Oncolytic viral therapy with a combination of HF10, a herpes simplex virus type 1 variant and granulocyte-macrophage colony-stimulating factor for murine ovarian cancer.

Ovarian cancer is the most frequent cause of gynecological cancer-related mortality as a majority of patients are diagnosed at an advanced stage with intraperitoneal dissemination because of the absence of initial symptoms. Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays an important role in the maturation of specialized antigen-presenting cells. In this study, we utilized a herpes simplex virus (HSV) amplicon expressing murine GM-CSF combined with HF10 (mGM-CSF amplicon), a highly attenuated HSV type 1 strain functioning as a helper virus to strengthen anti-tumor immune response, for the treatment of ovarian cancer with intraperitoneal dissemination. A mouse ovarian cancer cell line, OV2944-HM-1 (HM-1), was intraperitoneally injected, following which HF10 only or the mGM-CSF amplicon was injected intraperitoneally three times. HF10 injection prolonged survival and decreased intraperitoneal dissemination, but to a lesser extent than the mGM-CSF amplicon. Although HF10 replication was not observed in HM-1 cells, expression of VP5, a late gene coding the major capsid protein of HSV, was detected. Moreover, mGM-CSF production was detected in transfected HM-1 cells. Immunohistochemical staining revealed the infiltration of CD4- and CD8-positive cells into the peritoneal tumor(s). A significantly increased CD4+ T cell concentration was observed in the spleen. Murine splenic cells after each treatment were stimulated with HM-1 cells, and the strongest immune response was observed in the mice that received mGM-CSF amplicon injections. These results suggested that the mGM-CSF amplicon is a promising agent for the treatment of advanced ovarian cancer with intraperitoneal dissemination.

Phase I Dose-escalation Clinical Trial of HF10 Oncolytic Herpes Virus in 17 Japanese Patients with Advanced Cancer.

Oncolytic virus therapy is a promising new therapeutic method, one of an eagerly anticipated class of biological therapies against cancer. There are many different classes of oncolytic virus. One of these, herpes oncolytic virus, is strongly oncolytic and has a large DNA genome as 150k bp. HF10 is a spontaneous mutant of herpes simplex virus -1 (HSV-1) that replicates within tumors and destroys cancers without damaging normal tissue and organs. Clinical trials of HF10 are underway in Japan and the United States. The first pilot study of HF10 was initiated in Japan in 2003. This study examined the safety and efficacy of HF10 in the treatment of breast cancer and head and neck cancers; the trial also included careful dose escalation studies. In 2005, a clinical trial using HF10 to treat pancreatic cancer was initiated. screened In this Japanese study, 17 patients received HF10 in their tumor sites. A clinical trial in the United States is also ongoing to evaluate safety, tolerability and evidence of antitumor activity in patients with refractory superficial solid tumors. Here, we report the evaluation of the 17 patients treated in Japan. Among the patients, 6 had recurrent breast cancer, 3 had recurrent head and neck cancer, and 8 had non-resectable pancreatic cancer. No severe adverse side effects have been observed, and some therapeutic potential has been reported based on pathological findings, tumor markers, and diagnostic radiography. Those results should encourage further clinical trials of HF10 around the world.

Enhanced antitumoral activity of oncolytic herpes simplex virus with gemcitabine using colorectal tumor models.

To enhance the oncolytic activity of herpes simplex viruses (HSVs) control of immune-suppression and immune-resistance by cancer cells is important. Myeloid-derived suppressor cells (MDSCs), which interfere with tumor-suppressive environments, are inhibited by gemcitabine (GEM) treatment. We investigated the oncolytic activity and systemic antitumor immunity induced by oncolytic HSVs in combination with GEM treatment. A mouse model with subcutaneous tumors on both sides of the lateral flanks was used. A highly attenuated HSV type 1, strain HF10, was inoculated into one side of each tumor three times following intraperitoneal injection of GEM. Histopathological changes and IFN-γ secretion of the tumor and leukocytes in the spleen were analyzed. These treatments were repeated to enhance oncolytic activity. HF10 inoculation reduced tumor growth only on the HF10-treated side. HF10 inoculation following GEM treatment resulted in greater reduction of tumor growth on the HF10-treated tumor; furthermore, reduction of tumors on the contralateral untreated side was also observed. Necrosis of the tumor was observed in areas where HSV-infected cells were detected. F4/80(+) macrophages around the tumor were eliminated, and CD4(+) T and CD8(+) T cells increased in the spleen. A single injection of GEM decreased CD11b(+) /Gr-1(+) MDSCs while retaining CD4(+) T cells and CD8(+) T cells. Repetition of this treatment regimen resulted in even greater reduction of tumor growth on both sides and complete rejection in some of the mice. Intratumoral injection of oncolytic HSVs following GEM injection reduced MDSCs. Repeated treatment with oncolytic HSVs following GEM resulted in enhanced oncolytic activity.

