Components Of Saliva Research Articles

The effect of saliva on the aroma release of esters in simulated baijiu under the impact of high ethanol concentration

As one of the most popular traditional spirits in China, baijiu has a unique food matrix with high ethanol concentration and a wealth of aroma compounds. The aroma profile volatilized from the cup that has been widely studied may be different from the aroma that consumers perceived during drinking. It is affected by numerous factors, and saliva is a critical one. This study revealed that ex-vivo saliva had a significant positive or negative influence on ester release in simulated solutions, and proved that the degree of effects was related to the hydrophobicity of the compounds. Moreover, the ethanol concentration of simulated baijiu could alter the effect of saliva on esters. Both the effect intensity and the result would be changed, and the performance of the esters was related to their log P-value. Then we examined the underlying mechanism between saliva components and esters under the effect of diverse ethanol concentrations in simulated baijiu solutions with diverse buffers. The high ethanol concentration of baijiu may make the impact of saliva components on the ester release changeable and different from other food matrices because of the chemical and biological change in this system.

An Overview of Physical, Microbiological and Immune Barriers of Oral Mucosa.

The oral mucosa, which is the lining tissue of the oral cavity, is a gateway to the body and it offers first-line protection against potential pathogens, exogenous chemicals, airborne allergens, etc. by means of its physical and microbiological-immune barrier functions. For this reason, oral mucosa is considered as a mirror to the health of the individual as well as a guard or early warning system. It is organized in two main components: a physical barrier, which consists of stratified epithelial cells and cell–cell junctions, and a microbiological-immune barrier that keeps the internal environment in a condition of homeostasis. Different factors, including microorganism, saliva, proteins and immune components, have been considered to play a critical role in disruption of oral epithelial barrier. Altered mucosal structure and barrier functions results in oral pathologies as well as systemic diseases. About 700 kinds of microorganisms exist in the human mouth, constituting the oral microbiota, which plays a significant role on the induction, training and function of the host immune system. The immune system maintains the symbiotic relationship of the host with this microbiota. Crosstalk between the oral microbiota and immune system includes various interactions in homeostasis and disease. In this review, after reviewing briefly the physical barriers of oral mucosa, the fundamentals of oral microbiome and oral mucosal immunity in regard to their barrier properties will be addressed. Furthermore, their importance in development of new diagnostic, prophylactic and therapeutic strategies for certain diseases as well as in the application for personalized medicine will be discussed.

A transwell assay method to evaluate Borrelia burgdorferi sensu stricto migratory chemoattraction toward tick saliva proteins

We developed a transwell assay to quantify migration of the Lyme disease agent, Borrelia burgdorferi sensu stricto (s.s.), toward Ixodes scapularis salivary gland proteins. The assay was designed to assess B. burgdorferi s.s. migration upward against gravity through a transwell polycarbonate membrane overlaid with 6% gelatin. Borreliae that channeled into the upper transwell chamber in response to test proteins were enumerated by flow cytometry. The transwell assay measured chemoattractant activity for B. burgdorferi s.s. from salivary gland extract (SGE) harvested from nymphal ticks during bloodmeal engorgement on mice 42 h post-attachment and saliva collected from adult ticks. Additionally, SGE protein fractions separated by size exclusion chromatography demonstrated various levels of chemoattractant activity in the transwell assay. Sialostatin L, and Salp-like proteins 9 and 11 were identified by mass spectrometry in SGE fractions that exhibited elevated activity. Recombinant forms of these proteins were tested in the transwell assay and showed positive chemoattractant properties compared to controls and another tick protein, S15A. These results were reproducible providing evidence that the transwell assay is a useful method for continuing investigations to find tick saliva components instrumental in driving B. burgdorferi s.s. chemotaxis.

