"Redirecting an anti-IL-1β antibody to bind a new, unrelated and computationally predicted epitope on hIL-17A"

Antibody engineering technology is at the forefront of therapeutic antibody development. The primary goal for engineering a therapeutic antibody is the generation of an antibody with a desired specificity, affinity, function, and developability profile. Mature antibodies are considered antigen specific, which may preclude their use as a starting point for antibody engineering. Here, we explore the plasticity of mature antibodies by engineering novel specificity and function to a pre-selected antibody template. Using a small, focused library, we engineered AAL160, an anti-IL-1β antibody, to bind the unrelated antigen IL-17A, with the introduction of seven mutations. The final redesigned antibody, 11.003, retains favorable biophysical properties, binds IL-17A with sub-nanomolar affinity, inhibits IL-17A binding to its cognate receptor and is functional in a cell-based assay. The epitope of the engineered antibody can be computationally predicted based on the sequence of the template antibody, as is confirmed by the crystal structure of the 11.003/IL-17A complex. The structures of the 11.003/IL-17A and the AAL160/IL-1β complexes highlight the contribution of germline residues to the paratopes of both the template and re-designed antibody. This case study suggests that the inherent plasticity of antibodies allows for re-engineering of mature antibodies to new targets, while maintaining desirable developability profiles.

704 The computationally designed human antibody, AU-007, mediates human immune activation by endogenous IL-2, while uniquely breaking the IL-2 auto-inhibitory loop and preventing Treg expansion

Background

IL-2 binds two forms of IL-2 receptor: a high affinity trimeric receptor composed of CD25, CD122, and CD132, and a low affinity dimeric receptor composed of CD122 and CD132. Binding to the dimeric receptors, expressed on effector cells, causes expansion of the effector arm of the immune system including CD8 T-cells, NK-cells and NKT-cells. Binding to the trimeric receptor, expressed on Tregs as well as on pulmonary and vascular epithelium, results in expansion of Treg cells and Vascular Leak Syndrome, both are undesired outcomes of high-dose recombinant IL-2 (Aldesleukin), approved for treatment of Melanoma and Renal-Cell-Carcinoma.

Methods

Flow-cytometry analysis of immune-cell populations of C57BL/6 mice and hPBMCs. Tumor-Growth-Index of murine cancer models.

Results

AU-007, is a computationally designed human antibody that bind the CD25-binding portion on IL-2, preventing binding of IL-2 to the trimeric receptor, but not the dimeric receptor. This leads to immune effector activation while also preventing the Treg expansion via the autoinhibitory loop caused by endogenous IL-2 secreted from activated T effector cells (figure 1). AU-007 binds human IL-2 with picomolar affinity and has excellent biophysical properties with low potential for anti-drug immunogenicity (figure 2). Administration of an AU-007/low dose hIL-2 complex to non-tumor bearing C57BL/6 mice promoted proliferation of effector cells with no effect on Tregs (figure 3). Additionally, an AU-007/low dose hIL-2 complex was highly effective in inhibiting tumor progression in a syngeneic B16F10 melanoma model (figure 4). pSTAT5 analysis of hPBMCs incubated with AU-007 and hIL-2 demonstrated activation of the effector cells and inhibition of Tregs expansion (figure 5). hPBMCs activated with anti-CD3/anti-CD28 and treated with either AU-007 or an isotype control antibody but without exogenous IL-2, showed expansion of effector cells. However, while the isotype control antibody expanded also Tregs , AU-007 inhibited Tregs proliferation, indicating that AU-007 captures endogenous IL-2 and prevents the Treg expansion autoinhibitory loop caused by endogenous IL-2 secreted from activated T effector cells (figure 6).Additionally, following establishment of the IL-2 auto-secretion feedback loop in mice genetically engineered to express hIL-2 instead of murine IL-2, AU-007 treatment significantly inhibited MC38 colorectal-tumor growth for twelve days, in a manner comparable to treatment with anti-PD1 (figure 7).

Conclusions

AU-007 is a human antibody that blocks the CD25-binding epitope on IL-2. It redirects endogenous IL-2 to promote effector cell expansion while simultaneously blocking the Treg expansion autoinhibitory loop, indicating its unique therapeutic profile and high potential as a novel cancer treatment. AU-007 is expected to enter clinical testing in 2021.

Abstract 704 Figure 1

Schematic representation of IL-2 mechanism of action and its dual role in controlling immune response. IL-2 structure consists of three binding epitope sites that interact with different forms of IL-2-R complexes with different affinities (Left Panel). IL-2R complexes expressed on different cell populations and their different affinities to IL-2 allow immunosuppression under conditions of low local concentrations of IL-2 and immune stimulation when IL-2 local concentration rises (middle panel). Au-007 utilize autocrine human IL-2 MOA to promote immune stimulation. Targeting IL-2 to different cell populations can be used to modulate the immune response toward towards immune activation. An anti-human IL-2 antibody tumor clearance while reducing IL-2's undesired interactions with endothelial CD25 expressing cells preventing IL-2 induced pulmonary edema and vascular leaking.

