Recent advances in understanding basophil functions in vivo

Circulating Basophils as a Prognostic Marker for Response to Bacillus Calmette-Guérin

PURPOSE

To predict recurrence and progression in non-muscle-invasive bladder cancer (NMIBC) patients receiving bacillus Calmette-Guérin (BCG), we evaluated circulating basophils as a biomarker that could be detected from the complete blood count.

PATIENTS AND METHODS

We use a pooled cohort of patients from the Centre Hospitalier Universitaire de Québec-Université Laval (2016-2020) and the Vancouver General Hospital (2010-2018) where a complete blood count was available before transurethral resection of bladder tumor (TURBT) of a high-grade NMIBC and subsequent BCG. Descriptive statistics described the cohort based on the dichotomous presence or absence of basophils on the complete blood count. Kaplan-Meier estimates and a log-rank test compared recurrence-free survival (RFS) and progression-free survival (PFS), with multivariable cox regression analysis used to estimate proportional hazard ratios.

RESULTS

The study cohort included 261 patients, with a median follow-up of 31.5 months (interquartile range 18.1-45.0 months). The median age was 74.0 years and 16.8% were female. Circulating basophils were detectable in 49 (18.9%) patients. Both RFS and PFS were significantly lower in patients with detectable basophils. Multivariable analysis demonstrated detectable basophils were an independent predictor of both recurrence (HR = 1.85; 95% confidence interval [CI] 1.20-2.85; P = .01) and progression (HR = 2.29; 95% CI 1.14-4.60; P = .02).

CONCLUSION

Our results confirm that baseline levels of circulating basophils are an immunological biomarker to predict recurrence and progression of NMIBC.

Use of red grape pomace and Aloe vera gel as nutraceuticals to ameliorate stocking density-induced stress in commercial male broilers

The combined effect of Aloe vera gel (AVG) administered through drinking water and dietary red grape pomace powder (RGP) on growth performance, physiological traits, welfare indicators, and meat quality in densely stocked broilers was evaluated. A total of 750, two-week-old male Ross 308 broilers (317.7 ± 10.12 g live weight) were randomly assigned to 25 cages, with each cage as an experimental unit. The broilers were stocked at a density of 30 birds per cage with a floor space of 1.32 m2. Dietary treatments were a standard grower or finisher diet (CON); CON containing 30 g RGP /kg diet plus either 1 (GPA1), 2 (GPA2), 3 (GPA3), or 4% (GPA4) AVG in drinking water. Treatment GPA1 promoted higher (P < 0.05) overall weight gain and overall feed conversion ratio (FCR) than CON. Positive quadratic effects (P < 0.05) were noted for mean corpuscular hemoglobin, basophils, 24-hour breast meat yellowness, chroma, and hue angle. The GPA2 group had the lowest (P < 0.05) gait score while the CON group had the highest score. Concurrent supplementation with a 30 g RGP /kg diet plus 1% AVG in drinking water enhanced weight gain, FCR, and finisher weight of densely stocked broilers. However, AVG doses beyond 1% did not enhance performance and physiological traits in densely stocked broilers.

Granulocyte development, tissue recruitment, and function during allergic inflammation

Granulocytes provide a fast innate response to pathogens and allergens. In allergy and anti-helminth immunity, epithelial cells of damaged barriers release alarmins like IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) but also chemokines like CXCL1 or CCL11 to promote cell recruitment and inflammation. In addition, mast cells positioned at barrier tissue sites also quickly release mediators upon specifically sensing antigens through IgE bound to FcεR1 on their surface. Released mediators induce the recruitment of different granulocytes in a timely ordered manner. First, neutrophils extravasate from the blood vasculature to the side of alarmin release and promote a potent inflammatory response. Alarmins and activated mast cells further promote activation of ILC2s and recruitment of basophils and eosinophils, which inhibit neutrophil recruitment and enhance tissue type 2 immunity. In addition to their potent pro-inflammatory effector functions, granulocytes can also contribute to termination and resolution of inflammation. Here, we summarize the development and tissue recruitment of granulocyte subsets, and describe general effector functions and aspects of their increasingly appreciated role in limiting tissue damage. We further discuss targeting approaches for therapeutic interventions in allergic disorders.

