Variable Domain Research Articles

Genetically Engineered T Cells and Recombinant Antibodies to Target Intracellular Neoantigens: Current Status and Future Directions

Recombinant antibodies and, more recently, T cell receptor (TCR)-engineered T cell therapies represent two immunological strategies that have come to the forefront of clinical interest for targeting intracellular neoantigens in benign and malignant diseases. T cell-based therapies targeting neoantigens use T cells expressing a recombinant complete TCR (TCR-T cell), a chimeric antigen receptor (CAR) with the variable domains of a neoepitope-reactive TCR as a binding domain (TCR-CAR-T cell) or a TCR-like antibody as a binding domain (TCR-like CAR-T cell). Furthermore, the synthetic T cell receptor and antigen receptor (STAR) and heterodimeric TCR-like CAR (T-CAR) are designed as a double-chain TCRαβ-based receptor with variable regions of immunoglobulin heavy and light chains (VH and VL) fused to TCR-Cα and TCR-Cβ, respectively, resulting in TCR signaling. In contrast to the use of recombinant T cells, anti-neopeptide MHC (pMHC) antibodies and intrabodies neutralizing intracellular neoantigens can be more easily applied to cancer patients. However, different limitations should be considered, such as the loss of neoantigens, the modification of antigen peptide presentation, tumor heterogenicity, and the immunosuppressive activity of the tumor environment. The simultaneous application of immune checkpoint blocking antibodies and of CRISPR/Cas9-based genome editing tools to engineer different recombinant T cells with enhanced therapeutic functions could make T cell therapies more efficient and could pave the way for its routine clinical application.

Lack of dominant-negative activity for tumor-related ZNRF3 missense mutations at endogenous levels.

ZNRF3, a negative regulator of β-catenin signaling, removes Wnt receptors from the membrane. Currently, it is unknown which tumor-associated variants can be considered driver mutations and through which mechanisms they contribute to cancer. Here we show that all truncating mutations analyzed at endogenous levels exhibit loss-of-function, with longer variants retaining partial activity. Regarding missense mutations, we show that 27/82 ZNRF3 variants in the RING and R-Spondin domain structures, lead to (partial) loss-of-function/hyperactivation. Mechanistically, defective R-Spondin domain variants appear to undergo endoplasmic-reticulum-associated degradation due to protein misfolding, leading to reduced protein levels. They fail to reach the membrane correctly, which can be partially restored for several variants by culturing cells at 27 °C. Although RING and R-Spondin domain mutations in RNF43/ZNRF3 are often considered to possess dominant-negative oncogene-like activity in cancers, our findings challenge this notion. When representative variants are heterozygously introduced into endogenous ZNRF3, their impact on β-catenin signaling mirrors that of heterozygous knockout, suggesting that the supposed dominant-negative effect is non-existent. In other words, so-called "hyperactivating" ZNRF3/RNF43 mutations behave as classical loss-of-function mutations at endogenous levels.

A simple yet effective ALE-FE method for the nonlinear planar dynamics of variable-length flexible rods

With recent advances in variable-length structures for use in soft actuation, energy harvesting, energy dissipation and metamaterials, the mathematical modelling and numerical simulation of physical systems with time-varying domains is becoming increasingly important. The planar nonlinear dynamics of one-dimensional elastic structures with variable domain is formulated from a Lagrangian approach by using a non-material reference frame. An Arbitrary Lagrangian-Eulerian (ALE) scheme is proposed where the domain is reparametrized based on a priori unknown configuration parameters. Based on this formulation, a Finite Element (FE) method is developed for theoretically predicting the evolution of a rod constrained at its ends by one or two sliding-sleeves, whose position and inclination can be varied in time, and under external loadings. Finally, case studies and instability problems are investigated to assess the reliability of the proposed formulation against others available and to demonstrate its effectiveness. With respect to previously developed methods for this type of structural problems, the present ALE-FE approach shows a strong theoretical and implementation simplicity, maintaining an efficient and fast convergence according to the cases analyzed. An open source code realized for the present ALE-FE model is made available for solving the nonlinear dynamics of planar systems constrained by one or two independent sliding sleeves. The present research paves the way for further extensions to easily implement solvers for the three-dimensional dynamics of flexible one- and two-dimensional structural systems with moving boundary conditions.

