ABSTRACT
Type 2 immunity is critical for defense against cutaneous infections but also underlies the development of allergic skin diseases. We report the identification in normal mouse dermis of an abundant, phenotypically unique group 2 innate lymphoid cell (ILC2) subset that depended on interleukin 7 (IL-7) and constitutively produced IL-13. Intravital multiphoton microscopy showed that dermal ILC2 cells specifically interacted with mast cells, whose function was suppressed by IL-13. Treatment of mice deficient in recombination-activating gene 1 (Rag1(-/-)) with IL-2 resulted in the population expansion of activated, IL-5-producing dermal ILC2 cells, which led to spontaneous dermatitis characterized by eosinophil infiltrates and activated mast cells. Our data show that ILC2 cells have both pro- and anti-inflammatory properties and identify a previously unknown interactive pathway between two innate populations of cells of the immune system linked to type 2 immunity and allergic diseases.
Subject(s)
Dermatitis/immunology , Immunity, Innate/immunology , Lymphocytes/immunology , Skin/immunology , Animals , Cell Communication/immunology , Cells, Cultured , Dermatitis/genetics , Dermatitis/metabolism , Dermis/cytology , Dermis/immunology , Dermis/metabolism , Eosinophils/immunology , Eosinophils/metabolism , Flow Cytometry , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/immunology , Homeodomain Proteins/metabolism , Immunity, Innate/genetics , Interleukin-13/immunology , Interleukin-13/metabolism , Interleukin-17/immunology , Interleukin-17/metabolism , Interleukin-2/immunology , Interleukin-2/pharmacology , Lymphocytes/drug effects , Lymphocytes/metabolism , Mast Cells/immunology , Mast Cells/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microscopy, Fluorescence, Multiphoton , Skin/metabolism , Videotape RecordingABSTRACT
Granzyme B (GzmB) is a protease with a well-characterized intracellular role in targeted destruction of compromised cells by cytotoxic lymphocytes. However, GzmB also cleaves extracellular matrix components, suggesting that it influences the interplay between cytotoxic lymphocytes and their environment. Here, we show that GzmB-null effector T cells and natural killer (NK) cells exhibited a cell-autonomous homing deficit in mouse models of inflammation and Ectromelia virus infection. Intravital imaging of effector T cells in inflamed cremaster muscle venules revealed that GzmB-null cells adhered normally to the vessel wall and could extend lamellipodia through it but did not cross it efficiently. In vitro migration assays showed that active GzmB was released from migrating cytotoxic lymphocytes and enabled chemokine-driven movement through basement membranes. Finally, proteomic analysis demonstrated that GzmB cleaved basement membrane constituents. Our results highlight an important role for GzmB in expediting cytotoxic lymphocyte diapedesis via basement membrane remodeling.
Subject(s)
Ectromelia virus/immunology , Ectromelia, Infectious/immunology , Granzymes/metabolism , Killer Cells, Natural/physiology , T-Lymphocytes, Cytotoxic/physiology , Animals , Basement Membrane/metabolism , Cell Movement/genetics , Cells, Cultured , Chemokines/metabolism , Extracellular Matrix Proteins/metabolism , Granzymes/genetics , Killer Cells, Natural/virology , Mice , Mice, Inbred C57BL , Mice, Knockout , Proteolysis , T-Lymphocytes, Cytotoxic/virology , Transendothelial and Transepithelial Migration/geneticsABSTRACT
The dysfunctional skin barrier in eczema patients may be attributed to decreased levels of ceramides in the stratum corneum. The aim of this study was to determine whether a two-part system consisting of a ceramide-dominant physiological lipid-based moisturizing cream and cleanser could ameliorate the signs and symptoms of moderate eczema in adults over 28 days compared to placebo. Assessments were conducted at baseline and every 7 days thereafter. Eczema area severity index score decreased significantly across all time points in both groups compared to baseline (P < .0001), however, this decrease was not significant between groups at day 28 (P = .7804). In contrast, transepidermal water loss and skin hydration significantly improved over time in the active group, while it either stayed the same or worsened in the placebo group (P = .0342 and P < .0001, respectively). There was no difference in the use of mometasone furoate as rescue medication over time between groups (P = .1579). Dermatology life quality index scores improved significantly in both groups (P < .0001), with no difference between groups (P = .5256). However, patient satisfaction was greater in the active compared to the placebo group for several parameters including relief of itch, dry skin, skin softness and smoothness (all P < .05). No patients withdrew from the study due to adverse events (AEs) and there were no serious AEs. The ceramide-dominant moisturizing cream and cleanser safely restores skin permeability and improves the signs and symptoms of eczema in adults.
