Development of an inhibiting antibody against equine interleukin 5 to treat insect bite hypersensitivity of horses.

Insect bite hypersensitivity (IBH) is the most common allergic skin disease of horses. It is caused by insect bites of the Culicoides spp. which mediate a type I/IVb allergy with strong involvement of eosinophil cells.

TRPV1 and TRPA1 Channels Are Both Involved Downstream of Histamine-Induced Itch.

Two histamine receptor subtypes (HR), namely H1R and H4R, are involved in the transmission of histamine-induced itch as key components. Although exact downstream signaling mechanisms are still elusive, transient receptor potential (TRP) ion channels play important roles in the sensation of histaminergic and non-histaminergic itch. The aim of this study was to investigate the involvement of TRPV1 and TRPA1 channels in the transmission of histaminergic itch.

Histamine 2 Receptor Agonism and Histamine 4 Receptor Antagonism Ameliorate Inflammation in a Model of Psoriasis.

Psoriasis is a chronic inflammatory skin disorder characterized by hyperproliferative keratinocytes and immune cell infiltration into the skin, often accompanied by itch. Histamine, acting via histamine 1-4 receptors, is known to modulate immune responses in the skin and to induce itch. The aim of this study was to test the role of histamine 2 receptors and histamine 4 receptors in the imiquimod-induced psoriasis-like skin inflammation model.

The role of the histamine H receptor in atopic dermatitis and psoriasis.

Atopic dermatitis (AD) and psoriasis are common skin diseases with a high negative impact on patients' quality of life. Both diseases are mediated by a pro-inflammatory infiltrate consisting of several cell types, such as T-cells, antigen-presenting cells and granulocytes and display disturbed keratinocyte differentiation. Given the fact that histamine levels are also highly elevated in inflamed skin, it is likely that histamine plays a relevant role in disease pathology.

Combined treatment with H1 and H4 receptor antagonists reduces inflammation in a mouse model of atopic dermatitis.

Background: Histamine 4 receptor (H4R) antagonists are considered as new therapeutics for the treatment of atopic dermatitis (AD) and first clinical trials have already shown promising results. Histamine 1 receptor (H1R) antagonists are traditionally used to treat AD although the evidence for the efficacy is weak. The combined blockade of both, H1R and H4R, might provide synergistic anti-inflammatory.

Stimulation of the histamine 4 receptor upregulates thymic stromal lymphopoietin (TSLP) in human and murine keratinocytes.

The cytokine thymic stromal lymphopoietin (TSLP) is involved in the development and the progression of allergic diseases. It is mainly released by epithelial cells at barriers such as skin and gut in response to danger signals. Overexpression of TSLP in keratinocytes (KC) can provoke the development of a type 2 inflammatory response.

The selective glucocorticoid receptor agonist mapracorat displays a favourable safety-efficacy ratio for the topical treatment of inflammatory skin diseases in dogs.

Background: Mapracorat is a nonsteroidal Selective Glucocorticoid Receptor Agonist (SEGRA) that is presumed to have a better therapeutic index compared to classical glucocorticoids.

Objectives: To compare the efficacy and safety of mapracorat with classical glucocorticoids used for the treatment of allergic skin diseases in dogs.

Animals: Six laboratory beagles.

Allergic inflammation is augmented via histamine H4 receptor activation: The role of natural killer cells in vitro and in vivo.

Background: Natural Killer cells (NK cells) are identified as pivotal mediators in allergic skin diseases and accumulate in lesions of atopic dermatitis (AD) patients. Histamine levels are increased in these lesions and histamine is involved in chemotaxis in dendritic cells and NK cells.

Objective: The aim of this study was to determine if the histamine H4 receptor (H4R) mediates NK cell chemotaxis and whether it influences interplay between NK cells and dendritic cells during the early phase of allergic inflammation.

PCR detects bands consistent with the expression of receptors associated with pruritus in canine dorsal root ganglia.

Background: Various mediators are involved in the induction of itch, i.e. pruritus; however, the in vivo pharmacology of pruritus seems to be different in distinct species, and little is known about receptors that are involved in the induction of itch in dogs.

Histamine induces proliferation in keratinocytes from patients with atopic dermatitis through the histamine 4 receptor.

Background: Epidermal hyperproliferation resulting in acanthosis is an important clinical observation in patients with atopic dermatitis, and its underlying mechanisms are not completely understood.

Objective: Because increased levels of histamine are present in lesional skin, we investigated the effect of histamine, especially with regard to histamine 4 receptor (H4R) activation, on the proliferation of human and murine keratinocytes.

Methods: The expression of H4R on human and murine keratinocytes was detected by using real-time PCR.

Pathogenetic and therapeutic implications of the histamine H4 receptor in inflammatory skin diseases and pruritus.

Chronic inflammatory skin diseases such as atopic dermatitis (AD) are clinically characterized by erythematous and pruritic skin lesions, immunologically mediated by an inflammatory infiltrate consisting of T-cells, antigen presenting cells (APC) and eosinophilic granulocytes. Histamine levels are increased in lesions of inflammatory skin diseases. It is likely that histamine also plays a pathogenetic role since various relevant cell types such as T-cells and APC express functional histamine receptors.

The histamine H receptor as a new target for treatment of canine inflammatory skin diseases.

Histamine is a well known mediator of allergic skin diseases and, with the discovery of the histamine H(4) receptor, the role of histamine is re-evaluated. There are only limited published data elucidating the role of the histamine H(4) receptor in dogs. Twelve beagles intradermally injected with histamine (0.

[Histamine as an immunomodulator].

The role of histamine as an important proinflammatory mediator has been well known for nearly 100 years. In regards to the immediate type allergic response, there is no debate about the importance of histamine. In addition, histamine has immunomodulatory functions, some of which are related to the histamine H2 receptor.

Histamine H4 receptor antagonism reduces hapten-induced scratching behaviour but not inflammation.

Effects of the histamine H(4) receptor antagonist JNJ 7777120 (1-[(5-chloro-1H-indol-2-yl)carbonyl]-4-methylpiperazine) were tested in two models of allergic contact dermatitis. Dermatitis was induced by 2,4-dinitrochlorobenzene and toluene-2,4-diisocyanate, which differ in their Th1-Th2 profile in that way that 2,4-dinitrochlorobenzene is a classical contact allergen with a pronounced Th1-mediated inflammation, while the respiratory chemical allergen toluene-2,4-diisocyanate induces a Th2-dominated inflammation. JNJ 7777120 (15 mg/kg) administered 2 h and 30 min before and 1 h after challenge did not reduce the hapten-induced ear swelling determined 24 h after challenge.