Role of viruses in periodontitis:An extensive review of herpesviruses,human immunodeficiency virus,coronavirus-19,papillomavirus and hepatitis viruses

Periodontitis is the inflammation of the supporting structures around the dentition.Several microbial agents,mostly bacteria,have been identified as causative factors for periodontal disease.On the other hand,oral cavity is a rich reservoir for viruses since it contains a wide variety of cell types that can be targeted by viruses.Traditionally,the focus of research about the oral flora has been on bacteria because the most widespread oral diseases,like periodontitis and dental caries,are outcomes of bacterial infection.However,recently and especially after the emergence of coronavirus disease 2019,there is a growing tendency toward including viruses also into the scope of oral microbiome investigations.The global high prevalence of periodontitis and viral infections may point out to a concomitant or synergistic effect between the two.Although the exact nature of the mechanism still is not clearly understood,this could be speculated through the manipulation of the immune system by viruses;hence facilitating the furthermore colonization of the oral tissues by bacteria.This review provides an extensive and detailed update on the role of the most common viruses including herpes family(herpes simplex,varicella-zoster,Epstein-Barr,cytomegalovirus),Human papillomaviruses,Human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2 in the initiation,progression and prognosis of periodontitis.

CHARACTERIZATION OF A HUMAN HERPES VIRUS－6（HHV－6） AND EPSTEIN－BARR VIRUS（EBV） ASSOCIATED LEUKEMIC CELL LINE，J6－1

This report characterizes the J6-1 cell line derived from a Chinese acute myelomonocytic leukemia patient and previously reported to be associated with EBV. These studies showed that J6-1 cells were also infected with HHV-6 as demonstrate at the DNA level by PCR and Southern blot hybridization and by expression of HHV-6 early membrane antigen on the J6-1 cell surface. Further characterization showed J6-1 was co-infected with EBV type 2. Generally, cells infected with EBV type 2 do not grow well in vitro. However, J6-1 , although difficult to maintain in vitro, has been grown for 15 years. Possibly, co-infection with HHV6 confers this property. In this regard, J6-1 cells exhibited density dependent growth which could be inhibited with an anti-HHV-6-MA monoclonal antibody(MAb). In contrast, anti-HHV-6-VCA MAb stimulated the J6-1 cell proliferation. Electron microscopic analysis showed that, morphologically, there were two types of J6-1 cell, one with lymphoblastoid features and one with a monocytoid appearance. Accordingly, the flow profile of the J6-1 cell line showed heterogeneity. with two populations comprised of CD15-, CD19+ cells with low light scatter(small cells) and a population with greater light scatter(larger cells) which was CD15+ , CD19+. The population was negative for progenitor cell markers(CD33, 34 ), and T cell markers. Southern analysis showed no T cell receptor rearrangement, however there was a clonal JH and kappa light chain expressing population. Glycocytochemical analysis showed several endogenous lectin receptors on the J6-1 cell surface: BSA-Xylose, BSA-Rhamnose, BSAGal. BSA-Lac. This cell line shares many characteristics with other monocytic/ lymphoblastoid cell lines isolated elsewhere and provides circumstantial evidence linking Herpes viruses, as least as co- factors,to leukemia cell growth.

Replication of human herpes virus 1(HHV-1) as a ubiquitous virus:A mini review

Human herpes viruses cause a range of human disorders including cold sores,roseola,genital warts and most importantly,tumours.These viruses cause chronic,latent and recurrent infections.Among them HHV-1,an alpha-herpesvirus could become latent after a primary infection,becoming reactivated after later provocation. Epidemically,they are found everywhere and are neurotropic.They also have a rapid and highly regulated replication cycle and usually a broad host and cell range.This article summarizes and focuses on replication strategies of the virus.

Impact of human herpes virus 6 in liver transplantation

Human herpes virus 6 (HHV-6) infects > 95% of humans.Primary infection which occurs mostly during the f irst 2 years of life in the form of roseola infantum,non-spe cif ic febrile illness,or an asymptomatic illness,results in latency.Reactivation of latent HHV-6 is common after liver transplantation.Since the majority of human beings harbor the latent virus,HHV-6 infections after liver transplantation are most probably caused by end ogenous reactivation or superinfection.In a minority of cases,primary HHV-6 infection may occur when an HHV-6-seronegative individual receives a liver allograft from an HHV-6-seropositive donor.The vast major ity of HHV-6 infections after liver transplantation are asy-mptomatic.Only in a minority of cases,when HHV-6 causes a febrile illness associated with rash and mye- losuppression,hepatitis,gastroenteritis,pneumonitis,and encephalitis after liver transplantation.In addition,HHV-6 has been implicated in a variety of indirect effects,such as allograft rejection and increased predis- pos ition to and severity of other infections,includingcytomegalovirus,hepatitis C virus,and opportunistic fungi.Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6,there is currently no recommended HHV-6-specific approach prevention after liver transplantation.Asymptomatic HHV-6 infection does not require antiviral treatment,while treatment of established HHV-6 disease is treated with intravenous ganciclovir,foscarnet,or cidofovir and this should be com plemented by a reduction in immunosuppression.