Subject(s)
Ceramides , Eczema , Adult , Eczema/diagnosis , Eczema/drug therapy , Humans , Permeability , Pruritus , Skin CreamABSTRACT
BACKGROUND: Clinical trial recruitment is challenging for investigators who often overestimate the pool of qualified, willing subjects. Moreover, there is a paucity of literature, particularly in dermatology, regarding recruitment and the comparative success of advertising strategies. METHODS: Both 'traditional' (physician referral, newspaper and radio advertisements, letterbox drops, posters/flyers, word-of-mouth) and 'modern' (patient recruitment services, social media, Google advertisements, websites, email) recruitment methods were used to enrol 100 patients (>18 years) diagnosed with moderate eczema for a randomised, double-blind, placebo-controlled trial investigating the efficacy and safety of a topical eczema treatment over 4 weeks. The relationships between recruitment method and patient age, sex, race, study completion and costs were analysed. RESULTS: The majority of patients recruited were young, with millennials and Gen Z comprising 77% of the study population. Both traditional and modern recruitment methods were equally successful in recruiting younger patients, with older patients predominately recruited by traditional methods. Eighty per cent more men were recruited by traditional compared to modern methods, whilst 67% more women than men were recruited by modern methods. Recruitment method neither appeared to be influenced by race, nor did it effect whether patients completed the study. Costs per enrolment were similar for both methods. CONCLUSIONS: This study shows that despite the high proportion of young patients and the rising popularity of social media and increased internet use, a combination of both traditional and modern recruitment methods was required to successfully meet the trial enrolment target of 100 adult patients with moderate eczema.
Subject(s)
Eczema/drug therapy , Patient Selection , Randomized Controlled Trials as Topic , Administration, Topical , Adolescent , Adult , Advertising , Age Factors , Aged , Australia , Double-Blind Method , Female , Humans , Male , Mass Media , Middle Aged , Social Media , Young AdultABSTRACT
BACKGROUND: Group 2 innate lymphoid cells (ILC2) have been implicated in the pathogenesis of allergic lung diseases. However, the upstream signals that regulate ILC2 function during pulmonary inflammation remain poorly understood. ILC2s have been shown to respond to exogenous IL-2, but the importance of endogenous IL-2 in ILC2 function in vivo remains unclear. OBJECTIVE: We sought to understand the role of IL-2 in the regulation of ILC2 function in the lung. METHODS: We used histology, flow cytometry, immunohistochemistry, ELISA, and quantitative PCR with knockout and reporter mice to dissect pulmonary ILC2 function in vivo. We examined the role of ILC2s in eosinophilic crystalline pneumonia, an idiopathic type 2 inflammatory lung condition of mice, and the effect of IL-2 deficiency on this disease. We determined the effect of IL-2 administration on pulmonary ILC2 numbers and function in mice in the steady state and after challenge with IL-33. RESULTS: We discovered an unexpected role for innate cell-derived IL-2 as a major cofactor of ILC2 function during pulmonary inflammation. Specifically, we found that IL-2 was essential for the development of eosinophilic crystalline pneumonia, a type 2 disease characterized by increased numbers of activated ILC2s. We show that IL-2 signaling serves 2 distinct functions in lung ILC2s, namely promoting cell survival/proliferation and serving as a cofactor for the production of type 2 cytokines. We further demonstrate that group 3 innate lymphoid cells are an innate immune source of IL-2 in the lung. CONCLUSION: Innate cell-derived IL-2 is a critical cofactor in regulating ILC2 function in pulmonary type 2 pathology.
