Salivary Gland Virus Research Articles

Unique immune cells in oral cavity are critical for enteric virus pathogenesis

Abstract We recently discovered that salivary glands are a major site of norovirus replication and oral-oral transmission is facilitated by saliva1. However, the cell types infected and the role of saliva in virus dissemination remains to be elucidated. Mice inoculated with norovirus were sampled and cells sorted into immune and epithelial cells. Mice became positive for virus in salivary glands and intestine plus associated lymphatic tissues. The majority of virus was present and replicating in CD45+ immune cells and EpCAM+ epithelial cells. Spatio-temporal analysis of the infection revealed that the earliest and highest viral pools were associated with the mandibular lymph nodes. Furthermore, a unique population of immune cells contained the highest concentration of virus, suggesting that these cells potentially play a sentinel role in disseminating norovirus. Notably, enteric infection of the intestine resulted in high levels of inflammation and cell death, however this was absent in the salivary glands, suggesting a level of immune modulation. Our findings suggest that the immune response in the salivary glands is different from that seen in the intestinal tract, and there is a unique population of immune cells which potentially plays an important role during the infection. 1 Ghosh S, et al. Enteric viruses replicate in salivary glands and infect through saliva. Nature. 2022; 607:345–350. doi: 10.1038/s41586-022-04895-8.

Oral mucosa lesions in confirmed and non-vaccinated cases for COVID-19: A systematic review

This systematic review purposed to investigate reports of oral lesions in confirmed COVID-19 patients summarizing clinical characteristics, histological findings, treatment and correlation of oral lesions and COVID-19 severity. Electronic search was conducted on November 2021 using seven databases to identify case reports/series describing lesions in oral mucosa in COVID-19 confirmed cases. A total of 5,179 studies were found, being 39 eligible from 19 countries, totalling 116 cases. It was observed only COVID-19 non-vaccinated cases and no sex or age predilection. The oral lesions presentation was mostly single location (69.8%), commonly in the tongue, lips, and palate, being ulcer the main clinical presentation. According to severity index for COVID-19, the reports were more frequent in patients with mild and moderate symptoms, being 75.8% in acute phase. The oral lesion appearance in post-acute COVID-19 were described after 14 to two months after patient recovery. Histologically, keratinocytes with perinuclear vacuolization, thrombosis and mononuclear inflammatory infiltrate were also described with the presence of the virus in keratinocytes, endothelial cells, and minor salivary glands. In conclusion, health care professionals should consider COVID-19 association when patient present ulcerated oral lesions and mild to moderate symptoms for COVID-19 or had acute-COVID-19.

Zika Virus in Salivary Glands of Five Different Species of Wild-Caught Mosquitoes from Mexico

Zika virus (ZIKV) is a mosquito-borne pathogen, and Aedes aegypti has been identified as the main vector of the disease. Other mosquito species in the Aedes and Culex genera have been suggested to have the potential for being competent vectors based on experimental exposition of mosquitoes to an infectious blood meal containing ZIKV. Here, we report the isolation in cell culture of ZIKV obtained from different body parts of wild-caught female mosquitoes (Ae. aegypti, Ae. vexans, Cx. quinquefasciatus, Cx. coronator, and Cx. tarsalis) and whole male mosquitoes (Ae. aegypti and Cx. quinquefasciatus) in Mexico. Importantly, this is the first report that shows the presence of the virus in the salivary glands of the wild-caught female mosquitoes species, Cx. coronator, Cx. tarsalis, and Ae. vexans. Our findings strongly suggest that all the species reported herein are potential vectors for ZIKV.

Connective tissue diseases: Epstein-Barr virus in Sjögren's syndrome salivary glands drives local autoimmunity.

