Topical suplatast tosilate (IPD) ameliorates Th2 cytokine-mediated dermatitis in caspase-1 transgenic mice by downregulating interleukin-4 and interleukin-5

Pharmaceutical targeting Th2-mediated immunity enhances immunotherapy response in breast cancer

BACKGROUND

Breast cancer is a complex disease with a highly immunosuppressive tumor microenvironment, and has limited clinical response to immune checkpoint blockade (ICB) therapy. T-helper 2 (Th2) cells, an important component of the tumor microenvironment (TME), play an essential role in regulation of tumor immunity. However, the deep relationship between Th2-mediated immunity and immune evasion in breast cancer remains enigmatic.

METHODS

Here, we first used bioinformatics analysis to explore the correlation between Th2 infiltration and immune landscape in breast cancer. Suplatast tosilate (IPD-1151 T, IPD), an inhibitor of Th2 function, was then employed to investigate the biological effects of Th2 blockade on tumor growth and immune microenvironment in immunocompetent murine breast cancer models. The tumor microenvironment was analyzed by flow cytometry, mass cytometry, and immunofluorescence staining. Furthermore, we examined the efficacy of IPD combination with ICB treatment by evaluating TME, tumor growth and mice survival.

RESULTS

Our bioinformatics analysis suggested that higher infiltration of Th2 cells indicates a tumor immunosuppressive microenvironment in breast cancer. In three murine breast cancer models (EO771, 4T1 and EMT6), IPD significantly inhibited the IL-4 secretion by Th2 cells, promoted Th2 to Th1 switching, remodeled the immune landscape and inhibited tumor growth. Remarkably, CD8⁺ T cell infiltration and the cytotoxic activity of cytotoxic T lymphocyte (CTL) in tumor tissues were evidently enhanced after IPD treatment. Furthermore, increased effector CD4⁺ T cells and decreased myeloid-derived suppressor cells and M2-like macrophages were also demonstrated in IPD-treated tumors. Importantly, we found IPD reinforced the therapeutic response of ICB without increasing potential adverse effects.

CONCLUSIONS

Our findings demonstrate that pharmaceutical inhibition of Th2 cell function improves ICB response via remodeling immune landscape of TME, which illustrates a promising combinatorial immunotherapy.

Mouse models of atopic dermatitis: a critical reappraisal

Mouse models for atopic dermatitis (AD) are an indispensable preclinical research tool for testing new candidate AD therapeutics and for interrogating AD pathobiology in vivo. In this Viewpoint, we delineate why, unfortunately, none of the currently available so-called "AD" mouse models satisfactorily reflect the clinical complexity of human AD, but imitate more "allergic" or "irriant" contact dermatitis conditions. This limits the predictive value of AD models for clinical outcomes of new tested candidate AD therapeutics and the instructiveness of mouse models for human AD pathophysiology research. Here, we propose to initiate a rational debate on the minimal criteria that a mouse model should meet in order to be considered relevant for human AD. We suggest that valid AD models should at least meet the following criteria: (a) an AD-like epidermal barrier defect with reduced filaggrin expression along with hyperproliferation, hyperplasia; (b) increased epidermal expression of thymic stromal lymphopoietin (TSLP), periostin and/or chemokines such as TARC (CCL17); (c) a characteristic dermal immune cell infiltrate with overexpression of some key cytokines such as IL-4, IL-13, IL-31 and IL-33; (d) distinctive "neurodermatitis" features (sensory skin hyperinnervation, defective beta-adrenergic signalling, neurogenic skin inflammation and triggering or aggravation of AD-like skin lesions by perceived stress); and (e) response of experimentally induced skin lesions to standard AD therapy. Finally, we delineate why humanized AD mouse models (human skin xenotransplants on SCID mice) offer a particularly promising preclinical research alternative to the currently available "AD" mouse models.

