The role of answer fluency and perceptual fluency as metacognitive cues for initiating analytic thinking

Although widely studied in other domains, relatively little is known about the metacognitive processes that monitor and control behaviour during reasoning and decision-making. In this paper, we examined the conditions under which two fluency cues are used to monitor initial reasoning: answer fluency, or the speed with which the initial, intuitive answer is produced (Thompson, Prowse Turner, & Pennycook, 2011), and perceptual fluency, or the ease with which problems can be read (Alter, Oppenheimer, Epley, & Eyre, 2007). The first two experiments demonstrated that answer fluency reliably predicted Feeling of Rightness (FOR) judgments to conditional inferences and base rate problems, which subsequently predicted the amount of deliberate processing as measured by thinking time and answer changes; answer fluency also predicted retrospective confidence judgments (Experiment 3b). Moreover, the effect of answer fluency on reasoning was independent from the effect of perceptual fluency, establishing that these are empirically independent constructs. In five experiments with a variety of reasoning problems similar to those of Alter et al. (2007), we found no effect of perceptual fluency on FOR, retrospective confidence or accuracy; however, we did observe that participants spent more time thinking about hard to read stimuli, although this additional time did not result in answer changes. In our final two experiments, we found that perceptual disfluency increased accuracy on the CRT (Frederick, 2005), but only amongst participants of high cognitive ability. As Alter et al.’s samples were gathered from prestigious universities, collectively, the data to this point suggest that perceptual fluency prompts additional processing in general, but this processing may results in higher accuracy only for the most cognitively able

Bone metastasis is associated with acquisition of mesenchymal phenotype and immune suppression in a model of spontaneous breast cancer metastasis

Abstract The most common site of breast cancer metastasis is the bone, occurring in approximately 70% of patients with advanced disease. Bone metastasis is associated with severe morbidities and high mortality. Therefore, deeper understanding of the mechanisms that enable bone-metastatic relapse are urgently needed. We report the establishment and characterization of a bone-seeking variant of breast cancer cells that spontaneously forms aggressive bone metastases following surgical resection of primary tumor. We characterized the modifications in the immune milieu during early and late stages of metastatic relapse and found that the formation of bone metastases is associated with systemic changes, as well as modifications of the bone microenvironment towards an immune suppressive milieu. Furthermore, we characterized the intrinsic changes in breast cancer cells that facilitate bone-tropism and found that they acquire mesenchymal and osteomimetic features. This model provides a clinically relevant platform to study the functional interactions between breast cancer cells and the bone microenvironment, in an effort to identify novel targets for intervention

Nectin4 is a novel TIGIT ligand which combines checkpoint inhibition and tumor specificity

Background The use of checkpoint inhibitors has revolutionized cancer therapy. Unfortunately, these therapies often cause immune-related adverse effects, largely due to a lack of tumor specificity. Methods We stained human natural killer cells using fusion proteins composed of the extracellular portion of various tumor markers fused to the Fc portion of human IgG1, and identified Nectin4 as a novel TIGIT ligand. Next, we generated a novel Nectin4 blocking antibody and demonstrated its efficacy as a checkpoint inhibitor in killing assays and in vivo. Results We identify Nectin4 to be a novel ligand of TIGIT. We showed that, as opposed to all other known TIGIT ligands, which bind also additional receptors, Nectin4 interacts only with TIGIT. We show that the TIGIT-Nectin4 interaction inhibits natural killer cell activity, a critical part of the innate immune response. Finally, we developed blocking Nectin4 antibodies and demonstrated that they enhance tumor killing in vitro and in vivo. Conclusion We discovered that Nectin4 is a novel ligand for TIGIT and demonstrated that specific antibodies against it enhance tumor cell killing in vitro and in vivo. Since Nectin4 is expressed almost exclusively on tumor cells, our Nectin4-blocking antibodies represent a combination of cancer specificity and immune checkpoint activity, which may prove more effective and safe for cancer immunotherapy

vMIP-II blocks the migration of freshly isolated naïve NK cells to Fractalkine.

