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CD8 + cytolytic T lymphocytes and the skin
Author(s) -
Panfilis G. De
Publication year - 1998
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/j.1600-0625.1998.tb00312.x
Subject(s) - ctl* , cd8 , immunology , cytotoxic t cell , biology , cd28 , cytolysis , immune system , population , microbiology and biotechnology , medicine , genetics , in vitro , environmental health
T lymphocytes show a special affinity for the skin. Although the roles played by the CD4 + population of T lymphocytes in immunodermatology were so far actively investigated, much less is known about the roles played in the skin by CD8 + cytolytic T lymphocytes (CTL). The activity of CD8 + CTL in the immunodermatological context, however, is likely to be most important; the immuno‐biology itself of CD8 + CTL, moreover, although far from being fully understood, shows intriguing characteristics. Immunophenotype, function and cytokine profile of CD8 + CTL are overviewed in the first section of this review. Phenotypically, not only CD8 + CTL can be subdivided into CD8 + CD28 + CD11b + and CD8 + CD28 ‐ CD11b + subsets, but also an up‐to‐now undetected CD8 + CD28 ‐ CD11b ‐ subset does exist. Functionally, not only “cytotoxic” but even “suppressor” subpopulations have been shown to exert cytolytic capabilities indeed, and “suppression” itself may be due to such a lytic capacity. According to cytokine synthesis, CD8 + CTL can be split into Tc1 and Tc2 subsets, each able to influence specific patterns of immune responses. The impact of CD8 + CTL in immunodermatology, overviewed in the second section of the current review, is crucial. The pathophysiology of inflammatory dermatoses is deeply influenced by the activity of CD8 + CTL: e.g., CD8 + CTL within psoriateic epidermis are possibly associated to the persistence of psoriatic lesions not undergoing resolution; on the other hand, in late lesions of lichen planus CD8 + CTL predominate, thus explaining presumably both the cytolytic attack against keratinocytes and the modulation of the inflammatory reaction up to the final resolution of the lesions; Tc1 cells are decreased in atopic dermatitis, and such a decrease can account both for IgE overproduction and for development of infections. Finally, CD8 + CTL can sustain against cutaneous viruses/tumors cytolytic immune responses not only of secondary but even of primary type, i.e. induced by Langerhans cells/dendritic cells either transfected or pulsed with skin virus/tumor‐associated antigens, thus allowing the production of vaccines against cutaneous viral/neoplastic diseases.