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Anti-tumour T cell responses play a crucial role in controlling the progression of colorectal cancer (CRC), making this disease a promising candidate for immunotherapy. However, responses to immune-targeted therapies are currently limited to subpopulations of patients and specific types of cancer. Clinical studies have therefore focussed on identifying biomarkers that predict immunotherapy responses and elucidating the immunological landscapes of different cancers. Meanwhile, our understanding of how preclinical tumour models resemble human disease has fallen behind, despite their crucial role in immune-targeted drug development. A deeper understanding of these models is therefore needed to improve the development of immunotherapies and the translation of findings made in these systems. MC38 colon adenocarcinoma is a widely used preclinical model, yet how it recapitulates human colorectal cancer remains poorly defined. This study investigated the tumour-T cell immune landscape of MC38 tumours using histology, immunohistochemistry, and flow cytometry. We demonstrate that early-stage tumours exhibit a nascent TME, lacking important immune-resistance mechanisms of clinical interest, while latestage tumours exhibit a mature TME resembling human tumours, with desmoplasia, T cell exhaustion, and T cell exclusion. Consequently, these findings clarify appropriate timepoint selection in the MC38 model when investigating both immunotherapies and mechanisms that contribute to immunotherapy resistance. Overall, this study provides a valuable resource that will enable appropriate application of the MC38 model and expedite the development and clinical translation of new immunotherapies. [ABSTRACT FROM AUTHOR]

This document is a corrigendum published in the journal Frontiers in Immunology. It corrects an error in Figure 10 of a previously published article titled "Late-stage MC38 tumours recapitulate features of human colorectal cancer - implications for appropriate timepoint selection in preclinical studies." The error involved a duplicated density plot in the figure. The authors apologize for the mistake but state that it does not affect the scientific conclusions of the article. The original article has been updated. [Extracted from the article]

Introduction: Coronary heart disease is a major contributor to the global burden of disease. Appropriate nutrition is a cornerstone of the prevention and treatment of coronary heart disease; however, barriers including cost and access to recommended foods limits long-term adherence for many. We are conducting, in adults with coronary heart disease, a randomised controlled trial comparing usual care with two dietary interventions in which usual care is augmented by 12 weeks free delivered groceries., Methods and Analysis: Three hundred adults recovering from an acute coronary event will be recruited from outpatient cardiovascular services in three regions of Aotearoa New Zealand. Participants will be randomly allocated to three arms: usual care (control group), usual care and the free delivery of foods high in dietary fibre or usual care and the free delivery of foods high in unsaturated fats. Interventions duration is 12 weeks, with a further 12 months follow-up. The primary outcome measures are change in low-density lipoprotein (LDL) cholesterol concentration following the intervention, and a cost-effectiveness analysis of healthcare access and social costs in the year after the intervention. A broad range of secondary outcome measures include other blood lipids, anthropometry, glycaemia, inflammatory markers, gut microbiome, dietary biomarkers, food acceptability, dietary change and the facilitators and barriers to dietary change. The trial will determine whether the free provision of groceries known to reduce cardiovascular risk within usual care will be clinically beneficial and justify the cost of doing so. Results may also provide an indication of the relative benefit of foods rich in dietary fibre or unsaturated fats in coronary heart disease management., Ethics and Dissemination: This trial, The Healthy Heart Study, has Health and Disability Ethics Committee approval (20/NTB/121), underwent Māori consultation, and has locality authority to be conducted in Canterbury, Otago and Southland., Trial Registration Number: ACTRN12620000689976, U1111-1250-1499., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The initiation of CD8 +  T cell responses against dead cell-associated Ags is tightly regulated, facilitating adaptive immunity against pathogens and tumors while preventing autoimmunity. It is now well established that dying cells actively regulate the generation of CD8 + T cell responses via the release or exposure of damage-associated molecular patterns. However, it is unclear whether nonproteasomal proteases (activated in stressed and dying cells) can influence the availability of Ags for cross-presentation. Using a mouse model of immunogenic necrosis, we investigated the role of tumor-derived proteases in the priming of CD8 + T cells. We demonstrate that proteases released from necrotic tumor cells can degrade whole-protein Ag, generating proteolytic intermediates that are efficiently cross-presented by dendritic cells and enhance CD8 + T cell cross-priming. We identify a dominant role for calpain proteases, which are activated during necrotic cell death induced by severe heat shock. Mechanistically, proteolytic intermediates generated by tumor-derived proteases associate with necrotic tumor cell debris, which acts as a vehicle for Ag transfer that facilitates highly efficient cross-presentation in dendritic cells. Our results suggest that proteolytic systems activated in Ag donor cells during cell death may influence the availability of antigenic substrates for cross-presentation, thereby regulating the antigenicity of cell death., (Copyright © 2022 by The American Association of Immunologists, Inc.)