Albuterol delivery via in-line intrapulmonary percussive ventilation superimposed on conventional mechanical ventilation in an adult lung model.

Background: Intrapulmonary percussive ventilation (IPV) is frequently used for airway clearance, together with delivery of aerosols containing medications. Drug delivery via IPV alone increases with decreasing percussion frequency and correlates with tidal volume (VT) while drug delivery via IPV during conventional mechanical ventilation (IPV/CMV) is not well characterized. We hypothesized that drug delivery via IPV/CMV would take place differently from that via IPV alone due to control of ventilation by CMV. Methods: An adult ventilator circuit was used for IPV/CMV. A normal or diseased lung model was configured to airway resistance (Raw) 5 cm H2O/L/s and lung compliance (CL) 100 mL/cm H2O or Raw 20 cm H2O/L/s and CL 50 mL/cm H2O, respectively. The ventilator settings were: pressure control continuous mandatory ventilation mode, 10 breaths/min, PEEP 5 cm H2O, FIO2 0.21, inspiratory time 1 s, no bias flow, and inspiratory pressure 10 or 15 cm H2O for the normal or diseased lung model, respectively, to reach VT 500 mL with IPV off. Albuterol nebulized from Phasitron 5 was captured in a filter placed before the lung model and quantitated by spectrophotometry. Results: The maximal efficiency of albuterol delivery via IPV/CMV was not different from that via IPV alone (3.7 ± 0.2% vs 4.2 ± 0.3%, mean ± SD of loading dose, P= .12). Albuterol delivery efficiency with IPV/CMV was lower for the diseased lung model than for the normal model (1.6 ± 0.3% vs 3.2 ± 0.5%, mean ± SD, P < .001), which increased with decreasing percussion frequency. In contrast, VT was lower for the normal lung model than for the diseased model (401 ± 14 mL vs 470 ± 11 mL, mean ± SD, P < .001). Conclusions: Albuterol delivery via IPV/CMV was modulated by percussion frequency but not increased with increasing VT The delivery efficiency was not sufficiently high for clinical use, in part due to nebulizer retention and extrapulmonary deposition.

Effects of tumor-infiltrating CD8+ T cells, PD1/PD-L1 axis, and expression patterns of HLA class I on the prognosis of patients with malignant pleural mesothelioma who underwent extra-pleural pneumonectomy.

Programmed cell death protein-1 (PD1), PD1 ligand 1 (PD-L1), and human leukocyte antigen (HLA) class I molecule play pivotal roles in T cell-induced anti-tumor immunity; however, the clinical impact of these parameters in resected malignant pleural mesothelioma (MPM) cases is unknown. We immunohistochemically evaluated the tumor infiltrated lymphocytes (TILs), PD1/PD-L1 axis, and expression of HLA class I in resected specimens from 58 patients with MPM who underwent extra-pleural pneumonectomy (EPP). Higher infiltration of CD3-TIL, CD8-TIL, and PD1-TIL, loss of HLA class I, and overexpression of PD-L1 by tumor cells (PD-L1 TC) or immune cells (PD-L1 IC) were observed in 34 (58.6%), 27 (46.6%), 41 (70.7%), 45 (77.6%), 29 (50.0%), and 33 (56.4%) of 58 cases, respectively. Interestingly, the CD3-TIL score positively correlated with PD-L1 TC and PD1-TIL scores. HLA class I expression level was inversely correlated with the expression levels of PD-L1 TC and PD-L1 IC. Multivariate analysis showed that age, histology, and node metastasis were independent prognostic factors for 5-year overall survival (OS) and loss of HLA class I coincided with a positive prognosis (p = 0.011). The concomitant lack of infiltrating CD8+ T cells with no loss of HLA class I predicted worse 5-year OS (p = 0.007). Moreover, cluster classifications among multiple immunoparameters showed that categories among CD3/PD-L1 TC/HLA class I (p = 0.043), CD8/PD1/HLA class I (p = 0.032), CD8/PD-L1 TC/HLA class I (p = 0.011), and PD1/PD-L1 TC/HLA class I (p = 0.032) predicted 5-year OS in EPP cases for MPM. These immunoparameters could guide surgical indications for patients with MPM.

