Plaque psoriasis is characterized by well-defined, raised, chronic erythematous plaques with silver patches observed commonly in the elbows, knees, scalp, umbilicus, and lumbar area ( 11– 13). Psoriasis is a chronic inflammatory skin disease with an autoimmune component and a strong genetic basis. It is becoming clear that γδT cells are heterogeneous populations of cells with multifunctional capacities in repairing host tissue ( 6), pathogen clearance ( 7), tumor surveillance ( 8, 9), and proinflammatory effects ( 10). Relative to αβT cells, γδT cells have been less studied and characterized. Although they constitute a small portion of the total T cell pool, γδT cells bridge the innate and adaptive immune system and contribute to various physiological and pathological processes ( 2).

They produce cytokines such as IL-17/IFN-γ/IL-22 ( 3– 5). γδT cells are major histocompatibility complex (MHC)-unrestricted innate-like lymphocytes with more unique antigen receptors compared to αβT cells ( 2). This group of T cells is usually less common than αβ T cells, but significantly enriched in mucosal and epithelial sites, such as the skin and respiratory, digestive, and reproductive tracts. In contrast, gamma delta (γδ) T cells have a TCR that is made up of one γ (gamma) chain and one δ (delta) chain ( 1). Most T cells are αβ (alpha beta) T cells with TCR composed of two glycoprotein chains called α (alpha) and β (beta) TCR chains. Gamma delta T cells (γδ T cells) are T cells that have a distinctive T-cell receptor (TCR) on their surface.

Potential therapeutic approaches targeting these cells in psoriasis have also been detailed. This review discusses the differentiation, development, distribution, and biological function of γδT cells and the mechanisms by which they contribute to psoriasis. Furthermore, γδT cells exhibit memory-cell-like characteristics that mediate repeated episodes of psoriatic inflammation. Dermal γδT cells are the major IL-17-producing cells in the skin that respond to IL-23 stimulation. Although γδT cells make up only a small portion of the total T cell pool, emerging evidence suggest that aberrantly activated γδT cells may play a role in the pathogenesis of psoriasis. They display unique developmental, distributional, and functional patterns and rapidly respond to various insults and contribute to diverse diseases. ΓδT cells are an unconventional population of T lymphocytes that play an indispensable role in host defense, immune surveillance, and homeostasis of the immune system. 2Beijing Key Laboratory of Clinic and Basic Research with Traditional Chinese Medicine on Psoriasis, Beijing Institute of Traditional Chinese Medicine, Beijing, China.1Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China.Cong Qi 1,2 Yazhuo Wang 1,2 Ping Li 1,2 Jingxia Zhao 1,2*

Julia gama 2021