Basophils control T cell priming through soluble mediators rather than antigen presentation

Basophils play an important role in the development of type 2 immunity and have been linked to protective immunity against parasites but also inflammatory responses in allergic diseases. While typically classified as degranulating effector cells, different modes of cellular activation have been identified, which together with the observation that different populations of basophils exist in the context of disease suggest a multifunctional role. In this review we aim to highlight the role of basophils play in antigen presentation of type 2 immunity and focus on the contribution basophils play in the context of antigen presentation and T cell priming. We will discuss evidence suggesting that basophils perform a direct role in antigen presentation and relate it to findings that indicate cellular cooperation with professional antigen-presenting cells, such as dendritic cells. We will also highlight tissue-specific differences in basophil phenotypes that might lead to distinct roles in cellular cooperation and how these distinct interactions might influence immunological and clinical outcomes of disease. This review thus aims to consolidate the seemingly conflicting literature on the involvement of basophils in antigen presentation and tries to find a resolution to the discussion whether basophils influence antigen presentation through direct or indirect mechanisms.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Basophil Depletion Alters Host Immunity, Intestinal Permeability, and Mammalian Host-to-Mosquito Transmission in Malaria

Malaria-induced bacteremia has been shown to result from intestinal mast cell (MC) activation. The appearance of MCs in the ileum and increased intestinal permeability to enteric bacteria are preceded by an early Th2-biased host immune response to infection, characterized by the appearance of IL-4, IL-10, mast cell protease (Mcpt)1 and Mcpt4, and increased circulating basophils and eosinophils. Given the functional similarities of basophils and MCs in the context of allergic inflammation and the capacity of basophils to produce large amounts of IL-4, we sought to define the role of basophils in increased intestinal permeability, in MC influx, and in the development of bacteremia in the context of malaria. Upon infection with nonlethal Plasmodium yoelii yoelii 17XNL, Basoph8 × ROSA-DTα mice or baso (-) mice that lack basophils exhibited increased intestinal permeability and increased ileal MC numbers, without any increase in bacterial 16S ribosomal DNA copy numbers in the blood, relative to baso (+) mice. Analysis of cytokines, chemokines, and MC-associated factors in the ileum revealed significantly increased TNF-α and IL-13 at day 6 postinfection in baso (-) mice compared with baso (+) mice. Moreover, network analysis of significantly correlated host immune factors revealed profound differences between baso (-) and baso (+) mice following infection in both systemic and ileal responses to parasites and translocated bacteria. Finally, basophil depletion was associated with significantly increased gametocytemia and parasite transmission to Anopheles mosquitoes, suggesting that basophils play a previously undescribed role in controlling gametocytemia and, in turn, mammalian host-to-mosquito parasite transmission.

Deciphering the Interdependent Labyrinth between Gut Microbiota and the Immune System

The human gut microbiome interacts with each other and the host, which has significant effects on health and disease development. Intestinal homeostasis and inflammation are maintained by the dynamic interactions between gut microbiota and the innate and adaptive immune systems. Numerous metabolic products produced by the gut microbiota play a role in mediating cross-talk between gut epithelial and immune cells. In the event of an imbalance between the immune system and microbiota, the body becomes susceptible to infections, and homeostasis is compromised. This review mainly focuses on the interplay between microbes and the immune system, such as, T-cell and B-cell mediated adaptive responses to microbiota and signaling pathways for effective communication between the two. We have also highlighted the role of microbes in the activation of the immune response, the development of memory cells, and how the immune system determines the diversity of human gut microbiota. The review also explains the relationship of commensal microbiota and their relation in the production of immunoglobulins.

A cardioimmunologist's toolkit: genetic tools to dissect immune cells in cardiac disease

Cardioimmunology is a field that encompasses the immune cells and pathways that modulate cardiac function in homeostasis and regulate the temporal balance between tissue injury and repair in disease. Over the past two decades, genetic fate mapping and high-dimensional sequencing techniques have defined increasing functional heterogeneity of innate and adaptive immune cell populations in the heart and other organs, revealing a complexity not previously appreciated and challenging established frameworks for the immune system. Given these rapid advances, understanding how to use these tools has become crucial. However, cardiovascular biologists without immunological expertise might not be aware of the strengths and caveats of immune-related tools and how they can be applied to examine the pathogenesis of myocardial diseases. In this Review, we guide readers through case-based examples to demonstrate how tool selection can affect data quality and interpretation and we provide critical analysis of the experimental tools that are currently available, focusing on their use in models of ischaemic heart injury and heart failure. The goal is to increase the use of relevant immunological tools and strategies among cardiovascular researchers to improve the precision, translatability and consistency of future studies of immune cells in cardiac disease.

