Chymase inhibitor improves dermatitis in NC/Nga mice

BACKGROUND: Mast cell chymase is thought to participate in allergic inflammation, but its precise role remains undetermined. Inbred NC/Nga mice develop skin lesions similar to atopic dermatitis (AD) when they grow up in a conventional environment. To elucidate the possible role of chymase in AD, we examined the effect of a chymase inhibitor on skin lesions of NC/Nga mice. METHODS: NC/Nga mice were given the chymase inhibitor SUN-C8257 daily at 150 mg/kg/day with drinking water, and the severity of the dermatitis was evaluated on day 35 of the experiment. The role of chymase in dermatitis was further investigated in vitro and in vivo using recombinant mouse mast cell protease-4 (mMCP-4). RESULTS: Administration of SUN-C8257 significantly reduced the clinical skin and histological score in NC/Nga mice. SUN-C8257 also inhibited the accumulation of inflammatory cells, such as eosinophils and mast cells, in the affected lesions in this model. mMCP-4 stimulated eosinophil migration in vitro, and intradermal injection of the enzyme resulted in a significant accumulation of inflammatory cells, including eosinophils, at the injection site. Thus amelioration of the skin lesions in NC/Nga mice by SUN-C8257 might be, at least in part, due to the suppression of cell infiltration in the lesions. CONCLUSION: Mast cell chymase may contribute to the pathogenesis of AD, and SUN-C8257 will be beneficial to the treatment of the skin disorder.     

Serum eosinophil cationic protein in patients with atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory disease of the skin, frequently associated with a family history of atopy, raised serum IgE levels and other immunological abnormalities. Both eosinophils and their basic proteins have been detected in the skin lesions of AD patients. We measured the levels of eosinophil cationic protein (ECP) in sera of 24 children with AD and found them to be increased, compared to nonatopic controls, both children and adults. High ECP values were also obtained in 3 patients with the hyper-IgE syndrome. However, no direct relationship between IgE and ECP serum levels could be established. We found no correlation between serum ECP and the number of circulating eosinophils, suggesting that part of ECP was produced by cells infiltrating the tissues. Measurement of ECP might represent a noninvasive tool to assess the activity of AD in relation to eosinophil involvement in this disease.     

Periostin facilitates eosinophil tissue infiltration in allergic lung and esophageal responses

Periostin is an extracellular matrix protein that has been primarily studied in the context of the heart, where it has been shown to promote cardiac repair and remodeling. In this study, we focused on the role of periostin in an allergic eosinophilic inflammatory disease (eosinophilic esophagitis (EE)) known to involve extensive tissue remodeling. Periostin was indeed markedly overexpressed (35-fold) in the esophagus of EE patients, particularly in the papillae, compared with control individuals. Periostin expression was downstream from transforming growth factor-β and interleukin-13, as these cytokines were elevated in EE esophageal samples and markedly induced periostin production by primary esophageal fibroblasts (107- and 295-fold, respectively, at 10 ng ml⁻¹). A functional role for periostin in eliciting esophageal eosinophilia was demonstrated, as periostin-null mice had a specific defect in allergen-induced eosinophil recruitment to the lungs and esophagus (66 and 72% decrease, respectively). Mechanistic analyses revealed that periostin increased (5.8-fold) eosinophil adhesion to fibronectin. As such, these findings extend the involvement of periostin to esophagitis and uncover a novel role for periostin in directly regulating leukocyte (eosinophil) accumulation in T helper type 2-associated mucosal inflammation in both mice and humans.     

Chymase Activities and Survival in Endotoxin-Induced Human Chymase Transgenic Mice

We examined the effects of overexpressed human chymase on survival and activity in lipopolysaccharide (LPS)-treated mice. Human chymase transgenic (Tg) and wild-type C57BL/6 (WT) mice were treated with LPS (0.03, 0.1 and 0.3 mg/day; intraperitoneal) for 2 weeks. Treatment with 0.03 mg LPS did not affect survival in either WT or Tg mice. WT mice were not affected by 0.1 mg/day of LPS, whereas 25% of Tg mice died. Survival of mice treated with 0.3 mg/day of LPS was 87.5% and 0% in WT and Tg, respectively. LPS-induced increases in chymase activity in the heart and skin were significantly greater in Tg than WT mice. These data suggest a possible contribution of human chymase activation to LPS-induced mortality.     

