Emerging Trends in Immunotherapy for Adult Sarcomas

Soft-tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that arise from the oncogenic transformation of mesenchymal tissue. There are over 100 distinct STS histological and molecular subtypes with unique clinical, therapeutic, and prognostic features with variable responses to therapy regimens. Given the quality-of-life concerns and limited efficacy with current regimens, including cytotoxic chemotherapy, there is a need for novel therapies and regimens to treat advanced STS. Although immune checkpoint inhibitors have demonstrated significant improvements in survival outcomes in other cancer types, there remains ambiguous data on the impact of immunotherapy in sarcoma. Biomarkers like PD-1/PD-L1 are not always predictive of outcomes. Therefore, researching emerging novel therapies, such as CAR-T and adoptive cell therapies, is critical to understanding STS biology, STS tumor immune microenvironment immunomodulatory strategies that improve immune response, and survival outcomes. We discuss the underlying biology of the STS tumor immune microenvironment, immunomodulatory strategies that augment pre-existing immune responses, and novel approaches to develop sarcoma-specific antigen-based therapies.

196 TLR9-activated B cells directly license adoptively transferred CD8+ T cells with potent tumor immunity

Background

The use of immunotherapies such as immune checkpoint blockade or adoptive cell therapy has substantially improved outcomes for many patients with advanced malignancies. However, a majority of these patients still do not respond or relapse. Thus, extensive efforts are being made to improve these therapies. We and others have demonstrated that adoptive cell therapy can be improved by the co-administration of TLR agonists intratumorally. TLR agonists have also been administered to patients alongside a number of other immunotherapies, but often induce toxic side effects that may be exacerbated by cell therapy. We hypothesized that TLR agonists could alternatively be used in ex vivo cell culture to propagate a more potent cell therapy product.

Methods

To address our question, we used a transgenic mouse model of tumor-infiltrating lymphocyte (TIL) therapy, pmel-1, in which CD8+ T cells express a TCR specific for a melanoma/melanocyte antigen. We activated CD8+ pmel-1 T cells with APCs and the Toll-like receptor 9 agonist, CpG. Cell therapy efficacy was determined against mice bearing established B16F10 melanoma. Mechanisms underlying TLR-improved T cell products were determined using ex vivo cell depletion strategies and blocking antibodies.

Results

CpG-expanded pmel-1 T cell products were much more effective against B16F10 melanoma in vivo than traditionally expanded T cells; they conferred more durable antitumor responses and improved survival of mice. CD8+ T cells generated in the presence of CpG also had heightened engraftment and persistence in the mice. We found that CpG did not act directly on T cells in culture, but on B cells, as depletion of B cells alone (not DCs, macrophages, NK cells, or CD4 cells) ablated the effects of CpG. B cells in CpG-treated cultures expressed a unique cytokine profile and upregulated several costimulatory markers on their cell surface, so we next questioned whether CpG improved the B cell/T cell axis via a direct or indirect (soluble) factor. Together, cell supernatant transfer experiments and costimulatory blockade experiments revealed that the direct interaction between B and T cells was required for the CpG-mediated improvement of the T cell product.

Conclusions

Our findings reveal a novel role for B cells in the generation of potent CD8+ T cell therapies against an aggressive solid tumor. These findings highlight a unique way B cells can become powerful APCs for generating effective antitumor CD8+ T cells and can be directly translated to improve cell therapy products for patients with advanced malignancies.

Ethics Approval

All animal procedures performed at the Medical University of South Carolina or Emory University were approved by each university’s Institutional Animal Care & Use Committee, protocol number 0488 or 201900225, respectively.

Discriminating value of HR-pQCT for fractures in women with similar FRAX scores: A substudy of the FRISBEE cohort

Areal bone mineral density (aBMD) has a low sensitivity to identify women at high fracture risk. The FRAX algorithm, by combining several clinical risk factors, might improve fracture prediction compared to aBMD alone. Several micro-architectural and biomechanical parameters which can be measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) are associated with fracture risk. HR-pQCT in combination or not with finite element analysis (FEA) may be used to improve bone strength prediction. Our aim was to assess whether HR-pQCT measurements (densities, cortical and trabecular microarchitecture, biomechanical proprieties assessed by FEA) had an added value in predicting fractures in a subgroup of women belonging to the Belgian FRISBEE cohort. One hundred nineteen women who sustained a fracture (aged 60 to 85 years) during the initial follow-up of our cohort had a radius and tibia examination by HR-pQCT and were compared with controls matched for their FRAX score at baseline. We found that low distal radius total (OR = 1.41 [1.07-1.86] per SD, p < 0.05) and trabecular densities (OR = 1.45 [1.10-1.90], p < 0.01), trabecular number (OR = 1.32 [1.01-1.72], p < 0.05), intra individual distribution of separation (OR = 0.73 [0.54-0.99], p < 0.05) as several FEA parameters were significantly associated with fractures. At the distal tibia, impaired cortical density (OR = 1.32 [1.03-1.70] per SD, p < 0.05) and thickness (OR = 1.29 [1.01-1.63], p < 0.05) and apparent modulus (OR = 1.30 [1.01-1.66], p < 0.05) were significantly correlated with fractures. A low ultra distal radial aBMD (UDR) measured at the time of HR-pQCT was significantly associated with fractures (OR = 1.67 [1.22-2.28], p < 0.01). Women from both groups were followed further after the realization of the HR-pQCT and 46 new fractures were registered. In this second part of the study, low UDR aBMD (OR = 1.66 [1.18-2.35], p < 0.01), total (OR = 1.48 [1.08-2.03], p < 0.05), cortical (OR = 1.40 [1.04-1.87], p < 0.05) and trabecular (OR = 1.37 [1.01-1.85], p < 0.05) densities or apparent modulus (OR = 1.49 [1.07-2.05], p < 0.05) at the radius were associated with a significant increase of fracture risk. At the tibia, only the cortical density was significantly associated with the fracture risk (OR = 1.34 [1.02-2.76], p < 0.05). These results confirm the interest of HR-pQCT measurements for the evaluation of fracture risk, also in women matched for their baseline FRAX score. They also highlight that UDR aBMD contains pertinent information.

