T cell migration and cardiovascular toxicity in immunotherapy

T cell migration and cardiovascular toxicity in immunotherapy. Adoptive T-cell transfer therapy has emerged as a promising therapeutic option with complete and durable responses in several disease conditions such as viral infection, autoimmune disease, atherosclerosis, and cancer. However, severe immune-mediated cardiovascular toxicities caused by cytokine release syndrome (CRS) are observed in most patients, and these adverse reactions remain a significant obstacle in developing effective and safe therapies. In studies conducted in the previous cycle of this grant, we showed that in vitro activated T cells are immediately sequestered at the perivascular space of non-specific tissue sites after the intravascular infusion. This non-specific accumulation is mediated by aberrant LFA-1 activation and may be closely associated with impaired T cell functions and increased risk of severe CRS and cardiovascular toxicity. In this study, we will build on these data and identify key mediators that can control the tissue-specific migration of adoptively transferred T cells and harness these mechanisms to increase the efficacy of T cell immunotherapy while reducing the risks associated with cardiovascular toxicity. To this end, we used (1) in vivo intravital multi- photon microscopy to determine the fate of the adoptively transferred therapeutic T cells after infusion and performed (2) an in vivo CRISPR–Cas9 knockout screen and (3) a high-throughput pharmacologic screening to discover key T cell-intrinsic mechanisms that regulate therapeutic CD8 T cell migration to targeted tissue sites. We will, (Aim 1) determine how clinically manufactured T cells interact with the endothelium in non-specific tissues after infusion and impact vascular barrier functions, (Aim 2) determine the molecular mechanisms that can minimize non-specific sequestration but improve specific T cell migration toward the target tissue site, and (Aim 3) determine whether the newly discovered T cell homing mechanisms (Aim 1 and Aim 2) are associated with therapeutic outcomes and the cardiovascular risk in patients. These studies will combine differential perturbations of novel mechanisms that regulate activated T cell migration in in vivo mouse models, state-of-the- art intravital multiphoton imaging, high-resolution pathway screenings, and assay analyses defining vascular inflammatory responses.