IL-7R licenses a population of epigenetically poised memory CD8+ T cells with superior antitumor efficacy that are critical for melanoma memory

Recurrence of advanced melanoma after therapy is a major risk factor for reduced survival, and treatment options are limited. Antitumor immune memory plays a critical role in preventing melanoma recurrence and memory T cells could be a potent cell-based therapy, but the identity, and functional properties of the required immune cells are incompletely understood. Here, we show that an IL-7Rhi tumor-specific CD8+ population is critical for antitumor memory and can be epigenetically augmented to drive powerful antitumor immune responses. Using a model of functional antimelanoma memory, we found that high IL-7R expression selectively marks a CD8+ population in lymphoid organs that plays critical roles in maintaining tumor remission after immunotherapy or surgical resection. This population has intrinsic cytotoxic activity, lacks markers of exhaustion and has superior antitumor efficacy. IL-7Rhi cells have a functionally poised epigenetic landscape regulated by DNA methylation, which can be augmented by hypomethylating agents to confer improved survival and complete melanoma clearance in naive mice. Importantly, greater than 95% of tumor-specific T cells in draining lymph nodes after therapy express high levels of IL-7R. This overlap between IL-7Rhi and antigen-specific T cells allows for enrichment of a potent functional CD8+ population without determining antigen-specificity, which we demonstrate in a melanoma model without a known antigen. We identify that IL-7R expression in human melanoma is an independent prognostic factor of improved survival. These findings advance our basic understanding of antitumor memory and suggest a cell-based therapy using high IL-7R expression to enrich for a lymph node population with superior antitumor activity that can be augmented by hypomethylating agents.

Cutting Edge: IL-21 and Tissue-Specific Signals Instruct Tbet+CD11c+ B Cell Development following Viral Infection

Tbet+CD11c+ B cells, also known as age-associated B cells (ABCs), are pivotal contributors to humoral immunity following infection and in autoimmunity, yet their in vivo generation is incompletely understood. We used a mouse model of systemic acute lymphocytic choriomeningitis virus infection to examine the developmental requirements of ABCs that emerged in the spleen and liver. IL-21 signaling through STAT3 was indispensable for ABC development. In contrast, IFN-γ signaling through STAT1 was required for B cell activation and proliferation. Mice that underwent splenectomy or were deficient in lymphotoxin α generated hepatic ABCs despite the lack of secondary lymphoid organ contributions, suggesting that the liver supported de novo generation of these cells separately from their development in lymphoid organs. Thus, IFN-γ and IL-21 signaling have distinct, stage-specific roles in ABC differentiation, while the tissue microenvironment provides additional cues necessary for their development.

Inflammasome activation in infected macrophages drives COVID-19 pathology

Severe COVID-19 is characterized by persistent lung inflammation, inflammatory cytokine production, viral RNA and a sustained interferon (IFN) response, all of which are recapitulated and required for pathology in the SARS-CoV-2-infected MISTRG6-hACE2 humanized mouse model of COVID-19, which has a human immune system1-20. Blocking either viral replication with remdesivir21-23 or the downstream IFN-stimulated cascade with anti-IFNAR2 antibodies in vivo in the chronic stages of disease attenuates the overactive immune inflammatory response, especially inflammatory macrophages. Here we show that SARS-CoV-2 infection and replication in lung-resident human macrophages is a critical driver of disease. In response to infection mediated by CD16 and ACE2 receptors, human macrophages activate inflammasomes, release interleukin 1 (IL-1) and IL-18, and undergo pyroptosis, thereby contributing to the hyperinflammatory state of the lungs. Inflammasome activation and the accompanying inflammatory response are necessary for lung inflammation, as inhibition of the NLRP3 inflammasome pathway reverses chronic lung pathology. Notably, this blockade of inflammasome activation leads to the release of infectious virus by the infected macrophages. Thus, inflammasomes oppose host infection by SARS-CoV-2 through the production of inflammatory cytokines and suicide by pyroptosis to prevent a productive viral cycle.

