House dust mite (HDM) challenge is commonly used in murine models of allergic asthma for preclinical pathophysiological studies. However, few studies define objective readouts or biomarkers in this model. In this study we characterized immune responses and defined molecular markers that are specifically altered after HDM challenge. In this murine model, we used repeated HDM challenge for two weeks which induced hallmarks of allergic asthma seen in humans, including airway hyper-responsiveness (AHR) and elevated levels of circulating total and HDM-specific IgE and IgG1. Kinetic studies showed that at least 24 h after last HDM challenge results in significant AHR along with eosinophil infiltration in the lungs. Histologic assessment of lung revealed increased epithelial thickness and goblet cell hyperplasia, in the absence of airway wall collagen deposition, suggesting ongoing tissue repair concomitant with acute allergic lung inflammation. Thus, this model may be suitable to delineate airway inflammation processes that precede airway remodeling and development of fixed airway obstruction. We observed that a panel of cytokines e.g. IFN-γ, IL-1β, IL-4, IL-5, IL-6, KC, TNF-α, IL-13, IL-33, MDC and TARC were elevated in lung tissue and bronchoalveolar fluid, indicating local lung inflammation. However, levels of these cytokines remained unchanged in serum, reflecting lack of systemic inflammation in this model. Based on these findings, we further monitored the expression of 84 selected genes in lung tissues by quantitative real-time PCR array, and identified 31 mRNAs that were significantly up-regulated in lung tissue from HDM-challenged mice. These included genes associated with human asthma (e.g. clca3, ear11, il-13, il-13ra2, il-10, il-21, arg1 and chia1) and leukocyte recruitment in the lungs (e.g. ccl11, ccl12 and ccl24). This study describes a biosignature to enable broad and systematic interrogation of molecular mechanisms and intervention strategies for airway inflammation pertinent to allergic asthma that precedes and possibly potentiates airway remodeling and fibrosis.

This study demonstrates that an immunomodulatory IDR peptide controls the pathophysiology of asthma in a murine model. As IL-33 is implicated in steroid-refractory severe asthma, our findings on the effects of IDR-1002 may contribute to the development of novel therapies for steroid-refractory severe asthma.

Amphiphilic aminoglycosides (AAGs) are an emerging source of antibacterials to combat infections caused by antibiotic-resistant bacteria. Mode-of-action studies indicate that AAGs predominately target bacterial membranes, thereby leading to depolarization and increased permeability. To assess whether AAGs also induce host-directed immunomodulatory responses, we determined the AAG-dependent induction of cytokines in macrophages in the absence or presence of lipopolysaccharide (LPS). Our results show for the first time that AAGs can boost the innate immune response, specifically the recruitment of immune cells such as neutrophils required for the resolution of infections. Moreover, AAGs can selectively control inflammatory responses induced in the presence of endotoxins to prevent septic shock. In conclusion, our study demonstrates that AAGs possess multifunctional properties that combine direct antibacterial activity with host-directed clearance effects reminiscent of those of host-defense peptides.

Antimicrobial peptides, also known as host defence peptides, are immunomodulatory molecules required to resolve infections. Antimicrobial peptides and proteins (APPs) are important in the control of infections in the lungs. Despite evidence that APPs exhibit a wide range of immune functions and modulate inflammation, the effect of inflammatory cytokines on the expression of APPs is not completely defined. In this study, we profiled the expression of 39 different APPs in human bronchial epithelial cells (HBEC) using Slow Off-rate Modified Aptamer (SOMAmer)-based protein array, in the presence and absence of three different inflammatory cytokines (IL-17, TNF and IFN-γ). Expression of 13 different APPs was altered in response to IL-17, TNF or IFN-γ. Independent validations of selected proteins from the proteomics screen i.e., those that were significantly enhanced by >2-fold change (p < 0.01) using western blots conclusively demonstrated that inflammatory cytokines alter the expression of APPs differentially. For example, the abundance of cathepsin S was enhanced by only IFN-γ, whereas lipocalin-2 was increased by IL-17 alone. Abundance of elafin increased in presence of IL-17 or TNF, but decreased in response to IFN-γ. Whereas the abundance of cathepsin V decreased following stimulation with IL-17, TNF and IFN-γ. The results of this study demonstrate that inflammatory cytokines alter the expression of APPs disparately. This suggests that the composition of the inflammatory cytokine milieu may influence APPs abundance and thus alter the processes required for infection control and regulation of inflammation in the lungs.

Amphiphilic aminoglycosides (AAGs) are an emerging source of antibacterials to combat infections caused by antibiotic-resistant bacteria. Mode-of-action studies indicate that AAGs predominately target bacterial membranes,thereby leading to depolarization and increased permeability.Toassess whether AAGs also induce host-directed immunomodulatory responses,w ed etermined the AAG-dependent induction of cytokines in macrophages in the absence or presence of lipopolysaccharide (LPS). Our results show for the first time that AAGs can boost the innate immune response,specifically the recruitment of immune cells such as neutrophils required for the resolution of infections.M oreover,A AGsc an selectively control inflammatory responses induced in the presence of endotoxins to prevent septic shock.Inconclusion, our study demonstrates that AAGs possess multifunctional properties that combine direct antibacterial activity with host-directed clearance effects reminiscent of those of host-defense peptides.The world is facing an enormous threat from the emergence and dissemination of bacteria that are resistant to almost all currently available antibiotics. [1,2] Twos trategies,m ultiplecomponent antibiotic adjuvants [3] and single-componentbased antibacterial polypharmacology [4] are currently under investigation to combat bacterial resistance.B oth strategies seek to exploit multiple modes of action. Recently,a mphiphilic aminoglycosides (AAGs) have emerged as as ource of antibacterial agents to combat bacterial resistance. [5][6][7][8][9][10][11][12][13][14] Modeof-action studies have shown that AAGs can show different modes of action [9,[11][12][13] to AGs, which bind to the 30S ribosomal subunit, thereby leading to the disruption of protein synthesis. [15] Fori nstance,i tw as shown that the antibacterial effect of an eamine-based AAGa gainst P. aeruginosa was caused by changes in membrane depolarization and permeability and not by inhibition of protein synthesis. [9,11] Strong evidence for membrane-targeting inter-actions of AAGs were also reported for amphiphilic neomycin and tobramycin analogues. [12,13] Encouraged by the multimodal activity of cationic amphiphilic host-defense peptides (HDPs) in the host-directed clearance of an infection, [16][17][18] we developed an interest in exploring whether AAGs can show HDP-like properties. AAGs that combine direct antibacterial effects with the induction of immunomodulatory responses in host immune cells may display superior efficacy against multiple-drugresistant (MDR) bacteria. It is noteworthy that for cationic amphiphilic HDPs like LL-37, the direct antibacterial activity is antagonized by physiological concentrations of divalent cations and polyanions,and other host factors. [16,17] However, HDP-mediated protection has been observed in several in vivo infection models,t hus suggesting that the broad range of immunomodulatory activities exhibited by these peptides is the predominant function of HDPs for the resolution of microbial infections. [17,[19][20][21] With this in ...