An Allosteric Anti-tryptase Antibody for the Treatment of Mast Cell-Mediated Severe Asthma

Maun, Henry R.; Jackman, Janet; Choy, David F.; Loyet, Kelly M.; Staton, Tracy; Jia, Guiquan; Dressen, Amy; Hackney, Jason A.; Bremer, Meire; Walters, Benjamin T.; Vij, Rajesh; Chen, Xiaocheng; Trivedi, Neil N.; Morando, Ashley; Lipari, Michael T.; Franke, Yvonne; Wu, Xiumin; Zhang, Juan; Liu, John; Wu, Ping; Chang, Diana; Orozco, Luz D.; Christensen, Erin; Wong, Manda; Corpuz, Racquel; Hang, Julie Q.; Lutman, Jeff; Sukumaran, Siddharth; Wu, Yan; Ubhayakar, Savita; Liang, Xiaorong; Schwartz, Lawrence B.; Babina, Magda; Woodruff, Prescott G.; Fahy, John V.; Ahuja, Rahul; Caughey, George H.; Kusi, Aija; Dennis, Mark S.; Eigenbrot, Charles; Kirchhofer, Daniel; Austin, Cary D.; Wu, Lawren C.; Koerber, James T.; Lee, Wyne P.; Yaspan, Brian L.; Alatsis, Kathila R.; Arron, Joseph R.; Lazarus, Robert A.; Yi, Tangsheng

doi:10.1016/j.cell.2019.09.009

Cited by 82 publications

(64 citation statements)

References 95 publications

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“…Balb/c mice are characterized by easy reproduction and minimal weight variation between males and females. While the balb/c mouse serves as a general-purpose animal model, this strain is used extensively for hybridoma and monoclonal antibody production, for example, for the formation of antineuropilin-1 antibodies [7], antibody anti-tryptase [8], and very useful for cancer therapy and immunology study [9]. Aged balb/c mice become susceptible to infection with Streptococcus pyogenes, representing a possible analogy with decreased resistance to infection in elderly humans [10].…”

Section: Discussionmentioning

confidence: 99%

The Effect of Mango Mistletoes (Dendrophthoe pentandra) Leaves Extract on Percentage of CD4+CD28+, CD8+CD28+, and interleukin-2 Levels of Aged Balb/c Mice

Handono

Pratama

Sermoati

et al. 2021

Open Access Maced J Med Sci

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BACKGROUND: Population aging is considered to be a global phenomenon today. Age-associated immune system dysfunction or “immunosenescence” is indicated by increased susceptibility to infections and chronic diseases, such as hypertension, diabetes mellitus, autoimmune diseases, heart disease, and atherosclerosis. One of the immunosenescence markers is a significant drop in CD28 and reduced proinflammatory cytokine interleukin-2 (IL-2). The mango mistletoes are deemed to have a better affinity for docking the CD28 and IL-2R receptors of α and β subunits than other plants. AIM: This study aims to determine the effect of ethanol extract of mango mistletoes on IL-2 levels, the percentage of CD4+CD28+, and the percentage of CD8+CD28+ in aged female mice. METHODS: The leaves of mango mistletoes were extracted using 96% ethanol solvent, and the extract was administered to aged female mice (18–20 months) orally with different doses for each group, namely 150, 300, and 600 mg/kg. Mango mistletoe leaves extract was administered once a day for 14 days. Then, the IL-2 levels of the mice were checked from their heart blood samples using Enzyme-Linked Immunosorbent Assay, while the percentages of CD4+CD28+ and CD8+CD28+ were examined from the spleen samples using flow cytometry. RESULTS: The ethanol extract of mango mistletoe leaves was able to increase the percentage of CD4+CD28+ significantly (p < 0.05) at doses of 300 and 600 mg/kg and increase the percentage of CD8+CD28+ significantly (p < 0.05) at a dose of 600 mg/kgBW, while other various doses had a strong enough correlation (r = 0.48) to increase IL-2 levels. CONCLUSION: The ethanol extract of mango mistletoe leaves has the good potential to inhibit the aging process in the immune system, as characterized by an increase in IL-2 levels and the percentage of CD4+CD28+ and CD8+CD28+.

