Einstein's tea leaf paradox induced localized aggregation of nanoparticles and their conversion to gold aerogels.

Normally, stirring is regarded as a technology to disperse the substances in liquid evenly. However, Einstein's tea leaf paradox (ETLP) describes the phenomenon that tea leaves concentrate in a "doughnut" shape via a secondary flow effect while stirring. Herein, to demonstrate ETLP-induced concentration in nanofluid, we simulated the nanoparticle trajectory under stirring and made a grayscale analysis of SiO2 nanofluids during stirring and standing processes. Unexpectedly, a localized concentration effect in the layer flow was found beside the macroscopic ETLP effect. Subsequently, the localized concentration was applied to achieve the ultrafast aggregation of Au nanoparticles to form gold aerogels (GAs). The skeleton size of GAs was adjusted from about 10 to 200 nm by only adjusting the temperature of HAuCl4 solution. The fabricated GAs had extremely high purity and crystallinity, revealing potential applications in photocatalysis and surface-enhanced Raman scattering.

Efficient production of bispecific antibodies-optimization of transfection strategy leads to high-level stable cell line generation of a Fabs-in-tandem immunoglobin.

Bispecific antibodies (bsAbs) are often composed of more than two component chains, such as Fabs-in-tandem immunoglobin (FIT-Ig) comprising three different component chains, which bring challenges for generating a high proportion of the correctly assembled bsAbs in a stable cell line. During the CHO-K1 stable cell line construction of a FIT-Ig, we investigated the FIT-Ig component chain ratio in transfection, where two sets of expression vectors were designed. Both designs utilized two vectors for co-transfection. Multiple transfections with plasmid ratio adjustment were applied, and the resultant minipools were evaluated for expression titer and quality of produced FIT-Ig. The results suggested that abundant outer Fab short chains (twofold chain genes versus other chains) can promote complete FIT-Ig assembly and therefore reduce the fragmental impurities of FIT-Ig. This adjustment of the component chain ratios at the beginning is beneficial to FIT-Ig stable cell line generation and brings favorable clones to process development.

Exploring health literacy in patients with chronic diseases in Chongqing, China: a cross-sectional study.

OBJECTIVES: Personal health literacy is the degree to which individuals have the ability to find, understand and use information and services to inform health-related decisions and actions for themselves and others. Health literacy levels remain low, despite the many measures that have been taken to improve it. In addition, the number of patients with chronic diseases is increasing. Our study aimed to explore the different aspects and factors influencing health literacy among patients with chronic diseases in Chongqing, China. DESIGN: Cross-sectional study. SETTING AND PATIENTS: This study was conducted in Chongqing using the 2018 National Questionnaire on Health Literacy of Residents administered to 27 336 patients with chronic diseases. OUTCOME MEASURES: The prevalence and factors of health literacy in patients with chronic diseases. RESULTS: Among the patients who participated in the study (n=27 336), 51.3% were males. Only 21.6% of the patients with chronic diseases had adequate health literacy (questionnaire score was equal to or exceeded 80% of the total questionnaire score). Patients with chronic diseases aged 25-34 years (OR=1.18, 95% CI 1.02 to 1.36) and 35-44 years (OR=1.18, 95 % CI 1.03 to 1.35) had higher health literacy than patients aged 65-69 years. Patients from rural areas had higher health literacy levels than those from urban areas (OR=0.92, 95% CI 0.86 to 1.00). Furthermore, married patients had lower health literacy than unmarried patients (OR=0.88, 95% CI 0.80 to 0.97). Patients who were illiterate or slightly literate (OR=0.10, 95% CI 0.08 to 0.12) had lower health literacy than patients who were in junior college or had a bachelor's degree or above. In addition, non-farmers had higher health literacy levels than farmers (OR=1.18, 95% CI 1.08 to 1.28). In terms of inadequate health literacy, patients who self-rated themselves as healthy had higher health literacy than those who self-rated as unhealthy (OR=1.80, 95% CI 1.33 to 2.43). CONCLUSIONS: The health literacy of patients with chronic conditions remains at a low level and varies significantly with their demographic and social characteristics. These findings indicate that targeted interventions may be useful to improve health literacy in patients with chronic conditions in China.

