Contact Hypersensitivity Response Research Articles

Resolvin E1 inhibits dendritic cell migration in the skin and attenuates contact hypersensitivity responses

Resolvin E1 inhibits dendritic cell migration in the skin and attenuates contact hypersensitivity responses

Estrogen inhibits acute and chronic contact hypersensitivity response in mice

Estrogen inhibits acute and chronic contact hypersensitivity response in mice

Importance of Water Content of the Stratum Corneum in Mouse Models for Contact Hypersensitivity

Although a marked rise in the prevalence of allergic diseases over the past few decades may be related to environmental factors in industrialized countries, evidence for the protective effect of humidity on the barrier function of the skin is still awaited. We asked whether an increase in the water content of stratum corneum at the site of hapten application had a strong impact on the magnitude of contact hypersensitivity (CHS). The magnitude of CHS, induced by either lipid-soluble or water-soluble hapten, was inversely correlated with the water content of stratum corneum at the hapten application site in the elicitation phase. An increase in the water content induced by exposure to high humidity for 6 hours was sufficient to ameliorate the magnitude of CHS even in mice with the genetic defect in attenuating the CHS responses, such as flaky tail mice. The reduced CHS was associated with downregulation of IL-1α, IL-4, and IFN-γ mRNA expression. Epicutaneously applied hapten can penetrate more readily through the stratum corneum with lower water content than that with higher water content, even after tape-stripping. These findings indicate that increased levels of water in the stratum corneum serve to ameliorate the CHS beyond the genetic effects.

Down-Regulation of CD62L Shedding in T Cells by CD39+ Regulatory T Cells Leads to Defective Sensitization in Contact Hypersensitivity Reactions

Injection of regulatory T cells (Tregs) followed by sensitization with 2,4,6-trinitrochlorobenzene induced a transient increase in size and cellularity of skin-draining lymph nodes (LNs) in mice. This led us to hypothesize that Tregs may affect the trafficking of T cells from and to peripheral LNs. Two to three hours after sensitization, we found fewer CD8+ T cells expressing CD62L in LNs compared with untreated controls. Injection of wild-type Tregs prevented this down-regulation of CD62L. In contrast, Tregs devoid of the adenosine triphosphate (ATP)-degrading ecto-enzyme CD39 were unable to do so. As for the mechanism of CD62L regulation, we found that ATP, which is released in skin upon hapten-exposure, is inducing the protease ADAM17 in LN-residing T cells via engagement of P2X7 ATP receptors. ADAM17 cleaves CD62L from the surface of CD8+ T cells, which in turn provide a signal for T cells to leave the LNs. This regulation of CD62L is disturbed by the presence of Tregs, because Tregs remove extracellular ATP from the tissue by activity of CD39 and, therefore, abrogate the shedding of CD62L. Thus, these data indicate that the regulation of ATP turnover by Tregs in skin and LNs is an important modulator for immune responses.

Sema4D is required in both the adaptive and innate immune responses of contact hypersensitivity.

Originally recognized as a regulator of axon guidance in the nervous system, Semaphorin 4D (Sema4D, CD100) also participates in various immune responses and many immune-related diseases. However, whether Sema4D is involved in the pathogenesis of contact hypersensitivity (CHS) remains unclear. In this study, we explored the role of Sema4D in oxazolone-induced CHS using Sema4D knockout (KO) mice. We found that Sema4D KO mice developed attenuated CHS responses, as indicated by milder ear-swelling, lower expression of IL-1β, IL-6, CXCL2 and CXCL5, and decreased recruitment of neutrophils, CD8+ T cells and CD4+ T cells. CHS was impaired in the wide type (WT) mice reconstituted with bone marrow from Sema4D KO mice, indicating that deletion of Sema4D gene in hematopoietic cells played a key role in the alleviated CHS in Sema4D KO mice. CHS was also attenuated in the WT mice transferred with draining lymph nodes (dLNs) cells from oxazolone-sensitized Sema4D KO mice, and the activation and differentiation of hapten-specific CD8+ T cells were impaired in Sema4D KO mice. Furthermore, Sema4D KO mice expressed less IL-1β and CXCL2 than WT mice after oxazolone sensitization, and after transferred with dLNs cells from oxazolone-sensitized WT mice, naïve Sema4D KO mice showed attenuated CHS responses upon oxazolone challenge, indicating that the innate immune response of CHS in Sema4D KO mice was also abrogated. Taken together, our findings revealed for the first time that Sema4D positively regulated both the adaptive and innate immune responses in CHS.

