Publications

Blockade of immune checkpoint proteins (e.g., CTLA-4, PD-1) improves overall survival in advanced melanoma; however, therapeutic benefit is limited to only a subset of patients. Because checkpoint blockade acts by "removing the brakes" on effector T cells, the efficacy of checkpoint blockade may be constrained by the limited pool of melanoma-reactive T cells in the periphery. In the thymus, autoimmune regulator (Aire) promotes deletion of T cells reactive against self-antigens that are also expressed by tumors. Thus, while protecting against autoimmunity, Aire also limits the generation of melanoma-reactive T cells. Here, we show that Aire deficiency in mice expands the pool of CD4+ T cells capable of melanoma cell eradication and has additive effects with anti-CTLA-4 antibody in slowing melanoma tumor growth and increasing survival. Moreover, pharmacologic blockade of central T cell tolerance and peripheral checkpoint blockade in combination enhanced antimelanoma immunity in a synergistic manner. In melanoma patients treated with anti-CTLA-4 antibody, clinical response to therapy was associated with a human Aire polymorphism. Together, these findings suggest that Aire-mediated central tolerance constrains the efficacy of peripheral checkpoint inhibition and point to simultaneous blockade of Aire and checkpoint inhibitors as a novel strategy to enhance antimelanoma immunity.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder that is closely associated with insulin resistance and type 2 diabetes. Previous studies have suggested that hepatocyte nuclear factor 1b (HNF1b) ameliorates insulin resistance. However, the role of HNF1b in the regulation of lipid metabolism and hepatic steatosis remains poorly understood. We found that HNF1b expression was decreased in steatotic livers. We injected mice with lentivirus (LV) expressing HNF1b shRNA to generate mice with hepatic knockdown of HNF1b. We also injected high fat (HF) diet-induced obese and db/db diabetic mice with LV expressing HNF1b to overexpress HNF1b. Knockdown of HNF1b increased hepatic lipid contents and induced insulin resistance in mice and in hepatocytes. Knockdown of HNF1b worsened HF diet-induced increases in hepatic lipid contents, liver injury and insulin resistance in mice and PA-induced lipid accumulation and impaired insulin signaling in hepatocytes. Moreover, overexpression of HNF1b alleviated HF diet-induced increases in hepatic lipid content and insulin resistance in mice. Knockdown of HNF1b increased expression of genes associated with lipogenensis and endoplasmic reticulum (ER) stress. DPP4 and NOX1 expression was increased by knockdown of HNF1b and HNF1b directly bound with the promoters of DPP4 and NOX1. Overexpression of DPP4 or NOX1 was associated with an increase in lipid droplets in hepatocytes and decreased expression of DPP4 or NOX1 suppressed the effects of knockdown of HNF1b knockdown on triglyceride (TG) formation and insulin signaling. Knockdown of HNF1b increased superoxide level and decreased glutathione content, which was inhibited by downregulation of DPP4 and NOX1. N-acetylcysteine (NAC) suppressed HNF1b knockdown-induced ER stress, TG formation and insulin resistance. Palmitic acid (PA) decreased HNF1b expression which was inhibited by NAC. Taken together, these studies demonstrate that HNF1b plays an essential role in controlling hepatic TG homeostasis and insulin sensitivity by regulating DPP4/NOX1mediated generation of superoxide.

OBJECTIVE

To understand patient, primary care clinician (PCC), and subspecialist perspectives on potential, unexplored roles for patients in electronic consultation and referral (eCR) systems.

DATA SOURCES

Primary focus group and survey data collected April-November 2015. Zuckerberg San Francisco General Hospital (ZSFG) is part of an integrated public health delivery system. Its mature eCR system was first implemented in 2005.

STUDY DESIGN

This mixed-methods study synthesizes patient, subspecialist, and PCC perspectives through two patient focus groups in English, Spanish, and Cantonese (n = 6); subspecialist focus groups (n = 2); and an electronic survey of all PCCs (n = 222/634, 35 percent response).

DATA COLLECTION/EXTRACTION METHODS

Focus groups were audio-recorded and transcribed. Two researchers coded the transcripts to identify recurrent themes. Survey data were analyzed using summary and bivariate statistics.

PRINCIPAL FINDINGS

Patients expressed minimal desire to directly engage in eCR, instead of emphasizing their PCC's role in advocating, informing, and finding health solutions. Subspecialists requested more consistent communication to patients about the electronic consultation process. Most PCCs (52 percent) supported patient engagement in the eCR process, particularly patient ability to track consult status and securely message with subspecialists.

CONCLUSIONS

Results suggest a continuum of opportunities for patients and their caregivers to engage in eCR systems.