ABBV-319: A CD19-targeting glucocorticoid receptor modulator antibody-drug conjugate therapy for B-cell malignancies

Glucocorticoids are key components of the current standard-of-care regimens (e.g., R-CHOP, EPOCH-R, Hyper-CVAD) for treatment of B-cell malignancy. However, systemic glucocorticoid treatment is associated with several adverse events. CD19 displays restricted expression in normal B-cells and is up-regulated in B-cell malignancies. ABBV-319 is a CD19-targeting antibody-drug conjugate (ADC) engineered to reduce glucocorticoid-associated toxicities while possessing three distinct mechanisms of action (MOA) to increase therapeutic efficacy: (1) antibody-mediated delivery of glucocorticoid receptor modulator (GRM) payload to activate apoptosis, (2) inhibition of CD19 signaling, and (3) enhanced Fc-mediated effector function via afucosylation of the antibody backbone. ABBV-319 elicited potent GRM-driven anti-tumor activity against multiple malignant B-cell lines in vitro as well as in cell line-derived xenografts (CDXs) and patient-derived xenografts (PDXs) in vivo. Remarkably, a single-dose of ABBV-319 induced sustained tumor regression and enhanced anti-tumor activity compared to repeat dosing of systemic prednisolone at the maximum tolerated dose (MTD) in mice. The unconjugated CD19 monoclonal antibody (mAb) also displayed anti-proliferative activity on a subset of B-cell lymphoma cell lines through the inhibition of PI3K signaling. Moreover, afucosylation of the CD19 mAb enhanced Fc-mediated antibody-dependent cellular cytotoxicity (ADCC), and this activity was maintained after conjugation with GRM payloads. Notably, ABBV-319 displayed superior efficacy compared to afucosylated CD19 mAb in human CD34+ PBMC-engrafted NSG-tg(Hu-IL15) transgenic mice, demonstrating enhanced anti-tumor activity when multiple MOAs are enabled. ABBV-319 also showed durable anti-tumor activity across multiple B-cell lymphoma PDX models, including non-germinal center B-cell (GCB) DLBCL and relapsed lymphoma post R-CHOP treatment. Collectively, these data support the ongoing evaluation of ABBV-319 in Phase I clinical trial (NCT05512390).

Self-Immolative Carbamate Linkers for CD19-Budesonide Antibody-Drug Conjugates

Antibody-drug conjugates consist of potent small-molecule payloads linked to a targeting antibody. Payloads must possess a viable functional group by which a linker for conjugation can be attached. Linker-attachment options remain limited for the connection to payloads via hydroxyl groups. A releasing group based on 2-aminopyridine was developed to enable stable attachment of para-aminobenzyl carbamate (PABC) linkers to the C21-hydroxyl group of budesonide, a glucocorticoid receptor agonist. Payload release involves a cascade of two self-immolative events that are initiated by the protease-mediated cleavage of the dipeptide-PABC bond. Budesonide release rates were determined for a series of payload-linker intermediates in buffered solution at pH 7.4 and 5.4, leading to the identification of 2-aminopyridine as the preferred releasing group. Addition of a poly(ethylene glycol) group improved linker hydrophilicity, thereby providing CD19-budesonide ADCs with suitable properties. ADC23 demonstrated targeted delivery of budesonide to CD19-expressing cells and inhibited B-cell activation in mice.

Repeated ethanol intoxications of Drosophila melanogaster adults increases the resistance to ethanol of their progeny

BACKGROUND

For decades, Drosophila melanogaster has been used as a model organism to understand the genetics and neurobiology of ethanol intoxication and tolerance. Previous research has shown that acute and chronic pre-exposures to ethanol can trigger the development of functional ethanol tolerance in flies and has unveiled some of the genetic pathways involved in the process. To our knowledge, however, no previous work has systematically explored whether repeated intoxications of adult flies can affect the ethanol tolerance of their progeny.

METHODS

Adult flies were intoxicated several times (once daily, over several days), and their F1 and F2 progeny were subjected to a functional tolerance test in which flies are exposed to ethanol and video recorded twice within 5 hr. Their behavior was subsequently analyzed to determine how long it took them to become sedated during the first and second exposures. One- and 2-way ANOVAs were used to determine whether parental treatment had an effect on their progeny's baseline resistance and/or acquired functional tolerance to ethanol.

RESULTS

Parental flies that were intoxicated several times produced F1 and F2 progeny with a significantly higher resistance to ethanol than progeny from unexposed controls. Further, parental intoxications inconsistently increased the progeny's capacity to develop rapid functional tolerance upon re-exposure to ethanol. The transmission of increased ethanol resistance to progeny lasted several days after the last parental intoxication.

