Systematic analysis of ACE2 and TMPRSS2 expression in salivary glands reveals underlying transmission mechanism caused by SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is a global pandemic that has caused severe health threats and fatalities in almost all communities. Studies have detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in saliva with a viral load that lasts for a long period. However, researchers are yet to establish whether SARS-CoV-2 can directly enter the salivary glands. Therefore, this study aimed to assess the presence of angiotensin-converting enzyme 2 (ACE2)/transmembrane serine proteases 2 (TMPRSS2) expression in salivary glands using publicly available databases. The distribution of ACE2 and TMPRSSs family in salivary gland tissue and other tissues was analyzed. The Genotype-Tissue Expression dataset was employed to explore the ACE2 and TMPRSS2 expression in various body organs and salivary glands in a healthy population. The single-cell sequencing data for salivary gland samples (including submandibular salivary gland and parotid gland) from mice were collected and analyzed. The components and proportions of salivary gland cells expressing the key protease TMPRSSs family were analyzed. Transcriptome data analysis showed that ACE2 and TMPRSS2 were expressed in salivary glands. The expression levels of ACE2 and TMPRSS2 were marginal without significant differences in different age groups or between men and women. Single-cell RNA sequence analysis indicated that TMPRSS2 was mainly expressed in salivary gland epithelial cells. We speculate that SARS-CoV-2 may be entered in salivary glands.

Shear wave elastography of parotid glands in pediatric patients with HIV infection.

OBJECTIVES: Parotid gland (PG) involvement is common among the patients with HIV infection. Shear wave elastography (SWE) is a noninvasive method used to measure the tissue stiffness of several organs including PG. The aim of this study was to evaluate the tissue stiffness values of PGs of HIV-infected children via SWE and compare the results with the counterparts of healthy subjects. MATERIALS AND METHODS: This single-center, prospective study included the PG examinations of 23 pediatric HIV patients and 40 healthy children via grayscale ultrasound and SWE. Independent sample T test and Mann-Whitney U test were used in statistical analysis. RESULTS: Stiffness of both PGs was significantly higher in patients' group when compared with control subjects. In addition, when the patients were separated into two groups according to the appearance of PG on grayscale ultrasound as homogeneous and heterogeneous, stiffness values were increased in the patients with homogeneous parenchymal appearance. No significant difference was achieved in terms of median CD4 and CD8 counts, HIV RNA levels or median duration of illnesses. CONCLUSIONS: PG examination of HIV-infected children via SWE reveals increased tissue stiffness when compared with healthy subjects. SWE can be used as an ultrasound-assisted noninvasive technique in this manner.

Immune reactivity after adenoviral-mediated aquaporin-1 cDNA transfer to human parotid glands.

OBJECTIVES: The purpose of this study was to examine the humoral and cellular immune reactivity to adenoviral vector (AdhAQP1) administration in the human parotid gland over the first 42 days of a clinical gene therapy trial. METHODS: Of eleven treated subjects, five were considered as positive responders (Baum et al, 2012). Herein, we measured serum neutralizing antibody titers, circulating cytotoxic lymphocytes, and lymphocyte proliferation in peripheral blood mononuclear cells. Additionally, after adenoviral vector stimulation of lymphocyte proliferation, we quantified secreted cytokine levels. RESULTS: Responders showed little to modest immune reactivity during the first 42 days following gene transfer. Additionally, baseline serum neutralizing antibody titers to serotype 5-adenovirus generally were not predictive of a subject's response to parotid gland administration of AdhAQP1. Cytokine profiling from activated peripheral blood mononuclear cells could not distinguish responders and non-responders. CONCLUSIONS: The data are the first to describe immune responses after adenoviral vector administration in a human parotid gland. Importantly, we found that modest (2-3 fold) changes in systemic cell-mediated immune reactivity did not preclude positive subject responses to gene transfer. However, changes beyond that level likely impeded the efficacy of gene transfer.

Activation of type I interferon signaling in the parotid and exorbital lachrymal glands during the acute phase of encephalomyocarditis (EMC) virus infection in mice.