Connective tissue diseases: Epstein–Barr virus in Sjogren's syndrome salivary glands drives local autoimmunity

Vaccine-induced Rabies in a Red Fox (Vulpes vulpes): Isolation of Vaccine Virus in Brain Tissue and Salivary Glands

Oral vaccination campaigns to eliminate fox rabies were initiated in Slovenia in 1995. In May 2012, a young fox (Vulpes vulpes) with typical rabies signs was captured. Its brain and salivary gland tissues were found to contain vaccine strain SAD B19. The Basic Logical Alignment Search Tool alignment of 589 nucleotides determined from the N gene of the virus isolated from the brain and salivary glands of the affected fox was 100% identical to the GenBank reference SAD B19 strain. Sequence analysis of the N and M genes (4,351 nucleotides) showed two nucleotide modifications at position 1335 (N gene) and 3114 (M gene) in the KC522613 isolate identified in the fox compared to SAD B19.

Double-strand adeno-associated virus-mediated exendin-4 expression in salivary glands is efficient in a diabetic rat model

AimExendin-4 (Ex-4) is an agonist of the glucagon-like peptide 1 (GLP-1) receptor, approved for the treatment of type 2 diabetes (T2DM). Several strategies have been tried to develop stable and efficacious Ex-4 expression systems. The purpose of the current study was to determine whether double-stranded adeno-associated virus (dsAAV)-mediated in vivo expression of exendin-4 in salivary glands (SG), improves pathology in the Sprague–Dawley (SD) rat model of diabetes mellitus (DM). MethodsThe effects of Ex-4 expression by recombinant dsAAV-NT4-Ex-4 were evaluated in vitro compared with a single-strand (ss) AAV. The dsAAV was delivered into SGs and the blood glucose and insulin levels were assessed in a rat model of DM. ResultsDsAAV-NT4-Ex-4 virus induces significant exendin-4 expression in vitro. Furthermore, Ex-4 expressed from dsAAV virus in SGs enhances insulins secretion in vivo and significantly controls the onset of hyperglycemia in rat model of DM. ConclusionsResults suggest that sustained secretion of Ex-4 following dsAAV-mediated gene therapy is feasible. SGs appear to be promising targets with potential clinical applicability for the treatment of DM. This represents the example of a successful use of Ex-4 for diabetes therapy, providing support for direct AAV-mediated in vivo as an easy, safe and efficient therapeutic strategy.

Natural Killer Cells Regulate Murine Cytomegalovirus-Induced Sialadenitis and Salivary Gland Disease

The transmission of herpesviruses depends on viral shedding at mucosal surfaces. The salivary gland represents a major site of persistent viral replication for many viruses, including cytomegalovirus. We established a mouse model of salivary gland dysfunction after acute viral infection and investigated the cellular requirements for the loss of secretion. Murine cytomegalovirus (MCMV) infection severely impaired saliva secretion independently of salivary gland virus levels. Lymphocytes or circulating monocytes/macrophages were not required for secretory dysfunction. Dysfunction occurred before glandular inflammation, suggesting that a soluble mediator initiated the disruption of acinar cell function. Despite genetic differences in innate resistance to MCMV, NK cells protected the host against acinar atrophy and the loss of secretions under conditions of an exceedingly low virus inoculum. NK cells also modulated the type of glandular inflammation after infection, as they prevented an influx of Siglec-F(+) polymorphonuclear leukocytes (PMNs). Therefore, beyond their recognized role in controlling MCMV replication, NK cells preserve organ integrity and function and regulate the innate inflammatory response within the gland.

Aislamiento de virus rábico en glándulas salives de murciélagos insectivoros

This study determined the presence of the rabies virus in salivary glands, as well as its titre and antigenic characterisation and the level of exposure to the virus from contact between domestic animals and humans. Twenty-six positive brain samples were selected, 80% of which were from the Brazilian free-tailed bat, Tadarida brasiliensis, corresponding to the period 1999-2005. Antigenic characterisation was conducted on a panel of 19 monoclonal antibodies targeting the rabies virus nucleoprotein supplied by the Centers for Disease Control and Prevention in Atlanta in the United States of America. The results revealed a high percentage of isolations in salivary glands (76.9%). Their average titres were compared in a batch of positive samples of brain and salivary glands, giving values of 4.75 and 3.81 respectively (expressed as log LD50/0.03 ml). The isolated viruses corresponded principally to variant 4 associated with T brasiliensis and variant 6 associated with the hoary bat, Lasiurus cinereus, and the red bat, L. borealis, and their respective subvariants. The level of exposure in domestic animals and humans was 50% during the period under study.