Contributions of neurotropic human herpesviruses herpes simplex virus 1 and human herpesvirus 6 to neurodegenerative disease pathology

Human herpesviruses （HVs） have developed ingenious mechanisms that enable them to traverse the defenses of the central nervous system （CNS）. The ability of HVs to enter a state of latency, a defining char- acteristic of this viral family, allows them to persist in the human host indefinitely. As such, HVs represent the most frequently detected pathogens in the brain. Under constant immune pressure, these infections are largely asymptomatic in healthy hosts. However, many neurotropic HVs have been directly connected with CNS pathology in the context of other stressors and genetic risk factors. In this review, we discuss the potential mechanisms by which neurotropic HVs contribute to neurodegenerative disease （NDD） patholo- gy by highlighting two prominent members of the HV family, herpes simplex virus 1 （HSV-1） and human herpesvirus 6 （HHV-6）. We （i） introduce the infectious pathways and replicative cycles of HSV-1 and HHV-6 and then （ii） review the clinical evidence supporting associations between these viruses and the NDDs Alzheimer＇s disease （AD） and multiple sclerosis （MS）, respectively. We then （iii） highlight and dis- cuss potential mechanisms by which these viruses exert negative effects on neurons and glia. Finally, we （iv） discuss how these viruses could interact with other disease-modifying factors to contribute to the initiation and/or progression of NDDs.

Human Herpes Virus Type 2 ( HSV2 ), Human Cytomegalovirus (HCMV) in the Male Genital Tract and Fertilization

The possibility of infection of the human male genital tract by human herpes virus type 2 (HSV2) or human cytomegalovirus (HCMV) is well established and their sexual transmission has been the object of many studies. Moreover, medically assisted procreation, which helps in numerous fertility problems, raises the question of new viral risks linked to the application of these new technologies. In this review, we shall consider current knowledge in terms of the presence of HSV 2 and HCMV in the different parts of the genital tract of immunocompetent or immunodepressed men. We shall also consider the possibility of viral transmission by the sexual act or by the various techniques used in medically assisted procreation. We shall describe studies in human beings and in animals.

SEARCH FOR HERPES SIMPLEX VIRUS TYPE2（HSV－2）AND HUMAN PAPILLOMAVIRUS（HPV）IN THE NORMAL AND ABNORMAL CERVICAL SAMPLES

The specimens of 111 cervical carcinomas. 68 chronic cervicitis and 43 normal cervical exfoliated epithelial cells were examined for the presence of HSV2 DNA sequences with DNA hybridization using HSV2 BgL Ⅱ N fragment probe labelled by 32PdCTP. The result showed that the infection rates of HSV2 in the samples of cervical cancer.chronic cervicitis and normal epithelial cells were 1 4. 41 %(16/111). 27.94%( 19/68) and 25.58% ( 11/43),respectively. It was implied that early stages carcinogenesis of cervical epithelial cells might be correlated with the HSV2 infection.Sixteen HSV 2 positive samples of cervical carcinomas were also examined for the presence of the sequences homologous to human papillomavirus (HPV) type 6B/11. 16 and 18 DNA using dot blot hybridization (Tm17℃). The result indicated that 13 out of 16 were HPV 16 DNA hybridization positive accounting for 81. 2% of all HSV-2 positive samples and none of them were positive for HPV type 6B/11 and 18. The result indicated that double infection of HSV 2 and HPV16 in the same cervical carcinoma tissues may provide a strong evidence of the viral synergistic interaction in the induction of female cervical

Preliminary study on Herpes simplex virus type 1 infection of human oral epithelial cell in vitro

Objective： To explore the functions and mechanisms of herpes simplex virus type I（HSV-1） while infecting human oral epithelial cells in vitro（being similar to the infection in vivo）. Methods：An abundance of HSV-1 strains amplified in Vero cells were used to infect human oral epithelial cells. The culture supernatant was collected to infect Vero cells again. Morphology of HSV-1 was identified by inverted microscope and transmission electron microscope. Nucleic acid of the virus was detected by PCR. Results：The infected human oral epithelial cells didn＇ t display an obvious cytopathic effect（CPE） under inverted microscope（while Vero cells which were infected by the culture supernatant showed typical（CPE）. The virus particles were not observed in the cytoplasm nor in nucleus of human oral epithelial cells, however under transmission electron microscope in the cytoplasm of Vero cells, the nucleic acid of HSV-1 could be detected in infected human oral epithelial cells, by PCR. Conclusion-HSV-1 can successfully infect human oral epithelial cells. This model may provide a useful approach for studying the pathogenesis of herpes virus-associated periodontal disease.

