scholarly journals Eosinophils and Bacteria, the Beginning of a Story

2021 ◽  
Vol 22 (15) ◽  
pp. 8004
Author(s):  
Edna Ondari ◽  
Esther Calvino-Sanles ◽  
Nicholas J. First ◽  
Monica C. Gestal
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Parasitic Infections ◽  
Th2 Responses ◽  
A Cell ◽  
Anti Inflammatory

Eosinophils are granulocytes primarily associated with TH2 responses to parasites or immune hyper-reactive states, such as asthma, allergies, or eosinophilic esophagitis. However, it does not make sense from an evolutionary standpoint to maintain a cell type that is only specific for parasitic infections and that otherwise is somehow harmful to the host. In recent years, there has been a shift in the perception of these cells. Eosinophils have recently been recognized as regulators of immune homeostasis and suppressors of over-reactive pro-inflammatory responses by secreting specific molecules that dampen the immune response. Their role during parasitic infections has been well investigated, and their versatility during immune responses to helminths includes antigen presentation as well as modulation of T cell responses. Although it is known that eosinophils can present antigens during viral infections, there are still many mechanistic aspects of the involvement of eosinophils during viral infections that remain to be elucidated. However, are eosinophils able to respond to bacterial infections? Recent literature indicates that Helicobacter pylori triggers TH2 responses mediated by eosinophils; this promotes anti-inflammatory responses that might be involved in the long-term persistent infection caused by this pathogen. Apparently and on the contrary, in the respiratory tract, eosinophils promote TH17 pro-inflammatory responses during Bordetella bronchiseptica infection, and they are, in fact, critical for early clearance of bacteria from the respiratory tract. However, eosinophils are also intertwined with microbiota, and up to now, it is not clear if microbiota regulates eosinophils or vice versa, or how this connection influences immune responses. In this review, we highlight the current knowledge of eosinophils as regulators of pro and anti-inflammatory responses in the context of both infection and naïve conditions. We propose questions and future directions that might open novel research avenues in the future.

Pulmonary immunity to viruses

2017 ◽  
Vol 131 (14) ◽  
pp. 1737-1762 ◽  
Author(s):  
S. Rameeza Allie ◽  
Troy D. Randall
Keyword(s):  
Immune Responses ◽  
Respiratory Tract ◽  
Viral Infection ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Lung Damage ◽  
Immune Memory ◽  
Chronic Obstructive ◽  
Adaptive Immune ◽  
Respiratory Viral Infections

Mucosal surfaces, such as the respiratory epithelium, are directly exposed to the external environment and therefore, are highly susceptible to viral infection. As a result, the respiratory tract has evolved a variety of innate and adaptive immune defenses in order to prevent viral infection or promote the rapid destruction of infected cells and facilitate the clearance of the infecting virus. Successful adaptive immune responses often lead to a functional state of immune memory, in which memory lymphocytes and circulating antibodies entirely prevent or lessen the severity of subsequent infections with the same virus. This is also the goal of vaccination, although it is difficult to vaccinate in a way that mimics respiratory infection. Consequently, some vaccines lead to robust systemic immune responses, but relatively poor mucosal immune responses that protect the respiratory tract. In addition, adaptive immunity is not without its drawbacks, as overly robust inflammatory responses may lead to lung damage and impair gas exchange or exacerbate other conditions, such as asthma or chronic obstructive pulmonary disease (COPD). Thus, immune responses to respiratory viral infections must be strong enough to eliminate infection, but also have mechanisms to limit damage and promote tissue repair in order to maintain pulmonary homeostasis. Here, we will discuss the components of the adaptive immune system that defend the host against respiratory viral infections.

scholarly journals Immunopathogenesis of Craniotomy Infection and Niche-Specific Immune Responses to Biofilm

2021 ◽  
Vol 12 ◽  
Author(s):  
Sharon DB de Morais ◽  
Gunjan Kak ◽  
Joseph P. Menousek ◽  
Tammy Kielian
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Critical Role ◽  
Adaptor Protein ◽  
Anatomical Location ◽  
Life Threatening ◽  
The Central Nervous System ◽  
Biofilm Infection

