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Chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), together with their comorbidities, bear a significant burden on public health. Increased appreciation of molecular networks underlying inflammatory airway disease needs to be translated into new therapies for distinct phenotypes not controlled by current treatment regimens. On the other hand, development of new safe and effective therapies for such respiratory diseases is an arduous and expensive process. Antibody-based (biological) therapies are successful in treating certain respiratory conditions not controlled by standard therapies such as severe allergic and refractory eosinophilic severe asthma, while in other inflammatory respiratory diseases, such as COPD, biologicals are having a more limited impact. Small molecule drug (SMD)-based therapies represent an active field in pharmaceutical research and development. SMDs expand biologicals' therapeutic targets by reaching the intracellular compartment by delivery as either an oral or topically-based formulation, offering both convenience and lower costs. Aim of this review is to compare and contrast the distinct pharmacological properties and clinical applications of SMDs- and antibody-based treatment strategies, their limitations and challenges, in order to highlight how they should be integrated for their optimal utilization and to fill the critical gaps in current treatment for chronic inflammatory respiratory diseases. This article is protected by copyright. All rights reserved.

Chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), together with their comorbidities, bear a significant burden on public health. Increased appreciation of molecular networks underlying inflammatory airway disease needs to be translated into new therapies for distinct phenotypes not controlled by current treatment regimens. On the other hand, development of new safe and effective therapies for such respiratory diseases is an arduous and expensive process. Antibody-based (biological) therapies are successful in treating certain respiratory conditions not controlled by standard therapies such as severe allergic and refractory eosinophilic severe asthma, while in other inflammatory respiratory diseases, such as COPD, biologicals are having a more limited impact. Small molecule drug (SMD)-based therapies represent an active field in pharmaceutical research and development. SMDs expand biologicals' therapeutic targets by reaching the intracellular compartment by delivery as either an oral or topically-based formulation, offering both convenience and lower costs. Aim of this review is to compare and contrast the distinct pharmacological properties and clinical applications of SMDs- and antibody-based treatment strategies, their limitations and challenges, in order to highlight how they should be integrated for their optimal utilization and to fill the critical gaps in current treatment for chronic inflammatory respiratory diseases. This article is protected by copyright. All rights reserved.

Inflammation is an important component of numerous cancers and chronic diseases and many inflammatory mediators have been shown to have potential prognostic roles. Tumor-infiltrating mast cells can promote tumor growth and angiogenesis, but the mechanism of mast cell activation is unclear. Early studies have shown that immunoglobulin free light chains (FLC) can trigger mast cell activation in an antigen-specific manner. Increased expression of FLC is observed within the stroma of many human cancers including those of breast, colon, lung, pancreas, kidney, and skin. These overexpressed FLCs are co-localized to areas of mast cell infiltration. Importantly, FLC expression is associated with basal-like cancers with an aggressive phenotype. Moreover, FLC is expressed in areas of inflammatory cell infiltration and its expression is significantly associated with poor clinical outcome. In addition, serum and bronchoalveolar fluid FLC concentrations are increased in patients with idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonitis (HP) compared to control subjects. In this review, we provide an update on the role of FLC in the pathogenesis of several lung disorders and indicate how this may contribute to new therapeutic opportunities.

The n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to enhance the effect of chemotherapeutic drugs in clinical studies in cancer patients and to induce apoptotic tumor cell death in vitro. Until now, EPA and DHA have never been investigated in multiple myeloma (MM). Human myeloma cells (L363, OPM-1, OPM-2 and U266) and normal peripheral blood mononuclear cells were exposed to EPA and DHA, and effects on mitochondrial function and apoptosis, caspase-3 activation, gene expression and drug toxicity were measured. Exposure to EPA and DHA induced apoptosis and increased sensitivity to bortezomib in MM cells. Importantly, they did not affect viability of normal human peripheral mononuclear cells. Messenger RNA expression arrays showed that EPA and DHA modulated genes involved in multiple signaling pathways including nuclear factor (NF) κB, Notch, Hedgehog, oxidative stress and Wnt. EPA and DHA inhibited NFκB activity and induced apoptosis through mitochondrial perturbation and caspase-3 activation. Our study suggests that EPA and DHA induce selective cytotoxic effects in MM and increase sensitivity to bortezomib and calls for further exploration into a potential application of these n-3 polyunsaturated fatty acids in the therapy of MM.