An energy management strategy for fuel-cell hybrid electric vehicles based on model predictive control with a variable time domain

Fuel-cell hybrid electric vehicles (FCHEVs) are emerging as a pivotal model for future new energy vehicles due to their high efficiency and zero pollution. Crafting an effective energy management strategy is crucial for enhancing the robustness and economic viability of these vehicles. Therefore, an energy management strategy (EMS) for FCHEVs was proposed based on model predictive control (MPC) with a variable time domain. This approach integrated driving pattern recognition and model predictive control to overcome the robustness challenges faced by conventional EMS. Variational modal decomposition (VMD) was integrated with a radial basis function neural network for velocity predictions across various frequencies, which mitigated the effect of prediction accuracy on vehicles’ energy efficiency. Additionally, driving pattern recognition (DPR) was used to determine the driving condition online, which enhanced the influence of prediction duration on energy efficiency. This system adapted the prediction duration to the current driving condition to optimize hydrogen consumption. The velocity prediction model achieved 75.61% of error reduction, which saved 4.40% of hydrogen based on simulations. Besides, the model demonstrated enhanced adaptability to unpredictable driving environments.

Physics-Informed Geometry-Aware Neural Operator

Engineering design problems often involve solving parametric Partial Differential Equations (PDEs) under variable PDE parameters and domain geometry. Recently, neural operators have shown promise in learning PDE operators and quickly predicting the PDE solutions. However, training these neural operators typically requires large datasets, the acquisition of which can be prohibitively expensive. To overcome this, physics-informed training offers an alternative way of building neural operators, eliminating the high computational costs associated with Finite Element generation of training data. Nevertheless, current physics-informed neural operators struggle with limitations, either in handling varying domain geometries or varying PDE parameters. In this research, we introduce a novel method, the Physics-Informed Geometry-Aware Neural Operator (PI-GANO), designed to simultaneously generalize across both PDE parameters and domain geometries. We adopt a geometry encoder to capture the domain geometry features, and design a novel pipeline to integrate this component within the existing Deep Compositional Operator Network architecture. Numerical results demonstrate the accuracy and efficiency of the proposed method. All the codes and data related to this work are available on GitHub: https://github.com/uq-group/codes/tree/main/PI-GANO.

High expression of variable domain of heavy-chain antibodies in Expi293F cells with optimized signal peptide and codons

The variable domain of heavy-chain antibody (VHH) has been developed widely in drug therapy, diagnosis, and research. Escherichia coli is the most popular expression system for VHH production, whereas low bioactivity occurs sometimes. Mammalian cells are one of the most ideal hosts for VHH expression at present. To improve the yield of VHH in Expi293F cells, we optimized the signal peptide (SP) and codons of VHH. Firstly, the fusion protein VHH1-Fc was used to screen SPs. The SP IFN-α2 showed the highest secretion as quantified by enzyme-linked immunosorbent assay (ELISA). Subsequently, codon optimization by improving GC3 and GC content doubled the yield of VHH1 and kept its binding activity to Senecavirus A (SVA). Finally, the mean yields of other 5 VHHs that fused with SP IFN-α2 and codon-optimized were over 191.6 mg/L, and these VHHs had high recovery and high purity in the culture supernatant. This study confirms that SP IFN-α2 and codon optimization could produce VHHs in Expi293F cells efficiently, which provides a reference for the large-scale production of VHHs.

Renal manifestations of MGUS.