Isolation of rabies virus from the parotid salivary glands of foxes (Pseudalopex vetulus) from Paraíba State, Northeastern Brazil

To determine the presence of rabies virus in the parotid salivary glands, 12 road-killed rabies-positive hoary foxes (Pseudoalopex vetulus) were tested by using the fluorescent antibody test (FAT) and mouse inoculation test (MIT). All 12 parotid salivary glands were positive for both tests, although in some cases several passages were required. The findings of this study support the importance of the hoary fox as rabies reservoir in the sem-iarid region of Paraíba State, Northeastern Brazil.

Quantitative PCR analysis of the salivary gland hypertrophy virus (GpSGHV) in a laboratory colony of Glossina pallidipes

Many species of tsetse flies can be infected by a virus that causes salivary gland hypertrophy (SGH) and virus isolated from Glossina pallidipes (GpSGHV) has recently been sequenced. Flies having SGH have a reduced fecundity and fertility. To better understand the impact of this virus in a laboratory colony of G. pallidipes, where the majority of flies are infected but asymptomatic, and to follow the development of SGH in symptomatic flies in relation to virus copy number, a quantitative PCR (qPCR) method was developed. The qPCR analyses revealed that in asymptomatic flies virus copy number averaged 1.68E+5, 2.05E+5 and 1.07E+7 log 10 in DNA from an excised leg, salivary glands and a whole fly, respectively. In symptomatic flies the virus copy number in the same organs averaged 1.34E+7, 1.42E+10 and 1.5E+9, respectively. Despite these statistically significant differences ( p ≪ 0.0001) in virus copy number between asymptomatic and symptomatic flies, there was no correlation between age and virus copy number for either sets in adult flies. A clear correlation between virus copy number in pupae and their mothers was observed. Reverse transcription quantitative PCR (RT-qPCR) of the viral messenger RNA encoding ODV-E66, an envelope protein, revealed a clear correlation between virus copy number and the level of gene expression with values of 2.77 log 10 in asymptomatic males and 6.10 log 10 in symptomatic males. Taken together these results confirm the close relationship between virus copy number and SGH syndrome. They demonstrate the vertical transmission of GpSGHV from mother to progeny, and suggest that the development of SGH may be correlated to the virus copy number acquired by the larva during its intra-uterine development.

50 Years Ago in The Journal of Pediatrics: Comments on current literature: congenital damage to the central nervous system as a result of intrauterine infection

Blattner RJ. J Pediatr 1958;52:620-6 As little as 50 years ago, the importance of intrauterine infection as a cause of damage to the fetal central nervous system (CNS) was not widely appreciated. Autopsy studies on large series of patients identified only syphilis as a relatively common etiology of intrauterine and early postnatal CNS damage. In 1957, Edith Potter described the clinical pathological correlation of intrauterine cytomegalic inclusion body disease (CMV) due to placental transfer of viruses. It was recognized that human “salivary gland virus,” rarely responsible for overt illness in mother, could cause severe or fatal disease when transferred placentally to the fetus. Examination of the urinary sediment for inclusion bodies was the only available diagnostic procedure. We now realize that intrauterine infections, both systemic and involving the CNS, are a frequent and important cause of morbidity and mortality in the neonatal period. As many as 2% of fetuses are infected in utero by viral, bacterial, fungal, or protozoal agents. The acronym TORCH is widely used, although it has recently been maligned for its simplicity and lack of specificity. Congenital CMV infection is the most common intrauterine infection in developed countries, affecting 0.2% to 2.2% live neonates. Contemporary obstetrics involves first and second trimester ultrasound examinations, which can reveal abnormalities that suggest possible intrauterine infections, including intracranial calcifications, hydrocephalus, hyperechoic bowel, and intrauterine growth restriction. There is great variability in the clinical specificity and yield of algorithms used to evaluate these patients. Thankfully, a variety of microbiological and molecular tools with a high degree of diagnostic specificity are now available. Potter's report indicated that transplacental fetal infection often went undiagnosed during pregnancy because the mother was asymptomatic or had nonspecific signs and symptoms at the time of acute infection. We now appreciate not only the frequency of these important infections but also the importance of the stage of gestation at which infection occurs and the risk of adverse outcome. Nowadays, the obstetric standard of care is to screen all pregnant women for rubella, syphilis, hepatitis B, group B streptococcus, Chlamydia, and gonorrhea (with some states also screening for HIV), the most common and preventable perinatally acquired infections. Examination of the placenta also is recommended when infection is being considered as a causal or contributing factor to preterm delivery, fetal tachycardia, maternal signs of chorioamnionitis, neonatal intensive care unit admission, stillbirth, fetal birth defects, or abnormalities in intrauterine growth.

