Herpes simplex virus (HSV), including HSV-1 and HSV-2, is an important pathogen that can cause many diseases. Usually these diseases are recurrent and incurable. After lytic infection on the surface of peripheral mucosa, HSV can enter sensory neurons and establish latent infection during which viral replication ceases. Moreover, latent virus can re-enter the replication cycle by reactivation and return to peripheral tissues to start recurrent infection. This ability to escape host immune surveillance during latent infection and to spread during reactivation is a viral survival strategy and the fundamental reason why no drug can completely eradicate the virus at present. Although there are many studies on latency and reactivation of HSV, and much progress has been made, many specific mechanisms of the process remain obscure or even controversial due to the complexity of this process and the limitations of research models. This paper reviews the major results of research on HSV latency and reactivation, and discusses future research directions in this field.
Herpes Simplex ; virology ; Herpesvirus 1, Human ; physiology ; Humans ; Virus Activation ; physiology ; Virus Latency ; physiology ; Virus Replication

Hepatitis B virus ; drug effects ; physiology ; Hodgkin Disease ; drug therapy ; Humans ; Immunoconjugates ; therapeutic use ; Virus Activation ; drug effects

Although vestibular neuritis is defined as acute peripheral vestibulopathy without associated hearing loss, a handful of cases reported sudden hearing loss without concurrent vertigo during follow-up of vestibular neuritis. In addition, some patients show benign paroxysmal postional vertigo(BPPV) ipsilateral to the lesion side with various interval after vestibular neuritis, and they are considered to be "secondary" BPPV. Viral and vascular etiologies have been assumed for the vestibular neuritis but, both of those failed to explain exact pathomechanism so far. Authors experienced a case of sudden hearing loss with simultaneous ipsilateral BPPV after vestibular neuritis. There has been no report of concurrent of BPPV and sudden hearing loss after vestibular neuritis. Sequential viral activations are considered to be responsible for this case.
Follow-Up Studies ; Hand ; Hearing Loss ; Hearing Loss, Sudden* ; Humans ; Vertigo* ; Vestibular Neuronitis* ; Virus Activation

Human bocavirus 1 (HBoV1) non-structural protein NS1 is a multifunctional protein important for virus replication and induction of apoptosis in host cell. To better understand the function of the NS1 protein, it is urgent to address reducing the toxicity of NS1 to host cells. In the present study, we established a stable cell line that regulates expression of NS1 of HBoV1. The recombinant lentivirus plasmid containing a regulatable promoter fused with ns1 gene was constructed and transfected into HEK 293T cells using transfection reagent. The HEK 293T cell lines stably expressing NS1-100 and NS1-70 proteins were established by screening resistant cells with puromycin and inducing NS1 expression with doxycycline. The expression of NS1 protein was determined by fluorescent labeling protein and Western blotting. HBoV1 promoter was transfected into stably expressing NS1 cell line and its trans-transcriptional activity was analyzed. The results showed that NS1 protein was expressed stably in the established cell lines and had a strong activation activity on the HBoV1 promoter driving luciferase gene. Taken together, this study provides a solid basis for further research on the function of NS1 and the pathogenesis of human bocavirus.
Human bocavirus ; Promoter Regions, Genetic ; Transcriptional Activation ; Viral Nonstructural Proteins ; Virus Replication

Objective: To investigate herpesvirus infection in early stage of hematopoietic stem cell transplantation (HSCT) by multiplex polymerase chain reaction (PCR), and to explore the association between multiple herpesviruses infection and clinical characteristics in HSCT patients and its impact on post-transplant complications and prognosis. Methods: A total of 734 peripheral blood samples were collected from 90 patients undergoing HSCT in the Department of Hematology, the First Affiliated Hospital of Soochow University between February 2017 and August 2017. The peripheral blood specimens were obtained before and within 90 days after transplantation at different time points. Lab-Aid824 Nucleic Acid Extraction Mini Reagent was used to extract DNA and multiplex PCR assay was used to simultaneously detect 8 kinds of human herpesviruses from genomic DNA. The incidence of various herpesvirus infections, its correlation with clinical features and effects on post-transplant complications and prognosis were analyzed. Results: The median follow-up time was 192 (range: 35-308) days. Among the 90 patients before transplantation, the incidence of herpes virus infection was 35.6% (32/90), including 12.2% (11/90) with one herpes virus infection and 23.3% (21/90) with multiple viruses infection. The incidence of herpes virus infection after transplantation was 77.8% (70/90), including 20.0% (18/90) with one herpes virus infection and 57.8% (52/90) with multiple herpes virus infection. Among the 52 patients with multiple herpes viruses infection, 30 (57.7%) patients were infected by 2 kinds of viruses, 18 (34.6%) patients by 3 kinds of viruses and 4 (7.7%) patients by 4 kinds of viruses. There was a correlation between HHV-6 and HHV-7 herpesvirus infection (OR=13.880, Q=0.026). EBV infection was related to HHV-7 infection (OR=0.093, Q=0.044). The age of patients was correlated with the incidence of HHV-1 infection before transplantation. There were 24 patients in our study experienced clinical symptoms associated with viral infection. The main manifestations were hemorrhagic cystitis (HC), interstitial pneumonia, enteritis, viral encephalitis and fever of unknown origin. EBV infection was related to HLA incompatibility and the inconsistent of the ABO blood group and grade Ⅱ-Ⅳ aGVHD after transplantation. HLA incompatibility and the unrelated donor and grade Ⅱ-Ⅳ aGVHD were related to multiple viruses infection. Conclusion: Multiple herpesviruses were common in patients undergoing HSCT, which were closely related to HLA mismatch, unrelated donor and grade Ⅱ-Ⅳ aGVHD.
DNA, Viral ; Hematopoietic Stem Cell Transplantation ; Herpesviridae ; Herpesviridae Infections ; Humans ; Multiplex Polymerase Chain Reaction ; Virus Activation

