Negative staining EM for the detection of Epstein-Barr virus in oral hairy leukoplakia

A rapidly new-typed detection of norovirus based on F0F1-ATPase molecular motor biosensor

In order to adapt port rapid detection of food borne norovirus, presently we developed a new typed detection method based on F₀F₁-ATPase molecular motor biosensor. A specific probe was encompassed the conservative region of norovirus and F₀F₁-ATPase within chromatophore was constructed as a molecular motor biosensor through the "ε-subunit antibody-streptomycin-biotin-probe" system. Norovirus was captured based on probe-RNA specific binding. Our results demonstrated that the Limit of Quantification (LOQ) is 0.005 ng/mL for NV RNA and also demonstrated that this method possesses specificity and none cross-reaction for food borne virus. What's more, the experiment used this method could be accomplished in 1 h. We detected 10 samples by using this method and the results were consistent with RT-PCR results. Overall, based on F₀F₁-ATPase molecular motors biosensor system we firstly established a new typed detection method for norovirus detection and demonstrated that this method is sensitive and specific and can be used in the rapid detection for food borne virus.

The LMP2A ITAM is essential for providing B cells with development and survival signals in vivo

In Epstein-Barr virus-transformed B cells, known as lymphoblastoid cell lines (LCLs), LMP2A binds the tyrosine kinases Syk and Lyn, blocking B-cell receptor (BCR) signaling and viral lytic replication. SH2 domains in Syk mediate binding to a phosphorylated immunoreceptor tyrosine-based activation motif (ITAM) in LMP2A. Mutation of the LMP2A ITAM in LCLs eliminates Syk binding and allows for full BCR signaling, thereby delineating the significance of the LMP2A-Syk interaction. In transgenic mice, LMP2A causes a developmental alteration characterized by a block in surface immunoglobulin rearrangement resulting in BCR-negative B cells. Normally B cells lacking cognate BCR are rapidly apoptosed; however, LMP2A transgenic B cells develop and survive without a BCR. When bred into the recombinase activating gene 1 null (RAG(-/-)) background, all LMP2A transgenic lines produce BCR-negative B cells that develop and survive in the periphery. These data indicate that LMP2A imparts developmental and survival signals to B cells in vivo. In this study, LMP2A ITAM mutant transgenic mice were generated to investigate whether the LMP2A ITAM is essential for the survival phenotype in vivo. LMP2A ITAM mutant B cells develop normally, although transgene expression is comparable to that in previously described nonmutated LMP2A transgenic B cells. Additionally, LMP2A ITAM mutant mice are unable to promote B-cell development or survival when bred into the RAG(-/-) background or when grown in methylcellulose containing interleukin-7. These data demonstrate that the LMP2A ITAM is required for LMP2A-mediated developmental and survival signals in vivo.

Oral hairy leukoplakia: an ultrastructural study and review of the literature

A 39-year-old, homosexual, Caucasian man with a 9-month history of acquired immunodeficiency syndrome by reduced CD4 lymphocyte count alone was found to have extensive, asymptomatic, nonremovable, corrugated, white patches on the lateral borders and ventral aspects of the tongue typical of oral hairy leukoplakia (OHL). Histologically, irregular hyperparakeratosis, acanthosis, and clusters of ballooned keratinocytes in the stratum spinosum were present in the biopsied lateral tongue. Some of the superficial ballooned keratinocytes had peripherally beaded nuclei, whereas others had ground glass intranuclear inclusions. Ultrastructurally, the ballooned keratinocytes had three important findings of diagnostic significance. First, frequent herpesvirus nucleocapsids were largely confined to superficial ballooned keratinocytes having marginated and condensed chromatin. In searching for herpesvirus nucleocapsids, the marginated and condensed chromatin was an invaluable marker for cells harboring the virions. Second, the marginated and condensed chromatin frequently had a distinctive punched-out or cribriform appearance. Third, the ground glass intranuclear inclusion bodies consisted of central, medium electron-dense, finely granular material containing frequent herpesvirus nucleocapsids and partially surrounded or capped by prominent, clumped chromatin. The patient died with progressive multifocal leukoencephalopathy 24 months after OHL was diagnosed.