Selective suppression of Th2-mediated airway eosinophil infiltration by low-molecular weight CCR3 antagonists

The effects of selective CC chemokine receptor (CCR)-3 antagonists on antigen-induced leukocyte accumulation in the lungs of mice adoptively transferred with in vitro-differentiated T(h)1 and T(h)2 were investigated. Inhalation of antigen by mice injected with T(h)1 and T(h)2 initiated the migration of T cells themselves into the lungs. Subsequently, neutrophils massively accumulated in T(h)1-transferred mice, whereas eosinophil infiltration was specifically induced by T(h)2. CCR3 antagonists, SB-297006 and/or SB-328437, suppressed antigen-induced accumulation of T(h)2 as well as eosinophils in the lungs, whereas they failed to affect T(h)1-mediated airway inflammation. Not only T(h)2 and eosinophil infiltration but also cellular mobilization in T(h)1-transferred mice was attenuated by an anti-CC chemokine ligand-11 antibody. CCR3 antagonists reduced chemokine production in the lungs of mice transferred with T(h)2 but not T(h)1, suggesting that down-regulation of chemokine synthesis is involved in the selective inhibition of T(h)2-mediated eosinophil infiltration by CCR3 antagonists.     

Inhibitory receptor gp49B regulates eosinophil infiltration during allergic inflammation

gp49B, an Ig-like receptor, negatively regulates the activity of mast cells and neutrophils through cytoplasmic immunoreceptor tyrosine-based inhibition motifs. To characterize the role of gp49B further in vivo, gp49B-deficient mice were tested in two allergic models. Responses to ragweed (RW) challenge in the lung and conjunctiva were assessed in models of allergic inflammation and during an infection with parasitic larvae of the nematode Ascaris suum. Infiltration by inflammatory cells into the lung during allergic responses was under negative control of the inhibitory receptor gp49B. Furthermore, an increase in conjunctival inflammation with a predominance of eosinophils, neutrophils, and degranulated mast cells was observed in RW-sensitized, gp49B-deficient mice, which had been challenged in the eye, as compared with C57BL/6 wild-type (WT) controls. Finally, an increase in allergic inflammation in the lungs of A. suum-infected, RW-sensitized mice was observed upon RW challenge, as compared with C57BL/6 WT controls. The observed influx of eosinophils into mucus membranes is characteristic of allergic asthma and allergic conjunctivitis and may contribute to airway hyper-responsiveness, airway remodeling, and mucus production. Expression of gp49B was detected on peripheral eosinophils of control mice and on eosinophils from lungs of mice treated with RW, suggesting a role for gp49B on eosinophils in dampening allergic inflammatory responses.     

cAMP-specific phosphodiesterase inhibitor,rolipram, reduces eosinophil infiltration evoked by leukotrienes or by histamine in guinea pig conjunctiva

The effect of rolipram, an isozyme IV-selective inhibitor of cAMP-specific phosphodiesterase, was evaluated in a guinea pig eye model of tissue eosinophilia. (R)-rolipram was administered by gavage to guinea pigs 1 h prior to topical ocular challenge with a mixture of leukotrienes (LTs) (10 ng LTB₄ + 1000 ng LTD₄/eye) or with histamine dihydrochloride (1 mg/eye). Conjunctivae were evaluated histologically 6 h after challenge. Eosinophil counts per millimeter of conjunctival epithelium in LT-challenged animals that received (R)-rolipram at dosages of 0.1, 0.3, 1, 3, or 10 mg/kg were reduced by 63, 63, 84, 81 and 90% respectively, compared to LT-challenged controls. Reduction was statistically significant (P<0.05) at all dosages. Eosinophil counts per millimeter of epithelium in histamine-challenged animals that received 10 mg/kg (R)-rolipram were reduced by 79% compared to histamine-challenged controls (P<0.01). The results indicate that (R)-rolipram inhibits the response to two distinct classes of mediator in this model of eosinophil infiltration, adding support to the contention that isozyme IV-selective cAMP phosphodiesterase inhibitors offer therapeutic potential for human asthma.     

Independent prognostic value of eosinophil and mast cell infiltration in colorectal cancer tissue

