PD-BAT: A novel approach of pooling basophil donors for expansion of commercial laboratory testing of Chronic Spontaneous Urticaria.

The type II autoimmune subtype of Chronic Spontaneous Urticaria (CSU) is characterized by the presence of IgG autoantibodies targeting IgE or the IgE high-affinity receptor (FcεRI) on mast cells and basophils. In evaluation of CSU patients, indirect basophil activation testing (BAT), has been utilized, involving the mixing of patient serum with heterologous peripheral blood donors, followed by flow cytometric assessment of basophil markers. However, the reliability of the indirect BAT results hinges on the quality of the donor basophils utilized. In this study, we introduce an innovative approach where multiple potential basophil donors undergo rigorous BAT characterization alongside control samples. By selecting and pooling donors with optimal performance, we significantly enhance the inter-assay reproducibility of the indirect BAT test.

Generation and engineering of potent single domain antibody-based bispecific IL-18 mimetics resistant to IL-18BP decoy receptor inhibition.

Here, we generated bispecific antibody (bsAb) derivatives that mimic the function of interleukin (IL)-18 based on single domain antibodies (sdAbs) specific to IL-18 Rα and IL-18 Rß. For this, camelids were immunized, followed by yeast surface display (YSD)-enabled discovery of VHHs targeting the individual receptor subunits. Upon reformatting into a strictly monovalent (1 + 1) bispecific sdAb architecture, several bsAbs triggered dose-dependent IL-18 R downstream signaling on IL-18 reporter cells, as well as IFN-γ release by peripheral blood mononuclear cells in the presence of low-dose IL-12. However, compared with IL-18, potencies and efficacies were considerably attenuated. By engineering paratope valencies and the spatial orientation of individual paratopes within the overall design architecture, we were able to generate IL-18 mimetics displaying significantly augmented functionalities, resulting in bispecific cytokine mimetics that were more potent than IL-18 in triggering proinflammatory cytokine release. Furthermore, generated IL-18 mimetics were unaffected from inhibition by IL-18 binding protein decoy receptor. Essentially, we demonstrate that this strategy enables the generation of IL-18 mimetics with tailor-made cytokine functionalities.

Facile One-Step Generation of Camelid VHH and Avian scFv Libraries for Phage Display by Golden Gate Cloning.

Since its development in the 1980s, the Nobel Prize-awarded phage display technology has been one of the most commonly used in vitro selection technologies for the discovery of therapeutic and diagnostic antibodies. Besides the importance of selection strategy, one key component of the successful isolation of highly specific recombinant antibodies is the construction of high-quality phage display libraries. However, previous cloning protocols relied on a tedious multistep process with subsequent cloning steps for the introduction of first heavy and then light chain variable genetic antibody fragments (VH and VL). This resulted in reduced cloning efficiency, higher frequency of missing VH or VL sequences, as well as truncated antibody fragments. With the emergence of Golden Gate Cloning (GGC) for the generation of antibody libraries, the possibility of more facile library cloning has arisen. Here, we describe a streamlined one-step GGC strategy for the generation of camelid heavy chain only variable phage display libraries as well as the simultaneous introduction of heavy chain and light chain variable regions from the chicken into a scFv phage display vector.

Deletion of NRF2 disturbs composition, morphology, and differentiation of the murine tail epidermis in chronological aging.

