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Ganciclovir (GCV) resistance is an emerging problem for transplant recipients. A sensitive and rapid real-time PCR approach for simultaneous and semiquantitative detection of human cytomegalovirus (HCMV) UL97 mutations in codons 460/520 was established by LightCycler and confirmed by restriction fragment length polymorphism and sequencing. Results from HCMV laboratory strains were compared with results from 11 GCV-resistant clinical isolates.Mutations in the human cytomegalovirus (HCMV) phosphotransferase gene (UL97) and polymerase gene (UL54) are responsible for resistance to ganciclovir (GCV) (UL97/UL54), cidofovir (UL54), or foscarnet (UL54) (2). Over 90% of GCVresistant clinical HCMV isolates have mutations in the UL97 gene (10). Most of the GCV-resistant clinical HCMV isolates feature mutations in the UL97 gene between codons 400 and 665 (9). Some of the most frequent mutations occur in codons 460, 594, and 595 (4, 7). There is a high impact for genotypic resistance screening with respect to known UL97 mutations conferring GCV resistance (4). The ratio of the wild-type and mutant strains present in HCMV-infected allogeneic hematopoietic stem cell transplant recipients may reflect clinical outcome (5, 11). Up to now, genotypic resistance screening has been performed by PCR-based restriction fragment length polymorphism (RFLP) assay and sequencing. Combinations of RFLP assays and sequencing analysis need at least 3 to 4 days for completion. RFLP assays for the detection of mutations in codons 460 and 520 have been described previously (3, 12). The relative frequencies of the UL97 mutations M460V, M460I, and H520Q were given previously, with the mutations found in 20 out of 75 (27%) unrelated ganciclovir-resistant isolates (4).We present a new LightCycler (LC) PCR assay using specific hybridization probes with melting point analysis for simultaneous characterization of the relevant UL97 codons 460 and 520 by a dual-color format with two specific pairs of hybridization probes for both codons which are each labeled with different fluorescence dyes (LC Red dye 640 and LC Red dye 705). The binding of the hybridization probe leads to a specific melting point for the wild-type sequence. In mutant strains, however, the mismatch between the hybridization probe and the mutant target sequence results in unstable binding of the probes, decreasing the melting temperature. The evaluation for the different codons can be performed by the use of different fluorescence channels. The reaction mixture utilized a master mix containing a LightCycler Fast Start hybridization probe kit (Roche Diagnostics, Mannheim, Germany) 1ϫ, 4.5 mM MgCl 2 , 0.6 M of each primer, 0.2 M of each hybridization probe, and an additional 2.5 U/reaction Fast Start Taq DNA polymerase (Roche Diagnostics, Mannheim, Germany) for increase of the sensitivity of the amplification reaction. An enhanced concentration of Fast Start Taq DNA polymerase (5 U/l) in the reaction mixture resulted in a higher sensitivity of our assay (8). The following program was used f...

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Adenovirus often causes respiratory infection in immunocompromised patients, but relevant attachment receptors have largely not been defined. We show that the antiviral protein bovine lactoferrin enhances infection of monocyte-derived dendritic cells (MDDC) by adenovirus species C serotype 2 (2C) isolates. Under the same conditions infection of MDDC by human cytomegalovirus was reduced. Adenoviral infection was prominently enhanced by bovine but not human lactoferrin, and was not prominently enhanced using blood monocyte-derived macrophages, suggesting that the relevant receptor is expressed on MDDC. Infection of MDDC in the presence of bovine lactoferrin was blocked by mannan, and an antibody to CD209/DC-SIGN but not isotype control or CD46 antibodies. Lastly, U937 macrophages ectopically expressing CD209/DC-SIGN, but not parental U937 cells, were efficiently infected by adenovirus 2C in the presence of bovine lactoferrin. These results may provide a tool, given the high efficiency of infection, to dissect responses by myeloid cells to clinical adenovirus isolates.Adenoviruses are common viral pathogens, particularly following allogeneic haematopoetic stem-cell transfer, with potentially fatal consequences (Feuchtinger et al., 2007). There is currently no universally accepted therapy. Adenovirus species C serotype 2 (2C) often causes respiratory infection, but the relevant attachment receptors on cells in the lung have largely not been defined.Cells that mediate innate immune responses to adenoviruses and adenoviral vectors include alveolar epithelial cells, macrophages, plasmocytoid and conventional dendritic cells (DC) (Muruve, 2004; Wu et al., 2010;Zhu et al., 2007). While great progress has been made in recent years in understanding the innate immune response to adenovirus and adenoviral vectors, particularly through intracellular inflammasomes and retinoic acid-inducible gene I-like receptors (Chiu et al., 2009;Di Paolo et al., 2009;Muruve et al., 2008;Zaiss et al., 2009), little is known about attachment receptors on myeloid cells. A variety of mechanisms and receptors may be used for adenoviral infection (Arnberg, 2009). The majority of adenoviruses initially engage an attachment receptor, following which RGD motifs within the penton base contact integrins that mediate viral internalization. The commonly used attachment receptor CAR (coxsackie virus and adenovirus receptor) is poorly accessible in the lung, and has been suggested to be not relevant for infection in vivo (Arnberg, 2009). CD46 is a second well characterized receptor that mediates efficient infection of many cell types including myeloid cells, but only functions for particular species B adenoviruses (Gaggar et al., 2003). Bridging molecules such as dipalmitoyl phosphatidylcholine, a major component of pulmonary surfactant, or lactoferrin, an antiviral protein abundantly expressed in the lung, mediate infection by species C adenoviruses (Balakireva et al., 2003;Johansson et al., 2007;Adams et al., 2009). Although the identity of dipalmitoyl ...