2023 White Paper on Recent Issues in Bioanalysis: ISR for ADA Assays, the Rise of dPCR vs qPCR, International Reference Standards for Vaccine Assays, Anti-AAV TAb Post-Dose Assessment, NanoString Validation, ELISpot as Gold Standard (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccines Immunogenicity & Technologies; Biotherapeutics Immunogenicity & Risk Assessment; ADA/NAb Assay/Reporting Harmonization)

The 17th Workshop on Recent Issues in Bioanalysis (17th WRIB) took place in Orlando, FL, USA on June 19-23, 2023. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 17th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week to allow an exhaustive and thorough coverage of all major issues in bioanalysis of biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on "EU IVDR 2017/746 Implementation and impact for the Global Biomarker Community: How to Comply with these NEW Regulations" and on "US FDA/OSIS Remote Regulatory Assessments (RRAs)" were the special features of the 17th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2023 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2023 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity. Part 1A (Mass Spectrometry Assays and Regulated Bioanalysis/BMV), P1B (Regulatory Inputs) and Part 2 (Biomarkers, IVD/CDx, LBA and Cell-Based Assays) are published in volume 16 of Bioanalysis, issues 8 and 9 (2024), respectively.

2022 White Paper on Recent Issues in Bioanalysis: Enzyme Assay Validation, BAV for Primary End Points, Vaccine Functional Assays, Cytometry in Tissue, LBA in Rare Matrices, Complex NAb Assays, Spectral Cytometry, Endogenous Analytes, Extracellular Vesicles Part 2 - Recommendations on Biomarkers/CDx, Flow Cytometry, Ligand-Binding Assays Development & Validation; Emerging Technologies; Critical Reagents Deep Characterization

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on LBA, Biomarkers/CDx and Cytometry. Part 1 (Mass Spectrometry and ICH M10) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 16 and 14 (2023), respectively.

Current nonclinical approaches for immune assessments of immuno-oncology biotherapeutics

Harnessing the immune system to kill tumors has been revolutionary and, as a result, has had an enormous benefit for patients in extending life and resulting in effective cures in some. However, activation of the immune system can come at the cost of undesirable adverse events such as cytokine release syndrome, immune-related adverse events, on-target/off-tumor toxicity, neurotoxicity and tumor lysis syndrome, which are safety risks that can be challenging to assess non-clinically. This article provides a review of the biology and mechanisms that can result in immune-mediated adverse effects and describes industry approaches using in vitro and in vivo models to aid in the nonclinical safety risk assessments for immune-oncology modalities. Challenges and limitations of knowledge and models are also discussed.

Trends in industrialization of biotherapeutics: a survey of product characteristics of 89 antibody-based biotherapeutics

There is considerable interest in the pharmaceutical industry toward development of antibody-based biotherapeutics because they can selectively bind diverse receptors and often possess desirable pharmacology. Here, we studied product characteristics of 89 marketed antibody-based biotherapeutics that were approved from 1986 to mid-2020 by gathering publicly available information. Our analyses revealed major trends in their emergence as the best-selling class of pharmaceuticals. Early on, most therapeutic monoclonal antibodies were developed to treat cancer, with CD20 being the most common target. Thanks to industrialization of antibody manufacturing technologies, their use has now blossomed to include 15 different therapeutic areas and nearly 60 targets, and the field is still growing! Drug manufacturers are solidifying their choices regarding types of antibodies and their molecular formats. IgG1 kappa continues to be the most common molecular format among marketed antibody-based biotherapeutics. Most antibody-based biotherapeutics approved since 2015 are either humanized or fully human, but the data we collected do not show a direct correlation between humanness and reported incidence of anti-drug antibodies. Furthermore, there have also been improvements in terms of drug product stability and high concentration liquid formulations suitable for subcutaneous route of administration, which are being approved more often in recent years. These improvements, however, have not been uniformly adopted across all therapeutic areas, suggesting that multiple options for drug product development are being used to serve diverse therapeutic purposes. Insights gained from this analysis may help us devise better end-to-end antibody-based biotherapeutic drug discovery and development strategies.

Therapeutic Protein Drug Interactions: A White Paper From the International Consortium for Innovation and Quality in Pharmaceutical Development

Typically, therapeutic proteins (TPs) have a low risk for eliciting meaningful drug interactions (DIs). However, there are select instances where TP drug interactions (TP-DIs) of clinical concern can occur. This white paper discusses the various types of TP-DIs involving mechanisms such as changes in disease state, target-mediated drug disposition, neonatal Fc receptor (FcRn), or antidrug antibodies formation. The nature of TP drug interaction being investigated should determine whether the examination is conducted as a standalone TP-DI study in healthy participants, in patients, or assessed via population pharmacokinetic analysis. DIs involving antibody-drug conjugates are discussed briefly, but the primary focus here will be DIs involving cytokine modulation. Cytokine modulation can occur directly by certain TPs, or indirectly due to moderate to severe inflammation, infection, or injury. Disease states that have been shown to result in indirect disease-DIs that are clinically meaningful have been listed (i.e., typically a twofold change in the systemic exposure of a coadministered sensitive cytochrome P450 substrate drug). Type of disease and severity of inflammation should be the primary drivers for risk assessment for disease-DIs. While more clinical inflammatory marker data needs to be collected, the use of two or more clinical inflammatory markers (such as C-reactive protein, albumin, or interleukin 6) may help broadly categorize whether the predicted magnitude of inflammatory disease-DI risk is negligible, weak, or moderate to strong. Based on current knowledge, clinical DI studies are not necessary for all TPs, and should no longer be conducted in certain disease patient populations such as psoriasis, which do not have sufficient systemic inflammation to cause a meaningful indirect disease-DI.