Enhanced Immunomodulatory Effect of Intravenous Immunoglobulin by Fc Galactosylation and Nonfucosylation.

Intravenous immunoglobulin (IVIG) is used as an immunomodulatory agent in the treatment of various autoimmune/inflammatory diseases although its mechanism of action remains elusive. Recently, nonfucosylated IgG has been shown to be preferentially bound to Fcγ receptor IIIa (FcγRIIIa) on circulating natural killer cells; therefore, we hypothesized that nonfucosylated IVIG may modulate immune responses through FcγRIIIa blockade. Here, homogeneous fucosylated or nonfucosylated glycoforms of normal polyclonal IgG bearing sialylated, galactosylated or nongalactosylated Fc oligosaccharides were generated by chemoenzymatic glycoengineering to investigate whether the IgG glycoforms can inhibit antibody-dependent cellular cytotoxicity (ADCC).　Among the six IgG glycoforms, galactosylated, nonfucosylated IgG [(G2)2] had the highest affinity to FcγRIIIa and 20 times higher potency to inhibit ADCC than native IgG. A pilot study of IVIG treatment in mice with collagen antibody-induced arthritis highlighted the low-dose (G2)2 glycoform of IVIG (0.1 g/kg) as an effective immunomodulatory agent as the 10-fold higher dose of native IVIG. These preliminary results suggest that the anti-inflammatory activity of IVIG is in part mediated via activating FcγR blockade by galactosylated, nonfucosylated IgG and that such nonfucosylated IgG glycoforms bound to FcγRs on immune cells play immunomodulatory roles in health and disease. This study provides insights into improved therapeutic strategies for autoimmune/inflammatory diseases using glycoengineered IVIG and recombinant Fc.

Micro-Heterogeneity of Antibody Molecules.

Therapeutic monoclonal antibodies (mAbs) are mostly of the IgG class and constitute highly efficacious biopharmaceuticals for a wide range of clinical indications. Full-length IgG mAbs are large proteins that are subject to multiple posttranslational modifications (PTMs) during biosynthesis, purification, or storage, resulting in micro-heterogeneity. The production of recombinant mAbs in nonhuman cell lines may result in loss of structural fidelity and the generation of variants having altered stability, biological activities, and/or immunogenic potential. Additionally, even fully human therapeutic mAbs are of unique specificity, by design, and, consequently, of unique structure; therefore, structural elements may be recognized as non-self by individuals within an outbred human population to provoke an anti-therapeutic/anti-drug antibody (ATA/ADA) response. Consequently, regulatory authorities require that the structure of a potential mAb drug product is comprehensively characterized employing state-of-the-art orthogonal analytical technologies; the PTM profile may define a set of critical quality attributes (CQAs) for the drug product that must be maintained, employing quality by design parameters, throughout the lifetime of the drug. Glycosylation of IgG-Fc, at Asn297 on each heavy chain, is an established CQA since its presence and fine structure can have a profound impact on efficacy and safety. The glycoform profile of serum-derived IgG is highly heterogeneous while mAbs produced in mammalian cells in vitro is less heterogeneous and can be "orchestrated" depending on the cell line employed and the culture conditions adopted. Thus, the gross structure and PTM profile of a given mAb, established for the drug substance gaining regulatory approval, have to be maintained for the lifespan of the drug. This review outlines our current understanding of common PTMs detected in mAbs and endogenous IgG and the relationship between a variant's structural attribute and its impact on clinical performance.

Importance and Monitoring of Therapeutic Immunoglobulin G Glycosylation.

