Single-cell RNA sequencing analysis of vestibular schwannoma reveals functionally distinct macrophage subsets

BACKGROUND

Vestibular schwannomas (VSs) remain a challenge due to their anatomical location and propensity to growth. Macrophages are present in VS but their roles in VS pathogenesis remains unknown.

OBJECTIVES

The objective was to assess phenotypic and functional profile of macrophages in VS with single-cell RNA sequencing (scRNAseq).

METHODS

scRNAseq was carried out in three VS samples to examine characteristics of macrophages in the tumour. RT-qPCR was carried out on 10 VS samples for CD14, CD68 and CD163 and a panel of macrophage-associated molecules.

RESULTS

scRNAseq revealed macrophages to be a major constituent of VS microenvironment with three distinct subclusters based on gene expression. The subclusters were also defined by expression of CD163, CD68 and IL-1β. AREG and PLAUR were expressed in the CD68+CD163+IL-1β+ subcluster, PLCG2 and NCKAP5 were expressed in CD68+CD163+IL-1β- subcluster and AUTS2 and SPP1 were expressed in the CD68+CD163-IL-1β+ subcluster. RT-qPCR showed expression of several macrophage markers in VS of which CD14, ALOX15, Interleukin-1β, INHBA and Colony Stimulating Factor-1R were found to have a high correlation with tumour volume.

CONCLUSIONS

Macrophages form an important component of VS stroma. scRNAseq reveals three distinct subsets of macrophages in the VS tissue which may have differing roles in the pathogenesis of VS.

Cross-tissue, single-cell stromal atlas identifies shared pathological fibroblast phenotypes in four chronic inflammatory diseases

BACKGROUND

Pro-inflammatory fibroblasts are critical for pathogenesis in rheumatoid arthritis, inflammatory bowel disease, interstitial lung disease, and Sjögren's syndrome and represent a novel therapeutic target for chronic inflammatory disease. However, the heterogeneity of fibroblast phenotypes, exacerbated by the lack of a common cross-tissue taxonomy, has limited our understanding of which pathways are shared by multiple diseases.

METHODS

We profiled fibroblasts derived from inflamed and non-inflamed synovium, intestine, lungs, and salivary glands from affected individuals with single-cell RNA sequencing. We integrated all fibroblasts into a multi-tissue atlas to characterize shared and tissue-specific phenotypes.

FINDINGS

Two shared clusters, CXCL10+CCL19+ immune-interacting and SPARC+COL3A1+ vascular-interacting fibroblasts, were expanded in all inflamed tissues and mapped to dermal analogs in a public atopic dermatitis atlas. We confirmed these human pro-inflammatory fibroblasts in animal models of lung, joint, and intestinal inflammation.

CONCLUSIONS

This work represents a thorough investigation into fibroblasts across organ systems, individual donors, and disease states that reveals shared pathogenic activation states across four chronic inflammatory diseases.

FUNDING

Grant from F. Hoffmann-La Roche (Roche) AG.

Spontaneously Resolving Joint Inflammation Is Characterised by Metabolic Agility of Fibroblast-Like Synoviocytes

Fibroblast-like synoviocytes (FLS) play an important role in maintaining joint homeostasis and orchestrating local inflammatory processes. When activated during injury or inflammation, FLS undergo transiently increased bioenergetic and biosynthetic demand. We aimed to identify metabolic changes which occur early in inflammatory disease pathogenesis which might support sustained cellular activation in persistent inflammation. We took primary human FLS from synovial biopsies of patients with very early rheumatoid arthritis (veRA) or resolving synovitis, and compared them with uninflamed control samples from the synovium of people without arthritis. Metabotypes were compared using NMR spectroscopy-based metabolomics and correlated with serum C-reactive protein levels. We measured glycolysis and oxidative phosphorylation by Seahorse analysis and assessed mitochondrial morphology by immunofluorescence. We demonstrate differences in FLS metabolism measurable after ex vivo culture, suggesting that disease-associated metabolic changes are long-lasting. We term this phenomenon 'metabolic memory'. We identify changes in cell metabolism after acute TNFα stimulation across disease groups. When compared to FLS from patients with early rheumatoid arthritis, FLS from patients with resolving synovitis have significantly elevated mitochondrial respiratory capacity in the resting state, and less fragmented mitochondrial morphology after TNFα treatment. Our findings indicate the potential to restore cell metabotypes by modulating mitochondrial function at sites of inflammation, with implications for treatment of RA and related inflammatory conditions in which fibroblasts play a role.

Dark Energy Survey Year 1 Results: Cosmological Constraints from Cluster Abundances, Weak Lensing, and Galaxy Correlations

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

Distinct genomic landscapes of gastroesophageal adenocarcinoma depending on PD-L1 expression identify mutations in RAS-MAPK pathway and TP53 as potential predictors of immunotherapy efficacy

BACKGROUND

The impact of molecular alterations on programmed death-ligand 1 (PD-L1) combined positive score (CPS) is not well studied in gastroesophageal adenocarcinomas (GEAs). We aimed to characterize genomic features of tumors with different CPSs in GEAs.

PATIENTS AND METHODS

Genomic alterations of 2518 GEAs were compared in three groups (PD-L1 CPS ≥ 10, high; CPS = 1-9, intermediate; CPS < 1, low) using next-generation sequencing. We assessed the impact of gene mutations on the efficacy of immune checkpoint inhibitors (ICIs) and tumor immune environment based on the Memorial Sloan Kettering Cancer Center and The Cancer Genome Atlas databases.

RESULTS

High, intermediate, and low CPSs were seen in 18%, 54% and 28% of GEAs, respectively. PD-L1 positivity was less prevalent in women and in tissues derived from metastatic sites. PD-L1 CPS was positively associated with mismatch repair deficiency/microsatellite instability-high, but independent of tumor mutation burden distribution. Tumors with mutations in KRAS, TP53, and RAS-mitogen-activated protein kinase (MAPK) pathway were associated with higher PD-L1 CPSs in the mismatch repair proficiency and microsatellite stability (pMMR&MSS) subgroup. Patients with RAS-MAPK pathway alterations had longer overall survival (OS) from ICIs compared to wildtype (WT) patients [27 versus 13 months, hazard ratio (HR) = 0.36, 95% confidence interval (CI): 0.19-0.7, P = 0.016] and a similar trend was observed in the MSS subgroup (P = 0.11). In contrast, patients with TP53 mutations had worse OS from ICIs compared to TP53-WT patients in the MSS subgroup (5 versus 21 months, HR = 2.39, 95% CI: 1.24-4.61, P = 0.016).

CONCLUSIONS

This is the largest study to investigate the distinct genomic landscapes of GEAs with different PD-L1 CPSs. Our data may provide novel insights for patient selection using mutations in TP53 and RAS-MAPK pathway and for the development of rational combination immunotherapies in GEAs.

