[Clinical features and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody associated acute disseminated encephalomyelitis]

Objective: To analyze the clinical features, outcome and prognosis of pediatric myelin oligodendrocyte glycoprotein (MOG) antibody associated acute disseminated encephalomyelitis (ADEM), and provide evidence for improving the diagnosis and treatment of this disease. Methods: This study involved 30 MOG antibody-associated ADEM patients in the Department of Neurology, Guangzhou Women and Children's Medical Center. Patients' clinical information were analyzed. Results: The mean onset age was (5.2±3.3) years old, the ration of male to female was 16∶14. Fifty percent of these patients had a history of precede infection or vaccination before onset. Encephalopathy and seizures were the most common clinical manifestations, followed by movement disorder. In addition, some patients had other positive autoantibodies. Brain Magnetic resonance imaging (MRI) showed extensive, asymmetrical, indefinite large patchy lesions in bilateral cortical and subcortical areas and the spinal cord was characterized by long segmental myelitis. In acute attack, the patients had a good response to corticosteroid combined immunoglobulin therapy. Most of these patients had a good prognosis and recurrence rate was about 20%. Conclusions: The onset age of MOG antibody-associated ADEM is around 5 years old. Encephalopathy and seizures were the most common clinical manifestations. Most patients have a good response to corticosteroid combined immunoglobulin therapy. Some patients may have a recurrent disease course.

Gm6377 suppressed SP 2/0 xenograft tumor by down-regulating Myc transcription

PURPOSE

Disturbed process of B-cell differentiation into plasmablasts (PBs)/plasma cells (PCs) is involved in multiple myeloma (MM). New strategies will be required to eliminate the MM cell clone for a long-term disease control. Because of its PB-like characteristics, the mus musculus myeloma SP 2/0 cell line was used in this study to search novel targets for PBs/PCs.

METHODS/PATIENTS

Affymetrix microarrays and RNA-sequencing assays were used to search a novel different molecule (Gm6377) between PBs/PCs and mature B cells. Cell counting kit-8 (CCK8), flow cytometry (FACS), xenograft mouse model, and the luciferase reporter system were used to assess the effect of Gm6377 on SP 2/0 cell proliferation, cell cycle, tumor growth, and Myc promoter activation, respectively.

RESULTS

We found that B cells expressed a high level of Gm6377 mRNA, whereas Gm6377 mRNA was decreased in PCs. In addition, SP 2/0 cells also expressed low levels of Gm6377 mRNA. Critically, Gm6377 overexpression suppressed SP 2/0 cell proliferation but not cell cycle. Furthermore, Gm6377 overexpression suppressed tumor progression in the SP 2/0 xenograft mouse model. Finally, we found that Gm6377 suppressed SP 2/0 cell proliferation by reducing the activation of the Myc promoter.

CONCLUSIONS

These results suggest that Gm6377 suppresses myeloma SP 2/0 cell growth by suppressing Myc. Thus, modulation of Gm6377 may be a potential therapeutic way to treat MM.

The extremely low energy cost of biosynthesis in holometabolous insect larvae

The metabolic cost of growth, which quantifies the amount of energy required to synthesize a unit of biomass, is an important component of an animal's ontogenetic energy budget. Here we investigated this quantity as well as other energy budget variables of the larvae of a holometabolous insect species, Vanessa cardui (painted lady). We found that the high growth rate of this caterpillar cannot be explained by its metabolic rate and the percentage of the metabolic energy allocated to growth; the key to understanding its fast growth is the extremely low cost of growth, 336 Joules/gram of dry mass. The metabolic cost of growth in caterpillars is 15-65 times lower than that of the endothermic and ectothermic species investigated in previous studies. Our results suggest that the low cost cannot be attributed to its body composition, diet composition, or body size. To explain the "cheap price" of growth in caterpillars, we assumed that a high metabolic cost for biosynthesis resulted in a high "quality" of cells, which have fewer errors during biosynthesis and higher resistance to stressors. Considering the life history of the caterpillars, i.e., tissue disintegration during metamorphosis and a short developmental period and lifespan, we hypothesized that an energy budget that allocates a large amount of energy to biosynthesizing high quality cells would be selected against in this species. As a preliminary test of this hypothesis, we estimated the metabolic cost of growth in larvae of Manduca sexta (tobacco hornworm) and nymphs of Blatta lateralis (Turkestan cockroach). The preliminary data supported our hypothesis.