NRF2 is a master regulator of the cellular protection against oxidative damage in mammals and of multiple pathways relevant in the mammalian aging process. In the epidermis of the skin NRF2 contributes additionally to the formation of an antioxidant barrier to protect from environmental insults and is involved in the differentiation process of keratinocytes. In chronological aging of skin, the capacity for antioxidant responses and the ability to restore homeostasis after damage are impaired. Surprisingly, in absence of extrinsic stressors, NRF2 deficient mice do not show any obvious skin phenotype, not even at old age. We investigated the differences in chronological epidermal aging of wild type and NRF2-deficient mice to identify the changes in aged epidermis that may compensate for absence of this important transcriptional regulator. While both genotypes showed elevated epidermal senescence markers (increased Lysophospholipids, decreased LaminB1 expression), the aged NRF2 deficient mice displayed disturbed epidermal differentiation manifested in irregular keratin 10 and loricrin expression. The tail skin displayed less age-related epidermal thinning and a less pronounced decline in proliferating basal epidermal cells compared to the wildtype controls. The stratum corneum lipid composition also differed, as we observed elevated production of barrier protective linoleic acid (C18:2) and reduced abundance of longer chain saturated lignoceric acid (C24:0) among the stratum corneum fatty acids in the aged NRF2-deficient mice. Thus, despite epidermal differentiation being disturbed in aged NRF2-deficient animals in homeostasis, adaptations in keratinocyte proliferation and barrier lipid synthesis could explain the lack of a more severe phenotype.

Cerebrospinal fluid in Borna disease virus 1 (BoDV-1) encephalitis.

Borna disease virus 1 (BoDV-1) has been recognized as a rare cause of very severe encephalitis with rapid onset in central Europe. Data on cerebrospinal fluid (CSF) analysis have not yet been analyzed in detail. Here, we present the first study on CSF changes in BoDV-1 encephalitis. We retrospectively analyzed CSFs from 18 BoDV-1 encephalitis cases from Bavaria, Germany, an endemic region, from 1996 to 2021. Data were obtained through review of medical records and institutional databases. We found that white blood cell count (WBC) in CSF is elevated in 13 of our 18 patients at first examination (average 83.2 ± 142.3 leukocytes/µl) and cytology showed predominance of lymphocytes. Patients with typical symptoms of meningoencephalitis had higher WBC in first CSF analyzation (133.5 ± 163.1 vs 4.0 ± 3.2/µl; p = 0.065). BoDV-1 PCR of CSF is not always positive when tested (7 of 9 cases). Four of five patients tested showed a polyvalent reaction against multiple viruses in the CSF suggesting that BoDV-1 may trigger autoimmune mechanisms. CSF changes in BoDV-1 encephalitis seem similar to those of other viral encephalitis and at the beginning WBC can be normal in up to 28%, making the diagnosis even more challenging. All in all, BoDV-1 should be included in the diagnostic workup of patients with rapidly evolving and/or severe encephalitis and patients with severe neuropathy and secondary encephalopathy with and without CSF changes. Repeated CSF examinations as well as BoDV-1 serology and CSF PCR have to be considered in endemic areas.

On the Role of Noncovalent Ligand-Substrate Interactions in Au(I) Catalysis: An Experimental and Computational Study of Protodeauration.

A systematic study of protodeauration, a crucial step often found in gold catalysis, was performed using isolated vinyl gold(I) complexes. By varying substituents on gold complexes, we explore how their properties influence protodeauration. Phenols were employed as the proton source, and their substituents were also varied, providing insight through variation of their acidity. A linear Hammett correlation is identified for the series of substituted vinyl gold(I) complexes, while a nonlinear trend is found for the series of substituted phenols. Computationally, we reproduce our experimental observations and identify significant noncovalent interactions (NCIs) between the proton donor and vinyl gold(I) complexes. This finding is of particular importance for gold-catalyzed reactions as they often employ linear two-coordinate complexes where the site of the reaction is spatially remote from the ligand bound to gold. The NCIs between substrates and intermediates lead to a significant acceleration of the protodeauration step in this work, opening the door to alternative strategies in the field of gold catalysis.

Consequences of Autophagy Deletion on the Age-Related Changes in the Epidermal Lipidome of Mice.