Constraints on Dark Matter Properties from Observations of Milky Way Satellite Galaxies

We perform a comprehensive study of Milky Way (MW) satellite galaxies to constrain the fundamental properties of dark matter (DM). This analysis fully incorporates inhomogeneities in the spatial distribution and detectability of MW satellites and marginalizes over uncertainties in the mapping between galaxies and DM halos, the properties of the MW system, and the disruption of subhalos by the MW disk. Our results are consistent with the cold, collisionless DM paradigm and yield the strongest cosmological constraints to date on particle models of warm, interacting, and fuzzy dark matter. At 95% confidence, we report limits on (i) the mass of thermal relic warm DM, m_{WDM}>6.5  keV (free-streaming length, λ_{fs}≲10h^{-1}  kpc), (ii) the velocity-independent DM-proton scattering cross section, σ_{0}<8.8×10^{-29}  cm^{2} for a 100 MeV DM particle mass [DM-proton coupling, c_{p}≲(0.3  GeV)^{-2}], and (iii) the mass of fuzzy DM, m_{ϕ}>2.9×10^{-21}  eV (de Broglie wavelength, λ_{dB}≲0.5  kpc). These constraints are complementary to other observational and laboratory constraints on DM properties.

Aryl Hydrocarbon Receptor Interacting Protein Maintains Germinal Center B Cells through Suppression of BCL6 Degradation

B cell lymphoma-6 (BCL6) is highly expressed in germinal center B cells, but how its expression is maintained is still not completely clear. Aryl hydrocarbon receptor interacting protein (AIP) is a co-chaperone of heat shock protein 90. Deletion of Aip in B cells decreased BCL6 expression, reducing germinal center B cells and diminishing adaptive immune responses. AIP was required for optimal AKT signaling in response to B cell receptor stimulation, and AIP protected BCL6 from ubiquitin-mediated proteasomal degradation by the E3-ubiquitin ligase FBXO11 by binding to the deubiquitinase UCHL1, thus helping to maintain the expression of BCL6. AIP was highly expressed in primary diffuse large B cell lymphomas compared to healthy tissue and other tumors. Our findings describe AIP as a positive regulator of BCL6 expression with implications for the pathobiology of diffuse large B cell lymphoma.

Notch signalling drives synovial fibroblast identity and arthritis pathology

The synovium is a mesenchymal tissue composed mainly of fibroblasts with a lining and sublining that surrounds the joints. In rheumatoid arthritis (RA), the synovial tissue undergoes marked hyperplasia, becomes inflamed and invasive and destroys the joint^1,2. Recently, we and others found that a subset of fibroblasts located in the sublining undergoes major expansion in RA and is linked to disease activity^3,4,5. However, the molecular mechanism by which these fibroblasts differentiate and expand in RA remains unknown. Here, we identified a critical role for NOTCH3 signaling in the differentiation of perivascular and sublining CD90(THY1)+ fibroblasts. Using single cell RNA-sequencing and synovial tissue organoids, we found that NOTCH3 signaling drives both transcriptional and spatial gradients in fibroblasts emanating from vascular endothelial cells outward. In active RA, NOTCH3 and NOTCH target genes are markedly upregulated in synovial fibroblasts. Importantly, genetic deletion of Notch3 or monoclonal antibody-blockade of NOTCH3 signaling attenuates inflammation and prevents joint damage in inflammatory arthritis. Our results indicate that synovial fibroblasts exhibit positional identity regulated by endothelium-derived Notch signaling and that this stromal crosstalk pathway underlies inflammation and pathology in inflammatory arthritis.

Evaluation of the change of outcomes over a 10-year period in patients with stage III colon cancer: pooled analysis of 6501 patients treated with fluorouracil, leucovorin, and oxaliplatin in the ACCENT database

BACKGROUND

Since 2004, adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX or FLOX) have been the standard of care for patients with resected colon cancer. Herein we examine the change of outcomes over a 10-year period in patients with stage III colon cancer who received this regimen.

PATIENTS AND METHODS

Individual patient data from the ACCENT database was used to compare the outcomes in older (1998-2003) and newer (2004-2009) treatment eras for patients with stage III colon cancer who received adjuvant FOLFOX or FLOX. The outcomes were compared between the two groups by the multivariate Cox proportional-hazards model adjusting for age, sex, performance score, T stage, N stage, tumor sidedness, and histological grade.

RESULTS

A total of 6501 patients with stage III colon cancer who received adjuvant FOLFOX or FLOX in six randomized trials were included in the analysis. Patients enrolled in the new era group experienced statistically significant improvement in time to recurrence [3-year rate, 76.1% versus 73.0%; adjusted hazard ratio (HRadj) = 0.83 (95% CI, 0.74-0.92), P = 0.0008], disease-free survival (DFS) [3-year rate, 74.7% versus 72.3%; HRadj = 0.88 (0.79-0.98), P = 0.024], survival after recurrence (SAR) [median time, 27.0 versus 17.7 months; HRadj = 0.65 (0.57-0.74), P < 0.0001], and overall survival (OS) [5-year rate, 80.9% versus 75.7%; HRadj = 0.78 (0.69-0.88), P < 0.0001]. The improved outcomes remained in patients diagnosed at 45 years of age or older, low-risk patients (T1-3 and N1), left colon, mismatch repair proficient (pMMR), BRAF, and KRAS wild-type tumors.

CONCLUSION

Improved outcomes were observed in patients with stage III colon cancer enrolled in clinical trials who received adjuvant FOLFOX/FLOX therapy in 2004 or later compared with patients in the older era. Prolonged SAR calls for revalidation of 3-year DFS as the surrogate endpoint of OS in adjuvant clinical trials and reevaluation of optimal follow-up of OS to confirm the trial findings based on the DFS endpoints.

CLINICAL TRIALS NUMBERS

NCT00079274; NCT00096278; NCT00004931; NCT00275210; NCT00265811; NCT00112918.

Detection of Cross-Correlation between Gravitational Lensing and γ Rays

In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.

Outer membrane protein size and LPS O-antigen define protective antibody targeting to the Salmonella surface

Lipopolysaccharide (LPS) O-antigen (O-Ag) is known to limit antibody binding to surface antigens, although the relationship between antibody, O-Ag and other outer-membrane antigens is poorly understood. Here we report, immunization with the trimeric porin OmpD from Salmonella Typhimurium (STmOmpD) protects against infection. Atomistic molecular dynamics simulations indicate this is because OmpD trimers generate footprints within the O-Ag layer sufficiently sized for a single IgG Fab to access. While STmOmpD differs from its orthologue in S. Enteritidis (SEn) by a single amino-acid residue, immunization with STmOmpD confers minimal protection to SEn. This is due to the OmpD-O-Ag interplay restricting IgG binding, with the pairing of OmpD with its native O-Ag being essential for optimal protection after immunization. Thus, both the chemical and physical structure of O-Ag are key for the presentation of specific epitopes within proteinaceous surface-antigens. This enhances combinatorial antigenic diversity in Gram-negative bacteria, while reducing associated fitness costs.

The O-antigen of LPS is known to limit the binding of antibody to bacterial surface antigens. Here the AUs show that the chemical and physical structure of the O-antigen are central factors in limiting the exposure of surface antigens to antibodies during Salmonella infection, thus defining their protective qualities.