Career decision-making self-efficacy mediates the effect of social support on career adaptability: A longitudinal study

In constructivist approaches to research on career adaptability it has been conceptualized that the development of one’s career is formed from the interplay between the individual and the environment. In this study we utilized structural equation modeling analysis of longitudinal data obtained from 145 Chinese undergraduate students to examine the effects of social support and career decision-making self-efficacy on career adaptability. Our results provided important evidence regarding the effects of career decision-making self-efficacy, which functions as a significant mediator of the effects of social support on career adaptability. We provide integrative conclusions for explaining the relationships between the environment, the individual, and the individual’s career outcome, and have enriched constructivist theories of careers, providing implications for counseling and practice.

Ultra-deep next-generation sequencing of plasma cell-free DNA in patients with advanced lung cancers: results from the Actionable Genome Consortium

BACKGROUND

Noninvasive genotyping using plasma cell-free DNA (cfDNA) has the potential to obviate the need for some invasive biopsies in cancer patients while also elucidating disease heterogeneity. We sought to develop an ultra-deep plasma next-generation sequencing (NGS) assay for patients with non-small-cell lung cancers (NSCLC) that could detect targetable oncogenic drivers and resistance mutations in patients where tissue biopsy failed to identify an actionable alteration.

PATIENTS AND METHODS

Plasma was prospectively collected from patients with advanced, progressive NSCLC. We carried out ultra-deep NGS using cfDNA extracted from plasma and matched white blood cells using a hybrid capture panel covering 37 lung cancer-related genes sequenced to 50 000× raw target coverage filtering somatic mutations attributable to clonal hematopoiesis. Clinical sensitivity and specificity for plasma detection of known oncogenic drivers were calculated and compared with tissue genotyping results. Orthogonal ddPCR validation was carried out in a subset of cases.

RESULTS

In 127 assessable patients, plasma NGS detected driver mutations with variant allele fractions ranging from 0.14% to 52%. Plasma ddPCR for EGFR or KRAS mutations revealed findings nearly identical to those of plasma NGS in 21 of 22 patients, with high concordance of variant allele fraction (r = 0.98). Blinded to tissue genotype, plasma NGS sensitivity for de novo plasma detection of known oncogenic drivers was 75% (68/91). Specificity of plasma NGS in those who were driver-negative by tissue NGS was 100% (19/19). In 17 patients with tumor tissue deemed insufficient for genotyping, plasma NGS identified four KRAS mutations. In 23 EGFR mutant cases with acquired resistance to targeted therapy, plasma NGS detected potential resistance mechanisms, including EGFR T790M and C797S mutations and ERBB2 amplification.

CONCLUSIONS

Ultra-deep plasma NGS with clonal hematopoiesis filtering resulted in de novo detection of targetable oncogenic drivers and resistance mechanisms in patients with NSCLC, including when tissue biopsy was inadequate for genotyping.

The Survival Processing Advantage of Face: The Memorization of the (Un)Trustworthy Face Contributes More to Survival Adaptation

Researchers have found that compared with other existing conditions (e.g., pleasantness), information relevant to survival produced a higher rate of retrieval; this effect is known as the survival processing advantage (SPA). Previous experiments have examined that the advantage of memory can be extended to some different types of visual pictorial material, such as pictures and short video clips, but there were some arguments for whether face stimulus could be seen as a boundary condition of SPA. The current work explores whether there is a mnemonic advantage to different trustworthiness of face for human adaptation. In two experiments, we manipulated the facial trustworthiness (untrustworthy, neutral, and trustworthy), which is believed to provide information regarding survival decisions. Participants were asked to predict their avoidance or approach response tendency, when encountering strangers (represented by three classified faces of trustworthiness) in a survival scenario and the control scenario. The final surprise memory tests revealed that it was better to recognize both the trustworthy faces and untrustworthy faces, when the task was related to survival. Experiment 1 demonstrated the existence of a SPA in the bipolarity of facial untrustworthiness and trustworthiness. In Experiment 2, we replicated the SPA of trustworthy and untrustworthy face recognitions using a matched design, where we found this kind of memory benefits only in recognition tasks but not in source memory tasks. These results extend the generality of SPAs to face domain.