Subject(s)
Interleukin-2/immunology , Lymphocytes/immunology , Pneumonia/immunology , Pulmonary Eosinophilia/immunology , Animals , Cytokines/blood , Cytokines/immunology , DNA-Binding Proteins/genetics , Female , Homeodomain Proteins/genetics , Immunity, Innate/immunology , Interleukin-2/genetics , Lung/cytology , Lung/immunology , Lung/pathology , Male , Mice , Mice, Knockout , Pneumonia/blood , Pulmonary Eosinophilia/blood , Spleen/immunologyABSTRACT
Primary localized cutaneous nodular amyloidosis (PLCNA) is a rare subtype of localized cutaneous amyloidosis and can be associated with various connective tissue disorders. It can be difficult to treat and past therapies include surgical excision, dermabrasion, electrodessication and curettage, cryotherapy and laser therapy. We present a case of a middle-aged woman with PLCNA associated with CREST (calcinosis, Raynaud phenomenon, oesophageal motility disorders, sclerodactyly and telangiectasia) syndrome and Sjögren's syndrome responding to cyclophosphamide with no new amyloid deposits and resolution of skin ulceration after many years of resistance to drug therapy. It is important to monitor these patients for progression into systemic amyloidosis.
Subject(s)
Amyloidosis/diagnosis , Amyloidosis/drug therapy , Cyclophosphamide/therapeutic use , Immunosuppressive Agents/therapeutic use , Amyloidosis/etiology , Female , Humans , Middle AgedABSTRACT
A 57-year-old woman with prior exposure to bisphosphonates developed myalgia, proximal muscle weakness and lichenoid rash over the upper extremities and face 3 days after infusion of zoledronic acid for the management of osteoporosis. The diagnosis of dermatomyositis was made on the basis of clinical, laboratory and histological findings. This is the first report of drug-induced dermatomyositis secondary to zoledronic acid.
Subject(s)
Bone Density Conservation Agents/adverse effects , Dermatomyositis/chemically induced , Diphosphonates/adverse effects , Drug Eruptions/etiology , Imidazoles/adverse effects , Female , Humans , Middle Aged , Osteoporosis/drug therapy , Zoledronic AcidABSTRACT
Over the last few years, intravital two-photon microscopy has matured into a powerful technology helping basic and clinical researchers obtain quantifiable details of complex biological mechanisms in live and intact tissues. Two-photon microscopy provides high spatial and temporal resolution in vivo with little phototoxicity that is unattainable by other optical tools like confocal microscopy. Using ultrashort laser pulses, two-photon microscopy allows the visualization of molecules, cells, and extracellular structures up to depths of 1 mm within tissues. Consequently, real-time imaging of the individual skin layers under both physiological and pathological conditions has revolutionized our understanding of cutaneous homeostasis, immunity, and tumor biology. This review provides an overview to two-photon microscopy of the skin by covering the basic concepts and current applications in diverse preclinical and clinical settings.
Subject(s)
Dermatology/methods , Intravital Microscopy/methods , Research Design , Skin Diseases/diagnosis , Skin Diseases/therapy , HumansABSTRACT
In 2016, the live attenuated zoster vaccine (Zostavax, Merck and Co, USA) was introduced into the Australian National Immunisation Program for people aged 70â¯years who are not significantly immunocompromised. We report the administration of Zostavax in an immunocompromised patient with chronic lymphocytic leukaemia and no evidence of primary varicella zoster virus (VZV) infection. The patient presented with a bilateral vesicular facial rash 22â¯days after receiving Zostavax and was initially managed as an outpatient with oral acyclovir. He re-presented three days later and was diagnosed with disseminated VZV infection complicated by meningoencephalitis. The patient died following cardiac arrest on day 10 of hospitalisation. This unfortunate case highlights the challenge of safely implementing a high titre live vaccine in a population where contraindications are prevalent. The non-live recombinant herpes zoster subunit vaccine (Shingrix, GSK) may provide a safe and effective option to protect immunocompromised patients from shingles and post-herpetic neuralgia.
