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Activation‐induced expression of MICA on T lymphocytes involves engagement of CD3 and CD28
Author(s) -
Molinero Luciana L.,
Fuertes Mercedes B.,
Rabinovich Gabriel A.,
Fainboim Leonardo,
Zwirner Norberto W.
Publication year - 2002
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.71.5.791
Subject(s) - nkg2d , biology , cd28 , cytotoxic t cell , cd3 , microbiology and biotechnology , cd8 , co stimulation , flow cytometry , western blot , immune system , immunology , biochemistry , in vitro , gene
MICA is an HLA‐related cell stress‐regulated antigen recognized by cytotoxic cells expressing the NKG2D molecule. Although resting lymphocytes do not express MICA, it can be induced on PHA‐activated T cells. Here, we demonstrate by Western blot that MICA is induced on allogeneic‐activated CD4 + and CD8 + T lymphocytes. Blocking activation with anti‐HLA class I, anti‐HLA‐DR, or anti‐CD86 mAb affected the expression of MICA slightly. When T cells were stimulated with anti‐CD3 or anti‐CD28 mAb plus PMA, a sustained up‐regulation of MICA was observed by Western blot, RT‐PCR, and flow cytometry. The expression of MICA reached a plateau at day 4 after CD3 engagement and at day 3 after anti‐CD28/PMA stimulation. Conversely, the proliferative response reached a peak at day 4. Hence, CD3 or CD28 engagement induces MICA expression on T lymphocytes. This activation‐induced expression might participate in NKG2D‐mediated cytotoxicity toward activated T cells to maintain homeostasis during an ongoing immune response.