Leveraging human-centered design and causal pathway diagramming toward enhanced specification and development of innovative implementation strategies: a case example of an outreach tool to address racial inequities in breast cancer screening.

BACKGROUND: Implementation strategies are strategies to improve uptake of evidence-based practices or interventions and are essential to implementation science. Developing or tailoring implementation strategies may benefit from integrating approaches from other disciplines; yet current guidance on how to effectively incorporate methods from other disciplines to develop and refine innovative implementation strategies is limited. We describe an approach that combines community-engaged methods, human-centered design (HCD) methods, and causal pathway diagramming (CPD)-an implementation science tool to map an implementation strategy as it is intended to work-to develop innovative implementation strategies. METHODS: We use a case example of developing a conversational agent or chatbot to address racial inequities in breast cancer screening via mammography. With an interdisciplinary team including community members and operational leaders, we conducted a rapid evidence review and elicited qualitative data through interviews and focus groups using HCD methods to identify and prioritize key determinants (facilitators and barriers) of the evidence-based intervention (breast cancer screening) and the implementation strategy (chatbot). We developed a CPD using key determinants and proposed strategy mechanisms and proximal outcomes based in conceptual frameworks. RESULTS: We identified key determinants for breast cancer screening and for the chatbot implementation strategy. Mistrust was a key barrier to both completing breast cancer screening and using the chatbot. We focused design for the initial chatbot interaction to engender trust and developed a CPD to guide chatbot development. We used the persuasive health message framework and conceptual frameworks about trust from marketing and artificial intelligence disciplines. We developed a CPD for the initial interaction with the chatbot with engagement as a mechanism to use and trust as a proximal outcome leading to further engagement with the chatbot. CONCLUSIONS: The use of interdisciplinary methods is core to implementation science. HCD is a particularly synergistic discipline with multiple existing applications of HCD to implementation research. We present an extension of this work and an example of the potential value in an integrated community-engaged approach of HCD and implementation science researchers and methods to combine strengths of both disciplines and develop human-centered implementation strategies rooted in causal perspective and healthcare equity.

Implementing an Organized Colorectal Cancer Screening Program: Lessons Learned From an Academic-Community Practice.

Introduction: The effectiveness of mailed fecal immunochemical test outreach might be enhanced through an organized colorectal cancer screening program, yet published real-world experiences are limited. We synthesized the process of implementing a colorectal cancer screening program that used mailed fecal immunochemical test outreach in a large integrated academic-community practice. Methods: Data from a pilot mailed fecal immunochemical test program were shared with healthcare system leadership, which inspired the creation of a cross-institutional organized colorectal cancer screening program. In partnership with a centralized population health team and primary care, we defined (1) the institutional approach to colorectal cancer screening, (2) the target population and method for screening, (3) the team responsible for implementation, (4) the healthcare team responsible for decisions and care, (5) a quality assurance structure, and (6) a method for identifying cancer occurrence. Results: The Fred Hutch/UW Medicine Population Health Colorectal Cancer Screening Program began in September 2021. The workflow for mailed fecal immunochemical test outreach included a mailed postcard, a MyChart message from the patient's primary care provider, a fecal immunochemical test kit with a letter signed by the primary care provider and program director, and up to 3 biweekly reminders. Patients without a colonoscopy 3 months after an abnormal fecal immunochemical test result received navigation through the program. In the first program year, we identified 9,719 patients eligible for outreach, and in an intention-to-treat analysis, 32% of patients completed colorectal cancer screening by fecal immunochemical test or colonoscopy. Conclusions: Real-world experiences detailing how to implement organized colorectal cancer screening programs might increase adoption. In our experience, broadly disseminating pilot data, early institutional support, robust data management, and strong cross-departmental relationships were critical to successfully implementing a colorectal cancer screening program that benefits all patients.

Lymphatic endothelial S1P promotes mitochondrial function and survival in naive T cells.

Effective adaptive immune responses require a large repertoire of naive T cells that migrate throughout the body, rapidly identifying almost any foreign peptide. Because the production of T cells declines with age, naive T cells must be long-lived. However, it remains unclear how naive T cells survive for years while constantly travelling. The chemoattractant sphingosine 1-phosphate (S1P) guides T cell circulation among secondary lymphoid organs, including spleen, lymph nodes and Peyer's patches, where T cells search for antigens. The concentration of S1P is higher in circulatory fluids than in lymphoid organs, and the S1P1 receptor (S1P1R) directs the exit of T cells from the spleen into blood, and from lymph nodes and Peyer's patches into lymph. Here we show that S1P is essential not only for the circulation of naive T cells, but also for their survival. Using transgenic mouse models, we demonstrate that lymphatic endothelial cells support the survival of T cells by secreting S1P via the transporter SPNS2, that this S1P signals through S1P1R on T cells, and that the requirement for S1P1R is independent of the established role of the receptor in guiding exit from lymph nodes. S1P signalling maintains the mitochondrial content of naive T cells, providing cells with the energy to continue their constant migration. The S1P signalling pathway is being targeted therapeutically to inhibit autoreactive T cell trafficking, and these findings suggest that it may be possible simultaneously to target autoreactive or malignant cell survival.