Systemic regulation of nodule structure and assimilated carbon distribution by nitrate in soybean.

Background: The nitrate regulates soybean nodulation and nitrogen fixation systemically, mainly in inhibiting nodule growth and reducing nodule nitrogenase activity, but the reason for its inhibition is still inconclusive. Methods: The systemic effect of nitrate on nodule structure, function, and carbon distribution in soybean (Glycine max (L.) Merr.) was studied in a dual-root growth system, with both sides inoculated with rhizobia and only one side subjected to nitrate treatment for four days. The non-nodulating side was genetically devoid of the ability to form nodules. Nutrient solutions with nitrogen concentrations of 0, 100, and 200 mg L-1 were applied as KNO3 to the non-nodulating side, while the nodulating side received a nitrogen-free nutrient solution. Carbon partitioning in roots and nodules was monitored using 13C-labelled CO2. Other nodule responses were measured via the estimation of the nitrogenase activity and the microscopic observation of nodule ultrastructure. Results: Elevated concentrations of nitrate applied on the non-nodulating side caused a decrease in the number of bacteroids, fusion of symbiosomes, enlargement of the peribacteroid spaces, and onset of degradation of poly-ß-hydroxybutyrate granules, which is a form of carbon storage in bacteroids. These microscopic observations were associated with a strong decrease in the nitrogenase activity of nodules. Furthermore, our data demonstrate that the assimilated carbon is more likely to be allocated to the non-nodulating roots, as follows from the competition for carbon between the symbiotic and non-symbiotic sides of the dual-root system. Conclusion: We propose that there is no carbon competition between roots and nodules when they are indirectly supplied with nitrate, and that the reduction of carbon fluxes to nodules and roots on the nodulating side is the mechanism by which the plant systemically suppresses nodulation under nitrogen-replete conditions.

Identification of duplicated suppressor of cytokine signaling 3 (SOCS3) genes in blunt snout bream (Megalobrama amblycephala).

The suppressor of cytokine signaling 3 (SOCS3) negatively regulates the responses of various immune cytokines. In this study, we identified socs3s genes of blunt snout bream. 209- and 216-aa long peptides are encoded by socs3a and socs3b genes, respectively. The socs3s mRNAs are expressed consistently during the entire process of embryonic development. Whole-mount in situ hybridization detected socs3a in the eyes and posterior somites at 12 h post fertilization (hpf), transcribed at the otic vesicle at 24 hpf, and transcribed at the eyes, brain, and otic vesicle at 36 hpf; while the socs3b mRNA was transcribed at the notochord at 12 hpf, expressed in the brain, eyes, and tailbud at 24 hpf, and detected in the brain at 36 hpf. The expression of socs3a is slightly different from that of socs3b in tissues of juvenile and adult blunt snout bream. After recombinant human growth hormone (hGH) treatment, the transcript levels of socs3s of blunt snout bream were increased in gills, spleen, kidney, and gonads. After Aerononas hydrophila infection, the mRNA levels of socs3s of blunt snout bream were significantly increased in the liver, spleen, intestine, and kidney tissues. Blunt snout bream were susceptible to various pathogenic microorganisms, we intraperitoneally injected blunt snout bream with A. hydrophila to explore the immune mechanism of socs3s. These results suggested that socs3s of blunt snout bream plays important roles in the regulation of embryonic development and tissue growth, and that socs3s may also play key roles in regulating the bacterial-induced congenital immune response. Socs3s genes has the potential to be used as targeted genes to improve the immunity against bacteria, which is conducive to the improvement of production and breeding.

Identification of proteins differentially expressed in the gills of grass carp (Ctenopharyngodon idella) after hypoxic stress by two-dimensional gel electrophoresis analysis.