Abstract 704 Figure 2

Au-007 bind human IL-2 with high affinity and inhibits the binding to CD25 while preserving the binding to CD122. Affinity and binding site are demonstrated using Surface Plasmon Resonance. Au-007 was captured on CM5 chip and soluble hIL-2 was injected, forming a complex. Subsequently, soluble CD25 was injected followed by injection of soluble CD122 (A). SPR trace of complex formation of Ab/IL-2/IL-2R arrows indicate where Au-007 (17.069), hIL-2, CD25 and CD122 were injected (B). SPR trace and calculated binding kinetics of chip bound Au-007 with hIL-2 serving as analyte (C). Biophysical profile of Au-007. Au-007 was subjected to five freeze thaw cycles, agitation for 3 days and incubation at 40°C for 1 week. Post treatment Au-007 integrity and indicated biophysical properties were measured (D).

Abstract 704 Figure 3

Au-007 demonstrated in-vivo potent immune stimulating effects in a dose depended manner, with no observed effect on Tregs. C57BL/6 healthy mice were administered daily with Au-007/hIL-2 complex for four days. On day five splenocytes were isolated and immune cells populations were analyzed using flow cytometry. (A) Dosing regimen outline. (B–E) Mean values of immune cells calculated as a percentage from parent population of each experimental group (n=6 per group)

Abstract 704 Figure 4

Au-007 inhibits tumor growth in an I/O resistant tumor model with a tolerable profile. C57BL/6 healthy mice were inoculated with B16F10 melanoma tumor cells (day 0), at day 5 mice were randomized to experimental groups (n=10 per group) and administered daily, with single injection per day of Ab/hIL-2 mix (20 ug/1 ug respectively) or with PBS for four days. From the end of schedule administration at day 8 until experiment endpoint, mice were monitored daily for tumor volume (A) and for mean percent of body weight change for each experimental group (B).

Abstract 704 Figure 5

AU-007 inhibits the effect of IL-2 on Tregs while preserving its effect on Teffs and NKs. (A and B) Phosphorylated STAT5 levels of human immune cell subsets responding to various concentrations of hIL-2 with and without 200 nM AU-007. Total naïve hPBMC culture were incubated with increasing doses of hIL-2 or with increasing doses of hIL-2 + 200nM AU-007 for 15 min. Immune cells subpopulations were analyzed by flow cytometry, gating was defined based on FMOs. (C–F) Phosphorylated STAT5 levels of human immune cell subsets responding to titrated AU-007 or isotype control. Total naïve hPBMC culture were incubated with hIL-2 and with increasing doses of indicated antibody for 15 min. Data presented is an average of 3 biological repeats from 3 human PBMC donors.

Abstract 704 Figure 6

Au-007 can rely on endogenous IL-2 to break auto-inhibitory loop in human PBMCs. Total hPBMCs were stimulated for 24h with anti-CD3/anti-CD28 (stimulation only, green) or stimulated with anti-CD3/anti-CD28 in the presence of: 200 nM of Au-007 mAb (red) or with 200 nM of isotype control mAb (blue). No exogenous IL-2 was added. Immune cells subpopulations were analyzed by flow cytometry. Percentage of immune cell sub-populations demonstrate exclusive inhibition of Tregs (A–E). Au-007 downregulate the suppressive markers of CD4+ regulatory Tregs from panel A, as defined by significant reduction in MFI of CD25 and FoxP3 (F and G). Gating was defined based on FMOs. Data presented is an average of 3 biological repeats from 3 human PBMC donors.

Abstract 704 Figure 7

Au-007 captures endogenous hIL-2 and inhibits tumor growth in colorectal cancer model (MC38). Genetically modified C57BL/6 mice, engineered to express human IL-2 in the background of complete knock-out of mouse IL-2, were inoculated with MC38 colorectal tumor cells. All animals treated with Au-007 showed significant inhibition in tumor growth with no observed significant adverse effects. (A) Administration outline: PBS (black), anti-mouse-PD-1 antibody (yellow), Au-007 pre-complexed with low dose IL-2 (blue) and Au-007 alone every three days followed with a single immune kick start with IL-2 (green, IL-2 single dose is marked in red). (B) Tumor growth progression of the four groups treated. (C) Percent of body weight changes per treatment.

Characterization of BDG8: An antibody-human IL-2 complex that selectively activates the effector arm of the immune system