IL-3 in the development and function of basophils

The β common chain (βc) cytokine family includes granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) and IL-5, all of which use βc as key signaling receptor subunit. GM-CSF, IL-3 and IL-5 have specific roles as hematopoietic growth factors. IL-3 binds with high affinity to the IL-3 receptor α (IL-3Rα/CD123) and then associates with the βc subunit. IL-3 is mainly synthesized by different subsets of T cells, but is also produced by several other immune [basophils, dendritic cells (DCs), mast cells, etc.] and non-immune cells (microglia and astrocytes). The IL-3Rα is also expressed by immune (basophils, eosinophils, mast cells, DCs, monocytes, and megacaryocytes) and non-immune cells (endothelial cells and neuronal cells). IL-3 is the most important growth and activating factor for human and mouse basophils, primary effector cells of allergic disorders. IL-3-activated basophils and mast cells are also involved in different chronic inflammatory disorders, infections, and several types of cancer. IL-3 induces the release of cytokines (i.e., IL-4, IL-13, CXCL8) from human basophils and preincubation of basophils with IL-3 potentiates the release of proinflammatory mediators and cytokines from IgE- and C5a-activated basophils. IL-3 synergistically potentiates IL-33-induced mediator release from human basophils. IL-3 plays a pathogenic role in several hematologic cancers and may contribute to autoimmune and cardiac disorders. Several IL-3Rα/CD123 targeting molecules have shown some efficacy in the treatment of hematologic malignancies.

Basophils and their effector molecules in allergic disorders

Basophils are the rarest granulocytes which represent <1% of peripheral blood leukocytes. Basophils bear several phenotypic similarities to tissue-resident mast cells and therefore had been erroneously considered as blood-circulating mast cells. However, recent researches have revealed that basophils play nonredundant roles in allergic inflammation, protective immunity against parasitic infections and regulation of innate and acquired immunity. Basophils are recruited to inflamed tissues and activated in an IgE-dependent or IgE-independent manner to release a variety of effector molecules. Such molecules, including IL-4, act on various types of cells and play versatile roles, including the induction and termination of allergic inflammation and the regulation of immune responses. Recent development of novel therapeutic agents has enabled us to gain further insights into basophil biology in human disorders. In this review, we highlight the recent advances in the field of basophil biology with a particular focus on the role of basophils in allergic inflammation. Further studies on basophils and their effector molecules will help us identify novel therapeutic targets for treating allergic disorders.

Behind the scenes with basophils: an emerging therapeutic target

Though basophils were originally viewed as redundant blood ‘mast cells’, the implementation of flow cytometry has established basophils as unique leukocytes with critical immunomodulatory functions. Basophils play an active role in allergic inflammation, autoimmunity, and hematological malignancies. They are distinguishable from other leukocytes by their characteristic metachromatic deep-purple cytoplasmic, round granules. Mature basophils are phenotypically characterized by surface expression of IL-3Rα (CD123); IL-3 drives basophil differentiation, degranulation, and synthesis of inflammatory mediators including type 2 cytokines. Basophil degranulation is the predominant source of histamine in peripheral blood, promoting allergic responses. Basophils serve as a bridge between innate and adaptive immunity by secreting IL-4 which supports eosinophil migration, monocyte differentiation into macrophages, B-cell activation, and CD4 T-cell differentiation into Th2 cells. Further, basophilia is a key phenomenon in myeloid neoplasms, especially chronic myeloid leukemia (CML) for which it is a diagnostic criterion. Increased circulating basophils, often with aberrant immunophenotype, have been detected in patients with CML and other myeloproliferative neoplasms (MPNs). The significance of basophils’ immunoregulatory functions in malignant and non-malignant diseases is an active area of research. Ongoing and future research can inform the development of immunotherapies that target basophils to impact allergic, autoimmune, and malignant disease states. This review article aims to provide an overview of basophil biology, identification strategies, and roles and dysregulation in diseases.

The Role of Trogocytosis in the Modulation of Immune Cell Functions

Trogocytosis is an active process, in which one cell extracts the cell fragment from another cell, leading to the transfer of cell surface molecules, together with membrane fragments. Recent reports have revealed that trogocytosis can modulate various biological responses, including adaptive and innate immune responses and homeostatic responses. Trogocytosis is evolutionally conserved from protozoan parasites to eukaryotic cells. In some cases, trogocytosis results in cell death, which is utilized as a mechanism for antibody-dependent cytotoxicity (ADCC). In other cases, trogocytosis-mediated intercellular protein transfer leads to both the acquisition of novel functions in recipient cells and the loss of cellular functions in donor cells. Trogocytosis in immune cells is typically mediated by receptor–ligand interactions, including TCR–MHC interactions and Fcγ receptor-antibody-bound molecule interactions. Additionally, trogocytosis mediates the transfer of MHC molecules to various immune and non-immune cells, which confers antigen-presenting activity on non-professional antigen-presenting cells. In this review, we summarize the recent advances in our understanding of the role of trogocytosis in immune modulation.