119 IL-6 is critical for memory responses elicited by Th17 cells to tumors

Background

Translation of novel T cell therapies is limited by cost and time-consuming protocols involving long-term T cell expansion. We found that shortening ex vivo expansion of either TCR-specific murine Th17 cells or human CAR Th17 cells licenses the cell product to eradicate large tumors in low doses and generate long-lived memory against tumor.1 Therapeutic Th17 cells induce the systemic release of IL-6, IL-17, GM-CSF, and MCP-1 among other cytokines in tumor-bearing hosts, reminiscent of clinical cytokine release syndrome. As the toxicity of cytokine release is managed in patients through IL-6 blockade, we addressed the impact of IL-6 on efficacy and durability of Th17 cell therapy. We hypothesized that IL-6, induced by Th17 cells, was fueling the durable memory properties of this cell product.

Methods

Th17 cells were expanded ex vivo using the TRP-1 transgenic mouse model in which CD4+ T cells express a TCR that recognizes tyrosinase-related protein 1 on melanoma. Naïve CD4+ T cells were polarized to the Th17 phenotype and infused into mice with B16F10 melanoma after a nonmyeloablative total body irradiation (5 Gy) preparative regimen.

Results

IL-6 blockade, targeting either IL-6R or neutralization of the cytokine, did not significantly impact the primary immune response of adoptively transferred Th17 cells against tumor. However, administering IL-6 blockade acutely after Th17 transfer resulted in a higher incidence of tumor relapse upon secondary tumor challenge, thereby compromising long-lived antitumor immunity.1 Mounting a secondary response to tumor was dependent on CD4+ T cells, but not CD8+ T cells, persisting in the host. Mechanistically, IL-6 blockade reduced pSTAT3 and Bcl2 in transferred T cells but did not greatly impact the concentration of other systemic cytokines. As a small fraction of Tregs remain in the Th17 cell product ex vivo, we examined the engraftment of those Tregs after transfer. IL-6 was critical to suppress engraftment of FoxP3+ donor T cells from the CD4+ T cell product. Thus, IL-6 promoted robust tumor infiltration by donor effector over regulatory cells for early Th17 cells relative to cell products expanded longer durations ex vivo.1

Conclusions

Overall, short-term expanded Th17 cells uniquely induced IL-6 unlike Th17 cells expanded longer ex vivo. IL-6 promoted Th17 survival, reduced engraftment of tumor-specific Tregs, and was critical to durable memory. This work may suggest that the universal strategy to inhibit IL-6 during cytokine release syndrome may come at the expense of long-term efficacy for specific cell therapy approaches.

Reference

Knochelmann HM, Dwyer CJ, Smith AS, Bowers JS, Wyatt MM, Nelson MH, Rangel Rivera GO, Horton JD, Krieg C, Armeson K, Lesinski GB, Rubinstein MP, Li Z, Paulos CM. IL-6 fuels durable memory for Th17 cell-mediated responses to tumors. Cancer Res. 2020. Epub ahead of print. PMID: 32561531.

Functional redundancy and compensation: Deletion of multiple murine Crisp genes reveals their essential role for male fertility

Mammalian Cysteine-RIch Secretory Protein (CRISP) family includes four members present in sperm and reported to regulate Ca²⁺ channels and fertilization. Based on our previous observations using single knockouts models and suggesting the existence of functional compensation among CRISP proteins, we investigated their relevance for male fertility by generating multiple Crisp gene mutants by CRISPR/Cas9 technology. Whereas targeting of Crisp1 and Crisp3 yielded subfertile males with early embryo developmental defects, the same deletion in zygotes from fertile Crisp2^-/- .Crisp4^-/- mice led to the generation of both triple and quadruple knockout mice exhibiting a complete or severe disruption of male fertility due to a combination of sperm transport, fertilization, and embryo developmental defects linked to intracellular Ca²⁺ dysregulation. These observations reveal that CRISP proteins are essential for male fertility and organize in functional modules that contribute distinctly to fertility success, bringing insights into the mechanisms underlying functional redundancy/compensation in protein families and emphasizing the importance of generating multiple and not just single knockout which might be masking the true functional relevance of family genes.

Osteoporosis treatment gap in a prospective cohort of volunteer women

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture. The high treatment gap in our cohort consisted of unselected volunteer patients highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

INTRODUCTION

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture, with a treatment gap around 80%. This can have dramatic consequences for patients and the healthcare systems.

METHODS

In this study based on longitudinal data from the FRISBEE (Fracture RIsk Brussels Epidemiological Enquiry) cohort of 3560 volunteer women aged 60 to 85 years, we evaluated the 1-year treatment gap after a first major incident fragility fracture.

RESULTS

There were 386 first validated fragility fractures, 285 major osteoporotic fractures (MOF) and 101 "other major" fractures. The rate of untreated patients was 85.0% (82.8% for MOF versus 91.0 % for "other major" fracture sites) (p = 0.04), with a lower rate for spine (70.5%) and hip (72.5%) versus shoulder (91.6%) and wrist (94.1%) (p < 0.0001). More specifically, the treatment gap for patients with osteoporosis, defined by a T-score < - 2.5 SD was 74.6% versus 76.5% for patients with osteoporosis defined by the presence of hip, shoulder, or spine fractures, independently of DXA results. When considering age groups, the rate of untreated women was 87.9% for women 60-70 years old, 88.2% between 70 and 80 years and 77.8% above 80 years (p = 0.03), with a greater difference between women who were younger or older than 80 years at inclusion: 88.1% versus 77.8% (p = 0.009). A diagnosis of osteoporosis (p = 0.01) and age (p = 0.03) were the only clinical risk factors (CRFs) significantly associated with treatment initiation.

CONCLUSIONS

This study highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

IL-6 fuels durable memory for Th17 cell-mediated responses to tumors

Accessibility of T cell transfer therapies is hindered by cost and time required for product development. We found that shortening ex vivo expansion of Th17 cells licenses a proinflammatory cell product which induces cytokine storm with high levels of systemic IL-6 in tumor-bearing hosts. Unique from other helper subsets, briefly expanded Th17 cells eradicate large tumors in low doses and generate long-lived memory against tumor rechallenge, suggesting a benefit to the inflammatory state. As the toxicity of cytokine release is managed in patients through IL-6 blockade, we addressed the physiologic impact of IL-6 on efficacy and durability of Th17 cell therapy in this immunocompetent model. We hypothesized that peak IL-6 induced by Th17 cells was critical to their durable memory properties. To address this, we used the TRP-1 transgenic mouse model where CD4+ T cells express a TCR that recognizes TRP-1 of B16F10 melanoma. Acute IL-6 blockade post Th17 transfer did not impact the primary antitumor response, yet abrogated long-term responses by promoting tumor relapse upon secondary challenge. Mechanistically, IL-6 blockade reduced pSTAT3 and Bcl2 in transferred T cells and promoted a greater frequency of FoxP3+ Treg cells in the peripheral blood and tumor-draining lymph nodes. Finally, serum IL-6 was inversely correlated with engraftment of tumor-specific Tregs from the transferred product. Overall, short-term expanded Th17 cells uniquely induce IL-6, which promotes Th17 survival, suppresses engraftment of tumor-specific Tregs, and is critical to durable memory. This work may suggest that the universal strategy to inhibit IL-6 during cytokine release syndrome may come at the expense of long-term efficacy for cell therapy.