Kidney disease is a common complication of monoclonal immunoglobulin (MIg)-secreting B-cell disorders and predominantly occurs in patients who do not meet the criteria for an overt hematological disease. To distinguish this situation from monoclonal gammopathy of undetermined significance, which lacks organ damage, the term monoclonal gammopathy of renal significance (MGRS) was introduced to depict the association of a small, otherwise indolent B-cell clone, with renal disease induced by the secreted MIg. The spectrum of renal disorders in MGRS is wide, encompassing both tubular and glomerular disorders, classified according to the composition of deposits and their ultrastructural pattern of organization. Renal lesions, independent of the tumor burden, are mostly governed by the molecular characteristics of the MIg variable domain and involve either direct (deposition or precipitation) or indirect (autoantibody activity, complement activation) mechanisms. The diagnosis, often suggested by careful analysis of renal and extrarenal symptoms, almost always requires histological confirmation by a kidney biopsy with light, immunofluorescence, and electron microscopy studies. Most patients do not have a known monoclonal gammopathy at presentation. Hematologic investigations should include serum and urine protein electrophoresis and immunofixation, serum-free light chain measurements, and bone marrow studies with flow cytometry and cytogenetics to determine the nature of the pathogenic clone (most commonly plasmocytic). Early diagnosis before the development of severe chronic kidney disease and rapid achievement of deep hematological response through clone-targeted chemotherapy (currently based on proteasome inhibitor and monoclonal anti-CD38 antibody-based combinations for plasma cell clones) are the main factors influencing long-term renal and patient outcomes.

Phenotype-genotype correlation in X-linked Charcot-Marie-Tooth disease: A French cohort study.

X-linked Charcot-Marie-Tooth disease type 1 (CMTX1) ranks as the second most prevalent hereditary neuropathy and, currently, has no definitive cure. Emerging preclinical trials offer hope for potential clinical studies in the near future. While it is widely accepted that experimental groups in these trials should be balanced for age and gender, there is a current shortfall in data regarding phenotype-genotype correlations. Our aim was to provide a more detailed understanding of these correlations to facilitate the formation of well-matched patient groups in upcoming clinical trials. We conducted a retrospective evaluation of CMTX1 patients from 13 designated reference centers in France. Data on genetics, clinical features, and nerve conduction were systematically gathered. We analyzed the genotype-phenotype correlations in 275 CMTX1 patients belonging to 162 families and carrying 87 distinct variants. Patients with variants affecting the transmembrane domains demonstrated significantly greater severity, as evidenced by a Charcot-Marie-Tooth Examination Score of 10.5, compared to 7.1 for those with intracellular domain variants and 8.7 for extracellular domain variants (p < 0.000). These patients also experienced an earlier age of onset, showed slower ulnar nerve conduction velocities and had more substantial loss of motor amplitude. This study confirms the presence of a correlation between the mutated protein domain and the clinical phenotype. Patients with a variant in the transmembrane domains demonstrated a more severe clinical and electrophysiological profile. Consequently, the genotype could play a prognostic role in addition to its diagnostic role, and it will be essential to consider this in future clinical trials.

Statin-associated regulation of hepatic PNPLA3 in patients without known liver disease.

Statins are used for metabolic dysfunction-associated steatotic liver disease (MASLD) (NAFLD) treatment, but their role in this context is unclear. Genetic variants of patatin-like phospholipase domain containing 3 (PNPLA3) are associated with MASLD susceptibility and statin treatment efficacy. Access to liver biopsies before established MASLD is limited, and statins and PNPLA3 in early liver steatosis are thus difficult to study. Liver biopsies were collected from 261 patients without known liver disease at surgery and stratified based on statin use and criteria for the metabolic syndrome (MS). Genotypes and transcript levels were measured using Illumina and Affymetrix arrays, and metabolic and lipoprotein profiles by clinical assays. Statin effects on PNPLA3, de novo lipogenesis (DNL), and lipid accumulation were further studied in vitro. The PNPLA3I148M genetic variant was associated with significantly lower hepatic levels of cholesterol synthesis-associated transcripts. Patients with MS had significantly higher hepatic levels of MASLD and lipogenesis-associated transcripts than non-MS patients. Patients with MS on statin therapy had significantly higher hepatic levels of PNPLA3, acetyl-CoA carboxylase alpha, and ATP citrate lyase, and statin use was associated with higher plasma fasting glucose, insulin, and HbA1c. Exposure of hepatocyte-like HepG2 cells to atorvastatin promoted intracellular accumulation of triglycerides and lipogenesis-associated transcripts. Atorvastatin-exposure of HepG2, sterol O-acyltransferase (SOAT) 2-only-HepG2, primary human hepatic stellate, and hepatic stellate cell-like LX2 cells significantly increased levels of PNPLA3 and SREBF2-target genes, whereas knockdown of SREBF2 attenuated this effect. Collectively, these observations suggest statin-associated regulation of PNPLA3 and DNL in liver. The potential interaction between PNPLA3 genotype and metabolic status should be considered in future studies in the context of statin therapy for MASLD.