Basophils, a neglected minority in the immune system, have come into the limelight at last

Basophils, the rarest granulocytes, were identified by Paul Ehrlich more than 140 years ago, much earlier than the discovery of T and B cells. Unfortunately, basophils were often mixed up with tissue-resident mast cells because of some phenotypic similarities between them and considered erroneously as minor relatives or blood-circulating precursors of mast cells. Moreover, basophil research was hindered by the rarity of basophils and the paucity of useful analytical tools, and therefore basophils had often been neglected in immunological studies. A series of studies using newly developed tools, including basophil-depleting antibodies and genetically engineered mice deficient only in basophils, have clearly defined previously unrecognized roles of basophils, that are distinct from those played by tissue-resident mast cells. In this mini-review, we highlight recent advances in our understanding of basophil functions, particularly focusing on their roles in the regulation of innate and acquired immunity, allergic reactions, autoimmunity and protective immunity against parasitic infections, mainly based on animal studies. Further studies on human basophils would facilitate the development of new strategies for the treatment of basophil-associated disorders.

The Interplay between Oxidative Stress, Inflammation and Angiogenesis in Bladder Cancer Development

In 2018, 550,000 people were diagnosed with bladder cancer (BC), of which nearly 200,000 people died. Moreover, men are 4 times more likely than women to be diagnosed with BC. The risk factors include exposure to environmental and occupational chemicals, especially tobacco smoke, benzidine and genetic factors. Despite numerous studies, the molecular basis of BC development remains unclear. A growing body of evidence suggests that inflammation, oxidant-antioxidant imbalance and angiogenesis disorders may play a significant role in the development and progression of bladder cancer. The patients with bladder cancer were characterised by an increased level of reactive oxygen species (ROS), the products of lipid peroxidation, proinflammatory cytokines and proangiogenic factors as compared to controls. Furthermore, it was shown that polymorphisms localised in genes associated with these pathways may modulate the risk of BC. Interestingly, ROS overproduction may induce the production of proinflammatory cytokines, which finally activated angiogenesis. Moreover, the available literature shows that both inflammation and oxidative stress may lead to activation of angiogenesis and tumour progression in BC patients.

A basophil-neuronal axis promotes itch

Itch is an evolutionarily conserved sensation that facilitates expulsion of pathogens and noxious stimuli from the skin. However, in organ failure, cancer, and chronic inflammatory disorders such as atopic dermatitis (AD), itch becomes chronic, intractable, and debilitating. In addition to chronic itch, patients often experience intense acute itch exacerbations. Recent discoveries have unearthed the neuroimmune circuitry of itch, leading to the development of anti-itch treatments. However, mechanisms underlying acute itch exacerbations remain overlooked. Herein, we identify that a large proportion of patients with AD harbor allergen-specific immunoglobulin E (IgE) and exhibit a propensity for acute itch flares. In mice, while allergen-provoked acute itch is mediated by the mast cell-histamine axis in steady state, AD-associated inflammation renders this pathway dispensable. Instead, a previously unrecognized basophil-leukotriene (LT) axis emerges as critical for acute itch flares. By probing fundamental itch mechanisms, our study highlights a basophil-neuronal circuit that may underlie a variety of neuroimmune processes.

IgE and IgG Antibodies as Regulators of Mast Cell and Basophil Functions in Food Allergy