Abstract 4225: Is biomarker-driven precision medicine possible by using high dimensional augmented intelligence assisted analysis of cancer immune responses

Checkpoint inhibitors have significantly accelerated cancer treatment but still a majority of patients do not respond. Biomarker driven patient stratification early to the right immunotherapeutic might enhance response and patient survival. Here we used high-dimensional mass cytometry (CyTOF) combined with machine-learning bioinformatics for the in-depth characterization of immune responses before and during anti-PD-1 immunotherapy. CyTOF allows us to monitor protein expression of 34 markers on a single cell while running 20 samples simultaneously. The analysis is data driven, can be adapted to high throughput approaches and can model arbitrary trial designs such as batch effects and paired designs and is quantitative over millions of events. Using CyTOF as a precision medicine tool we could predict response to anti-PD-1 using liquid blood biopsies. Biobanked peripheral blood mononuclear cells (PBMCs) from 51 patients with stage IV melanoma before and after 12 weeks of anti-PD-1 therapy was analyzed. We observed a clear T cell response on therapy. The most evident difference in responders before therapy was an enhanced frequency of CD14+ CD16+HLA-DRhi classical monocytes. We validated our results using conventional flow and found a clear correlation of enhanced monocyte frequencies before therapy initiation with clinical response such as lower hazard and extended progression-free and overall survival. In a second study we used CyTOF to monitor immune response in 21 non small cell lung cancer (NSCLC) patients that initially responded and then progressed under anti-PD-1 to a novel combination immunotherapy of anti-PD-1 plus an IL-15 super-agonist (ALT-803). In this phase Ib clinical study a response in the CD8+ T cell compartment was observed. Unexpected our high dimensional unbiased analysis was able to detect and characterize a strong expansion of innate tumor-reactive effector NK cells starting around day 4 of therapy. Taken together, our unbiased artificial intelligence driven immune workflow might support patient selection prior to therapy, and serve as a novel tool for precision medicine to select the right drug combination and identify new drug-able cell populations.

Citation Format: Carsten Krieg, Luis Cardenas, Silvia Guglietta, John Wrangle, Mark Rubinstein, Mark Robinson. Is biomarker-driven precision medicine possible by using high dimensional augmented intelligence assisted analysis of cancer immune responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4225.

Unexpected Stretching of Entangled Ring Macromolecules

In the melt state at equilibrium, entangled nonconcatenated ring macromolecules adapt more compact conformations compared to their linear analogs and do not form an entanglement network. We show here that, when subjected to uniaxial stretching, they exhibit a unique response, which sets them apart from any other polymer. Remarkably, whereas both linear and ring polymers strain-harden, the viscosity of the rings increases dramatically (the melt thickens) at very low stretch rates due to the unraveling of their conformations along the stretching direction. At high rates, stretching leads to viscosity thinning similar to that of entangled linear polymers, albeit with subtle differences.

Recent updates in cancer immunotherapy: a comprehensive review and perspective of the 2018 China Cancer Immunotherapy Workshop in Beijing

The immune system is the hard-wired host defense mechanism against pathogens as well as cancer. Five years ago, we pondered the question if the era of cancer immunotherapy was upon us (Li et al., Exp Hem Oncol 2013). Exciting progresses have been made at all fronts since then, including (1) sweeping approval of six agents by the US Food and Drug Administration (FDA) to block the PD-1/PD-L1 pathway for treatment of 13 cancer types; (2) a paradigm shifting indication of PD-1 and CTLA4 blockers for the management of a broad class of cancers with DNA mismatch repair defect, the first-ever tissue agnostic approval of cancer drugs; (3) real world practice of adoptive T cell therapy with two CD19-directed chimeric antigen receptor T cell products (CAR-T) for relapsed and/or refractory B cell malignancies including acute lymphoid leukemia and diffuse large B cell lymphoma, signaling the birth of a field now known as synthetic immunology; (4) the award of 2018 Nobel Prize in Physiology and Medicine from the Nobel Committee to Tasuku Honjo and James Allison "for their discovery of cancer medicine by inhibition of negative immune regulation" ( www.nobelprize.org/prizes/medicine/2018 ); and (5) the emerging new concept of normalizing rather than amplifying anti-tumor immunity for guiding the next wave of revolution in the field of immuno-oncology (IO) (Sanmamed and Chen, Cell 2018).This article will highlight the significant developments of immune-oncology as of October 2018. The US FDA approved indications of all seven immune checkpoint blockers, and two CD19-directed CAR-T products are tabulated for easy references. We organized our discussion into the following sections: introduction, cell therapy, emerging immunotherapeutic strategies, expediting oncology drug development in an era of breakthrough therapies, new concepts in cancer immunology and immunotherapy, and concluding remarks. Many of these topics were covered by the 2018 China Cancer Immunotherapy Workshop in Beijing, the fourth annual conference co-organized by the Chinese American Hematologist and Oncologist Network (CAHON), China FDA (CFDA; now known as China National Medical Product Administration (NMPA)), and the Tsinghua University. We significantly expanded our discussion of important IO developments beyond what were covered in the conference, and proposed a new Three Rs conceptual framework for cancer immunotherapy, which is to reverse tolerance, rejuvenate the immune system, and restore immune homeostasis. We conclude that the future of immuno-oncology as a distinct discipline of cancer medicine has arrived.

Abstract B34: Safety and activity of the IL-15/sIL-15Rα complex ALT-803 in combination with the anti-PD1 mAb nivolumab in metastatic non-small cell lung cancer

This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR05) of the Conference Proceedings.

Citation Format: John Wrangle, Vamshidar Velchetti, Manish Patel, Samantha Suriano, Marzena Swiderska-syn, Kate Anderton, James Ravenel, Elisabeth Hill, Amy Rock, Hing Wong, Mark Rubinstein. Safety and activity of the IL-15/sIL-15Rα complex ALT-803 in combination with the anti-PD1 mAb nivolumab in metastatic non-small cell lung cancer [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr B34.