Detection of CMB-Cluster Lensing using Polarization Data from SPTpol

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Podoplanin regulates the migration of mesenchymal stromal cells and their interaction with platelets

Mesenchymal stromal cells (MSCs) upregulate podoplanin at sites of infection, chronic inflammation and cancer. Here, we investigated the functional consequences of podoplanin expression on the migratory potential of MSCs and their interactions with circulating platelets. Expression of podoplanin significantly enhanced the migration of MSCs compared to MSCs lacking podoplanin. Rac-1 inhibition altered the membrane localisation of podoplanin and in turn significantly reduced MSC migration. Blocking Rac-1 activity had no effect on the migration of MSCs lacking podoplanin, indicating that it was responsible for regulation of migration through podoplanin. When podoplanin-expressing MSCs were seeded on the basal surface of a porous filter, they were able to capture platelets perfused over the uncoated apical surface and induce platelet aggregation. Similar microthrombi were observed when endothelial cells (ECs) were co-cultured on the apical surface. Confocal imaging shows podoplanin-expressing MSCs extending processes into the EC layer, and these processes could interact with circulating platelets. In both models, platelet aggregation induced by podoplanin-expressing MSCs was inhibited by treatment with recombinant soluble C-type lectin-like receptor 2 (CLEC-2; encoded by the gene Clec1b). Thus, podoplanin may enhance the migratory capacity of tissue-resident MSCs and enable novel interactions with cells expressing CLEC-2.

Summary: Podoplanin enhances the migration of mesenchymal stromal cells in a Rac-1-dependent manner, enabling direct interactions of subendothelial stroma with circulating platelets.

Targeting early changes in the synovial microenvironment: a new class of immunomodulatory therapy?

Objectives

Controlled immune responses rely on integrated crosstalk between cells and their microenvironment. We investigated whether targeting proinflammatory signals from the extracellular matrix that persist during pathological inflammation provides a viable strategy to treat rheumatoid arthritis (RA).

Methods

Monoclonal antibodies recognising the fibrinogen-like globe (FBG) of tenascin-C were generated by phage display. Clones that neutralised FBG activation of toll-like receptor 4 (TLR4), without impacting pathogenic TLR4 activation, were epitope mapped by crystallography. Antibodies stained synovial biopsies of patients at different stages of RA development. Antibody efficacy in preventing RA synovial cell cytokine release, and in modulating collagen-induced arthritis in rats, was assessed.

Results

Tenascin-C is expressed early in the development of RA, even before disease diagnosis, with higher levels in the joints of people with synovitis who eventually developed RA than in people whose synovitis spontaneously resolved. Anti-FBG antibodies inhibited cytokine release by RA synovial cells and prevented disease progression and tissue destruction during collagen-induced arthritis.

Conclusions

Early changes in the synovial microenvironment contribute to RA progression; blocking proinflammatory signals from the matrix can ameliorate experimental arthritis. These data highlight a new drug class that could offer early, disease-specific immune modulation in RA, without engendering global immune suppression.

Intestinal CD103+CD11b+ cDC2 Conventional Dendritic Cells Are Required for Primary CD4+ T and B Cell Responses to Soluble Flagellin

Systemic immunization with soluble flagellin (sFliC) from Salmonella Typhimurium induces mucosal responses, offering potential as an adjuvant platform for vaccines. Moreover, this engagement of mucosal immunity is necessary for optimal systemic immunity, demonstrating an interaction between these two semi-autonomous immune systems. Although TLR5 and CD103⁺CD11b⁺ cDC2 contribute to this process, the relationship between these is unclear in the early activation of CD4⁺ T cells and the development of antigen-specific B cell responses. In this work, we use TLR5-deficient mice and CD11c-cre.Irf4 ^fl/fl mice (which have reduced numbers of cDC2, particularly intestinal CD103⁺CD11b⁺ cDCs), to address these points by studying the responses concurrently in the spleen and the mesenteric lymph nodes (MLN). We show that CD103⁺CD11b⁺ cDC2 respond rapidly and accumulate in the MLN after immunization with sFliC in a TLR5-dependent manner. Furthermore, we identify that whilst CD103⁺CD11b⁺ cDC2 are essential for the induction of primary T and B cell responses in the mucosa, they do not play such a central role for the induction of these responses in the spleen. Additionally, we show the involvement of CD103⁺CD11b⁺ cDC2 in the induction of Th2-associated responses. CD11c-cre.Irf4 ^fl/fl mice showed a reduced primary FliC-specific Th2-associated IgG1 responses, but enhanced Th1-associated IgG2c responses. These data expand our current understanding of the mucosal immune responses promoted by sFliC and highlights the potential of this adjuvant for vaccine usage by taking advantage of the functionality of mucosal CD103⁺CD11b⁺ cDC2.

CD103+CD11b+ mucosal classical dendritic cells initiate long-term switched antibody responses to flagellin

Antibody responses induced at mucosal and nonmucosal sites demonstrate a significant level of autonomy. Here, we demonstrate a key role for mucosal interferon regulatory factor-4 (IRF4)-dependent CD103+CD11b+ (DP), classical dendritic cells (cDCs) in the induction of T-dependent immunoglobulin G (IgG) and immunoglobulin A (IgA) responses in the mesenteric lymph node (MLN) following systemic immunization with soluble flagellin (sFliC). In contrast, IRF8-dependent CD103+CD11b- (SP) are not required for these responses. The lack of this response correlated with a complete absence of sFliC-specific plasma cells in the MLN, small intestinal lamina propria, and surprisingly also the bone marrow (BM). Many sFliC-specific plasma cells accumulating in the BM of immunized wild-type mice expressed α4β7+, suggesting a mucosal origin. Collectively, these results suggest that mucosal DP cDC contribute to the generation of the sFliC-specific plasma cell pool in the BM and thus serve as a bridge linking the mucosal and systemic immune system.

Functionally distinct disease-associated fibroblast subsets in rheumatoid arthritis

Fibroblasts regulate tissue homeostasis, coordinate inflammatory responses, and mediate tissue damage. In rheumatoid arthritis (RA), synovial fibroblasts maintain chronic inflammation which leads to joint destruction. Little is known about fibroblast heterogeneity or if aberrations in fibroblast subsets relate to pathology. Here, we show functional and transcriptional differences between fibroblast subsets from human synovial tissues using bulk transcriptomics of targeted subpopulations and single-cell transcriptomics. We identify seven fibroblast subsets with distinct surface protein phenotypes, and collapse them into three subsets by integrating transcriptomic data. One fibroblast subset, characterized by the expression of proteins podoplanin, THY1 membrane glycoprotein and cadherin-11, but lacking CD34, is threefold expanded in patients with RA relative to patients with osteoarthritis. These fibroblasts localize to the perivascular zone in inflamed synovium, secrete proinflammatory cytokines, are proliferative, and have an in vitro phenotype characteristic of invasive cells. Our strategy may be used as a template to identify pathogenic stromal cellular subsets in other complex diseases.