e15004

Background: Interleukin 2 is a 15.4 kDa type I cytokine of the four helix bundle structure. IL-2 signaling has two opposite effects, it can enhance immune response by activation of effector cells and regulate immune response by activation proliferation of regulatory T cells (Tregs). IL-2 mediates its effect by binding to two forms of IL-2 receptor: i) trimeric receptors made of IL-2Rα (CD25), IL-2Rβ (CD122), and a common IL-2Rγ (γc, CD132) chains or ii) a dimeric receptor of only the IL-2Rβ and IL-2Rγ subunits. In Tregs, activation of the trimeric receptor is associated with FoxP3 mediated transcription leading to the production of suppression factors. Tregs express higher levels of the αβγ trimeric IL-2 receptor than effector cells. However binding of IL-2 to the βγ dimer is associated with activation of effector cells expressing relatively high levels of the βγ dimer and express low levels of trimer. High dose IL-2 therapy is used in melanoma and metastatic renal cell carcinoma with response rates 10%-15%. While efficacious, this approach has several disadvantages: 1) IL-2 dependent adverse effects such as Vascular Leak Syndrome (VLS) excluding many patients from being considered 2) The short half-life of IL-2 requires frequent administration, resulting in repeated spikes in the level of circulating IL-2. 3) Administered IL-2 is not selective and enhances a non-desired activation of Tregs. Methods: Antibodies were computational designed to bind to a specific epitope on Il-2 allowing for the binding to the CD122/CD132 complex and exclude the CD122/CD132/CD25 complex. Results: Here we show that we specifically designed and tested a humanized antibody (BD8) that: i) binds tightly the human IL-2 (hIL-2) and ii) the antibody- hIL-2 complex preferentially to bind the IL-2Rβ sub-unit and blocks the IL-2Rα subunit. We show administering the BD8 Ab-IL-2 complex to C57BL/6 mice has a profound effect on activation of MP CD8+, NK and NKT effector cells with minimal effect on Tregs. In mice the antibody-hIL-2 complex serum half -life is much longer then the half-life of hIL-2. In the B16-F10 Melanoma model, BD8-hIL2 resulted in robust effect compared to hIL-2 alone. Conclusions: BD8 is a computationally designed antibody specifically binds to IL-2 inducing the activation of effector cells without stimulating Tregs and demonstrates efficacy in animal cancer models.

Aggregation of catalytically active Ru nanoparticles to inactive bulk, monitored in situ during an allylic isomerization reaction. Influence of solvent, surfactant and stirring

The exploration of catalytic isomerization reactions of an allylic alcohol to ketone, in the presence of μ-oxo-triruthenium acetate as a precatalyst in alcohol solvents, has established that the catalyst is heterogeneous in nature and proceeds by means of the in situ formed Ru⁰ nanoparticles (Ru⁰NPs). This reaction is used as an indicator for evaluating the kinetics and mechanism for metallic NP formation and self-assembly. In ethanol, complete conversion of the reactant is achieved under all experimental conditions tested. Conversely, in iso-propanol or n-pentanol the catalytic particles swiftly lose activity and the reaction arrests after partial conversion. We conclude that, in ethanol the process of NP self-assembly results in the formation of active and stable NPs of a specific size, named C-particles. Consequently, we propose an additional step for the established mechanism of NP self-assembly, namely the aggregation of C-NPs to inactive bulk-metal, labeled as D (C + C → D). D-particles differ from other NPs present in the catalytic cycle in size and in the catalytic activity. The effect of surfactant and mixing is also explored and the acquired observations strongly support the proposed mechanism of catalyst formation and decay. Addition of surfactants and/or mixing slowed down the reaction rate but dramatically improved the lifetime of the catalyst and the observed conversions. We attribute this phenomenon to the inhibition of the aggregation step of the active C-NPs to inactive D bulk-metal. The aggregation step of C-NPs to inactive D-bulk is assumed for the first time. This assumption prompts all the experimental data to be consistent. Introduction of the new kinetic step enables the use of the proposed mechanism with the reactions, where the catalyst loses its activity in the course of the reaction, and it converts the mechanism of the metal NP self-assembly into the more universal form.

To explain the decay of the activity of Ru-NPs catalysts, that formed in situ during allylic isomerization, we add a new step to a classic mechanism of transition-metal NPs self-assembly: the aggregation of two catalytically active NPs (C) to inactive bulk-metal (D).

Ancient origins of RGK protein function: modulation of voltage-gated calcium channels preceded the protostome and deuterostome split

RGK proteins, Gem, Rad, Rem1, and Rem2, are members of the Ras superfamily of small GTP-binding proteins that interact with Ca²⁺ channel β subunits to modify voltage-gated Ca²⁺ channel function. In addition, RGK proteins affect several cellular processes such as cytoskeletal rearrangement, neuronal dendritic complexity, and synapse formation. To probe the phylogenetic origins of RGK protein–Ca²⁺ channel interactions, we identified potential RGK-like protein homologs in genomes for genetically diverse organisms from both the deuterostome and protostome animal superphyla. RGK-like protein homologs cloned from Danio rerio (zebrafish) and Drosophila melanogaster (fruit flies) expressed in mammalian sympathetic neurons decreased Ca²⁺ current density as reported for expression of mammalian RGK proteins. Sequence alignments from evolutionarily diverse organisms spanning the protostome/deuterostome divide revealed conservation of residues within the RGK G-domain involved in RGK protein – Ca_vβ subunit interaction. In addition, the C-terminal eleven residues were highly conserved and constituted a signature sequence unique to RGK proteins but of unknown function. Taken together, these data suggest that RGK proteins, and the ability to modify Ca²⁺ channel function, arose from an ancestor predating the protostomes split from deuterostomes approximately 550 million years ago.