Herpes simplex virus-1 infection or Simian virus 40-mediated immortalization of corneal cells causes permanent translocation of NLRP3 to the nuclei

AIM: To investigate into the potential involvement of pyrin containing 3 gene(NLRP3), a member of the nucleotide-binding oligomerization domain-like receptors with cytosolic pattern recognition, in the host defense of corneas against viruses.METHODS: The herpes viral keratitis model was utilized in BALB/c mice with inoculation of herpes simplex virus-1(HSV-1). Corneal tissues removed during therapy of patients with viral keratitis as well as a Simian vacuolating virus 40(SV40)-immortalized human corneal epithelial cell line were also examined.Immunohistochemistry was used to detect NLRP3 in these subjects, focusing on their distribution in tissue or cells. Western blot was used to measure the level of NLRP3 and another two related molecules in NLPR3 inflammasome, namely caspase-1 and IL-1β.RESULTS: The NLRP3 activation induced by HSV-1infection in corneas was accompanied with redistribution of NLRP3 from the cytoplasm to the nucleus in both murine and human corneal epithelial cells. Furthermore,in the SV40-immortalized human corneal epithelial cells,NLRP3 was exclusively located in the nucleus, and treatment of the cells with high concentration of extracellular potassium(known as an inhibitor of NLRP3activation) effectively drove NLRP3 back to the cytoplasm as reflected by both immunohistochemistry and Western blot.· CONCLUSION: It is proposed that herpes virus infection activates and causes redistribution of NLRP3 to nuclei. Whether this NLRP3 translocation occurs with other viral infections and in other cell types merit further study.

Hepatitis C virus in human B lymphocytes transformed by Epstein-Barr virus in vitro by in situ reverse transcriptase-polymerase chain reaction

AIM: To study persistence and replication of hepatitis C virus (HCV) in patients' peripheral blood mononuclear cells (PBMC) cultured in vitro. METHODS: Epstein Barr virus (EBV) was used to transform the hepatitis C virus from a HCV positive patient to permanent lymphoblastoid cell lines (LCL). Positive and negative HCV RNA strands of the cultured cells and growth media were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) each month. Core and NS5 proteins of HCV were further tested using immunohistochemical SP method and in situ RT-PCR. RESULTS: HCV RNA positive strands were consistently detected the cultured cells for one year. The negative-strand RNA in LCL cells and the positive-strand RNA in supernatants were observed intermittently. Immunohistochemical results medicated expression of HCV NS3 and C proteins in LCL cytoplasm mostly. The positive signal of PCR product was dark blue and mainly localized to the LCL cytoplasm. The RT-PCR signal was eliminated by overnight RNase digestion but not DNase digestion. CONCLUSION: HCV may exist and remain functional in a cultured cell line for a long period.

Incidence of human cytomegalovirus in pregnant women attending pre-natal clinic in Northern Nigeria

Objective:To investigate the incidence of human cytomegalo virus(HCMV) in pregnant women.Methods: One hundred and twenty two(122) blood samples and 80 umbilical cord fluids were tested for IgG and IgM respectively using the enzyme linked immunosorbent assay(ELISA).Results:Of the 122 samples screened for IgG and IgM only 56(47.1%) tested positive for IgG while 63(52.9%) were positive for IgM with 3 samples non-specific.Pregnant women with signs of normal pregnancy made up 60%of the positive results while 20%had a history of ectopic pregnancy and 20%with a history of miscarriages.Of the total of 80 umbilical cord fluids tested,only 59(73.8) tested positive.Eleven of the selected 40 umblical cord fluid was positive to IgG to human cytomegalovirus along with mother and child.Antibody titration result gave diagnostic titre for both IgG and IgM from the 40 umbilical cord fluids.There was a significant relationship between mother,child and umbilical cord fluids(χ~2 = 1.360,CI = 99%,P = 0.568).Conclusion:There could be a possible neonatal infection,and the infection is common among toddlers and children of pre-school age.