279 Skin dendritic cells show increased migration to lymph nodes in CD73 deficient mice leading to exacerbated contact hypersensitivity reactions

279 Skin dendritic cells show increased migration to lymph nodes in CD73 deficient mice leading to exacerbated contact hypersensitivity reactions

446 In vivo dynamics of reactive oxygen species (ROS) and NF-kB activation during acute and chronic contact hypersensitivity reaction (CHSR)

446 In vivo dynamics of reactive oxygen species (ROS) and NF-kB activation during acute and chronic contact hypersensitivity reaction (CHSR)

Immunosuppressive Effect of Litsea cubeba L. Essential Oil on Dendritic Cell and Contact Hypersensitivity Responses.

Litsea cubeba L., also named as Makauy, is a traditional herb and has been used as cooking condiment or tea brewing to treat diseases for aborigines. The present study was undertaken to explore the chemical compositions of the fruit essential oil of L. cubeba (LCEO) and the immunomodulatory effect of LCEO on dendritic cells and mice. The LCEO was analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) with direct injection (DI/GC) or headspace-solid phase microextraction (HS-SPME/GC). In total, 56 components were identified, of which 48 were detected by DI/GC and 49 were detected by HS-SPME/GC. The principal compounds were citral (neral and geranial). An immunosuppressive activity of LCEO was investigated with bone marrow-derived dendritic cells (DCs) which have a critical role to trigger the adaptive immunity. Additionally, the inhibitory effect of LCEO on immune response was elucidated by performing the contact hypersensitivity (CHS) responses in mice. Our results clearly showed that LCEO decreases the production of TNF-α and cytokine IL-12 in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated DCs. CHS response and the infiltrative T cells were inhibited in the tested ears of the mice co-treated with LCEO. We demonstrate, for the first time, that the LCEO mainly containing citral exhibits an immunosuppressive effect on DCs and mice, indicating that LCEO can potentially be applied in the treatment of CHS, inflammatory diseases, and autoimmune diseases.

Lack of TAK1 in dendritic cells inhibits the contact hypersensitivity response induced by trichloroethylene in local lymph node assay

Trichloroethylene (TCE) is a ubiquitous environmental contaminant. Occupational TCE exposure has been associated with severe, generalized contact hypersensitivity (CHS) skin disorder. The development of CHS depends on innate and adaptive immune functions. Transforming growth factor-β activated kinase-1 (TAK1) controls the survival of dendritic cells (DCs) that affect the immune system homeostasis. We aimed to investigate the role of TAK1 activity in DC on TCE-induced CHS response. Control mice and DC-specific TAK1 deletion mice were treated with 80% (v/v) TCE using local lymph node assay (LLNA) to establish a TCE-induced CHS model. The draining lymph nodes (DLNs) were excised and the lymphocytes were measure for proliferation by BrdU-ELISA, T-cell phenotype analysis by flow cytometry and signaling pathway activation by western blot. The ears were harvested for histopathological analysis. Control mice in the 80% TCE group displayed an inflammatory response in the ears, increased lymphocyte proliferation, elevated regulatory T-cell and activated T-cell percentages, and more IFN-γ producing CD8+ T cells in DLNs. In contrast to control mice, DC-specific TAK1 deletion mice in the 80% TCE group showed an abolished CHS response and this was associated with defective T-cell expansion, activation and IFN-γ production. This effect may occur through Jnk and NF-κB signaling pathways. Overall, this study demonstrates a pivotal role of TAK1 in DCs in controlling TCE-induced CHS response and suggests that targeting TAK1 function in DCs may be a viable approach to preventing and treating TCE-related occupational health hazards.