Competitive and non-competitive regulation of calcium-dependent inactivation in CaV1.2 L-type Ca2+ channels by calmodulin and Ca2+-binding protein 1

CaV1.2 interacts with the Ca(2+) sensor proteins, calmodulin (CaM) and calcium-binding protein 1 (CaBP1), via multiple, partially overlapping sites in the main subunit of CaV1.2, α1C. Ca(2+)/CaM mediates a negative feedback regulation of Cav1.2 by incoming Ca(2+) ions (Ca(2+)-dependent inactivation (CDI)). CaBP1 eliminates this action of CaM through a poorly understood mechanism. We examined the hypothesis that CaBP1 acts by competing with CaM for common interaction sites in the α1C- subunit using Förster resonance energy transfer (FRET) and recording of Cav1.2 currents in Xenopus oocytes. FRET detected interactions between fluorescently labeled CaM or CaBP1 with the membrane-attached proximal C terminus (pCT) and the N terminus (NT) of α1C. However, mutual overexpression of CaM and CaBP1 proved inadequate to quantitatively assess competition between these proteins for α1C. Therefore, we utilized titrated injection of purified CaM and CaBP1 to analyze their mutual effects. CaM reduced FRET between CaBP1 and pCT, but not NT, suggesting competition between CaBP1 and CaM for pCT only. Titrated injection of CaBP1 and CaM altered the kinetics of CDI, allowing analysis of their opposite regulation of CaV1.2. The CaBP1-induced slowing of CDI was largely eliminated by CaM, corroborating a competition mechanism, but 15-20% of the effect of CaBP1 was CaM-resistant. Both components of CaBP1 action were present in a truncated α1C where N-terminal CaM- and CaBP1-binding sites have been deleted, suggesting that the NT is not essential for the functional effects of CaBP1. We propose that CaBP1 acts via interaction(s) with the pCT and possibly additional sites in α1C.

A common Ca2+-driven interdomain module governs eukaryotic NCX regulation

Na(+)/Ca(2+) exchanger (NCX) proteins mediate Ca(2+)-fluxes across the cell membrane to maintain Ca(2+) homeostasis in many cell types. Eukaryotic NCX contains Ca(2+)-binding regulatory domains, CBD1 and CBD2. Ca(2+) binding to a primary sensor (Ca3-Ca4 sites) on CBD1 activates mammalian NCXs, whereas CALX, a Drosophila NCX ortholog, displays an inhibitory response to regulatory Ca(2+). To further elucidate the underlying regulatory mechanisms, we determined the 2.7 Å crystal structure of mammalian CBD12-E454K, a two-domain construct that retains wild-type properties. In conjunction with stopped-flow kinetics and SAXS (small-angle X-ray scattering) analyses of CBD12 mutants, we show that Ca(2+) binding to Ca3-Ca4 sites tethers the domains via a network of interdomain salt-bridges. This Ca(2+)-driven interdomain switch controls slow dissociation of "occluded" Ca(2+) from the primary sensor and thus dictates Ca(2+) sensing dynamics. In the Ca(2+)-bound conformation, the interdomain angle of CBD12 is very similar in NCX and CALX, meaning that the interdomain distances cannot account for regulatory diversity in NCX and CALX. Since the two-domain interface is nearly identical among eukaryotic NCXs, including CALX, we suggest that the Ca(2+)-driven interdomain switch described here represents a general mechanism for initial conduction of regulatory signals in NCX variants.

Relevance of the serial position effect in the differential diagnosis of mild cognitive impairment, Alzheimer-type dementia, and normal ageing

Serial position effects are observed when a person memorises a series of words exceeding his or her attention span. Cognitively normal individuals recall words at the beginning and end of the list more frequently than those in the middle, which reflects the way that short- and long-term episodic memory works.

OBJECTIVE

To study the serial position effect in patients with mild cognitive impairment (MCI) compared to subjects with Alzheimer-type dementia (AD) or normal ageing (NA).

METHODS

30 AD, 25 MCI and 20 NA subjects underwent neurological and neuropsychological assessment. The Rey Auditory Verbal Learning Test (RAVLT) was used to study primacy, middle, and recency effects and delayed recall for each group.

RESULTS

The general memory pattern of MCI subjects was very similar to that of AD subjects, and was characterised by reduced learning capacity, rapid forgetfulness and clear recency effect in learning. With regard to delayed recall, however, there were differences in performance; MCI subjects' ability to recall words at the beginning and middle of the list was similar to that of normal subjects, while their memory of words at the end of the list was poor, as in AD subjects.

CONCLUSIONS

RAVLT is a tool permitting us to distinguish between MCI and NA subjects. The recency index for the delayed recall task is a valid indicator for distinguishing between MCI patients and patients with normal ageing.