Herpes simplex virus requires poly(ADP-ribose) polymerase activity for efficient replication and induces extracellular signal-related kinase-dependent phosphorylation and ICP0-dependent nuclear localization of tankyrase 1.

Tankyrase 1 is a poly(ADP-ribose) polymerase (PARP) which localizes to multiple subcellular sites, including telomeres and mitotic centrosomes. Poly(ADP-ribosyl)ation of the nuclear mitotic apparatus (NuMA) protein by tankyrase 1 during mitosis is essential for sister telomere resolution and mitotic spindle pole formation. In interphase cells, tankyrase 1 resides in the cytoplasm, and its role therein is not well understood. In this study, we found that herpes simplex virus (HSV) infection induced extensive modification of tankyrase 1 but not tankyrase 2. This modification was dependent on extracellular signal-regulated kinase (ERK) activity triggered by HSV infection. Following HSV-1 infection, tankyrase 1 was recruited to the nucleus. In the early phase of infection, tankyrase 1 colocalized with ICP0 and thereafter localized within the HSV replication compartment, which was blocked in cells infected with the HSV-1 ICP0-null mutant R7910. In the absence of infection, ICP0 interacted with tankyrase 1 and efficiently promoted its nuclear localization. HSV did not replicate efficiently in cells depleted of both tankyrases 1 and 2. Moreover, XAV939, an inhibitor of tankyrase PARP activity, decreased viral titers to 2 to 5% of control values. We concluded that HSV targets tankyrase 1 in an ICP0- and ERK-dependent manner to facilitate its replication.

Antitumor activities of valproic acid on Epstein-Barr virus-associated T and natural killer lymphoma cells.

Epstein-Barr virus (EBV), which infects B cells, T cells, and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, histone deacetylase (HDAC) inhibitors have been reported to have anticancer effects against various tumor cells. In the present study, we evaluated the killing effect of valproic acid (VPA), which acts as an HDAC inhibitor, on EBV-positive and -negative T and NK lymphoma cells. Treatment of multiple T and NK cell lines (SNT13, SNT16, Jurkat, SNK6, KAI3 and KHYG1) with 0.1-5 mM of VPA inhibited HDAC, increased acetylated histone levels and reduced cell viability. No significant differences were seen between EBV-positive and -negative cell lines. Although VPA induced apoptosis in some T and NK cell lines (SNT16, Jurkat and KHYG1) and cell cycle arrest, it did not induce lytic infection in EBV-positive T or NK cell lines. Because the killing effect of VPA was modest (1 mM VPA reduced cell viability by between 22% and 56%), we tested the effects of the combination of 1 mM of VPA and 0.01 µM of the proteasome inhibitor bortezomib. The combined treated of cells with VPA and bortezomib had an additive killing effect. Finally, we administered VPA to peripheral blood mononuclear cells from three patients with EBV-associated T or NK lymphoproliferative diseases. In these studies, VPA had a greater killing effect against EBV-infected cells than uninfected cells, and the effect was increased when VPA was combined with bortezomib. These results indicate that VPA has antitumor effects on T and NK lymphoma cells and that VPA and bortezomib may have synergistic effects, irrespective of the presence of EBV.

Application of flow cytometric in situ hybridization assay to Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases.