Nutritional influences on enzyme activities in saliva of Asian and African elephants

Asian and African elephants show morphological adaptations to their ecological niche including the oral cavity. Variety and preferences of forage plants differ between both herbivorous elephant species. Diet can affect salivary enzymes. Asian elephants were shown to have a higher salivary amylase activity than African elephants. Species-specific differences were presumed to be influenced by feeding during collection procedure. This study aimed to determine the influence of feeding on enzyme activities in saliva of both elephant species to differentiate from species-specific effects. Additionally, season and housing conditions on salivary enzyme activities in non-fed elephants of both species were investigated. Salivary amylase (sAA), lysozyme (sLYS) and peroxidase (sPOD) activity were measured photometrically or fluorometrically. Results of this study reinforce previous observations of higher basic sAA activity in Asian elephants compared to African elephants. Salivary LYS and sPOD activity showed neither species-specific nor housing-specific differences. Independent from season, most elephants of both species revealed a lack of or low sPOD activity. Feeding caused a temporary decrease of sAA, sLYS and sPOD activity in both elephant species kept in four of eight tested zoos. Furthermore, sAA activity in Asian elephants was higher and sLYS activity lower in Spring than in Autumn. This study summarizes that sAA and sLYS are components of Asian and African elephant saliva in an active conformation in contrast to sPOD. Diet varying between season and zoos might influence sAA and sLYS activities primarily in Asian elephants but temporary low effects suggest sufficient buffer capacity of elephant saliva of both species.

Short communication: Saliva and salivary components affect goat rumen fermentation in short-term batch incubations

The research about the role of saliva in ruminants has been mainly focused on its buffering capacity together with facilitation of the rumination process. However, the role of salivary bioactive components on modulating the activity of the rumen microbiota has been neglected until recently. This study developed an in vitro approach to assess the impact of different components in saliva on rumen microbial fermentation. Four different salivary fractions were prepared from four goats: (i) non-filtrated saliva (NFS), (ii) filtrated through 0.25 µm to remove microorganisms and large particles (FS1), (iii) centrifuged through a 30 kDa filter to remove large proteins, (FS2), and (iv) autoclaved saliva (AS) to keep only the minerals. Two experiments were conducted in 24 h batch culture incubations with 6 ml of total volume consisting of 2 ml of rumen fluid and 4 ml of saliva/buffer mix. In Experiment 1, the effect of increasing the proportion of saliva (either NFS or FS1) in the solution (0%, 16%, 33% and 50% of the total volume) was evaluated. Treatment FS1 promoted greater total volatile fatty acids (VFA) (+8.4%) and butyrate molar proportion (+2.8%) but lower NH3-N concentrations than NFS fraction. Replacing the bicarbonate buffer solution by increasing proportions of saliva resulted in higher NH3-N, total VFA (+8.0%) and propionate molar proportion (+11%). Experiment 2 addressed the effect of the different fractions of saliva (NFS, FS1, FS2 and AS). Saliva fractions led to higher total VFA and NH3-N concentrations than non-saliva incubations, which suggests that the presence of some salivary elements enhanced rumen microbial activity. Fraction FS1 promoted a higher concentration of total VFA (+7.8%) than the other three fractions, and higher propionate (+26%) than NFS and AS. This agrees with findings from Experiment 1 and supports that ‘microbe-free saliva’, in which large salivary proteins are maintained, boosts rumen fermentation. Our results show the usefulness of this in vitro approach and suggest that different salivary components can modulate rumen microbial fermentation, although the specific metabolites and effects they cause need further research.

Analyzing the Properties of Saliva to Act as a Viable Fuel Source and Its Capabilities to Interact with Microbial Fuel Cell (MFC) Powered Theoretical Diagnostic Devices Beneficial to Low-income Communities