The present study was carried out to clarify the mechanisms of EMC virus-induced sialodacryoadenitis in mice during the acute phase infection focusing on the activation of type I interferon (IFN) signaling in the parotid and exorbital lachrymal glands. In the parotid gland, a few apoptotic acinar cells were detected at 2days post inoculation (DPI). The ratio of apoptotic acinar cells increased at 3 and 4DPI. On the other hand, in the exorbital lachrymal gland, apoptosis of acinar cells and infiltration of inflammatory cells mainly composed of mononuclear cells started at 3DPI, and prominent acinar cell damage developed at 4DPI. Viral RNA was detected at 3 and 4DPI in both glands and the expression level was higher in the exorbital lachrymal gland than in the parotid gland. The up-regulation of IFN-stimulated genes (ISGs), such as Irf7, Pkr and Oas, was quickly induced at 2DPI in the parotid gland, and this probably contributed to suppress viral replication and to eliminate affected cells by apoptosis. In the exorbital lachrymal gland, the expression levels of ISGs mRNAs were not elevated at 2DPI, suggesting no induction of an effective anti-viral response such as apoptosis at this time point. In the exorbital lachrymal gland, the mRNA expression of IFN beta and IFN alpha (type I IFNs) was weak- to strong-positive at 1DPI, and became negative at 2DPI. The weak- to strong-positive expression of IFNs at 1DPI is likely related to the abrupt viral replication and pathological changes in the exorbital lachrymal gland through activating the negative feedback regulation that depressed the IFN signaling cascade at 2DPI. In conclusion, the present study showed the changes in factors involved in the activation of type I IFN signaling cascade in the parotid and exorbital lachrymal glands and their differences between the two glands during the acute phase of EMC virus infection in mice.

Epstein-barr virus-associated extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT Lymphoma) arising in the parotid gland of a child with ataxia telangiectasia.

Hematologic malignancies, in particular T-cell lymphomas/leukemias, are prevalent in patients with ataxia telangiectasia (AT), with most reported cases being clinically aggressive and high grade. Epstein-Barr virus (EBV) is often associated with lymphoid proliferations/neoplasms arising in immunodeficient patients. Reports of low-grade B-cell neoplasms in the ataxia telangiectasia population are extremely rare. Here, we describe a case of EBV-associated extranodal marginal zone lymphoma (mucosa-associated lymphoid tissue lymphoma) of the parotid gland in a 16-year-old boy with AT. In addition, we review the literature of hematologic malignancies in the AT population as well as the occurrence of EBV in mucosa-associated lymphoid tissue lymphoma.

[STUDY OF SAFETY OF PAROTITIS VACCINE].

AIM: Monitoring of post-vaccinal complications in children immunized with a parotitis vaccine. MATERIALS AND METHODS: Observation of 198 945 children, immunized with 16 lots of parotitis vaccine with Leningrad-3 strain (L-3), was carried out for 3 years. Paired samples of sera and saliva were obtained from children, in whom adverse events were registered for 42 days after vaccination. Titers of specific IgM and IgG were determined in blood sera. Analysis of nucleotide sequences of genes F, SH and NH of RNA of parotitis virus was carried out from samples of blood and saliva. RESULTS: Intensive parameter of vaccine-associated aseptic meningitis under the conditions of the experiments was 0 for 100 000 immunized. Frequency of occurrence of post-vaccinal parotitis was 0.06% from the number of vaccinated--18 cases of vaccine-associated parotitis were registered and laboratory confirmed. A significant difference in specific activity was detected for 3 lots of the vaccine, that were associated with cases of development of parotitis, relative to that of 13 lots of vaccine, development of parotitis was not registered after administration of those. CONCLUSION: The study carried out confirmed low neurovirulence of the parotitis vaccine with the L-3 strain of parotitis virus, as well as a low degree of its reactogenicity. A relatively high immunization dose of the used vaccine could be one of the reasons of development of post-vaccinal complications in part of the immunized children.

Infection of mice, ferrets, and rhesus macaques with a clinical mumps virus isolate.