[Prognostic analysis of allogeneic hematopoietic stem-cell transplantation in 47 patients with acute myeloid leukemia and MLL rearrangement]

目的

研究混合谱系白血病（MLL）基因重排阳性急性髓系白血病（AML）患者行异基因造血干细胞移植（allo-HSCT）的预后特点。

方法

回顾性分析2009年9月至2016年5月于苏州大学附属第一医院行allo-HSCT的47例MLL基因重排阳性AML患者的临床资料。

结果

全部47例MLL重排阳性AML患者中男24例，女23例，中位年龄30（15~58）岁，M₄/M₅共36例（76.6%）。移植后2年总生存（OS）率为（64.4±8.4）%，无病生存（DFS）率为（47.3±9.3）%，复发率为41.0%，移植相关死亡率为17.9%。45例患者检出11q23易位，2例染色体核型正常患者检出MLL部分串联重复。t（6;11）组（16例）、t（9;11）组（15例）、其他类型组（16例）的2年OS率差异无统计学意义（χ²=1.509，P=0.472）。多因素分析显示，移植时年龄>45岁是影响OS的独立危险因素[HR=4.454（95%CI 1.314~15.099），P=0.016]，移植前MRD阳性是影响患者DFS[HR=4.236（95%CI 1.238~14.495），P=0.021]、复发[HR=5.491（95% CI 1.371~21.995），P=0.016]的独立不良预后因素，移植前疾病处于非CR状态患者移植相关死亡风险增高[HR=10.370（95%CI 1.043~103.110），P=0.046]。

结论

移植时年龄>45岁、移植前疾病处于非CR状态、移植前MRD阳性为影响allo-HSCT治疗MLL基因重排阳性AML患者预后的危险因素。

Modeling of Li diffusion in nanocrystalline Li-Si anode material

To quantify the Li diffusion behavior in nanocrystalline anode materials for lithium-ion batteries (LIBs), a hybrid model of the first principles calculation and diffusion kinetics was developed. The dependence of the Li diffusion on the electronic structure, solute concentration, grain size and temperature was described for the nanocrystalline Li-Si system. In contrast to conventional polycrystalline materials in which the activation barrier for Li diffusion decreases with the increase of concentration before amorphization, there exists a coordination effect of the solute concentration and grain size on the Li diffusion in nanocrystalline materials. A maximum diffusion coefficient can be obtained in the nanocrystalline Li-Si by a combination of the concentration and grain size, which is increased by two orders of magnitude from that in the coarse-grained counterpart. The present work advanced the understanding of the Li diffusion mechanisms during lithiation/delithiation of LIBs and may facilitate the development of nanocrystalline anode materials.

Changes in nitric oxide levels and their relationship with callose deposition during the interaction between soybean and Soybean mosaic virus

The present study aimed to investigate changes in nitric oxide (NO) level and its relationship with callose deposition during the interaction between soybean and Soybean mosaic virus (SMV). Soybean cv. 'Jidou 7' and SMV strains N3 and SC-8 were used to constitute incompatible and compatible combinations. Intracellular NO was labelled with the NO-specific fluorescence probe DAF-FM DA. Confocal laser scanning microscopy (CLSM) was then used to observe changes in NO production during SMV infection-induced defence responses in soybean. The results showed NO fluorescence increased rapidly at 2-72 h post-inoculation, peaked at 72 h and then decreased in the incompatible combination. However, in the compatible combination, extremely weak NO fluorescence appeared in the early stage (2-24 h) post-inoculation, but was not observed thereafter. Injections of the NO scavenger c-PTIO prior to inoculation postponed the onset of NO production to 48 or 72 h post-inoculation. The same occurred when injections of NR or NOS inhibitors were applied prior to inoculation. The observation of callose fluorescence in the incompatible combination revealed that either the elimination or reduction of NO in the early stage led to a delay in callose formation, enabling the virus to cause systemic infection. Together with our previous findings, this study indicates that viral infection could induce NO production and callose deposition during the incompatible interaction between soybean and SMV. The production of NO involves NR and NOS enzymatic pathways, and NO mediates the process of callose deposition at plasmodesmata.

Trends of Activities of Daily Living Disability Situation and Association with Chronic Conditions among Elderly Aged 80 Years and Over in China

OBJECTIVES

In China, few studies reported the disability situation and the association between disabilities with chronic conditions in aged people. This study investigates the cross-sectional trends of prevalence and severity of activities of daily living disability (ADL) in Chinese oldest-old people from 1998 to 2008, and identified the potential risk factors of disability.