CONCLUSION

To our knowledge, this is the first demonstration that repeated parental daily intoxications affect the progeny's response to ethanol in fruit flies. Our findings support the use of D. melanogaster to explore conserved pathways underlying the transmission of ethanol tolerance and can help in the identificaton of novel strategies for managing alcohol use disorder.

POS0365 ANTI-TNF GLUCOCORTICOID RECEPTOR MODULATOR ANTIBODY DRUG CONJUGATE FOR THE TREATMENT OF AUTOIMMUNE DISEASES

Background:

Glucocorticoids (GC) are potent drugs used for treating many inflammatory diseases. While GCs are effective in many immune diseases, dose and duration of administration is limited due to significant side effects. Resting immune cells have very little TNF expression on the cell surface and it is only in an activated state that TNF expression is upregulated. Upon immune cell stimulation, TNF is upregulated and although a significant amount of TNF is cleaved from an activated cell, a portion remains on the cell surface. We have observed that anti-TNF antibodies bind to transmembrane TNF (tmTNF) and undergo endocytosis to the lysosome (1). We have developed a stable antibody drug conjugate (ADC), ABBV-3373, that has a proprietary, highly potent, glucocorticoid receptor modulator (GRM) payload linked to an anti-TNF monoclonal antibody (mAb) that is able to deliver the GC payload to activated immune cells.

Objectives:

We hypothesized that a TNF ADC with a GRM payload would be able to deliver increased efficacy through both TNF inhibition and targeted GRM payload delivery to activated immune cells while sparing systemic glucocorticoid side effects.

Methods:

A mouse surrogate TNF GRM ADC was characterized in an acute in vivo contact hypersensitivity model of inflammation (CHS) and in a mouse model of collagen induced arthritis (mCIA). Additionally, the human anti-TNF GRM ADC, ABBV-3373 has been characterized in healthy volunteers.

Results:

In the CHS model the anti-TNF GRM ADC significantly inhibited the inflammatory response with minimal effect on systemic GC biomarkers. In mCIA a single dose of an anti-TNF GRM ADC, administered at disease onset, was able to completely inhibit arthritis for greater than 30 days while an anti-TNF mAb only partially inhibited disease. ABBV-3373, a human anti-TNF GRM ADC with a GC payload, was evaluated in a Phase 1 study in healthy volunteers. ABBV-3373 demonstrated antibody-like PK profile and ABBV-3373 did not impact cortisol levels at predicted efficacious doses while control subjects that received a single oral dose of 10 mg prednisone demonstrated expected decreases in cortisol levels.

Conclusion:

These data suggest that an anti-TNF ADC delivering a GRM payload into activated immune cells may provide improved efficacy in immune mediated diseases, while minimizing systemic side effects associated with standard GC treatment.

References:

[1]Deora, A. et al. MABs. 2017;9(4):680-695.

Disclosure of Interests:

Bob Stoffel Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Michael McPherson Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Axel Hernandez Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Christian Goess Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Suzanne Mathieu Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Wendy Waegell Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Shaughn Bryant Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Adrian Hobson Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Melanie Ruzek Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Yinuo Pang Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Hartmut Kupper Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Ronilda D’Cunha Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Julie Parmentier Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie, Timothy Radstake Shareholder of: AbbVie, Grant/research support from: AbbVie, Employee of: AbbVie

Tracking and Assessing Oil Spill Toxicity to Aquatic Organisms: A Novel Approach

An in situ exposure and effects bioassay system was developed for assessing the toxicity of oil spills to aquatic organisms. The assessment tool combines components of 2 previously developed systems, the sediment ecotoxicity assessment ring (SEA Ring) and the drifting particle simulator. The integrated drifting exposure and effects assessment ring (DEEAR) is comprised of a Global Positioning System (GPS) float, a drifter drogue, the SEA Ring, and the Cyclops-7 fluorescent sensor. Polyethylene passive sampling devices (PED) were mounted for an additional means to characterize water quality conditions and exposures. The DEEAR is optimized for evaluating oil exposure and toxicity in the shallow surface mixing layer of marine waters. A short-term preliminary test was conducted in San Diego, California, USA, to verify the operation of the GPS tracking, the iridium communications, and the integrated SEA Ring exposure system. Further, a proof-of-concept demonstration was conducted offshore in the Santa Barbara Channel, where natural oil seeps produce surface slicks and sheens. Two DEEAR units were deployed for 24 h-one within the oil slick and one in an area outside observable slicks. An aerial drone provided tracking of the surface oil and optimal sites for deployment. The DEEAR proof-of-concept demonstrated integrated real-time tracking and characterization of oil exposures by grab samples, PED, and fluorescent sensors. Oil exposures were directly linked to toxic responses in fish and mysids. This novel integrated system shows promise for use in a variety of aquatic sites to more accurately determine in situ oil exposure and toxicity. Environ Toxicol Chem 2021;40:1452-1462. © 2021 SETAC.

