Reciprocal Cytokine-Mediated Cellular Interactions in Mouse Epidermis: Promotion of γ δ T-Cell Growth by IL-7 and TNFα and Inhibition of Keratinocyte Growth by γIFN

A unique subset of γδ T cells, termed dendritic epidermal T cells (DETC), resides in symbiosis with keratinocytes in mouse epidermis. We have shown previously that interleukin 7 (IL-7) which is produced by keratinocytes, promotes growth and prevents apoptosis in DETC. To extend this observation, we examined 12 cytokines, each of which is expressed by epidermal cells at mRNA and/or protein levels, for their capacities to modulate the growth of DETC. Cytokines examined included IL-1α, IL-2, IL-3, IL-4, IL-6, IL-7, IL-8, IL-10, tumor necrosis factor-α (TNFα), interferon-γ (IFNγ) granulocyte/macrophage-colony stimulating factor (GM-CSF) and macrophage inflammatory protein-1γ (MIP-1γ). When tested individually, IL-2 and IL-7 promoted maximal growth of the long-term cultured DETC line 7-17. When tested in combinations, synergistic growth- promoting effects were seen with IL-2 and IL-4 or IL-7, and with IL-7 and IL-4 or TNFγ. Dose-response experiments demonstrated that TNFγ, which is produced by keratinocytes, enhances IL,-7-induced DETC proliferation, but inhibits IL-2 – induced proliferation. The mouse keratinocyte-derived cell line Pam 212 was used to test these cytokines for their capacities to regulate keratinocyte growth. Only γIFN, which is produced by DETC, inhibited proliferation in a dose-dependent fashion. These results illustrate three reciprocal pathways by which epidermal cytokines regulate the growth of epidermal cells: 1) a paracrine mechanism by which keratinocyte-derived cytokines (e.g., IL-7 and TNFα) promote the growth of DETC, 2) an autocrine mechanism by which DETC-derived cytokines (e.g., IL-2 and IL-4) support their own growth, and 3) a reciprocal pathway in which a cytokine produced by resident epidermal leukocytes (e.g., γIFN) modulates the growth of keratinocytes

Mast cells mediate neutrophil recruitment and vascular leakage through the NLRP3 inflammasome in histamine-independent urticaria

Urticarial rash observed in cryopyrin-associated periodic syndrome (CAPS) caused by nucleotide-binding oligomerization domain–leucine-rich repeats containing pyrin domain 3 (NLRP3) mutations is effectively suppressed by anti–interleukin (IL)-1 treatment, suggesting a pathophysiological role of IL-1β in the skin. However, the cellular mechanisms regulating IL-1β production in the skin of CAPS patients remain unclear. We identified mast cells (MCs) as the main cell population responsible for IL-1β production in the skin of CAPS patients. Unlike normal MCs that required stimulation with proinflammatory stimuli for IL-1β production, resident MCs from CAPS patients constitutively produced IL-1β. Primary MCs expressed inflammasome components and secreted IL-1β via NLRP3 and apoptosis-associated speck-like protein containing a caspase recruitment domain when stimulated with microbial stimuli known to activate caspase-1. Furthermore, MCs expressing disease-associated but not wild-type NLRP3 secreted IL-1β and induced neutrophil migration and vascular leakage, the histological hallmarks of urticarial rash, when transplanted into mouse skin. Our findings implicate MCs as IL-1β producers in the skin and mediators of histamine-independent urticaria through the NLRP3 inflammasome

TIGIT/CD155 axis mediates resistance to immunotherapy in patients with melanoma with the inflamed tumor microenvironment

Background Patients with cancer benefit from treatment with immune checkpoint inhibitors (ICIs), and those with an inflamed tumor microenvironment (TME) and/or high tumor mutation burden (TMB), particularly, tend to respond to ICIs; however, some patients fail, whereas others acquire resistance after initial response despite the inflamed TME and/or high TMB. We assessed the detailed biological mechanisms of resistance to ICIs such as programmed death 1 and/or cytotoxic T-lymphocyte-associated protein 4 blockade therapies using clinical samples. Methods We established four pairs of autologous tumor cell lines and tumor-infiltrating lymphocytes (TILs) from patients with melanoma treated with ICIs. These tumor cell lines and TILs were subjected to comprehensive analyses and in vitro functional assays. We assessed tumor volume and TILs in vivo mouse models to validate identified mechanism. Furthermore, we analyzed additional clinical samples from another large melanoma cohort. Results Two patients were super-responders, and the others acquired resistance: the first patient had a non-inflamed TME and acquired resistance due to the loss of the beta-2 microglobulin gene, and the other acquired resistance despite having inflamed TME and extremely high TMB which are reportedly predictive biomarkers. Tumor cell line and paired TIL analyses showed high CD155, TIGIT ligand, and TIGIT expression in the tumor cell line and tumor-infiltrating T cells, respectively. TIGIT blockade or CD155-deletion activated T cells in a functional assay using an autologous cell line and paired TILs from this patient. CD155 expression increased in surviving tumor cells after coculturing with TILs from a responder, which suppressed TIGIT+ T-cell activation. Consistently, TIGIT blockade or CD155-deletion could aid in overcoming resistance to ICIs in vivo mouse models. In clinical samples, CD155 was related to resistance to ICIs in patients with melanoma with an inflamed TME, including both primary and acquired resistance. Conclusions The TIGIT/CD155 axis mediates resistance to ICIs in patients with melanoma with an inflamed TME, promoting the development of TIGIT blockade therapies in such patients with cancer