The complex diantennary-type oligosaccharides at Asn297 residues of the IgG heavy chains have a profound impact on the safety and efficacy of therapeutic IgG monoclonal antibodies (mAbs). Fc glycosylation of a mAb is an established critical quality attribute (CQA), and its oligosaccharide profile is required to be thoroughly characterized by state-of-the-art analytical methods. The Fc oligosaccharides are highly heterogeneous, and the differentially glycosylated species (glycoforms) of IgG express unique biological activities. Glycoengineering is a promising approach for the production of selected mAb glycoforms with improved effector functions, and non- and low-fucosylated mAbs exhibiting enhanced antibody-dependent cellular cytotoxicity activity have been approved or are under clinical evaluation for treatment of cancers, autoimmune/chronic inflammatory diseases, and infection. Recently, the chemoenzymatic glycoengineering method that allows for the transfer of structurally defined oligosaccharides to Asn-linked GlcNAc residues with glycosynthase has been developed for remodeling of IgG-Fc oligosaccharides with high efficiency and flexibility. Additionally, various glycoengineering methods have been developed that utilize the Fc oligosaccharides of IgG as reaction handles to conjugate cytotoxic agents by "click chemistry", providing new routes to the design of antibody-drug conjugates (ADCs) with tightly controlled drug-antibody ratios (DARs) and homogeneity. This review focuses on current understanding of the biological relevance of individual IgG glycoforms and advances in the development of next-generation antibody therapeutics with improved efficacy and safety through glycoengineering.

Cytokine Adsorption to Polymyxin B-Immobilized Fiber: An in vitro Study.

BACKGROUND: Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) are episodes of acute respiratory worsening characterized by diffuse alveolar damage superimposed on usual interstitial pneumonia. Direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) is reported to have beneficial effects on the respiratory status and outcome in patients with AE-IPF although its mechanism of action is not fully elucidated. OBJECTIVE: To investigate whether and how the PMX-immobilized fiber (PMX-F) adsorbs cytokines because reduction of the serum levels of various cytokines has been noted in AE-IPF patients receiving PMX-DHP. METHODS: The propensity of recombinant cytokines for adsorption onto PMX-F was examined by incubating cytokines with heparin-coated or uncoated PMX-F for 2 h at 37°C. Cytokines were quantitated by multiplex bead array assay or ELISA. RESULTS: Interleukin (IL)-8, RANTES, platelet-derived growth factor-bb, and transforming growth factor-ß were substantially adsorbed onto PMX-F without heparin coating. The adsorbed cytokines could be eluted with PMX sulfate, indicating that the PMX moiety is involved in cytokine adsorption. Importantly, although IL-1ß, monocyte chemoattractant protein-1, fibroblast growth factor 2, and vascular endothelial growth factor-A were adsorbed onto PMX-F to lesser extents, the adsorption was enhanced by heparin coating of PMX-F. Furthermore, heparin-coated PMX-F acquired the capability to adsorb IL-6, IL-12, and tumor necrosis factor α. An affinity of heparin to PMX was determined (Kd = 0.061 ± 0.032 mg/mL), which accounts for the enhanced cytokine adsorption onto PMX-F upon heparin coating. CONCLUSIONS: Various cytokines involved in inflammation, fibrosis, and vascular permeability were shown to be adsorbed onto PMX-F. Removal of multiple cytokines may be associated with positive impacts of PMX-DHP in patients with AE-IPF.

Variations in the Efficiency of Albuterol Delivery and Intrapulmonary Effects With Differential Parameter Settings on Intrapulmonary Percussive Ventilation.

BACKGROUND: Intrapulmonary percussive ventilation (IPV) is used for airway clearance and delivery of aerosol medications, including bronchodilators. Despite the common use of IPV for drug delivery, few data are available regarding optimization of inhalation therapy with IPV. In this study, we investigated the influence of IPV setting parameters and lung mechanics on drug delivery via IPV alone. METHODS: An IPV device was connected to a lung model via a trachea model and a flow analyzer. Albuterol nebulized from the IPV device was collected onto a filter attached between the trachea and lung models, and was quantitated by spectrophotometry (230 nm). RESULTS: Albuterol delivery to the lung model was increased up to 2.1-fold, with decreasing percussion frequency. Decreasing percussion frequency concomitantly increased the tidal volume, and albuterol delivery was correlated with tidal volume (r = 0.91, P < .001). Airway resistance had a negative impact on albuterol delivery, whereas lung compliance had no significant effect. Increasing operational pressure increased albuterol delivery while increasing peak inspiratory pressure. CONCLUSIONS: Albuterol delivery and tidal volume with IPV can be improved by maintaining low levels of percussion frequency and increasing operational pressure. When increasing operational pressure, the peak inspiratory pressure and airway resistance levels need to be carefully monitored for safe inhalation therapy with IPV.