Abstract B24: Development of small-molecule RAS inhibitors using Affimer reagents

Ras proteins are small GTPases that are mutationally activated in around 30% of all human cancers. Oncogenic mutations in Ras trigger uncontrolled cellular differentiation and division through uninhibited Ras-GTP signaling. Despite major efforts in developing inhibitors, lack of treatments directly targeting Ras in cancer led to the current assumption that Ras is undruggable. A new approach, which involves use of biologics, has shown great potential for development of Ras inhibitors, as demonstrated by recent increase in the number of antibody mimetic reagents targeting Ras, including single domain antibodies, monobodies and DARPins. We have developed modulators of Ras activity using novel artificial binding proteins, termed Affimers. Affimers are small 91-amino-acid scaffold proteins that constrain one or two randomized nine amino acid loop regions for molecular recognition. Affimers isolated against KRas, the most commonly mutated Ras family member, displayed low nanomolar binding affinities, were shown to be effective at inhibiting nucleotide exchange and blocked interaction between Ras and its effector Raf. When expressed in mammalian cells, Affimers bound with endogenous Ras and inhibited Ras-mediated signaling. Site-directed mutagenesis of Affimer variable regions revealed three residues critical for binding and inhibition. X-ray crystal structure of Affimer in complex with KRas demonstrated that these residues bind into a hydrophobic pocket on Ras, previously described with small molecules. Currently, we are determining whether this interaction gives insight into new modes of therapeutic development using molecular docking in attempt to mimic the Affimer residues with small molecules. This project provides a unique opportunity to further our understanding of Ras biology through the development of reagents that modulate Ras activity. In addition, structural insights into mode of inhibition allow the modelling and design of small-molecule compounds, providing novel therapeutic strategies to slow Ras-addicted tumor growth.

Citation Format: Katarzyna Haza, Heather Martin, Christian Tiede, Kevin Tipping, Chi Trinh, Holly Foster, Rachel Trowbridge, Richard Foster, Thomas Edwards, Alexander Breeze, Michael McPherson, Darren Tomlinson. Development of small-molecule RAS inhibitors using Affimer reagents [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B24.

Ultraefficient Cap-Exchange Protocol To Compact Biofunctional Quantum Dots for Sensitive Ratiometric Biosensing and Cell Imaging

An ultraefficient cap-exchange protocol (UCEP) that can convert hydrophobic quantum dots (QDs) into stable, biocompatible, and aggregation-free water-dispersed ones at a ligand:QD molar ratio (LQMR) as low as 500, some 20-200-fold less than most literature methods, has been developed. The UCEP works conveniently with air-stable lipoic acid (LA)-based ligands by exploiting tris(2-carboxylethyl phosphine)-based rapid in situ reduction. The resulting QDs are compact (hydrodynamic radius, R_h, < 4.5 nm) and bright (retaining > 90% of original fluorescence), resist nonspecific adsorption of proteins, and display good stability in biological buffers even with high salt content (e.g., 2 M NaCl). These advantageous properties make them well suited for cellular imaging and ratiometric biosensing applications. The QDs prepared by UCEP using dihydrolipoic acid (DHLA)-zwitterion ligand can be readily conjugated with octa-histidine (His₈)-tagged antibody mimetic proteins (known as Affimers). These QDs allow rapid, ratiometric detection of the Affimer target protein down to 10 pM via a QD-sensitized Förster resonance energy transfer (FRET) readout signal. Moreover, compact biotinylated QDs can be readily prepared by UCEP in a facile, one-step process. The resulting QDs have been further employed for ratiometric detection of protein, exemplified by neutravidin, down to 5 pM, as well as for fluorescence imaging of target cancer cells.

Impact of proctoring on success rates for percutaneous revascularisation of coronary chronic total occlusions

OBJECTIVE

To assess the impact of proctoring for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in six UK centres.

METHODS

We retrospectively analysed 587 CTO procedures from six UK centres and compared success rates of operators who had received proctorship with success rates of the same operators before proctorship (pre-proctored) and operators in the same institutions who had not been proctored (non-proctored). There were 232 patients in the pre-proctored/non-proctored group and 355 patients in the post-proctored group. Complexity was assessed by calculating the Japanese CTO (JCTO) score for each case.

