Differential regulation of BIRC2 and BIRC3 expression by inflammatory cytokines and glucocorticoids in pulmonary epithelial cells

Baker's yeast beta glucan supplementation was associated with an improved innate immune mRNA expression response after exercise

Beta glucans are found in many natural sources, however, only Baker's Yeast Beta Glucan (BYBG) has been well documented to have structure-function effects that are associated with improved innate immune response to stressors (e.g., exercise, infection, etc.). The purpose was to identify a BYBG-associated mRNA expression pattern following exercise. Participants gave IRB-approved consent and were randomized to BYBG (Wellmune®; N=9) or Placebo (maltodextrin; N=10) for 6-weeks prior to performing 90 min of whole-body exercise. Paxgene blood samples were collected prior to exercise (PRE), after exercise (POST), two hours after exercise (2H), and four hours after exercise (4H). Total RNA was isolated and analyzed for the expression of 770 innate immune response mRNA (730 mRNA targets; 40 housekeepers/controls; Nanostring nCounter). The raw data were normalized against housekeeping controls and expressed as Log2 fold change from PRE for a given condition. Significance was set at p < 0.05 with adjustments for multiple comparisons and false discovery rate. We identified 47 mRNA whose expression was changed after exercise with BYBG and classified them to four functional pathways: 1) Immune Cell Maturation (8 mRNA), 2) Immune Response and Function (5 mRNA), 3) Pattern Recognition Receptors and DAMP or PAMP Detection (25 mRNA), and 4) Detection and Resolution of Tissue Damage (9 mRNA). The identified mRNA whose expression was altered after exercise with BYBG may represent an innate immune response pattern and supports previous conclusions that BYBG improves immune response to a future sterile inflammation or infection.

Inducible gene expression of IκB-kinase ε is dependent on nuclear factor-κB in human pulmonary epithelial cells

While IκB-kinase-ε (IKKε) induces immunomodulatory genes following viral stimuli, its up-regulation by inflammatory cytokines remains under-explored. Since airway epithelial cells respond to airborne insults and potentiate inflammation, IKKε expression was characterized in pulmonary epithelial cell lines (A549, BEAS-2B) and primary human bronchial epithelial cells grown as submersion or differentiated air-liquid interface cultures. IKKε expression was up-regulated by the pro-inflammatory cytokines, interleukin-1β (IL-1β) and tumour necrosis factor-α (TNFα). Thus, mechanistic interrogations in A549 cells were used to demonstrate the NF-κB dependence of cytokine-induced IKKε. Furthermore, chromatin immunoprecipitation in A549 and BEAS-2B cells revealed robust recruitment of the NF-κB subunit, p65, to one 5' and two intronic regions within the IKKε locus (IKBKE). In addition, IL-1β and TNFα induced strong RNA polymerase 2 recruitment to the 5' region, the first intron, and the transcription start site. Stable transfection of the p65-binding regions into A549 cells revealed IL-1β- and TNFα-inducible reporter activity that required NF-κB, but was not repressed by glucocorticoid. While critical NF-κB motifs were identified in the 5' and downstream intronic regions, the first intronic region did not contain functional NF-κB motifs. Thus, IL-1β- and TNFα-induced IKKε expression involves three NF-κB-binding regions, containing multiple functional NF-κB motifs, and potentially other mechanisms of p65 binding through non-classical NF-κB binding motifs. By enhancing IKKε expression, IL-1β may prime, or potentiate, responses to alternative stimuli, as modelled by IKKε phosphorylation induced by phorbol 12-myristate 13-acetate. However, since IKKε expression was only partially repressed by glucocorticoid, IKKε-dependent responses could contribute to glucocorticoid-resistant disease.

