The bitterness of genitourinary infections: Properties, ligands of genitourinary bitter taste receptors and mechanisms linking taste sensing to inflammatory processes in the genitourinary tract.

BACKGROUND: Though, first identified in the gastrointestinal tract, bitter taste receptors are now believed to be ubiquitously expressed in several regions of the body, including the respiratory tract, where they play a critical role in sensing and clearance of excess metabolic substrates, toxins, debris, and pathogens. More recently, bitter taste receptor expression has been reported in cells, tissues and organs of the genitourinary (GU) system, suggesting that these receptors may play an integral role in mediating inflammatory responses to microbial aggression in the GU tract. However, the mechanisms, linking bitter taste receptor sensing with inflammatory responses are not exactly clear. Here, I review recent data on the properties and ligands of bitter taste receptors and suggest mechanisms of bitter taste receptor signaling in the GU tract, and the molecular pathways that link taste sensing to inflammatory responses in GU tract. METHOD: Computer-aided search was conducted in Scopus, PubMed, Web of Science and Google Scholar for relevant peer-reviewed articles published between 1990 and 2018, investigating the functional implication of bitter taste receptors in GU infections, using the following keywords: extra-oral bitter taste receptors, bitter taste receptors, GU bitter taste receptors, kidney OR renal OR ureteral OR urethral OR bladder OR detrusor smooth muscle OR testes OR spermatozoa OR prostate OR vaginal OR cervix OR ovarian OR endometrial OR myometrial OR placenta OR cutaneous bitter taste receptors. To identify research gaps on etiopathogenesis of GU infections/inflammation, additional search was conducted using the following keywords: GU inflammatory signaling, GU microbes, GU bacteria, GU virus, GU protozoa, GU microbial metabolites, and GU infection. The retrieved articles were filtered and further screened for relevance according to the aim of the study. A narrative review was performed for selected literatures. RESULTS: Bitter taste receptors of the GU tract may constitute essential components of the pathogenetic mechanisms of GU infections/inflammation that are activated by microbial components, known as quorum sensing signal molecules. Based on accumulating evidences, indicating that taste receptors may signal downstream to activate inflammatory cascades, in addition to the nitric oxide-induced microbicidal effects produced upon taste receptor activation, it is suggested that the anti-inflammatory activities of bitter taste receptor stimulation are mediated via pathways involving the nuclear factor κB by downstream signaling of the metabolic and stress sensors, adenosine monophosphate-activated protein kinase and nicotinamide adenine dinucleotide-dependent silent mating type information regulation 2 homolog 1 (sirtuin 1), resulting to the synthesis of anti-inflammatory cytokines/chemokines, and antimicrobial factors, which ultimately, under normal conditions, leads to the elimination of microbial aggression. CONCLUSIONS: GU bitter taste receptors may represent critical players in GU tract infections/inflammation. Bitter taste receptors may serve as important therapeutic target for treatment of a number of infectious diseases that affect the GU tract.

Regulation of mononuclear phagocyte function by the microbiota at mucosal sites.

Mucosal tissues contain distinct microbial communities that differ drastically depending on the barrier site, and as such, mucosal immune responses have evolved to be tailored specifically for their location. Whether protective or regulatory immune responses against invading pathogens or the commensal microbiota occur is controlled by local mononuclear phagocytes (MNPs). Comprising macrophages and dendritic cells (DCs), the functions of these cells are highly dependent on the local environment. For example, the intestine contains the greatest bacterial load of any site in the body, and hence, intestinal MNPs are hyporesponsive to bacterial stimulation. This is thought to be one of the major mechanisms by which harmful immune responses directed against the trillions of harmless bacteria that line the gut lumen are avoided. Regulation of MNP function by the microbiota has been characterized in the most depth in the intestine but there are several mucosal sites that also contain their own microbiota. In this review, we present an overview of how MNP function is regulated by the microbiota at mucosal sites, highlighting recent novel pathways by which this occurs in the intestine, and new studies elucidating these interactions at mucosal sites that have been characterized in less depth, including the urogenital tract.

