Dual IL-6 and CTLA-4 blockade regresses pancreatic tumors in a T cell- and CXCR3-dependent manner.

This study aimed to enhance antitumor immune responses to pancreatic cancer via Ab-based blockade of IL-6 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Mice bearing s.c. or orthotopic pancreatic tumors were treated with blocking Abs to IL­6 and/or CTLA-4. In both tumor models, dual IL-6 and CTLA-4 blockade significantly inhibited tumor growth. Additional investigations revealed that dual therapy induced an overwhelming infiltration of T cells into the tumor as well as changes in CD4+ T cell subsets. Dual blockade therapy elicited CD4+ T cells to secrete increased IFN-γ in vitro. Likewise, in vitro stimulation of pancreatic tumor cells with IFN-γ profoundly increased tumor cell production of CXCR3-specific chemokines, even in the presence of IL-6. In vivo blockade of CXCR3 prevented orthotopic tumor regression in the presence of the combination treatment, demonstrating a dependence on the CXCR3 axis for antitumor efficacy. Both CD4+ and CD8+ T cells were required for the antitumor activity of this combination therapy, as their in vivo depletion via Abs impaired outcomes. These data represent the first report to our knowledge of IL-6 and CTLA­4 blockade as a means to regress pancreatic tumors with defined operative mechanisms of efficacy.

Combined MEK/PD-L1 Inhibition Alters Peripheral Cytokines and Lymphocyte Populations Correlating with Improved Clinical Outcomes in Advanced Biliary Tract Cancer.

PURPOSE: Biliary tract cancers (BTC) are aggressive malignancies refractory to chemotherapy and immunotherapy. MEK inhibition (MEKi)-based regimens may have utility in this disease when combined with PD-L1 blockade. We hypothesize that dual MEK/PD-L1 inhibition alters circulating soluble and cellular immune mediators to improve clinical outcomes in patients with advanced BTC. EXPERIMENTAL DESIGN: We examined immune features in peripheral blood from 77 patients with advanced BTC enrolled in a phase II clinical trial investigating atezolizumab with or without cobimetinib. Plasma and peripheral blood mononuclear cells (PBMC) were isolated from whole blood to evaluate soluble factors and immune cell populations. Baseline blood samples were additionally compared with healthy donors to identify immune signatures unique to BTC. RESULTS: At baseline, the soluble factors platelet-derived growth factor B (PDGF)-BB, placental growth factor (PlGF)-1, IL5, and IL17A were elevated in patients with BTC compared with healthy adult donors, and higher baseline frequencies of CD8+BTLA+ T cells correlated with better overall survival (OS) in this trial. There were also significant treatment-related alterations in several factors, including decreased PDGF-BB following combination treatment, that correlated with improved OS and progression-free survival (PFS). Higher baseline levels of IL23 and RANTES corresponded to improved clinical outcomes following combination treatment. Dual MEK/PD-L1 inhibition increased populations of CD4+TIM3+ and decreased CD8+VISTA+ T cells, correlating with worse OS and better PFS, respectively. CONCLUSIONS: This work represents a comprehensive analysis of peripheral immune features in patients with BTC and systemic responses to dual MEK/PD-L1 inhibition. These data support further investigation to understand how MEKi combines with immunotherapeutic approaches to improve clinical outcomes for patients with advanced BTC.

Finding Silver Linings: A Mixed Methods Analysis of COVID-19's Challenges and Opportunities for College Students' Functioning and Outlook.

This study examines the impact of the COVID-19 pandemic on college students' lives. A mixed methods approach, analyzing open- and closed-ended questions about challenges and opportunities, reveals numerous ways in which the pandemic has impacted students in general and differentially by gender, sexual orientation, race/ethnicity, and family income. Cisgender male and heterosexual students generally reported less of a mental health impact from the pandemic. Gender and sexual minorities, and low- to middle-income students, also noted some effects of the pandemic more often than their peers. Finally, thematic analysis revealed that where students found challenges, they also found opportunities within the broad categories of Lifestyle and Routines, Academic/Professional, Health, Interpersonal, and Societal impacts, evidencing heterogeneity and resilience in finding silver linings despite the challenging pandemic. This research has implications for equitably deploying and tailoring university and mental health resources both during and beyond the pandemic to improve student well-being and success.

Multicenter randomized phase II trial of atezolizumab with or without cobimetinib in biliary tract cancers.

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Expression of tdTomato and luciferase in a murine lung cancer alters the growth and immune microenvironment of the tumor.

