Skin Immune Cell Research Articles

The 17,18-epoxyeicosatetraenoic acid–G protein–coupled receptor 40 axis ameliorates contact hypersensitivity by inhibiting neutrophil mobility in mice and cynomolgus macaques

Metabolites of eicosapentaenoic acid exert various physiologic actions. 17,18-Epoxyeicosatetraenoic acid (17,18-EpETE) is a recently identified new class of antiallergic and anti-inflammatory lipid metabolite of eicosapentaenoic acid, but its effects on skin inflammation and the underlying mechanisms remain to be investigated. We evaluated the effectiveness of 17,18-EpETE for control of contact hypersensitivity in mice and cynomolgus macaques. We further sought to reveal underlying mechanisms by identifying the responsible receptor and cellular target of 17,18-EpETE. Contact hypersensitivity was induced by topical application of 2,4-dinitrofluorobenzene. Skin inflammation and immune cell populations were analyzed by using flow cytometric, immunohistologic, and quantitative RT-PCR analyses. Neutrophil mobility was examined by means of imaging analysis invivo and neutrophil culture invitro. The receptor for 17,18-EpETE was identified by using the TGF-α shedding assay, and the receptor's involvement in the anti-inflammatory effects of 17,18-EpETE was examined by using KO mice and specific inhibitor treatment. We found that preventive or therapeutic treatment with 17,18-EpETE ameliorated contact hypersensitivity by inhibiting neutrophil mobility in mice and cynomolgus macaques. 17,18-EpETE was recognized by G protein-coupled receptor (GPR) 40 (also known as free fatty acid receptor 1) and inhibited chemoattractant-induced Rac activation and pseudopod formation in neutrophils. Indeed, the antiallergic inflammatory effect of 17,18-EpETE was abolished in the absence or inhibition of GPR40. 17,18-EpETE inhibits neutrophil mobility through GPR40 activation, which is a potential therapeutic target to control allergic inflammatory diseases.

In vivo quantification of quantum dot systemic transport in C57BL/6 hairless mice following skin application post-ultraviolet radiation

BackgroundPrevious work has demonstrated size, surface charge and skin barrier dependent penetration of nanoparticles into the viable layers of mouse skin. The goal of this work was to characterize the tissue distribution and mechanism of transport of nanoparticles beyond skin, with and without Ultraviolet Radiation (UVR) induced skin barrier disruption. Atomic absorption spectroscopy (AAS), flow cytometry and confocal microscopy were used to examine the effect of UVR dose (180 and 360 mJ/cm2 UVB) on the skin penetration and systemic distribution of quantum dot (QD) nanoparticles topically applied at different time-points post UVR using a hairless C57BL/6 mouse model.ResultsResults indicate that QDs can penetrate mouse skin, regardless of UVR exposure, as evidenced by the increased cadmium in the local lymph nodes of all QD treated mice. The average % recovery for all treatment groups was 69.68% with ~66.84% of the applied dose recovered from the skin (both epicutaneous and intracutaneous). An average of 0.024% of the applied dose was recovered from the lymph nodes across various treatment groups. When QDs are applied 4 days post UV irradiation, at the peak of the skin barrier defect and LC migration to the local lymph node, there is an increased cellular presence of QD in the lymph node; however, AAS analysis of local lymph nodes display no difference in cadmium levels due to UVR treatment.ConclusionsOur data suggests that Langerhans cells (LCs) can engulf QDs in skin, but transport to the lymph node may occur by both cellular (dendritic and macrophage) and non-cellular mechanisms. It is interesting that these specific nanoparticles were retained in skin similarly regardless of UVR barrier disruption, but the observed skin immune cell interaction with nanoparticles suggest a potential for immunomodulation, which we are currently examining in a murine model of skin allergy.

Effects of Ixeris dentata water extract and caffeic acid on allergic inflammation in vivo and in vitro.

BackgroundIxeris dentata Nakai has been used for the treatment of mithridatism, calculous, indigestion, pneumonia, hepatitis, and tumors in Korea, China, and Japan. However, the effect of a water extract of Ixeris dentata (ID) and its molecular mechanism on allergic inflammation has not been elucidated. In this study, we attempted to evaluate the effects of ID and its major compound caffeic acid on allergic inflammation in vivo and in vitro.MethodsID was applied to 2, 4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis (AD)-like skin lesion mice and immune cell infiltration, cytokine production, and the activation of mitogen-activated protein kinases (MAPKs) were investigated. Moreover, the effect of ID on compound 48/80-induced anaphylactic shock was investigated in a mouse model. The human keratinocyte cell line (HaCaT cells) and human mast cells (HMC-1) were treated with ID or caffeic acid to investigate the effects on the production of chemokines and proinflammatory cytokines and on the activation of MAPKs.ResultsID inhibited the serum levels of IgE and interleukin (IL)-1β in DNFB-induced AD-like skin lesion mouse models and suppressed anaphylactic shock in the mouse models. ID and caffeic acid inhibited the production of chemokines and adhesion molecules in HaCaT cells. In addition, ID reduced the release of tumor necrosis factor-α and IL-8 via the inhibition of MAPKs phosphorylation in HMC-1 cells.ConclusionsThese results suggest that ID is a potential therapeutic agent for allergic inflammatory diseases, including dermatitis.