The impact of the sepsis on female urogenital system: the role of pregabalin.

PURPOSE: The aim of the study was to investigate the oxidative damage and inflammatory effects of sepsis on the urogenital system in the Lipopolysaccharide (LPS)-induced sepsis model and ameliorating role of Pregabalin (PGB). METHODS: Twenty-four female Wistar Albino rats (12 months old) were divided into 3 groups as follows: Sepsis group (Group S) (5 mg/kg LPS, i.p, single dose); Sepsis+ PGB group (Group SP) (5 mg/kg LPS, i.p, single dose and 30 mg/kg PGB); Control group (Group C) (0.1 ml/oral and i.p. saline, single dose), 6 h after LPS administration, the animals were killed. Subsequently, analyses of urogenital tissue oxidant/antioxidant status, histopathological and immunohistochemical analyses were performed. RESULTS: Total oxidative status (TOS) and oxidative stress index (OSI) values in the urogenital tissues were increased in Group S (Total anti-oxidative status (TAS) decreased) compared to the Control group (p < 0.05). PGB improved these values (p < 0.05). The immunohistochemical markers [Caspase-3, granulocyte colony-stimulating factor (G-CSF), interleukin-6 (IL-6), Serum Amyloid A (SAA) and inducible nitric oxide synthase (iNOS)] were significantly increased in Group S except for bladder (p < 0.001). Statistically significant immunohistochemical positiveness was found only for IL-6 in urinary bladder, though all the others values were negative. With the administration of PGB (Group SP), the expressions of these immunoreactions were markedly decreased (p < 0.001). CONCLUSIONS: These findings demonstrated that sepsis caused oxidative stress and inflammation in the urogenital tissues. We have revealed that PGB ameliorated tissue damage caused by sepsis.

Koala immunology and infectious diseases: How much can the koala bear?

Infectious diseases are contributing to the decline of the iconic Australian marsupial, the koala (Phascolarctos cinereus). Infections with the obligate intracellular bacteria, Chlamydia pecorum, cause debilitating ocular and urogenital-tract disease while the koala-retrovirus (KoRV) has been implicated in host immunosuppression and exacerbation of chlamydial pathogenesis. Although histological studies have provided insight into the basic architecture of koala immune tissues, our understanding of the koala immune response to infectious disease has been limited, until recently, by a lack of species-specific immune reagents. Recent advances in the characterisation of key immune genes have focused on advancing our understanding of the immune response to Chlamydia infection, revealing commonalities in disease pathologies and immunity between koalas and other hosts and paving the way for the development of a koala Chlamydia vaccine. This review summarises these recent findings and highlights key aspects of the koala immune system requiring further attention with particular regard to their most prominent infectious diseases.

Commensal Fungi in Health and Disease.

Fungi are increasingly being recognized as common members of the microbiomes found on nearly all mucosal surfaces, and interest is growing in understanding how these organisms may contribute to health and disease. In this review, we investigate recent developments in our understanding of the fungal microbiota or "mycobiota" including challenges faced in characterizing it, where these organisms are found, their diversity, and how they interact with host immunity. Growing evidence indicates that, like the bacterial microbiota, the fungal microbiota is often altered in disease states, and increasingly studies are being designed to probe the functional consequences of such fungal dysbiosis on health and disease.

Intravaginal Chlamydia trachomatis Challenge Infection Elicits TH1 and TH17 Immune Responses in Mice That Promote Pathogen Clearance and Genital Tract Damage.

