Clinical Failure of CMV Retinitis With Intravitreal Cidofovir Is Associated With Antiviral Resistance

Smith, Irene L.; Taşkintuna, İbrahim; Rahhal, Firas M.; Powell, Henry C.; Ai, Everett; Mueller, A. J.; Spector, Stephen A.; Freeman, William R.

doi:10.1001/archopht.116.2.178

Cited by 67 publications

(60 citation statements)

References 46 publications

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“…3.2 SB105 and SB105_A10 inhibit the replication of GCV-resistant strains of HCMV. In view of the occurrence of GCV-resistant strains during prolonged treatment therapies, the anticytomegaloviral activity of dendrimers in this context was evaluated by measuring the effect of SB105 and SB105_A10 upon two GCV-resistant strains, TR and VR5438, that lack drug phosphorylation activity due to mutations in the UL97 gene (Smith et al, 1998;Gerna et al, 1998;Baldanti et al, 2002). Fig.…”

Section: Discussionmentioning

confidence: 99%

“…HCMV VR5438 and TR are GCV-resistant strains isolated from AIDS patients undergoing GCV therapy and that developed CMV retinitis: their effective IC50 are 18 M for VR5438 and 33 M for TR. Nucleotide sequence analysis of their UL97 gene revealed amino acid alterations of codon 595 (Leu-Phe) for VR5438 and the lack of codons 591-594 for TR (Gerna et al, 1998;Baldanti et al, 2002;Smith et al, 1998). VR5438 and TR strains were propagated in HELFs and titrated by the indirect immunoperoxidase staining procedure on HELFs using a monoclonal antibody (MAb) reactive to the HCMV IE1 and IE2 proteins (clone E13; Argene Biosoft) (Revello et al, 2001).…”

Section: Cells Culture Conditions and Virusesmentioning

confidence: 99%

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Peptide-derivatized dendrimers inhibit human cytomegalovirus infection by blocking virus binding to cell surface heparan sulfate

et al. 2010

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Dendrimers are hyperbranched synthetic well-defined molecules with a number of potential applications, especially in relation to the need for new antiviral agents. One subclass of dendrimers are peptide derivatized-dendrimers which consist of a peptidyl branching core and covalently attached surface peptide functional units. Few studies have addressed the potential uses of peptide dendrimers as direct-acting antiviral agents. Here, we report on the ability of two peptide dendrimers, SB105 and SB105_A10, to directly and almost completely inhibit human cytomegalovirus (HCMV) replication in both primary fibroblasts and endothelial cells; the agents were also found to inhibit murine CMV replication, whereas they were not able to inhibit the adenovirus or vesicular stomatitis virus. The peptide dendrimers prevented adsorption of the HCMV to cells at 4° C, whereas SB104, a dendrimer with a different amino acid sequence within the functional group and minimal anticytomegaloviral activity, was ineffective in blocking HCMV attachment. In effect, SB105_A10 bound to human cells through an interaction with cell surface heparan sulfate and thereby blocked virion attachment to target cells. These results indicate that the SB105 and SB105_A10 dendrimers could provide a useful starting point for the development of novel molecules to block HCMV infection.

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Section: Discussionmentioning

confidence: 99%

Section: Cells Culture Conditions and Virusesmentioning

confidence: 99%

Peptide-derivatized dendrimers inhibit human cytomegalovirus infection by blocking virus binding to cell surface heparan sulfate

et al. 2010

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“…A bacterial artificial chromosome (BAC) containing the genome of the HCMV TR strain was obtained from Oregon Health Science University. TR, a clinical HCMV strain derived from an ocular vitreous fluid sample from a patient with HIV disease (49), was cloned into a BAC after limited passage in fibroblasts (50). HCMV strain TR and recombinant UL116-Flag-TR virus were propagated in human foreskin fibroblasts (HFF-1; ATCC SCRC-1041) grown in minimal essential medium (Invitrogen) supplemented with 10% fetal calf serum, glutamine (100 mg/liter), and gentamicin (350 mg/liter).…”

Section: Methodsmentioning

confidence: 99%

The Human Cytomegalovirus UL116 Gene Encodes an Envelope Glycoprotein Forming a Complex with gH Independently from gL