Abstract PR05: Safety and activity of the IL-15/sIL-15Rα complex ALT-803 in combination with the anti-PD1 mAb nivolumab in metastatic non-small cell lung cancer

Background: Despite the unprecedented efficacy of immunotherapy with PD-1/PD-L1 blockade in non-small cell lung cancer, treatment failure is common and an area of unmet clinical need. IL-2/IL-15Rbg agonists, which potently augment the activity of CD8+ T and NK cells, have shown the ability to induce complete and durable responses in select cancers. However, this class of drugs has been neither combined with PD-1 targeted immunotherapies nor examined extensively in NSCLC. We hypothesized that the addition of an IL-15 superagonist (ALT-803) would be safe and improve the efficacy of anti-PD-1 mAb (nivolumab) in metastatic NSCLC patients in second-line therapy.

Methods: In this phase Ib trial, patients with metastatic NSCLC who were eligible to initiate or to continue receiving nivolumab (anti-PD-1 mAb) after first-line therapy were enrolled to trial, including patients with disease relapsed on or refractory to PD-1 blockade. Nivolumab was administered in combination with ALT-803 at four dose levels. The primary objective of the study was to define safety and tolerability and a recommended phase II dose of ALT-803 in combination with nivolumab, with secondary objectives including immune correlates and clinical parameters including response rate.

Results: In a first-in-human combination, 21 NSCLC patients were treated at 4 dose levels of ALT-803 in combination with the approved dose of nivolumab. No dose-limiting toxicities were observed, and the most common adverse events were fever, flu-like symptoms, and injection site reactions. The recommended phase II dose (RP2D) of therapy is weekly subcutaneous ALT-803 at 20 mcg/kg in combination with intravenous nivolumab 240 mg every 14 days. Multiple objective responses were observed, including when ALT-803 was added to a failing PD-1 mAb regimen.

Discussion: The recommended phase II dose of ALT-803 plus nivolumab was determined and the regimen can safely be administered in the outpatient setting. Responses among patients with PD-1 mAb relapsed disease with the addition of ALT-803 to their regimen demonstrate for the first time evidence of antitumor activity for a new class of agents for NSCLC and in patients with disease progression on PD-1/PD-L1 pathway blockade.

This abstract is also being presented as Poster B34.

Citation Format: John Wrangle, Vamshidar Velchetti, Manish Patel, Samantha Suriano, Marzena Swiderska-syn, Kate Anderton, James Ravenel, Elisabeth Hill, Amy Rock, Hing Wong, Mark Rubinstein. Safety and activity of the IL-15/sIL-15Rα complex ALT-803 in combination with the anti-PD1 mAb nivolumab in metastatic non-small cell lung cancer [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr PR05.

Association of rare missense variants in the second intracellular loop of NaV1.7 sodium channels with familial autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder often accompanied by intellectual disability, language impairment and medical co-morbidities. The heritability of autism is high and multiple genes have been implicated as causal. However, most of these genes have been identified in de novo cases. To further the understanding of familial autism, we performed whole-exome sequencing on five families in which second- and third-degree relatives were affected. By focusing on novel and protein-altering variants, we identified a small set of candidate genes. Among these, a novel private missense C1143F variant in the second intracellular loop of the voltage-gated sodium channel Na_V1.7, encoded by the SCN9A gene, was identified in one family. Through electrophysiological analysis, we show that Na_V1.7^C1143F exhibits partial loss-of-function effects, resulting in slower recovery from inactivation and decreased excitability in cultured cortical neurons. Furthermore, for the same intracellular loop of Na_V1.7, we found an excess of rare variants in a case-control variant-burden study. Functional analysis of one of these variants, M932L/V991L, also demonstrated reduced firing in cortical neurons. However, although this variant is rare in Caucasians, it is frequent in Latino population, suggesting that genetic background can alter its effects on phenotype. Although the involvement of the SCN1A and SCN2A genes encoding Na_V1.1 and Na_V1.2 channels in de novo ASD has previously been demonstrated, our study indicates the involvement of inherited SCN9A variants and partial loss-of-function of Na_V1.7 channels in the etiology of rare familial ASD.

Inducible ablation of dopamine D2 receptors in adult mice impairs locomotion, motor skill learning and leads to severe parkinsonism

Motor execution and planning are tightly regulated by dopamine D1 and D2 receptors present in basal ganglia circuits. Although stimulation of D1 receptors is known to enhance motor function, the global effect of D2 receptor (D2R) stimulation or blockade remains highly controversial, with studies showing increasing, decreasing or no changes in motor activity. Moreover, pharmacological and genetic attempts to block or eliminate D2R have led to controversial results that questioned the importance of D2R in motor function. In this study, we generated an inducible Drd2 null-allele mouse strain that circumvented developmental compensations found in constitutive Drd2^-/- mice and allowed us to directly evaluate the participation of D2R in spontaneous locomotor activity and motor learning. We have found that loss of D2R during adulthood causes severe motor impairments, including hypolocomotion, deficits in motor coordination, impaired learning of new motor routines and spontaneous catatonia. Moreover, severe motor impairment, resting tremor and abnormal gait and posture, phenotypes reminiscent of Parkinson's disease, were evident when the mutation was induced in aged mice. Altogether, the conditional Drd2 knockout model studied here revealed the overall fundamental contribution of D2R in motor functions and explains some of the side effects elicited by D2R blockers when used in neurological and psychiatric conditions, including schizophrenia, bipolar disorder, Tourette's syndrome, dementia, alcohol-induced delusions and obsessive-compulsive disorder.