Protective effect of linoleic acid against inflammatory reactions by mast cell via caspase-1 cascade pathways

Blockade of caspase-1 was reported to be a new target for allergic inflammation treatment. Here, we present the effect of linoleic acid (LA), a constituent of Allium hookeri (AH), to alleviate mast cell-mediated allergic inflammation. Pretreatment of LA and AH significantly reduced caspase-1 activation without displaying host cell cytotoxicity in activated human mast cells. IC₅₀ value of LA on caspase-1 activity is 0.014 μM. LA and AH pretreatment effectively regulated increased levels of interleukin (IL)-1β, IL-6, IL-8, thymic stromal lymphopoietin, and tumor necrosis factor on activated human mast cells. Moreover, LA and AH were effective against activations of nuclear factor-κB and mitogen-activated protein kinases in human mast cells. In summary, LA and AH alleviate allergic inflammatory reactions via blocking caspase-1 cascade signaling pathway. These results provide evidence for the anti-allergic inflammatory properties of LA and AH and corroborate its potential use for the treatment and prevention of allergic diseases. PRACTICAL APPLICATIONS: Allium hookeri (AH) is used as traditional food to treat various diseases and contains an essential fatty acid, linoleic acid (LA). LA and AH alleviate mast cell-mediated allergic inflammatory reactions via inhibiting inflammatory mediators. These results provide evidence for the anti-allergic inflammatory properties of LA and AH and corroborate its potential use for the treatment and prevention of allergic diseases.

Schisandra chinensis and Its Main Constituent Schizandrin Attenuate Allergic Reactions by Down-Regulating Caspase-1 in Ovalbumin-Sensitized Mice

Schisandra chinensis (SC) and its main constituent, schizandrin (SCH) exhibit anti-inflammatory and anti-allergic activities. Allergic and inflammatory reactions are aggravated via caspase-1 signaling pathway. However, the regulatory effects of SC and SCH on caspase-1 activation have not been clarified yet. In this study, we aimed to clarify the anti-allergic effects of SC and SCH using an ovalbumin (OVA)-sensitized mice and anti-CD3 and anti-CD28 antibodies-stimulated splenocytes. SC or SCH significantly inhibited the levels of immunoglobulin (Ig)E, IgG1, or interleukin (IL)-4 in serum of OVA-sensitized mice. SC or SCH significantly inhibited the levels of IL-6, tumor necrosis factor (TNF)-[Formula: see text], and IL-1[Formula: see text] in spleen of the OVA-sensitized mice. SC or SCH significantly suppressed the expression of caspase-1 and receptor-interacting protein (RIP)-2 in spleen of the OVA-sensitized mice. In activated splenocytes, SC or SCH significantly decreased the expression of caspase-1 and RIP-2 as well as the production of IL-6 and TNF-[Formula: see text]. We suggest that SC and SCH exert an anti-allergic effect by down-regulating caspase-1 signaling.

Novel, Alternative, and Controversial Therapies of Rhinitis

Rhinitis is a multifactorial disease characterized by sneezing, rhinorrhea, postnasal drip, and nasal congestion. This condition affects 10% to 40% of the population and is responsible for billions of spent health care dollars and impairment in quality of life for those affected. Currently available medical and vaccine therapies are effective for a large segment of this population; however, a subset of patients still has difficult-to-control rhinitis. This article reviews the current progress being made in novel drug and vaccine development and delves into alternative medical, surgical, and homeopathic strategies that may be promising adjunctive treatments for the difficult-to-treat rhinitis patient.

Andrographolide suppresses thymic stromal lymphopoietin in phorbol myristate acetate/calcium ionophore A23187-activated mast cells and 2,4-dinitrofluorobenzene-induced atopic dermatitis-like mice model

BACKGROUND

Atopic dermatitis (AD) is one of the most common inflammatory cutaneous diseases. Thymic stromal lymphopoietin (TSLP) has been demonstrated to be an important immunologic factor in the pathogenesis of AD. The production of TSLP can be induced by a high level of intracellular calcium concentration and activation of the receptor-interacting protein 2/caspase-1/NF-κB pathway. Andrographolide (ANDRO), a natural bicyclic diterpenoid lactone, has been found to exert anti-inflammatory effects in gastrointestinal inflammatory disorders through suppressing the NF-κB pathway.