Introduction: The WHO has stated that about 50% of the world lacks access to secure and continuous supply of electricity, heavily impacting the healthcare industry in these countries. Microbial Fuel Cells (MFCs) can be a low cost-efficient energy source capable of powering medical devices in low-income countries. Due to the components and impurities found in saliva, this biofluid can behave like an electrolyte and a viable fuel source to power the MFC. With this capability, saliva has the potential to power micro-gadgets with microbial fuel cells capable of degrading the components of saliva. Thus, this study explores saliva’s potential to act as a fuel source to power microbial fuel cells within medical diagnosis devices. Methods: A systematic review was conducted through primary and secondary research articles exploring and comparing the use of saliva as an energy source compared to other biofluids. Key terms focused for meta-analyses include: ‘semiconductors’, ‘saliva’, ‘microbial fuel cells’, ‘point-of-care’. Results: Previous research has discovered that lysozyme enzymes present in saliva can create an electrical charge that can successively power biomedical devices. Researchers have also created paper-based batteries containing frozen exoelectrogenic cells, powered by the bacterial degradation of human spit. Saliva has been demonstrated to contain similar biomarkers to urine, a successful diagnostic biofluid, and can therefore be used as a diagnostic biofluid as well. Discussion: Given saliva’s capabilities, a hypothetical diagnostic device powered using saliva as the biofluid, was designed. Bacteria break down the saliva, allowing protons to travel from the anode to the cathode resulting in electricity. It was determined that graphite would be the most cost-efficient and energy producing electrode material for the device. In addition, this electricity that is produced will power the diagnostic device attached. Conclusion: Saliva can act as a fuel source, capable of powering diagnostic devices using microbial fuel cells with saliva. These properties can be beneficial to many people who do not have access to preliminary diagnosis. This can result in immediate treatment and help prevent further spread of diseases, vital for those in low-income countries. Broad scale applications of using saliva can be directed towards exterior lighting systems and powering larger medical devices.

Gargling Effect of Zamzam Water on Salivary pH

Caries is a multifactorial infection disease that happened during the decrease of salivary pH caused by acids from bacterial metabolism. Bicarbonate is an important buffer component in saliva that can help neutralize salivary pH. Zamzam water has high bicarbonate content. This study aimed to evaluate the effect of gargled with Zamzam water on salivary pH. This experimental research was done with pre-test and post-test control group design involving 40 dentistry students at the University of Sriwijaya aged 18-23 years old, with DMF-T score ≤3. Samples were divided into 2 groups, the Zamzam water group, and thedistilled water group. Samples gargled their mouth with 10 ml of a 25% sucrose solution for one minute, then saliva was collected with spitting method and salivary pH was measured with digital pH meter and recorded as initial pH. Samples then gargledwith 20 ml of Zamzam water or distilled water according to each group for one minute, then saliva was collected in the same way as before, and pH was measured and recorded as final pH. Data were analyzed with paired t-test and Mann-Whitney. The result showed that salivary pH increased significantly after gargled with Zamzam water (p0,05). The mean difference of salivary pH aftergargled with Zamzam water was statistically higher than distilled water (p0,05). In conclusion, Gargled with Zamzam water can increase salivary pH.

Electronic Spiking Protein-Based COVID Sensors

Viruses are ultimate nanotechnology objects with cleverly designed capsid proteins to bind with cell membranes and exquisite DNA/RNA machinery to invade cells and replicate themselves using cells' machinery. Here I will discuss an electronic virus sensor that uses aptamers designed to bind with the COVID-19 spiking proteins S1 and S2 to capture the virus inside a quantum mechanical tunneling gap device. The current through the gap, that is sized to match the COVID-19 diameter of 125 nm, is monitored to detect the presence of the virus. The gap impedance also changes and can be monitored. The sensor works with small amount of saliva deposited over its active area. Saliva is a complex fluid composed of 99.49% water, enzymes, human cells, bacteria, opiorphin, haptocorrin, alfa-amylase, antibacterial compounds, mucus, and electrolytes (sodium, potassium, calcium, etc.). It also contains 60 nm -100 nm exosomes. Except for human cells, bacteria and exosomes, all other fresh saliva components have small molecules (mucus can produce large particles in old saliva). Exosomes and any other nanoparticles inside the fresh saliva can potentially produce false positive results. False negative results, on the other hand, are produced when the viruses in the saliva do not bind with the sensor aptamers. Filtering is used to exclude large (>200 nm) particles. Ultrasonication as well as electric field biasing/excitation techniques are used to ensure virus-aptamer encounter and binding. Exosomes' sizes make them difficult to exclude using filtering. Currently I am developing a technique based on dielectrophoretic responses of exosomes and viruses to preferentially trap the COVID-19 and repel the exosomes. The sensor's limit of detection is close to a single virus owing to its transduction technique of quantum mechanical tunneling current. I will discuss COVID-19 electronic sensor performance and its performance along with its fabrication and applications in this talk.