RESULTS

CTO PCI success was greater in the post-proctored compared with the pre-proctored/non-proctored group (77.5% vs 62.1%, p<0.0001). In more complex cases where JCTO≥2, the difference in success was greater (70.7% vs 49.5%, p=0.0003). After proctoring, there was an increase in CTO PCI activity in centres from 2.5% to 3.5%, p<0.0001 (as a proportion of total PCI), and the proportion of very difficult cases with JCTO score ≥3 increased from 15.3% (35/229) to 29.7% (105/354), p<0.0001.

CONCLUSIONS

Proctoring resulted in an increase in procedural success for CTO PCI, an increase in complex CTO PCI and an increase in total CTO PCI activity. Proctoring may be a valuable way to improve access to CTO PCI and the likelihood of procedural success.

An overview of American higher education

This overview of postsecondary education in the United States reviews the dramatic changes over the past fifty years in the students who go to college, the institutions that produce higher education, and the ways it is financed. The article, by Sandy Baum, Charles Kurose, and Michael McPherson, creates the context for the articles that follow on timely issues facing the higher education community and policy makers. The authors begin by observing that even the meaning of college has changed. The term that once referred primarily to a four-year period of academic study now applies to virtually any postsecondary study--academic or occupational, public or private, two-year or four-year-- that can result in a certificate or degree. They survey the factors underlying the expansion of postsecondary school enrollments; the substantial increases in female, minority, disadvantaged, and older students; the development of public community colleges; and the rise of for-profit colleges. They discuss the changing ways in which federal and state governments help students and schools defray the costs of higher education as well as more recent budget tensions that are now reducing state support to public colleges. And they review the forces that have contributed to the costs of producing higher education and thus rising tuitions. The authors also cite evidence on broad measures of college persistence and outcomes, including low completion rates at community and for-profit colleges, the increasing need for remedial education for poorly prepared high school students, and a growing gap between the earnings of those with a bachelor's degree and those with less education. They disagree with critics who say that investments in higher education, particularly for students at the margin, no longer pay off. A sustained investment in effective education at all levels is vital to the nation's future, they argue. But they caution that the American public no longer seems willing to pay more for more students to get more education. They therefore urge the higher education community to make every effort to find innovations, including creative uses of information technology, that can hold down costs while producing quality education.

Acousto-optic Bragg imaging of biological tissue

Acousto-optic Bragg imaging is a technique that uses the interaction of light with ultrasound to optically image obstructions in acoustical fields. Existing reports of acousto-optic Bragg imaging based on transmission of acoustic fields through obstructions exhibit strong acoustic impedance mismatches manifested by poor image quality and missing details of physical structures of obstructions. In this work, the image quality was improved to exhibit detailed physical structures of an object by using an improved Bragg imaging system described in Sec. III below. This paper investigates the possibility of extending an acoustic Bragg imaging technique in transmission mode to image animal or plant tissues; a small azalea leaf is used as an illustration in this case. The Bragg image produced clearly shows the veins of the vascular azalea leaf serving as a proof of concept for cost-effective potential application of acoustic Bragg imaging of biological objects in the medical field. Moreover, acousto-optic Bragg imaging is potentially harmless to biological cells and is sensitive to density and elastic variations in the tissue.

Commensal microbiota and CD8+ T cells shape the formation of invariant NKT cells

Commensal bacteria play an important role in formation of the immune system, but the mechanisms involved are incompletely understood. In this study, we analyze CD1d-restricted invariant NKT (iNKT) cells in germfree mice and in two colonies of C57BL/6 mice termed conventional flora and restricted flora (RF), stably bearing commensal microbial communities of diverse but distinct composition. In germfree mice, iNKT cells were moderately reduced, suggesting that commensal microbiota were partially required for the antigenic drive in maintaining systemic iNKT cells. Surprisingly, even greater depletion of iNKT cell population occurred in RF mice. This was in part attributable to reduced RF levels of intestinal microbial taxa (Sphingomonas spp.) known to express antigenic glycosphingolipid products. However, memory and activated CD8(+) T cells were also expanded in RF mice, prompting us to test whether CD8(+) T cell activity might be further depleting iNKT cells. Indeed, iNKT cell numbers were restored in RF mice bearing the CD8alpha(-/-) genotype or in adult wild-type RF mice acutely depleted with anti-CD8 Ab. Moreover, iNKT cells were restored in RF mice bearing the Prf1(-/-) phenotype, a key component of cytolytic function. These findings indicate that commensal microbiota, through positive (antigenic drive) and negative (cytolytic depletion by CD8(+) T cells) mechanisms, profoundly shape the iNKT cell compartment. Because individuals greatly vary in the composition of their microbial communities, enteric microbiota may play an important epigenetic role in the striking differences in iNKT cell abundance in humans and therefore in their potential contribution to host immune status.

