Eosinophil cell: pray tell us what you do!:

In utero exposure to genistein decreased intranasal house dust mite-induced respiratory allergy in middle-aged male B6C3F1 offspring

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental effects are increasing. To understand if in utero GEN exposure modulated postnatal respiratory allergies in the middle age, we conducted a time course study in the B6C3F1 offspring (PND 240-330) using a common household allergen (house dust mites: HDM; 10 μg/mouse for PND 240 and 290, and 50 μg/mouse for PND 330, a middle age in mice) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20 mg/kg body weight). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly dosings of HDM extracts, and they were euthanized at day 3 following the final HDM exposure. In utero exposure to GEN decreased HDM allergen-induced respiratory allergy in male B6C3F1 offspring at PND 330 as reflected by decreases in airway hyperresponsiveness (e.g., Penh value), HDM-specific IgG₁ (a Th2 type Ab) and the activity of eosinophil peroxidase in the lung (an indication of eosinophil recruitment to the lungs). However, in utero exposure to GEN had minimal effects on HDM allergen-induced respiratory allergy in the middle-aged female offspring. Changes in serum total IgE, HDM-specific IgE, and lung histopathology scores in both male and female offspring were not biologically significant. Overall, in utero GEN exposure exerted a protective effect on respiratory allergy in the middle-aged male, but not female, B6C3F1 offspring following later-life HDM exposures.

In Utero exposure to genistein enhanced intranasal house dust mite allergen-induced respiratory sensitization in young adult B6C3F1 mice

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental immunotoxic effects are increasing. To understand how in utero GEN exposure may modulate postnatal respiratory sensitization, we conducted a time course study using a common household allergen (house dust mites: HDM; 10μg/mouse) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20mg/kg bw). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly doses of HDM extracts, and they were euthanized at day 3 following the final HDM exposure at four different time points (postnatal day (PND) 80, 120, 160, and 200). In utero GEN combined with postnatal HDM exposures (GEN+HDM) increased total IgE production in both young female and male B6C3F1 offspring (e.g., PND 80 in females and PND 120 in males). Increased antigen-specific IgG1, IgG2a and IgG2b levels were also observed at various time points in both female and male offspring. In addition, increases in macrophage number in bronchoalveolar lavage fluid of both female and male GEN+HDM offspring at PND 80 and PND 120, respectively, were observed when compared to the vehicle group. For T cells, an increase over the vehicle in female GEN+HDM offspring was observed at PND 80. Due to similar patterns of increases, it seems likely that GEN+HDM-induced increases in total IgE and macrophages are related. Overall, in utero GEN plus later-life HDM exposures exert increases in total IgE and HDM-specific IgG production as well as macrophage recruitments to the lung in young adult mice.

Until Death Do Us Part: Necrosis and Oxidation Promote the Tumor Microenvironment

Tumor proliferation is concomitant with autophagy, limited apoptosis, and resultant necrosis. Necrosis is associated with the release of damage-associated molecular pattern molecules (DAMPs), which act as 'danger signals', recruiting inflammatory cells, inducing immune responses, and promoting wound healing. Most of the current treatment strategies for cancer (chemotherapy, radiation therapy, hormonal therapy) promote DAMP release following therapy-induced tumor death by necroptosis and necrosis. Myeloid cells (monocytes, dendritic cells (DCs), and granulocytes), as well as mesenchymal stromal cells (MSCs) belong to the early immigrants in response to unscheduled cell death, initiating and modulating the subsequent inflammatory response. Responding to DAMPs, MSCs, and DCs promote an immunosuppressive milieu, while eosinophils induce oxidative conditions limiting the biologic activity of DAMPs over time and distance. Regulatory T cells are strongly affected by pattern recognition receptor signaling in the tumor microenvironment and limit immune reactivity coordinately with myeloid-derived suppressor cells. Means to 'aerobically' oxidize DAMPs provide a novel strategy for limiting tumor progression. The present article summarizes our current understanding of the impact of necrosis on the tumor microenvironment and the influence of oxidative conditions found within this setting.

Histologic features in colon biopsies can discriminate mycophenolate from GVHD-induced colitis

Mycophenolate mofetil (MMF) is a T-cell inhibitor frequently used in the treatment of acute allograft rejection. MMF may cause colitis that clinically and histologically resembles graft-versus-host disease (GVHD). The aim of this study was to evaluate a wide range of histologic features that may help differentiate MMF from GVHD-induced colitis and to validate significant features on a cohort of bone marrow transplant patients who were also taking MMF as part of their immunosuppressive regimen and developed a diarrheal illness due to colitis. Routinely processed colonic biopsies from 17 patients with MMF colitis and 40 patients with GVHD-induced colitis were evaluated for the overall grade of colitis (grades 1 to 4) and histologically for a wide range of inflammatory, epithelial, and architectural changes in a blinded manner. Statistically significant features were then tested in a cohort of 20 bone marrow transplant patients who also received MMF, and later developed a diarrheal illness. Both univariate and multivariate analyses (including receiver operating characteristic analysis) were performed. Morphologic features shown to be independently associated with MMF include the presence and quantity of lamina propria eosinophils and endocrine cell aggregates and the presence and quantity of apoptotic microabscesses, hypereosinophilic (degenerated) crypts, and crypt distortion. Eosinophils were present in all MMF patients, but apoptotic microabscesses were present in none and endocrine cell aggregates in only 1 case. When a grade-by-grade comparison was made between MMF and GVHD, grade 1 or 2 MMF also showed an increased prevalence rate and quantity of lamina propria neutrophils in comparison with grade 1 or 2 GVHD. By receiver operating characteristic analysis, a combination of lamina propria eosinophils >15 per 10 HPF, combined with a lack of endocrine cell aggregates and apoptotic microabscesses, revealed sensitivity, specificity, and positive and negative predictive values of 76%, 93%, 81%, and 90%, respectively, for identification of MMF colitis. On the basis of these data, we conclude that a variety of histologic features, in particular, eosinophils >15 per 10 HPF, lack of endocrine cell aggregates in the lamina propria, and lack of apoptotic microabscesses, can be used by pathologists to help separate MMF from GVHD-induced colitis in routine clinical practice.

