Reproducibility of a novel model of murine asthma-like pulmonary inflammation

Sensitization to cockroach allergens (CRA) has been implicated as a major cause of asthma, especially among inner-city populations. Endotoxin from Gram-negative bacteria has also been investigated for its role in attenuating or exacerbating the asthmatic response. We have created a novel model utilizing house dust extract (HDE) containing high levels of both CRA and endotoxin to induce pulmonary inflammation (PI) and airway hyperresponsiveness (AHR). A potential drawback of this model is that the HDE is in limited supply and preparation of new HDE will not contain the exact components of the HDE used to define our model system. The present study involved testing HDEs collected from various homes for their ability to cause PI and AHR. Dust collected from five homes was extracted in phosphate buffered saline overnight. The levels of CRA and endotoxin in the supernatants varied from 7·1 to 49·5 mg/ml of CRA and 1·7–6  µ g/ml of endotoxin in the HDEs. Following immunization and two pulmonary exposures to HDE all five HDEs induced AHR, PI and plasma IgE levels substantially higher than normal mice. This study shows that HDE containing high levels of cockroach allergens and endotoxin collected from different sources can induce an asthma-like response in our murine model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75467/1/j.1365-2249.2004.02461.x.pd

Allergens induce enhanced bronchoconstriction and leukotriene production in C5 deficient mice

Abstract Background Previous genetic analysis has shown that a deletion in the complement component 5 gene-coding region renders mice more susceptible to allergen-induced airway hyperresponsiveness (AHR) due to reduced IL-12 production. We investigated the role of complement in a murine model of asthma-like pulmonary inflammation. Methods In order to evaluate the role of complement B10 mice either sufficient or deficient in C5 were studied. Both groups of mice immunized and challenged with a house dust extract (HDE) containing high levels of cockroach allergens. Airways hyper-reactivity was determined with whole-body plesthysmography. Bronchoalveolar lavage (BAL) was performed to determine pulmonary cellular recruitment and measure inflammatory mediators. Lung homogenates were assayed for mediators and plasma levels of IgE determined. Pulmonary histology was also evaluated. Results C5-deficient mice showed enhanced AHR to methylcholine challenge, 474% and 91% increase above baseline Penh in C5-deficient and C5-sufficient mice respectively, p < 0.001. IL-12 levels in the lung homogenate (LH) were only slightly reduced and BAL IL-12 was comparable in C5-sufficient and C5-deficient mice. However, C5-deficient mice had significantly higher cysteinyl-leukotriene levels in the BAL fluid, 1913 +/- 246 pg/ml in C5d and 756 +/- 232 pg/ml in C5-sufficient, p = 0.003. Conclusion These data demonstrate that C5-deficient mice show enhanced AHR due to increased production of cysteinyl-leukotrienes.http://deepblue.lib.umich.edu/bitstream/2027.42/116863/1/12931_2006_Article_520.pd

Differences in normal values for murine white blood cell counts and other hematological parameters based on sampling site

Objective and design: The effect of blood sampling site on the hemogram and neutrophil adhesion molecules was examined in BALB/c mice.¶ Materials and methods: Blood samples were drawn from the tail, eye, and heart during anesthesia with ketamine and xylazine. Cell numbers were quantified with an automated counter and flow cytometry was used to quantify CD11b and CD18.¶ Results: Total white blood cell (WBC) counts were highest from tail, lower from eye, and significantly lower from heart blood. In general, differences between tail and heart counts reflected changes in all cell types. RBCs, platelets and hematocrits were significantly increased in tail compared to heart blood. Although CD18 levels were not different, CD11b was significantly higher on neutrophils from tail compared to heart blood.¶ Conclusions: In anesthetized BALB/c mice, sampling site readily influences blood counts and neutrophil CD11b. The findings underscore the need to standardize sampling site when measuring these parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41822/1/11-50-10-523_10500523.pd