Two-dimensional gel electrophoresis (2-DE) was combined with liquid chromatography-mass spectrometry (LC-MS/MS) to identify the differential proteomics of grass carp gills after hypoxic stress to better understand the roles of proteins in the hypoxic response and to explore the possible molecular mechanisms. Protein spots were obtained from a hypoxia-stressed group (372 ± 11 individuals) and a control group (406 ± 14 individuals) using the lmage Master 2D Platinum 7.0 analysis software. Fifteen protein spots were expressed differentially in the hypoxia-stressed group and varied significantly after exposure to the hypoxic conditions. In addition, these differential proteins were identified by mass spectrometry and then searched in a database. We found the expression and upregulation of the toll-like receptor 4, ephx1 protein, isocitrate dehydrogenase, L-lactate dehydrogenase, GTP-binding nuclear protein Ran, and glyceraldehyde-3-phosphate dehydrogenase; however, the expression of the keratin type II cytoskeletal 8, type I cytokeratin, ARP3 actin-related protein 3 homolog, thyroid hormone receptor alpha-A, ATP synthase subunit beta, citrate synthase, tropomyosin 2, and tropomyosin 3 were downregulated. Six proteins were found in the hypoxia-inducible factor-1 (HIF-1) signaling pathway. We concluded that the grass carp gill is involved in response processes, including energy generation, metabolic processes, cellular structure, antioxidation, immunity, and signal transduction, to hypoxic stress. To our knowledge, this is the first study to conduct a proteomics analysis of expressed proteins in the gills of grass carp, and this study will help increase the understanding of the molecular mechanisms involved in hypoxic stress responses in fish at the protein level.

Generation of Fabs-in-tandem immunoglobulin molecules for dual-specific targeting.

Bispecific antibody (BsAb) has become an important trend in developing next generation biologics therapies. By simultaneously engaging two molecular targets, BsAbs show distinctive mechanism of actions that could lead to clinical benefits unattainable by conventional monoclonal antibodies (mAbs). Successful launch provided clinical validation and encourage more BsAb development in the pipeline of pharmaceutical companies. Fabs-in-tandem immunoglobulin (FIT-Ig™) format was initially described in 2017. This unique design provides a symmetrical and tetravalent IgG-like bispecific molecule with correct association of 2 sets of VH/VL pairs, where two Fabs are fused directly in a crisscross orientation without any mutations or use of peptide linkers. FIT-Ig can be readily made from 2 existing monoclonal antibodies by basic molecular biology techniques with high expression level in mammalian cells, and easily purified to homogeneity using standard approaches without extensive optimization. FIT-Ig molecules exhibit favorable drug-like properties, in vitro and in vivo functions, as well as manufacturing efficiency for commercial development. Here, we provide an example of construction and preliminary characterization of a FIT-Ig molecule with discussions on optimization and general utility.

Evaluation of Chronic Disease Prevention and Control Public Service Advertisement on the Awareness and Attitude Change among Urban Population in Chongqing, China: A Cross-Sectional Study.

The aim of this study is to evaluate the influence of public service advertising on the awareness and attitude of Chongqing urban citizens. The theme of the public service advertisement launched in Chongqing was chronic disease prevention and control. A self-designed questionnaire was used in an outdoor intercept survey to collect information about the perception of citizens toward the effect of the advertisement on awareness and attitude situation. Respondents had good knowledge of chronic disease (17.11 ± 3.23, total score: 23), but only 58.4% of participants thought cancer is one type of chronic disease. The awareness of cancer as a chronic disease among the group who had seen this advertisement (63.6%) was higher than that of the group who had not seen the advertisement (56.5%) (p = 0.046). The attitude of respondents was good after watching the advertisement, approximately 77.4% of respondents attempted to remind their family and friends to prevent chronic diseases, roughly. 78.2% tried to persuade their family and friends to change their unhealthy lifestyle habits, and 84.7% of participants reported that the advertising increased the possibility of their own future lifestyle change. There was minimal change of awareness of the participants who saw the advertisement. This study did not show significant differences on chronic disease related knowledge between the participants who have seen the advertisement and who have not seen the advertisement. The public service advertisement may help participants improve the attitude of future behavior change. Further researches combining the sustained intervention and support through clinical and community health programs media campaigns are needed to support public health.

Fabs-in-tandem immunoglobulin is a novel and versatile bispecific design for engaging multiple therapeutic targets.

