Over the last 2 decades, affirmative diagnoses of osteoarthritis (OA) in the United States have tripled due to increasing rates of obesity and an aging population. Hemp-derived cannabidiol (CBD) is the major nontetrahydrocannabinol component of cannabis and has been promoted as a potential treatment for a wide variety of disparate inflammatory conditions. Here, we evaluated CBD for its ability to modulate the production of proinflammatory cytokines in vitro and in murine models of induced inflammation and further validated the ability of a liposomal formulation to increase bioavailability in mice and in humans. Subsequently, the therapeutic potential of both naked and liposomally encapsulated CBD was explored in a 4-week, randomized placebo-controlled, double-blinded study in a spontaneous canine model of OA. In vitro and in mouse models, CBD significantly attenuated the production of proinflammatory cytokines IL-6 and TNF-α while elevating levels of anti-inflammatory IL-10. In the veterinary study, CBD significantly decreased pain and increased mobility in a dose-dependent fashion among animals with an affirmative diagnosis of OA. Liposomal CBD (20 mg/day) was as effective as the highest dose of nonliposomal CBD (50 mg/day) in improving clinical outcomes. Hematocrit, comprehensive metabolic profile, and clinical chemistry indicated no significant detrimental impact of CBD administration over the 4-week analysis period. This study supports the safety and therapeutic potential of hemp-derived CBD for relieving arthritic pain and suggests follow-up investigations in humans are warranted.

SUMMARY Autophagy plays a critical role in the maintenance of immunological memory. However, the molecular mechanisms involved in autophagy-regulated effector memory formation in CD8+ T cells remain unclear. Here we show that deficiency in NIX-dependent mitophagy leads to metabolic defects in effector memory T cells. Deletion of NIX caused HIF1α accumulation and altered cellular metabolism from long-chain fatty acid to short/branched-chain fatty acid oxidation, thereby compromising ATP synthesis during effector memory formation. Preventing HIF1α accumulation restored long-chain fatty acid metabolism and effector memory formation in antigen-specific CD8+ T cells. Our study suggests that NIX-mediated mitophagy is critical for effector memory formation in T cells.

In humans, the natural killer (NK) cell marker CD161 identifies several subsets of T cells, including a polyclonal CD8 αβ T cell receptor–expressing subset with characteristic specificity for tissue-localized viruses. This subset also displays enhanced cytotoxic and memory phenotypes. Here, we characterized this unique T cell subset and determined its potential suitability for use in chimeric antigen receptor (CAR) T cell therapy. In mice, gene expression profiling among the CD161-equivalent CD8+ T cell populations (CD8+NK1.1+) revealed substantial up-regulation of granzymes, perforin, killer lectin-like receptors, and innate signaling molecules in comparison to CD8+NK1.1− T cells. Adoptive transfer of CD8+NK1.1+ cells from previously exposed animals offered substantially enhanced protection and improved survival against melanoma tumors and influenza infection compared to CD8+NK1.1− cells. Freshly isolated human CD8+CD61+ T cells exhibited heightened allogeneic killing activity in comparison to CD8+CD61− T cells or total peripheral blood mononuclear cells (PBMCs). To determine whether this subset might improve the antitumor efficacy of CAR T cell therapy against solid tumors, we compared bulk PBMCs, CD8+CD161−, and CD8+CD161+ T cells transduced with a human epidermal growth factor receptor-2 (HER2)–specific CAR construct. In vitro, CD8+CD161+ CAR-transduced T cells killed HER2+ targets faster and with greater efficiency. Similarly, these cells mediated enhanced in vivo antitumor efficacy in xenograft models of HER2+ pancreatic ductal adenocarcinoma, exhibiting elevated expression of granzymes and reduced expression of exhaustion markers. These data suggest that this T cell subset presents an opportunity to improve CAR T cell therapy for the treatment of solid tumors.

Mammalian immune responses are initiated by “danger” signals––immutable molecular structures known as PAMPs. When detected by fixed, germline encoded receptors, pathogen‐associated molecular pattern (PAMPs) subsequently inform the polarization of downstream adaptive responses depending upon identity and localization of the PAMP. Here, we report the existence of a completely novel “PAMP” that is not a molecular structure but an antigenic pattern. This pattern––the incidence of peptide epitopes with stretches of 100% sequence identity bound to both dendritic cell (DC) major histocompatibility (MHC) class I and MHC class II––strongly induces TH1 immune polarization and activation of the cellular immune response. Inherent in the existence of this PAMP is the concomitant existence of a molecular sensor complex with the ability to scan and compare amino acid sequence identities of bound class I and II peptides. We provide substantial evidence implicating the multienzyme aminoacyl‐tRNA synthetase (mARS) complex and its AIMp1 structural component as the key constituents of this complex. The results demonstrate a wholly novel mechanism by which T‐helper (TH) polarization is governed and provide critical information for the design of vaccination strategies intended to provoke cell‐mediated immunity.

Hemp-derived cannabidiol (CBD) is the major non-psychoactive component of cannabis and has been promoted as a potential treatment for a wide variety of disparate inflammatory conditions. Here we evaluated CBD for its ability to modulate the production of pro-inflammatory cytokines in vitro and in murine models of induced inflammation and further validated the ability of a liposomal formulation to increase bioavailability in mice and in humans. Subsequently, the therapeutic potential of both naked and liposomally-encapsulated CBD was explored in a 4-week, randomized placebo-controlled, double-blinded study in a spontaneous canine model of osteoarthritis. In vitro and in mouse models, CBD significantly attenuated the production of pro-inflammatory cytokines IL-6 and TNF-a while elevating levels of anti-inflammatory IL-10. In the veterinary study, CBD significantly decreased pain and increased mobility in a dose-dependent fashion among animals with an affirmative diagnosis of osteoarthritis. Liposomal CBD (20 mg/day) was as effective as the highest dose of non-liposomal CBD (50 mg/day) in improving clinical outcomes. Hematocrit, comprehensive metabolic profile, and clinical chemistry indicated no significant detrimental impact of CBD administration over the four week analysis period. This study supports the safety and therapeutic potential of hemp-derived CBD for relieving arthritic pain and suggests follow-up investigations in humans is warranted.