Paul E. Pfeffer

The psychosocial and psychiatric side of cystic fibrosis in adolescents and adults

Increasing numbers of cystic fibrosis (CF) patients are surviving into adulthood. An understanding of the psychiatric and psychosocial aspects of CF in adults and adolescents is therefore more important than ever. There is a large body of evidence indicating that the psychological and psychosocial functioning of people with CF is similar to that of well people, until the disease becomes severe. However, there is also evidence that patients do suffer an increased likelihood of psychiatric problems, such as depression, and of scoring poorly on physical functioning measures of quality of life. Studies have found conflicting evidence as to any association between degree of respiratory impairment and psychological functioning. Coping styles seem to have a large effect upon the quality of life of CF patients. People with cystic fibrosis can have problems with sexuality, platonic relationships and independence. Families of patients also suffer problems, which can affect the patients themselves. Non-compliance is a complicated problem with many patients. New treatments for people with CF are emerging, such as lobe transplants from live donors and gene therapy, with possible new psychosocial problems resulting. Furthermore, older studies are becoming increasingly inapplicable as treatment and prognosis changes. Therefore, more research is needed in this field.

Distinct endotypes of steroid-resistant asthma characterized by IL-17Ahigh and IFN-γhigh immunophenotypes: Potential benefits of calcitriol

Background A small population of patients with severe asthma does not respond to glucocorticoids (steroid resistant [SR]). They have high morbidity, highlighting an urgent need for strategies to enhance glucocorticoid responsiveness. Objective We investigated the immunologic differences between steroid-sensitive (SS) and SR asthmatic patients and the effect on immunophenotype of oral calcitriol treatment because it has been previously shown to beneficially modulate the clinical response to glucocorticoids in patients with SR asthma. Methods CD8-depleted PBMCs were isolated from 12 patients with SS and 23 patients with SR asthma and cultured for 7 days with anti-CD3 and IL-2 with or without dexamethasone. Cytokine production was assessed in supernatants by using the Cytometric Bead Array. Patients with SR asthma were subsequently randomized to oral calcitriol or placebo therapy, and identical studies were repeated. Results Patients with SR asthma produced significantly increased IL-17A and IFN-γ levels compared with those in patients with SS asthma, although it was evident that cells from individual patients might overproduce one or the other of these cytokines. Production of IL-17A was inversely and production of IL-13 was positively associated with the clinical response to prednisolone. Oral calcitriol, compared with placebo, therapy of the patients with SR asthma significantly improved dexamethasone-induced IL-10 production in vitro while suppressing dexamethasone-induced IL-17A production. This effect mirrored the previously demonstrated improvement in clinical response to oral glucocorticoids in calcitriol-treated patients with SR asthma. Conclusions IL-17Ahigh and IFN-γhigh immunophenotypes exist in patients with SR asthma. These data identify immunologic pathways that likely underpin the beneficial clinical effects of calcitriol in patients with SR asthma by directing the SR cytokine profile toward a more SS immune phenotype, suggesting strategies for identifying vitamin D responder immunophenotypes.

Immunoregulatory mechanisms of vitamin D relevant to respiratory health and asthma

Vitamin D deficiency is prevalent among people with various immune‐mediated conditions, including autoimmune diseases and asthma. Serum 25(OH)D levels inversely correlate with asthma severity, glucocorticoid responsiveness/dosage, and markers of pathogenesis, such as airway remodeling, IgE, and eosinophilia. Trials involving supplementation with active vitamin D or a precursor are beginning to emerge with variable results that, in part, reflect differences in study design. This review looks at the mechanisms by which vitamin D may protect against asthma, including increasing glucocorticoid responsiveness, skewing immune cells towards a regulatory phenotype, reducing the incidence of infections, airway remodeling, eosinophilia, and lowering the levels of IgE. Also discussed is the therapeutic potential for vitamin D, which is likely to be applicable to immune‐mediated conditions beyond simply asthma.

Vitamin D and lung disease

The classic role of vitamin D in the regulation of calcium and phosphate metabolism, and its effects on bone health, are well established. More recently a critical role in immunity and respiratory health has been proposed. This arises from evidence for the capacity to generate the active metabolite, 1α,25-dihydroxyvitamin D3 (1,25(OH)D3), locally in many tissues beyond the kidney; expression of the vitamin D receptor (VDR) in immune and structural cells not involved in calcium-phosphate homeostasis; and control by 1,25(OH)D3 of the transcription of genes associated with numerous different biological processes through its nuclear VDR. Abnormalities in the vitamin D axis, including a high prevalence of vitamin D insufficiency worldwide, now appear important in a wide range of pulmonary diseases including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. Actions of vitamin D on innate immune responses, for example, production of antimicrobial peptides and autophagy, and on adaptive immune responses, for example, promoting regulatory lymphocytes, are believed to underpin these associations.

Enrichment of immunoregulatory proteins in the biomolecular corona of nanoparticles within human respiratory tract lining fluid.

