What does IL-17 do in psoriasis?
In psoriasis, we have found that IL-17E, produced by epidermal keratinocytes in the lesional skin, activates dermal macrophages to produce inflammatory cytokines, including TNF, and neutrophil chemokines, such as IL-8.
What interleukin level is important for psoriasis?
IL-17, as well as IL-23, have emerged as the most important cytokines in psoriasis. Patients with psoriatic lesions had 30 times more IL-17 level than those with normal skin. Three agents directed against either IL-17 or IL-17 receptors have been approved for psoriasis.
What is the function of IL-17A?
Interleukin-17 (IL-17, also known as IL-17A) is a key cytokine that links T cell activation to neutrophil mobilization and activation. As such, IL-17 can mediate protective innate immunity to pathogens or contribute to the pathogenesis of inflammatory diseases, such as psoriasis and rheumatoid arthritis.
What is an IL-17A inhibitor?
IL-17A is a pro-inflammatory cytokine. It belongs to the IL-17 family, which consists of IL-17A-F [8]. IL-17A plays a role in neutrophil recruitment, host defense and immuno-inflammatory pathology [7]. It is secreted mainly by Th17, but also by Treg cells, NK cells, mast cells and neutrophils [9].
What is the difference between IL-17 and IL-23?
Both IL-17 and IL-23 are implicated in PsA pathogenesis; however, IL-17-mediated inflammation may be more central in the development of cardiometabolic comorbidities and axial spondyloarthritis, whereas IL-23 may be more important in IBD immunopathogenesis.
Is IL-17A inflammatory?
IL-17A promotes inflammation by inducing various proinflammatory cytokines and chemokines, recruiting neutrophils, enhancing antibody production, and activating T cells. IL-17A expression is also augmented in autoimmune diseases such as multiple sclerosis and rheumatoid arthritis.
What is the difference between IL-17 and IL-17A?
IL-17A signals through IL-17RA in combination with IL-17RC. Whereas the IL-17RA subunit is ubiquitously expressed, IL17RC is mainly present on non-hematopoietic epithelial and mesenchymal cells. Interestingly, IL-17A interacts with its receptor as a homodimer or as a heterodimer with IL-17F (73).
How does Th17 cause inflammation?
Trafficking of Th17 cells Inflammation and pathogenesis induced by Th17 cells is a result of the pro-inflammatory cytokines these cells produce, but another important and often overlooked factor is the chemokines and chemokine receptors that mediate trafficking of activated T cells into diseased tissue.
What happens in the body during a Th17 response?
The Th17 cytokines IL-17A and IL-17F trigger the production of pro-inflammatory cytokines in target tissues, which not only mediate inflammation through the recruitment of innate immune cells such as neutrophils, but also promote further Th17 activation in a positive feedback manner [5].