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Sialyl lewis x antigen‐expressing human CD4 + T and CD8 + T cells as initial immune responders in memory phenotype subsets
Author(s) -
Zhang Yue,
Ohkuri Takayuki,
Wakita Daiko,
Narita Yoshinori,
Chamoto Kenji,
Kitamura Hidemitsu,
Nishimura Takashi
Publication year - 2008
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0907599
Subject(s) - biology , phenotype , immune system , antigen , cd8 , immunology , cytotoxic t cell , microbiology and biotechnology , in vitro , gene , genetics
Cytokine production by memory T cells in secondary immune responses has a critical role in host defenses. Previously, we had demonstrated that a unique antigen composed of sialyl lewis x (sLe x ) was expressed on CD45RO + memory‐phenotype subsets of human T cells. Here, we found that the sLe x antigen was up‐regulated on CD45RA + naïve human CD4 + T and CD8 + T cells by TCR stimulation. In addition, sLe x antigen‐expressing CD4 + T and CD8 + T cells in human PBMCs were activated immediately by cytokine stimulations composed of IL‐2 plus IL‐12 or IL‐15 in an antigen‐independent manner. Moreover, the sLe x ‐positive human CD8 + T cells significantly enhanced reverse antibody‐dependent cellular cytotoxicity compared with a sLe x ‐negative population. These findings clearly indicate that sLe x antigen‐expressing memory phenotype CD4 + T and CD8 + T cells contribute to early‐stage immunity by providing a source of IFN‐γ and cytotoxicity, suggesting that they would be a key immunomodulator in host defenses.