Exploring the relationships between oral sensory physiology and oral processing with mid infrared spectra of saliva

Saliva is a critical component during eating, as it performs an important role in sensory perception and processing of food. However, the individual variations and relationships between oral sensory physiology, oral processing and saliva with food are not well understood. The aim of this study was to analyse as well as to interpret individual variations and relationships between the mid infrared (MIR) spectra of saliva and oral physiology and behaviour (e.g. fungiform papillae, saliva flow, and oral processing time). The fungiform papillae density of the tongue, resting saliva flow rate and oral processing time were measured in participants from a sensory study (n = 52). The MIR spectra of unstimulated saliva samples sourced from participants were collected and used to develop partial least squares (PLS) regression models. These models were utilised to interpret the relationships and individual variations between saliva quantity, oral sensing physiology, and oral processing with the saliva spectra. The coefficient of determination (R2) and the standard error in cross validation (SECV) obtained were for saliva flow rate (R2 0.65–0.83, SECV 0.25–0.31), papillae density of tongue (R2 0.73–0.83, SECV 7.4–11.2), and oral processing time (R2 0.7–0.87, SECV 1.66–3.04). Optimal models were obtained when participants were divided into groups namely young male, young female, and older participants. Different PLS loadings in the MIR fingerprint regions were observed between different groups, which demonstrates that different components of saliva connect with oral sensing physiology and oral processing differences among different demographic groups. These results indicated the potential of the salivary fingerprint spectra to understand the consumer eating experience and food selection more deeply, providing a tool in marketing and sensory experiments.

Features of the Metabolic Profile of Saliva in Lung Cancer and COPD: The Effect of Smoking Status.

The aim of the study was to compare the metabolic characteristics of the salivary composition in lung cancer, chronic obstructive pulmonary disease (COPD) and their combination, depending on the smoking history. The study group included 392 patients with lung cancer of various histological types. The division into subgroups was carried out in accordance with the severity of COPD and smoking experience. Salivary biochemical composition was determined according to 34 indicators. For data processing, the principal component method was used. Different groups of biochemical saliva markers are informative when separately accounting for the smoking factor and the presence of COPD in lung cancer. For smoking, antioxidant enzymes and electrolyte components of saliva are informative; for COPD metabolic enzymes, lipid peroxidation products, sialic acids and electrolyte components are informative. While taking into account the smoking factor and the presence of COPD, biochemical markers corresponding to the presence/absence and severity of COPD are the priority. Changes occurring in the background of smoking are of a secondary nature, manifesting as much as possible with a smoking history of more than 50 pack-years. Thus, the metabolic changes that occur in lung cancer in combination with COPD, depending on the smoking factor, can be estimated using saliva.

Biological Markers in Anxiety Disorders.

Anxiety disorders are one of the most commonly reported disorders in psychiatry, causing a high medical and socio-economic burden. Recently, there has been a soaring interest in the biological basis of anxiety disorders, which is reflected in an increasing number of articles related to the topic. Due to the ambiguity of the diagnosis and a large number of underdiagnosed patients, researchers are looking for laboratory tests that could facilitate the diagnosis of anxiety disorders in clinical practice and would allow for the earliest possible implementation of appropriate treatment. Such potential biomarkers may also be useable in monitoring the efficacy of pharmacological therapy for anxiety disorders. Therefore this article reviews the literature of potential biomarkers such as components of saliva, peripheral blood, cerebrospinal fluid (CSF), and neuroimaging studies. There are promising publications in the literature that can be useful. The most valuable and promising markers of saliva are cortisol, lysozyme, and α-amylase (sAA). In the blood, in turn, we can distinguish serotonin, brain-derived serum neurotrophic factor (BDNF), cortisol, and microRNA. Structural changes in the amygdala and hippocampus are promising neuroimaging markers, while in CSF, potential markers include oxytocin and 5-Hydroxyindoleacetic acid (5-HIAA). Unfortunately, research in the field of biomarkers is hampered by insufficient knowledge about the etiopathogenesis of anxiety disorders, the significant heterogeneity of anxiety disorders, frequent comorbidities, and low specificity of biomarkers. The development of appropriate biomarker panels and their assessment using new approaches may have the prospective to overcome the above-mentioned obstacles.

Salivary Biomarkers of Stress, Anxiety and Depression.