OBJECTIVE

To explore the effect of ANDRO on the production of TSLP in human mast cells and AD mice model.

METHODS

We utilized enzyme-linked immunosorbent assay, real-time reverse transcription polymerase chain reaction analysis, Western blot analysis, and immunofluorescence staining assay to investigate the effects of ANDRO on AD.

RESULTS

ANDRO ameliorated the increase in the intracellular calcium, protein, and messenger RNA levels of TSLP induced by phorbol myristate acetate/calcium ionophore A23187, through the blocking of the receptor-interacting protein 2/caspase-1/NF-κB pathway in human mast cell line 1 cells. ANDRO, via oral or local administration, also attenuated clinical symptoms in 2,4-dinitrofluorobenzene-induced AD mice model and suppressed the levels of TSLP in lesional skin.

CONCLUSION

Taken together, ANDRO may be a potential therapeutic agent for AD through suppressing the expression of TSLP.

Suplatast tosilate alleviates nasal symptoms through the suppression of nuclear factor of activated T-cells-mediated IL-9 gene expression in toluene-2,4-diisocyanate-sensitized rats

Histamine H1 receptor (H1R) gene is upregulated in patients with pollinosis; its expression level is highly correlated with the nasal symptom severity. Antihistamines are widely used as allergy treatments because they inhibit histamine signaling by blocking H1R or suppressing H1R signaling as inverse agonists. However, long-term treatment with antihistamines does not completely resolve toluene-2,4-diisocyanate (TDI)-induced nasal symptoms, although it can decrease H1R gene expression to the basal level, suggesting additional signaling is responsible for the pathogenesis of the allergic symptoms. Here, we show that treatment with suplatast tosilate in combination with antihistamines markedly alleviates nasal symptoms in TDI-sensitized rats. Suplatast suppressed TDI-induced upregulation of IL-9 gene expression. Suplatast also suppressed ionomycin/phorbol-12-myristate-13-acetate-induced upregulation of IL-2 gene expression in Jurkat cells, in which calcineurin (CN)/nuclear factor of activated T-cells (NFAT) signaling is known to be involved. Immunoblot analysis demonstrated that suplatast inhibited binding of NFAT to DNA. Furthermore, suplatast suppressed ionomycin-induced IL-9 mRNA upregulation in RBL-2H3 cells, in which CN/NFAT signaling is also involved. These data suggest that suplatast suppressed NFAT-mediated IL-9 gene expression in TDI-sensitized rats and this might be the underlying mechanism of the therapeutic effects of combined therapy of suplatast with antihistamine.

A natural dye, Niram improves atopic dermatitis through down-regulation of TSLP

Naju Jjok (Polygonum tinctorium Lour.) has been known to treat skin diseases in traditional Korean medicine. A natural textile dye, Niram made from Naju Jjok has traditionally been used to dye clothes. Thymic stromal lymphopoietin (TSLP) plays an important role in the development of atopic dermatitis (AD). Thus, we investigated that Niram might ameliorate AD through regulation of TSLP. Niram significantly inhibited the levels of TSLP through blockade of caspase-1/receptor-interacting protein 2 pathway in stimulated mast cells. Further, Niram ameliorated clinical symptoms in AD mouse. Niram significantly inhibited the infiltration of inflammatory cells in lesional skin. The levels of TSLP, caspase-1, IL-4, and IL-6 were inhibited in lesional skin applied topically with Niram. Niram significantly inhibited the serum levels of IgE and histamine in AD mouse. Finally, Niram significantly inhibited the levels of TSLP in polyriboinosinic polyribocytidylic acid-stimulated human keratinocyte HaCaT cells. These results establish Niram as a functional dye embracing the aspects of not only a traditional use but also a pharmacological effect.