Autophagy is a controlled mechanism of intracellular self-digestion with functions in metabolic adaptation to stress, in development, in proteostasis and in maintaining cellular homeostasis in ageing. Deletion of autophagy in epidermal keratinocytes does not prevent the formation of a functional epidermis and the permeability barrier but causes increased susceptibility to damage stress and metabolic alterations and accelerated ageing phenotypes. We here investigated how epidermal autophagy deficiency using Keratin 14 driven Atg7 deletion would affect the lipid composition of the epidermis of young and old mice. Using mass spectrometric lipidomics we found a reduction of age-related accumulation of storage lipids in the epidermis of autophagy-deficient mice, and specific changes in chain length and saturation of fatty acids in several lipid classes. Transcriptomics and immunostaining suggest that these changes are accompanied by changes in expression and localisation of lipid and fatty acid transporter proteins, most notably fatty acid binding protein 5 (FABP5) in autophagy knockouts. Thus, maintaining autophagic activity at an advanced age may be necessary to maintain epidermal lipid homeostasis in mammals.

Ultrastructure of the Dentin Pellicle and the Impact of Erosion.

While the ultrastructure of the enamel pellicle and its erosion protective properties are well studied, the dentin pellicle is still neglected in dental research. Therefore, the ultrastructure and erosion protective properties of a pellicle formed on bovine dentin specimens were investigated in the present study. The dentin pellicle was formed in situ for 3, 30, 120, and 360 min at buccal or palatal oral sites of 3 subjects and analyzed by transmission electron microscopy. In order to clarify the impact of an erosive challenge to the ultrastructure of the pellicle and the underlying dentin, specimens were exposed to the oral cavity and eroded in vivo with 0.1% or 1% citric acid either immediately or after 30 min of pellicle formation. Specimens that were eroded without exposure to the oral cavity served as control. In another trial, specimens with a 30-min pellicle were exposed to the oral cavity for a further 60 min after the erosive challenge to investigate the effect of saliva on the impaired pellicle and dentin. Transmission electron micrographs reveal a globular and granular structured pellicle layer, which was thicker when the pellicle was formed buccally or with longer formation times. Erosion with citric acid reduced the thickness of the pellicle and interrupted its continuity. The dentin was also affected by erosion, which was represented by a lower electron density and formation of demineralized lacunae. These were infiltrated by a granular structured material when specimens were exposed to the oral cavity. After further intraoral exposure, the infiltration was more pronounced, indicating a significant impact of saliva on the demineralized dentin. A reformation of the dentin pellicle on the other hand did not occur. In conclusion, the dentin pellicle is neither acid-resistant nor able to effectively protect dentin from erosion.

Resourceful Actors, Not Weak Victims: Reframing Refugees' Stigmatized Identity Enhances Long-Term Academic Engagement.

Refugees suffer from a stigmatized identity portraying them as weak, unskilled victims. We developed a brief (~10-min) intervention that reframed refugees' identity as being, by its very nature, a source of strength and skills. Reading and writing exercises, provided by a university, highlighted how refugees' experiences helped them acquire skills such as perseverance and the ability to cope with adversity, which could help them succeed in a new country. In Experiment 1 (N = 93), the intervention boosted refugees' (a) confidence in their ability to succeed at an imagined university and (b) challenge seeking: Participants were 70% more likely to take on an academic exercise labeled as difficult. In Experiment 2, the intervention, delivered to refugees entering an online university (N = 533), increased engagement in the online-learning environment by 23% over the subsequent year. There was also evidence of greater course completion. It is possible to reframe stigmatized individuals' identity as inherently strong and resourceful, helping them put their strengths to use.

Environmentally Friendly, Photochemical Access to [ N ∧ C ∧ N ]AuIII Pincer Complexes By Oxidative Addition.

Starting from commercially available DMSAuCl and diazonium salts, cationic [ N ∧ C ∧ N ]AuIII complexes were synthesized in a selective, photosensitizer-free, photochemical reaction by irradiation with blue LED light. This new protocol represents the first easy synthesis of these types of pincer complexes in moderate to excellent yield starting from a readily available gold(I) precursor with nitrogen as the only by-product. Owing to the disadvantages of known protocols, especially the toxicity in the case of a transmetalation with mercury or the necessity for a mostly twofold excess of a gold precursor, this method offers an attractive alternative towards this kind of gold(III) complexes. In addition, the first arylated [ N ∧ C ∧ N ]Au(III) pincer complex was synthesized by using this technology.

