Optimal Management of Refractory Crohn's Disease: Current Landscape and Future Direction.

Refractory Crohn's disease, defined as ongoing inflammation despite the trial of multiple advanced therapies, impacts a number of individuals with Crohn's disease, and leads to significant burden in quality of life and cost. Interventions such as early implementation of advanced therapies, optimization of current therapies prior to switching to an alternative, as well as understanding the overlapping pathophysiology between immune-mediated disorders, however, can help shift the current landscape and reduce the number of patients with refractory disease. As such, in this review we summarize the key takeaways of the latest research in the management of moderate-to-severe Crohn's disease, focusing on maximization of our currently available medications, while also exploring topics such as combination advanced therapies. We also describe evidence for emerging and alternative therapeutic modalities, including fecal microbiota transplant, exclusive enteral feeding, hyperbaric oxygen, stem cell therapy, bone marrow transplant, and posaconazole, with a focus on both the potential impact and specific indications for each.

Direct piriform-to-auditory cortical projections shape auditory-olfactory integration.

In a real-world environment, the brain must integrate information from multiple sensory modalities, including the auditory and olfactory systems. However, little is known about the neuronal circuits governing how odors influence and modulate sound processing. Here, we investigated the mechanisms underlying auditory-olfactory integration using anatomical, electrophysiological, and optogenetic approaches, focusing on the auditory cortex as a key locus for cross-modal integration. First, retrograde and anterograde viral tracing strategies revealed a direct projection from the piriform cortex to the auditory cortex. Next, using in vivo electrophysiological recordings of neuronal activity in the auditory cortex of awake male or female mice, we found that odors modulate auditory cortical responses to sound. Finally, we used in vivo optogenetic manipulations during electrophysiology to demonstrate that olfactory modulation in auditory cortex, specifically, odor-driven enhancement of sound responses, depends on direct input from the piriform cortex. Together, our results identify a novel role of piriform-to-auditory cortical circuitry in shaping olfactory modulation in the auditory cortex, shedding new light on the neuronal mechanisms underlying auditory-olfactory integration.

Beyond the Lactate Paradox: How Lactate and Acidity Impact T Cell Therapies against Cancer.

T cell therapies, including CAR T cells, have proven more effective in hematologic malignancies than solid tumors, where the local metabolic environment is distinctly immunosuppressive. In particular, the acidic and hypoxic features of the tumor microenvironment (TME) present a unique challenge for T cells. Local metabolism is an important consideration for activated T cells as they undergo bursts of migration, proliferation and differentiation in hostile soil. Tumor cells and activated T cells both produce lactic acid at high rates. The role of lactic acid in T cell biology is complex, as lactate is an often-neglected carbon source that can fuel TCA anaplerosis. Circulating lactate is also an important means to regulate redox balance. In hypoxic tumors, lactate is immune-suppressive. Here, we discuss how intrinsic- (T cells) as well as extrinsic (tumor cells and micro-environmental)-derived metabolic factors, including lactate, suppress the ability of antigen-specific T cells to eradicate tumors. Finally, we introduce recent discoveries that target the TME in order to potentiate T cell-based therapies against cancer.