Genuine traditional Korean medicine, Naju Jjok (Chung-Dae, Polygonum tinctorium) improves 2,4-dinitrofluorobenzene-induced atopic dermatitis-like lesional skin

PURPOSE

Naju Jjok (NJJ, Polygonum tinctorium) is a clear heat and release toxin medicinal. It has been used to treat various inflammatory diseases and as a dye in clothing in traditional Korean medicine. However, the effect of NJJ on atopic dermatitis (AD) has not been elucidated. Therefore, we examined whether NJJ would have an inhibitory effect on AD using the mimic AD murine model and in vitro model.

METHODS

We treated NJJ on 2,4-dinitrofluorobenzene (DNFB)-induced AD-like skin lesions in NC/Nga mice, phorbol myristate acetate/calcium ionophore A23187-stimulated human mast cell line (HMC-1) cells, and anti-CD3/anti-CD28-stimulated splenocytes. Histological analysis, ELISA, PCR, and Western blot analysis were performed.

RESULTS

The oral administration with NJJ suppressed the total clinical severity in DNFB-induced AD-like lesional skin. NJJ significantly suppressed the levels of inflammatory mRNA and protein in AD-like lesional skin. NJJ significantly suppressed the levels of IgE and interleukin-4 in the serum of DNFB-induced AD mice. The expression of mast cells-derived caspase-1 was suppressed by NJJ in AD-like lesional skin. In addition, topical application with NJJ improved clinical symptoms in DNFB-induced AD mice. The topical application with NJJ significantly suppressed the levels of IgE and histamine in the serum of DNFB-induced AD mice. NJJ suppressed the production and mRNA expression of TSLP by blockade of caspase-1 signal pathway in the activated HMC-1 cells. Furthermore, NJJ significantly decreased the production of tumor necrosis factor-α from the stimulated splenocytes.

CONCLUSIONS

In conclusion, these results propose curative potential of natural dye, NJJ by showing the scientific evidence on anti-AD effect of NJJ which has been used traditionally.

The β-sitosterol attenuates atopic dermatitis-like skin lesions through down-regulation of TSLP

The compound β-sitosterol (BS) is one of the most common forms of phytosterols and has anti-cancer, anti-oxidant, anti-bacterial, and anti-inflammatory effects. However, the effect of BS on atopic dermatitis (AD) has not been elucidated. Therefore, we investigated whether BS would be an effective treatment against AD. We treated BS on 2,4-dinitrofluorobenzene (DNFB)-induced AD-like skin lesions in NC/Nga mice, anti-CD3/anti-CD28-stimulated splenocytes, and phorbol myristate acetate/calcium ionophore A23187-stimulated human mast cell line (HMC-1) cells. Histological analysis, ELISA, PCR, caspase-1 assay, and Western blot analysis were performed. BS reduced the total clinical severity in DNFB-treated NC/Nga mice. Infiltration of inflammatory cells and number of scratching were clearly reduced in the BS-treated group compared with the DNFB-treated group. BS significantly reduced the levels of inflammation-related mRNA and protein in the AD skin lesions. BS significantly reduced the levels of histamine, IgE, and interleukin-4 in the serum of DNFB-treated NC/Nga mice. The activation of mast cell-derived caspase-1 was decreased by treatment with BS in the AD skin lesions. BS also significantly decreased the production of tumor necrosis factor-α from the stimulated splenocytes. In the stimulated human mast cell line, HMC-1 cells, increased intracellular calcium levels were decreased by treatment with BS. Further, BS inhibited the production and mRNA expression of TSLP through blocking of caspase-1 and nuclear factor-κB signal pathways in the stimulated HMC-1 cells. These results provide additional evidence that BS may be considered an effective therapeutic drug for the treatment of AD.