Comorbidity and survival of hepatocellular carcinoma patients at a VA medical canter

e15682

Background: To determine whether comorbidity indices predict survival in hepatocellular carcinoma (HCC) pts. Methods: In an IRB approved protocol, we reviewed the records of pts with tissue diagnosis of HCC seen at a VA Medical Center between 1/1/1999 to 12/31/2008. Comorbidity was assessed with four comorbidity indices, the Charlson Comorbidity Index (CMI), the Kaplan- Feinstein Index (KFI), the Cumulative Illness Rating Scale (CIRS), and VA Comorbidity Scale (VACS). Demographics, ECOG PS, stage, alpha-fetoprotein (AFP) at diagnosis, hepatitis B (HBV) and C (HCV) status, alcohol use, and iron overload were also reviewed. Cox survival regression analysis was performed. Results: There were 44 pts. All pts were men. The median (M) age at diagnosis was 60.5 years (range 35–86). The overall M survival was 230 days (4–2784). There were Stage I 12 (27%) pts, Stage II 7 (16%) pts, Stage III 14 (32%) pts, and Stage IV 11 (25%) pts. The M ECOG PS was 1.0 (0–4), stage 3 (1–4), CMI 5.75 (1–16), CIRS15 3.0 (1–5), CIRS16 6.0 (1–14), CIRS17 2.0 (0.83–5.0), CIRS18 0 (0–2), CIRS19 0 (0–1), KFI 3.0 (1–3), VACS 6.0 (2–9), and AFP 56.35 (1.1–379567). HBV was positive in 10 pts (23%), HCV 26 (59%) pts, alcohol use 37 (84%) pts, and iron overload 11 (25%) pts. In univariate survival analysis, stage (p<.038), ECOG PS (p<.001), AFP (p<.009), presence of iron overload (p<.006), and CMI (p<.019) were significant in predicting survival. However, age, HBV, HCV, alcohol use, CIRS15, CIRS16, CIRS17, CIRS18, KFI, and VACS were not significant for survival. In multivariate survival analyses that included stage and a comorbidity index, the CMI approaches significance (p<.077). Conclusions: In this sample, the CMI was a predictor for survival in pts with HCC. Further analysis in a larger sample is needed to provide a more definitive conclusion. This was supported by the New Jersey Commission for Cancer Research 09–1133-CCR-EO.

No significant financial relationships to disclose.

Colitis immunoregulation by CD8+ T cell requires T cell cytotoxicity and B cell peptide antigen presentation

Deficient immunoregulation by CD4+ T cells is an important susceptibility trait for inflammatory bowel disease, but the role of other regulatory cell types is less understood. This study addresses the role and mechanistic interaction of B cells and CD8+ T cells in controlling immune-mediated colitis. The genetic requirements for B cells and CD8+ T cells to confer protective immunoregulation were assessed by cotransfer with colitogenic Galphai2-/- T cells into immune-deficient mice. Disease activity in Galphai2-/- T cell recipients was evaluated by CD4+ T intestinal lymphocyte abundance, cytokine production levels, and large intestine histology. B cells deficient in B7.1/B7.2, CD40, major histocompatibility complex (MHC) II (Abb), or native B cell antigen receptor (MD4) were competent for colitis protection. However, transporter-1-deficient B cells failed to protect, indicating a requirement for peptide MHC I presentation to CD8+ T cells. CD8+ T cells deficient in native T cell receptor repertoire (OT-1) or cytolysis (perforin-/-) also were nonprotective. These finding reveal an integrated role for antigen-specific perforin-dependent CD8+ T cell cytotoxicity in colitis immunoregulatory and its efficient induction by a subset of mesenteric B lymphocytes.

Systemic control of plasmacytoid dendritic cells by CD8+ T cells and commensal microbiota

The composition of the intestinal microbial community is a distinctive individual trait that may divergently influence host biology. Because dendritic cells (DC) regulate the quality of the host response to microbiota, we evaluated DC in mice bearing distinct enteric microbial communities divergent for colitis susceptibility. Surprisingly, a selective, systemic reduction of plasmacytoid dendritic cells (pDC) was observed in isogenic mice with different microbiota: restricted flora (RF) vs specific pathogen free (SPF). This reduction was not observed in germfree mice, suggesting that the pDC deficiency was not simply due to a lack of intestinal microbial products. The microbial action was linked to cytotoxic CD8(+) T cells, since pDC in RF mice were preserved in the CD8(-/-) and perforin(-/-) genotypes, partially restored by anti-CD8beta Ab, and augmented in SPF mice bearing the TAP(-/-) genotype. Direct evidence for pDC cytolysis was obtained by rapid and selective pDC depletion in SPF mice transferred with RF CD8(+) T cells. These data indicate that commensal microbiota, via CTL activation, functionally shape systemic immune regulation that may modify risk of inflammatory disease.

