Existence of activated and memory CD4+ T cells in... : Clinical & Experimental Immunology (original) (raw)

Existence of activated and memory CD4+ T cells in peripheral blood and their skin infiltration in CD8 deficiency

• K. KATAMURA
• G. TAI
• T. TACHIBANA
• H. YAMABE
• K. OHMORI
• M. MAYUMI
• S. MATSUDA
• S. KOYASU
• K. FURUSHO

Clinical & Experimental Immunology

115

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1

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:p

124

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130

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January 1999

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SUMMARY

CD8 deficiency is a rare primary immunodeficiency caused by the defect of a tyrosine kinase, ZAP-70, which transduces signals from the T cell receptor. We report here a case of CD8 deficiency, having CD4+ T cells with a unique phenotype. The patient's T cells did not respond to anti-CD3 stimulation in vitro, suggesting that they were naive. However, many CD4+ T cells with activated and memory phenotypes, which expressed CD45RO+, HLA-DR+ and CD25+, were present in the peripheral blood, and these cells accumulated in the perivascular area of his infiltrative erythematous skin lesions. The patient's T cells could be activated by a high concentration of phytohaemagglutinin (PHA), indicating the presence of an alternate signalling pathway which bypasses ZAP-70 and activates CD4+ T cells in vivo. The origin and role of activated CD4+ T cells in the pathogenesis involved in the skin lesions are discussed.

Copyright © 1999 Blackwell Science Ltd.