Abstract 2607: Honokiol, a phytochemical from magnolia plant, prevents UV radiation-induced immune suppression in mice through inhibition of PGE2 and DNA methylation

Abstract The exposure of ultraviolet radiation (UVR) to murine skin suppresses the development of allergic contact hypersensitivity (CHS) response which is considered to be a prototypic T-cell mediated immune response. UVR-induced suppression of immune system has been implicated in skin cancer risk. Honokiol has been shown to have anti-skin carcinogenic activity, and here we have assessed the effect of honokiol on UVR-induced immunosuppression and its possible mechanism of action. Our CHS experiments revealed that exposure of C3H/HeN mouse skin with UVB radiation (150 mJ/cm2) for 4 consecutive days resulted in significant suppression of CHS response (75%, P<0.001) to the skin contact sensitizer, 2,4-dinitrofluorobenzene (DNFB), which was associated with the enhancement in the levels of cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production. Topical treatment of mice with honokiol (0.5 and 1.0 mg/cm2 skin area) in hydrophilic-cream based topical formulation or indomethacin (50 μg/mouse), a COX-2 inhibitor, significantly inhibits UV radiation-induced suppression of CHS response (P<0.01-0.005). The exposure of mice with UVB resulted in DNA hypermethylation, increase in DNA methyltransferase (Dnmt) activity, and elevated levels of Dnmt proteins in mouse skin, while treatment of mice with honokiol before each UVB exposure reduced the levels of DNA methylation as well as Dnmt activity compared with non-honokiol-treated control mice. The COX-2 deficient mice are resistant to UV-induced suppression of CHS response. Treatment of UVB exposed COX-2-deficient mice with PGE2 (50 μg/mouse/day) results in UV-induced suppression of CHS, increase in DNA methylation and Dnmt activity in the skin. Further, treatment of honokiol reversed the effect of PGE2 on UV-induced suppression of CHS response in COX-2-deficient mice. Treatment of C3H/HeN mice with 5-aza-2’-deoxycytidine (5-Aza-dc, 1.0 mg/kg body weight, i.p.), a DNA demethylating agent, after each UVB exposure restored the CHS response which was associated with a reduction in Dnmt activity and global DNA methylation levels compared to the UV-exposed mice which were not treated with 5-Aza-dc. We also compared the effect of honokiol with commercially available anti-cancer drugs, such as imiquimod and 5-fluorouracil, on CHS response in UV-exposed mice. Topical treatment of mice with equi-molar concentrations of honokiol and cancer drugs did not show significant difference in terms of inhibition of UVB induced immune suppression and thus suggests honokiol as a substitute for these drugs. These findings provide evidence that honokiol acts through inhibition of inflammatory mediators and subsequently DNA demethylation in UVR-exposed mouse skin. Citation Format: Santosh K. Katiyar, Tripti Singh, Ram Prasad. Honokiol, a phytochemical from magnolia plant, prevents UV radiation-induced immune suppression in mice through inhibition of PGE2 and DNA methylation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2607.

Epidermal NLRP10 contributes to contact hypersensitivity responses in mice.

The nucleotide binding and oligomerization domain-like receptor (NLR) protein NLRP10 is highly expressed in the epidermis and contributes to cell-autonomous responses against invasive bacteria. To investigate the role of NLRP10 in inflammatory responses of the skin we analyzed the effect of full-body and keratinocyte-specific depletion of NLRP10 in croton oil-induced irritant contact dermatitis (ICD) and 1-fluoro-2,4-dinitrobenzene (DNFB)-induced contact hypersensitivity (CHS) in mice. Nlrp10(-/-) mice were phenotypically normal and skin repair after wounding was not affected by lack of NLRP10. Similarly, we did not detect a contribution of NLRP10 to the ICD response induced by croton oil. In contrast, Nlrp10(-/-) mice showed significantly reduced inflammation in the DNFB-induced CHS response as compared to control animals. Microscopic analysis revealed significantly reduced numbers of CD4(+) and CD8(+) T cells in the infiltrates of animals lacking NLRP10 expression after CHS challenge. Epidermis-specific deletion of Nlrp10 by keratin-14 promotor driven Cre-recombinase was sufficient to account for this phenotype, although lymphocyte recruitment seemed to be unaltered in animals lacking NLRP10 expression in keratinocytes. Taken together, we provide evidence that NLRP10 contributes to T-cell-mediated inflammatory responses in the skin and highlight a physiological role of NLRP10 in epidermal keratinocytes.

Identification of Biological and Pharmaceutical Mast Cell‐ and Basophil‐Related Targets

Identification of Biological and Pharmaceutical Mast Cell‐ and Basophil‐Related Targets

TIM-4 is differentially expressed in the distinct subsets of dendritic cells in skin and skin-draining lymph nodes and controls skin Langerhans cell homeostasis.