Detection of Epstein-Barr virus (EBV) DNA and antigens in oral mucosa of renal transplant patients without clinical evidence of oral hairy leukoplakia (OHL)

The use of the polymerase chain reaction (PCR) to detect the presence of Epstein-Barr virus (EBV) DNA in oral mucosa in the absence of specific lesions gives rise to the problem of identifying the real viral replication sites. To verify whether the detection of EBV is due to salivary contamination or its true replicative capacity in oral mucosa, saliva samples and exfoliated cells from four different oral mucosa sites were taken from 40 renal transplant patients and 20 normal subjects for examination by PCR using two pairs of primers specific for the BamHI-L and BamHI-K genomic regions. EBV-specific sequences were detected in one or more of the oral mucosa samples from 29 transplant patients (72.5%) and six healthy controls (30%), and in the saliva samples of 16 transplant patients (40%) and three healthy controls (15%). A total of 89 oral mucosa smears from 29 transplant patients, and 13 from healthy subjects, were EBV-positive. The positive samples were also investigated by means of in situ hybridization in order to confirm the intracellular presence of the viral genome, and by means of immunofluorescence testing with monoclonal antibodies to assess the possible expression of viral antigens. Hybridization with the EBV-specific probe was observed in 40/ 89 and 2/13 samples, respectively. Latent antigens (with or without lytic antigens) were detected in only 23 of the 40 samples (collected from eight different transplant patients) that were positive by in situ hybridization. Our data show that EBV is more frequently present in the oral mucosa of immunodeficient patients (where it can efficiently replicate) than in normal subjects.

Hairy leucoplakia and HIV-2--a case report and review of the literature

Type 2 human immunodeficiency virus (HIV-2), originally confined to West Africa, has lately appeared with increasing frequency in Europe. Oral lesions affect a large proportion of patients with AIDS. Hairy leucoplakia (HL), a clinical expression of Epstein-Barr virus (EBV), is a lesion of the oral mucosa (usually the lateral margin of the tongue) that is observed in patients who are immunocompromised due to HIV or, more rarely, due to immunosuppressive medication or other causes. We review the definition, clinical signs, histopathology, diagnosis, prognosis and treatment of HL, and report the (to our knowledge) first detailed description of an HIV-2-seropositive patient with HL, which affected the lateral and dorsal tongue and was the first clinical sign of HIV infection (this patient was at that time only the second native Spaniard in whom unique HIV-2 infection had been detected). EBV detection and subtyping by in situ hybridization and polymerase chain reaction were performed in paraffin-embedded tissue from the HL lesion of the dorsal tongue; EBV-1 and EBV-2 were detected by the latter technique.

Oral hairy leukoplakia in a patient with ulcerative colitis

A 30-year-old man with ulcerative colitis developed oral hairy leukoplakia (OHL). Serological examination for human immunodeficiency virus (HIV)-1 and HIV-2 infection showed no abnormalities. Biopsy specimen of the lateral tongue showed ballooned prickle cells, and electron microscopy revealed herpes-type viruses. Immunologic investigation of the patient showed a marked decrease in T-helper cells as a result of immunosuppressive regimen. The present report appears to be the first well-documented case of OHL in an HIV-negative patient with ulcerative colitis. OHL may be a marker for severe immunosuppression but is not necessarily associated with HIV infection. Patients with iatrogenic immunosuppression should be monitored for OHL. Concerning the marked decrease in T-helper cells in this case, the presence of OHL may imply the examination of T-lymphocyte subsets in patients such as HIV-infected individuals or in organ transplant recipients.

Oral manifestations in HIV-infected patients: diagnosis and management

Oral lesions have been observed since the beginning of the AIDS epidemic. The number of HIV-infected patients is still increasing, especially in the heterosexual population. Oral diseases in HIV-infected patients are often more difficult to diagnose because the clinical presentations may differ from the same diseases in HIV-negative patients. HIV-associated oral lesions have diagnostic, prognostic, and therapeutic impact. Approximately 10% of the HIV-infected population will have oral manifestations as a first sign of their disease. In HIV-infected men oral hairy leukoplakia and oral candidiasis are useful markers for disease progression. This article summarizes the oral manifestations and the management of oral health in persons with HIV infection.

