Owing to an error during the production process, in Fig. 2c of this Letter, all four groups of mice were incorrectly labelled as 'WT' (wild type), but the two groups on the left (filled and open blue boxes) should have been labelled 'WT' , whereas the two groups on the right (filled and open yellow boxes) should have been labelled 'KO' (knockout), as in the key for Fig. 2b. The original Letter has been corrected online.

IntroductionIn response to the burden of chronic disease among older adults, different chronic disease self-management tools have been created to optimise disease management. However, these seldom consider all aspects of disease management are not usually developed specifically for seniors or created for sustained use and are primarily focused on a single disease. We created an eHealth self-management application called ‘KeepWell’ that supports seniors with complex care needs in their homes. It incorporates the care for two or more chronic conditions from among the most prevalent high-burden chronic diseases.Methods and analysisWe will evaluate the effectiveness, cost and uptake of KeepWell in a 6-month, pragmatic, hybrid effectiveness–implementation randomised controlled trial. Older adults age ≥65 years with one or more chronic conditions who are English speaking are able to consent and have access to a computer or tablet device, internet and an email address will be eligible. All consenting participants will be randomly assigned to KeepWell or control. The allocation sequence will be determined using a random number generator.Primary outcome is perceived self-efficacy at 6 months. Secondary outcomes include quality of life, health background/status, lifestyle (nutrition, physical activity, caffeine, alcohol, smoking and bladder health), social engagement and connections, eHealth literacy; all collected via a Health Risk Questionnaire embedded within KeepWell (intervention) or a survey platform (control). Implementation outcomes will include reach, effectiveness, adoption, fidelity, implementation cost and sustainability.Ethics and disseminationEthics approval has been received from the North York General Hospital Research and Ethics Board. The study is funded by the Canadian Institutes of Health Research and the Ontario Ministry of Health. We will work with our team to develop a dissemination strategy which will include publications, presentations, plain language summaries and an end-of-grant meeting.Trial registration numberNCT04437238.

Despite obesity reaching pandemic proportions, its impact on antigen-specific T cell responses is still unclear. We have recently demonstrated that obesity results in increased expression of PD-1 on T cells, and checkpoint blockade targeting PD-1/PD-L1 surprisingly resulted in greater clinical efficacy in cancer therapy. Adverse events associated with this therapy center around autoimmune reactions. In this study, we examined the impact of obesity on T cell priming and on autoimmune pathogenesis using the mouse model experimental autoimmune encephalomyelitis (EAE), which is mediated by autoreactive myelin-specific T cells generated after immunization. We observed that diet-induced obese (DIO) mice had a markedly delayed EAE onset and developed milder clinical symptoms compared to mice on control diet (CD). This delay was associated with impaired generation of myelin-specific T cell numbers and concurrently correlated with increased PD-L1 upregulation on antigen-presenting cells in secondary lymphoid organs. PD-1 blockade during the priming stage of EAE restored disease onset and severity and increased numbers of pathogenic CD4+ T cells in the central nervous system (CNS) of DIO mice to similar levels to those of CD mice. Administration of anti-PD-1 after onset of clinical symptoms did not increase EAE pathogenesis demonstrating that initial priming is the critical juncture affected by obesity. These findings demonstrate that obesity impairs antigen-specific T cell priming, but this can be reversed with PD-1 blockade. Our results further suggest that PD-1 blockade may increase the risk of autoimmune toxicities, particularly in obesity.

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