Molecular Basis for the Differential Function of HAVCR1 Mucin Variants.

Background/Objectives: The hepatitis A virus (HAV) cellular receptor 1 (HAVCR1) is a type I integral membrane glycoprotein discovered in monkeys and humans as a HAV receptor. HAVCR1 contains an N-terminal immunoglobulin-like variable domain (IgV) followed by a mucin-like domain (Muc), a transmembrane domain, and a cytoplasmic tail with a canonical tyrosine kinase phosphorylation site. The IgV binds phosphatidylserine on apoptotic cells, extracellular vesicles, and enveloped viruses. Insertions/deletions at position 156 (156ins/del) of the Muc were associated in humans with susceptibility to atopic, autoimmune, and infectious diseases. However, the molecular basis for the differential function of the HAVCR1 variants is not understood. Methods: We used mutagenesis, apoptotic cell binding, and signal transduction analyses to study the role of the 156ins/del in the function of HAVCR1. Results: We found that the HAVCR1 variant without insertions at position 156 (156delPMTTTV, or short-HAVCR1) bound more apoptotic cells than that containing a six amino acid insertion (156insPMTTTV, or long-HAVCR1). Furthermore, short-HAVCR1 induced stronger cell signaling and phagocytosis than long-HAVCR1. Conclusions: Our data indicated that the 156ins/del determine how the IgV is presented at the cell surface and modulate HAVCR1 binding, signaling, and phagocytosis, suggesting that variant-specific targeting could be used as therapeutic interventions to treat immune and infectious diseases.

Structural insights into thyroid hormone receptors.

Thyroid hormone receptors (TRs) are essential components of the endocrine system, mediating the cellular effects of thyroid hormones. The two TR genes, THRA and THRB, encode four isoforms, with TRα1 and TRβ1 being the most prevalent. TRs are ligand-dependent transcription factors and members of the nuclear receptor superfamily, indispensable for human growth, development and metabolism. Dysfunctional TR signaling can lead to conditions like resistance to thyroid hormone (RTH) syndrome, thyroid cancer, and metabolic disorders. Structurally, TRs comprise several domains: a variable N-terminal domain, a conserved DNA-binding domain, and a ligand-binding domain that mediates interaction with hormones and transcriptional coregulators. TRs predominantly function as heterodimers with the retinoid X receptor (RXR), binding to thyroid hormone response elements (TREs) in target genes to regulate their transcription. This review examines the structural studies on TRs, primarily performed through X-ray crystallography, that have provided detailed insights into TR functions, including DNA recognition, ligand binding, and coregulator interactions. We also discuss how these findings have deepened our understanding of TR mechanisms and contributed to the interpretation of pathogenic mutations.

Site-specifically Phosphorylated Hsp90C-terminal Domain Variants Provide Access to Deciphering the Chaperone Code.

The ubiquitous molecular chaperone Heat shock protein 90 (Hsp90) is pivotal in many cellular processes through folding of client proteins under stressed and normal conditions. Despite intensive research on its function as a chaperone, the influence of posttranslational modifications on Hsp90 (the 'chaperone code'), and its interactions with co-chaperones and client proteins, still remains to be elucidated. The C-terminal domain (CTD) of Hsp90 is essential for formation of the active homodimer state of Hsp90 and contains recognition sites for co-chaperones and client proteins. Here we used expressed protein selenoester ligation to introduce site-selective phosphorylations in the Hsp90 CTD, while preserving the native amino acid sequence. The two phosphorylations do not affect the overall secondary structure, but in combination, slightly decrease the thermal stability of the CTD. The Hsp90 CTD functions as a chaperone in decreasing aggregation of model client proteins, but the C-terminal phosphorylations do not significantly alter the anti-aggregation activity for these clients. The optimization of expressed protein selenoester ligation (EPSL) to carry out several steps in one pot provides an efficient route to access site-specifically modified Hsp90 CTD variants, allowing the generation of Hsp90 variants with site-specific PTMs to decipher the chaperone code.