An optimally designed anti-human CD40 antibody with potent B cell suppression for the treatment of autoimmune diseases

Antibodies targeting the CD40-CD40L pathway have great potential for treating autoimmune diseases like rheumatoid arthritis, systemic lupus erythematosus (SLE), lupus nephritis (LN), and inflammatory bowel diseases (IBD). However, in addition to the known difficulty in generating a purely antagonistic CD40 antibody, the presence of CD40 and CD40L on platelets creates additional unique challenges for the safety, target coverage, and clearance of antibodies targeting this pathway. Previously described therapeutic antibodies targeting this pathway have various shortcomings, and the full therapeutic potential of this axis has yet to be realized. Herein, we describe the generation and characterization of BI 655064, a novel, purely antagonistic anti-CD40 antibody that potently neutralizes CD40-CD40L-dependent B-cell stimulation without evidence of impacting platelet functions. This uniquely optimized antibody targeting a highly challenging pathway was obtained by applying stringent functional and biophysical criteria during the lead selection process. BI 655064 has favorable target-mediated drug disposition (TMDD)-saturation pharmacokinetics, consistent with that of a high-quality therapeutic monoclonal antibody.

Development and characterization of a 3D in vitro model mimicking acneic skin

Acne is an inflammatory skin disease of the pilosebaceous unit, involving four essential factors: hyperseborrhoea combined to a modification of sebum composition, colonization by Cutibacterium (C.) acnes, hyperkeratinization and secreted inflammation. Understanding and mimicking compromised skin is essential to further develop appropriate therapeutic solutions. This study aimed to develop new in vitro 3D models mimicking acneic skin, by combining two main factors involved in the physiopathology, namely, altered sebum composition and C. acnes invasion. Normal human keratinocytes were first used to generate reconstructed human epidermis (RHE) that were then left untreated (control) or treated topically with a combination of both peroxidized squalene and C. acnes cultures. Once validated, this model considered relevant to mimic acneic skin, was further improved by using different phylotypes of C. acnes strains specifically isolated from healthy and acneic patients. While both phylotypes IB and II did not significantly alter RHE, C. acnes IA1 strains induce major acneic skin hallmarks such as hyperkeratinization, secreted inflammation and altered barrier function. Interestingly, these results are obtained independently of the origin of IA1 phylotypes (acneic vs. healthy patient), thus suggesting a role of the ecosystem in controlling C. acnes virulence in healthy skin. In conclusion, by combining two major factors involved in the physiopathology of acne, we (1) succeeded to design in vitro 3D models mimicking this skin disorder and (2) highlighted how C. acnes phylotypes can have an impact on epidermal physiology. These relevant models will be suitable for the substantiation of therapeutic molecules dedicated to acne treatment.

Safety, pharmacokinetics and pharmacodynamics of BI 655064 in phase 1 clinical trials in healthy Chinese and Japanese subjects

Aims

To evaluate the safety, pharmacokinetics and pharmacodynamics of BI 655064 in healthy Chinese and Japanese subjects after administration of single doses of 80‐240 mg and multiple dosing of 240 mg once weekly over 4 weeks.

Methods

Two phase 1, double‐blind, placebo‐controlled studies were conducted (single‐rising doses of BI 655064 in Chinese/Japanese male subjects [n = 12 per BI 655064 dose group] or repeated 240 mg BI 655064 in Chinese male subjects [n = 9]). Plasma samples were collected to investigate BI 655064 pharmacokinetics, pharmacodynamics (CD40 receptor occupancy [RO]) and immunogenicity, along with the safety and tolerability of BI 655064.

Results

BI 655064 showed good overall tolerability following single‐dose administration of 80‐240 mg and repeated administration of 240 mg BI 655064 over 4 weeks. More Chinese subjects reported adverse events compared with Japanese subjects following single‐dose administration (59.4% vs 3.1%). BI 655064 exhibited nonlinear, saturable kinetics, with higher doses resulting in slower apparent clearance (0.514‐0.713 mL min⁻¹), and disproportionately higher total exposure (AUC_0‐inf; 5610‐7780 μg·h mL⁻¹) and maximum plasma concentration (15 700‐21 300 ng mL⁻¹) with 240 mg BI 655064. Ninety percent inhibition of CD40 RO was achieved with doses ≥120 mg, and a direct relationship between BI 655064 plasma concentration and inhibition of CD40 RO was observed. Most subjects had a positive treatment‐emergent antidrug antibody response.