Bacterial infections in the central nervous system (CNS) can be life threatening and often impair neurological function. Biofilm infection is a complication following craniotomy, a neurosurgical procedure that involves the removal and replacement of a skull fragment (bone flap) to access the brain for surgical intervention. The incidence of infection following craniotomy ranges from 1% to 3% with approximately half caused by Staphylococcus aureus (S. aureus). These infections present a significant therapeutic challenge due to the antibiotic tolerance of biofilm and unique immune properties of the CNS. Previous studies have revealed a critical role for innate immune responses during S. aureus craniotomy infection. Experiments using knockout mouse models have highlighted the importance of the pattern recognition receptor Toll-like receptor 2 (TLR2) and its adaptor protein MyD88 for preventing S. aureus outgrowth during craniotomy biofilm infection. However, neither molecule affected bacterial burden in a mouse model of S. aureus brain abscess highlighting the distinctions between immune regulation of biofilm vs. planktonic infection in the CNS. Furthermore, the immune responses elicited during S. aureus craniotomy infection are distinct from biofilm infection in the periphery, emphasizing the critical role for niche-specific factors in dictating S. aureus biofilm-leukocyte crosstalk. In this review, we discuss the current knowledge concerning innate immunity to S. aureus craniotomy biofilm infection, compare this to S. aureus biofilm infection in the periphery, and discuss the importance of anatomical location in dictating how biofilm influences inflammatory responses and its impact on bacterial clearance.

scholarly journals IL-10 in Mast Cell-Mediated Immune Responses: Anti-Inflammatory and Proinflammatory Roles

2021 ◽  
Vol 22 (9) ◽  
pp. 4972
Author(s):  
Kazuki Nagata ◽  
Chiharu Nishiyama
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Specific Ige ◽  
Contact Hypersensitivity ◽  
Parasitic Infections ◽  
Type I ◽  
Anti Inflammatory ◽  
Molecular Patterns

Mast cells (MCs) play critical roles in Th2 immune responses, including the defense against parasitic infections and the initiation of type I allergic reactions. In addition, MCs are involved in several immune-related responses, including those in bacterial infections, autoimmune diseases, inflammatory bowel diseases, cancers, allograft rejections, and lifestyle diseases. Whereas antigen-specific IgE is a well-known activator of MCs, which express FcεRI on the cell surface, other receptors for cytokines, growth factors, pathogen-associated molecular patterns, and damage-associated molecular patterns also function as triggers of MC stimulation, resulting in the release of chemical mediators, eicosanoids, and various cytokines. In this review, we focus on the role of interleukin (IL)-10, an anti-inflammatory cytokine, in MC-mediated immune responses, in which MCs play roles not only as initiators of the immune response but also as suppressors of excessive inflammation. IL-10 exhibits diverse effects on the proliferation, differentiation, survival, and activation of MCs in vivo and in vitro. Furthermore, IL-10 derived from MCs exerts beneficial and detrimental effects on the maintenance of tissue homeostasis and in several immune-related diseases including contact hypersensitivity, auto-immune diseases, and infections. This review introduces the effects of IL-10 on various events in MCs, and the roles of MCs in IL-10-related immune responses and as a source of IL-10.

scholarly journals The Antiviral Properties of Cyclosporine. Focus on Coronavirus, Hepatitis C Virus, Influenza Virus, and Human Immunodeficiency Virus Infections

Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 192 ◽  
Author(s):  
Paulina Glowacka ◽  
Lidia Rudnicka ◽  
Olga Warszawik-Hendzel ◽  
Mariusz Sikora ◽  
Mohamad Goldust ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Influenza Virus ◽  
Hepatitis C ◽  
Beneficial Effect ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Skin Diseases ◽  
Current Knowledge ◽  
Immunosuppressive Treatment ◽  
Immunodeficiency Virus