Glycosylation engineering of therapeutic IgG antibodies: challenges for the safety, functionality and efficacy.

Glycosylation of the Fc region of IgG has a profound impact on the safety and clinical efficacy of therapeutic antibodies. While the biantennary complex-type oligosaccharide attached to Asn297 of the Fc is essential for antibody effector functions, fucose and outer-arm sugars attached to the core heptasaccharide that generate structural heterogeneity (glycoforms) exhibit unique biological activities. Hence, efficient and quantitative glycan analysis techniques have been increasingly important for the development and quality control of therapeutic antibodies, and glycan profiles of the Fc are recognized as critical quality attributes. In the past decade our understanding of the influence of glycosylation on the structure/function of IgG-Fc has grown rapidly through X-ray crystallographic and nuclear magnetic resonance studies, which provides possibilities for the design of novel antibody therapeutics. Furthermore, the chemoenzymatic glycoengineering approach using endoglycosidase-based glycosynthases may facilitate the development of homogeneous IgG glycoforms with desirable functionality as next-generation therapeutic antibodies. Thus, the Fc glycans are fertile ground for the improvement of the safety, functionality, and efficacy of therapeutic IgG antibodies in the era of precision medicine.

Enhanced sialylation of a human chimeric IgG1 variant produced in human and rodent cell lines.

Glycosylation of the IgG-Fc is essential for optimal binding and activation of Fcγ receptors and the C1q component of complement. However, it has been reported that the effector functions are down-regulated when the Fc glycans terminate in sialic acid residues and that sialylated IgG mediates anti-inflammatory effects of intravenous immunoglobulin (IVIG). Although recombinant IgG is hypo-sialylated, Fc sialylation is shown to be markedly increased when a mouse/human chimeric IgG3 Phe243Ala (F243A) variant is expressed in Chinese hamster ovary (CHO)-K1 cells. Here we investigate whether sialylation is increased in IgG1 F243A when expressed in CHO-K1, mouse myeloma J558L and human embryonic kidney (HEK) 293. Although the sialylation level was 2-5% for IgG1 wild type (WT), it was increased to 31%, 10% and 33% for the variant from CHO-K1, J558L and HEK293 cells, respectively. Interestingly, an increased addition of bisecting GlcNAc and α(1-3)-galactose residues to the Fc glycan was observed for HEK293-derived and J558L-derived IgG1 F243A, respectively. Fucosylation of HEK293-derived IgG1 F243A was maintained despite increased bisecting GlcNAc content. Although sialic acid and bisecting GlcNAc residues are reported to have an opposing effect on antibody-dependent cellular cytotoxicity (ADCC), IgG1 F243A showed 7 times lower ADCC activities than IgG1 WT, irrespective of bisecting GlcNAc residue. Thus, highly sialylated, human cell-derived IgG1 F243A with lowered ADCC activity may be of interest for the development of therapeutic antibodies with anti-inflammatory properties as an alternative to IVIG.

Vigorous inflammatory responses in noninfectious pulmonary complication induced by donor lymphocyte infusion.

BACKGROUND: Donor lymphocyte infusion (DLI) is used for treatment of hematologic malignancy relapse or mixed chimerism after allogeneic hematopoietic stem cell transplantation. Although graft-versus-host disease is well recognized as one of the adverse effects of DLI, there are limited reports on noninfectious pulmonary complications (NIPCs) after DLI. CASE REPORT: A 55-year-old woman with acute myeloid leukemia received DLI for conversion from recipient predominant to complete donor chimerism on Day +193 after allogeneic HSCT. Eight weeks later, she complained of dyspnea with fever; chest computed tomography revealed diffuse, bilateral, ground glass opacity and reticular appearance. She was diagnosed as having NIPC based on serum and bronchoalveolar lavage fluid (BALF) findings. She was successfully treated with prednisolone (PSL) and completely recovered. DISCUSSION: We analyzed the cell profile from the BALF and 27 cytokines and chemokines in the serum using the Bio-Plex platform. The cells consisted of recipient predominant macrophages and T cells. The serum cytokine and chemokine profile showed significant elevation of interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor-α, macrophage inflammatory protein (MIP)-1α, and MIP-1ß, which declined with the improvement of symptoms after initiation of PSL treatment. CONCLUSION: Inflammatory effectors by recipient cells, rather than allogeneic responses by donor cells, played an important role in the pathogenesis of NIPCs after DLI in the present case.

