FcγRIIb Inhibits Allergic Lung Inflammation in a Murine Model of Allergic Asthma

Allergic asthma is characterized by airway eosinophilia, increased mucin production and allergen-specific IgE. Fc gamma receptor IIb (FcγRIIb), an inhibitory IgG receptor, has recently emerged as a negative regulator of allergic diseases like anaphylaxis and allergic rhinitis. However, no studies to date have evaluated its role in allergic asthma. Our main objective was to study the role of FcγRIIb in allergic lung inflammation. We used a murine model of allergic airway inflammation. Inflammation was quantified by BAL inflammatory cells and airway mucin production. FcγRIIb expression was measured by qPCR and flow cytometry and the cytokines were quantified by ELISA. Compared to wild type animals, FcγRIIb deficient mice mount a vigorous allergic lung inflammation characterized by increased bronchoalveolar lavage fluid cellularity, eosinophilia and mucin content upon ragweed extract (RWE) challenge. RWE challenge in sensitized mice upregulated FcγRIIb in the lungs. Disruption of IFN-γ gene abrogated this upregulation. Treatment of naïve mice with the Th1-inducing agent CpG DNA increased FcγRIIb expression in the lungs. Furthermore, treatment of sensitized mice with CpG DNA prior to RWE challenge induced greater upregulation of FcγRIIb than RWE challenge alone. These observations indicated that RWE challenge upregulated FcγRIIb in the lungs by IFN-γ- and Th1-dependent mechanisms. RWE challenge upregulated FcγRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells. FcγRIIb deficient mice also exhibited an exaggerated RWE-specific IgE response upon sensitization when compared to wild type mice. We propose that FcγRIIb physiologically regulates allergic airway inflammation by two mechanisms: 1) allergen challenge mediates upregulation of FcγRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells by an IFN-γ dependent mechanism; and 2) by attenuating the allergen specific IgE response during sensitization. Thus, stimulating FcγRIIb may be a therapeutic strategy in allergic airway disorders.     

Spectrum of Asthma in Children—II,Allergic Components

The incidence of a variety of clinical and immunological features of an allergic state was studied at 7, 10, and 14 years of age in a group of children suffering from one of four grades of asthma, ranging from mild subclinical to severe unremitting, and compared with the incidence in a control group of non-asthmatic children. The incidence of all features of allergy was significantly higher in the asthmatics but no one feature unequivocally distinguished the asthmatics from the controls. Almost all the asthmatics showed several features of the allergic state at 14 years of age. A cluster of allergic features was a differentiating characteristic of the asthmatics, and the children with the most allergic manifestations were usually the children with the most severe and persistent asthma. The first appearance of and subsequent variation in some of the allergic manifestations often did not correspond to the clinical course of the asthma.Though many manifestations of asthma can be understood on an allergic basis the mechanism by which emotional disturbance, exercise, viral infections, and non-allergenic stimuli precipitate attacks of asthma and the relation of these factors to allergy are unknown.     

Survivors of Myocardial Infarction due to “Essential” Atherosclerosis

Currently, the porphyrias are classified in four main groups: congenital porphyria, acute intermittent porphyria, porphyria cutanea tarda hereditaria, and porphyria cutanea tarda symptomatica. The acquired form of porphyria (porphyria cutanea tarda symptomatica) occurs in older males and is nearly always associated with chronic alcoholism and hepatic cirrhosis. The main clinical changes are dermatological, with excessive skin fragility and photosensitivity resulting in erosions and bullae. Biochemically, high levels of uroporphyrin are found in the urine and stools. Treatment to date has been symptomatic and usually unsuccessful.A case of porphyria cutanea tarda symptomatica is presented showing dramatic improvement of both the skin lesions and porphyrin levels in urine and blood following repeated phlebotomy.Possible mechanisms of action of phlebotomy on porphyria cutanea tarda symptomatica are discussed.     

Prevention of Influenza Virus-Induced Immunopathology by TGF-β Produced during Allergic Asthma

Asthma is believed to be a risk factor for influenza infection, however little experimental evidence exists to directly demonstrate the impact of asthma on susceptibility to influenza infection. Using a mouse model, we now report that asthmatic mice are actually significantly more resistant to a lethal influenza virus challenge. Notably, the observed increased resistance was not attributable to enhanced viral clearance, but instead, was due to reduced lung inflammation. Asthmatic mice exhibited a significantly reduced cytokine storm, as well as reduced total protein levels and cytotoxicity in the airways, indicators of decreased tissue injury. Further, asthmatic mice had significantly increased levels of TGF-β1 and the heightened resistance of asthmatic mice was abrogated in the absence of TGF-β receptor II. We conclude that a transient increase in TGF-β expression following acute asthma can induce protection against influenza-induced immunopathology.     

A New Meaning to “Partnerships”

Abstract

Michael Straight. Nancy Hanks. Durham: Duke University Press, 1988. 429 pages. $22.50 hardback. Reviewed by Samuel Hope.

Business Committee for the Arts Arts Education: A Resource Guide New York: Business Committee for the Arts, 1989 Packet format, 32 pages. $15.00 Reviewed by Samuel Hope.