Conclusions

BI 655064 pharmacokinetic and safety profiles in East Asian male subjects were consistent with those observed in a Western population. No adjustments in the BI 655064 dosing recommendations are warranted for future clinical trials.

Retrospective analysis of model-based predictivity of human pharmacokinetics for anti-IL-36R monoclonal antibody MAB92 using a rat anti-mouse IL-36R monoclonal antibody and RNA expression data (FANTOM5)

Accurate prediction of the human pharmacokinetics (PK) of a candidate monoclonal antibody from nonclinical data is critical to maximize the success of clinical trials. However, for monoclonal antibodies exhibiting nonlinear clearance due to target-mediated drug disposition, PK predictions are particularly challenging. That challenge is further compounded for molecules lacking cross-reactivity in a nonhuman primate, in which case a surrogate antibody selective for the target in rodent may be required. For these cases, prediction of human PK must account for any interspecies differences in binding kinetics, target expression, target turnover, and potentially epitope. We present here a model-based method for predicting the human PK of MAB92 (also known as BI 655130), a humanized IgG1 κ monoclonal antibody directed against human IL-36R. Preclinical PK was generated in the mouse with a chimeric rat anti-mouse IgG2a surrogate antibody cross-reactive against mouse IL-36R. Target-specific parameters such as antibody binding affinity (K_D), internalization rate of the drug target complex (k_int), target degradation rate (k_deg), and target abundance (R₀) were integrated into the model. Two different methods of assigning human R₀ were evaluated: the first assumed comparable expression between human and mouse and the second used high-resolution mRNA transcriptome data (FANTOM5) as a surrogate for expression. Utilizing the mouse R₀ to predict human PK, AUC_0-∞ was substantially underpredicted for nonsaturating doses; however, after correcting for differences in RNA transcriptome between species, AUC_0-∞ was predicted largely within 1.5-fold of observations in first-in-human studies, demonstrating the validity of the modeling approach. Our results suggest that semi-mechanistic models incorporating RNA transcriptome data and target-specific parameters may improve the predictivity of first-in-human PK.

Mercury Isotopic Fractionation during Pedogenesis in a Tropical Forest Soil Catena (French Guiana): Deciphering the Impact of Historical Gold Mining

We used natural mercury (Hg) stable isotopes to investigate the Hg cycle in a rainforest soil catena (French Guiana) partially gold-mined during the early 1950s. Litterfall showed homogeneous Δ¹⁹⁹Hg values [-0.18 ± 0.05‰, i.e., a modern gaseous elemental Hg (GEM) isotopic signature]. After litter decomposition, Hg bound to organic matter (OM) is mixed with Hg from pristine (-0.55 ± 0.22‰) or gold-mined (-0.09 ± 0.16‰) mineral materials. Negative Δ¹⁹⁹Hg values in deep pristine mineral horizons (-0.60 ± 0.16‰) suggest the transfer of Hg bound to dissolved OM depleted in odd isotopes due to mass-independent fractionation during Hg abiotic reduction. Perennial palm tree leaves collected above gold-mined and pristine soil recorded contrasting Δ¹⁹⁹Hg signatures likely resulting from GEM re-emission processes from soils and leaf surfaces. Upslope, soil δ²⁰²Hg signatures showed a negative shift (ε ∼ -1‰) with depth attributed to mass-dependent fractionation during Hg sorption and complexation onto iron oxides and dissolved OM. Downslope, higher δ²⁰²Hg values in soils resulted from hydromorphy [lower humification, greater Hg(II) reduction, etc.]. The unique Hg isotopic signatures of Amazonian soils probably result in multistep fractionation processes during pedogenesis (millions of years) and in a potentially different Hg isotopic signature of preanthropogenic background GEM.

Current strategies in the non-clinical safety assessment of biologics: New targets, new molecules, new challenges

Nonclinical safety testing of biopharmaceuticals can present significant challenges to human risk assessment with these innovative and often complex drugs. Emerging topics in this field were discussed recently at the 2016 Annual US BioSafe General Membership meeting. The presentations and subsequent discussions from the main sessions are summarized. The topics covered included: (i) specialty biologics (oncolytic virus, gene therapy, and gene editing-based technologies), (ii) the value of non-human primates (NHPs) for safety assessment, (iii) challenges in the safety assessment of immuno-oncology drugs (T cell-dependent bispecifics, checkpoint inhibitors, and costimulatory agonists), (iv) emerging therapeutic approaches and modalities focused on microbiome, oligonucleotide, messenger ribonucleic acid (mRNA) therapeutics, (v) first in human (FIH) dose selection and the minimum anticipated biological effect level (MABEL), (vi) an update on current regulatory guidelines, International Council for Harmonization (ICH) S1, S3a, S5, S9 and S11 and (vii) breakout sessions that focused on bioanalytical and PK/PD challenges with bispecific antibodies, cytokine release in nonclinical studies, determining adversity and NOAEL for biologics, the value of second species for toxicology assessment and what to do if there is no relevant toxicology species.

