Human cytomegalovirus (HCMV) employs multiple mechanisms to evade the immune system and succeeds to persist lifelong in the host. Human dendritic cells (DC) are the main antigen-presenting cells and play the key role in inducing and maintaining immune responses. Here, we studied the interaction of HCMV with DC. We found that DC, irrespectively of their stage of maturation, were fully permissive for HCMV when endothelial celladapted HCMV strains were applied. When fibroblast-adapted strains were used, viral replication was abrogated at the level of immediate early (IE) and/or early (E) gene expression. Irrespective of the HCMV strain used, infection of DC prevented the signal delivery essential for T cell activation in a multistep manner. Furthermore, we observed an altered expression of adhesion molecules. This might contribute to an impairment of DC migration. Our data indicate that a soluble factor induced by IE and/or E genes is involved in these processes. The impairment of DC function upon HCMV infection may contribute to virus-mediated immunosuppression and help the virus to establish persistence in the host.

The herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) and varicella-zoster virus (VZV) can cause life-threatening infections of the central nervous system and lead to severe infections in immunocompromised subjects and newborns. In these cases, rapid diagnosis is crucial. We developed three different real-time PCR assays based on TaqMan chemistry for the LightCycler instrument to detect HSV-1, HSV-2, and VZV. When the TaqMan assays were compared to our in-house nested PCR assays, the test systems had equal sensitivities of <10 plasmid copies per assay. When clinical samples were investigated by TaqMan PCR to detect HSV-1, HSV-2, and VZV DNA, 95, 100, and 96% of the samples determined to be positive by nested PCR, respectively, were positive by the real-time PCR assays. The specificities of all PCR assays were almost 100%. Furthermore, the TaqMan PCR assays could be performed within 2.5 h, whereas nested PCR results were available after 9 h. In addition to offering more rapid results, the TaqMan PCR assays appear to be less expensive than nested PCR assays due to less hands-on time. In summary, TaqMan PCR is an excellent alternative to conventional nested PCR assays for the rapid detection of HSV-1, HSV-2, and VZV in clinical samples.Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) cause a variety of clinical symptoms in the central nervous system (CNS). In immunocompromised patients, the virus leads to severe clinical outcomes, including mucocutaneous disease and pneumonia. At delivery, HSV can be transmitted to the newborn and, following this exposure, can cause severe disseminated infections and death.The varicella-zoster virus (VZV)-the causative agent of chicken pox and shingles-can also cause severe systemic infections of the CNS and the respiratory tract in immunocompetent individuals as well as in immunocompromised patients. The latter may also suffer from disseminated diseases of multiple organ systems.Rapid laboratory diagnosis is urgently needed to distinguish HSV from VZV infections when the CNS is involved, especially in cases with clinically confusing dermal manifestations. Furthermore, rapid diagnosis of HSV and VZV infections is crucial in neonates to prevent a lethal outcome of disease (8, 9). Today, effective therapy of HSV and VZV infections is possible with antiviral drugs such as acyclovir. However, therapy must be initiated very early after the onset of disease to decrease lethality and to minimize the number of patients sustaining persistent neurological damage (15). Thus, the ability to rapidly diagnose HSV and VZV infections is a key feature in the virology laboratory. Molecular diagnostic assays using PCR are the standard for detecting herpesvirus infections of the CNS (1, 2, 10). Modifications of the basic PCR technique have been used to increase the sensitivity of detection of the viruses, e.g., by using nested PCR assays. Although very sensitive, this technique has the disadvantage of being highly susceptible to contamination, potentially leading to false-positive results (...

Human cytomegalovirus (HCMV) strains can be classified into four glycoprotein B (gB) genotypes, and there has been evidence of differences in viral virulence. In this study, intragenic variability of HCMV gB strains was analyzed. The gB gene was amplified by nested polymerase chain reaction using samples from immunosuppressed patients. The genotype of fragments corresponding to the cleavage site of gB was determined by restriction fragment analysis; fragments corresponding to the N-and C-termini (gBn and gBc) were sequenced and compared with published sequences. At the cleavage site, the four known genotypes were found. Typing revealed four major genotypes at the N-terminus and two at the C-terminus. In 22 of 44 strains, the gB type determined at the cleavage site was different from the gBn or gBc type (or either), indicating that intragenic variability within the gB gene occurs frequently.Glycoprotein B (gB) of the human cytomegalovirus (HCMV) characteristic nucleotide and peptide sequence. They proposed a genotyping scheme that employs restriction fragment length plays an important role in virus infectivity. This protein is a major component of the virion envelope and is transported to the plasma polymorphism (RFLP) after amplifying a fragment that corresponds to the cleavage site of the gB protein. membrane of infected cells. It has been shown that monoclonal antibodies to gB inhibit virus penetration into cells and blockThere is increasing evidence that strains with different gB genotypes may vary in virulence. Infections with HCMV gB transmission of infectious virus from cell to cell [1]. Furthermore, anti-gB antibodies constitute up to 70% of the total serum neutype 1 were previously correlated with a more favorable outcome than infections with gB types 2 -4 when bone marrow tralizing activity found in persons with past HCMV infection, indicating that gB is a major target for neutralizing antibodies transplant recipients and human immunodeficiency virus (HIV) -infected patients were analyzed [13 -15]. Therefore, [2, 3]. Common and strain-specific epitopes have been described [4, 5]. In addition, it has been shown that gB protein induces genotyping of gB may be helpful in predicting the clinical outcome of HCMV infection. cytotoxic T cell responses [6][7][8][9].The gB precursor protein of 906 amino acids undergoes It has been argued that the four gB genotypes determined in samples from geographically restricted areas are not repreglycosylation and proteolytic cleavage between residues 460 and 461 during transport through the exocytotic pathway. The sentative and that additional gB genotypes may be found in samples from other geographic areas. Therefore, we sequenced amino-and carboxy-terminal fragments remain disulfidebonded. The gene coding for gB is highly variable in regions variable regions within the N-and C-terminal parts of gB from a vast number of clinical isolates from German patients and corresponding to the N-terminus and the cleavage site and less variable in regions corresponding to the C-termi...