UNLABELLED When inhaled nanoparticles deposit in the lungs, they transit through respiratory tract lining fluid (RTLF) acquiring a biomolecular corona reflecting the interaction of the RTLF with the nanomaterial surface. Label-free snapshot proteomics was used to generate semi-quantitative profiles of corona proteins formed around silica (SiO2) and poly(vinyl) acetate (PVAc) nanoparticles in RTLF, the latter employed as an archetype drug delivery vehicle. The evolved PVAc corona was significantly enriched compared to that observed on SiO2 nanoparticles (698 vs. 429 proteins identified); however both coronas contained a substantial contribution from innate immunity proteins, including surfactant protein A, napsin A and complement (C1q and C3) proteins. Functional protein classification supports the hypothesis that corona formation in RTLF constitutes opsonisation, preparing particles for phagocytosis and clearance from the lungs. These data highlight how an understanding of the evolved corona is necessary for the design of inhaled nanomedicines with acceptable safety and tailored clearance profiles. FROM THE CLINICAL EDITOR Inhaled nanoparticles often acquire a layer of protein corona while they go through the respiratory tract. Here, the authors investigated the identity of these proteins. The proper identification would improve the understanding of the use of inhaled nanoparticles in future therapeutics.

Vitamin D supplementation during pregnancy: Effect on the neonatal immune system in a randomized controlled trial

&NA; Figure. No caption available. Background: Programming of the immune system during fetal development can influence asthma‐related risk factors and outcomes in later life. Vitamin D is a well‐recognized immune modulator, and deficiency of this nutrient during pregnancy is hypothesized to influence disease development in offspring. Objective: We sought to investigate the effect on neonatal immunity of maternal supplementation with 4400 IU/d vitamin D3 during the second and third trimesters of pregnancy by using a subset of cord blood samples from a randomized, double‐blind, placebo‐controlled clinical trial (the Vitamin D Antenatal Asthma Reduction Trial). Methods: Cord blood samples from neonates born to mothers supplemented with 4400 IU/d (n = 26) or 400 IU/d (n = 25) of vitamin D3 were analyzed for immune cell composition by flow cytometry, Toll‐like receptor (TLR) expression by quantitative PCR, and cytokine secretion after stimulation with mitogenic, TLR, and T‐cell stimuli by cytometric bead array. Responsiveness to the glucocorticoid dexamethasone was determined. Results: Supplementation of mothers with 4400 IU of vitamin D3 resulted in an enhanced broad‐spectrum proinflammatory cytokine response of cord blood mononuclear cells to innate and mitogenic stimuli (P = .0009), with an average 1.7‐ to 2.1‐fold increase in levels of several proinflammatory cytokines (GM‐CSF, IFN‐&ggr;, IL‐1&bgr;, IL‐6, and IL‐8) across stimuli, a higher gene expression level of TLR2 (P = .02) and TLR9 (P = .02), a greater than 4‐fold increase in IL‐17A (P = .03) production after polyclonal T‐cell stimulation, and an enhanced IL‐10 response of cord blood mononuclear cells to dexamethasone treatment in culture (P = .018). Conclusion: Vitamin D exposure during fetal development influences the immune system of the neonate, which can contribute to protection from asthma‐related, including infectious, outcomes in early life.

Urban Particulate Matter–Activated Human Dendritic Cells Induce the Expansion of Potent Inflammatory Th1, Th2, and Th17 Effector Cells

Exposure to urban particulate matter (UPM) exacerbates asthmatic lung inflammation. Lung dendritic cells (DCs) are critical for stimulating T cell immunity and in maintaining airway tolerance, but they also react to airway UPM. The adjuvant role of UPM in enhancing primary immune responses by naive cells to allergen has been reported, but the direct effects of UPM-activated DCs on the functionality of human memory CD4 T cells (Tms), which constitute the majority of T cells in the lung, has not been investigated. Blood CD1c(+) DCs were purified and activated with UPM in the presence or absence of house dust mite or tetanus toxoid control antigen. 5-(and -6)-Carboxyfluorescein diacetate succinimidyl ester-labeled blood Tms were cocultured with autologous DCs, T cell proliferation and effector function were assessed using flow cytometry, and secreted cytokines were measured by combined bead array. UPM-DCs elicited IFN-γ and IL-13 secretion and induced proliferation in Tms isolated from both allergic patients with asthma and healthy control subjects, whereas only IL-13 was produced by Tms from patients with atopic asthma stimulated by house dust mite-loaded DCs. UPM-DCs drove the expansion and differentiation of a mixed population of Th1, Th2, and Th17 cell effectors through a mechanism that was dependent on major histocompatibility class II but not on cytokine-driven expansion. The data suggest that UPM not only has adjuvant properties but is also a source of antigen that stimulates the generation of Th2, Th1, and Th17 effector phenotypes, which have been implicated in both exacerbations of asthma and chronic inflammatory diseases.