Stress, anxiety and depressive disorders are often characterized by the activation of the stress axis, which results in similar symptoms at some point in these disorders. These disorders are closely related to each other—they occur simultaneously or follow one another. The diagnosis of stress, anxiety and depression is not a perfect procedure currently—it is based on patient observation and an interview with the patient and their family. There are no laboratory tests that would dispel the doubts of the doctor making the diagnosis and allow the appropriate treatment to be implemented as soon as possible. Therefore, this study will review the components of saliva that could be helpful in the quick diagnosis of stress, anxiety and/or depression. Such potential salivary biomarkers could also be useful in monitoring the effectiveness of pharmacological treatment prescribed by a psychiatrist. The following are promising salivary biomarkers of stress, anxiety or depression: cortisol, immunoglobulin A (sIgA), lysozyme, melatonin, α-amylase (sAA), chromogranin A (CgA) and fibroblast growth factor 2 (FGF-2). To the best valuable potential salivary markers of stress, we can include cortisol, lysozyme, sAA and CgA. To differentiate depression from stress, salivary cortisol and melatonin can be helpful. Fluctuations in the concentrations of the above-mentioned substances in saliva indicate a particularly strong relationship with typical human psychological problems, such as stress, depression or anxiety.

Changing the Recipe: Pathogen Directed Changes in Tick Saliva Components.

Ticks are obligate hematophagous parasites and are important vectors of a wide variety of pathogens. These pathogens include spirochetes in the genus Borrelia that cause Lyme disease, rickettsial pathogens, and tick-borne encephalitis virus, among others. Due to their prolonged feeding period of up to two weeks, hard ticks must counteract vertebrate host defense reactions in order to survive and reproduce. To overcome host defense mechanisms, ticks have evolved a large number of pharmacologically active molecules that are secreted in their saliva, which inhibits or modulates host immune defenses and wound healing responses upon injection into the bite site. These bioactive molecules in tick saliva can create a privileged environment in the host’s skin that tick-borne pathogens take advantage of. In fact, evidence is accumulating that tick-transmitted pathogens manipulate tick saliva composition to enhance their own survival, transmission, and evasion of host defenses. We review what is known about specific and functionally characterized tick saliva molecules in the context of tick infection with the genus Borrelia, the intracellular pathogen Anaplasma phagocytophilum, and tick-borne encephalitis virus. Additionally, we review studies analyzing sialome-level responses to pathogen challenge.

Lipids and Their Importance in Dentistry

Lipids in the structure of cell membranes in the oral environment determine the elasticity, fluidity and permeability of the cell membrane and participate in intercellular transport and signal transduction pathways between the salivary glands and other tissues. Lipids are also important main components of saliva. The properties and number of lipid component in cells and tissues vary according to various physiological and pathological conditions. Identification of lipids, which play a major role in disease states, is used to evaluate the diagnosis and treatment response of diseases. This also applies to various oral diseases. For example, in the presence of chronic periodontititis, caries and calculus, the amount of lipids in saliva increases. Oral surface lipids of pathogenic bacteria such as Porhynomonas gingivalis, one of the main bacteria causing periodontitis, also cause negative effects.

Effect of simulated saliva components on the in vitro digestion of peanut oil body emulsion.

The digestion properties of natural oil bodies (OBs) are very important to their potential applications such as traditional fat replacement or bioactive delivery systems. However, study on the complete digestion behaviours of OBs has not been reported yet. In this paper, peanut OBs were extracted by an aqueous medium method, and their digestion behaviour was studied using completed in vitro oral-gastric-intestinal digestion simulation. In particular, the effects of saliva components, mainly α-amylase and mucin, on the digestion of the peanut OBs were systematically investigated. The OB emulsion microstructure, average particle size d4,3, ζ-potential, and surface protein compositions during oral, gastric and intestinal digestion, and the free fatty acid (FFA) release rate of the peanut OBs during intestinal digestion were determined. Interestingly, it was revealed from both the periodic acid-Schiff staining technique and the confocal laser microscopy characterization that glycosidic bonds exist on the surface of the peanut OBs, though how they were produced was unknown. The results from the digestion measurements showed that α-amylase in saliva can break the glycosidic bonds in oral digestion, promoting the digestion of the OBs in the gastric and intestinal environments. Saliva mucin caused bridging flocculation of OBs by electrostatic attraction in the gastric tract, and depletion flocculation of OBs in the intestinal tract. The former hindered the fusion of oil droplets, and the latter promoted FFA release rate by increasing the contacting surface area of OBs with bile salts.