Epstein-Barr virus (EBV) infects various types of lymphocytes and is associated with not only B cell-origin lymphoma, but also T or natural killer cell lymphoproliferative diseases (T/NK LPD). Recently, we established a novel assay to identify EBV-infected cells using FISH. Using this assay, dual staining with antibodies to both surface antigens and an EBV-encoded small RNA (EBER) probe can be performed. In the present study, we applied this recently developed FISH assay to EBV-associated T/NK LPD to confirm its diagnostic utility. Using FISH, we prospectively analyzed peripheral blood from patients with suspected EBV-associated T/NK LPD. The results were compared with those obtained using immunobead sorting followed by quantitative PCR. In all, 26 patients were included study. Using FISH, 0.15-67.0% of peripheral blood lymphocytes were found to be positive for EBER. Dual staining was used to determine EBER-positive cell phenotypes in 23 of 26 subjects (88.5%). In five of seven patients with hydroa vacciniforme-like lymphoma (an EBV-positive cutaneous T cell lymphoma), EBER-positive cells were identified as CD3(+) CD4(-) CD8(-) TCRγδ(+) T cells. Furthermore, in a 25-year-old male patient with systemic EBV-positive T cell LPD, two lymphocyte lineages were positive for EBER: CD4(+) CD8(-) and CD4(-) CD8(+) T cells. Thus, we confirmed that our newly developed assay is useful for quantifying and characterizing EBV-infected lymphocytes in EBV-associated T/NK LPD and that it can be used not only to complement the pathological diagnosis, but also to clarify the pathogenesis and to expand the spectrum of EBV-associated diseases.

Development of a human herpesvirus 6 species-specific immunoblotting assay.

In order to assess the full spectrum of human herpesvirus 6A (HHV-6A)- and HHV-6B-associated diseases, we sought to develop an HHV-6 species-specific serological assay based on immunoblot analysis. The immunodominant proteins encoded by open reading frame U11, p100 for HHV-6A (strain U1102) and 101K for HHV-6B (strain Z29), were selected to generate virus species-specific antigens. Recombinant p100 and 101K were produced in a prokaryotic expression system. The expression of these proteins was confirmed by using anti-His tag and 101K-specific monoclonal antibodies. HHV-6 species-specific antibodies were detected by immunoblotting in patient sera. Eighty-seven serum samples obtained from various subjects were utilized to determine the reliability of the method for clinical use. Ten of twelve exanthem subitum convalescent-phase sera reacted exclusively with 101K, whereas none of twelve acute-phase sera reacted with either protein. Two of three sera collected from HHV-6A-infected patients reacted with p100 and 101K. Although all five acute and convalescent-phase sera obtained from transplant recipients reacted exclusively with 101K, two of six convalescent-phase sera obtained from patients with drug-induced hypersensitivity syndrome reacted with both p100 and 101K. Of 38 sera obtained from healthy adults, 31 were positive for 101K antibody, while 4 reacted with both proteins. However, PCR analysis of peripheral blood mononuclear cells and saliva from these subjects did not detect HHV-6A DNA. In conclusion, this novel serological assay based on immunoblot analysis using recombinant HHV-6A p100 and HHV-6B 101K allowed us to discriminate between HHV-6A- and HHV-6B-specific antibodies.

Herpes simplex virus 1 protein kinase Us3 and major tegument protein UL47 reciprocally regulate their subcellular localization in infected cells.

Us3 is a serine-threonine protein kinase encoded by herpes simplex virus 1 (HSV-1). We have identified UL47, a major virion protein, as a novel physiological substrate of Us3. In vitro kinase assays and systematic analysis of mutations at putative Us3 phosphorylation sites near the nuclear localization signal of UL47 showed that serine at residue 77 (Ser-77) was required for Us3 phosphorylation of UL47. Replacement of UL47 Ser-77 by alanine produced aberrant accumulation of UL47 at the nuclear rim and impaired the nuclear localization of UL47 in a significant fraction of infected cells. The same defect in UL47 localization was produced by an amino acid substitution in Us3 that inactivated its protein kinase activity. In contrast, a phosphomimetic mutation at UL47 Ser-77 restored wild-type nuclear localization. The UL47 S77A mutation also reduced viral replication in the mouse cornea and the development of herpes stromal keratitis in mice. In addition, UL47 formed a stable complex with Us3 in infected cells, and nuclear localization of Us3 was significantly impaired in the absence of UL47. These results suggested that Us3 phosphorylation of UL47 Ser-77 promoted the nuclear localization of UL47 in cell cultures and played a critical role in viral replication and pathogenesis in vivo. Furthermore, UL47 appeared to be required for efficient nuclear localization of Us3 in infected cells. Therefore, Us3 protein kinase and its substrate UL47 demonstrated a unique regulatory feature in that they reciprocally regulated their subcellular localization in infected cells.

