Current Developments in the Immunology of Psoriasis

Abstract

Psoriasis is a frequent inflammatory skin disease. Fundamental research on the pathogenesis of psoriasis has substantially increased our understanding of skin immunology, which has helped to introduce innovative and highly effective therapies. Psoriasis is a largely T lymphocyte-mediated disease in which activation of innate immune cells and pathogenic T cells result in skin inflammation and hyperproliferation of keratinocytes. B cells have thus far largely been neglected regarding their role for the pathogenesis of psoriasis. However, recent data shed light on their role in inflammatory skin diseases. Interestingly, interleukin (IL)-10-producing regulatory B cells have been assumed to ameliorate psoriasis. In this review, we will discuss the development of disease, pathogenicity, and current developments in therapeutic options. We describe different roles of T cells, B cells, and cytokines for the immunopathology and disease course of psoriasis.

Keywords: Biologics; Cytokines; Lymphocytes; Psoriasis; Regulatory B cells.

Figure 1

The pathogenesis of Psoriasis. A) Damaged keratinocytes during exposure to microbial or mechanical injury foster activation of antigen-presenting cells (APC) such as macrophages and dermal dendritic cells (DC). B) APCs including Langerhans cells (LC), DCs and potentially B cells interact with T cells leading to their activation and pro-inflammatory cytokine production. C) Regulatory B cells (B_reg) may modulate inflammation. B_reg secrete IL-10 that interferes with activation of other leukocytes including macrophages (M∅) and T cells to counteract inflammation