In recent years, many mumps outbreaks have occurred in vaccinated populations worldwide. The reasons for these outbreaks are not clear. Animal models are needed to investigate the causes of outbreaks and to understand the pathogenesis of mumps virus (MuV). In this study, we have examined the infection of three animal models with an isolate of mumps virus from a recent outbreak (MuV-IA). We have found that while both ferrets and mice generated humoral and cellular immune responses to MuV-IA infection, no obvious signs of illness were observed in these animals; rhesus macaques were the most susceptible to MuV-IA infection. Infection of rhesus macaques via both intranasal and intratracheal routes with MuV-IA led to the typical clinical signs of mumps 2 weeks to 4 weeks postinfection. However, none of the infected macaques showed any fever or neurologic signs during the experimental period. Mumps viral antigen was detected in parotid glands by immunohistochemistry (IHC). Rhesus macaques represent the best animal model for the study of mumps virus pathogenesis.

Hantavirus-specific IgA in saliva and viral antigen in the parotid gland in patients with hemorrhagic fever with renal syndrome.

The Hantavirus genus comprises rodent borne, zoonotic viruses of the Bunyaviridae family that cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia and hantavirus cardiopulmonary syndrome (HCPS) in the Americas. Rodent saliva contains infectious hantavirus and evidence suggests that hantavirus is also shed in human saliva, but person-to-person transmission is rare. In saliva, immunoglobulin (Ig) A is the predominant immunoglobulin class. Secretory IgA serves as an important first line of defence on epithelial surfaces and the binding of secretory IgA to pathogens can inhibit adherence of microorganisms to mucosal cells and neutralize viruses. This study investigated the presence and importance of salivary IgA in relation to viral antigen in the saliva by testing Puumala hantavirus (PUUV) specific IgA, and RNA in saliva in acutely ill patients with HFRS. In saliva samples, PUUV specific IgA was detected in 12 of 33 (36%) patients with HFRS and 20 (61%) were PUUV RNA positive. There was a statistically significant inverse association between the presence of salivary IgA antibodies and PUUV RNA in the saliva. PUUV-specific IgA in saliva was not found in a long-term follow-up, while PUUV IgA in serum was detected in three patients, 28-32 months after the initial study. Notably, both PUUV RNA and PUUV nucleocapsid antigen were detected in endothelial cells within the parotid gland of a deceased patient with HFRS.

AAV5-mediated gene transfer to the parotid glands of non-human primates.

Salivary glands are potentially useful target sites for multiple clinical applications of gene transfer. Previously, we have shown that serotype 2 adeno-associated viral (AAV2) vectors lead to stable gene transfer in the parotid glands of rhesus macaques. As AAV5 vectors result in considerably greater transgene expression in murine salivary glands than do AAV2 vectors, herein we have examined the use of AAV5 vectors in macaques at two different doses (n = 3 per group; 10(10) or 3 x 10(11) particles per gland). AAV5 vector delivery, as with AAV2 vectors, led to no untoward clinical, hematological or serum chemistry responses in macaques. The extent of AAV5-mediated expression of rhesus erythropoietin (RhEpo) was dose-dependent and similar to that seen with an AAV2 vector. However, unlike results with the AAV2 vector, AAV5 vector-mediated RhEpo expression was transient. Maximal expression peaked at day 56, was reduced by approximately 80% on day 84 and thereafter remained near background levels until day 182 (end of experiment). Quantitative PCR studies of high-dose vector biodistribution at this last time point showed much lower AAV5 copy numbers in the targeted parotid gland (approximately 1.7%) than found with the same AAV2 vector dose. Molecular analysis of the conformation of vector DNA indicated a markedly lower level of concatamerization for the AAV5 vector compared with that of a similar AAV2 vector. In addition, cellular immunological studies suggest that host response differences may occur with AAV2 and AAV5 vector delivery at this mucosal site. The aggregate data indicate that results with AAV5 vectors in murine salivary glands apparently do not extend to macaque glands.

Characterization of large mumps outbreak among vaccinated Palestinian refugees.