Identification and functional characterization of indole-3-acetamide-mediated IAA biosynthesis in plant-associated Fusarium species

The plant hormone indole-3-acetic acid (IAA) can be synthesized from tryptophan via the intermediate indole-3-acetamide (IAM). The two genes, IaaM (encoding tryptophan monooxygenase) and IaaH (encoding indole-3-acetamide hydrolase) that constitute the IAM pathway have been described in plant-associated bacteria. We have identified putative homologs of the bacterial IaaM and IaaH genes in four Fusarium species -Fusarium proliferatum, Fusarium verticillioides, Fusarium fujikuroi, and Fusarium oxysporum. In all four species the two genes are organized next to each other in a head to head orientation and are separated by a short non-coding region. However, the pathway is fully functional only in the orchid endophytic strain F. proliferatum ET1, which produces significant amounts of IAM and IAA. Minor amounts of IAM are produced by the corn pathogen F. verticillioides strain 149, while in the two other species, the rice pathogen F. fujikuroi strain m567 and the tomato pathogen F. oxysporum f. sp. lycopersici strain 42-87 the IAM pathway is inactive. Deletion of the entire gene locus in F. proliferatum ET1 resulted in drastic reduction of IAA production. Conversely, transgenic strains of F. fujikuroi over-expressing the F. proliferatum IAM genes produced elevated levels of both IAM and IAA. Analysis of the intergenic promoter region in F. proliferatum showed that transcriptional activation in direction of the IaaH gene is about 3-fold stronger than in direction of the IaaM gene. The regulation of the IAM genes and the limiting factors of IAA production via the IAM pathway are discussed.

RGK family G-domain:GTP analog complex structures and nucleotide-binding properties

The RGK family of small G-proteins, including Rad, Gem, Rem1, and Rem2, is inducibly expressed in various mammalian tissues and interacts with voltage-dependent calcium channels and Rho kinase. Many questions remain regarding their physiological roles and molecular mechanism. Previous crystallographic studies reported RGK G-domain:guanosine di-phosphate structures. To test whether RGK proteins undergo a nucleotide-induced conformational change, we determined the crystallographic structures of Rad:GppNHp and Rem2:GppNHp to 1.7 and 1.8 Å resolutions, respectively. Also, we characterized the nucleotide-binding properties and conformations for Gem, Rad, and several structure-based mutants using fluorescence spectroscopy. The results suggest that RGK G-proteins may not behave as Ras-like canonical nucleotide-induced molecular switches. Further, the RGK proteins have differing structures and nucleotide-binding properties, which may have implications for their varied action on effectors.

Structure-function studies of the G-domain from human gem, a novel small G-protein

Gem, a member of the Rad,Gem/Kir subfamily of small G-proteins, has unique sequence features. We report here the crystallographic structure determination of the Gem G-domain in complex with nucleotide to 2.4 A resolution. Although the basic Ras protein fold is maintained, the Gem switch regions emphatically differ from the Ras paradigm. Our ensuing biochemical characterization indicates that Gem G-domain markedly prefers GDP over GTP. Two known functions of Gem are distinctly affected by spatially separated clusters of mutations.

Chemical development of latent fingerprints: 1,2-indanedione has come of age

The performance of 1,2-indanedione as a latent fingerprint reagent on some types of paper was found to exceed that of DFO, the leading fluorogenic fingerprint reagent. It even exceeds the performance of the sequence, DFO, followed by ninhydrin. No new prints could be observed when ninhydrin was applied after indanedione. On a large number of actual exhibits (used checks) indanedione developed 46% more identifiable prints than the sequence DFO-ninhydrin. A standard procedure for fingerprint development by indanedione is proposed. Best results are obtained with a 0.2% indanedione solution in HFE7100 solvent containing 7% ethyl acetate, but no acetic acid. It can be recommended to start using 1,2-indanedione, which is already commercially available, in actual fingerprint casework.

Plasma-soluble E-selectin after cardiopulmonary bypass in children: is it a marker of the postoperative course?

OBJECTIVE

To investigate the relationship and possible role of soluble adhesion molecule E-selectin in the postoperative course in children undergoing cardiopulmonary bypass (CPB).

DESIGN

Prospective cohort study.

SETTING

Pediatric intensive care unit of a university hospital.

PARTICIPANTS

Thirteen children who were candidates for cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Serial blood samples of 13 CPB patients were collected from the arterial catheter or from the bypass circuits preoperatively; on initiation of CPB; on termination of CPB; and 1, 2, 4, 8, 12, 18, 24, and 48 hours postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70 degrees C until use. Circulating soluble selectin molecules were measured with a sandwich enzyme-linked immunosorbent assay technique. There were significant changes in plasma levels of soluble E-selectins in patients after CPB, and these levels were associated with patient characteristics, operative variables, and postoperative course. Soluble E-selectin correlated significantly with inotropic support and the use of anti-inflammatory drugs. There was a significant association between the development of postoperative sepsis and soluble E-selectin levels. No correlation was found between soluble E-selectins and duration of CPB, aortic cross-clamping, or hemodynamic variables, including heart rate and mean systemic arterial pressure.

CONCLUSION

These results suggest a relationship between CPB-induced mediators and early and late clinical effects. Although the mechanism for the increase of soluble E-selectin remains to be elucidated, the upregulation of soluble E-selectin indicates neutrophil activation, and its inhibition may represent a target for reducing the inflammatory response associated with CPB.

Pindolol augmentation in treatment-resistant obsessive compulsive disorder: a double-blind placebo controlled trial

OBJECTIVE

To evaluate the efficacy of pindolol augmentation in treatment-resistant obsessive compulsive disorder (OCD) patients who were unsuccessfully treated with serotonin reuptake inhibitors.