Overall peritumoural inflammatory cell infiltration is a prognostic variable in solid tumours, but the survival-related impact of the individual cell types within the infiltrate has still not been fully evaluated and compared with the conventional disease classification. In the present study, the prognostic value of individual white cell counts in the peritumoural inflammatory infiltrate in colorectal cancer was assessed. Intra-operative tumour tissue samples from 584 patients undergoing elective surgery for colorectal cancer were included. None of the patients received pre- or post-operative adjuvant chemotherapy. Tissue blocks were cut from the periphery of the tumours and embedded in paraffin. All blocks included both tumour tissue and normal bowel tissue. Serial sections of 4 microm were analysed for tumour tissue inflammatory cell infiltration using a computer- and video-assisted microscope, which allowed semi-automated quantification of cells within a fixed area. Total white cells and individual counts of eosinophils, neutrophils, mast cells, lymphocytes, and plasma cells were evaluated in every tumour specimen. Stratification into four groups with similar numbers of events was used to dichotomize the cell counts with respect to survival. The median observation period was 61 (49-75) months. In a multivariate analysis including Dukes' stage, gender, age, peri-operative blood transfusion, tumour location, and counts of specific inflammatory cells, only advanced Dukes' stage ( p< 0.0001), high age ( p=0.0003), and tumour location in the rectum predicted poor survival, while high counts of eosinophils ( p=0.006) and mast cells ( p=0.02) predicted good survival. Tumour-associated eosinophilia and mastocytosis appear to be independent prognostic variables in colorectal cancer. Future studies should investigate the potential biological role of tumour tissue eosinophils and mast cells in the modulation of tumour growth.     

Variation in genes encoding eosinophil granule proteins in atopic dermatitis patients from Germany

Background  

Atopic dermatitis (AD) is believed to result from complex interactions between genetic and environmental factors. A main feature of AD as well as other allergic disorders is serum and tissue eosinophilia. Human eosinophils contain high amounts of cationic granule proteins, including eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN), eosinophil peroxidase (EPO) and major basic protein (MBP). Recently, variation in genes encoding eosinophil granule proteins has been suggested to play a role in the pathogenesis of allergic disorders. We therefore genotyped selected single nucleotide polymorphisms within the ECP, EDN, EPO and MBP genes in a cohort of 361 German AD patients and 325 healthy controls.     

Renal failure caused by leukaemic infiltration in chronic lymphocytic leukaemia.

A case of B-CLL which was complicated by chronic renal failure due to leukaemic infiltration of the kidney is reported. Treatment with chlorambucil, prednisolone, and renal bed irradiation resulted in a substantial improvement in renal function which persisted until the the patient''s death from marrow failure some eight years later. The temporal association between treatments and response suggested that renal bed radiotherapy had contributed to the improvement in renal function. This case is one of only two reported cases in which chronic renal failure due to CLL has been treated with radiotherapy. It is unique in that the renal response was shown histologically. Leukaemic infiltration of the kidney is common in CLL but, characteristically, is not associated with renal impairment. An improvement in renal function has been described in two patients with acute renal failure after chemotherapy.     

Secretory IgA induces antigen-independent eosinophil survival and cytokine production without inducing effector functions

BACKGROUND: Eosinophils in human beings reside in tissues, especially the mucosal tissues of the gastrointestinal tract and inflamed airways. Secretory IgA (S-IgA) is the predominant antibody secreted by these tissues and likely plays a role in the innate immune response. OBJECTIVE: Because eosinophils and S-IgA are often colocalized in mucosal tissues, we examined the potential regulatory effects of S-IgA without antigens on survival, gene expression, and effector functions of human eosinophils. METHODS: Eosinophils were incubated with S-IgA in solution without antigens (soluble S-IgA) or with S-IgA immobilized to mimic multivalent antigen cross-linking. Eosinophil activation was monitored by superoxide anion generation and degranulation. Survival was assessed between 24 and 96 hours. Gene and protein expression were examined by microarray and ELISA. Eosinophil lysates were examined by immunoblot for extracellular signal-regulated kinase (ERK) phosphorylation. RESULTS: Immobilized S-IgA stimulated eosinophil superoxide production and degranulation; soluble S-IgA did not. Although immobilized S-IgA inhibited eosinophil survival in vitro, soluble S-IgA enhanced survival; this involved autocrine production of GM-CSF. Soluble S-IgA without antigens induced increases in mRNA levels of various cytokines, chemokines, signal transduction molecules, antiapoptotic factors, and cell surface markers. By using ELISA, we confirmed protein expression of selected mediators. Eosinophil interaction with soluble S-IgA likely involves FcalphaRI (CD89) and ERK pathway activation. CONCLUSION: Secretory IgA without multivalent antigens may regulate survival and gene expression of eosinophils. Eosinophils in mucosal tissues can be either primed for action (cytokine production and survival) or fully activated (degranulation and superoxide release) by different forms of S-IgA.     

Prostatic infiltration in chronic lymphatic leukaemia.

Forty six men with chronic lymphatic leukaemia (CLL) were studied for up to seven years. Six patients required surgery for prostatic outlet obstruction. Histological examination of the prostatic chippings showed variable degrees of infiltration with small mature lymphocytes in all six patients, suggestive of a leukaemic origin for the cells. Patients with chronic lymphatic leukaemia who undergo prostatectomy may have a higher incidence of leukaemic infiltration than has been previously recognised.     