T cell immunoglobulin and mucin-4 (TIM-4), mainly expressed on dendritic cells (DC) and macrophages, plays an essential role in regulating immune responses. Langerhans cells (LC), which are the sole DC subpopulation residing at the epidermis, are potent mediators of immune surveillance and tolerance. However, the significance of TIM-4 on epidermal LCs, along with other cutaneous DCs, remains totally unexplored. For the first time, we discovered that epidermal LCs expressed TIM-4 and displayed an increased level of TIM-4 expression upon migration. We also found that dermal CD207+ DCs and lymph node (LN) resident CD207−CD4+ DCs highly expressed TIM-4, while dermal CD207− DCs and LN CD207−CD4− DCs had limited TIM-4 expressions. Using TIM-4-deficient mice, we further demonstrated that loss of TIM-4 significantly upregulated the frequencies of epidermal LCs and LN resident CD207−CD4+ DCs. In spite of this, the epidermal LCs of TIM-4-deficient mice displayed normal phagocytic and migratory abilities, comparable maturation status upon the stimulation as well as normal repopulation under the inflamed state. Moreover, lack of TIM-4 did not affect dinitrofluorobenzene-induced contact hypersensitivity response. In conclusion, our results indicated that TIM-4 was differentially expressed in the distinct subsets of DCs in skin and skin-draining LNs, and specifically regulated epidermal LC and LN CD207−CD4+ DC homeostasis.

577 PPARγ activation is necessary for normal contact hypersensitivity responses and may promote cutaneous anti-tumor immune responses

577 PPARγ activation is necessary for normal contact hypersensitivity responses and may promote cutaneous anti-tumor immune responses

590 UVB generates microvesicle particles via Platelet-activating Factor-receptor signaling: a novel pathway by which a skin-specific stimulus exerts systemic effects

590 UVB generates microvesicle particles via Platelet-activating Factor-receptor signaling: a novel pathway by which a skin-specific stimulus exerts systemic effects

A novel splenic B1 regulatory cell subset suppresses allergic disease through phosphatidylinositol 3-kinase–Akt pathway activation

IL-10-producing regulatory B (B10) cells potently suppress allergic diseases, such as contact hypersensitivity (CHS). Splenic B10cells share overlapping phenotypic markers with CD5+ B1 Bcells, CD1dhiCD21+CD23- marginal zone (MZ) Bcells, and CD1dhiCD21+CD23+ T2-MZ precursor Bcells but do not exclusively belong to either subset. In this study we investigated the signaling mechanisms and a novel phenotypic parameter of B10cells. We performed microarray analysis comparing IL-10+ and IL-10- Bcells. B cell-specific phosphatase and tensin homolog (PTEN)-deficient mice, which exhibit aberrant activation of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway in Bcells, were examined. Microarray analysis revealed that the PI3K-Akt pathway is important for IL-10 production in Bcells. PI3K-Akt pathway inhibitors reduced B10cell numbers invitro. B10 cell numbers were significantly increased in Bcell-specific PTEN-deficient mice. The CHS response was significantly diminished in PTEN-deficient mice. Unexpectedly, splenic B10cells in these mice were found within the B1 B-cell subset but not within the MZ B-cell subset. In wild-type mice not only MZ B10cells but also B1-B10cells were identified in the spleen. In addition, these 2 B10cell subsets were predominantly found within the CD9+CD80+ B-cell fraction. A novel splenic B1 regulatory cell subset (B1-B10cells) was identified. Our findings show that the PI3K-Akt pathway in Bcells is critical for B10cell development and CHS response and that CD9/CD80 coexpression is a novelphenotypic parameter for both MZ-B10 and B1-B10cells.

Synthesis and biological evaluation of novel orally available 1-phenyl-6-aminouracils containing dimethyldihydrobenzofuranol structure for the treatment of allergic skin diseases.

We have designed and efficiently synthesized novel 1-phenyl-6-aminouracils by replacing the chroman moiety in CX-659S, a nonsteroidal dermatologic candidate, with dimethyldihydrobenzofuranol to cancel CX-659S asymmetric center. Medicinal chemistry effort culminated in the discovery of 13d bearing a 3-methyl group at the 1-phenyl group as a promising compound. Compound 13d, having good in vitro ADME profile and moderate oral bioavailability in mice, showed potent anti-inflammatory activity against hapten-induced contact hypersensitivity reaction in mice following topical and oral administration. The effects of 13d were equipotent to that of tacrolimus or prednisolone. In addition, compound 13d, having potent hydroxyl radical-scavenging activity, showed more potent suppressive effect on substance P-induced pruritus in mice than oxatomide.