Characterization of a vector‐non‐transmissible isolate of Tomato spotted wilt virus

The characteristics of a thrips‐non‐transmissible isolate of Tomato spotted wilt virus (TSWV), designated TSWV‐M, were compared with those of a thrips‐transmissible isolate, designated TSWV‐T. TSWV‐M showed a narrower host range than TSWV‐T. Adult thrips failed to transmit TSWV‐M, although the vector acquired the virus during the larval stages. TSWV‐M was detected by RT‐PCR in adult thrips bodies, but not in thrips heads, suggesting that loss of thrips transmissibility was the result of the absence of virus in adult thrips salivary glands. Whereas N (nucleoprotein), NSs (non‐structural protein) and GC (the C‐terminal portion of the glycoprotein precursor protein) were present in similar amounts in leaf tissue from TSWV‐M‐ or TSWV‐T‐infected plants, GN (the N‐terminal portion of the glycoprotein precursor protein) was present at much lower amounts in TSWV‐M‐ than in TSWV‐T‐infected plants. SDS‐PAGE and immunoblotting analysis of TSWV‐M and TSWV‐T virion preparations with GN‐ and GC‐specific antibodies revealed similar amounts of the GN and GC glycoproteins in TSWV‐T virions, but lower amounts of GN than GC in TSWV‐M virions. This resulted in a statistically significant reduction in the GN/GC ratio in TSWV‐M virions. In affinoblots, the GC and GN glycoproteins of TSWV‐M exhibited weak binding with lectins showing affinity for N‐linked oligosaccharide structures. Sequence analysis of M RNA (medium segment of the TSMV genome) revealed no deletions or frameshift mutations in the GN/GC precursor of TSWV‐M. However, five amino acid changes were detected in the GN/GC precursor. A single, relatively conservative amino acid substitution (V→I) was observed in the NSm protein. Sequence analysis of S RNA (small portion of the TSMV genome) revealed a large intergenic region with no changes in the N protein and with three amino acid changes in the NSs protein.

AEDES AEGYPTI VECTORIAL CAPACITY IS DETERMINED BY THE INFECTING GENOTYPE OF DENGUE VIRUS

Dengue viruses causing severe, hemorrhagic disease have displaced less virulent strains in the Americas during the past three decades. The American (AM) genotype of dengue serotype 2 has been endemic in the Western Hemisphere and South Pacific, causing outbreaks of dengue fever (DF), but has not been linked to dengue hemorrhagic fever (DHF). The Southeast Asian (SEA) genotype of dengue was introduced into this hemisphere in 1981, has caused outbreaks with numerous cases of DHF, and has displaced the AM genotype in several countries. We investigated the effect of viral genotype on the potential for transmission by infecting Aedes aegypti mosquitoes collected in South Texas with six viruses, representing these two genotypes. Viral replication in the midgut was significantly higher in SEA-infected mosquitoes, and virus-specific proteins could be detected in salivary glands 7 days earlier in SEA- than AM-infected mosquitoes. This much earlier appearance of dengue virus in salivary glands resulted in an estimated 2- to 65-fold increase in the vectorial capacity of these mosquitoes for the viruses that can cause DHF. This may be one of the mechanisms through which more virulent flaviviruses spread and displace others globally.