Synthetic translational coupling element for multiplexed signal processing and cellular control.

Repurposing natural systems to develop customized functions in biological systems is one of the main thrusts of synthetic biology. Translational coupling is a common phenomenon in diverse polycistronic operons for efficient allocation of limited genetic space and cellular resources. These beneficial features of translation coupling can provide exciting opportunities for creating novel synthetic biological devices. Here, we introduce a modular synthetic translational coupling element (synTCE) and integrate this design with de novo designed riboregulators,toehold switches. A systematic exploration of sequence domain variants for synTCEs led to the identification of critical design considerations for improving the system performance. Next, this design approach was seamlessly integrated into logic computations and applied to construct multi-output transcripts with well-defined stoichiometric control. This module was further applied to signaling cascades for combined signal transduction and multi-input/multi-output synthetic devices. Further, the synTCEs can precisely manipulate the N-terminal ends of output proteins, facilitating effective protein localization and cellular population control. Therefore, the synTCEs could enhance computational capability and applicability of riboregulators for reprogramming biological systems, leading to future applications in synthetic biology, metabolic engineering and biotechnology.

Engineered bispecific antibodies with enhanced breadth and potency against SARS-CoV-2 variants and SARS-related coronaviruses.

The concern of COVID-19 persists due to the continuous emergence of variants and the potential spillover of animal coronaviruses. The broad-spectrum neutralizing antibodies play a pivotal role in the prevention and treatment of coronavirus (CoV) infections. Here, we constructed 18 bi-specific antibodies (bsAbs) using 9 antibodies isolated from COVID-19 convalescents and vaccinated individuals, designed as dual variable domain immunoglobulin (DVD-Ig). A bsAb 5-HI showed a high binding capability to the S1 subunit of spike and exhibited breadth and potency against pseudotyped SARS-CoV-2 variants of concerns (VOCs) and SARS-related-CoVs (SARSr-CoVs), with half maximal effective concentration (EC50) of 0.028-3.444 nM and 50% inhibitory concentration (IC50) of 0.008-0.800 nM. In addition, it retained neutralization potency against the peudotyped virus of recently prevalent JN.1 strain (IC50, 12.74 nM). We found that the parental antibodies showed weak or no binding to the receptor binding domain (RBD) of the SARS-CoV, EG.5.1, and JN.1. However, the 5-HI maintained the binding with RBD and prevented the binding between hACE2 and RBD (IC50 for the RBD of SARS-CoV, 1.067 nM; EG.5.1, 0.423 nM; JN.1, 0.223 nM). In neutralization assays with the authentic virus, we found that the5-HI effectively neutralized Omicron variants XBB.1.5 (IC50, 0.308 nM), EG.5.1 (IC50, 0.129 nM), and JN.1 (IC50, 13.692 nM), while its parental antibodies showed weakened or no neutralization. Therefore, the5-HI represents a promising candidate for further development in the treatment and prevention of ongoing evolved SARS-CoV-2 VOCs and other SARSr-CoVs that potentially emerge in the future.

Loss of DOT1L function disrupts neuronal transcription, animal behavior, and leads to a novel neurodevelopmental disorder.

Individuals with monoallelic pathogenic variants in the histone lysine methyltransferase DOT1L display global developmental delay and varying congenital anomalies. However, the impact of monoallelic loss of DOT1L remains unclear. Here, we present a largely female cohort of 11 individuals with DOT1L variants with developmental delays and dysmorphic facial features. We found that DOT1L variants include missense variants clustered in the catalytic domain, frameshift, and stop-gain variants. We demonstrate that specific variants cause loss of methyltransferase activity and therefore sought to define the effects of decreased DOT1L function. Using RNA-sequencing of cultured neurons and single nucleus RNA-sequencing of mouse cortical tissue, we found that partial Dot1l depletion causes sex-specific transcriptional responses and disrupts transcription of synaptic genes. Further, Dot1l loss alters neuron branching and expression of synaptic proteins. Lastly using zebrafish and mouse models, we found behavioral disruptions that include sex-specific deficits in mice. Overall, we define how DOT1L loss leads to neurological dysfunction by demonstrating that partial Dot1l loss impacts transcription, neuron morphology, and behavior across multiple models and systems.