Shift in skin microbiota of Western European women across aging

AIMS

The objective of our study was to compare the microbiota diversity between two different age groups of Western European women.

METHODS AND RESULTS

Skin-swab samples were collected directly on the forehead of 34 healthy Western European women: 17 younger (21-31 years old) and 17 older individuals (54-69 years old). Bacterial communities were evaluated using the 16S rRNA gene sequencing. Data revealed a higher alpha diversity on the skin of older individuals compared with younger ones. Overall microbiota structure was different between the two age groups, as demonstrated by beta diversity analysis, which also highlighted a high interpersonal variation within older individuals. Furthermore, taxonomic composition analysis showed both an increase in Proteobacteria and a decrease in Actinobacteria on the older skin. At the genus level, older skin exhibited a significant increase in Corynebacterium and a decrease in Propionibacterium relative abundance.

CONCLUSIONS

Our study revealed a shift in the distribution of skin microbiota during chronological aging in Western European women.

SIGNIFICANCE AND IMPACT OF STUDY

Altogether these results could become the basis to develop new approaches aiming to rebalance the skin microbiota, which is modified during the aging process.

CPAP by helmet for treatment of acute respiratory failure after pediatric liver transplantation

ARF after pediatric liver transplantation accounts for high rate of morbidity and mortality associated with this procedure. The role of CPAP in postoperative period is still unknown. The aim of the study was to describe current practice and risk factors associated with the application of helmet CPAP. In this retrospective observational cohort study, 119 recipients were divided into two groups based on indication to CPAP after extubation. Perioperative variables were studied, and determinants of CPAP application were analyzed in a multivariate logistic model. Sixty patients (60/114) developed ARF and were included in the CPAP group. No differences were found between the two groups for primary disease, graft type, and blood product transfused. At multivariate analysis, weight <11 kg (OR = 2.9; 95% CI = 1.1-7.3; P = .026), PaO₂ /FiO₂ <380 before extubation (OR = 5.4; 95% CI = 2.1-13.6; P < .001), need of vasopressors (OR = 2.6; 95% CI = 1.1-6.4; P = .038), and positive fluid balance >148 mL/kg (OR = 4.0; 95% CI = 1.6-10.1; P = .004) were the main determinants of CPAP application. In the CPAP group, five patients (8.4%) needed reintubation. Pediatric liver recipients with lower weight, higher need of inotropes/vasopressors, higher positive fluid balance after surgery, and lower PaO₂ /FiO₂ before extubation were at higher odds of developing ARF needing CPAP application.

Ab initio Everolimus-based Versus Standard Calcineurin Inhibitor Immunosuppression Regimen in Liver Transplant Recipients

AIM

We designed a retrospective case-control study to determine the efficacy and feasibility of everolimus (EVR) combined with low-dose tacrolimus (Tac) ab initio versus standard-dose Tac after liver transplantation (LT).

METHODS

Seventy-one adult LT patients, receiving EVR and low-dose Tac without corticosteroids or induction therapy from postoperative day 1 (EVR group) were compared with a well-matched control group of 61 recipients treated with standard-dose Tac in association with antimetabolite.

RESULTS

Baseline characteristics for the two groups were comparable. The overall patient and graft survival rates were similar (P = .908). Liver function was stable during the follow-up. In the EVR group, biopsy-proven acute rejection occurred in two cases (2.8%), whereas chronic rejection occurred in one (1.4%). The EVR group experienced a better renal function already after 2 weeks (estimated glomerular filtration rate: 89.85 [36.46 to 115.3] mL/min/1.73 m² vs. 68.77 [16.11 to 115.42] mL/min/1.73 m²; P = .013), which was also observed after a median time of 27 months (range, 0 to 82 months) from LT (estimated glomerular filtration rate: 80 [45 to 118.3] mL/min/1.73 m² vs. 70.9 [45 to 88.4] mL/min/1.73 m²; P = .04). After a median time of 27 months, the EVR group showed lower incidence of arterial hypertension and insulin-dependent diabetes mellitus.

CONCLUSION

Ab initio EVR-based immunosuppression could be a valid option immediately after surgery in recipients at high-risk for post-LT renal impairment.