This review updates current knowledge regarding the risk of viral infections, including COVID-19, in patients treated with cyclosporine. We also shortly refer to bacterial infections and parasitic infestations in patients treated with cyclosporin. Cyclosporine is an immunosuppressive drug, which is widely used in medicine, including in the treatment of autoimmune skin diseases in dermatology, rheumatology, ophthalmology and nephrology, and in organ transplantation. A usual concern associated with immunosuppressive treatment is the potential risk of infections. Interestingly, several data indicate a relatively low risk of infections, especially viral infections, in patients receiving cyclosporine. It was shown that cyclosporine exerts an inhibitory effect on the replication of some viruses, or may have a potentially beneficial effect on the disease course in infections. These include hepatitis C, influenza virus, rotavirus, human immunodeficiency virus and coronavirus infections. Available data indicate that cyclosporine may have a beneficial effect on COVID-19, which is caused by the coronavirus SARS-COV2.

scholarly journals PPARs in Liver Diseases and Cancer: Epigenetic Regulation by MicroRNAs

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Marion Peyrou ◽  
Pierluigi Ramadori ◽  
Lucie Bourgoin ◽  
Michelangelo Foti
Keyword(s):  
Liver Diseases ◽  
Metabolic Diseases ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Hepatocellular Adenoma ◽  
Peroxisome Proliferator ◽  
Cancer Therapies ◽  
Ppar Agonists ◽  
Expression And Activity

Peroxisome-proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that exert in the liver a transcriptional activity regulating a whole spectrum of physiological functions, including cholesterol and bile acid homeostasis, lipid/glucose metabolism, inflammatory responses, regenerative mechanisms, and cell differentiation/proliferation. Dysregulations of the expression, or activity, of specific PPAR isoforms in the liver are therefore believed to represent critical mechanisms contributing to the development of hepatic metabolic diseases, disorders induced by hepatic viral infections, and hepatocellular adenoma and carcinoma. In this regard, specific PPAR agonists have proven to be useful to treat these metabolic diseases, but for cancer therapies, the use of PPAR agonists is still debated. Interestingly, in addition to previously described mechanisms regulating PPARs expression and activity, microRNAs are emerging as new important regulators of PPAR expression and activity in pathophysiological conditions and therefore may represent future therapeutic targets to treat hepatic metabolic disorders and cancers. Here, we reviewed the current knowledge about the general roles of the different PPAR isoforms in common chronic metabolic and infectious liver diseases, as well as in the development of hepatic cancers. Recent works highlighting the regulation of PPARs by microRNAs in both physiological and pathological situations with a focus on the liver are also discussed.

scholarly journals Infections in Patients with Lymphoproliferative Diseases Treated with Target Therapy. Italian Multicentric Retrospective Study Seifem 2017

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4164-4164 ◽  
Author(s):  
Gianpaolo Nadali ◽  
Gessica Marchesini ◽  
Davide Facchinelli ◽  
Francesca Farina ◽  
Maria Chiara Tisi ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Board Of Directors ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Life Experience ◽  
Cell Lymphoma ◽  
Real Life ◽  
P Value ◽  
Advisory Committees ◽  
Tract Infections