Integration of B cells and CD8+ T in the protective regulation of systemic epithelial inflammation

Mechanisms that control abnormal CD4(+) T cell-mediated tissue damage are a significant factor in averting and resolving chronic inflammatory epithelial diseases. B cells can promote such immunoregulation, and this is thought to involve interaction with MHC II- or CD1-restricted regulatory T cells. The purpose of this study is to genetically define the interacting cells targeted by protective B cells, and to elucidate their regulatory mechanisms in CD4(+) T cell inflammation. Transfer of G alpha i2-/- CD3(+) T cells into lymphopenic mice causes a dose-dependent multi-organ inflammatory disease including the skin, intestine, and lungs. Disease activity is associated with elevated levels of serum TNF-alpha and IFN-gamma, and an activated IL-17 producing CD4(+) T cell population. Mesenteric node B cells from wild type mice suppress disease activity, serum cytokine expression, and levels of CD4(+) T cells producing TNF-alpha IFN-gamma, and IL-17. The protective function of B cells requires genetic sufficiency of IL-10, MHC I and TAP1. Regulatory B cells induce the expansion and activation of CD8(+) T cells, which is correlated with disease protection. These results demonstrate that CD8(+) T cells can ameliorate lymphopenic systemic inflammatory disease, through peptide/MHC I-dependent B cell interaction.

Villous B cells of the small intestine are specialized for invariant NK T cell dependence

B cells are important in mucosal microbial homeostasis through their well-known role in secretory IgA production and their emerging role in mucosal immunoregulation. Several specialized intraintestinal B cell compartments have been characterized, but the nature of conventional B cells in the lamina propria is poorly understood. In this study, we identify a B cell population predominantly composed of surface IgM(+) IgD(+) cells residing in villi of the small intestine and superficial lamina propria of the large intestine, but distinct from the intraepithelial compartment or organized intestinal lymphoid structures. Small intestinal (villous) B cells are diminished in genotypes that alter the strength of BCR signaling (Bruton tyrosine kinase(xid), Galphai2(-/-)), and in mice lacking cognate BCR specificity. They are not dependent on enteric microbial sensing, because they are abundant in mice that are germfree or genetically deficient in TLR signaling. However, villous B cells are reduced in the absence of invariant NK T cells (Jalpha18(-/-) or CD1d(-/-) mice). These findings define a distinct population of conventional B cells in small intestinal villi, and suggest an immunologic link between CD1-restricted invariant NK T cells and this B cell population.

Hydrazine and amphetamine binding to amine oxidases: old drugs with new prospects

Tranylcypromine (TCP), an amphetamine, is a reversible inhibitor of copper-containing amine oxidases. We have solved the structure of the complex of TCP with the amine oxidase from E. coli (ECAO) and shown that only the (+)-enantiomer of TCP binds. Kinetic studies on 2-phenylethylamine and TCP binding to wild-type ECAO and mutational variants fully support the model in which binding of the protonated amine is the first step in the catalytic cycle. Hydrazines are irreversible inhibitors of copper-containing amine oxidases. Binding of hydrazines leads to an adduct ("Adduct 1") with a chromophore at 430 nm which converts at higher pH to another adduct ("Adduct 2") with a chromophore at 520 nm. We have determined the structures of Adduct 1 and 2 for 2-hydrazinopyridine reacted with ECAO. It has been found that Adduct 1 corresponds to the hydrazone and azo tautomers whilst Adduct 2 corresponds to the azo tautomer coordinated to the active site copper. The implications of these results in developing more specific drugs are discussed.

Abundant and diverse fungal microbiota in the murine intestine

Enteric microbiota play a variety of roles in intestinal health and disease. While bacteria in the intestine have been broadly characterized, little is known about the abundance or diversity of enteric fungi. This study utilized a culture-independent method termed oligonucleotide fingerprinting of rRNA genes (OFRG) to describe the compositions of fungal and bacterial rRNA genes from small and large intestines (tissue and luminal contents) of restricted-flora and specific-pathogen-free mice. OFRG analysis identified rRNA genes from all four major fungal phyla: Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. The largest assemblages of fungal rRNA sequences were related to the genera Acremonium, Monilinia, Fusarium, Cryptococcus/Filobasidium, Scleroderma, Catenomyces, Spizellomyces, Neocallimastix, Powellomyces, Entophlyctis, Mortierella, and Smittium and the order Mucorales. The majority of bacterial rRNA gene clones were affiliated with the taxa Bacteroidetes, Firmicutes, Acinetobacter, and Lactobacillus. Sequence-selective PCR analyses also detected several of these bacterial and fungal rRNA genes in the mouse chow. Fluorescence in situ hybridization analysis with a fungal small-subunit rRNA probe revealed morphologically diverse microorganisms resident in the mucus biofilm adjacent to the cecal and proximal colonic epithelium. Hybridizing organisms comprised about 2% of the DAPI (4',6-diamidino-2-phenylindole, dihydrochloride)-positive organisms in the mucus biofilm, but their abundance in fecal material may be much lower. These data indicate that diverse fungal taxa are present in the intestinal microbial community. Their abundance suggests that they may play significant roles in enteric microbial functions.