FAITH: Frequency-domain Attention In Two Horizons for time series forecasting

Time Series Forecasting (TSF) plays a crucial role in various sectors, including industrial maintenance, weather prediction, energy management, traffic control, and financial planning. Current deep learning-based predictive models often exhibit significant deviations between their forecasting outcomes and the ground truth because they lack an efficient method to extract both the global frequency-domain information of each variable and the relationships between different variables. To tackle this challenge, we introduce an innovative model—Frequency-domain Attention In Two Horizons (FAITH). FAITH decomposes time series into trend and seasonal components using a multi-scale adaptive decomposition and fusion architecture and processes them separately. It utilizes two modules—the Frequency Channel Feature Extraction Module (FCEM) and the Frequency Temporal Feature Extraction Module (FTEM)—to capture inter-channel relationships at a finer granularity and to extract global temporal information from the frequency domain of different variables. This significantly enhances its ability to handle long-term dependencies and complex patterns. Furthermore, FAITH achieves theoretically linear complexity by modifying the time-frequency domain transformation method, effectively reducing computational costs. Extensive experiments across six benchmarks for long-term forecasting and five benchmarks for short-term forecasting demonstrate that FAITH outperforms existing models in various domains, such as electricity, weather, and traffic. These results validate the effectiveness and superiority of FAITH in both long-term and short-term time series forecasting tasks. Our codes and data are available at https://github.com/LRQ577/FAITH

Neutralizing VHH Antibodies Targeting the Spike Protein of PEDV.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that infect pigs' intestinal epithelial cells, causing high morbidity and mortality. Due to the rapid mutation of PEDV, vaccine efficacy is uncertain, prompting exploration of alternative treatments. Nanobodies, also known as variable heavy chain domains of heavy chain-only antibodies (VHHs), offer significant potential in biomedical applications due to their small size and high specificity. In this study, yeast two-hybrid technology was employed to screen for eight specific VHH sequences targeting the PEDV S protein from a synthetically constructed nanobody yeast library. The VHH genes were then cloned into expression plasmids for recombinant protein production, and the resulting VHHs (termed PEDV S-VHHs) were purified. Indirect immunofluorescence assay (IFA) and Western blotting analysis confirmed that these VHHs specifically bind to both PEDV and its S protein. Neutralization assays demonstrated that seven PEDV S-VHHs exhibited potent neutralizing activity against PEDV. Additionally, a combination of these seven antibodies showed enhanced antiviral effects. Preliminary predictions were also made regarding the binding sites between these VHHs and PEDV. The PEDV S-VHHs described in this study hold potential as candidates for the prevention and treatment of PEDV infection.

Association between psychological traits and occlusal tactile acuity of healthy individuals.

Tactile acuity is a somatosensory measure of the extent to which humans can discern tactile stimuli. It is influenced by how peripheral signals are processed centrally. In the oral cavity, Occlusal Tactile Acuity (OTA) is the ability to perceive minimal thicknesses between antagonist teeth. The aim of the current study was to assess the association between psychological traits and OTA of otherwise healthy individuals. Sixty-three volunteers (32 males; mean age ± SD: 24.6 ± 2.7 years) participated in this study. Somatosensory amplification, anxiety, depression, physical symptoms and pain catastrophizing were scored using questionnaires, and subgroups of severity were created per variable based on cut-offs. OTA was measured using 9 aluminium foils with thickness (ranging from 8 to 72 μm) and one sham test (without foil). Each thickness was tested 10 times in random order, the participants were instructed to report whether they felt the foil between their molars and the mean percentage of correct answers was computed. A linear mixed model was used with OTA as a dependent variable and psychological domain as an independent variable. Significantly different OTA was observed among the anxiety subgroups (p = .003), supporting a decreased perception of thicknesses 24 and 32 μm (p = .018 and p < .001, respectively) in participants with moderate/severe anxiety compared to those with no/mild anxiety. Significantly different OTA was also observed among the pain catastrophizing subgroups (p = .008), showing decreased perception of thicknesses 32 and 40 μm (p < .001 and p = .007, respectively) in severe catastrophizing levels, compared to no/mild catastrophizing levels. No significant differences were observed for the other variables. Healthy adults with increased anxiety or pain catastrophizing levels show decreased interdental acuity as compared to participants with minor or no psychological impairment.

