Stratification of peanut allergic murine model into anaphylaxis severity risk groups using thermography.

Murine models are readily used to investigate mechanisms potentially involved in anaphylaxis. Determining successful sensitization with current methods remain potentially lethal, invasive, expensive and/or cumbersome. Here we describe the use of thermography to read intradermal testing to detect peanut allergic sensitization in the murine model and as a first time sensitive tool for anaphylaxis stratification. The relative wheal size in the thermal image can be used to stratify anaphylaxis severity risk groups prior to a challenge. This screening method is nonlethal, inexpensive, minimally invasive and can be carried out expeditiously.

Mesenchymal Stem Cell Soluble Mediators and Cystic Fibrosis.

Human Mesenchymal stem cells (hMSCs) secrete products (supernatants) that are anti-inflammatory and antimicrobial. We have previously shown that hMSCs decrease inflammation and Pseudomonas aeruginosa infection in the in vivo murine model of Cystic Fibrosis (CF). Cystic Fibrosis (CF) is a genetic disease in which pulmonary infection and inflammation becomes the major cause of morbidity and mortality. Our studies focus on determining how MSCs contribute to improved outcomes in the CF mouse model centering on how the MSCs impact the inflammatory response to pathogenic organisms. We hypothesize that MSCs secrete products that are anti-inflammatory in scenarios of chronic pulmonary infections using the murine model of infection and inflammation with a specific interest in Pseudomonas aeruginosa (gram negative). Further, our studies will identify whether the MSCs are impacting this inflammatory response through the regulation of peroxisome proliferator activator receptor gamma (PPARγ) which aides in decreasing inflammation.

Interleukin-17 Pathophysiology and Therapeutic Intervention in Cystic Fibrosis Lung Infection and Inflammation.

Cystic fibrosis (CF) is characterized by an excessive neutrophilic inflammatory response within the airway as a result of defective cystic fibrosis transmembrane receptor (CFTR) expression and function. Interleukin-17A induces airway neutrophilia and mucin production associated with Pseudomonas aeruginosa colonization, which is associated with the pathophysiology of cystic fibrosis. The objectives of this study were to use the preclinical murine model of cystic fibrosis lung infection and inflammation to investigate the role of IL-17 in CF lung pathophysiology and explore therapeutic intervention with a focus on IL-17. Cftr-deficient mice (CF mice) and wild-type mice (WT mice) infected with P. aeruginosa had robust IL-17 production early in the infection associated with a persistent elevated inflammatory response. Intratracheal administration of IL-17 provoked a neutrophilic response in the airways of WT and CF animals which was similar to that observed with P. aeruginosa infection. The neutralization of IL-17 prior to infection significantly improved the outcomes in the CF mice, suggesting that IL-17 may be a therapeutic target. We demonstrate in this report that the pathophysiological contribution of IL-17 may be due to the induction of chemokines from the epithelium which is augmented by a deficiency of Cftr and ongoing inflammation. These studies demonstrate the in vivo contribution of IL-17 in cystic fibrosis lung disease and the therapeutic validity of attenuating IL-17 activity in cystic fibrosis.

Antimicrobial Properties of Mesenchymal Stem Cells: Therapeutic Potential for Cystic Fibrosis Infection, and Treatment.

Cystic fibrosis (CF) is a genetic disease in which the battle between pulmonary infection and inflammation becomes the major cause of morbidity and mortality. We have previously shown that human MSCs (hMSCs) decrease inflammation and infection in the in vivo murine model of CF. The studies in this paper focus on the specificity of the hMSC antimicrobial effectiveness using Pseudomonas aeruginosa (gram negative bacteria) and Staphylococcus aureus (gram positive bacteria). Our studies show that hMSCs secrete bioactive molecules which are antimicrobial in vitro against Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumonia, impacting the rate of bacterial growth and transition into colony forming units regardless of the pathogen. Further, we show that the hMSCs have the capacity to enhance antibiotic sensitivity, improving the capacity to kill bacteria. We present data which suggests that the antimicrobial effectiveness is associated with the capacity to slow bacterial growth and the ability of the hMSCs to secrete the antimicrobial peptide LL-37. Lastly, our studies demonstrate that the tissue origin of the hMSCs (bone marrow or adipose tissue derived), the presence of functional cystic fibrosis transmembrane conductance regulator (CFTR: human, Cftr: mouse) activity, and response to effector cytokines can impact both hMSC phenotype and antimicrobial potency and efficacy. These studies demonstrate, the unique capacity of the hMSCs to manage different pathogens and the significance of their phenotype in both the antimicrobial and antibiotic enhancing activities.

Non-covalent ligand conjugation to biotinylated DNA nanoparticles using TAT peptide genetically fused to monovalent streptavidin.

DNA nanoparticles (DNA NPs), which self-assemble from DNA plasmids and poly-L-lysine (pLL)-polyethylene glycol (PEG) block copolymers, transfect several cell types in vitro and in vivo with minimal toxicity and immune response. To further enhance the gene transfer efficiency of DNA NP and control its tropism, we established a strategy to efficiently attach peptide ligands to DNA NPs. The non-covalent biotin-streptavidin (SA) interaction was used for ligand conjugation to overcome problems associated with covalent conjugation methods. A fusion protein of SA with the HIV-1 TAT peptide was cloned, expressed, purified and attached to biotinylated DNA NPs. A modified SA system with tetrameric structure but monovalent biotin binding capacity was adopted and shown to reduce the aggregation of biotinylated DNA NPs compared to neutravidin. Compared to unmodified DNA NPs, TAT modified DNA NPs significantly enhanced in vitro gene transfer, particularly at low DNA concentrations. Studies of cellular uptake and cellular distribution of the DNA NPs indicated that attaching TAT enhanced binding of DNA NPs to cell surface but not internalization at high DNA concentrations. In vivo studies showed that TAT modified DNA NPs mediated equal level of gene transfer to the mouse airways via the luminal route compared to unmodified DNA NPs.