Synovial fibroblasts are thought to be central mediators of joint destruction in rheumatoid arthritis (RA). Here the authors use single-cell transcriptomics and flow cytometry to identify synovial fibroblast subsets that are expanded and display distinct tissue distribution and function in patients with RA.

Abstract P2-09-09: Polyligand profiling differentiates cancer patients according to their benefit of treatment

Introduction: Deconvolution of multi-nodal perturbations in cancer network architecture demands highly multiplexed profiling assays. We demonstrate the value of polyligand profiling of tumor systems states using libraries of single stranded oligodeoxynucleotides (ssODN) to distinguish between tumor tissue from breast cancer patients who did or did not derive benefit from treatment regimens containing trastuzumab.

Methods: This study included cases from women with invasive breast cancer who received chemotherapy+ trastuzumab (C+T) or trastuzumab monotherapy with available retrospective data on the time to next treatment (TTNT). A library of 2x1012 unique ssODN was exposed to FFPE tissues from patients who benefited (B) or not (NB) from trastuzumab-based regimens in several rounds of positive and negative selection. Two enriched libraries were screened on independent set of 42 B and 19 NB cases using a modified IHC protocol for detection of bound ssODNs. Poly-Ligand Profiles (PLP) were scored by a blinded pathologist. Two libraries, EL-NB and EL-B, showed significant p-values between groups of responders and non-responders. A Cox-PH model was fitted using either tumors' HER2 status or PLP test results as the independent variable. Median survival time was calculated from the Kaplan-Meier estimate. A separate group of 63 cases with TTNT data from chemotherapy without trastuzumab was used as a control to distinguish prognostic from predictive performance.

Results: The PLP scores of EL-NB and EL-B were assessed by receiver operating characteristic (ROC) curves and resulted in a combined AUC value of 0.81. EL-NB and EL-B were able to effectively classify B and NB patients with either HER2-negative/equivocal (AUC = 0.73) or HER2-positive cancers (AUC = 0.84). In contrast, HER2 status alone yielded an AUC value of 0.47. The combined PLP scores for the independent set of 63 patients treated with C excluding trastuzumab resulted in an AUC value of 0.53, indicating that the assay was predictive and not simply prognostic. Kaplan-Meier curves analysis shows that PLP+ cases have 429 days median TTNT, while PLP- cases have 129 days (HR = 0.38, log-rank p = 0.001). Analysis based on HER2 status showed no significant difference in TTNT between patients that were HER2+ (280 days) or HER2-negative/equivocal (336 days, HR = 1.27, log-rank p =0.45).

Summary: Performance of the PLP assay in differentiating patients who did or did not benefit from trastuzumab therapy outperforms the standard IHC assay for HER2 status. These results represent a promising step towards the development of a CDx to identify the 50-70% of HER2+ patients who will not benefit from trastuzumab. In addition, PLP also has the potential to identify the HER2-negative/equivocal patients who may benefit from trastuzumab-containing regimens.

Citation Format: Domenyuk V, Gatalica Z, Santhanam R, Wei X, Stark A, Kennedy P, Toussaint B, Levenberg S, Wang R, Xiao N, Greil R, Rinnerthaler G, Gampenrieder S, Heimberger AB, Berry DJ, Barker A, Demetri GD, Quackenbush J, Marshall JL, Poste G, Vacirca JL, Vidal GA, Schwartzberg LS, Halbert DD, Voss A, Miglarese MR, Famulok M, Mayer G, Spetzler D. Polyligand profiling differentiates cancer patients according to their benefit of treatment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-09.

Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger

On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from [Formula: see text] to [Formula: see text] kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material.

Light curves of the neutron star merger GW170817/SSS17a: Implications for r-process nucleosynthesis

On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.

Stromal cell markers are differentially expressed in the synovial tissue of patients with early arthritis

Introduction

Previous studies have shown increased expression of stromal markers in synovial tissue (ST) of patients with established rheumatoid arthritis (RA). Here, ST expression of stromal markers in early arthritis in relationship to diagnosis and prognostic outcome was studied.

Methods

ST from 56 patients included in two different early arthritis cohorts and 7 non-inflammatory controls was analysed using immunofluorescence to detect stromal markers CD55, CD248, fibroblast activation protein (FAP) and podoplanin. Diagnostic classification (gout, psoriatic arthritis, unclassified arthritis (UA), parvovirus associated arthritis, reactive arthritis and RA), disease outcome (resolving vs persistent) and clinical variables were determined at baseline and after follow-up, and related to the expression of stromal markers.

Results

We observed expression of all stromal markers in ST of early arthritis patients, independent of diagnosis or prognostic outcome. Synovial expression of FAP was significantly higher in patients developing early RA compared to other diagnostic groups and non-inflammatory controls. In RA FAP protein was expressed in both lining and sublining layers. Podoplanin expression was higher in all early inflammatory arthritis patients than controls, but did not differentiate diagnostic outcomes. Stromal marker expression was not associated with prognostic outcomes of disease persistence or resolution. There was no association with clinical or sonographic variables.

Conclusions

Stromal cell markers CD55, CD248, FAP and podoplanin are expressed in ST in the earliest stage of arthritis. Baseline expression of FAP is higher in early synovitis patients who fulfil classification criteria for RA over time. These results suggest that significant fibroblast activation occurs in RA in the early window of disease.

Rheumatoid synovial fibroblasts differentiate into distinct subsets in the presence of cytokines and cartilage

Background

We investigated two distinct synovial fibroblast populations that were located preferentially in the lining or sub-lining layers and defined by their expression of either podoplanin (PDPN) or CD248, and explored their ability to undergo self-assembly and transmigration in vivo.

Methods

Synovial fibroblasts (SF) were cultured in vitro and phenotypic changes following stimulation with interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1 were examined. To examine the phenotype of SF in vivo, a severe combined immunodeficiency (SCID) human-mouse model of cartilage destruction was utilised.

Results

SF in the lining layer in rheumatoid arthritis (RA) expressed high levels of PDPN compared to the normal synovium, whereas CD248 expression was restricted to sub-lining layer cells. TNF-α or IL1 stimulation in vitro resulted in an increased expression of PDPN. In contrast, stimulation with TGF-β1 induced CD248 expression. In the SCID human-mouse model, rheumatoid SF recapitulated the expression of PDPN and CD248. Fibroblasts adjacent to cartilage expressed PDPN, and attached to, invaded, and degraded cartilage. PDPN⁺ CD248^– SF preceded the appearance of PDPN^– CD248⁺ cells in contralateral implants.

Conclusions

We have identified two distinct SF populations identified by expression of either PDPN or CD248 which are located within different anatomical compartments of the inflamed synovial membrane. These markers discriminate between SF subsets with distinct biological properties. As PDPN-expressing cells are associated with early fibroblast migration and cartilage erosion in vivo, we propose that PDPN-expressing cells may be an attractive therapeutic target in RA.

