Human Translational Research in Psoriasis Using CLA+ T Cells

Abstract

Focusing on the study of human memory CLA+ T cells to understand psoriasis pathology constitutes an innovative approach to explore the pathological mechanism of this chronic cutaneous inlammatory disease. CLA+ T cells can be considered peripheral cell biomarkers in the study of T-cell mediated human skin diseases. During the last few years, new evidences have been found that link streptococcal infection with IL-17 response in psoriasis by studying the interaction between Streptococcus pyogenes with CLA+ T cells and autologous epidermal cells. S. pyogenes constitutes the best clinically characterized trigger of psoriasis and by exploring its efect on CLA+ T cells and epidermal cells in psoriasis may allow understanding psoriasis by using patient's clinical samples ex vivo. Keywords: psoriasis, CLA+ T cells, translational research, Streptococcus pyogenes, IL17 CLA+ T cells and the regional cutaneous immune systemThe adaptive immune responses taking place during cutaneous chronic inlammation in psoriasis preferentially involve a subset of memory T lymphocytes, which are related to the skin and that belong to the cutaneous immune system, and constitute one of the best characterized regional immune systems of the body and known for decades [1]. In the humans, the cutaneous lymphocyte-associated antigen (CLA) is a surface cell marker that allows identifying T cells that belong to the cutaneous immune system. The CLA antigen is a carbohydrate expressed by 15% of human circulating T cells, and on most (>90%) skin-iniltrating T cells, contrary to other inlamed organs [2]. CLA is expressed preferentially on memory antigenexperienced T cells.© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The CLA is one of the adhesion molecule that, together with chemokine receptors, allows T cells to selectively migrate to the skin, in either homeostatic or inlammatory conditions, by binding to endothelial cell wall via adhesion molecules or ligands. The molecular interactions between CLA/E-selectin, very late antigen-4 (VLA-4)/vascular cell adhesion protein-1 (VCAM-1), lymphocyte function-associated antigen-1 (LFA-1)/intercellular adhesion molecule-1 (ICAM-1), and chemokine ligands for chemokine, C-C motif receptor (CCR) 10, CCR4, CCR6, and CCR8 constitute a code bar system enabling skin iniltration [3].The importance of circulating CLA+ T cells for understanding the skin immune system is not only based on their capacity to selectively migrate to skin, but also on the fact that these circulating memory T cells are functionally related to the immune response taking place in the cutaneous inlamed lesions. This feature is based on the recirculating capacity of those cells between lesional skin and blood during cutaneous inlammation in psoriasis [3]. The adhesive interaction between LFA-1 ...