Imaging techniques based on fluorescence and bioluminescence have been important tools in visualizing tumor progression and studying the effect of drugs and immunotherapies on tumor immune microenvironment in animal models of cancer. However, transgenic expression of foreign proteins may induce immune responses in immunocompetent syngeneic tumor transplant models and augment the efficacy of experimental drugs. In this study, we show that the growth rate of Lewis lung carcinoma (LL/2) tumors was reduced after transduction of tdTomato and luciferase (tdTomato/Luc) compared to the parental cell line. tdTomato/Luc expression by LL/2 cells altered the tumor microenvironment by increasing tumor-infiltrating lymphocytes (TILs) while inhibiting tumor-induced myeloid-derived suppressor cells (MDSCs). Interestingly, tdTomato/Luc expression did not alter the response of LL/2 tumors to anti-PD-1 and anti-CTLA-4 antibodies. These results suggest that the use of tdTomato/Luc-transduced cancer cells to conduct studies in immune competent mice may lead to cell-extrinsic tdTomato/Luc-induced alterations in tumor growth and tumor immune microenvironment that need to be taken into consideration when evaluating the efficacy of anti-cancer drugs and vaccines in immunocompetent animal models.

Context-Dependent Immunomodulatory Effects of MEK Inhibition Are Enhanced with T-cell Agonist Therapy.

MEK inhibition (MEKi) is proposed to enhance antitumor immunity but has demonstrated mixed results as an immunomodulatory strategy in human clinical trials. MEKi exerts direct immunomodulatory effects on tumor cells and tumor-infiltrating lymphocytes (TIL), but these effects have not been independently investigated. Here we modeled tumor-specific MEKi through CRISPR/Cas-mediated genome editing of tumor cells [MEK1 knockout (KO)] and pharmacologic MEKi with cobimetinib in a RAS-driven model of colorectal cancer. This approach allowed us to distinguish tumor-mediated and tumor-independent mechanisms of MEKi immunomodulation. MEK1 KO tumors demonstrated upregulation of JAK/STAT signaling, enhanced MHCI expression, CD8+ T-cell infiltration and T-cell activation, and impaired tumor growth that is immune dependent. Pharmacologic MEKi recapitulated tumor-intrinsic effects but simultaneously impaired T-cell activation in the tumor microenvironment. We confirmed a reduction in human peripheral-lymphocyte activation from a clinical trial of anti-PD-L1 (atezolizumab) with or without cobimetinib in biliary tract cancers. Impaired activation of TILs treated with pharmacologic MEKi was reversible and was rescued with the addition of a 4-1BB agonist. Collectively, these data underscore the ability of MEKi to induce context-dependent immunomodulatory effects and suggest that T cell-agonist therapy maximizes the beneficial effects of MEKi on the antitumor immune response.

Heat Shock Protein-90 Inhibition Alters Activation of Pancreatic Stellate Cells and Enhances the Efficacy of PD-1 Blockade in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a prominent fibrotic stroma, which is a result of interactions between tumor, immune and pancreatic stellate cells (PSC), or cancer-associated fibroblasts (CAF). Targeting inflammatory pathways present within the stroma may improve access of effector immune cells to PDAC and response to immunotherapy. Heat shock protein-90 (Hsp90) is a chaperone protein and a versatile target in pancreatic cancer. Hsp90 regulates a diverse array of cellular processes of relevance to both the tumor and the immune system. However, to date the role of Hsp90 in PSC/CAF has not been explored in detail. We hypothesized that Hsp90 inhibition would limit inflammatory signals, thereby reprogramming the PDAC tumor microenvironment to enhance sensitivity to PD-1 blockade. Treatment of immortalized and primary patient PSC/CAF with the Hsp90 inhibitor XL888 decreased IL6, a key cytokine that orchestrates immune changes in PDAC at the transcript and protein level in vitro XL888 directly limited PSC/CAF growth and reduced Jak/STAT and MAPK signaling intermediates and alpha-SMA expression as determined via immunoblot. Combined therapy with XL888 and anti-PD-1 was efficacious in C57BL/6 mice bearing syngeneic subcutaneous (Panc02) or orthotopic (KPC-Luc) tumors. Tumors from mice treated with both XL888 and anti-PD-1 had a significantly increased CD8+ and CD4+ T-cell infiltrate and a unique transcriptional profile characterized by upregulation of genes associated with immune response and chemotaxis. These data demonstrate that Hsp90 inhibition directly affects PSC/CAF in vitro and enhances the efficacy of anti-PD-1 blockade in vivo.

Suppressive myeloid cells are expanded by biliary tract cancer-derived cytokines in vitro and associate with aggressive disease.

