Effects of Angipars on oxidative inflammatory indices in a murine model of periodontitis.

BACKGROUND AND THE PURPOSE OF THE STUDY: There are strong evidences linking overproduction of reactive oxygen species and periodontal diseases. The aim of this study was to evaluate efficacy of Angipars a natural potent anti oxidative agent on markers of the oxidative damages and periodontal inflammation in the rat. METHODS: Periodontitis was induced by single injection of lipopolysaccharide (LPS) from E. coli (10 µg/µl saline) into rat mandibular gingiva. After 10 days, animals in the test group received Angipars (2.1 mg/kg) by gavage once a day and those of control group received same amount of vehicle. The amount of interleukin (IL)-1ß, lipid peroxidation (LPO), and 8-hydroxydeoxyguanosine (8-OHdG) were measured in gingival biopsy samples and the degree of apical migration of junctional epithelium (JE), alveolar bone resorption, and the number of polymorphonuclears (PMN) were evaluated by histological analysis of block samples of the left mandibular first molars. RESULTS: Periodontitis group showed a significant increase in periodontal IL-1ß, LPO, 8-OHdG, apical migration of JE, alveolar bone resorption and number of PMNs. Angipars treatment resulted in a significant decrease in gingival IL-1ß, LPO, 8-OHdG and the apical migration of JE; however, the reduction of alveolar bone resorption was not significant. The number of PMN increased significantly after treatment with Angipars. While intake of vehicle resulted in a significant decrease in gingival IL-1ß and LPO, the reduction of 8-OHdG, apical migration of JE, and alveolar bone resorption were not significant. Interestingly, PMNs were increased in groups received Angipars or the vehicle. CONCLUSION: From the results of this study, it seems that Angipars is beneficial in periodontitis by reduction of inflammatory and oxidative damage. Unexpected increase of PMN count by Angipars strengthens the hypothesis that chronic inflammatory disorders like periodontitis may need more time to get best advantage of anti oxidative drugs like Angipars. Regarding role of microbes in pathogenesis of periodontitis, further studies should be focused on antimicrobial effects of Angipars.

A case of diffuse leptomeningeal oligodendrogliomatosis associated with HHV-6 variant A.

We describe a rare case of diffuse leptomeningeal oligodendrogliomatosis associated with the human herpes virus 6 variant A (HHV-6 A). A 2-year-old boy presented with progressive neurological symptoms and hydrocephalus. The patient had a VP shunt placement but did not fully recover. HHV-6 A was detected in both CSF and serum by nested PCR. His symptoms improved repeatedly, but temporarily, on antiviral treatment. An open brain biopsy, ten months after presentation, revealed leptomeningeal tumour as well as the presence of viral DNA in the tumour tissue. The role of HHV-6 A could be that of a reactivated opportunist. However, this case also raises the question whether this neurotropic virus, with malignant transforming properties in vitro, may have a role in pathogenesis in some cases of brain malignancy.

Synergistic effect of IFN-gamma and human cytomegalovirus protein UL40 in the HLA-E-dependent protection from NK cell-mediated cytotoxicity.

Human CMV (HCMV) has evolved several strategies to evade the immune system of the infected host. Here, we investigated the role of the HCMV-encoded protein UL40 in the modulation of NK cell lysis. UL40 carries in its leader sequence a nonameric peptide similar to that found in many HLA class I molecules leader sequences. This peptide up-regulates the expression of HLA-E, the ligand for the NK cell inhibitory receptor CD94/NKG2A. The UL40-encoded HLA-E-binding peptide was present in all HCMV clinical (4636, 13B, 109B, 3C) and laboratory (AD169) strains analyzed. However, transfection of UL40 in different cell lines (293T, 721.221, K562) did not consistently confer protection from NK lysis (as measured using NKL and the newly generated NK line Nishi), despite a moderate up-regulation of HLA-E. Interestingly, combined transfection and treatment with IFN-gamma increased the inhibitory effect, via an HLA-E- and CD94/NKG2A-dependent mechanism. Although cells transfected with UL40 derived from either AD169 or 3C showed protection from NK cell lysis, infection of fibroblasts with the viruses resulted in a strong inhibition only with the clinical strain 3C. Our results suggest that UL40 and IFN-gamma-dependent up-regulation of HLA-E is only one possible mechanism to avoid NK cell recognition of HCMV infected cells.

Variations in the cytomegalovirus DNA polymerase and phosphotransferase genes in relation to foscarnet and ganciclovir sensitivity.