Cutaneous immunopathology of long-standing complex regional pain syndrome.

Both increased mast cells numbers and raised immune mediator concentrations indicate immune activation in the affected skin of patients with early complex regional pain syndrome (CRPS), but little is known about regional immune cell involvement in late-stage CRPS. The aim of the current study was to determine skin immune cell populations in long-standing CRPS. Using 6-mm skin punch biopsies from CRPS-affected and non-affected tissues, and a combination of chemical and immunofluorescence staining, we examined the density and function of key cell populations including mast cells, epidermal Langerhans cells (LCs) and tissue resident T-cells. We found no significant differences in either overall immune cell infiltrates, or mast cell density between CRPS-affected and non-affected sub-epidermal tissue sections, contrasting recent findings in early CRPS by other groups. However, CD1a(+) LC densities in the epidermal layer were significantly decreased in affected compared to non-affected CRPS limbs (p<0.01). T-cell clones isolated from CRPS-affected sub-epidermal tissues displayed a trend towards increased IL-13 production in ELISPOT assays when compared to T-cells isolated from non-affected areas, suggesting a Th2 bias. Immune cell abnormalities are maintained in late-stage CRPS disease as manifest by changes in epidermal LC density and tissue resident T-cell phenotype.

FTY720 ameliorates sclerodermatous chronic GVHD by expansion of splenic regulatory cells and inhibition of skin immune cell infiltration

FTY720 ameliorates sclerodermatous chronic GVHD by expansion of splenic regulatory cells and inhibition of skin immune cell infiltration

생약복합조성물(HemoHIM)의 자외선 조사로 억제된 랑게르한스 세포의 항원제시기능 방호효과

방사선 조사에 대한 방호 효과와 방사선 치료에 의한 부작용 경감 효과를 가지는 새로운 생약복합조성물(HemoHIM)의 자외선 조사에 의한 피부 면역계 방호 효과에 대해 알아보았다. IL-4와 GM-CSF로 분화시킨 수 지상세포에 자외선을 직접 조사하여 항원전달기능의 감소를 유발하는 자외선 조사 조건을 확립하고, HemoHIM을 자외선 조사 전 후에 처리하여 자외선에 의해 감소한 수지상세포의 항원전달기능이 회복되는 것을 확인하였다. 그리고 접촉성 과민반응 모델을 이용하여 피부의 Langerhans 세포의 항원전달기능의 감소를 유발하는 자외선 조사 조건을 확립하고, Langerhans 세포의 항원전달기능의 감소를 유발하고 HemoHIM을 각각 복강 또는 경구로 투여하는 방법으로 처리하였을 때, 억제된 Langerhans 세포의 항원전달 기능을 회복시키는 효과가 있다는 것을 확인하였다. 이상의 결과로 HemoHIM은 자외선 조사로 저하된 피부 면역 기능을 회복시키는 효과가 있다는 것을 증명하였고, 피부 면역 기능을 개선하는 새로운 자외선 차단제 개발을 위한 소재로 사용할 가능성을 제시하였다. In the previous results, we developed an effective products to apply as functional foods for overcome of radiation damage and reduction of side effects in radiotherapy. To verify the prevention of UVB-induced immunosuppression of immune cell function by HemoHIM, we studied on the mechanism of the skin immune function for the protection in UVB irradiation. In studies presented here, we showed that HemoHIM can prevent UVB-induced impairment of skin immune cell function by in vitro and in vivo assay. Exposure of freshly cultured murine dendritic cells (DCs) with IL-4/GM-CSF to UVB irradiation resulted in impairment of accessory function. This suppression could be prevented by addition of HemoHIM before or after to the cultures of UVB-irradiated DCs. We also tested the effects of HemoHIM on the suppression of contact hypersensitivity (CHS) treated oral or intraperitoneal administration. This UVB-suppressed CHS was prevented by administration of HemoHIM to UVB-irradiated mice. These results suggest that HemoHIM may prevent UVB-induced immune suppression in the skin.