BACKGROUND: BTC is an aggressive disease exacerbated by inflammation and immune suppression. Expansion of immunosuppressive cells occurs in biliary tract cancer (BTC), yet the role of BTC-derived cytokines in this process is unclear. METHODS: Activated signalling pathways and cytokine production were evaluated in a panel of human BTC cell lines. Human peripheral blood mononuclear cells (PBMCs) were cultured with BTC supernatants, with and without cytokine neutralising antibodies, and analysed by flow cytometry or immunoblot. A human BTC tissue microarray (TMA, n = 69) was stained for IL-6, GM-CSF, and CD33+S100a9+ cells and correlated with clinical outcomes. RESULTS: Immunomodulatory factors (IL-6, GM-CSF, MCP-1) were present in BTC supernatants. BTC supernatants expanded CD33dimCD11b+HLA-DRlow/- myeloid-derived suppressor cells (MDSCs) from human PBMCs. Neutralisation of IL-6 and GM-CSF in BTC supernatants inhibited activation of STAT3/5, respectively, in PBMCs, with heterogeneous effects on MDSC expansion in vitro. Staining of a BTC TMA revealed a positive correlation between IL-6 and GM-CSF, with each cytokine and more CD33+S100a9+ cells. Increased CD33+S100a9+ staining positively correlated with higher tumour grade, differentiation and the presence of satellite lesions. CONCLUSION: BTC-derived factors promote suppressive myeloid cell expansion, and higher numbers of CD33+S100a9+ cells in resectable BTC tumours correlates with more aggressive disease.

Optical Control of Cytokine Signaling via Bioinspired, Polymer-Induced Latency.

Cytokine signaling is challenging to study and therapeutically exploit as the effects of these proteins are often pleiotropic. A subset of cytokines can, however, achieve signal specificity via association with latency-inducing proteins, which cage the cytokine until disrupted by discreet biological stimuli. Inspired by this precision, here, we describe a strategy for synthetic induction of cytokine latency via modification with photolabile polymers that mimic latency while attached then restore protein activity in response to light, thus controlling the magnitude, duration, and location of cytokine signals. We characterize the high dynamic range of cytokine activity modulation and find that polymer-induced latency, alone, can prolong in vivo circulation and bias receptor subunit binding. We further show that protein derepression can be achieved with a near single-cell resolution and demonstrate the feasibility of transcutaneous photoactivation. Future extensions of this approach could enable multicolor, optical reprogramming of cytokine signaling networks and more precise immunotherapies.

MEK inhibition suppresses B regulatory cells and augments anti-tumor immunity.

Mitogen-activated protein kinase (MAPK) kinase (MEK) is an integral component of the RAS pathway and a therapeutic target in RAS-driven cancers. Although tumor responses to MEK inhibition are rarely durable, MEK inhibitors have shown substantial activity and durable tumor regressions when combined with systemic immunotherapies in preclinical models of RAS-driven tumors. MEK inhibitors have been shown to potentiate anti-tumor T cell immunity, but little is known about the effects of MEK inhibition on other immune subsets, including B cells. We show here that treatment with a MEK inhibitor reduces B regulatory cells (Bregs) in vitro, and reduces the number of Bregs in tumor draining lymph nodes in a colorectal cancer model in vivo. MEK inhibition does not impede anti-tumor humoral immunity, and B cells contribute meaningfully to anti-tumor immunity in the context of MEK inhibitor therapy. Treatment with a MEK inhibitor is associated with improved T cell infiltration and an enhanced response to anti-PD1 immunotherapy. Together these data indicate that MEK inhibition may reduce Bregs while sparing anti-tumor B cell function, resulting in enhanced anti-tumor immunity.

Preliminary analysis of resting state functional connectivity in young adults with subtypes of bipolar disorder.

BACKGROUND: A precision medicine approach to bipolar disorder (BD) requires greater knowledge of neural mechanisms, especially within the BD phenotype. The present study evaluated differences in resting state functional connectivity (RSFC) between young adults followed longitudinally since childhood with full-threshold type I BD (BD-I)-characterized by distinct manic episodes-or a more sub-syndromal presentation of BD (BD Not Otherwise Specified [BD-NOS]), compared to one another and to healthy controls (HC). Independent Components Analysis (ICA), a multivariate data-driven method, and dual regression were used to explore whether connectivity within resting state networks (RSNs) differentiated the groups, especially for characteristic fronto-limbic alterations in BD. METHODS: Young adults (ages 18-30) with BD-I (n = 28), BD-NOS (n = 14), and HCs (n = 52) underwent structural and RSFC neuroimaging. ICA derived 30 components from RSFC data; a subset of these components, representing well-characterized RSNs, was used for between-group analyses. RESULTS: Participants with BD-I had significantly greater connectivity strength between the executive control network and right caudate vs. HCs. Participants with BD-NOS had significantly greater connectivity strength between the sensorimotor network and left precentral gyrus vs. HCs, which was significantly related to psychiatric symptoms. LIMITATIONS: Limitations included small BD-NOS sample size and variation in BD mood state and medication status. CONCLUSIONS: Results for BD-I participants support prior findings of fronto-limbic alterations characterizing BD. Alterations in the sensorimotor network for adults with BD-NOS aligns with the small but growing body of evidence that sensorimotor network alterations may represent a marker for vulnerability to BD. Further study is required to evaluate specificity.