Food allergy is a major health issue, affecting the lives of 8% of U.S. children and their families. There is an urgent need to identify the environmental and endogenous signals that induce and sustain allergic responses to ingested allergens. Acute reactions to foods are triggered by the activation of mast cells and basophils, both of which release inflammatory mediators that lead to a range of clinical manifestations, including gastrointestinal, cutaneous, and respiratory reactions as well as systemic anaphylaxis. Both of these innate effector cell types express the high affinity IgE receptor, FcϵRI, on their surface and are armed for adaptive antigen recognition by very-tightly bound IgE antibodies which, when cross-linked by polyvalent allergen, trigger degranulation. These cells also express inhibitory receptors, including the IgG Fc receptor, FcγRIIb, that suppress their IgE-mediated activation. Recent studies have shown that natural resolution of food allergies is associated with increasing food-specific IgG levels. Furthermore, oral immunotherapy, the sequential administration of incrementally increasing doses of food allergen, is accompanied by the strong induction of allergen-specific IgG antibodies in both human subjects and murine models. These can deliver inhibitory signals via FcγRIIb that block IgE-induced immediate food reactions. In addition to their role in mediating immediate hypersensitivity reactions, mast cells and basophils serve separate but critical functions as adjuvants for type 2 immunity in food allergy. Mast cells and basophils, activated by IgE, are key sources of IL-4 that tilts the immune balance away from tolerance and towards type 2 immunity by promoting the induction of Th2 cells along with the innate effectors of type 2 immunity, ILC2s, while suppressing the development of regulatory T cells and driving their subversion to a pathogenic pro-Th2 phenotype. This adjuvant effect of mast cells and basophils is suppressed when inhibitory signals are delivered by IgG antibodies signaling via FcγRIIb. This review summarizes current understanding of the immunoregulatory effects of mast cells and basophils and how these functions are modulated by IgE and IgG antibodies. Understanding these pathways could provide important insights into innovative strategies for preventing and/or reversing food allergy in patients.

Immunobiology of Acquired Resistance to Ticks

Ticks are blood-sucking arthropods of great importance in the medical and veterinary fields worldwide. They are considered second only to mosquitos as vectors of pathogenic microorganisms that can cause serious infectious disorders, such as Lyme borreliosis and tick-borne encephalitis. Hard (Ixodid) ticks feed on host animals for several days and inject saliva together with pathogens to hosts during blood feeding. Some animal species can acquire resistance to blood-feeding by ticks after a single or repeated tick infestation, resulting in decreased weights and numbers of engorged ticks or the death of ticks in subsequent infestations. Importantly, this acquired tick resistance (ATR) can reduce the risk of pathogen transmission from pathogen-infected ticks to hosts. This is the basis for the development of tick antigen-targeted vaccines to forestall tick infestation and tick-borne diseases. Accumulation of basophils is detected in the tick re-infested skin lesion of animals showing ATR, and the ablation of basophils abolishes ATR in mice and guinea pigs, illustrating the critical role for basophils in the expression of ATR. In this review article, we provide a comprehensive overview of recent advances in our understanding of the cellular and molecular mechanisms responsible for the development and manifestation of ATR, with a particular focus on the role of basophils.

Salmonid Antibacterial Immunity: An Aquaculture Perspective

The aquaculture industry is continuously threatened by infectious diseases, including those of bacterial origin. Regardless of the disease burden, aquaculture is already the main method for producing fish protein, having displaced capture fisheries. One attractive sector within this industry is the culture of salmonids, which are (a) uniquely under pressure due to overfishing and (b) the most valuable finfish per unit of weight. There are still knowledge gaps in the understanding of fish immunity, leading to vaccines that are not as effective as in terrestrial species, thus a common method to combat bacterial disease outbreaks is the use of antibiotics. Though effective, this method increases both the prevalence and risk of generating antibiotic-resistant bacteria. To facilitate vaccine design and/or alternative treatment efforts, a deeper understanding of the teleost immune system is essential. This review highlights the current state of teleost antibacterial immunity in the context of salmonid aquaculture. Additionally, the success of current techniques/methods used to combat bacterial diseases in salmonid aquaculture will be addressed. Filling the immunology knowledge gaps highlighted here will assist in reducing aquaculture losses in the future.

Heterogeneity in the initiation, development and function of type 2 immunity

Type 2 immune responses operate under varying conditions in distinct tissue environments and are crucial for protection against helminth infections and for the maintenance of tissue homeostasis. Here we explore how different layers of heterogeneity influence type 2 immunity. Distinct insults, such as allergens or infections, can induce type 2 immune responses through diverse mechanisms, and this can have heterogeneous consequences, ranging from acute or chronic inflammation to deficits in immune regulation and tissue repair. Technological advances have provided new insights into the molecular heterogeneity of different developmental lineages of type 2 immune cells. Genetic and environmental heterogeneity also contributes to the varying magnitude and quality of the type 2 immune response during infection, which is an important determinant of the balance between pathology and disease resolution. Hence, understanding the mechanisms underlying the heterogeneity of type 2 immune responses between individuals and between different tissues will be crucial for treating diseases in which type 2 immunity is an important component.