Generation and functional characterization of anti-human and anti-mouse IL-36R antagonist monoclonal antibodies

Deficiency of interleukin (IL)-36 receptor antagonist (DITRA) syndrome is a rare autosomal recessive disease caused by mutations in IL36RN. IL-36R is a cell surface receptor and a member of the IL1R family that is involved in inflammatory responses triggered in skin and other epithelial tissues. Accumulating evidence suggests that IL-36R signaling may play a role in the pathogenesis of psoriasis. Therapeutic intervention of IL-36R signaling offers an innovative treatment paradigm for targeting epithelial cell-mediated inflammatory diseases such as the life-threatening psoriasis variant called generalized pustular psoriasis (GPP). We report the discovery and characterization of MAB92, a potent, high affinity anti-human IL-36 receptor antagonistic antibody that blocks human IL-36 ligand (α, β and γ)-mediated signaling. In vitro treatment with MAB92 directly inhibits human IL-36R-mediated signaling and inflammatory cytokine production in primary human keratinocytes and dermal fibroblasts. MAB92 shows exquisite species specificity toward human IL-36R and does not cross react to murine IL-36R. To enable in vivo pharmacology studies, we developed a mouse cross-reactive antibody, MAB04, which exhibits overlapping binding and pharmacological activity as MAB92. Epitope mapping indicates that MAB92 and MAB04 bind primarily to domain-2 of the human and mouse IL-36R proteins, respectively. Treatment with MAB04 abrogates imiquimod and IL-36-mediated skin inflammation in the mouse, further supporting an important role for IL-36R signaling in epithelial cell-mediated inflammation.

After Muskoka

Substantial progress has been accomplished in reducing maternal, neonatal, and infant mortality, but the work to meet the Millennium Development Goals, boosted by numerous initiatives, including Muskoka, is far from finished. Since 2016, the Sustainable Development Goals, as well as the International Strategy for Women's, Children's, and Adolescent Health 2016 - 2030, have provided to the countries and development partners a consistent framework for action enlarged to all of the dimensions of human development, while keeping women, children, and adolescents at its heart. In this context, the Muskoka program, after an initial 5-year cycle, will continue in 2017.

The French Muskoka Fund: origin, objectives, and implementation

Through its Priority Solidarity Fund, France set up a partnership with four United Nations agencies, WHO, UNICEF, UNFPA, and UN WOMEN for the years 2011-2015 with an annual budget of 19 M €. An additional sixth year supplementary is underway. The program was developed through a common framework of actions coordinated and harmonized at the level of the target countries: integrated management of childhood diseases, mother-child nutrition, prenatal, perinatal, and postpartum follow-up, sexual and reproductive health, and adolescent health. The contribution of WHO was based on its normative role; UNICEF offered its operational capacity in the field, and UNFPA its focus on reproductive health, while UN WOMEN dealt with gender questions. The countries targeted specifically were: Benin, Burkina Faso, Côte d'Ivoire, Guinea, Haiti, Mali, Nigeria, Central Africa Republic, Democratic Republic of the Congo, Senegal, Chad, and Togo.

Identification and characterization of an antagonistic anti-mouse CD40 antibody

Targeting CD40-CD40L interactions has been an interesting drug concept for the treatment of autoimmune diseases given this pathway’s role in the development of both humoral and cell mediated immune responses. While preclinical blockade of CD40L is well documented in various autoimmune animal models of disease, limited data exists for CD40 blockade due to lack of a truly antagonistic anti-mouse CD40 tool antibody (Ab). Here we describe the in vitro and in vivo characterization of a fully antagonistic anti-mouse CD40 monoclonal Ab (BI CD40-1); a chimeric rat Fv anti-mouse CD40 mAb engineered with a mouse IgG2a Fc containing mutations to abrogate Fcγ receptor binding. BI CD40-1 blocks molecular CD40-CD40L interactions (IC50 = 0.25 nM) and exhibits potent binding to CD40 expressed on mouse B cells (EC50 = 0.42 nM ± 0.08). In vitro profiling of BI CD40-1 using a mouse splenocyte proliferation assay confirmed potent antagonistic activity (IC50 = 0.27 nM ± 0.09) as well as absence of any agonistic properties (stimulation index &lt; 2 @ 67 nM). Administration of BI CD40-1 to mice prior to ovalbumin (OVA) immunization resulted in dose-dependent blockade of OVA-specific IgG responses (100, 100, 74, 0% inhibition at 10, 3, 1, and 0.3 MPK; day 13) correlating with similar dose dependent receptor occupancy and inhibition of B cell activation as measured by ex vivo CD54 upregulation. Prophylactic dosing in cGVHD model of scleroderma showed dose dependent protection in disease development as seen by decreased dermal thickness, myofibroblast counts and collagen deposition. BI CD40-1 represents a novel fully antagonistic anti-mouse CD40 mAb, an important tool for mechanistic understanding of the therapeutic value of targeting of CD40 in inflammatory diseases.

Signal Transduction and Intracellular Trafficking by the Interleukin 36 Receptor

Improper signaling of the IL-36 receptor (IL-36R), a member of the IL-1 receptor family, has been associated with various inflammation-associated diseases. However, the requirements for IL-36R signal transduction remain poorly characterized. This work seeks to define the requirements for IL-36R signaling and intracellular trafficking. In the absence of cognate agonists, IL-36R was endocytosed and recycled to the plasma membrane. In the presence of IL-36, IL-36R increased accumulation in LAMP1+ lysosomes. Endocytosis predominantly used a clathrin-mediated pathway, and the accumulation of the IL-36R in lysosomes did not result in increased receptor turnover. The ubiquitin-binding Tollip protein contributed to IL-36R signaling and increased the accumulation of both subunits of the IL-36R.