During a large mumps virus (MuV) outbreak which occurred in the Palestinian refugee camps of the West Bank, 68.1% (2,636/3,871) of the cases were vaccinated with one dose of trivalent measles, mumps, and rubella (MMR) vaccine. Attack rates by camp ranged from less than 1 case per 1,000 people in the population to 43/1,000 (overall, 11/1,000). The outbreak lasted from December 2003 to June 2005, with two peaks, one from April to May 2004 and the other from March to April 2005. To control the outbreak, a mass MMR vaccination campaign was conducted in May 2005. Evaluation of the immune status of cases (n=59) and healthy controls (n=51) revealed high levels of mumps immunoglobulin G (IgG) and a low MuV-specific IgM in clinical cases indicative of a booster immune response. This suggested a secondary rather than a primary infection due to the insufficient protection conferred by the single vaccine dose included in the vaccination program. This prediction was further confirmed by the low seroprevalence (68.6%) found in the healthy control group, which was below the threshold level required for MuV herd immunity. Mumps diagnosis was established mainly by reverse transcription-PCR in clinical samples obtained within 48 h from the onset of disease. Of the parotid fluids and nasopharyngeal aspirates analyzed, 92% were positive for MuV RNA, while only 33% of the urine samples were positive. Phylogenetic analysis of the MuV SH gene identified the outbreak strain as the H genotype, which has been in circulation worldwide at least since 1989.

Lymphoepithelial carcinoma of the parotid gland: is an association with Epstein-Barr virus possible in non-endemic areas?

Lymphoepithelial carcinoma (LEC) is a rare histological type of cancer of the salivary glands. Here is reported a case of LEC of the parotid gland that developed in a Caucasian female, whose serology was positive for Epstein-Barr virus antibody. The patient underwent surgical treatment and postoperative radiotherapy. Because of the relatively limited clinical data concerning LEC of the salivary glands compared to other more common histological types, the clinical course, optimal treatment and prognosis have not been extensively studied. The aim of this report was to summarize all the key points, following a comprehensive literature review.

HIV-associated benign lymphoepithelial cysts of the parotid glands confirmed by HIV-1 p24 antigen immunostaining.

Approximately 1%-10% of patients with HIV infection have been reported to have salivary gland enlargement. Parotid swelling in patients with HIV is often associated with salivary gland disease, including benign lymphoepithelial cysts (BLECs). The presence of BLEC can serve as an indicator of HIV infection, and the diagnosis of HIV-associated BLEC is usually based on clinical course, HIV confirmatory blood testing, such as western blot or viral detection, and imaging studies, but not on biopsies or immunostaining. To exclude other diseases such as tuberculosis and malignant lymphoma and to further improve the diagnostic accuracy of BLEC, the detection of the HIV-1 p24 antigen by immunohistochemistry is a useful diagnostic method. We report a case of a 65-year-old Japanese man with swelling of the parotid glands and HIV-associated BLEC confirmed via HIV-1 p24 immunohistochemical staining.

Bilateral isolated submandibular gland mumps.

Isolated submandibular swellings pose a diagnostic challenge to the practising otolaryngologist. We report an unusual case of mumps isolated to bilateral submandibular glands. We discuss the case and the literature surrounding this condition and remind clinicians that mumps should be considered as a diagnosis in the presence of submandibular gland swelling in the absence of typical parotid swelling associated with mumps. Early consideration of this differential diagnosis, serological testing and a multidisciplinary approach may help to clinch the diagnosis earlier and prevent spread of the virus.

Benign lymphoepithelial parotid lesions in vertically HIV-infected patients.

Benign lymphoepithelial parotid lesions (BLL) are frequently reported in HIV-infected patients, although their clinical and prognostic significance in HIV infection has not been clearly defined. Ultrasonography (USG) has been shown to be a reliable method in monitoring the progression of such lesions. The purpose of this study was to describe the spectrum of sonographic and Doppler findings and to monitor any clinically evident physical change of parotid glands in a cohort of congenitally HIV-infected patients taking antiretroviral therapy. USG findings-based on their severity-have been grouped in three different patterns (0, 1, 2). Our cohort consisted of 51 patients with HIV in various Centers for Disease Control (CDC) stages and being given different antiretroviral protocols. The median USG follow-up was 36 months. The most frequent USG pattern was aspecific parotid gland enlargement (type 0, 45,1%). Patients with either lower CD4+ % (p < 0.20) and higher absolute and percent CD8+ cell count (p < 0.001 and p < 0.003) presented more frequently a type 2 USG pattern. None of them had any symptoms ascribed to "sicca syndrome" and only one patient developed non-Hodgkin's lymphoma during the follow-up, although his USG pattern at baseline was type 0. In summary, the spectrum of USG findings of BLL in vertically HIV-infected patients is broad. Because of the reported, although rare, possible malignant transformation of BLL in HIV-infected children, it is advisable to perform-even in asymptomatic patients-USG at least once per year or in concomitance with any physical modification of the parotid lesions.