In recent years, the development of bispecific antibody (bsAb) has become a major trend in the biopharmaceutical industry. By simultaneously engaging 2 molcular targets, bsAbs show unique mechanisms of action that could lead to clinical benefits unattainable by conventional monoclonal antibodies. Various bsAb generation formats have been described, and several are being investigated in clinical development. However, some bsAb constructs have proven to be problematic due to their unfavorable physicochemical and pharmacokinetic properties, as well as poor manufacturing efficiencies. We describe here a new bispecific design, Fabs-in-tandem immunoglobulin (FIT-Ig), in which 2 antigen-binding fragments are fused directly in a crisscross orientation without any mutations or use of peptide linkers. This unique design provides a symmetric IgG-like bispecific molecule with correct association of 2 sets of VH/VL pairs. We show that FIT-Ig molecules exhibit favorable drug-like properties, in vitro and in vivo functions, as well as manufacturing efficiency for commercial development.

Circulating Biomarkers for Predicting Infliximab Response in Rheumatoid Arthritis: A Systematic Bioinformatics Analysis.

BACKGROUND Infliximab shows good efficacy in treating refractory rheumatoid arthritis (RA). However, many patients responded poorly and related studies were inconsistent in predictive biomarkers. This study aimed to identify circulating biomarkers for predicting infliximab response in RA. MATERIAL AND METHODS Public databases of Gene Expression Omnibus (GEO) and ArrayExpress were searched for related microarray datasets, focused on the response to infliximab in RA. All peripheral blood samples were collected before infliximab treatment and gene expression profiles were measured using microarray. Differential genes associated with infliximab efficacy were analyzed. The genes recognized by half of the datasets were regarded as candidate biomarkers and validated by prospective datasets. RESULTS Eight microarray datasets were identified with 374 blood samples of RA patients, among which 191 (51.1%) were diagnosed as non-responders in the subsequent infliximab treatment. Five genes (FKBP1A, FGF12, ANO1, LRRC31, and AKR1D1) were associated with the efficacy and recognized by half of the datasets. The 5-gene model showed a good predictive power in random- and prospective-designed studies, with AUC (area under receiver operating characteristic [ROC] curve)=0.963 and 1.000, and it was also applicable at the early phase of treatment (at week 2) for predicting the response at week 14 (AUC=1.000). In the placebo group, the model failed to predict the response (AUC=0.697), indicating the model's specificity in infliximab treatment. CONCLUSIONS The model of FKBP1A, FGF12, ANO1, LRRC31, and AKR1D1 in peripheral blood is useful for efficiently predicting the response to infliximab treatment in rheumatoid arthritis.

RPC4046, A Novel Anti-interleukin-13 Antibody, Blocks IL-13 Binding to IL-13 α1 and α2 Receptors: A Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation First-in-Human Study.

INTRODUCTION: A unique anti-interleukin (IL)-13 monoclonal antibody, RPC4046, was generated on the basis of differential IL-13 receptor (R) blockade as assessed in a murine asthma model; the safety, tolerability, pharmacokinetics, and pharmacodynamics of RPC4046 were evaluated in a first-in-human study. METHODS: Anti-IL-13 antibodies with varying receptor blocking specificity were evaluated in the ovalbumin-induced murine asthma model. A randomized, double-blind, placebo-controlled, dose-escalation first-in-human study (NCT00986037) was conducted with RPC4046 in healthy adults and patients with mild to moderate controlled asthma. RESULTS: In the ovalbumin model, blocking IL-13 binding to both IL-13Rs (IL-13Rα1 and IL-13Rα2) inhibited more asthma phenotypic features and more fully normalized the distinct IL-13 gene transcription associated with asthma compared with blocking IL-13Rα1 alone. In humans, RPC4046 exposure increased dose-dependently; pharmacokinetics were similar in healthy and asthmatic subjects, and blockade of both IL-13Rs uniquely affected IL-13 gene transcription. A minority of participants (28%) had antidrug antibodies, which were transient and appeared not to affect pharmacokinetics. Adverse event profiles were similar in healthy and asthmatic subjects, without dose-related or administration route differences, systemic infusion-related reactions, or asthma symptom worsening. Adverse events were mild to moderate, with none reported as probably related to RPC4046 or leading to discontinuations. Non-serious upper respiratory tract infections were more frequent with RPC4046 versus placebo. CONCLUSION: RPC4046 is a novel anti-IL-13 antibody that blocks IL-13 binding to both receptors and more fully blocks the asthma phenotype. These results support further investigation of RPC4046 for IL-13-related allergic/inflammatory diseases (e.g., asthma and eosinophilic esophagitis). FUNDING: AbbVie Inc. sponsored the studies and contributed to the design and conduct of the studies, data management, data analysis, interpretation of the data, and in the preparation and approval of the manuscript.