Abstract A34: Beyond immune checkpoint: First-in-class antibody targeting soluble NKG2D ligand sMIC for cancer immunotherapy

In response to oncogenic insult, human cells were induced to express a family of MHC I-chain related molecules A and B (MICA and MICB, generally termed MIC) on the surface which serve as the ligands for the activating immune receptor NKG2D expressed by all human NK and cytotoxic T cells. Theoretically, engagement of NKG2D by tumor cell surface MIC is deemed to signal and provoke the immune system to eliminate transformed cells. Clinically, almost all advanced tumors in cancer patients produce soluble MIC through proteolytic shedding mediated by metalloproteases, or by release in exosomes derived from the cell membrane. Tumor-derived sMIC is known to be highly immune suppressive and profoundly insults the immune system by downregulating receptor NKG2D expression on effector NK and T cells, driving the expansion of tumor-favoring myeloid suppression cells, skewing macrophages into alternatively activated phenotypes, and perturbing NK cell peripheral maintenance. High levels of serum sMIC significantly correlate with advanced diseases of many types of cancer. These observations clearly endorse sMIC to be a cancer immune therapeutic target. However, due to mice lack homologues to human MIC, this concept was not proven until our recent studies. Using a “humanized” MIC-transgenic spontaneous mouse model which recapitulates the NKG2D-mediated onco-immune dynamics of human cancer patients, we show that neutralizing circulating sMIC with a first-in-field non-blocking antibody B10 that does not block the interaction of MIC with NKG2D revamps endogenous innate and antigen-specific CD8 T cell responses. We show that therapy with the non-blocking sMIC-neutralizing antibody results in effectively debulk of primary tumor and elimination of metastasis, with no observed toxicity. Furthermore, we show that clearing sMIC with the first-in-class neutralizing antibody B10 also enhanced the efficacy of other cancer immunotherapeutic modalities, such as immune checkpoint blockade or adoptive cell-based therapy pre-clinically. Our study has launched a new avenue of cancer immunotherapy which can be readily translated into clinical trials.

Note: This abstract was not presented at the conference.

Citation Format: Jennifer D. Wu, Jinyu D. Zhang, Fahmin Basher, Mark Rubinstein. Beyond immune checkpoint: First-in-class antibody targeting soluble NKG2D ligand sMIC for cancer immunotherapy. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A34.

Hypothalamic-specific proopiomelanocortin deficiency reduces alcohol drinking in male and female mice

Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE-/-), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE-/- mice of both sexes had less intake and less preference. Although nPE-/- showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE-/- showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE-/- of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE-/- did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol 'binge' drinking, escalation and 'relapse', probably via hypothalamic-mediated mechanisms, with sex differences.

Developmental toxicity of nicotine: A transdisciplinary synthesis and implications for emerging tobacco products

While the health risks associated with adult cigarette smoking have been well described, effects of nicotine exposure during periods of developmental vulnerability are often overlooked. Using MEDLINE and PubMed literature searches, books, reports and expert opinion, a transdisciplinary group of scientists reviewed human and animal research on the health effects of exposure to nicotine during pregnancy and adolescence. A synthesis of this research supports that nicotine contributes critically to adverse effects of gestational tobacco exposure, including reduced pulmonary function, auditory processing defects, impaired infant cardiorespiratory function, and may contribute to cognitive and behavioral deficits in later life. Nicotine exposure during adolescence is associated with deficits in working memory, attention, and auditory processing, as well as increased impulsivity and anxiety. Finally, recent animal studies suggest that nicotine has a priming effect that increases addiction liability for other drugs. The evidence that nicotine adversely affects fetal and adolescent development is sufficient to warrant public health measures to protect pregnant women, children, and adolescents from nicotine exposure.

Abstract B024: First-in-class antibody targeting soluble NKG2D ligand sMIC to enhance checkpoint cancer immunotherapy

In response to oncogenic insult, human cells were induced to express a family of MHC I-chain related molecules A and B (MICA and MICB, generally termed MIC) on the surface which serve as the ligands for the activating immune receptor NKG2D expressed by all human NK, CD8 T, NKT, and subsets of γδ T cells. Theoretically, engagement of NKG2D by tumor cell surface MIC is deemed to signal and provoke the immune system to eliminate transformed cells. Clinically, almost all advanced tumors in cancer patients produce soluble MIC through proteolytic shedding mediated by metalloproteases, or by release in exosomes derived from the cell membrane. Tumor-derived sMIC is known to be highly immune suppressive and profoundly insults the immune system by downregulating receptor NKG2D expression on effector NK and T cells, driving the expansion of tumor-favoring myeloid suppression cells, skewing macrophages into alternatively activated phenotypes, and perturbing NK cell peripheral maintenance. High levels of serum sMIC significantly correlate with advanced diseases of many types of cancer. These observations clearly endorse sMIC to be a cancer immune therapeutic target. However, due to mice lack homologues to human MIC, this concept was not proven until our recent studies. Using a “humanized” MIC-transgenic spontaneous mouse model which recapitulates the NKG2D-mediated onco-immune dynamics of human cancer patients, we show that neutralizing circulating sMIC with a first-in-field non-blocking antibody B10 that does not block the interaction of MIC with NKG2D revamps endogenous innate and antigen-specific CD8 T cell responses and remodels tumor microenvironment to be more immune reactive. We show that therapy with the non-blocking sMIC-neutralizing antibody results in effectively debulk of primary tumor and elimination of metastasis, with no observed toxicity. Furthermore, we show that clearing sMIC with the first-in-class neutralizing antibody B10 also enhanced the efficacy of other cancer immunotherapeutic modalities, such as immune checkpoint blockade or adoptive cell-based therapy pre-clinically. Our study has launched a new avenue of cancer immunotherapy which can be readily translated into clinical trials.

Citation Format: Jennifer D. Wu, Jinyu Zhang, Fahmin Basher, Mark Rubinstein. First-in-class antibody targeting soluble NKG2D ligand sMIC to enhance checkpoint cancer immunotherapy [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B024.

Effect of administration timing of postchemotherapy granulocyte colony-stimulating factor on host-immune cell recovery and CD8+ T-cell response

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic growth factor, is a standard supportive therapy given during cancer treatment. It induces acceleration in neutrophil recovery through stimulation of mobilization of hematopoietic progenitors. Given that the latter is also induced by chemotherapy itself, the timing of administration of G-CSF postchemotherapy might impact the resultant overall effects. The present study aimed to determine the optimal timing of G-CSF postchemotherapy to exert its optimal effects on the immune cell recovery and its impact on antigen-specific CD8⁺ T-cell response. B6 mice were treated once with cyclophosphamide (4 mg/mouse; CTX) and then daily with G-CSF (5 g/mouse) from Days 1-5, 2-5 or 5-9 post-CTX treatment. The total numbers of various immune cell types were analyzed on Days 7, 9 and 12 post-CTX treatment. To evaluate effects on CD8⁺ T-cell response, a pmel-1 transgenic mouse model was used in combination with prime boost peptide vaccination therapy. The total number of white blood cells (WBC), neutrophils, monocytes, lymphocytes, granulocytes and dendritic cells (DC) were significantly increased after G-CSF treatment in particular when G-CSF was administered from Days 2-5 post-CTX treatment. Application of this timing of G-CSF and CTX treatment after adoptive transfer of T-cells followed by prime-boost vaccination with antigenic peptide did not block the expansion of the donor pmel-1 CD8⁺ T-cells. In conclusion, adjusting the timing of treatment with G-CSF postchemotherapy can optimize its promoting effects on recovery of myeloid cells without altering the associated antigen-specific immunity.