Reversal of neurobehavioral social deficits in dystrophic mice using inhibitors of phosphodiesterases PDE5A and PDE9A

Duchenne muscular dystrophy is caused by mutations in the DYSTROPHIN gene. Although primarily associated with muscle wasting, a significant portion of patients (approximately 25%) are also diagnosed with autism spectrum disorder. We describe social behavioral deficits in dystrophin-deficient mice and present evidence of cerebellar deficits in cGMP production. We demonstrate therapeutic potential for selective inhibitors of the cGMP-specific PDE5A and PDE9A enzymes to restore social behaviors in dystrophin-deficient mice.

Locus of Control and Academic Achievement in High School Students

This study investigated the hypothesized relationship between internal locus of control and academic achievement among a sample of 187 students in Grades 8 through 12 using the Nowicki-Strickland Locus of Control Scale for Children. Analysis indicated that students in the higher GPA group reported higher scores on internal locus of control.

Soluble flagellin coimmunization attenuates Th1 priming to Salmonella and clearance by modulating dendritic cell activation and cytokine production

Soluble flagellin (sFliC) from Salmonella Typhimurium (STm) can induce a Th2 response to itself and coadministered antigens through ligation of TLR5. These properties suggest that sFliC could potentially modulate responses to Th1 antigens like live STm if both antigens are given concurrently. After coimmunization of mice with sFliC and STm there was a reduction in Th1 T cells (T-bet(+) IFN-γ(+) CD4 T cells) compared to STm alone and there was impaired clearance of STm. In contrast, there was no significant defect in the early extrafollicular B-cell response to STm. These effects are dependent upon TLR5 and flagellin expression by STm. The mechanism for these effects is not related to IL-4 induced to sFliC but rather to the effects of sFliC coimmunization on DCs. After coimmunization with STm and sFliC, splenic DCs had a lower expression of costimulatory molecules and profoundly altered kinetics of IL-12 and TNFα expression. Ex vivo experiments using in vivo conditioned DCs confirmed the effects of sFliC were due to altered DC function during a critical window in the coordinated interplay between DCs and naïve T cells. This has marked implications for understanding how limits in Th1 priming can be achieved during infection-induced, Th1-mediated inflammation.

Non-cleft causes of velopharyngeal dysfunction: implications for treatment

Although a history of cleft palate is the most common cause of velopharyngeal dysfunction (VPD), there are other disorders that can also cause hypernasality and/or nasal emission. These include other structural anomalies of the velopharyngeal valve (velopharyngeal insufficiency), neurophysiological disorders that result in inadequate velopharyngeal movement (velopharyngeal incompetence), and even faulty articulation placement in the pharynx (velopharyngeal mislearning). Unfortunately, individuals with non-cleft causes of hypernasality and/or nasal emission do not typically present at a cleft palate/craniofacial center where there are professionals who specialize in the evaluation and treatment of these disorders. As a result, they are often misdiagnosed and do not receive appropriate treatment. In this review, we present various conditions that can cause hypernasality and/or nasal emission during speech. We discuss appropriate treatment based on the underlying cause of the condition. It is important that pediatric otolaryngologists are able to recognize these disorders so that affected patients are referred to specialists in velopharyngeal dysfunction for treatment.

Resolving Salmonella infection reveals dynamic and persisting changes in murine bone marrow progenitor cell phenotype and function

The generation of immune cells from BM precursors is a carefully regulated process. This is essential to limit the potential for oncogenesis and autoimmunity yet protect against infection. How infection modulates this is unclear. Salmonella can colonize systemic sites including the BM and spleen. This resolving infection has multiple IFN-γ-mediated acute and chronic effects on BM progenitors, and during the first week of infection IFN-γ is produced by myeloid, NK, NKT, CD4(+) T cells, and some lineage-negative cells. After infection, the phenotype of BM progenitors rapidly but reversibly alters, with a peak ∼ 30-fold increase in Sca-1(hi) progenitors and a corresponding loss of Sca-1(lo/int) subsets. Most strikingly, the capacity of donor Sca-1(hi) cells to reconstitute an irradiated host is reduced; the longer donor mice are exposed to infection, and Sca-1(hi) c-kit(int) cells have an increased potential to generate B1a-like cells. Thus, Salmonella can have a prolonged influence on BM progenitor functionality not directly related to bacterial persistence. These results reflect changes observed in leucopoiesis during aging and suggest that BM functionality can be modulated by life-long, periodic exposure to infection. Better understanding of this process could offer novel therapeutic opportunities to modulate BM functionality and promote healthy aging.

Bevacizumab use and risk of cardiovascular adverse events among elderly patients with colorectal cancer receiving chemotherapy: a population-based study

BACKGROUND

Cardiovascular risk attributable to bevacizumab (Avastin(®), BEV) for treatment of metastatic colorectal cancer (CRC) remains unclear. We conducted a population-based cohort study to assess the safety of BEV use among patients aged ≥ 65.

PATIENTS AND METHODS

We identified CRC patients diagnosed from 2005 to 2007 who received chemotherapy and were followed until 31 December 2009. Outcomes were 3-year risk of arterial thromboembolic events (ATEs), cardiomyopathy or congestive heart failure (CM/CHF), and cardiac death (CD) after chemotherapy initiation. We fitted Cox-proportional hazards (PHs) models with inverse-probability-of-treatment-weights and calculated hazard ratios (HRs) for the risk of adverse events.

RESULTS

We identified 6803 CRC patients (median age: 73 years). Those with cardiac comorbidity were less likely to receive BEV (P < 0.0001). BEV is associated with an elevated risk of ATEs (HR = 1.82, 95% CI = 1.20-2.76, P < 0.001; rate difference: 3.5 additional cases/1000 person-years). We observed no association between BEV and CD or CM/CHF.

CONCLUSIONS

In general practice, the cardiovascular risk of BEV in elderly CRC is modest. The observed ATEs risk is lower than reported in clinical trials, which may be due to careful patient selection. Our findings may facilitate clinical decision-making of BEV use in elderly patients.

Systemic flagellin immunization stimulates mucosal CD103+ dendritic cells and drives Foxp3+ regulatory T cell and IgA responses in the mesenteric lymph node

Mucosal immunity is poorly activated after systemic immunization with protein Ags. Nevertheless, induction of mucosal immunity in such a manner would be an attractive and simple way to overcome the intrinsic difficulties in delivering Ag to such sites. Flagellin from Salmonella enterica serovar Typhimurium (FliC) can impact markedly on host immunity, in part via its recognition by TLR5. In this study, we show that systemic immunization with soluble FliC (sFliC) drives distinct immune responses concurrently in the mesenteric lymph nodes (MLN) and the spleen after i.p. and s.c. immunization. In the MLN, but not the spleen, sFliC drives a TLR5-dependent recruitment of CD103(+) dendritic cells (DCs), which correlates with a diminution in CD103(+) DC numbers in the lamina propria. In the MLN, CD103(+) DCs carry Ag and are the major primers of endogenous and transgenic T cell priming. A key consequence of these interactions with CD103(+) DCs in the MLN is an increase in local regulatory T cell differentiation. In parallel, systemic sFliC immunization results in a pronounced switching of FliC-specific B cells to IgA in the MLN but not elsewhere. Loss of TLR5 has more impact on MLN than splenic Ab responses, reflected in an ablation of IgA, but not IgG, serum Ab titers. Therefore, systemic sFliC immunization targets CD103(+) DCs and drives distinct mucosal T and B cell responses. This offers a potential "Trojan horse" approach to modulate mucosal immunity by systemically immunizing with sFliC.