The use of flow cytometry in the clinical laboratory has grown substantially in the past decade. Flow cytometric analysis provides a rapid qualitative and quantitative description of multiple characteristics of individual cells. For example, it is possible to detect the cell size and granularity, aspects of DNA and RNA content and the presence of cell surface and nuclear markers which are used to characterize the phenotype of single cells. Flow cytometry has been used for the immunophenotyping of a variety of specimens including whole blood, bone marrow, serous cavity fluids, (cerebrospinal fluid) CSF, urine and all types of body fluids. The technique has also been applied to human bronchoalveolar lavage (BAL) fluid, peritoneal fluids and blood. In this review, we describe the current status of the application of flow cytometry as a diagnostic tool in various lung diseases. We focus on the analysis of BAL cell composition in chronic obstructive lung disease (COPD), asthma, lung cancer, sarcoidosis, tuberculosis and idiopathic eosinophilic pneumonia (IEP).

Mast cell-mediated diseases, such as allergies and asthma, affect a growing percentage of the population, with significant unmet medical needs. As we slowly untangle the regulatory mechanisms that modulate these complex genetic and environment-influenced diseases, new opportunities in an area of potentially highly specific and effective therapeutic interventions are emerging. In this thesis, we aimed to a) investigate how the activation of a prime effector cell in allergy - the mast cell - can be regulated by dietary compounds such as short-chain fatty acids (SCFAs), b) study the transcriptional response in human mast cells in response to various stimuli to better understand endogenous feedback loops and c) develop a new technology platform to identify and validate novel regulators of human mast cell degranulation. We summarized the known effects of dietary fiber and its metabolites on immune and non-immune cells (Chapter 2.1), and more specifically, in the context of mast cell-mediated disease (Chapter 2.2). Given the plausible correlation between dietary fiber intake and mast cell–mediated pathology, we investigated the effects of the SCFAs (acetate, propionate, and butyrate) on human mast cell activation, including the molecular mechanisms involved. We showed that butyrate and propionate, but not acetate, potently inhibited human mast cell activation via inhibition of histone deacetylase (HDAC) activity (Chapter 3). Interestingly, butyrate downregulated expression of key signaling molecules involved in IgE-mediated mast cell activation (e.g., BTK, SYK, and LAT), which coincided with deacetylation near promoter regions of such genes. To investigate potential mechanisms underlying gene expression changes in response to butyrate-induced HDAC inhibition, we integrated RNA-Seq and time-course ChIP-Seq data from butyrate-treated primary human mast cells (Chapter 4). Although butyrate evoked broad histone acetylation, our data indicated that butyrate selectively regulated gene transcription in primary human mast cells and had stronger modulatory effects on only a small subset of chromatin regions. Next, we sought to map the transcriptional landscape of activated mast cells using a variety of stimuli that target either the high-affinity IgE receptor (FcεRI)- or Mas-Related G Protein-Coupled Receptor-X2 (MRGPRX2) receptor, and found that mast cells tightly control their own activity by regulating the expression of both positive and negative regulators of (mast) cell activation (Chapter 5). Our understanding of the molecules that regulate mast cell activation and degranulation is primarily based on evidence obtained in (mast cell deficient) mouse models. Unfortunately, the follow-up validation of the exact roles of these regulators in mediating degranulation in human mast cells has been hampered by (i) the limited availability of primary human mast cells and (ii) the lack of suitable methodology to functionally interrogate the putative roles of such regulators of degranulation using small numbers of primary cells. To this end, we developed a novel technology platform that allows for rapid identification of regulators of human mast cell degranulation using functional genomics coupled to high-resolution confocal microscopy (Chapter 6). In Chapter 7 we discuss the interpretations and implications of our main findings, as well as possible limitations of the study. Furthermore, suggestions for future research directions are proposed, in addition to novel therapeutic strategies for targeting mast functions. In this thesis, we uncovered molecular mechanisms that have evolved to control human mast cell activation. Future studies are bound to discover additional (deficiencies in the) regulatory mechanisms that control mast cell function.