Analysis of Biochemical Parameters in Children with Chronic Tonsillitis

Chronic tonsillitis are frequent in pediatric pathology with numerous involved risk factors and pathogenic mechanisms. In this study, epidemiological data and biochemical values addressed to inflammation and mineral, lipid and hepatic metabolism were analyzed for 37 children of school age with chronic tonsillitis. We found that in the majority of cases, chronic tonsillitis was associated with increasing number of blood circulating inflammatory cells, high values of transaminases, cholesterol, triglycerides and low values of procalcitonin, C-reactive protein, calcium, vitamin D and serum iron. The results indicated relations of the biochemical profile analyzed with risk factors and systemic mechanisms for initiation and maintenance of chronic tonsillitis, aspects that can be used to optimize the prognosis of chronic tonsillitis in children.

Use of Neutrophil, Eosinophil, Basophil, and Platelet to Lymphocyte Ratio to Predict Patient Satisfaction After Septoplasty Plus Inferior Turbinate Reduction

AIM

Investigation of the predictive value of neutrophil, platelet, eosinophil, and basophil to lymphocyte ratio (NLR, PLR, ELR, and BLR) in evaluation of patients' satisfaction of septoplasty + inferior turbinate reduction operations.

PATIENTS AND METHODS

Seventy-six patients who were operated because of nasal obstruction were enrolled in the study. They were invited to the hospital and asked to answer a modified nasal obstruction symptom evaluation (NOSE) survey to determine their degree of satisfaction. Patients were divided into 2 groups according to their modified NOSE survey results, dissatisfied and satisfied groups. The 2 groups were compared in terms of demographic data, surgery, and hematological values. In addition, correlation analysis was performed between NLR, PLR, ELR, BLR, and modified NOSE scores.

RESULTS

There were 29 patients in the dissatisfied group and 47 patients in the satisfied group. Both groups were similar in terms of mean age, gender, surgery type, septal deviation type, smoking, hemoglobin, neutrophil, and white blood count (P > 0.05). There were significant differences between the 2 groups in terms of ELR and BLR (P < 0.05). In addition, there were negative and statistically significant correlations between modified NOSE scores and ELR and BLR. As ELR and BLR values increased, the satisfaction rate decreased.

CONCLUSION

Eosinophil to lymphocyte ratio and BLR could be used to predict patient satisfaction after septoplasty and inferior turbinate reduction and for selection of patients.

The regenerative potential of skin and the immune system

Skin has the natural ability to heal and replace dead cells regulated by a network of complex immune processes. This ability is conferred by the population of resident immune cells that act in coordination with other players to provide a homeostatic environment under constant challenge. Other than providing structure and integrity, the epidermis and dermis also house distinct immune properties. The dermal part is represented by fibroblasts and endothelial cells followed by an array of immune cells which includes dendritic cells (DCs), macrophages, mast cells, NK-cells, neutrophils, basophils, eosinophils, αβ T lymphocytes, B-cells and platelets. On the other hand, the functionally active immune cells in the epidermis comprise keratinocytes, DCs, NKT-cells, γδ T cells and αβ T cells (CD4+ and CD8+). Keratinocytes create a unique microenvironment for the cells of the immune system by promoting immune recognition and cellular differentiation. T lymphocytes exhibit tissue-specific tropism toward the epidermis and the lymphatic drainage system important for their function in immune regulation. This diversity in immune regulators makes the skin a unique organ to overcome pathogenic or foreign invasion. In addition, the highly coordinated molecular events make the skin an attractive model to understand and explore its regenerative potential.

Absolute basophil count is associated with time to recurrence in patients with high-grade T1 bladder cancer receiving bacillus Calmette-Guérin after transurethral resection of the bladder tumor

BACKGROUND

Basophils, eosinophils and monocytes may be involved in BCG-induced immune responses and be associated with outcomes of bladder cancer patients receiving intravesical BCG. Our objective was to explore the association of baseline counts of basophils, eosinophils and monocytes with outcomes of patients with high-grade T1 bladder cancer receiving a standard course of intravesical BCG.

METHODS

We retrospectively reviewed medical records of patients with primary T1 HG/G3 bladder cancer. After re-TURBT, patients were treated with a 6-week course of intravesical BCG induction followed by intravesical BCG every week for 3 weeks given at 3, 6, 12, 18, 24, 30 and 36 months from initiation of therapy The analysis of potential risk factors for recurrence, muscle invasion and cancer-specific and overall survival was performed using univariable Cox regression models. Those factors that presented, at univariate analysis, an association with the event at a liberal p < 0.1, have been selected for the development of a multivariable model.