Do Only White or Asian Males Belong in Genius Organizations? How Academic Organizations' Fixed Theories of Excellence Help or Hinder Different Student Groups' Sense of Belonging.

High-profile organizations often emphasize fixed giftedness rather than malleable effort-based criteria as critical for excellent achievements. With giftedness being primarily associated with White or Asian males, such organizational implicit theories of excellence may shape individuals' sense of belonging depending on the extent to which they match the gifted White/Asian male prototype, i.e., the prototypical gifted person which is typically imagined to be a White or Asian male. Previous research has reported fixed excellence theories emphasizing giftedness (vs. malleable theories emphasizing effort) to impair the sense of belonging of females and negatively stereotyped ethnic minorities. We investigate the combined effects of gender and ethnicity. We predicted that, while individuals whose gender and ethnicity do not match the gifted prototype show a reduced sense of belonging in fixed organizations, White/Asian males who match the gifted prototype show the opposite effect, experiencing a higher sense of belonging in fixed (vs. malleable) organizations. In an experimental study (N = 663 students), we manipulated advertising material used by a highly selective academic institution in Germany and tested effects on students' belonging. Whereas the original material emphasized giftedness as essential for excelling (fixed excellence version), our manipulated version stressed effort (malleable version). As expected, females from stereotyped ethnic minority groups felt less belonging in the fixed (vs. malleable) organization, while White/Asian males anticipated stronger belonging in the fixed (vs. malleable) organization. Fixed views of excellence impair negatively stereotyped individuals' belonging but may even strengthen the belonging of prototypical academic elites.

Black and White Patients With Inflammatory Bowel Disease Show Similar Biologic Use Patterns With Medicaid Insurance.

BACKGROUND: Prior studies have identified racial disparities in the treatment and outcomes of inflammatory bowel disease (IBD). These disparities could be secondary to differences in biology, care delivery, or access to appropriate therapy. The primary aim of this study was to compare medication use among Medicaid-insured black and white patients with IBD, given uniform access to gastroenterologists and therapies. METHODS: We analyzed Medicaid Analytic eXtract data from 4 states (California, Georgia, North Carolina, and Texas) between 2006 and 2011. We compared the use of IBD-specific therapies, including analyses of postoperative therapy among patients with Crohn disease (CD). We performed bivariate analyses and multivariable logistic regression, adjusting for potential confounders. RESULTS: We identified 14,735 patients with IBD (4672 black [32%], 8277 with CD [58%]). In multivariable analysis, there was no significant difference in the odds of anti-tumor necrosis factor use by race for CD (adjusted odds ratio [aOR] = 1.13; 95% confidence interval [CI], 0.99-1.28] or ulcerative colitis (aOR = 1.12; 95% CI, 0.96-1.32). Black patients with CD were more likely than white patients to receive combination therapy (aOR = 1.50; 95% CI, 1.15-1.96), and black patients were more likely than white patients to receive immunomodulator monotherapy after surgery for CD (31% vs 18%; P = 0.004). CONCLUSIONS: In patients with Medicaid insurance, where access to IBD-specific therapy should be similar for all individuals, there was no significant disparity by race in the utilization of IBD-specific therapies. Disparities in IBD treatment discussed in prior literature seem to be driven by socioeconomic or other issues affecting access to care.