METHOD

Fourteen treatment-resistant OCD patients were treated with paroxetine for 17.4+/-2.1 weeks up to 60 mg/d after they failed at least two other serotonin reuptake inhibitor trials. The patients, who did not respond to open-label paroxetine treatment, were assigned to a double-blind, placebo-controlled pindolol (2.5 mgx3/d) augmentation. All the subjects were evaluated biweekly for a six-week period with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Anxiety Scale (HAM-Anx), and Montgomery Asberg Depression Rating Scale (MADRS). Data was analyzed by paired t-test, and ANOVA with repeated measures.

RESULTS

Pindolol augmentation to paroxetine (n=8) as compared to placebo augmentation (n=6), was associated with a significant (P<0.01) improvement in Y-BOCS as measured by paired t-test after the fourth week of the treatment and by ANOVA with repeated measures (df: 4.9, f: 3,3, P<0.006). Although no significant differences were found between placebo and pindolol groups on HAM-Anx and MADRS, a trend for improvement in the pindolol group was noted.

CONCLUSIONS

The results of our study demonstrated that pindolol may augment the therapeutic effect of paroxetine in treatment-resistant OCD patients.

Obsessive compulsive disorder: serotonin and beyond

OCD was considered a rare, treatment refractory disorder of psychological origin, up until 20 years ago. Research in the last two decades has altered the perspectives regarding OCD. It is now clear that OCD is a prevalent disorder--about 2% of the population suffer from OCD--and that it is amenable both to psychological (cognitive-behavioural approach) and pharmacological intervention (with serotonergic medication). The biochemical and neuroanatomical (the frontal basal-thalamo cortical circuit) pathophysiology of OCD is also beginning to emerge. OCD is unique with regards to its specific response to serotonergic medication that blocks reuptake. Clomiprimine, fluoxetine, fluvoxemine, paroxetine, sertraline and citalopram were all found to be effective treatments for OCD based on large, multicentre, double-blind, placebo-controlled studies. As only serotonergic medications appear to be effective in OCD, the serotonergic hypothesis has been formulated and tested. Indeed, pharmacological challenges with specific serotonin agonists such as mCPP and sumatriptan, which were associated with transient exacerbation of OCD symptoms, are in line with the specific role of 5HT in the pathogenesis of OCD. However, this serotonergic hypothesis, while necessary, is not sufficient. It is clear that the dopaminergic and autoimmune mechanism are also implicated in the pathogenesis of OCD. Further studies are required to understand the relevance of the serotonergic and non-serotonergic systems in OCD, and to highlight the various possible subtypes of this intriguing disorder.

Dissociation between the state of leukocyte adhesiveness/aggregation in the peripheral blood and the availability of the CD11B/CD18 and CD62L antigens on the surface of the cells in patients with stress

We adopted whole blood flow cytometry and direct labeling of the CD11b/CD18 and the CD62L antigens to study the relationship between their expression on the surface of peripheral leukocytes and the state of leukocyte adhesiveness/aggregation (LAA) as revealed by the leukergy test. We examined patients with infection/inflammation, acute stress and controls. The mean +/- S.D. channel fluorescence intensity of CD11b/CD18 antigen did not differ between patients with infection/inflammation (173 +/- 78) and controls (167 +/- 72). However, a significant (p < 0.0001) difference between these groups was noted regarding LAA state. There was a significant (p = 0.04) reduction in CD11b/CD18 in stress (135 +/- 60) and a significant (p < 0.001) increment in LAA. In both study groups, there was a significant reduction in CD62L. Patients were divided into those with CD11b/CD18 above and below the control's average. No correlation was found between the antigens and LAA. We assume that LAA in patients with stress state is CD11b/CD18 and CD62L independent.

Response to missile attacks on civilian targets in patients with panic disorder

BACKGROUND

The complex interaction that exists between biological and cognitive factors determines the reaction of panic-disorder patients to stressors. The current study was conducted to systematically assess the behavioral effects of a real, life-threatening event on panic-disorder patients.

METHOD

Sixty-five panic-disorder patients completed structured telephone interviews during the first 4 weeks of the Persian Gulf War. Evaluation included frequency of panic attacks, anxiety levels, and function levels both during and between air raid alarms.

RESULTS

The findings indicate that panic-disorder patients, despite high levels of anxiety, did not demonstrate an increased frequency of panic attacks during the Persian Gulf War. In addition, the majority of patients reported good-to-high levels of functioning during the crisis in both everyday and alarm-related functioning. Grouping of subjects according to proximity to risk or current antipanic treatment did not produce significant differences in the frequency of panic attacks or levels of anxiety.

CONCLUSION

The findings suggest that vulnerability of patients with panic disorder to a "panic-stricken" response does not increase during real-life stressors. The lack of increased frequency of panic attacks observed under these circumstances provides additional support for the opinion that panic and fear are two distinct entities.