Splitting livers: Trans-hilar or trans-umbilical division? Technical aspects and comparative outcomes

Controversy remains about the best line of division for liver splitting, through Segment IV or through the umbilical fissure. Both techniques are currently used, with the choice varying between surgical teams in the absence of an evidence-based choice. We conducted a single-center retrospective analysis of 47 left split liver grafts that were procured with two different division techniques: "classical" (N = 28, Group A) or through the umbilical fissure and plate (N = 19, Group B). The allocation of recipients to each group was at random; a single transplant team performed all transplantations. Demographics, characteristics, technical aspects, and outcomes were similar in both groups. The grafts in Group A, prepared with the classical technique, were procured more often with a single BD orifice compared with the grafts in Group B; however, this was not associated with a higher incidence of biliary problems in this series of transplants (96% actual graft survival rate [median ± s.d.

FOLLOW-UP

26 ± 20 months]). Both techniques provide good quality split grafts and an excellent outcome; surgical expertise with a given technique is more relevant than the technique itself. The classical technique, however, seems to be more flexible in various ways, and surgeons may find it to be preferable.

Roux-en-Y hepatico-jejunostomy for a left segmental graft: Do not twist the loop, stick it!

Biliary complications remain a major challenge for long-term success after LT, as it is, as a rule, the most common technical - early and late - complication that occurs, and because these complications contribute to a significant number of late graft losses and retransplantations. In the pediatric age group, both biliary atresia, as the patient's condition, and the use of a left liver graft, obtained by a liver division technique, make it necessary for the use of a Roux-en-Y jejunal loop for the biliary reconstruction in the majority of cases. A slight modification of the technique is presented, consisting of a straight positioning along the cut surface (rather than the conventional position that results in a harpoon shape). A favorable outcome in terms of a technical complication and graft survival was observed. This way of doing this is an interesting variation and adds to the surgical armamentarium.

Non-alcoholic fatty liver disease and hepatocellular carcinoma in a 7-year-old obese boy: coincidence or comorbidity?

BACKGROUND

Hepatocellular carcinoma (HCC) may develop from non-alcoholic fatty liver disease (NAFLD) either in the presence or in the absence of established cirrhosis. Non-cirrhotic patients with NAFLD-related HCC are usually adult, male and obese. However, this association has not been reported yet in younger age groups. Objectives In the present study, the clinical case of a 7-yaer-old obese boy with steatosis and HCC is presented.

METHODS

A 7-year-old boy, with no evidence of chronic liver disease, was admitted for assessment of a liver mass. Preliminary assessment was suggestive of a combined and severe liver steatosis together with a malignant disease.

RESULTS

A biopsy confirmed the suspected diagnosis of HCC; interestingly, the non-neoplastic liver was surrounded and characterized by the presence of steatosis and ballooning, and being absent of lobular inflammation and fibrosis. Chemotherapy and diet changes were conducted successfully with ultrasound characteristics suggesting improvements on both aspects: conventional liver mass resection could take place.

CONCLUSIONS

This case report suggests that HCC might develop in paediatric age patients with obesity-related NAFLD, even in the absence of fibrosis.

CCR1 plays a critical role in modulating pain through hematopoietic and non-hematopoietic cells

Inflammation is associated with immune cells infiltrating into the inflammatory site and pain. CC chemokine receptor 1 (CCR1) mediates trafficking of leukocytes to sites of inflammation. However, the contribution of CCR1 to pain is incompletely understood. Here we report an unexpected discovery that CCR1-mediated trafficking of neutrophils and CCR1 activity on non-hematopoietic cells both modulate pain. Using a genetic approach (CCR1^−/− animals) and pharmacological inhibition of CCR1 with selective inhibitors, we show significant reductions in pain responses using the acetic acid-induced writhing and complete Freund's adjuvant-induced mechanical hyperalgesia models. Reductions in writhing correlated with reduced trafficking of myeloid cells into the peritoneal cavity. We show that CCR1 is highly expressed on circulating neutrophils and their depletion decreases acetic acid-induced writhing. However, administration of neutrophils into the peritoneal cavity did not enhance acetic acid-induced writhing in wild-type (WT) or CCR1^−/− mice. Additionally, selective knockout of CCR1 in either the hematopoietic or non-hematopoietic compartments also reduced writhing. Together these data suggest that CCR1 functions to significantly modulate pain by controlling neutrophil trafficking to the inflammatory site and having an unexpected role on non-hematopoietic cells. As inflammatory diseases are often accompanied with infiltrating immune cells at the inflammatory site and pain, CCR1 antagonism may provide a dual benefit by restricting leukocyte trafficking and reducing pain.