Novel basophil- or eosinophil-depleted mouse models for functional analyses of allergic inflammation

Basophils and eosinophils play important roles in various host defense mechanisms but also act as harmful effectors in allergic disorders. We generated novel basophil- and eosinophil-depletion mouse models by introducing the human diphtheria toxin (DT) receptor gene under the control of the mouse CD203c and the eosinophil peroxidase promoter, respectively, to study the critical roles of these cells in the immunological response. These mice exhibited selective depletion of the target cells upon DT administration. In the basophil-depletion model, DT administration attenuated a drop in body temperature in IgG-mediated systemic anaphylaxis in a dose-dependent manner and almost completely abolished the development of ear swelling in IgE-mediated chronic allergic inflammation (IgE-CAI), a typical skin swelling reaction with massive eosinophil infiltration. In contrast, in the eosinophil-depletion model, DT administration ameliorated the ear swelling in IgE-CAI whether DT was administered before, simultaneously, or after, antigen challenge, with significantly lower numbers of eosinophils infiltrating into the swelling site. These results confirm that basophils and eosinophils act as the initiator and the effector, respectively, in IgE-CAI. In addition, antibody array analysis suggested that eotaxin-2 is a principal chemokine that attracts proinflammatory cells, leading to chronic allergic inflammation. Thus, the two mouse models established in this study are potentially useful and powerful tools for studying the in vivo roles of basophils and eosinophils. The combination of basophil- and eosinophil-depletion mouse models provides a new approach to understanding the complicated mechanism of allergic inflammation in conditions such as atopic dermatitis and asthma.

Understanding eosinophilic esophagitis: the cellular and molecular mechanisms of an emerging disease

Eosinophilic esophagitis (EoE) has been increasingly recognized as a unique clinicopathological entity over the past two decades. In this short time, the mechanisms of a complex disease have begun to emerge. Patient studies suggest that EoE is an immunologic disease related to atopy. At the cellular level, eosinophils, mast cells, and B and T lymphocytes are increased in the esophageal mucosa in a patchy distribution throughout the length of the esophagus. Laboratory investigations have implicated aeroallergens, food allergens, and a unique T helper type 2 cytokine profile. EoE appears to be an antigen-driven hypersensitivity reaction characterized by a mixed IgE-dependent/delayed-type reaction and a distinct cascade of cytokines and growth factors. The causative events that lead to EoE in humans remain unknown.

Semen quality in Schistosoma haematobium infected men in Madagascar

The seminal vesicles and the prostate are frequently affected by egg-induced inflammation in Schistosoma haematobium infected men. The objective of this study was to assess the semen quality in men with male genital schistosomiasis (MGS). The examination of the semen samples was performed in men aged 15 to 49 years living an S. haematobium endemic area in Madagascar prior to anti-schistosoma treatment with praziquantel and five months later. Men from the high endemic Sirama sugarcane plantation with positive egg excretion in the urine and circulating anodic antigen (CAA) present in serum (n=85) were compared to men (without egg excretion and no CAA) from the neighbouring low-endemic Mataipako village (n=57). The proportion of men with egg excretion in semen was significantly higher in Sirama than in Mataipako (53% versus 4%), whereas the median ejaculate volume was significantly lower in Sirama (1.8 ml versus 2.4 ml). There was no statistical difference in median spermatocyte counts and in the proportions of men detected with azoospermia. The mean apoptotic rate was 7.8% in a subgroup of 30 men from Sirama. A positive correlation was found between apoptotic rate and seminal eosinophil cationic protein (ECP) level (rho=0.560; P<0.001). At follow up, egg excretion and ECP level in semen declined significantly and were paralleled by a significant reduction in the apoptotic rate. The study suggests that S. haematobium infection is associated with sperm apoptosis and a reduced production of seminal fluid. Egg induced inflammation in the seminal vesicles and the prostate could be underlying mechanism for both observations.

Eosinophilia and first-line coagulation testing

Although eosinophilia (eosinophil count >0.60 x 10(9)/l), is a prothrombotic condition, little is known on the association between eosinophil count in blood and first-line coagulations tests, including fibrinogen, activated partial thromboplastin time (APTT), prothrombin time (PT) and platelet count. Cumulative results of APTT, PT, fibrinogen, platelet and eosinophil counts were retrieved from 6,944 outpatients >15 years old referred to our laboratory for routine blood testing over the previous 3 years. The median value and the percentage of patients with abnormal values of platelet count and fibrinogen but not APTT and PT, were significantly higher in patients with eosinophilia. This epidemiological association in a large subset of patients provides an additional potential mechanism to explain the link between eosinophilia and thrombosis and is consistent with the hypothesis that platelet count and fibrinogen might be worthwhile assessing in the presence of an abnormal eosinophil count.