B-Lymphocytes ; immunology ; Hepatitis B ; complications ; Humans ; Liver Transplantation ; adverse effects ; Lymphocyte Activation ; Lymphoproliferative Disorders ; etiology ; Male ; Middle Aged ; Risk Factors ; Virus Activation

Allergens ; immunology ; Animals ; Asthma ; etiology ; Enzyme Activation ; Lung ; pathology ; Matrix Metalloproteinases ; physiology ; Mice ; Respiratory Syncytial Virus Infections ; enzymology ; pathology

No abstract available.
Antiviral Agents/*therapeutic use ; Colitis, Ulcerative/*drug therapy ; *Cytomegalovirus ; Cytomegalovirus Infections/*drug therapy ; Ganciclovir/*therapeutic use ; Humans ; *Virus Activation

No abstract available.
Antiviral Agents/*therapeutic use ; Colitis, Ulcerative/*drug therapy ; *Cytomegalovirus ; Cytomegalovirus Infections/*drug therapy ; Ganciclovir/*therapeutic use ; Humans ; *Virus Activation

INTRODUCTIONHepatitis B virus (HBV) reactivation has been reported in B-cell lymphoma patients with resolved hepatitis B (hepatitis B surface antigen [HBsAg]-negative and hepatitis B core antibody [HBcAb]-positive). This study aimed to assess HBV reactivation and hepatitis occurrence in diffuse large B-cell lymphoma (DLBCL) patients with resolved hepatitis B receiving rituximab-containing chemotherapy compared with HBsAg-negative/HBcAb-negative patients to identify risk factors for HBV reactivation and hepatitis occurrence and to analyze whether HBV reactivation and hepatitis affect the survival of DLBCL patients with resolved hepatitis B.

METHODSWe reviewed the clinical data of 278 patients with DLBCL treated with rituximab-containing therapy between January 2004 and May 2008 at Sun Yat-sen University Cancer Center, China. Predictive factors for HBV reactivation, hepatitis development, and survival were examined by univariate analysis using the chi-square or Fisher's exact test and by multivariate analysis using the Cox regression model.

RESULTSAmong the 278 patients, 165 were HBsAg-negative. Among these 165 patients, 6 (10.9%) of 55 HBcAb-positive (resolved HBV infection) patients experienced HBV reactivation compared with none (0%) of 110 HBcAb-negative patients (P = 0.001). Patients with resolved hepatitis B had a higher hepatitis occurrence rate than HBsAg-negative/HBcAb-negative patients (21.8% vs. 8.2%, P = 0.013). HBcAb positivity and elevated baseline alanine aminotransferase (ALT) levels were independent risk factors for hepatitis. Among the 55 patients with resolved hepatitis B, patients with elevated baseline serum ALT or aspartate aminotransferase (AST) levels were more likely to develop hepatitis than those with normal serum ALT or AST levels (P = 0.037, P = 0.005, respectively). An elevated baseline AST level was an independent risk factor for hepatitis in these patients. Six patients with HBV reactivation recovered after immediate antiviral therapy, and chemotherapy was continued. HBcAb positivity, HBV reactivation, or hepatitis did not negatively affect the survival of DLBCL patients.

CONCLUSIONSDLBCL patients with resolved hepatitis B may have a higher risk of developing HBV reactivation and hepatitis than HBsAg-negative/HBcAb-negative patients. Close monitoring and prompt antiviral therapy are required in these patients.

China ; Hepatitis B ; Hepatitis B Antibodies ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Humans ; Lymphoma, Large B-Cell, Diffuse ; Mortality ; Prognosis ; Risk Factors ; Rituximab ; Virus Activation