Eating Disorders in Adolescent and Young Adult Males: Presenting Characteristics

PURPOSE

Data on the clinical characteristics of adolescent males with eating disorders are limited. The purpose of this study was to describe the demographic characteristics, presenting vital signs, laboratory results, and relevant risk factors for eating disorders among males presenting to an outpatient adolescent and young adult medicine practice.

METHODS

Retrospective chart review of male eating disorder patients aged of 11-25 years presenting to the University of California, San Francisco Adolescent and Young Adult Eating Disorder Program between June 1, 2011, and November 1, 2014. Charts were reviewed for demographic and clinical characteristics and risk factors for eating disorders.

RESULTS

Thirty-three patients were included; mean age was 16 years. Patients presented with mean heart rate was 58.7 bpm, and orthostatic heart rate change was 22 bpm, with 51.5% meeting Society for Adolescent Health and Medicine hospital admission criteria. Mean percent of median body mass index was 88%. Of patients with available laboratory data, 33.3% were anemic, 23.8% leukopenic, 19.0% thrombocytopenic, and 10.0% neutropenic. Half had a history of a psychiatric disorder; 41.5% had a history of overweight or obesity, and 12.1% had a family history of an eating disorder. The DSM-IV-TR and DSM-5 diagnostic criteria were retrospectively applied to patients, with an increase in diagnosis of anorexia nervosa from 36.4% to 48.5%. Diagnoses of Eating Disorder Not Otherwise Specified, now Other Specified Feeding or Eating Disorder in DSM-5, decreased from 62.6% to 45.5%.

CONCLUSIONS

Male patients with eating disorders presented with significant abnormalities; patients were bradycardic and orthostatic; and more than half met Society for Adolescent Health and Medicine admission criteria. Patients with available laboratory data demonstrated significant abnormalities consistent with malnutrition. Given that eating disorders are less likely to be detected in males, it is important to recognize early signs of malnutrition, particularly in those who present within the normal body mass index range for age.

Abstract 2468: Antibody targeting soluble NKG2D ligand sMIC induces regression of primary tumors and eliminates metastasis in multiple pre-clinical cancer models

Expression of the MHC I-chain related molecules A and B (MICA/B) on epithelial cell surface in response to transformation or DNA damage can signal the immune system of the abnormality and thus initiate active immune surveillance by Natural Killer (NK) cells and cytotoxicity T cells. We and others have shown that malignant tumor cells can shed MICA/B to down regulate NKG2D expression and negatively impact NK and CD8 T cell function in cancer patients. Increased tumor-specific shedding of cell surface NKG2D ligand, MHC I chain related molecule (MIC), is associated with advanced stage and metastasis in many types of epithelial cancer. High serum levels of soluble MIC (sMIC) insults the immune system not only by down-regulating NKG2D expression on natural killer (NK) cells and effector T cells but also perturbing NK cell peripheral maintenance. Whether sMIC is an effective cancer therapeutic target has not been addressed due to the lack of specific sMIC-blocking reagent and clinically relevant pre-clinical animal models. Using a “humanized” clinically relevant spontaneous prostate carcinoma TRAMP/MIC bi-transgenic mouse model and multiple engineered syngeneic transplantable tumor models, we unprecedentedly show that therapy with a sMIC-specific monoclonal antibody induced rapid regression of primary tumors and metastasis without systemic toxicity. The therapy revamped a myriad of anti-tumor immune responses including NK cell homeostatic renewal and function, CD4 T cells to Th1 and Th17 responses. Using the well-defined melanoma model, we further show that anti-sMIC therapy augments Pmel-1 antigen-specific CD8 T cell responses. Notably, depletion of NK cells mitigated the therapeutic effect of anti-sMIC antibody and the effector function of both CD4 and CD8 T cells. We conclude that sMIC is an effective therapeutic target to potentiate innate and adoptive immune responses against MIC+ malignancies.

Citation Format: Jennifer D. Wu, Fahmin Basher, Mark Rubinstein. Antibody targeting soluble NKG2D ligand sMIC induces regression of primary tumors and eliminates metastasis in multiple pre-clinical cancer models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2468. doi:10.1158/1538-7445.AM2015-2468

Anti-tumor response in T cells with CD8 independent high affinity TCR remains unaffected with aging (VAC11P.1009)

Advancement in adoptive cell therapy has led to the use of T cells engineered with tumor antigen reactive high affinity T cell receptors (TCR) in clinical trials. However, T cell engineered with anti-tumor epitope reactive TCR from an aged individual could affect the clinical outcome. In order to study if aging affects the functional efficacy of a CD8 independent high affinity TCR, we compared anti-tumor T cell response from young/old TCR transgenic h3T(human TIL derived Tyrosinase TCR) mice developed in our lab using TIL1383I TCR obtained from TILs of a melanoma patient. In vitro comparison of h3T T cells from old/young mice shows that antigen specific stimulation of the T cells from old mice resulted in an increased expression of CD25 and increased cytokine(IL2,IFNy,TNFa) secretion as compared to T cells from young mice. Remarkably, an overall decreased immune response from old hgp100 reactive T cells from Pmel transgenic mice was observed. Further, adoptively transferred h3T old/young splenocytes in vivo showed comparable control of human melanoma tumor 624-MEL established in a xenograft model. Further, aged T cells engineered with TIL1383I TCR and transferred to treat established melanoma in aged HLA-A2 recipient also showed efficient tumor control. These results demonstrate that aging does not dampen the recognition and activation of CD8+T cells bearing CD8 independent high affinity TCR and thus its broad immunotherapeutic potential in treating patients across all ages.