P067 Immune Checkpoint Inhibitor Colitis in a Community-Based Hospital System.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have significantly changed the oncologic treatment landscape for a wide array of cancers over the past few decades. While these medications can produce a durable remission for patients they also come with a risk of inflammatory toxicities. With the widespread use of immune checkpoint inhibitors there have been increased reports of immune-related adverse events (irAEs) including severe gastrointestinal toxicities such as colitis. While multiple studies have assessed ICI colitis in tertiary care settings little is reported on the characteristics and treatment outcomes of ICI colitis in a community-based population. Additionally, the utility of gastroenterologists in the diagnosis and management of ICI colitis is poorly defined. The aim of this study is to report the characteristics and treatment outcomes of ICI colitis in a community-based hospital system. METHODS: This is a single-center retrospective case-series of patients with ICI colitis. Charts were reviewed from patients in the Prisma Health Upstate Network from 2/1/2016 to 12/31/2020. Potential cases of ICI colitis were identified using a diagnosis code of "toxic colitis", "indeterminate colitis", "unspecified colitis", and "noninfective gastroenteritis and colitis" (ICD-10 K52.1, K 52.3, K 52.89 and K52.9) as well as a prior infusion (within 12 months) of pembrolizumab, nivolumab, cemiplimab, atezolizumab, avelumab, durvalumab, or ipilimumab. Charts were abstracted for demographics, tumor type, checkpoint inhibitor used, mode of colitis diagnosis, endoscopic severity of inflammation, and treatments used. Study was approved by the Institutional Review Board at Prisma Health Upstate. RESULTS: The mean (±SD) age for the 37 patients was 64.1 ± 13.2 years. The patient population was predominantly male (62%) and Caucasian (100%). The cancer type in the patient population were melanoma (43.2%), non-small cell lung cancer (18.9%), renal cell carcinoma (10.8%), and other (27%). Patients with ICI colitis were most-commonly treated with ipilimumab (35.1%), nivolumab (35%), pembrolizumab (10.8%), and other (13.5%). The mean time to colitis onset was 25.7 ± 29.7 weeks. Over 56% of the patient population reported abdominal pain and 45.9% were hospitalized. Only 64.8% were evaluated by a gastroenterologist. Cross sectional abdominal imaging by computed tomography (CT) was obtained in 20 (54.0%) and showed colitis in 13. 54% obtained a colonoscopy with inflammation severity stratified into normal (25.0%), mild (40.0%), moderate (20.0%) and severe (15.0%). Endoscopic extent showed proctitis (0%), left-sided disease (5.0%), right-sided disease (5.0%), pancolitis (55.0%), and isolated ileal disease (25%). Histology showed 90.0% with active inflammation and 10.0% with microscopic colitis. Outcomes were resolution with steroids (64.8%), antibiotics (5.4%), biologic (10.8%), surgery (5.4%), hospice (8.1%). Of those that received biologic therapy, 6 received infliximab and 1 received vedolizumab. CONCLUSION: As immune checkpoint inhibitors gain approval in more cancer treatment ICI-colitis is being seen in a community-based setting. The most common treatment were steroids and often required a prolonged course. Biologic use in our series (18.9%) was much lower than prior reports from academic tertiary referral centers (>50%). Only 64.8% of patients saw a gastroenterologist for ICI-colitis symptoms. Early gastroenterology referral in the community setting could help to identify more severe disease and patients necessitating escalation to biologic therapy.

Characteristics of Fecal Microbiota Transplantation Use in Inflammatory Bowel Disease Cohort.