Recent Advances in Site Specific Conjugations of Antibody Drug Conjugates (ADCs).

Antibody-drug conjugates (ADCs) take the advantage of antigen specificity of monoclonal antibodies to deliver highly potent cytotoxic drugs selectively to antigen-expressing tumor cells. The recent approval of Adcetris™ and Kadcyla™ as well as emerging data from numerous ongoing clinical trials underscore the role of ADCs as a new therapeutic option for cancer patients. However, conventional conjugation methods generally result in a heterogeneous mixture of ADCs, which can result in significant therapeutic liabilities and can lead to complicated manufacturing processes. The increased understanding from the clinical investigation of current ADCs and site-specific bioconjugation technologies has enabled scientists to accelerate the discovery and development of the next generation ADCs with defined and homogeneous composition. The present manuscript reviews the recent advances and trends in the research and development of novel ADCs obtained by site-specific conjugation method.

Evaluation of anti-smoking television advertising on tobacco control among urban community population in Chongqing, China.

BACKGROUND: China is the largest producer and consumer of tobacco in the world. Considering the constantly growing urban proportion, persuasive tobacco control measures are important in urban communities. Television, as one of the most pervasive mass media, can be used for this purpose. METHODS: The anti-smoking advertisement was carried out in five different time slots per day from 15 May to 15 June in 2011 across 12 channels of Chongqing TV. A cross-sectional study was conducted in the main municipal areas of Chongqing. A questionnaire was administered in late June to 1,342 native residents aged 18-45, who were selected via street intercept survey. RESULTS: Respondents who recognized the advertisement (32.77 %) were more likely to know or believe that smoking cigarettes caused impotence than those who did not recognize the advertisement (26.11 %). According to 25.5 % of smokers, the anti-smoking TV advertising made them consider quitting smoking. However, females (51.7 %) were less likely to be affected by the advertisement to stop and think about quitting smoking compared to males (65.6 %) (OR = 0.517, 95 % CI [0.281-0.950]). In addition, respondents aged 26-35 years (67.4 %) were more likely to try to persuade others to quit smoking than those aged 18-25 years (36.3 %) (OR = 0.457, 95 % CI [0.215-0.974]). Furthermore, non-smokers (87.4 %) were more likely to find the advertisement relevant than smokers (74.8 %) (OR = 2.34, 95 % CI [1.19-4.61]). CONCLUSIONS: This study showed that this advertisement did not show significant differences on smoking-related knowledge and attitude between non-smokers who had seen the ad and those who had not. Thus, this form may not be the right tool to facilitate change in non-smokers. The ad should instead be focused on the smoking population. Gender, smoking status, and age influenced the effect of anti-smoking TV advertising on the general population in China.

Generation and characterization of ABT-981, a dual variable domain immunoglobulin (DVD-Ig(TM)) molecule that specifically and potently neutralizes both IL-1α and IL-1ß.