RESULTS

A total of 1045 patients with primary T1 HG/G3 were included. A total of 678 (64.9%) recurrences, 303 (29.0%) progressions and 150 (14.3%) deaths were observed during follow-up. Multivariate analysis showed that logarithmic transformation of basophils count was associated with a 30% increment in the hazard of recurrence per unit increase of logarithmic basophils count (HR 1.30; 95% confidence interval 1.09-1.54; p = 0.0026). Basophil count modeled by quartiles was also significantly associated with time to recurrence [second vs. lower quartile HR 1.42 (1.12-1.79); p = 0.003, third vs. lower quartile HR 1.26 (1.01-1.57); p = 0.041; upper vs. lower quartile HR 1.36 (1.1-1.68); p = 0.005]. The limitations of a retrospective study are applicable.

CONCLUSION

Baseline basophil count may predict recurrence in BCG-treated HG/G3 T1 bladder cancer patients. External validation is warranted.

The Notch signaling pathway promotes basophil responses during helminth-induced type 2 inflammation

Basophils promote type 2 inflammation that mediates worm clearance during murine infection with the gastrointestinal helminth parasite Trichuris muris. Webb et al. show for the first time that basophil–intrinsic Notch signaling is required for basophil gene expression and a functional program that support helminth expulsion.

Type 2 inflammation drives the clearance of gastrointestinal helminth parasites, which infect over two billion people worldwide. Basophils are innate immune cells that support host-protective type 2 inflammation during murine infection with the helminth Trichuris muris. However, the mechanisms required for basophil function and gene expression regulation in this context remain unclear. We show that during T. muris infection, basophils localized to the intestine and up-regulated Notch receptor expression, rendering them sensitive to Notch signals that rapidly regulate gene expression programs. In vitro, Notch inhibition limited basophil cytokine production in response to cytokine stimulation. Basophil-intrinsic Notch signaling was required for T. muris–elicited changes in genome-wide basophil transcriptional programs. Mice lacking basophil-intrinsic functional Notch signaling had impaired worm clearance, decreased intestinal type 2 inflammation, altered basophil localization in the intestine, and decreased CD4⁺ T helper 2 cell responses following infection. These findings demonstrate that Notch is required for basophil gene expression and effector function associated with helminth expulsion during type 2 inflammation.

Crucial Role for Basophils in Acquired Protective Immunity to Tick Infestation

Ticks are blood-sucking arthropods that can transmit various pathogenic organisms to host animals and humans, causing serious infectious diseases including Lyme disease. Tick feeding induces innate and acquired immune responses in host animals, depending on the combination of different species of animals and ticks. Acquired tick resistance (ATR) can diminish the chance of pathogen transmission from infected ticks to the host. Hence, the elucidation of cellular and molecular mechanism underlying ATR is important for the development of efficient anti-tick vaccines. In this review article, we briefly overview the history of studies on ATR and summarize recent findings, particularly focusing on the role for basophils in the manifestation of ATR. In several animal species, including cattle, guinea pigs, rabbits and mice, basophil accumulation is observed at the tick re-infestation site, even though the frequency of basophils among cellular infiltrates varies in different animal species, ranging from approximately 3% in mice to 70% in guinea pigs. Skin-resident, memory CD4⁺ T cells contribute to the recruitment of basophils to the tick re-infestation site through production of IL-3 in mice. Depletion of basophils before the tick re-infestation abolishes ATR in guinea pigs infested with Amblyomma americanum and mice infested with Haemaphysalis longicornis, demonstrating the crucial role of basophils in the manifestation of ATR. The activation of basophils via IgE and its receptor FcεRI is essential for ATR in mice. Histamine released from activated basophils functions as an important effector molecule in murine ATR, probably through promotion of epidermal hyperplasia which interferes with tick attachment or blood feeding in the skin. Accumulating evidence suggests the following scenario. The 1^st tick infestation triggers the production of IgE against tick saliva antigens in the host, and blood-circulating basophils bind such IgE on the cell surface via FcεRI. In the 2^nd infestation, IgE-armed basophils are recruited to tick-feeding sites and stimulated by tick saliva antigens to release histamine that promotes epidermal hyperplasia, contributing to ATR. Further studies are needed to clarify whether this scenario in mice can be applied to ATR in other animal species and humans.