The capsular polysaccharide Vi from Salmonella typhi is a B1b antigen

Vaccination with purified capsular polysaccharide Vi Ag from Salmonella typhi can protect against typhoid fever, although the mechanism for its efficacy is not clearly established. In this study, we have characterized the B cell response to this vaccine in wild-type and T cell-deficient mice. We show that immunization with typhoid Vi polysaccharide vaccine rapidly induces proliferation in B1b peritoneal cells, but not in B1a cells or marginal zone B cells. This induction of B1b proliferation is concomitant with the detection of splenic Vi-specific Ab-secreting cells and protective Ab in Rag1-deficient B1b cell chimeras generated by adoptive transfer-induced specific Ab after Vi immunization. Furthermore, Ab derived from peritoneal B cells is sufficient to confer protection against Salmonella that express Vi Ag. Expression of Vi by Salmonella during infection did not inhibit the development of early Ab responses to non-Vi Ags. Despite this, the protection conferred by immunization of mice with porin proteins from Salmonella, which induce Ab-mediated protection, was reduced postinfection with Vi-expressing Salmonella, although protection was not totally abrogated. This work therefore suggests that, in mice, B1b cells contribute to the protection induced by Vi Ag, and targeting non-Vi Ags as subunit vaccines may offer an attractive strategy to augment current Vi-based vaccine strategies.

Thymic function is maintained during Salmonella-induced atrophy and recovery

Thymic atrophy is a frequent consequence of infection with bacteria, viruses, and parasites and is considered a common virulence trait between pathogens. Multiple reasons have been proposed to explain this atrophy, including premature egress of immature thymocytes, increased apoptosis, or thymic shutdown to prevent tolerance to the pathogen from developing. The severe loss in thymic cell number can reflect an equally dramatic reduction in thymic output, potentially reducing peripheral T cell numbers. In this study, we examine the relationship between systemic Salmonella infection and thymic function. During infection, naive T cell numbers in peripheral lymphoid organs increase. Nevertheless, this occurs despite a pronounced thymic atrophy caused by viable bacteria, with a peak 50-fold reduction in thymocyte numbers. Thymic atrophy is not dependent upon homeostatic feedback from peripheral T cells or on regulation of endogenous glucocorticoids, as demonstrated by infection of genetically altered mice. Once bacterial numbers fall, thymocyte numbers recover, and this is associated with increases in the proportion and proliferation of early thymic progenitors. During atrophy, thymic T cell maturation is maintained, and single-joint TCR rearrangement excision circle analysis reveals there is only a modest fall in recent CD4(+) thymic emigrants in secondary lymphoid tissues. Thus, thymic atrophy does not necessarily result in a matching dysfunctional T cell output, and thymic homeostasis can constantly adjust to systemic infection to ensure that naive T cell output is maintained.

CD248 expression on mesenchymal stromal cells is required for post-natal and infection-dependent thymus remodelling and regeneration

The role of mesenchymal stromal cells (MSCs) in regulating immune responses in the thymus is currently unclear. Here we report the existence and role of a MSC population in the thymus that expresses the pericyte and MSC marker CD248 (endosialin). We show using a CD248-deficient mouse model, that CD248 expression on these cells is required for full post-natal thymus development and regeneration post-Salmonella infection. In CD248^−/− mice the thymus is hypocellular and regeneration is poorer, with significant loss of all thymocyte populations. This identifies the requirement of CD248 to maintain optimal thymic cellularity post-partum and infection.

T-zone localized monocyte-derived dendritic cells promote Th1 priming to Salmonella

Control of intracellular Salmonella infection requires Th1 priming and IFN-γ production. Here, we show that efficient Th1 priming after Salmonella infection requires CD11c(+) CD11b(hi) F4/80(+) monocyte-derived dendritic cells (moDCs). In non-infected spleens, moDCs are absent from T-cell zones (T zones) of secondary lymphoid tissues, but by 24 h post-infection moDCs are readily discernible in these sites. The accumulation of moDCs is more dependent upon bacterial viability than bacterial virulence. Kinetic studies showed that moDCs were necessary to prime but not sustain Th1 responses, while ex vivo studies showed that antigen-experienced moDCs were sufficient to induce T-cell proliferation and IFN-γ production via a TNF-α-dependent mechanism. Importantly, moDCs and cDCs when co-cultured induced superior Th1 differentiation than either subset alone, and this activity was independent of TNF-α. Thus, optimal Th1 development to Salmonella requires the rapid accumulation of moDCs within T zones and their collaboration with cDCs.

CD31 is required on CD4+ T cells to promote T cell survival during Salmonella infection

Hematopoietic cells constitutively express CD31/PECAM1, a signaling adhesion receptor associated with controlling responses to inflammatory stimuli. Although expressed on CD4(+) T cells, its function on these cells is unclear. To address this, we have used a model of systemic Salmonella infection that induces high levels of T cell activation and depends on CD4(+) T cells for resolution. Infection of CD31-deficient (CD31KO) mice demonstrates that these mice fail to control infection effectively. During infection, CD31KO mice have diminished numbers of total CD4(+) T cells and IFN-γ-secreting Th1 cells. This is despite a higher proportion of CD31KO CD4(+) T cells exhibiting an activated phenotype and an undiminished capacity to prime normally and polarize to Th1. Reduced numbers of T cells reflected the increased propensity of naive and activated CD31KO T cells to undergo apoptosis postinfection compared with wild-type T cells. Using adoptive transfer experiments, we show that loss of CD31 on CD4(+) T cells alone is sufficient to account for the defective CD31KO T cell accumulation. These data are consistent with CD31 helping to control T cell activation, because in its absence, T cells have a greater propensity to become activated, resulting in increased susceptibility to become apoptotic. The impact of CD31 loss on T cell homeostasis becomes most pronounced during severe, inflammatory, and immunological stresses such as those caused by systemic Salmonella infection. This identifies a novel role for CD31 in regulating CD4 T cell homeostasis.

B cell priming for extrafollicular antibody responses requires Bcl-6 expression by T cells

T follicular helper cells (Tfh cells) localize to follicles where they provide growth and selection signals to mutated germinal center (GC) B cells, thus promoting their differentiation into high affinity long-lived plasma cells and memory B cells. T-dependent B cell differentiation also occurs extrafollicularly, giving rise to unmutated plasma cells that are important for early protection against microbial infections. Bcl-6 expression in T cells has been shown to be essential for the formation of Tfh cells and GC B cells, but little is known about its requirement in physiological extrafollicular antibody responses. We use several mouse models in which extrafollicular plasma cells can be unequivocally distinguished from those of GC origin, combined with antigen-specific T and B cells, to show that the absence of T cell-expressed Bcl-6 significantly reduces T-dependent extrafollicular antibody responses. Bcl-6(+) T cells appear at the T-B border soon after T cell priming and before GC formation, and these cells express low amounts of PD-1. Their appearance precedes that of Bcl-6(+) PD-1(hi) T cells, which are found within the GC. IL-21 acts early to promote both follicular and extrafollicular antibody responses. In conclusion, Bcl-6(+) T cells are necessary at B cell priming to form extrafollicular antibody responses, and these pre-GC Tfh cells can be distinguished phenotypically from GC Tfh cells.