Laboratory diagnosis of equine rabies and its implications for human postexposure prophylaxis

Laboratory diagnosis is essential to confirm suspected cases of equine rabies and to determine the medical care needed for human postexposure antirabies prophylaxis. Equine rabies transmitted by the vampire bat, Desmodus rotundus, has increased gradually in the State of São Paulo. The present study has several objectives, the most important being the evaluation of fluorescent antibody test (FAT) and virus-isolation laboratory tests performed with different equine nervous system tissues (cortical, hippocampus, cerebellar, brainstem and cervical medullar) to determine the tissue for which the two techniques have the highest sensitivity. Analysis by FAT of these five regions of the central nervous system (CNS) from 35 animals showed that there was a greater amount of viral antigen in the brainstem and cervical medullar tissues than in the hippocampus, cortical and cerebellar tissues. While there were no significant differences in the mortality rate of mice inoculated with suspension prepared from the different tissues, a trend towards higher mortality rate was detected with brainstem and cervical medullar tissues. Laboratory diagnosis was not affected by whether the animal had been vaccinated or not, or whether it had died following the natural course of the disease or as a result of euthanasia. Isolation of the rabies virus in equine salivary glands demonstrated the potential risk for humans exposed to infected animals.

Cytomegalovirus Infection in the Fetus and Neonate

After completing this article, readers should be able to: 1. Describe the transmission of cytomegalovirus (CMV) to the fetus and newborn and the differences between congenital, natal, and postnatal infection with CMV. 2. Delineate the clinical manifestations and sequelae of congenital, natal, and postnatal infection with CMV. 3. Know how to diagnose CMV infection in the fetus and newborn. 4. Describe potential treatment options for neonatal CMV infections. Human CMV is a DNA virus of the herpesvirus group. CMV infection was described first in the early 1900s in pathologic specimens from an infant who died of presumed congenital syphilis. The virus initially was named salivary gland virus due to the characteristic pathologic changes seen in the salivary glands. It was isolated in tissue culture in 1956, and in the early 1960s, the more descriptive name cytomegalovirus was adopted. CMV infection of host cells results in a characteristic massive enlargement of the affected cells that contain intranuclear and cytoplasmic inclusions (Fig. 1). Figure 1. Section of lung from a 15-week fetus that died with disseminated CMV infection. Courtesy of Dr Beverly Rogers, Dallas, Tex. Infection of the fetus and neonate with CMV is an important health problem worldwide. In the United States, CMV is the most common congenital viral infection, affecting 0.2% to 2.5% of all live births. Of the 40,000 infants born each year with congenital CMV infection, more than 8,000 develop mental retardation, cerebral palsy, or, most commonly, hearing impairment. Infection with CMV is ubiquitous, occurring in all populations and socioeconomic groups throughout the year without any seasonal variation. Person-to-person transmission of CMV occurs by close contact with infected body fluids and secretions. CMV can be isolated from body tissues and fluids such as tears, saliva, human milk, urine, stool, semen, cervical secretions, amniotic fluid, blood, and transplanted organs. In addition, infected secretions on …

Cytomegalovirus in renal transplantation.

Cytomegalovirus (CMV) was first isolated from the salivary gland and kidney of two dying infants with cytomegalic inclusion bodies and reported in 1956 (1). Two other laboratories isolated CMV at approximately the same time. Thus, CMV was initially called "salivary gland virus" or "salivary gland inclusion disease virus". In 1960, Weller et al. (2) proposed the use of the term cytomegalovirus. Klemola and Kaarianinen (3) first described CMV mononucleosis, the principal presentation of previously healthy individuals, in 1965. CMV was first isolated in a renal transplant patient in 1965,

Selective Elimination of High Constitutive Activity or Chemokine Binding in the Human Herpesvirus 8 Encoded Seven Transmembrane Oncogene ORF74