IL-12 priming and selective IL-2Rα engagement leads to enhanced CD8+ T cell persistence and anti-tumor immunity in the absence of lymphodepletion. (P1424)

Effective T cell therapy against metastatic cancer requires high frequencies of functional tumor-reactive T cells. However, achieving sustained and elevated levels of tumor-reactive T cells has proven difficult and usually requires highly toxic preconditioning of patients with radiation or chemotherapy to destroy host lymphocytes and suppressive cells. Using the mouse CD8+ T cell pmel-1 TCR transgenic model, we found that the combination of 1) in vitro IL-12-priming of donor T cells during activation and 2) the administration of IL-2/anti-IL-2 mAb complexes after adoptive transfer promoted the dramatic and systemic increase in tumor-reactive T cells in the absence of host lymphodepletion. Importantly, this combinatorial therapy led to the cure of over half of mice with established subcutaneous B16 tumors. Interestingly, while IL-2/anti-IL-2 mAb complexes synergized with ex vivo IL-12-priming, IL-15/sIL-15Rα-Fc complexes failed to mediate comparable synergistic activity despite signaling through the shared IL-2Rβγ subunits. Given that IL-12 priming strongly promotes the upregulation of the high affinity IL-2 receptor subunit, IL-2Rα, our results suggest that selective IL-2Rα engagement uniquely promotes T cell persistence and anti-tumor efficacy in the absence of lymphodepletion. Our findings underscore the importance of T cell polarizing conditions in dictating the requirement of adoptively transferred T cells for exogenous cytokine.

Total body irradiation enhances the anti-tumor efficacy of adoptively transferred CD8+ T cells stimulated ex vivo with IL-12 (162.41)

Stimulation of T cells with IL-12 improves their cytolytic capabilities and ability to persist in vivo. Despite these enhanced functional characteristics, we have found that these cells can only eliminate established tumors in mice preconditioned with cyclophosphamide (CTX). While this result demonstrates the importance of lymphodepletion in adoptive cell transfer (ACT) regimens, it is unclear if other forms of lymphodepletion would also enhance the efficacy of IL-12 primed cells. Since the most successful lymphodepleting regimen in metastatic melanoma clinical trials uses total body irradiation (TBI), we sought to determine if TBI preconditioning combined with ACT of IL-12 stimulated pmel-1 CD8+ T cells might be similarly synergistic. When we adoptively transferred pmel-1 CD8+ T cells primed with antigen and IL-12 (pmelIL-12) into mice preconditioned with TBI, we saw significantly elevated numbers of donor T cells compared with mice adoptively transferred with pmel-1 CD8+ T cells primed with antigen alone (pmelsham). Importantly, the increase in donor T cell numbers seen with the combination of TBI + pmelIL-12 translated to significant delays in melanoma outgrowth. Strikingly, the addition of pmelsham to TBI preconditioning resulted in no improvement in anti-tumor immunity compared to TBI alone. Thus both CTX and TBI host preconditioning greatly enhance the anti-tumor efficacy of transferred T-cells stimulated with IL-12.

Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs. Thus, individuals with D4 receptor polymorphisms might show enhanced reinforcing responses to MP and AMPH and attenuated locomotor response to AMPH.

Long-term cytokine therapy with IL-15/IL-15Rα complexes leads to impaired NK cell function (131.11)

Immunotherapies targeting effector lymphocytes are promising approaches for the treatment of cancer and infectious diseases. One such approach employs IL-15/IL-15Rα complexes which are considerably more potent than IL-15 in expanding cytotoxic lymphocytes including NK and CD8 T cells. Recent studies demonstrated that short-term treatment with IL-15/IL-15Rα complexes is highly effective in driving a transient but substantial reduction in tumor burden via immune-mediated mechanisms whereas continuous cytokine therapy improves survival only modestly and fails to control tumor outgrowth. Given the limited efficacy of long-term therapy, we sought to investigate the impact of continuous in vivo stimulation with IL-15/IL-15Rα complexes on NK and CD8 T cells in tumor-free mice. Long-term treatment with IL-15/IL-15Rα complexes triggered massive expansion of NK and CD8 T cells. Strikingly, however, NK cells exhibited marked defects in activation, IFNγ production, degranulation, and cytotoxicity whereas CD8 T cells showed enhanced functional capacity. Additionally, continuous treatment generated a suppressive environment for transferred naïve NK and CD8 T cells and resulted in accumulation of CD11b+Gr1+ cells. The mechanistic basis for NK cell dysfunction upon chronic stimualation with IL-15/IL-15Ra complexes will be discussed. Our results have important clinical implications for the design of immunotherapies and vaccines using multiple doses of immunostimulatory agents.

Laryngeal epithelial thickness: a comparison between optical coherence tomography and histology

OBJECTIVES

Optical coherence tomography, an imaging modality using near-infrared light, produces cross-sectional tissue images with a lateral pixel resolution of 10 microm. However, normative data is first needed on epithelial thickness for lesion characterisation, and, to date, little exists. The purpose of our study is to measure normal laryngeal epithelial thickness by in vivo optical coherence tomography, and compare these values to those obtained from fixed ex-vivo laryngectomy specimens.

DESIGN AND SETTING

Prospective at a single medical center in California, United States.

PARTICIPANTS

A total of 116 patients undergoing operative endoscopy.

MAIN OUTCOME MEASURES

Optical coherence tomography images of clinically normal laryngeal subsites were selected. Calibrated measurements of epithelial thickness at various laryngeal subsites were recorded. Measurements of epithelial thickness from corresponding areas were obtained using optical micrometry on histologically normal regions of 15 total laryngectomy specimens. Descriptive statistics were performed.

RESULTS

Mean epithelial optical coherence tomography thicknesses were: true vocal cords (81 microm), false vocal cords (78 microm), subglottis (61 microm), aryepiglottic folds (111 microm), laryngeal epiglottis (116 microm) and lingual epiglottis (170 microm). Epithelial thicknesses in fixed tissues were: true vocal cords (103 microm), false vocal cords (79 microm), aryepiglottic folds (205 microm) subglottis (61 microm), laryngeal epiglottis (38 microm) and lingual epiglottis (130 microm).

CONCLUSIONS

Optical coherence tomography does not have the artifacts associated with conventional histologic techniques. The inevitable development of office-based optical coherence tomography devices will increase the precision of laryngeal measurements and contribute to the clinical application of this technology in diagnosing laryngeal disease.

Role of dopamine D1-like receptors in methamphetamine locomotor responses of D2 receptor knockout mice

Behavioral sensitization to psychostimulants manifests as an increased locomotor response with repeated administration. Dopamine systems are accepted to play a fundamental role in sensitization, but the role of specific dopamine receptor subtypes has not been completely defined. This study used the combination of dopamine D2 receptor-deficient mice and a D1-like antagonist to examine dopamine D1 and D2 receptor involvement in acute and sensitized locomotor responses to methamphetamine. Absence of the dopamine D2 receptor resulted in attenuation of the acute stimulant effects of methamphetamine. Mutant and wild-type mice exhibited sensitization that lasted longer within the time period of the challenge test in the mutant animals. Pretreatment with the D1-like receptor antagonist SCH 23390 produced more potent reductions in the acute and sensitized locomotor responses to methamphetamine in D2 receptor-deficient mice than in wild-type mice; however, the expression of locomotor sensitization when challenged with methamphetamine alone was equivalently attenuated by previous treatment with SCH 23390. These data suggest that dopamine D2 receptors play a key role in the acute stimulant and sensitizing effects of methamphetamine and act in concert with D1-like receptors to influence the acquisition of methamphetamine-induced behavioral sensitization, traits that may influence continued methamphetamine use.