Soluble flagellin, FliC, induces an Ag-specific Th2 response, yet promotes T-bet-regulated Th1 clearance of Salmonella typhimurium infection

Clearance of disseminated Salmonella infection requires bacterial-specific Th1 cells and IFN-γ production, and Th1-promoting vaccines are likely to help control these infections. Consequently, vaccine design has focused on developing Th1-polarizing adjuvants or Ag that naturally induce Th1 responses. In this study, we show that, in mice, immunization with soluble, recombinant FliC protein flagellin (sFliC) induces Th2 responses as evidenced by Ag-specific GATA-3, IL-4 mRNA, and protein induction in CD62L(lo) CD4(+) T cells without associated IFN-γ production. Despite these Th2 features, sFliC immunization can enhance the development of protective Th1 immunity during subsequent Salmonella infection in an Ab-independent, T-cell-dependent manner. Salmonella infection in sFliC-immunized mice resulted in augmented Th1 responses, with greater bacterial clearance and increased numbers of IFN-γ-producing CD4(+) T cells, despite the early induction of Th2 features to sFliC. The augmented Th1 immunity after sFliC immunization was regulated by T-bet although T-bet is dispensable for primary responses to sFliC. These findings show that there can be flexibility in T-cell responses to some subunit vaccines. These vaccines may induce Th2-type immunity during primary immunization yet promote Th1-dependent responses during later infection. This suggests that designing Th1-inducing subunit vaccines may not always be necessary since this can occur naturally during subsequent infection.

Absent bactericidal activity of mouse serum against invasive African nontyphoidal Salmonella results from impaired complement function but not a lack of antibody

Nontyphoidal strains of Salmonella are a major cause of fatal bacteremia in Africa. Developing a vaccine requires an improved understanding of the relevant mechanisms of protective immunity, and the mouse model of Salmonella infection is useful for studying immunity to Salmonella in vivo. It is important to appreciate the similarities and differences between immunity to Salmonella in mice and men. Ab is important for protection against nontyphoidal Salmonella in both species, and we have previously found an important role for Ab in cell-free complement-mediated bactericidal activity against Salmonella in Africans. It is unclear whether this modality of immunity is relevant in the mouse model. C57BL/6, BALB/c, and C3H mice immunized with heat-killed Salmonella Typhimurium strains D23580 (African invasive strain) and SL1344 and live-attenuated strain SL3261 produced a Salmonella-specific Ab response. Sera from these mice deposited reduced levels of C3 on Salmonella compared with human sera and were unable to kill both wild-type and galE(-) rough mutant of D23580, indicating absent cell-free killing via classical and alternative complement pathways. Supplementing immune mouse sera with human complement enabled killing of Salmonella, whereas addition of human anti-Salmonella Ab to immune mouse sera had no effect. These findings indicate that mouse serum cannot effect [corrected] cell-free complement-dependent killing of Salmonella, because of the reduced mouse complement ability to kill these bacteria compared with human complement. This difference in Ab-dependent immunity to Salmonella in mice and men must be considered when applying findings from the mouse model of Salmonella disease and vaccination response to man.

Dysregulated humoral immunity to nontyphoidal Salmonella in HIV-infected African adults

Nontyphoidal Salmonellae are a major cause of life-threatening bacteremia among HIV-infected individuals. Although cell-mediated immunity controls intracellular infection, antibodies protect against Salmonella bacteremia. We report that high-titer antibodies specific for Salmonella lipopolysaccharide (LPS) are associated with a lack of Salmonella-killing in HIV-infected African adults. Killing was restored by genetically shortening LPS from the target Salmonella or removing LPS-specific antibodies from serum. Complement-mediated killing of Salmonella by healthy serum is shown to be induced specifically by antibodies against outer membrane proteins. This killing is lost when excess antibody against Salmonella LPS is added. Thus, our study indicates that impaired immunity against nontyphoidal Salmonella bacteremia in HIV infection results from excess inhibitory antibodies against Salmonella LPS, whereas serum killing of Salmonella is induced by antibodies against outer membrane proteins.

The STAT3 inhibitor NSC 74859 is effective in hepatocellular cancers with disrupted TGF-beta signaling

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide, with few effective therapeutic options for advanced disease. At least 40% of HCCs are clonal, potentially arising from STAT3+, NANOG+ and OCT3/4+ liver progenitor/stem cell transformation, along with inactivation of transforming growth factor-beta (TGF-beta) signaling. Here we report significantly greater signal transducer and activator of transcription 3 (STAT3) and tyrosine phosphorylated STAT3 in human HCC tissues (P<0.0030 and P<0.0455, respectively) than in human normal liver. Further, in HCC cells with loss of response to TGF-beta, NSC 74859, a STAT3-specific inhibitor, markedly suppresses growth. In contrast, CD133(+) status did not affect the response to STAT3 inhibition: both CD133(+) Huh-7 cells and CD133(-) Huh-7 cells are equally sensitive to NSC 74859 treatment and STAT3 inhibition, with an IC(50) of 100 muM. Thus, the TGF-beta/beta2 spectrin (beta2SP) pathway may reflect a more functional 'stem/progenitor' state than CD133. Furthermore, NSC 74859 treatment of Huh-7 xenografts in nude mice significantly retarded tumor growth, with an effective dose of only 5 mg/kg. Moreover, NSC 74859 inhibited tyrosine phosphorylation of STAT3 in HCC cells in vivo. We conclude that inhibiting interleukin 6 (IL6)/STAT3 in HCCs with inactivation of the TGF-beta/beta2SP pathway is an effective approach in management of HCCs. Thus, IL6/STAT3, a major signaling pathway in HCC stem cell renewal and proliferation, can provide a novel approach to the treatment of specific HCCs.

The dynamics of sexual conflict over mating rate with endosymbiont infection that affects reproductive phenotypes

Maternally inherited endosymbionts have been implicated as significant drivers of sexual conflict within their hosts, typically through sex-ratio manipulation. Empirical studies show that some of these endosymbionts have the potential to influence sexual conflict not by sex-ratio distortion, but by altering reproductive traits within their hosts. Research has already shown that reproductive traits involved in mating/fertilization process are integral 'players' in sexual conflict, thus suggesting the novel hypothesis that endosymbiont-induced changes in reproductive phenotypes can impact the dynamics of sexual conflict. Here, we use a standard quantitative genetic approach to model the effects of endosymbiont-induced changes in a female reproductive trait on the dynamics of sexual conflict over mating/fertilization rate. Our model shows that an endosymbiont-induced alteration of a host female reproductive trait that affects mating rate can maintain the endosymbiont infection within the host population, and does so in the absence of sex-ratio distortion and cytoplasmic incompatibility.