Evidence that eosinophil infiltration in the OK-432/fibrinogen-injected Meth-A tumor in mice is mediated by locally produced IL-5

It was previously demonstrated that a single injection of OK-432 (a penicillin-treated freeze-dried Streptococcus) mixed with fibrinogen into cancer tissues induces marked infiltration by eosinophils of the tumor stroma and leads to tumor necrosis. In the present study, we examined mechanisms regulating the local accumulation of eosinophils and the role of infiltrating eosinophils in tumor regression using the OK-432/fibrinogen injected Meth-A fibrosarcoma tumor. After injection of OK-432/fibrinogen into the tumor on the left flank of the BALB/c mice, eosinophil infiltration became obvious in the tumor stroma on day 3 following the accumulation of macrophages and neutrophils, was massive on day 5 and decreased by day 10. After the decrease in the infiltration of eosinophils, the tumor injected with OK-432/fibrinogen diminished markedly in size with ulceration as compared with control. Northern blot analysis revealed that expression of IL-5 mRNA in the tumor tissue was not detected on day 0, was significantly on day 3, reached the maximum on day 5, and thereafter decreased by day 10. Although intraperitoneal injection of rat anti-IL-5 monoclonal antibody in tumor bearing mice prior to OK-432 injection inhibited the infiltration of eosinophils, the antitumor effects of OK-432 persisted. In the blood, neither eosinophilia nor IL-5 activity was recognized during the course of the experiment. These results suggest that intratumoral injection of OK-432/fibrinogen induces local production of IL-5, which in turn recruits eosinophils into the tumor tissue, however, the infiltrating eosinophils do not play an important role in tumor regression.     

Vitamin D in atopic dermatitis,chronic urticaria and allergic contact dermatitis

Vitamin D influences allergen-induced pathways in the innate and adaptive immune system, and its potential immunomodulatory role in allergic skin disorders has been explored. This comprehensive review article provides an overview of the role of vitamin D in three common dermatologic conditions: atopic dermatitis (AD), chronic urticaria, and allergic contact dermatitis (ACD). Whereas the literature regarding vitamin D and AD has resulted in mixed findings, several studies have described an inverse relationship between vitamin D levels and AD severity, and improvement in AD with vitamin D supplementation. Similarly, several studies report an inverse relationship between vitamin D levels and severity of chronic urticaria. Although current research in humans remains limited, an increased likelihood of ACD has been demonstrated in vitamin D-deficient mice. Additional well-designed clinical trials will be necessary to determine whether vitamin D supplementation should be recommended for prevention or adjuvant treatment of these common dermatologic conditions.     

Neointimal and tubulointerstitial infiltration by recipient mesenchymal cells in chronic renal-allograft rejection.

BACKGROUND: Tissue remodeling depends on mesenchymal cells (fibroblasts and myofibroblasts) and is a prominent feature of chronic renal-transplant rejection. It is not known whether the mesenchymal cells that participate in remodeling originate locally or from circulating precursor cells. METHODS: We obtained biopsy specimens of renal allografts from six male recipients of an allograft from a female donor, four female recipients of an allograft from a male donor, two male recipients of an allograft from a male donor, and two female recipients of an allograft from a female donor. All the allografts were undergoing chronic rejection. All but two specimens were obtained within six months after transplantation. We used immunohistochemical methods to identify mesenchymal cells with smooth-muscle alpha-actin and in situ hybridization to identify mesenchymal cells with Y-chromosome DNA. RESULTS: No Y-chromosome bodies were identified in the case of the two renal-allograft specimens in which both the donor and the recipient were female. In the case of the two renal-allograft specimens in which both the donor and the recipient were male, approximately 40 percent of mesenchymal cells contained a Y-chromosome body. In the case of the six specimens in which the donor was female and the recipient was male, a mean (+/-SD) of 34+/-16 percent of mesenchymal cells in the neointima, 38+/-12 percent of such cells in the adventitia, and 30+/-7 percent of such cells in the interstitium contained the Y-chromosomal marker, indicating that they originated from the recipient rather than the donor. In the case of the four renal-allograft specimens in which the donor was male and the recipient was female, the respective values were 24+/-15 percent, 33+/-9 percent, and 23+/-8 percent, indicating a persistent population of donor mesenchymal cells. CONCLUSIONS: The presence of mesenchymal cells of host origin in the vascular and interstitial compartments of renal allografts undergoing chronic rejection provides evidence that a circulating mesenchymal precursor cell has the potential to migrate to areas of inflammation.