Subject(s)
Herpes Zoster Vaccine/adverse effects , Herpes Zoster/prevention & control , Immunocompromised Host/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Vaccination , Acyclovir/therapeutic use , Aged , Antiviral Agents/therapeutic use , Australia , Contraindications, Procedure , Exanthema , Fatal Outcome , Heart Arrest , Herpes Zoster Vaccine/administration & dosage , Hospitalization , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/complications , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Male , Meningoencephalitis/complications , Meningoencephalitis/drug therapy , Meningoencephalitis/immunology , Neuralgia, Postherpetic , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Varicella Zoster Virus Infection/complications , Varicella Zoster Virus Infection/drug therapy , Varicella Zoster Virus Infection/immunologySubject(s)
Endothelial Cells/pathology , Endothelium, Lymphatic/pathology , Hemangioma/pathology , Skin Neoplasms/pathology , Aged , Endothelial Cells/metabolism , Endothelium, Lymphatic/metabolism , Female , Follow-Up Studies , Hemangioma/metabolism , Hemangioma/therapy , Humans , Immunohistochemistry , Male , Middle Aged , Retrospective Studies , Skin Neoplasms/metabolism , Skin Neoplasms/therapyABSTRACT
Site-specific differences in skin response to pathogens and in the course of cutaneous inflammatory diseases are well appreciated. The composition and localization of cutaneous leukocytes has been studied extensively using histology and flow cytometry. However, the precise three-dimensional (3D) distribution of distinct immune cell subsets within skin at different body sites requires visualization of intact living skin. We used intravital multiphoton microscopy in transgenic reporter mice in combination with quantitative flow cytometry to generate a 3D immune cell atlas of mouse skin. The 3D location of innate and adaptive immune cells and site-specific differences in the densities of macrophages, T cells, and mast cells at four defined sites (ear, back, footpad, and tail) is presented. The combinatorial approach further demonstrates an as yet unreported age-dependent expansion of dermal gamma-delta T cells. Localization of dermal immune cells relative to anatomical structures was also determined. Although dendritic cells were dispersed homogeneously within the dermis, mast cells preferentially localized to the perivascular space. Finally, we show the functional relevance of site-specific mast cell disparities using the passive cutaneous anaphylaxis model. These approaches are applicable to assessing immune cell variations and potential functional consequences in the setting of infection, as well as the pathogenesis of inflammatory skin conditions.
Subject(s)
Dermatitis/pathology , Dermoscopy/methods , Imaging, Three-Dimensional/methods , Leukocytes/pathology , Microscopy, Fluorescence, Multiphoton/methods , Skin/pathology , Animals , Bacterial Proteins/genetics , Dendritic Cells/pathology , Dermis/blood supply , Dermis/pathology , Ear, External , Epidermis/pathology , Female , Flow Cytometry , Green Fluorescent Proteins/genetics , Luminescent Proteins/genetics , Lymphocyte Subsets/pathology , Macrophages/pathology , Male , Mast Cells/pathology , Mice, Inbred C57BL , Mice, Transgenic , Skin/blood supplyABSTRACT
The skin provides an effective physical and biological barrier against environmental and pathogenic insults whilst ensuring tolerance against commensal microbes. This protection is afforded by the unique anatomy and cellular composition of the skin, particularly the vast network of skin-associated immune cells. These include the long-appreciated tissue-resident macrophages, dendritic cells, and mast cells, as well as the more recently described dermal γδ T cells and innate lymphoid cells. Collectively, these cells orchestrate the defense against a wide range of pathogens and environmental challenges, but also perform a number of homeostatic functions. Here, we review recent developments in our understanding of the various roles that leukocyte subsets play in cutaneous immunobiology, and introduce the newer members of the skin immune system. Implications for human disease are discussed.