BCL6b mediates the enhanced magnitude of the secondary response of memory CD8+ T lymphocytes

A characteristic of the secondary response of CD8(+) T cells that distinguishes it from the primary response is the generation of greater numbers of effector cells. Because effector CD8(+) T cells are derived from a pool of less differentiated, replicating cells in secondary lymphoid organs, and because IL-2 mediates effector differentiation, the enhanced secondary response may reflect the enlargement of this generative pool by the transient repression of IL-2-mediated differentiation. We have examined for this function the transcriptional repressor BCL6b, a homologue of BCL6 that represses IL-2-induced B cell differentiation. BCL6b is expressed in a small subset of antigen-experienced CD8(+) T cells. Ectopic expression of BCL6b in CD8(+) T cells diminishes their growth in response to IL-2 in vitro. Female mice in which the BCL6b gene has been interrupted have normal primary responses of CD8(+) T cells to infection with vaccinia expressing the H-Y epitope, Uty, but Uty-specific, BCL6b(-/-), memory CD8(+) T cells have diminished recall proliferative responses to this epitope in vitro. BCL6b(-/-) mice also have normal primary CD8(+) T cell responses to influenza infection, but nucleoprotein peptide-specific, BCL6b(-/-), memory CD8(+) T cells have a cell autonomous defect in the number of effector cells generated in response to reinfection. Therefore, BCL6b is required for the enhanced magnitude of the secondary response of memory CD8(+) T cells.

Novel Strategies in Cancer Therapeutics: Targeting Enzymes Involved in Cell Cycle Regulation and Cellular Proliferation

Tumor development, growth, and progression depend on some combination of altered cell cycle regulation, excessive growth factor pathway activation, and decreased apoptosis. Understanding the complex molecular mechanisms that underlie these processes should therefore lead to the identification of potential targets for therapeutic intervention. The estrogen receptor and HER-2/neu were among the earliest targets investigated, ultimately leading to the widespread use of tamoxifen and trastuzumab, respectively, in the treatment of breast cancer. Major research advances have since led to other classes of targeted therapies, including cyclin-dependent kinase inhibitors, histone deactylase inhibitors, and receptor tyrosine kinase inhibitors. The following review provides a discussion of the molecular biology associated with each of these types of therapies as well as a detailed summary of the preclinical and clinical data published on selected compounds from each of these subgroups.

Oral capecitabine vs intravenous 5-fluorouracil and leucovorin: integrated efficacy data and novel analyses from two large, randomised, phase III trials

This study evaluates the efficacy of capecitabine using data from a large, well-characterised population of patients with metastatic colorectal cancer (mCRC) treated in two identically designed phase III studies. A total of 1207 patients with previously untreated mCRC were randomised to either oral capecitabine (1250 mg m⁻² twice daily, days 1−14 every 21 days; n=603) or intravenous (i.v.) bolus 5-fluorouracil/leucovorin (5-FU/LV; Mayo Clinic regimen; n=604). Capecitabine demonstrated a statistically significant superior response rate compared with 5-FU/LV (26 vs 17%; P<0.0002). Subgroup analysis demonstrated that capecitabine consistently resulted in superior response rates (P<0.05), even in patient subgroups with poor prognostic indicators. The median time to response and duration of response were similar and time to progression (TTP) was equivalent in the two arms (hazard ratio (HR) 0.997, 95% confidence interval (CI) 0.885–1.123, P=0.95; median 4.6 vs 4.7 months with capecitabine and 5-FU/LV, respectively). Multivariate Cox regression analysis identified younger age, liver metastases, multiple metastases and poor Karnofsky Performance Status as independent prognostic indicators for poor TTP. Overall survival was equivalent in the two arms (HR 0.95, 95% CI 0.84–1.06, P=0.48; median 12.9 vs 12.8 months, respectively). Capecitabine results in superior response rate, equivalent TTP and overall survival, an improved safety profile and improved convenience compared with i.v. 5-FU/LV as first-line treatment for MCRC. For patients in whom fluoropyrimidine monotherapy is indicated, capecitabine should be strongly considered. Following encouraging results from phase I and II trials, randomised trials are evaluating capecitabine in combination with irinotecan, oxaliplatin and radiotherapy. Capecitabine is a suitable replacement for i.v. 5-FU as the backbone of colorectal cancer therapy.

A phase I and pharmacokinetic study of squalamine, a novel antiangiogenic agent, in patients with advanced cancers

PURPOSE

A Phase I study of squalamine, a novel antiangiogenic agent originally isolated from the dogfish shark Squalus acanthias, was conducted in patients with advanced cancers to: (a) determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT) and pharmacokinetics of squalamine lactate when given as a 120-h continuous i.v. infusion every two weeks; and (b) to obtain information on prolonged (>120-h) continuous i.v. infusions in patients who have tolerated 120-h infusions.

EXPERIMENTAL DESIGN

A rapid dose escalation scheme was used that permitted intrapatient dose escalation. Three or more patients were treated at each dose, of which at least one patient started treatment de novo at that dose. Once DLT was encountered, the dose was decreased by one dose level, and the duration of infusion was prolonged from 10 up to 30 days in 5-day increments.

RESULTS

Nineteen patients were treated at eight squalamine dose levels; the number of patients/dose level who received 120-h infusions were [expressed as dose in mg/m(2)/day (number of patients initiated de novo at that dose/total number of patients treated at that dose)]: 6 (3/3), 12 (3/6), 24 (1/5), 48 (2/6), 96 (4/10), 192 (2/6), 384 (3/8), and 538 (1/5). DLT was encountered at 384 mg/m(2)/day (1/3 de novo patients, 5/8 total patients) and 538 mg/m(2)/day (1/1 de novo patients, 4/5 total patients) and consisted of hepatotoxicity, characterized by grade 3 transaminase elevations that resolved 3-11 days after ceasing squalamine infusion. Three patients did not experience hepatotoxicity when first treated at 384 mg/m(2)/day but developed DLT at the same dose when de-escalated from 538 mg/m(2)/day. Other toxicities included grade 1-3 fatigue, grade 1-2 nausea, anorexia, and neuromuscular symptoms. The maximum duration of continuous i.v. infusion was 20 days at a dose rate of 192 mg/m(2)/day in one patient without adverse effects. Pharmacokinetic calculations revealed a linear relationship between area under the curve or Cmax and squalamine dose rate up to 384 mg/m(2)/day, with a prolonged terminal squalamine persistence in patient plasma (median t(1/2) = 18 h; range, 8-48 h). Transient tumor responses were observed in a patient with synovial cell sarcoma and a patient with breast carcinoma with cutaneous metastases.

CONCLUSIONS

The best tolerated dose rate of squalamine when administered as a 120-h continuous i.v. infusion was 192 mg/m(2)/day; however, patients without prior exposure to squalamine appeared to tolerate a dose rate of 384 mg/m(2)/day without DLT. On the basis of preclinical evidence of synergy with cytotoxic agents and demonstration of human safety from this trial, additional clinical trials have been initiated with squalamine in combination with chemotherapy for patients with late stage lung cancer and ovarian cancer.