Constitutive Lck Activity Drives Sensitivity Differences between CD8+ Memory T Cell Subsets.

CD8(+) T cells develop increased sensitivity following Ag experience, and differences in sensitivity exist between T cell memory subsets. How differential TCR signaling between memory subsets contributes to sensitivity differences is unclear. We show in mouse effector memory T cells (TEM) that >50% of lymphocyte-specific protein tyrosine kinase (Lck) exists in a constitutively active conformation, compared with <20% in central memory T cells (TCM). Immediately proximal to Lck signaling, we observed enhanced Zap-70 phosphorylation in TEM following TCR ligation compared with TCM Furthermore, we observed superior cytotoxic effector function in TEM compared with TCM, and we provide evidence that this results from a lower probability of TCM reaching threshold signaling owing to the decreased magnitude of TCR-proximal signaling. We provide evidence that the differences in Lck constitutive activity between CD8(+) TCM and TEM are due to differential regulation by SH2 domain-containing phosphatase-1 (Shp-1) and C-terminal Src kinase, and we use modeling of early TCR signaling to reveal the significance of these differences. We show that inhibition of Shp-1 results in increased constitutive Lck activity in TCM to levels similar to TEM, as well as increased cytotoxic effector function in TCM Collectively, this work demonstrates a role for constitutive Lck activity in controlling Ag sensitivity, and it suggests that differential activities of TCR-proximal signaling components may contribute to establishing the divergent effector properties of TCM and TEM. This work also identifies Shp-1 as a potential target to improve the cytotoxic effector functions of TCM for adoptive cell therapy applications.

A map of the distribution of sphingosine 1-phosphate in the spleen.

Despite the importance of signaling lipids, many questions remain about their function because few tools are available for charting lipid gradients in vivo. Here we generated a sphingosine 1-phosphate (S1P) reporter mouse and used this mouse to define the distribution of S1P in the spleen. Unexpectedly, the presence of blood did not serve as a predictor of the concentration of signaling-available S1P. Large areas of the red pulp had low concentrations of S1P, while S1P was sensed by cells inside the white pulp near the marginal sinus. The lipid phosphate phosphatase LPP3 maintained low S1P concentrations in the spleen and enabled efficient shuttling of marginal zone B cells. The exquisitely tight regulation of S1P availability might explain how a single lipid can simultaneously orchestrate the movements of many cells of the immune system.

Genetic suppression of inflammation blocks the tumor-promoting effects of TGF-ß in gastric tissue.

The contributions of TGF-ß signaling to cancer are complex but involve the inflammatory microenvironment as well as cancer cells themselves. In mice encoding a TGF-ß mutant that precludes its binding to the latent TGF-ß binding protein (Tgfb1(-/C33S)), we observed multiorgan inflammation and an elevated incidence of various types of gastrointestinal solid tumors due to impaired conversion of latent to active TGF-ß1. By genetically eliminating activators of latent TGF-ß1, we further lowered the amount of TGF-ß, which enhanced tumor frequency and multiorgan inflammation. This model system was used to further investigate the relative contribution of TGF-ß1 to lymphocyte-mediated inflammation in gastrointestinal tumorigenesis. Toward this end, we generated Tgfb1(-/C33S);Rag2(-/-) mice that lacked adaptive immune function, which eliminated tumor production. Analysis of tissue from Tgfb1(-/C33S) mice indicated decreased levels of P-Smad3 compared with wild-type animals, whereas tissue from Tgfb1(-/C33S);Rag2(-/-) mice had normal P-Smad3 levels. Inhibiting the inflammatory response normalized levels of interleukin (IL)-1ß and IL-6 and reduced tumor cell proliferation. In addition, Tgfb1(-/C33S);Rag2(-/-) mice exhibited reduced paracrine signaling in the epithelia, mediated by hepatocyte growth factor produced by gastric stroma. Together, our results indicate that many of the responses of the gastric tissue associated with decreased TGF-ß1 may be directly or indirectly affected by inflammatory processes, which accompany loss of TGF-ß1, rather than a direct effect of loss of the cytokine.