Basophils are dispensable for the establishment of protective adaptive immunity against primary and challenge infection with the intestinal helminth parasite Strongyloides ratti

Infections with helminth parasites are controlled by a concerted action of innate and adaptive effector cells in the frame of a type 2 immune response. Basophils are innate effector cells that may also contribute to the initiation and amplification of adaptive immune responses. Here, we use constitutively basophil-deficient Mcpt8-Cre mice to analyze the impact of basophils during initiation and execution of the protective type 2 responses to both, a primary infection and a challenge infection of immune mice with the helminth parasite Strongyloides ratti. Basophil numbers expanded during parasite infection in blood and mesenteric lymph nodes. Basophil deficiency significantly elevated intestinal parasite numbers and fecal release of eggs and larvae during a primary infection. However, basophils were neither required for the initiation of a S. ratti-specific cellular and humoral type 2 immune response nor for the efficient protection against a challenge infection. Production of Th2 cytokines, IgG1 and IgE as well as mast cell activation were not reduced in basophil-deficient Mcpt8-Cre mice compared to basophil-competent Mcpt8-WT littermates. In addition, a challenge infection of immune basophil-deficient and WT mice resulted in a comparable reduction of tissue migrating larvae, parasites in the intestine and fecal release of eggs and L1 compared to mice infected for the first time. We have shown previously that S. ratti infection induced expansion of Foxp3+ regulatory T cells that interfered with efficient parasite expulsion. Here we show that depletion of regulatory T cells reduced intestinal parasite burden also in absence of basophils. Thus basophils were not targeted specifically by S. ratti-mediated immune evasive mechanisms. Our collective data rather suggests that basophils are non-redundant innate effector cells during murine Strongyloides infections that contribute to the early control of intestinal parasite burden.

Melanomacrophage functions in the liver of the caecilian Siphonops annulatus

Melanomacrophages are phagocytes that synthesize melanin. They are found in the liver and spleen of ectothermic vertebrates, and in the kidney of fish. In agnathan and elasmobranch fish, melanomacrophages are seen as isolated cells, and forming clusters in all the other vertebrates. The natural phagocytic activity of melanomacrophages is poorly characterized, as most of the research works have focused on induced phagocytic activity only. Furthermore, little is known about amphibian melanomacrophages, mainly about those in caecilians - wormlike amphibians in the order of Gymnophiona, which is the least known group of terrestrial vertebrates. The present research work aimed at the structure and function of hepatic melanomacrophages of Siphonops annulatus, a species largely found in South America. We identified the role of these cells in the control of circulating basophils (pro-melanogenic cells), in the turnover of liver collagen stroma and in the hemocatheresis, interrelated physiological mechanisms.

The role of basophils as innate immune regulatory cells in allergy and immunotherapy

Basophils are circulating cells that are associated quite exclusively with allergy response and hypersensitivity reactions but their role in the immune network might be much more intriguing and complex than previously expected. The feasibility of testing their biology in vitro for allergy research and diagnosis, due fundamentally to their quite easy availability in the peripheral blood, made them the major source for assessing allergy in the laboratory assay, when yet many further cells such as mast cells and eosinophils are much more involved as effector cells in allergy than circulating basophils. Interestingly, basophil numbers change rarely in peripheral blood during an atopic response, while we might yet observe an increase in eosinophils and modification in the biology of mast cells in the tissue during an hypersensitivity response. Furthermore, the fact that basophils are very scanty in numbers suggests that they should mainly serve as regulatory cells in immunity, rather than effector leukocytes, as still believed by the majority of physicians. In this review we will try to describe and elucidate the possible role of these cells, known as "innate IL4-producing cells" in the immune regulation of allergy and their function in allergen immunotherapy.

Antinuclear antibodies in autoimmune and allergic diseases

Antinuclear antibodies (ANA) are primarily significant in the diagnosis of systemic connective tissue diseases. The relationship between their occurrence in allergic diseases is poorly documented. However, the mechanism of allergic and autoimmune diseases has a common thread. In both cases, an increased production of IgE antibodies and presence of ANA in selected disease entities is observed. Equally important is the activation of basophils secreting proinflammatory factors and affecting the differentiation of TH17 lymphocytes. Both autoimmune and allergic diseases have complex multi-pathogenesis and often occur in genetically predisposed individuals. The presence of antinuclear antibodies was confirmed in many systemic connective tissue diseases and some allergic diseases. Examples include atopic dermatitis, non-allergic asthma, and pollen allergy. Co-occurring allergic and autoimmune disorders induce further search for mechanisms involved in the aetiopathogenesis of both groups of diseases.