Abstract B055: The impact of rapamycin and tacrolimus treatment on resident CD8+ T-cell populations in cutaneous squamous cell carcinoma

Abstract Organ transplant recipients have an increased risk of non-melanoma skin cancer (NMSC) development. Immunosuppressive agents, given to these patients to prevent organ rejection, are widely recognized to play a key role in the increased incidence of malignancy. However, different immunosuppressive agents, such as rapamycin and tacrolimus, which both prevent organ rejection, convey different risks of tumor formation. Using a UV-induced murine model of squamous cell carcinoma (SCC); HPV38 E6E7, we aim to determine whether these discrepancies are due to differences in the mechanism of immune suppression, in contrast to the much discussed direct effects of these drugs on tumor cells (i.e. immune-independent). Using customized rapamycin- and tacrolimus-incorporated feed to allow long-term administration, clinically relevant whole blood drug concentrations were obtained and validated using LC-MS/MS. Both systemic and local immunosuppression was functionally determined via adoptively transferred transgenic T-cell assay and skin allograft rejection profile, respectively. Notably however, preliminary data suggests phenotypic and functional differences of skin-residing T-cell subpopulations may exist when mice are treated with either rapamycin or tacrolimus, alluding to their potential role in the pathogenesis of NMSC. Short-term contact hypersensitivity responses (CHS) to OVA were abrogated in both rapamycin and tacrolimus-treated mice. However, prolonging the challenge phase enhanced the long-term CHS response in rapamycin-treated but not in tacrolimus-treated mice compared to normal feed controls. This enhanced response was correlated with an increased number of effector memory CD8+ T-cell population in the challenged ear skin. Using established chronic UV dosing schedules for SCC development in HPV38 E6E7 mice, tumor samples along with surrounding UV-exposed skin and fur-covered UV-protected skin samples were analyzed with FACs under the influence of these drugs. Preliminary data suggests that the formation of resident-memory CD8+ T-cells may be favored when treated with rapamycin, as higher percentages of CD8+ T-cells were present in the lesions of rapamycin-treated mice compared to tacrolimus and controls. In addition, LC-MS/MS analysis indicated that the concentration of rapamycin in the skin was significantly lower when compared to tacrolimus, whilst clinically relevant immunosuppressive concentrations of both drugs were maintained in the blood and kidneys. Through this project, we will expand our knowledge base regarding mechanisms of SCC formation in immunosuppressed patients. Citation Format: Ji-Won Jung, Paul J. Taylor, Fiona Simpson, Ian H. Frazer, James W. Wells. The impact of rapamycin and tacrolimus treatment on resident CD8+ T-cell populations in cutaneous squamous cell carcinoma. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B055.

Methods to Investigate the Role of Toll-Like Receptors in Allergic Contact Dermatitis.

Allergic contact disease is a common inflammatory skin disease resulting from hyperresponsiveness to harmless nonprotein substances such as metals, fragrances, or rubber. Recent research has highlighted a prominent role of Toll-like receptors, particularly TLR4 in contact allergen-induced innate immune activation that crucially contributes to the pathogenesis of this disease. Here we describe several methods to investigate the role of Toll-like receptors in contact allergen-induced pro-inflammatory responses. These include expansion of disease-relevant human primary cells including endothelial cells and keratinocytes and their manipulation of TLR signaling by transfection, retroviral infection and RNA interference, basic methods to induce contact hypersensitivity in mice, and protocols for adoptive transfer of hapten-stimulated dendritic cells and T cells from TLR-deficient mice to wild-type mice and vice versa wild-type mice to TLR-deficient mice in order to explore cell-specific roles of TLRs in contact hypersensitivity responses.

Potencjalna rola komórek dendrytycznych krwi w fazie efektorowej nadwrażliwości kontaktowej – badanie wstępne

Potencjalna rola komórek dendrytycznych krwi w fazie efektorowej nadwrażliwości kontaktowej – badanie wstępne