While ascension of Chlamydia trachomatis into the upper genital tract of women can cause pelvic inflammatory disease and Fallopian tube damage, most infections elicit no symptoms or overt upper genital tract pathology. Consistent with this asymptomatic clinical presentation, genital C. trachomatis infection of women generates robust TH2 immunity. As an animal model that modeled this response would be invaluable for delineating bacterial pathogenesis and human host defenses, herein we explored if pathogen-specific TH2 immunity is similarly elicited by intravaginal (ivag) infection of mice with oculogenital C. trachomatis serovars. Analogous to clinical infection, ascension of primary C. trachomatis infection into the mouse upper genital tract produced no obvious tissue damage. Clearance of ivag challenge infection was mediated by interferon (IFN)-γ-producing CD4+ T cells, while IFN-γ signaling blockade concomitant with a single ivag challenge promoted tissue damage by enhancing Chlamydia-specific TH17 immunity. Likewise, IFN-γ and IL-17 signaling blockade or CD4+ T cell depletion eliminated the genital pathology produced in untreated controls by multiple ivag challenge infections. Conversely, we were unable to detect formation of pathogen-specific TH2 immunity in C. trachomatis-infected mice. Together, our work revealed C. trachomatis infection of mice generates TH1 and TH17 immune responses that promote pathogen clearance and immunopathological tissue damage. Absence of Chlamydia-specific TH2 immunity in these mice newly highlights the need to identify experimental models of C. trachomatis genital infection that more closely recapitulate the human host response.

Commensal bacteria and immunity of the gastrointestinal, respiratory and genitourinary tracts.

Commensal bacteria are microorganisms that occur among others in the gastrointestinal, respiratory and urogenital tract not exhibit the characteristics of pathogenicity, and act on the immune system and the metabolism of macroorganism and "create" protective barrier against pathogenic bacteria. Currently, it is estimated that the number of commensal bacteria inhabiting in and on human, are more than ten times the number of cells that build the body. The composition of these microorganisms depends on health and physiological status of macroorganism, including its immune status, but also largely on environmental factors (living and diet). These bacteria affecting the immune system in the gastrointestinal, respiratory and urogenital tract, stimulate the synthesis of a number of immunological substances that interact multiphase, for example: blocking the adhesion of pathogenic microorganisms and to reduce or entirely eliminate their influence on the contact and macroorganism.

Differential expression of novel biomarkers (TLR-2, TLR-4, COX-2, and Nrf-2) of inflammation and oxidative stress in semen of leukocytospermia patients.

Chronic genitourinary inflammation results in Leukocytospermia (LCS), an elevated number of white blood cells (WBCs) in semen, which, in association with oxidative stress, may suppress sperm function, and manifest as male factor infertility. The current clinical diagnosis of LCS employs manual enumeration of WBCs and requires complex staining and laboratory skills or measurement of inflammatory cytokines and chemokines levels. Many patients with idiopathic infertility are asymptomatic. In search of better inflammatory markers for LCS, we evaluated expression of toll-like receptors 2 and 4 (TLR-2/4), cyclooxygenase-2 (COX-2), and nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) in semen samples of age-matched infertile patients with and without LCS. We employed the usage of specific Western blot evaluation, cytokine array; immunofluorescence microscopy (IFM) followed by computer-based analysis, and other molecular approaches. As compared with non-LCS patients (n = 38), semen samples from LCS patients (n = 47) displayed significantly lower total sperm count (p < 0.01), motility (p < 0.0001), normal head count (p < 0.0001), and a significantly higher white blood cell count (p < 0.0001). Differential cytokine profiling of seminal plasma by antibody array revealed up-regulation of several pro-inflammatory chemokines in LCS samples. Western blot analysis of LCS seminal plasma (n = 15) also showed a significant increase in expression of TLR-2 (p < 0.001) and 4 (p < 0.01), COX-2 (p < 0.001), and Nrf-2 (p < 0.001) as compared with semen samples from non-LCS patients (n = 15). Computer-based objective IFM analysis of spermatozoa from LCS patients showed increased expression of TLR-4 (p < 0.001), Cox-2 (p < 0.01), and (Nrf-2) (p < 0.01). Significant differences in the subcellular localization of these proteins were evident in the sperm head and tail segments of LCS samples. Altogether, these observations suggest that TLR-2/4, COX-2, and Nrf-2 can serve as novel biomarkers of inflammation and oxidative stress. Therefore, developing a rapid assay for these biomarkers may facilitate early diagnosis and management of LCS especially in idiopathic and asymptomatic male infertility patients.