Caló

Cortese

Ciferri³

et al. 2016

J Virol

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Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and is the leading viral cause of birth defects after congenital infection. HCMV infection relies on the recognition of cell-specific receptors by one of the viral envelope glycoprotein complexes. Either the gH/gL/gO or the gH/gL/UL128/UL130/UL131A (Pentamer) complex has been found to fulfill this role, accounting for HCMV entry into almost all cell types. We have studied the UL116 gene product, a putative open reading frame identified by in silico analysis and predicted to code for a secreted protein. Virus infection experiments in mammalian cells demonstrated that UL116 is expressed late in the HCMV replication cycle and is a heavily glycosylated protein that first localizes to the cellular site of virus assembly and then inserts into the virion envelope. Transient-transfection studies revealed that UL116 is efficiently transported to the plasma membrane when coexpressed with gH and that gL competes with UL116 for gH binding. Further evidence for gH/UL116 complex formation was obtained by coimmunoprecipitation experiments on both transfected and infected cells and biochemical characterization of the purified complex. In summary, our results show that the product of the UL116 gene is an HCMV envelope glycoprotein that forms a novel gH-based complex alternative to gH/gL. Remarkably, the gH/UL116 complex is the first herpesvirus gH-based gL-less complex. IMPORTANCE HCMV infection can cause severe disease in immunocompromised adults and infants infected in utero.The dissection of the HCMV entry machinery is important to understand the mechanism of viral infection and to identify new vaccine antigens. The gH/gL/gO and gH/gL/UL128/UL130/UL131 (Pentamer) complexes play a key role in HCMV cell entry and tropism. Both complexes are formed by an invariant gH/gL scaffold on which the other subunits assemble. Here, we show that the UL116 gene product is expressed in infected cells and forms a heterodimer with gH. The gH/UL116 complex is carried on the infectious virions, although in smaller amounts than gH/gL complexes. No gH/UL116/gL ternary complex formed in transfected cells, suggesting that the gH/UL116 complex is independent from gL. This new gH-based gL-free complex represents a potential target for a protective HCMV vaccine and opens new perspectives on the comprehension of the HCMV cell entry mechanism and tropism. H uman cytomegalovirus (HCMV) is a ubiquitous betaherpesvirus infecting 40 to 60% of the human population (1).HCMV infection usually is mild or asymptomatic in immunocompetent individuals, while it can cause severe disease in immunocompromised adults. Infants infected in utero can suffer from disseminated HCMV disease and impaired neurological development (2). Transplant patients do not adequately control HCMV infection or reactivation, often resulting in graft rejection and death (3). Preventing primary HCMV infection could significantly decrease the frequency of organ rejection in seronegative recip...

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“…Standard plaque assays were used also in different experiments to determine viral titers in the supernatants harvested from infected cells. HCMV TR was derived from an ocular specimen (47), and after a few passages on fibroblasts, it was cloned into a bacterial artificial chromosome (48,49). Reconstitution of infectious TR was performed as previously described (50) by cotransfecting HFFs with the corresponding TR bacterial artificial chromosome and a plasmid expressing HCMV pp71.…”

Section: Hcmv Preparations and Infection Conditionsmentioning

confidence: 99%

Distinct Roles for Human Cytomegalovirus Immediate Early Proteins IE1 and IE2 in the Transcriptional Regulation of MICA and PVR/CD155 Expression

Pignoloni

Fionda

Dell’Oste

et al. 2016

The Journal of Immunology

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Elimination of virus-infected cells by cytotoxic lymphocytes is triggered by activating receptors, among which NKG2D and DNAM-1/CD226 play an important role. Their ligands, that is, MHC class I–related chain (MIC) A/B and UL16-binding proteins (ULBP)1–6 (NKG2D ligand), Nectin-2/CD112, and poliovirus receptor (PVR)/CD155 (DNAM-1 ligand), are often induced on virus-infected cells, although some viruses, including human CMV (HCMV), can block their expression. In this study, we report that infection of different cell types with laboratory or low-passage HCMV strains upregulated MICA, ULBP3, and PVR, with NKG2D and DNAM-1 playing a role in NK cell–mediated lysis of infected cells. Inhibition of viral DNA replication with phosphonoformic acid did not prevent ligand upregulation, thus indicating that early phases of HCMV infection are involved in ligand increase. Indeed, the major immediate early (IE) proteins IE1 and IE2 stimulated the expression of MICA and PVR, but not ULBP3. IE2 directly activated MICA promoter via its binding to an IE2-responsive element that we identified within the promoter and that is conserved among different alleles of MICA. Both IE proteins were instead required for PVR upregulation via a mechanism independent of IE DNA binding activity. Finally, inhibiting IE protein expression during HCMV infection confirmed their involvement in ligand increase. We also investigated the contribution of the DNA damage response, a pathway activated by HCMV and implicated in ligand regulation. However, silencing of ataxia telangiectasia mutated, ataxia telangiectasia and Rad3–related protein, and DNA-dependent protein kinase did not influence ligand expression. Overall, these data reveal that MICA and PVR are directly regulated by HCMV IE proteins, and this may be crucial for the onset of an early host antiviral response.

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Clinical Failure of CMV Retinitis With Intravitreal Cidofovir Is Associated With Antiviral Resistance

Cited by 67 publications

References 46 publications

Peptide-derivatized dendrimers inhibit human cytomegalovirus infection by blocking virus binding to cell surface heparan sulfate

Peptide-derivatized dendrimers inhibit human cytomegalovirus infection by blocking virus binding to cell surface heparan sulfate

The Human Cytomegalovirus UL116 Gene Encodes an Envelope Glycoprotein Forming a Complex with gH Independently from gL

Distinct Roles for Human Cytomegalovirus Immediate Early Proteins IE1 and IE2 in the Transcriptional Regulation of MICA and PVR/CD155 Expression

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