Gaseous nitric oxide exhibits minimal effect on skin fibroblast extracellular matrix gene expression and immune cell viability

NO (nitric oxide) molecule is produced by various mammalian cell types and plays a significant role in inflammation, infection and wound healing processes. Recently, gNO (gaseous nitric oxide) therapy has been utilized for its potential clinical application as an antimicrobial agent, with special focus on skin infection. In a previous study, we demonstrated that 200 ppm gNO, 8 h/day for three consecutive days significantly reduced the number of bacteria in dermal wounds without compromising the viability and function of skin cells. To increase the feasibility and ease of its clinical use, we propose that different doses of gNO (5 to 10 K ppm) for 8 h and as short as 10 min be used, respectively. To achieve this, we set up in vitro experiments and asked whether (i) different doses of gNO have any toxic effect on immune cells and (ii) gNO has any modulating effect on key ECM (extracellular matrix) components in fibroblasts. To further investigate the effect of gNO, expression of more than 100 key ECM genes have been examined using gene array in human fibroblasts. As immune cells play an important role in wound healing, the effect of gNO on proliferation and viability of human and mouse lymphocytes was also examined. The findings showed that, the 5, 25, 75 and 200 ppm of gNO for 8 h slightly increased the expression of Col 5A3 (collagen type V alpha 3), and gNO at 5 ppm decreased the expression of MMP-1 (matrix metalloproteinase 1), while exposure of fibroblast to 10 K ppm of gNO for 10 min does not show any significant changes in ECM genes. Exposure to gNO resulted in inhibition of lymphocyte proliferation without affecting the cell viability. Taken together, our findings show that skin could be treated with gNO without compromising the role of ECM and immune cells in low concentrations with long time exposure or high concentrations for a shorter exposure time.

Peritransplant Use of Ultraviolet-B Irradiation (UV-B) Therapy Is Detrimental to Allogeneic Stem Cell Transplantation Outcome

Whole-body UV-B phototherapy has been used for the treatment of graft-versus-host disease (GVHD) of the skin and has systemic immunosuppressive and tolerogenic effects. We hypothesized that whole-body UV-B therapy would improve donor engraftment and decrease the incidence and severity of GVHD that is associated with decreased intensity allogeneic hematopoietic stem cell transplantation. This study tested the feasibility of using UV-B phototherapy that was initiated before grafting and continued until engraftment to determine its effect on transplantation outcome. Eight patients (median age, 55.5 years; range, 32-65 years) with hematologic malignancies were included. Allogeneic peripheral blood stem cells were obtained from matched related (n = 5) or matched unrelated (n = 3) donors. Conditioning regimen was fludarabine 30 mg/m 2 intravenously for 5 days, cyclophosphamide 1 g/m 2/d intravenously for 2 days, and equine antithymocyte globulin 30 mg/kg/d for 2 days. GVHD prophylaxis included cyclosporine, methylprednisolone, and escalating doses of narrowband UV-B (311 nm) according to skin tolerance, 3 days a week, from 10 days before to 28 days after transplantation. The conditioning regimen and the UV-B therapy were well tolerated. Two patients received all 14 prescribed UV-B treatments (cumulative doses of 2000 and 3260 mJ/cm 2, respectively) and 6 patients received 8 to 13 treatments with a cumulative dose range of 528-3465 mJ/cm 2. There was a rapid decrease in epidermal CD1a + cells by day of transplantation. Myeloid engraftment was rapid. One patient had secondary engraftment failure at 3 months and another had mixed chimerism at day 100. Seven of 8 patients developed severe acute GVHD (grade III, n = 5; grade IV, n = 2). Six had skin involvement, 5 had gastrointestinal involvement, and 1 had liver involvement. Four patients died (2 from sepsis, 1 from acute GVHD, and 1 from chronic GVHD). Four patients are alive (130-287 days), 3 with extensive chronic GVHD. We conclude that extended peritransplant UV-B therapy at the standard minimally erythemogenic dose is detrimental to the outcome of allogeneic stem cell transplantation. It is unclear how UV-B at this immunsuppressive dose might have altered skin and systemic cytokine and immune cell compositions in the host and increased GVHD- and treatment-related mortalities. Different UV-B dose and schedules should be further explored. However, although other phototherapeutic modalities may be effective against GVHD, extended UV-B therapy should not be used during early phases of decreased conditioning allogeneic transplantation.

Peritransplant Use of Ultraviolet-B (UVB) Phototherapy Is Detrimental to Outcome of Allogeneic Stem Cell Transplantation.