Severe hemolytic anemia due to auto anti-N

Auto anti-N is infrequently encountered and, in most reported cases, does not cause clinical hemolysis. This case reports an auto anti-N associated with severe hemolytic anemia (Hb=2.7 g/dL) in a 6-year-old Caucasian girl with a history of vomiting, fever, and abdominal pain. Upon admission, she was found to have a metabolic acidosis, secondary to her severe anemia, with abnormal liver function tests. As in three other case reports, the autoimmune hemolytic anemia resolved, with disappearance of the auto anti-N, after corticosteroid therapy.

Drug receptor identification from multiple tissues using cellular-derived mRNA display libraries

The use of display technologies to identify small molecule receptors from proteome libraries would provide a significant advantage in drug discovery. We have used mRNA display to select, based on affinity, proteins that bind to a drug of interest. A library of mRNA-protein fusion molecules was constructed from human liver, kidney, and bone marrow transcripts and selected using an immobilized FK506-biotin conjugate. Three rounds of selection produced full-length FKBP12 (FK506 binding protein 12 kDa) as the dominant clone. An analogous method was also used to map the minimal drug binding domain within FKBP12. Using this approach, it is anticipated that mRNA display could eventually play a key role in the discovery and characterization of new drug receptor interactions.

Venlafaxine in the treatment of premenstrual dysphoric disorder

OBJECTIVE

To evaluate the efficacy and safety of venlafaxine, a new-generation antidepressant that selectively inhibits serotonin and norepinephrine reuptake, in the treatment of premenstrual dysphoric disorder (PMDD).

METHOD

We conducted a randomized, double-blind, placebo-controlled, parallel-group, flexible-dose trial. After three screening cycles, including a single-blind placebo cycle, 164 women were randomly assigned to double-blind treatment with venlafaxine (50-200 mg/day) or placebo for four menstrual cycles. Primary outcome measures were the total premenstrual symptom scores as assessed by a daily symptom report (DSR) and the Hamilton Rating Scale for Depression.

RESULTS

Venlafaxine was significantly more effective than placebo in reducing PMDD symptoms as assessed by DSR scores (P <.001 for last observation carried forward and observed analyses). Sixty percent of venlafaxine versus 35% of placebo subjects improved >50% (P =.003). Forty-three percent of venlafaxine subjects versus 25% of placebo subjects experienced symptom remission, defined as reduction of DSR scores to the postmenstrual level (P =.034). Venlafaxine treatment was significantly better than placebo for all statistically derived DSR factors (mood, function, pain, and physical symptoms). Improvement was relatively swift, with approximately 80% symptom reduction in the first treatment cycle. Mean venlafaxine doses ranged from 50 mg/day in the first treatment cycle to 130 mg/day in the fourth treatment cycle. Adverse events such as nausea, insomnia, and dizziness were mild and transient.

CONCLUSIONS

Venlafaxine is significantly more efficacious than placebo for PMDD treatment. Response to treatment can occur in the first treatment cycle, and venlafaxine is well tolerated. Further studies are needed to evaluate the potential of intermittent (luteal phase) dosing for this cyclic disorder and the efficacy of long-term maintenance treatment with venlafaxine.

S-nitrosoglutathione increases cystic fibrosis transmembrane regulator maturation

Endogenous S-nitrosoglutathione (GSNO) is known to increase the expression of certain proteins at concentrations present in the normal human airway. We hypothesized that GSNO would increase expression and maturation of the cystic fibrosis transmembrane conductance regulator (CFTR). Cells expressing DeltaF508 and wild type CFTR were exposed to GSNO and analyzed for expression and maturation by Western blot analysis. Physiologically relevant concentrations of GSNO resulted in dose- and time-dependent increases in expression. The GSNO-induced increases were eliminated by cycloheximide, suggesting a posttranscriptional effect. Unlike proteasome inhibitors, GSNO resulted in an increase CFTR maturation. The GSNO effect could be reversed by dithiothreitol and inhibited by acivicin, a gamma glutamyl transpeptidase inhibitor. These observations suggest that GSNO leads to maturation of mutated DeltaF508 CFTR, a process associated with restoration of CFTR function. Because endogenous levels of GSNO are low in the cystic fibrosis (CF) airway, these results raise the possibility that GSNO replacement therapy could be an effective treatment for CF.