BACKGROUND: There is a growing interest in the role of gut bacteria in a number of diseases and an emerging hypothesis that inflammatory bowel disease (IBD) is triggered by microbial dysbiosis in genetically susceptible individuals. Currently, fecal microbiota transplantation (FMT) is utilized for the treatment of Clostridium difficile colitis. Data on the efficacy of FMT for IBD are mixed, but patients are interested in its use for the treatment of IBD. We sought to describe the use of FMT (self or medical professional administered) in individuals with IBD using IBD Partners, an Internet-based cohort. METHODS: Patients enrolled in the IBD Partners cohort were offered the opportunity to complete an optional survey on the use of FMT between January 2017 to September 2018 (n = 5430). A cross-sectional analysis was performed within patients who completed the survey and did not have a pouch or ostomy. Patients' demographic characteristics, disease activity and phenotype, mode of FMT delivery, and patient-reported efficacy were compared. RESULTS: Among 3274 eligible patients, 51 (1.6%) responded that they had an FMT in the past. Of patients undergoing FMT, 22 patients had the FMT for C. difficile while 29 reported that the FMT was for another indication. Most patients receiving FMT for an indication other than C. difficile had ulcerative colitis/indeterminate colitis (25, 86.2%). Colonoscopy (68.2%) and nasogastric tube (18.2%) were the most common routes of administration for patients receiving FMT for C. difficile colitis. Self-administration (72.4%) and enemas (17.2%) were the most common routes of administration in patients receiving FMT for an alternate indication. Patients reporting FMT for an indication other than C. difficile were less likely to have a physician directing their FMT treatment (20.6%) as compared to patients receiving FMT for C. difficile (86.3%). Patient-reported efficacy was lower for FMT given for a non-C. difficile indication. CONCLUSIONS: Patients undergoing FMT for an indication other than C. difficile infection were more likely to have ulcerative colitis, self-administer FMT, and were less likely to be receiving FMT under the guidance of a medical professional. FMT was not as effective for symptoms when given for a non-C. difficile indication. Patients should be counseled on potential harms and lack of proven benefit associated with FMT for IBD indications to try to discourage self-administered FMT without proper medical oversite.

Systematic analysis of the binding behaviour of UHRF1 towards different methyl- and carboxylcytosine modification patterns at CpG dyads.

The multi-domain protein UHRF1 is essential for DNA methylation maintenance and binds DNA via a base-flipping mechanism with a preference for hemi-methylated CpG sites. We investigated its binding to hemi- and symmetrically modified DNA containing either 5-methylcytosine (mC), 5-hydroxymethylcytosine (hmC), 5-formylcytosine (fC), or 5-carboxylcytosine (caC). Our experimental results indicate that UHRF1 binds symmetrically carboxylated and hybrid methylated/carboxylated CpG dyads in addition to its previously reported substrates. Complementary molecular dynamics simulations provide a possible mechanistic explanation of how the protein could differentiate between modification patterns. First, we observe different local binding modes in the nucleotide binding pocket as well as the protein's NKR finger. Second, both DNA modification sites are coupled through key residues within the NKR finger, suggesting a communication pathway affecting protein-DNA binding for carboxylcytosine modifications. Our results suggest a possible additional function of the hemi-methylation reader UHRF1 through binding of carboxylated CpG sites. This opens the possibility of new biological roles of UHRF1 beyond DNA methylation maintenance and of oxidised methylcytosine derivates in epigenetic regulation.

A One-Step Process for the Construction of Phage Display scFv and VHH Libraries.

In this work we present a one-step cloning approach for the establishment of antibody phage display libraries relying on type IIs restriction enzymes. We show that single chain variable fragment (scFv) libraries with adequate qualities can readily be cloned in a 'scar-less' manner and that the isolation of antigen-specific antibodies from immunized chickens is feasible within three selection rounds. Moreover, we demonstrate the general applicability of this method by rapidly constructing and panning VHH single domain antibody phage display libraries from immunized Llama repertoires.

The Host Factor Erlin-1 is Required for Efficient Hepatitis C Virus Infection.

Development of hepatitis C virus (HCV) infection cell culture systems has permitted the identification of cellular factors that regulate the HCV life cycle. Some of these cellular factors affect steps in the viral life cycle that are tightly associated with intracellular membranes derived from the endoplasmic reticulum (ER). Here, we describe the discovery of erlin-1 protein as a cellular factor that regulates HCV infection. Erlin-1 is a cholesterol-binding protein located in detergent-resistant membranes within the ER. It is implicated in cholesterol homeostasis and the ER-associated degradation pathway. Silencing of erlin-1 protein expression by siRNA led to decreased infection efficiency characterized by reduction in intracellular RNA accumulation, HCV protein expression and virus production. Mechanistic studies revealed that erlin-1 protein is required early in the infection, downstream of cell entry and primary translation, specifically to initiate RNA replication, and later in the infection to support infectious virus production. This study identifies erlin-1 protein as an important cellular factor regulating HCV infection.