Innate Defense against Fungal Pathogens.

Human fungal infections have been on the rise in recent years and proved increasingly difficult to treat as a result of the lack of diagnostics, effective antifungal therapies, and vaccines. Most pathogenic fungi do not cause disease unless there is a disturbance in immune homeostasis, which can be caused by modern medical interventions, disease-induced immunosuppression, and naturally occurring human mutations. The innate immune system is well equipped to recognize and destroy pathogenic fungi through specialized cells expressing a broad range of pattern recognition receptors (PRRs). This review will outline the cells and PRRs required for effective antifungal immunity, with a special focus on the major antifungal cytokine IL-17 and recently characterized antifungal inflammasomes.

[Comparative analysis of informative-diagnostic properties of mucosa immune-reactivity parameters].

AIM: Study the features of immune-reactivity expression in mucosa depending on their topicity and etiopathogenesis of the pathological process. MATERIALS AND METHODS: Data from 30 clinically healthy children and 77 children with acute and recurrent diseases of respiratory tract: 51--with acute and 15--with chronic bronchitis; as well as 132 women: 41--with active stage of acute urogenital chlamydia infection, 29--with recurrent chronic process, 30--with non-recurrent form and 32 clinically healthy women were analyzed. Saline and urogenital tract mucosa discharge was analyzed for IgG, sIgA and secretory component, IL-1beta, 4, 6, 8, 9, 10, 12, IFNgamma, TNFalpha and GM-CSF, TLR-2, TLR-3, TLR-4, TLR-8 gene expression levels as well as content of lysozyme, total protein and leucocytes. RESULTS: Solidity, universality and practically single-stage triggering of mucosa immune reaction mechanisms to intervention by foreign agents regardless of their localization was confirmed. A dependence of immune-reactivity expression on the form of pathologic process, its localization and qualitative and quantitative characteristics of the infectious agents was clearly seen. The highest level of clinical-laboratory and immunological parameters is inherent for patients with acute processes in urogenital tract (cervical canal and urethra), especially cause by mixed infections. CONCLUSION: Immune diagnostic parameters of mucosa among which TLR system is especially notable have high information properties allowing not only diagnostics of inflammatory process but also differentiating its form and character our course.

Rat ß3-adrenoceptor protein expression: antibody validation and distribution in rat gastrointestinal and urogenital tissues.

ß3-Adrenoceptors play important roles in the regulation of urogenital and probably gastrointestinal function. However, despite recent progress, their detection at the protein level has remained difficult due to a lack of sufficiently validated selective antibodies. Therefore, we have explored the selectivity of two antibodies for the detection of rodent ß3-adrenoceptors in immunoblots and immunohistochemistry. Of two reportedly promising candidates, antibody AB15688 did not exhibit subtype selectivity in immunoblots. In contrast, the antibody Sc1473 exhibited at least some selectivity in immunoblots and more promising results in immunocytochemical and immunohistochemical stains in cells transfected with cloned ß-adrenoceptor subtypes and in rat and mouse tissues. In a systematic screening of rat gastrointestinal and urogenital tissues, Sc1473 produced selective staining in the epithelial cell lining of the stomach and the urothelium of ureter and bladder. We conclude that the two tested antibodies are inappropriate or at least insufficient for immunoblotting applications, but Sc1473 appears to be useful for immunohistochemical detection of ß3-adrenoceptor protein in rodent tissues. The ß3-adrenoceptor protein exhibits a distinct expression pattern in the rat gastrointestinal and urogenital tract, which is at least partly in line with previously reported functional data.

[Mechanisms of urinary tract sterility maintenance]. / Mechanizmy utrzymania sterylnosci ukladu moczowego.