Spatiotemporally different DNA repair systems participate in Epstein-Barr virus genome maturation.

Productive replication of Epstein-Barr virus occurs in discrete sites in nuclei, called replication compartments, where viral DNA replication proteins and host homologous recombinational repair (HRR) and mismatch repair (MMR) factors are recruited. Three-dimensional (3D) surface reconstruction imaging clarified the spatial arrangements of these factors within the replication compartments. Subnuclear domains, designated BMRF1 cores, which were highly enriched in viral polymerase processivity factor BMRF1 could be identified inside the replication compartments. Pulse-chase experiments revealed that newly synthesized viral genomes organized around the BMRF1 cores were transferred inward. HRR factors could be demonstrated mainly outside BMRF1 cores, where de novo synthesis of viral DNA was ongoing, whereas MMR factors were found predominantly inside. These results imply that de novo synthesis of viral DNA is coupled with HRR outside the cores, followed by MMR inside cores for quality control of replicated viral genomes. Thus, our approach unveiled a viral genome manufacturing plant.

Bortezomib induces apoptosis in T lymphoma cells and natural killer lymphoma cells independent of Epstein-Barr virus infection.

Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage of caspases and polyadenosine diphosphate-ribose polymerase, increased expression of phosphorylated IκB, and decreased expression of inhibitor of apoptotic proteins were detected by immunoblotting in bortezomib-treated cell lines. We found that bortezomib induced lytic infection in EBV-positive T cell lines, although the existence of EBV did not modulate the killing effect of bortezomib. Finally, we administered bortezomib to peripheral blood mononuclear cells from five patients with EBV-associated lymphoproliferative diseases. Bortezomib had a greater killing effect on EBV-infected cells. These results indicate that bortezomib killed T or NK lymphoma cells by inducing apoptosis, regardless of the presence or absence of EBV.

Identification of Epstein-Barr virus-infected CD27+ memory B-cells in liver or stem cell transplant patients.

To analyse the phenotype of Epstein-Barr virus (EBV)-infected lymphocytes in EBV-associated infections, cells from eight haematopoietic stem cell/liver transplantation recipients with elevated EBV viral loads were examined by a novel quantitative assay designed to identify EBV-infected cells by using a flow cytometric detection of fluorescent in situ hybridization (FISH) assay. By this assay, 0.05-0.78% of peripheral blood lymphocytes tested positive for EBV, and the EBV-infected cells were CD20+ B-cells in all eight patients. Of the CD20+ EBV-infected lymphocytes, 48-83% of cells tested IgD positive and 49-100% of cells tested CD27 positive. Additionally, the number of EBV-infected cells assayed by using FISH was significantly correlated with the EBV-DNA load, as determined by real-time PCR (r2  = 0.88, P < 0.0001). The FISH assay enabled us to characterize EBV-infected cells and perform a quantitative analysis in patients with EBV infection after stem cell/liver transplantation.