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Section: Discussionmentioning

confidence: 99%

The Effect of Mango Mistletoes (Dendrophthoe pentandra) Leaves Extract on Percentage of CD4+CD28+, CD8+CD28+, and interleukin-2 Levels of Aged Balb/c Mice

Handono

Pratama

Sermoati

et al. 2021

Open Access Maced J Med Sci

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“…Mast cells contribute to the pathobiology of severe asthma by mediating airflow obstruction and AHR [202]. A role for mast cells in severe asthma was shown with imatinib, which blocks stem cell factor signalling by inhibiting the mast/stem cell growth factor receptor KIT with reductions in airway methacholine reactivity, serum tryptase levels, and airway mast cell counts [203].…”

Section: Mast Cellsmentioning

confidence: 99%

“…A role for mast cells in severe asthma was shown with imatinib, which blocks stem cell factor signalling by inhibiting the mast/stem cell growth factor receptor KIT with reductions in airway methacholine reactivity, serum tryptase levels, and airway mast cell counts [203]. Recent studies identified that mast cell-derived tryptase, the dominant secretory granule protein in mast cells, is elevated in BALF and blood from severe asthmatics with either type 2-low or type 2-high disease [138,202]. Moreover, due to common polymorphisms in the two genes producing b-tryptase, it is possible to have 2,3 or 4 active b-tryptase alleles, and serum tryptase levels correlate with the number of active b-tryptase alleles [202].…”

Section: Mast Cellsmentioning

confidence: 99%

“…Recent studies identified that mast cell-derived tryptase, the dominant secretory granule protein in mast cells, is elevated in BALF and blood from severe asthmatics with either type 2-low or type 2-high disease [138,202]. Moreover, due to common polymorphisms in the two genes producing b-tryptase, it is possible to have 2,3 or 4 active b-tryptase alleles, and serum tryptase levels correlate with the number of active b-tryptase alleles [202]. A neutralizing antibody directed against human b-tryptase has been developed that inhibits airway tryptase in non-human primates and can potentially be developed into a new treatment option for type 2-low severe asthmatics.…”

Section: Mast Cellsmentioning

confidence: 99%

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Treatment options in type-2 low asthma

2020

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Monoclonal antibodies targeting IgE or the type-2 cytokines IL-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma respectively. However, these therapies are not appropriate for 30–50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, “type-2 low” asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, though poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity, occupational exposures and may be driven by persistent bacterial infections and by activation of a recently-described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits which can be identified and addressed. We particularly focus on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally we review ongoing research into other pathways including TNF, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems and is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

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“…Our results for protease production and identification of rAbs to MT-SP1 (aka, matriptase), and urokinase plasminogen activator (uPA) showed that conformationally selective inhibitory antibodies can be identified from a naïve human Fab library displayed on bacteriophage. Several inhibitory antibodies have been developed to other proteases including HGFA [10], Factor XIa [11], MMP9 [12] and β-tryptase [13]. Another advantage of rAbs is that the antibody sequence of the binder allows for in vitro affinity maturation, mimicking an immune response, to select Abs with higher affinity and lower off-rate [14].…”

Section: Introductionmentioning

confidence: 99%

Structure of an affinity-matured inhibitory recombinant fab against urokinase plasminogen activator reveals basis of potency and specificity

Sevillano

Bohn

Zimanyi

et al. 2021

Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics

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Affinity maturation of U33, a recombinant Fab inhibitor of uPA, was used to improve the affinity and the inhibitory effect compared to the parental Fab. Arginine scanning of the six CDR loops of U33 was done to identify initial binding determinants since uPA prefers arginine in its primary substrate binding pocket. Two CDR loops were selected to create an engineered affinity maturation library of U33 that was diversified around ArgL91 (CDR L3) and ArgH52 (CDR H2). Biopanning of the randomized U33 library under stringent conditions resulted in eight Fabs with improved binding properties. One of the most potent inhibitors, AB2, exhibited a 13fold decrease in IC50 when compared to U33 largely due to a decrease in its off rate. To identify contributions of interfacial residues that might undergo structural rearrangement upon interface formation we used X-ray footprinting and mass spectrometry (XFMS). Four residues showed a pronounced decrease in solvent accessibility, and their clustering suggests that AB2 targets the active site and also engages residues in an adjacent pocket unique to human uPA. The 2.9 Å resolution crystal structure of AB2-bound to uPA shows a binding mode in which the CDR L1 loop inserts into the active site cleft and acts as a determinant of inhibition. The selectivity determinant of this binding mode is unlike previously identified inhibitory Fabs against uPA related serine proteases, MTSP-1, HGFA and FXIa. CDRs H2 and L3 loops aid in interface formation and provide critical saltbridges to remodel loops surrounding the active site of uPA providing specificity and further evidence that antibodies can be potent and selective inhibitors of proteolytic enzymes.

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An Allosteric Anti-tryptase Antibody for the Treatment of Mast Cell-Mediated Severe Asthma

Cited by 82 publications

References 95 publications

The Effect of Mango Mistletoes (Dendrophthoe pentandra) Leaves Extract on Percentage of CD4+CD28+, CD8+CD28+, and interleukin-2 Levels of Aged Balb/c Mice

The Effect of Mango Mistletoes (Dendrophthoe pentandra) Leaves Extract on Percentage of CD4+CD28+, CD8+CD28+, and interleukin-2 Levels of Aged Balb/c Mice

Treatment options in type-2 low asthma

Structure of an affinity-matured inhibitory recombinant fab against urokinase plasminogen activator reveals basis of potency and specificity

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