Abstract 898: Survival for patients with early-onset colorectal cancer - An overall survival analysis from the National Cancer Database, 2004-2015

Hazard Ratios (95% CI) of Overall Mortality by Comparing Early-onset and Later-onset CRCAgeUnadjustedAdjusted for Stage OnlyFully Adjusted except StageFully Adjusted<501.04 (1.02-1.05)0.89 (0.88-0.90)1.02 (1.00-1.03)0.95 (0.93-0.96)51 - 551.001.001.001.00<200.83 (0.71-0.97)1.08 (0.93-1.26)1.05 (0.90-1.23)1.04 (0.88-1.22)20 - 241.04 (0.95-1.14)1.08 (0.99-1.18)1.05 (0.96-1.16)1.07 (0.97-1.17)25 - 291.07 (1.01-1.14)0.93 (0.88-0.99)1.01 (0.94-1.08)0.94 (0.88-1.00)30 - 341.05 (1.00-1.09)0.85 (0.82-0.89)1.00 (0.95-1.06)0.90 (0.85-0.95)35 - 390.99 (0.96-1.03)0.83 (0.80-0.85)0.97 (0.93-1.02)0.88 (0.84-0.92)40 - 441.02 (1.00-1.05)0.88 (0.86-0.90)1.00 (0.98-1.03)0.94 (0.92-0.96)45 - 491.05 (1.03-1.07)0.91 (0.90-0.93)1.02 (1.00-1.04)0.96 (0.94-0.98)51 - 551.001.001.001.00

Despite significantly reduced colorectal cancer (CRC) incidence in Americans aged 50 and older since 2000, the incidence of CRC among those <50 has been steadily rising in the U.S. Understanding survival of early-onset CRC (EOCRC; <50 years), relative to those over 50 years, is fundamental to informing treatment approaches and understanding unique biological distinctiveness within EOCRC. To inform these questions, we established a large, nationwide, registry-based CRC cohort (N=769,871) from the National Cancer Database between January 1, 2004 through December 31, 2015. After initial analyses, to avoid possible screening detection bias at age 50 in our population (0-90 years), which was marked with a remarkable proportion of earlier stage and the lowest hazard ratio (HR) in all ages, patients diagnosed at age 51-55 were selected as the comparison group. Overall survival was assessed by the Kaplan-Meier method and Cox proportional hazards regression. Of 769,871 CRC patients (49% women; 83% white), 46% died over a median follow-up of 2.9 years, and 14% were EOCRC. Compared with CRC diagnosed at ages 51-55 years, EOCRC patients had a modestly lower 10-year survival rate (53.6% [95% CI, 53.2%-54.0%] vs. 54.3% [95% CI, 53.8%-54.8%]) in unadjusted analysis. However, after adjusting for stage at diagnosis, EOCRC patients had better survival compared to subjects diagnosed at ages 51-55 (adjusted HR for mortality: 0.95 [95% CI, 0.93-0.96]). The survival advantage appeared greatest for patients diagnosed at stages I-II and ages 35-39. In conclusion, after adjusting for stage at diagnosis, EOCRC is associated with a modestly improved survival when compared to subjects who presented between ages 51-55 years. This reinforces the importance of early CRC detection in the younger population. Further study is needed to understand the underlying heterogeneity of survival within early-onset patients by stage and age.

Citation Format: En Cheng, Holly N. Blackburn, Kimmie Ng, Donna Spiegelman, Melinda L. Irwin, Xiaomei Ma, Cary P. Gross, Fred K. Tabung, Edward L. Giovannucci, Pamela L. Kunz, Xavier Llor, Kevin Billingsley, Jeffrey A. Meyerhardt, Nita Ahuja, Charles S. Fuchs. Survival for patients with early-onset colorectal cancer - An overall survival analysis from the National Cancer Database, 2004-2015 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 898.

Analysis of Survival Among Adults With Early-Onset Colorectal Cancer in the National Cancer Database

IMPORTANCE

While increased adherence to colorectal cancer (CRC) screening guidelines in the US has been associated with significant reductions in cancer incidence in US individuals aged 50 years and older, the incidence of CRC among those aged younger than 50 years has been steadily increasing. Understanding the survival among individuals with early-onset CRC compared with those aged 50 years and older is fundamental to informing treatment approaches and understanding the unique biological distinctiveness within early-onset CRC.

OBJECTIVE

To characterize the overall survival for individuals with early-onset CRC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the National Cancer Database. Included individuals were ages 0 to 90 years and diagnosed with primary CRC from January 1, 2004, through December 31, 2015. Individuals diagnosed at ages 51 through 55 years were selected as the reference group and defined as later-onset CRC for this study. Individuals diagnosed at age 50 years were excluded to minimize an apparent screening detection bias at that age in our population, given that these individuals disproportionately presented with earlier stage. All statistical analyses were conducted from January 4, 2020, through December 26, 2020.

EXPOSURES

Early-onset CRC was defined as age younger than 50 years at diagnosis.

MAIN OUTCOMES AND MEASURES

Overall survival was assessed by Kaplan-Meier analysis and Cox proportional hazards regression.