<p>(A) Freshly isolated naïve NK cells were double stained with Fck-Ig and with anti-CD56 mAb. The percentages of the various populations are indicated in the figure. (B) CX3CR1 expression on the transfectant 293T-CX3CR1 cells (black open histogram) or on 293T parental cells (filled grey histogram). (C) Binding of Fck-Ig (left histogram) or vMIP-II-Ig (right histogram) to 293T-CX3CR1 transfectant (black open histogram) or to the 293T parental cells (filled grey histogram). (D) 293T-CX3CR1 cells were incubated with (black empty histogram) and without (dark gray empty histogram) rvMIP-II for 1 hour in 4°C and then stained with Fck-Ig. The light gray filled histogram is the staining of Fck-Ig on the 293T parental cells. (E) Freshly isolated naïve NK cells were incubated at 4°C for 1 hour with and without the proteins indicated in the x axis. RhFck was placed in the bottom chamber and the numbers of migrated cells was determined by FACS following 3 hours incubation at 37°C. The migration of the NK cells without the appropriate chemokine was set as 1 and the results are presented as fold increase (FI). **P<0.01. NS - not significant. Figure shows one representative experiment out of four performed.</p

vMIP-II-Ig binds PBLs and naïve NK cells.

<p>Freshly isolated PBLs (A), freshly isolated naïve NK cells (B), Monocytes (C) and Neutrophils (D), (the various cell types are indicated in the right of the figure), were stained with different KSHV chemokines fused to human IgG1: vIL6-Ig, vMIP-I-Ig, vMIP-II-Ig or vMIP-III-Ig (X axis, indicated in the top of the figure). PBLs were double stained with the indicated chemokines fused to IgG and with anti-CD3. The percentages of various populations are indicated inside the dot plot. The Median Fluorescence Intensity (MFI) of the vMIP-II-Ig staining of CD3+ cells (A) and of NK cells (B) is indicated and is marked by an arrow. Figure shows one representative staining out of more than 3 performed.</p

vMIP-II-Ig mainly recognizes the naïve CD56^Dim CD16^Pos NK cell population which express the CX3CR1 and CXCR1 chemokine receptors.

<p>(A) Freshly isolated naïve NK cells were double stained with anti-CD56 mAb together with control-Ig or with vMIP-II-Ig. The CD56^Dim CD16^Pos and CD56^Bright CD16^Neg NK cell populations are indicated by an arrow. The percentages of the various populations are indicated. (B) Expression of various chemokine receptors on freshly isolated naïve NK cells. Staining was performed with anti-CD56 mAb together with specific antibodies against CCR1, CCR2, CCR3, CCR5 and CXCR4. The percentages of the various populations are indicated. (C) CCR5 expression varies between different individuals. Staining of various donors (indicated on top of the dot plots) was performed with anti-CD56 mAb together with specific antibodies against CCR5. (D and E) Chemokine receptors expressed primarily by the CD56^Dim CD16^Pos population. Freshly isolated naïve NK cells were double stained with anti-CD56 mAb together with anti-CXCR1 (D) or anti-CX3CR1 (E). The percentages of the various populations are indicated. Figure shows one representative experiment out of three performed.</p

vMIP-II binds activated NK cells that express CCR5.

<p>(A) vMIP-II-Ig binding to activated NK cells (Act-NK) (black open histogram). The filled grey histogram is the secondary antibody staining. (B) Activated NK cells were double stained with anti-CD56 together with anti-CX3CR1 (left dot plot) or with anti CXCR1 (right dot plot). Numbers represent percentages. (C) Activated NK cells were double stained with anti-CD56 mAb and antibodies against CCR1, CCR2, CCR3, CCR5 and CXCR4 (indicated in the X axis). Numbers represent percentages. (D and E) rhRANTES (D) or rvMIP-II (E) were placed in the bottom chamber of transwell plates and the migration of activated NK was quantified by FACS following a 3 hours incubation period at 37°C. The migration of the NK cells without the appropriate chemokine was set as 1 and the results are presented as fold increase (FI). ***P<0.001. NS - not significant. Figure shows one representative experiment out of four performed.</p