Cytokine release assays: current practices and future directions

As a result of the CD28 superagonist biotherapeutic monoclonal antibody (TGN 1412) "cytokine storm" incident, cytokine release assays (CRA) have become hazard identification and prospective risk assessment tools for screening novel biotherapeutics directed against targets having a potential risk for eliciting adverse pro-inflammatory clinical infusion reactions. Different laboratories may have different strategies, assay formats, and approaches to the reporting, interpretation, and use of data for either decision making or risk assessment. Additionally, many independent contract research organizations (CROs), academic and government laboratories are involved in some aspect of CRA work. As a result, while some pharmaceutical companies are providing CRA data as part of the regulatory submissions when necessary, technical and regulatory practices are still evolving to provide data predictive of cytokine release in humans and that are relevant to safety. This manuscript provides an overview of different approaches employed by the pharmaceutical industry and CROs, for the use and application of CRA based upon a survey and post survey follow up conducted by ILSI-Health and Environmental Sciences Institute (HESI) Immunotoxicology Committee CRA Working Group. Also discussed is ongoing research in the academic sector, the regulatory environment, current limitations of the assays, and future directions and recommendations for cytokine release assays.

Depletion-interaction effects on the tunneling conductivity of nanorod suspensions

We study by simulation and theory how the addition of insulating spherical particles affects the conductivity of fluids of conducting rods, modeled by spherocylinders. The electrical connections are implemented as tunneling processes, leading to a more detailed and realistic description than a discontinuous percolation approach. We find that the spheres enhance the tunneling conductivity for a given concentration of rods and that the enhancement increases with rod concentration into the regime where the conducting network is well established. By reformulating the network of rods using a critical path analysis, we quantify the effect of depletion-induced attraction between the rods due to the spheres. Furthermore, we show that our conductivity data are quantitatively reproduced by an effective-medium approximation, which explicitly relates the system tunneling conductance to the structure of the rod-sphere fluid.

[Urinary dribbling in girls: which investigations in 2012?]

Continuous urinary leakage, despite normal deliberate voiding, must suggest the diagnosis of ectopic ureter, more specifically in girls. Ectopic ureter is usually associated with duplex kidney and complete ureteral duplication. The strategy of investigations has changed over the past few years, due to MRI development in the analysis of urinary tract malformations. We report the case of a 4-year-old girl who presented with these symptoms and had a suspicion of left duplex kidney on the prenatal ultrasonography (US). Two US examinations during the first months of life were compatible with a left duplex kidney without any complication. Another US at the age of 4 years was reported as normal. We completed the investigation with MR urography, which revealed a left duplex kidney with a poorly functioning dysplastic upper pole, and the orifice of the ureter of this upper pole inserting in the vagina. The surgical treatment, realized by celioscopy, was partial nephrectomy of the upper pole, removing most of the ectopic ureter. US is the first exam to investigate urinary tract malformations. However, duplex kidney with small dysplastic pole and ectopic insertion of a nondilated ureter may be difficult to see, and a normal US should never end the investigations. Intravenous urography and renal scintigraphy used to be the reference complementary exams, but are now replaced by MR urography. Without using ionizing radiation, MR urography can visualize duplex kidney and ectopic ureteral insertion with high resolution, and evaluates renal function of each kidney and each pole. These morphological and functional data are essential to determine the surgical treatment.

Liver transplantation for refractory severe pruritus related to widespread multifocal hepatic focal nodular hyperplasia (FNH) in a child: case report and review of literature

FNH is a rare and benign tumor of the liver. It is not a conventional indication for liver transplantation, and no transplant for FNH in a child has been reported to date. Multifocal FNH growing in adolescent age to a widespread tumor invading the whole liver and associated with severe refractory pruritus was an unusual indication for transplantation in a 13-yr-old girl. The operation and the follow-up were uneventful, allowing full recovery and disappearance of pruritus.

Tunneling and percolation transport regimes in segregated composites

We consider the problem of electron transport in segregated conductor-insulator composites in which the conducting particles are connected to all others via tunneling conductances, thus forming a global tunneling-connected resistor network. Segregation is induced by the presence of large insulating particles, which forbid the much smaller conducting fillers from occupying uniformly the three-dimensional volume of the composite. By considering both colloidal-like and granular-like dispersions of the conducting phase, modeled respectively by dispersions in the continuum and in the lattice, we evaluate by Monte Carlo simulations the effect of segregation on the composite conductivity σ, and show that an effective-medium theory applied to the tunneling network reproduces accurately the Monte Carlo results. The theory clarifies that the main effect of segregation in the continuum is that of reducing the mean interparticle distances, leading to a strong enhancement of the conductivity. In the lattice-segregation case the conductivity enhancement is instead given by the lowering of the percolation thresholds for first and beyond-first nearest neighbors. Our results generalize to segregated composites the tunneling-based description of both the percolation and hopping regimes introduced previously for homogeneous disordered systems.

AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications

The mammalian target of rapamycin (mTOR) serine/threonine kinase is the catalytic subunit of two multi-protein complexes, referred to as mTORC1 and mTORC2. Signaling downstream of mTORC1 has a critical role in leukemic cell biology by controlling mRNA translation of genes involved in both cell survival and proliferation. mTORC1 activity can be downmodulated by upregulating the liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway. Here, we have explored the therapeutic potential of the anti-diabetic drug, metformin (an LKB1/AMPK activator), against both T-cell acute lymphoblastic leukemia (T-ALL) cell lines and primary samples from T-ALL patients displaying mTORC1 activation. Metformin affected T-ALL cell viability by inducing autophagy and apoptosis. However, it was much less toxic against proliferating CD4(+) T-lymphocytes from healthy donors. Western blot analysis demonstrated dephosphorylation of mTORC1 downstream targets. Unlike rapamycin, we found a marked inhibition of mRNA translation in T-ALL cells treated with metformin. Remarkably, metformin targeted the side population of T-ALL cell lines as well as a putative leukemia-initiating cell subpopulation (CD34(+)/CD7(-)/CD4(-)) in patient samples. In conclusion, metformin displayed a remarkable anti-leukemic activity, which emphasizes future development of LKB1/AMPK activators as clinical candidates for therapy in T-ALL.

Differential roles of estrogen receptors α and β in control of B-cell maturation and selection

It is clear that estrogen can accelerate and exacerbate disease in some lupus-prone mouse strains. It also appears that estrogen can contribute to disease onset or flare in a subset of patients with lupus. We have previously shown estrogen alters B-cell development to decrease lymphopoiesis and increase the frequency of marginal zone B cells. Furthermore, estrogen diminishes B-cell receptor signaling and allows for the increased survival of high-affinity DNA-reactive B cells. Here, we analyze the contribution of estrogen receptor α or β engagement to the altered B-cell maturation and selection mediated by increased exposure to estrogen. We demonstrate that engagement of either estrogen receptor α or β can alter B-cell maturation, but only engagement of estrogen receptor α is a trigger for autoimmunity. Thus, maturation and selection are regulated differentially by estrogen. These observations have therapeutic implications.

Hormonal regulation of B-cell function and systemic lupus erythematosus

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been performed, which propose as casual actors genetic predispositions and sex hormones effects. We will describe in this review how the sex hormones estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence in a mouse model of lupus. Finally, we will discuss the relevance and implications of these results for human disease.

Electron-phonon interaction and charge carrier mass enhancement in SrTiO3

We report a comprehensive THz, infrared and optical study of Nb-doped SrTiO3 as well as dc conductivity and Hall effect measurements. Our THz spectra at 7 K show the presence of an unusually narrow (<2 meV) Drude peak. For all carrier concentrations the Drude spectral weight shows a factor of three mass enhancement relative to the effective mass in the local density approximation, whereas the spectral weight contained in the incoherent midinfrared response indicates that the mass enhancement is at least a factor two. We find no evidence of a particularly large electron-phonon coupling that would result in small polaron formation.

Topological change of the Fermi surface in low-density Rashba gases: application to superconductivity

In this Letter we show how, for small values of the Fermi energy compared to the spin-orbit splitting of Rashba type, a topological change of the Fermi surface leads to an effective reduction of the dimensionality in the electronic density of states in the low charge density regime. We investigate its consequences on the onset of the superconducting instability. We show that the superconducting critical temperature is significantly tuned in this regime by the spin-orbit coupling. We suggest that materials with strong spin-orbit coupling are good candidates for enhanced superconductivity.

Spin-Hall conductivity in electron-phonon coupled systems

We derive the ac spin-Hall conductivity sigmasH(omega) of two-dimensional spin-orbit coupled systems interacting with dispersionless phonons of frequency omega0. For the linear Rashba model, we show that the electron-phonon contribution to the spin-vertex corrections breaks the universality of sigmasH(omega) at low frequencies and provides a nontrivial renormalization of the interband resonance. On the contrary, in a generalized Rashba model for which the spin-vertex contributions are absent, the coupling to the phonons enters only through the self-energy, leaving the low-frequency behavior of sigmasH(omega) unaffected by the electron-phonon interaction.

The complete genome sequence of Lactobacillus bulgaricus reveals extensive and ongoing reductive evolution

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is a representative of the group of lactic acid-producing bacteria, mainly known for its worldwide application in yogurt production. The genome sequence of this bacterium has been determined and shows the signs of ongoing specialization, with a substantial number of pseudogenes and incomplete metabolic pathways and relatively few regulatory functions. Several unique features of the L. bulgaricus genome support the hypothesis that the genome is in a phase of rapid evolution. (i) Exceptionally high numbers of rRNA and tRNA genes with regard to genome size may indicate that the L. bulgaricus genome has known a recent phase of important size reduction, in agreement with the observed high frequency of gene inactivation and elimination; (ii) a much higher GC content at codon position 3 than expected on the basis of the overall GC content suggests that the composition of the genome is evolving toward a higher GC content; and (iii) the presence of a 47.5-kbp inverted repeat in the replication termination region, an extremely rare feature in bacterial genomes, may be interpreted as a transient stage in genome evolution. The results indicate the adaptation of L. bulgaricus from a plant-associated habitat to the stable protein and lactose-rich milk environment through the loss of superfluous functions and protocooperation with Streptococcus thermophilus.