Degradation of phosphorylated p53 by viral protein-ECS E3 ligase complex.

p53-signaling is modulated by viruses to establish a host cellular environment advantageous for their propagation. The Epstein-Barr virus (EBV) lytic program induces phosphorylation of p53, which prevents interaction with MDM2. Here, we show that induction of EBV lytic program leads to degradation of p53 via an ubiquitin-proteasome pathway independent of MDM2. The BZLF1 protein directly functions as an adaptor component of the ECS (Elongin B/C-Cul2/5-SOCS-box protein) ubiquitin ligase complex targeting p53 for degradation. Intringuingly, C-terminal phosphorylation of p53 resulting from activated DNA damage response by viral lytic replication enhances its binding to BZLF1 protein. Purified BZLF1 protein-associated ECS could be shown to catalyze ubiquitination of phospho-mimetic p53 more efficiently than the wild-type in vitro. The compensation of p53 at middle and late stages of the lytic infection inhibits viral DNA replication and production during lytic infection, suggesting that the degradation of p53 is required for efficient viral propagation. Taken together, these findings demonstrate a role for the BZLF1 protein-associated ECS ligase complex in regulation of p53 phosphorylated by activated DNA damage signaling during viral lytic infection.

Herpes simplex virus induces the marked up-regulation of the zinc finger transcriptional factor INSM1, which modulates the expression and localization of the immediate early protein ICP0.

BACKGROUND: Herpes simplex viruses (HSVs) rapidly shut off macromolecular synthesis in host cells. In contrast, global microarray analyses have shown that HSV infection markedly up-regulates a number of host cell genes that may play important roles in HSV-host cell interactions. To understand the regulatory mechanisms involved, we initiated studies focusing on the zinc finger transcription factor insulinoma-associated 1 (INSM1), a host cell protein markedly up-regulated by HSV infection. RESULTS: INSM1 gene expression in HSV-1-infected normal human epidermal keratinocytes increased at least 400-fold 9 h after infection; INSM1 promoter activity was also markedly stimulated. Expression and subcellular localization of the immediate early HSV protein ICP0 was affected by INSM1 expression, and chromatin immunoprecipitation (ChIP) assays revealed binding of INSM1 to the ICP0 promoter. Moreover, the role of INSM1 in HSV-1 infection was further clarified by inhibition of HSV-1 replication by INSM1-specific siRNA. CONCLUSIONS: The results suggest that INSM1 up-regulation plays a positive role in HSV-1 replication, probably by binding to the ICP0 promoter.

Herpes simplex virus type 1 UL14 tegument protein regulates intracellular compartmentalization of major tegument protein VP16.

BACKGROUND: Herpes simplex virus type 1 (HSV-1) has a complicated life-cycle, and its genome encodes many components that can modify the cellular environment to facilitate efficient viral replication. The protein UL14 is likely involved in viral maturation and egress (Cunningham C. et al), and it facilitates the nuclear translocation of viral capsids and the tegument protein VP16 during the immediate-early phase of infection (Yamauchi Y. et al, 2008). UL14 of herpes simplex virus type 2 exhibits multiple functions (Yamauchi Y. et al, 2001, 2002, 2003). METHODS: To better understand the function(s) of UL14, we generated VP16-GFP-incorporated UL14-mutant viruses with either single (K51M) or triple (R60A, R64A, E68D) amino acid substitutions in the heat shock protein (HSP)-like sequence of UL14. We observed the morphology of cells infected with UL14-null virus and amino acid-substituted UL14-mutant viruses at different time points after infection. RESULTS: UL14(3P)-VP16GFP and UL14D-VP16GFP (UL14-null) viruses caused similar defects with respect to growth kinetics, compartmentalization of tegument proteins, and cellular morphology in the late phase. Both the UL14D-VP16GFP and UL14(3P)-VP16GFP viruses led to the formation of an aggresome that incorporated some tegument proteins but did not include nuclear-egressed viral capsids. CONCLUSIONS: Our findings suggest that a cluster of charged residues within the HSP-like sequence of UL14 is important for the molecular chaperone-like functions of UL14, and this activity is required for the acquisition of functionality of VP16 and UL46. In addition, UL14 likely contributes to maintaining cellular homeostasis following infection, including cytoskeletal organization. However, direct interactions between UL14 and VP16, UL46, or other cellular or viral proteins remain unclear.

Immunologic and virologic analyses in pediatric liver transplant recipients with chronic high Epstein-Barr virus loads.