Premise‐Variable‐Domain‐Partition‐Dependent Output Feedback Switched Controllers Design for Switched IT2 Fuzzy Systems With Switching Signal Transmission Delays and Local Nonlinear Model

ABSTRACTThis article studies the guaranteed cost extended dissipative stabilization problem of switched IT2 fuzzy systems (SIT2FSs) with switching signal transmission delays and local nonlinear model. The guaranteed cost performance, guaranteed cost strict dissipative performance, guaranteed cost − performance and guaranteed cost passivity performance are considered for SIT2FSs in a unified form. First, a novel asynchronous control scheme is proposed for SIT2FSs with local nonlinear model. The controller gains in mismatched interval are designed separately. By using a premise‐variable‐domain‐partition‐dependent switched fuzzy Lyapunov functions (PDSFLFs) approach, the membership‐function‐shape‐independent (MFSI) existence conditions of a class of IT2 fuzzy switched controllers, which can ensure the guaranteed cost extended dissipative performance of SIT2FSs, are established. Then, by utilizing the shape information of membership functions and dividing the premise variable domain into multiple partitions, the membership‐function‐shape‐dependent (MFSD) existence conditions of a class of premise‐variable‐domain‐partition‐dependent (PVDPD) IT2 fuzzy switched controllers are presented. The results indicate that less conservative results can be achieved by using the PVDPD IT2 fuzzy switched controllers, and better system performance can be gotten compared with the Type‐1 fuzzy switched controllers. Finally, the effectiveness of the results is demonstrated through a robot arm model.

Conformational Differences in the Light Chain Constant Domain of Immunoglobulin G and Free Light Chain May Influence Proteolysis in AL Amyloidosis

Immunoglobulin light chain amyloidosis (AL) is a life-threatening disease caused by the deposition of light chain (LC) and its fragments containing variable (VL) and portions of constant (CL) domains. AL patients feature either monoclonal free LCs (FLCs) circulating as covalent and noncovalent homodimers, or monoclonal immunoglobulin (Ig) wherein the LC and heavy chain (HC) form disulfide-linked heterodimers, or both. The role of full-length Ig in AL amyloidosis is unclear as prior studies focused on FLC or VL domain. We used a mammalian cell-based expression system to generate four AL patient-derived full-length IgGs, two non-AL IgG controls, and six corresponding FLC proteins derived from an IGLV6-57 germline precursor. Comparison of proteins’ secondary structure, thermal stability, proteolytic susceptibility, and disulfide link reduction suggested the importance of local vs. global conformational stability. Analysis of IgGs vs. corresponding FLCs using hydrogen–deuterium exchange mass spectrometry revealed major differences in the local conformation/dynamics of the CL domain. In all IgGs vs. FLCs, segments containing β-strand and α-helix βAC-αACBC were more dynamic/exposed while segment βDC-βEC was less dynamic/exposed. Notably, these segments overlapped proteolysis-prone regions whose in vivo cleavage generates LC fragments found in AL deposits. Altogether, the results suggest that preferential cleavage in segments βAC-αACBC of FLC or βDC-βEC of LC in IgG helps generate amyloid protein precursors. We propose that protecting these segments using small-molecule stabilizers, which bind to the interfacial cavities CL-CL in FLC and/or CL-CH1 in IgG, is a potential therapeutic strategy to complement current approaches targeting VL-VL or VL-CL stabilization of LC dimer.