DESIGN

A combination of population-based longitudinal prospective study and probabilistically sampling cross-sectional studies.

SETTING

The Chinese Longitudinal Healthy Longevity Survey (CLHLS) was based on a random sampling of aged people from twenty-two provinces in China.

PARTICIPANTS

A total of 52,667 participants aged from 80 years old to 105 years old sampled in the year of 1998 (n=8,768), 2000 (n=10,940), 2002 (n=10,905), 2005 (n=10,396) and 2008 (n=11,658) were analyzed respectively.

RESULTS

The prevalence of ADL disability decreased from the year of 1998 (18%) to 2008 (12%). The disability prevalence significantly increased in 2002 and decreased in 2008 (P<0.001) in total participants than the year of 1998. The prevalence trends of low ADL disability level were almost identical with that of the total ADL disability. Stroke/cerebrovascular disease (CVD) and cognitive impairment were the strongest risk factors of disability. Vision impairment became less associated with ADL disability (P=0.045), while the association between multimorbidity and ADL disability became stronger (P=0.033).

CONCLUSIONS

The prevalence of ADL disability declined among the oldest-old population in China from the year of 1998 to 2008 without obeying a linear pattern. Temporal trends of ADL disability mainly attributed to the change of low disability level prevalence. Stroke/CVD and cognitive impairment were the most common risk factors of disability. Vision impairment caused disability has become less common, while risks of multimorbidity related disability increased.

[Mass spectrometry combined with gene analysis for prenatal diagnosis of glutaric acidemia type Ⅰ]

Objective: To investigate the value of amniotic fluid metabolite detection by mass spectrometry combined with gene mutation analysis in the prenatal diagnosis of glutaric acidemia type Ⅰ (GA-Ⅰ). Method: From January 2009 to December 2016, Department of Pediatric Endocrinology and Genetic, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine carried out prenatal diagnosis for 24 cases of pregnant women with GA-Ⅰproband. 24 pregnant women without organic acidemia proband for conventional prenatal diagnosis at the same period were used as the control group. The pregnant women of the two groups had the amniocentesis at 16 to 20 weeks of gestation.The levels of glutaryl carnitine (C5DC) and octanoylcarnitine (C8) in amniotic fluid were detected by tandem mass spectrometry, and the levels of glutaric acid was determined by gas chromatography-mass spectrometry. All the amniotic fluid cells underwent GCDH gene testing. Result: A total of 4 cases of fetuses were diagnosed by gene mutation analysis combined with mass spectrometry detection, the levels of C5DC (1.58(0.89-2.85) μmol/L), C5DC/C8 (19.74(12.40-25.93))and glutaric acid (129.96 (90.09-66.02) mmol/mol Cr) were significantly higher than the upper limit of the reference, of which in one case with the proband only on mutation was detected, and in the amniotic fluid cells also only one mutation was detected, the diagnosis was made according to the significantly increased levels of amniotic fluid C5DC, C5DC/C8 and glutaric acid. Twenty cases of fetuses were identified as non-GA-Ⅰchildren, of whom in 2 cases of proband only one mutation was detected, and also in amniotic fluid cells one mutation was detected, in 2 cases the diagnosis was excluded because the normal levels of C5DC, C5DC/C8 and glutaric acid. There were 2 cases whose levels of C5DC or glutaric acid were slightly higher than the upper limit of the reference, but the diagnosis was excluded according to genetic testing. Conclusion: Prenatal diagnosis cannot be made by gene analysis when the proband mutation is not clear, and it cannot determine whether the fetus is patient when the mass spectrometry detection of amniotic fluid metabolite is mildly abnormal, while mass spectrometry detection of amniotic fluid C5DC, C5DC/C8 and glutaric acid levels combined with GCDH gene analysis can make up the deficiencies, and make the prenatal diagnosis of GA-Ⅰ more reliably.