BACKGROUND: Long-term Epstein-Barr virus (EBV) monitoring for potentially life-threatening posttransplant lymphoproliferative disorder (PTLD) has identified asymptomatic patients who maintain high EBV loads over long periods. METHODS: Thirty-one pediatric liver transplant recipients were designated as 11 chronic high EBV load carriers (EBV DNA level >5000 copies/mL of whole blood for >6 months) and 20 control recipients. Serial quantification of EBV DNA, measurement of interleukin 10 (IL-10) concentrations, EBV-specific tetramer staining, and relative quantification of EBV gene expression in peripheral blood mononuclear cells were performed. RESULTS: Most of the chronic high EBV load carriers were seronegative at transplant, the median time to resolution of a chronic high EBV load was 23 months, and no recipient developed late-onset PTLD. EBV DNA was detected predominantly in CD19(+) cells. The plasma concentration of IL-10 and the EBV-specific CD8(+) cell frequency did not differ significantly between the chronic high EBV load carriers and the control recipients. Analysis of gene expression showed that EBV-encoded small RNA 1, BamHI A rightward transcripts, and latent membrane protein 2 were positive in peripheral blood mononuclear cells from chronic high EBV load carriers. CONCLUSIONS: EBV-infected cells in the blood of chronic high EBV load carriers expressed a highly restricted set of latency genes, suggesting that the EBV-infected cells escaped from a T cell response.

Oncolytic activity of naturally attenuated herpes-simplex virus HF10 against an immunocompetent model of oral carcinoma.

Prognosis for advanced oral carcinoma remains poor. Oncolytic virotherapy uses replication-competent viruses to infect and kill only the tumor cells. However, it has been difficult to investigate the oncolytic activity of viruses against oral carcinomas in mouse models. This study established a mouse model of oral cancer and investigated the in vitro and in vivo anti-tumor effects of HF10, a highly attenuated, replication-competent herpes simplex virus (HSV)-1. Mouse tongue cancer was induced by injecting 4-nitroquinoline 1-oxide into the mouse tongue. The murine oral cancer cell line isolated from this tumor, named NMOC1, formed invasive carcinoma within a week when injected into mouse tongue. HF10 successfully infected, replicated, and spread in the cancer cells in vitro. HF10 was able to kill cancer cells isolated from human or mouse tongue tumor. HF10 injection into tongue carcinomas prolonged mouse survival without any side effects or weight loss. Intertumoral injection of GFP-expressing HF10 confirmed that viral spread was confined within the tumors. Immunohistochemical staining showed that HF10 induced infiltration of CD8-positive T cells around HSV-infected cells in the tumor mass, implying increased anti-tumor immunity. We successfully established an oral cancer cell line and showed that HF10 is a promising therapeutic agent for oral cancer.

Quantitative analysis of Epstein-Barr virus (EBV)-related gene expression in patients with chronic active EBV infection.

Chronic active Epstein-Barr virus (CAEBV) infection is a systemic Epstein-Barr virus (EBV)-positive lymphoproliferative disorder characterized by persistent or recurrent infectious mononucleosis-like symptoms in patients with no known immunodeficiency. The detailed pathogenesis of the disease is unknown and no standard treatment regimen has been developed. EBV gene expression was analysed in peripheral blood samples collected from 24 patients with CAEBV infection. The expression levels of six latent and two lytic EBV genes were quantified by real-time RT-PCR. EBV-encoded small RNA 1 and BamHI-A rightward transcripts were abundantly detected in all patients, and latent membrane protein (LMP) 2 was observed in most patients. EBV nuclear antigen (EBNA) 1 and LMP1 were detected less frequently and were expressed at lower levels. EBNA2 and the two lytic genes were not detected in any of the patients. The pattern of latent gene expression was determined to be latency type II. EBNA1 was detected more frequently and at higher levels in the clinically active patients. Quantifying EBV gene expression is useful in clarifying the pathogenesis of CAEBV infection and may provide information regarding a patient's disease prognosis, as well as possible therapeutic interventions.

Multiplex real-time PCR assay for simultaneous quantification of BK polyomavirus, JC polyomavirus, and adenovirus DNA.

