Different in Vivo Models

2000 ◽  
Vol 11 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Olaf Weber ◽  
Jürgen Reefschläger ◽  
Helga Rübsamen-Waigmann ◽  
Siegfried Raddatz ◽  
Matthias Hesseling ◽  
...  
Keyword(s):  
Animal Models ◽  
Antiviral Activity ◽  
Clinical Isolate ◽  
Human Cytomegalovirus ◽  
Murine Cytomegalovirus ◽  
Human Tissues ◽  
In Vivo Models ◽  
Peptide Aldehydes

Novel peptide aldehydes (PAs) were identified as potent inhibitors of human cytomegalovirus (HCMV) in vitro. Although these compounds were highly effective against HCMV, they did not exhibit any activity against murine cytomegalovirus (MCMV). The purpose of this study was to test the antiviral activity of PA 8 as a representative of this novel class of inhibitors against HCMV in vivo. Because of the strict species specificity of HCMV we had to use two artificial animal models. In the first model, HCMV-infected human cells were entrapped into agarose plugs and transplanted into mice. In the second model, SCID mice were transplanted with human tissues that were subsequently infected with a clinical isolate of HCMV. In these two models the antiviral activity of PA 8 was clearly demonstrated, ganciclovir only being slightly superior in its in vivo antiviral activity.

Advancements in Cancer Therapeutics

2021 ◽  
pp. 89-115
Author(s):  
Serda Kecel Gunduz ◽  
Bilge Bicak ◽  
Aysen E. Ozel
Keyword(s):  
Protein Design ◽  
Complex Structure ◽  
Cancer Therapeutics ◽  
New Drugs ◽  
In Vivo Studies ◽  
Drug Induced ◽  
Dimensional Simulation ◽  
Dynamics And Function

In this chapter, computational approaches for the discovery of new drugs that are useful for diagnosis and treatment of disease will be described in three parts. MD technique uniquely supports protein design attempts by giving information about protein dynamics associated with atomic-level descriptions of the relationship between dynamics and function. The purpose of molecular docking is to provide an estimate of the ligand-receptor complex structure using computational methods. By this estimation, the mechanism of drug binding and action are described by determining the three-dimensional simulation of drug and drug-induced macrostructure. ADME characteristics are physicochemically significant descriptors and pharmacokinetically relevant properties used to design more effective drugs and new analogs. As a result, in-silico calculations can provide robust preliminary information as to drug activity and mechanism in the drug production process, as well as in vitro and in vivo studies.

scholarly journals Adoptive transfer of anti-cytomegalovirus effect of interleukin-2- activated bone marrow: potential application in transplantation

Blood ◽  
1991 ◽  
Vol 78 (3) ◽  
pp. 720-727 ◽  
Author(s):  
R Agah ◽  
BS Charak ◽  
V Chen ◽  
A Mazumder
Keyword(s):  
Bone Marrow ◽  
Interleukin 2 ◽  
Murine Cytomegalovirus ◽  
Mcmv Infection ◽  
Murine Bone Marrow ◽  
Therapeutic Setting ◽  
Infected Cells ◽  
Novel Strategy

Abstract This work is a continuation of our studies that showed that interleukin- 2 (IL-2)-activated murine bone marrow (ABM) cells have potent cytotoxic potential against murine cytomegalovirus (MCMV)-infected targets in vitro, without loss of reconstitutive ability in vivo. Our data show that ABM cells lyse the MCMV-infected cells in vitro, at both acute and chronic stages of infection; this lysis is specific for the MCMV- infected cells. ABM cells supplemented with IL-2 therapy virtually eradicated the viral infection and prolonged the survival of MCMV- infected Balb/c mice, whether or not they were immunocompromised by irradiation (P less than .001 in both situations). Efficacy of ABM cells alone or IL-2 alone was less than the combination of ABM cells and IL-2. The efficacy of combination treatment with ABM cells and IL-2 in improving the survival of MCMV-infected mice was comparable, whether used in a preventive or a therapeutic setting. Therapy with ABM plus IL- 2 also prevented the reactivation of chronic MCMV infection after irradiation. Preliminary findings indicate that Thy-1+ and asialo GM1+ cells limited the MCMV proliferation by approximately 30% and 80%, respectively, while BM macrophages limited the proliferation of MCMV by 100%. These results suggest that BM transplantation (BMT) with ABM cells followed by IL-2 therapy may constitute a novel strategy to improve the host resistance against cytomegalovirus infection after BMT.

In vitro infection of megakaryocytes and their precursors by human cytomegalovirus

Blood ◽  
2000 ◽  
Vol 95 (2) ◽  
pp. 487-493 ◽  
Author(s):  
Kirsten Crapnell ◽  
Esmail D. Zanjani ◽  
Aniruddho Chaudhuri ◽  
Joao L. Ascensao ◽  
Stephen St. Jeor ◽  
...  
Keyword(s):  
Life Cycle ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Allogeneic Bone Marrow Transplantation ◽  
Laboratory Strain ◽  
Allogeneic Bone ◽  
Cd34 Cells ◽  
Hcmv Disease