Vitamin D Influences Asthmatic Pathology through Its Action on Diverse Immunological Pathways

The prevalence of vitamin D insufficiency and deficiency has increased markedly in recent decades to current epidemic levels (Hyppönen E, et al. Am J Clin Nutr 2007;85:860-868). In parallel, there has been an increase in the incidence of a range of immune-mediated conditions ranging from cancer to autoimmune and respiratory diseases, including chronic obstructive pulmonary disease and asthma (Holick MF. N Engl J Med 2007;357:266-281; Finklea et al. Adv Nutr 2011;2:244-253). There is also an association with increased respiratory infections, which are the most common cause of asthma exacerbations (Finklea et al. Adv Nutr 2011;2:244-253). Together, this has resulted in considerable interest in the therapeutic potential of vitamin D to prevent and improve treatment of asthma and other respiratory diseases. To this end, data from clinical trials involving supplementation with active vitamin D, or more commonly a precursor, are starting to emerge. This review considers mechanisms by which vitamin D may act on the immune system to dampen inappropriate inflammatory responses in the airway while also promoting tolerance and antimicrobial defense mechanisms that collectively maintain respiratory health.

Urban Particulate Matter Suppresses Priming of T Helper Type 1 Cells by Granulocyte/Macrophage Colony–Stimulating Factor–Activated Human Dendritic Cells

Urban particulate matter (UPM) exacerbates asthmatic lung inflammation and depresses lung immunity. Lung dendritic cells (DCs) react to airway particulates, and have a critical role in linking innate and adaptive immunity, but the direct effects of UPM on DCs, that have been activated by granulocyte/macrophage colony-stimulating factor (GM-CSF), a product of stimulated normal human bronchial epithelial cells, has not been investigated. Human blood CD1c(+) DCs were purified and activated with UPM in the presence or absence of GM-CSF with and without LPS, and DC maturation was assessed by flow cytometry. DC stimulatory capacity and priming of 5-(and -6)-carboxyfluorescein diacetate succinimidyl ester-labeled naive CD4 T cells was investigated using the allogeneic mixed lymphocyte reaction. T cell proliferation and effector function were assessed using flow cytometry and secreted cytokines were measured by combined bead array. UPM enhanced DC maturation in an LPS-independent manner. DCs activated by UPM plus GM-CSF (UPM + GM-CSF DCs) induced higher naive CD4 T cell proliferation in the allogeneic mixed lymphocyte reaction than DCs pretreated by GM-CSF alone (GM-CSF DCs), and elicited both substantially lower levels of IFN-γ, IL-13, and IL-5 secretion, and lower frequencies of alloantigen-specific T helper (Th) type 1 effector cells than naive CD4 T cells primed by GM-CSF DCs. UPM-stimulated DCs produced IL-6 and TNF-α. Neutralization of IL-6 decreased naive CD4 T cell proliferation stimulated by UPM + GM-CSF DCs, and significantly increased the frequency of alloantigen-specific Th1 effector cells, but did not reverse UPM-induced inhibition of IFN-γ secretion. We conclude that UPM enhances GM-CSF-induced DC maturation and stimulatory capacity, but inhibits the generation of Th1 cells. Thus, UPM exposure may impair Th1 responses to pulmonary pathogens.

Vitamin D Counteracts an IL-23–Dependent IL-17A+IFN-γ+ Response Driven by Urban Particulate Matter

&NA; Urban particulate matter (UPM) air pollution and vitamin D deficiency are detrimentally associated with respiratory health. This is hypothesized to be due in part to regulation of IL‐17A, which UPM is reported to promote. Here, we used a myeloid dendritic cell (DC)‐memory CD4+ T cell co‐culture system to characterize UPM‐driven IL‐17A+ cells, investigate the mechanism by which UPM‐primed DCs promote this phenotype, and address evidence for cross‐regulation by vitamin D. CD1c+ myeloid DCs were cultured overnight with or without a reference source of UPM and/or active vitamin D (1,25[OH]2D3) before they were co‐cultured with autologous memory CD4+ T cells. Supernatants were harvested for cytokine analysis on Day 5 of co‐culture, and intracellular cytokine staining was performed on Day 7. UPM‐primed DCs increased the proportion of memory CD4+ T cells expressing the T helper 17 cell (Th17)‐associated cytokines IL‐17A, IL‐17F, and IL‐22, as well as IFN‐&ggr;, granulocyte‐macrophage colony‐stimulating factor, and granzyme B. Notably, a large proportion of the UPM‐driven IL‐17A+ cells co‐expressed these cytokines, but not IL‐10, indicative of a proinflammatory Th17 profile. UPM‐treated DCs expressed elevated levels of il23 mRNA and increased secretion of IL‐23p40. Neutralization of IL‐23 in culture reduced the frequency of IL‐17A+IFN‐&ggr;+ cells without affecting cell proliferation. 1,25(OH)2D3 counteracted the UPM‐driven DC maturation and inhibited the frequency of IL‐17A+IFN‐&ggr;+ cells, most prominently when DCs were co‐treated with the corticosteroid dexamethasone, while maintaining antiinflammatory IL‐10 synthesis. These data indicate that UPM might promote an inflammatory milieu in part by inducing an IL‐23‐driven proinflammatory Th17 response. Restoring vitamin D sufficiency may counteract these UPM‐driven effects without obliterating important homeostatic immune functions.