Survey of Saliva Components and Virus Sensors for Prevention of COVID-19 and Infectious Diseases.

The United States Centers for Disease Control and Prevention considers saliva contact the lead transmission mean of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19). Saliva droplets or aerosols expelled by sneezing, coughing, breathing, and talking may carry this virus. People in close distance may be exposed directly to these droplets or indirectly when touching the droplets that fall on surrounding surfaces and ending up contracting COVID-19 after touching the mucosa tissue of their faces. It is of great interest to quickly and effectively detect the presence of SARS-CoV-2 in an environment, but the existing methods only work in laboratory settings, to the best of our knowledge. However, it may be possible to detect the presence of saliva in the environment and proceed with prevention measures. However, detecting saliva itself has not been documented in the literature. On the other hand, many sensors that detect different organic components in saliva to monitor a person’s health and diagnose different diseases, ranging from diabetes to dental health, have been proposed and they may be used to detect the presence of saliva. This paper surveys sensors that detect organic and inorganic components of human saliva. Humidity sensors are also considered in the detection of saliva because a large portion of saliva is water. Moreover, sensors that detect infectious viruses are also included as they may also be embedded into saliva sensors for a confirmation of the presence of the virus. A classification of sensors by their working principles and the substances they detect is presented, including the sensors’ specifications, sample size, and sensitivity. Indications of which sensors are portable and suitable for field application are presented. This paper also discusses future research and challenges that must be resolved to realize practical saliva sensors. Such sensors may help minimize the spread of not only COVID-19 but also other infectious diseases.

Adsorption of SARS-CoV-2 Spike Protein S1 at Oxide Surfaces Studied by High-Speed Atomic Force Microscopy.

The ongoing coronavirus disease 2019 (COVID‐19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) represents a serious threat to the health of millions of people. Respiratory viruses such as SARS‐CoV‐2 can be transmitted via airborne and fomite routes. The latter requires virion adsorption at abiotic surfaces and most likely involves the SARS‐CoV‐2 spike protein subunit 1 (S1), which is the outermost point of its envelope. Understanding S1 spike protein interaction with fomite surfaces thus represents an important milestone on the road to fighting the spread of COVID‐19. Herein, high‐speed atomic force microscopy (HS‐AFM) is used to monitor the adsorption of the SARS‐CoV‐2 spike protein S1 at Al2O3(0001) and TiO2(100) surfaces in situ. While the single‐crystalline oxide substrates are chosen to model the native surface oxides of Al‐ and Ti‐based fomites, adsorption is studied in electrolytes that mimic the pH and major ionic components of mucosal secretions and saliva, respectively. Quantitative analysis of the obtained HS‐AFM images indicates that S1 spike protein adsorption at these surfaces is mostly governed by electrostatic interactions with possible contributions from van der Waals interactions. It thus proceeds more rapidly at the TiO2(100) than at the Al2O3(0001) surface.

Effects of hemodialysis treatment on saliva flow rate and saliva composition during in-center maintenance dialysis: a cross-sectional study

Aim To analyze changes in saliva flow rate and clinical measures from unstimulated whole saliva (UWS) among patients undergoing hemodialysis for end-stage kidney disease (ESKD). Background Chronic hemodialysis causes changes in blood chemistry as well as dry mouth, due to removal of excess fluids. UWS is used to examine saliva flow rate as an indicator of mouth dryness. Whether UWS can be used to measure changes in clinical variables following hemodialysis has not been explored. Design A cross-sectional quantitative study. Methods Patients with ESKD were recruited by purposive sampling (n = 100) between 1 January and 30 June 2015 from a hospital in northern Taiwan. UWS was collected 1-hour pre-dialysis (T1), mid-dialysis (T2), and 1-hour post-dialysis (T3). Saliva flow rate and clinical variables were analyzed. Results Saliva flow rate increased significantly from T1 to T3 (Wald χ2 = 10.40, p < .01). Changes in saliva from T1 to T3 included decreases in blood urea nitrogen and creatinine (Wald χ2 = 97.12, p < .001 and Wald χ2 = 36.98, p < .001, respectively). The pH and osmolality also decreased (p < .001 and p < .01, respectively). Changes in electrolytes included decreases in potassium and calcium (Wald χ2 = 6.71, p < .05 and Wald χ2 = 17.64, p < .01, respectively) and increases in chloride (Wald χ2 = 17.64, p < .001). Conclusion Our findings demonstrated saliva flow rate and several saliva components were altered during hemodialysis. The total volume of saliva secretion increased following dialysis, which can reduce xerostomia. Therefore, medical personnel could provide interventions of relieving dry mouth symptoms and increasing saliva flow rate before hemodialysis treatment.