Interleukin-1 (IL-1) cytokines such as IL-1α, IL-1ß, and IL-1Ra contribute to immune regulation and inflammatory processes by exerting a wide range of cellular responses, including expression of cytokines and chemokines, matrix metalloproteinases, and nitric oxide synthetase. IL-1α and IL-1ß bind to IL-1R1 complexed to the IL-1 receptor accessory protein and induce similar physiological effects. Preclinical and clinical studies provide significant evidence for the role of IL-1 in the pathogenesis of osteoarthritis (OA), including cartilage degradation, bone sclerosis, and synovial proliferation. Here, we describe the generation and characterization of ABT-981, a dual variable domain immunoglobulin (DVD-Ig) of the IgG1/k subtype that specifically and potently neutralizes IL-1α and IL-1ß. In ABT-981, the IL-1ß variable domain resides in the outer domain of the DVD-Ig, whereas the IL-1α variable domain is located in the inner position. ABT-981 specifically binds to IL-1α and IL-1ß, and is physically capable of binding 2 human IL-1α and 2 human IL-1ß molecules simultaneously. Single-dose intravenous and subcutaneous pharmacokinetics studies indicate that ABT-981 has a half-life of 8.0 to 10.4 d in cynomolgus monkey and 10.0 to 20.3 d in rodents. ABT-981 exhibits suitable drug-like-properties including affinity, potency, specificity, half-life, and stability for evaluation in human clinical trials. ABT-981 offers an exciting new approach for the treatment of OA, potentially addressing both disease modification and symptom relief as a disease-modifying OA drug.

Electroreduction of hexavalent chromium using a polypyrrole-modified electrode under potentiostatic and potentiodynamic conditions.

Polypyrrole (ppy)-modified electrode was used for electroreduction of Cr(VI) and showed favorable advantage with extremely higher removal percentage and current efficiency over stainless steel (SS) electrode. In potentiostatic (PS) process and in stagnant solution, ppy electrode achieved a Cr(VI) removal efficiency of 16% and a current efficiency of 23% compared to 0 for SS electrode at a potential of -0.8V. In potentiodynamic (PD) process and in stagnant solutions, ppy electrode exhibited a Cr(VI) removal efficiency of 56% at a potential range from -0.8 to 0.8V whereas SS electrode presented none at the same conditions. Solution stirring promoted mass transportation and dramatically improved Cr(VI) removal efficiency, achieving 92% (ppy electrode) and 18% (SS electrode) in PS process and 100% (ppy electrode) and 36% (SS electrode) in PD process at 100rpm. ppy electrode exhibited an efficient Cr(VI) reduction at a wide potential range from -0.8 to 0.8V than the potential ranges of -0.8 to 0V and 0-0.8V. While ppy stability under PD condition of -0.8 to 0.8V was not as satisfactory as PS condition at -0.8V, but better than PS condition at 0.8V. These results demonstrate that ppy-modified electrode in PD process may be a promising alternative for Cr(VI) electroreduction.

An intronic CYP46A1 polymorphism is associated with Alzheimer disease in a Chinese Han population.

Excess cholesterol is removed from the brain via hydroxylation mediated by cholesterol 24S-hydroxylase (CYP46), which is a mechanism of maintaining cholesterol homeostasis in the brain. The CYP46A1 gene has been suggested as a genetic risk factor for sporadic late-onset Alzheimer's disease (AD). In this report, we analyzed an intronic CYP46A1 single nucleotide polymorphism (SNP) in 508 sporadic AD patients and 549 controls in a Chinese Han population. Our results indicated that the distribution of CYP46A1 SNP rs754203 genotypes was significantly different in AD patients compared to controls (χ(2) = 6.59, P = 0.037). The frequency of at least one of CYP46A1 T allele (C/T or T/T) was higher in AD patients compared to controls (χ(2) = 6.58, P = 0.01). The age- and sex-adjusted odds ratio for the risk of AD in carriers of CYP46A1 T allele (C/T + T/T) was 1.69 (95 % confidence interval, 1.12-2.56). We conclude that this intronic polymorphism in CYP46A1 gene is associated with AD in a Chinese Han population, and the CYP46A1 T allele might be a risk factor for AD.

Diabodies: molecular engineering and therapeutic applications.