Interleukin (IL)-39 [IL-23p19/Epstein-Barr virus-induced 3 (Ebi3)] induces differentiation/expansion of neutrophils in lupus-prone mice

Interleukin (IL)-12 family cytokines play critical roles in autoimmune diseases. Our previous study has shown that IL-23p19 and Epstein-Barr virus-induced 3 (Ebi3) form a new IL-12 family heterodimer, IL-23p19/Ebi3, termed IL-39, and knock-down of p19 or Ebi3 reduced diseases by transferred GL7⁺ B cells in lupus-prone mice. In the present study, we explore further the possible effect of IL-39 on murine lupus. We found that IL-39 in vitro and in vivo induces differentiation and/or expansion of neutrophils. GL7⁺ B cells up-regulated neutrophils by secreting IL-39, whereas IL-39-deficient GL7⁺ B cells lost the capacity to up-regulate neutrophils in lupus-prone mice and homozygous CD19^cre (CD19-deficient) mice. Finally, we found that IL-39-induced neutrophils had a positive feedback on IL-39 expression in activated B cells by secreting B cell activation factor (BAFF). Taken together, our results suggest that IL-39 induces differentiation and/or expansion of neutrophils in lupus-prone mice.

MicroRNA-320 regulates matrix metalloproteinase-13 expression in chondrogenesis and interleukin-1β-induced chondrocyte responses

OBJECTIVE

Metalloproteinases (MMPs) are key regulators of osteoarthritis (OA) and collagen degradation and have been shown to participate in endochondral ossification. The aim of this study was to determine whether microRNA-320 (miR-320) regulates the expression of MMP-13 in chondrogenesis and inflammation.

EXPERIMENTAL DESIGN

miR-320 expression was assessed in vitro, in the ATDC5 cell model of chondrogenesis and in interleukin-1β (IL-1β)-treated primary mouse chondrocytes (PMCs), and in vivo, in normal and OA human cartilage by in situ hybridization. ATDC5 and PMCs were transfected with miR-320 or its antisense inhibitor (anti-miR-320), respectively. The roles of activated MAP kinases (MAPK) and NF-κB were evaluated by using specific inhibitors. Direct interaction between miR-320 and its putative binding site in the 3'-untranslated region (3'-UTR) of Mmp-13 mRNA was confirmed by the luciferase reporter assay.

RESULTS

miR-320 expression was elevated in chondrogenic and hypertrophic ATDC5, while significantly reduced in OA cartilage compared with normal cartilage. Stimulation with IL-1β led to a significant reduction in miR-320 expression in PMCs. Upregulation of MMP-13 expression was correlated with downregulation of miR-320 expression in both PMCs and ATDC5. Overexpression of miR-320 suppressed the activity of a reporter construct containing the 3'-UTR and inhibited MMP-13 expression in both ATDC5 and IL-1β-treated PMCs, while treatment with anti-miR-320 enhanced MMP-13 expression. NF-κB and MAPK activation downregulated miR-320 expression.

CONCLUSION

Cartilage development and homeostasis are influenced by miR-320, which directly targets MMP-13 and regulates chondrogenesis and the IL-1β-stimulated catabolic effect in mouse chondrocytes.

Abstract P5-01-06: 18F-radiolabeled PARP-1 inhibitor uptake as a marker of PARP-1 activity in breast cancer

Objectives: The nuclear enzyme PARP-1 plays a central role in sensing DNA damage and facilitating repair. Tumors with BRCA1/2 mutations are highly dependent on PARP-1 as an alternative mechanism for DNA repair, and PARP inhibitors generate synthetic lethality in tumors with BRCA mutations, resulting in cell cycle arrest and apoptosis. Zhou et al. recently synthesized an 18F-labeled PARP-1 inhibitor (18F-FluorThanatrace) for PET, and demonstrated high specific tracer uptake in a xenograft model of breast cancer (Zhou, Bioorg Med Chem, 22:1700, 2014). The current study seeks to quantify the relationship between 18F-FluorThanatrace binding (both in vitro and on PET imaging of human tumor xenografts) and the level of constitutively active PARP-1, using multiple human breast cancer cell lines, including a BRCA1 defective line.

Methods: BRCA1 defective HCC1937, triple negative MDA-MB-231, and luminal A MCF-7 human breast cancer lines were assessed for constitutive PARP-1 activity via a chemiluminescent ELISA assay for PAR and by Western blot. The same cell lines were incubated with 18F-FluorThanatrace over various time increments, and tracer uptake was assayed via a gamma counter. Specificity of tracer binding was verified via co-incubation with competitive inhibitor Olaparib, and specific tracer uptake was calculated as the difference between uptake with and without Olaparib. Specific tracer uptake was compared to levels of constitutive PARP-1 activity in all cell lines. In addition, HCC1937 and MDA-MB-231 xenograft tumor models were imaged via 18F-FluorThanatrace-PET/CT, and PET uptake was correlated with PARP-1 activity.

