Development and Characterization of an Allergic Asthma Rat Model for Interventional Studies

Allergic asthma is one of the most common chronic diseases of the airways, however it still remains underdiagnosed and hence undertreated. Therefore, an allergic asthma rat model would be useful to be applied in future therapeutic strategy studies. The aim of the present study was to develop an objective model of allergic asthma in atopic rats that allows the induction and quantification of anaphylactic shock with quantitative variables. Female Brown Norway rats were intraperitoneally sensitized with ovalbumin (OVA), alum and Bordetella pertussis toxin and boosted a week later with OVA in alum. At day 28, all rats received an intranasal challenge with OVA. Anaphylactic response was accurately assessed by changes in motor activity and body temperature. Leukotriene concentration was determined in the bronchoalveolar lavage fluid (BALF), and total and IgE anti-OVA antibodies were quantified in blood and BALF samples. The asthmatic animals’ motility and body temperature were reduced after the shock for at least 20 h. The asthmatic animals developed anti-OVA IgE antibodies both in BALF and in serum. These results show an effective and relatively rapid model of allergic asthma in female Brown Norway rats that allows the quantification of the anaphylactic response.

Seroprevalence of pertussis in adult population

Introduction/Objective. Seroepidemiological studies are crucial for better understanding of pertussis epidemiology. The aim of this study was to assess the seroprevalence of anti-Bordetella pertussis toxin antibodies (anti-PT IgG) in the adult population of Novi Sad, and to evaluate the differences by age and sex. Methods. A cross-sectional study was conducted in 468 healthy adults aged ? 20 years stratified into seven age groups. The youngest of our participants received the last dose of the vaccine at least 18 years ago. Positive results of anti-PT IgG concentrations were considered a consequence of natural pertussis infection or reinfection. A commercial ELISA kit (EuroimmunR, Lubeck, Germany), with anti-PT IgG with four calibrators (5 IU/mL, 25 IU/mL, 100 IU/mL, and 200 IU/mL) was used. Results. Most of the subjects (53.8%) had anti-PT IgG of > 5 to < 62.5 IU/mL. The proportion of participants with high concentrations (62.5 to < 125 IU/mL) was statistically significantly higher in females than in males (5.4% vs. 0.4%, p = 0.002). The highest values of anti-PT IgG were detected among subjects in the age group of 20?24 years (17.5 ?} 22.2 IU/mL), and in the participants ? 60 years of age (15.0 ?} 29.4 IU/ mL). The percentage of anti-PT IgG concentration of ? 62.5 IU/mL was the highest among subjects aged ? 60 years (6.6%) and among those aged 20?24 years (5%). Conclusions. The limited duration of vaccine-induced immunity with subsequent infection or reinfection enables the circulation of pertussis in the adult population of Novi Sad that serves as the reservoir of infection for transmission to vulnerable persons.

Monocyte Selectivity and Tissue Localization Suggests a Role for Breast and Kidney–Expressed Chemokine (Brak) in Macrophage Development

Although numerous chemokines act on monocytes, none of them is specific for these cells. Here, we show that breast and kidney–expressed chemokine (BRAK) is a highly selective monocyte chemoattractant. Migration efficacy and Bordetella pertussis toxin–sensitive Ca2+ mobilization responses to BRAK were strongly enhanced after treatment of monocytes with the cyclic AMP–elevating agents prostaglandin E2 and forskolin. BRAK is the first monocyte-selective chemokine, as other types of blood leukocytes or monocyte-derived dendritic cells and macrophages did not respond. Expression in normal skin keratinocytes and dermal fibroblasts as well as lamina propria cells in normal intestinal tissues suggests a homeostatic rather than an inflammatory function for this chemokine. In addition, macrophages were frequently found to colocalize with BRAK-producing fibroblasts. We propose that BRAK is involved in the generation of tissue macrophages by recruiting extravasated precursors to fibroblasts, which are known to secrete essential cytokines for macrophage development.