On the strongly regular graphs obtained from quasi-symmetric 2-(31,7,7) designs

It is known that the five non-isomorphic quasi-symmetric 2-(31, 7, 7) designs lead to non-isomorphic strongly regular graphs with parameters (155, 42, 17, 9). We will show that there exist no isomorphisms among these graphs and the block graphs of the Steiner triple systems STS(31) except the isomorphism between the block graphs of the point-plane design and the point-line design of PG(4, 2)

Identification and Multidimensional Optimization of an Asymmetric Bispecific IgG Antibody Mimicking the Function of Factor VIII Cofactor Activity

<div><p>In hemophilia A, routine prophylaxis with exogenous factor VIII (FVIII) requires frequent intravenous injections and can lead to the development of anti-FVIII alloantibodies (FVIII inhibitors). To overcome these drawbacks, we screened asymmetric bispecific IgG antibodies to factor IXa (FIXa) and factor X (FX), mimicking the FVIII cofactor function. Since the therapeutic potential of the lead bispecific antibody was marginal, FVIII-mimetic activity was improved by modifying its binding properties to FIXa and FX, and the pharmacokinetics was improved by engineering the charge properties of the variable region. Difficulties in manufacturing the bispecific antibody were overcome by identifying a common light chain for the anti-FIXa and anti-FX heavy chains through framework/complementarity determining region shuffling, and by pI engineering of the two heavy chains to facilitate ion exchange chromatographic purification of the bispecific antibody from the mixture of byproducts. Engineering to overcome low solubility and deamidation was also performed. The multidimensionally optimized bispecific antibody hBS910 exhibited potent FVIII-mimetic activity in human FVIII-deficient plasma, and had a half-life of 3 weeks and high subcutaneous bioavailability in cynomolgus monkeys. Importantly, the activity of hBS910 was not affected by FVIII inhibitors, while anti-hBS910 antibodies did not inhibit FVIII activity, allowing the use of hBS910 without considering the development or presence of FVIII inhibitors. Furthermore, hBS910 could be purified on a large manufacturing scale and formulated into a subcutaneously injectable liquid formulation for clinical use. These features of hBS910 enable routine prophylaxis by subcutaneous delivery at a long dosing interval without considering the development or presence of FVIII inhibitors. We expect that hBS910 (investigational drug name: ACE910) will provide significant benefit for severe hemophilia A patients.</p> </div

Characterizations of a neutralizing antibody broadly reactive to multiple gluten peptide:HLA-DQ2.5 complexes in the context of celiac disease

Abstract In human celiac disease (CeD) HLA-DQ2.5 presents gluten peptides to antigen-specific CD4+ T cells, thereby instigating immune activation and enteropathy. Targeting HLA-DQ2.5 with neutralizing antibody for treating CeD may be plausible, yet using pan-HLA-DQ antibody risks affecting systemic immunity, while targeting selected gluten peptide:HLA-DQ2.5 complex (pHLA-DQ2.5) may be insufficient. Here we generate a TCR-like, neutralizing antibody (DONQ52) that broadly recognizes more than twenty-five distinct gluten pHLA-DQ2.5 through rabbit immunization with multi-epitope gluten pHLA-DQ2.5 and multidimensional optimization. Structural analyses show that the proline-rich and glutamine-rich motif of gluten epitopes critical for pathogenesis is flexibly recognized by multiple tyrosine residues present in the antibody paratope, implicating the mechanisms for the broad reactivity. In HLA-DQ2.5 transgenic mice, DONQ52 demonstrates favorable pharmacokinetics with high subcutaneous bioavailability, and blocks immunity to gluten while not affecting systemic immunity. Our results thus provide a rationale for clinical testing of DONQ52 in CeD

Therapeutic potential of multidimensionally optimized bispecific antibody, hBS910.

<p>(A) FVIII-mimetic activity of hBS910 in thrombin generation assay (TGA). Effect of hBS910 (circles) or recombinant human FVIII (squares) on thrombin generation in FVIII-deficient plasma is shown. The reaction was triggered by FXIa, synthetic phospholipid, and Ca²⁺. The Y-axis indicates the peak height, a thrombin generation parameter (in many cases, the bars depicting s.d. are shorter than the height of the symbols). Data were collected in triplicate for each plasma lot and are expressed as mean ± s.d. (B) Pharmacokinetics of hBS910 in cynomolgus monkeys. Time profiles of plasma concentration of hBS910 after intravenous (circles) or subcutaneous (squares) injection are shown.</p

Improvement of therapeutic potential of the bispecific antibody.

<p>(A) Improving FVIII-mimetic activity of the bispecific antibody. Effect of hBS1 (circles), hBS106 (squares), and hBS910 (diamonds) on FX activation in the presence of FIXa, FX, and synthetic phospholipid is shown. The Y-axis indicates the absorbance at 405 nm of the chromogenic substrate assay (in many cases, the bars depicting s.d. are shorter than the height of the symbols). (B) Improving pharmacokinetics of the bispecific antibody. Time profiles of plasma concentration of hBS106 (circles), hBS128 (squares), and hBS228 (diamonds) in mice after subcutaneous injection at a dose of 1 mg/kg are shown. All the data were collected in triplicate and are expressed as mean ± s.d.</p

Improvement of pharmaceutical properties of bispecific antibodies.

<p>(A) Antibody solution profiles of hBS376 and hBS560 at different antibody concentrations, pH, and NaCl concentrations. The antibody solution under each condition was photographed and the state determined (P, precipitation; L, liquid–liquid phase separation; –, clear liquid). (B) Cation exchange chromatography of hBS560 and hBS660 before (black) and after incubation at 40°C for 2 weeks (red). Acidic peak indicating deamidation at HCDR3 increased after incubation at 40°C for 2 weeks for hBS560. No marked increase of acidic peak was observed for hBS660.</p

Isoelectric point engineering to facilitate purification of the target bispecific antibody.

<p>(A) Isoelectric points of target bispecific (squares) antibodies and homodimeric byproducts (anti-FIXa monospecific antibodies (circles) and anti-FX monospecific antibodies (diamonds)) determined by cIEF. (B) Cation exchange purification chromatogram of the target bispecific antibody of hBS560 from its homodimeric byproducts with step-wise elution with different NaCl concentrations. Peak 1, anti-FX homodimeric antibody; Peak 2, target bispecific antibody; Peak 3, anti-FIXa homodimeric antibody. Each peak area of peak 1, peak 2 and peak 3 was 9.9%, 85.7% and 4.4%, respectively.</p