Climbing simulated vegetation to heights of ungulate hosts by larvae of Dermacentor albipictus (Acari: Ixodidae)

Larvae of winter ticks, Dermacentor albipictus (Packard), ascend vegetation in autumn and form clumps that attach to passing ungulate hosts. We tested the hypothesis that vegetation height determines the height of clumps. During the vegetation-to-ungulate transmission period (early September to mid-November), larvae were released at the base of simulated vegetation (nylon rods 245 cm tall) in outdoor and laboratory trials and in the absence of host cues. Rod height exceeded the height of the tallest ungulate host, which is the moose, Alces alces (L.). Most larvae stopped climbing and formed clumps 50-190 cm above ground, which coincided with torso heights of moose; elk, Cervus elaphus L.; and deer, Odocoileus spp. Rafinesque. More clumps formed in outdoor trials than in laboratory trials and clump heights tended to increase over the course of the experiment, but clump number, size, and height did not correlate with weather conditions. Winter tick larvae appear to determine their height above ground in the absence of external cues, but this mechanism may be modified by external conditions.

American Academy of Pediatrics. Committee on Children With Disabilities. Care coordination: integrating health and related systems of care for children with special health care needs

Care coordination is a process that links children with special health care needs and their families to services and resources in a coordinated effort to maximize the potential of the children and provide them with optimal health care. Care coordination often is complicated because there is no single entry point to multiple systems of care, and complex criteria determine the availability of funding and services among public and private payers. Economic and sociocultural barriers to coordination of care exist and affect families and health care professionals. In their important role of providing a medical home for all children, primary care pediatricians have a vital role in the process of care coordination, in concert with the family.

Managing STIs identified after testing outside genitourinary medicine departments: one model of care

OBJECTIVES

To develop a local strategy for managing cases of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) which have been identified in the departments of obstetrics and gynaecology (O&G).

METHODS

Weekly notification from the local microbiology laboratory to genitourinary medicine (GUM) departments of all positive CT and GC results generated by tests performed in the two local O&G departments. Direct contact made by GUM departments to index patients identified and "fast track" appointments made. Data recorded for future audit include numbers attending, details of health adviser input, and success of contact tracing.

RESULTS

Over 18 months, 294 women were identified and 231 (78%) attended GUM departments; 142 (48%) had received antibiotics before attending GUM departments and of these, 58 (41%) had risked reinfection by an untreated partner and 48 (20%) were found on screening to have a previously undiagnosed genital infection. Over 90% were interviewed by a health adviser. Appropriate follow up was achieved in 87% of index cases. Of the contacts, 194 were treated--150 in the local GUM department. Of these 150 men, 99 (66%) had an identifiable genital infection and 84% of those with CT/non-gonococcal urethritis were asymptomatic. There have been no complaints either formal or informal, by women managed by this system.

CONCLUSIONS

GUM clinics are the ideal setting to achieve successful treatment of patients with sexually acquired infections, which must include notification and treatment of their partners if reinfection is to be avoided. For patients with infections diagnosed on other settings, such as O&G, a system of direct notification of results to GUM departments by an agreed protocol can be highly successful. For such a system to work, close cooperation and trust between departments is essential.

An epidemiologic profile of children with special health care needs

OBJECTIVE

To present an epidemiologic profile of children with special health care needs using a new definition of the population developed by the federal Maternal and Child Health Bureau.

METHODS

We operationalized the new definition using the recently released 1994 National Health Interview Survey on Disability. Estimates are based on 30 032 completed interviews for children <18 years old. The overall response rate was 87%.

RESULTS

Eighteen percent of US children <18 years old in 1994, or 12.6 million children nationally, had a chronic physical, developmental, behavioral, or emotional condition and required health and related services of a type or amount beyond that required by children generally. This estimate includes children with existing special health care needs but excludes the at-risk population. Prevalence was higher for older children, boys, African-Americans, and children from low-income and single-parent households. Children with existing special health care needs had three times as many bed days and school absence days as other children. An estimated 11% of children with existing special health care needs were uninsured, 6% were without a usual source of health care, 18% were reported as dissatisfied with one or more aspects of care received at their usual source of care, and 13% had one or more unmet health needs in the past year.

CONCLUSIONS

A substantial minority of US children were identified as having an existing special health care need using national survey data. Children with existing special health care needs are disproportionately poor and socially disadvantaged. Moreover, many of these children face significant barriers to health care.