Physiologically, urine and the urinary tract are maintained sterile because of physical and chemical properties of urine and the innate immune system's action. The urinary tract is constantly exposed to the invasion of microorganisms from the exterior environment, also because of the anatomical placement of the urethra, in the vicinity of the rectum. Particularly vulnerable to urinary tract infections (UTI) are women (an additional risk factor is pregnancy), but also the elderly and children. The main pathogens causing UTI are bacteria; in 70-95% of cases it is the bacterium Escherichia coli. Infections caused by viruses and fungi are less common and are associated with decreased immunity, pharmacotherapy, or some diseases. Bacteria have evolved a number of factors that facilitate the colonization of the urinary tract: the cover and cell membrane antigens O and K1, lipopolysaccharide (LPS), fimbriae, pile and cilia. On the other hand, the human organism has evolved mechanisms to hinder colonization of the urinary tract: mechanisms arising from the anatomical structure of the urinary tract, the physicochemical properties of the urine and the activity of the innate immune system, also known as non-specific, which isolates and destroys pathogens using immunological processes, and the mechanisms for release of antimicrobial substances such as Tamm-Horsfall protein, mucopolysaccharides, immunoglobulins IgA and IgG, lactoferrin, lipocalin, neutrophils, cytokines and antimicrobial peptides. This review aims to analyze the state of knowledge on the mechanisms to maintain the sterility of the urinary tract used by the human organism and bacterial virulence factors to facilitate the colonization of the urinary tract.

[The comparative characteristic of immune status of males with bacterial inflammatory urogenital pathology of different etiology in the city of Orenburg].

The article discusses presence of typical characteristics of parameters of system immunity under gonococcal and nonspecific uretroprostatitis and diagnostic value of these indicators. The reliable differences of immunologic indicators in patients with gonorrhea are established as compared to patients with nonspecific bacterial uretroprostatitis. The study established in peripheral blood the reliable decrease of level of leukocytes, relative amount of monocytes, phagocyte index, functional reserve of leukocytes at the expense of spontaneous and stimulated NBT test, IgA, sIgA. On the contrary, the study detected increasing of level of IgM and lactoferrin in patients with gonorrhea as compared to corresponding indicators in patients nonspecific infections. Under gonorrhea, the largest deviation of indicators from standard values was established for lactoferrin. The detected differences of immunologic parameters can be used as differentiating markers of nonspecific and gonococcal uretroprostatitis and criteria of effectiveness of immune correction.

[Effect of Corynebacterium non diphtheriae on functional activity and apoptosis of macrophages].

AIM: Determine the ability of Corynebacterium non diphtheriae to induce phagocytosis and apoptosis of macrophages and evaluate regulatory effect of nuetrophilokines (NPK) induced by Corynebacterium non diphtheriae on these processes. MATERIALS AND METHODS: The ability of Corynebacterium non diphtheriae, isolated from upper respiratory tract, skin and urogenital tract (UGT) were studied for the ability to induce phagocytosis and apoptosis of mice macrophages (MP; in vitro during staining by May-Grunwald with additional staining by Romanowsky-Giemsa) before and after the addition of NPK induced by Corynebacterium non diphtheriae. RESULTS: Phagocytic index (PI) was the same for all the Corynebacterium non diphtheriae species, phagocytic number (PN) and index of phagocytosis completion (IPC)--were minimal relative to corynebacteria isolated from UGT. All the studied corynebacteria species induced MP apoptosis; the most pronounced apoptogenic effect was detected in Corynebacterium pseudotuberculosis isolated from UGT. NPK increased PN against corynebacteria isolated from the studied biotopes, IPC--only during studies of corynebacteria isolated from skin. The effect of NPK resulted in a reduction of apoptogenic effect for almost all the Corynebacterium non diphtheriae, regardless of the isolation location. CONCLUSION: A pronounced apoptogenic effect and insufficiency of phagocytosis processes induced by corynebacteria are the means of realization of Corynebacterium non diphtheriae pathogenic effect. NPK use is possible for immune correction of immune deficiency conditions developing against the background of diseases determined by Corynebacterium non diphtheriae.