Apart from congenital human cytomegalovirus (HCMV) infection, manifest HCMV disease occurs primarily in immunocompromised patients. In allogeneic bone marrow transplantation, HCMV is frequently associated with graft failure and cytopenias involving all hematopoietic lineages, but thrombocytopenia is the most commonly reported hematologic complication. The authors hypothesized that megakaryocytes (MK) may be a specific target for HCMV. Although the susceptibility of immature hematopoietic progenitors cells to HCMV has been established, a productive viral life cycle has only been linked to myelomonocytic maturation. The authors investigated whether HCMV can also infect MK and impair their function. They demonstrated that HCMV did not affect the thrombopoietin (TPO)-driven proliferation of CD34+ cells until MK maturation occurred. MK challenged with HCMV showed a 50% more rapid loss of viability than mock-infected cells. MK and their early precursors were clearly shown to be susceptible to HCMV in vitro, as evidenced by the presence of HCMV in magnetic column-purified CD42+ MK and 2-color fluorescent staining with antibodies directed against CD42a and HCMV pp65 antigen. These findings were confirmed by the infection of MK with a laboratory strain of HCMV containing the β-galactosidase (β-gal) gene. Using chromogenic β-gal substrates, HCMV was detected during MK differentiation of infected CD34+ cells and after infection of fully differentiated MK. Production of infectious virus was observed in cultures infected MK, suggesting that HCMV can complete its life cycle. These results demonstrate that MK are susceptible to HCMV infection and that direct infection of these cells in vivo may contribute to the thrombocytopenia observed in patients infected with HCMV.

scholarly journals Computational toxicology

2015 ◽  
Vol 34 (12) ◽  
pp. 1304-1309 ◽  
Author(s):  
RT Naven ◽  
S Louise-May
Keyword(s):  
Critical Role ◽  
Pharmaceutical Research ◽  
In Vitro Models ◽  
New Drugs ◽  
Data Sets ◽  
Predictive Toxicology ◽  
Drug Induced ◽  
Chemical Toxicology

Predictive toxicology plays a critical role in reducing the failure rate of new drugs in pharmaceutical research and development. Despite recent gains in our understanding of drug-induced toxicity, however, it is urgent that the utility and limitations of our current predictive tools be determined in order to identify gaps in our understanding of mechanistic and chemical toxicology. Using recently published computational regression analyses of in vitro and in vivo toxicology data, it will be demonstrated that significant gaps remain in early safety screening paradigms. More strategic analyses of these data sets will allow for a better understanding of their domain of applicability and help identify those compounds that cause significant in vivo toxicity but which are currently mis-predicted by in silico and in vitro models. These ‘outliers’ and falsely predicted compounds are metaphorical lighthouses that shine light on existing toxicological knowledge gaps, and it is essential that these compounds are investigated if attrition is to be reduced significantly in the future. As such, the modern computational toxicologist is more productively engaged in understanding these gaps and driving investigative toxicology towards addressing them.

scholarly journals Adoptive transfer of anti-cytomegalovirus effect of interleukin-2- activated bone marrow: potential application in transplantation

Blood ◽  
1991 ◽  
Vol 78 (3) ◽  
pp. 720-727
Author(s):  
R Agah ◽  
BS Charak ◽  
V Chen ◽  
A Mazumder
Keyword(s):  
Bone Marrow ◽  
Interleukin 2 ◽  
Murine Cytomegalovirus ◽  
Mcmv Infection ◽  
Murine Bone Marrow ◽  
Therapeutic Setting ◽  
Infected Cells ◽  
Novel Strategy

This work is a continuation of our studies that showed that interleukin- 2 (IL-2)-activated murine bone marrow (ABM) cells have potent cytotoxic potential against murine cytomegalovirus (MCMV)-infected targets in vitro, without loss of reconstitutive ability in vivo. Our data show that ABM cells lyse the MCMV-infected cells in vitro, at both acute and chronic stages of infection; this lysis is specific for the MCMV- infected cells. ABM cells supplemented with IL-2 therapy virtually eradicated the viral infection and prolonged the survival of MCMV- infected Balb/c mice, whether or not they were immunocompromised by irradiation (P less than .001 in both situations). Efficacy of ABM cells alone or IL-2 alone was less than the combination of ABM cells and IL-2. The efficacy of combination treatment with ABM cells and IL-2 in improving the survival of MCMV-infected mice was comparable, whether used in a preventive or a therapeutic setting. Therapy with ABM plus IL- 2 also prevented the reactivation of chronic MCMV infection after irradiation. Preliminary findings indicate that Thy-1+ and asialo GM1+ cells limited the MCMV proliferation by approximately 30% and 80%, respectively, while BM macrophages limited the proliferation of MCMV by 100%. These results suggest that BM transplantation (BMT) with ABM cells followed by IL-2 therapy may constitute a novel strategy to improve the host resistance against cytomegalovirus infection after BMT.

scholarly journals NK cell metabolic adaptation to infection promotes survival and viral clearance.

2021 ◽  
Author(s):  
Francisco Victorino ◽  
Tarin Bigley ◽  
Eugene Park ◽  
Cong-Hui Yao ◽  
Jeanne Benoit ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Hypoxia Inducible Factor ◽  
Murine Cytomegalovirus ◽  
Metabolic Adaptation ◽  
Mcmv Infection ◽  
Metabolic Functions ◽  
Cytokine Stimulation

Natural killer (NK) cells are essential for early protection against virus infection, and must metabolically adapt to the energy demands of activation. Here, we found upregulation of the metabolic adaptor hypoxia inducible factor-1α (HIF-1α) is a feature of NK cells during murine cytomegalovirus (MCMV) infection in vivo. HIF-1α-deficient NK cells failed to control viral load, causing increased morbidity. No defects were found in effector functions of HIF-1α KO NK cells however, their numbers were significantly reduced. Loss of HIF-1α did not affect NK cell proliferation during in vivo infection and in vitro cytokine stimulation. Instead, we found HIF-1α-deficient NK cells showed increased expression of the pro-apoptotic protein Bim and glucose metabolism was impaired during cytokine stimulation in vitro. Similarly, during MCMV infection HIF-1α-deficient NK cells upregulated Bim and had increased caspase activity. Thus, NK cells require HIF-1a-dependent metabolic functions to repress Bim expression and sustain cell numbers for an optimal virus response.

Sign in / Sign up

Export Citation Format

Share Document