Immunohistochemical assessment of fractalkine, inflammatory cells, and human herpesvirus 7 in human salivary glands.

Human fractalkine (CX3CL1), a delta-chemokine, is implicated in the mediation of multiple cell functions. In addition to serving as a chemotactic factor for mononuclear cell subtypes, membrane-bound fractalkine may promote viral infection by interacting with virions that encode putative fractalkine-binding proteins. Fractalkine expression in normal epithelial tissues studied to date is either constitutive or is upregulated with inflammation. In salivary glands, the expression of fractalkine is unknown. Moreover, salivary glands are a major site for the persistent and productive infection by human herpesvirus (HHV)-7, which encodes two putative fractalkine-binding gene products, U12 and U51. Surprisingly, the cellular distribution of HHV-7 in major salivary glands has not been explored. We therefore determined by immunohistochemistry the cellular localization of fractalkine in three different salivary glands: parotid, submandibular, and labial glands. Fractalkine expression was highly variable, ranging from high to undetectable levels. We further examined the association of fractalkine with inflammatory cell infiltration or HHV-7 infection of salivary epithelial cells. Inflammatory cells were always adjacent to epithelial cells expressing fractalkine, consistent with a function of fractalkine in inflammatory cell recruitment and/or retention in salivary glands. In contrast, HHV-7-infected epithelial cells did not always express fractalkine, suggesting that fractalkine may not be an absolute requirement for viral entry.

Epstein-Barr virus status and the histopathological changes of parotid gland lymphoid infiltrates in HIV-positive children.

This study examined the EBV status and the morphology in parotid glands of a large cohort of HIV-positive pediatric patients. Nineteen children with vertically acquired HIV infection, ranging in age from three months to seven years and two months, were analyzed. Seventeen patients were assessed for serological evidence of EBV infection; nine showed evidence of past infection, one each re-activation and current infection and six did not have serological evidence of EBV. Immunohistochemistry and in situ hybridization for EBER 1 and 2 were performed on formalin-fixed, paraffin-embedded tissue. Fourteen of the 19 cases were classified as severe or established myoepithelial sialadenitis (MESA) and five were regarded as having mild MESA. The majority of intraepithelial lymphocytes were of B-cell lineage, while the pericystic infiltrate contained CD8-positive T-lymphocytes. p24 immunohistochemistry for HIV showed positive follicular dendritic cells, lymphoid cells and macrophages. Ten of 14 cases were positive for EBER 1 and 2. These included cases that were serologically negative for EBV. This study confirms that the morphology and immunophenotype of pediatric HIV-associated parotid lesions are similar to those seen in adults. Ten of 14 cases with evidence of EBV within the lymphoid infiltrate showed the same morphology and immunophenotype as cases in which EBV was not detected either by serology or by in situ hybridization. These findings indicate that EBV is not uniformly found in either the tissue or serum of these patients, and may not have a pathogenetic role in HIV-associated lymphoepithelial lesions in the pediatric age group.

Detection of canine herpesvirus 1 in a wide range of tissues using the polymerase chain reaction.

Canine herpesvirus 1 (CHV-1), a member of the alphaherpesvirus sub-family, is known to cause fatal infections in litters of puppies and may also be involved in infertility, abortion, and stillbirths in adult dogs. The purpose of this study was to determine the presence of CHV-1 DNA using the polymerase chain reaction (PCR) in twelve key sites that have been associated with latency for the other herpesviruses. A 605 base pair portion of the viral glycoprotein B (gB) gene was amplified using degenerate primers, cloned, and sequenced. Conventional 20 mer primers were designed using this sequence information to amplify a 120 bp fragment of gB situated between the original degenerate primers. The specificity of amplification was confirmed by Southern Blot hybridisation using an internal oligonucleotide probe. DNA was extracted from tissue samples taken from twelve dogs at post mortem and from twenty-four blood samples. Nine out of twelve dogs showed evidence of infection with CHV-1; the tissues most commonly affected were lumbo-sacral ganglia (5/12 dogs), tonsil (5/12), parotid salivary gland (4/9), and liver (4/9). No positive results were detected within the twenty-four blood samples. These results indicate that exposure to CHV-1 may be much more common than previously suggested.