A double-blind crossover comparison of clomipramine and desipramine in the treatment of panic disorder

OBJECTIVE

To compare the efficacy of clomipramine hydrochloride (CMI), a serotonin reuptake inhibitor with the noradrenergic tricyclic antidepressant agent, and desipramine hydrochloride (DMI) for patients with panic disorder (PD).

METHOD

Following a 2-week, single-blind placebo washout phase, 17 PD outpatients completed a 16-week, double-blind, crossover comparison of CMI and DMI. Key outcome measures included panic attacks frequency, the NIMH Global Scales for Anxiety, Depression and Impairment, Hamilton Anxiety Scale (Psychic and Somatic Subscales), Zung Anxiety Inventory (Raw and Index Subscales) and the Spielberger State Anxiety Scale.

RESULTS

Both CMI and DMI led to significant improvement from baseline placebo state in panic attacks frequency and behavioral ratings (p<0.001). CMI led to a greater reduction in the frequency of panic attacks (p=0.028) and was superior to DMI on ratings of anxiety: NIMH Global Anxiety, Zung Anxiety Scale (Raw and Index) and the Spielberger Anxiety Scale. No difference was found between the drugs on the NIMH Global Impairment Scale and the Hamilton Somatic and Psychic Scales.

CONCLUSION

Both drugs appeared to have significant therapeutic effects in patients with PD, but CMI appeared to be more effective. The effectiveness of the serotonergic drug suggests that the role of the serotonergic system in the pathogenesis of PD should be further explored.

Neutrophilia of infection/inflammation: are we really dealing with "inflamed" leukocytes?

We adopted whole blood flow cytometry and direct labeling of the CD11b/CD18 and CD62L antigens to study the relationship between their expression and leukocytosis in patients with infection/inflammation, acute stress and healthy volunteers. Mean +/- S.D. channel fluorescence intensity of CD11b/CD18 antigen on peripheral blood polymorphonuclears did not differ between patients with infection/ inflammation (173+/-78) and controls (167+/-72), but was significantly (p = 0.04) reduced in stress (135+/-60). No correlation was found between CD11b/CD18 antigen level and either polymorphonuclears absolute number or serum C-reactive protein. A significant negative correlation was noted between CD62L antigen expression on polymorphonuclears and their absolute number. We assume that cells with increased CD11b/CD18 surface concentrations are retained in the capillaries and that part of the leukocytes in the peripheral blood are stressed leukocytes with reduced CD11b/CD18. Thus, leukocytes detected in peripheral blood are not necessarily the most "inflamed" ones.

Treatment of severe, drug resistant obsessive compulsive disorder with the 5HT1D agonist sumatriptan

The serotonergic system has been implicated in both the aetiology and pharmacological treatment of obsessive compulsive disorder. In pharmacological challenge tests, mCPP, a 5-HT agonist, with an affinity for 5HT2C as well as 5HT1A and 5HT1D receptors, was associated with a transient exacerbation of obsessive compulsive symptoms. Chronic administration of mCPP was found to bring about some relief of these symptoms. Sumatriptan is an antimigraine agent, which interacts most potently with 5HT1D receptors. In the cases to be presented, we report the effects of chronic administration of Sumatriptan to three severe, treatment resistant, OCD patients. Following chronic administration of sumatriptan, these patients, who have been resistant to any former pharmacological treatment, responded with an improvement in their depression and a modest reduction in their obsessive compulsive symptoms.

Down-regulation of the CD62L antigen as a possible mechanism for neutrophilia during inflammation

The expressions of both the CD11b/CD18 and CD62L (L-selectin) antigens as well as the absolute number of white blood cells in the peripheral circulating pool of blood in 116 patients with various inflammatory conditions were determined. A highly significant (P<0.0001) negative correlation (r = -0.57) was noted between the absolute number of peripheral blood polymorphonuclear leucocytes and the expression of the CD62L antigen on their surface. In view of the role of CD62L antigen in the rolling of leucocytes along endothelial cells in the microvasculature, its down-regulation might explain, at least in part, the demargination and appearance of neutrophilia during inflammation.

Healing environment in psychiatric hospital design

Mental health professionals have long speculated that the physical environment in which treatment occurs has an impact on both the treatment process and its outcome. The few empirical studies that evaluated the effects of psychoenvironmental design have shown encouraging results and demonstrated clinically desirable behavioral changes and even reduced psychopathology. In view of the concept that architecture is a tool in the therapeutic process, the design and execution of the psychiatric hospital in the Chaim Sheba Medical Center at Tel-Hashomer, Israel, were conducted by a multidisciplinary team of architects, mental health professionals, and administrators. The hospital contains three acute inpatient wards and a day care and large outpatient clinic. Its operation began in 1991. This paper deals with the merging of "user-friendly" architectural and environmental design components that create an integral healing environment. The paper discusses the positive effects of specific components on patients and staff, and suggests that our model of psychoenvironmental approach to psychiatric hospital design can provide an important and effective tool in the pursuit of a humane, efficient containment and reduction of severe psychopathology.