Abstract Introduction: in the last 5 years new "target drugs" to treat lymphoproliferative disorders have been introduced in clinical practice, such as monoclonal antibodies (obinutuzumab, ofatumumab, brentuximab), BTK inhibitors (ibrutinib) and PI3K inhibitors (idelalisib). Efficacy and safety of these drugs were assessed in registrative trials and data regarding infectious complications in the "real life" experience are currently unavailable. We aimed to assess the incidence of major infections in patients treated with the above mentioned drugs. Methods: 555 patients were treated, for registered indications, with idelalisib, ibrutinib, brentuximab, ofatumumab and obinutuzumab (single agents or in combination as licensed) in 13 hematology centres in Italy, from time of their commercial availability to December 2016. The observation period was one year after study entry. Patients in clinical trials or treated within patient named programs were excluded as well as patients with active infections at beginning of treatment. Results: in 132/555 patients (24%) infections occurred for a total number of 187 events, 56% of whom were of grade 3. The median age was 64 years (range 20-86), 46,2% (61/132) of patients were treated with 3 or more previous lines of therapy, 55/132 (42%) experienced 2 or more infective episodes. A bacterial cause of infection was reported in 35% of cases, viral in 22% and an invasive fungal infection (IFI) in 9% (17/187). In 2% of cases the infection was of mixed origin (bacterial/viral or bacterial/fungal) while in 32% of cases there was not microbiological documentation. The lower respiratory tract was the most frequent site of infection in 39% of cases (73/187) while the upper respiratory tract was involved in 30% of events (39/187). The urinary tract infections were 13% (24/187). Other sites involved were skin and soft tissue 7%, sepsis 7%, gastrointestinal site 5%, central nervous system 2% and fever of unknown origin 6%. Patients treated with idelalisib were 106 (80% affected by chronic lymphocytic leukemia - CLL- and 20% follicular lymphoma) and 35 (33%) experienced one ore more infections for a total of 49 episodes. The incidence of bacterial infections was 37%, of viral infections 37% and of IFI 6%. In 235 patients treated with ibrutinib, 70 (30%) had one ore more events for a total of 102 infective episodes. 60/70 (86%) patients had CLL and 10/70 (14%) had indolent or mantle cell lymphoma The incidence of bacterial infections was 50%, viral 20% and IFI 16%. Focusing on IFI, 17 events were reported in 15 patients. According to the EORTC criteria, 11 cases (4 possible, 1 probable, 6 proven) were reported in patients treated with ibrutinib, 3 cases of possible IFI in patients treated with idelalisib and 3 cases of proven IFI in patients treated with brentuximab. The incidence of IFI in patients treated with ibrutinib (11/102 events) and idelalisib (3/49 events) was not different (11% vs. 6% respectively; p-value = 0.55) even considering proven/probable cases only (3% in ibrutinib vs. 0% in idelalisib p-value = 0.11). The incidence of bacterial infections in patients treated with ibrutinib (35/102) was not statistically different compared to patients treated with idelalisib (18/49) (34% vs. 37% respectively p-value =0.87). Noteworthy, the incidence of viral infections in patients treated with idelalisib (18/49) was significantly higher compared to patients treated with ibrutinib (14/102) (37% vs. 14% respectively; p-value =0.015). Brentuximab was used in 175 patients, 70% of cases for Hodgkin Lymphoma and 30% for T cell lymphoma. The rate of infections was 11% for a total of 27 infection episodes. The incidence of bacterial, viral and fungal infections was 37%, 30% and 11% respectively. In 22% of cases the cause of infection could not be established. Patients treated with ofatumumab or obinutuzumab were 39 and in 7/39 (18%) an infective episode was reported (four of bacterial origin, one viral and four undetermined). All patients were affected by CLL. Conclusions: this "real life" experience confirm that the incidence of infections in patients treated with "target drugs" is not negligible. Ongoing analysis that take into account patient's clinical and demographical characteristics, may give insights on risk factors that will contribute to better characterizing patients at different risk levels. Figure. Figure. Disclosures Cattaneo: GILEAD: Other: Advisory Board. Candoni:Pfizer: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Merck SD: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau. Fanci:Gilead: Honoraria; Pfizer Pharmaceuticals: Honoraria; Merck: Consultancy, Honoraria, Speakers Bureau. Del Principe:Gilead: Membership on an entity's Board of Directors or advisory committees. Busca:Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merk: Honoraria, Speakers Bureau; Pfizer Pharmaceuticals: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria; Novartis: Speakers Bureau.

Neopterin as a marker of inflammation

2015 ◽  
Vol 51 (2) ◽  
pp. 153-156
Author(s):  
Magdalena Bartold ◽  
Joanna Matowicka-Karna
Keyword(s):  
Blood Serum ◽  
Human Body ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Immunological Response ◽  
Body Fluids ◽  
Parasitic Infections ◽  
Specific Marker ◽  
Neopterin Concentration ◽  
Living Bacteria

Neopterin is a non-specific marker of immunological response of human body of cellular type. It belongs to the chemical group known as pteridines. Neopterin has been widely associated with inter alia viral infections, bacterial infections (by intracellular living bacteria), parasitic infections, skin burns or autoimmune diseases. Neopterin is a very important parameter diagnostically not only in diagnosis and monitoring of treatment but also a reliable indicator of macrophages’ activity. Most frequently neopterin concentration is measured in body fluids like blood, serum or urine, but it may be used as an indicator in other body fluids.