Novel chimeric antigen receptor-expressing T cells targeting the malignant mesothelioma-specific antigen sialylated HEG1

The selection of highly specific target antigens is critical for the development of clinically efficient and safe chimeric antigen receptors (CARs). In search of diagnostic marker for malignant mesothelioma (MM), we have established SKM9-2 monoclonal antibody (mAb) which recognizes a MM-specific molecule, sialylated Protein HEG homolog 1 (HEG1), with high specificity and sensitivity. In this study, to develop a novel therapeutic approach against MM, we generated SKM9-2 mAb-derived CARs that included the CD28 (SKM-28z) or 4-1BB (SKM-BBz) costimulatory domain. SKM-28z CAR-T cells showed continuous growth and enhanced Tim-3, LAG-3, and PD-1 expression in vitro, which might be induced by tonic signaling caused by self-activation; however, these phenotypes were not observed in SKM-BBz CAR-T cells. In addition, SKM-BBz CAR-T cells exhibited slightly stronger in vitro killing activity against MM cell lines than SKM-28z CAR-T cells. More importantly, only SKM-BBz CAR-T cells, but not SKM-28z CAR-T cells, significantly inhibited tumor growth in vivo in a MM cell line xenograft mouse model. Gene expression profiling and reporter assays revealed differential signaling pathway activation; in particular, SKM-BBz CAR-T cells exhibited enhanced NF-kB signaling and reduced NFAT activation. In addition, SKM-BBz CAR-T cells showed upregulation of early memory markers, such as TCF7 and CCR7, as well as downregulation of pro-apoptotic proteins, such as BAK1 and BID, which may be associated with phenotypical and functional differences between SKM-BBz and SKM-28z CAR-T cells. In conclusion, we developed novel SKM9-2-derived CAR-T cells with the 4-1BB costimulatory domain, which could provide a promising therapeutic approach against refractory MM.

Synergy between Interleukin-1β, Interferon-γ, and Glucocorticoids to Induce TLR2 Expression Involves NF-κB, STAT1, and the Glucocorticoid Receptor

Glucocorticoids act via the glucocorticoid receptor (GR; NR3C1) to downregulate inflammatory gene expression and are effective treatments for mild to moderate asthma. However, in severe asthma and virus-induced exacerbations, glucocorticoid therapies are less efficacious, possibly due to reduced repressive ability and/or the increased expression of proinflammatory genes. In human A549 epithelial and primary human bronchial epithelial cells, toll-like receptor (TLR)-2 mRNA and protein were supra-additively induced by interleukin-1β (IL-1β) plus dexamethasone (IL-1β+Dex), interferon-γ (IFN-γ) plus dexamethasone (IFN-γ+Dex), and IL-1β plus IFN-γ plus dexamethasone (IL-1β+IFN-γ+Dex). Indeed, ∼34- to 2100-fold increases were apparent at 24 hours for IL-1β+IFN-γ+Dex, and this was greater than for any single or dual treatment. Using the A549 cell model, TLR2 induction by IL-1β+IFN-γ+Dex was antagonized by Org34517, a competitive GR antagonist. Further, when combined with IL-1β, IFN-γ, or IL-1β+IFN-γ, the enhancements by dexamethasone on TLR2 expression required GR. Likewise, inhibitor of κB kinase 2 inhibitors reduced IL-1β+IFN-γ+Dex-induced TLR2 expression, and TLR2 expression induced by IL-1β+Dex, with or without IFN-γ, required the nuclear factor (NF)-κB subunit, p65. Similarly, signal transducer and activator of transcription (STAT)-1 phosphorylation and γ-interferon-activated sequence-dependent transcription were induced by IFN-γ These, along with IL-1β+IFN-γ+Dex-induced TLR2 expression, were inhibited by Janus kinase (JAK) inhibitors. As IL-1β+IFN-γ+Dex-induced TLR2 expression also required STAT1, this study reveals cooperation between JAK-STAT1, NF-κB, and GR to upregulate TLR2 expression. Since TLR2 agonism elicits inflammatory responses, we propose that synergies involving TLR2 may occur within the cytokine milieu present in the immunopathology of glucocorticoid-resistant disease, and this could promote glucocorticoid resistance. SIGNIFICANCE STATEMENT: This study highlights that in human pulmonary epithelial cells, glucocorticoids, when combined with the inflammatory cytokines interleukin-1β (IL-1β) and interferon-γ (IFN-γ), can synergistically induce the expression of inflammatory genes, such as TLR2. This effect involved positive combinatorial interactions between NF-κB/p65, glucocorticoid receptor, and JAK-STAT1 signaling to synergistically upregulate TLR2 expression. Thus, synergies involving glucocorticoid enhancement of TLR2 expression may occur in the immunopathology of glucocorticoid-resistant inflammatory diseases, including severe asthma.