Epidemiology of obsessive-compulsive disorder: a world view

The worldwide prevalence of obsessive-compulsive disorder (OCD) is approximately 2% of the general population. Symptoms of OCD include fear of contamination by dirt or germs; constant checking; repetitive, intrusive thoughts of a somatic, aggressive, or sexual nature; extreme slowness; and an inordinate concern with orderliness and symmetry. Differential diagnosis is sometimes complicated by the overlap between OCD and obsessive-compulsive personality disorder (OCPD). The most common complication of OCD is depression. However, while both serotonergic and nonserotonergic antidepressants are effective in treating patients with depression, only serotonergic medications are effective in treating OCD patients. Because OCD patients often attempt to conceal their symptoms, it is incumbent on clinicians to screen for OCD in every mental status examination, since appropriate treatment can often result in improved quality of life.

Emergence of kleptomania during treatment for depression with serotonin selective reuptake inhibitors

Kleptomania, one of the rare impulse-control disorders, is characterized by an irresistible impulse to steal objects not needed for personal use or monetary value. There is a comorbidity between mood disorders, eating disorders, anxiety disorders, personality disorders, and kleptomania. Several recent case reports have suggested that serotonin reuptake inhibitors could be effective in the treatment of obsessive-compulsive spectrum disorders and specifically in kleptomania. We describe three depressed patients who paradoxically experienced kleptomanic behavior during treatment with serotonin selective reuptake inhibitors.

New developments in obsessive-compulsive disorder research: implications for clinical management

Over the past decade, epidemiological, phenomenological, pharmacological, neurobiological, brain imaging and genetic research has contributed to a substantial change in our understanding of obsessive-compulsive disorder (OCD). Once regarded as a rare psychodynamic illness, OCD is now recognized as a common condition affecting 2-3% of the population. Better recognition combined with the demonstrated efficacy of serotonin reuptake inhibitors, such as clomipramine and the selective serotonin reuptake inhibitors (SSRIs), has dramatically improved the prognosis of this disorder, which exacts a considerable personal and economic burden. While the aetiology is still not understood, increasingly sophisticated research techniques are enabling us to begin to uncover the underlying pathophysiology of this illness. This paper reviews some of the recent developments which have enhanced our understanding of OCD and considers their potential impact on clinical management.

Alternation learning in obsessive-compulsive disorder

The Wisconsin Card Sorting Test (WCST) and an alternation learning task were administered to 15 women with obsessive-compulsive disorder (OCD) and 15 age-, sex-, education-, and intelligence-matched healthy controls. OCD patients were significantly slower on the WCST as compared to the controls. Their performance on the alternation learning task was impaired relative to the control group, though this difference was diminished when we used education as a covariate. We found a significant positive correlation between performance on the alternation task and severity of symptoms in the OCD group. Performance of similar alternation tasks is impaired by damage to the orbitofrontal cortex in nonhuman primates. Therefore the data presented support the hypothesis of orbitofrontal cortex dysfunction in OCD.

The pathogenesis and treatment of obsessive-compulsive disorder

The outlook for patients with obsessive-compulsive disorder (OCD) began to change in the early 1980s with the introduction of clomipramine (CMI), a serotonergic antidepressant. The observation that only drugs with a serotonergic profile are effective in OCD has been the basis for the serotonergic hypothesis of OCD. The serotonin-selective reuptake inhibitors are effective alternatives for CMI and can be used when the patient cannot use or tolerate CMI. In this review, we examine the pathophysiology of OCD, based on drug response profile, peripheral markers of serotonergic function, pharmacologic challenge studies, and neuroimaging. We also consider the medications found to be effective in OCD, the length of treatment, with special regard for maintenance therapy, and such issues as the approach for the treatment-resistant patient, augmentation strategies, and nonpharmacological treatments.

Olfactory sensitivity in major depressive disorder and obsessive compulsive disorder

Olfactory sensitivity to two odorants, isoamyl acetate and androsterone, was assessed in 14 obsessive compulsive disorder (OCD) patients, nine major depressive disorder (MDD) patients, and 16 sex- and age-matched healthy controls. Tests were performed during a drug-free period, and 3 and 6 weeks after initiation of antidepressant drug therapy. No difference in olfactory sensitivity, to either odorant, was found between OCD patients and controls at any time. In MDD patients, a significant increase in the sensitivity to isoamyl acetate was observed 6 weeks after initiation of treatment, compared to controls.

Nikkomycin production in pellets of Streptomyces tendae

In previous submerged fermentation experiments mycelial suspensions of Streptomyces tendae were viscous and availability of oxygen limited the yield of nikkomycins (Nk), a complex of secondary metabolites which includes nucleoside-peptides with antibiotic activity. Increasing agitation improved oxygen transfer but consumed considerable power and shear-damaged cells. In this paper, cellular aggregates (pellets) were used to reduce viscosity and protect cells from shear. Under the conditions tested, specific productivity of S. tendae pellets increased with increasing size up to 1.4 mm diameter and then decreased. The maximal specific productivity of S. tendae pellets (44 mg Nk/g dry weight/h) occurred at a very low cell concentration. Pellet formation or high biomass concentration was required for the production of bioactive dipeptide and tripeptide Nks. It is speculated that accumulation of intermediates in large pellets activates the production of mature secondary metabolites.