BACKGROUND: Identification of human cytomegalovirus (CMV) genome variation is important for understanding mutations associated with drug resistance. OBJECTIVES: To investigate the CMV resistance to foscarnet (PFA) and ganciclovir (GCV) in patients treated with antiviral drugs and to identify the DNA polymerase (UL54) and phosphotransferase (UL97) gene mutations inducing resistance. STUDY DESIGN: Antiviral susceptibility of CMV strains/isolates for PFA and GCV was compared by plaque reduction assay and in situ ELISA. UL54 and UL97 gene mutations were identified by sequencing. Growth phenotype of two CMV recombinants with mutations in UL54 was studied. RESULTS: Six of seven GCV resistant strains had alterations within the UL97. Five of them also had alterations in the UL54 (F412C, L802M or K513E), previously shown to induce GCV resistance. Seven isolates had no or reduced susceptibility to PFA, which had alterations in the UL54 (D588N, E756K, V781I or L802M). By in vitro mutagenesis, it was shown that a mutation at codon D588N of UL54 conferred 9-fold reduced susceptibility to PFA, while a mutation at codon V781I induced 4-fold reduced susceptibility to PFA and GCV. Both recombinants showed the same kinetics of protein expression (IE, E, and L antigen) and virus yields as the CMV Towne strain. CONCLUSIONS: The recombinants containing alterations within the UL54 (D588N and V781I) showed a reduced susceptibility to antiviral drugs but no change in the replication rate compared to the CMV Towne.

Sequence analysis of UL54 and UL97 genes and evaluation of antiviral susceptibility of human cytomegalovirus isolates obtained from kidney allograft recipients before and after treatment.

The frequency of infections caused by drug-resistant cytomegalovirus (CMV) in solid-organ transplant recipients is not known. Only a few resistant strains have been described in transplant recipients. Antiviral susceptibility to ganciclovir (GCV) and foscarnet (PFA) of CMV isolates from 24 renal transplant patients with CMV viremia and CMV disease before and after therapy were investigated by a solid phase ELISA. The CMV DNA polymerase (UL54) and viral phosphotransferase (UL97) genes were also sequenced. Ten patients did not receive antiviral treatment; five and nine patients were treated with PFA and GCV, respectively. No appearance of drug-resistant viruses was observed in the present study, but one isolate showed a reduced sensitivity to PFA after treatment with GCV. This finding could not be explained by the presence or development of mutations that have been associated with drug resistance in UL54. We found no evidence that short-term treatment of CMV with PFA- or GCV-induced resistance.

Growth phenotypes of cytomegalovirus isolates do not correlate with glycoprotein B, major immediate early genotypes or antiviral sensitivity.

Human Cytomegalovirus (CMV) is generally described from in vitro experiments as a slowly replicating virus. A doubling time of one day in blood, however, has been shown in vivo. The growth phenotypes of CMV isolates and laboratory strains were studied in human fibroblasts. The viruses were found to replicate either rapidly or slowly. Comparison of CMV protein expression in lung and foreskin fibroblast cultures showed that two tissue culture adapted CMV strains (AD169 and Towne) and 3 clinical isolates belonged to the rapidly replicating viruses, whereas another 3 clinical isolates replicated slowly. CMV antigen concentrations were 6-fold and virus yields were 10-1000-fold higher for the rapidly replicating viruses than for the slow replicators. The antigen expression of two slowly replicating isolates was enhanced after 20 passages compared to the isolates at passage 5, but it was not as efficient as that of strain Towne. Slow or fast replication was related neither to major immediate early gene exon 4, and gB genotypes, nor to antiviral susceptibility. Proteins of the beta cascade may contribute to differences in the replication rate of CMV isolates.

Human cytomegalovirus strain-dependent changes in NK cell recognition of infected fibroblasts.

NK cells play a key role in the control of CMV infection in mice, but the mechanism by which NK cells can recognize and kill CMV-infected cells is unclear. In this study, the modulation of NK cell susceptibility of human CMV (hCMV)-infected cells was examined. We used a human lung and a human foreskin fibroblast cell line infected with clinical isolates (4636, 13B, or 109B) or with laboratory strains (AD169, Towne). The results indicate that all three hCMV clinical isolates confer a strong NK resistance, whereas only marginal or variable effects in the NK recognition were found when the laboratory strains were used. The same results were obtained regardless of the conditions of infection, effector cell activation status, cell culture conditions, and/or donor-target cell combinations. The NK cell inhibition did not correlate with HLA class I expression levels on the surface of the target cell and was independent of the leukocyte Ig-like receptor-1, as evaluated in Ab blocking experiments. No relevant changes were detected in the adhesion molecules ICAM-I and LFA-3 expressed on the cell surface of cells infected with hCMV clinical and laboratory strains. We conclude that hCMV possesses other mechanisms, related neither to target cell expression of HLA-I or adhesion molecules nor to NK cell expression of leukocyte Ig-like receptor-1, that confer resistance to NK cell recognition. Such mechanisms may be lost during in vitro passage of the virus. These results emphasize the differences between clinical hCMV isolates compared with laboratory strains.