PD-1 blockade therapy promotes infiltration of tumor-attacking exhausted T cell clonotypes

PD-1 blockade exerts clinical efficacy against various types of cancer by reinvigorating T cells that directly attack tumor cells (tumor-specific T cells) in the tumor microenvironment (TME), and tumor-infiltrating lymphocytes (TILs) also comprise nonspecific bystander T cells. Here, using single-cell sequencing, we show that TILs include skewed T cell clonotypes, which are characterized by exhaustion (T-ex) or nonexhaustion signatures (Tnon-ex). Among skewed clonotypes, those in the T-ex, but not those in the Tnon-ex, cluster respond to autologous tumor cell lines. After PD-1 blockade, non-preexisting tumor-specific clonotypes in the T-ex cluster appear in the TME. Tumor-draining lymph nodes (TDLNs) without metastasis harbor a considerable number of such clonotypes, whereas these clonotypes are rarely detected in peripheral blood. We propose that tumor-infiltrating skewed T cell clonotypes with an exhausted phenotype directly attack tumor cells and that PD-1 blockade can promote infiltration of such T-ex clonotypes, mainly from TDLNs

Early treatment with tolvaptan improves diuretic response in acute heart failure with renal dysfunction

Background: Poor response to diuretics is associated with worse prognosis in patients with acute heart failure (AHF). We hypothesized that treatment with tolvaptan improves diuretic response in patients with AHF. Methods: We performed a secondary analysis of the AQUAMARINE open-label randomized study in which a total of 217 AHF patients with renal impairment (eGFR <60 mL/min/1.73 m(2)) were randomized to either tolvaptan or conventional treatment. We evaluated diuretic response to 40 mg furosemide or its equivalent based on two different parameters: change in body weight and net fluid loss within 48 h. Results: The mean time from patient presentation to randomization was 2.9 h. Patients with a better diuretic response showed greater relief of dyspnea and less worsening of renal function. Tolvaptan patients showed a significantly better diuretic response measured by diuretic response based both body weight [-1.16 (IQR -3.00 to -0.57) kg/40 mg vs. -0.51 (IQR -1.13 to -0.20) kg/40 mg; P <0.001] and net fluid loss [ 2125.0 (IQR 1370.0-3856.3) mL/40 mg vs. 1296.3 (IQR 725.2-1726.5) mL/40 mg; P <0.001]. Higher diastolic blood pressure and use of tolvaptan were independent predictors of a better diuretic response. Conclusions: Better diuretic response was associated with greater dyspnea relief and less WRF. Early treatment with tolvaptan significantly improved diuretic response in AHF patients with renal dysfunction

Post-vaccination subcutaneous aluminum granuloma

Vaccination is a successful and cost-effective public health intervention. Aluminum-containing adjuvants are used worldwide to improve the immune response of vaccines. Side effects of aluminum-containing adjuvants in skin and subcutis are usually accompanied by persistent itch, and it may be challenging to diagnose asymptomatic cases. Here we present a case of a 1-year-old girl with asymptomatic subcutaneous nodules. Magnetic resonance imaging (MRI) revealed subcutaneous lesions: 16 mm on the upper right and 4 mm on the upper left arms. Histological examination revealed a granulomatous reaction with lymphoid follicle-like structures in the subcutis, accompanied by a considerable number of macrophages with PAS-positive granular cytoplasm. Moreover, the granules stained positive with aluminon staining, which revealed the existence of aluminum. These findings indicate post-vaccination aluminum granuloma. Due to the benign nature of aluminum granuloma and the benefit of routine vaccination, we decided to recommend that the patient continue taking the routine vaccination