Results: BRCA1-defective HCC1937 had higher constitutive PARP-1 activity than cell lines with intact BRCA1. In vitro levels of 18F-FluorThanatrace uptake correlated with constitutive PARP-1 activity across cell lines. In addition, 18F-FluorThanatrace measured by PET in xenograft breast cancer tumor models correlated with constitutive PARP-1 activity.

Conclusions: Tumor uptake of 18F-FluorThanatrace, both in vitro and on PET imaging of xenograft tumor models, quantitatively reflects differences in PARP-1 activity across different breast cancer cell lines, including BRCA1 defective. This motivates further studies of 18F-FluorThanatrace as an in vivo measure of PARP-1 activity and possibly as a predictive marker for PARP-1 therapy in patients, including those with BRCA1/2 mutations.

Citation Format: Edmonds CE, Lieberman BP, Xu K, Zeng C, Makvandi M, Li S, Hou C, Lee H, Greenberg RA, Mankoff DA, Mach RH. 18F-radiolabeled PARP-1 inhibitor uptake as a marker of PARP-1 activity in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-06.

Social Identity: The Cause of Distinction Between Group-Reference and Self-Reference Effects

We used a subliminal priming procedure to explore whether or not the intensity of identity salience facilitates the advantage of memory in distinguishing between the strength of the group-reference effect and that of the self-reference effect. In Experiment 1 (N = 124), participants were primed with in-group, out-group, or combined salience conditions before encoding adjectives with reference to the in-group and out-group, and were then subsequently given a surprise free-recall test. These results showed that the intensity of social identity could predict the memory advantage of group-reference tasks; moreover, the memory effect of group-reference tasks was strongest in the combined salience condition compared with in-group or out-group salience alone. In Experiment 2 (N = 81), we used different referential conditions and found that the intensity of social identity changed with identity salience and was a possible cause of differences between the intensity of the group-reference effect and that of the self-reference effect.

Plasma soluble Tim-3 emerges as an inhibitor in sepsis: sepsis contrary to membrane Tim-3 on monocytes

Immune dysfunction is the main characteristic of sepsis. T cell Ig and mucin domain protein 3 (Tim-3) on the monocytes has been reported to promote immune homeostasis during sepsis, but the influences of plasm soluble Tim-3 (sTim-3) on the immune system during sepsis remain unknown. Here, 100 patients with different severities of sepsis (40 sepsis, 42 severe sepsis, and 18 septic shock) were enrolled in this study. The Tim-3 and human leukocyte antigen-DR (HLA-DR) on the circulating monocytes were detected using flow cytometry. Plasma sTim-3 was detected by enzyme-linked immunosorbent assay. Inflammatory factors and two kinds of A disintegrin and metalloprotease (ADAM) - ADAM10 and ADAM17 were assessed. The Tim-3 and HLA-DR on the monocytes decreased with increasing sepsis severity. The sTim-3 was reduced in the sepsis and severe sepsis patients but was elevated in the septic shock patients who exhibited significant immunosuppression as predicted by HLA-DR. sTim-3 levels were negatively correlated with IL-12 and TNF-α. ADAM10 and ADAM17, sheddases of Tim-3, exhibited trends toward elevations in the septic shock group. In conclusion, sTim-3 was involved in the development of sepsis. The homeostasis-promoting role of the Tim-3 on the monocytes was disrupted, while the inhibitory role of sTim-3 emerged during sepsis-induced immunosuppression.

Blockade of the T cell immunoglobulin and mucin domain protein 3 pathway exacerbates sepsis-induced immune deviation and immunosuppression

Sepsis is a life-threatening condition, but the pathophysiological basis and biomarkers for the monitoring of sepsis and as targets for therapy remain to be determined. We have shown previously that T cell immunoglobulin and mucin domain protein 3 (Tim-3), a negative immune regulator, is involved in the physiopathology of sepsis, but the underlying mechanisms remain unclear. In the present study, we showed that Tim-3 signalling modulated the response patterns of both macrophages and T helper cells in sepsis. Blockade of the Tim-3 pathway exacerbated sepsis-induced proinflammatory macrophage responses and lymphocyte apoptosis during the early phase of sepsis, and enhanced the shift to anti-inflammatory responses for both macrophages and T helper cells during the late phase of sepsis. Tim-3 signalling was found to regulate CD80 and CD86 expression on macrophages both in vivo and in vitro. Co-culture of T cells with Tim-3 knock-down macrophages led to a biased T helper type 2 (Th2) response, partially explaining how Tim-3 signalling shapes inflammation patterns in vivo. Further studies on this pathway might shed new light on the pathogenesis of sepsis and suggest new approaches for intervention.