Splenic Kaposi’s sarcoma in a human immunodeficiency virusnegative patient:A case report

BACKGROUND Kaposi’s sarcoma(KS)is a malignancy that usually affects the skin of the lower extremities,and may involve internal organs.It originates from the vascular endothelium.It is well known that the development of KS is associated with human herpes virus 8(i.e.HHV8)infections.Sporadic KS cases have mainly been found in Africa.Isolated splenic KS in Asia has rarely been reported.We present here a case of KS primarily involving the spleen in a human immunodeficiency virus(HIV)-negative Chinese patient.CASE SUMMARY A 50-year-old male patient was admitted to hospital due to abdominal distension and discomfort,reduced food intake and weight loss.Medical examination revealed that the patient had moderate anemia,a low platelet count,slight fatty liver and a huge mass in the spleen.Spleen lymphoma was considered.An anti-HIV test was negative.The whole spleen was surgically excised.The final pathological diagnosis was nodular stage spleen KS,and the patient underwent total splenectomy.He recovered well and was discharged from hospital 12 d after surgery.Two weeks later,the patient developed liver metastasis and died within 1 mo after surgery.CONCLUSION KS is difficult to diagnose and pathological examination is necessary.KS has a poor prognosis and should be diagnosed and treated early to improve survival.

Ribosome Inactivating Proteins from Plants Inhibiting Viruses

Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.

THE CERVIX MULTI－VIRUSES INFECTION AND THE DEVELOPMENT OF CERVICAL CARCINOMAS

The infections of human papilloma virus (HPV),herpes simplex virus type 2 (HSV-2) and Epstein-Barr virus (EBV) to human cervical epithelium are universal and some of them are associated with the development of cervical carcinomas. One hundred and eleven cervical cancer biopsies taken from Beijing area and Xiangyuan county in Shanxi province of China were examined for the presence of DNA sequences of HPV, HSV-2 and EBV by means of Dot blot hybridization. The experiment results showed that the total infectious rates of HPV, HSV-2 and EBV were 71.17% (79/111), 14.44%(16/111) and 15.63% (15/96), respectively. Seventy-nine samples positive for HPV were further analysed for the viral types distribution, the result indicated that the positive specimens of HPV type 16 accounted for 72.15%, otherwise, the biopsies positive for HPV type 18and 6B/11 only accounted for 16-46% and 11.39%,respectively. The data suggested that HPV infection,especially HPV type 16, may play an important role in the development of cervical carcinomas- 16 specimens positive for HSV-2 were examined for HPV DNAsequences and the result uncovered that 13 out of them were HPV16 positive (81.25%), 11 samples containing EBV genomes were also examined for HPV DNA sequences and the result indicated that 9 of 11 were detectable for HPV DNA. The experiment results proved a direct evtidence of multi-virus infection in cervix and of the synergistic interaction among viruses in the process of cervical epithelial carcinogenesis.Comparing of the viruses' infection of two areas, the frequencies of HPV infection in Beijing and Xiangyuan areas were 72.84% (59/ 81) and 66.67% (20/30) , the infectious rates of HSV-2 in the two areas were 8.64%(7/81) and 30% (9/30) (P<0.05), the rates of EBV infection in the two areas were 12.5% (10/80) and 31.25% (5/16)(0.1>P>0.05). The results proved another strong evidence that the high incidence of cervical cancer in Xiangyuan county may be closely correlated with multiviruses infection and with multi-virus synergistic interaction.

从病人外周血单个核细胞中检测HHV－6：分离培养和基因扩增

收集婴幼儿急疹及淋巴系统增生性疾病患者外周血单个核细胞进行体外培养，从７例婴幼儿急疹及２例淋巴系统增生性疾病患者中分离出一种病毒，此病毒能在ＰＨＡ激活的人脐血单个核细胞中传代生长，产生典型ＣＰＥ：形成气球样巨细胞。电镜下观察，感染细胞中可见直径１８０ｎｍ左右，有包膜，疱疹样病毒颗粒；血清学试验证明分离株与ＨＳＶ－１，２、ＨＣＭＶ、及ＥＢＶ无抗原交叉，而与ＨＨＶ－６ＧＳ株间存在抗原一致性；多聚酶链反应表明该分离株ＨＨＶ－６特异性ＤＮＡ阳性；综合以上结果，初步认为该分离株为ＨＨＶ－６。同时还用ｐＣＲ法对所收集的标本直接检测ＨＨＶ－６特异性ＤＮＡ。ＰＣＲ法与病毒分离法相比较，前者ＨＨＶ－６检出率为８８．８％（１６／１８）．后者为３８．９％（７／１８）。