Livingston Biddle. Our Government and the Arts. New York: ACA Books, 1988. 539 pages. $16.95 paperback. Reviewed by Samuel Hope.

Benjamin Ginsberg. The Captive Public: How Mass Opinion Promotes State Power. New York: Basic Books, 1986. 272 pages. $8.95 paperback. Reviewed by Samuel Hope.

Miklos Haraszti. The Velvet Prison: Artists under State Socialism. New York: Basic Books, 1987. 164 pages. $14.95 hardback. Reviewed by Samuel Hope.     

Patients with Asthma and Comorbid Allergic Rhinitis: Is Optimal Quality of Life Achievable in Real Life?

Objectives

Asthma trials suggest that patients reaching total disease control have an optimal Health Related Quality of Life (HRQoL). Moreover, rhinitis is present in almost 80% of asthmatics and impacts asthma control and patient HRQoL. We explored whether optimal HRQoL was reachable in a real-life setting, and evaluated the disease and patient related patterns associated to optimal HRQoL achievement.

Methods and Findings

Asthma and rhinitis HRQoL, illness perception, mood profiles, rhinitis symptoms and asthma control were assessed by means of validated tools in patients classified according to GINA and ARIA guidelines. Optimal HRQoL, identified by a Rhinasthma Global Summary (GS) score ≤20 (score ranging from 0 to 100, where 100 represents the worst possible HRQoL), was reached by 78/209 (37.32%). With the exception of age, no associations were found between clinical and demographic characteristics and optimal HRQoL achievement. Patients reaching an optimal HRQoL differed in disease perception and mood compared to those not reaching an optimal HRQoL. Asthma control was significantly associated with optimal HRQoL (χ² = 49.599; p<0.001) and well-controlled and totally controlled patients significantly differed in achieving optimal HRQoL (χ² = 7.617; p<0.006).

Conclusion

Approximately one third of the patients in our survey were found to have an optimal HRQoL. While unsatisfactory disease control was the primary reason why the remainder failed to attain optimal HRQoL, it is clear that illness perception and mood also played parts. Therefore, therapeutic plans should be directed not only toward achieving the best possible clinical control of asthma and comorbid rhinitis, but also to incorporating individualized elements according to patient-related characteristics.     

Studies of Male Survivors of Myocardial Infarction due to “Essential” Atherosclerosis: II. Lipids and Lipoproteins

Serum lipids (total, ester and free cholesterol, phospholipid and standard S_f 0-12, 12-20, 20-100 and 100-400 lipoproteins) were determined in 102 men, ages 30-70, with atherosclerotic coronary heart disease (C.H.D.), free of hypertension, diabetes or other complicating variables. All the lipid fractions had a lognormal distribution. All were significantly higher than in the controls up to the seventh decade. An explanation for the declining serum lipid levels with age was found. Contrary to previous reports, there was no abnormality in the relation of various lipid fractions to one another in C.H.D. A spurious correlation between C/P ratio and total cholesterol was found in both groups. In separating coronary and control subjects, cholesterol and 0-12 lipoproteins were the most reliable criteria and were equal in this respect. The misclassification rises from 20% in the fourth to 33% in the seventh decade. C/P ratio offered no improvement. The triglyceride-containing 100-400 lipoprotein was an inferior discriminator. Employing all the lipid fractions, discriminant analysis provided a minimum 12% misclassification in the fourth decade. There was no demonstrable relationship of cholesterol to body measurements, physical activity or family history of C.H.D.     

Six Amino Acid Residues in a 1200 ?2 Interface Mediate Binding of Factor VIII to an IgG4κ Inhibitory Antibody

The development of neutralizing anti-factor VIII (FVIII) antibodies complicates the treatment of many hemophilia A patients. The C-terminal C2 domain is a particularly antigenic FVIII region. A crystal structure of recombinant FVIII-C2 bound to an Fab fragment of the patient-derived monoclonal antibody BO2C11, which recognizes an immunodominant inhibitor epitope on FVIII and blocks its ability to bind von Willebrand factor (VWF) and phospholipids, revealed that 15 amino acids in FVIII contact this antibody. Forty-three recombinant FVIII-C2 proteins, each with a surface-exposed side chain mutated to alanine or another residue, were generated, and surface plasmon resonance studies were carried out to evaluate effects of these substitutions on BO2C11/FVIII-C2 binding affinity. Thermodynamic analysis of experiments carried out at three temperatures indicated that one beta hairpin turn at the antigen-antibody interface (FVIII-F2196, N2198, M2199 and F2200) plus two non-contiguous arginines (FVIII-R2215 and R2220), contributed appreciably to the affinity. B-domain-deleted (BDD) FVIII-F2196A, FVIII-F2196K and FVIII-M2199A were generated and characterized. Their pro-coagulant activities and binding to VWF were similar to those of WT-BDD-FVIII, and FVIII-F2196K avoided neutralization by BO2C11 and murine inhibitory mAb 1B5. This study suggests specific sites for amino acid substitutions to rationally design FVIII variants capable of evading immunodominant neutralizing anti-FVIII antibodies.