Unexpected power-law stress relaxation of entangled ring polymers

After many years of intense research, most aspects of the motion of entangled polymers have been understood. Long linear and branched polymers have a characteristic entanglement plateau and their stress relaxes by chain reptation or branch retraction, respectively. In both mechanisms, the presence of chain ends is essential. But how do entangled polymers without ends relax their stress? Using properly purified high-molar-mass ring polymers, we demonstrate that these materials exhibit self-similar dynamics, yielding a power-law stress relaxation. However, trace amounts of linear chains at a concentration almost two decades below their overlap cause an enhanced mechanical response. An entanglement plateau is recovered at higher concentrations of linear chains. These results constitute an important step towards solving an outstanding problem of polymer science and are useful for manipulating properties of materials ranging from DNA to polycarbonate. They also provide possible directions for tuning the rheology of entangled polymers.

Interleukin-18 binding protein in the sera of patients with Wegener's granulomatosis

INTRODUCTION

In the present study, we examined the levels of the pro-inflammatory cytokine IL-18 and its natural inhibitor, the IL-18 binding protein (IL-18BP), in sera of Wegener's granulomatosis (WG) patients at various stages of the disease.

PATIENTS AND METHODS

Sera from eight consecutive biopsy-proven systemic WG patients (four men and four women; age at diagnosis 58.4 +/- 13.8 years) were obtained longitudinally with a follow-up period of 55.2 +/- 30 months. Sera obtained from 50 healthy subjects were used as controls.

RESULTS AND DISCUSSION

Serum levels of IL-18, IL-18BP, and free IL-18 obtained during an active phase of the disease (Birmingham Vasculitis Activity Score, BVAS > 10) were more than twofold higher than levels in the same patients during inactive disease stages (BVAS < 5; P < 0.002; P < 0.006, and P < 0.03 for IL-18, IL-18BP, and free IL-18, respectively). During inactive stages, the levels of these markers were comparable to those of healthy controls. The elevated levels of IL-18 and IL-18BP in sera during active stages of disease suggest a possible role in the pathogenesis and course of the WG.

CONCLUSION

Despite the elevated IL-18BP levels during active disease, free IL-18 remained higher than in the inactive disease stages, suggesting a potential benefit of administration of exogenous IL-18BP as a novel therapeutic approach for active WG.

Patients' attitudes towards trainee surgeons performing cataract surgery at a teaching hospital

AIM

To evaluate patients' preferences of surgeon to perform their cataract surgery if given a choice between consultant and trainee.

METHODS

A questionnaire based patient satisfaction survey was conducted in a large University Teaching Hospital in the UK. One hundred and eighty patients undergoing first eye cataract surgery between January and March 2006 were asked a number of set questions on their preferences regarding the surgeon performing the operation. Primary outcome measure was the patient's preference for who would perform their cataract surgery (consultant or trainee).

RESULTS

Overall, 126 (70%) accepted that trainee surgeons should operate as part of their training. Only 102 (81%) of these (57% of the total) would be happy to be operated on themselves by a supervised surgical trainee. Ninety-eight (78%) patients objected to being operated on by a trainee if they were to be unsupervised. One hundred and forty-two (79%) patients stated they would choose to wait longer for their surgery if it meant that a consultant would perform their operation. This preference was held significantly more strongly among patients who had been listed for surgery from a consultant's clinic rather than from the pooled 'cataract clinic' (P=0.048). One hundred and forty-four (80%) patients thought they should be told the name and designation of the surgeon who was to perform their operation.

CONCLUSIONS

Patients undergoing their first cataract procedure appear to have a preference for their named consultant to perform their surgery. If 'patient choice' extends to the choice of operating surgeon, then there are clear implications for the training of future UK ophthalmologists.

Prevention of potential errors in resuscitation medications orders by means of a computerised physician order entry in paediatric critical care

INTRODUCTION

Computerised physician order entry with clinical decision support system (CPOE+CDSS) is an important tool in attempting to reduce medication errors. The objective of this study was to evaluate the impact of a CPOE+CDSS on (1) the frequency of errors in ordering resuscitation (CPR) medications and (2) the time for printing out the order form, in a paediatric critical care department (PCCD).

METHODS

SETTING

An 18-bed PCCD in a tertiary-care children's hospital.

DESIGN

Prospective cohort study.

MEASURES

Compilation and comparison of number of errors and time to fill in forms before and after implementation of CPOE+CDSS. Time to fill in conventional, simulated and CPOE forms was measured and compared.

RESULTS

There were three reported incidents of errors among 13,124 CPR medications orders during the year preceding implementation of CPOE+CDSS. These represent errors that escaped the triple check by three independent staff members. There were no errors after CPOE+CDSS was implemented (100% error reduction for 46,970 orders). Time to completion of drug forms dropped from 14 min 42 s to 2 min 14s (p < 0.001).

CONCLUSIONS

CPOE+CDSS completely eliminated errors in filling in the forms and significantly reduced time to completing the form.

Simultaneous deletion of MyD88 and Trif delays major histocompatibility and minor antigen mismatch allograft rejection

This study investigated whether ablation of all Toll-like receptor (TLR) signaling influenced skin allograft rejection across a complete donor/recipient mismatch of major histocompatibility and minor antigens. We predicted that defective TLR signaling would interfere with the activation of donor dendritic cells (DC) in vivo, by preventing DC activation in response to local environmental ("danger") signals. The ablation of TLR signals would therefore be associated with decreased activation of host T cells and decreased graft rejection. Using mice with deletions of the proximal TLR adapter proteins MyD88 or Trif, and those with simultaneous deletions of both MyD88 and Trif, we demonstrated that absence of both MyD88 and Trif adapter proteins prolonged skin graft survival, notably across a complete MHC and minor antigen barrier. Absence of MyD88 or Trif alone only had a modest effect on graft survival across even a minor MHC antigen difference. Prolonged survival of skin grafts from mice deficient in both MyD88 and Trif was associated with diminished migration of donor cells to draining lymph nodes and, subsequently, with delayed infiltration of host T cells into the grafted tissue.