Vaginal microbiota and its role in HIV transmission and infection.

The urogenital tract appears to be the only niche of the human body that shows clear differences in microbiota between men and women. The female reproductive tract has special features in terms of immunological organization, an epithelial barrier, microbiota, and influence by sex hormones such as estrogen. While the upper genital tract is regarded as free of microorganisms, the vagina is colonized by bacteria dominated by Lactobacillus species, although their numbers vary considerably during life. Bacterial vaginosis is a common pathology characterized by dysbiosis, which increases the susceptibility for HIV infection and transmission. On the other hand, HIV infections are often characterized by a disturbed vaginal microbiota. The endogenous vaginal microbiota may protect against HIV by direct production of antiviral compounds, through blocking of adhesion and transmission by ligands such as lectins, and/or by stimulation of immune responses. The potential role of probiotics in the prevention of HIV infections and associated symptoms, by introducing them to the vaginal and gastrointestinal tract (GIT), is also discussed. Of note, the GIT is a site of considerable HIV replication and CD4(+) T-cell destruction, resulting in both local and systemic inflammation. Finally, genetically engineered lactobacilli show promise as new microbicidal agents against HIV.

Secretory leukocyte protease inhibitor binds to Neisseria gonorrhoeae outer membrane opacity protein and is bactericidal.

PROBLEM: Secretory leukocyte protease inhibitor (SLPI) is an innate immune peptide present on the genitourinary tract mucosa that has antimicrobial activity. In this study, we investigated the interaction of SLPI with Neisseria gonorrhoeae. METHOD OF STUDY: ELISA and far-Western blots were used to analyze binding of SLPI to gonococci. The binding site for SLPI was identified by tryptic digests and mass spectrometry. Antimicrobial activity of SLPI for gonococci was determined using bactericidal assays. SLPI protein levels in cell supernatants were measured by ELISA, and SLPI mRNA levels were assessed by quantitative RT-PCR. RESULTS: SLPI bound directly to the gonococcal Opa protein and was bactericidal. Epithelial cells from the reproductive tract constitutively expressed SLPI at different levels. Gonococcal infection of cells did not affect SLPI expression. CONCLUSION: We conclude that SLPI is bactericidal for gonococci and is expressed by reproductive tract epithelial cells and thus is likely to play a role in the pathogenesis of gonococcal infection.

A novel mouse model of Schistosoma haematobium egg-induced immunopathology.

Schistosoma haematobium is the etiologic agent for urogenital schistosomiasis, a major source of morbidity and mortality for more than 112 million people worldwide. Infection with S. haematobium results in a variety of immunopathologic sequelae caused by parasite oviposition within the urinary tract, which drives inflammation, hematuria, fibrosis, bladder dysfunction, and increased susceptibility to urothelial carcinoma. While humans readily develop urogenital schistosomiasis, the lack of an experimentally-tractable model has greatly impaired our understanding of the mechanisms that underlie this important disease. We have developed an improved mouse model of S. haematobium urinary tract infection that recapitulates several aspects of human urogenital schistosomiasis. Following microinjection of purified S. haematobium eggs into the bladder wall, mice consistently develop macrophage-rich granulomata that persist for at least 3 months and pass eggs in their urine. Importantly, egg-injected mice also develop urinary tract fibrosis, bladder dysfunction, and various urothelial changes morphologically reminiscent of human urogenital schistosomiasis. As expected, S. haematobium egg-induced immune responses in the immediate microenvironment, draining lymph nodes, and systemic circulation are associated with a Type 2-dominant inflammatory response, characterized by high levels of interleukin-4, eosinophils, and IgE. Taken together, our novel mouse model may help facilitate a better understanding of the unique pathophysiological mechanisms of epithelial dysfunction, tissue fibrosis, and oncogenesis associated with urogenital schistosomiasis.