Epstein-Barr virus in lingual epithelium of liver transplant patients

Thirty-three liver transplant patients and 20 controls were examined for the presence of EBV in epithelium of the lateral border of the tongue by negative staining electron microscopy. Five of the specimens (15%) showed particles typical of the herpes virus family, while all controls were negative for EBV. In 3 of the 5 patients moderate oral hairy leukoplakia was observed clinically. Our results indicate that EBV may be expressed at the lateral border of the tongue of liver transplant patients, who in some cases show oral hairy leukoplakia clinically.

Detection of Epstein-Barr virus and human papillomavirus type 16 DNA in hairy leukoplakia by in situ hybridisation and the polymerase chain reaction

Demonstration of Epstein-Barr virus (EBV) is considered desirable for the accurate diagnosis of hairy leukoplakia (HL). Previous studies have reported possible associations with human papillomavirus (HPV) infection although this is not a universal finding. Presence of EBV and HPV 16 was examined in biopsy specimens from 18 cases of HL and ten control specimens by in situ hybridisation using digoxigenin-labelled synthetic oligonucleotide probes and by the polymerase chain reaction (PCR). The presence of EBV was demonstrated in 12 cases by both techniques. Of the remaining six cases EBV could be detected in three by in situ hybridisation but not by PCR; EBV was not detected by either method in a further three cases. All samples were negative for HPV 16 by both techniques under conditions of high stringency, although when stringency of in situ hybridisation was reduced, four samples appeared to harbour HPV DNA sequences. This study provides further evidence to support the role of EBV in the pathogenesis of HL and suggests that HPV 16 is not regularly encountered.

Hairy leukoplakia with involvement of the buccal mucosa

Oral hairy leukoplakia occurs mainly on the tongue of human immunodeficiency virus (HIV)-infected persons. An HIV-infected patient with hairy leukoplakia involving the tongue and buccal mucosa was studied by light and electron microscopic methods, in situ hybridization, and polymerase chain reaction. Our findings indicate that hairy leukoplakia may involve the buccal mucosa and should be considered in the differential diagnosis of white oral lesions in HIV-positive patients. Epstein-Barr virus particles were found in the epithelial cells of both buccal and tongue mucosa.

Hairy leukoplakia--a histological study

Hairy leukoplakia is a recently described oral mucosal condition seen in immunosuppressed individuals, usually in association with HIV infection, when it is thought to be a sign of decreasing immunocompetence. It probably results from reactivation of infection by Epstein-Barr virus (EBV) and usually presents as bilateral white patches on the lateral borders of the tongue. From a histological study of 20 cases we have found that the typical appearance of hairy leukoplakia is of acanthotic, hyperparakeratinized epithelium with Candida hyphae sometimes present in the parakeratin. A band of EBV infected, koilocyte-like cells is present in the upper part of the prickle cell layers, these cells being swollen and pale staining, with prominent cell borders and perinuclear vacuoles. There is a paucity of inflammation in both the epithelium and lamina propria. An atypical appearance shows the koilocyte-like cells lying isolated or in small groups, irregularly arranged in the prickle cell layer and without a hyperparakeratinized surface. Diagnosis of hairy leukoplakia should normally be confirmed by demonstrating EBV in the koilocyte-like cells by immunocytochemistry or DNA in situ hybridization.

Demonstration of Epstein-Barr virus in scrape material of lateral border of tongue in heart transplant patients by negative staining electron microscopy

Scrape material from the lateral border of the tongue of 50 heart transplant patients and 20 controls was studied for the presence of EBV by negative staining electron microscopy. Mild oral hairy leukoplakia was observed in two cases. Particles of the herpes virus were found in 20% of the specimens. Controls were negative for EBV. The study has shown that EBV may be expressed at the lateral border of the tongue during immunosuppression, occasionally resulting in the clinical appearance of hairy leukoplakia.