HIV 感染者唾液 CMV、HHV-6、HHV-7和 HHV-8巢式 PCR 检测分析

巢式PCR技术检测245例HIV感染者唾液CMV、HHV-6、HHV-7和HHV-8 DNA,检出率分别为34.7%、83.3%、70.2%和14.3%;30例健康对照组分别为10.0%、56.7%、70.0%和0%,2组比较,P<0.01。使用HAART(n=100)与未使用HAART的HIV患者(n=145)比较,4种HHV唾液检出率无差异(P>0.05)。受检者都存在CMV、HHV-6、HHV-7和HHV-8多重感染。

新疆Kaposi肉瘤组织内EBV、HHV-8双重感染的调查

应用PCR方法，对20例新疆Kaposi肉瘤病理组织进行了EBV和HHV－8双重感染的调查。结果：20例Kaposi肉瘤病理组织中14例检出HHV－8DNA（70％），EBV均为阴性。正常皮肤对照：10例这两种疱疹类病毒均为阴性。作者认为新疆Kaposi肉瘤的发生与EBV的相关性很小，但明显与HHV－8感染有关，但是否HHV－8感染就是新疆Kaposi肉瘤发生的决定因素，仍需进一步研究。

慢性牙周炎EBV-1和HHV-6感染及危险因素分析

目的探讨慢性牙周炎龈沟液中EB病毒1型(EBV-1)、人疱疹病毒6型(HHV-6)感染率及其感染发生的相关危险因素。方法采用巢式PCR检测并比较59例慢性牙周炎(CP)患者、56例牙周健康者龈下样本中的EBV-1和HHV-6阳性率。用病例-对照研究策略,EBV-1和HHV-6阳性者为病例组,EBV-1和HHV-6阴性者为对照组,应用logistic多因素回归分析EBV-1和HHV-6在牙周组织的感染与性别、年龄、是否吸烟、牙周袋深度、慢性牙周炎、糖尿病、冠心病、慢性胃炎等是否相关。结果慢性牙周炎(CP)样本中EBV-1的阳性感染率是71.2%,显著高于牙周健康者的EBV-1阳性感染率17.9%(P<0.01)。CP样本中HHV-6的阳性感染率是47.5%,显著高于牙周健康者的HHV-6阳性感染率10.7%(P<0.01)。EBV-1感染与年龄、牙周袋深度、CP有相关性(均P<0.05,OR值分别为11.374,7.695,4.498,95%可信区间均不包含1),HHV-6感染与年龄、CP有相关性(均P<0.05,OR值分别为6.909,5.193,95%可信区间不包含1)。结论慢性牙周炎患者牙周组织具有EBV-1和HHV-6的高感染率,且EBV-1的感染危险因素可能与年龄、牙周袋深度和慢性牙周炎有关;HHV-6的感染危险因素可能与年龄、慢性牙周炎有关。

玫瑰糠疹与HHV-7感染的相关性及外周血T淋巴细胞亚群的研究

目的:探讨玫瑰糠疹发病与人类疱疹病毒-7(HHV-7)的关系及外周血T淋巴细胞亚群的变化。方法:用PCR和免疫组化的方法研究了玫瑰糠疹发病与HHV-7的关系及外周血T淋巴细胞亚群比例的变化。结果:玫瑰糠疹患者HHV-7阳性率(88.89%)明显高于健康对照组(52.78%,χ2=9.68,P<0.01);玫瑰糠疹患者CD3+比例明显低于健康对照组(t=5.09,P<0.01),CD4+比例低于健康对照组(t=2.07,P<0.05),CD8+比例明显高于对照组(t=4.76,P<0.01),CD4+/CD8+比例与对照组相比明显降低(1.12:1.30,t=4.31,P<0.01);HHV-7感染者CD4+/CD8+值明显低于HHV-7非感染者(Z=4.9525,P<0.001)。结论:玫瑰糠疹的发病可能与HHV-7感染后引起的细胞免疫反应有关。

反式激活HIV-1LTR的人疱疹病毒6型(HHV-6)基因片段的初步研究

艾滋病（ＡＩＤＳ）主要是由人免疫缺陷病毒（ＨＩＶ）侵入人体后，破坏人的免疫系统造成的。许多流行病学研究已证明，疱疹病毒与ＨＩＶ的共感染可以导致对ＨＩＶ－１启动子的激活，并加速细胞的病理性反应〔１〕，从而加大个体对ＨＩＶ感染的敏感和加快疾病的进程。人疱...