Association between cytokine removal by polymyxin B hemoperfusion and improved pulmonary oxygenation in patients with acute exacerbation of idiopathic pulmonary fibrosis.

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is characterized by severe worsening dyspnea of unknown etiology and high mortality without effective treatment. Recently, direct hemoperfusion with polymyxin B (PMX)-immobilized fiber cartridge (PMX-DHP) has been reported to improve pulmonary oxygenation and survival in patients with AE-IPF although its mechanism of action remains unknown. To gain insights into the pathobiology of AE-IPF through the beneficial effects of PMX-DHP, we analyzed the profile of cytokines adsorbed onto PMX-fibers used in 9 AE-IPF patients. In addition, the sera of these AE-IPF patients collected immediately before and after PMX-DHP, 9 stable IPF patients and 8 healthy individuals were also analyzed. The serum levels of cytokines including IL-9, IL-12, IL-17, PDGF and VEGF were significantly decreased immediately after PMX-DHP (P<0.02), and VEGF and IL-12 were most prominently reduced. In addition to PDGF and VEGF, IL-1ß, IL-1ra, IL-8, IL-23, FGF basic, GM-CSF, IP-10, RANTES and TGF-ß were eluted from used PMX-fibers. Interestingly, improved pulmonary oxygenation after PMX-DHP was correlated well with the quantities of eluted VEGF. These results suggest that adsorption of proinflammatory, profibrotic and proangiogenic cytokines onto PMX-fibers is one of the mechanisms of action of PMX-DHP in AE-IPF. Notably, removal of VEGF by PMX-DHP may contribute to the rapid improvement in oxygenation by suppressing vascular permeability in the lung.

Novel glycan biomarkers for the detection of lung cancer.

Lung cancer has a poor prognosis and a 5-year survival rate of 15%. Therefore, early detection is vital. Diagnostic testing of serum for cancer-associated biomarkers is a noninvasive detection method. Glycosylation is the most frequent post-translational modification of proteins and it has been shown to be altered in cancer. In this paper, high-throughput HILIC technology was applied to serum samples from 100 lung cancer patients, alongside 84 age-matched controls and significant alterations in N-linked glycosylation were identified. Increases were detected in glycans containing Sialyl Lewis X, monoantennary glycans, highly sialylated glycans and decreases were observed in core-fucosylated biantennary glycans, with some being detectable as early as in Stage I. The N-linked glycan profile of haptoglobin demonstrated similar alterations to those elucidated in the total serum glycome. The most significantly altered HILIC peak in lung cancer samples includes predominantly disialylated and tri- and tetra-antennary glycans. This potential disease marker is significantly increased across all disease groups compared to controls and a strong disease effect is visible even after the effect of smoking is accounted for. The combination of all glyco-biomarkers had the highest sensitivity and specificity. This study identifies candidates for further study as potential biomarkers for the disease.

Folding of an MHC class II-restricted tumor antigen controls its antigenicity via MHC-guided processing.

CD4(+) and CD8(+) T cell responses to endogenous retroviral envelope glycoprotein gp90 generate protective immunity to murine colon carcinoma CT26. A panel of I-A(d)-restricted T cell hybridomas recognize gp90 synthesized by CT26 cells but not by other gp90-expressing tumors. Here we report that antigenicity resides in an incompletely folded form of gp90 that is unique to CT26. In contrast to more compact forms of gp90 that are present in other tumors, this open conformer is captured by recycling I-A(d) on antigen-presenting cells and is processed intracellularly. Thus, gp90 acquires immunodominance via MHC-guided processing, and the generation of an MHC class II-restricted response can be controlled by the intracellular folding environment of antigen-expressing cells.