Cognitive performance of youth with primary generalized anxiety disorder versus primary obsessive-compulsive disorder.

BACKGROUND: Despite gains made in the study of childhood anxiety, differential diagnosis remains challenging because of indistinct boundaries between disorders and high comorbidity. This is certainly true for generalized anxiety disorder (GAD) and obsessive-compulsive disorder (OCD) as they share multiple cognitive processes (e.g., rumination, intolerance of uncertainty, and increased attention to threat). Disentangling such cognitive characteristics and, subsequently, underlying mechanisms could serve to inform assessment and treatment practices, and improve prognoses. METHODS: The current study sought to compare the cognitive performance (working memory, visuospatial memory, planning ability/efficiency, and cognitive flexibility), indexed by the Cambridge Neuropsychological Automated Battery (CANTAB) among three nonoverlapping groups of youth: (1) those diagnosed with OCD (n = 28), (2) those diagnosed with GAD, not OCD (n = 34), and (3) typically-developing controls (TDC) (n = 65). RESULTS: Results showed that OCD and GAD youth demonstrated neurocognitive deficits in planning ability/efficiency, cognitive flexibility, and visual processing when compared to TDC, with potential diagnostic specificity such that youth with GAD or OCD had unique deficits compared to TDC and to one another. Specifically, youth with OCD demonstrated significantly impaired planning ability compared to youth in the GAD and TDS groups, whereas youth with GAD demonstrated greater cognitive inflexibility and delayed visual processing compared to youth in the OCD and TDC groups. CONCLUSIONS: Future studies should expand upon these findings with more comprehensive assessment of cognitive functioning by including self- and parent-report forms, and neuroimaging to link behavioral findings with subjective ratings and neurocircuitry. Altogether, data can then inform future assessment and treatment targets.

Developmental evaluation of family functioning deficits in youths and young adults with childhood-onset bipolar disorder.

BACKGROUND: Childhood-onset bipolar disorder (BD) is a serious condition that affects the patient and family. While research has documented familial dysfunction in individuals with BD, no studies have compared developmental differences in family functioning in youths with BD vs. adults with prospectively verified childhood-onset BD. METHODS: The Family Assessment Device (FAD) was used to examine family functioning in participants with childhood-onset BD (n = 116) vs. healthy controls (HCs) (n = 108), ages 7-30 years, using multivariate analysis of covariance and multiple linear regression. RESULTS: Participants with BD had significantly worse family functioning in all domains (problem solving, communication, roles, affective responsiveness, affective involvement, behavior control, general functioning) compared to HCs, regardless of age, IQ, and socioeconomic status. Post-hoc analyses suggested no influence for mood state, global functioning, comorbidity, and most medications, despite youths with BD presenting with greater severity in these areas than adults. Post-hoc tests eliminating participants taking lithium (n = 17) showed a significant diagnosis-by-age interaction: youths with BD had worse family problem solving and communication relative to HCs. LIMITATIONS: Limitations include the cross-sectional design, clinical differences in youths vs. adults with BD, ambiguity in FAD instructions, participant-only report of family functioning, and lack of data on psychosocial treatments. CONCLUSIONS: Familial dysfunction is common in childhood-onset BD and endures into adulthood. Early identification and treatment of both individual and family impairments is crucial. Further investigation into multi-level, family-based mechanisms underlying childhood-onset BD may clarify the role family factors play in the disorder, and offer avenues for the development of novel, family-focused therapeutic strategies.

Preliminary mapping of the structural effects of age in pediatric bipolar disorder with multimodal MR imaging.

This study investigates multimodal structural MR imaging biomarkers of development trajectories in pediatric bipolar disorder. T1-weighted and diffusion-weighted MR imaging was conducted to investigate cross-sectional group differences with age between typically developing controls (N = 26) and youths diagnosed with bipolar disorder (N = 26). Region-based analysis was used to examine cortical thickness of gray matter and diffusion tensor parameters in superficial white matter, and tractography-based analysis was used to examine deep white matter fiber bundles. Patients and controls showed significantly different maturation trajectories across brain areas; however, the magnitude of differences varied by region. The rate of cortical thinning with age was greater in patients than controls in the left frontal pole. While controls showed increasing fractional anisotropy (FA) and axial diffusivity (AD) with age, patients showed an opposite trend of decreasing FA and AD with age in fronto-temporal-striatal regions located in both superficial and deep white matter. The findings support fronto-temporal-striatal alterations in the developmental trajectories of youths diagnosed with bipolar disorder, and further, show the value of multimodal computational techniques in the assessment of neuropsychiatric disorders. These preliminary results warrant further investigation into longitudinal changes and the effects of treatment in the brain areas identified in this study.