The physiologic reservoir of Epstein-Barr virus does not map to upper aerodigestive tissues.

The human Epstein-Barr herpesvirus (EBV) has distinct oncogenic potential, but with over 90% of the adult world population infected, malignancy is a rare outcome of carrier status. However, EBV's association with over half of Hodgkin's and non-Hodgkin's lymphomas as well as several solid tumors, notably nasopharyngeal carcinoma, makes EBV-linked malignancies one of the largest single cancer entities. EBV is a B-lymphotropic virus, well controlled by surveillant T cells in immunocompetent hosts. To determine the presence and site of principal virus reservoirs is a likely prerequisite for understanding the etiology of EBV-associated tumors. Its near 100% association with nasopharyngeal carcinoma led to postulates that the upper aerodigestive tract tissue may be common sites of persistent latent or low-grade replicating infection. Using a protocol designed to avoid viral crosscontamination, the authors employed polymerase chain reaction to detect genomic EBV DNA sequences in 231 biopsies from different mucosal sites in the upper aerodigestive tract, as well as from salivary gland tissue and neck nodes in individuals not suspected to have EBV-related malignancy. Only two samples, one from oral cavity mucosa and one from parotid gland tissue, were positive for EBV. The observation that oropharyngeal tissue is not the principal EBV reservoir has mechanistic implications for the development of EBV-positive tumors in that locale.

Role of cytomegalovirus, Epstein-Barr virus, and human herpes virus-8 in benign lymphoepithelial cysts of the parotid gland.

OBJECTIVE: To provide background and evaluate the role of herpesviruses in benign lymphoepithelial cysts (BLC) of the parotid gland. STUDY DESIGN: Case series derived from review of pathology specimens. METHODS: Radiolabeled polymerase chain reaction (PCR) analysis was used to detect for the presence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpes virus 8 (HHV-8) DNA sequences in 14 paraffin embedded specimens and 1 freshly aspirated BLC specimen. Thirteen normal parotid tissue specimens obtained from paraffin embedded blocks were used as a control group. RESULTS: CMV was detected with nearly equal frequency between the two groups (23% of normal vs. 20% in BLC). HHV-8 was found in 13% of the BLC group and in none of the normal group (P =.4841). There was significant difference in EBV detection between the normal (0%) and the BLC (33%) groups (P =.0437). CONCLUSION: CMV and HHV-8 does not appear to be associated with BLCs. Although EBV is found more frequently in BLC than in normal parotid controls, further studies are needed to elucidate the role of this virus in BLC pathogenesis.

Human herpesvirus 6 in oral fluids from healthy individuals.

BACKGROUND: Human herpesvirus 6 (HHV6) is the etiologic agent of exanthem subitum. The virus is latent in salivary glands and saliva is the main form of viral transmission. The objective of this study was to assess HHV6 incidence in the fluids from healthy individuals using a standardised technique for collecting and extracting viral DNA from gingival crevicular fluid, whole saliva and parotid gland saliva. DESIGN: Samples of oral fluids and peripheral blood were collected from 28 blood donors and HHV6 was detected using PCR assay. Parotid gland saliva and gingival crevicular fluid were collected by endodontic paper cones in order to not contaminate these fluids with whole saliva. RESULTS: Of the 28 donors, 20 (71.4%) presented positive results in at least one of the three oral fluids researched. Whole saliva was positive in 19 (67.8%) volunteers, while only four (14.2%) samples of gingival crevicular fluid and four of parotid gland saliva proved to be positive. CONCLUSIONS: The results suggest that HHV6 is present in the saliva of a large proportion of the healthy adult population. The use of endodontic paper cones for oral fluid collection and viral extraction was efficient, simple, cheap and painless. In spite of, the small number of cases studied it was possible to demonstrate that neither gingival crevicular fluid nor parotid gland saliva were the principal source of HHV6 in whole saliva.