RESULTS

Among 769 871 individuals with CRC (377 890 [49.1%] women; 636 791 White individuals [82.7%]), 353 989 individuals (46.0%) died (median [range] follow-up: 2.9 [0-14.0] years), 102 168 individuals (13.3%) had early-onset CRC, and 78 812 individuals (10.2%) had later-onset CRC. Individuals with early-onset CRC, compared with those diagnosed with CRC at ages 51 through 55 years, had a lower 10-year survival rate (53.6% [95% CI, 53.2%-54.0%] vs 54.3% [95% CI, 53.8%-54.8%]; P < .001) in unadjusted analysis. However, after adjustment for other factors associated with mortality, most notably stage, individuals with early-onset CRC had a lower risk of death compared with individuals diagnosed from ages 51 through 55 years (adjusted hazard ratio [HR], 0.95 [95% CI, 0.93-0.96]; P < .001). In the model adjusted for stage, the HR for individuals with early-onset CRC was 0.89 (95% CI, 0.88-0.90; P < .001). The survival advantage was greatest for individuals diagnosed at ages 35 through 39 years (adjusted HR, 0.88 [95% CI, 0.84-0.92]; P < .001) and stages I (adjusted HR, 0.87 [95% CI, 0.81-0.93]; P < .001) and II (adjusted HR, 0.86 [95% CI, 0.82-0.90]; P < .001) and was absent among those diagnosed at ages 25 years or younger and stages III through IV.

CONCLUSIONS AND RELEVANCE

These findings suggest that there is a survival benefit for individuals with early-onset CRC compared with those diagnosed with CRC at later ages. Further study is needed to understand the underlying heterogeneity of survival among individuals with early-onset CRC by age and stage.

Dickkopf-2 regulates the stem cell marker LGR5 in colorectal cancer via HNF4α1

Enhanced stemness in colorectal cancer has been reported and it contributes to aggressive progression, but the underlying mechanisms remain unclear. Here we report a Wnt ligand, Dickkopf-2 (DKK2) is essential for developing colorectal cancer stemness. Genetic depletion of DKK2 in intestinal epithelial or stem cells reduced tumorigenesis and expression of the stem cell marker genes including LGR5 in a model of colitis-associated cancer. Sequential mutations in APC, KRAS, TP53, and SMAD4 genes in colonic organoids revealed a significant increase of DKK2 expression by APC knockout and further increased by additional KRAS and TP53 mutations. Moreover, DKK2 activates proto-oncogene tyrosine-protein kinse Src followed by increased LGR5 expressing cells in colorectal cancer through degradation of HNF4α1 protein. These findings suggest that DKK2 is required for colonic epithelial cells to enhance LGR5 expression during the progression of colorectal cancer.

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APC, KRAS, and TP53 mutations induce DKK2 expression in murine colon cancer

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DKK2 increases Src phosphorylation in colon cancer cells

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Activated Src leads to degradation of HNF4α1 protein

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This DKK2 downstream signaling enhances LGR5 expression in colon cancer

Identifying the low risk patient in surgical intensive and intermediate care units using continuous monitoring

BACKGROUND

Continuous predictive monitoring has been employed successfully to predict subclinical adverse events. Should low values on these models, however, reassure us that a patient will not have an adverse outcome? Negative predictive values of such models could help predict safe patient discharge. The goal of this study was to validate the negative predictive value of an ensemble model for critical illness (using previously developed models for respiratory instability, hemorrhage, and sepsis) based on bedside monitoring data in the intensive care units and intermediate care unit.

METHODS

We calculated the relative risk of 3 critical illnesses for all patients every 15 minutes (n= 124,588) for 2,924 patients downgraded from the surgical intensive care units and intermediate care unit between May 2014 to May 2016. We constructed an ensemble model to estimate at the time of intensive care units or intermediate care unit discharge the probability of favorable outcome after downgrade.

RESULTS

Outputs form the ensemble model stratified patients by risk of favorable and bad outcomes in both intensive care units/intermediate care unit; area under the receiver operating characteristic curve = .639/.629 respectively for favorable outcomes and .645/.641 for adverse events. These performance characteristics are commensurate with published models for predicting readmission. The ensemble model remained a statistically significant predictor after adjusting for hospital duration of stay and admitting service. The rate of favorable outcome in the highest and lowest deciles in the intensive care units were 76.2% and 27.3% (2.8-fold decrease) and 88.3% and 33.2% in the intermediate care unit (2.7-fold decrease), respectively.

CONCLUSION

An ensemble model for critical illness predicts favorable outcome after downgrade and safe patient discharge (hospital stay <7 days, no readmission, upgrade, or death).