Scanning the Immunopathogenesis of Psoriasis (original) (raw)

Advances in Understanding the Immunological Pathways in Psoriasis

International Journal of Molecular Sciences

Psoriasis vulgaris is a chronic, immune-mediated, inflammatory, polygenic skin disorder affecting approximately 2% of the population. It has a great impact on quality of life; patients often experience depression, anxiety, stigma as well as suicidal behavior. Even though psoriasis is one of the most studied dermatological conditions, the pathogenesis of the disease is still not completely elucidated. The complex interactions between keratinocytes, dendritic cells, T-lymphocytes, neutrophils and mast cells are responsible for the histopathological changes seen in psoriasis. The pathogenic model leading to the formation of psoriatic plaques has however evolved a lot over the years. There is now enough evidence to support the role of interleukin (IL) -23, IL-17, IL-22, T helper (Th) -17 cells, Th-22 cells, T regulatory cells, transforming growth factor (TGF)-β1 and IL-10 in the pathogenesis of the disease. Moreover, several inflammatory and anti-inflammatory molecules are currently bei...

The roles of cells and cytokines in the pathogenesis of psoriasis

International Journal of Dermatology, 2012

Psoriasis is considered an immune chronic disease in which T cells are accepted as important. Nowadays, it is believed that psoriasis is most likely a T helper (Th)1/Th17 induced inflammatory disease. However, some other cells, such as endothelial cells, dendritic cells, monocytic cells, neutrophils, keratinocytes, and several cytokines, appear to have, at different stages of the disease, an important role in its pathogenesis. For instance, the response to psoriasis therapy is dependent not only on the inactivation of Th1 and Th17 immune responses but also on the inactivation of dendritic cell products. Moreover, interleukin (IL)-23 deregulation appears to be an independent factor in the pathogenesis of psoriasis. Indeed, currently, the IL-23/Th17 axis is believed to be crucial in psoriasis pathogenesis, and its inhibition appears to be important for therapeutic achievement. This review presents the roles and interactions of cells and cytokines that are related to psoriasis pathogenesis.

Role of the immune system and immunological circuits in psoriasis

Giornale italiano di dermatologia e venereologia : organo ufficiale, Società italiana di dermatologia e sifilografia, 2011

Psoriasis vulgaris is a chronic skin disease in which our understanding of the pathogenesis has substantially grown in recent years. Our current appreciation of the role of the immune system is that it plays a necessary and driving role in the disease process. Investigations into the genetics of psoriasis has spurred further examinations into the contributions of immune mediators such as IL-23, IL-17, IL-22, and TNF as well as cellular mediators including a variety of dendritic cell populations of the skin and the growing number of T cell types, including the Th17 and Th22 subsets. Investigations into how these soluble and cellular elements interact with each other and the skin and form complex signal circuits to engender the psoriasis phenotype is starting to become elucidated. Furthermore, these recent advances have been fruitful in leading to the development of new classes of biologic therapeutics that are remarkably effective in halting the disease process.

Orchestrated Cytokines Mediated by Biologics in Psoriasis and Its Mechanisms of Action

Biomedicines, 2022

Psoriasis is an autoimmune disease mediated by disturbed T cells and other immune cells, and is defined by deep-red, well-demarcated skin lesions. Due to its varied etiologies and indefinite standard pathogenesis, it is challenging to consider the right treatment exclusively for each psoriasis patient; thus, researchers yearn to seek even more precise treatments other than topical treatment and systemic therapy. Using biologics to target specific immune components, such as upregulated cytokines secreted by activated immune cells, is the most advanced therapy for psoriasis to date. By inhibiting the appropriate pro-inflammatory cytokines, cellular signaling can be altered and, thus, can inhibit further downstream inflammatory pathways. Herein, the roles of cytokines with their mechanisms of action in progressing psoriasis and how the usage of biologics alleviates cellular inflammation are discussed. In addition, other potential pro-inflammatory cytokines, with their mechanism of acti...