Engraftment failure and graft versus host disease (GVHD) are major obstacles to success of non-myeloablative allogeneic stem cell transplantation. Whole body UVB phototherapy has been used for the treatment of skin GVHD and has systemic immunosuppressive effects. In addition, extracorporeal photopheresis (ECP) has been used for treatment and prevention of GVHD. We hypothesized that whole body UVB phototherapy may have immunosuppressive effects similar to ECP and improve donor engraftment and reduce the incidence and severity of GVHD. The aim of this study was to test the feasibility of using UVB phototherapy initiated prior to grafting and continued until engraftment and determine its impact on transplant outcome. Eight patients median age 55.5 (range 32–65) years with hematological malignancies who were >55 years of age or had received prior autologous or allogeneic transplantation with myeloablative conditioning or had comorbid conditions that precluded their eligibility for myeloablative transplantation were included in this study. The graft source was matched related (n=5) or matched unrelated (n=3) donor allogeneic peripheral blood stem cells. All donors were male, median age (range) 59 (46–67) years. Conditioning regimen was fludarabine 30 mg/m2 iv for 5 days (days −8 to −4); cyclophosphamide 1 g/m2/day iv for 2 days (days −3 to −2); equine anti-thymocyte globulin (ATG) 30 mg/kg/day for 2 days (days −2 to −1). GVHD prophylaxis included cyclosporine A (CSA), methylprednisolone and escalating doses of UVB to skin tolerance 3 times a week between T-10 and T+28. The conditioning regimen and the UVB phototherapy were well tolerated. Two patients received all 14 prescribed UVB (cummulative doses 2000 and 3260 mJ) and, six patients received 8–13 treatments (cummulative dose range of 528–3465 mJ). Neutrophil (>500ml) and platelet recovery (>20,000/ml) occurred in median of 13 (12–17) and 6.5 days (1–35), respectively. One patient had secondary engraftment failure and another had mixed chimerism at day 100. Seven of eight patients developed severe acute GVHD, Grade III (n=5) and IV (n=2). Six had skin, 5 had GI and 1 had liver involvement. Four patients died from sepsis (n=2), acute GVHD (n=1), or chronic GVHD (n=1). The protocol was closed early due to high severe GVHD rate (87.5%, 95%CI: 60–92%) that satisfied the early-stopping rule. Four patients are alive (130–287 days), 2 without GVHD or relapse. We conclude that addition of peritransplant UVB phototherapy using the standard minimally erythemogenic protocol is detrimental to outcome of allogeneic stem cell transplantation. It is unclear how UVB phototherapy at immunsupressive doses might have altered skin and systemic cytokine and immune cell composition in the host and increased the incidence of GVHD and the treatment related mortality. Therefore although other phototherapeutic modalities may be effective against GVHD, UVB therapy is not recommended during early phases of reduced conditioning allogeneic transplantation.

Cellular and molecular composition of human skin in long-term xenografts on SCID mice.

We report on the immunophenotypical characterization of adult human skin transplanted onto severe combined immunodeficient (SCID) mice. Thirty animals were followed for up to 12 months after receiving split-thickness xenografts, of which 28 were tolerated for the whole test period. Antigen mapping revealed an almost complete preservation of human cellular and extracellular tissue components in long-term transplants including skin immune cells (Langerhans-cells, macrophages, lymphocytes) and also parts of the engrafted endothelium. Hence, xenografts on SCID mice offer a versatile experimental tool for the in vivo study of both human skin immune cell function and endothelial cell-mediated interactions in an environment completely devoid of interferences by adoptive host immune response.

Effects of therapy with azathioprine and prednisolone and ultraviolet irradiation on mouse skin immune function and immune cell markers.

The effects of ultraviolet irradiation (UVI) (290-400 nm) and/or systemic immunosuppressive drug therapy (azathioprine and prednisolone) on the immunocompetence of the skin of hairless (HRA/Skh-1) mice were investigated. Mice were studied for the density of ATPase+, Ia+ and Thyl X 2+ cells in the dorsal epidermis and contact hypersensitivity (CH) of skin to dinitrofluorobenzene (DNFB). Prednisolone therapy alone and UVI alone each reduced the densities of the three skin immune cell markers and CH responsiveness; azathioprine therapy alone had no such effects. When a suberythemal dose of UVI that induced a moderately depressive effect on these two skin parameters was used, additional azathioprine therapy produced no further depression; additional prednisolone therapy further depressed the densities of ATPase+ and Ia+ cells and CH responsiveness; additional therapy with combined azathioprine and prednisolone induced profound depression of the incidences of the three immune cell markers and of CH responsiveness. These data point to interaction between azathioprine/prednisolone therapy and UVI in depressing local immune function within skin which may contribute to the increased susceptibility of the sun-exposed skin of immunosuppressed kidney transplant recipients to infective and carcinogenic processes.