scholarly journals Mast Cell Responses to Viruses and Pathogen Products

2019 ◽  
Vol 20 (17) ◽  
pp. 4241 ◽  
Author(s):  
Jean S. Marshall ◽  
Liliana Portales-Cervantes ◽  
Edwin Leong
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Immune Responses ◽  
Viral Infection ◽  
Viral Infections ◽  
Inflammatory Responses ◽  
Local Source ◽  
Type I ◽  
Viral Challenge ◽  
Cell Responses

Mast cells are well accepted as important sentinel cells for host defence against selected pathogens. Their location at mucosal surfaces and ability to mobilize multiple aspects of early immune responses makes them critical contributors to effective immunity in several experimental settings. However, the interactions of mast cells with viruses and pathogen products are complex and can have both detrimental and positive impacts. There is substantial evidence for mast cell mobilization and activation of effector cells and mobilization of dendritic cells following viral challenge. These cells are a major and under-appreciated local source of type I and III interferons following viral challenge. However, mast cells have also been implicated in inappropriate inflammatory responses, long term fibrosis, and vascular leakage associated with viral infections. Progress in combating infection and boosting effective immunity requires a better understanding of mast cell responses to viral infection and the pathogen products and receptors we can employ to modify such responses. In this review, we outline some of the key known responses of mast cells to viral infection and their major responses to pathogen products. We have placed an emphasis on data obtained from human mast cells and aim to provide a framework for considering the complex interactions between mast cells and pathogens with a view to exploiting this knowledge therapeutically. Long-lived resident mast cells and their responses to viruses and pathogen products provide excellent opportunities to modify local immune responses that remain to be fully exploited in cancer immunotherapy, vaccination, and treatment of infectious diseases.

scholarly journals Mechanisms of Mixed Th1/Th2 Responses in Mice Induced by Albizia julibrissin Saponin Active Fraction by in Silico Analysis

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Jing Du ◽  
Junjie Jin ◽  
Juanjuan Wang ◽  
Hongxiang Sun
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
In Silico Analysis ◽  
Active Fraction ◽  
Adaptive Immune Responses ◽  
Adjuvant Activity ◽  
Albizia Julibrissin ◽  
Adaptive Immune ◽  
Flight Mass Spectrometry ◽  
Th2 Responses

The purified active fraction of Albizia julibrissin saponin (AJSAF) is an ideal adjuvant candidate that improves antigen-specific both cellular and humoral immune responses and elicits mixed Th1/Th2 responses, but its mechanisms remain unclear. The key features of action of AJSAF were investigated in mice immunized with Newcastle disease virus-based recombinant influenza vaccine (rL-H5) and AJSAF at the same leg (AJSAF+rL-H5) or different legs (AJSAF/rL-H5). The adjuvant activity of AJSAF on rL-H5 is strictly dependent on their spatial colocalization. Serum H5 antigen (H5Ag)-specific IgG, IgG1, IgG2a, and IgG2b antibody titers in AJSAF+rL-H5 group were significantly higher than those in AJSAF/rL-H5 group. The mechanisms of selectivity of Th1 or Th2 in mice induced by AJSAF was explored by the transcriptomic and proteomic profiles of H5Ag-stimulated splenocytes from the immunized mice using gene microarray and two-dimensional difference gel electrophoresis coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared to rL-H5 alone, AJSAF/rL-H5 induced more differentially expressed genes (DEGs) than AJSAF+rL-H5, whereas AJSAF+rL-H5 upregulated higher mRNA expression of Th1 (T-bet, IFN-γ, TNF-α, IL-12β, and IL-12Rβ1) and Th2 (IL-10 and AICDA) immune response genes. The neutrophil response and its derived S100A8 and S100A9 might be involved in the AJSAF-mediated Th1 response. Meanwhile, AJSAF might induce the adaptive immune responses by improving a local innate immune microenvironment. These findings expanded the current knowledge on the mechanisms of action of saponin-based adjuvants, and provided new insights into how adjuvants shape adaptive immune responses.

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