Cytokine network in psoriasis revisited

European cytokine network, 2011

Psoriasis is a chronic genetically determined, erythemato-squamous disease associated with many comorbidities. Evidence from clinical studies and experimental models support the concept that psoriasis is a T cell-mediated inflammatory skin disease and T helper (Th) cells - Th1, Th17 and Th22 - play an important role in the pathogenesis. Th1 cytokines IFNγ, IL-2, as well as Th17 cytokines IL-17A, IL-17F, IL-22, IL-26, and TNFα (Th1 and Th17 cytokine) are increased in serum and lesional skin. IL-22 produced by Th17 and new subset of T helper cells, Th22, is also increased within psoriatic lesions and in the serum. Other recently recognized cytokines of significant importance in psoriasis are IL-23, IL-20 and IL-15. The IL-23/Th17 pathway plays a dominant role in psoriasis pathogenesis. Currently due to enormous methodological progress, more and more clinical and histopathological psoriatic features could be explained by particular cytokine imbalance, which still is one of the most fas...

Psoriasis pathogenesis and the development of novel targeted immune therapies

Journal of Allergy and Clinical Immunology, 2017

Psoriasis is caused by a complex interplay between the immune system, psoriasis-associated susceptibility loci, autoantigens, and multiple environmental factors. Over the last 2 decades, research has unequivocally shown that psoriasis represents a bona fide T cell-mediated disease primarily driven by pathogenic T cells that produce high levels of IL-17 in response to IL-23. The discovery of the central role for the IL-23/type 17 T-cell axis in the development of psoriasis has led to a major paradigm shift in the pathogenic model for this condition. The activation and upregulation of IL-17 in prepsoriatic skin produces a ''feed forward'' inflammatory response in keratinocytes that is self-amplifying and drives the development of mature psoriatic plaques by inducing epidermal hyperplasia, epidermal cell proliferation, and recruitment of leukocyte subsets into the skin. Clinical trial data for mAbs against IL-17 signaling (secukinumab, ixekizumab, and brodalumab) and newer IL-23p19 antagonists (tildrakizumab, guselkumab, and risankizumab) underscore the central role of these cytokines as predominant drivers of psoriatic disease. Currently, we are witnessing a translational revolution in the treatment and management of psoriasis. Emerging bispecific antibodies offer the potential for even better disease control, whereas small-molecule drugs offer future alternatives to the use of biologics and less costly long-term disease management.

Immunopathogenesis of psoriasis

Experimental Dermatology, 2007

Psoriasis is a chronic skin disease that affects about 1.5% of the Caucasian population and is characterized by typical macroscopic and microscopic skin alterations. Psoriatic lesions are sharply demarcated, red and slightly raised lesions with silverwhitish scales. The microscopic alterations of psoriatic plaques include an infiltration of immune cells in the dermis and epidermis, a dilatation and an increase in the number of blood vessels in the upper dermis, and a massively thickened epidermis with atypical keratinocyte differentiation. It is considered a fact that the immune system plays an important role in the pathogenesis of psoriasis. Since the early 1990s, it has been assumed that T1 cells play the dominant role in the initiation and maintenance of psoriasis. However, the profound success of antitumor necrosis factor-a therapy, when compared with T-cell depletion therapies, should provoke us to critically re-evaluate the current hypothesis for psoriasis pathogenesis. Recently made discoveries regarding other T-cell populations such as Th17 and regulatory T cells, dendritic cells, macrophages, the keratinocyte signal transduction and novel cytokines including interleukin (IL)-22, IL-23 and IL-20, let us postulate that the pathogenesis of psoriasis consists of distinct subsequent stages, in each of them different cell types playing a dominant role. Our model helps to explain the varied effectiveness of the currently tested immune modulating therapies and may enable the prediction of the success of future therapies.

Current Concepts of Psoriasis Immunopathogenesis

International Journal of Molecular Sciences

Psoriasis is a recurrent, chronic, immune-mediated, systemic inflammatory disease of the skin, joints, and other organic systems. After atopic dermatitis, chronic stationary psoriasis is the most common inflammatory skin disease, affecting an average of 2–4% of the world’s population. The disease carries a significant burden due to its numerous comorbidities and the major impact on patients’ social and emotional aspects of life. According to current knowledge, psoriasis is a multifactorial disease that occurs in genetically predisposed individuals under various environmental factors, which trigger an immune response disorder with a series of complex inflammatory cascades. The disease is initiated and maintained by mutual interaction of the innate and adaptive immune cells, primarily dendritic cells, T lymphocytes, and keratinocytes, whose leading role alternates at different stages of the disease, consisting mainly in the IL-23/Th17 pathway. Inflammatory events result in consequent ...