Open reading frame 74 (ORF74) encoded by human herpesvirus 8 is a highly constitutively active seven transmembrane (7TM) receptor stimulated by angiogenic chemokines, e.g. growth-related oncogene-alpha, and inhibited by angiostatic chemokines e.g. interferon-gamma-inducible protein. Transgenic mice expressing ORF74 under control of the CD2 promoter develop highly vascularized Kaposi's sarcoma-like tumors. Through targeted mutagenesis we here create three distinct phenotypes of ORF74: a receptor with normal, high constitutive signaling through the phospholipase C pathway but deprived of binding and action of chemokines obtained through deletion of 22 amino acids from the N-terminal extension; an ORF74 with high constitutive activity but with selective elimination of stimulatory regulation by angiogenic chemokines obtained through substitution of basic residues at the extracellular ends of TM-V or TM-VI; and an ORF74 lacking constitutive activity but with preserved ability to be stimulated by agonist chemokines obtained through introduction of an Asp residue on the hydrophobic, presumed membrane-exposed face of TM-II. It is concluded that careful molecular dissection can selectively eliminate either agonist or inverse agonist modulation as well as high constitutive activity of the virally encoded oncogene ORF74 and that these mutant forms presumably can be used in transgenic animals to identify the molecular mechanism of its transforming activity.

Bluetongue virus in laboratory-reared Culicoides variipennis sonorensis: applications of dot-blot, ELISA, and immunoelectron microscopy.

An avidin-biotin complex (ABC) dot-blot, an antigen capture enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy (IEM) were used to detect bluetongue (BLU) virus or viral antigen or both in adult Culicoides variipennis sonorensis Wirth & Jones. The dot-blot and ELISA procedures detected viral antigen in 10-22% (depending on serotype) of the biting midges infected with BLU-2, BLU-10, BLU-13, and BLU-17 and approximately 68% of the midges infected with BLU-11. IEM analyses revealed BLU virus in salivary glands, fat body, and thoracic muscle tissue from infected insects. There appeared to be selective growth of the virus in salivary gland tissue.

Eficacia de la administracion de suero y vacuna en el tratamiento antirrabico de ovinos infectados experimentalmente

The objectives of this study were to examine the humoral immune response of sheep to experimental infection with an isolate of rabies virus from a fox, to analyse the efficacy of vaccination as a method of post-infection treatment, and to find a suitable animal model to evaluate new procedures for human vaccination following infection. A total of 47 sheep were used. Initially, 26 sheep received an intramuscular injection of a suspension of virus (titre: 10(6.8) 50% lethal dose for mice by the intracerebral route). Half of the sheep were subsequently treated using a vaccine on the day of infection and at 3, 7, 14 and 30 days post-infection. The remaining half comprised the unvaccinated controls. This vaccination protected seven of thirteen sheep, while nine of the thirteen controls died. Subsequently, 21 sheep were inoculated under the same conditions as in the previous trial. The animals were divided into three groups of seven animals each. The first group was vaccinated in the same way as described above. The second group received an injection of anti-rabies immunoglobulin of human origin (26.3 IU/kg of body weight), followed by the course of vaccine treatment 24 hours later. The remaining group acted as unvaccinated controls. Of the seven sheep given vaccine alone, four were protected, while all seven animals given immunoglobulin and vaccine were protected. Six of the seven untreated controls died. In this study, no apparently-healthy carriers of rabies virus were created by any of the treatments used, nor was there any shortening of the incubation periods. Additional observations were made concerning incubation periods and the course of the disease, as well as symptoms, lesions and the presence of rabies virus in various nerve centres and salivary glands of the experimental sheep.

Detection of cytomegalovirus and Epstein-Barr virus in labial salivary glands in Sjogren's syndrome and non-specific sialadenitis.

To investigate the role of herpes viruses in Sjogren's syndrome, minor (labial) salivary gland tissues from Sjogren's syndrome and from non‐specific sialadenitis were examined for Epstein‐Barr virus (EBV) and human cytomegalovirus (HCMV) DNA by the polymerase chain reaction. Almost half of all salivary glands studied contained EBV and/or HCMV. There was, however, no significant difference between the detection of EBV or HCMV in salivary glands from patients with Sjogren's syndrome or non‐specific sialadenitis. The findings are consistent with the persistence of EBV and HCMV in minor salivary glands following primary infection, but do not indicate a direct role for either virus in the aetiology of Sjogren's syndrome, and do not exclude reactivation of the viruses in this disease.