Strong interactions between Salp15 homologues from the tick I. ricinus and distinct types of the outer surface OspC protein from Borrelia

Ticks belonging to the genus Ixodes are parasites feeding on vertebrate blood and vectors for many pathogenic microbes, including Borrelia burgdorferi sensu lato spirochetes, the causative agent of Lyme borreliosis. The tick saliva contains a mixture of bioactive molecules showing a wide range of properties for efficient engorgement. One of the most extensively studied components of tick saliva is a 15-kDa salivary gland protein (Salp15) from Ixodes scapularis. This multifunctional protein suppresses the immune response of hosts through pleiotropic action on a few crucial defense pathways. Salp15 and its homologue from I. ricinus Iric1 have been also shown to bind to Borrelia burgdorferi sensu stricto outer surface protein C (OspC) permitting the spirochetes to evade antibody-mediated killing in the human host. Further studies revealed that Salp15 and Iric1 protected B. burgdorferi s. s. and B. garinii expressing OspC against the complement system. OspC is the most variable protein on the outer surface of Borrelia, which in addition to Salp15 can also bind other ligands, such as plasminogen, fibrinogen, fibronectin or complement factor 4. So far several OspC variants produced by B. burgdorferi s. l. spirochetes were shown to be capable of binding Salp15 or its homologue, but the protection against borreliacidal antibodies has only been proven in the case of B. burgdorferi s. s. The question of Salp15 contribution to Borrelia survival during the infection has been comprehensively studied during the last decades. In contrast, the organization of the OspC-Salp15 complex has been poorly explored. This report describes the binding between three Salp15 homologues from the tick Ixodes ricinus (Iric1, Iric2 and Iric3) and OspC from four B. burgdorferi sensu lato strains in terms of the binding parameters, analyzed with two independent biophysical methods – Microscale thermophoresis (MST) and Biolayer interferometry (BLI). The results of both experiments show a binding constant at the nanomolar level, which indicates very strong interactions. While the Iric1-OspC binding has been reported before, we show in this study that also Iric2 and Iric3 are capable of OspC binding with high affinity. This observation suggests that these two Salp15 homologues might be used by B. burgdorferi s. l. in a way analogous to Iric1. A comparison of the results from the two methods let us propose that N-terminal immobilization of OspC significantly increases the affinity between the two proteins. Finally, our results indicate that the Iric binding site is located in close proximity of the OspC epitopes recognized by human antibodies, which may have important biological and medical implications.

The Effects of A Mosquito Salivary Protein on Sporozoite Traversal of Host Cells.

Malaria begins when Plasmodium-infected Anopheles mosquitoes take a blood meal on a vertebrate. During the initial probing process, mosquitoes inject saliva and sporozoites into the host skin. Components of mosquito saliva have the potential to influence sporozoite functionality. Sporozoite-associated mosquito saliva protein 1 (SAMSP1; AGAP013726) was among several proteins identified when sporozoites were isolated from saliva, suggesting it may have an effect on Plasmodium. Recombinant SAMSP1 enhanced sporozoite gliding and cell traversal activity in vitro. Moreover, SAMSP1 decreased neutrophil chemotaxis in vivo and in vitro, thereby also exerting an influence on the host environment in which the sporozoites reside. Active or passive immunization of mice with SAMSP1 or SAMSP1 antiserum diminished the initial Plasmodium burden after infection. Passive immunization of mice with SAMSP1 antiserum also added to the protective effect of a circumsporozoite protein monoclonal antibody. SAMSP1 is, therefore, a mosquito saliva protein that can influence sporozoite infectivity in the vertebrate host.