Abstract B48: Preclinical development of meta-[211At] astatobenzylguanidine ([211At] MABG) targeted radiotherapy for neuroblastoma

Background: Neuroblastoma (NB) is a radiosensitive malignancy accounting for 10% of childhood cancer mortality. NB cells frequently express the norepinephrine transporter (NET) providing a specific mechanism for uptake of NET-ligands. Meta-[131I]iodobenzylguanidine ([131I]MIBG) is a NET-ligand radiotherapeutic that shows single-agent response rates in refractory NB of 40-50%. However, due to the long path lengths of 131 I beta (β)-emission, and low biological effectiveness compared to alpha (α)-emitting radionuclides, [131I]MIBG is generally not curative, perhaps due to non-targeting of isolated circulating tumor cells. Here we report our efforts to optimize NET-targeted radiotherapy by developing relevant preclinical models of refractory NB for α-particle therapeutic [211At] MABG therapy.

Methods: We first determined NET (SLC6A2) mRNA and protein expression in 35 human NB cell lines using quantitative RT-PCR and western blotting. We then chose 5 lines with absent to intermediate levels of native NET expression (NB1691, SKNSH, IMR5, NLF and SKNBE2) for dual forced overexpression of human NET and luciferase cDNAs. We used [125I]MIBG for cell-based uptake assays in all isogenic pairs and biodistribution experiments in athymic mice bearing three separate NET-transduced xenografts (N=5 per cell line). These cell lines were also treated with [131I]MIBG and/or external beam radiation (XRT) followed by multi-log cytotoxicity assays. Therapeutic trials of [131I]MIBG (25 mCi/kg) in NB1691 subcutaneous xenograft and metastatic mouse models were also conducted. In parallel, [211At] MABG was synthesized by: (i) cyclotron-production of 211 At via 209 Bi(α,2n)211At reaction (ii) distillation of 211 At from the target, and (iii) solid phase no-carrier-added synthesis of [211At] MABG by radioastato-destannylation. [211At] MABG uptake studies were performed in isogenic NB cell lines.

Results: Unlike primary human NBs, NET expression was low in the majority of 35 cell-lines studied (median normalized expression value = 0.145; range 0.000-1.005), but all transduced lines showed significant overexpression (0.860-1.107) comparable to human primary tumors. Transduced lines showed 4-10 fold higher uptake of [125I]MIBG than non-transduced isogenic parental cell lines in vitro, and demonstrated significant tumor-specific uptake and retention in vivo with tumor-muscle ratios ranging from 13.80 to 29.48. In vitro cytotoxicity experiments using [131I]MIBG showed NET-expressing cell lines to be more susceptible to treatment compared to non-NET expressing pairs (IC50 of 2.937nCi vs. 15.99 nCi). Treatment of mice bearing NB1691-NET xenografts with [131I]MIBG showed tumor growth delay (p=0.0065), but no significant impact on survival, likely due to de novo radioresistance (1200 cGy of XRT had no impact on NB1691 proliferation; IMR-05 showed 97% decreased cell viability). Lastly, we successfully synthesized [211At] MABG, with radiochemical yields of ∼20% and showed NET specific uptake of [211At] MABG into 1691 NET transfected cells.

Conclusions: Development of targeted radiotherapy for neuroblastoma has been limited by the lack of preclinical models and alternative therapeutics. Our development of multiple isogenic pairs with varying NET expression, documentation of de novo radiation sensitivity, and the production of [211At] MABG, will allow for rapid assessment of targeted radiotherapeutic strategies (including combination approaches) to support clinical development of alpha-particle therapeutics in a childhood cancer.

Citation Format: V Batra, AM Chacko, M Gagliardi, C Hou, J L. Mikitsh, R H. Freifelder, A Kachur, B C. LeGeyt, A Schmitz, L Toto, G Vaidyanathan, M R. Zalutsky, K K. Matthay, W A. Weiss, W C. Gustafson, D Pryma, J M. Maris. Preclinical development of meta-[211At] astatobenzylguanidine ([211At] MABG) targeted radiotherapy for neuroblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B48.