In recent years, virus-induced nephropathy caused mainly by BK polyomavirus (BKPyV), JC polyomavirus (JCPyV), and adenovirus has emerged as a problem in renal transplant patients. In the present study, we developed a multiplex real-time PCR assay to quantify the viral load of BKPyV, JCPyV, and adenovirus simultaneously. The dynamic range covered at least 6 orders of magnitude. This system was specific and reproducible, even in the presence of large amounts of DNA of other viruses. To validate this assay, urine samples from 124 renal transplant patients and serum samples from 18 hemorrhagic cystitis patients after hematopoietic stem cell transplantation were examined. In the urine samples from renal transplant patients, BKPyV was detected in 28 patients (22.6%), JCPyV was detected in 51 patients (41.1%), and adenovirus was detected in 2 patients (1.6%). The maximum amounts of each virus detected were 2.7 x 10(9), 8.7 x 10(8), and 1.2 x 10(2) copies/ml, respectively. Decoy cells were observed in 31 patients. The quantities of both BKPyV and JCPyV DNA were greater in samples with decoy cells. Two patients whose BKPyV viral loads exceeded 10(8) copies/ml had elevated serum creatinine levels and were diagnosed with BKPyV nephropathy based on graft biopsies. In serum samples from hemorrhagic cystitis patients, BKPyV, JCPyV, and adenovirus was detected in six, two, and three patients, respectively. Strong correlations were observed between the viral DNA copy numbers determined in the multiplex assays and those determined in single assays. Since this new assay is rapid, sensitive, and specific, it can be used for quantitative analyses of viruses in urine and serum samples after transplantation.

Protective role of Fas-FasL signaling in lethal infection with herpes simplex virus type 2 in mice.

Herpes simplex virus type 2 (HSV-2) induces acute local infection followed by latent infection in the nervous system and often leads to the development of lethal encephalitis in immunocompromised hosts. The mechanisms of immune protection against lethal HSV-2 infection, however, have not been clarified. In this study, we examined the roles of Fas-Fas ligand (FasL) signaling in lethal infection with HSV-2 by using mice with mutated Fas (lpr) or FasL (gld) in C57BL/6 background. Both lpr and gld mice exhibited higher mortality than wild-type (WT) C57BL/6 mice after infection with virulent HSV-2 strain 186 and showed significantly increased viral titers in the spinal cord compared with WT mice 9 days after infection, just before the mice started to die. There were no differences in the numbers of CD4+ and CD8+ T cells infiltrated in the spinal cord or in the levels of HSV-2-specific gamma interferon produced by those cells in a comparison of lpr and WT mice 9 days after infection. Adoptive transfer studies demonstrated that CD4+ T cells from WT mice protected gld mice from lethal infection by HSV-2. Furthermore, CD4+ T cells infiltrated in the spinal cord of HSV-2-infected WT mice expressed functional FasL that induced apoptosis of Fas-expressing target cells in vitro. These results suggest that FasL-mediated cytotoxic activity of CD4+ T cells plays an important role in host defense against lethal infection with HSV-2.

Differences in the regulatory and functional effects of the Us3 protein kinase activities of herpes simplex virus 1 and 2.

Us3 protein kinases encoded by herpes simplex virus 1 (HSV-1) and 2 (HSV-2) are serine/threonine protein kinases and play critical roles in viral replication and pathogenicity in vivo. In the present study, we investigated differences in the biological properties of HSV-1 and HSV-2 Us3 protein kinases and demonstrated that HSV-2 Us3 did not have some of the HSV-1 Us3 kinase functions, including control of nuclear egress of nucleocapsids, localization of UL31 and UL34, and cell surface expression of viral envelope glycoprotein B. In agreement with the observations that HSV-2 Us3 was less important for these functions, the effect of HSV-2 Us3 kinase activity on virulence in mice following intracerebral inoculation was much lower than that of HSV-1 Us3. Furthermore, we showed that alanine substitution in HSV-2 Us3 at a site (aspartic acid at position 147) corresponding to one that can be autophosphorylated in HSV-1 Us3 abolished HSV-2 Us3 kinase activity. Thus, the regulatory and functional effects of Us3 kinase activity are different between HSV-1 and HSV-2.