Reactivation of human herpesvirus 6 during pregnancy.

Reactivation of human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) during pregnancy and transmission of the viruses to the fetus were investigated by polymerase chain reaction (PCR) and serology. In all, 104 blood samples were obtained 3 times during pregnancy and once at delivery. In another 107 women, samples were obtained only at delivery. Cord blood samples were obtained from both groups of women. HHV-6 DNA was detected in 41%-44% of the samples during months 3-8 of pregnancy, in 25% at delivery, and in 24% of age-matched controls. HHV-6 DNA was found in 1.0% of the cord blood samples. CMV DNA was detected in 1.7% of leukocytes from 104 pregnant women but in no cord blood sample. IgG antibodies to HHV-6 were found in 96% and CMV IgG in 62.5% of the women. HHV-6 IgG titers were significantly higher in HHV-6 PCR-positive women. Thus, HHV-6 reactivation seems common during pregnancy, and transfer of HHV-6 to the fetus may occur in approximately 1% of pregnancies.

Infrequent detection of cytomegalovirus and Epstein-Barr virus DNA in synovial membrane of patients with rheumatoid arthritis.

OBJECTIVE: To study the role of the cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus types 1 and 2 (HSV-1 and 2), varicella zoster virus (VZV), and human herpes virus 6 (HHV-6) in the etiology of rheumatoid arthritis (RA). METHODS: Polymerase chain reaction (PCR) was used to detect DNA of the different herpes viruses in synovial membranes from 31 patients with chronic RA and 14 control patients. Specific antibodies were determined by indirect immunofluorescence and ELISA. RESULTS: Out of 31 patients with RA, CMV DNA was detected in synovial membranes from 2 patients and EBV DNA was detected in synovial membranes from 2 other patients. All samples from the patients with RA were negative for DNA from HSV-1 and 2, VZV, and HHV-6. All samples from the 14 control patients were negative in all PCR assays. No statistically significant differences in IgG antibodies were found for CMV, HSV-1, VZV, and HHV-6 in patients with RA compared to controls. Higher titers of IgG antibodies against EBV viral capsid antigen were found in patients with RA, with a significance of p < 0.05. CONCLUSION: Both CMV and EBV DNA were detected in synovial membranes from 6% of the patients with RA. We cannot exclude the possibility that these viruses were associated with disease development in a minority of patients with RA.

Cytomegalovirus DNA in peripheral blood leukocytes and plasma from bone marrow transplant recipients.

Granulocytes, monocytes, and T- and B-lymphocytes were separated from 28 blood samples collected from 5 bone marrow transplant (BMT) recipients. About 40% of granulocyte, monocyte, and B-lymphocyte samples were CMV DNA-positive by polymerase chain reaction in recipients with cytomegalovirus (CMV) infection. CMV DNA was rarely detected in separated T-lymphocytes. Within each of the simultaneously separated paired samples, there were several with single positive cell subtypes. Monocytes, granulocytes, and B-lymphocytes were the single positive samples in some instances. Thus, it is important to have all of the different cell subtypes present in samples for detection of CMV DNA in peripheral blood. We also studied the appearance of CMV DNA in plasma and peripheral blood leukocytes (PBLs) from 351 blood samples collected from 30 BMT recipients during a follow-up period of at least 3 months after BMT. All cell subtypes were represented in the PBL samples. In the 13 recipients who developed symptoms possibly associated with CMV infection or CMV disease, a correlation with the detection of CMV DNA in < or = 2 x 10(5) PBLs was found. In PBLs from 11 of the 13 BMT recipients, CMV DNA was detected before the onset of symptoms. CMV DNA was not detected in < or = 2 x 10(5) PBLs from recipients without CMV infection. The virus load in PBLs decreased during ganciclovir treatment. Nine of the 13 recipients displayed PCR-positive plasma samples, and CMV DNA was detected frequently after the onset of symptoms.