Bispecific antibodies are capable of interacting with two different antigens and when selected properly, can redirect cytotoxic effector cells to tumor cells for effective killing. These antibodies are therefore of great interest in the research and development of cancer treatment. Over the last two decades, many different bispecific antibody-derived molecular formats have been described, among which diabodies represent an important class of engineered molecules that possess tumor-targeting function. Since diabodies were first introduced in the early 1990s, extensive efforts have been made to optimize their physicochemical and key functional properties, as well as to provide in vivo proof of concept of their antitumor efficacy in animal models. With the clinical validation of the T-cell-retargeting mechanism for cancer therapy currently in place, there is renewed interest in this bispecific class of biologic molecules, with additional novel formats being described in recent years. Even with the remaining challenges of the manufacturing yields and drug-like properties, diabodies and their derivatives remain viable therapeutic modalities that warrant further consideration and development.

Unusual water-mediated antigenic recognition of the proinflammatory cytokine interleukin-18.

The unique cytokine interleukin-18 (IL-18) acts synergistically with IL-12 to regulate T-helper 1 and 2 lymphocytes and, as such, seems to underlie the pathogenesis of various autoimmune and allergic diseases. Several anti-IL-18 agents are in clinical development, including the recombinant human antibody ABT-325, which is entering trials for autoimmune diseases. Given competing cytokine/receptor and cytokine/receptor decoy interactions, understanding the structural basis for recognition is critical for effective development of anti-cytokine therapies. Here we report three crystal structures: the murine antibody 125-2H Fab fragment bound to human IL-18, at 1.5 A resolution; the 125-2H Fab (2.3 A); and the ABT-325 Fab (1.5 A). These structures, along with human/mouse IL-18 chimera binding data, allow us to make three key observations relevant to the biology and antigenic recognition of IL-18 and related cytokines. First, several IL-18 residues shift dramatically (> 10 A) upon binding 125-2H, compared with unbound IL-18 (Kato, Z., Jee, J., Shikano, H., Mishima, M., Ohki, I., Ohnishi, H., Li, A., Hashimoto, K., Matsukuma, E., Omoya, K., Yamamoto, Y., Yoneda, T., Hara, T., Kondo, N., and Shirakawa, M. (2003) Nat. Struct. Biol. 10, 966-971). IL-18 thus exhibits plasticity that may be common to its interactions with other receptors. Related cytokines may exhibit similar plasticity. Second, ABT-325 and 125-2H differ significantly in combining site character and architecture, thus explaining their ability to bind IL-18 simultaneously at distinct epitopes. These data allow us to define the likely ABT-325 epitope and thereby explain the distinct neutralizing mechanisms of both antibodies. Third, given the high 125-2H potency, 10 well ordered water molecules are trapped upon complex formation in a cavity between two IL-18 loops and all six 125-2H complementarity-determining regions. Thus, counterintuitively, tight and specific antibody binding may in some cases be water-mediated.

Molecular construction and optimization of anti-human IL-1alpha/beta dual variable domain immunoglobulin (DVD-Ig) molecules.

Signal transduction through the interleukin-1 receptor (IL-1R) pathway mediates a strong pro-inflammatory response, which contributes to a number of human diseases such as rheumatoid arthritis. Within the IL-1 family, IL-1alpha and IL-1beta are both agonistic ligands for IL-1R, whereas IL-1 receptor antagonist (IL-1ra) is an endogenous antagonist that binds to IL-R, but does not signal. Therefore, the ideal therapeutic strategy would be blocking both IL-1alpha and IL-1beta, but not IL-1ra. However, due to low sequence homology between the three members of the family, it has been exceedingly difficult to identify potent therapeutic agents, e.g., monoclonal antibodies (mAbs), that selectively recognize both IL-1alpha and IL-1beta, but not IL-1ra. Currently, several anti-IL-1 therapeutic agents in clinical development either inhibit only IL-1beta (i.e., anti-IL-1beta mAb), or recognize all three ligands (i.e., anti-IL-1R mAb or IL-1R Trap). We have recently developed a novel dual variable domain immunoglobulin (or DVD-Ig) technology that enables engineering the distinct specificities of two mAbs into a single functional, dual-specific, tetravalent IgG-like molecule. Based on this approach, we have developed anti-human IL-1alpha/beta DVD-Ig molecules using several pairs of monoclonal antibodies with therapeutic potential, and present a case study for optimal design of a DVD-Ig agent for a specific target pair combination.