Immune modulation for treatment of allergic disease

Immune modulation for treatment of allergic diseases aims to decrease the pathologic immune response rather than to cause a return to an immunologically naive or unresponsive state. Our expanding knowledge of innate and adaptive immune responses at the molecular level has led to development of immunomodulators for several allergic diseases, particularly asthma, allergic rhinitis, and eosinophilic esophagitis. Although successful immune modulation in mouse models of allergic disease have often failed to translate into significant results in human clinical trials, much has been learned about the pleotropic nature of cytokines and their effector mechanisms and of the varied phenotypes of allergic disease. We examine strategies of immune modulation in allergic diseases that have undergone human clinical trials, all with the common goal of decreasing the T-helper 2 (Th2) response, but through different mechanisms: blocking critical Th2 cytokines, inhibiting Th2 cytokine synthesis, blocking critical Th2 effector molecules, inhibiting important cells in the Th2 response, and stimulating Th1 responses. Therapies directed against specific effector molecules, such as immunoglobulin E and prostaglandin D2, hold promise in immune modulation of allergic disease, as do targeting the IL-4/IL-13 receptor and augmenting Th1/Th2 balance with Toll-like receptor agonists.

Future forms of immunotherapy and immunomodulators in allergic disease

Future forms of immunotherapy, particularly toll-like receptor agonists, have shown promising results in animal models of allergic disease although most have failed to translate into successful human clinical trials. These results have helped to elucidate the pleotropic roles of cytokines as well as the diverse phenotypes of allergic diseases, particularly asthma. The goals of these therapies are to improve patient symptoms and quality of life, to prevent and favorably alter disease course, and to maintain a good risk/benefit ratio along with a cost-effective profile.

Mast cells in atopic dermatitis

Mast cells play as the major effector cells in immediate hypersensitivity through activation via the high-affinity IgE receptor, Fc epsilon RI, although many other functions have recently been discovered for this cell type. Given the broad array of proinflammatory mediators secreted from Fc epsilon RI-activated mast cells, as well as sensitization to allergens, IgE elevation, and increased mast cells in a majority of atopic dermatitis patients, mast cells are believed to be involved in the pathogenesis of atopic dermatitis. Numerous animal models have been used to study this epidemic disease. Here we review the recent progress to synthesize our current understanding of this disease and potential mechanisms for a mast cell's role in the disease.

Suplatast tosilate inhibits histamine signaling by direct and indirect down-regulation of histamine H1 receptor gene expression through suppression of histidine decarboxylase and IL-4 gene transcriptions

Allergic rhinitis (AR) is an inflammatory disorder typified by symptoms such as sneezing, congestion, and rhinorrhea. Histamine plays important roles in eliciting AR symptoms. Up-regulation of the histamine H(1) receptor (H1R) and histidine decarboxylase (HDC) mRNAs was observed in AR patients. Th2 cytokines are also involved in the pathogenesis of AR. We examined the effect of suplatast tosilate on nasal symptoms, and H1R, HDC, and IL-4 gene expression using toluene-2,4-diisocyanate (TDI)-sensitized rats and HeLa cells expressing endogenous H1R. Provocation with TDI increased nasal symptoms, HDC activity, the histamine content of nasal lavage fluid, and the expression of H1R, HDC, and IL-4 mRNAs in TDI-sensitized rats. Pretreatment with suplatast for 2 wk significantly suppressed TDI-induced nasal symptoms and elevation of H1R, HDC, and IL-4 mRNAs. Suplatast also suppressed HDC activity in the nasal mucosa and the histamine content of the nasal lavage fluid. Bilateral injection of IL-4 into the nasal cavity of normal rats up-regulated H1R mRNA, while intranasal application of histamine up-regulated IL-4 mRNA. Suplatast suppressed IL-4-induced up-regulation of H1R mRNA in HeLa cells. However, it did not inhibit histamine-induced H1R mRNA elevation. These results suggest that suplatast alleviates nasal symptoms by inhibiting histamine signaling in TDI-sensitized rats through the suppression of histamine- and IL-4-induced H1R gene expression by the inhibitions of HDC and IL-4 gene transcriptions, respectively.